{"text": "Nevertheless , the main outcome of the reported experience is the proposed redesign approach for part consolidation using metal AM .", "entity": [{"entity": "part consolidation", "entity_type": "concept or principle", "pos": [97, 115]}, {"entity": "metal AM", "entity_type": "manufacturing process", "pos": [122, 130]}], "task": "NER"}
{"text": "The proposed approach is general , well structured , and detailed enough to be immedialtely applicable at industrial level , but it needs further testing on different case studies to prove the benefits .", "entity": [{"entity": "be", "entity_type": "material", "pos": [76, 78]}, {"entity": "industrial", "entity_type": "application", "pos": [106, 116]}, {"entity": "testing", "entity_type": "process characterization", "pos": [146, 153]}, {"entity": "case studies", "entity_type": "concept or principle", "pos": [167, 179]}], "task": "NER"}
{"text": "An interesting framework to part consolidation and functional integration exploiting AM technologies is presented and validated in .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [15, 24]}, {"entity": "part consolidation", "entity_type": "concept or principle", "pos": [28, 46]}, {"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [85, 100]}], "task": "NER"}
{"text": "In a further development of their approach , the authors have recently addressed the relevant problem of detecting the possible candidates for part consolidation , as reported in .", "entity": [{"entity": "part consolidation", "entity_type": "concept or principle", "pos": [143, 161]}, {"entity": "as", "entity_type": "material", "pos": [164, 166]}], "task": "NER"}
{"text": "Potentially , when dealing with part consolidation , the designer may consider the need of part decomposition .", "entity": [{"entity": "part consolidation", "entity_type": "concept or principle", "pos": [32, 50]}, {"entity": "decomposition", "entity_type": "machanical property", "pos": [96, 109]}], "task": "NER"}
{"text": "The need to increase the number of parts in a product fabricated by AM may be due to many reasons : printability , productivity , functionality , artistry , and interchangeability .", "entity": [{"entity": "fabricated", "entity_type": "concept or principle", "pos": [54, 64]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [68, 70]}, {"entity": "be", "entity_type": "material", "pos": [75, 77]}, {"entity": "printability", "entity_type": "process parameter", "pos": [100, 112]}, {"entity": "productivity", "entity_type": "concept or principle", "pos": [115, 127]}], "task": "NER"}
{"text": "Printability is actually the main reason being related to the limited working envelope of AM machines .", "entity": [{"entity": "Printability", "entity_type": "process parameter", "pos": [0, 12]}, {"entity": "AM machines", "entity_type": "machine or equipment", "pos": [90, 101]}], "task": "NER"}
{"text": "In the part decomposition problem in AM is addressed , but it is the first and unique example of research on this topic .", "entity": [{"entity": "decomposition", "entity_type": "machanical property", "pos": [12, 25]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [37, 39]}, {"entity": "research", "entity_type": "concept or principle", "pos": [97, 105]}], "task": "NER"}
{"text": "9 Conclusion and future challenges DfAM is about design for the whole AM product life cycle .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [49, 55]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [70, 72]}, {"entity": "life cycle", "entity_type": "concept or principle", "pos": [81, 91]}], "task": "NER"}
{"text": "This paper has presented a framework of tools and methods for DfAM and has shown the strong interaction between these life cycle stages and AM product design .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [27, 36]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [40, 45]}, {"entity": "life cycle", "entity_type": "concept or principle", "pos": [118, 128]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [140, 142]}, {"entity": "design", "entity_type": "engineering feature", "pos": [151, 157]}], "task": "NER"}
{"text": "The state of the art was presented on many of these design tools and their applicability was illustrated using many of the latest examples from research and industry .", "entity": [{"entity": "art", "entity_type": "application", "pos": [17, 20]}, {"entity": "design", "entity_type": "engineering feature", "pos": [52, 58]}, {"entity": "research", "entity_type": "concept or principle", "pos": [144, 152]}, {"entity": "industry", "entity_type": "application", "pos": [157, 165]}], "task": "NER"}
{"text": "9.1 AM suitability exploration A growing number of companies are exploring the commercial use of AM within their supply chain .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [4, 6]}, {"entity": "companies", "entity_type": "application", "pos": [51, 60]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [97, 99]}, {"entity": "supply chain", "entity_type": "concept or principle", "pos": [113, 125]}], "task": "NER"}
{"text": "For that , better methods and tools are needed to help the designer obtain an overview that identifies the match between functional and economical demands of the intended product and all stages of AM in product development .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [30, 35]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [197, 199]}, {"entity": "product development", "entity_type": "concept or principle", "pos": [203, 222]}], "task": "NER"}
{"text": "Methods for early cost estimation are lacking , while current figures for production cost per cm3 are not based on established calculation methods and lack experimental and industrial verification .", "entity": [{"entity": "cost estimation", "entity_type": "concept or principle", "pos": [18, 33]}, {"entity": "production cost", "entity_type": "concept or principle", "pos": [74, 89]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [156, 168]}, {"entity": "industrial", "entity_type": "application", "pos": [173, 183]}], "task": "NER"}
{"text": "Late life cycle stages of postprocessing , inspection and certification have a significant impact on production cost and general applicability of AM , but these stages are underrepresented in current DfAM approaches .", "entity": [{"entity": "life cycle", "entity_type": "concept or principle", "pos": [5, 15]}, {"entity": "postprocessing", "entity_type": "concept or principle", "pos": [26, 40]}, {"entity": "inspection", "entity_type": "process characterization", "pos": [43, 53]}, {"entity": "impact", "entity_type": "concept or principle", "pos": [91, 97]}, {"entity": "production cost", "entity_type": "concept or principle", "pos": [101, 116]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [146, 148]}], "task": "NER"}
{"text": "Finally , more education on Additive Manufacturing is needed , as the majority of product designers and engineers are still trained to think subtractive .", "entity": [{"entity": "Additive Manufacturing", "entity_type": "manufacturing process", "pos": [28, 50]}, {"entity": "as", "entity_type": "material", "pos": [63, 65]}, {"entity": "subtractive", "entity_type": "manufacturing process", "pos": [141, 152]}], "task": "NER"}
{"text": "9.2 Product design for AM goals Topology optimization enables strategies that go beyond lightweight design to include minimizing support usage and thermal deformation , optimizing local heat input , and with that the local material properties , porosity and strength .", "entity": [{"entity": "Product design", "entity_type": "engineering feature", "pos": [4, 18]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [23, 25]}, {"entity": "Topology optimization", "entity_type": "engineering feature", "pos": [32, 53]}, {"entity": "go", "entity_type": "material", "pos": [78, 80]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [88, 99]}, {"entity": "design", "entity_type": "engineering feature", "pos": [100, 106]}, {"entity": "support", "entity_type": "application", "pos": [129, 136]}, {"entity": "thermal deformation", "entity_type": "process characterization", "pos": [147, 166]}, {"entity": "local heat input", "entity_type": "concept or principle", "pos": [180, 196]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [223, 242]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [245, 253]}, {"entity": "strength", "entity_type": "machanical property", "pos": [258, 266]}], "task": "NER"}
{"text": "TO methods need further enhancement to tackle optimization as a 3D problem while taking all later product development stages into account .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [46, 58]}, {"entity": "as", "entity_type": "material", "pos": [59, 61]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [64, 66]}, {"entity": "product development", "entity_type": "concept or principle", "pos": [98, 117]}], "task": "NER"}
{"text": "Generative design strategies have the benefit that they generate many possible design solutions , but as is the case with TO , few production and inspection constraints are currently integrated .", "entity": [{"entity": "Generative design", "entity_type": "enabling technology", "pos": [0, 17]}, {"entity": "design", "entity_type": "engineering feature", "pos": [79, 85]}, {"entity": "as", "entity_type": "material", "pos": [102, 104]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [131, 141]}, {"entity": "inspection", "entity_type": "process characterization", "pos": [146, 156]}], "task": "NER"}
{"text": "Lattice structures show explicit benefits , especially in application fields involving energy absorption and heat conduction .", "entity": [{"entity": "Lattice structures", "entity_type": "engineering feature", "pos": [0, 18]}, {"entity": "energy absorption", "entity_type": "process characterization", "pos": [87, 104]}, {"entity": "heat conduction", "entity_type": "concept or principle", "pos": [109, 124]}], "task": "NER"}
{"text": "They are however computationally intensive , which limits the optimization possibilities for large lattices to a limited set of parameters .", "entity": [{"entity": "limits", "entity_type": "concept or principle", "pos": [51, 57]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [62, 74]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [99, 107]}, {"entity": "set", "entity_type": "application", "pos": [121, 124]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [128, 138]}], "task": "NER"}
{"text": "When looking at the part interior , specially designed porosity is seen as a promising new feature for internal transport of gasses and fluids .", "entity": [{"entity": "designed", "entity_type": "engineering feature", "pos": [46, 54]}, {"entity": "as", "entity_type": "material", "pos": [72, 74]}, {"entity": "feature", "entity_type": "engineering feature", "pos": [91, 98]}, {"entity": "transport", "entity_type": "process characterization", "pos": [112, 121]}, {"entity": "fluids", "entity_type": "material", "pos": [136, 142]}], "task": "NER"}
{"text": "Both the optimal process settings as well as models for their application need further research to be applicable in everyday product design .", "entity": [{"entity": "optimal process", "entity_type": "process parameter", "pos": [9, 24]}, {"entity": "as", "entity_type": "material", "pos": [34, 36]}, {"entity": "as", "entity_type": "material", "pos": [42, 44]}, {"entity": "research", "entity_type": "concept or principle", "pos": [87, 95]}, {"entity": "be", "entity_type": "material", "pos": [99, 101]}, {"entity": "product design", "entity_type": "engineering feature", "pos": [125, 139]}], "task": "NER"}
{"text": "To fully exploit the benefits of functional material complexity , further research must be conducted on rules and CAD representations of FGM related design intent .", "entity": [{"entity": "functional material complexity", "entity_type": "concept or principle", "pos": [33, 63]}, {"entity": "research", "entity_type": "concept or principle", "pos": [74, 82]}, {"entity": "be", "entity_type": "material", "pos": [88, 90]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [114, 117]}, {"entity": "FGM", "entity_type": "manufacturing process", "pos": [137, 140]}, {"entity": "design", "entity_type": "engineering feature", "pos": [149, 155]}], "task": "NER"}
{"text": "However , the development of design tools and methods is still a matter of basic research and far from industrial application .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [29, 35]}, {"entity": "research", "entity_type": "concept or principle", "pos": [81, 89]}, {"entity": "industrial", "entity_type": "application", "pos": [103, 113]}], "task": "NER"}
{"text": "The future of additive manufacturing is also looking towards 4D applications where those challenges will be even more relevant .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [14, 36]}, {"entity": "4D", "entity_type": "concept or principle", "pos": [61, 63]}, {"entity": "be", "entity_type": "material", "pos": [105, 107]}], "task": "NER"}
{"text": "For the final optimization of geometry so that it combines AM benefits with efficient production and inspection , a lot of research has been conducted .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [14, 26]}, {"entity": "geometry", "entity_type": "concept or principle", "pos": [30, 38]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [59, 61]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [86, 96]}, {"entity": "inspection", "entity_type": "process characterization", "pos": [101, 111]}, {"entity": "research", "entity_type": "concept or principle", "pos": [123, 131]}], "task": "NER"}
{"text": "At an individual process level design knowledge is available and constantly being extended or refined .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [17, 24]}, {"entity": "design", "entity_type": "engineering feature", "pos": [31, 37]}], "task": "NER"}
{"text": "Further research is needed to enable improved integration in upstream product design steps like TO and generative design .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [8, 16]}, {"entity": "product design", "entity_type": "engineering feature", "pos": [70, 84]}, {"entity": "generative design", "entity_type": "enabling technology", "pos": [103, 120]}], "task": "NER"}
{"text": "Integrating processing and manufacturing with design in AM is feasible since the full digital chain is there .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [27, 40]}, {"entity": "design", "entity_type": "engineering feature", "pos": [46, 52]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [56, 58]}, {"entity": "digital chain", "entity_type": "enabling technology", "pos": [86, 99]}], "task": "NER"}
{"text": "In current AM practice only a few zones in a product are defined where process settings can be defined , for example for the top and bottom facing surfaces and the bulk of the product in L-PBF .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [11, 13]}, {"entity": "process settings", "entity_type": "process parameter", "pos": [71, 87]}, {"entity": "be", "entity_type": "material", "pos": [92, 94]}, {"entity": "facing", "entity_type": "manufacturing process", "pos": [140, 146]}, {"entity": "L-PBF", "entity_type": "manufacturing process", "pos": [187, 192]}], "task": "NER"}
{"text": "If machine learning and closed loop control can be used to define the optimal settings for each deposition area , the need for support structures as well as the effects of thermal stresses and deformations are expected to reduce/diminish .", "entity": [{"entity": "machine", "entity_type": "machine or equipment", "pos": [3, 10]}, {"entity": "closed loop control", "entity_type": "concept or principle", "pos": [24, 43]}, {"entity": "be", "entity_type": "material", "pos": [48, 50]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [96, 106]}, {"entity": "area", "entity_type": "process parameter", "pos": [107, 111]}, {"entity": "support structures", "entity_type": "engineering feature", "pos": [127, 145]}, {"entity": "as", "entity_type": "material", "pos": [146, 148]}, {"entity": "as", "entity_type": "material", "pos": [154, 156]}, {"entity": "thermal stresses", "entity_type": "machanical property", "pos": [172, 188]}, {"entity": "deformations", "entity_type": "concept or principle", "pos": [193, 205]}], "task": "NER"}
{"text": "This will have large impact on the AM products and the way they are designed .", "entity": [{"entity": "impact", "entity_type": "concept or principle", "pos": [21, 27]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [35, 37]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [68, 76]}], "task": "NER"}
{"text": "A combination of computational and knowledge-based methods would be an optimal solution for DfAM in the future to define qualified AM design solutions .", "entity": [{"entity": "be", "entity_type": "material", "pos": [65, 67]}, {"entity": "solution", "entity_type": "concept or principle", "pos": [79, 87]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [94, 96]}], "task": "NER"}
{"text": "Data analytic methods could be used to explore and discover knowledge from existing validated designs or dig out implicit knowledge from large industrial practice and experimental data sets .", "entity": [{"entity": "Data", "entity_type": "concept or principle", "pos": [0, 4]}, {"entity": "be", "entity_type": "material", "pos": [28, 30]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [94, 101]}, {"entity": "industrial", "entity_type": "application", "pos": [143, 153]}, {"entity": "experimental data", "entity_type": "concept or principle", "pos": [167, 184]}], "task": "NER"}
{"text": "A collaborative cloud-based DfAM platform would be more sustainable for the world if people could share their designs and design knowledge as well as other AM processing related data sets .", "entity": [{"entity": "platform", "entity_type": "machine or equipment", "pos": [33, 41]}, {"entity": "be", "entity_type": "material", "pos": [48, 50]}, {"entity": "sustainable", "entity_type": "concept or principle", "pos": [56, 67]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [110, 117]}, {"entity": "design", "entity_type": "engineering feature", "pos": [122, 128]}, {"entity": "as", "entity_type": "material", "pos": [139, 141]}, {"entity": "as", "entity_type": "material", "pos": [147, 149]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [156, 158]}, {"entity": "data", "entity_type": "concept or principle", "pos": [178, 182]}], "task": "NER"}
{"text": "This would enable and advance wide KBE in DfAM , save a lot of cost and time and improve quality over the trial and error practice in current DfAM .", "entity": [{"entity": "quality", "entity_type": "concept or principle", "pos": [89, 96]}, {"entity": "trial and error", "entity_type": "concept or principle", "pos": [106, 121]}], "task": "NER"}
{"text": "This will result in new application areas , new process constraints and new AM features The main goal of this review is to provide a detailed and comprehensive description of the published work from the past decade regarding AM of ceramic materials with possible applications in dentistry .", "entity": [{"entity": "areas", "entity_type": "process parameter", "pos": [36, 41]}, {"entity": "process", "entity_type": "concept or principle", "pos": [48, 55]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [76, 78]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [225, 227]}, {"entity": "ceramic materials", "entity_type": "material", "pos": [231, 248]}, {"entity": "dentistry", "entity_type": "application", "pos": [279, 288]}], "task": "NER"}
{"text": "The main printable materials and most common technologies are also addressed , underlining their advantages and main drawbacks .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [19, 28]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [45, 57]}], "task": "NER"}
{"text": "Methods Online databases were consulted on this topic .", "entity": [{"entity": "databases", "entity_type": "enabling technology", "pos": [15, 24]}], "task": "NER"}
{"text": "Results Ceramic materials are broadly used in dentistry to restore/replace damaged or missing teeth , due to their biocompatibility , chemical stability and mechanical and aesthetic properties .", "entity": [{"entity": "Ceramic materials", "entity_type": "material", "pos": [8, 25]}, {"entity": "dentistry", "entity_type": "application", "pos": [46, 55]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [115, 131]}, {"entity": "chemical stability", "entity_type": "machanical property", "pos": [134, 152]}, {"entity": "mechanical", "entity_type": "application", "pos": [157, 167]}, {"entity": "aesthetic", "entity_type": "concept or principle", "pos": [172, 181]}], "task": "NER"}
{"text": "Due to their brittleness nature , a very tight control of the manufacturing process is needed to obtain dental pieces with adequate mechanical properties .", "entity": [{"entity": "brittleness nature", "entity_type": "machanical property", "pos": [13, 31]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [62, 83]}, {"entity": "dental pieces", "entity_type": "machine or equipment", "pos": [104, 117]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [132, 153]}], "task": "NER"}
{"text": "Additive manufacturing is an emerging technology that constitutes an interesting and viable manufacturing alternative to the conventional subtractive methods .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [0, 22]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [38, 48]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [92, 105]}, {"entity": "conventional subtractive methods", "entity_type": "manufacturing process", "pos": [125, 157]}], "task": "NER"}
{"text": "AM enables the production of customized complex 3D parts in a more sustainable and less expensive way .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [15, 25]}, {"entity": "3D parts", "entity_type": "application", "pos": [48, 56]}, {"entity": "sustainable", "entity_type": "concept or principle", "pos": [67, 78]}], "task": "NER"}
{"text": "AM of ceramics can be achieved with an extensive variety of methods .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "ceramics", "entity_type": "material", "pos": [6, 14]}, {"entity": "be", "entity_type": "material", "pos": [19, 21]}], "task": "NER"}
{"text": "Although very promising , AM of ceramic dental materials remains understudied and further work is required to make it a widespread technology in dentistry .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [26, 28]}, {"entity": "ceramic dental materials", "entity_type": "material", "pos": [32, 56]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [131, 141]}, {"entity": "dentistry", "entity_type": "application", "pos": [145, 154]}], "task": "NER"}
{"text": "In dentistry , as in many other fields , the production of dental pieces is increasingly becoming automated .", "entity": [{"entity": "dentistry", "entity_type": "application", "pos": [3, 12]}, {"entity": "as", "entity_type": "material", "pos": [15, 17]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [45, 55]}, {"entity": "dental pieces", "entity_type": "machine or equipment", "pos": [59, 72]}], "task": "NER"}
{"text": "Computer aided design and/or computer aided manufacturing have become progressively widespread within the medical and dental fields .", "entity": [{"entity": "Computer aided design", "entity_type": "enabling technology", "pos": [0, 21]}, {"entity": "computer aided manufacturing", "entity_type": "enabling technology", "pos": [29, 57]}, {"entity": "medical", "entity_type": "application", "pos": [106, 113]}, {"entity": "dental", "entity_type": "application", "pos": [118, 124]}], "task": "NER"}
{"text": "These tools are generally used in the manufacture of dental pieces in machining centers , where extra material is removed from a block to obtain the piece with the desired shape .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [6, 11]}, {"entity": "manufacture", "entity_type": "concept or principle", "pos": [38, 49]}, {"entity": "dental pieces", "entity_type": "machine or equipment", "pos": [53, 66]}, {"entity": "machining centers", "entity_type": "machine or equipment", "pos": [70, 87]}, {"entity": "material", "entity_type": "material", "pos": [102, 110]}], "task": "NER"}
{"text": "This technique is known as subtractive manufacturing .", "entity": [{"entity": "as", "entity_type": "material", "pos": [24, 26]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [39, 52]}], "task": "NER"}
{"text": "Nowadays , a new type of technology is emerging , additive manufacturing , also referred to as 3D printing , that allow building up pieces by adding materials layer-by-layer , based on a computerized 3D model .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [25, 35]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [50, 72]}, {"entity": "as", "entity_type": "material", "pos": [92, 94]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [95, 106]}, {"entity": "materials layer-by-layer", "entity_type": "concept or principle", "pos": [149, 173]}, {"entity": "3D model", "entity_type": "application", "pos": [200, 208]}], "task": "NER"}
{"text": "This type of technology has suffered great developments in a wide range of areas , allowing to produce pieces of all classes of materials , including materials of biological origin .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [13, 23]}, {"entity": "range", "entity_type": "process parameter", "pos": [66, 71]}, {"entity": "areas", "entity_type": "process parameter", "pos": [75, 80]}, {"entity": "classes of materials", "entity_type": "material", "pos": [117, 137]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [150, 159]}], "task": "NER"}
{"text": "AM focus has been moving from prototype fabrication to rapid manufacturing of small or medium quantities of end-use products .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "prototype", "entity_type": "concept or principle", "pos": [30, 39]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [40, 51]}, {"entity": "rapid manufacturing", "entity_type": "manufacturing process", "pos": [55, 74]}], "task": "NER"}
{"text": "Among the main areas of AM application stands out : - Aerospace : AM technology is particularly suitable to obtain a limited number of pieces that are usually required for aerospace applications , with complex geometries and made of advanced materials which are difficult , costly and time-consuming to manufacture .", "entity": [{"entity": "areas", "entity_type": "process parameter", "pos": [15, 20]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [24, 26]}, {"entity": "Aerospace", "entity_type": "application", "pos": [54, 63]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [66, 79]}, {"entity": "aerospace", "entity_type": "application", "pos": [172, 181]}, {"entity": "complex geometries", "entity_type": "concept or principle", "pos": [202, 220]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [242, 251]}, {"entity": "manufacture", "entity_type": "concept or principle", "pos": [303, 314]}], "task": "NER"}
{"text": "- Automotive : AM technology is an important tool in this industry , since it can reduce the development cycle , manufacturing and product costs of automotive components .", "entity": [{"entity": "Automotive", "entity_type": "application", "pos": [2, 12]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [15, 28]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [45, 49]}, {"entity": "industry", "entity_type": "application", "pos": [58, 66]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [113, 126]}, {"entity": "automotive", "entity_type": "application", "pos": [148, 158]}], "task": "NER"}
{"text": "It allows producing small quantities of structural and functional parts and thus , is particularly interesting for racing vehicles , where light-weight alloys and composites are used to obtain highly complex structures .", "entity": [{"entity": "light-weight", "entity_type": "machanical property", "pos": [139, 151]}, {"entity": "alloys", "entity_type": "material", "pos": [152, 158]}, {"entity": "composites", "entity_type": "material", "pos": [163, 173]}, {"entity": "complex structures", "entity_type": "concept or principle", "pos": [200, 218]}], "task": "NER"}
{"text": "- Energy : AM technology allows the fast development and fabrication of prototypes to reduce the cost and lead-time of research and development of new solutions that reduce the fossil energy dependency .", "entity": [{"entity": "AM technology", "entity_type": "manufacturing process", "pos": [11, 24]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [57, 68]}, {"entity": "prototypes", "entity_type": "concept or principle", "pos": [72, 82]}, {"entity": "lead-time", "entity_type": "process parameter", "pos": [106, 115]}, {"entity": "research", "entity_type": "concept or principle", "pos": [119, 127]}], "task": "NER"}
{"text": "It increases the design possibilities to improve energy efficiency and/or power density , in alternatives that use renewable and clean energies .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [17, 23]}, {"entity": "power", "entity_type": "process parameter", "pos": [74, 79]}, {"entity": "density", "entity_type": "machanical property", "pos": [80, 87]}], "task": "NER"}
{"text": "- Biomedical : Recent developments in the biomaterials field , biologic sciences and biomedicine have potentiated the use of AM techniques .", "entity": [{"entity": "Biomedical", "entity_type": "application", "pos": [2, 12]}, {"entity": "biomaterials field", "entity_type": "material", "pos": [42, 60]}, {"entity": "biomedicine", "entity_type": "application", "pos": [85, 96]}, {"entity": "AM techniques", "entity_type": "manufacturing process", "pos": [125, 138]}], "task": "NER"}
{"text": "Customization is a critical factor in this area and AM allows the production of a wide range of products with specific properties and shapes that meet the patient needs .", "entity": [{"entity": "critical factor", "entity_type": "machanical property", "pos": [19, 34]}, {"entity": "area", "entity_type": "process parameter", "pos": [43, 47]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [52, 54]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [66, 76]}, {"entity": "range", "entity_type": "process parameter", "pos": [87, 92]}, {"entity": "specific properties", "entity_type": "machanical property", "pos": [110, 129]}], "task": "NER"}
{"text": "For example , it is possible to produce diagnostic platforms , orthopedic and dental implants , drug delivery systems , medical devices , tissue scaffolds and artificial organs .", "entity": [{"entity": "dental", "entity_type": "application", "pos": [78, 84]}, {"entity": "medical devices", "entity_type": "application", "pos": [120, 135]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [145, 154]}, {"entity": "artificial organs", "entity_type": "application", "pos": [159, 176]}], "task": "NER"}
{"text": "Biofabrication through AM emerged in the recent years as a new alternative to fabricate tissues .", "entity": [{"entity": "Biofabrication", "entity_type": "manufacturing process", "pos": [0, 14]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [23, 25]}, {"entity": "as", "entity_type": "material", "pos": [54, 56]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [78, 87]}], "task": "NER"}
{"text": "Here , living cells are deposited layer-by-layer in combination with different biomaterials to obtain complex living structures .", "entity": [{"entity": "cells", "entity_type": "application", "pos": [14, 19]}, {"entity": "layer-by-layer", "entity_type": "concept or principle", "pos": [34, 48]}, {"entity": "biomaterials", "entity_type": "material", "pos": [79, 91]}], "task": "NER"}
{"text": "In the dentistry field , the use of AM to produce endurable dental structures is expected to bring advantages over conventional manufacturing methods , as reported on other fields .", "entity": [{"entity": "dentistry field", "entity_type": "application", "pos": [7, 22]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [36, 38]}, {"entity": "dental structures", "entity_type": "machine or equipment", "pos": [60, 77]}, {"entity": "conventional manufacturing", "entity_type": "manufacturing process", "pos": [115, 141]}, {"entity": "as", "entity_type": "material", "pos": [152, 154]}], "task": "NER"}
{"text": "In particular , it shall : - Allow the production of customized near-net-shape dental pieces with intricate details .", "entity": [{"entity": "production", "entity_type": "manufacturing process", "pos": [39, 49]}, {"entity": "near-net-shape", "entity_type": "manufacturing process", "pos": [64, 78]}, {"entity": "dental pieces", "entity_type": "machine or equipment", "pos": [79, 92]}], "task": "NER"}
{"text": "Product complexity shall not add cost to production beyond the design stage , because once the design is set , costs are independent of the shape .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [8, 18]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [41, 51]}, {"entity": "design", "entity_type": "engineering feature", "pos": [63, 69]}, {"entity": "design", "entity_type": "engineering feature", "pos": [95, 101]}, {"entity": "set", "entity_type": "application", "pos": [105, 108]}], "task": "NER"}
{"text": "- Allow reduction of dental parts production time and consequently of time-to-market .", "entity": [{"entity": "reduction", "entity_type": "concept or principle", "pos": [8, 17]}, {"entity": "dental", "entity_type": "application", "pos": [21, 27]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [34, 44]}], "task": "NER"}
{"text": "Traditional subtractive technologies involve several time-consuming steps , while AM allows a faster direct production starting simply from a 3D scan of the oral cavity .", "entity": [{"entity": "subtractive", "entity_type": "manufacturing process", "pos": [12, 23]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [82, 84]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [108, 118]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [142, 144]}], "task": "NER"}
{"text": "- Limit human error relevance in the procedures .", "entity": [{"entity": "Limit", "entity_type": "concept or principle", "pos": [2, 7]}, {"entity": "error", "entity_type": "concept or principle", "pos": [14, 19]}], "task": "NER"}
{"text": "Minor human intervention is required in AM due to the lower number of manufacturing steps .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [40, 42]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [70, 83]}], "task": "NER"}
{"text": "- Decrease the environmental impact , ensuring a higher manufacturing sustainability .", "entity": [{"entity": "impact", "entity_type": "concept or principle", "pos": [29, 35]}, {"entity": "manufacturing sustainability", "entity_type": "concept or principle", "pos": [56, 84]}], "task": "NER"}
{"text": "Being an additive technique , it reduces material waste and energy consumption and eliminates the use of conventional manufacturing tools .", "entity": [{"entity": "additive", "entity_type": "material", "pos": [9, 17]}, {"entity": "material", "entity_type": "material", "pos": [41, 49]}, {"entity": "conventional manufacturing", "entity_type": "manufacturing process", "pos": [105, 131]}], "task": "NER"}
{"text": "Globally , AM allows moving from mass production to mass customization , with significant efficiency increase and production costs decrease .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [11, 13]}, {"entity": "mass production", "entity_type": "concept or principle", "pos": [33, 48]}, {"entity": "production costs", "entity_type": "concept or principle", "pos": [114, 130]}], "task": "NER"}
{"text": "The expected dissemination of this technology applied to dental prosthesis shall result in equipmentcost decrease .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [35, 45]}, {"entity": "dental prosthesis", "entity_type": "machine or equipment", "pos": [57, 74]}], "task": "NER"}
{"text": "Thus , the reduction of final product price is predictable , increasing the accessibility of dental care to the poorest sectors of the population .", "entity": [{"entity": "reduction", "entity_type": "concept or principle", "pos": [11, 20]}, {"entity": "predictable", "entity_type": "concept or principle", "pos": [47, 58]}, {"entity": "dental", "entity_type": "application", "pos": [93, 99]}, {"entity": "population", "entity_type": "biomedical", "pos": [135, 145]}], "task": "NER"}
{"text": "Due to the recent expiration of the main 3D printing patents , the access to printers became easier and less expensive .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [41, 52]}, {"entity": "printers", "entity_type": "machine or equipment", "pos": [77, 85]}], "task": "NER"}
{"text": "Digital dentistry is reported to be one of the fastest growing sectors of the AM technologies .", "entity": [{"entity": "dentistry", "entity_type": "application", "pos": [8, 17]}, {"entity": "be", "entity_type": "material", "pos": [33, 35]}, {"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [78, 93]}], "task": "NER"}
{"text": "There are several possible applications of AM techniques in dentistry , e.g .", "entity": [{"entity": "AM techniques", "entity_type": "manufacturing process", "pos": [43, 56]}, {"entity": "dentistry", "entity_type": "application", "pos": [60, 69]}], "task": "NER"}
{"text": "crowns , bridges , dentures , models , surgical guides , implants and orthodontics materials .", "entity": [{"entity": "dentures", "entity_type": "application", "pos": [19, 27]}, {"entity": "implants", "entity_type": "application", "pos": [57, 65]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [83, 92]}], "task": "NER"}
{"text": "Several challenges emerge when this technique is considered to produce endurable dental devices .", "entity": [{"entity": "dental devices", "entity_type": "application", "pos": [81, 95]}], "task": "NER"}
{"text": "For example , the reliability of the process , surface finishing of the samples and materials density are among the major concerns .", "entity": [{"entity": "reliability", "entity_type": "process characterization", "pos": [18, 29]}, {"entity": "process", "entity_type": "concept or principle", "pos": [37, 44]}, {"entity": "surface finishing", "entity_type": "manufacturing process", "pos": [47, 64]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [72, 79]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [84, 93]}, {"entity": "density", "entity_type": "machanical property", "pos": [94, 101]}], "task": "NER"}
{"text": "Concerning dental materials that can be used in AM , polymers are the most studied and used ones , followed by metals .", "entity": [{"entity": "dental", "entity_type": "application", "pos": [11, 17]}, {"entity": "be", "entity_type": "material", "pos": [37, 39]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [48, 50]}, {"entity": "polymers", "entity_type": "material", "pos": [53, 61]}, {"entity": "metals", "entity_type": "material", "pos": [111, 117]}], "task": "NER"}
{"text": "AM of ceramic dental materials is still underdeveloped , mainly due to the difficulties to produce pieces with suitable surface finishing , mechanical properties and dimensional accuracy .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "ceramic dental materials", "entity_type": "material", "pos": [6, 30]}, {"entity": "surface finishing", "entity_type": "manufacturing process", "pos": [120, 137]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [140, 161]}, {"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [166, 186]}], "task": "NER"}
{"text": "The available literature regarding AM of ceramic materials represents less than 5 % of the total AM published related work .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [35, 37]}, {"entity": "ceramic materials", "entity_type": "material", "pos": [41, 58]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [97, 99]}], "task": "NER"}
{"text": "The studies are even fewer in what concerns ceramic materials for dental applications .", "entity": [{"entity": "ceramic materials", "entity_type": "material", "pos": [44, 61]}, {"entity": "dental applications", "entity_type": "application", "pos": [66, 85]}], "task": "NER"}
{"text": "This paper presents a recent overview of published work concerning AM of ceramic materials for dental applications .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [67, 69]}, {"entity": "ceramic materials", "entity_type": "material", "pos": [73, 90]}, {"entity": "dental applications", "entity_type": "application", "pos": [95, 114]}], "task": "NER"}
{"text": "A summary of potentially printable dental biomaterials and brief descriptions of the most common digital manufacturing technologies are also provided , highlighting the main features , advantages and drawbacks , to better understand the potential and restrictions of each technology .", "entity": [{"entity": "dental", "entity_type": "application", "pos": [35, 41]}, {"entity": "biomaterials", "entity_type": "material", "pos": [42, 54]}, {"entity": "digital manufacturing", "entity_type": "manufacturing process", "pos": [97, 118]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [272, 282]}], "task": "NER"}
{"text": "The used keywords strings were : 3D printing AND Dental ; Additive manufacturing AND Dental .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [33, 44]}, {"entity": "Dental", "entity_type": "application", "pos": [49, 55]}, {"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [58, 80]}, {"entity": "Dental", "entity_type": "application", "pos": [85, 91]}], "task": "NER"}
{"text": "Additive manufacturing of bioceramics for dental applicationsbut included in the remaining sections to complement this review and provide any additional remarks .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [0, 22]}, {"entity": "bioceramics", "entity_type": "material", "pos": [26, 37]}, {"entity": "dental", "entity_type": "application", "pos": [42, 48]}], "task": "NER"}
{"text": "3 Ceramic dental materials Bioceramics are broadly used in the dental field .", "entity": [{"entity": "Ceramic dental materials", "entity_type": "material", "pos": [2, 26]}, {"entity": "Bioceramics", "entity_type": "material", "pos": [27, 38]}, {"entity": "dental", "entity_type": "application", "pos": [63, 69]}], "task": "NER"}
{"text": "These materials have some attractive features/attributes which are similar to natural dentition properties , e.g .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [6, 15]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [96, 106]}], "task": "NER"}
{"text": "compressive strength , thermal conductivity , radiopacity , colour stability , aesthetics .", "entity": [{"entity": "compressive strength", "entity_type": "machanical property", "pos": [0, 20]}, {"entity": "thermal conductivity", "entity_type": "machanical property", "pos": [23, 43]}, {"entity": "stability", "entity_type": "machanical property", "pos": [67, 76]}], "task": "NER"}
{"text": "However , these materials are brittle , hard and sometimes difficult to process .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [16, 25]}, {"entity": "brittle", "entity_type": "machanical property", "pos": [30, 37]}, {"entity": "process", "entity_type": "concept or principle", "pos": [72, 79]}], "task": "NER"}
{"text": "Bioceramics can be divided in 4 categories , depending on their main system composition : glasB-based systems ; glasB-based systems with fillers , usually crystalline ; crystalline-based systems with glass fillers ; polycrystalline solids .", "entity": [{"entity": "Bioceramics", "entity_type": "material", "pos": [0, 11]}, {"entity": "be", "entity_type": "material", "pos": [16, 18]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [76, 87]}, {"entity": "glass fillers", "entity_type": "material", "pos": [200, 213]}], "task": "NER"}
{"text": "GlasB-based systems consist of materials that are made mostly of silicon dioxide and can comprise different amounts of alumina .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [31, 40]}, {"entity": "silicon dioxide", "entity_type": "material", "pos": [65, 80]}, {"entity": "alumina", "entity_type": "material", "pos": [119, 126]}], "task": "NER"}
{"text": "Feldspars are composed of aluminosilicates , found in nature , containing different quantities of potassium and sodium .", "entity": [{"entity": "aluminosilicates", "entity_type": "material", "pos": [26, 42]}, {"entity": "sodium", "entity_type": "material", "pos": [112, 118]}], "task": "NER"}
{"text": "Feldspars can be modified in several ways in order to produce the glass used in the dental area .", "entity": [{"entity": "be", "entity_type": "material", "pos": [14, 16]}, {"entity": "glass", "entity_type": "material", "pos": [66, 71]}, {"entity": "dental", "entity_type": "application", "pos": [84, 90]}, {"entity": "area", "entity_type": "process parameter", "pos": [91, 95]}], "task": "NER"}
{"text": "Additionally , synthetic forms of alumina silicate glasses may as well be manufactured for dental ceramics .", "entity": [{"entity": "alumina", "entity_type": "material", "pos": [34, 41]}, {"entity": "glasses", "entity_type": "material", "pos": [51, 58]}, {"entity": "as", "entity_type": "material", "pos": [63, 65]}, {"entity": "be", "entity_type": "material", "pos": [71, 73]}, {"entity": "dental", "entity_type": "application", "pos": [91, 97]}, {"entity": "ceramics", "entity_type": "material", "pos": [98, 106]}], "task": "NER"}
{"text": "The glass composition is almost the same as the pure glass category , being that the difference resides in the amount of different types of crystals that can either be added or grown in the glassy matrix .", "entity": [{"entity": "glass", "entity_type": "material", "pos": [4, 9]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [10, 21]}, {"entity": "as", "entity_type": "material", "pos": [41, 43]}, {"entity": "glass", "entity_type": "material", "pos": [53, 58]}, {"entity": "be", "entity_type": "material", "pos": [70, 72]}], "task": "NER"}
{"text": "Nowadays , the primary crystal types are leucite , lithium dissilicate or fluoroapatite .", "entity": [{"entity": "leucite", "entity_type": "material", "pos": [41, 48]}, {"entity": "lithium", "entity_type": "material", "pos": [51, 58]}], "task": "NER"}
{"text": "Intended as an alternative to traditional metal ceramics , crystalline-based systems with glass fillers were developed .", "entity": [{"entity": "as", "entity_type": "material", "pos": [9, 11]}, {"entity": "metal ceramics", "entity_type": "material", "pos": [42, 56]}, {"entity": "glass fillers", "entity_type": "material", "pos": [90, 103]}], "task": "NER"}
{"text": "They are composed of glasB-infiltrated , partially sintered alumina .", "entity": [{"entity": "sintered", "entity_type": "manufacturing process", "pos": [51, 59]}, {"entity": "alumina", "entity_type": "material", "pos": [60, 67]}], "task": "NER"}
{"text": "Polycrystaline solids are made by directly sintering crystals together , forming a dense , air-free , glasB-free , polycrystalline structure .", "entity": [{"entity": "Polycrystaline solids", "entity_type": "material", "pos": [0, 21]}, {"entity": "directly sintering crystals", "entity_type": "material", "pos": [34, 61]}, {"entity": "forming", "entity_type": "manufacturing process", "pos": [73, 80]}, {"entity": "polycrystalline structure", "entity_type": "machanical property", "pos": [115, 140]}], "task": "NER"}
{"text": "In the next sections , a brief description is presented regarding the main properties of the most frequently used bioceramics in dental applications .", "entity": [{"entity": "properties", "entity_type": "concept or principle", "pos": [75, 85]}, {"entity": "bioceramics", "entity_type": "material", "pos": [114, 125]}, {"entity": "dental applications", "entity_type": "application", "pos": [129, 148]}], "task": "NER"}
{"text": "3.1 Zirconia Zirconia ceramics were introduced in dentistry in the early nineties , as endosseous implants in dental prosthetic surgery .", "entity": [{"entity": "Zirconia", "entity_type": "material", "pos": [4, 12]}, {"entity": "ceramics", "entity_type": "material", "pos": [22, 30]}, {"entity": "dentistry", "entity_type": "application", "pos": [50, 59]}, {"entity": "as", "entity_type": "material", "pos": [84, 86]}, {"entity": "implants", "entity_type": "application", "pos": [98, 106]}, {"entity": "dental", "entity_type": "application", "pos": [110, 116]}, {"entity": "surgery", "entity_type": "application", "pos": [128, 135]}], "task": "NER"}
{"text": "This material is known to have exceptional mechanical properties and ease of machining in the pre-sintering stage through CAD/CAM .", "entity": [{"entity": "material", "entity_type": "material", "pos": [5, 13]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [43, 64]}, {"entity": "machining", "entity_type": "manufacturing process", "pos": [77, 86]}, {"entity": "pre-sintering", "entity_type": "manufacturing process", "pos": [94, 107]}, {"entity": "CAD/CAM", "entity_type": "enabling technology", "pos": [122, 129]}], "task": "NER"}
{"text": "Zirconia is biocompatible with the tissues in the oral cavity and has been reported to be osteoconductive , which means that this ceramic facilitates bone formation when in contact with it .", "entity": [{"entity": "Zirconia", "entity_type": "material", "pos": [0, 8]}, {"entity": "biocompatible", "entity_type": "machanical property", "pos": [12, 25]}, {"entity": "be", "entity_type": "material", "pos": [70, 72]}, {"entity": "ceramic", "entity_type": "material", "pos": [130, 137]}, {"entity": "bone", "entity_type": "biomedical", "pos": [150, 154]}, {"entity": "contact", "entity_type": "application", "pos": [173, 180]}], "task": "NER"}
{"text": "Regarding mechanical properties , zirconia ceramics are considered to have high strength , hardness , wear resistance , resistance to corrosion , modulus of elasticity similar to steel , coefficient of thermal expansion similar to iron , and the highest fracture toughness among the most used ceramics .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [10, 31]}, {"entity": "zirconia ceramics", "entity_type": "material", "pos": [34, 51]}, {"entity": "strength", "entity_type": "machanical property", "pos": [80, 88]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [91, 99]}, {"entity": "wear resistance", "entity_type": "machanical property", "pos": [102, 117]}, {"entity": "resistance", "entity_type": "machanical property", "pos": [120, 130]}, {"entity": "corrosion", "entity_type": "concept or principle", "pos": [134, 143]}, {"entity": "modulus of elasticity", "entity_type": "machanical property", "pos": [146, 167]}, {"entity": "steel", "entity_type": "material", "pos": [179, 184]}, {"entity": "coefficient of thermal expansion", "entity_type": "machanical property", "pos": [187, 219]}, {"entity": "iron", "entity_type": "material", "pos": [231, 235]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [254, 262]}, {"entity": "ceramics", "entity_type": "material", "pos": [293, 301]}], "task": "NER"}
{"text": "Zirconia-based ceramics can be stabilized in tetragonal or cubic phases depending on the used dopant , its concentration and temperature during the thermal treatments .", "entity": [{"entity": "ceramics", "entity_type": "material", "pos": [15, 23]}, {"entity": "be", "entity_type": "material", "pos": [28, 30]}, {"entity": "tetragonal", "entity_type": "engineering feature", "pos": [45, 55]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [125, 136]}, {"entity": "thermal treatments", "entity_type": "manufacturing process", "pos": [148, 166]}], "task": "NER"}
{"text": "For dental applications , zirconia is commonly stabilized with 3 mol % yttria .", "entity": [{"entity": "dental applications", "entity_type": "application", "pos": [4, 23]}, {"entity": "zirconia", "entity_type": "material", "pos": [26, 34]}, {"entity": "yttria", "entity_type": "material", "pos": [71, 77]}], "task": "NER"}
{"text": "The excellent mechanical properties of stabilized tetragonal zirconia are related with the stresB-induced from tetragonal to monoclinical transformation , which is accompanied by a 4.5 % volume increase .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [14, 35]}, {"entity": "stabilized tetragonal zirconia", "entity_type": "material", "pos": [39, 69]}, {"entity": "tetragonal", "entity_type": "engineering feature", "pos": [111, 121]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [187, 193]}], "task": "NER"}
{"text": "This behaviour leads to the development of compression zone , shielding the propagating crack tip which inhibits further crack propagation , successfully enhancing toughness .", "entity": [{"entity": "compression zone", "entity_type": "process characterization", "pos": [43, 59]}, {"entity": "crack propagation", "entity_type": "concept or principle", "pos": [121, 138]}, {"entity": "toughness", "entity_type": "machanical property", "pos": [164, 173]}], "task": "NER"}
{"text": "Nevertheless , there are some disadvantageous aspects of zirconia ceramics .", "entity": [{"entity": "zirconia ceramics", "entity_type": "material", "pos": [57, 74]}], "task": "NER"}
{"text": "3.2 Alumina Alumina , also called aluminum oxide , was first introduced in the 1970s .", "entity": [{"entity": "Alumina", "entity_type": "material", "pos": [4, 11]}, {"entity": "aluminum oxide", "entity_type": "material", "pos": [34, 48]}], "task": "NER"}
{"text": "However , the initial applications presented a fracture rate of the order of 13 % .", "entity": [{"entity": "fracture rate", "entity_type": "process characterization", "pos": [47, 60]}], "task": "NER"}
{"text": "This observed failure was related to a higher porosity .", "entity": [{"entity": "failure", "entity_type": "concept or principle", "pos": [14, 21]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [46, 54]}], "task": "NER"}
{"text": "With further developments , a decade later , a second improved generation of alumina ceramics was presented , characterized by higher density and smaller grains .", "entity": [{"entity": "alumina", "entity_type": "material", "pos": [77, 84]}, {"entity": "density", "entity_type": "machanical property", "pos": [134, 141]}, {"entity": "grains", "entity_type": "concept or principle", "pos": [154, 160]}], "task": "NER"}
{"text": "This led to a decrease of the fracture rate to less than 5 % .", "entity": [{"entity": "led", "entity_type": "application", "pos": [5, 8]}, {"entity": "fracture rate", "entity_type": "process characterization", "pos": [30, 43]}], "task": "NER"}
{"text": "Nowadays , there is available a third generation of alumina ceramic components , with properties such as high purity , high density and finer microstructure .", "entity": [{"entity": "alumina ceramic components", "entity_type": "material", "pos": [52, 78]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [86, 96]}, {"entity": "as", "entity_type": "material", "pos": [102, 104]}, {"entity": "density", "entity_type": "machanical property", "pos": [124, 131]}, {"entity": "finer microstructure", "entity_type": "engineering feature", "pos": [136, 156]}], "task": "NER"}
{"text": "Alumina is used in dental applications for fabrication of endodontic posts , orthodontic brackets , dental implants , crowns and bridges and in ceramic abutments .", "entity": [{"entity": "Alumina", "entity_type": "material", "pos": [0, 7]}, {"entity": "dental applications", "entity_type": "application", "pos": [19, 38]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [43, 54]}, {"entity": "endodontic posts", "entity_type": "machine or equipment", "pos": [58, 74]}, {"entity": "orthodontic", "entity_type": "application", "pos": [77, 88]}, {"entity": "dental", "entity_type": "application", "pos": [100, 106]}, {"entity": "ceramic abutments", "entity_type": "engineering feature", "pos": [144, 161]}], "task": "NER"}
{"text": "High purity alumina has usually a purity of 99.99 % and has been developed as an alternative to surgical metal alloys for dental applications .", "entity": [{"entity": "alumina", "entity_type": "material", "pos": [12, 19]}, {"entity": "as", "entity_type": "material", "pos": [21, 23]}, {"entity": "metal alloys", "entity_type": "material", "pos": [105, 117]}, {"entity": "dental applications", "entity_type": "application", "pos": [122, 141]}], "task": "NER"}
{"text": "According to US Food and Drug Administration , only the high-purity Al2O3 can be used for medical grade ceramics .", "entity": [{"entity": "Al2O3", "entity_type": "material", "pos": [68, 73]}, {"entity": "be", "entity_type": "material", "pos": [78, 80]}, {"entity": "medical", "entity_type": "application", "pos": [90, 97]}, {"entity": "ceramics", "entity_type": "material", "pos": [104, 112]}], "task": "NER"}
{"text": "Impurities such as SiO2 , metal silicates and alkali metal oxides that form glassy grain boundary phases must be minimized to less than 0.1 wt % , since the in vivo degradation of such glassy phases leads to the appearance of stress concentration sites where cracks can be initiated , leading to the catastrophic failure of the component .", "entity": [{"entity": "Impurities", "entity_type": "machanical property", "pos": [0, 10]}, {"entity": "as", "entity_type": "material", "pos": [16, 18]}, {"entity": "metal silicates", "entity_type": "material", "pos": [26, 41]}, {"entity": "alkali metal oxides", "entity_type": "material", "pos": [46, 65]}, {"entity": "grain boundary", "entity_type": "concept or principle", "pos": [83, 97]}, {"entity": "be", "entity_type": "material", "pos": [110, 112]}, {"entity": "degradation", "entity_type": "concept or principle", "pos": [165, 176]}, {"entity": "stress concentration", "entity_type": "process characterization", "pos": [226, 246]}, {"entity": "be", "entity_type": "material", "pos": [270, 272]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [313, 320]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [328, 337]}], "task": "NER"}
{"text": "It is possible to enhance alumina toughness and fracture strength by controlling the grain size and the porosity .", "entity": [{"entity": "alumina", "entity_type": "material", "pos": [26, 33]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [48, 56]}, {"entity": "grain size", "entity_type": "machanical property", "pos": [85, 95]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [104, 112]}], "task": "NER"}
{"text": "This can be achieved using adequate sintering cycles , and adding some additives , zirconium oxide and chromium oxide ) .", "entity": [{"entity": "be", "entity_type": "material", "pos": [9, 11]}, {"entity": "sintering cycles", "entity_type": "manufacturing process", "pos": [36, 52]}, {"entity": "additives", "entity_type": "material", "pos": [71, 80]}, {"entity": "zirconium oxide", "entity_type": "material", "pos": [83, 98]}, {"entity": "chromium oxide", "entity_type": "material", "pos": [103, 117]}], "task": "NER"}
{"text": "3.3 Leucite Leucite is a potassium alumina-silicate .", "entity": [{"entity": "Leucite", "entity_type": "material", "pos": [4, 11]}, {"entity": "potassium alumina-silicate", "entity_type": "material", "pos": [25, 51]}], "task": "NER"}
{"text": "This material displays a tetragonal structure at room temperature .", "entity": [{"entity": "material", "entity_type": "material", "pos": [5, 13]}, {"entity": "tetragonal", "entity_type": "engineering feature", "pos": [25, 35]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [36, 45]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [54, 65]}], "task": "NER"}
{"text": "At 625 it suffers a displacive phase transformation from tetragonal to cubic , together with a volume expansion of 1.2 % .", "entity": [{"entity": "phase", "entity_type": "concept or principle", "pos": [31, 36]}, {"entity": "tetragonal", "entity_type": "engineering feature", "pos": [57, 67]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [95, 101]}], "task": "NER"}
{"text": "Leucite has been widely used as a constituent of dental ceramics to modify the coefficient of thermal expansion , which is very important when the ceramic is to be fused or baked onto metal .", "entity": [{"entity": "Leucite", "entity_type": "material", "pos": [0, 7]}, {"entity": "as", "entity_type": "material", "pos": [9, 11]}, {"entity": "dental", "entity_type": "application", "pos": [49, 55]}, {"entity": "ceramics", "entity_type": "material", "pos": [56, 64]}, {"entity": "coefficient of thermal expansion", "entity_type": "machanical property", "pos": [79, 111]}, {"entity": "ceramic", "entity_type": "material", "pos": [147, 154]}, {"entity": "be", "entity_type": "material", "pos": [161, 163]}, {"entity": "metal", "entity_type": "material", "pos": [184, 189]}], "task": "NER"}
{"text": "Usually leucite-based materials are used for veneering ceramics in metal-ceramic restorations , also referred to as feldspathic porcelains .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [22, 31]}, {"entity": "ceramics", "entity_type": "material", "pos": [55, 63]}, {"entity": "as", "entity_type": "material", "pos": [113, 115]}], "task": "NER"}
{"text": "Leucite is attained by incongruent melting of feldspar at temperatures between 1150 and 1530 .", "entity": [{"entity": "Leucite", "entity_type": "material", "pos": [0, 7]}, {"entity": "melting", "entity_type": "manufacturing process", "pos": [35, 42]}, {"entity": "feldspar", "entity_type": "material", "pos": [46, 54]}, {"entity": "temperatures", "entity_type": "process parameter", "pos": [58, 70]}], "task": "NER"}
{"text": "Despite the mechanical properties of feldspathic porcelains being the weakest within ceramic dental materials , their global performance is perceived as quite successful .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [12, 33]}, {"entity": "ceramic dental materials", "entity_type": "material", "pos": [85, 109]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [125, 136]}, {"entity": "as", "entity_type": "material", "pos": [150, 152]}], "task": "NER"}
{"text": "3.4 Lithium dissilicate Lithium silicate-based glasB-ceramics were recently introduced as machinable materials to respond to the demanded increased strength , toughness and wear resistance , required for the fabrication of dental pieces .", "entity": [{"entity": "Lithium", "entity_type": "material", "pos": [4, 11]}, {"entity": "Lithium", "entity_type": "material", "pos": [24, 31]}, {"entity": "as", "entity_type": "material", "pos": [42, 44]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [101, 110]}, {"entity": "demanded increased strength", "entity_type": "machanical property", "pos": [129, 156]}, {"entity": "toughness", "entity_type": "machanical property", "pos": [159, 168]}, {"entity": "wear resistance", "entity_type": "machanical property", "pos": [173, 188]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [208, 219]}, {"entity": "dental pieces", "entity_type": "machine or equipment", "pos": [223, 236]}], "task": "NER"}
{"text": "This ceramic material is used in the fabrication of single and multiunit dental restorations , mainly dental crowns , bridges , and veneers , due to its excellent mechanical and optical properties .", "entity": [{"entity": "ceramic material", "entity_type": "material", "pos": [5, 21]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [37, 48]}, {"entity": "dental", "entity_type": "application", "pos": [73, 79]}, {"entity": "dental crowns", "entity_type": "process characterization", "pos": [102, 115]}, {"entity": "veneers", "entity_type": "machine or equipment", "pos": [132, 139]}, {"entity": "mechanical", "entity_type": "application", "pos": [163, 173]}, {"entity": "optical properties", "entity_type": "machanical property", "pos": [178, 196]}], "task": "NER"}
{"text": "In general , lithium disilicate presents a microstructure constituted by interlocking needle-like crystals embedded in a glass matrix .", "entity": [{"entity": "lithium", "entity_type": "material", "pos": [13, 20]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [43, 57]}, {"entity": "glass matrix", "entity_type": "material", "pos": [121, 133]}], "task": "NER"}
{"text": "As a result of this morphology , cracks are forced to propagate around each individual lithium disilicate crystal .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "morphology", "entity_type": "concept or principle", "pos": [20, 30]}, {"entity": "lithium", "entity_type": "material", "pos": [87, 94]}], "task": "NER"}
{"text": "This type of microstructure increases both strength and toughness relatively to other commonly used glasB-ceramics : they have a strength twice as higher as that of the first generation of leucite-reinforced ceramics .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [13, 27]}, {"entity": "strength", "entity_type": "machanical property", "pos": [43, 51]}, {"entity": "toughness", "entity_type": "machanical property", "pos": [56, 65]}, {"entity": "strength", "entity_type": "machanical property", "pos": [129, 137]}, {"entity": "as", "entity_type": "material", "pos": [144, 146]}, {"entity": "as", "entity_type": "material", "pos": [154, 156]}, {"entity": "ceramics", "entity_type": "material", "pos": [208, 216]}], "task": "NER"}
{"text": "3.5 Mica Mica minerals are a group of sheet silicate minerals , or layer type silicates , that consist of varying complex formulae of Si , K , Na , Ca , F , O , Fe and Al .", "entity": [{"entity": "Mica", "entity_type": "material", "pos": [4, 8]}, {"entity": "sheet", "entity_type": "material", "pos": [38, 43]}, {"entity": "layer", "entity_type": "process parameter", "pos": [67, 72]}, {"entity": "silicates", "entity_type": "material", "pos": [78, 87]}, {"entity": "Si", "entity_type": "material", "pos": [134, 136]}, {"entity": "K", "entity_type": "material", "pos": [139, 140]}, {"entity": "Na", "entity_type": "material", "pos": [143, 145]}, {"entity": "Ca", "entity_type": "material", "pos": [148, 150]}, {"entity": "F", "entity_type": "manufacturing process", "pos": [153, 154]}, {"entity": "O", "entity_type": "material", "pos": [157, 158]}, {"entity": "Fe", "entity_type": "material", "pos": [161, 163]}, {"entity": "Al", "entity_type": "material", "pos": [168, 170]}], "task": "NER"}
{"text": "The mechanical properties are dictated by the specific crystal structure formed by the cleavage planes situated along the layers .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [4, 25]}, {"entity": "crystal structure", "entity_type": "machanical property", "pos": [55, 72]}, {"entity": "cleavage planes", "entity_type": "concept or principle", "pos": [87, 102]}], "task": "NER"}
{"text": "Crack propagation is more likely to occur along the cleavage planes .", "entity": [{"entity": "Crack propagation", "entity_type": "concept or principle", "pos": [0, 17]}, {"entity": "cleavage planes", "entity_type": "concept or principle", "pos": [52, 67]}], "task": "NER"}
{"text": "Mica-based glasB-ceramics are relevant for dental materials due to their good machinability , high strength and resistivity to thermal expansion as well as biocompatibility .", "entity": [{"entity": "dental", "entity_type": "application", "pos": [43, 49]}, {"entity": "machinability", "entity_type": "machanical property", "pos": [78, 91]}, {"entity": "strength", "entity_type": "machanical property", "pos": [99, 107]}, {"entity": "resistivity", "entity_type": "machanical property", "pos": [112, 123]}, {"entity": "thermal expansion", "entity_type": "concept or principle", "pos": [127, 144]}, {"entity": "as", "entity_type": "material", "pos": [145, 147]}, {"entity": "as", "entity_type": "material", "pos": [153, 155]}], "task": "NER"}
{"text": "3.6 Others ceramic dental materials Besides the examples mentioned above , there are other ceramic materials used in the dentistry field .", "entity": [{"entity": "ceramic dental materials", "entity_type": "material", "pos": [11, 35]}, {"entity": "ceramic materials", "entity_type": "material", "pos": [91, 108]}, {"entity": "dentistry field", "entity_type": "application", "pos": [121, 136]}], "task": "NER"}
{"text": "For over 30 years , calcium phosphate-based formulations are recognized by their good osteoconductivity and biocompatibility in reconstructive surgeries .", "entity": [{"entity": "calcium phosphate-based formulations", "entity_type": "material", "pos": [20, 56]}, {"entity": "osteoconductivity", "entity_type": "machanical property", "pos": [86, 103]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [108, 124]}], "task": "NER"}
{"text": "Tricalcium phosphate presents three polymorphs .", "entity": [{"entity": "phosphate", "entity_type": "material", "pos": [11, 20]}], "task": "NER"}
{"text": "These include : monoclinic , and hexagonal and rhombohedral form .", "entity": [{"entity": "monoclinic", "entity_type": "engineering feature", "pos": [16, 26]}, {"entity": "hexagonal", "entity_type": "engineering feature", "pos": [33, 42]}, {"entity": "rhombohedral form", "entity_type": "engineering feature", "pos": [47, 64]}], "task": "NER"}
{"text": "Hydroxyapatite 62 ) is the main component of enamel , and is responsible for the bright white appearance and elimination of the diffuse reflectivity of light by closing the small pores of the enamel surface .", "entity": [{"entity": "Hydroxyapatite 62", "entity_type": "material", "pos": [0, 17]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [32, 41]}, {"entity": "enamel", "entity_type": "material", "pos": [45, 51]}, {"entity": "pores", "entity_type": "machanical property", "pos": [179, 184]}, {"entity": "enamel", "entity_type": "material", "pos": [192, 198]}], "task": "NER"}
{"text": "HA can be used as filler in the repair of craniofacial defects or small holes and depressions on enamel surface , as grafting material and as coating in implant dentistry .", "entity": [{"entity": "be", "entity_type": "material", "pos": [7, 9]}, {"entity": "as", "entity_type": "material", "pos": [15, 17]}, {"entity": "craniofacial defects", "entity_type": "biomedical", "pos": [42, 62]}, {"entity": "enamel", "entity_type": "material", "pos": [97, 103]}, {"entity": "as", "entity_type": "material", "pos": [114, 116]}, {"entity": "material", "entity_type": "material", "pos": [126, 134]}, {"entity": "as", "entity_type": "material", "pos": [139, 141]}, {"entity": "implant", "entity_type": "application", "pos": [153, 160]}, {"entity": "dentistry", "entity_type": "application", "pos": [161, 170]}], "task": "NER"}
{"text": "Bioactive glasses are silicate-based materials that can form a strong chemical bond with the tissues .", "entity": [{"entity": "Bioactive glasses", "entity_type": "material", "pos": [0, 17]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [37, 46]}], "task": "NER"}
{"text": "They present great interest in regeneration and healing of bone tissue .", "entity": [{"entity": "regeneration", "entity_type": "concept or principle", "pos": [31, 43]}, {"entity": "bone", "entity_type": "biomedical", "pos": [59, 63]}], "task": "NER"}
{"text": "Their ability to support osteoblast cells , to bond to both soft and hard tissue and their capability of stimulating angiogenesis in the presence of vascular endothelial growth factor make them an attractive alternative relatively to other scaffold materials .", "entity": [{"entity": "support", "entity_type": "application", "pos": [17, 24]}, {"entity": "osteoblast cells", "entity_type": "biomedical", "pos": [25, 41]}, {"entity": "soft and hard tissue", "entity_type": "concept or principle", "pos": [60, 80]}, {"entity": "angiogenesis", "entity_type": "concept or principle", "pos": [117, 129]}, {"entity": "vascular endothelial growth factor", "entity_type": "biomedical", "pos": [149, 183]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [240, 248]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [249, 258]}], "task": "NER"}
{"text": "Finally , dental impression materials still play a significant role in dentistry .", "entity": [{"entity": "dental", "entity_type": "application", "pos": [10, 16]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [28, 37]}, {"entity": "dentistry", "entity_type": "application", "pos": [71, 80]}], "task": "NER"}
{"text": "Gypsum products are among the most frequently used materials by dental professionals , since its properties are easily modified by physical and chemical means .", "entity": [{"entity": "Gypsum", "entity_type": "material", "pos": [0, 6]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [51, 60]}, {"entity": "dental", "entity_type": "application", "pos": [64, 70]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [97, 107]}], "task": "NER"}
{"text": "Gypsum may be used as impression material , mold material for processing complete dentures , as binders for silica in gold alloy casting investment , soldering investment , and investment for low-melting-point nickel-chromium alloys .", "entity": [{"entity": "Gypsum", "entity_type": "material", "pos": [0, 6]}, {"entity": "be", "entity_type": "material", "pos": [11, 13]}, {"entity": "as", "entity_type": "material", "pos": [19, 21]}, {"entity": "material", "entity_type": "material", "pos": [33, 41]}, {"entity": "mold", "entity_type": "machine or equipment", "pos": [44, 48]}, {"entity": "material", "entity_type": "material", "pos": [49, 57]}, {"entity": "dentures", "entity_type": "application", "pos": [82, 90]}, {"entity": "as", "entity_type": "material", "pos": [93, 95]}, {"entity": "silica", "entity_type": "material", "pos": [108, 114]}, {"entity": "gold alloy", "entity_type": "material", "pos": [118, 128]}, {"entity": "casting", "entity_type": "manufacturing process", "pos": [129, 136]}, {"entity": "soldering", "entity_type": "manufacturing process", "pos": [150, 159]}, {"entity": "low-melting-point", "entity_type": "concept or principle", "pos": [192, 209]}, {"entity": "alloys", "entity_type": "material", "pos": [226, 232]}], "task": "NER"}
{"text": "3.7 Composites A composite material is defined as a combination of two or more materials .", "entity": [{"entity": "Composites", "entity_type": "material", "pos": [4, 14]}, {"entity": "composite material", "entity_type": "material", "pos": [17, 35]}, {"entity": "as", "entity_type": "material", "pos": [47, 49]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [79, 88]}], "task": "NER"}
{"text": "The resulting combination renders unique properties with characteristics different from the individual components .", "entity": [{"entity": "properties", "entity_type": "concept or principle", "pos": [41, 51]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [103, 113]}], "task": "NER"}
{"text": "In dentistry , ceramic composites may comprise combinations such as ceramic-metal , ceramic-polymer , or ceramic-ceramic Examples of current dental ceramic-ceramic composites include aluminacomposites , commercially available as structural ceramics for dental devices .", "entity": [{"entity": "dentistry", "entity_type": "application", "pos": [3, 12]}, {"entity": "ceramic composites", "entity_type": "engineering feature", "pos": [15, 33]}, {"entity": "as", "entity_type": "material", "pos": [65, 67]}, {"entity": "ceramic-polymer", "entity_type": "material", "pos": [84, 99]}, {"entity": "dental ceramic-ceramic composites", "entity_type": "material", "pos": [141, 174]}, {"entity": "as", "entity_type": "material", "pos": [226, 228]}, {"entity": "ceramics", "entity_type": "material", "pos": [240, 248]}, {"entity": "dental devices", "entity_type": "application", "pos": [253, 267]}], "task": "NER"}
{"text": "These materials , contain either alumina-toughened zirconia or zirconia-toughened alumina , depending on the percentage of the main component .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [6, 15]}, {"entity": "alumina-toughened zirconia", "entity_type": "material", "pos": [33, 59]}, {"entity": "alumina", "entity_type": "material", "pos": [82, 89]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [132, 141]}], "task": "NER"}
{"text": "These composites combine the transformation toughening capabilities of zirconia along with the lower susceptibility to low temperature degradation in biological fluids .", "entity": [{"entity": "composites", "entity_type": "material", "pos": [6, 16]}, {"entity": "toughening", "entity_type": "manufacturing process", "pos": [44, 54]}, {"entity": "zirconia", "entity_type": "material", "pos": [71, 79]}, {"entity": "susceptibility", "entity_type": "machanical property", "pos": [101, 115]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [123, 134]}, {"entity": "degradation", "entity_type": "concept or principle", "pos": [135, 146]}, {"entity": "biological fluids", "entity_type": "material", "pos": [150, 167]}], "task": "NER"}
{"text": "More recently , with the development of nanotechnology , the bionanocomposites have emerged .", "entity": [{"entity": "nanotechnology", "entity_type": "concept or principle", "pos": [40, 54]}, {"entity": "bionanocomposites", "entity_type": "material", "pos": [61, 78]}], "task": "NER"}
{"text": "These materials are expected to mimic native tissue structure , withstand high biting force and harsh oral cavity environment , e.g .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [6, 15]}, {"entity": "mimic", "entity_type": "machine or equipment", "pos": [32, 37]}, {"entity": "tissue structure", "entity_type": "concept or principle", "pos": [45, 61]}, {"entity": "force", "entity_type": "concept or principle", "pos": [86, 91]}], "task": "NER"}
{"text": "sudden change of temperature or osmotic pressure and invasion of various pathogens .", "entity": [{"entity": "temperature", "entity_type": "process parameter", "pos": [17, 28]}, {"entity": "osmotic pressure", "entity_type": "machanical property", "pos": [32, 48]}], "task": "NER"}
{"text": "Possible applications for bionanocomposites in the dental field include dental tissue regeneration or its substitution .", "entity": [{"entity": "bionanocomposites", "entity_type": "material", "pos": [26, 43]}, {"entity": "dental", "entity_type": "application", "pos": [51, 57]}, {"entity": "dental tissue regeneration", "entity_type": "concept or principle", "pos": [72, 98]}], "task": "NER"}
{"text": "4 Digital manufacturing CAD/CAM production of fixed prosthetic restorations such as inlays , onlays , veneers , crowns , and fixed partial dentures is a relatively well established technology used by dental health professionals for over 20 years .", "entity": [{"entity": "Digital manufacturing", "entity_type": "manufacturing process", "pos": [2, 23]}, {"entity": "CAD/CAM", "entity_type": "enabling technology", "pos": [24, 31]}, {"entity": "prosthetic", "entity_type": "application", "pos": [52, 62]}, {"entity": "as", "entity_type": "material", "pos": [81, 83]}, {"entity": "onlays", "entity_type": "application", "pos": [93, 99]}, {"entity": "veneers", "entity_type": "machine or equipment", "pos": [102, 109]}, {"entity": "fixed partial dentures", "entity_type": "application", "pos": [125, 147]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [181, 191]}, {"entity": "dental", "entity_type": "application", "pos": [200, 206]}], "task": "NER"}
{"text": "All CAD/CAM systems involve three steps .", "entity": [{"entity": "CAD/CAM", "entity_type": "enabling technology", "pos": [4, 11]}], "task": "NER"}
{"text": "The first one corresponds to the data acquisition , through various scanning technologies that allow to transform the site/product geometry into digital data to be processed by the computer .", "entity": [{"entity": "data acquisition", "entity_type": "process characterization", "pos": [33, 49]}, {"entity": "scanning", "entity_type": "concept or principle", "pos": [68, 76]}, {"entity": "geometry", "entity_type": "concept or principle", "pos": [131, 139]}, {"entity": "data", "entity_type": "concept or principle", "pos": [153, 157]}, {"entity": "be", "entity_type": "material", "pos": [161, 163]}, {"entity": "computer", "entity_type": "enabling technology", "pos": [181, 189]}], "task": "NER"}
{"text": "This is followed by manipulation and processing of the data set using a CAD software .", "entity": [{"entity": "data", "entity_type": "concept or principle", "pos": [55, 59]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [72, 75]}], "task": "NER"}
{"text": "Finally , the processed data are used for manufacturing of structures in the desired material through CAM .", "entity": [{"entity": "processed data", "entity_type": "concept or principle", "pos": [14, 28]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [42, 55]}, {"entity": "material", "entity_type": "material", "pos": [85, 93]}, {"entity": "CAM", "entity_type": "enabling technology", "pos": [102, 105]}], "task": "NER"}
{"text": "In dentistry , there are three different production concepts available , depending on the location of the steps of the CAD/CAM processes : - chairside production , - laboratory production , - centralized fabrication in a production center .", "entity": [{"entity": "dentistry", "entity_type": "application", "pos": [3, 12]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [41, 51]}, {"entity": "CAD/CAM", "entity_type": "enabling technology", "pos": [119, 126]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [151, 161]}, {"entity": "laboratory", "entity_type": "concept or principle", "pos": [166, 176]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [204, 215]}, {"entity": "production center", "entity_type": "application", "pos": [221, 238]}], "task": "NER"}
{"text": "The production can be carried out through several different technologies , that can be divided into two manufacturing processes : subtractive and additive manufacturing .", "entity": [{"entity": "production", "entity_type": "manufacturing process", "pos": [4, 14]}, {"entity": "be", "entity_type": "material", "pos": [19, 21]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [60, 72]}, {"entity": "be", "entity_type": "material", "pos": [84, 86]}, {"entity": "manufacturing processes", "entity_type": "manufacturing process", "pos": [104, 127]}, {"entity": "subtractive", "entity_type": "manufacturing process", "pos": [130, 141]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [146, 168]}], "task": "NER"}
{"text": "4.1 Subtractive manufacturing There are several subtractive manufacturing techniques .", "entity": [{"entity": "Subtractive manufacturing", "entity_type": "manufacturing process", "pos": [4, 29]}, {"entity": "subtractive manufacturing", "entity_type": "manufacturing process", "pos": [48, 73]}], "task": "NER"}
{"text": "The most used in dental ceramics processing is based on milling of pre-sintered or fully sintered blocks , through a computer numeric controlled machine .", "entity": [{"entity": "dental ceramics processing", "entity_type": "manufacturing process", "pos": [17, 43]}, {"entity": "milling", "entity_type": "manufacturing process", "pos": [56, 63]}, {"entity": "pre-sintered", "entity_type": "machanical property", "pos": [67, 79]}, {"entity": "fully sintered blocks", "entity_type": "process characterization", "pos": [83, 104]}, {"entity": "computer", "entity_type": "enabling technology", "pos": [117, 125]}, {"entity": "machine", "entity_type": "machine or equipment", "pos": [145, 152]}], "task": "NER"}
{"text": "The CAM software automatically translates the CAD model into tool path for the CNC machine .", "entity": [{"entity": "CAM", "entity_type": "enabling technology", "pos": [4, 7]}, {"entity": "CAD model", "entity_type": "enabling technology", "pos": [46, 55]}, {"entity": "tool path", "entity_type": "concept or principle", "pos": [61, 70]}, {"entity": "CNC machine", "entity_type": "machine or equipment", "pos": [79, 90]}], "task": "NER"}
{"text": "This involves computation of the commands series that dictate the CNC milling , including sequencing , milling tools , and tool motion direction and magnitude .", "entity": [{"entity": "computation", "entity_type": "concept or principle", "pos": [14, 25]}, {"entity": "CNC milling", "entity_type": "manufacturing process", "pos": [66, 77]}, {"entity": "milling", "entity_type": "manufacturing process", "pos": [103, 110]}, {"entity": "tool motion direction", "entity_type": "process parameter", "pos": [123, 144]}, {"entity": "magnitude", "entity_type": "process parameter", "pos": [149, 158]}], "task": "NER"}
{"text": "The accuracy of tool positioning has been reported to be within 10 .", "entity": [{"entity": "accuracy", "entity_type": "process characterization", "pos": [4, 12]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [16, 20]}, {"entity": "be", "entity_type": "material", "pos": [37, 39]}], "task": "NER"}
{"text": "The 3-axis milling systems are the most commonly used in dental milling systems .", "entity": [{"entity": "milling", "entity_type": "manufacturing process", "pos": [11, 18]}, {"entity": "dental", "entity_type": "application", "pos": [57, 63]}], "task": "NER"}
{"text": "In such systems , the milling burs move in three axes according to a defined path .", "entity": [{"entity": "milling burs", "entity_type": "concept or principle", "pos": [22, 34]}], "task": "NER"}
{"text": "SM is extensively used in dentistry for the production of dental pieces such as crowns and bridges .", "entity": [{"entity": "SM", "entity_type": "material", "pos": [0, 2]}, {"entity": "dentistry", "entity_type": "application", "pos": [26, 35]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [44, 54]}, {"entity": "dental pieces", "entity_type": "machine or equipment", "pos": [58, 71]}, {"entity": "as", "entity_type": "material", "pos": [77, 79]}], "task": "NER"}
{"text": "SM technology allows the processing of materials , which would otherwise be difficult to manipulate .", "entity": [{"entity": "SM", "entity_type": "material", "pos": [0, 2]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [39, 48]}, {"entity": "be", "entity_type": "material", "pos": [73, 75]}], "task": "NER"}
{"text": "This way , the exhaustive artisanal production techniques are decreased or even eliminated , thus allowing the dental technician to enhance the creative component of his manual manufacturing process .", "entity": [{"entity": "production", "entity_type": "manufacturing process", "pos": [36, 46]}, {"entity": "dental", "entity_type": "application", "pos": [111, 117]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [153, 162]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [177, 198]}], "task": "NER"}
{"text": "SM is a well-established technology which has the advantage of using intrinsically homogeneous materials which are unaffected by operating conditions .", "entity": [{"entity": "SM", "entity_type": "material", "pos": [0, 2]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [25, 35]}, {"entity": "homogeneous materials", "entity_type": "material", "pos": [83, 104]}], "task": "NER"}
{"text": "Furthermore , it requires low post-processing and the costs regarding the involved equipment are relatively reduced .", "entity": [{"entity": "post-processing", "entity_type": "concept or principle", "pos": [30, 45]}, {"entity": "equipment", "entity_type": "machine or equipment", "pos": [83, 92]}], "task": "NER"}
{"text": "However , this is a wasteful process because the piece is milled from an intact block with a significant loss of material amount .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [29, 36]}, {"entity": "milled", "entity_type": "manufacturing process", "pos": [58, 64]}, {"entity": "material", "entity_type": "material", "pos": [113, 121]}], "task": "NER"}
{"text": "Factors such as the objectscomplexity , the dimension of the tooling equipment and the properties of the material can affect and limit the accuracy of this process .", "entity": [{"entity": "as", "entity_type": "material", "pos": [13, 15]}, {"entity": "dimension", "entity_type": "engineering feature", "pos": [44, 53]}, {"entity": "tooling", "entity_type": "concept or principle", "pos": [61, 68]}, {"entity": "equipment", "entity_type": "machine or equipment", "pos": [69, 78]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [87, 97]}, {"entity": "material", "entity_type": "material", "pos": [105, 113]}, {"entity": "limit", "entity_type": "concept or principle", "pos": [129, 134]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [139, 147]}, {"entity": "process", "entity_type": "concept or principle", "pos": [156, 163]}], "task": "NER"}
{"text": "4.2 Additive manufacturing Additive manufacturing , also referred to as solid freeform fabrication , rapid prototyping or 3D printing , involves processing methodologies that are capable of producing structures by depositing materials layer-by-layer resorting to a computer generated design file .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [4, 26]}, {"entity": "Additive", "entity_type": "material", "pos": [27, 35]}, {"entity": "as", "entity_type": "material", "pos": [69, 71]}, {"entity": "freeform fabrication", "entity_type": "manufacturing process", "pos": [78, 98]}, {"entity": "rapid prototyping", "entity_type": "enabling technology", "pos": [101, 118]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [122, 133]}, {"entity": "materials layer-by-layer", "entity_type": "concept or principle", "pos": [225, 249]}, {"entity": "computer", "entity_type": "enabling technology", "pos": [265, 273]}, {"entity": "design", "entity_type": "engineering feature", "pos": [284, 290]}], "task": "NER"}
{"text": "The workpiece is virtually sliced into several two-dimensional layers .", "entity": [{"entity": "workpiece", "entity_type": "concept or principle", "pos": [4, 13]}, {"entity": "two-dimensional", "entity_type": "concept or principle", "pos": [47, 62]}], "task": "NER"}
{"text": "Then , an AM machine generates the tool-path along the x and y directions .", "entity": [{"entity": "AM machine", "entity_type": "machine or equipment", "pos": [10, 20]}, {"entity": "tool-path", "entity_type": "process parameter", "pos": [35, 44]}, {"entity": "y", "entity_type": "material", "pos": [61, 62]}], "task": "NER"}
{"text": "Each material layer is deposited one on top of the other , consecutively , forming a three-dimensional part .", "entity": [{"entity": "material", "entity_type": "material", "pos": [5, 13]}, {"entity": "layer", "entity_type": "process parameter", "pos": [14, 19]}, {"entity": "forming", "entity_type": "manufacturing process", "pos": [75, 82]}, {"entity": "three-dimensional", "entity_type": "concept or principle", "pos": [85, 102]}], "task": "NER"}
{"text": "Ceramics present a higher melting point , higher susceptibility to thermal shook and lower sintrerability than the other group of materials .", "entity": [{"entity": "Ceramics", "entity_type": "material", "pos": [0, 8]}, {"entity": "melting point", "entity_type": "machanical property", "pos": [26, 39]}, {"entity": "susceptibility", "entity_type": "machanical property", "pos": [49, 63]}, {"entity": "sintrerability", "entity_type": "machanical property", "pos": [91, 105]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [130, 139]}], "task": "NER"}
{"text": "Thus , it is quite difficult to obtained fully consolidated parts , without defects , using AM methods that produced directly sintered bodies .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [76, 83]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [92, 94]}, {"entity": "directly sintered bodies", "entity_type": "manufacturing process", "pos": [117, 141]}], "task": "NER"}
{"text": "In most of the cases , AM is used to obtain preliminary 3D structures in green that are built from mixture powders with organic or inorganic binder materials and need to be submitted to further steps of debinding and sintering .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [23, 25]}, {"entity": "3D structures", "entity_type": "concept or principle", "pos": [56, 69]}, {"entity": "powders", "entity_type": "material", "pos": [107, 114]}, {"entity": "binder", "entity_type": "material", "pos": [141, 147]}, {"entity": "be", "entity_type": "material", "pos": [170, 172]}, {"entity": "debinding", "entity_type": "concept or principle", "pos": [203, 212]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [217, 226]}], "task": "NER"}
{"text": "Some authors refer to these methods as indirect , contrarily to direct methods where the ceramic powder is sintered during the manufacturing procedure .", "entity": [{"entity": "as", "entity_type": "material", "pos": [36, 38]}, {"entity": "ceramic powder", "entity_type": "material", "pos": [89, 103]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [107, 115]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [127, 140]}], "task": "NER"}
{"text": "The debinding step depends on the organic components and became diffusion limited by increasing the thickness of the part , leading to higher debinding times The debinding temperature need to be carefully chosen .", "entity": [{"entity": "debinding", "entity_type": "concept or principle", "pos": [4, 13]}, {"entity": "organic components", "entity_type": "machine or equipment", "pos": [34, 52]}, {"entity": "diffusion", "entity_type": "concept or principle", "pos": [64, 73]}, {"entity": "debinding", "entity_type": "concept or principle", "pos": [142, 151]}, {"entity": "debinding temperature", "entity_type": "process characterization", "pos": [162, 183]}, {"entity": "be", "entity_type": "material", "pos": [192, 194]}], "task": "NER"}
{"text": "If is to high the removal rate of the volatile products resulting from the binder decomposition is too high , the pressure may increase and lead to crack formation and/or delamination .", "entity": [{"entity": "binder decomposition", "entity_type": "process characterization", "pos": [75, 95]}, {"entity": "pressure", "entity_type": "concept or principle", "pos": [114, 122]}, {"entity": "lead", "entity_type": "material", "pos": [140, 144]}, {"entity": "delamination", "entity_type": "concept or principle", "pos": [171, 183]}], "task": "NER"}
{"text": "A possible solution to overcome the internal stresses generated during debinding may be the use of plasticizing agents .", "entity": [{"entity": "solution", "entity_type": "concept or principle", "pos": [11, 19]}, {"entity": "internal stresses", "entity_type": "machanical property", "pos": [36, 53]}, {"entity": "debinding", "entity_type": "concept or principle", "pos": [71, 80]}, {"entity": "be", "entity_type": "material", "pos": [85, 87]}], "task": "NER"}
{"text": "The defects can also be avoided through the introduction of open spaces in the structure .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "be", "entity_type": "material", "pos": [21, 23]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [79, 88]}], "task": "NER"}
{"text": "That can be achieved by adding compounds able to evaporate/decompose at lower temperature than the debinding process temperature 2 .", "entity": [{"entity": "be", "entity_type": "material", "pos": [9, 11]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [78, 89]}, {"entity": "debinding", "entity_type": "concept or principle", "pos": [99, 108]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [117, 128]}], "task": "NER"}
{"text": "There are several applications for AM in dentistry .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [35, 37]}, {"entity": "dentistry", "entity_type": "application", "pos": [41, 50]}], "task": "NER"}
{"text": "One of the earliest is medical modelling , for surgery guide , where anatomical modelsare created .", "entity": [{"entity": "medical", "entity_type": "application", "pos": [23, 30]}, {"entity": "surgery", "entity_type": "application", "pos": [47, 54]}], "task": "NER"}
{"text": "The models can also be used as supports for the fabrication of restorations , for example , to help in the addition of veneered materials .", "entity": [{"entity": "be", "entity_type": "material", "pos": [20, 22]}, {"entity": "as", "entity_type": "material", "pos": [28, 30]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [48, 59]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [128, 137]}], "task": "NER"}
{"text": "In digital orthodontics , there are systems available that digitally realign the patientteeth to make a series of 3D printed models for the manufacture of aligners .", "entity": [{"entity": "digital orthodontics", "entity_type": "application", "pos": [3, 23]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [114, 124]}, {"entity": "manufacture", "entity_type": "concept or principle", "pos": [140, 151]}], "task": "NER"}
{"text": "3D printing technology can also be used to produce novel titanium dental implants with a porous or rough surface and different types of restorations/components in metallic or polymeric materials .", "entity": [{"entity": "3D printing technology", "entity_type": "enabling technology", "pos": [0, 22]}, {"entity": "be", "entity_type": "material", "pos": [32, 34]}, {"entity": "titanium", "entity_type": "material", "pos": [57, 65]}, {"entity": "dental", "entity_type": "application", "pos": [66, 72]}, {"entity": "porous", "entity_type": "machanical property", "pos": [89, 95]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [105, 112]}, {"entity": "metallic", "entity_type": "material", "pos": [163, 171]}, {"entity": "polymeric materials", "entity_type": "material", "pos": [175, 194]}], "task": "NER"}
{"text": "In the next sections , the main AM technologies available , referred in 1 , are described , namely indirect methods , such as binder jetting , material extrusion and jetting and Vat polymerization/stereolitography , and direct methods , which include direct energy deposition and powder bed fusion .", "entity": [{"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [32, 47]}, {"entity": "as", "entity_type": "material", "pos": [123, 125]}, {"entity": "jetting", "entity_type": "manufacturing process", "pos": [133, 140]}, {"entity": "material extrusion", "entity_type": "manufacturing process", "pos": [143, 161]}, {"entity": "jetting", "entity_type": "manufacturing process", "pos": [166, 173]}, {"entity": "Vat polymerization/stereolitography", "entity_type": "manufacturing process", "pos": [178, 213]}, {"entity": "direct energy deposition", "entity_type": "manufacturing process", "pos": [251, 275]}, {"entity": "powder bed fusion", "entity_type": "manufacturing process", "pos": [280, 297]}], "task": "NER"}
{"text": "4.2.1 Binder jetting Binder jetting uses two materials , a powder-based material and a binder .", "entity": [{"entity": "Binder jetting", "entity_type": "manufacturing process", "pos": [6, 20]}, {"entity": "Binder", "entity_type": "material", "pos": [21, 27]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [45, 54]}, {"entity": "powder-based material", "entity_type": "material", "pos": [59, 80]}, {"entity": "binder", "entity_type": "material", "pos": [87, 93]}], "task": "NER"}
{"text": "Usually in the liquid form , the organic binder acts as an adhesive between ceramic powder particles .", "entity": [{"entity": "binder", "entity_type": "material", "pos": [41, 47]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}, {"entity": "adhesive", "entity_type": "material", "pos": [59, 67]}, {"entity": "ceramic powder particles", "entity_type": "material", "pos": [76, 100]}], "task": "NER"}
{"text": "A print head deposits alternated layers of the building material and the binding material , moving horizontally along the x and y axes of the machine .", "entity": [{"entity": "print head", "entity_type": "machine or equipment", "pos": [2, 12]}, {"entity": "material", "entity_type": "material", "pos": [56, 64]}, {"entity": "binding material", "entity_type": "material", "pos": [73, 89]}, {"entity": "y", "entity_type": "material", "pos": [110, 111]}, {"entity": "machine", "entity_type": "machine or equipment", "pos": [142, 149]}], "task": "NER"}
{"text": "After each layer , the build platform is lowered and the process repeated over the previous layer .", "entity": [{"entity": "layer", "entity_type": "process parameter", "pos": [11, 16]}, {"entity": "build platform", "entity_type": "machine or equipment", "pos": [23, 37]}, {"entity": "process", "entity_type": "concept or principle", "pos": [57, 64]}, {"entity": "layer", "entity_type": "process parameter", "pos": [92, 97]}], "task": "NER"}
{"text": "BJ presents several advantages , such as the ability to use a range of materials as well as a large number of combinations powder/binder , being generally a fast printing process .", "entity": [{"entity": "BJ", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "as", "entity_type": "material", "pos": [38, 40]}, {"entity": "range", "entity_type": "process parameter", "pos": [62, 67]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [71, 80]}, {"entity": "as", "entity_type": "material", "pos": [81, 83]}, {"entity": "as", "entity_type": "material", "pos": [89, 91]}, {"entity": "printing process", "entity_type": "manufacturing process", "pos": [162, 178]}], "task": "NER"}
{"text": "The drawbacks of this technology are mainly related to the high porosity and consequent low mechanical properties of the printed pieces .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [22, 32]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [64, 72]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [92, 113]}], "task": "NER"}
{"text": "This is due to factors such as the high friction within the powder particles , their random agglomeration and the absence of an external force to compress the powder and improve packaging .", "entity": [{"entity": "as", "entity_type": "material", "pos": [28, 30]}, {"entity": "friction", "entity_type": "concept or principle", "pos": [40, 48]}, {"entity": "powder particles", "entity_type": "material", "pos": [60, 76]}, {"entity": "force", "entity_type": "concept or principle", "pos": [137, 142]}, {"entity": "powder", "entity_type": "material", "pos": [159, 165]}], "task": "NER"}
{"text": "The flowability and spreadability of powders are especially important for BJ .", "entity": [{"entity": "powders", "entity_type": "material", "pos": [37, 44]}, {"entity": "BJ", "entity_type": "manufacturing process", "pos": [74, 76]}], "task": "NER"}
{"text": "Using powders with large particle sizes can enhance the flowability , however it may jeopardize the sinterability and densification behaviour after printing .", "entity": [{"entity": "powders", "entity_type": "material", "pos": [6, 13]}, {"entity": "particle", "entity_type": "concept or principle", "pos": [25, 33]}, {"entity": "sinterability", "entity_type": "machanical property", "pos": [100, 113]}, {"entity": "densification behaviour", "entity_type": "machanical property", "pos": [118, 141]}], "task": "NER"}
{"text": "Contrarily , very fine particle size may lead to considerable agglomeration and reduced flowability .", "entity": [{"entity": "particle", "entity_type": "concept or principle", "pos": [23, 31]}, {"entity": "lead", "entity_type": "material", "pos": [41, 45]}], "task": "NER"}
{"text": "Since after sintering , the pieces density rarely exceeds 50 % of the theoretical value , this technology seems not to be suitable for structural parts .", "entity": [{"entity": "sintering", "entity_type": "manufacturing process", "pos": [12, 21]}, {"entity": "density", "entity_type": "machanical property", "pos": [35, 42]}, {"entity": "theoretical", "entity_type": "concept or principle", "pos": [70, 81]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [95, 105]}, {"entity": "be", "entity_type": "material", "pos": [119, 121]}], "task": "NER"}
{"text": "In order to overcome this issue , the printed piece may be infiltered under vacuum with a glass material that penetrates in the pores by capillary effect .", "entity": [{"entity": "be", "entity_type": "material", "pos": [56, 58]}, {"entity": "glass material", "entity_type": "material", "pos": [90, 104]}, {"entity": "pores", "entity_type": "machanical property", "pos": [128, 133]}, {"entity": "capillary effect", "entity_type": "concept or principle", "pos": [137, 153]}], "task": "NER"}
{"text": "4.2.2 Material extrusion and jetting Generally , in the material extrusion process the material is heated and extruded through a nozzle .", "entity": [{"entity": "Material extrusion", "entity_type": "manufacturing process", "pos": [6, 24]}, {"entity": "jetting", "entity_type": "manufacturing process", "pos": [29, 36]}, {"entity": "material extrusion", "entity_type": "manufacturing process", "pos": [56, 74]}, {"entity": "material", "entity_type": "material", "pos": [87, 95]}, {"entity": "extruded", "entity_type": "manufacturing process", "pos": [110, 118]}, {"entity": "nozzle", "entity_type": "machine or equipment", "pos": [129, 135]}], "task": "NER"}
{"text": "The nozzle can move horizontally , and the build platform can move vertically to enable the addition of each subsequent layer .", "entity": [{"entity": "nozzle", "entity_type": "machine or equipment", "pos": [4, 10]}, {"entity": "build platform", "entity_type": "machine or equipment", "pos": [43, 57]}, {"entity": "layer", "entity_type": "process parameter", "pos": [120, 125]}], "task": "NER"}
{"text": "This process , also known as fused deposition modeling , is the most widespread and inexpensive process within 3D printing technology .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "as", "entity_type": "material", "pos": [26, 28]}, {"entity": "deposition modeling", "entity_type": "concept or principle", "pos": [35, 54]}, {"entity": "process", "entity_type": "concept or principle", "pos": [96, 103]}, {"entity": "3D printing technology", "entity_type": "enabling technology", "pos": [111, 133]}], "task": "NER"}
{"text": "However , there are some drawbacks such as not being as fast as other AM processes and presenting an accuracy limited by the nozzle radius , which reduces the final product quality .", "entity": [{"entity": "as", "entity_type": "material", "pos": [40, 42]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}, {"entity": "as", "entity_type": "material", "pos": [57, 59]}, {"entity": "AM processes", "entity_type": "manufacturing process", "pos": [70, 82]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [101, 109]}, {"entity": "nozzle", "entity_type": "machine or equipment", "pos": [125, 131]}, {"entity": "product quality", "entity_type": "concept or principle", "pos": [165, 180]}], "task": "NER"}
{"text": "In order to increase the final quality it is necessary to control factors such as extrusion speed and ensure constant pressure and flow .", "entity": [{"entity": "quality", "entity_type": "concept or principle", "pos": [31, 38]}, {"entity": "as", "entity_type": "material", "pos": [79, 81]}, {"entity": "pressure", "entity_type": "concept or principle", "pos": [118, 126]}], "task": "NER"}
{"text": "Another form of AM using material extrusion is material jetting process , where the material is deposited in the form of droplets , instead of filament , to form a 2D pattern .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [16, 18]}, {"entity": "material extrusion", "entity_type": "manufacturing process", "pos": [25, 43]}, {"entity": "material jetting", "entity_type": "manufacturing process", "pos": [47, 63]}, {"entity": "material", "entity_type": "material", "pos": [84, 92]}, {"entity": "droplets", "entity_type": "concept or principle", "pos": [121, 129]}, {"entity": "filament", "entity_type": "material", "pos": [143, 151]}, {"entity": "2D pattern", "entity_type": "engineering feature", "pos": [164, 174]}], "task": "NER"}
{"text": "The printed layer is cured using ultraviolet radiation , immediately after the deposition .", "entity": [{"entity": "layer", "entity_type": "process parameter", "pos": [12, 17]}, {"entity": "cured", "entity_type": "manufacturing process", "pos": [21, 26]}, {"entity": "ultraviolet radiation", "entity_type": "concept or principle", "pos": [33, 54]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [79, 89]}], "task": "NER"}
{"text": "The process is repeated until the complete 3D part is formed .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "3D part", "entity_type": "application", "pos": [43, 50]}], "task": "NER"}
{"text": "5 shows an example of an occlusal surface of a dental crown produced by this technique from a ceramic suspension of yttria partially stabilized zirconia .", "entity": [{"entity": "surface", "entity_type": "concept or principle", "pos": [34, 41]}, {"entity": "dental crown", "entity_type": "process characterization", "pos": [47, 59]}, {"entity": "ceramic", "entity_type": "material", "pos": [94, 101]}, {"entity": "yttria", "entity_type": "material", "pos": [116, 122]}, {"entity": "partially stabilized zirconia", "entity_type": "material", "pos": [123, 152]}], "task": "NER"}
{"text": "It is possible to observe surface waviness associated with layer-by-layer deposition .", "entity": [{"entity": "surface waviness", "entity_type": "process characterization", "pos": [26, 42]}, {"entity": "layer-by-layer deposition", "entity_type": "concept or principle", "pos": [59, 84]}], "task": "NER"}
{"text": "Material extrusion techniques also include robocasting .", "entity": [{"entity": "Material extrusion", "entity_type": "manufacturing process", "pos": [0, 18]}, {"entity": "robocasting", "entity_type": "manufacturing process", "pos": [43, 54]}], "task": "NER"}
{"text": "In this process , a filament of a paste is extruded through a nozzle while it moves over a platform , building the object layer-by-layer .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [8, 15]}, {"entity": "filament", "entity_type": "material", "pos": [20, 28]}, {"entity": "extruded", "entity_type": "manufacturing process", "pos": [43, 51]}, {"entity": "nozzle", "entity_type": "machine or equipment", "pos": [62, 68]}, {"entity": "platform", "entity_type": "machine or equipment", "pos": [91, 99]}, {"entity": "layer-by-layer", "entity_type": "concept or principle", "pos": [122, 136]}], "task": "NER"}
{"text": "The paste exits the nozzle with a given shape , without being necessary waiting for its solidification or drying to build the next layer .", "entity": [{"entity": "nozzle", "entity_type": "machine or equipment", "pos": [20, 26]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [88, 102]}, {"entity": "drying", "entity_type": "manufacturing process", "pos": [106, 112]}, {"entity": "build", "entity_type": "process parameter", "pos": [116, 121]}, {"entity": "layer", "entity_type": "process parameter", "pos": [131, 136]}], "task": "NER"}
{"text": "Freeze-form Extrusion Fabrication is another example of extrusion-based AM technology .", "entity": [{"entity": "Extrusion", "entity_type": "manufacturing process", "pos": [12, 21]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [72, 85]}], "task": "NER"}
{"text": "Contrarily to most of the other extrusion freeform fabrication methods , in FEF , the organic binder content is only 2vol % and the solids loading of the paste can be higher than 50 vol % .", "entity": [{"entity": "extrusion", "entity_type": "manufacturing process", "pos": [32, 41]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [51, 62]}, {"entity": "binder", "entity_type": "material", "pos": [94, 100]}, {"entity": "be", "entity_type": "material", "pos": [164, 166]}], "task": "NER"}
{"text": "During FEF the piece is built by keeping the surrounding environment of the building platform below the freezing temperature of water .", "entity": [{"entity": "building platform", "entity_type": "machine or equipment", "pos": [76, 93]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [113, 124]}], "task": "NER"}
{"text": "This solidifies the paste after the deposition on each layer during the fabrication process .", "entity": [{"entity": "deposition", "entity_type": "concept or principle", "pos": [36, 46]}, {"entity": "layer", "entity_type": "process parameter", "pos": [55, 60]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [72, 83]}], "task": "NER"}
{"text": "FEF enables the production of relatively large parts , when compared with traditional robocasting .", "entity": [{"entity": "production", "entity_type": "manufacturing process", "pos": [16, 26]}, {"entity": "robocasting", "entity_type": "manufacturing process", "pos": [86, 97]}], "task": "NER"}
{"text": "In extrusion techniques , the mechanical properties can be improved by controlling the crystallographic texture of the materials .", "entity": [{"entity": "extrusion techniques", "entity_type": "manufacturing process", "pos": [3, 23]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [30, 51]}, {"entity": "be", "entity_type": "material", "pos": [56, 58]}, {"entity": "texture", "entity_type": "engineering feature", "pos": [104, 111]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [119, 128]}], "task": "NER"}
{"text": "This may be achieved by mixing a small number of large particles of anisotropic shape with fine particles .", "entity": [{"entity": "be", "entity_type": "material", "pos": [9, 11]}, {"entity": "mixing", "entity_type": "concept or principle", "pos": [24, 30]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [55, 64]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [68, 79]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [96, 105]}], "task": "NER"}
{"text": "During extrusion , the anisotropic particles align in the shear direction .", "entity": [{"entity": "extrusion", "entity_type": "manufacturing process", "pos": [7, 16]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [23, 34]}, {"entity": "shear direction", "entity_type": "machanical property", "pos": [58, 73]}], "task": "NER"}
{"text": "In a later sintering step , the aligned particles grow absorbing the fine particles , leading to highly textured and dense ceramics .", "entity": [{"entity": "sintering", "entity_type": "manufacturing process", "pos": [11, 20]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [40, 49]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [74, 83]}, {"entity": "ceramics", "entity_type": "material", "pos": [123, 131]}], "task": "NER"}
{"text": "4.2.3 Vat polymerization/stereolitography Vat polymerization/stereolitography was created by Chuck Hull in 1986 and was the AM technology pioneer .", "entity": [{"entity": "Vat polymerization/stereolitography", "entity_type": "manufacturing process", "pos": [6, 41]}, {"entity": "Vat", "entity_type": "machine or equipment", "pos": [42, 45]}, {"entity": "Chuck", "entity_type": "machine or equipment", "pos": [93, 98]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [124, 137]}], "task": "NER"}
{"text": "SLA was the first AM to be applied in medicine , which was used to produce surgical models for alloplastic implant surgery in 1994 .", "entity": [{"entity": "SLA", "entity_type": "machine or equipment", "pos": [0, 3]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [18, 20]}, {"entity": "be", "entity_type": "material", "pos": [24, 26]}, {"entity": "medicine", "entity_type": "concept or principle", "pos": [38, 46]}, {"entity": "alloplastic implant surgery", "entity_type": "application", "pos": [95, 122]}], "task": "NER"}
{"text": "In vat polymerization printing , a specific type of light is used to build parts one layer at a time , in a vat containing light-cured photopolymer resin mixed with ceramic powder .", "entity": [{"entity": "vat polymerization", "entity_type": "manufacturing process", "pos": [3, 21]}, {"entity": "build", "entity_type": "process parameter", "pos": [69, 74]}, {"entity": "layer", "entity_type": "process parameter", "pos": [85, 90]}, {"entity": "vat", "entity_type": "machine or equipment", "pos": [108, 111]}, {"entity": "photopolymer resin", "entity_type": "material", "pos": [135, 153]}, {"entity": "ceramic powder", "entity_type": "material", "pos": [165, 179]}], "task": "NER"}
{"text": "The light travels each layer through the surface of the liquid resin .", "entity": [{"entity": "layer", "entity_type": "process parameter", "pos": [23, 28]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [41, 48]}, {"entity": "resin", "entity_type": "material", "pos": [63, 68]}], "task": "NER"}
{"text": "Then , the building platform descends allowing that another layer of resin spreads over the surface , and thus repeating the process .", "entity": [{"entity": "building platform", "entity_type": "machine or equipment", "pos": [11, 28]}, {"entity": "layer", "entity_type": "process parameter", "pos": [60, 65]}, {"entity": "resin", "entity_type": "material", "pos": [69, 74]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [92, 99]}, {"entity": "process", "entity_type": "concept or principle", "pos": [125, 132]}], "task": "NER"}
{"text": "This technology enables a rapid fabrication and allows to create complex shapes with high level of accuracy and good finish .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [5, 15]}, {"entity": "rapid fabrication", "entity_type": "manufacturing process", "pos": [26, 43]}, {"entity": "complex shapes", "entity_type": "machanical property", "pos": [65, 79]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [99, 107]}], "task": "NER"}
{"text": "The curing depth is a critical parameter that determines the accuracy of the formability .", "entity": [{"entity": "curing depth", "entity_type": "process parameter", "pos": [4, 16]}, {"entity": "parameter", "entity_type": "concept or principle", "pos": [31, 40]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [61, 69]}, {"entity": "formability", "entity_type": "machanical property", "pos": [77, 88]}], "task": "NER"}
{"text": "6 shows a zirconia implant printed trough this method .", "entity": [{"entity": "zirconia", "entity_type": "material", "pos": [10, 18]}, {"entity": "implant", "entity_type": "application", "pos": [19, 26]}], "task": "NER"}
{"text": "When compared to conventional polymer-based SLA , using ceramics can affect the line width and the curing depth .", "entity": [{"entity": "SLA", "entity_type": "machine or equipment", "pos": [44, 47]}, {"entity": "ceramics", "entity_type": "material", "pos": [56, 64]}, {"entity": "curing depth", "entity_type": "process parameter", "pos": [99, 111]}], "task": "NER"}
{"text": "Also , since conventional SLA equipment uses dispersions with viscosities lower than 5 Pa.s , the particle size and the solids volume fraction of the ceramics preparations must be adjusted to meet the requirements of both formability and sinterability .", "entity": [{"entity": "SLA", "entity_type": "machine or equipment", "pos": [26, 29]}, {"entity": "equipment", "entity_type": "machine or equipment", "pos": [30, 39]}, {"entity": "particle", "entity_type": "concept or principle", "pos": [98, 106]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [127, 142]}, {"entity": "ceramics", "entity_type": "material", "pos": [150, 158]}, {"entity": "be", "entity_type": "material", "pos": [177, 179]}, {"entity": "formability", "entity_type": "machanical property", "pos": [222, 233]}, {"entity": "sinterability", "entity_type": "machanical property", "pos": [238, 251]}], "task": "NER"}
{"text": "To obtain ceramics with a high density , it is essential a fine particle size and a high solids volume fraction .", "entity": [{"entity": "ceramics", "entity_type": "material", "pos": [10, 18]}, {"entity": "density", "entity_type": "machanical property", "pos": [31, 38]}, {"entity": "particle", "entity_type": "concept or principle", "pos": [64, 72]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [96, 111]}], "task": "NER"}
{"text": "Overall , SLA presents excellent surface finishing , but is still considered to be relatively expensive and present a lengthily post-processing time for unprocessed resin removal and additional curing .", "entity": [{"entity": "SLA", "entity_type": "machine or equipment", "pos": [10, 13]}, {"entity": "surface finishing", "entity_type": "manufacturing process", "pos": [33, 50]}, {"entity": "be", "entity_type": "material", "pos": [80, 82]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [128, 143]}, {"entity": "resin", "entity_type": "material", "pos": [165, 170]}, {"entity": "curing", "entity_type": "manufacturing process", "pos": [194, 200]}], "task": "NER"}
{"text": "For ceramics , a final thermal cycle allows to remove the organic resin and sintering the material , increasing its density .", "entity": [{"entity": "ceramics", "entity_type": "material", "pos": [4, 12]}, {"entity": "thermal cycle", "entity_type": "process parameter", "pos": [23, 36]}, {"entity": "resin", "entity_type": "material", "pos": [66, 71]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [76, 85]}, {"entity": "material", "entity_type": "material", "pos": [90, 98]}, {"entity": "density", "entity_type": "machanical property", "pos": [116, 123]}], "task": "NER"}
{"text": "4.2.4 Direct energy deposition techniques Direct energy deposition is a more complex additive printing process , commonly used to repair or add additional material to existing components .", "entity": [{"entity": "Direct energy deposition", "entity_type": "manufacturing process", "pos": [6, 30]}, {"entity": "Direct energy deposition", "entity_type": "manufacturing process", "pos": [42, 66]}, {"entity": "additive", "entity_type": "material", "pos": [85, 93]}, {"entity": "process", "entity_type": "concept or principle", "pos": [103, 110]}, {"entity": "material", "entity_type": "material", "pos": [155, 163]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [176, 186]}], "task": "NER"}
{"text": "A typical DED machine consists of a nozzle mounted on a multi axis arm , which deposits melted material onto the specified surface , where it solidifies .", "entity": [{"entity": "DED machine", "entity_type": "machine or equipment", "pos": [10, 21]}, {"entity": "nozzle", "entity_type": "machine or equipment", "pos": [36, 42]}, {"entity": "melted", "entity_type": "concept or principle", "pos": [88, 94]}, {"entity": "material", "entity_type": "material", "pos": [95, 103]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [123, 130]}], "task": "NER"}
{"text": "The material is heated and melted using a laser , electron beam or plasma arc .", "entity": [{"entity": "material", "entity_type": "material", "pos": [4, 12]}, {"entity": "melted", "entity_type": "concept or principle", "pos": [27, 33]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [42, 47]}, {"entity": "electron beam", "entity_type": "concept or principle", "pos": [50, 63]}, {"entity": "plasma arc", "entity_type": "concept or principle", "pos": [67, 77]}], "task": "NER"}
{"text": "The piece is lowered by a distance equivalent to the layer thickness .", "entity": [{"entity": "layer thickness", "entity_type": "process parameter", "pos": [53, 68]}], "task": "NER"}
{"text": "Although this process typically uses metal , it can also use polymers and ceramics , either provided in wire or powder form .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [14, 21]}, {"entity": "metal", "entity_type": "material", "pos": [37, 42]}, {"entity": "polymers", "entity_type": "material", "pos": [61, 69]}, {"entity": "ceramics", "entity_type": "material", "pos": [74, 82]}, {"entity": "powder", "entity_type": "material", "pos": [112, 118]}], "task": "NER"}
{"text": "For ceramic materials , it allows achieving almost 100 % density and avoids shrinkage or distortion , eliminating the need of debinding or sintering steps .", "entity": [{"entity": "ceramic materials", "entity_type": "material", "pos": [4, 21]}, {"entity": "density", "entity_type": "machanical property", "pos": [57, 64]}, {"entity": "shrinkage", "entity_type": "concept or principle", "pos": [76, 85]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [89, 99]}, {"entity": "debinding", "entity_type": "concept or principle", "pos": [126, 135]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [139, 148]}], "task": "NER"}
{"text": "Wilkes and Wissenbach were pioneer in studying the applicability of this method to manufacture ceramic components for medical applications .", "entity": [{"entity": "manufacture", "entity_type": "concept or principle", "pos": [83, 94]}, {"entity": "ceramic", "entity_type": "material", "pos": [95, 102]}, {"entity": "medical applications", "entity_type": "application", "pos": [118, 138]}], "task": "NER"}
{"text": "4.2.5 Powder bed fusion Powder-based printing technologies include selective laser sintering , direct metal laser sintering , selective laser melting and electron beam melting .", "entity": [{"entity": "Powder bed fusion", "entity_type": "manufacturing process", "pos": [6, 23]}, {"entity": "printing technologies", "entity_type": "enabling technology", "pos": [37, 58]}, {"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [67, 92]}, {"entity": "direct metal laser sintering", "entity_type": "manufacturing process", "pos": [95, 123]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [126, 149]}, {"entity": "electron beam melting", "entity_type": "manufacturing process", "pos": [154, 175]}], "task": "NER"}
{"text": "All these technologies use heat to fuse the powdered materials .", "entity": [{"entity": "technologies", "entity_type": "concept or principle", "pos": [10, 22]}, {"entity": "heat", "entity_type": "concept or principle", "pos": [27, 31]}, {"entity": "fuse", "entity_type": "manufacturing process", "pos": [35, 39]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [53, 62]}], "task": "NER"}
{"text": "The differences rely on the energy source and powder materials .", "entity": [{"entity": "source", "entity_type": "application", "pos": [35, 41]}, {"entity": "powder materials", "entity_type": "material", "pos": [46, 62]}], "task": "NER"}
{"text": "For instance , SLS , DMLS , and SLM all use lasers , while EBM uses electron beam as energy source In the sintering processes , the powders are not completely melted .", "entity": [{"entity": "SLS", "entity_type": "manufacturing process", "pos": [15, 18]}, {"entity": "DMLS", "entity_type": "manufacturing process", "pos": [21, 25]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [32, 35]}, {"entity": "EBM", "entity_type": "manufacturing process", "pos": [59, 62]}, {"entity": "electron beam", "entity_type": "concept or principle", "pos": [68, 81]}, {"entity": "as", "entity_type": "material", "pos": [82, 84]}, {"entity": "source", "entity_type": "application", "pos": [92, 98]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [106, 115]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [116, 125]}, {"entity": "powders", "entity_type": "material", "pos": [132, 139]}, {"entity": "melted", "entity_type": "concept or principle", "pos": [159, 165]}], "task": "NER"}
{"text": "This leads to porous internal structures and rough surfaces .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [14, 20]}, {"entity": "internal structures", "entity_type": "machanical property", "pos": [21, 40]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [51, 59]}], "task": "NER"}
{"text": "In the melting processes , the powders are well fused , creating parts with enhanced mechanical properties and higher densities .", "entity": [{"entity": "melting", "entity_type": "manufacturing process", "pos": [7, 14]}, {"entity": "powders", "entity_type": "material", "pos": [31, 38]}, {"entity": "fused", "entity_type": "concept or principle", "pos": [48, 53]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [85, 106]}], "task": "NER"}
{"text": "The process begins with the spreading of a layer of material over the build platform , typically 0.1 mm thick .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "layer", "entity_type": "process parameter", "pos": [43, 48]}, {"entity": "material", "entity_type": "material", "pos": [52, 60]}, {"entity": "build platform", "entity_type": "machine or equipment", "pos": [70, 84]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [101, 103]}], "task": "NER"}
{"text": "The energy source fuses the first layer or first cross section of the model .", "entity": [{"entity": "source", "entity_type": "application", "pos": [11, 17]}, {"entity": "fuses", "entity_type": "manufacturing process", "pos": [18, 23]}, {"entity": "layer", "entity_type": "process parameter", "pos": [34, 39]}, {"entity": "cross section", "entity_type": "concept or principle", "pos": [49, 62]}, {"entity": "model", "entity_type": "concept or principle", "pos": [70, 75]}], "task": "NER"}
{"text": "The build platform is then lowered and a new layer of powder is spread across the previous using a roller .", "entity": [{"entity": "build platform", "entity_type": "machine or equipment", "pos": [4, 18]}, {"entity": "layer", "entity_type": "process parameter", "pos": [45, 50]}, {"entity": "powder", "entity_type": "material", "pos": [54, 60]}, {"entity": "spread", "entity_type": "concept or principle", "pos": [64, 70]}, {"entity": "roller", "entity_type": "machine or equipment", "pos": [99, 105]}], "task": "NER"}
{"text": "7 shows a dental piece made of alumina-zirconia composite obtained by this process .", "entity": [{"entity": "dental piece", "entity_type": "machine or equipment", "pos": [10, 22]}, {"entity": "alumina-zirconia composite", "entity_type": "material", "pos": [31, 57]}, {"entity": "process", "entity_type": "concept or principle", "pos": [75, 82]}], "task": "NER"}
{"text": "The manufacturing time for powder bed fusion based techniques is lower than for other AM techniques .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [4, 17]}, {"entity": "powder bed fusion", "entity_type": "manufacturing process", "pos": [27, 44]}, {"entity": "AM techniques", "entity_type": "manufacturing process", "pos": [86, 99]}], "task": "NER"}
{"text": "In fact , as it happens with direct energy deposition , since these techniques do not involve the use of binders for the production of intermediate green pieces , it is not required any debinding process .", "entity": [{"entity": "as", "entity_type": "material", "pos": [10, 12]}, {"entity": "direct energy deposition", "entity_type": "manufacturing process", "pos": [29, 53]}, {"entity": "binders", "entity_type": "material", "pos": [105, 112]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [121, 131]}, {"entity": "debinding", "entity_type": "concept or principle", "pos": [186, 195]}], "task": "NER"}
{"text": "However , due to the high heating and cooling rates , thermal shock may occur , which may lead to cracking .", "entity": [{"entity": "heating", "entity_type": "manufacturing process", "pos": [26, 33]}, {"entity": "cooling rates", "entity_type": "process parameter", "pos": [38, 51]}, {"entity": "lead", "entity_type": "material", "pos": [90, 94]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [98, 106]}], "task": "NER"}
{"text": "This may be avoided by pre-heating the powder .", "entity": [{"entity": "be", "entity_type": "material", "pos": [9, 11]}, {"entity": "powder", "entity_type": "material", "pos": [39, 45]}], "task": "NER"}
{"text": "5 Additive manufacturing of bioceramics for dental applications Ceramic materials where only recently considered in AM processing due to their intrinsic properties .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [2, 24]}, {"entity": "bioceramics", "entity_type": "material", "pos": [28, 39]}, {"entity": "dental applications", "entity_type": "application", "pos": [44, 63]}, {"entity": "Ceramic materials", "entity_type": "material", "pos": [64, 81]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [116, 118]}, {"entity": "intrinsic properties", "entity_type": "concept or principle", "pos": [143, 163]}], "task": "NER"}
{"text": "The high melting points of ceramics make them difficult to melt under normal heating methods .", "entity": [{"entity": "melting points", "entity_type": "machanical property", "pos": [9, 23]}, {"entity": "ceramics", "entity_type": "material", "pos": [27, 35]}, {"entity": "melt", "entity_type": "concept or principle", "pos": [59, 63]}, {"entity": "heating", "entity_type": "manufacturing process", "pos": [77, 84]}], "task": "NER"}
{"text": "Although it is possible to melt some ceramics , this process can cause new phase formation .", "entity": [{"entity": "melt", "entity_type": "concept or principle", "pos": [27, 31]}, {"entity": "ceramics", "entity_type": "material", "pos": [37, 45]}, {"entity": "process", "entity_type": "concept or principle", "pos": [53, 60]}, {"entity": "phase", "entity_type": "concept or principle", "pos": [75, 80]}], "task": "NER"}
{"text": "On the other hand , several factors associated to the processing of the ceramic materials and to the characteristics of the raw materials used may affect the porosity of the final piece .", "entity": [{"entity": "ceramic materials", "entity_type": "material", "pos": [72, 89]}, {"entity": "raw materials", "entity_type": "material", "pos": [124, 137]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [158, 166]}], "task": "NER"}
{"text": "An increase of porosity impairs the mechanical properties of the final product .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [15, 23]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [36, 57]}], "task": "NER"}
{"text": "However , it can be favourable for cellular growth or implant fixation , required for specific applications .", "entity": [{"entity": "be", "entity_type": "material", "pos": [17, 19]}, {"entity": "cellular growth", "entity_type": "process characterization", "pos": [35, 50]}, {"entity": "implant", "entity_type": "application", "pos": [54, 61]}], "task": "NER"}
{"text": "This section will report published work where different bioceramics , such as zirconia , alumina , calcium phosphates and ceramic composites , with possible applications in dentistry , are processed using various AM technologies .", "entity": [{"entity": "bioceramics", "entity_type": "material", "pos": [56, 67]}, {"entity": "as", "entity_type": "material", "pos": [75, 77]}, {"entity": "alumina", "entity_type": "material", "pos": [89, 96]}, {"entity": "calcium phosphates", "entity_type": "material", "pos": [99, 117]}, {"entity": "ceramic composites", "entity_type": "engineering feature", "pos": [122, 140]}, {"entity": "dentistry", "entity_type": "application", "pos": [173, 182]}, {"entity": "processed", "entity_type": "concept or principle", "pos": [189, 198]}, {"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [213, 228]}], "task": "NER"}
{"text": "5.1 Additive manufacturing of zirconia The information concerning the AM of zirconia-based compositions , with possible applications in dentistry is present in 2 .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [4, 26]}, {"entity": "zirconia", "entity_type": "material", "pos": [30, 38]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [70, 72]}, {"entity": "zirconia-based compositions", "entity_type": "material", "pos": [76, 103]}, {"entity": "dentistry", "entity_type": "application", "pos": [136, 145]}], "task": "NER"}
{"text": "Ebert demonstrated the possibility to build dense three-dimensional components of the size of a crown , with its characteristic occlusal surface topography , through material extrusion technology , using zirconia ceramic suspensions .", "entity": [{"entity": "build", "entity_type": "process parameter", "pos": [38, 43]}, {"entity": "three-dimensional", "entity_type": "concept or principle", "pos": [50, 67]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [68, 78]}, {"entity": "crown", "entity_type": "machine or equipment", "pos": [96, 101]}, {"entity": "surface topography", "entity_type": "concept or principle", "pos": [137, 155]}, {"entity": "material extrusion", "entity_type": "manufacturing process", "pos": [166, 184]}, {"entity": "zirconia ceramic", "entity_type": "material", "pos": [204, 220]}], "task": "NER"}
{"text": "The printed and sintered samples were not completely free of procesB-related defects , mainly due to clogged nozzles during printing .", "entity": [{"entity": "sintered", "entity_type": "manufacturing process", "pos": [16, 24]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [25, 32]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [77, 84]}, {"entity": "clogged nozzles", "entity_type": "machine or equipment", "pos": [101, 116]}], "task": "NER"}
{"text": "However , it was possible to obtain specimens with relative density of 96.9 % , with mechanical properties comparable to those of conventionally produced 3Y-TZP via cold isostatic pressing .", "entity": [{"entity": "relative density", "entity_type": "machanical property", "pos": [51, 67]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [85, 106]}, {"entity": "3Y-TZP", "entity_type": "material", "pos": [154, 160]}, {"entity": "cold isostatic pressing", "entity_type": "manufacturing process", "pos": [165, 188]}], "task": "NER"}
{"text": "Moin , established that it is feasible to use high-end digital light processing technology to fabricate a root analogue implant with a certain amount of precision .", "entity": [{"entity": "digital light processing", "entity_type": "manufacturing process", "pos": [55, 79]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [94, 103]}, {"entity": "root analogue", "entity_type": "application", "pos": [106, 119]}, {"entity": "implant", "entity_type": "application", "pos": [120, 127]}, {"entity": "precision", "entity_type": "process characterization", "pos": [153, 162]}], "task": "NER"}
{"text": "However , the results showed a printed RAI with a 6.67 % larger surface area .", "entity": [{"entity": "surface area", "entity_type": "process parameter", "pos": [64, 76]}], "task": "NER"}
{"text": "A large number of factors are recognized to influence the precision of this printing technique , namely the resolution of the digital mirroring device and the composition of the ceramic/ photopolymer mixture .", "entity": [{"entity": "precision", "entity_type": "process characterization", "pos": [58, 67]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [108, 118]}, {"entity": "digital mirroring device", "entity_type": "machine or equipment", "pos": [126, 150]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [159, 170]}, {"entity": "photopolymer", "entity_type": "material", "pos": [187, 199]}], "task": "NER"}
{"text": "The authors claim that the precise control over spatially grade composition , microstructure design/distribution and shape are potential advantages over milling of unsintered ceramics .", "entity": [{"entity": "precise control", "entity_type": "concept or principle", "pos": [27, 42]}, {"entity": "spatially grade composition", "entity_type": "engineering feature", "pos": [48, 75]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [78, 92]}, {"entity": "milling", "entity_type": "manufacturing process", "pos": [153, 160]}, {"entity": "unsintered", "entity_type": "machanical property", "pos": [164, 174]}, {"entity": "ceramics", "entity_type": "material", "pos": [175, 183]}], "task": "NER"}
{"text": "Osman also used a SLA method to efficiently print customized zirconia dental implants with sufficient dimensional accuracy .", "entity": [{"entity": "SLA", "entity_type": "machine or equipment", "pos": [18, 21]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [44, 49]}, {"entity": "zirconia", "entity_type": "material", "pos": [61, 69]}, {"entity": "dental", "entity_type": "application", "pos": [70, 76]}, {"entity": "sufficient dimensional accuracy", "entity_type": "concept or principle", "pos": [91, 122]}], "task": "NER"}
{"text": "The study evaluated among other aspects , the dimensional accuracy , surface topography and mechanical properties .", "entity": [{"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [46, 66]}, {"entity": "surface topography", "entity_type": "concept or principle", "pos": [69, 87]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [92, 113]}], "task": "NER"}
{"text": "The authors report that the dimensional accuracy of the printed implant was high and the achieved mechanical properties showed flexural strength close to those of conventionally produced ceramics .", "entity": [{"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [28, 48]}, {"entity": "implant", "entity_type": "application", "pos": [64, 71]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [98, 119]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [127, 144]}, {"entity": "ceramics", "entity_type": "material", "pos": [187, 195]}], "task": "NER"}
{"text": "SLA was again used by Xing , to produce ZrO2 complex shaped ceramic components with high dimensional accuracy and proper properties .", "entity": [{"entity": "SLA", "entity_type": "machine or equipment", "pos": [0, 3]}, {"entity": "ZrO2", "entity_type": "material", "pos": [40, 44]}, {"entity": "ceramic", "entity_type": "material", "pos": [60, 67]}, {"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [89, 109]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [121, 131]}], "task": "NER"}
{"text": "The surface roughness of the unpolished ZrO2 showed an anisotropic behavior with values ranging from 0.41 to 1.07 on the measuring direction .", "entity": [{"entity": "surface roughness", "entity_type": "machanical property", "pos": [4, 21]}, {"entity": "ZrO2", "entity_type": "material", "pos": [40, 44]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [55, 66]}], "task": "NER"}
{"text": "This phenomenon could be eliminated through polishing , reducing Ra to a nanometer scale .", "entity": [{"entity": "be", "entity_type": "material", "pos": [22, 24]}, {"entity": "polishing", "entity_type": "manufacturing process", "pos": [44, 53]}, {"entity": "nanometer scale", "entity_type": "engineering feature", "pos": [73, 88]}], "task": "NER"}
{"text": "The sintered ceramics had isotropic mechanical properties close to milled zirconia due to the homogeneity of the grain size .", "entity": [{"entity": "sintered", "entity_type": "manufacturing process", "pos": [4, 12]}, {"entity": "ceramics", "entity_type": "material", "pos": [13, 21]}, {"entity": "isotropic", "entity_type": "machanical property", "pos": [26, 35]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [47, 57]}, {"entity": "milled", "entity_type": "manufacturing process", "pos": [67, 73]}, {"entity": "grain size", "entity_type": "machanical property", "pos": [113, 123]}], "task": "NER"}
{"text": "In the work of Scheithauer , the droplet formation behavior of zirconia suspensions for thermoplastic 3D printing was investigated .", "entity": [{"entity": "droplet", "entity_type": "concept or principle", "pos": [33, 40]}, {"entity": "zirconia", "entity_type": "material", "pos": [63, 71]}, {"entity": "thermoplastic 3D printing", "entity_type": "manufacturing process", "pos": [88, 113]}], "task": "NER"}
{"text": "The precise deposition of small adjacent droplets of molten thermoplastic suspensions containing ceramic particles allowed to obtain filament-like structures by coalescence of adjacent droplets .", "entity": [{"entity": "deposition", "entity_type": "concept or principle", "pos": [12, 22]}, {"entity": "droplets", "entity_type": "concept or principle", "pos": [41, 49]}, {"entity": "thermoplastic", "entity_type": "material", "pos": [60, 73]}, {"entity": "ceramic", "entity_type": "material", "pos": [97, 104]}, {"entity": "coalescence of adjacent droplets", "entity_type": "concept or principle", "pos": [161, 193]}], "task": "NER"}
{"text": "The researchers introduced the droplet fusion factor in order to calculate the necessary distance between two droplets to produce those filaments .", "entity": [{"entity": "droplet fusion factor", "entity_type": "process characterization", "pos": [31, 52]}, {"entity": "droplets", "entity_type": "concept or principle", "pos": [110, 118]}, {"entity": "filaments", "entity_type": "material", "pos": [136, 145]}], "task": "NER"}
{"text": "The results showed that filament-like structures with a smooth surface and a nearly homogeneous cross section could be produced for suspensions with a dff of 44 % or higher .", "entity": [{"entity": "smooth surface", "entity_type": "concept or principle", "pos": [56, 70]}, {"entity": "homogeneous", "entity_type": "concept or principle", "pos": [84, 95]}, {"entity": "cross section", "entity_type": "concept or principle", "pos": [96, 109]}, {"entity": "be", "entity_type": "material", "pos": [116, 118]}], "task": "NER"}
{"text": "In a previous work , the same research group used the same process to print zirconia samples .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [30, 38]}, {"entity": "process", "entity_type": "concept or principle", "pos": [59, 66]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [70, 75]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [85, 92]}], "task": "NER"}
{"text": "They were able to produce ceramic parts with high density and homogeneous microstructures .", "entity": [{"entity": "ceramic", "entity_type": "material", "pos": [26, 33]}, {"entity": "density", "entity_type": "machanical property", "pos": [50, 57]}, {"entity": "homogeneous microstructures", "entity_type": "machanical property", "pos": [62, 89]}], "task": "NER"}
{"text": "On one hand the heating rates required for thermal debinding are very low and it must be carried out in a powder bed , increasing the time and complexity of the process .", "entity": [{"entity": "heating", "entity_type": "manufacturing process", "pos": [16, 23]}, {"entity": "thermal debinding", "entity_type": "process characterization", "pos": [43, 60]}, {"entity": "be", "entity_type": "material", "pos": [86, 88]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [106, 116]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [143, 153]}, {"entity": "process", "entity_type": "concept or principle", "pos": [161, 168]}], "task": "NER"}
{"text": "In another work of the same group , the authors combined AM and functionally graded materials to create zirconia-based customizable smart materials .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [57, 59]}, {"entity": "functionally graded materials", "entity_type": "material", "pos": [64, 93]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [138, 147]}], "task": "NER"}
{"text": "By using T3DP technology , it was possible to selectively deposit two different materials beside each other , offering the prospect of combining suspensions with different contents of a pore forming agents to obtained components with dense and porous areas inside .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [14, 24]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [80, 89]}, {"entity": "pore forming agents", "entity_type": "process parameter", "pos": [186, 205]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [218, 228]}, {"entity": "dense and porous", "entity_type": "engineering feature", "pos": [234, 250]}, {"entity": "areas", "entity_type": "process parameter", "pos": [251, 256]}], "task": "NER"}
{"text": "The presence of zones with different porosities reduces the elastic modulus , diminishing the stress shielding , which should be benefic for dental implants .", "entity": [{"entity": "porosities", "entity_type": "machanical property", "pos": [37, 47]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [60, 75]}, {"entity": "stress shielding", "entity_type": "machanical property", "pos": [94, 110]}, {"entity": "be", "entity_type": "material", "pos": [126, 128]}, {"entity": "dental", "entity_type": "application", "pos": [141, 147]}], "task": "NER"}
{"text": "More , the presence of open pores shall favor the osteointegration .", "entity": [{"entity": "pores", "entity_type": "machanical property", "pos": [28, 33]}, {"entity": "osteointegration", "entity_type": "machanical property", "pos": [50, 66]}], "task": "NER"}
{"text": "The work of Shao , showed the possibility of successfully printing ZrO2 ceramic parts by a new extrusion-based process , 3D Gel-Printing .", "entity": [{"entity": "ZrO2 ceramic", "entity_type": "material", "pos": [67, 79]}, {"entity": "extrusion-based process", "entity_type": "manufacturing process", "pos": [95, 118]}, {"entity": "3D Gel-Printing", "entity_type": "manufacturing process", "pos": [121, 136]}], "task": "NER"}
{"text": "The authors were able to produce printed and sintered cuboid samples with a regular appearance .", "entity": [{"entity": "sintered", "entity_type": "manufacturing process", "pos": [45, 53]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [61, 68]}], "task": "NER"}
{"text": "Parameters such as surface roughness , relative density , hardness and transverse rupture strength of printed and sintered samples were compared with those obtained in other 3D printing processes .", "entity": [{"entity": "Parameters", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "as", "entity_type": "material", "pos": [16, 18]}, {"entity": "roughness", "entity_type": "machanical property", "pos": [27, 36]}, {"entity": "relative density", "entity_type": "machanical property", "pos": [39, 55]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [58, 66]}, {"entity": "transverse rupture strength", "entity_type": "machanical property", "pos": [71, 98]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [114, 122]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [123, 130]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [174, 185]}], "task": "NER"}
{"text": "It was found that 3DGP led to samples with higher density , hardness and surface finishing than those obtained by syringe extrusion , and that presented higher transverse rupture strength than others produced by gel casting .", "entity": [{"entity": "led", "entity_type": "application", "pos": [23, 26]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [30, 37]}, {"entity": "density", "entity_type": "machanical property", "pos": [50, 57]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [60, 68]}, {"entity": "surface finishing", "entity_type": "manufacturing process", "pos": [73, 90]}, {"entity": "syringe", "entity_type": "machine or equipment", "pos": [114, 121]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [122, 131]}, {"entity": "transverse rupture strength", "entity_type": "machanical property", "pos": [160, 187]}, {"entity": "gel casting", "entity_type": "manufacturing process", "pos": [212, 223]}], "task": "NER"}
{"text": "More , no defects or deformation was observed from outside of the printed samples .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [10, 17]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [21, 32]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [74, 81]}], "task": "NER"}
{"text": "The authors refer the importance of aspects such as printing conditions , rheological behavior of the slurry as well as the solid loading on the final properties of the printed/sintered samples .", "entity": [{"entity": "as", "entity_type": "material", "pos": [36, 38]}, {"entity": "rheological", "entity_type": "machanical property", "pos": [74, 85]}, {"entity": "slurry", "entity_type": "material", "pos": [102, 108]}, {"entity": "as", "entity_type": "material", "pos": [109, 111]}, {"entity": "as", "entity_type": "material", "pos": [117, 119]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [151, 161]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [186, 193]}], "task": "NER"}
{"text": "Faes combined the advantages of AM extrusion and UV curing into a single 3D printing technique , to obtain pieces with an high shape stability and green strength .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [32, 34]}, {"entity": "UV curing", "entity_type": "concept or principle", "pos": [49, 58]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [73, 84]}, {"entity": "shape stability", "entity_type": "engineering feature", "pos": [127, 142]}, {"entity": "strength", "entity_type": "machanical property", "pos": [153, 161]}], "task": "NER"}
{"text": "This novel syringe-based AM process , based on the use of a photopolymerizable dispersion , leads to economic benefits since it reduces the raw material consumption .", "entity": [{"entity": "AM process", "entity_type": "manufacturing process", "pos": [25, 35]}, {"entity": "photopolymerizable", "entity_type": "machanical property", "pos": [60, 78]}, {"entity": "dispersion", "entity_type": "concept or principle", "pos": [79, 89]}, {"entity": "raw material", "entity_type": "material", "pos": [140, 152]}], "task": "NER"}
{"text": "High shrinkage was observed during sintering , leading to cracking .", "entity": [{"entity": "shrinkage", "entity_type": "concept or principle", "pos": [5, 14]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [35, 44]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [58, 66]}], "task": "NER"}
{"text": "This must be due to a low load of ceramic particles in the dispersion .", "entity": [{"entity": "be", "entity_type": "material", "pos": [10, 12]}, {"entity": "ceramic", "entity_type": "material", "pos": [34, 41]}, {"entity": "dispersion", "entity_type": "concept or principle", "pos": [59, 69]}], "task": "NER"}
{"text": "It is suggested to increase the amount of ceramic particles , keeping the rheological behavior , which can be achieved through the introduction of steric repulsive forces in the dispersion , for example using other resins .", "entity": [{"entity": "ceramic", "entity_type": "material", "pos": [42, 49]}, {"entity": "rheological", "entity_type": "machanical property", "pos": [74, 85]}, {"entity": "be", "entity_type": "material", "pos": [86, 88]}, {"entity": "forces", "entity_type": "concept or principle", "pos": [164, 170]}, {"entity": "dispersion", "entity_type": "concept or principle", "pos": [178, 188]}, {"entity": "resins", "entity_type": "material", "pos": [215, 221]}], "task": "NER"}
{"text": "5.2 Additive manufacturing of alumina 3 gathers the main findings of published work regarding the AM of alumina-based formulations with possible applications in the dental field .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [4, 26]}, {"entity": "alumina 3", "entity_type": "material", "pos": [30, 39]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [98, 100]}, {"entity": "alumina-based formulations", "entity_type": "material", "pos": [104, 130]}, {"entity": "dental", "entity_type": "application", "pos": [165, 171]}], "task": "NER"}
{"text": "Work carried out by Scheithauer , showed the possibility of printing dense alumina pieces using 3D printing of high-filled suspensions with thermoplastic binder systems .", "entity": [{"entity": "alumina", "entity_type": "material", "pos": [75, 82]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [96, 107]}, {"entity": "thermoplastic binder systems", "entity_type": "machine or equipment", "pos": [140, 168]}], "task": "NER"}
{"text": "The authors achieved samples with high densities , homogeneous microstructures and very good bonding between the printed layers .", "entity": [{"entity": "samples", "entity_type": "concept or principle", "pos": [21, 28]}, {"entity": "homogeneous microstructures", "entity_type": "machanical property", "pos": [51, 78]}, {"entity": "bonding", "entity_type": "concept or principle", "pos": [93, 100]}], "task": "NER"}
{"text": "This study also highlights the importance of the rheological properties of the slurries , i.e .", "entity": [{"entity": "rheological properties", "entity_type": "machanical property", "pos": [49, 71]}], "task": "NER"}
{"text": "low viscosity allows an easy flow through the needle to form small droplets , which can improve the printing resolution .", "entity": [{"entity": "viscosity", "entity_type": "machanical property", "pos": [4, 13]}, {"entity": "droplets", "entity_type": "concept or principle", "pos": [67, 75]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [109, 119]}], "task": "NER"}
{"text": "It is concluded that thermoplastic 3D printing presents several advantages over other suspension-based technologies , namely the fact that the green layer solidifying occur by simple cooling , the versatility of ceramic materials that can be used and the applicability in limited areas .", "entity": [{"entity": "thermoplastic 3D printing", "entity_type": "manufacturing process", "pos": [21, 46]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [103, 115]}, {"entity": "layer", "entity_type": "process parameter", "pos": [149, 154]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [176, 182]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [183, 190]}, {"entity": "ceramic materials", "entity_type": "material", "pos": [212, 229]}, {"entity": "be", "entity_type": "material", "pos": [239, 241]}, {"entity": "areas", "entity_type": "process parameter", "pos": [280, 285]}], "task": "NER"}
{"text": "It is recognized the potential of the technique to print multimaterial and multifunctional components , as well as to obtain pieces with material and/or property gradients in different dimensions .", "entity": [{"entity": "print", "entity_type": "manufacturing process", "pos": [51, 56]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [91, 101]}, {"entity": "as", "entity_type": "material", "pos": [104, 106]}, {"entity": "as", "entity_type": "material", "pos": [112, 114]}, {"entity": "material", "entity_type": "material", "pos": [137, 145]}, {"entity": "property", "entity_type": "concept or principle", "pos": [153, 161]}, {"entity": "dimensions", "entity_type": "engineering feature", "pos": [185, 195]}], "task": "NER"}
{"text": "However , the authors claim that heating rates for thermal debinding must be very low and that the process must be performed in a powder bed .", "entity": [{"entity": "heating", "entity_type": "manufacturing process", "pos": [33, 40]}, {"entity": "thermal debinding", "entity_type": "process characterization", "pos": [51, 68]}, {"entity": "be", "entity_type": "material", "pos": [74, 76]}, {"entity": "process", "entity_type": "concept or principle", "pos": [99, 106]}, {"entity": "be", "entity_type": "material", "pos": [112, 114]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [130, 140]}], "task": "NER"}
{"text": "Dehurtevent , presented a study which provides promising results for manufacturing dense 3D alumina crown frameworks by SLA .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [69, 82]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [89, 91]}, {"entity": "crown", "entity_type": "machine or equipment", "pos": [100, 105]}, {"entity": "SLA", "entity_type": "machine or equipment", "pos": [120, 123]}], "task": "NER"}
{"text": "The authors established a comparison between the physical and mechanical properties of SLA-manufactured alumina ceramics of different compositions and viscosity to those of subtractive-manufactured ceramics .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [62, 83]}, {"entity": "alumina", "entity_type": "material", "pos": [104, 111]}, {"entity": "viscosity", "entity_type": "machanical property", "pos": [151, 160]}, {"entity": "ceramics", "entity_type": "material", "pos": [198, 206]}], "task": "NER"}
{"text": "Their results showed an acceptability window for viscosity of the slurries that allows producing SLA manufactured alumina pieces .", "entity": [{"entity": "viscosity", "entity_type": "machanical property", "pos": [49, 58]}, {"entity": "SLA", "entity_type": "machine or equipment", "pos": [97, 100]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [101, 113]}, {"entity": "alumina", "entity_type": "material", "pos": [114, 121]}], "task": "NER"}
{"text": "Additionally , the authors were able to achieve a composition that originated a reliable material with the anisotropic shrinkage , high density , flexural strength , and Weibull characteristics suitable for SLA manufacturing .", "entity": [{"entity": "composition", "entity_type": "concept or principle", "pos": [50, 61]}, {"entity": "material", "entity_type": "material", "pos": [89, 97]}, {"entity": "anisotropic shrinkage", "entity_type": "process characterization", "pos": [107, 128]}, {"entity": "density", "entity_type": "machanical property", "pos": [136, 143]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [146, 163]}, {"entity": "SLA", "entity_type": "machine or equipment", "pos": [207, 210]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [211, 224]}], "task": "NER"}
{"text": "Nevertheless , it was observed that although an oversize of 35 % allow manufacturing complex morphologies , differential shrinkage led to deformation of the final structure .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [71, 84]}, {"entity": "complex morphologies", "entity_type": "concept or principle", "pos": [85, 105]}, {"entity": "shrinkage", "entity_type": "concept or principle", "pos": [121, 130]}, {"entity": "led", "entity_type": "application", "pos": [131, 134]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [138, 149]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [163, 172]}], "task": "NER"}
{"text": "In the work of Maleksaeedi , a powder-bed inkjet 3D-printing and vacuum infiltration process was used for producing alumina parts with high density and improved mechanical properties .", "entity": [{"entity": "inkjet 3D-printing", "entity_type": "manufacturing process", "pos": [42, 60]}, {"entity": "vacuum infiltration process", "entity_type": "biomedical", "pos": [65, 92]}, {"entity": "alumina", "entity_type": "material", "pos": [116, 123]}, {"entity": "density", "entity_type": "machanical property", "pos": [140, 147]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [161, 182]}], "task": "NER"}
{"text": "The authors utilized vacuum infiltration process to enhance the packing of the green parts after printing , by impregnating the 3D-printed parts with highly solid loaded slurries .", "entity": [{"entity": "vacuum infiltration process", "entity_type": "biomedical", "pos": [21, 48]}, {"entity": "green parts", "entity_type": "machanical property", "pos": [79, 90]}, {"entity": "3D-printed parts", "entity_type": "application", "pos": [128, 144]}], "task": "NER"}
{"text": "Their results showed that the vacuum infiltration process was able to significantly increase the density , reduce the porosity and increase the strength of the 3D-printed alumina components .", "entity": [{"entity": "vacuum infiltration process", "entity_type": "biomedical", "pos": [30, 57]}, {"entity": "density", "entity_type": "machanical property", "pos": [97, 104]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [118, 126]}, {"entity": "strength", "entity_type": "machanical property", "pos": [144, 152]}, {"entity": "3D-printed", "entity_type": "manufacturing process", "pos": [160, 170]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [179, 189]}], "task": "NER"}
{"text": "Moreover , the bending strength was improved up to 15 times of the original strength .", "entity": [{"entity": "bending strength", "entity_type": "machanical property", "pos": [15, 31]}, {"entity": "strength", "entity_type": "machanical property", "pos": [76, 84]}], "task": "NER"}
{"text": "5.3 Additive manufacturing of other ceramics The potential of AM has been explored in several dental applications with other ceramic materials .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [4, 26]}, {"entity": "ceramics", "entity_type": "material", "pos": [36, 44]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [62, 64]}, {"entity": "dental applications", "entity_type": "application", "pos": [94, 113]}, {"entity": "ceramic materials", "entity_type": "material", "pos": [125, 142]}], "task": "NER"}
{"text": "4 summarizes information regarding various calcium phosphates compositions and other bioceramics , as well as gypsum , mainly for bone regeneration .", "entity": [{"entity": "calcium phosphates", "entity_type": "material", "pos": [43, 61]}, {"entity": "bioceramics", "entity_type": "material", "pos": [85, 96]}, {"entity": "as", "entity_type": "material", "pos": [99, 101]}, {"entity": "as", "entity_type": "material", "pos": [107, 109]}, {"entity": "bone regeneration", "entity_type": "concept or principle", "pos": [130, 147]}], "task": "NER"}
{"text": "Lopez , produced bioactive tricalcium phosphate scaffolds using a material extrusion technology , robocasting .", "entity": [{"entity": "tricalcium phosphate scaffolds", "entity_type": "biomedical", "pos": [27, 57]}, {"entity": "material extrusion", "entity_type": "manufacturing process", "pos": [66, 84]}, {"entity": "robocasting", "entity_type": "manufacturing process", "pos": [98, 109]}], "task": "NER"}
{"text": "The printed scaffolds were able to restore critical mandibular segmental defects to levels similar to native bone after a 8 week period implant in an adult rabbit mandibular defect model .", "entity": [{"entity": "scaffolds", "entity_type": "engineering feature", "pos": [12, 21]}, {"entity": "mandibular segmental defects", "entity_type": "biomedical", "pos": [52, 80]}, {"entity": "bone", "entity_type": "biomedical", "pos": [109, 113]}, {"entity": "implant", "entity_type": "application", "pos": [136, 143]}, {"entity": "adult rabbit mandibular defect model", "entity_type": "concept or principle", "pos": [150, 186]}], "task": "NER"}
{"text": "Histological and scanning electron microscopy analysis showed directional bony ingrowth into the scaffold interstices , tracking healing pathway origins to defect walls and marrow spaces .", "entity": [{"entity": "scanning electron microscopy", "entity_type": "process characterization", "pos": [17, 45]}, {"entity": "directional bony ingrowth", "entity_type": "concept or principle", "pos": [62, 87]}, {"entity": "scaffold interstices", "entity_type": "biomedical", "pos": [97, 117]}, {"entity": "defect", "entity_type": "concept or principle", "pos": [156, 162]}, {"entity": "marrow spaces", "entity_type": "concept or principle", "pos": [173, 186]}], "task": "NER"}
{"text": "More , it was observed new bone growth and scaffold resorption at bone/scaffold interfaces .", "entity": [{"entity": "bone growth", "entity_type": "concept or principle", "pos": [27, 38]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [43, 51]}, {"entity": "bone/scaffold interfaces", "entity_type": "engineering feature", "pos": [66, 90]}], "task": "NER"}
{"text": "Another work using robocasting technology is the one carried out by Slots in which porous TCP implants were developed using storable and reusable inks composed of fatty acid/TCP .", "entity": [{"entity": "robocasting", "entity_type": "manufacturing process", "pos": [19, 30]}, {"entity": "porous TCP implants", "entity_type": "application", "pos": [83, 102]}], "task": "NER"}
{"text": "The total fabrication time including ink preparation , printing and sintering was less than 5 h for 8 cm2 of implant .", "entity": [{"entity": "fabrication time", "entity_type": "process parameter", "pos": [10, 26]}, {"entity": "ink", "entity_type": "material", "pos": [37, 40]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [68, 77]}, {"entity": "implant", "entity_type": "application", "pos": [109, 116]}], "task": "NER"}
{"text": "The printed implants were able to retain their shape after sintering and were chemically unchanged by the printing and sintering process .", "entity": [{"entity": "implants", "entity_type": "application", "pos": [12, 20]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [59, 68]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [119, 128]}, {"entity": "process", "entity_type": "concept or principle", "pos": [129, 136]}], "task": "NER"}
{"text": "Mesenchymal stem cells were able to grow on the implants , secrete collagen and alkaline phosphate and mineralize the implant .", "entity": [{"entity": "Mesenchymal stem cells", "entity_type": "material", "pos": [0, 22]}, {"entity": "implants", "entity_type": "application", "pos": [48, 56]}, {"entity": "collagen", "entity_type": "material", "pos": [67, 75]}, {"entity": "alkaline phosphate", "entity_type": "material", "pos": [80, 98]}, {"entity": "implant", "entity_type": "application", "pos": [118, 125]}], "task": "NER"}
{"text": "Additionally , they possessed clinically relevant mechanical strength and presented osteoconductive properties .", "entity": [{"entity": "mechanical strength", "entity_type": "machanical property", "pos": [50, 69]}, {"entity": "osteoconductive", "entity_type": "machanical property", "pos": [84, 99]}], "task": "NER"}
{"text": "The process demonstrated to be sufficiently simple and effective to enable rapid , on-demand , in-hospital production of patient-specific ceramic implants for treatment of bone trauma .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "be", "entity_type": "material", "pos": [28, 30]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [44, 50]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [107, 117]}, {"entity": "ceramic", "entity_type": "material", "pos": [138, 145]}, {"entity": "bone", "entity_type": "biomedical", "pos": [172, 176]}], "task": "NER"}
{"text": "In the study conducted by Fahimipour , a biomimetic porous TCP/alginate/gelatin scaffold containing PLGA ) microspheres for slow release of VEGF was processed through extrusion technology .", "entity": [{"entity": "biomimetic", "entity_type": "concept or principle", "pos": [41, 51]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [80, 88]}, {"entity": "PLGA", "entity_type": "material", "pos": [100, 104]}, {"entity": "microspheres", "entity_type": "concept or principle", "pos": [107, 119]}, {"entity": "VEGF", "entity_type": "material", "pos": [140, 144]}, {"entity": "processed", "entity_type": "concept or principle", "pos": [149, 158]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [167, 176]}], "task": "NER"}
{"text": "The printable ink was selected according to the gel point of different formulations of TCP/alginate/gelatin .", "entity": [{"entity": "ink", "entity_type": "material", "pos": [14, 17]}, {"entity": "gel point", "entity_type": "machanical property", "pos": [48, 57]}], "task": "NER"}
{"text": "The process faced some difficulties , for example in what concerns the needle blocking during extrusion if the gel point is above room temperature .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "faced", "entity_type": "manufacturing process", "pos": [12, 17]}, {"entity": "blocking", "entity_type": "concept or principle", "pos": [78, 86]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [94, 103]}, {"entity": "gel point", "entity_type": "machanical property", "pos": [111, 120]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [135, 146]}], "task": "NER"}
{"text": "Nevertheless , it was possible to achieve satisfactory mechanical and biological features supporting cell viability necessary for bone tissue regeneration.Tamimi , prepared customized 3D-printed monetite onlays by binder jetting .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [55, 65]}, {"entity": "cell viability", "entity_type": "process characterization", "pos": [101, 115]}, {"entity": "bone", "entity_type": "biomedical", "pos": [130, 134]}, {"entity": "3D-printed", "entity_type": "manufacturing process", "pos": [184, 194]}, {"entity": "onlays", "entity_type": "application", "pos": [204, 210]}, {"entity": "binder jetting", "entity_type": "manufacturing process", "pos": [214, 228]}], "task": "NER"}
{"text": "The onlays were design to facilitate the diffusion of cells and nutrients from high bone metabolic to low bone metabolic areas .", "entity": [{"entity": "onlays", "entity_type": "application", "pos": [4, 10]}, {"entity": "design", "entity_type": "engineering feature", "pos": [16, 22]}, {"entity": "diffusion", "entity_type": "concept or principle", "pos": [41, 50]}, {"entity": "cells", "entity_type": "application", "pos": [54, 59]}, {"entity": "bone", "entity_type": "biomedical", "pos": [84, 88]}, {"entity": "bone metabolic areas", "entity_type": "process characterization", "pos": [106, 126]}], "task": "NER"}
{"text": "The research showed that bone metabolic activity in onlays is anatomy-dependant and correlates with the ability of bone augmentation .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [4, 12]}, {"entity": "bone metabolic activity", "entity_type": "concept or principle", "pos": [25, 48]}, {"entity": "onlays", "entity_type": "application", "pos": [52, 58]}, {"entity": "bone", "entity_type": "biomedical", "pos": [115, 119]}], "task": "NER"}
{"text": "The authors were able to achieve osseointegration of dental implants in bone augmented with the printed monetite onlays .", "entity": [{"entity": "osseointegration", "entity_type": "machanical property", "pos": [33, 49]}, {"entity": "dental", "entity_type": "application", "pos": [53, 59]}, {"entity": "bone", "entity_type": "biomedical", "pos": [72, 76]}, {"entity": "monetite", "entity_type": "material", "pos": [104, 112]}], "task": "NER"}
{"text": "Klammert also used binder jetting technology to produce several specific craniofacial implants of TCP .", "entity": [{"entity": "binder jetting", "entity_type": "manufacturing process", "pos": [19, 33]}, {"entity": "craniofacial implants", "entity_type": "application", "pos": [73, 94]}], "task": "NER"}
{"text": "The printed parts were able to comply with geometric requirements and provide an adequate accuracy of fit , even though the authors did not use a commercial CAD solution .", "entity": [{"entity": "accuracy of fit", "entity_type": "process characterization", "pos": [90, 105]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [157, 160]}], "task": "NER"}
{"text": "Fieldint and colleagues face several challenges to adapt and optimize the processing parameters to produce scaffolds using a 3D binder jetting printer and commercially available binders .", "entity": [{"entity": "face", "entity_type": "concept or principle", "pos": [24, 28]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [85, 95]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [107, 116]}, {"entity": "3D binder jetting printer", "entity_type": "machine or equipment", "pos": [125, 150]}, {"entity": "binders", "entity_type": "material", "pos": [178, 185]}], "task": "NER"}
{"text": "The authors report that the addition of dopants to the ceramic powder decreased the to phase transformation of TCP sintered at 1250 Additionally , the density increased leading to a 250 % increase in compressive strength , when compared to pure TCP scaffolds .", "entity": [{"entity": "dopants", "entity_type": "material", "pos": [40, 47]}, {"entity": "ceramic powder", "entity_type": "material", "pos": [55, 69]}, {"entity": "phase", "entity_type": "concept or principle", "pos": [87, 92]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [115, 123]}, {"entity": "density", "entity_type": "machanical property", "pos": [151, 158]}, {"entity": "compressive strength", "entity_type": "machanical property", "pos": [200, 220]}, {"entity": "TCP scaffolds", "entity_type": "biomedical", "pos": [245, 258]}], "task": "NER"}
{"text": "Shao prepared by extrusion , four groups of bioceramic scaffolds for treatment of bone defects : Mg-substituted wollastonite-based ; TCP-based ; wollastonite-based ; and bredigite-based .", "entity": [{"entity": "extrusion", "entity_type": "manufacturing process", "pos": [17, 26]}, {"entity": "bioceramic scaffolds", "entity_type": "biomedical", "pos": [44, 64]}, {"entity": "bone defects", "entity_type": "biomedical", "pos": [82, 94]}], "task": "NER"}
{"text": "Additionally , CSi-Mg10 printed parts revealed the largest pore dimension but the lowest porosity , mainly due to the considerable shrinkage of the scaffolds during sintering .", "entity": [{"entity": "pore dimension", "entity_type": "process parameter", "pos": [59, 73]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [89, 97]}, {"entity": "shrinkage", "entity_type": "concept or principle", "pos": [131, 140]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [148, 157]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [165, 174]}], "task": "NER"}
{"text": "Asadi-Eydivand , prepared gypsum-based scaffolds also for the treatment of bone defects .", "entity": [{"entity": "gypsum-based scaffolds", "entity_type": "engineering feature", "pos": [26, 48]}, {"entity": "bone defects", "entity_type": "biomedical", "pos": [75, 87]}], "task": "NER"}
{"text": "They investigated the effect of thermic treatment on the structural , mechanical , and physical properties of samples produced by extrusion/jetting .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [70, 80]}, {"entity": "physical properties", "entity_type": "machanical property", "pos": [87, 106]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [110, 117]}], "task": "NER"}
{"text": "For the lowest temperature , the samples showed adequate mechanical properties , but high cytotoxicity .", "entity": [{"entity": "temperature", "entity_type": "process parameter", "pos": [15, 26]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [33, 40]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [57, 78]}, {"entity": "cytotoxicity", "entity_type": "machanical property", "pos": [90, 102]}], "task": "NER"}
{"text": "In contrast , temperatures in the range of 500 led to lower cytotoxic scaffolds but insufficient mechanical strength .", "entity": [{"entity": "temperatures", "entity_type": "process parameter", "pos": [14, 26]}, {"entity": "range", "entity_type": "process parameter", "pos": [34, 39]}, {"entity": "led", "entity_type": "application", "pos": [47, 50]}, {"entity": "cytotoxic scaffolds", "entity_type": "biomedical", "pos": [60, 79]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [97, 116]}], "task": "NER"}
{"text": "For temperatures higher than 1000 higher compressive strength and greater viability were observed .", "entity": [{"entity": "temperatures", "entity_type": "process parameter", "pos": [4, 16]}, {"entity": "compressive strength", "entity_type": "machanical property", "pos": [41, 61]}], "task": "NER"}
{"text": "However , above 1200 decomposition of calcium sulfate occurs , leading to mass loss .", "entity": [{"entity": "decomposition", "entity_type": "machanical property", "pos": [21, 34]}, {"entity": "calcium", "entity_type": "material", "pos": [38, 45]}], "task": "NER"}
{"text": "5.4 Additive manufacturing of ceramic composites 5 gathers the information about AM of ceramic-based composites possible applications in dentistry .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [4, 26]}, {"entity": "ceramic composites", "entity_type": "engineering feature", "pos": [30, 48]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [81, 83]}, {"entity": "ceramic-based composites", "entity_type": "material", "pos": [87, 111]}, {"entity": "dentistry", "entity_type": "application", "pos": [137, 146]}], "task": "NER"}
{"text": "In the work carried out by GoyoB-Ball porous robocasted structures made of 10 mol % ceria-stabilized zirconia and alumina composite were produced .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [38, 44]}, {"entity": "zirconia", "entity_type": "material", "pos": [101, 109]}, {"entity": "alumina composite", "entity_type": "material", "pos": [114, 131]}], "task": "NER"}
{"text": "The authors found that round lattice structures have compression strength similar to cortical bone , are not cytotoxic and induce osseous differentiation .", "entity": [{"entity": "round lattice structures", "entity_type": "engineering feature", "pos": [23, 47]}, {"entity": "compression strength", "entity_type": "machanical property", "pos": [53, 73]}, {"entity": "cortical bone", "entity_type": "material", "pos": [85, 98]}, {"entity": "cytotoxic", "entity_type": "concept or principle", "pos": [109, 118]}], "task": "NER"}
{"text": "More , the printed parts showed good aesthetics , chemical stability and negligible corrosion and wear .", "entity": [{"entity": "chemical stability", "entity_type": "machanical property", "pos": [50, 68]}, {"entity": "corrosion", "entity_type": "concept or principle", "pos": [84, 93]}, {"entity": "wear", "entity_type": "concept or principle", "pos": [98, 102]}], "task": "NER"}
{"text": "Due to the high structural integrity , the printed parts could be used as scaffolds for load bearing applications during the osteointegration process .", "entity": [{"entity": "structural integrity", "entity_type": "machanical property", "pos": [16, 36]}, {"entity": "be", "entity_type": "material", "pos": [63, 65]}, {"entity": "as", "entity_type": "material", "pos": [71, 73]}, {"entity": "osteointegration", "entity_type": "machanical property", "pos": [125, 141]}], "task": "NER"}
{"text": "Rahim established a comparison between composites prepared by extrusion and by injection moulding .", "entity": [{"entity": "composites", "entity_type": "material", "pos": [39, 49]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [62, 71]}, {"entity": "injection moulding", "entity_type": "manufacturing process", "pos": [79, 97]}], "task": "NER"}
{"text": "The samples were composed of polyamide 12 , incorporated with bioceramic fillers , from 10 to 40 % content .", "entity": [{"entity": "samples", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "polyamide 12", "entity_type": "material", "pos": [29, 41]}, {"entity": "bioceramic fillers", "entity_type": "material", "pos": [62, 80]}], "task": "NER"}
{"text": "The results of their work showed that the addition of fillers improved or maintained the strength and stiffness of the parts , while reducing toughness and flexibility .", "entity": [{"entity": "strength", "entity_type": "machanical property", "pos": [89, 97]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [102, 111]}, {"entity": "toughness", "entity_type": "machanical property", "pos": [142, 151]}, {"entity": "flexibility", "entity_type": "machanical property", "pos": [156, 167]}], "task": "NER"}
{"text": "Melting behaviour of polyamide 12 did not depend on the processing techniques , but was affected by the addition of fillers and by the cooling rate .", "entity": [{"entity": "Melting", "entity_type": "manufacturing process", "pos": [0, 7]}, {"entity": "polyamide 12", "entity_type": "material", "pos": [21, 33]}, {"entity": "processing techniques", "entity_type": "concept or principle", "pos": [56, 77]}, {"entity": "cooling rate", "entity_type": "process parameter", "pos": [135, 147]}], "task": "NER"}
{"text": "Incorporation of fillers improved the thermal stability .", "entity": [{"entity": "thermal stability", "entity_type": "machanical property", "pos": [38, 55]}], "task": "NER"}
{"text": "It was found that fuse deposition modelling allows producing medical implants with acceptable mechanical performances for non-load bearing applications .", "entity": [{"entity": "fuse deposition", "entity_type": "concept or principle", "pos": [18, 33]}, {"entity": "medical implants", "entity_type": "application", "pos": [61, 77]}, {"entity": "mechanical", "entity_type": "application", "pos": [94, 104]}, {"entity": "non-load bearing", "entity_type": "machanical property", "pos": [122, 138]}], "task": "NER"}
{"text": "Jan manufactured ceramic objects by powder bed fusion , using selective laser melting technology .", "entity": [{"entity": "manufactured", "entity_type": "concept or principle", "pos": [4, 16]}, {"entity": "ceramic", "entity_type": "material", "pos": [17, 24]}, {"entity": "powder bed fusion", "entity_type": "manufacturing process", "pos": [36, 53]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [62, 85]}], "task": "NER"}
{"text": "The authors were able to produce parts with good mechanical properties , with approximately 100 % density , without needing sintering processes or post-processing , which constitutes an advantage .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [49, 70]}, {"entity": "density", "entity_type": "machanical property", "pos": [98, 105]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [124, 133]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [134, 143]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [147, 162]}], "task": "NER"}
{"text": "The study reports some process challenges that need to be overcome , for instance , the thermally induced stresses , caused by the deposition of the new cold powder layers on top of the preheated ceramic , and the surface roughness values .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [23, 30]}, {"entity": "be", "entity_type": "material", "pos": [55, 57]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [131, 141]}, {"entity": "cold powder layers", "entity_type": "material", "pos": [153, 171]}, {"entity": "ceramic", "entity_type": "material", "pos": [196, 203]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [214, 231]}], "task": "NER"}
{"text": "6 Challenges Additive manufacturing is recognized as a promising technology with advantages not only in the production of customized healthcare products to improve population health and quality of life , but also by its possibility of decreasing environmental impact , enhancing the manufacturing sustainability .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [13, 35]}, {"entity": "as", "entity_type": "material", "pos": [50, 52]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [65, 75]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [108, 118]}, {"entity": "population", "entity_type": "biomedical", "pos": [164, 174]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [186, 193]}, {"entity": "impact", "entity_type": "concept or principle", "pos": [260, 266]}, {"entity": "manufacturing sustainability", "entity_type": "concept or principle", "pos": [283, 311]}], "task": "NER"}
{"text": "However , the inherent challenges of 3D printing should not be overlooked .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [37, 48]}, {"entity": "be", "entity_type": "material", "pos": [60, 62]}], "task": "NER"}
{"text": "Aspects such as surface quality , dimensional accuracy and the mechanical properties need improvement to allow producing effective high-quality products .", "entity": [{"entity": "as", "entity_type": "material", "pos": [13, 15]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [24, 31]}, {"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [34, 54]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [63, 84]}], "task": "NER"}
{"text": "Concerning surface quality , it depends on the AM used technique , processing conditions and raw material characteristics , which affect the thickness of each printed layer .", "entity": [{"entity": "surface quality", "entity_type": "process parameter", "pos": [11, 26]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [47, 49]}, {"entity": "raw material", "entity_type": "material", "pos": [93, 105]}, {"entity": "layer", "entity_type": "process parameter", "pos": [167, 172]}], "task": "NER"}
{"text": "Powder bed AM leads to lower surface quality than the other AM techniques , due to the presence of large and partially melted powder particles in the printed piecessurfaces .", "entity": [{"entity": "Powder bed", "entity_type": "machine or equipment", "pos": [0, 10]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [11, 13]}, {"entity": "surface quality", "entity_type": "process parameter", "pos": [29, 44]}, {"entity": "AM techniques", "entity_type": "manufacturing process", "pos": [60, 73]}, {"entity": "melted", "entity_type": "concept or principle", "pos": [119, 125]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [133, 142]}], "task": "NER"}
{"text": "Relatively to the thickness of the printed layers , extrusion techniques typically lead to high layer thicknesses due to the large diameter of the deposition nozzle .", "entity": [{"entity": "extrusion techniques", "entity_type": "manufacturing process", "pos": [52, 72]}, {"entity": "lead", "entity_type": "material", "pos": [83, 87]}, {"entity": "layer thicknesses", "entity_type": "process parameter", "pos": [96, 113]}, {"entity": "diameter", "entity_type": "concept or principle", "pos": [131, 139]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [147, 157]}], "task": "NER"}
{"text": "Powder bed fusion and vat polymerization origin lower layer thicknesses due to the ability to precisely focus the energy beam radius .", "entity": [{"entity": "Powder bed fusion", "entity_type": "manufacturing process", "pos": [0, 17]}, {"entity": "vat polymerization", "entity_type": "manufacturing process", "pos": [22, 40]}, {"entity": "layer thicknesses", "entity_type": "process parameter", "pos": [54, 71]}, {"entity": "energy beam radius", "entity_type": "process parameter", "pos": [114, 132]}], "task": "NER"}
{"text": "Material jetting techniques are the ones that produce the finest layer thickness due to the small jetted droplets .", "entity": [{"entity": "Material jetting", "entity_type": "manufacturing process", "pos": [0, 16]}, {"entity": "layer thickness", "entity_type": "process parameter", "pos": [65, 80]}, {"entity": "droplets", "entity_type": "concept or principle", "pos": [105, 113]}], "task": "NER"}
{"text": "Dimensional accuracy is critical in the production of dental pieces , because these must fit tightly the needs of each patient .", "entity": [{"entity": "Dimensional accuracy", "entity_type": "process characterization", "pos": [0, 20]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [40, 50]}, {"entity": "dental pieces", "entity_type": "machine or equipment", "pos": [54, 67]}, {"entity": "fit", "entity_type": "concept or principle", "pos": [89, 92]}], "task": "NER"}
{"text": "A variety of issues affects dimensional accuracy .", "entity": [{"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [28, 48]}], "task": "NER"}
{"text": "The work of Lee summarizes the dimensional accuracy in different manufacturing processes .", "entity": [{"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [31, 51]}, {"entity": "manufacturing processes", "entity_type": "manufacturing process", "pos": [65, 88]}], "task": "NER"}
{"text": "spreading compaction/densification of the powder within the layers , evaporation of material by laser/heat and shrinkage during solidification .", "entity": [{"entity": "powder", "entity_type": "material", "pos": [42, 48]}, {"entity": "evaporation", "entity_type": "concept or principle", "pos": [69, 80]}, {"entity": "material", "entity_type": "material", "pos": [84, 92]}, {"entity": "shrinkage", "entity_type": "concept or principle", "pos": [111, 120]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [128, 142]}], "task": "NER"}
{"text": "Mechanical properties are influenced by the presence of defects : surface quality and porosity are critical factors .", "entity": [{"entity": "Mechanical properties", "entity_type": "concept or principle", "pos": [0, 21]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [56, 63]}, {"entity": "surface quality", "entity_type": "process parameter", "pos": [66, 81]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [86, 94]}, {"entity": "critical factors", "entity_type": "machanical property", "pos": [99, 115]}], "task": "NER"}
{"text": "Different solutions have been proposed to reduce porosity .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [49, 57]}], "task": "NER"}
{"text": "For example , choosing ceramic powders with an adequate granulometric distribution , adding dopants or a viscous liquid-forming phase , infiltrating the sintered body with vitreous materials and applying cold/hot isostatic pressure to the green body .", "entity": [{"entity": "ceramic powders", "entity_type": "material", "pos": [23, 38]}, {"entity": "granulometric distribution", "entity_type": "process characterization", "pos": [56, 82]}, {"entity": "dopants", "entity_type": "material", "pos": [92, 99]}, {"entity": "phase", "entity_type": "concept or principle", "pos": [128, 133]}, {"entity": "infiltrating", "entity_type": "concept or principle", "pos": [136, 148]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [153, 161]}, {"entity": "vitreous", "entity_type": "process characterization", "pos": [172, 180]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [181, 190]}, {"entity": "cold/hot isostatic pressure", "entity_type": "process parameter", "pos": [204, 231]}, {"entity": "green body", "entity_type": "concept or principle", "pos": [239, 249]}], "task": "NER"}
{"text": "Shrinkage is also a concern in AM processes since it affects significantly the pieces dimensions and may lead to cracking .", "entity": [{"entity": "Shrinkage", "entity_type": "concept or principle", "pos": [0, 9]}, {"entity": "AM processes", "entity_type": "manufacturing process", "pos": [31, 43]}, {"entity": "dimensions", "entity_type": "engineering feature", "pos": [86, 96]}, {"entity": "lead", "entity_type": "material", "pos": [105, 109]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [113, 121]}], "task": "NER"}
{"text": "The printing strategy needs to be optimized to prevent the impact of this phenomenon .", "entity": [{"entity": "be", "entity_type": "material", "pos": [31, 33]}, {"entity": "impact", "entity_type": "concept or principle", "pos": [59, 65]}], "task": "NER"}
{"text": "Possible solutions to minimize this issue are : - Increasing the amount of ceramic particles in the pastes , while keeping the rheological behavior unchanged , which may be achieved adding steric dispersants - Adding to the mixture particles that can expand due to phase transformation or reaction during sintering - Decreasing the sintering temperature , without compromising density - Considering it in the CAD design of the parts .", "entity": [{"entity": "ceramic", "entity_type": "material", "pos": [75, 82]}, {"entity": "rheological", "entity_type": "machanical property", "pos": [127, 138]}, {"entity": "be", "entity_type": "material", "pos": [139, 141]}, {"entity": "steric dispersants", "entity_type": "material", "pos": [189, 207]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [232, 241]}, {"entity": "phase", "entity_type": "concept or principle", "pos": [265, 270]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [305, 314]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [332, 341]}, {"entity": "density", "entity_type": "machanical property", "pos": [377, 384]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [409, 412]}], "task": "NER"}
{"text": "In most of the mentioned studies along this work , the ceramic materials are composed of mixtures of a sacrificial polymeric binder with ceramic particles for the production of the green product .", "entity": [{"entity": "ceramic materials", "entity_type": "material", "pos": [55, 72]}, {"entity": "binder", "entity_type": "material", "pos": [125, 131]}, {"entity": "ceramic", "entity_type": "material", "pos": [137, 144]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [163, 173]}, {"entity": "green product", "entity_type": "machanical property", "pos": [181, 194]}], "task": "NER"}
{"text": "This means that additional post-processing steps , such as sintering , are required to remove the binder and achieve a fully dense ceramic component .", "entity": [{"entity": "post-processing", "entity_type": "concept or principle", "pos": [27, 42]}, {"entity": "as", "entity_type": "material", "pos": [56, 58]}, {"entity": "binder", "entity_type": "material", "pos": [98, 104]}, {"entity": "fully dense", "entity_type": "process parameter", "pos": [119, 130]}, {"entity": "ceramic", "entity_type": "material", "pos": [131, 138]}], "task": "NER"}
{"text": "This is true for the majority of the AM technologies with few exceptions such as direct selective laser sintering and selective laser melting techniques , where the ceramic particles are directly sintered or melted , respectively .", "entity": [{"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [37, 52]}, {"entity": "as", "entity_type": "material", "pos": [78, 80]}, {"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [88, 113]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [118, 141]}, {"entity": "ceramic", "entity_type": "material", "pos": [165, 172]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [196, 204]}, {"entity": "melted", "entity_type": "concept or principle", "pos": [208, 214]}], "task": "NER"}
{"text": "Dental ceramic pieces made by direct ink deposition still present low mechanical properties , compared to other conventional means to produce molded parts .", "entity": [{"entity": "Dental ceramic pieces", "entity_type": "material", "pos": [0, 21]}, {"entity": "direct ink deposition", "entity_type": "manufacturing process", "pos": [30, 51]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [70, 91]}], "task": "NER"}
{"text": "Limitations of this layering technique include poor bonding adhesion between layers and the occurrence of porosity .", "entity": [{"entity": "bonding", "entity_type": "concept or principle", "pos": [52, 59]}, {"entity": "adhesion", "entity_type": "machanical property", "pos": [60, 68]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [106, 114]}], "task": "NER"}
{"text": "The protocols should be as simple as possible , leading to slurries/inks with appropriate composition , flow consistency and behavior and specific viscoelastic properties .", "entity": [{"entity": "protocols", "entity_type": "concept or principle", "pos": [4, 13]}, {"entity": "be", "entity_type": "material", "pos": [21, 23]}, {"entity": "as", "entity_type": "material", "pos": [24, 26]}, {"entity": "as", "entity_type": "material", "pos": [34, 36]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [90, 101]}, {"entity": "consistency", "entity_type": "concept or principle", "pos": [109, 120]}, {"entity": "viscoelastic properties", "entity_type": "machanical property", "pos": [147, 170]}], "task": "NER"}
{"text": "They should contain a high solid volume fraction not only to minimize shrinkage during drying and therefore resist the involved stresses , but also to increase the density of the final product .", "entity": [{"entity": "solid volume fraction", "entity_type": "machanical property", "pos": [27, 48]}, {"entity": "shrinkage", "entity_type": "concept or principle", "pos": [70, 79]}, {"entity": "drying", "entity_type": "manufacturing process", "pos": [87, 93]}, {"entity": "density", "entity_type": "machanical property", "pos": [164, 171]}], "task": "NER"}
{"text": "Another important challenge is bacteriological safety of the final products intended to be in close contact with tissues/organs .", "entity": [{"entity": "bacteriological safety", "entity_type": "process characterization", "pos": [31, 53]}, {"entity": "be", "entity_type": "material", "pos": [88, 90]}, {"entity": "contact", "entity_type": "application", "pos": [100, 107]}], "task": "NER"}
{"text": "These structures must be able to endure strict sterilization protocols without losing their intrinsic properties .", "entity": [{"entity": "be", "entity_type": "material", "pos": [22, 24]}, {"entity": "protocols", "entity_type": "concept or principle", "pos": [61, 70]}, {"entity": "intrinsic properties", "entity_type": "concept or principle", "pos": [92, 112]}], "task": "NER"}
{"text": "7 Final considerations Ceramic materials play an important role as dental materials .", "entity": [{"entity": "Ceramic materials", "entity_type": "material", "pos": [23, 40]}, {"entity": "as", "entity_type": "material", "pos": [64, 66]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [74, 83]}], "task": "NER"}
{"text": "Their high chemical and mechanical resistance , as well as their aesthetic properties , make them an excellent option to replace damaged dental tissues .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [24, 34]}, {"entity": "as", "entity_type": "material", "pos": [48, 50]}, {"entity": "as", "entity_type": "material", "pos": [56, 58]}, {"entity": "aesthetic", "entity_type": "concept or principle", "pos": [65, 74]}, {"entity": "dental", "entity_type": "application", "pos": [137, 143]}], "task": "NER"}
{"text": "Conventional manufacturing methods to produce ceramic dental pieces are generally based on subtractive techniques .", "entity": [{"entity": "Conventional manufacturing", "entity_type": "manufacturing process", "pos": [0, 26]}, {"entity": "ceramic", "entity_type": "material", "pos": [46, 53]}, {"entity": "subtractive", "entity_type": "manufacturing process", "pos": [91, 102]}], "task": "NER"}
{"text": "These lead to significant material and tool waste and present limitations in the production of parts with complex geometry .", "entity": [{"entity": "lead", "entity_type": "material", "pos": [6, 10]}, {"entity": "material", "entity_type": "material", "pos": [26, 34]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [39, 43]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [81, 91]}, {"entity": "complex geometry", "entity_type": "concept or principle", "pos": [106, 122]}], "task": "NER"}
{"text": "The rising demand for custom-tailored and patient specific dental products renders dentistry to be one of the rapidly expanding segments of additive manufacturing technologies .", "entity": [{"entity": "dental", "entity_type": "application", "pos": [59, 65]}, {"entity": "dentistry", "entity_type": "application", "pos": [83, 92]}, {"entity": "be", "entity_type": "material", "pos": [96, 98]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [140, 162]}], "task": "NER"}
{"text": "These technologies have been successfully used in many production sectors and present many advantages for processing dental structures , compared with subtracting technologies .", "entity": [{"entity": "technologies", "entity_type": "concept or principle", "pos": [6, 18]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [55, 65]}, {"entity": "dental structures", "entity_type": "machine or equipment", "pos": [117, 134]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [163, 175]}], "task": "NER"}
{"text": "These include less production steps with consequent impact in the total manufacturing time , lower consumables and raw materials consumption , and adequacy to produce very small and complex dental parts .", "entity": [{"entity": "production", "entity_type": "manufacturing process", "pos": [19, 29]}, {"entity": "impact", "entity_type": "concept or principle", "pos": [52, 58]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [72, 85]}, {"entity": "raw materials", "entity_type": "material", "pos": [115, 128]}, {"entity": "dental", "entity_type": "application", "pos": [190, 196]}], "task": "NER"}
{"text": "It thus opens possibility to mass production of customized dental products , with evident benefit to the patients and/or healthcare systems .", "entity": [{"entity": "mass production", "entity_type": "concept or principle", "pos": [29, 44]}, {"entity": "dental", "entity_type": "application", "pos": [59, 65]}], "task": "NER"}
{"text": "However , there are still concerns about application of AM to ceramics due to their intrinsically poor mechanical properties , the accuracy of the obtained pieces , their density and surface finishing .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [56, 58]}, {"entity": "ceramics", "entity_type": "material", "pos": [62, 70]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [103, 124]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [131, 139]}, {"entity": "density", "entity_type": "machanical property", "pos": [171, 178]}, {"entity": "surface finishing", "entity_type": "manufacturing process", "pos": [183, 200]}], "task": "NER"}
{"text": "This comprehensive review shows that , dental bioceramics can be processed through AM by different techniques , e.g .", "entity": [{"entity": "dental bioceramics", "entity_type": "material", "pos": [39, 57]}, {"entity": "be", "entity_type": "material", "pos": [62, 64]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [83, 85]}], "task": "NER"}
{"text": "material extrusion/jetting , vat polymerization , binder jetting , and powder bed fusion .", "entity": [{"entity": "material", "entity_type": "material", "pos": [0, 8]}, {"entity": "vat polymerization", "entity_type": "manufacturing process", "pos": [29, 47]}, {"entity": "binder jetting", "entity_type": "manufacturing process", "pos": [50, 64]}, {"entity": "powder bed fusion", "entity_type": "manufacturing process", "pos": [71, 88]}], "task": "NER"}
{"text": "The first technology is the most widely used .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [10, 20]}], "task": "NER"}
{"text": "The studies confirmed that almost any shape could be produced , with different degrees of complexity .", "entity": [{"entity": "be", "entity_type": "material", "pos": [50, 52]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [90, 100]}], "task": "NER"}
{"text": "specific mechanical properties , different degrees of porosity and/or density , biodegradability , osteointegration and cytotoxicity .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [9, 30]}, {"entity": "degrees of porosity", "entity_type": "process characterization", "pos": [43, 62]}, {"entity": "density", "entity_type": "machanical property", "pos": [70, 77]}, {"entity": "biodegradability", "entity_type": "machanical property", "pos": [80, 96]}, {"entity": "osteointegration", "entity_type": "machanical property", "pos": [99, 115]}, {"entity": "cytotoxicity", "entity_type": "machanical property", "pos": [120, 132]}], "task": "NER"}
{"text": "Despite the great potential for dental industry , the application of AM to ceramic dental materials is still under study .", "entity": [{"entity": "dental", "entity_type": "application", "pos": [32, 38]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [69, 71]}, {"entity": "ceramic dental materials", "entity_type": "material", "pos": [75, 99]}], "task": "NER"}
{"text": "In resume , further developments of AM technology are expected to give a significant contribution to bring production costs down , improve manufactured materials properties and render the production processes more efficient and competitive .", "entity": [{"entity": "AM technology", "entity_type": "manufacturing process", "pos": [36, 49]}, {"entity": "production costs", "entity_type": "concept or principle", "pos": [107, 123]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [139, 151]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [162, 172]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [188, 198]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [199, 208]}], "task": "NER"}
{"text": "An interesting approach , when printing 3D complex dental ceramic structures , could be to combine the best attributes of AM technologies with conventional surface finishing methods .", "entity": [{"entity": "3D", "entity_type": "concept or principle", "pos": [40, 42]}, {"entity": "dental ceramic structures", "entity_type": "material", "pos": [51, 76]}, {"entity": "be", "entity_type": "material", "pos": [85, 87]}, {"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [122, 137]}, {"entity": "conventional surface finishing methods", "entity_type": "manufacturing process", "pos": [143, 181]}], "task": "NER"}
{"text": "One of the critical issues in orthopaedic regenerative medicine is the design of bone scaffolds and implants that replicate the biomechanical properties of the host bones .", "entity": [{"entity": "orthopaedic", "entity_type": "application", "pos": [30, 41]}, {"entity": "medicine", "entity_type": "concept or principle", "pos": [55, 63]}, {"entity": "design", "entity_type": "engineering feature", "pos": [71, 77]}, {"entity": "bone scaffolds", "entity_type": "biomedical", "pos": [81, 95]}, {"entity": "implants", "entity_type": "application", "pos": [100, 108]}, {"entity": "biomechanical properties", "entity_type": "machanical property", "pos": [128, 152]}, {"entity": "host bones", "entity_type": "biomedical", "pos": [160, 170]}], "task": "NER"}
{"text": "Porous metals have found themselves to be suitable candidates for repairing or replacing the damaged bones since their stiffness and porosity can be adjusted on demands .", "entity": [{"entity": "Porous metals", "entity_type": "material", "pos": [0, 13]}, {"entity": "be", "entity_type": "material", "pos": [39, 41]}, {"entity": "damaged bones", "entity_type": "machanical property", "pos": [93, 106]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [119, 128]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [133, 141]}, {"entity": "be", "entity_type": "material", "pos": [146, 148]}], "task": "NER"}
{"text": "Another advantage of porous metals lies in their open space for the in-growth of bone tissue , hence accelerating the osseointegration process .", "entity": [{"entity": "porous metals", "entity_type": "material", "pos": [21, 34]}, {"entity": "bone", "entity_type": "biomedical", "pos": [81, 85]}, {"entity": "osseointegration", "entity_type": "machanical property", "pos": [118, 134]}], "task": "NER"}
{"text": "The fabrication of porous metals has been extensively explored over decades , however only limited controls over the internal architecture can be achieved by the conventional processes .", "entity": [{"entity": "fabrication", "entity_type": "manufacturing process", "pos": [4, 15]}, {"entity": "porous metals", "entity_type": "material", "pos": [19, 32]}, {"entity": "internal architecture", "entity_type": "machanical property", "pos": [117, 138]}, {"entity": "be", "entity_type": "material", "pos": [143, 145]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [175, 184]}], "task": "NER"}
{"text": "Recent advances in additive manufacturing have provided unprecedented opportunities for producing complex structures to meet the increasing demands for implants with customized mechanical performance .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [19, 41]}, {"entity": "complex structures", "entity_type": "concept or principle", "pos": [98, 116]}, {"entity": "implants", "entity_type": "application", "pos": [152, 160]}, {"entity": "mechanical", "entity_type": "application", "pos": [177, 187]}], "task": "NER"}
{"text": "At the same time , topology optimization techniques have been developed to enable the internal architecture of porous metals to be designed to achieve specified mechanical properties at will .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [19, 40]}, {"entity": "internal architecture", "entity_type": "machanical property", "pos": [86, 107]}, {"entity": "porous metals", "entity_type": "material", "pos": [111, 124]}, {"entity": "be", "entity_type": "material", "pos": [128, 130]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [161, 182]}], "task": "NER"}
{"text": "Thus implants designed via the topology optimization approach and produced by additive manufacturing are of great interest .", "entity": [{"entity": "implants", "entity_type": "application", "pos": [5, 13]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [14, 22]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [31, 52]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [78, 100]}], "task": "NER"}
{"text": "This paper reviews the state-of-the-art of topological design and manufacturing processes of various types of porous metals , in particular for titanium alloys , biodegradable metals and shape memory alloys .", "entity": [{"entity": "state-of-the-art", "entity_type": "concept or principle", "pos": [23, 39]}, {"entity": "topological design", "entity_type": "engineering feature", "pos": [43, 61]}, {"entity": "manufacturing processes", "entity_type": "manufacturing process", "pos": [66, 89]}, {"entity": "porous metals", "entity_type": "material", "pos": [110, 123]}, {"entity": "titanium alloys", "entity_type": "material", "pos": [144, 159]}, {"entity": "biodegradable metals", "entity_type": "material", "pos": [162, 182]}, {"entity": "shape memory alloys", "entity_type": "material", "pos": [187, 206]}], "task": "NER"}
{"text": "Bone is a complex tissue that continually undergoes dynamic biological remodelling , i.e. , the coupled process whereby osteoclasts resorb mature bone tissue followed by osteoblasts that generate new bone to maintain healthy homeostasis of bone .", "entity": [{"entity": "Bone", "entity_type": "biomedical", "pos": [0, 4]}, {"entity": "dynamic", "entity_type": "concept or principle", "pos": [52, 59]}, {"entity": "process", "entity_type": "concept or principle", "pos": [104, 111]}, {"entity": "bone", "entity_type": "biomedical", "pos": [146, 150]}, {"entity": "osteoblasts", "entity_type": "biomedical", "pos": [170, 181]}, {"entity": "bone", "entity_type": "biomedical", "pos": [200, 204]}, {"entity": "bone", "entity_type": "biomedical", "pos": [240, 244]}], "task": "NER"}
{"text": "This unique feature of bone underpins its ability to remodel itself to repair damage .", "entity": [{"entity": "feature", "entity_type": "engineering feature", "pos": [12, 19]}, {"entity": "bone", "entity_type": "biomedical", "pos": [23, 27]}, {"entity": "damage", "entity_type": "machanical property", "pos": [78, 84]}], "task": "NER"}
{"text": "However , when a bone defect exceeds a critical non-healable size , external intervention is required to supplement self-healing if the defect is to be bridged .", "entity": [{"entity": "bone defect", "entity_type": "biomedical", "pos": [17, 28]}, {"entity": "non-healable size", "entity_type": "process parameter", "pos": [48, 65]}, {"entity": "defect", "entity_type": "concept or principle", "pos": [136, 142]}, {"entity": "be", "entity_type": "material", "pos": [149, 151]}], "task": "NER"}
{"text": "Despite recent advances in biomaterials and tissue engineering , repair of such a critical-sized bone defect still remains a challenge .", "entity": [{"entity": "biomaterials", "entity_type": "material", "pos": [27, 39]}, {"entity": "tissue engineering", "entity_type": "concept or principle", "pos": [44, 62]}, {"entity": "bone defect", "entity_type": "biomedical", "pos": [97, 108]}], "task": "NER"}
{"text": "The optimal choice is to use autograft .", "entity": [{"entity": "autograft", "entity_type": "biomedical", "pos": [29, 38]}], "task": "NER"}
{"text": "However , harvesting autograft tissue creates the morbidity associated with a second surgical site .", "entity": [{"entity": "autograft tissue", "entity_type": "biomedical", "pos": [21, 37]}], "task": "NER"}
{"text": "The insufficiencies of application of autograft and allograft tissue have led to greater research efforts to identify biomimetic materials and structures that are suitable for skeletal repair without the inherent problems .", "entity": [{"entity": "autograft", "entity_type": "biomedical", "pos": [38, 47]}, {"entity": "allograft tissue", "entity_type": "material", "pos": [52, 68]}, {"entity": "led", "entity_type": "application", "pos": [74, 77]}, {"entity": "research", "entity_type": "concept or principle", "pos": [89, 97]}, {"entity": "biomimetic materials", "entity_type": "material", "pos": [118, 138]}], "task": "NER"}
{"text": "Metals and alloys have a long history of application as bone implants .", "entity": [{"entity": "Metals", "entity_type": "material", "pos": [0, 6]}, {"entity": "alloys", "entity_type": "material", "pos": [11, 17]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}, {"entity": "implants", "entity_type": "application", "pos": [61, 69]}], "task": "NER"}
{"text": "Among them , the use of stainless steels , cobalt based alloys , and titanium and its alloys are well established due to their good biocompatibility , satisfactory mechanical strength and superior corrosion resistance .", "entity": [{"entity": "stainless steels", "entity_type": "material", "pos": [24, 40]}, {"entity": "cobalt", "entity_type": "material", "pos": [43, 49]}, {"entity": "alloys", "entity_type": "material", "pos": [56, 62]}, {"entity": "titanium", "entity_type": "material", "pos": [69, 77]}, {"entity": "alloys", "entity_type": "material", "pos": [86, 92]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [132, 148]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [164, 183]}, {"entity": "corrosion resistance", "entity_type": "concept or principle", "pos": [197, 217]}], "task": "NER"}
{"text": "However , implants made of these materials are usually much stiffer than natural bones , leading to stress shielding - a major source for bone resorption and eventual failure of such implants .", "entity": [{"entity": "implants", "entity_type": "application", "pos": [10, 18]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [33, 42]}, {"entity": "stress shielding", "entity_type": "machanical property", "pos": [100, 116]}, {"entity": "source", "entity_type": "application", "pos": [127, 133]}, {"entity": "bone resorption", "entity_type": "concept or principle", "pos": [138, 153]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [167, 174]}, {"entity": "implants", "entity_type": "application", "pos": [183, 191]}], "task": "NER"}
{"text": "Cortical bone has elastic moduli ranging from 3 to 30 GPa , while trabecular or cancellous bone has significantly lower elastic moduli of 0.02GPa .", "entity": [{"entity": "Cortical bone", "entity_type": "material", "pos": [0, 13]}, {"entity": "elastic moduli", "entity_type": "machanical property", "pos": [18, 32]}, {"entity": "GPa", "entity_type": "machanical property", "pos": [54, 57]}, {"entity": "cancellous bone", "entity_type": "biomedical", "pos": [80, 95]}, {"entity": "elastic moduli", "entity_type": "machanical property", "pos": [120, 134]}], "task": "NER"}
{"text": "Most current implant materials have much higher moduli than those of bones , e.g. , Ti6Al4V has a modulus of around 110 GPa and CoCrMo alloys have a modulus of around 210 GPa .", "entity": [{"entity": "implant", "entity_type": "application", "pos": [13, 20]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [84, 91]}, {"entity": "GPa", "entity_type": "machanical property", "pos": [120, 123]}, {"entity": "CoCrMo alloys", "entity_type": "material", "pos": [128, 141]}, {"entity": "GPa", "entity_type": "machanical property", "pos": [171, 174]}], "task": "NER"}
{"text": "Therefore , to avoid stress shielding at the bone-implant interface , the equivalent Young 's modulus and yield stress have to be adjusted when using these bulk materials .", "entity": [{"entity": "stress shielding", "entity_type": "machanical property", "pos": [21, 37]}, {"entity": "bone-implant interface", "entity_type": "engineering feature", "pos": [45, 67]}, {"entity": "yield stress", "entity_type": "machanical property", "pos": [106, 118]}, {"entity": "be", "entity_type": "material", "pos": [127, 129]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [161, 170]}], "task": "NER"}
{"text": "An effective method is to introduce adjustable porosity or relative density as proposed by Gibson and Ashby for isotropic materials .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [47, 55]}, {"entity": "relative density", "entity_type": "machanical property", "pos": [59, 75]}, {"entity": "as", "entity_type": "material", "pos": [76, 78]}, {"entity": "isotropic materials", "entity_type": "material", "pos": [112, 131]}], "task": "NER"}
{"text": "Traditional methods for fabricating open-cell porous metals include liquid state processing , solid state processing , electro-deposition and vapour deposition .", "entity": [{"entity": "fabricating", "entity_type": "manufacturing process", "pos": [24, 35]}, {"entity": "porous metals", "entity_type": "material", "pos": [46, 59]}, {"entity": "liquid state", "entity_type": "concept or principle", "pos": [68, 80]}, {"entity": "solid state processing", "entity_type": "material", "pos": [94, 116]}, {"entity": "electro-deposition", "entity_type": "manufacturing process", "pos": [119, 137]}, {"entity": "vapour deposition", "entity_type": "process characterization", "pos": [142, 159]}], "task": "NER"}
{"text": "Although the shape and size of the pores can be adjusted by changing the parameters of these manufacturing processes , only a randomly organized porous structure can be achievable .", "entity": [{"entity": "pores", "entity_type": "machanical property", "pos": [35, 40]}, {"entity": "be", "entity_type": "material", "pos": [45, 47]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [73, 83]}, {"entity": "manufacturing processes", "entity_type": "manufacturing process", "pos": [93, 116]}, {"entity": "porous", "entity_type": "machanical property", "pos": [145, 151]}, {"entity": "be", "entity_type": "material", "pos": [166, 168]}], "task": "NER"}
{"text": "However , additive manufacturing technologies can fabricate porous metals with predefined external shape and internal architecture .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [10, 32]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [50, 59]}, {"entity": "metals", "entity_type": "material", "pos": [67, 73]}, {"entity": "internal architecture", "entity_type": "machanical property", "pos": [109, 130]}], "task": "NER"}
{"text": "Metal-based additive manufacturing techniques , such as selective laser melting and electron beam melting , are computer controlled fabrication process based on layer-wise manufacturing principles .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [12, 34]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [66, 71]}, {"entity": "electron beam melting", "entity_type": "manufacturing process", "pos": [84, 105]}, {"entity": "computer", "entity_type": "enabling technology", "pos": [112, 120]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [132, 143]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [172, 185]}], "task": "NER"}
{"text": "SLM and EBM are increasingly used for the fabrication of porous metals with complex architecture .", "entity": [{"entity": "SLM", "entity_type": "manufacturing process", "pos": [0, 3]}, {"entity": "EBM", "entity_type": "manufacturing process", "pos": [8, 11]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [42, 53]}, {"entity": "porous metals", "entity_type": "material", "pos": [57, 70]}, {"entity": "architecture", "entity_type": "application", "pos": [84, 96]}], "task": "NER"}
{"text": "Instead of using electron beam as the energy source in EBM , the SLM technology uses laser beam with adjustable wavelength .", "entity": [{"entity": "electron beam", "entity_type": "concept or principle", "pos": [17, 30]}, {"entity": "as", "entity_type": "material", "pos": [31, 33]}, {"entity": "source", "entity_type": "application", "pos": [45, 51]}, {"entity": "EBM", "entity_type": "manufacturing process", "pos": [55, 58]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [65, 68]}, {"entity": "laser beam", "entity_type": "concept or principle", "pos": [85, 95]}, {"entity": "wavelength", "entity_type": "concept or principle", "pos": [112, 122]}], "task": "NER"}
{"text": "Therefore , EBM can only process conductive metals whereas SLM can process polymer or ceramics as well as metal .", "entity": [{"entity": "EBM", "entity_type": "manufacturing process", "pos": [12, 15]}, {"entity": "process", "entity_type": "concept or principle", "pos": [25, 32]}, {"entity": "metals", "entity_type": "material", "pos": [44, 50]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [59, 62]}, {"entity": "process", "entity_type": "concept or principle", "pos": [67, 74]}, {"entity": "polymer", "entity_type": "material", "pos": [75, 82]}, {"entity": "ceramics", "entity_type": "material", "pos": [86, 94]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}, {"entity": "as", "entity_type": "material", "pos": [103, 105]}], "task": "NER"}
{"text": "Furthermore , due to more diffuse energy , EBM process has larger minimum feature size , median powder particle size , layer thickness , resolution and surface finish .", "entity": [{"entity": "EBM", "entity_type": "manufacturing process", "pos": [43, 46]}, {"entity": "minimum feature size", "entity_type": "process parameter", "pos": [66, 86]}, {"entity": "powder particle", "entity_type": "material", "pos": [96, 111]}, {"entity": "layer thickness", "entity_type": "process parameter", "pos": [119, 134]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [137, 147]}, {"entity": "surface finish", "entity_type": "engineering feature", "pos": [152, 166]}], "task": "NER"}
{"text": "The robust application of MAM technologies requires extensive material , process and design knowledge , specific to each MAM technology .", "entity": [{"entity": "technologies", "entity_type": "concept or principle", "pos": [30, 42]}, {"entity": "material", "entity_type": "material", "pos": [62, 70]}, {"entity": "process", "entity_type": "concept or principle", "pos": [73, 80]}, {"entity": "design", "entity_type": "engineering feature", "pos": [85, 91]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [125, 135]}], "task": "NER"}
{"text": "MAM system behaviour is subject to significant stochastic error and experimental uncertainties , requiring that are necessary to simplify the problem .", "entity": [{"entity": "stochastic error", "entity_type": "concept or principle", "pos": [47, 63]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [68, 80]}], "task": "NER"}
{"text": "Sources of error include : complex and transient heat transfer phenomena , geometric effects with poorly defined powder thermal properties .", "entity": [{"entity": "error", "entity_type": "concept or principle", "pos": [11, 16]}, {"entity": "transient", "entity_type": "concept or principle", "pos": [39, 48]}, {"entity": "heat transfer", "entity_type": "concept or principle", "pos": [49, 62]}, {"entity": "powder", "entity_type": "material", "pos": [113, 119]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [128, 138]}], "task": "NER"}
{"text": "MAM prediction error can lead to excess melt pool temperature , resulting in undesirable microstructure , residual stress , local porosity , and surface roughness .", "entity": [{"entity": "prediction error", "entity_type": "concept or principle", "pos": [4, 20]}, {"entity": "lead", "entity_type": "material", "pos": [25, 29]}, {"entity": "excess melt pool temperature", "entity_type": "process characterization", "pos": [33, 61]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [89, 103]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [106, 121]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [130, 138]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [145, 162]}], "task": "NER"}
{"text": "Understanding the effects of design decisions on temperature related process defects is critically important to the process control .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [29, 35]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [49, 60]}, {"entity": "process defects", "entity_type": "concept or principle", "pos": [69, 84]}, {"entity": "process control", "entity_type": "concept or principle", "pos": [116, 131]}], "task": "NER"}
{"text": "Comprehensive reviews of AM technologies can be found elsewhere .", "entity": [{"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [25, 40]}, {"entity": "be", "entity_type": "material", "pos": [45, 47]}], "task": "NER"}
{"text": "Recent successes in orthopaedic regenerative medicine have promised an exciting future of AM technology .", "entity": [{"entity": "orthopaedic", "entity_type": "application", "pos": [20, 31]}, {"entity": "medicine", "entity_type": "concept or principle", "pos": [45, 53]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [90, 103]}], "task": "NER"}
{"text": "The world 's first additively manufactured mandible was implanted in a patient by Dr. Jules Poukens and his team in 2012 in Belgium .", "entity": [{"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [19, 42]}, {"entity": "implanted", "entity_type": "manufacturing process", "pos": [56, 65]}], "task": "NER"}
{"text": "A full lower jaw implant was coated with hydroxyapatite and implanted in an 83 year old lady .", "entity": [{"entity": "lower jaw implant", "entity_type": "application", "pos": [7, 24]}, {"entity": "coated", "entity_type": "application", "pos": [29, 35]}, {"entity": "hydroxyapatite", "entity_type": "material", "pos": [41, 55]}, {"entity": "implanted", "entity_type": "manufacturing process", "pos": [60, 69]}], "task": "NER"}
{"text": "Skull reconstructions with AM parts have been performed successfully by using digital design and AM .", "entity": [{"entity": "Skull reconstructions", "entity_type": "enabling technology", "pos": [0, 21]}, {"entity": "AM parts", "entity_type": "machine or equipment", "pos": [27, 35]}, {"entity": "design", "entity_type": "engineering feature", "pos": [86, 92]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [97, 99]}], "task": "NER"}
{"text": "Mertens successfully reconstructed a class III defect using AM manufactured titanium implants , which provided both midfacial support and a graft fixture .", "entity": [{"entity": "class III defect", "entity_type": "manufacturing standard", "pos": [37, 53]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [60, 62]}, {"entity": "titanium implants", "entity_type": "application", "pos": [76, 93]}, {"entity": "midfacial support", "entity_type": "application", "pos": [116, 133]}, {"entity": "fixture", "entity_type": "machine or equipment", "pos": [146, 153]}], "task": "NER"}
{"text": "Jardini in Brazil designed and AM fabricated a customized implant for the surgical reconstruction of a large cranial defect .", "entity": [{"entity": "designed", "entity_type": "engineering feature", "pos": [18, 26]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [31, 33]}, {"entity": "implant", "entity_type": "application", "pos": [58, 65]}, {"entity": "reconstruction", "entity_type": "concept or principle", "pos": [83, 97]}, {"entity": "cranial defect", "entity_type": "biomedical", "pos": [109, 123]}], "task": "NER"}
{"text": "Typical design and application approaches of porous metallic implants normally include the design of scaffold , AM and post-processing as illustrated in 1 .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [8, 14]}, {"entity": "porous metallic implants", "entity_type": "application", "pos": [45, 69]}, {"entity": "design", "entity_type": "engineering feature", "pos": [91, 97]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [101, 109]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [112, 114]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [119, 134]}, {"entity": "as", "entity_type": "material", "pos": [135, 137]}], "task": "NER"}
{"text": "This review aims to identify the current status and the future directions of design-oriented AM technology in producing porous metallic structures for bone tissue repair , with a particular emphasis on topological design of internal architecture of porous metals for bone implants .", "entity": [{"entity": "AM technology", "entity_type": "manufacturing process", "pos": [93, 106]}, {"entity": "porous metallic structures", "entity_type": "engineering feature", "pos": [120, 146]}, {"entity": "bone tissue repair", "entity_type": "concept or principle", "pos": [151, 169]}, {"entity": "topological design", "entity_type": "engineering feature", "pos": [202, 220]}, {"entity": "internal architecture", "entity_type": "machanical property", "pos": [224, 245]}, {"entity": "porous metals", "entity_type": "material", "pos": [249, 262]}, {"entity": "bone implants", "entity_type": "application", "pos": [267, 280]}], "task": "NER"}
{"text": "2 Structure and properties of bone 2.1 Structure of bone Bone is a natural composite containing both organic components and inorganic crystalline mineral , as illustrated in 2 .", "entity": [{"entity": "Structure", "entity_type": "concept or principle", "pos": [2, 11]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [16, 26]}, {"entity": "bone", "entity_type": "biomedical", "pos": [30, 34]}, {"entity": "Structure", "entity_type": "concept or principle", "pos": [39, 48]}, {"entity": "bone", "entity_type": "biomedical", "pos": [52, 56]}, {"entity": "composite", "entity_type": "material", "pos": [75, 84]}, {"entity": "organic components", "entity_type": "machine or equipment", "pos": [101, 119]}, {"entity": "as", "entity_type": "material", "pos": [156, 158]}], "task": "NER"}
{"text": "The structure of bone is similar to reinforced concrete that is used in the building industry .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [4, 13]}, {"entity": "bone", "entity_type": "biomedical", "pos": [17, 21]}, {"entity": "reinforced", "entity_type": "concept or principle", "pos": [36, 46]}, {"entity": "concrete", "entity_type": "material", "pos": [47, 55]}, {"entity": "building industry", "entity_type": "application", "pos": [76, 93]}], "task": "NER"}
{"text": "The function of HA crystals and collagen molecules are like the steel rod and cement to concrete : one part provides flexibility and the other provides strength and toughness .", "entity": [{"entity": "HA crystals", "entity_type": "material", "pos": [16, 27]}, {"entity": "collagen molecules", "entity_type": "material", "pos": [32, 50]}, {"entity": "steel", "entity_type": "material", "pos": [64, 69]}, {"entity": "rod", "entity_type": "machine or equipment", "pos": [70, 73]}, {"entity": "cement", "entity_type": "material", "pos": [78, 84]}, {"entity": "concrete", "entity_type": "material", "pos": [88, 96]}, {"entity": "flexibility", "entity_type": "machanical property", "pos": [117, 128]}, {"entity": "strength", "entity_type": "machanical property", "pos": [152, 160]}, {"entity": "toughness", "entity_type": "machanical property", "pos": [165, 174]}], "task": "NER"}
{"text": "Type-I collagen is a triple helix of nm in diameter and nm in length .", "entity": [{"entity": "collagen", "entity_type": "material", "pos": [7, 15]}, {"entity": "triple helix", "entity_type": "engineering feature", "pos": [21, 33]}, {"entity": "diameter", "entity_type": "concept or principle", "pos": [43, 51]}], "task": "NER"}
{"text": "It is the primary organic components of bone .", "entity": [{"entity": "organic components", "entity_type": "machine or equipment", "pos": [18, 36]}, {"entity": "bone", "entity_type": "biomedical", "pos": [40, 44]}], "task": "NER"}
{"text": "Other non-collagenous proteins include glycoproteins and bone specific proteoglycans .", "entity": [{"entity": "glycoproteins", "entity_type": "material", "pos": [39, 52]}, {"entity": "bone", "entity_type": "biomedical", "pos": [57, 61]}, {"entity": "proteoglycans", "entity_type": "material", "pos": [71, 84]}], "task": "NER"}
{"text": "Hydroxyapatite is the inorganic component of bone and is plate-shaped of 50 25 nm in size and 1.5nm thick .", "entity": [{"entity": "Hydroxyapatite", "entity_type": "material", "pos": [0, 14]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [32, 41]}, {"entity": "bone", "entity_type": "biomedical", "pos": [45, 49]}], "task": "NER"}
{"text": "The HA crystals are oriented in a periodic array in the fibrils , preferentially with their c axis parallel to the collagen fibrils .", "entity": [{"entity": "HA crystals", "entity_type": "material", "pos": [4, 15]}, {"entity": "fibrils", "entity_type": "biomedical", "pos": [56, 63]}, {"entity": "c", "entity_type": "material", "pos": [92, 93]}, {"entity": "collagen fibrils", "entity_type": "material", "pos": [115, 131]}], "task": "NER"}
{"text": "% of the dry bone .", "entity": [{"entity": "bone", "entity_type": "biomedical", "pos": [13, 17]}], "task": "NER"}
{"text": "Bone has a hierarchical structure .", "entity": [{"entity": "Bone", "entity_type": "biomedical", "pos": [0, 4]}, {"entity": "hierarchical structure", "entity_type": "engineering feature", "pos": [11, 33]}], "task": "NER"}
{"text": "The hierarchical levels of bone include macroscale , microscale , sub-microscale , nanoscale , and sub-nanoscale .", "entity": [{"entity": "bone", "entity_type": "biomedical", "pos": [27, 31]}, {"entity": "macroscale", "entity_type": "concept or principle", "pos": [40, 50]}, {"entity": "microscale", "entity_type": "concept or principle", "pos": [53, 63]}, {"entity": "sub-microscale", "entity_type": "engineering feature", "pos": [66, 80]}, {"entity": "sub-nanoscale", "entity_type": "engineering feature", "pos": [99, 112]}], "task": "NER"}
{"text": "The macroscale level represents the overall shape of the bone .", "entity": [{"entity": "macroscale", "entity_type": "concept or principle", "pos": [4, 14]}, {"entity": "bone", "entity_type": "biomedical", "pos": [57, 61]}], "task": "NER"}
{"text": "Bone can be classified as compact bone , and trabecular bone .", "entity": [{"entity": "Bone", "entity_type": "biomedical", "pos": [0, 4]}, {"entity": "be", "entity_type": "material", "pos": [9, 11]}, {"entity": "as", "entity_type": "material", "pos": [14, 16]}, {"entity": "bone", "entity_type": "biomedical", "pos": [34, 38]}, {"entity": "trabecular bone", "entity_type": "material", "pos": [45, 60]}], "task": "NER"}
{"text": "Compact bone is almost solid , with only spaces for osteocytes , canaliculi , blood vessels , and erosion cavities etc .", "entity": [{"entity": "Compact", "entity_type": "manufacturing process", "pos": [0, 7]}, {"entity": "bone", "entity_type": "biomedical", "pos": [8, 12]}, {"entity": "osteocytes", "entity_type": "biomedical", "pos": [52, 62]}, {"entity": "canaliculi", "entity_type": "engineering feature", "pos": [65, 75]}, {"entity": "blood vessels", "entity_type": "biomedical", "pos": [78, 91]}], "task": "NER"}
{"text": "There are large spaces in trabecular bone .", "entity": [{"entity": "trabecular bone", "entity_type": "material", "pos": [26, 41]}], "task": "NER"}
{"text": "The pores in trabecular bone are filled with bone marrow , and the porosity varies between 50 and 90 % .", "entity": [{"entity": "pores", "entity_type": "machanical property", "pos": [4, 9]}, {"entity": "trabecular bone", "entity_type": "material", "pos": [13, 28]}, {"entity": "bone marrow", "entity_type": "biomedical", "pos": [45, 56]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [67, 75]}], "task": "NER"}
{"text": "The building block of compact bone is the osteons , which are of the size ranging from 10 to 500 whereas the trabecular bone is made of a porous network of trabeculae .", "entity": [{"entity": "compact", "entity_type": "manufacturing process", "pos": [22, 29]}, {"entity": "bone", "entity_type": "biomedical", "pos": [30, 34]}, {"entity": "osteons", "entity_type": "biomedical", "pos": [42, 49]}, {"entity": "trabecular bone", "entity_type": "material", "pos": [109, 124]}, {"entity": "porous", "entity_type": "machanical property", "pos": [138, 144]}, {"entity": "trabeculae", "entity_type": "material", "pos": [156, 166]}], "task": "NER"}
{"text": "At the micron- and nano-scales , aggregated type-I collagen and HA form the collagen fibril .", "entity": [{"entity": "nano-scales", "entity_type": "engineering feature", "pos": [19, 30]}, {"entity": "collagen", "entity_type": "material", "pos": [51, 59]}, {"entity": "collagen fibril", "entity_type": "material", "pos": [76, 91]}], "task": "NER"}
{"text": "The reinforced collagen fibre is a universal building element for both compact and trabecular bones .", "entity": [{"entity": "reinforced collagen fibre", "entity_type": "material", "pos": [4, 29]}, {"entity": "element", "entity_type": "material", "pos": [54, 61]}, {"entity": "compact and trabecular bones", "entity_type": "biomedical", "pos": [71, 99]}], "task": "NER"}
{"text": "2.2 Mechanical properties of bone Mechanical properties of bone vary significantly with age , anatomical site and bone quality .", "entity": [{"entity": "Mechanical properties", "entity_type": "concept or principle", "pos": [4, 25]}, {"entity": "bone", "entity_type": "biomedical", "pos": [29, 33]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [45, 55]}, {"entity": "bone", "entity_type": "biomedical", "pos": [59, 63]}, {"entity": "bone", "entity_type": "biomedical", "pos": [114, 118]}], "task": "NER"}
{"text": "Among the various biomechanical properties of bone , elastic modulus has attracted the most research interest because of its critical importance for characterizing various bone pathologies and guiding artificial implant design .", "entity": [{"entity": "biomechanical properties", "entity_type": "machanical property", "pos": [18, 42]}, {"entity": "bone", "entity_type": "biomedical", "pos": [46, 50]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [53, 68]}, {"entity": "research", "entity_type": "concept or principle", "pos": [92, 100]}, {"entity": "bone", "entity_type": "biomedical", "pos": [172, 176]}, {"entity": "implant", "entity_type": "application", "pos": [212, 219]}, {"entity": "design", "entity_type": "engineering feature", "pos": [220, 226]}], "task": "NER"}
{"text": "The elastic modulus and strength of bone are anisotropic .", "entity": [{"entity": "elastic modulus", "entity_type": "machanical property", "pos": [4, 19]}, {"entity": "strength", "entity_type": "machanical property", "pos": [24, 32]}, {"entity": "bone", "entity_type": "biomedical", "pos": [36, 40]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [45, 56]}], "task": "NER"}
{"text": "Compact bone is both stronger and stiffer when loaded longitudinally along the diaphyseal axis than the radial transverse directions .", "entity": [{"entity": "Compact", "entity_type": "manufacturing process", "pos": [0, 7]}, {"entity": "bone", "entity_type": "biomedical", "pos": [8, 12]}, {"entity": "diaphyseal axis", "entity_type": "engineering feature", "pos": [79, 94]}], "task": "NER"}
{"text": "Trabecular bone is an anisotropic and porous composite .", "entity": [{"entity": "Trabecular bone", "entity_type": "material", "pos": [0, 15]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [22, 33]}, {"entity": "porous composite", "entity_type": "material", "pos": [38, 54]}], "task": "NER"}
{"text": "Like many biological materials , trabecular bone displays time-dependent behaviour as well as damage susceptibility during cyclic loading .", "entity": [{"entity": "biological materials", "entity_type": "material", "pos": [10, 30]}, {"entity": "trabecular bone", "entity_type": "material", "pos": [33, 48]}, {"entity": "as", "entity_type": "material", "pos": [83, 85]}, {"entity": "as", "entity_type": "material", "pos": [91, 93]}, {"entity": "susceptibility", "entity_type": "machanical property", "pos": [101, 115]}, {"entity": "cyclic loading", "entity_type": "machanical property", "pos": [123, 137]}], "task": "NER"}
{"text": "The mechanical properties of trabecular bone depend on not only the porosity , but also the architectural arrangement of the individual trabeculae .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [4, 25]}, {"entity": "trabecular bone", "entity_type": "material", "pos": [29, 44]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [68, 76]}, {"entity": "trabeculae", "entity_type": "material", "pos": [136, 146]}], "task": "NER"}
{"text": "The physical and mechanical properties of human bone are summarized in 1 .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [17, 38]}, {"entity": "bone", "entity_type": "biomedical", "pos": [48, 52]}], "task": "NER"}
{"text": "2.3 Requirements for the design of orthopaedic implants A successful porous metallic implant would restore the function of bone and promote regeneration of bone tissue at the damaged site .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [25, 31]}, {"entity": "orthopaedic implants", "entity_type": "application", "pos": [35, 55]}, {"entity": "porous metallic implant", "entity_type": "application", "pos": [69, 92]}, {"entity": "bone", "entity_type": "biomedical", "pos": [123, 127]}, {"entity": "regeneration", "entity_type": "concept or principle", "pos": [140, 152]}, {"entity": "bone", "entity_type": "biomedical", "pos": [156, 160]}], "task": "NER"}
{"text": "An ideal bone scaffold should possess the following characteristics : biocompatibility ; suitable surface for cell attachment , proliferation and differentiation ; highly porous with an interconnected pore network for cell ingrowth and transport of nutrients and metabolic waste ; mechanical properties to match the requirements of the surrounding tissues to reduce or eliminate stress shielding , and to meet anatomic loading requirements to avoid mechanical failure .", "entity": [{"entity": "bone scaffold", "entity_type": "biomedical", "pos": [9, 22]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [70, 86]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [98, 105]}, {"entity": "cell attachment", "entity_type": "engineering feature", "pos": [110, 125]}, {"entity": "porous", "entity_type": "machanical property", "pos": [171, 177]}, {"entity": "pore", "entity_type": "machanical property", "pos": [201, 205]}, {"entity": "cell ingrowth", "entity_type": "concept or principle", "pos": [218, 231]}, {"entity": "transport", "entity_type": "process characterization", "pos": [236, 245]}, {"entity": "metabolic waste", "entity_type": "concept or principle", "pos": [263, 278]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [281, 302]}, {"entity": "stress shielding", "entity_type": "machanical property", "pos": [379, 395]}, {"entity": "mechanical failure", "entity_type": "machanical property", "pos": [449, 467]}], "task": "NER"}
{"text": "Porous metals are implanted to repair bone defects of critical size and , in most cases , serve as load-bearing devices .", "entity": [{"entity": "Porous metals", "entity_type": "material", "pos": [0, 13]}, {"entity": "implanted", "entity_type": "manufacturing process", "pos": [18, 27]}, {"entity": "bone defects", "entity_type": "biomedical", "pos": [38, 50]}, {"entity": "as", "entity_type": "material", "pos": [83, 85]}], "task": "NER"}
{"text": "Bone is usually anisotropic with different stiffness and strength in different directions , but normally there are no extremely weak directions .", "entity": [{"entity": "Bone", "entity_type": "biomedical", "pos": [0, 4]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [16, 27]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [43, 52]}, {"entity": "strength", "entity_type": "machanical property", "pos": [57, 65]}], "task": "NER"}
{"text": "Therefore , suitable porous metals will approximate the stiffness of surrounding bones , making them effective for load transfer and alleviating the stress shielding effect .", "entity": [{"entity": "porous metals", "entity_type": "material", "pos": [21, 34]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [56, 65]}, {"entity": "stress shielding", "entity_type": "machanical property", "pos": [149, 165]}], "task": "NER"}
{"text": "The key characteristics to design porous metallic implants include the careful selection of porosity , pore size , and pore interconnectivity , aiming to achieve satisfactory clinical outcomes .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [27, 33]}, {"entity": "metallic", "entity_type": "material", "pos": [41, 49]}, {"entity": "implants", "entity_type": "application", "pos": [50, 58]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [92, 100]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [103, 112]}, {"entity": "pore", "entity_type": "machanical property", "pos": [119, 123]}], "task": "NER"}
{"text": "These structural features have a profound effect on mechanical properties and biological performance of the metallic implants .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [52, 73]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [89, 100]}, {"entity": "metallic", "entity_type": "material", "pos": [108, 116]}, {"entity": "implants", "entity_type": "application", "pos": [117, 125]}], "task": "NER"}
{"text": "Bone regeneration in porous implants in vivo involves recruitment and penetration of cells from the surrounding bone tissue and vascularization .", "entity": [{"entity": "Bone regeneration", "entity_type": "concept or principle", "pos": [0, 17]}, {"entity": "porous implants", "entity_type": "application", "pos": [21, 36]}, {"entity": "penetration", "entity_type": "concept or principle", "pos": [70, 81]}, {"entity": "cells", "entity_type": "application", "pos": [85, 90]}, {"entity": "bone", "entity_type": "biomedical", "pos": [112, 116]}, {"entity": "vascularization", "entity_type": "concept or principle", "pos": [128, 143]}], "task": "NER"}
{"text": "Higher porosity may facilitate these processes and benefit the bone ingrowth .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [7, 15]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [37, 46]}, {"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [63, 76]}], "task": "NER"}
{"text": "For instance , more bone ingrowth was found in porous titanium coatings of higher porosity after the implants were placed into a canine model for 8 weeks .", "entity": [{"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [20, 33]}, {"entity": "porous", "entity_type": "machanical property", "pos": [47, 53]}, {"entity": "coatings", "entity_type": "application", "pos": [63, 71]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [82, 90]}, {"entity": "implants", "entity_type": "application", "pos": [101, 109]}, {"entity": "canine model", "entity_type": "application", "pos": [129, 141]}], "task": "NER"}
{"text": "Similarly , bone ingrowth was shown to be deeper and greater in porous polymer scaffolds of higher porosity .", "entity": [{"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [12, 25]}, {"entity": "be", "entity_type": "material", "pos": [39, 41]}, {"entity": "porous", "entity_type": "machanical property", "pos": [64, 70]}, {"entity": "polymer", "entity_type": "material", "pos": [71, 78]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [99, 107]}], "task": "NER"}
{"text": "The influence of pore size on the bone ingrowth is still controversial in literature .", "entity": [{"entity": "pore size", "entity_type": "process parameter", "pos": [17, 26]}, {"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [34, 47]}], "task": "NER"}
{"text": "The optimal pore size for mineralized bone ingrowth is claimed to be 100in the research by Itala .", "entity": [{"entity": "pore size", "entity_type": "process parameter", "pos": [12, 21]}, {"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [38, 51]}, {"entity": "be", "entity_type": "material", "pos": [66, 68]}, {"entity": "research", "entity_type": "concept or principle", "pos": [79, 87]}], "task": "NER"}
{"text": "They implanted triangle-shaped titanium implants of different plate thickness with pore size ranging from 50 to 125 into rabbit femur and found that there was no clear lower limit of pore size for consistent bone ingrowth .", "entity": [{"entity": "implanted", "entity_type": "manufacturing process", "pos": [5, 14]}, {"entity": "titanium implants", "entity_type": "application", "pos": [31, 48]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [83, 92]}, {"entity": "limit", "entity_type": "concept or principle", "pos": [174, 179]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [183, 192]}, {"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [208, 221]}], "task": "NER"}
{"text": "Recently Braem assessed the feasibility of early bone ingrowth into a predominantly microporous Ti coating in the compact bone of rabbit tibiae and found that new bone formed in micropores of less than 10 Large pores are believed to favour vascularization .", "entity": [{"entity": "feasibility", "entity_type": "concept or principle", "pos": [28, 39]}, {"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [49, 62]}, {"entity": "microporous", "entity_type": "machanical property", "pos": [84, 95]}, {"entity": "coating", "entity_type": "application", "pos": [99, 106]}, {"entity": "compact", "entity_type": "manufacturing process", "pos": [114, 121]}, {"entity": "bone", "entity_type": "biomedical", "pos": [122, 126]}, {"entity": "bone", "entity_type": "biomedical", "pos": [163, 167]}, {"entity": "pores", "entity_type": "machanical property", "pos": [183, 188]}, {"entity": "vascularization", "entity_type": "concept or principle", "pos": [240, 255]}], "task": "NER"}
{"text": "Bai suggested an upper limit of pore size for vascularization , 400 beyond which no significant difference was observed with increasing pore size .", "entity": [{"entity": "limit", "entity_type": "concept or principle", "pos": [23, 28]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [32, 41]}, {"entity": "vascularization", "entity_type": "concept or principle", "pos": [46, 61]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [136, 145]}], "task": "NER"}
{"text": "Kuboki found that , when the pore size ranged from 300 to 400 the implantation of porous hydroxyapatite scaffolds into rats showed higher alkaline phosphates activity , osteocalcin content and bone ingrowth .", "entity": [{"entity": "pore size", "entity_type": "process parameter", "pos": [29, 38]}, {"entity": "implantation", "entity_type": "manufacturing process", "pos": [66, 78]}, {"entity": "porous hydroxyapatite scaffolds", "entity_type": "engineering feature", "pos": [82, 113]}, {"entity": "alkaline phosphates", "entity_type": "material", "pos": [138, 157]}, {"entity": "osteocalcin", "entity_type": "biomedical", "pos": [169, 180]}, {"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [193, 206]}], "task": "NER"}
{"text": "However , Naoya implanted 300 600 and 900 AM manufactured porous Ti scaffolds into rabbit tibia and they found 600 and 900 scaffolds demonstrated significantly higher bone ingrowth than 300 scaffolds .", "entity": [{"entity": "implanted", "entity_type": "manufacturing process", "pos": [16, 25]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [42, 44]}, {"entity": "porous", "entity_type": "machanical property", "pos": [58, 64]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [68, 77]}, {"entity": "tibia", "entity_type": "biomedical", "pos": [90, 95]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [123, 132]}, {"entity": "bone ingrowth", "entity_type": "concept or principle", "pos": [167, 180]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [190, 199]}], "task": "NER"}
{"text": "In addition to vascularization , specific surface area of scaffolds is another essential factor with respect to fixation ability .", "entity": [{"entity": "vascularization", "entity_type": "concept or principle", "pos": [15, 30]}, {"entity": "surface area", "entity_type": "process parameter", "pos": [42, 54]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [58, 67]}], "task": "NER"}
{"text": "Scaffolds with smaller pores are considered to have larger surface area and therefore more space for bone tissue ingrowth .", "entity": [{"entity": "Scaffolds", "entity_type": "engineering feature", "pos": [0, 9]}, {"entity": "pores", "entity_type": "machanical property", "pos": [23, 28]}, {"entity": "surface area", "entity_type": "process parameter", "pos": [59, 71]}, {"entity": "bone tissue ingrowth", "entity_type": "concept or principle", "pos": [101, 121]}], "task": "NER"}
{"text": "Another important feature of bone implants is the permeability of the porous metal since the transportation of cells , nutrients and growth factors require the flow of blood through the porous scaffolds .", "entity": [{"entity": "feature", "entity_type": "engineering feature", "pos": [18, 25]}, {"entity": "bone implants", "entity_type": "application", "pos": [29, 42]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [50, 62]}, {"entity": "porous metal", "entity_type": "material", "pos": [70, 82]}, {"entity": "cells", "entity_type": "application", "pos": [111, 116]}, {"entity": "porous scaffolds", "entity_type": "engineering feature", "pos": [186, 202]}], "task": "NER"}
{"text": "In simple terms , permeability is characterised by using gradient pressure to push liquid through porous material .", "entity": [{"entity": "simple", "entity_type": "manufacturing process", "pos": [3, 9]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [18, 30]}, {"entity": "pressure", "entity_type": "concept or principle", "pos": [66, 74]}, {"entity": "porous material", "entity_type": "material", "pos": [98, 113]}], "task": "NER"}
{"text": "Zhang stated that permeability may influence vascular invasion and the supply of nutrients required to sustain cell growth and may also provide an outlet for the removal of cell debris , thereby increasing its osteoconductive potential .", "entity": [{"entity": "permeability", "entity_type": "machanical property", "pos": [18, 30]}, {"entity": "vascular invasion", "entity_type": "concept or principle", "pos": [45, 62]}, {"entity": "cell growth", "entity_type": "process characterization", "pos": [111, 122]}, {"entity": "cell debris", "entity_type": "biomedical", "pos": [173, 184]}, {"entity": "osteoconductive potential", "entity_type": "machanical property", "pos": [210, 235]}], "task": "NER"}
{"text": "High permeability of titanium implants enhances the osseointegration process .", "entity": [{"entity": "permeability", "entity_type": "machanical property", "pos": [5, 17]}, {"entity": "titanium implants", "entity_type": "application", "pos": [21, 38]}, {"entity": "osseointegration", "entity_type": "machanical property", "pos": [52, 68]}], "task": "NER"}
{"text": "Further research on the effect of permeability of porous metallic implants is in demand .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [8, 16]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [34, 46]}, {"entity": "porous metallic implants", "entity_type": "application", "pos": [50, 74]}], "task": "NER"}
{"text": "In summary , porosity , pore size and pore interconnectivity are key factors that will significantly influence the mechanical properties and biological performance of scaffolds such as bone ingrowth and transportation of cells and nutrients .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [13, 21]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [24, 33]}, {"entity": "pore", "entity_type": "machanical property", "pos": [38, 42]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [115, 136]}, {"entity": "biological performance of scaffolds", "entity_type": "concept or principle", "pos": [141, 176]}, {"entity": "as", "entity_type": "material", "pos": [182, 184]}, {"entity": "cells", "entity_type": "application", "pos": [221, 226]}], "task": "NER"}
{"text": "For example , increasing the porosity may enhance the biological processes , but it can decrease the stiffness and strength drastically .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [29, 37]}, {"entity": "biological processes", "entity_type": "concept or principle", "pos": [54, 74]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [101, 110]}, {"entity": "strength", "entity_type": "machanical property", "pos": [115, 123]}], "task": "NER"}
{"text": "Therefore , finding the optimal topologies for scaffolds is of critical importance .", "entity": [{"entity": "topologies", "entity_type": "concept or principle", "pos": [32, 42]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [47, 56]}], "task": "NER"}
{"text": "However , conventional CAD-based design techniques are inefficient and usually fail to obtain the optimal scaffold design because a prohibitively large number of trials would be required in order to achieve a balanced performance , e.g. , desirable stiffness and good permeability .", "entity": [{"entity": "CAD-based design", "entity_type": "enabling technology", "pos": [23, 39]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [106, 114]}, {"entity": "design", "entity_type": "engineering feature", "pos": [115, 121]}, {"entity": "be", "entity_type": "material", "pos": [122, 124]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [218, 229]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [249, 258]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [268, 280]}], "task": "NER"}
{"text": "On the contrary , topology optimization techniques are capable of quickly finding the optimal topologies which satisfy multiple objectives and constraints simultaneously to provide site-specific biological performance .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [18, 39]}, {"entity": "topologies", "entity_type": "concept or principle", "pos": [94, 104]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [206, 217]}], "task": "NER"}
{"text": "3 Topological design of porous metallic structures for orthopaedic implants 3.1 Porous metallic implants and topology optimization techniques As mentioned previously , bone is a 3D inhomogeneous structure with elaborate features from macro-to nano-scales .", "entity": [{"entity": "Topological design", "entity_type": "engineering feature", "pos": [2, 20]}, {"entity": "porous metallic structures", "entity_type": "engineering feature", "pos": [24, 50]}, {"entity": "orthopaedic implants", "entity_type": "application", "pos": [55, 75]}, {"entity": "Porous metallic implants", "entity_type": "application", "pos": [80, 104]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [109, 130]}, {"entity": "As", "entity_type": "material", "pos": [142, 144]}, {"entity": "bone", "entity_type": "biomedical", "pos": [168, 172]}, {"entity": "3D inhomogeneous structure", "entity_type": "engineering feature", "pos": [178, 204]}, {"entity": "nano-scales", "entity_type": "engineering feature", "pos": [243, 254]}], "task": "NER"}
{"text": "While it is impossible , and perhaps unnecessary , to recreate all details of natural bone in the porous metallic implant , ideally the implant should have similar hierarchical configurations on multiple scales .", "entity": [{"entity": "bone", "entity_type": "biomedical", "pos": [86, 90]}, {"entity": "porous metallic implant", "entity_type": "application", "pos": [98, 121]}, {"entity": "implant", "entity_type": "application", "pos": [136, 143]}], "task": "NER"}
{"text": "It is essential that the implant should possess properties similar to the host bone and the ambient tissue .", "entity": [{"entity": "implant", "entity_type": "application", "pos": [25, 32]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [48, 58]}, {"entity": "host bone", "entity_type": "biomedical", "pos": [74, 83]}, {"entity": "ambient tissue", "entity_type": "material", "pos": [92, 106]}], "task": "NER"}
{"text": "This calls for a well-established design methodology integrating structural stiffness with fluid permeability to allow the implant to have both adequate rigidity to resist the physical loading and sufficient permeability to transfer cells , nutrients , etc .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [34, 40]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [76, 85]}, {"entity": "fluid permeability", "entity_type": "machanical property", "pos": [91, 109]}, {"entity": "implant", "entity_type": "application", "pos": [123, 130]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [208, 220]}, {"entity": "cells", "entity_type": "application", "pos": [233, 238]}], "task": "NER"}
{"text": "Fully solid metals , e.g .", "entity": [{"entity": "metals", "entity_type": "material", "pos": [12, 18]}], "task": "NER"}
{"text": "Such a stiffness mismatch is regarded as one of the most significant problems in implant design as the resulting stress shielding would often lead to implantation failures .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [7, 16]}, {"entity": "as", "entity_type": "material", "pos": [38, 40]}, {"entity": "implant", "entity_type": "application", "pos": [81, 88]}, {"entity": "design", "entity_type": "engineering feature", "pos": [89, 95]}, {"entity": "as", "entity_type": "material", "pos": [96, 98]}, {"entity": "stress shielding", "entity_type": "machanical property", "pos": [113, 129]}, {"entity": "lead", "entity_type": "material", "pos": [142, 146]}, {"entity": "implantation", "entity_type": "manufacturing process", "pos": [150, 162]}], "task": "NER"}
{"text": "Recently , porous metals were used in orthopaedic surgeries to replace damaged bones .", "entity": [{"entity": "porous metals", "entity_type": "material", "pos": [11, 24]}, {"entity": "orthopaedic", "entity_type": "application", "pos": [38, 49]}, {"entity": "damaged bones", "entity_type": "machanical property", "pos": [71, 84]}], "task": "NER"}
{"text": "Porous scaffolds are geometrically similar to natural hard tissues which are composed of constituting materials penetrated by interconnected pores .", "entity": [{"entity": "Porous scaffolds", "entity_type": "engineering feature", "pos": [0, 16]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [102, 111]}, {"entity": "pores", "entity_type": "machanical property", "pos": [141, 146]}], "task": "NER"}
{"text": "Porous metals can be designed to duplicate the properties of bones if their structures could be designed digitally and fabricated using advanced manufacturing technology .", "entity": [{"entity": "Porous metals", "entity_type": "material", "pos": [0, 13]}, {"entity": "be", "entity_type": "material", "pos": [18, 20]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [47, 57]}, {"entity": "be", "entity_type": "material", "pos": [93, 95]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [119, 129]}, {"entity": "manufacturing technology", "entity_type": "manufacturing process", "pos": [145, 169]}], "task": "NER"}
{"text": "Conventional porous scaffolds typically consist of a vast number of randomly shaped pores in different sizes and therefore it is almost impossible to quantitatively analyse their properties .", "entity": [{"entity": "porous scaffolds", "entity_type": "engineering feature", "pos": [13, 29]}, {"entity": "pores", "entity_type": "machanical property", "pos": [84, 89]}, {"entity": "quantitatively", "entity_type": "concept or principle", "pos": [150, 164]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [179, 189]}], "task": "NER"}
{"text": "To obtain a simplified model , researchers usually assume that scaffolds are constructed of periodically-repeating unit cells along all directions and the architecture of the micro unit cells can distinctly define the macro properties of the scaffolds .", "entity": [{"entity": "model", "entity_type": "concept or principle", "pos": [23, 28]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [63, 72]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [115, 125]}, {"entity": "architecture", "entity_type": "application", "pos": [155, 167]}, {"entity": "micro unit cells", "entity_type": "concept or principle", "pos": [175, 191]}, {"entity": "macro", "entity_type": "engineering feature", "pos": [218, 223]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [242, 251]}], "task": "NER"}
{"text": "Typical traditional design strategies of periodic bone scaffolds include Computer Aided Design , image-based design and implicit surfaces , as illustrated in 3 .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [20, 26]}, {"entity": "bone scaffolds", "entity_type": "biomedical", "pos": [50, 64]}, {"entity": "Computer Aided Design", "entity_type": "enabling technology", "pos": [73, 94]}, {"entity": "design", "entity_type": "engineering feature", "pos": [109, 115]}, {"entity": "implicit surfaces", "entity_type": "engineering feature", "pos": [120, 137]}, {"entity": "as", "entity_type": "material", "pos": [140, 142]}], "task": "NER"}
{"text": "CAD-based design are obtained by using various CAD tools .", "entity": [{"entity": "CAD-based design", "entity_type": "enabling technology", "pos": [0, 16]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [47, 50]}], "task": "NER"}
{"text": "Computer-aided system for tissue scaffolds is a further development based on these scaffold libraries , aiming to efficiently automate the entire design process for desired topologies .", "entity": [{"entity": "scaffolds", "entity_type": "engineering feature", "pos": [33, 42]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [83, 91]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [146, 160]}, {"entity": "topologies", "entity_type": "concept or principle", "pos": [173, 183]}], "task": "NER"}
{"text": "Bio-inspired design is an alternative to improve the mechanical performance of bone scaffolds and enrich the scaffold library .", "entity": [{"entity": "Bio-inspired design", "entity_type": "engineering feature", "pos": [0, 19]}, {"entity": "mechanical", "entity_type": "application", "pos": [53, 63]}, {"entity": "bone scaffolds", "entity_type": "biomedical", "pos": [79, 93]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [109, 117]}], "task": "NER"}
{"text": "Other CAD-based approaches may also be used in designing scaffolds .", "entity": [{"entity": "be", "entity_type": "material", "pos": [36, 38]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [57, 66]}], "task": "NER"}
{"text": "Image-based design , as proposed by Hollister , is based on Computed Tomography or Magnetic Resonance Image data for reconstruction of a defect .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [12, 18]}, {"entity": "as", "entity_type": "material", "pos": [21, 23]}, {"entity": "Computed Tomography", "entity_type": "process characterization", "pos": [60, 79]}, {"entity": "Magnetic Resonance Image data", "entity_type": "process characterization", "pos": [83, 112]}, {"entity": "reconstruction", "entity_type": "concept or principle", "pos": [117, 131]}, {"entity": "defect", "entity_type": "concept or principle", "pos": [137, 143]}], "task": "NER"}
{"text": "It uses Boolean combination of defect image and architecture image to create 3D scaffold image .", "entity": [{"entity": "defect", "entity_type": "concept or principle", "pos": [31, 37]}, {"entity": "architecture", "entity_type": "application", "pos": [48, 60]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [77, 79]}, {"entity": "image", "entity_type": "concept or principle", "pos": [89, 94]}], "task": "NER"}
{"text": "Implicit surface modelling uses single mathematical equations to freely introduce pore shapes such as triply periodic minimal surfaces , which is highly flexible in designing scaffolds .", "entity": [{"entity": "Implicit surface", "entity_type": "engineering feature", "pos": [0, 16]}, {"entity": "mathematical equations", "entity_type": "concept or principle", "pos": [39, 61]}, {"entity": "pore", "entity_type": "machanical property", "pos": [82, 86]}, {"entity": "as", "entity_type": "material", "pos": [99, 101]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [126, 134]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [175, 184]}], "task": "NER"}
{"text": "CAD-based randomization approach starts from cell elements to fill a specific volume in computer software , where standard cell elements are usually packaged while new cell elements can also be created .", "entity": [{"entity": "CAD-based randomization", "entity_type": "enabling technology", "pos": [0, 23]}, {"entity": "cell elements", "entity_type": "engineering feature", "pos": [45, 58]}, {"entity": "specific volume", "entity_type": "engineering feature", "pos": [69, 84]}, {"entity": "computer", "entity_type": "enabling technology", "pos": [88, 96]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [114, 122]}, {"entity": "cell elements", "entity_type": "engineering feature", "pos": [123, 136]}, {"entity": "cell elements", "entity_type": "engineering feature", "pos": [168, 181]}, {"entity": "be", "entity_type": "material", "pos": [191, 193]}], "task": "NER"}
{"text": "This method can effectively imitate real bones by the randomization process , thus promoting the bone attachment and bone cell in-growth , as well as increasing the damage tolerance .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [68, 75]}, {"entity": "bone attachment", "entity_type": "machine or equipment", "pos": [97, 112]}, {"entity": "bone cell", "entity_type": "biomedical", "pos": [117, 126]}, {"entity": "as", "entity_type": "material", "pos": [139, 141]}, {"entity": "as", "entity_type": "material", "pos": [147, 149]}, {"entity": "damage tolerance", "entity_type": "machanical property", "pos": [165, 181]}], "task": "NER"}
{"text": "While the aforementioned methods enable scaffolds to obtain desirable stiffness and permeability , these approaches demand a vast number of attempts to achieve anticipated properties .", "entity": [{"entity": "scaffolds", "entity_type": "engineering feature", "pos": [40, 49]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [70, 79]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [84, 96]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [172, 182]}], "task": "NER"}
{"text": "One of the main challenges in the application of porous scaffolds to orthopaedic implants is the adaptation of their mechanical and biomedical properties to those of natural bones .", "entity": [{"entity": "porous scaffolds", "entity_type": "engineering feature", "pos": [49, 65]}, {"entity": "orthopaedic implants", "entity_type": "application", "pos": [69, 89]}, {"entity": "mechanical", "entity_type": "application", "pos": [117, 127]}, {"entity": "biomedical", "entity_type": "application", "pos": [132, 142]}], "task": "NER"}
{"text": "The implanted scaffolds are placed in a complex environment and their performance is affected by many factors .", "entity": [{"entity": "implanted", "entity_type": "manufacturing process", "pos": [4, 13]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [70, 81]}], "task": "NER"}
{"text": "Some of them such as high permeability and good stiffness are competing with each other since a larger pore size is obtained usually at the cost of a lower mechanical strength .", "entity": [{"entity": "as", "entity_type": "material", "pos": [18, 20]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [26, 38]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [48, 57]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [103, 112]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [156, 175]}], "task": "NER"}
{"text": "Hence , to increase the mass transfer , while retaining a strong supporting framework , there is a need to maintain a delicate trade-off between the porosity of the fabricated scaffold and its strength .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [76, 85]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [149, 157]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [165, 175]}, {"entity": "strength", "entity_type": "machanical property", "pos": [193, 201]}], "task": "NER"}
{"text": "Topology optimization a mathematical method capable of rearranging the materials to attain desired properties while satisfying prescribed constraints can complement the trial-and-error approach and provide a powerful tool to design complex scaffolds with features on multiple scales .", "entity": [{"entity": "Topology optimization", "entity_type": "engineering feature", "pos": [0, 21]}, {"entity": "mathematical", "entity_type": "concept or principle", "pos": [24, 36]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [71, 80]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [99, 109]}, {"entity": "trial-and-error", "entity_type": "concept or principle", "pos": [169, 184]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [217, 221]}, {"entity": "design", "entity_type": "engineering feature", "pos": [225, 231]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [240, 249]}], "task": "NER"}
{"text": "It is a branch of computational mechanics and was originally developed in structural engineering .", "entity": [{"entity": "structural engineering", "entity_type": "concept or principle", "pos": [74, 96]}], "task": "NER"}
{"text": "It has been widely used for designing structures and materials for desirable mechanical performance and physical properties .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [53, 62]}, {"entity": "mechanical", "entity_type": "application", "pos": [77, 87]}, {"entity": "physical properties", "entity_type": "machanical property", "pos": [104, 123]}], "task": "NER"}
{"text": "Through two decades of development , this method has gone far beyond the traditional structural engineering context .", "entity": [{"entity": "structural engineering", "entity_type": "concept or principle", "pos": [85, 107]}], "task": "NER"}
{"text": "Typically , there are two ways to define a structure in topology optimization .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [43, 52]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [56, 77]}], "task": "NER"}
{"text": "The first is a point-by-point description in which a void or a solid phase in a local element is represented by an elemental density .", "entity": [{"entity": "void", "entity_type": "concept or principle", "pos": [53, 57]}, {"entity": "phase", "entity_type": "concept or principle", "pos": [69, 74]}, {"entity": "local element", "entity_type": "concept or principle", "pos": [80, 93]}, {"entity": "density", "entity_type": "machanical property", "pos": [125, 132]}], "task": "NER"}
{"text": "The Evolutionary Structural Optimization and the Solid Isotropic Material with Penalization methods use this type of description and have gained considerable success in solving a wide range of engineering optimization problems .", "entity": [{"entity": "Structural Optimization", "entity_type": "concept or principle", "pos": [17, 40]}, {"entity": "Isotropic Material", "entity_type": "material", "pos": [55, 73]}, {"entity": "range", "entity_type": "process parameter", "pos": [184, 189]}, {"entity": "engineering", "entity_type": "application", "pos": [193, 204]}], "task": "NER"}
{"text": "In the field of computational material design , the topology optimization approach is termed as an homogenizationmethod because the homogenization method is used to calculate the effective properties of a unit cell and the material distribution is rearranged through topology optimization to enable the material to attain target properties .", "entity": [{"entity": "material", "entity_type": "material", "pos": [30, 38]}, {"entity": "design", "entity_type": "engineering feature", "pos": [39, 45]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [52, 73]}, {"entity": "as", "entity_type": "material", "pos": [93, 95]}, {"entity": "homogenization method", "entity_type": "manufacturing process", "pos": [132, 153]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [189, 199]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [205, 214]}, {"entity": "material", "entity_type": "material", "pos": [223, 231]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [232, 244]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [267, 288]}, {"entity": "material", "entity_type": "material", "pos": [303, 311]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [329, 339]}], "task": "NER"}
{"text": "The seminal work of inverse homogenization was conducted by Sigmund in the 1990s for the design of materials with prescribed elastic properties .", "entity": [{"entity": "homogenization", "entity_type": "manufacturing process", "pos": [28, 42]}, {"entity": "design", "entity_type": "engineering feature", "pos": [89, 95]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [99, 108]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [125, 132]}], "task": "NER"}
{"text": "Thereafter , great achievements were obtained in the design of exceptional material properties including negative thermal expansion coefficient and negative refraction index .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [53, 59]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [75, 94]}, {"entity": "thermal expansion coefficient", "entity_type": "machanical property", "pos": [114, 143]}, {"entity": "refraction index", "entity_type": "machanical property", "pos": [157, 173]}], "task": "NER"}
{"text": "Later , this method was extended to the design of scaffold materials with their stiffness matrices matching those of anisotropic native bones .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [40, 46]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [50, 58]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [59, 68]}, {"entity": "stiffness matrices", "entity_type": "machanical property", "pos": [80, 98]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [117, 128]}], "task": "NER"}
{"text": "By using the SIMP based structural optimization , Guest and Prevost developed a topology optimization technique to find a scaffold with pores in the shape of a Schwartz primitive structure , resulting in the maximum permeability .", "entity": [{"entity": "structural optimization", "entity_type": "concept or principle", "pos": [24, 47]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [80, 101]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [122, 130]}, {"entity": "pores", "entity_type": "machanical property", "pos": [136, 141]}, {"entity": "Schwartz primitive structure", "entity_type": "biomedical", "pos": [160, 188]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [216, 228]}], "task": "NER"}
{"text": "They also combined bulk modulus and permeability in a single objective function and tailored these two competing properties in a multi-physics optimization problem .", "entity": [{"entity": "bulk modulus", "entity_type": "machanical property", "pos": [19, 31]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [36, 48]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [113, 123]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [143, 155]}], "task": "NER"}
{"text": "Using a similar density-based optimization method , scaffolds with elastic tensors similar to those of natural bones were designed ; and the performance of these scaffolds in subsequent tissue ingrowth was investigated .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [30, 42]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [52, 61]}, {"entity": "elastic tensors", "entity_type": "concept or principle", "pos": [67, 82]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [122, 130]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [141, 152]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [162, 171]}], "task": "NER"}
{"text": "It is found that bone remodeling is at its best when the scaffold elastic tensor matches or is slightly higher than the elastic properties of the host bone .", "entity": [{"entity": "bone", "entity_type": "biomedical", "pos": [17, 21]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [57, 65]}, {"entity": "elastic tensor", "entity_type": "concept or principle", "pos": [66, 80]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [120, 127]}, {"entity": "host bone", "entity_type": "biomedical", "pos": [146, 155]}], "task": "NER"}
{"text": "The last row in 3 shows the porous structures with the maximum bulk and shear moduli , respectively , at a given porosity .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [28, 34]}, {"entity": "shear moduli", "entity_type": "machanical property", "pos": [72, 84]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [113, 121]}], "task": "NER"}
{"text": "These unit cells were obtained using the Bi-directional Evolutionary Structural Optimization method , which shows faster convergence and unambiguous material definition .", "entity": [{"entity": "unit cells", "entity_type": "concept or principle", "pos": [6, 16]}, {"entity": "Structural Optimization method", "entity_type": "concept or principle", "pos": [69, 99]}, {"entity": "material", "entity_type": "material", "pos": [149, 157]}], "task": "NER"}
{"text": "The BESO method , which allows the material to be added and removed simultaneously during the optimization process , is an extension of the original evolutionary ESO method proposed by Xie and Steven .", "entity": [{"entity": "BESO method", "entity_type": "concept or principle", "pos": [4, 15]}, {"entity": "material", "entity_type": "material", "pos": [35, 43]}, {"entity": "be", "entity_type": "material", "pos": [47, 49]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [94, 106]}], "task": "NER"}
{"text": "As shown in 3 on topology optimization , various unit cells with maximal bulk modulus , maximal shear modulus , prescribed stiffness ratios in three directions , and functionally graded structures can be obtained through the BESO method .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [17, 38]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [49, 59]}, {"entity": "bulk modulus", "entity_type": "machanical property", "pos": [73, 85]}, {"entity": "shear modulus", "entity_type": "machanical property", "pos": [96, 109]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [123, 132]}, {"entity": "functionally graded structures", "entity_type": "engineering feature", "pos": [166, 196]}, {"entity": "be", "entity_type": "material", "pos": [201, 203]}, {"entity": "BESO method", "entity_type": "concept or principle", "pos": [225, 236]}], "task": "NER"}
{"text": "The second class of topology optimization methods , represented by the level-set algorithm , focus on tracking phase boundaries .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [20, 41]}, {"entity": "algorithm", "entity_type": "concept or principle", "pos": [81, 90]}, {"entity": "phase boundaries", "entity_type": "concept or principle", "pos": [111, 127]}], "task": "NER"}
{"text": "The level-set method provides an effective technique to represent smooth boundaries and to control topology changes .", "entity": [{"entity": "smooth boundaries", "entity_type": "engineering feature", "pos": [66, 83]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [99, 107]}], "task": "NER"}
{"text": "A variational level-set technique for periodic material design problems governed by Navierand Maxwell 's equations was developed to attain material with maximal permeability .", "entity": [{"entity": "material", "entity_type": "material", "pos": [47, 55]}, {"entity": "design", "entity_type": "engineering feature", "pos": [56, 62]}, {"entity": "material", "entity_type": "material", "pos": [139, 147]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [161, 173]}], "task": "NER"}
{"text": "Level-set topology optimization enables the no-slip boundary condition of fluids in Stokes flow to be naturally satisfied .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [10, 31]}, {"entity": "boundary condition", "entity_type": "concept or principle", "pos": [52, 70]}, {"entity": "fluids", "entity_type": "material", "pos": [74, 80]}, {"entity": "be", "entity_type": "material", "pos": [99, 101]}], "task": "NER"}
{"text": "Periodic structures of scaffolds with the maximal effective diffusivity aimed at providing an ideal environment for nutrient transportation were studied by a level-set based optimization method .", "entity": [{"entity": "scaffolds", "entity_type": "engineering feature", "pos": [23, 32]}, {"entity": "diffusivity", "entity_type": "process characterization", "pos": [60, 71]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [174, 186]}], "task": "NER"}
{"text": "There have been tremendous advances in recent years in the area of using topology optimization techniques to design multi-functional materials with periodic structures , as shown in a comprehensive review by Cadman .", "entity": [{"entity": "area", "entity_type": "process parameter", "pos": [59, 63]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [73, 94]}, {"entity": "design", "entity_type": "engineering feature", "pos": [109, 115]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [133, 142]}, {"entity": "as", "entity_type": "material", "pos": [170, 172]}], "task": "NER"}
{"text": "Several of these developments are directly related to the design of scaffolds .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [58, 64]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [68, 77]}], "task": "NER"}
{"text": "Both stiffness and diffusive transport properties were considered by Hollister and Challis .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [5, 14]}, {"entity": "transport", "entity_type": "process characterization", "pos": [29, 38]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [39, 49]}], "task": "NER"}
{"text": "Using topology optimization , Hollister and co-workers also created an interbody fusion cage for improved arthrodesis .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [6, 27]}, {"entity": "fusion", "entity_type": "concept or principle", "pos": [81, 87]}, {"entity": "arthrodesis", "entity_type": "application", "pos": [106, 117]}], "task": "NER"}
{"text": "The outcomes of their research were used in clinic to support bone regeneration for craniofacial reconstruction .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [22, 30]}, {"entity": "clinic", "entity_type": "application", "pos": [44, 50]}, {"entity": "support", "entity_type": "application", "pos": [54, 61]}, {"entity": "bone regeneration", "entity_type": "concept or principle", "pos": [62, 79]}, {"entity": "craniofacial reconstruction", "entity_type": "manufacturing process", "pos": [84, 111]}], "task": "NER"}
{"text": "3.2 Constraints in structural design for additive manufacturing Although AM can theoretically produce structures in any shape , the quality of the structures may vary significantly depending on the design and fabrication parameters .", "entity": [{"entity": "structural design", "entity_type": "engineering feature", "pos": [19, 36]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [41, 63]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [73, 75]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [132, 139]}, {"entity": "design", "entity_type": "engineering feature", "pos": [198, 204]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [209, 220]}], "task": "NER"}
{"text": "Therefore , it is necessary to consider the processability of the designed parts during the topological design process , including the constraints and limitations of AM technologies .", "entity": [{"entity": "designed", "entity_type": "engineering feature", "pos": [66, 74]}, {"entity": "topological design", "entity_type": "engineering feature", "pos": [92, 110]}, {"entity": "process", "entity_type": "concept or principle", "pos": [111, 118]}, {"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [166, 181]}], "task": "NER"}
{"text": "However , there is still limited research on creating design guidelines to achieve this goal .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [33, 41]}, {"entity": "design", "entity_type": "engineering feature", "pos": [54, 60]}], "task": "NER"}
{"text": "Kranz experimentally investigated the restrictions of Laser Additive Manufacturing of Ti6Al4V and presented a comprehensive structured catalogue .", "entity": [{"entity": "Laser Additive Manufacturing", "entity_type": "manufacturing process", "pos": [54, 82]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [86, 93]}], "task": "NER"}
{"text": "In their research , restrictions and recommendations were presented based on experimental measurements of different characteristics such as cavities , walls , bores , gap , hollow cylinder , overhangs and support structures .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [9, 17]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [77, 89]}, {"entity": "as", "entity_type": "material", "pos": [92, 94]}, {"entity": "overhangs", "entity_type": "process parameter", "pos": [191, 200]}, {"entity": "support structures", "entity_type": "engineering feature", "pos": [205, 223]}], "task": "NER"}
{"text": "They also found that the quality of AM parts was highly dependent on the materials , machines and process parameters .", "entity": [{"entity": "quality", "entity_type": "concept or principle", "pos": [25, 32]}, {"entity": "AM parts", "entity_type": "machine or equipment", "pos": [36, 44]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [73, 82]}, {"entity": "machines", "entity_type": "machine or equipment", "pos": [85, 93]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [98, 116]}], "task": "NER"}
{"text": "Therefore , similar guidelines could be achieved through similar methodology on different material systems .", "entity": [{"entity": "be", "entity_type": "material", "pos": [37, 39]}, {"entity": "methodology", "entity_type": "concept or principle", "pos": [65, 76]}, {"entity": "material", "entity_type": "material", "pos": [90, 98]}], "task": "NER"}
{"text": "Among many parameters , frequently discussed one includes overhanging structures , which may lead to some undesirable defects .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [11, 21]}, {"entity": "overhanging structures", "entity_type": "concept or principle", "pos": [58, 80]}, {"entity": "lead", "entity_type": "material", "pos": [93, 97]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [118, 125]}], "task": "NER"}
{"text": "In an AM process , the overhanging structure is not supported by solidified section or bottom substrate when it is being built .", "entity": [{"entity": "AM process", "entity_type": "manufacturing process", "pos": [6, 16]}, {"entity": "overhanging structure", "entity_type": "concept or principle", "pos": [23, 44]}, {"entity": "substrate", "entity_type": "material", "pos": [94, 103]}], "task": "NER"}
{"text": "Therefore , the overhanging structure is strongly influenced by the orientation of building - ) .", "entity": [{"entity": "overhanging structure", "entity_type": "concept or principle", "pos": [16, 37]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [68, 79]}], "task": "NER"}
{"text": "Therefore , the critical fabrication angle is of great importance since it determines the form of overhanging structure , hence the processability .", "entity": [{"entity": "critical fabrication angle", "entity_type": "engineering feature", "pos": [16, 42]}, {"entity": "overhanging structure", "entity_type": "concept or principle", "pos": [98, 119]}], "task": "NER"}
{"text": "4 shows the sketch of a circular pore with overhanging arc AB , which can be processable if the fabrication angle were larger than the critical value c. Otherwise , supporting structures have to be used , which are normally avoided to prevent damage of parts in post-processing .", "entity": [{"entity": "pore", "entity_type": "machanical property", "pos": [33, 37]}, {"entity": "overhanging arc", "entity_type": "process parameter", "pos": [43, 58]}, {"entity": "AB", "entity_type": "material", "pos": [59, 61]}, {"entity": "be", "entity_type": "material", "pos": [74, 76]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [96, 107]}, {"entity": "be", "entity_type": "material", "pos": [195, 197]}, {"entity": "damage", "entity_type": "machanical property", "pos": [243, 249]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [262, 277]}], "task": "NER"}
{"text": "A better choice in design is to adopt structures with special geometrical arrangement such as an octahedral lattice , whose lateral schematic is shown in 4 .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [19, 25]}, {"entity": "as", "entity_type": "material", "pos": [91, 93]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [108, 115]}], "task": "NER"}
{"text": "When the downward sloping surface CD has a larger fabrication angle than the critical angle c , no supporting structures are required .", "entity": [{"entity": "surface", "entity_type": "concept or principle", "pos": [26, 33]}, {"entity": "CD", "entity_type": "material", "pos": [34, 36]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [50, 61]}, {"entity": "critical angle", "entity_type": "engineering feature", "pos": [77, 91]}, {"entity": "c", "entity_type": "material", "pos": [92, 93]}], "task": "NER"}
{"text": "There were also attempts to design structures so that they could be fabricated using AM without support .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [28, 34]}, {"entity": "be", "entity_type": "material", "pos": [65, 67]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [85, 87]}, {"entity": "support", "entity_type": "application", "pos": [96, 103]}], "task": "NER"}
{"text": "This approach is interesting and useful , but may not be generally applicable to scaffold designs .", "entity": [{"entity": "be", "entity_type": "material", "pos": [54, 56]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [81, 89]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [90, 97]}], "task": "NER"}
{"text": "Other researchers examined the suitability of using SIMP and BESO topology optimization algorithms to design structures for AM .", "entity": [{"entity": "BESO topology optimization algorithms", "entity_type": "concept or principle", "pos": [61, 98]}, {"entity": "design", "entity_type": "engineering feature", "pos": [102, 108]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [124, 126]}], "task": "NER"}
{"text": "4 Current status of AM and topology optimization in producing porous metallic structures AM technologies are superior to conventional fabrication techniques for producing porous metallic implants with complex and customized structures , as shown in 5 .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [20, 22]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [27, 48]}, {"entity": "porous metallic structures", "entity_type": "engineering feature", "pos": [62, 88]}, {"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [89, 104]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [134, 145]}, {"entity": "porous metallic implants", "entity_type": "application", "pos": [171, 195]}, {"entity": "as", "entity_type": "material", "pos": [237, 239]}], "task": "NER"}
{"text": "In addition to the geometric flexibility , composites with two or more phases can be manufactured .", "entity": [{"entity": "flexibility", "entity_type": "machanical property", "pos": [29, 40]}, {"entity": "composites", "entity_type": "material", "pos": [43, 53]}, {"entity": "be", "entity_type": "material", "pos": [82, 84]}], "task": "NER"}
{"text": "These advantages enable AM to become a promising tool for the production of biomedical implant devices , controlled drug delivery systems , and engineered tissues .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [24, 26]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [49, 53]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [62, 72]}, {"entity": "biomedical implant devices", "entity_type": "machine or equipment", "pos": [76, 102]}], "task": "NER"}
{"text": "Examples include artificial joints and load-bearing implants produced by AM using biocompatible materials such as hydroxyapatite , Ti , Ta and Coalloys and customized prostheses such as intervertebral spacers .", "entity": [{"entity": "artificial joints", "entity_type": "application", "pos": [17, 34]}, {"entity": "load-bearing", "entity_type": "engineering feature", "pos": [39, 51]}, {"entity": "implants", "entity_type": "application", "pos": [52, 60]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [73, 75]}, {"entity": "biocompatible materials", "entity_type": "material", "pos": [82, 105]}, {"entity": "as", "entity_type": "material", "pos": [111, 113]}, {"entity": "Ti", "entity_type": "material", "pos": [131, 133]}, {"entity": "Ta", "entity_type": "material", "pos": [136, 138]}, {"entity": "as", "entity_type": "material", "pos": [183, 185]}], "task": "NER"}
{"text": "There has been growing research interest in using topology optimization to design bone scaffolds and orthopaedic implants , however significant challenges still remain before these concepts could be used in clinical practice .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [23, 31]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [50, 71]}, {"entity": "design", "entity_type": "engineering feature", "pos": [75, 81]}, {"entity": "bone scaffolds", "entity_type": "biomedical", "pos": [82, 96]}, {"entity": "orthopaedic implants", "entity_type": "application", "pos": [101, 121]}, {"entity": "be", "entity_type": "material", "pos": [168, 170]}, {"entity": "clinical practice", "entity_type": "application", "pos": [207, 224]}], "task": "NER"}
{"text": "An important issue that may not be neglected when applying topology optimization to scaffold design is to consider the differences in physical , chemical and mechanical properties of base materials produced by AM and conventional fabrication techniques .", "entity": [{"entity": "be", "entity_type": "material", "pos": [32, 34]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [59, 80]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [84, 92]}, {"entity": "design", "entity_type": "engineering feature", "pos": [93, 99]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [158, 179]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [188, 197]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [210, 212]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [230, 241]}], "task": "NER"}
{"text": "The material property in AM process may greatly affect the final topological shape of scaffold , which may differ from the original CAD model obtained from topology optimization .", "entity": [{"entity": "material property", "entity_type": "concept or principle", "pos": [4, 21]}, {"entity": "AM process", "entity_type": "manufacturing process", "pos": [25, 35]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [86, 94]}, {"entity": "CAD model", "entity_type": "enabling technology", "pos": [132, 141]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [156, 177]}], "task": "NER"}
{"text": "Moreover , good understanding of the change in mechanical properties in AM process may assist more accurate optimal design in topology optimization procedure .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [47, 68]}, {"entity": "AM process", "entity_type": "manufacturing process", "pos": [72, 82]}, {"entity": "accurate", "entity_type": "process characterization", "pos": [99, 107]}, {"entity": "design", "entity_type": "engineering feature", "pos": [116, 122]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [126, 147]}], "task": "NER"}
{"text": "This section will review the status of research on AM fabrication of three main families of alloys and the application of topology optimization .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [39, 47]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [51, 53]}, {"entity": "alloys", "entity_type": "material", "pos": [92, 98]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [122, 143]}], "task": "NER"}
{"text": "4.1 Biocompatible Ti alloys Metals in biological systems may experience corrosion and release ions , which may result in many adverse physiological effects .", "entity": [{"entity": "Biocompatible Ti alloys Metals", "entity_type": "material", "pos": [4, 34]}, {"entity": "biological systems", "entity_type": "concept or principle", "pos": [38, 56]}, {"entity": "corrosion", "entity_type": "concept or principle", "pos": [72, 81]}], "task": "NER"}
{"text": "Therefore , the biocompatibility of any implant must be quantified to decrease the patient 's risk and the failure of the implantation .", "entity": [{"entity": "biocompatibility", "entity_type": "machanical property", "pos": [16, 32]}, {"entity": "implant", "entity_type": "application", "pos": [40, 47]}, {"entity": "be", "entity_type": "material", "pos": [53, 55]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [107, 114]}, {"entity": "implantation", "entity_type": "manufacturing process", "pos": [122, 134]}], "task": "NER"}
{"text": "The cytotoxicity of typical surgical implant alloys and pure metals have been broadly studied in the past decades .", "entity": [{"entity": "cytotoxicity", "entity_type": "machanical property", "pos": [4, 16]}, {"entity": "implant", "entity_type": "application", "pos": [37, 44]}, {"entity": "alloys", "entity_type": "material", "pos": [45, 51]}, {"entity": "pure metals", "entity_type": "material", "pos": [56, 67]}], "task": "NER"}
{"text": "It is now commonly accepted that vanadium may cause sterile abscess and aluminium may cause scar tissue , whereas titanium , zirconium , niobium and tantalum exhibit excellent biocompatibility .", "entity": [{"entity": "vanadium", "entity_type": "material", "pos": [33, 41]}, {"entity": "sterile abscess", "entity_type": "machine or equipment", "pos": [52, 67]}, {"entity": "aluminium", "entity_type": "material", "pos": [72, 81]}, {"entity": "scar tissue", "entity_type": "biomedical", "pos": [92, 103]}, {"entity": "titanium", "entity_type": "material", "pos": [114, 122]}, {"entity": "zirconium", "entity_type": "material", "pos": [125, 134]}, {"entity": "niobium", "entity_type": "material", "pos": [137, 144]}, {"entity": "tantalum", "entity_type": "material", "pos": [149, 157]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [176, 192]}], "task": "NER"}
{"text": "Another important motivation behind the design of biocompatible Ti alloys is the opportunity to decrease the modulus of Ti alloys by adding elements .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [40, 46]}, {"entity": "biocompatible Ti alloys", "entity_type": "material", "pos": [50, 73]}, {"entity": "Ti alloys", "entity_type": "material", "pos": [120, 129]}, {"entity": "elements", "entity_type": "material", "pos": [140, 148]}], "task": "NER"}
{"text": "As mentioned above , the elements should be biocompatible .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "elements", "entity_type": "material", "pos": [25, 33]}, {"entity": "be", "entity_type": "material", "pos": [41, 43]}], "task": "NER"}
{"text": "Various Ti alloys composed of low modulus biocompatible elements were developed .", "entity": [{"entity": "Ti alloys", "entity_type": "material", "pos": [8, 17]}, {"entity": "biocompatible elements", "entity_type": "engineering feature", "pos": [42, 64]}], "task": "NER"}
{"text": "These alloys exhibited lower modulus than the commonly used Ti6Al4V .", "entity": [{"entity": "alloys", "entity_type": "material", "pos": [6, 12]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [60, 67]}], "task": "NER"}
{"text": "One example is Ti13Nb13Zr , which showed improved bone biocompatibility and a modulus of 79 GPa .", "entity": [{"entity": "Ti13Nb13Zr", "entity_type": "material", "pos": [15, 25]}, {"entity": "bone", "entity_type": "biomedical", "pos": [50, 54]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [55, 71]}, {"entity": "GPa", "entity_type": "machanical property", "pos": [92, 95]}], "task": "NER"}
{"text": "Other Ti alloys which exhibited lower modulus included Ti29Nb13Ta4.6Zr and Ti35Nb5Ta7Zr .", "entity": [{"entity": "Ti alloys", "entity_type": "material", "pos": [6, 15]}, {"entity": "Ti35Nb5Ta7Zr", "entity_type": "material", "pos": [75, 87]}], "task": "NER"}
{"text": "In recent years , AM produced porous Ti alloy scaffolds were widely reported with Ti6Al4V in dominance , such as the Ti6Al4V implants in sheep cervical spine in 5 .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [18, 20]}, {"entity": "porous Ti alloy scaffolds", "entity_type": "engineering feature", "pos": [30, 55]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [82, 89]}, {"entity": "as", "entity_type": "material", "pos": [110, 112]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [117, 124]}, {"entity": "implants", "entity_type": "application", "pos": [125, 133]}, {"entity": "cervical spine", "entity_type": "biomedical", "pos": [143, 157]}], "task": "NER"}
{"text": "Ryan combined the multi-stage AM technology with the powder metallurgy process to produce porous Ti alloy scaffolds using wax templates generated by CAD .", "entity": [{"entity": "AM technology", "entity_type": "manufacturing process", "pos": [30, 43]}, {"entity": "powder metallurgy", "entity_type": "manufacturing process", "pos": [53, 70]}, {"entity": "porous Ti alloy scaffolds", "entity_type": "engineering feature", "pos": [90, 115]}, {"entity": "wax", "entity_type": "material", "pos": [122, 125]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [149, 152]}], "task": "NER"}
{"text": "The pore size of their designs ranged from 200 to 400 and the porosity reached 66.8 % .", "entity": [{"entity": "pore size", "entity_type": "process parameter", "pos": [4, 13]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [23, 30]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [62, 70]}], "task": "NER"}
{"text": "This method could achieve controlled porous structure and ensure high resolution in manufacturing .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [37, 43]}, {"entity": "high resolution", "entity_type": "process parameter", "pos": [65, 80]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [84, 97]}], "task": "NER"}
{"text": "The resulting microstructure and surface roughness were similar to parts manufactured by conventional methods .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [14, 28]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [33, 50]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [73, 85]}], "task": "NER"}
{"text": "This method could also be extended to the fabrication of other metallic structures which are difficult to be directly made by AM .", "entity": [{"entity": "be", "entity_type": "material", "pos": [23, 25]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [42, 53]}, {"entity": "metallic structures", "entity_type": "machine or equipment", "pos": [63, 82]}, {"entity": "be", "entity_type": "material", "pos": [106, 108]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [126, 128]}], "task": "NER"}
{"text": "Murr manufactured different porous Ti6Al4V implants using AM based on micro-CT scan and CAD models built by Materialise software .", "entity": [{"entity": "manufactured", "entity_type": "concept or principle", "pos": [5, 17]}, {"entity": "porous", "entity_type": "machanical property", "pos": [28, 34]}, {"entity": "implants", "entity_type": "application", "pos": [43, 51]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [58, 60]}, {"entity": "micro-CT scan", "entity_type": "process characterization", "pos": [70, 83]}, {"entity": "CAD models", "entity_type": "enabling technology", "pos": [88, 98]}, {"entity": "software", "entity_type": "concept or principle", "pos": [120, 128]}], "task": "NER"}
{"text": "They studied the influence of geometric features of unit cells on the mechanical properties of the porous structures and found that when the porosity changed from 59 % to 88 % , the elastic modulus decreased from 3.03 to 0.58 GPa , which proved that the elastic modulus of porous metals could be readily adjusted through the porosity .", "entity": [{"entity": "unit cells", "entity_type": "concept or principle", "pos": [52, 62]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [70, 91]}, {"entity": "porous", "entity_type": "machanical property", "pos": [99, 105]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [141, 149]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [182, 197]}, {"entity": "GPa", "entity_type": "machanical property", "pos": [226, 229]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [254, 269]}, {"entity": "porous metals", "entity_type": "material", "pos": [273, 286]}, {"entity": "be", "entity_type": "material", "pos": [293, 295]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [325, 333]}], "task": "NER"}
{"text": "Similarly Pattanyak studied porous Ti implants based on micro-CT scan on human cancellous bones , which focused on structures with complicated internal structures for bone ingrowth applications .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [28, 34]}, {"entity": "implants", "entity_type": "application", "pos": [38, 46]}, {"entity": "micro-CT scan", "entity_type": "process characterization", "pos": [56, 69]}, {"entity": "cancellous bones", "entity_type": "biomedical", "pos": [79, 95]}, {"entity": "internal structures", "entity_type": "machanical property", "pos": [143, 162]}, {"entity": "bone ingrowth applications", "entity_type": "application", "pos": [167, 193]}], "task": "NER"}
{"text": "The implants were manufactured via SLM using Ti powder of less than 45 in size .", "entity": [{"entity": "implants", "entity_type": "application", "pos": [4, 12]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [18, 30]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [35, 38]}, {"entity": "Ti powder", "entity_type": "material", "pos": [45, 54]}], "task": "NER"}
{"text": "They found that the compressive strength decreased from 120 to 35 MPa when the porosity changed from 55 % to 75 % .", "entity": [{"entity": "compressive strength", "entity_type": "machanical property", "pos": [20, 40]}, {"entity": "MPa", "entity_type": "concept or principle", "pos": [66, 69]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [79, 87]}], "task": "NER"}
{"text": "Hollander produced a variety of Ti6Al4V implants , ranging from porous cylinder to solid human vertebra model with irregular shapes .", "entity": [{"entity": "Ti6Al4V", "entity_type": "material", "pos": [32, 39]}, {"entity": "implants", "entity_type": "application", "pos": [40, 48]}, {"entity": "porous", "entity_type": "machanical property", "pos": [64, 70]}, {"entity": "model", "entity_type": "concept or principle", "pos": [104, 109]}], "task": "NER"}
{"text": "Porous Ti6Al4V structures were shown to be effective in supporting cell growth and new bone tissue growth , and cell based study suggested that Ti6Al4V possesses high cyto-biocompatibility .", "entity": [{"entity": "Porous Ti6Al4V structures", "entity_type": "material", "pos": [0, 25]}, {"entity": "be", "entity_type": "material", "pos": [40, 42]}, {"entity": "cell growth", "entity_type": "process characterization", "pos": [67, 78]}, {"entity": "bone tissue growth", "entity_type": "concept or principle", "pos": [87, 105]}, {"entity": "cell based study", "entity_type": "concept or principle", "pos": [112, 128]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [144, 151]}, {"entity": "cyto-biocompatibility", "entity_type": "machanical property", "pos": [167, 188]}], "task": "NER"}
{"text": "In vitro studies were performed with porous Ti6Al4V structures .", "entity": [{"entity": "porous Ti6Al4V structures", "entity_type": "material", "pos": [37, 62]}], "task": "NER"}
{"text": "Cell spreading and proliferation were observed across the entire surface and inside the porous structure .", "entity": [{"entity": "Cell", "entity_type": "application", "pos": [0, 4]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [65, 72]}, {"entity": "porous", "entity_type": "machanical property", "pos": [88, 94]}], "task": "NER"}
{"text": "Porous Ti6Al4V scaffolds were found performing well in animal models since induced new bone growth and osseointegration were achieved on both bare and surface-coated porous Ti6Al4V structures .", "entity": [{"entity": "Porous", "entity_type": "machanical property", "pos": [0, 6]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [15, 24]}, {"entity": "bone growth", "entity_type": "concept or principle", "pos": [87, 98]}, {"entity": "osseointegration", "entity_type": "machanical property", "pos": [103, 119]}, {"entity": "surface-coated porous Ti6Al4V structures", "entity_type": "material", "pos": [151, 191]}], "task": "NER"}
{"text": "Although porous Ti6Al4V had been widely studied , the potential release of toxic ions led researchers towards looking for safer alternative alloys .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [9, 15]}, {"entity": "led", "entity_type": "application", "pos": [86, 89]}, {"entity": "alloys", "entity_type": "material", "pos": [140, 146]}], "task": "NER"}
{"text": "Therefore , Ti alloys such as Ti24Nb4Zr8Sn , Ti7.5Mo and Ti40Nb were designed and fabricated by AM , which exhibited comparable mechanical properties to their counterparts by conventional manufacturing approaches .", "entity": [{"entity": "Ti alloys", "entity_type": "material", "pos": [12, 21]}, {"entity": "as", "entity_type": "material", "pos": [27, 29]}, {"entity": "Ti40Nb", "entity_type": "material", "pos": [57, 63]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [69, 77]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [82, 92]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [96, 98]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [128, 149]}, {"entity": "conventional manufacturing", "entity_type": "manufacturing process", "pos": [175, 201]}], "task": "NER"}
{"text": "There was significant research interest in using topology optimization for the design of porous Ti alloy scaffolds .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [22, 30]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [49, 70]}, {"entity": "design", "entity_type": "engineering feature", "pos": [79, 85]}, {"entity": "porous Ti alloy scaffolds", "entity_type": "engineering feature", "pos": [89, 114]}], "task": "NER"}
{"text": "While early works mainly focused on the theoretical consideration of the structural design of the unit cells , recent efforts put more emphasis on integrating topology optimization with AM , e.g .", "entity": [{"entity": "theoretical", "entity_type": "concept or principle", "pos": [40, 51]}, {"entity": "structural design", "entity_type": "engineering feature", "pos": [73, 90]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [98, 108]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [159, 180]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [186, 188]}], "task": "NER"}
{"text": "Refs.. 4.2 Shape memory alloys Shape Memory Alloys are capable of regaining their original shape after severe deformations when stimulated by external environments .", "entity": [{"entity": "Shape memory alloys", "entity_type": "material", "pos": [11, 30]}, {"entity": "Alloys", "entity_type": "material", "pos": [44, 50]}, {"entity": "deformations", "entity_type": "concept or principle", "pos": [110, 122]}], "task": "NER"}
{"text": "Due to this unique property , SMAs have found their way in orthopaedic implant applications .", "entity": [{"entity": "property", "entity_type": "concept or principle", "pos": [19, 27]}, {"entity": "SMAs", "entity_type": "material", "pos": [30, 34]}, {"entity": "orthopaedic implant", "entity_type": "application", "pos": [59, 78]}], "task": "NER"}
{"text": "Typical SMAs include NiTi or nitinol which normally contains approximately 50 at % Ni and 50 at % Ti .", "entity": [{"entity": "SMAs", "entity_type": "material", "pos": [8, 12]}, {"entity": "NiTi", "entity_type": "material", "pos": [21, 25]}, {"entity": "nitinol", "entity_type": "material", "pos": [29, 36]}, {"entity": "Ni", "entity_type": "material", "pos": [83, 85]}, {"entity": "Ti", "entity_type": "material", "pos": [98, 100]}], "task": "NER"}
{"text": "The shape memory effect in NiTi comes from the austenite/martensite phase transformation since martensite is a low temperature stable phase with the absence of stress whereas austenite is a high temperature stable phase .", "entity": [{"entity": "shape memory effect", "entity_type": "machanical property", "pos": [4, 23]}, {"entity": "NiTi", "entity_type": "material", "pos": [27, 31]}, {"entity": "austenite/martensite phase transformation", "entity_type": "material", "pos": [47, 88]}, {"entity": "martensite", "entity_type": "material", "pos": [95, 105]}, {"entity": "temperature stable phase", "entity_type": "machanical property", "pos": [115, 139]}, {"entity": "stress", "entity_type": "machanical property", "pos": [160, 166]}, {"entity": "austenite", "entity_type": "material", "pos": [175, 184]}, {"entity": "temperature stable phase", "entity_type": "machanical property", "pos": [195, 219]}], "task": "NER"}
{"text": "Currently , more than 90 % of all commercial SMAs are based on NiTi and its ternary alloys - NiTiCu and NiTiNb .", "entity": [{"entity": "SMAs", "entity_type": "material", "pos": [45, 49]}, {"entity": "NiTi", "entity_type": "material", "pos": [63, 67]}, {"entity": "ternary alloys", "entity_type": "material", "pos": [76, 90]}, {"entity": "NiTiNb", "entity_type": "material", "pos": [104, 110]}], "task": "NER"}
{"text": "Solid NiTi has a modulus of 48 GPa , which is much lower than other Ti alloys .", "entity": [{"entity": "NiTi", "entity_type": "material", "pos": [6, 10]}, {"entity": "GPa", "entity_type": "machanical property", "pos": [31, 34]}, {"entity": "Ti alloys", "entity_type": "material", "pos": [68, 77]}], "task": "NER"}
{"text": "Furthermore , NiTi allows for relatively large reversible deformation of up to 8 % .", "entity": [{"entity": "NiTi", "entity_type": "material", "pos": [14, 18]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [58, 69]}], "task": "NER"}
{"text": "NiTi has higher stiffness than bone under tendon , and is able to deform over a large strain range at an almost constant stress .", "entity": [{"entity": "NiTi", "entity_type": "material", "pos": [0, 4]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [16, 25]}, {"entity": "bone", "entity_type": "biomedical", "pos": [31, 35]}, {"entity": "tendon", "entity_type": "biomedical", "pos": [42, 48]}, {"entity": "strain", "entity_type": "machanical property", "pos": [86, 92]}, {"entity": "range", "entity_type": "process parameter", "pos": [93, 98]}, {"entity": "stress", "entity_type": "machanical property", "pos": [121, 127]}], "task": "NER"}
{"text": "Due to these characteristics , NiTi has been widely used in medical devices , such as surgical tools , stents , orthodontic wires , plates and staples for bone fractures .", "entity": [{"entity": "NiTi", "entity_type": "material", "pos": [31, 35]}, {"entity": "medical devices", "entity_type": "application", "pos": [60, 75]}, {"entity": "as", "entity_type": "material", "pos": [83, 85]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [95, 100]}, {"entity": "stents", "entity_type": "machine or equipment", "pos": [103, 109]}, {"entity": "orthodontic", "entity_type": "application", "pos": [112, 123]}, {"entity": "bone fractures", "entity_type": "biomedical", "pos": [155, 169]}], "task": "NER"}
{"text": "Main attractive features of SMAs are : capability to recover the original shape after large deformation , capability to recover the original shape from a stable deformed shape when heated and a high damping capacity .", "entity": [{"entity": "SMAs", "entity_type": "material", "pos": [28, 32]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [92, 103]}, {"entity": "deformed shape", "entity_type": "machanical property", "pos": [161, 175]}, {"entity": "capacity", "entity_type": "concept or principle", "pos": [207, 215]}], "task": "NER"}
{"text": "For biomedical applications , the presence of Ni in NiTi has been a continuous concern since Ni is one of the highest sensitivities in metallic allergy tests .", "entity": [{"entity": "biomedical applications", "entity_type": "application", "pos": [4, 27]}, {"entity": "Ni", "entity_type": "material", "pos": [46, 48]}, {"entity": "NiTi", "entity_type": "material", "pos": [52, 56]}, {"entity": "Ni", "entity_type": "material", "pos": [93, 95]}, {"entity": "sensitivities", "entity_type": "process parameter", "pos": [118, 131]}, {"entity": "metallic", "entity_type": "material", "pos": [135, 143]}], "task": "NER"}
{"text": "Therefore , attempts were made either to develop surface modification techniques or to use substitution elements to mitigate this effect without sacrificing the biocompatibility .", "entity": [{"entity": "surface modification", "entity_type": "manufacturing process", "pos": [49, 69]}, {"entity": "elements", "entity_type": "material", "pos": [104, 112]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [161, 177]}], "task": "NER"}
{"text": "For example , TiNb and the related TiNbX system were developed which exhibited elastic strains as high as 4.2 % .", "entity": [{"entity": "TiNb", "entity_type": "material", "pos": [14, 18]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [79, 86]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}, {"entity": "as", "entity_type": "material", "pos": [103, 105]}], "task": "NER"}
{"text": "Common methods for making porous NiTi structures are based on powder metallurgy and self-propagating high temperature synthesis of a mixture of elemental powders or pre-alloyed NiTi powder with space holding materials .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [26, 32]}, {"entity": "NiTi", "entity_type": "material", "pos": [33, 37]}, {"entity": "powder metallurgy", "entity_type": "manufacturing process", "pos": [62, 79]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [106, 117]}, {"entity": "powders", "entity_type": "material", "pos": [154, 161]}, {"entity": "NiTi", "entity_type": "material", "pos": [177, 181]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [208, 217]}], "task": "NER"}
{"text": "After removing space holding materials at relatively low temperature , the structures are further sintered at high temperature .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [29, 38]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [57, 68]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [98, 106]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [115, 126]}], "task": "NER"}
{"text": "Due to high reactivity of Ti and Ni , the sintering of porous structures is normally done in high vacuum .", "entity": [{"entity": "Ti", "entity_type": "material", "pos": [26, 28]}, {"entity": "Ni", "entity_type": "material", "pos": [33, 35]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [42, 51]}, {"entity": "porous", "entity_type": "machanical property", "pos": [55, 61]}], "task": "NER"}
{"text": "However , these methods have difficulties in precisely controlling the porous structures of NiTi , i.e. , pore size and pore shape .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [71, 77]}, {"entity": "NiTi", "entity_type": "material", "pos": [92, 96]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [106, 115]}, {"entity": "pore", "entity_type": "machanical property", "pos": [120, 124]}], "task": "NER"}
{"text": "To overcome this problem , AM technologies such as SLM have been used to produce NiTi implants .", "entity": [{"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [27, 42]}, {"entity": "as", "entity_type": "material", "pos": [48, 50]}, {"entity": "NiTi", "entity_type": "material", "pos": [81, 85]}, {"entity": "implants", "entity_type": "application", "pos": [86, 94]}], "task": "NER"}
{"text": "It was shown that AM produced NiTi parts exhibited similar mechanical properties as those fabricated by conventional methods such as casting .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [18, 20]}, {"entity": "NiTi", "entity_type": "material", "pos": [30, 34]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [59, 80]}, {"entity": "as", "entity_type": "material", "pos": [81, 83]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [90, 100]}, {"entity": "as", "entity_type": "material", "pos": [130, 132]}], "task": "NER"}
{"text": "In contrary to the substantial research on Ti alloys , no reports on the application of topology optimization in the design of SMA scaffolds involving AM fabrication can be found in the literature up to date .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [31, 39]}, {"entity": "Ti alloys", "entity_type": "material", "pos": [43, 52]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [88, 109]}, {"entity": "design", "entity_type": "engineering feature", "pos": [117, 123]}, {"entity": "SMA scaffolds", "entity_type": "biomedical", "pos": [127, 140]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [151, 153]}, {"entity": "be", "entity_type": "material", "pos": [170, 172]}], "task": "NER"}
{"text": "4.3 Biodegradable metals Biodegradable materials , including both polymer-based and metal-based ones , are used for some medical implants which will gradually degrade in human body over a period of time .", "entity": [{"entity": "Biodegradable metals", "entity_type": "material", "pos": [4, 24]}, {"entity": "Biodegradable materials", "entity_type": "machanical property", "pos": [25, 48]}, {"entity": "medical implants", "entity_type": "application", "pos": [121, 137]}], "task": "NER"}
{"text": "In some clinical cases , biomaterials are only needed temporarily in the body and are expected to support the healing process and to disappear after the healing process is completed .", "entity": [{"entity": "biomaterials", "entity_type": "material", "pos": [25, 37]}, {"entity": "support", "entity_type": "application", "pos": [98, 105]}, {"entity": "process", "entity_type": "concept or principle", "pos": [118, 125]}, {"entity": "process", "entity_type": "concept or principle", "pos": [161, 168]}], "task": "NER"}
{"text": "5 shows a biodegradable Mg stent after expansion .", "entity": [{"entity": "biodegradable Mg stent", "entity_type": "material", "pos": [10, 32]}], "task": "NER"}
{"text": "Compared to polymer-based materials , biodegradable metals have higher stiffness and strength , and are more suitable for load bearing conditions .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [26, 35]}, {"entity": "biodegradable metals", "entity_type": "material", "pos": [38, 58]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [71, 80]}, {"entity": "strength", "entity_type": "machanical property", "pos": [85, 93]}], "task": "NER"}
{"text": "As the degradable alloys are expected to degrade inside human body , the main compositions of the alloys should be metallic elements that can be metabolized , and demonstrate appropriate degradation rates in the human body .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "degradable alloys", "entity_type": "application", "pos": [7, 24]}, {"entity": "alloys", "entity_type": "material", "pos": [98, 104]}, {"entity": "be", "entity_type": "material", "pos": [112, 114]}, {"entity": "elements", "entity_type": "material", "pos": [124, 132]}, {"entity": "be", "entity_type": "material", "pos": [142, 144]}, {"entity": "degradation rates", "entity_type": "process characterization", "pos": [187, 204]}], "task": "NER"}
{"text": "Due to its unique characteristics , Mg alloys were used to manufacture cardiovascular stents and bone screws .", "entity": [{"entity": "Mg alloys", "entity_type": "material", "pos": [36, 45]}, {"entity": "manufacture", "entity_type": "concept or principle", "pos": [59, 70]}, {"entity": "cardiovascular stents", "entity_type": "machine or equipment", "pos": [71, 92]}, {"entity": "bone screws", "entity_type": "machine or equipment", "pos": [97, 108]}], "task": "NER"}
{"text": "The degradable magnesium alloy bone screws were found clinically equivalent to the conventional Ti screws ; and no foreign body reaction , osteolysis , or systemic inflammatory reaction were observed for the Mg alloy screws .", "entity": [{"entity": "magnesium alloy", "entity_type": "material", "pos": [15, 30]}, {"entity": "bone screws", "entity_type": "machine or equipment", "pos": [31, 42]}, {"entity": "Ti", "entity_type": "material", "pos": [96, 98]}, {"entity": "osteolysis", "entity_type": "biomedical", "pos": [139, 149]}, {"entity": "Mg alloy", "entity_type": "material", "pos": [208, 216]}], "task": "NER"}
{"text": "A key parameter that needs to be considered in designing a biodegradable metallic implant is its degradation rate in human body .", "entity": [{"entity": "parameter", "entity_type": "concept or principle", "pos": [6, 15]}, {"entity": "be", "entity_type": "material", "pos": [30, 32]}, {"entity": "biodegradable metallic implant", "entity_type": "application", "pos": [59, 89]}, {"entity": "degradation rate", "entity_type": "process characterization", "pos": [97, 113]}], "task": "NER"}
{"text": "Pure Mg is known to have a fast degradation in high chloride physiological environment but it may produce hydrogen gas at a high rate from corrosion , which can not be dealt with by the host tissue .", "entity": [{"entity": "Pure Mg", "entity_type": "material", "pos": [0, 7]}, {"entity": "degradation", "entity_type": "concept or principle", "pos": [32, 43]}, {"entity": "gas", "entity_type": "concept or principle", "pos": [115, 118]}, {"entity": "corrosion", "entity_type": "concept or principle", "pos": [139, 148]}, {"entity": "be", "entity_type": "material", "pos": [165, 167]}], "task": "NER"}
{"text": "Fe-based biodegradable materials are known to exhibit a slow degradation rate .", "entity": [{"entity": "biodegradable materials", "entity_type": "machanical property", "pos": [9, 32]}, {"entity": "degradation rate", "entity_type": "process characterization", "pos": [61, 77]}], "task": "NER"}
{"text": "Animal tests showed that large portions of the pure Fe stent remained intact in the blood vessels 12 months post-surgery .", "entity": [{"entity": "Fe", "entity_type": "material", "pos": [52, 54]}, {"entity": "blood vessels", "entity_type": "biomedical", "pos": [84, 97]}], "task": "NER"}
{"text": "Alloying is a typical method to adjust the degradation rate of a metal .", "entity": [{"entity": "Alloying", "entity_type": "engineering feature", "pos": [0, 8]}, {"entity": "degradation rate", "entity_type": "process characterization", "pos": [43, 59]}, {"entity": "metal", "entity_type": "material", "pos": [65, 70]}], "task": "NER"}
{"text": "For instance , by adding elements such as Y , Sr , Zn , Zr and Ca , Mg alloys were shown to have much lower degradation rates in comparison with pure Mg .", "entity": [{"entity": "elements", "entity_type": "material", "pos": [25, 33]}, {"entity": "as", "entity_type": "material", "pos": [39, 41]}, {"entity": "Sr", "entity_type": "material", "pos": [46, 48]}, {"entity": "Zn", "entity_type": "material", "pos": [51, 53]}, {"entity": "Zr", "entity_type": "material", "pos": [56, 58]}, {"entity": "Ca", "entity_type": "material", "pos": [63, 65]}, {"entity": "Mg alloys", "entity_type": "material", "pos": [68, 77]}, {"entity": "degradation rates", "entity_type": "process characterization", "pos": [108, 125]}, {"entity": "pure Mg", "entity_type": "material", "pos": [145, 152]}], "task": "NER"}
{"text": "Such alloys also exhibited high strength , which is desirable for load-bearing applications .", "entity": [{"entity": "alloys", "entity_type": "material", "pos": [5, 11]}, {"entity": "strength", "entity_type": "machanical property", "pos": [32, 40]}, {"entity": "load-bearing", "entity_type": "engineering feature", "pos": [66, 78]}], "task": "NER"}
{"text": "In addition to alloying , amorphous structures like metallic glass alloys MgZnCa showed low degradation rate and high strength .", "entity": [{"entity": "alloying", "entity_type": "engineering feature", "pos": [15, 23]}, {"entity": "amorphous structures", "entity_type": "concept or principle", "pos": [26, 46]}, {"entity": "metallic glass alloys MgZnCa", "entity_type": "material", "pos": [52, 80]}, {"entity": "degradation rate", "entity_type": "process characterization", "pos": [92, 108]}, {"entity": "strength", "entity_type": "machanical property", "pos": [118, 126]}], "task": "NER"}
{"text": "However , metallic glass alloys are generally difficult to manufacture , which would add the cost to the application of this type of material .", "entity": [{"entity": "metallic glass", "entity_type": "material", "pos": [10, 24]}, {"entity": "alloys", "entity_type": "material", "pos": [25, 31]}, {"entity": "manufacture", "entity_type": "concept or principle", "pos": [59, 70]}, {"entity": "material", "entity_type": "material", "pos": [133, 141]}], "task": "NER"}
{"text": "Porous Mg alloy implants were investigated as temporary bone replacements in an animal model .", "entity": [{"entity": "Porous", "entity_type": "machanical property", "pos": [0, 6]}, {"entity": "Mg alloy", "entity_type": "material", "pos": [7, 15]}, {"entity": "implants", "entity_type": "application", "pos": [16, 24]}, {"entity": "as", "entity_type": "material", "pos": [43, 45]}, {"entity": "bone", "entity_type": "biomedical", "pos": [56, 60]}, {"entity": "model", "entity_type": "concept or principle", "pos": [87, 92]}], "task": "NER"}
{"text": "They were shown to be able to enhance bone remodelling and appropriate host response .", "entity": [{"entity": "be", "entity_type": "material", "pos": [19, 21]}, {"entity": "bone remodelling", "entity_type": "concept or principle", "pos": [38, 54]}], "task": "NER"}
{"text": "However , porous Mg alloys degrade too rapidly in vivo , which may leave subcutaneous gas cavities .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [10, 16]}, {"entity": "Mg alloys", "entity_type": "material", "pos": [17, 26]}, {"entity": "subcutaneous", "entity_type": "biomedical", "pos": [73, 85]}, {"entity": "gas", "entity_type": "concept or principle", "pos": [86, 89]}], "task": "NER"}
{"text": "Since an open porous implant has large surface area , only alloys with slow degradation rate should be considered for making the porous structure , e.g .", "entity": [{"entity": "porous implant", "entity_type": "application", "pos": [14, 28]}, {"entity": "surface area", "entity_type": "process parameter", "pos": [39, 51]}, {"entity": "alloys", "entity_type": "material", "pos": [59, 65]}, {"entity": "degradation rate", "entity_type": "process characterization", "pos": [76, 92]}, {"entity": "be", "entity_type": "material", "pos": [100, 102]}, {"entity": "porous", "entity_type": "machanical property", "pos": [129, 135]}], "task": "NER"}
{"text": "Mg-4 wt. % Y .", "entity": [{"entity": "Y", "entity_type": "material", "pos": [11, 12]}], "task": "NER"}
{"text": "The element yttrium helps promote grain refinement , thus resulting in a slow degradation and sufficient cyto-compatibility .", "entity": [{"entity": "element", "entity_type": "material", "pos": [4, 11]}, {"entity": "grain refinement", "entity_type": "process characterization", "pos": [34, 50]}, {"entity": "degradation", "entity_type": "concept or principle", "pos": [78, 89]}, {"entity": "cyto-compatibility", "entity_type": "machanical property", "pos": [105, 123]}], "task": "NER"}
{"text": "Nguyen manufactured porous Mg alloys using SLM and suggested that the dimension , surface morphology and the oxygen pick-up of the laser-melted Mg were strongly dependent on the laser processing parameters .", "entity": [{"entity": "manufactured", "entity_type": "concept or principle", "pos": [7, 19]}, {"entity": "Mg alloys", "entity_type": "material", "pos": [27, 36]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [43, 46]}, {"entity": "dimension", "entity_type": "engineering feature", "pos": [70, 79]}, {"entity": "surface morphology", "entity_type": "process characterization", "pos": [82, 100]}, {"entity": "oxygen", "entity_type": "material", "pos": [109, 115]}, {"entity": "Mg", "entity_type": "material", "pos": [144, 146]}, {"entity": "laser processing", "entity_type": "concept or principle", "pos": [178, 194]}], "task": "NER"}
{"text": "Due to the high evaporation rate at elevated temperatures , few attempts were made to fabricate Mg scaffolds directly using AM .", "entity": [{"entity": "evaporation rate", "entity_type": "process characterization", "pos": [16, 32]}, {"entity": "temperatures", "entity_type": "process parameter", "pos": [45, 57]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [86, 95]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [99, 108]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [124, 126]}], "task": "NER"}
{"text": "Instead , a technique combining 3D printing and gravity casting was shown to be effective in producing topologically-ordered porous Mg structures , where a porous NaCl mould was created using SLM and then Mg alloy was cast into the mould .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [32, 43]}, {"entity": "casting", "entity_type": "manufacturing process", "pos": [56, 63]}, {"entity": "be", "entity_type": "material", "pos": [77, 79]}, {"entity": "porous", "entity_type": "machanical property", "pos": [125, 131]}, {"entity": "Mg", "entity_type": "material", "pos": [132, 134]}, {"entity": "porous", "entity_type": "machanical property", "pos": [156, 162]}, {"entity": "NaCl", "entity_type": "material", "pos": [163, 167]}, {"entity": "mould", "entity_type": "machine or equipment", "pos": [168, 173]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [192, 195]}, {"entity": "Mg alloy", "entity_type": "material", "pos": [205, 213]}, {"entity": "cast", "entity_type": "manufacturing process", "pos": [218, 222]}, {"entity": "mould", "entity_type": "machine or equipment", "pos": [232, 237]}], "task": "NER"}
{"text": "After removing the NaCl , porous Mg structure with porosity of 41 % and pore size of 1 mm was obtained .", "entity": [{"entity": "NaCl", "entity_type": "material", "pos": [19, 23]}, {"entity": "porous", "entity_type": "machanical property", "pos": [26, 32]}, {"entity": "Mg", "entity_type": "material", "pos": [33, 35]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [51, 59]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [72, 81]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [87, 89]}], "task": "NER"}
{"text": "The compressive strength of the porous Mg was reported to be 13 MPa , which is comparable to porous Mg produced by powder metallurgy .", "entity": [{"entity": "compressive strength", "entity_type": "machanical property", "pos": [4, 24]}, {"entity": "porous", "entity_type": "machanical property", "pos": [32, 38]}, {"entity": "Mg", "entity_type": "material", "pos": [39, 41]}, {"entity": "be", "entity_type": "material", "pos": [58, 60]}, {"entity": "MPa", "entity_type": "concept or principle", "pos": [64, 67]}, {"entity": "porous", "entity_type": "machanical property", "pos": [93, 99]}, {"entity": "Mg", "entity_type": "material", "pos": [100, 102]}, {"entity": "powder metallurgy", "entity_type": "manufacturing process", "pos": [115, 132]}], "task": "NER"}
{"text": "A review on porous biodegradable metals for hard tissue scaffolds can be found in Ref.. A theoretical study of topological design of polymeric scaffolds considering the effect of biodegradation was conducted by Chen .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [12, 18]}, {"entity": "biodegradable metals", "entity_type": "material", "pos": [19, 39]}, {"entity": "hard tissue scaffolds", "entity_type": "biomedical", "pos": [44, 65]}, {"entity": "be", "entity_type": "material", "pos": [70, 72]}, {"entity": "theoretical", "entity_type": "concept or principle", "pos": [90, 101]}, {"entity": "topological design", "entity_type": "engineering feature", "pos": [111, 129]}, {"entity": "polymeric scaffolds", "entity_type": "engineering feature", "pos": [133, 152]}], "task": "NER"}
{"text": "No reports on the application of topology optimization in the design of biodegradable metallic scaffolds involving AM fabrication have appeared in the literature so far .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [33, 54]}, {"entity": "design", "entity_type": "engineering feature", "pos": [62, 68]}, {"entity": "biodegradable metallic scaffolds", "entity_type": "biomedical", "pos": [72, 104]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [115, 117]}], "task": "NER"}
{"text": "5 Heat-treatment and surface modification of porous metallic structures produced by AM 5.1 Heat-treatment The mechanical properties of AM produced materials depend heavily on the processing parameters , including building layer thickness , scan speed , energy density and focal offset distance .", "entity": [{"entity": "surface modification", "entity_type": "manufacturing process", "pos": [21, 41]}, {"entity": "porous metallic structures", "entity_type": "engineering feature", "pos": [45, 71]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [84, 86]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [110, 131]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [135, 137]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [147, 156]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [190, 200]}, {"entity": "building layer thickness", "entity_type": "process parameter", "pos": [213, 237]}, {"entity": "scan speed", "entity_type": "process parameter", "pos": [240, 250]}, {"entity": "energy density", "entity_type": "process parameter", "pos": [253, 267]}, {"entity": "focal offset distance", "entity_type": "process parameter", "pos": [272, 293]}], "task": "NER"}
{"text": "Usually AM produced materials have relatively high yield stress and ultimate tensile strength , but a relatively low ductility .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [8, 10]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [20, 29]}, {"entity": "yield stress", "entity_type": "machanical property", "pos": [51, 63]}, {"entity": "ultimate tensile strength", "entity_type": "machanical property", "pos": [68, 93]}, {"entity": "ductility", "entity_type": "machanical property", "pos": [117, 126]}], "task": "NER"}
{"text": "In order to improve the mechanical properties of AM produced porous biomaterials so that they can mimic the human tissues and fulfil the desired functions , post-treatment is of critical importance .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [24, 45]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [49, 51]}, {"entity": "porous", "entity_type": "machanical property", "pos": [61, 67]}, {"entity": "biomaterials", "entity_type": "material", "pos": [68, 80]}, {"entity": "mimic", "entity_type": "machine or equipment", "pos": [98, 103]}, {"entity": "post-treatment", "entity_type": "manufacturing process", "pos": [157, 171]}], "task": "NER"}
{"text": "It is known that the microstructures of aB-built materials by AM are very different from those by traditional casting or forging approaches .", "entity": [{"entity": "microstructures", "entity_type": "material", "pos": [21, 36]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [49, 58]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [62, 64]}, {"entity": "casting", "entity_type": "manufacturing process", "pos": [110, 117]}, {"entity": "forging", "entity_type": "manufacturing process", "pos": [121, 128]}], "task": "NER"}
{"text": "AM is a layer-wise build-up process with high cooling rates that lead to significant internal thermal stresses in the structure .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "process", "entity_type": "concept or principle", "pos": [28, 35]}, {"entity": "cooling rates", "entity_type": "process parameter", "pos": [46, 59]}, {"entity": "lead", "entity_type": "material", "pos": [65, 69]}, {"entity": "thermal stresses", "entity_type": "machanical property", "pos": [94, 110]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [118, 127]}], "task": "NER"}
{"text": "During the building process , the scanning by either a laser or an electron beam may cause the instabilities of the melt pool , resulting in increased porosity and high surface roughness .", "entity": [{"entity": "building process", "entity_type": "process characterization", "pos": [11, 27]}, {"entity": "scanning", "entity_type": "concept or principle", "pos": [34, 42]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [55, 60]}, {"entity": "electron beam", "entity_type": "concept or principle", "pos": [67, 80]}, {"entity": "melt pool", "entity_type": "material", "pos": [116, 125]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [151, 159]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [169, 186]}], "task": "NER"}
{"text": "The post-treatment process also enables the reduction of thermal stresses in AM produced structures .", "entity": [{"entity": "post-treatment", "entity_type": "manufacturing process", "pos": [4, 18]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [44, 53]}, {"entity": "thermal stresses", "entity_type": "machanical property", "pos": [57, 73]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [77, 79]}], "task": "NER"}
{"text": "For Ti6Al4V , post heat-treatment is typically performed within the + region , which can control the morphology and size of the without significantly influencing the prior-grain size .", "entity": [{"entity": "Ti6Al4V", "entity_type": "material", "pos": [4, 11]}, {"entity": "post heat-treatment", "entity_type": "manufacturing process", "pos": [14, 33]}, {"entity": "morphology", "entity_type": "concept or principle", "pos": [101, 111]}], "task": "NER"}
{"text": "A proper heat-treatment process may substantially improve the mechanical properties of AM produced materials .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [24, 31]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [62, 83]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [87, 89]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [99, 108]}], "task": "NER"}
{"text": "Thone observed significant improvement in ductility and fatigue strength after heat-treatment of SLM produced Ti6Al4V .", "entity": [{"entity": "ductility", "entity_type": "machanical property", "pos": [42, 51]}, {"entity": "fatigue strength", "entity_type": "machanical property", "pos": [56, 72]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [97, 100]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [110, 117]}], "task": "NER"}
{"text": "They revealed that the tensile strength of heat-treated Ti6Al4V slightly decreased from 1080 MPa to 945 MPa but the elongation at failure increased significantly from 1.6 % to 11.6 % , along with remarkably prolonged fatigue life of parts from 28,900 to 290,000 cycles .", "entity": [{"entity": "tensile strength", "entity_type": "machanical property", "pos": [23, 39]}, {"entity": "heat-treated", "entity_type": "manufacturing process", "pos": [43, 55]}, {"entity": "MPa", "entity_type": "concept or principle", "pos": [93, 96]}, {"entity": "MPa", "entity_type": "concept or principle", "pos": [104, 107]}, {"entity": "elongation", "entity_type": "machanical property", "pos": [116, 126]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [130, 137]}, {"entity": "fatigue life", "entity_type": "machanical property", "pos": [217, 229]}], "task": "NER"}
{"text": "The improvements in the mechanical properties after post heat-treatment are mainly due to the elimination of thermal stresses and the changes of microstructures .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [24, 45]}, {"entity": "post heat-treatment", "entity_type": "manufacturing process", "pos": [52, 71]}, {"entity": "thermal stresses", "entity_type": "machanical property", "pos": [109, 125]}, {"entity": "microstructures", "entity_type": "material", "pos": [145, 160]}], "task": "NER"}
{"text": "On the other hand , an adequate selection of AM processing variables can facilitate in-situ heat treatment .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [45, 47]}, {"entity": "in-situ heat", "entity_type": "concept or principle", "pos": [84, 96]}], "task": "NER"}
{"text": "The microstructure of Ti6Al4V made by SLM is often dominated by martensite due to rapid cooling , which can be decomposed to lamellar + structure during SLM process by tuning the processing variables .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [4, 18]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [22, 29]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [38, 41]}, {"entity": "martensite", "entity_type": "material", "pos": [64, 74]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [88, 95]}, {"entity": "be", "entity_type": "material", "pos": [108, 110]}, {"entity": "lamellar", "entity_type": "concept or principle", "pos": [125, 133]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [136, 145]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [153, 156]}, {"entity": "process", "entity_type": "concept or principle", "pos": [157, 164]}], "task": "NER"}
{"text": "After the optimization of processing conditions , Xu produced Ti6Al4V with comparable or better mechanical properties than forged Ti6Al4V .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [10, 22]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [62, 69]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [96, 117]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [130, 137]}], "task": "NER"}
{"text": "5.2 Surface modification Surface modification plays an important role in enhancing the biological performance of AM produced porous biomaterials , particularly bioactivity and biocompatibility .", "entity": [{"entity": "Surface modification", "entity_type": "manufacturing process", "pos": [4, 24]}, {"entity": "Surface", "entity_type": "concept or principle", "pos": [25, 32]}, {"entity": "biological performance of AM", "entity_type": "concept or principle", "pos": [87, 115]}, {"entity": "porous", "entity_type": "machanical property", "pos": [125, 131]}, {"entity": "biomaterials", "entity_type": "material", "pos": [132, 144]}, {"entity": "bioactivity", "entity_type": "machanical property", "pos": [160, 171]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [176, 192]}], "task": "NER"}
{"text": "Ti alloys are normally covered by one layer of 3nm thick native oxide , namely TiO2 , which provides excellent chemical inertness , corrosion resistance and biocompatibility .", "entity": [{"entity": "Ti alloys", "entity_type": "material", "pos": [0, 9]}, {"entity": "layer", "entity_type": "process parameter", "pos": [38, 43]}, {"entity": "oxide", "entity_type": "material", "pos": [64, 69]}, {"entity": "TiO2", "entity_type": "material", "pos": [79, 83]}, {"entity": "chemical inertness", "entity_type": "machanical property", "pos": [111, 129]}, {"entity": "corrosion resistance", "entity_type": "concept or principle", "pos": [132, 152]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [157, 173]}], "task": "NER"}
{"text": "In the human body , Ti alloy implants may experience non-specific protein adsorption and interrogation of neutrophils and macrophages , which may attract fibroblasts to an encapsulation process .", "entity": [{"entity": "Ti alloy implants", "entity_type": "application", "pos": [20, 37]}, {"entity": "adsorption", "entity_type": "concept or principle", "pos": [74, 84]}, {"entity": "neutrophils", "entity_type": "concept or principle", "pos": [106, 117]}, {"entity": "macrophages", "entity_type": "biomedical", "pos": [122, 133]}, {"entity": "fibroblasts", "entity_type": "biomedical", "pos": [154, 165]}, {"entity": "encapsulation", "entity_type": "concept or principle", "pos": [172, 185]}], "task": "NER"}
{"text": "To ensure an effective biological bond between Ti alloy implants and surrounding bones , surface modification is essential to improve the conductivity of bones or the bioactivity of titanium .", "entity": [{"entity": "Ti alloy implants", "entity_type": "application", "pos": [47, 64]}, {"entity": "surface modification", "entity_type": "manufacturing process", "pos": [89, 109]}, {"entity": "conductivity", "entity_type": "machanical property", "pos": [138, 150]}, {"entity": "bioactivity", "entity_type": "machanical property", "pos": [167, 178]}, {"entity": "titanium", "entity_type": "material", "pos": [182, 190]}], "task": "NER"}
{"text": "The surface morphology of Ti alloy implants depends on the history of material processing .", "entity": [{"entity": "surface morphology", "entity_type": "process characterization", "pos": [4, 22]}, {"entity": "Ti alloy implants", "entity_type": "application", "pos": [26, 43]}, {"entity": "material", "entity_type": "material", "pos": [70, 78]}], "task": "NER"}
{"text": "For AM produced porous Ti alloys , powders tend to become small liquid spheres when heated up by laser or electron beams .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [4, 6]}, {"entity": "porous", "entity_type": "machanical property", "pos": [16, 22]}, {"entity": "alloys", "entity_type": "material", "pos": [26, 32]}, {"entity": "powders", "entity_type": "material", "pos": [35, 42]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [97, 102]}, {"entity": "electron beams", "entity_type": "concept or principle", "pos": [106, 120]}], "task": "NER"}
{"text": "Such a effect is a complex metallurgical process that leads to a rough surface and residual powder particles .", "entity": [{"entity": "metallurgical", "entity_type": "application", "pos": [27, 40]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [71, 78]}, {"entity": "residual powder", "entity_type": "material", "pos": [83, 98]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [99, 108]}], "task": "NER"}
{"text": "These loosely connected powder particles can be removed through blasting or other post-processing methods before implantation .", "entity": [{"entity": "powder particles", "entity_type": "material", "pos": [24, 40]}, {"entity": "be", "entity_type": "material", "pos": [45, 47]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [82, 97]}, {"entity": "implantation", "entity_type": "manufacturing process", "pos": [113, 125]}], "task": "NER"}
{"text": "Surface modification or activation of Ti surface can be achieved by various techniques such as plasma spray , physical or chemical vapour deposition , ion implantation , electrochemical oxidation , acidic or alkali etching , solheat-treatment , and surface machining or grinding .", "entity": [{"entity": "Surface modification", "entity_type": "manufacturing process", "pos": [0, 20]}, {"entity": "Ti", "entity_type": "material", "pos": [38, 40]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [41, 48]}, {"entity": "be", "entity_type": "material", "pos": [53, 55]}, {"entity": "as", "entity_type": "material", "pos": [92, 94]}, {"entity": "vapour deposition", "entity_type": "process characterization", "pos": [131, 148]}, {"entity": "ion implantation", "entity_type": "concept or principle", "pos": [151, 167]}, {"entity": "electrochemical oxidation", "entity_type": "concept or principle", "pos": [170, 195]}, {"entity": "etching", "entity_type": "manufacturing process", "pos": [215, 222]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [249, 256]}, {"entity": "machining", "entity_type": "manufacturing process", "pos": [257, 266]}, {"entity": "grinding", "entity_type": "manufacturing process", "pos": [270, 278]}], "task": "NER"}
{"text": "For porous metallic structures , there are two main approaches , based on surface coating and surface corrosion .", "entity": [{"entity": "porous metallic structures", "entity_type": "engineering feature", "pos": [4, 30]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [74, 81]}, {"entity": "coating", "entity_type": "application", "pos": [82, 89]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [94, 101]}, {"entity": "corrosion", "entity_type": "concept or principle", "pos": [102, 111]}], "task": "NER"}
{"text": "A popular coating-based method is solprocess , which is a simple yet versatile method for creating oxide coatings at relatively low temperatures .", "entity": [{"entity": "simple", "entity_type": "manufacturing process", "pos": [58, 64]}, {"entity": "oxide coatings", "entity_type": "material", "pos": [99, 113]}, {"entity": "temperatures", "entity_type": "process parameter", "pos": [132, 144]}], "task": "NER"}
{"text": "For implants with a complex topology , dip coating is normally used .", "entity": [{"entity": "implants", "entity_type": "application", "pos": [4, 12]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [28, 36]}, {"entity": "dip coating", "entity_type": "manufacturing process", "pos": [39, 50]}], "task": "NER"}
{"text": "The solprocess may deposit thin inorganic coatings .", "entity": [{"entity": "coatings", "entity_type": "application", "pos": [42, 50]}], "task": "NER"}
{"text": "The chemical composition and microstructures of the coating can be better controlled by the solprocess than by other methods .", "entity": [{"entity": "chemical composition", "entity_type": "concept or principle", "pos": [4, 24]}, {"entity": "microstructures", "entity_type": "material", "pos": [29, 44]}, {"entity": "coating", "entity_type": "application", "pos": [52, 59]}, {"entity": "be", "entity_type": "material", "pos": [64, 66]}], "task": "NER"}
{"text": "Brie used solto form a bioceramic coating on porous Ti6Al7Nb implants .", "entity": [{"entity": "bioceramic coating", "entity_type": "material", "pos": [23, 41]}, {"entity": "porous", "entity_type": "machanical property", "pos": [45, 51]}, {"entity": "implants", "entity_type": "application", "pos": [61, 69]}], "task": "NER"}
{"text": "The coating uniformly covered the external and internal surfaces of the implants ; and the coated porous structures exhibited improved biocompatibility .", "entity": [{"entity": "coating", "entity_type": "application", "pos": [4, 11]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [56, 64]}, {"entity": "implants", "entity_type": "application", "pos": [72, 80]}, {"entity": "coated", "entity_type": "application", "pos": [91, 97]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [135, 151]}], "task": "NER"}
{"text": "Other methods include electrolytic deposition and plasma spray .", "entity": [{"entity": "electrolytic deposition", "entity_type": "concept or principle", "pos": [22, 45]}, {"entity": "plasma spray", "entity_type": "manufacturing process", "pos": [50, 62]}], "task": "NER"}
{"text": "ED can produce CaP coatings having a thickness of a few microns to several hundred microns , which can be controlled by applying appropriate current density and processing time .", "entity": [{"entity": "ED", "entity_type": "process characterization", "pos": [0, 2]}, {"entity": "CaP coatings", "entity_type": "material", "pos": [15, 27]}, {"entity": "be", "entity_type": "material", "pos": [103, 105]}, {"entity": "density", "entity_type": "machanical property", "pos": [149, 156]}], "task": "NER"}
{"text": "This may also assist to control the surface morphology of CaP coatings from needle-like to plate-like structures .", "entity": [{"entity": "surface morphology", "entity_type": "process characterization", "pos": [36, 54]}, {"entity": "CaP coatings", "entity_type": "material", "pos": [58, 70]}], "task": "NER"}
{"text": "Coating through ED can produce uniformly and fully covered surface , which makes it suitable for functionalizing porous structures .", "entity": [{"entity": "Coating", "entity_type": "application", "pos": [0, 7]}, {"entity": "ED", "entity_type": "process characterization", "pos": [16, 18]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [59, 66]}, {"entity": "porous", "entity_type": "machanical property", "pos": [113, 119]}], "task": "NER"}
{"text": "Chai found that the bioactivity of the CaP coated Ti6Al4V scaffold to ) was significantly improved and it was possible to produce osteoinductive for the repair of bone defects .", "entity": [{"entity": "bioactivity", "entity_type": "machanical property", "pos": [20, 31]}, {"entity": "coated", "entity_type": "application", "pos": [43, 49]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [58, 66]}, {"entity": "osteoinductive", "entity_type": "biomedical", "pos": [130, 144]}, {"entity": "bone defects", "entity_type": "biomedical", "pos": [163, 175]}], "task": "NER"}
{"text": "Corrosion-based surface treatment involves interfacial chemical reactions of structures in corrosive solution .", "entity": [{"entity": "surface treatment", "entity_type": "manufacturing process", "pos": [16, 33]}, {"entity": "interfacial chemical reactions", "entity_type": "process characterization", "pos": [43, 73]}, {"entity": "corrosive solution", "entity_type": "machanical property", "pos": [91, 109]}], "task": "NER"}
{"text": "Such chemical processes include alkali treatment , acid etching and anodization treatments .", "entity": [{"entity": "processes", "entity_type": "concept or principle", "pos": [14, 23]}, {"entity": "alkali treatment", "entity_type": "manufacturing process", "pos": [32, 48]}, {"entity": "acid etching", "entity_type": "manufacturing process", "pos": [51, 63]}, {"entity": "anodization treatments", "entity_type": "manufacturing process", "pos": [68, 90]}], "task": "NER"}
{"text": "5 to show the surface morphology of scaffold before and after HCl etching treatment .", "entity": [{"entity": "surface morphology", "entity_type": "process characterization", "pos": [14, 32]}, {"entity": "scaffold", "entity_type": "engineering feature", "pos": [36, 44]}, {"entity": "etching", "entity_type": "manufacturing process", "pos": [66, 73]}], "task": "NER"}
{"text": "The chemical reaction may produce a thin oxide layer on the surface of the metal , usually resulting in improved bioactivity .", "entity": [{"entity": "chemical reaction", "entity_type": "concept or principle", "pos": [4, 21]}, {"entity": "oxide", "entity_type": "material", "pos": [41, 46]}, {"entity": "layer", "entity_type": "process parameter", "pos": [47, 52]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [60, 67]}, {"entity": "metal", "entity_type": "material", "pos": [75, 80]}, {"entity": "bioactivity", "entity_type": "machanical property", "pos": [113, 124]}], "task": "NER"}
{"text": "The thickness of the active layer can be controlled from tens of nanometer to hundreds of microns by adjusting processing variables .", "entity": [{"entity": "layer", "entity_type": "process parameter", "pos": [28, 33]}, {"entity": "be", "entity_type": "material", "pos": [38, 40]}, {"entity": "nanometer", "entity_type": "engineering feature", "pos": [65, 74]}], "task": "NER"}
{"text": "Alkali treatment was initially introduced by Kim to improve the bioactivity of Ti implants owing to a biologically active bone-like apatite layer on Ti surface .", "entity": [{"entity": "Alkali treatment", "entity_type": "manufacturing process", "pos": [0, 16]}, {"entity": "bioactivity", "entity_type": "machanical property", "pos": [64, 75]}, {"entity": "Ti implants", "entity_type": "application", "pos": [79, 90]}, {"entity": "bone-like apatite layer", "entity_type": "material", "pos": [122, 145]}, {"entity": "Ti", "entity_type": "material", "pos": [149, 151]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [152, 159]}], "task": "NER"}
{"text": "Anodization is a mature electrochemical process capable of producing protective layers on the metal surface with adjustable surface microstructure and crystal structure .", "entity": [{"entity": "Anodization", "entity_type": "manufacturing process", "pos": [0, 11]}, {"entity": "electrochemical process", "entity_type": "manufacturing process", "pos": [24, 47]}, {"entity": "protective layers", "entity_type": "application", "pos": [69, 86]}, {"entity": "metal", "entity_type": "material", "pos": [94, 99]}, {"entity": "surface microstructure", "entity_type": "concept or principle", "pos": [124, 146]}, {"entity": "crystal structure", "entity_type": "machanical property", "pos": [151, 168]}], "task": "NER"}
{"text": "Special care should be taken with regard to the possible negative effect on mechanical properties after corrosion-based surface treatment .", "entity": [{"entity": "be", "entity_type": "material", "pos": [20, 22]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [76, 97]}, {"entity": "surface treatment", "entity_type": "manufacturing process", "pos": [120, 137]}], "task": "NER"}
{"text": "It was reported that alkali treatment might result in the deterioration of mechanical strength of porous Ti alloy scaffolds and also cause the embrittlement of the struts in the scaffolds .", "entity": [{"entity": "alkali treatment", "entity_type": "manufacturing process", "pos": [21, 37]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [75, 94]}, {"entity": "porous Ti alloy scaffolds", "entity_type": "engineering feature", "pos": [98, 123]}, {"entity": "embrittlement", "entity_type": "machanical property", "pos": [143, 156]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [164, 170]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [178, 187]}], "task": "NER"}
{"text": "6 Challenges and future directions Additive manufacturing provides unprecedented opportunities for producing customized medical implants as this technology can fabricate structures of complex external shapes and intricate internal architectures .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [35, 57]}, {"entity": "medical implants", "entity_type": "application", "pos": [120, 136]}, {"entity": "as", "entity_type": "material", "pos": [137, 139]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [145, 155]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [160, 169]}, {"entity": "internal architectures", "entity_type": "machanical property", "pos": [222, 244]}], "task": "NER"}
{"text": "Topology optimization has become a powerful digital tool for the design of optimal structures and materials .", "entity": [{"entity": "Topology optimization", "entity_type": "engineering feature", "pos": [0, 21]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [52, 56]}, {"entity": "design", "entity_type": "engineering feature", "pos": [65, 71]}, {"entity": "optimal structures", "entity_type": "engineering feature", "pos": [75, 93]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [98, 107]}], "task": "NER"}
{"text": "The integration of these two technologies sees a promising future in designing and manufacturing biocompatible orthopaedic implants with desired mechanical properties and minimal side effects on patients in clinical applications .", "entity": [{"entity": "technologies", "entity_type": "concept or principle", "pos": [29, 41]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [83, 96]}, {"entity": "biocompatible orthopaedic implants", "entity_type": "application", "pos": [97, 131]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [145, 166]}, {"entity": "clinical applications", "entity_type": "application", "pos": [207, 228]}], "task": "NER"}
{"text": "Key challenges and future directions in integrating the two technologies are as follows : i ) A comprehensive and reliable database containing detailed information on the mechanical and biological properties of human bones is yet to be established .", "entity": [{"entity": "technologies", "entity_type": "concept or principle", "pos": [60, 72]}, {"entity": "as", "entity_type": "material", "pos": [77, 79]}, {"entity": "database", "entity_type": "enabling technology", "pos": [123, 131]}, {"entity": "mechanical", "entity_type": "application", "pos": [171, 181]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [197, 207]}, {"entity": "be", "entity_type": "material", "pos": [233, 235]}], "task": "NER"}
{"text": "This database should include properties of bones for different age , gender groups and at different locations .", "entity": [{"entity": "database", "entity_type": "enabling technology", "pos": [5, 13]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [29, 39]}], "task": "NER"}
{"text": "Such information is required as the design of the topology optimization process .", "entity": [{"entity": "as", "entity_type": "material", "pos": [29, 31]}, {"entity": "design", "entity_type": "engineering feature", "pos": [36, 42]}, {"entity": "topology optimization process", "entity_type": "engineering feature", "pos": [50, 79]}], "task": "NER"}
{"text": "ii ) Sophisticated topology optimization algorithms capable of dealing with multi-functional designs on multiple length scales simultaneously needs to be developed .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [19, 40]}, {"entity": "algorithms", "entity_type": "concept or principle", "pos": [41, 51]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [93, 100]}, {"entity": "length scales", "entity_type": "process characterization", "pos": [113, 126]}, {"entity": "be", "entity_type": "material", "pos": [151, 153]}], "task": "NER"}
{"text": "Preliminary studies along this line can be found in Refs.. iii ) Topological design of the lattice structures that can be easily produced by AM and exhibit anisotropic mechanical properties similar to human bones is another promising direction , despite that the fact that there has been extensive research on topology optimization based on continuum models .", "entity": [{"entity": "be", "entity_type": "material", "pos": [40, 42]}, {"entity": "Topological design", "entity_type": "engineering feature", "pos": [65, 83]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [91, 109]}, {"entity": "be", "entity_type": "material", "pos": [119, 121]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [141, 143]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [156, 167]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [179, 189]}, {"entity": "research", "entity_type": "concept or principle", "pos": [298, 306]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [310, 331]}, {"entity": "continuum models", "entity_type": "concept or principle", "pos": [341, 357]}], "task": "NER"}
{"text": "iv ) Constraints and limitations of current AM technologies , such as the critical angle of the overhanging structure and the difficulty in removing the supporting structure , should be involved in newly-developed topology optimization algorithms so that the designs could actually be fabricated by AM .", "entity": [{"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [44, 59]}, {"entity": "as", "entity_type": "material", "pos": [67, 69]}, {"entity": "critical angle", "entity_type": "engineering feature", "pos": [74, 88]}, {"entity": "overhanging structure", "entity_type": "concept or principle", "pos": [96, 117]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [164, 173]}, {"entity": "be", "entity_type": "material", "pos": [183, 185]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [214, 235]}, {"entity": "algorithms", "entity_type": "concept or principle", "pos": [236, 246]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [259, 266]}, {"entity": "be", "entity_type": "material", "pos": [282, 284]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [299, 301]}], "task": "NER"}
{"text": "v ) The long-term in vivo material/biological performance of porous metallic implants that are designed through topology optimization techniques and produced by AM needs to be rigorously assessed in order to ascertain the advantages and drawbacks of such implants .", "entity": [{"entity": "v", "entity_type": "material", "pos": [0, 1]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [46, 57]}, {"entity": "porous metallic implants", "entity_type": "application", "pos": [61, 85]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [95, 103]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [112, 133]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [161, 163]}, {"entity": "be", "entity_type": "material", "pos": [173, 175]}, {"entity": "implants", "entity_type": "application", "pos": [255, 263]}], "task": "NER"}
{"text": "vi ) Novel alloying systems capable of enhancing the mechanical and biological performance of porous metallic implants are in great demand , together with new post-treatment technologies for improving the bioactivity and biocompatibility .", "entity": [{"entity": "alloying", "entity_type": "engineering feature", "pos": [11, 19]}, {"entity": "mechanical", "entity_type": "application", "pos": [53, 63]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [79, 90]}, {"entity": "porous metallic implants", "entity_type": "application", "pos": [94, 118]}, {"entity": "post-treatment", "entity_type": "manufacturing process", "pos": [159, 173]}, {"entity": "bioactivity", "entity_type": "machanical property", "pos": [205, 216]}, {"entity": "biocompatibility", "entity_type": "machanical property", "pos": [221, 237]}], "task": "NER"}
{"text": "7 Conclusions In this paper , the current status of the topological design of porous metallic implants and the fabrication of such implants using additive manufacturing is reviewed .", "entity": [{"entity": "topological design", "entity_type": "engineering feature", "pos": [56, 74]}, {"entity": "porous metallic implants", "entity_type": "application", "pos": [78, 102]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [111, 122]}, {"entity": "implants", "entity_type": "application", "pos": [131, 139]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [146, 168]}], "task": "NER"}
{"text": "First the mechanical properties of human bones are discussed .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [10, 31]}], "task": "NER"}
{"text": "Then it is demonstrated that topology optimization is a powerful digital tool that can be used to obtain optimal internal architectures for porous implants which not only satisfy multifunctional requirements but also mimic human bones .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [29, 50]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [73, 77]}, {"entity": "be", "entity_type": "material", "pos": [87, 89]}, {"entity": "internal architectures", "entity_type": "machanical property", "pos": [113, 135]}, {"entity": "porous implants", "entity_type": "application", "pos": [140, 155]}, {"entity": "mimic", "entity_type": "machine or equipment", "pos": [217, 222]}], "task": "NER"}
{"text": "Furthermore it is shown that additive manufacturing is the most promising and disruptive technology in the fabrication of porous orthopaedic implants designed through topology optimization .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [29, 51]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [89, 99]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [107, 118]}, {"entity": "porous orthopaedic implants", "entity_type": "application", "pos": [122, 149]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [150, 158]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [167, 188]}], "task": "NER"}
{"text": "To further improve the mechanical and biological performance of these structures , both post-treatment and surface modification are necessary .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [23, 33]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [49, 60]}, {"entity": "post-treatment", "entity_type": "manufacturing process", "pos": [88, 102]}, {"entity": "surface modification", "entity_type": "manufacturing process", "pos": [107, 127]}], "task": "NER"}
{"text": "Based on these discussions , challenges and future directions of the integration topology optimization with additive manufacturing are identified .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [81, 102]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [108, 130]}], "task": "NER"}
{"text": "This review provides useful information to researchers and practitioners who are working in various areas of the truly multidisciplinary topic of bone implant design and fabrication Additive manufacturing of polymer-fiber composites has transformed AM into a robust manufacturing paradigm and enabled producing highly customized parts with significantly improved mechanical properties , compared to un-reinforced polymers .", "entity": [{"entity": "areas", "entity_type": "process parameter", "pos": [100, 105]}, {"entity": "bone implant", "entity_type": "application", "pos": [146, 158]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [170, 181]}, {"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [182, 204]}, {"entity": "polymer-fiber composites", "entity_type": "material", "pos": [208, 232]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [249, 251]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [266, 279]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [363, 384]}, {"entity": "polymers", "entity_type": "material", "pos": [413, 421]}], "task": "NER"}
{"text": "Almost all commercially available AM methods could benefit from various fiber reinforcement techniques .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [34, 36]}, {"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [72, 91]}], "task": "NER"}
{"text": "Recent developments in 3D printing methods of fiber reinforced polymers , namely , fused deposition modeling , laminated object manufacturing , stereolithography , extrusion , and selective laser sintering are reviewed in this study to understand the trends and future directions in the respective areas .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [23, 34]}, {"entity": "fiber reinforced polymers", "entity_type": "material", "pos": [46, 71]}, {"entity": "fused deposition modeling", "entity_type": "manufacturing process", "pos": [83, 108]}, {"entity": "laminated object manufacturing", "entity_type": "manufacturing process", "pos": [111, 141]}, {"entity": "stereolithography", "entity_type": "manufacturing process", "pos": [144, 161]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [164, 173]}, {"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [180, 205]}, {"entity": "trends", "entity_type": "concept or principle", "pos": [251, 257]}, {"entity": "areas", "entity_type": "process parameter", "pos": [298, 303]}], "task": "NER"}
{"text": "In addition to extra strength , fibers have also been used in 4D printing to control and manipulate the change of shape or swelling after 3D printing , right out of the printing bed .", "entity": [{"entity": "strength", "entity_type": "machanical property", "pos": [21, 29]}, {"entity": "fibers", "entity_type": "material", "pos": [32, 38]}, {"entity": "4D printing", "entity_type": "manufacturing process", "pos": [62, 73]}, {"entity": "swelling", "entity_type": "concept or principle", "pos": [123, 131]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [138, 149]}, {"entity": "bed", "entity_type": "machine or equipment", "pos": [178, 181]}], "task": "NER"}
{"text": "Although AM of fiber/polymer composites are increasingly developing and under intense attention , there are some issues needed to be addressed including void formation , poor adhesion of fibers and matrix , blockage due to filler inclusion , increased curing time , modelling , simulation , etc .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [9, 11]}, {"entity": "composites", "entity_type": "material", "pos": [29, 39]}, {"entity": "be", "entity_type": "material", "pos": [130, 132]}, {"entity": "void", "entity_type": "concept or principle", "pos": [153, 157]}, {"entity": "adhesion", "entity_type": "machanical property", "pos": [175, 183]}, {"entity": "fibers", "entity_type": "material", "pos": [187, 193]}, {"entity": "inclusion", "entity_type": "material", "pos": [230, 239]}, {"entity": "curing time", "entity_type": "process parameter", "pos": [252, 263]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [266, 275]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [278, 288]}], "task": "NER"}
{"text": "Additive manufacturing , also known as 3D printing , is defined asa process of adding materials to fabricate objects from three-dimensional models in successive layers , versus traditional subtractive manufacturing methods .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [0, 22]}, {"entity": "as", "entity_type": "material", "pos": [36, 38]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [39, 50]}, {"entity": "process", "entity_type": "concept or principle", "pos": [68, 75]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [86, 95]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [99, 108]}, {"entity": "three-dimensional models", "entity_type": "enabling technology", "pos": [122, 146]}, {"entity": "traditional subtractive manufacturing", "entity_type": "manufacturing process", "pos": [177, 214]}], "task": "NER"}
{"text": "Numerous novel AM processes have been developed over the span of more than 20years of AM development with applications in aerospace , automotive , biomedical , digital art , architectural design , etc .", "entity": [{"entity": "AM processes", "entity_type": "manufacturing process", "pos": [15, 27]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [86, 88]}, {"entity": "aerospace", "entity_type": "application", "pos": [122, 131]}, {"entity": "automotive", "entity_type": "application", "pos": [134, 144]}, {"entity": "biomedical", "entity_type": "application", "pos": [147, 157]}, {"entity": "art", "entity_type": "application", "pos": [168, 171]}, {"entity": "design", "entity_type": "engineering feature", "pos": [188, 194]}], "task": "NER"}
{"text": "There has been an exponential increase in AM technology in recent years and it continues to grow due to its versatility and low cost for rapid prototyping and manufacturing applications .", "entity": [{"entity": "AM technology", "entity_type": "manufacturing process", "pos": [42, 55]}, {"entity": "rapid prototyping", "entity_type": "enabling technology", "pos": [137, 154]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [159, 172]}], "task": "NER"}
{"text": "All of these features , combined with AMcustomizability to fabricate complex monolithic structures and geometries , with micrometer resolution , helped AM grow to a multibillion-dollar industry .", "entity": [{"entity": "fabricate", "entity_type": "manufacturing process", "pos": [59, 68]}, {"entity": "monolithic structures", "entity_type": "machanical property", "pos": [77, 98]}, {"entity": "geometries", "entity_type": "concept or principle", "pos": [103, 113]}, {"entity": "micrometer resolution", "entity_type": "process parameter", "pos": [121, 142]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [152, 154]}, {"entity": "industry", "entity_type": "application", "pos": [185, 193]}], "task": "NER"}
{"text": "To date , the dominant part of the 3D printing industry has immensely relied on single material printing .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [35, 46]}, {"entity": "material", "entity_type": "material", "pos": [87, 95]}], "task": "NER"}
{"text": "This issue , paired with limited choices of available resins compatible with commercial printers , has severely limited variations in the physical and chemical properties of 3D printed objects .", "entity": [{"entity": "resins", "entity_type": "material", "pos": [54, 60]}, {"entity": "printers", "entity_type": "machine or equipment", "pos": [88, 96]}, {"entity": "variations", "entity_type": "concept or principle", "pos": [120, 130]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [160, 170]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [174, 184]}], "task": "NER"}
{"text": "These limitations have led to development of multi-material printers with partial control on material composition and properties , offering layered composite materials .", "entity": [{"entity": "led", "entity_type": "application", "pos": [23, 26]}, {"entity": "multi-material", "entity_type": "concept or principle", "pos": [45, 59]}, {"entity": "material", "entity_type": "material", "pos": [93, 101]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [102, 113]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [118, 128]}, {"entity": "composite materials", "entity_type": "material", "pos": [148, 167]}], "task": "NER"}
{"text": "Furthermore , multiple printing heads have allowed printing blended composites with functional and variable features .", "entity": [{"entity": "printing heads", "entity_type": "machine or equipment", "pos": [23, 37]}, {"entity": "composites", "entity_type": "material", "pos": [68, 78]}], "task": "NER"}
{"text": "3D printing of fiber reinforced composites is currently conducted by stereolithography , laminated object manufacturing , fused deposition modeling , selective laser sintering , and extrusion .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [0, 11]}, {"entity": "fiber reinforced composites", "entity_type": "material", "pos": [15, 42]}, {"entity": "stereolithography", "entity_type": "manufacturing process", "pos": [69, 86]}, {"entity": "laminated object manufacturing", "entity_type": "manufacturing process", "pos": [89, 119]}, {"entity": "fused deposition modeling", "entity_type": "manufacturing process", "pos": [122, 147]}, {"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [150, 175]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [182, 191]}], "task": "NER"}
{"text": "This is one of the hottest topics in the field of additive manufacturing and is under intense attention .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [50, 72]}], "task": "NER"}
{"text": "This also offers significant improvement in mechanical properties , however , it requires a complex procedure to be manufactured and is difficult to be incorporated into processing .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [44, 65]}, {"entity": "be", "entity_type": "material", "pos": [113, 115]}, {"entity": "be", "entity_type": "material", "pos": [149, 151]}], "task": "NER"}
{"text": "Implementing the traditional methods of composite manufacturing in AM is not practical and new technologies are needed to assist with the development of new AM methods .", "entity": [{"entity": "composite manufacturing", "entity_type": "manufacturing process", "pos": [40, 63]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [67, 69]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [95, 107]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [157, 159]}], "task": "NER"}
{"text": "Advances in development of composite 3D printers have not prevented development in pre-blended materials with fillers such as nanoparticles , carbon nanotubes , fibers and graphene in order to achieve unique characteristics and capabilities .", "entity": [{"entity": "composite", "entity_type": "material", "pos": [27, 36]}, {"entity": "3D printers", "entity_type": "machine or equipment", "pos": [37, 48]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [95, 104]}, {"entity": "as", "entity_type": "material", "pos": [123, 125]}, {"entity": "carbon nanotubes", "entity_type": "material", "pos": [142, 158]}, {"entity": "fibers", "entity_type": "material", "pos": [161, 167]}, {"entity": "graphene", "entity_type": "material", "pos": [172, 180]}], "task": "NER"}
{"text": "Fiber reinforcement , in particular , appears to be an attractive filler to improve the properties of polymers .", "entity": [{"entity": "Fiber reinforcement", "entity_type": "engineering feature", "pos": [0, 19]}, {"entity": "be", "entity_type": "material", "pos": [49, 51]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [88, 98]}, {"entity": "polymers", "entity_type": "material", "pos": [102, 110]}], "task": "NER"}
{"text": "Pre-blended materials using discontinuous fibers asan additive have been under intense investigation asa suitable alternative to multi-head printers with complex and costly designs .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [12, 21]}, {"entity": "fibers", "entity_type": "material", "pos": [42, 48]}, {"entity": "additive", "entity_type": "material", "pos": [54, 62]}, {"entity": "printers", "entity_type": "machine or equipment", "pos": [140, 148]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [173, 180]}], "task": "NER"}
{"text": "These additive based materials exhibit unique characteristics and capabilities , depending on the additive used .", "entity": [{"entity": "additive", "entity_type": "material", "pos": [6, 14]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [21, 30]}, {"entity": "additive", "entity_type": "material", "pos": [98, 106]}], "task": "NER"}
{"text": "Suitable mechanical , electrical , or thermal properties can be accomplished in an inexpensive manner .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [9, 19]}, {"entity": "electrical", "entity_type": "application", "pos": [22, 32]}, {"entity": "thermal properties", "entity_type": "concept or principle", "pos": [38, 56]}, {"entity": "be", "entity_type": "material", "pos": [61, 63]}], "task": "NER"}
{"text": "Polymers , in particular , have been the center of attention due to ease of production and availability .", "entity": [{"entity": "Polymers", "entity_type": "material", "pos": [0, 8]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [76, 86]}], "task": "NER"}
{"text": "The 3D printing industry primarily involves polymers in various forms , such as reactive , liquid solutions , and thermoplastic melts .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [4, 15]}, {"entity": "polymers", "entity_type": "material", "pos": [44, 52]}, {"entity": "as", "entity_type": "material", "pos": [77, 79]}, {"entity": "thermoplastic", "entity_type": "material", "pos": [114, 127]}], "task": "NER"}
{"text": "These benefits , joined by enhancements from fiber reinforcement , offer a favorable combination for future development of AM technology .", "entity": [{"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [45, 64]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [123, 136]}], "task": "NER"}
{"text": "In addition , almost all of the existing AM methods can be benefited from fiber reinforcement .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [41, 43]}, {"entity": "be", "entity_type": "material", "pos": [56, 58]}, {"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [74, 93]}], "task": "NER"}
{"text": "Although fiber reinforcement in 3D printing sounds promising , there are numerous issues which need to be resolved .", "entity": [{"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [9, 28]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [32, 43]}, {"entity": "be", "entity_type": "material", "pos": [103, 105]}], "task": "NER"}
{"text": "Namely , the effect of fibers on resolution , agglomerate formation , heterogeneous composite formation , blockage of printer heads , non-adhesion , and increased curing times .", "entity": [{"entity": "fibers", "entity_type": "material", "pos": [23, 29]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [33, 43]}, {"entity": "agglomerate formation", "entity_type": "process characterization", "pos": [46, 67]}, {"entity": "heterogeneous composite formation", "entity_type": "manufacturing process", "pos": [70, 103]}, {"entity": "printer", "entity_type": "machine or equipment", "pos": [118, 125]}, {"entity": "curing times", "entity_type": "process parameter", "pos": [163, 175]}], "task": "NER"}
{"text": "This paper reviews recent advances in AM of polymer based fiber reinforced composites and potential methods for modelling and analysis of these 3D printed structures .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [38, 40]}, {"entity": "polymer", "entity_type": "material", "pos": [44, 51]}, {"entity": "fiber reinforced composites", "entity_type": "material", "pos": [58, 85]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [112, 121]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [144, 154]}], "task": "NER"}
{"text": "Latest development and improvement to existing methods will be reviewed in detail , in order to understand the challenges in 3D printing of polymer composites with fiber reinforcement .", "entity": [{"entity": "be", "entity_type": "material", "pos": [60, 62]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [125, 136]}, {"entity": "polymer composites", "entity_type": "material", "pos": [140, 158]}, {"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [164, 183]}], "task": "NER"}
{"text": "3D printing of fiber reinforced polymer composites Fiber reinforcement can greatly improve the properties of 3D printed parts with polymer matrix .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [0, 11]}, {"entity": "fiber reinforced polymer composites", "entity_type": "material", "pos": [15, 50]}, {"entity": "Fiber", "entity_type": "material", "pos": [51, 56]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [95, 105]}, {"entity": "3D printed parts", "entity_type": "application", "pos": [109, 125]}, {"entity": "polymer", "entity_type": "material", "pos": [131, 138]}], "task": "NER"}
{"text": "Fiber orientation and void content of composites are the main concerns in 3D printing of these composites .", "entity": [{"entity": "Fiber orientation", "entity_type": "engineering feature", "pos": [0, 17]}, {"entity": "void", "entity_type": "concept or principle", "pos": [22, 26]}, {"entity": "composites", "entity_type": "material", "pos": [38, 48]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [74, 85]}, {"entity": "composites", "entity_type": "material", "pos": [95, 105]}], "task": "NER"}
{"text": "Most of the commercially available 3D printing techniques would benefit from fiber reinforcement .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [35, 46]}, {"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [77, 96]}], "task": "NER"}
{"text": "In this section , all of these techniques for 3D printing of polymer-fiber composites are reviewed in detail to demonstrate their strengths and weaknesses in additive manufacturing of polymer-fiber composites .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [46, 57]}, {"entity": "polymer-fiber composites", "entity_type": "material", "pos": [61, 85]}, {"entity": "strengths", "entity_type": "machanical property", "pos": [130, 139]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [158, 180]}, {"entity": "polymer-fiber composites", "entity_type": "material", "pos": [184, 208]}], "task": "NER"}
{"text": "These methods are FDM , LOM , SL , extrusion , and SLS .", "entity": [{"entity": "FDM", "entity_type": "manufacturing process", "pos": [18, 21]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [24, 27]}, {"entity": "SL", "entity_type": "manufacturing process", "pos": [30, 32]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [35, 44]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [51, 54]}], "task": "NER"}
{"text": "2.1 Fused deposition modeling FDM is currently the most applied AM technology , according to WohlerReport from Stratasys , Inc. Commercial FDM machines held 41.5 % of the market share , with the total of 15,000 FDM machines sold by the end of 2010 .", "entity": [{"entity": "Fused deposition modeling", "entity_type": "manufacturing process", "pos": [4, 29]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [30, 33]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [64, 77]}, {"entity": "Stratasys", "entity_type": "application", "pos": [111, 120]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [139, 142]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [211, 214]}], "task": "NER"}
{"text": "The key elements of the FDM system include material feed mechanism , liquefier , print head , gantry , and build surface .", "entity": [{"entity": "elements", "entity_type": "material", "pos": [8, 16]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [24, 27]}, {"entity": "material feed mechanism", "entity_type": "engineering feature", "pos": [43, 66]}, {"entity": "print head", "entity_type": "machine or equipment", "pos": [81, 91]}, {"entity": "build surface", "entity_type": "process parameter", "pos": [107, 120]}], "task": "NER"}
{"text": "Several process parameters are essential in FDM , including bead width , air gap , model build temperature , and raster orientation .", "entity": [{"entity": "process parameters", "entity_type": "concept or principle", "pos": [8, 26]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [44, 47]}, {"entity": "bead width", "entity_type": "process characterization", "pos": [60, 70]}, {"entity": "model", "entity_type": "concept or principle", "pos": [83, 88]}, {"entity": "build", "entity_type": "process parameter", "pos": [89, 94]}, {"entity": "raster orientation", "entity_type": "process parameter", "pos": [113, 131]}], "task": "NER"}
{"text": "The effects of raster orientation on tensile and compression test results have been investigated in detail .", "entity": [{"entity": "raster orientation", "entity_type": "process parameter", "pos": [15, 33]}, {"entity": "tensile", "entity_type": "machanical property", "pos": [37, 44]}, {"entity": "compression test", "entity_type": "process characterization", "pos": [49, 65]}], "task": "NER"}
{"text": "The temperature distribution during the FDM process can be monitored by IR camera .", "entity": [{"entity": "temperature", "entity_type": "process parameter", "pos": [4, 15]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [16, 28]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [40, 43]}, {"entity": "be", "entity_type": "material", "pos": [56, 58]}, {"entity": "IR", "entity_type": "process characterization", "pos": [72, 74]}, {"entity": "camera", "entity_type": "machine or equipment", "pos": [75, 81]}], "task": "NER"}
{"text": "The surface roughness and cross section shape of the FDM fabricated parts are under intense study .", "entity": [{"entity": "surface roughness", "entity_type": "machanical property", "pos": [4, 21]}, {"entity": "cross section", "entity_type": "concept or principle", "pos": [26, 39]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [53, 56]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [57, 67]}], "task": "NER"}
{"text": "1 and 2 illustrate the bonding mechanism in the FDM of polymer composites along crosB-section of printed parts .", "entity": [{"entity": "bonding mechanism", "entity_type": "process characterization", "pos": [23, 40]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [48, 51]}, {"entity": "polymer composites", "entity_type": "material", "pos": [55, 73]}], "task": "NER"}
{"text": "Several building rules have been proposed to improve the strength and accuracy of the FDM printed parts , such as build parts to ensure tensile loads are carried axially along printed directions , deal with the stress concentration at corners , use negative air gap to increase both strength and stiffness , consider that small bead width leads to extra printing time and better surface quality , be aware the part accuracy affected by the build orientation , and realize that tensile loaded area tends to fail easier than compression loaded area .", "entity": [{"entity": "strength", "entity_type": "machanical property", "pos": [57, 65]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [70, 78]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [86, 89]}, {"entity": "as", "entity_type": "material", "pos": [111, 113]}, {"entity": "tensile loads", "entity_type": "process characterization", "pos": [136, 149]}, {"entity": "stress concentration", "entity_type": "process characterization", "pos": [211, 231]}, {"entity": "strength", "entity_type": "machanical property", "pos": [283, 291]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [296, 305]}, {"entity": "bead width", "entity_type": "process characterization", "pos": [328, 338]}, {"entity": "surface quality", "entity_type": "process parameter", "pos": [379, 394]}, {"entity": "be", "entity_type": "material", "pos": [397, 399]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [415, 423]}, {"entity": "build orientation", "entity_type": "process parameter", "pos": [440, 457]}, {"entity": "tensile", "entity_type": "machanical property", "pos": [477, 484]}, {"entity": "area", "entity_type": "process parameter", "pos": [492, 496]}, {"entity": "compression", "entity_type": "machanical property", "pos": [523, 534]}, {"entity": "area", "entity_type": "process parameter", "pos": [542, 546]}], "task": "NER"}
{"text": "Recently , fiber reinforcement in FDM has been very popular amongst researchers .", "entity": [{"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [11, 30]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [34, 37]}], "task": "NER"}
{"text": "Most of the efforts have focused on development of filaments with short fiber additives .", "entity": [{"entity": "filaments", "entity_type": "material", "pos": [51, 60]}, {"entity": "short fiber", "entity_type": "material", "pos": [66, 77]}, {"entity": "additives", "entity_type": "material", "pos": [78, 87]}], "task": "NER"}
{"text": "Inclusion of fibers in filament reduces tape swelling at the printing head during deposition and increases the stiffness .", "entity": [{"entity": "Inclusion", "entity_type": "material", "pos": [0, 9]}, {"entity": "fibers", "entity_type": "material", "pos": [13, 19]}, {"entity": "filament", "entity_type": "material", "pos": [23, 31]}, {"entity": "swelling", "entity_type": "concept or principle", "pos": [45, 53]}, {"entity": "printing head", "entity_type": "machine or equipment", "pos": [61, 74]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [82, 92]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [111, 120]}], "task": "NER"}
{"text": "Glass fiber reinforced polypropylene was evaluated by Carneiro , Silva and showed 30 % and 40 % improvement for the modulus and strength , respectively , compared to pure PP .", "entity": [{"entity": "Glass fiber reinforced polypropylene", "entity_type": "material", "pos": [0, 36]}, {"entity": "strength", "entity_type": "machanical property", "pos": [128, 136]}, {"entity": "pure PP", "entity_type": "material", "pos": [166, 173]}], "task": "NER"}
{"text": "Vapor grown carbon fibers and single wall carbon nanotubes were compounded with acrylonitrile butadiene styrene for the FDM process .", "entity": [{"entity": "carbon fibers", "entity_type": "material", "pos": [12, 25]}, {"entity": "single wall carbon nanotubes", "entity_type": "material", "pos": [30, 58]}, {"entity": "acrylonitrile butadiene styrene", "entity_type": "material", "pos": [80, 111]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [120, 123]}], "task": "NER"}
{"text": "The VGCFs can be easily aligned by the extrusion process .", "entity": [{"entity": "be", "entity_type": "material", "pos": [14, 16]}, {"entity": "extrusion process", "entity_type": "manufacturing process", "pos": [39, 56]}], "task": "NER"}
{"text": "Tensile strength of 5wt % of VGCFs and SWNTs filled FDM parts increased 18 % and 31 % , respectively .", "entity": [{"entity": "Tensile strength", "entity_type": "machanical property", "pos": [0, 16]}, {"entity": "SWNTs", "entity_type": "material", "pos": [39, 44]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [52, 55]}], "task": "NER"}
{"text": "However , the strain to failure of printed parts reinforced with VGCFs and SWNTs was dramatically decreased .", "entity": [{"entity": "strain", "entity_type": "machanical property", "pos": [14, 20]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [24, 31]}, {"entity": "reinforced", "entity_type": "concept or principle", "pos": [49, 59]}, {"entity": "SWNTs", "entity_type": "material", "pos": [75, 80]}], "task": "NER"}
{"text": "ABS containing oriented VGCFs and SWNTs exhibited modulus improvements up to 93 % .", "entity": [{"entity": "ABS", "entity_type": "material", "pos": [0, 3]}, {"entity": "SWNTs", "entity_type": "material", "pos": [34, 39]}], "task": "NER"}
{"text": "The fiber orientation can be observed in 3 .", "entity": [{"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [4, 21]}, {"entity": "be", "entity_type": "material", "pos": [26, 28]}], "task": "NER"}
{"text": "Thermotropic liquid crystalline polymers with excellent tensile strength , such as ABS and polypropylene , were used in fiber reinforced FDM parts in order to overcome the drawbacks of low aspect ratio of fiber in short fiber filled parts .", "entity": [{"entity": "Thermotropic liquid crystalline polymers", "entity_type": "material", "pos": [0, 40]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [56, 72]}, {"entity": "as", "entity_type": "material", "pos": [80, 82]}, {"entity": "ABS", "entity_type": "material", "pos": [83, 86]}, {"entity": "polypropylene", "entity_type": "material", "pos": [91, 104]}, {"entity": "fiber", "entity_type": "material", "pos": [120, 125]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [137, 140]}, {"entity": "aspect ratio", "entity_type": "engineering feature", "pos": [189, 201]}, {"entity": "fiber", "entity_type": "material", "pos": [205, 210]}, {"entity": "short fiber", "entity_type": "material", "pos": [214, 225]}], "task": "NER"}
{"text": "Processing temperature was one of the important parameters which affects the surface morphology of TLCP and its mechanical behavior .", "entity": [{"entity": "temperature", "entity_type": "process parameter", "pos": [11, 22]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [48, 58]}, {"entity": "surface morphology", "entity_type": "process characterization", "pos": [77, 95]}, {"entity": "mechanical", "entity_type": "application", "pos": [112, 122]}], "task": "NER"}
{"text": "Higher carbon fiber ratio has a high maximum decomposition temperature , thus providing high thermal stability .", "entity": [{"entity": "carbon fiber", "entity_type": "material", "pos": [7, 19]}, {"entity": "maximum decomposition temperature", "entity_type": "process parameter", "pos": [37, 70]}, {"entity": "thermal stability", "entity_type": "machanical property", "pos": [93, 110]}], "task": "NER"}
{"text": "Ning , Cong evaluated the effect of weight ratio and length of carbon fiber on physical properties of the FDM samples with ABS matrix .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [36, 42]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [63, 75]}, {"entity": "physical properties", "entity_type": "machanical property", "pos": [79, 98]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [106, 109]}, {"entity": "ABS matrix", "entity_type": "material", "pos": [123, 133]}], "task": "NER"}
{"text": "The 5 and 7.5wt % carbon fiber content showed the best improvement in tensile strength and Young 's modulus , respectively .", "entity": [{"entity": "carbon fiber", "entity_type": "material", "pos": [18, 30]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [70, 86]}], "task": "NER"}
{"text": "These researchers have also concluded that longer carbon fibers can increase tensile strength and Young 's modulus at the expense of toughness and ductility .", "entity": [{"entity": "carbon fibers", "entity_type": "material", "pos": [50, 63]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [77, 93]}, {"entity": "toughness", "entity_type": "machanical property", "pos": [133, 142]}, {"entity": "ductility", "entity_type": "machanical property", "pos": [147, 156]}], "task": "NER"}
{"text": "As described in 4 , with aligned carbon fiber during the FDM process , 30wt % CF-ABS composites exhibited great improvement in strength and Youngmodulus .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [33, 45]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [57, 60]}, {"entity": "composites", "entity_type": "material", "pos": [85, 95]}, {"entity": "strength", "entity_type": "machanical property", "pos": [127, 135]}, {"entity": "Youngmodulus", "entity_type": "machanical property", "pos": [140, 152]}], "task": "NER"}
{"text": "These printed CF-ABS parts exhibit specific strength higher than Aluminum .", "entity": [{"entity": "specific strength", "entity_type": "machanical property", "pos": [35, 52]}, {"entity": "Aluminum", "entity_type": "material", "pos": [65, 73]}], "task": "NER"}
{"text": "The triangular channels between beads decreased by incorporating carbon fibers due to the reduced die-swell and increased thermal conductivity .", "entity": [{"entity": "beads", "entity_type": "process characterization", "pos": [32, 37]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [65, 78]}, {"entity": "thermal conductivity", "entity_type": "machanical property", "pos": [122, 142]}], "task": "NER"}
{"text": "However , inclusion of carbon fiber into the feedstock caused internal voids inside of the beads responsible for stress concentration , resulting in failure at lower stresses .", "entity": [{"entity": "inclusion", "entity_type": "material", "pos": [10, 19]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [23, 35]}, {"entity": "feedstock", "entity_type": "material", "pos": [45, 54]}, {"entity": "internal voids", "entity_type": "concept or principle", "pos": [62, 76]}, {"entity": "beads", "entity_type": "process characterization", "pos": [91, 96]}, {"entity": "stress concentration", "entity_type": "process characterization", "pos": [113, 133]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [149, 156]}], "task": "NER"}
{"text": "It can be seen in 5 that the FDM samples exhibited significant pore formation , with internal voids , as well as voids formed between the deposited beads during printing .", "entity": [{"entity": "be", "entity_type": "material", "pos": [7, 9]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [29, 32]}, {"entity": "pore", "entity_type": "machanical property", "pos": [63, 67]}, {"entity": "internal voids", "entity_type": "concept or principle", "pos": [85, 99]}, {"entity": "as", "entity_type": "material", "pos": [102, 104]}, {"entity": "as", "entity_type": "material", "pos": [110, 112]}, {"entity": "deposited beads", "entity_type": "process characterization", "pos": [138, 153]}], "task": "NER"}
{"text": "Continuous fiber reinforcement is currently one of the biggest challenges researchers face in 3D printing of polymer composites .", "entity": [{"entity": "Continuous fiber reinforcement", "entity_type": "material", "pos": [0, 30]}, {"entity": "face", "entity_type": "concept or principle", "pos": [86, 90]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [94, 105]}, {"entity": "polymer composites", "entity_type": "material", "pos": [109, 127]}], "task": "NER"}
{"text": "It offers significant improvement in mechanical properties compared to discontinuous fibers , however , there is still no robust and standard paradigm developed for 3D printing of continuous fiber composites .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [37, 58]}, {"entity": "fibers", "entity_type": "material", "pos": [85, 91]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [133, 141]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [165, 176]}, {"entity": "continuous fiber composites", "entity_type": "material", "pos": [180, 207]}], "task": "NER"}
{"text": "Recently , Matsuzaki , Ueda developed an innovative technique for in-nozzle impregnation of continuous fiber and thermoplastic matrix .", "entity": [{"entity": "impregnation", "entity_type": "manufacturing process", "pos": [76, 88]}, {"entity": "continuous fiber", "entity_type": "material", "pos": [92, 108]}, {"entity": "thermoplastic matrix", "entity_type": "material", "pos": [113, 133]}], "task": "NER"}
{"text": "The resin filament and fiber were supplied separately , before heating and mixing in the printing head .", "entity": [{"entity": "resin filament", "entity_type": "material", "pos": [4, 18]}, {"entity": "fiber", "entity_type": "material", "pos": [23, 28]}, {"entity": "heating", "entity_type": "manufacturing process", "pos": [63, 70]}, {"entity": "mixing", "entity_type": "concept or principle", "pos": [75, 81]}, {"entity": "printing head", "entity_type": "machine or equipment", "pos": [89, 102]}], "task": "NER"}
{"text": "The schematic of this process demonstrating the printing head and continuous fiber integration is presented in 6 .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [22, 29]}, {"entity": "printing head", "entity_type": "machine or equipment", "pos": [48, 61]}, {"entity": "continuous fiber", "entity_type": "material", "pos": [66, 82]}], "task": "NER"}
{"text": "Carbon fibers and twisted yarns of natural jute fibers were used as reinforcement .", "entity": [{"entity": "Carbon fibers", "entity_type": "material", "pos": [0, 13]}, {"entity": "fibers", "entity_type": "material", "pos": [48, 54]}, {"entity": "as", "entity_type": "material", "pos": [65, 67]}], "task": "NER"}
{"text": "Superiority of continuous fiber composites versus short fiber reinforcement and other 3D printing methods can be observed in 7 .", "entity": [{"entity": "continuous fiber composites", "entity_type": "material", "pos": [15, 42]}, {"entity": "short fiber reinforcement", "entity_type": "material", "pos": [50, 75]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [86, 97]}, {"entity": "be", "entity_type": "material", "pos": [110, 112]}], "task": "NER"}
{"text": "Namiki , Ueda implemented the same technique for printing polyactic acid /carbon fiber composite parts .", "entity": [{"entity": "fiber composite", "entity_type": "material", "pos": [81, 96]}], "task": "NER"}
{"text": "Some gaps were reported between PLA filaments , which can be reduced by increasing the resolution .", "entity": [{"entity": "PLA filaments", "entity_type": "material", "pos": [32, 45]}, {"entity": "be", "entity_type": "material", "pos": [58, 60]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [87, 97]}], "task": "NER"}
{"text": "Tensile strength of continuous carbon fiber reinforced PLA prepared by FDM , as reported by Li , Li , can reach up to 91MPa , while in the case of short carbon fiber , it is only 68MPa .", "entity": [{"entity": "Tensile strength", "entity_type": "machanical property", "pos": [0, 16]}, {"entity": "continuous carbon fiber", "entity_type": "material", "pos": [20, 43]}, {"entity": "PLA", "entity_type": "material", "pos": [55, 58]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [71, 74]}, {"entity": "as", "entity_type": "material", "pos": [77, 79]}, {"entity": "Li", "entity_type": "material", "pos": [92, 94]}, {"entity": "Li", "entity_type": "material", "pos": [97, 99]}, {"entity": "short carbon fiber", "entity_type": "material", "pos": [147, 165]}], "task": "NER"}
{"text": "Weak bonding between PLA and carbon fiber can significantly affect the mechanical properties in this method , however , surface modification of carbon fiber bundle with methylene dichloride and PLA particles improved adhesion and increased tensile and flexural strength .", "entity": [{"entity": "bonding", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "PLA", "entity_type": "material", "pos": [21, 24]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [29, 41]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [71, 92]}, {"entity": "surface modification", "entity_type": "manufacturing process", "pos": [120, 140]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [144, 156]}, {"entity": "methylene dichloride", "entity_type": "material", "pos": [169, 189]}, {"entity": "PLA", "entity_type": "material", "pos": [194, 197]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [198, 207]}, {"entity": "adhesion", "entity_type": "machanical property", "pos": [217, 225]}, {"entity": "tensile", "entity_type": "machanical property", "pos": [240, 247]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [252, 269]}], "task": "NER"}
{"text": "8 presents the ultimate tensile and flexural strength of pure PLA , carbon fiber-PLA , and modified carbon fiber-PLA .", "entity": [{"entity": "tensile", "entity_type": "machanical property", "pos": [24, 31]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [36, 53]}, {"entity": "PLA", "entity_type": "material", "pos": [62, 65]}, {"entity": "carbon fiber-PLA", "entity_type": "material", "pos": [68, 84]}, {"entity": "carbon fiber-PLA", "entity_type": "material", "pos": [100, 116]}], "task": "NER"}
{"text": "Green circles in 8 indicate different phases of the tensile process , namely , loading of the PLA material between fixture and test sample at the beginning of the test and a slight drop of the curve slope due to fiber-matrix interface debonding .", "entity": [{"entity": "tensile", "entity_type": "machanical property", "pos": [52, 59]}, {"entity": "process", "entity_type": "concept or principle", "pos": [60, 67]}, {"entity": "PLA material", "entity_type": "material", "pos": [94, 106]}, {"entity": "fixture", "entity_type": "machine or equipment", "pos": [115, 122]}, {"entity": "sample", "entity_type": "concept or principle", "pos": [132, 138]}, {"entity": "interface", "entity_type": "concept or principle", "pos": [225, 234]}], "task": "NER"}
{"text": "Marked circles in 8 signify the process of load change from resin to fiber at the beginning of the test .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [32, 39]}, {"entity": "resin", "entity_type": "material", "pos": [60, 65]}, {"entity": "fiber", "entity_type": "material", "pos": [69, 74]}], "task": "NER"}
{"text": "The next circle in 8 shows the plastic elongation of PLA polymer chains that continue to bear load after the failure of carbon fibers .", "entity": [{"entity": "plastic", "entity_type": "material", "pos": [31, 38]}, {"entity": "elongation", "entity_type": "machanical property", "pos": [39, 49]}, {"entity": "PLA", "entity_type": "material", "pos": [53, 56]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [109, 116]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [120, 133]}], "task": "NER"}
{"text": "Tian , Liu performed a systemic analysis on interface and performance of printed continuous carbon fiber reinforced PLA composites and the effect of process parameters on the temperature and pressure in the process .", "entity": [{"entity": "interface", "entity_type": "concept or principle", "pos": [44, 53]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [58, 69]}, {"entity": "continuous carbon fiber", "entity_type": "material", "pos": [81, 104]}, {"entity": "PLA composites", "entity_type": "material", "pos": [116, 130]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [149, 167]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [175, 186]}, {"entity": "pressure", "entity_type": "concept or principle", "pos": [191, 199]}, {"entity": "process", "entity_type": "concept or principle", "pos": [207, 214]}], "task": "NER"}
{"text": "9 shows crosB-section of the tensile bar and continuous fibers in the fracture surface , and 10 demonstrates the capability of this method in 3D printing large curvatures , without losing the continuous fiber reinforcement .", "entity": [{"entity": "tensile bar", "entity_type": "machine or equipment", "pos": [29, 40]}, {"entity": "continuous fibers", "entity_type": "material", "pos": [45, 62]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [70, 78]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [142, 153]}, {"entity": "continuous fiber reinforcement", "entity_type": "material", "pos": [192, 222]}], "task": "NER"}
{"text": "Melenka , Cheung evaluated continuous Kevlar fiber-reinforced 3D printed Nylon structures using commercial desktop printers in order to predict the tensile properties .", "entity": [{"entity": "continuous Kevlar fiber-reinforced", "entity_type": "material", "pos": [27, 61]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [62, 72]}, {"entity": "printers", "entity_type": "machine or equipment", "pos": [115, 123]}, {"entity": "tensile properties", "entity_type": "machanical property", "pos": [148, 166]}], "task": "NER"}
{"text": "Stiffness and ultimate strength showed significant increase with high volume of fiber reinforcement .", "entity": [{"entity": "Stiffness", "entity_type": "machanical property", "pos": [0, 9]}, {"entity": "ultimate strength", "entity_type": "machanical property", "pos": [14, 31]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [70, 76]}, {"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [80, 99]}], "task": "NER"}
{"text": "Carbon fibers were placed between layers of 3D printed polymer to improve strength and fatigue life , while thermal treatment was performed to further increase the mechanical properties .", "entity": [{"entity": "Carbon fibers", "entity_type": "material", "pos": [0, 13]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [44, 54]}, {"entity": "strength", "entity_type": "machanical property", "pos": [74, 82]}, {"entity": "fatigue life", "entity_type": "machanical property", "pos": [87, 99]}, {"entity": "thermal treatment", "entity_type": "manufacturing process", "pos": [108, 125]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [164, 185]}], "task": "NER"}
{"text": "However , Van Der Klift , Koga showed that increasing the number of carbon fiber layers results in larger void areas , which had negative effect on the tensile strength .", "entity": [{"entity": "carbon fiber", "entity_type": "material", "pos": [68, 80]}, {"entity": "void", "entity_type": "concept or principle", "pos": [106, 110]}, {"entity": "areas", "entity_type": "process parameter", "pos": [111, 116]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [152, 168]}], "task": "NER"}
{"text": "Impregnation of plastics into the fiber bundle could be achieved in the temperature range of 200Layer thickness of 0.4and hatch spacing of about 0.6mm guaranteed bonding strength between lines and layers .", "entity": [{"entity": "Impregnation", "entity_type": "manufacturing process", "pos": [0, 12]}, {"entity": "plastics", "entity_type": "material", "pos": [16, 24]}, {"entity": "fiber bundle", "entity_type": "material", "pos": [34, 46]}, {"entity": "be", "entity_type": "material", "pos": [53, 55]}, {"entity": "temperature range", "entity_type": "process parameter", "pos": [72, 89]}, {"entity": "hatch spacing", "entity_type": "process parameter", "pos": [122, 135]}, {"entity": "bonding strength", "entity_type": "machanical property", "pos": [162, 178]}], "task": "NER"}
{"text": "These parameters could achieve maximum flexural strength of 335MPa and flexural modulus of 30GPa .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [6, 16]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [39, 56]}], "task": "NER"}
{"text": "2.2 Laminated object manufacturing In LOM , which was developed by Helisys of Torrance , CA and shipped in 1991 , 3D parts are manufactured by cutting 2D crosB-sections with a laser or cutter and sequentially laminating the sheets .", "entity": [{"entity": "Laminated object manufacturing", "entity_type": "manufacturing process", "pos": [4, 34]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [38, 41]}, {"entity": "Helisys of Torrance", "entity_type": "engineering feature", "pos": [67, 86]}, {"entity": "CA", "entity_type": "material", "pos": [89, 91]}, {"entity": "3D parts", "entity_type": "application", "pos": [114, 122]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [127, 139]}, {"entity": "cutting", "entity_type": "manufacturing process", "pos": [143, 150]}, {"entity": "2D", "entity_type": "concept or principle", "pos": [151, 153]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [176, 181]}, {"entity": "sheets", "entity_type": "material", "pos": [224, 230]}], "task": "NER"}
{"text": "Paper , metals , plastics , fabrics , synthetic materials , and composites are amongst the materials that can be utilized in LOM .", "entity": [{"entity": "metals", "entity_type": "material", "pos": [8, 14]}, {"entity": "plastics", "entity_type": "material", "pos": [17, 25]}, {"entity": "synthetic materials", "entity_type": "material", "pos": [38, 57]}, {"entity": "composites", "entity_type": "material", "pos": [64, 74]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [91, 100]}, {"entity": "be", "entity_type": "material", "pos": [110, 112]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [125, 128]}], "task": "NER"}
{"text": "Polymer matrix composites of C-shaped panels were directly fabricated by curved LOM .", "entity": [{"entity": "Polymer matrix composites", "entity_type": "material", "pos": [0, 25]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [59, 69]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [80, 83]}], "task": "NER"}
{"text": "A vacuum thermoforming apparatus was applied to bond commercial prepregs .", "entity": [{"entity": "vacuum thermoforming", "entity_type": "manufacturing process", "pos": [2, 22]}, {"entity": "prepregs", "entity_type": "material", "pos": [64, 72]}], "task": "NER"}
{"text": "The shear strength of fabricated composites was measured to be approximately 24.8MPa , which was suggested by the authors to be acceptable for normal applications .", "entity": [{"entity": "shear strength", "entity_type": "machanical property", "pos": [4, 18]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [22, 32]}, {"entity": "composites", "entity_type": "material", "pos": [33, 43]}, {"entity": "be", "entity_type": "material", "pos": [60, 62]}, {"entity": "be", "entity_type": "material", "pos": [125, 127]}], "task": "NER"}
{"text": "The LOM process was applied to print 3D parts of unidirectional and continuous glass fibers with 52and epoxy matrix .", "entity": [{"entity": "LOM", "entity_type": "manufacturing process", "pos": [4, 7]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [31, 36]}, {"entity": "3D parts", "entity_type": "application", "pos": [37, 45]}, {"entity": "unidirectional", "entity_type": "concept or principle", "pos": [49, 63]}, {"entity": "continuous glass fibers", "entity_type": "material", "pos": [68, 91]}, {"entity": "epoxy matrix", "entity_type": "material", "pos": [103, 115]}], "task": "NER"}
{"text": "The final part and its cross section are presented in 13 .", "entity": [{"entity": "cross section", "entity_type": "concept or principle", "pos": [23, 36]}], "task": "NER"}
{"text": "Decent interfacial bonding was shown by interlayer microstructures of LOM polymer composites .", "entity": [{"entity": "interfacial bonding", "entity_type": "concept or principle", "pos": [7, 26]}, {"entity": "interlayer microstructures", "entity_type": "material", "pos": [40, 66]}, {"entity": "LOM polymer composites", "entity_type": "material", "pos": [70, 92]}], "task": "NER"}
{"text": "The major issue for the LOM process was the incapability of the heat roller to bring parts to full consolidation and cure .", "entity": [{"entity": "LOM", "entity_type": "manufacturing process", "pos": [24, 27]}, {"entity": "heat roller", "entity_type": "machine or equipment", "pos": [64, 75]}, {"entity": "consolidation", "entity_type": "concept or principle", "pos": [99, 112]}, {"entity": "cure", "entity_type": "concept or principle", "pos": [117, 121]}], "task": "NER"}
{"text": "It is helpful to increase the interface strength and reduce void contents to under 5 % by a post consolidation cycle .", "entity": [{"entity": "interface", "entity_type": "concept or principle", "pos": [30, 39]}, {"entity": "void", "entity_type": "concept or principle", "pos": [60, 64]}, {"entity": "consolidation", "entity_type": "concept or principle", "pos": [97, 110]}], "task": "NER"}
{"text": "Sonmez and Hahn studied heat transfer and stress in LOM to understand the effect of process parameters on the resulting stress and temperature distributions .", "entity": [{"entity": "heat transfer", "entity_type": "concept or principle", "pos": [24, 37]}, {"entity": "stress", "entity_type": "machanical property", "pos": [42, 48]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [52, 55]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [84, 102]}, {"entity": "stress", "entity_type": "machanical property", "pos": [120, 126]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [131, 142]}, {"entity": "distributions", "entity_type": "concept or principle", "pos": [143, 156]}], "task": "NER"}
{"text": "Large rollers were more favorable for bonding , due to a less concentrated stress distribution .", "entity": [{"entity": "bonding", "entity_type": "concept or principle", "pos": [38, 45]}, {"entity": "stress distribution", "entity_type": "machanical property", "pos": [75, 94]}], "task": "NER"}
{"text": "Recently , a new method called laser assisted AM for continuous fiber reinforced thermoplastic composites was developed by researchers at Kansas State University , with the motivation of reducing the waste associated with LOM .", "entity": [{"entity": "laser", "entity_type": "enabling technology", "pos": [31, 36]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [46, 48]}, {"entity": "continuous fiber reinforced thermoplastic", "entity_type": "material", "pos": [53, 94]}, {"entity": "composites", "entity_type": "material", "pos": [95, 105]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [222, 225]}], "task": "NER"}
{"text": "The authors proposed using prepreg tape instead of pre-cut prepreg sheet .", "entity": [{"entity": "prepreg", "entity_type": "material", "pos": [27, 34]}, {"entity": "prepreg", "entity_type": "material", "pos": [59, 66]}], "task": "NER"}
{"text": "The tape strips were placed layer by layer using a CO2 laser beam and consolidation roller , prior to laser cutting of each layer .", "entity": [{"entity": "layer by layer", "entity_type": "concept or principle", "pos": [28, 42]}, {"entity": "CO2", "entity_type": "material", "pos": [51, 54]}, {"entity": "beam", "entity_type": "machine or equipment", "pos": [61, 65]}, {"entity": "consolidation", "entity_type": "concept or principle", "pos": [70, 83]}, {"entity": "laser cutting", "entity_type": "manufacturing process", "pos": [102, 115]}, {"entity": "layer", "entity_type": "process parameter", "pos": [124, 129]}], "task": "NER"}
{"text": "14 demonstrates this process schematically , as well as its tensile properties in comparison with various AM and conventional methods of composite manufacturing .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [21, 28]}, {"entity": "as", "entity_type": "material", "pos": [45, 47]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}, {"entity": "tensile properties", "entity_type": "machanical property", "pos": [60, 78]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [106, 108]}, {"entity": "composite manufacturing", "entity_type": "manufacturing process", "pos": [137, 160]}], "task": "NER"}
{"text": "This method exhibits superior mechanical properties due to continuous fiber reinforcement , high fiber weight ratio , minimized void content , and superior interfacial bonding .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [30, 51]}, {"entity": "continuous fiber reinforcement", "entity_type": "material", "pos": [59, 89]}, {"entity": "fiber weight ratio", "entity_type": "engineering feature", "pos": [97, 115]}, {"entity": "minimized void content", "entity_type": "process parameter", "pos": [118, 140]}, {"entity": "interfacial bonding", "entity_type": "concept or principle", "pos": [156, 175]}], "task": "NER"}
{"text": "2.3 Stereolithography The 3D parts fabricated by SL exhibit weak mechanical properties , which hinder their further applications as functional components under loading conditions .", "entity": [{"entity": "Stereolithography", "entity_type": "manufacturing process", "pos": [4, 21]}, {"entity": "3D parts", "entity_type": "application", "pos": [26, 34]}, {"entity": "SL", "entity_type": "manufacturing process", "pos": [49, 51]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [65, 86]}, {"entity": "as", "entity_type": "material", "pos": [129, 131]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [143, 153]}], "task": "NER"}
{"text": "However , adding fibers to the resin can increase the potential of SL in 3D printing functional components .", "entity": [{"entity": "fibers", "entity_type": "material", "pos": [17, 23]}, {"entity": "resin", "entity_type": "material", "pos": [31, 36]}, {"entity": "SL", "entity_type": "manufacturing process", "pos": [67, 69]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [73, 84]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [96, 106]}], "task": "NER"}
{"text": "Although continuous fiber is ideal for reinforcement , high weight ratio of short fibers can yield comparable results , however , their efficiency is limited due to fracture during mixing , random orientation , and un-even length .", "entity": [{"entity": "continuous fiber", "entity_type": "material", "pos": [9, 25]}, {"entity": "reinforcement", "entity_type": "process parameter", "pos": [39, 52]}, {"entity": "weight", "entity_type": "process parameter", "pos": [60, 66]}, {"entity": "short fibers", "entity_type": "material", "pos": [76, 88]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [165, 173]}, {"entity": "mixing", "entity_type": "concept or principle", "pos": [181, 187]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [197, 208]}], "task": "NER"}
{"text": "Multi-wall carbon nanotubes with a low weight ratio were mixed in SL resin by mechanical mixing and ultrasonic dispersion .", "entity": [{"entity": "carbon nanotubes", "entity_type": "material", "pos": [11, 27]}, {"entity": "weight", "entity_type": "process parameter", "pos": [39, 45]}, {"entity": "SL", "entity_type": "manufacturing process", "pos": [66, 68]}, {"entity": "resin", "entity_type": "material", "pos": [69, 74]}, {"entity": "mechanical mixing", "entity_type": "concept or principle", "pos": [78, 95]}, {"entity": "ultrasonic dispersion", "entity_type": "process characterization", "pos": [100, 121]}], "task": "NER"}
{"text": "The tensile strength and fracture strength were increased by 5.7 % and 26 % , respectively , by adding 0.025wt % MWNTs .", "entity": [{"entity": "tensile strength", "entity_type": "machanical property", "pos": [4, 20]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [25, 33]}], "task": "NER"}
{"text": "Carbon fiber has been successfully applied to reinforce polymers , however , the primary issue for utilizing carbon fiber in SL is that it is opaque to the UV light .", "entity": [{"entity": "Carbon fiber", "entity_type": "material", "pos": [0, 12]}, {"entity": "polymers", "entity_type": "material", "pos": [56, 64]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [109, 121]}, {"entity": "SL", "entity_type": "manufacturing process", "pos": [125, 127]}, {"entity": "UV light", "entity_type": "enabling technology", "pos": [156, 164]}], "task": "NER"}
{"text": "Consequently , regions of the resin blocked by carbon fibers remains uncured by UV light .", "entity": [{"entity": "resin", "entity_type": "material", "pos": [30, 35]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [47, 60]}, {"entity": "UV light", "entity_type": "enabling technology", "pos": [80, 88]}], "task": "NER"}
{"text": "Using glass fiber instead of carbon fiber can be beneficial for decreasing the opacity to UV light .", "entity": [{"entity": "glass fiber", "entity_type": "material", "pos": [6, 17]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [29, 41]}, {"entity": "be", "entity_type": "material", "pos": [46, 48]}, {"entity": "UV light", "entity_type": "enabling technology", "pos": [90, 98]}], "task": "NER"}
{"text": "The SL plus vacuum cast process was investigated to improve the tensile strength .", "entity": [{"entity": "SL", "entity_type": "manufacturing process", "pos": [4, 6]}, {"entity": "vacuum cast", "entity_type": "manufacturing process", "pos": [12, 23]}, {"entity": "process", "entity_type": "concept or principle", "pos": [24, 31]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [64, 80]}], "task": "NER"}
{"text": "Tensile samples produced by SL and polymer-glass fiber nonwoven-polymer sandwich structures were introduced by vacuum cast , which showed a significant increase of 36 % in ultimate tensile strength and 11 % increase in stiffness .", "entity": [{"entity": "Tensile", "entity_type": "machanical property", "pos": [0, 7]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [8, 15]}, {"entity": "SL", "entity_type": "manufacturing process", "pos": [28, 30]}, {"entity": "fiber", "entity_type": "material", "pos": [49, 54]}, {"entity": "sandwich structures", "entity_type": "engineering feature", "pos": [72, 91]}, {"entity": "vacuum cast", "entity_type": "manufacturing process", "pos": [111, 122]}, {"entity": "ultimate tensile strength", "entity_type": "machanical property", "pos": [172, 197]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [219, 228]}], "task": "NER"}
{"text": "The viscosity of the resin , especially at low shear rates , increased in the composite resins with significant volume fractions of fibers .", "entity": [{"entity": "viscosity", "entity_type": "machanical property", "pos": [4, 13]}, {"entity": "resin", "entity_type": "material", "pos": [21, 26]}, {"entity": "composite resins", "entity_type": "material", "pos": [78, 94]}, {"entity": "volume fractions", "entity_type": "process parameter", "pos": [112, 128]}, {"entity": "fibers", "entity_type": "material", "pos": [132, 138]}], "task": "NER"}
{"text": "The surface coating of fibers can effectively reduce the viscosity , which is an advantage which allows processing of resins with higher fiber concentrations .", "entity": [{"entity": "surface", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "coating", "entity_type": "application", "pos": [12, 19]}, {"entity": "fibers", "entity_type": "material", "pos": [23, 29]}, {"entity": "viscosity", "entity_type": "machanical property", "pos": [57, 66]}, {"entity": "resins", "entity_type": "material", "pos": [118, 124]}, {"entity": "fiber concentrations", "entity_type": "machanical property", "pos": [137, 157]}], "task": "NER"}
{"text": "Laser scanning based SL was used to add 20vol % of short glass fibers into an acrylic based photo polymer .", "entity": [{"entity": "Laser", "entity_type": "enabling technology", "pos": [0, 5]}, {"entity": "SL", "entity_type": "manufacturing process", "pos": [21, 23]}, {"entity": "glass fibers", "entity_type": "material", "pos": [57, 69]}, {"entity": "acrylic", "entity_type": "material", "pos": [78, 85]}, {"entity": "polymer", "entity_type": "material", "pos": [98, 105]}], "task": "NER"}
{"text": "15 shows the microstructures of molded and laser-scanned specimen with 20vol % glass fiber .", "entity": [{"entity": "microstructures", "entity_type": "material", "pos": [13, 28]}, {"entity": "glass fiber", "entity_type": "material", "pos": [79, 90]}], "task": "NER"}
{"text": "Fiber filled composites represents a higher elastic modulus and ultimate tensile strength .", "entity": [{"entity": "Fiber filled composites", "entity_type": "material", "pos": [0, 23]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [44, 59]}, {"entity": "ultimate tensile strength", "entity_type": "machanical property", "pos": [64, 89]}], "task": "NER"}
{"text": "The shrinkage of fiber reinforced composites was also observed to be lower than their non-reinforced counterparts .", "entity": [{"entity": "shrinkage", "entity_type": "concept or principle", "pos": [4, 13]}, {"entity": "fiber reinforced composites", "entity_type": "material", "pos": [17, 44]}, {"entity": "be", "entity_type": "material", "pos": [66, 68]}], "task": "NER"}
{"text": "Dual porlymerization scheme , including UV radiation and thermal treatments , was proposed to cure resins containing a high volume ratio of carbon fibers .", "entity": [{"entity": "UV", "entity_type": "concept or principle", "pos": [40, 42]}, {"entity": "radiation", "entity_type": "manufacturing process", "pos": [43, 52]}, {"entity": "thermal treatments", "entity_type": "manufacturing process", "pos": [57, 75]}, {"entity": "cure", "entity_type": "concept or principle", "pos": [94, 98]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [124, 130]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [140, 153]}], "task": "NER"}
{"text": "It was estimated that one quarter of resin remains uncured , which was primarily inside of carbon fibers .", "entity": [{"entity": "resin", "entity_type": "material", "pos": [37, 42]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [91, 104]}], "task": "NER"}
{"text": "After an hour of thermal treatment , the tensile strength was increased by 95 % .", "entity": [{"entity": "thermal treatment", "entity_type": "manufacturing process", "pos": [17, 34]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [41, 57]}], "task": "NER"}
{"text": "Llewellyn-Jones , Drinkwater used ultrasonic manipulation to distribute glass microfibers in the resin .", "entity": [{"entity": "ultrasonic manipulation", "entity_type": "process characterization", "pos": [34, 57]}, {"entity": "glass microfibers", "entity_type": "material", "pos": [72, 89]}, {"entity": "resin", "entity_type": "material", "pos": [97, 102]}], "task": "NER"}
{"text": "A variety of fiber orientation angles were achieved , demonstrating the versatility of the process .", "entity": [{"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [13, 30]}, {"entity": "process", "entity_type": "concept or principle", "pos": [91, 98]}], "task": "NER"}
{"text": "This method allows smart material fabrication , such as resin-filled capsules for self-healing or piezoelectric particles for energy harvesting .", "entity": [{"entity": "material", "entity_type": "material", "pos": [25, 33]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [34, 45]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [112, 121]}, {"entity": "energy harvesting", "entity_type": "concept or principle", "pos": [126, 143]}], "task": "NER"}
{"text": "2.4 Extrusion Extrusion , as one of the most recent developments in 3D printing , emerged to overcome the limitations of the FDM method with its versatility and cost-effectiveness .", "entity": [{"entity": "Extrusion", "entity_type": "manufacturing process", "pos": [4, 13]}, {"entity": "as", "entity_type": "material", "pos": [26, 28]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [68, 79]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [125, 128]}], "task": "NER"}
{"text": "In this AM technique , layers of the material solution are directly deposited in a volatile solvent to produce freeform 3D structures .", "entity": [{"entity": "AM technique", "entity_type": "manufacturing process", "pos": [8, 20]}, {"entity": "material", "entity_type": "material", "pos": [37, 45]}, {"entity": "freeform 3D", "entity_type": "concept or principle", "pos": [111, 122]}], "task": "NER"}
{"text": "Lightweight cellular carbon fiber and SiC whiskers filled composites have been demonstrated by applying 3D extrusion printing method , as described in 16 .", "entity": [{"entity": "Lightweight", "entity_type": "concept or principle", "pos": [0, 11]}, {"entity": "cellular carbon fiber", "entity_type": "process characterization", "pos": [12, 33]}, {"entity": "SiC whiskers", "entity_type": "material", "pos": [38, 50]}, {"entity": "composites", "entity_type": "material", "pos": [58, 68]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [104, 106]}, {"entity": "as", "entity_type": "material", "pos": [135, 137]}], "task": "NER"}
{"text": "Epoxy-based inks , which exhibited the desired viscoelasticity and long pot-life in the absence and presence of highly anisotropic carbon fibers , were prepared .", "entity": [{"entity": "Epoxy-based inks", "entity_type": "material", "pos": [0, 16]}, {"entity": "viscoelasticity", "entity_type": "machanical property", "pos": [47, 62]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [119, 130]}, {"entity": "fibers", "entity_type": "material", "pos": [138, 144]}], "task": "NER"}
{"text": "The SiC-filled and SiC/C filled transverse specimens showed a substantial increase in Youngmodulus , over the pure resin from 2.66 to 10.61 and 8.06 respectively .", "entity": [{"entity": "Youngmodulus", "entity_type": "machanical property", "pos": [86, 98]}, {"entity": "pure resin", "entity_type": "material", "pos": [110, 120]}], "task": "NER"}
{"text": "Tensile strength of printed composites was comparable to the cast epoxy resin samples , with longitudinal specimens exhibiting slightly higher strength than that the transverse specimens .", "entity": [{"entity": "Tensile strength", "entity_type": "machanical property", "pos": [0, 16]}, {"entity": "composites", "entity_type": "material", "pos": [28, 38]}, {"entity": "cast", "entity_type": "manufacturing process", "pos": [61, 65]}, {"entity": "resin", "entity_type": "material", "pos": [72, 77]}, {"entity": "strength", "entity_type": "machanical property", "pos": [143, 151]}], "task": "NER"}
{"text": "17 shows a comparison in tensile strength of 3D printed tensile bars , using various fillers , as well as their microstructure .", "entity": [{"entity": "tensile strength", "entity_type": "machanical property", "pos": [25, 41]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [45, 55]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}, {"entity": "as", "entity_type": "material", "pos": [103, 105]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [112, 126]}], "task": "NER"}
{"text": "PLA/MWNTs composite was used to fabricate conductive 3D microstructures , with arbitrary shapes as small as 100with a method called liquid deposition modeling .", "entity": [{"entity": "composite", "entity_type": "material", "pos": [10, 19]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [32, 41]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [53, 55]}, {"entity": "as", "entity_type": "material", "pos": [96, 98]}, {"entity": "as", "entity_type": "material", "pos": [105, 107]}, {"entity": "deposition modeling", "entity_type": "concept or principle", "pos": [139, 158]}], "task": "NER"}
{"text": "2.5 Selective laser sintering SLS is a powder based AM process .", "entity": [{"entity": "Selective laser sintering", "entity_type": "manufacturing process", "pos": [4, 29]}, {"entity": "powder", "entity_type": "material", "pos": [39, 45]}, {"entity": "AM process", "entity_type": "manufacturing process", "pos": [52, 62]}], "task": "NER"}
{"text": "The laser scans the powder bed , layer by layer , to form a 3D structure , as demonstrated in 18 .", "entity": [{"entity": "laser scans", "entity_type": "enabling technology", "pos": [4, 15]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [20, 30]}, {"entity": "layer by layer", "entity_type": "concept or principle", "pos": [33, 47]}, {"entity": "3D structure", "entity_type": "concept or principle", "pos": [60, 72]}, {"entity": "as", "entity_type": "material", "pos": [75, 77]}], "task": "NER"}
{"text": "It mainly deals with wax , ceramics , metals and polymers .", "entity": [{"entity": "wax", "entity_type": "material", "pos": [21, 24]}, {"entity": "ceramics", "entity_type": "material", "pos": [27, 35]}, {"entity": "metals", "entity_type": "material", "pos": [38, 44]}, {"entity": "polymers", "entity_type": "material", "pos": [49, 57]}], "task": "NER"}
{"text": "Major polymers used by SLS include nylon , i.e .", "entity": [{"entity": "polymers", "entity_type": "material", "pos": [6, 14]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [23, 26]}, {"entity": "nylon", "entity_type": "material", "pos": [35, 40]}], "task": "NER"}
{"text": "polyamide , crystalline thermoplastics : polyethylene , PEEK , and PCL .", "entity": [{"entity": "polyamide", "entity_type": "material", "pos": [0, 9]}, {"entity": "crystalline thermoplastics", "entity_type": "material", "pos": [12, 38]}, {"entity": "polyethylene", "entity_type": "material", "pos": [41, 53]}, {"entity": "PEEK", "entity_type": "material", "pos": [56, 60]}, {"entity": "PCL", "entity_type": "material", "pos": [67, 70]}], "task": "NER"}
{"text": "SLS can be categorized in solid state sintering , liquid phase sintering-partial melting , full melting , and chemically induced binding .", "entity": [{"entity": "SLS", "entity_type": "manufacturing process", "pos": [0, 3]}, {"entity": "be", "entity_type": "material", "pos": [8, 10]}, {"entity": "solid state sintering", "entity_type": "manufacturing process", "pos": [26, 47]}, {"entity": "liquid phase", "entity_type": "machanical property", "pos": [50, 62]}, {"entity": "melting", "entity_type": "manufacturing process", "pos": [81, 88]}, {"entity": "melting", "entity_type": "manufacturing process", "pos": [96, 103]}], "task": "NER"}
{"text": "SSS is a thermal process that occurs at temperatures between TMelt /2 and TMelt , where TMelt is the melting temperature .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [17, 24]}, {"entity": "temperatures", "entity_type": "process parameter", "pos": [40, 52]}, {"entity": "melting temperature", "entity_type": "process parameter", "pos": [101, 120]}], "task": "NER"}
{"text": "In liquid phase sintering-partial melting , usually the binder material becomes liquefied , while structural material remains solid .", "entity": [{"entity": "liquid phase", "entity_type": "machanical property", "pos": [3, 15]}, {"entity": "melting", "entity_type": "manufacturing process", "pos": [34, 41]}, {"entity": "binder", "entity_type": "material", "pos": [56, 62]}, {"entity": "material", "entity_type": "material", "pos": [63, 71]}], "task": "NER"}
{"text": "The full melting technique melts the powder entirely and exhibits properties comparable to those of bulk material .", "entity": [{"entity": "melting", "entity_type": "manufacturing process", "pos": [9, 16]}, {"entity": "powder", "entity_type": "material", "pos": [37, 43]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [66, 76]}, {"entity": "material", "entity_type": "material", "pos": [105, 113]}], "task": "NER"}
{"text": "It can be applied to a wide variety of materials , however , the long process time and preheating of powders is necessary .", "entity": [{"entity": "be", "entity_type": "material", "pos": [7, 9]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [39, 48]}, {"entity": "process time", "entity_type": "concept or principle", "pos": [70, 82]}, {"entity": "preheating", "entity_type": "manufacturing process", "pos": [87, 97]}, {"entity": "powders", "entity_type": "material", "pos": [101, 108]}], "task": "NER"}
{"text": "1 lists the range of materials and their associated binding mechanism in SLS .", "entity": [{"entity": "range", "entity_type": "process parameter", "pos": [12, 17]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [21, 30]}, {"entity": "mechanism", "entity_type": "concept or principle", "pos": [60, 69]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [73, 76]}], "task": "NER"}
{"text": "CNT was added in Polyamide 12 in order to improve the mechanical behaviors .", "entity": [{"entity": "CNT", "entity_type": "material", "pos": [0, 3]}, {"entity": "Polyamide 12", "entity_type": "material", "pos": [17, 29]}, {"entity": "mechanical", "entity_type": "application", "pos": [54, 64]}], "task": "NER"}
{"text": "The laser sintered parts had 13 % greater flexural modulus , 10.9 % higher flexural strength , and 54 % larger Youngmodulus .", "entity": [{"entity": "laser", "entity_type": "enabling technology", "pos": [4, 9]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [75, 92]}, {"entity": "Youngmodulus", "entity_type": "machanical property", "pos": [111, 123]}], "task": "NER"}
{"text": "The crystallization temperature of PA12-CNT powder was increased , compared to the pure PA12 , which was responsible in hindering the movement of PA12 chains by the interfacial force between CNTs and PA12 .", "entity": [{"entity": "crystallization", "entity_type": "concept or principle", "pos": [4, 19]}, {"entity": "powder", "entity_type": "material", "pos": [44, 50]}, {"entity": "pure PA12", "entity_type": "material", "pos": [83, 92]}, {"entity": "PA12", "entity_type": "material", "pos": [146, 150]}, {"entity": "interfacial force", "entity_type": "enabling technology", "pos": [165, 182]}, {"entity": "CNTs", "entity_type": "material", "pos": [191, 195]}, {"entity": "PA12", "entity_type": "material", "pos": [200, 204]}], "task": "NER"}
{"text": "However , the porosity also increased in the CNT composites .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [14, 22]}, {"entity": "CNT composites", "entity_type": "material", "pos": [45, 59]}], "task": "NER"}
{"text": "MWNTs were also mixed with PA12 for the investigation of its effect on mechanical properties .", "entity": [{"entity": "PA12", "entity_type": "material", "pos": [27, 31]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [71, 92]}], "task": "NER"}
{"text": "Goodridge , Shofner also confirmed enhancement in mechanical properties of PA12 with inclusion of CNT , exhibiting 22 % increase in storage modulus .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [50, 71]}, {"entity": "PA12", "entity_type": "material", "pos": [75, 79]}, {"entity": "inclusion", "entity_type": "material", "pos": [85, 94]}, {"entity": "CNT", "entity_type": "material", "pos": [98, 101]}], "task": "NER"}
{"text": "A high volume ratio of carbon fiber was added into PA12 .", "entity": [{"entity": "volume", "entity_type": "concept or principle", "pos": [7, 13]}, {"entity": "carbon fiber", "entity_type": "material", "pos": [23, 35]}, {"entity": "PA12", "entity_type": "material", "pos": [51, 55]}], "task": "NER"}
{"text": "CNT-coated PA12 also improved heat conduction and heat absorption compared to pure PA12.. Furthermore , simulation results on laser sintering of PA12-CNT suggested that inclusion of CNT helps the laser heat to be conducted wider and deeper into the powder bed .", "entity": [{"entity": "PA12", "entity_type": "material", "pos": [11, 15]}, {"entity": "heat conduction", "entity_type": "concept or principle", "pos": [30, 45]}, {"entity": "heat absorption", "entity_type": "machanical property", "pos": [50, 65]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [104, 114]}, {"entity": "laser sintering", "entity_type": "manufacturing process", "pos": [126, 141]}, {"entity": "inclusion", "entity_type": "material", "pos": [169, 178]}, {"entity": "CNT", "entity_type": "material", "pos": [182, 185]}, {"entity": "laser heat", "entity_type": "process parameter", "pos": [196, 206]}, {"entity": "be", "entity_type": "material", "pos": [210, 212]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [249, 259]}], "task": "NER"}
{"text": "The result of these simulations can be observed in 19 .", "entity": [{"entity": "simulations", "entity_type": "enabling technology", "pos": [20, 31]}, {"entity": "be", "entity_type": "material", "pos": [36, 38]}], "task": "NER"}
{"text": "Uniform distribution of carbon fibers and good interfacial adhesion between fibers and matrix was achieved by pre-modification of carbon fibers through oxidation .", "entity": [{"entity": "distribution", "entity_type": "concept or principle", "pos": [8, 20]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [24, 37]}, {"entity": "adhesion", "entity_type": "machanical property", "pos": [59, 67]}, {"entity": "fibers", "entity_type": "material", "pos": [76, 82]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [130, 143]}, {"entity": "oxidation", "entity_type": "manufacturing process", "pos": [152, 161]}], "task": "NER"}
{"text": "By adding the maximum weight ratio of carbon fibers , the flexural strength and flexural modulus were enhanced 114 % and 243.4 % , respectively .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [22, 28]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [38, 51]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [58, 75]}], "task": "NER"}
{"text": "Glass beads were used asadditives in SLS of Nylon powders , in order to determine the mechanical properties , as a function of material composition .", "entity": [{"entity": "Glass beads", "entity_type": "material", "pos": [0, 11]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [37, 40]}, {"entity": "Nylon", "entity_type": "material", "pos": [44, 49]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [86, 107]}, {"entity": "as", "entity_type": "material", "pos": [110, 112]}, {"entity": "material", "entity_type": "material", "pos": [127, 135]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [136, 147]}], "task": "NER"}
{"text": "Zhu , Yan proposed a novel method to prepare high-performance carbon fibers/PA12/epoxy ternary composites by infiltrating the porous green carbon fibers/PA12 parts built by SLS , with high-performance thermosetting epoxy resin , prior to curing the resin ; this process is described in 20 .", "entity": [{"entity": "carbon", "entity_type": "material", "pos": [62, 68]}, {"entity": "composites", "entity_type": "material", "pos": [95, 105]}, {"entity": "infiltrating", "entity_type": "concept or principle", "pos": [109, 121]}, {"entity": "porous", "entity_type": "machanical property", "pos": [126, 132]}, {"entity": "carbon", "entity_type": "material", "pos": [139, 145]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [173, 176]}, {"entity": "epoxy", "entity_type": "material", "pos": [215, 220]}, {"entity": "curing", "entity_type": "manufacturing process", "pos": [238, 244]}, {"entity": "resin", "entity_type": "material", "pos": [249, 254]}, {"entity": "process", "entity_type": "concept or principle", "pos": [262, 269]}], "task": "NER"}
{"text": "The end result is a ternary composite system with novolac epoxy resin , reinforced with carbon fibers coated with a thin 595nm layer of PA12 .", "entity": [{"entity": "ternary composite system", "entity_type": "material", "pos": [20, 44]}, {"entity": "novolac epoxy resin", "entity_type": "material", "pos": [50, 69]}, {"entity": "reinforced", "entity_type": "concept or principle", "pos": [72, 82]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [88, 101]}, {"entity": "layer", "entity_type": "process parameter", "pos": [127, 132]}, {"entity": "PA12", "entity_type": "material", "pos": [136, 140]}], "task": "NER"}
{"text": "This method with 33 % volume fraction of carbon fibers yielded an ultimate tensile strength of 101.03MPa and a flexural strength of 153.43MPa .", "entity": [{"entity": "volume fraction", "entity_type": "process parameter", "pos": [22, 37]}, {"entity": "carbon fibers", "entity_type": "material", "pos": [41, 54]}, {"entity": "ultimate tensile strength", "entity_type": "machanical property", "pos": [66, 91]}, {"entity": "flexural strength", "entity_type": "machanical property", "pos": [111, 128]}], "task": "NER"}
{"text": "3 Four-Dimensional printing of active Polymer-Fiber composites Addition of fiber in 3D printed polymers is not always for improving the mechanical properties .", "entity": [{"entity": "Polymer-Fiber composites", "entity_type": "material", "pos": [38, 62]}, {"entity": "fiber", "entity_type": "material", "pos": [75, 80]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [84, 94]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [136, 157]}], "task": "NER"}
{"text": "Fibers , as well other additives , are also used in manufacturing of smart composites , to control the structure transformation .", "entity": [{"entity": "Fibers", "entity_type": "material", "pos": [0, 6]}, {"entity": "as", "entity_type": "material", "pos": [9, 11]}, {"entity": "additives", "entity_type": "material", "pos": [23, 32]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [52, 65]}, {"entity": "composites", "entity_type": "material", "pos": [75, 85]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [103, 112]}], "task": "NER"}
{"text": "This implementation in 3D printing opened a new field called 4D printing .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [23, 34]}, {"entity": "4D printing", "entity_type": "manufacturing process", "pos": [61, 72]}], "task": "NER"}
{"text": "4D printing refers to a multi-material printing with the ability to transform over time or change its shape after the printing .", "entity": [{"entity": "4D printing", "entity_type": "manufacturing process", "pos": [0, 11]}, {"entity": "multi-material printing", "entity_type": "manufacturing process", "pos": [24, 47]}], "task": "NER"}
{"text": "These structures can be programmable and transformed from one or two dimensional structures to 3D objects .", "entity": [{"entity": "be", "entity_type": "material", "pos": [21, 23]}, {"entity": "3D objects", "entity_type": "application", "pos": [95, 105]}], "task": "NER"}
{"text": "Recent advances in AM made precise placement of material at micro-scale during 3D printing of complex structures possible .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [19, 21]}, {"entity": "material", "entity_type": "material", "pos": [48, 56]}, {"entity": "micro-scale", "entity_type": "concept or principle", "pos": [60, 71]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [79, 90]}, {"entity": "complex structures", "entity_type": "concept or principle", "pos": [94, 112]}], "task": "NER"}
{"text": "This allows implementing programmable and computational material in AM in order to control the shape of the material after printing .", "entity": [{"entity": "material", "entity_type": "material", "pos": [56, 64]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [68, 70]}, {"entity": "material", "entity_type": "material", "pos": [108, 116]}], "task": "NER"}
{"text": "These materials can change their shape under light , temperature change , or immersion into a solvent .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [6, 15]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [53, 64]}], "task": "NER"}
{"text": "3D printing technology has enabled active material to achieve an even higher complexity and accuracy .", "entity": [{"entity": "3D printing technology", "entity_type": "enabling technology", "pos": [0, 22]}, {"entity": "material", "entity_type": "material", "pos": [42, 50]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [77, 87]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [92, 100]}], "task": "NER"}
{"text": "Fiber additives play an important role in 4D printing ; controlling the fiber alignment allows programmable transformation , right out of the printing bed .", "entity": [{"entity": "Fiber additives", "entity_type": "material", "pos": [0, 15]}, {"entity": "4D printing", "entity_type": "manufacturing process", "pos": [42, 53]}, {"entity": "fiber alignment", "entity_type": "engineering feature", "pos": [72, 87]}, {"entity": "bed", "entity_type": "machine or equipment", "pos": [151, 154]}], "task": "NER"}
{"text": "Ge , Qi developed a method to print thermomechanically programmable composites with complex shapes .", "entity": [{"entity": "Ge", "entity_type": "material", "pos": [0, 2]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [30, 35]}, {"entity": "composites", "entity_type": "material", "pos": [68, 78]}, {"entity": "complex shapes", "entity_type": "machanical property", "pos": [84, 98]}], "task": "NER"}
{"text": "The matrix and fibers used were an elastomer and a glassy polymer , with tailored thermomechanical behavior , respectively .", "entity": [{"entity": "fibers", "entity_type": "material", "pos": [15, 21]}, {"entity": "elastomer", "entity_type": "material", "pos": [35, 44]}, {"entity": "polymer", "entity_type": "material", "pos": [58, 65]}, {"entity": "thermomechanical", "entity_type": "concept or principle", "pos": [82, 98]}], "task": "NER"}
{"text": "21 demonstrates the process in which the inkjet deposited material on the bed , prior to photopolymerization of the film by UV light , forms a layer .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [20, 27]}, {"entity": "inkjet", "entity_type": "manufacturing process", "pos": [41, 47]}, {"entity": "material", "entity_type": "material", "pos": [58, 66]}, {"entity": "bed", "entity_type": "machine or equipment", "pos": [74, 77]}, {"entity": "photopolymerization", "entity_type": "manufacturing process", "pos": [89, 108]}, {"entity": "UV light", "entity_type": "enabling technology", "pos": [124, 132]}, {"entity": "layer", "entity_type": "process parameter", "pos": [143, 148]}], "task": "NER"}
{"text": "Gladman , Matsumoto printed plant-inspired architectures , with a hydrogel composite ink , composed of stiff cellulose fibrils embedded in a soft acrylamide matrix .", "entity": [{"entity": "hydrogel composite", "entity_type": "material", "pos": [66, 84]}, {"entity": "cellulose fibrils", "entity_type": "material", "pos": [109, 126]}, {"entity": "acrylamide matrix", "entity_type": "material", "pos": [146, 163]}], "task": "NER"}
{"text": "Alignment of cellulose fibrils controlled the swelling of the 3D printed part upon immersion in water .", "entity": [{"entity": "cellulose fibrils", "entity_type": "material", "pos": [13, 30]}, {"entity": "swelling", "entity_type": "concept or principle", "pos": [46, 54]}, {"entity": "3D printed part", "entity_type": "application", "pos": [62, 77]}], "task": "NER"}
{"text": "These structures are programmable based on the printing direction and orientation of embedded cellulose fibrils inside the structure .", "entity": [{"entity": "orientation", "entity_type": "concept or principle", "pos": [70, 81]}, {"entity": "cellulose fibrils", "entity_type": "material", "pos": [94, 111]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [123, 132]}], "task": "NER"}
{"text": "4 Modeling and analytical techniques Polymer-fiber composites produced by AM can be analyzed using existing theories based on the manufacturing technique and the reinforcement type .", "entity": [{"entity": "Modeling", "entity_type": "enabling technology", "pos": [2, 10]}, {"entity": "Polymer-fiber composites", "entity_type": "material", "pos": [37, 61]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [74, 76]}, {"entity": "be", "entity_type": "material", "pos": [81, 83]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [130, 143]}, {"entity": "reinforcement", "entity_type": "process parameter", "pos": [162, 175]}], "task": "NER"}
{"text": "Existing macro and micro mechanical modelling techniques can be applied to AM with slight modifications .", "entity": [{"entity": "macro", "entity_type": "engineering feature", "pos": [9, 14]}, {"entity": "mechanical modelling", "entity_type": "concept or principle", "pos": [25, 45]}, {"entity": "be", "entity_type": "material", "pos": [61, 63]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [75, 77]}], "task": "NER"}
{"text": "Microstructure of 3D printed parts often differ from those prepared by traditional manufacturing methods and with the immerging of new AM methods , there is a demand for modelling and analysis of these structures .", "entity": [{"entity": "Microstructure", "entity_type": "concept or principle", "pos": [0, 14]}, {"entity": "3D printed parts", "entity_type": "application", "pos": [18, 34]}, {"entity": "traditional manufacturing", "entity_type": "manufacturing process", "pos": [71, 96]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [135, 137]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [170, 179]}], "task": "NER"}
{"text": "4.1 Short fiber composite theories There are several theories for predicting the properties of short fiber composites .", "entity": [{"entity": "Short fiber composite", "entity_type": "material", "pos": [4, 25]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [81, 91]}, {"entity": "short fiber composites", "entity_type": "material", "pos": [95, 117]}], "task": "NER"}
{"text": "Depending on their assumptions , they can be applied to various 3D printing methods .", "entity": [{"entity": "be", "entity_type": "material", "pos": [42, 44]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [64, 75]}], "task": "NER"}
{"text": "Fibers alignment , shape , length , and its bonding with the matrix are crucial in accuracy of the modelling .", "entity": [{"entity": "Fibers alignment", "entity_type": "engineering feature", "pos": [0, 16]}, {"entity": "bonding", "entity_type": "concept or principle", "pos": [44, 51]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [83, 91]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [99, 108]}], "task": "NER"}
{"text": "The modified rule of mixtures is the simplest method to predict the tensile properties of short fiber composites , by assuming perfect fiberinterfacial bonding .", "entity": [{"entity": "rule of mixtures", "entity_type": "concept or principle", "pos": [13, 29]}, {"entity": "tensile properties", "entity_type": "machanical property", "pos": [68, 86]}, {"entity": "short fiber composites", "entity_type": "material", "pos": [90, 112]}, {"entity": "fiberinterfacial bonding", "entity_type": "concept or principle", "pos": [135, 159]}], "task": "NER"}
{"text": "MROM is given by cu = 1 2 V f fu + V m m where 1 2 is fiber efficiency factor for the strength of the composite , in which , 1 and 2 are the fiber orientation and fiber length factors , respectively ; cu and fu are ultimate strength of the composite and fiber , respectively ; V f and V m represent the volume fraction of the fiber and matrix ; and m is the matrix stress at the composite failure .", "entity": [{"entity": "cu", "entity_type": "material", "pos": [17, 19]}, {"entity": "V", "entity_type": "material", "pos": [26, 27]}, {"entity": "f", "entity_type": "manufacturing process", "pos": [28, 29]}, {"entity": "V", "entity_type": "material", "pos": [35, 36]}, {"entity": "fiber efficiency factor", "entity_type": "machanical property", "pos": [54, 77]}, {"entity": "strength", "entity_type": "machanical property", "pos": [86, 94]}, {"entity": "composite", "entity_type": "material", "pos": [102, 111]}, {"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [141, 158]}, {"entity": "fiber length factors", "entity_type": "engineering feature", "pos": [163, 183]}, {"entity": "cu", "entity_type": "material", "pos": [201, 203]}, {"entity": "ultimate strength", "entity_type": "machanical property", "pos": [215, 232]}, {"entity": "composite", "entity_type": "material", "pos": [240, 249]}, {"entity": "fiber", "entity_type": "material", "pos": [254, 259]}, {"entity": "V", "entity_type": "material", "pos": [277, 278]}, {"entity": "f", "entity_type": "manufacturing process", "pos": [279, 280]}, {"entity": "V", "entity_type": "material", "pos": [285, 286]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [303, 318]}, {"entity": "fiber", "entity_type": "material", "pos": [326, 331]}, {"entity": "matrix stress", "entity_type": "concept or principle", "pos": [358, 371]}, {"entity": "composite failure", "entity_type": "process characterization", "pos": [379, 396]}], "task": "NER"}
{"text": "If the fiber length is equal to L and uniform , fiber orientation factor is equal to 1 and fiber length factor is given by the critical fiber length , r f is fiber radius , and i is interfacial shear stress between matrix and fibers .", "entity": [{"entity": "fiber length", "entity_type": "concept or principle", "pos": [7, 19]}, {"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [48, 65]}, {"entity": "fiber length factor", "entity_type": "engineering feature", "pos": [91, 110]}, {"entity": "critical fiber length", "entity_type": "machanical property", "pos": [127, 148]}, {"entity": "f", "entity_type": "manufacturing process", "pos": [153, 154]}, {"entity": "fiber radius", "entity_type": "engineering feature", "pos": [158, 170]}, {"entity": "interfacial shear stress", "entity_type": "machanical property", "pos": [182, 206]}, {"entity": "fibers", "entity_type": "material", "pos": [226, 232]}], "task": "NER"}
{"text": "In order to consider the effect of fiber orientation and non-uniform fiber length in the model , 1 and 2 should be modified .", "entity": [{"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [35, 52]}, {"entity": "fiber length", "entity_type": "concept or principle", "pos": [69, 81]}, {"entity": "model", "entity_type": "concept or principle", "pos": [89, 94]}, {"entity": "be", "entity_type": "material", "pos": [112, 114]}], "task": "NER"}
{"text": "Modified Kelly and Tyson model proposed for fibers shorter and longer than the critical fiber length with considering fiber orientation , as follows .", "entity": [{"entity": "model", "entity_type": "concept or principle", "pos": [25, 30]}, {"entity": "fibers", "entity_type": "material", "pos": [44, 50]}, {"entity": "critical fiber length", "entity_type": "machanical property", "pos": [79, 100]}, {"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [118, 135]}, {"entity": "as", "entity_type": "material", "pos": [138, 140]}], "task": "NER"}
{"text": "However , fiber orientation factor 1 in this model is fitted empirically .", "entity": [{"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [10, 27]}, {"entity": "model", "entity_type": "concept or principle", "pos": [45, 50]}], "task": "NER"}
{"text": "Fu and Lauke used two probability density functions for modelling the fiber length and fiber orientation distributions with the intention of predicting the elastic properties .", "entity": [{"entity": "probability density functions", "entity_type": "concept or principle", "pos": [22, 51]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [56, 65]}, {"entity": "fiber length", "entity_type": "concept or principle", "pos": [70, 82]}, {"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [87, 104]}, {"entity": "distributions", "entity_type": "concept or principle", "pos": [105, 118]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [156, 163]}], "task": "NER"}
{"text": "There are various theories for predicting the stiffness properties of short-fiber composites .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [46, 55]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [56, 66]}, {"entity": "composites", "entity_type": "material", "pos": [82, 92]}], "task": "NER"}
{"text": "The Morimodel is another well-known theory that considers a non-dilute composite containing many identical spheroidal particles .", "entity": [{"entity": "composite", "entity_type": "material", "pos": [71, 80]}, {"entity": "particles", "entity_type": "concept or principle", "pos": [118, 127]}], "task": "NER"}
{"text": "It is assumed that the composite experiences an average stress different from that of the applied stress .", "entity": [{"entity": "composite", "entity_type": "material", "pos": [23, 32]}, {"entity": "average", "entity_type": "concept or principle", "pos": [48, 55]}, {"entity": "stress", "entity_type": "machanical property", "pos": [56, 62]}], "task": "NER"}
{"text": "Longitudinal and transverse elastic moduli in Morimodel are where V f is the volume fraction of filler and m is the Poissonratio of the matrix ; A1 , A2 , A3 , A4 , A5 , and A are functions of the Eshelbytensor and the properties of the fiber and the matrix , with more explanation given in .", "entity": [{"entity": "elastic moduli", "entity_type": "machanical property", "pos": [28, 42]}, {"entity": "V", "entity_type": "material", "pos": [66, 67]}, {"entity": "f", "entity_type": "manufacturing process", "pos": [68, 69]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [77, 92]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [219, 229]}, {"entity": "fiber", "entity_type": "material", "pos": [237, 242]}], "task": "NER"}
{"text": "In theory , the aforementioned equations for short fiber composites , can be used to model 3D printed parts , however , length and orientation of the fibers used in the process should match the assumptions .", "entity": [{"entity": "short fiber composites", "entity_type": "material", "pos": [45, 67]}, {"entity": "be", "entity_type": "material", "pos": [74, 76]}, {"entity": "model", "entity_type": "concept or principle", "pos": [85, 90]}, {"entity": "3D printed parts", "entity_type": "application", "pos": [91, 107]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [131, 142]}, {"entity": "fibers", "entity_type": "material", "pos": [150, 156]}, {"entity": "process", "entity_type": "concept or principle", "pos": [169, 176]}], "task": "NER"}
{"text": "FDM , SLS , and extrusion with short fiber reinforcement can be modeled with these analytical methods .", "entity": [{"entity": "FDM", "entity_type": "manufacturing process", "pos": [0, 3]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [6, 9]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [16, 25]}, {"entity": "short fiber reinforcement", "entity_type": "material", "pos": [31, 56]}, {"entity": "be", "entity_type": "material", "pos": [61, 63]}], "task": "NER"}
{"text": "However , 3D printed parts often contain considerable fraction of void content and modifications may be necessary when applying these methods on additive manufacturing .", "entity": [{"entity": "3D printed parts", "entity_type": "application", "pos": [10, 26]}, {"entity": "fraction", "entity_type": "concept or principle", "pos": [54, 62]}, {"entity": "void", "entity_type": "concept or principle", "pos": [66, 70]}, {"entity": "be", "entity_type": "material", "pos": [101, 103]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [145, 167]}], "task": "NER"}
{"text": "Void in composite materials are comprehensively explained in .", "entity": [{"entity": "Void", "entity_type": "concept or principle", "pos": [0, 4]}, {"entity": "composite materials", "entity_type": "material", "pos": [8, 27]}], "task": "NER"}
{"text": "4.2 Classical laminate plate theory CLPT is an extension of the classical plate theory for isotropic and homogeneous materials with some modifications to reflect the inhomogeneity of orthotropic materials in thickness direction .", "entity": [{"entity": "Classical laminate plate theory", "entity_type": "concept or principle", "pos": [4, 35]}, {"entity": "classical plate theory", "entity_type": "concept or principle", "pos": [64, 86]}, {"entity": "isotropic", "entity_type": "machanical property", "pos": [91, 100]}, {"entity": "homogeneous materials", "entity_type": "material", "pos": [105, 126]}, {"entity": "orthotropic", "entity_type": "material", "pos": [183, 194]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [195, 204]}], "task": "NER"}
{"text": "CLTP is applicable to all 3D printed parts that exhibit orthogonal behavior .", "entity": [{"entity": "3D printed parts", "entity_type": "application", "pos": [26, 42]}], "task": "NER"}
{"text": "Here , we present a brief summary of CLPT for laminated plates consisting of multiple unidirectional laminae .", "entity": [{"entity": "laminated plates", "entity_type": "machine or equipment", "pos": [46, 62]}, {"entity": "unidirectional laminae", "entity_type": "biomedical", "pos": [86, 108]}], "task": "NER"}
{"text": "The stiffness matrix of each ply can be described as .", "entity": [{"entity": "stiffness matrix", "entity_type": "machanical property", "pos": [4, 20]}, {"entity": "be", "entity_type": "material", "pos": [37, 39]}, {"entity": "as", "entity_type": "material", "pos": [50, 52]}], "task": "NER"}
{"text": "Transformed reduced stiffness matrix for various fiber orientation can be computed using transformation matrix as follow , and is the angle of the fiber reinforcement .", "entity": [{"entity": "stiffness matrix", "entity_type": "machanical property", "pos": [20, 36]}, {"entity": "fiber orientation", "entity_type": "engineering feature", "pos": [49, 66]}, {"entity": "be", "entity_type": "material", "pos": [71, 73]}, {"entity": "transformation matrix", "entity_type": "concept or principle", "pos": [89, 110]}, {"entity": "as", "entity_type": "material", "pos": [111, 113]}, {"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [147, 166]}], "task": "NER"}
{"text": "Then , in-plane , coupling , and bending stiffness matrices can be obtained by , respectively where z represents the vertical position in the ply from the midplane .", "entity": [{"entity": "bending", "entity_type": "manufacturing process", "pos": [33, 40]}, {"entity": "be", "entity_type": "material", "pos": [64, 66]}, {"entity": "vertical", "entity_type": "concept or principle", "pos": [117, 125]}, {"entity": "midplane", "entity_type": "concept or principle", "pos": [155, 163]}], "task": "NER"}
{"text": "Finally , we can write a connection between the applied loads and the associated strains in the laminate , as follows , N M = A B B D 0 where N is normal stress resultants , M is moment resultants , 0 represent strain term in midplane , and is the twist of the laminated plate .", "entity": [{"entity": "laminate", "entity_type": "concept or principle", "pos": [96, 104]}, {"entity": "as", "entity_type": "material", "pos": [107, 109]}, {"entity": "N", "entity_type": "material", "pos": [120, 121]}, {"entity": "B", "entity_type": "material", "pos": [128, 129]}, {"entity": "N", "entity_type": "material", "pos": [142, 143]}, {"entity": "stress", "entity_type": "machanical property", "pos": [154, 160]}, {"entity": "strain", "entity_type": "machanical property", "pos": [211, 217]}, {"entity": "midplane", "entity_type": "concept or principle", "pos": [226, 234]}, {"entity": "laminated plate", "entity_type": "machine or equipment", "pos": [261, 276]}], "task": "NER"}
{"text": "The strain along the plate thickness can be given by , x y xy = x 0 y 0 xy 0 + z x y xy Additionally , by using the same principle , CLPT can be applied to evaluate the strength and elastic constants of FDM printed parts with void content .", "entity": [{"entity": "strain", "entity_type": "machanical property", "pos": [4, 10]}, {"entity": "be", "entity_type": "material", "pos": [41, 43]}, {"entity": "y", "entity_type": "material", "pos": [51, 52]}, {"entity": "y", "entity_type": "material", "pos": [57, 58]}, {"entity": "y", "entity_type": "material", "pos": [60, 61]}, {"entity": "be", "entity_type": "material", "pos": [142, 144]}, {"entity": "strength", "entity_type": "machanical property", "pos": [169, 177]}, {"entity": "elastic constants", "entity_type": "process parameter", "pos": [182, 199]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [203, 206]}, {"entity": "void", "entity_type": "concept or principle", "pos": [226, 230]}], "task": "NER"}
{"text": "As mentioned earlier , FDM process is associated with void formation between printing beads , which needs to be considered in the modeling .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [23, 26]}, {"entity": "void", "entity_type": "concept or principle", "pos": [54, 58]}, {"entity": "beads", "entity_type": "process characterization", "pos": [86, 91]}, {"entity": "be", "entity_type": "material", "pos": [109, 111]}, {"entity": "modeling", "entity_type": "enabling technology", "pos": [130, 138]}], "task": "NER"}
{"text": "In the method developed by Rodriguez , Thomas for ABS materials , The FDM part is defined as an unidirectional ABScomposite with a laminate structure .", "entity": [{"entity": "ABS materials", "entity_type": "material", "pos": [50, 63]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [70, 73]}, {"entity": "as", "entity_type": "material", "pos": [90, 92]}, {"entity": "unidirectional", "entity_type": "concept or principle", "pos": [96, 110]}, {"entity": "laminate", "entity_type": "concept or principle", "pos": [131, 139]}], "task": "NER"}
{"text": "This structure is consisting of vertically stacked layers with contiguous material and voids .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [5, 14]}, {"entity": "material", "entity_type": "material", "pos": [74, 82]}, {"entity": "voids", "entity_type": "concept or principle", "pos": [87, 92]}], "task": "NER"}
{"text": "The unidirectional elastic constants are given as and represent the elastic modulus , shear modulus and Poissonratio of the extruded polymer used in the FDM process .", "entity": [{"entity": "unidirectional", "entity_type": "concept or principle", "pos": [4, 18]}, {"entity": "elastic constants", "entity_type": "process parameter", "pos": [19, 36]}, {"entity": "as", "entity_type": "material", "pos": [47, 49]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [68, 83]}, {"entity": "shear modulus", "entity_type": "machanical property", "pos": [86, 99]}, {"entity": "extruded", "entity_type": "manufacturing process", "pos": [124, 132]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [153, 156]}], "task": "NER"}
{"text": "The 1 is the area void density in the plane normal to filament direction .", "entity": [{"entity": "area void density", "entity_type": "machanical property", "pos": [13, 30]}, {"entity": "filament", "entity_type": "material", "pos": [54, 62]}], "task": "NER"}
{"text": "This method was used in various works for single material FDM parts containing void , however , certain modifications are needed in order to apply it to multi-material 3D printing .", "entity": [{"entity": "material", "entity_type": "material", "pos": [49, 57]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [58, 61]}, {"entity": "void", "entity_type": "concept or principle", "pos": [79, 83]}, {"entity": "multi-material 3D printing", "entity_type": "manufacturing process", "pos": [153, 179]}], "task": "NER"}
{"text": "More information regarding void in composite structures can be found in .", "entity": [{"entity": "void", "entity_type": "concept or principle", "pos": [27, 31]}, {"entity": "composite structures", "entity_type": "concept or principle", "pos": [35, 55]}, {"entity": "be", "entity_type": "material", "pos": [60, 62]}], "task": "NER"}
{"text": "4.3 Finite element method FEM is particularly interesting for modelling 3D printed part due to its flexibility in analyzing complex geometries in both macro and micro scale .", "entity": [{"entity": "Finite element method", "entity_type": "concept or principle", "pos": [4, 25]}, {"entity": "FEM", "entity_type": "concept or principle", "pos": [26, 29]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [62, 71]}, {"entity": "3D printed part", "entity_type": "application", "pos": [72, 87]}, {"entity": "flexibility", "entity_type": "machanical property", "pos": [99, 110]}, {"entity": "complex geometries", "entity_type": "concept or principle", "pos": [124, 142]}, {"entity": "macro and micro scale", "entity_type": "concept or principle", "pos": [151, 172]}], "task": "NER"}
{"text": "It can be applied to continuous and short fiber 3D printed composites .", "entity": [{"entity": "be", "entity_type": "material", "pos": [7, 9]}, {"entity": "short fiber", "entity_type": "material", "pos": [36, 47]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [48, 58]}], "task": "NER"}
{"text": "The primary distinction of most composites by AM is the significant void content that needs to be incorporated into the respective finite element model .", "entity": [{"entity": "composites", "entity_type": "material", "pos": [32, 42]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [46, 48]}, {"entity": "void", "entity_type": "concept or principle", "pos": [68, 72]}, {"entity": "be", "entity_type": "material", "pos": [95, 97]}, {"entity": "finite element model", "entity_type": "concept or principle", "pos": [131, 151]}], "task": "NER"}
{"text": "Perhaps the most appealing approaches for mechanical modelling of fiber composites are homogenization , which was described briefly in CLPT , and unit-cell based methods .", "entity": [{"entity": "mechanical modelling", "entity_type": "concept or principle", "pos": [42, 62]}, {"entity": "fiber composites", "entity_type": "material", "pos": [66, 82]}, {"entity": "homogenization", "entity_type": "manufacturing process", "pos": [87, 101]}], "task": "NER"}
{"text": "Both approaches can be implemented in FEM , thus , applicable to all AM methods .", "entity": [{"entity": "be", "entity_type": "material", "pos": [20, 22]}, {"entity": "FEM", "entity_type": "concept or principle", "pos": [38, 41]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [69, 71]}], "task": "NER"}
{"text": "Conversely , there has been a lack of attention to modelling of these processes , and with increasing the popularity of 3D printing among practitioners , the need for simulation of the 3D printing process is certain .", "entity": [{"entity": "modelling", "entity_type": "enabling technology", "pos": [51, 60]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [70, 79]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [120, 131]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [167, 177]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [185, 196]}], "task": "NER"}
{"text": "UC is a single or multiple fibers embedded in the matrix with the volume fraction similar to those of the composite .", "entity": [{"entity": "fibers", "entity_type": "material", "pos": [27, 33]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [66, 81]}, {"entity": "composite", "entity_type": "material", "pos": [106, 115]}], "task": "NER"}
{"text": "A finite element model of this geometry using two different materials is constructed and various loadings are applied to characterize the behavior of the UC .", "entity": [{"entity": "finite element model", "entity_type": "concept or principle", "pos": [2, 22]}, {"entity": "geometry", "entity_type": "concept or principle", "pos": [31, 39]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [60, 69]}], "task": "NER"}
{"text": "In the case of composites with random fiber orientations the composite behavior is approximated by direct averaging over all orientations .", "entity": [{"entity": "composites", "entity_type": "material", "pos": [15, 25]}, {"entity": "fiber orientations", "entity_type": "engineering feature", "pos": [38, 56]}, {"entity": "composite", "entity_type": "material", "pos": [61, 70]}, {"entity": "orientations", "entity_type": "concept or principle", "pos": [125, 137]}], "task": "NER"}
{"text": "Unit cells depend upon the microstructure of the composite ; some common types of unite cell are presented in 24 .", "entity": [{"entity": "Unit cells", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [27, 41]}, {"entity": "composite", "entity_type": "material", "pos": [49, 58]}, {"entity": "cell", "entity_type": "application", "pos": [88, 92]}], "task": "NER"}
{"text": "24 presents a UC for discontinuous short fiber composites with random orientations , 24 and shows UC for continuous fiber reinforced with unidirectional orientation and 3D braided structure , respectively .", "entity": [{"entity": "short fiber composites", "entity_type": "material", "pos": [35, 57]}, {"entity": "orientations", "entity_type": "concept or principle", "pos": [70, 82]}, {"entity": "continuous fiber", "entity_type": "material", "pos": [105, 121]}, {"entity": "unidirectional orientation", "entity_type": "concept or principle", "pos": [138, 164]}, {"entity": "3D braided structure", "entity_type": "engineering feature", "pos": [169, 189]}], "task": "NER"}
{"text": "Another commonly used approach is multiscale methods by combining micro level and homogenized macro stress analysis .", "entity": [{"entity": "micro level", "entity_type": "concept or principle", "pos": [66, 77]}, {"entity": "homogenized", "entity_type": "manufacturing process", "pos": [82, 93]}, {"entity": "stress", "entity_type": "machanical property", "pos": [100, 106]}], "task": "NER"}
{"text": "Microscopic level analysis can increase the accuracy , but are often too expensive to be used in practice .", "entity": [{"entity": "Microscopic level analysis", "entity_type": "concept or principle", "pos": [0, 26]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [44, 52]}, {"entity": "be", "entity_type": "material", "pos": [86, 88]}], "task": "NER"}
{"text": "Multiscale modelling takes advantage of the efficiency of macroscopic models and the accuracy of the microscopic models .", "entity": [{"entity": "Multiscale modelling", "entity_type": "concept or principle", "pos": [0, 20]}, {"entity": "macroscopic", "entity_type": "concept or principle", "pos": [58, 69]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [85, 93]}], "task": "NER"}
{"text": "The microscope analysis is normally performed at the area of interest with high stress concentration .", "entity": [{"entity": "microscope", "entity_type": "machine or equipment", "pos": [4, 14]}, {"entity": "area", "entity_type": "process parameter", "pos": [53, 57]}, {"entity": "stress concentration", "entity_type": "process characterization", "pos": [80, 100]}], "task": "NER"}
{"text": "25 shows a multiscale simulation with microscale analysis performed on two different areas of interest and macroscale analysis in the entire domain .", "entity": [{"entity": "multiscale simulation", "entity_type": "enabling technology", "pos": [11, 32]}, {"entity": "microscale analysis", "entity_type": "concept or principle", "pos": [38, 57]}, {"entity": "areas of interest", "entity_type": "concept or principle", "pos": [85, 102]}, {"entity": "macroscale analysis", "entity_type": "process characterization", "pos": [107, 126]}, {"entity": "domain", "entity_type": "concept or principle", "pos": [141, 147]}], "task": "NER"}
{"text": "5 Conclusions 3D printing of composite structures can be a turning point for AM technology .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [14, 25]}, {"entity": "composite structures", "entity_type": "concept or principle", "pos": [29, 49]}, {"entity": "be", "entity_type": "material", "pos": [54, 56]}, {"entity": "turning", "entity_type": "manufacturing process", "pos": [59, 66]}, {"entity": "AM technology", "entity_type": "manufacturing process", "pos": [77, 90]}], "task": "NER"}
{"text": "The potential of fabricating functional devices , directly from commercial 3D printers with controllable properties , created a huge rush for new developments and research in this field .", "entity": [{"entity": "fabricating", "entity_type": "manufacturing process", "pos": [17, 28]}, {"entity": "3D printers", "entity_type": "machine or equipment", "pos": [75, 86]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [105, 115]}, {"entity": "research", "entity_type": "concept or principle", "pos": [163, 171]}], "task": "NER"}
{"text": "The attractive combination of endless possibilities in the range of composite materials and extra customization of AM offers a unique new area in the manufacturing field , for researchers and developers to explore .", "entity": [{"entity": "range", "entity_type": "process parameter", "pos": [59, 64]}, {"entity": "composite materials", "entity_type": "material", "pos": [68, 87]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [115, 117]}, {"entity": "area", "entity_type": "process parameter", "pos": [138, 142]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [150, 163]}], "task": "NER"}
{"text": "AM of composites enables precise control of the physical , electrochemical , thermal , and optical properties ; these structures can even transform their shape over time in 4D printing .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "composites", "entity_type": "material", "pos": [6, 16]}, {"entity": "precise control", "entity_type": "concept or principle", "pos": [25, 40]}, {"entity": "electrochemical", "entity_type": "concept or principle", "pos": [59, 74]}, {"entity": "optical properties", "entity_type": "machanical property", "pos": [91, 109]}, {"entity": "4D printing", "entity_type": "manufacturing process", "pos": [173, 184]}], "task": "NER"}
{"text": "Fiber reinforcement significantly improves the mechanical properties of 3D printed parts .", "entity": [{"entity": "Fiber reinforcement", "entity_type": "engineering feature", "pos": [0, 19]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [47, 68]}, {"entity": "3D printed parts", "entity_type": "application", "pos": [72, 88]}], "task": "NER"}
{"text": "It can be implemented in various AM techniques , such as FDM , SLA , SLS , LOM , and extrusion .", "entity": [{"entity": "be", "entity_type": "material", "pos": [7, 9]}, {"entity": "AM techniques", "entity_type": "manufacturing process", "pos": [33, 46]}, {"entity": "as", "entity_type": "material", "pos": [54, 56]}, {"entity": "SLA", "entity_type": "machine or equipment", "pos": [63, 66]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [69, 72]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [75, 78]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [85, 94]}], "task": "NER"}
{"text": "Printed CF-ABS composites were even reported with higher specific strength than Aluminum .", "entity": [{"entity": "composites", "entity_type": "material", "pos": [15, 25]}, {"entity": "specific strength", "entity_type": "machanical property", "pos": [57, 74]}, {"entity": "Aluminum", "entity_type": "material", "pos": [80, 88]}], "task": "NER"}
{"text": "The alignment of fibers in 3D printing of composites was one of the major challenges in the reviewed literature and its improvement attracted tremendous research interest in almost all of the existing AM methods .", "entity": [{"entity": "fibers", "entity_type": "material", "pos": [17, 23]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [27, 38]}, {"entity": "composites", "entity_type": "material", "pos": [42, 52]}, {"entity": "research", "entity_type": "concept or principle", "pos": [153, 161]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [201, 203]}], "task": "NER"}
{"text": "Recent advances in FDM printing of continuous fiber reinforced thermoplastics took these improvements one step further to establish AM as a dependable manufacturing method for various industries .", "entity": [{"entity": "FDM", "entity_type": "manufacturing process", "pos": [19, 22]}, {"entity": "continuous fiber reinforced thermoplastics", "entity_type": "material", "pos": [35, 77]}, {"entity": "step", "entity_type": "concept or principle", "pos": [106, 110]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [132, 134]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [151, 164]}, {"entity": "industries", "entity_type": "application", "pos": [184, 194]}], "task": "NER"}
{"text": "In one of the interesting and innovative developments , continuous carbon fiber and PLA were mixed in the printing head before depositing into the printing bed , increasing the fiber/matrix adhesion .", "entity": [{"entity": "continuous carbon fiber", "entity_type": "material", "pos": [56, 79]}, {"entity": "PLA", "entity_type": "material", "pos": [84, 87]}, {"entity": "printing head", "entity_type": "machine or equipment", "pos": [106, 119]}, {"entity": "bed", "entity_type": "machine or equipment", "pos": [156, 159]}, {"entity": "fiber/matrix adhesion", "entity_type": "engineering feature", "pos": [177, 198]}], "task": "NER"}
{"text": "Laser assisted AM for continuous fiber reinforced thermoplastic composites demonstrates superior mechanical properties and at the mean time solves the issue of material waste for LOM .", "entity": [{"entity": "Laser", "entity_type": "enabling technology", "pos": [0, 5]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [15, 17]}, {"entity": "continuous fiber reinforced thermoplastic", "entity_type": "material", "pos": [22, 63]}, {"entity": "composites", "entity_type": "material", "pos": [64, 74]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [97, 118]}, {"entity": "material", "entity_type": "material", "pos": [160, 168]}, {"entity": "LOM", "entity_type": "manufacturing process", "pos": [179, 182]}], "task": "NER"}
{"text": "Furthermore , developments in 3D printing of fiber reinforced composite structures allowed precise placement of material at micro-scale , to fabricate complex structures in 4D printing of active composites , with ability to transform over time , right after the 3D printing .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [30, 41]}, {"entity": "fiber reinforced composite structures", "entity_type": "material", "pos": [45, 82]}, {"entity": "material", "entity_type": "material", "pos": [112, 120]}, {"entity": "micro-scale", "entity_type": "concept or principle", "pos": [124, 135]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [141, 150]}, {"entity": "complex structures", "entity_type": "concept or principle", "pos": [151, 169]}, {"entity": "4D printing", "entity_type": "manufacturing process", "pos": [173, 184]}, {"entity": "active composites", "entity_type": "material", "pos": [188, 205]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [262, 273]}], "task": "NER"}
{"text": "However , most 3D printing methodologies for composite materials still face major challenges , which need to be overcome before becoming a mainstream manufacturing method .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [15, 26]}, {"entity": "composite materials", "entity_type": "material", "pos": [45, 64]}, {"entity": "face", "entity_type": "concept or principle", "pos": [71, 75]}, {"entity": "be", "entity_type": "material", "pos": [109, 111]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [150, 163]}], "task": "NER"}
{"text": "Void formation during printing , poor adhesion of fibers and polymer matrix , and challenges in continuous fiber printing are all amongst the existing issues in 3D printing of fiber composites .", "entity": [{"entity": "Void", "entity_type": "concept or principle", "pos": [0, 4]}, {"entity": "adhesion", "entity_type": "machanical property", "pos": [38, 46]}, {"entity": "fibers", "entity_type": "material", "pos": [50, 56]}, {"entity": "polymer", "entity_type": "material", "pos": [61, 68]}, {"entity": "continuous fiber", "entity_type": "material", "pos": [96, 112]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [161, 172]}, {"entity": "fiber composites", "entity_type": "material", "pos": [176, 192]}], "task": "NER"}
{"text": "Moreover , most of the commercial 3D printers designed for specific resins and introduction of fillers can lead to blockage , wear , non-adhesion , and increased curing times .", "entity": [{"entity": "3D printers", "entity_type": "machine or equipment", "pos": [34, 45]}, {"entity": "resins", "entity_type": "material", "pos": [68, 74]}, {"entity": "lead", "entity_type": "material", "pos": [107, 111]}, {"entity": "wear", "entity_type": "concept or principle", "pos": [126, 130]}, {"entity": "curing times", "entity_type": "process parameter", "pos": [162, 174]}], "task": "NER"}
{"text": "AM of composites is a relatively new technique and there is a lack of research on modelling the structures produced by this process .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "composites", "entity_type": "material", "pos": [6, 16]}, {"entity": "research", "entity_type": "concept or principle", "pos": [70, 78]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [82, 91]}, {"entity": "process", "entity_type": "concept or principle", "pos": [124, 131]}], "task": "NER"}
{"text": "Existing theories for short and continuous fiber composites can be modified for 3D printed parts .", "entity": [{"entity": "continuous fiber composites", "entity_type": "material", "pos": [32, 59]}, {"entity": "be", "entity_type": "material", "pos": [64, 66]}, {"entity": "3D printed parts", "entity_type": "application", "pos": [80, 96]}], "task": "NER"}
{"text": "On the other hand , FEM is a powerful tool to analyze composite structures , and it can be applied for 3D printing with slight modifications of existing finite element models .", "entity": [{"entity": "FEM", "entity_type": "concept or principle", "pos": [20, 23]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [38, 42]}, {"entity": "composite structures", "entity_type": "concept or principle", "pos": [54, 74]}, {"entity": "be", "entity_type": "material", "pos": [88, 90]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [103, 114]}, {"entity": "finite element models", "entity_type": "concept or principle", "pos": [153, 174]}], "task": "NER"}
{"text": "In conclusion , AM of fiber reinforced polymer composites is tremendously promising in turning 3D printing from a prototyping method to a robust manufacturing technique .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [16, 18]}, {"entity": "fiber reinforced polymer composites", "entity_type": "material", "pos": [22, 57]}, {"entity": "turning", "entity_type": "manufacturing process", "pos": [87, 94]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [95, 106]}, {"entity": "prototyping", "entity_type": "concept or principle", "pos": [114, 125]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [145, 158]}], "task": "NER"}
{"text": "The unique characteristics of 3D printing , such as high customization , combined with extra strength from fiber reinforcement and the ability to produce functional complex 3D structures with total control over material properties , helped AM of fiber-polymer composites gain enormous attention from a broad range of science industries .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [30, 41]}, {"entity": "as", "entity_type": "material", "pos": [49, 51]}, {"entity": "strength", "entity_type": "machanical property", "pos": [93, 101]}, {"entity": "fiber reinforcement", "entity_type": "engineering feature", "pos": [107, 126]}, {"entity": "3D structures", "entity_type": "concept or principle", "pos": [173, 186]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [211, 230]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [240, 242]}, {"entity": "fiber-polymer composites", "entity_type": "material", "pos": [246, 270]}, {"entity": "range", "entity_type": "process parameter", "pos": [308, 313]}, {"entity": "industries", "entity_type": "application", "pos": [325, 335]}], "task": "NER"}
{"text": "The aerospace industry , automotive industry , biomedical science , electronic industries , and robotics are only a few examples of those attracted by AM of fiber reinforced polymer composites .", "entity": [{"entity": "aerospace industry", "entity_type": "application", "pos": [4, 22]}, {"entity": "automotive industry", "entity_type": "application", "pos": [25, 44]}, {"entity": "biomedical", "entity_type": "application", "pos": [47, 57]}, {"entity": "industries", "entity_type": "application", "pos": [79, 89]}, {"entity": "robotics", "entity_type": "application", "pos": [96, 104]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [151, 153]}, {"entity": "fiber reinforced polymer composites", "entity_type": "material", "pos": [157, 192]}], "task": "NER"}
{"text": "As the application of additive manufacturing reaches an unprecedented scale in both academia and industry , a reflection upon the state-of-the-art developments in the design for additive manufacturing and structural optimisation , becomes vital for successfully shaping the future AM-landscape .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [22, 44]}, {"entity": "industry", "entity_type": "application", "pos": [97, 105]}, {"entity": "reflection", "entity_type": "process characterization", "pos": [110, 120]}, {"entity": "state-of-the-art", "entity_type": "concept or principle", "pos": [130, 146]}, {"entity": "design for additive manufacturing", "entity_type": "engineering feature", "pos": [167, 200]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [205, 228]}, {"entity": "shaping", "entity_type": "manufacturing process", "pos": [262, 269]}], "task": "NER"}
{"text": "A framework , highlighting both the interdependencies between these two central aspects in AM and the necessity for a holistic approach to structural optimization , using lightweight strategies such as topology optimization and/or latticing , was established to summarize the reviewed content .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [2, 11]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [91, 93]}, {"entity": "structural optimization", "entity_type": "concept or principle", "pos": [139, 162]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [171, 182]}, {"entity": "as", "entity_type": "material", "pos": [199, 201]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [211, 223]}], "task": "NER"}
{"text": "Primarily focusing on isotropic material considerations and basic stiffnesB-optimal problems , these concepts have already found wide application , bridging the gaps between design and manufacturing as well as academia and industry .", "entity": [{"entity": "isotropic material", "entity_type": "material", "pos": [22, 40]}, {"entity": "bridging", "entity_type": "concept or principle", "pos": [148, 156]}, {"entity": "design", "entity_type": "engineering feature", "pos": [174, 180]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [185, 198]}, {"entity": "as", "entity_type": "material", "pos": [199, 201]}, {"entity": "as", "entity_type": "material", "pos": [207, 209]}, {"entity": "industry", "entity_type": "application", "pos": [223, 231]}], "task": "NER"}
{"text": "In pursuit of streamlining the AM-workflow towards digitally print-ready designs , studies are increasingly investigating mathematically-based structural optimization approaches in conjunction with DfAM-specific constraints , providing a portfolio of solutions like generative design , which is gaining traction in industry .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [73, 80]}, {"entity": "structural optimization", "entity_type": "concept or principle", "pos": [143, 166]}, {"entity": "generative design", "entity_type": "enabling technology", "pos": [266, 283]}, {"entity": "industry", "entity_type": "application", "pos": [315, 323]}], "task": "NER"}
{"text": "Besides an overview on economically-driven to performance-driven design optimizations , insight into commercial AM-specific software is provided , elucidating potentials and challenges for the community .", "entity": [{"entity": "design optimizations", "entity_type": "concept or principle", "pos": [65, 85]}, {"entity": "software", "entity_type": "concept or principle", "pos": [124, 132]}], "task": "NER"}
{"text": "Graphical abstract Unlabelled Image Highlights Extensive review , providing a joint perspective on design and structural optimisation in additive manufacturing .", "entity": [{"entity": "Image", "entity_type": "concept or principle", "pos": [30, 35]}, {"entity": "joint", "entity_type": "concept or principle", "pos": [78, 83]}, {"entity": "design", "entity_type": "engineering feature", "pos": [99, 105]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [110, 133]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [137, 159]}], "task": "NER"}
{"text": "Overview on the lightweighting approaches topology optimization and latticing , considering isotropic material assumptions .", "entity": [{"entity": "lightweighting", "entity_type": "machanical property", "pos": [16, 30]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [42, 63]}, {"entity": "isotropic material", "entity_type": "material", "pos": [92, 110]}], "task": "NER"}
{"text": "Consolidated summary , elucidating the gaps between design and manufacturing as well as academia and industry .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [52, 58]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [63, 76]}, {"entity": "as", "entity_type": "material", "pos": [77, 79]}, {"entity": "as", "entity_type": "material", "pos": [85, 87]}, {"entity": "industry", "entity_type": "application", "pos": [101, 109]}], "task": "NER"}
{"text": "Establishment of a design for AM framework , highlighting the interdependencies between state-of-the art research topics .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [19, 25]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [30, 32]}, {"entity": "art", "entity_type": "application", "pos": [101, 104]}], "task": "NER"}
{"text": "Additive manufacturing , also referred to as 3D-printing , has evolved greatly over the last three decades , emerging from the mere application in prototyping , it has now indisputably established its position as a viable fabrication alternative for end-use parts .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [0, 22]}, {"entity": "as", "entity_type": "material", "pos": [42, 44]}, {"entity": "3D-printing", "entity_type": "manufacturing process", "pos": [45, 56]}, {"entity": "prototyping", "entity_type": "concept or principle", "pos": [147, 158]}, {"entity": "as", "entity_type": "material", "pos": [165, 167]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [222, 233]}], "task": "NER"}
{"text": "This applies to a wide range of industries , including medical engineering , automotive , aerospace and consumer products , .", "entity": [{"entity": "range", "entity_type": "process parameter", "pos": [23, 28]}, {"entity": "industries", "entity_type": "application", "pos": [32, 42]}, {"entity": "medical engineering", "entity_type": "application", "pos": [55, 74]}, {"entity": "automotive", "entity_type": "application", "pos": [77, 87]}, {"entity": "aerospace", "entity_type": "application", "pos": [90, 99]}, {"entity": "consumer products", "entity_type": "application", "pos": [104, 121]}], "task": "NER"}
{"text": "lower energy consumption , has driven the research into identifying lightweight and robust designs .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [42, 50]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [68, 79]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [91, 98]}], "task": "NER"}
{"text": "Topology optimisation and latticing have emerged as the two major lightweighting strategies , best exploiting the design freedoms offered by AM .", "entity": [{"entity": "Topology optimisation", "entity_type": "engineering feature", "pos": [0, 21]}, {"entity": "as", "entity_type": "material", "pos": [49, 51]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [66, 80]}, {"entity": "design freedoms", "entity_type": "concept or principle", "pos": [114, 129]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [141, 143]}], "task": "NER"}
{"text": "The former represents a rigorous approach , improving the specific stiffness , whereas the latter can be considered as a design approach for weight-reduction in parts that usually have a high safety factor , which has in fact been widely adopted as a common design practice in today 's AM-specific software .", "entity": [{"entity": "specific stiffness", "entity_type": "machanical property", "pos": [58, 76]}, {"entity": "be", "entity_type": "material", "pos": [102, 104]}, {"entity": "as", "entity_type": "material", "pos": [116, 118]}, {"entity": "design", "entity_type": "engineering feature", "pos": [121, 127]}, {"entity": "safety factor", "entity_type": "engineering feature", "pos": [192, 205]}, {"entity": "as", "entity_type": "material", "pos": [215, 217]}, {"entity": "design", "entity_type": "engineering feature", "pos": [258, 264]}, {"entity": "software", "entity_type": "concept or principle", "pos": [298, 306]}], "task": "NER"}
{"text": "multifunctionality and bio-inspired designs , are gaining interest and could help shape the future of structurally advanced AM-parts .", "entity": [{"entity": "bio-inspired designs", "entity_type": "engineering feature", "pos": [23, 43]}], "task": "NER"}
{"text": "This development is supported by the steady improvements in printer hardware and AM-specific software as well as the enrichment of the available material palette .", "entity": [{"entity": "printer", "entity_type": "machine or equipment", "pos": [60, 67]}, {"entity": "software", "entity_type": "concept or principle", "pos": [93, 101]}, {"entity": "as", "entity_type": "material", "pos": [102, 104]}, {"entity": "as", "entity_type": "material", "pos": [110, 112]}, {"entity": "material", "entity_type": "material", "pos": [145, 153]}], "task": "NER"}
{"text": "In fact , AM is attributed a central role in the successful realization of the new industrial revolution , i.e .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [10, 12]}, {"entity": "industrial revolution", "entity_type": "concept or principle", "pos": [83, 104]}], "task": "NER"}
{"text": "Industry 4.0 , affecting both the way we design and fabricate .", "entity": [{"entity": "Industry 4.0", "entity_type": "enabling technology", "pos": [0, 12]}, {"entity": "design", "entity_type": "engineering feature", "pos": [41, 47]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [52, 61]}], "task": "NER"}
{"text": "This is clearly reflected by the prediction of a threefold increase in the industry 's market value as stated in the Wohlers report .", "entity": [{"entity": "prediction", "entity_type": "concept or principle", "pos": [33, 43]}, {"entity": "industry", "entity_type": "application", "pos": [75, 83]}, {"entity": "as", "entity_type": "material", "pos": [100, 102]}], "task": "NER"}
{"text": "Jiang envisage among others intensified manufacturing of both critical and non-critical spare parts as well as increased customization of products with AM , which will require improvements in the structural performance and adequate design practices , respectively .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [40, 53]}, {"entity": "as", "entity_type": "material", "pos": [100, 102]}, {"entity": "as", "entity_type": "material", "pos": [108, 110]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [152, 154]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [196, 218]}, {"entity": "design", "entity_type": "engineering feature", "pos": [232, 238]}], "task": "NER"}
{"text": "From a design and structural standpoint , reviews in AM have so far focused on either the development of design rules and frameworks in the context of DfAM or the role of e.g .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [7, 13]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [53, 55]}, {"entity": "design rules", "entity_type": "concept or principle", "pos": [105, 117]}], "task": "NER"}
{"text": "TO , latticing , processing parameters , materials and bio-inspired approaches , respectively .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [28, 38]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [41, 50]}, {"entity": "bio-inspired", "entity_type": "concept or principle", "pos": [55, 67]}], "task": "NER"}
{"text": "Herein , a joint scope including a much wider consideration for DfAM in structural optimization for AM is captured , reviewing two key lightweighting strategies in AM , namely TO and latticing and providing insight into the academic versus the commercial landscape .", "entity": [{"entity": "joint", "entity_type": "concept or principle", "pos": [11, 16]}, {"entity": "structural optimization", "entity_type": "concept or principle", "pos": [72, 95]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [100, 102]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [135, 149]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [164, 166]}], "task": "NER"}
{"text": "1 introduces a framework , relating key intrinsic and extrinsic DfAM aspects that were identified in the field of design and structural optimisation for AM .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [15, 24]}, {"entity": "design", "entity_type": "engineering feature", "pos": [114, 120]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [125, 148]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [153, 155]}], "task": "NER"}
{"text": "An intrinsic aspect is , therefore , representing the primary drivers when designing for AM , whereas the extrinsic factors can be regarded as current research topics in design and structural optimization for AM .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [89, 91]}, {"entity": "extrinsic factors", "entity_type": "concept or principle", "pos": [106, 123]}, {"entity": "be", "entity_type": "material", "pos": [128, 130]}, {"entity": "as", "entity_type": "material", "pos": [140, 142]}, {"entity": "research", "entity_type": "concept or principle", "pos": [151, 159]}, {"entity": "design and structural optimization", "entity_type": "concept or principle", "pos": [170, 204]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [209, 211]}], "task": "NER"}
{"text": "The remit of this paper , however , goes beyond this framework , highlighting the underlying dependencies between the individual extrinsic factors in the state-of-the-art research today .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [53, 62]}, {"entity": "extrinsic factors", "entity_type": "concept or principle", "pos": [129, 146]}, {"entity": "state-of-the-art research", "entity_type": "concept or principle", "pos": [154, 179]}], "task": "NER"}
{"text": "Three interrelated themes referred to as entail procesB- and material-induced aspects , lightweighting strategies as well as broader DfAM-factors and are arranged analogously to the chronological order of headings in this paper .", "entity": [{"entity": "as", "entity_type": "material", "pos": [38, 40]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [88, 102]}, {"entity": "as", "entity_type": "material", "pos": [114, 116]}, {"entity": "as", "entity_type": "material", "pos": [122, 124]}], "task": "NER"}
{"text": "This review focuses on structural optimisation in AM with particular emphasis on DfAM .", "entity": [{"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [23, 46]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [50, 52]}], "task": "NER"}
{"text": "As most works on lightweighting strategies are based on isotropic material assumptions , reinforced-materials and the procesB-induced anisotropy caused by the fabrication in a layer-by-layer fashion or infill pattern , are not assessed .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [17, 31]}, {"entity": "isotropic material", "entity_type": "material", "pos": [56, 74]}, {"entity": "reinforced-materials", "entity_type": "material", "pos": [89, 109]}, {"entity": "anisotropy", "entity_type": "machanical property", "pos": [134, 144]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [159, 170]}, {"entity": "layer-by-layer fashion", "entity_type": "concept or principle", "pos": [176, 198]}, {"entity": "infill", "entity_type": "process parameter", "pos": [202, 208]}], "task": "NER"}
{"text": "As the role of anisotropy for topology optimisation in AM was discussed in , elucidating that this research is still in its infancy and requiring more fundamental investigations for a critical review , this paper summarizes the more consolidated knowledge in this field .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "anisotropy", "entity_type": "machanical property", "pos": [15, 25]}, {"entity": "topology optimisation", "entity_type": "engineering feature", "pos": [30, 51]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [55, 57]}, {"entity": "research", "entity_type": "concept or principle", "pos": [99, 107]}], "task": "NER"}
{"text": "A DfAM framework , encapsulating intrinsic and extrinsic aspects of the cutting-edge research on AM-friendly structural optimisation , preludes the main part of this work and provides context and structure to the reviewed studies .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [7, 16]}, {"entity": "research", "entity_type": "concept or principle", "pos": [85, 93]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [109, 132]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [196, 205]}], "task": "NER"}
{"text": "The joint focus on structural optimisation in AM using TO and latticing with incorporation of DfAM aspects constitutes the remit of this paper .", "entity": [{"entity": "joint", "entity_type": "concept or principle", "pos": [4, 9]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [19, 42]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [46, 48]}], "task": "NER"}
{"text": "Secondly , the synergistic and expertise-dominated application of cellular structures , as design approach to lightweighting , will be addressed .", "entity": [{"entity": "cellular structures", "entity_type": "engineering feature", "pos": [66, 85]}, {"entity": "as", "entity_type": "material", "pos": [88, 90]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [110, 124]}, {"entity": "be", "entity_type": "material", "pos": [132, 134]}], "task": "NER"}
{"text": "Hereby , focus is put on their application and significance in standard engineering problems rather than the medical field , as reviewed elsewhere .", "entity": [{"entity": "standard", "entity_type": "concept or principle", "pos": [63, 71]}, {"entity": "engineering", "entity_type": "application", "pos": [72, 83]}, {"entity": "medical", "entity_type": "application", "pos": [109, 116]}, {"entity": "as", "entity_type": "material", "pos": [125, 127]}], "task": "NER"}
{"text": "Moreover , it is important to note that the reviewed works are primarily looking into basic structural problems , concentrating on improved stiffness under volume constraints .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [140, 149]}, {"entity": "volume constraints", "entity_type": "process parameter", "pos": [156, 174]}], "task": "NER"}
{"text": "2 Structural optimisation with isotropic material in AM The role of structural optimisation in AM is increasing across industries with lightweighting strategies that can broadly be differentiated into mathematically-driven and expertise-driven , with recent studies seeing increased utilization of both .", "entity": [{"entity": "Structural optimisation", "entity_type": "concept or principle", "pos": [2, 25]}, {"entity": "isotropic material", "entity_type": "material", "pos": [31, 49]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [53, 55]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [68, 91]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [95, 97]}, {"entity": "industries", "entity_type": "application", "pos": [119, 129]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [135, 149]}, {"entity": "be", "entity_type": "material", "pos": [178, 180]}], "task": "NER"}
{"text": "Here , TO is frequently adopted for the design of structurally-sound AM-parts and has meanwhile surpassed the use of shape and size optimization in isolation .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [40, 46]}, {"entity": "structurally-sound AM-parts", "entity_type": "machanical property", "pos": [50, 77]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [132, 144]}], "task": "NER"}
{"text": "However , it has become a general practice in commercial software to post-process TO-solutions by optimizing the size or shape of the final structure to adhere e.g .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [57, 65]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [69, 81]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [140, 149]}], "task": "NER"}
{"text": "to minimum feature sizes that match the resolution of the printer .", "entity": [{"entity": "minimum feature sizes", "entity_type": "process parameter", "pos": [3, 24]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [40, 50]}, {"entity": "printer", "entity_type": "machine or equipment", "pos": [58, 65]}], "task": "NER"}
{"text": "In contrast , expertise-driven structural optimisation such as latticing is not a lightweighting strategy per se , as stiffness is greatly compromised in exchange for e.g .", "entity": [{"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [31, 54]}, {"entity": "as", "entity_type": "material", "pos": [60, 62]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [82, 96]}, {"entity": "se", "entity_type": "material", "pos": [110, 112]}, {"entity": "as", "entity_type": "material", "pos": [115, 117]}], "task": "NER"}
{"text": "A good example of this is the latticing of a part for weight reductions and enhanced functionality in areas where stiffness can be sacrificed .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [54, 60]}, {"entity": "areas", "entity_type": "process parameter", "pos": [102, 107]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [114, 123]}, {"entity": "be", "entity_type": "material", "pos": [128, 130]}], "task": "NER"}
{"text": "Generative design formally merges these two schemes through a parallel implementation to provide a portfolio of solutions i.e .", "entity": [{"entity": "Generative design", "entity_type": "enabling technology", "pos": [0, 17]}], "task": "NER"}
{"text": "1 Topology optimisation in AM Bendsand Kikuchi 's as well as Sigmund 's landmark work , introducing the concept of shape and TO centred on the homogenization approach and the MATLAB implementation of a density-based TO , respectively , laid the foundation for today 's TO-methods .", "entity": [{"entity": "Topology optimisation", "entity_type": "engineering feature", "pos": [2, 23]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [27, 29]}, {"entity": "as", "entity_type": "material", "pos": [50, 52]}, {"entity": "as", "entity_type": "material", "pos": [58, 60]}, {"entity": "homogenization", "entity_type": "manufacturing process", "pos": [143, 157]}], "task": "NER"}
{"text": "The most prominent TO approaches can be summarized as follows : Density-based ; Level Set ; Evolutionary/Genetic Algorithms ; Topological Derivatives and Phase Field .", "entity": [{"entity": "be", "entity_type": "material", "pos": [37, 39]}, {"entity": "as", "entity_type": "material", "pos": [51, 53]}, {"entity": "Set", "entity_type": "application", "pos": [86, 89]}, {"entity": "Algorithms", "entity_type": "concept or principle", "pos": [113, 123]}, {"entity": "Phase", "entity_type": "concept or principle", "pos": [154, 159]}], "task": "NER"}
{"text": "Discrete TO can be described as a method that explores the optimal connection of the elements , whereas continuum TO determines the optimal spatial distribution of material within a domain .", "entity": [{"entity": "be", "entity_type": "material", "pos": [16, 18]}, {"entity": "as", "entity_type": "material", "pos": [29, 31]}, {"entity": "elements", "entity_type": "material", "pos": [85, 93]}, {"entity": "continuum", "entity_type": "concept or principle", "pos": [104, 113]}, {"entity": "spatial distribution", "entity_type": "process characterization", "pos": [140, 160]}, {"entity": "material", "entity_type": "material", "pos": [164, 172]}, {"entity": "domain", "entity_type": "concept or principle", "pos": [182, 188]}], "task": "NER"}
{"text": "At the core of each structural TO problem lies an objective function that needs to be minimized or maximized while being subjected to a set of constraints such as volume , displacement or frequency .", "entity": [{"entity": "core", "entity_type": "machine or equipment", "pos": [7, 11]}, {"entity": "be", "entity_type": "material", "pos": [83, 85]}, {"entity": "set", "entity_type": "application", "pos": [136, 139]}, {"entity": "as", "entity_type": "material", "pos": [160, 162]}], "task": "NER"}
{"text": "As part of an iterative process , in methods utilizing density as a design variable , Finite Element Analysis , sensitivity analysis , regularizations and optimisation steps are repeated in this order until convergence is achieved .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "process", "entity_type": "concept or principle", "pos": [24, 31]}, {"entity": "density", "entity_type": "machanical property", "pos": [55, 62]}, {"entity": "as", "entity_type": "material", "pos": [63, 65]}, {"entity": "design", "entity_type": "engineering feature", "pos": [68, 74]}, {"entity": "Finite Element Analysis", "entity_type": "concept or principle", "pos": [86, 109]}, {"entity": "sensitivity analysis", "entity_type": "concept or principle", "pos": [112, 132]}, {"entity": "regularizations", "entity_type": "concept or principle", "pos": [135, 150]}], "task": "NER"}
{"text": "In the context of DfAM , research today is geared towards print-ready TO designs bridging challenges of design and fabrication .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [25, 33]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [73, 80]}, {"entity": "bridging", "entity_type": "concept or principle", "pos": [81, 89]}, {"entity": "design", "entity_type": "engineering feature", "pos": [104, 110]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [115, 126]}], "task": "NER"}
{"text": "This refers to methods that change the numerically optimal solution either intrinsically through the imposition of manufacturing constraints or in subsequent post-processing steps which alter the geometrical layout .", "entity": [{"entity": "solution", "entity_type": "concept or principle", "pos": [59, 67]}, {"entity": "manufacturing constraints", "entity_type": "concept or principle", "pos": [115, 140]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [158, 173]}, {"entity": "layout", "entity_type": "concept or principle", "pos": [208, 214]}], "task": "NER"}
{"text": "Support-free designs and strategies to reduce the support volume are facilitators for a time- and cost-efficient fabrication .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [13, 20]}, {"entity": "support", "entity_type": "application", "pos": [50, 57]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [113, 124]}], "task": "NER"}
{"text": "In pursuit of both physically and digitally print-ready designs , smooth boundary representations have drawn great attention in recent years .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [56, 63]}, {"entity": "smooth boundary", "entity_type": "engineering feature", "pos": [66, 81]}], "task": "NER"}
{"text": "In this review , this refers to mesh-refinements , ensuring a better surface representation or CAD-friendly geometries .", "entity": [{"entity": "surface", "entity_type": "concept or principle", "pos": [69, 76]}, {"entity": "geometries", "entity_type": "concept or principle", "pos": [108, 118]}], "task": "NER"}
{"text": "In this context , correct digitalizing of TO-solutions will be pivotal for future CAD/CAM software , including an automated design procedure that integrates DfAM considerations and requires less AM-expertise .", "entity": [{"entity": "be", "entity_type": "material", "pos": [60, 62]}, {"entity": "CAD/CAM software", "entity_type": "enabling technology", "pos": [82, 98]}, {"entity": "design", "entity_type": "engineering feature", "pos": [124, 130]}], "task": "NER"}
{"text": "Emerging TO methods with DfAM consideration for smooth boundary representation include the Development Method and the Morphable Method .", "entity": [{"entity": "smooth boundary", "entity_type": "engineering feature", "pos": [48, 63]}], "task": "NER"}
{"text": "Herein , basic geometric shapes and polygons , capturing the geometrical layouts , have served as simple design primitives for representing topologies .", "entity": [{"entity": "geometric shapes", "entity_type": "engineering feature", "pos": [15, 31]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}, {"entity": "design", "entity_type": "engineering feature", "pos": [105, 111]}, {"entity": "topologies", "entity_type": "concept or principle", "pos": [140, 150]}], "task": "NER"}
{"text": "1 SIMP-based designs for AM Density-based TO methods are most prevalent in academia and follow the general procedure .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [13, 20]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [25, 27]}], "task": "NER"}
{"text": "A well-established continuum method often referred to as the SIMP approach , first introduced by Bends , relates the elements relative densities to the effective material moduli using the power law .", "entity": [{"entity": "continuum", "entity_type": "concept or principle", "pos": [19, 28]}, {"entity": "as", "entity_type": "material", "pos": [54, 56]}, {"entity": "elements", "entity_type": "material", "pos": [117, 125]}, {"entity": "material", "entity_type": "material", "pos": [162, 170]}, {"entity": "power", "entity_type": "process parameter", "pos": [188, 193]}], "task": "NER"}
{"text": "As most works use linear elastic assumptions with the standard density-based TO approaches , they lack the ability to solve problems with large deformations accurately .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [25, 32]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [54, 62]}, {"entity": "deformations", "entity_type": "concept or principle", "pos": [144, 156]}, {"entity": "accurately", "entity_type": "process characterization", "pos": [157, 167]}], "task": "NER"}
{"text": "However , regarding DfAM , designs with elastoplastic print consumables , as commonly used , could particularly benefit from more realistic material considerations .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [27, 34]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [54, 59]}, {"entity": "as", "entity_type": "material", "pos": [74, 76]}, {"entity": "material", "entity_type": "material", "pos": [140, 148]}], "task": "NER"}
{"text": "Major findings in studies on non-linear TO include : 1 ) the difference between linear and non-linear modelling of large deformations is particularly evident in buckling and snap-through scenarios ; 2 ) a non-linear analysis made insignificant changes to the stiffness/compliance of a linear elastic structure but altered the topology significantly ; 3 ) non-linearity assumptions are beneficial for realizing compliant mechanisms ; 4 ) issues with excessive distortions or convergence of the numerical model can be solved .", "entity": [{"entity": "non-linear modelling", "entity_type": "concept or principle", "pos": [91, 111]}, {"entity": "deformations", "entity_type": "concept or principle", "pos": [121, 133]}, {"entity": "buckling", "entity_type": "machanical property", "pos": [161, 169]}, {"entity": "non-linear analysis", "entity_type": "concept or principle", "pos": [205, 224]}, {"entity": "linear elastic structure", "entity_type": "engineering feature", "pos": [285, 309]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [326, 334]}, {"entity": "compliant mechanisms", "entity_type": "concept or principle", "pos": [410, 430]}, {"entity": "model", "entity_type": "concept or principle", "pos": [503, 508]}, {"entity": "be", "entity_type": "material", "pos": [513, 515]}], "task": "NER"}
{"text": "1 Academic approaches to structurally optimized AM-friendly parts With the maturation of TO-codes in recent years towards greater computational efficiency and complexity , the inclusion of DfAM aspects is on the rise .", "entity": [{"entity": "computational efficiency", "entity_type": "concept or principle", "pos": [130, 154]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [159, 169]}, {"entity": "inclusion", "entity_type": "material", "pos": [176, 185]}], "task": "NER"}
{"text": "Most of today 's research on TO for AM is economically-driven and deals with support volume reduction , their complete elimination or simplified removal .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [17, 25]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [36, 38]}, {"entity": "support", "entity_type": "application", "pos": [77, 84]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [92, 101]}], "task": "NER"}
{"text": "Support-free structures with reasonably good quality can generally be expected for an inclination angle in the realm of 45 , which has been widely adopted for structural optimization problems anything lower is associated with additional fabrication cost motivating efforts in achieving conformity between design and print .", "entity": [{"entity": "quality", "entity_type": "concept or principle", "pos": [45, 52]}, {"entity": "be", "entity_type": "material", "pos": [67, 69]}, {"entity": "inclination angle", "entity_type": "engineering feature", "pos": [86, 103]}, {"entity": "structural optimization", "entity_type": "concept or principle", "pos": [159, 182]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [237, 248]}, {"entity": "design", "entity_type": "engineering feature", "pos": [305, 311]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [316, 321]}], "task": "NER"}
{"text": "However , it should be noted that fine-tuning of process parameters in polymer FDM has shown to allow even lower print-angles .", "entity": [{"entity": "be", "entity_type": "material", "pos": [20, 22]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [49, 67]}, {"entity": "polymer", "entity_type": "material", "pos": [71, 78]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [79, 82]}], "task": "NER"}
{"text": "Performance is inevitably compromised by imposing manufacturing constraints but opposed to accounting for support volume , performance-driven factors in TO methods , including e.g .", "entity": [{"entity": "Performance", "entity_type": "concept or principle", "pos": [0, 11]}, {"entity": "manufacturing constraints", "entity_type": "concept or principle", "pos": [50, 75]}, {"entity": "support", "entity_type": "application", "pos": [106, 113]}], "task": "NER"}
{"text": "In , the performance and printability of a structure derived from a coupled truss and SIMP-based optimisation approach were investigated .", "entity": [{"entity": "performance", "entity_type": "concept or principle", "pos": [9, 20]}, {"entity": "printability", "entity_type": "process parameter", "pos": [25, 37]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [43, 52]}, {"entity": "coupled truss", "entity_type": "engineering feature", "pos": [68, 81]}], "task": "NER"}
{"text": "By projecting a truss framework onto the corresponding TO-solution , the material was re-distributed , promoting adherence to overhang angle limits .", "entity": [{"entity": "truss", "entity_type": "machine or equipment", "pos": [16, 21]}, {"entity": "framework", "entity_type": "concept or principle", "pos": [22, 31]}, {"entity": "material", "entity_type": "material", "pos": [73, 81]}, {"entity": "overhang angle limits", "entity_type": "process parameter", "pos": [126, 147]}], "task": "NER"}
{"text": "As a result , a topology that does require less support but has reasonably high performance was created .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [16, 24]}, {"entity": "support", "entity_type": "application", "pos": [48, 55]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [80, 91]}], "task": "NER"}
{"text": "Additionally , it was found that the printing direction is a key control parameter between manufacturability and performance .", "entity": [{"entity": "parameter", "entity_type": "concept or principle", "pos": [73, 82]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [91, 108]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [113, 124]}], "task": "NER"}
{"text": "An efficient DfAM filter for TO , avoiding support structures , has also been the subject of research in the works of Langelaar , in which a projection method was proposed for 2D and 3D cases .", "entity": [{"entity": "filter", "entity_type": "application", "pos": [18, 24]}, {"entity": "support structures", "entity_type": "engineering feature", "pos": [43, 61]}, {"entity": "research", "entity_type": "concept or principle", "pos": [93, 101]}, {"entity": "2D", "entity_type": "concept or principle", "pos": [176, 178]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [183, 185]}], "task": "NER"}
{"text": "More recently , Langelaar has extended this AM-filter approach to a method for optimizing topology , support layout and build orientation simultaneously , providing designers and engineers with a portfolio of results with the corresponding fabrication cost and part performance .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [90, 98]}, {"entity": "support", "entity_type": "application", "pos": [101, 108]}, {"entity": "layout", "entity_type": "concept or principle", "pos": [109, 115]}, {"entity": "build orientation", "entity_type": "process parameter", "pos": [120, 137]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [240, 251]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [266, 277]}], "task": "NER"}
{"text": "The support-filter itself is based on the premise of a layer-wise AM fabrication , whereby it is examined whether the base elements in the underlying layer offer support considering the critical support-free inclination angle of 45Together with a sensitivity filter based on the adjoint method , the AM-filter formulation is integrated into the code of Andreassen , making it an easily accessible tool for print-ready AM-parts with improved structural performance .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [66, 68]}, {"entity": "elements", "entity_type": "material", "pos": [123, 131]}, {"entity": "layer", "entity_type": "process parameter", "pos": [150, 155]}, {"entity": "support", "entity_type": "application", "pos": [162, 169]}, {"entity": "inclination angle", "entity_type": "engineering feature", "pos": [208, 225]}, {"entity": "sensitivity", "entity_type": "process parameter", "pos": [247, 258]}, {"entity": "filter", "entity_type": "application", "pos": [259, 265]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [397, 401]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [441, 463]}], "task": "NER"}
{"text": "Numerical examples provided in illustrated the printability of TO-structures as a function of printing orientation .", "entity": [{"entity": "printability", "entity_type": "process parameter", "pos": [47, 59]}, {"entity": "as", "entity_type": "material", "pos": [77, 79]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [103, 114]}], "task": "NER"}
{"text": "a half MBB beam , Langelaar highlighted not only the effectiveness of the filter to avoid shallow angles and its effect on the final topology compared to the unconstrained model , but also the variation in compliance with the building orientation .", "entity": [{"entity": "half MBB beam", "entity_type": "engineering feature", "pos": [2, 15]}, {"entity": "effectiveness", "entity_type": "concept or principle", "pos": [53, 66]}, {"entity": "filter", "entity_type": "application", "pos": [74, 80]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [133, 141]}, {"entity": "model", "entity_type": "concept or principle", "pos": [172, 177]}, {"entity": "variation", "entity_type": "concept or principle", "pos": [193, 202]}, {"entity": "building orientation", "entity_type": "process parameter", "pos": [226, 246]}], "task": "NER"}
{"text": "An extension of this method could potentially be promising for multidirectional slicing in robotic AM .", "entity": [{"entity": "be", "entity_type": "material", "pos": [46, 48]}, {"entity": "multidirectional slicing", "entity_type": "concept or principle", "pos": [63, 87]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [99, 101]}], "task": "NER"}
{"text": "Gaynor and co-workers as well as Qian , showed that the Heaviside Projection offered an alternative means to constraining the overhang angles in TO-solutions .", "entity": [{"entity": "as", "entity_type": "material", "pos": [22, 24]}, {"entity": "as", "entity_type": "material", "pos": [30, 32]}, {"entity": "overhang angles", "entity_type": "process parameter", "pos": [126, 141]}], "task": "NER"}
{"text": "In this scheme was employed to enforce a binary solution from the greyscale SIMP-solution by controlling the minimum radial length scale .", "entity": [{"entity": "binary", "entity_type": "concept or principle", "pos": [41, 47]}, {"entity": "radial length", "entity_type": "process parameter", "pos": [117, 130]}], "task": "NER"}
{"text": "determine the minimum self-supporting angle in 2D .", "entity": [{"entity": "self-supporting angle", "entity_type": "engineering feature", "pos": [22, 43]}, {"entity": "2D", "entity_type": "concept or principle", "pos": [47, 49]}], "task": "NER"}
{"text": "Gaynor and Guest found major changes in the topology and deterioration in performance with increasing self-supporting angles .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [44, 52]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [74, 85]}, {"entity": "self-supporting angles", "entity_type": "engineering feature", "pos": [102, 124]}], "task": "NER"}
{"text": "In the Heaviside Projection was employed both on the density and the density gradient to obtain well-defined boundaries and constrain the perimeter length in undercuts and overhangs for 3D cases .", "entity": [{"entity": "density", "entity_type": "machanical property", "pos": [53, 60]}, {"entity": "density gradient", "entity_type": "machanical property", "pos": [69, 85]}, {"entity": "boundaries", "entity_type": "engineering feature", "pos": [109, 119]}, {"entity": "undercuts", "entity_type": "engineering feature", "pos": [158, 167]}, {"entity": "overhangs", "entity_type": "process parameter", "pos": [172, 181]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [186, 188]}], "task": "NER"}
{"text": "improved convergence to a discrete solution .", "entity": [{"entity": "discrete solution", "entity_type": "concept or principle", "pos": [26, 43]}], "task": "NER"}
{"text": "As an example , a cantilever beam was optimized for individual minimum overhang angles , illustrating that overhang angle and gradient constraint need to be concurrently changed and that the compliance is significantly increased over the unconstrained pendant , especially for increased overhang angles .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "cantilever beam", "entity_type": "machine or equipment", "pos": [18, 33]}, {"entity": "minimum overhang angles", "entity_type": "process parameter", "pos": [63, 86]}, {"entity": "overhang angle", "entity_type": "process parameter", "pos": [107, 121]}, {"entity": "be", "entity_type": "material", "pos": [154, 156]}, {"entity": "overhang angles", "entity_type": "process parameter", "pos": [287, 302]}], "task": "NER"}
{"text": "Leary proposed an approach in which infeasible inclination angles are initially identified , followed by a layout transmission into a support-free design and the determination of the optimal building orientation .", "entity": [{"entity": "inclination angles", "entity_type": "engineering feature", "pos": [47, 65]}, {"entity": "layout", "entity_type": "concept or principle", "pos": [107, 113]}, {"entity": "design", "entity_type": "engineering feature", "pos": [147, 153]}, {"entity": "building orientation", "entity_type": "process parameter", "pos": [191, 211]}], "task": "NER"}
{"text": "Firstly , a binary topology was obtained through thresholding of the gradient values to identify the perimeters and its local gradients .", "entity": [{"entity": "binary topology", "entity_type": "concept or principle", "pos": [12, 27]}, {"entity": "local gradients", "entity_type": "concept or principle", "pos": [120, 135]}], "task": "NER"}
{"text": "Subsequently , smoothing of the boundary was performed using the rolling average method .", "entity": [{"entity": "boundary", "entity_type": "engineering feature", "pos": [32, 40]}, {"entity": "rolling average", "entity_type": "concept or principle", "pos": [65, 80]}], "task": "NER"}
{"text": "The actual novelties are the iterative internal and external boundary modifications centred on a recursive subdivision of domains to ensure the final design complies with the allowable inclination angle .", "entity": [{"entity": "boundary", "entity_type": "engineering feature", "pos": [61, 69]}, {"entity": "design", "entity_type": "engineering feature", "pos": [150, 156]}, {"entity": "inclination angle", "entity_type": "engineering feature", "pos": [185, 202]}], "task": "NER"}
{"text": "The change in the geometrical layout increased the volume fraction of the part , however , due to the avoidance of support , experimental results showed a reduction in fabrication time .", "entity": [{"entity": "layout", "entity_type": "concept or principle", "pos": [30, 36]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [51, 66]}, {"entity": "support", "entity_type": "application", "pos": [115, 122]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [125, 137]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [155, 164]}, {"entity": "fabrication time", "entity_type": "process parameter", "pos": [168, 184]}], "task": "NER"}
{"text": "Benchmarking against standard TO result , numerical analyses showcased : a ) different stress distributions while the maximum von Mises stress stayed constant and b ) the heat transfer is increased , which is of particular interest for e.g .", "entity": [{"entity": "standard", "entity_type": "concept or principle", "pos": [21, 29]}, {"entity": "stress distributions", "entity_type": "machanical property", "pos": [87, 107]}, {"entity": "von Mises stress", "entity_type": "machanical property", "pos": [126, 142]}, {"entity": "b", "entity_type": "material", "pos": [163, 164]}, {"entity": "heat transfer", "entity_type": "concept or principle", "pos": [171, 184]}], "task": "NER"}
{"text": "metal-AM , as entrapment of excessive temperature , leads to microstructural changes over time as shown by .", "entity": [{"entity": "as", "entity_type": "material", "pos": [11, 13]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [38, 49]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [61, 76]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}], "task": "NER"}
{"text": "It is important to note , however , that a weight increase is associated with this method , which should be carefully weighed against the material savings achieved by avoiding the supports or the ease in manufacturing .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [43, 49]}, {"entity": "be", "entity_type": "material", "pos": [105, 107]}, {"entity": "material", "entity_type": "material", "pos": [138, 146]}, {"entity": "supports", "entity_type": "application", "pos": [180, 188]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [204, 217]}], "task": "NER"}
{"text": "In contrast , a more recent paper by Thore investigates the abovementioned factor of stresses in support-free TO-solutions , while adhering to the volume constraint , linking economy and fabrication .", "entity": [{"entity": "investigates", "entity_type": "concept or principle", "pos": [43, 55]}, {"entity": "volume constraint", "entity_type": "process parameter", "pos": [147, 164]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [187, 198]}], "task": "NER"}
{"text": "Contrary to the above works , digitally print-ready designs , accounting for research that highlight efforts to facilitate the transition between design and print such as methods that require minimal post-processing to be manufacture-ready are gaining interest .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [52, 59]}, {"entity": "research", "entity_type": "concept or principle", "pos": [77, 85]}, {"entity": "transition", "entity_type": "concept or principle", "pos": [127, 137]}, {"entity": "design", "entity_type": "engineering feature", "pos": [146, 152]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [157, 162]}, {"entity": "as", "entity_type": "material", "pos": [168, 170]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [200, 215]}, {"entity": "be", "entity_type": "material", "pos": [219, 221]}], "task": "NER"}
{"text": "Interpreting density-based TO solutions , even when they are discrete , poses a bottleneck for post-processes such as shape optimisation or the use of CAD programs for the conversion into AM-compatible file formats .", "entity": [{"entity": "bottleneck", "entity_type": "concept or principle", "pos": [80, 90]}, {"entity": "as", "entity_type": "material", "pos": [115, 117]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [151, 154]}, {"entity": "file", "entity_type": "manufacturing standard", "pos": [202, 206]}], "task": "NER"}
{"text": "A smooth boundary representation is , therefore , an aspect of particular attention in the context of TO .", "entity": [{"entity": "smooth boundary", "entity_type": "engineering feature", "pos": [2, 17]}], "task": "NER"}
{"text": "An approach which is post-processing the layout of a TO-solution was recently presented by Liu .", "entity": [{"entity": "post-processing", "entity_type": "concept or principle", "pos": [21, 36]}, {"entity": "layout", "entity_type": "concept or principle", "pos": [41, 47]}], "task": "NER"}
{"text": "Here , a multi-step transformation method from a greyscale SIMP-based solution into STL and IGES formats has been presented .", "entity": [{"entity": "solution", "entity_type": "concept or principle", "pos": [70, 78]}, {"entity": "STL", "entity_type": "manufacturing standard", "pos": [84, 87]}, {"entity": "IGES", "entity_type": "manufacturing standard", "pos": [92, 96]}], "task": "NER"}
{"text": "It is comprised of : 1 ) density thresholding and mesh refinement ; 2 ) skeletonisation ; 3 ) identify small features and increase their elemental density ; 4 ) density filtering ; 5 ) density thresholding while preserving volume fraction ; 6 ) create STL file utilizing ; 7 ) boundary interpretation using spline fitting ; 8 ) obtain IGES file from an in-build MATLAB function .", "entity": [{"entity": "density", "entity_type": "machanical property", "pos": [25, 32]}, {"entity": "mesh refinement", "entity_type": "concept or principle", "pos": [50, 65]}, {"entity": "skeletonisation", "entity_type": "enabling technology", "pos": [72, 87]}, {"entity": "density", "entity_type": "machanical property", "pos": [147, 154]}, {"entity": "density", "entity_type": "machanical property", "pos": [161, 168]}, {"entity": "density", "entity_type": "machanical property", "pos": [185, 192]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [223, 238]}, {"entity": "STL", "entity_type": "manufacturing standard", "pos": [252, 255]}, {"entity": "file", "entity_type": "manufacturing standard", "pos": [256, 260]}, {"entity": "boundary interpretation", "entity_type": "concept or principle", "pos": [277, 300]}, {"entity": "spline fitting", "entity_type": "enabling technology", "pos": [307, 321]}, {"entity": "IGES file", "entity_type": "manufacturing standard", "pos": [335, 344]}], "task": "NER"}
{"text": "Shape optimisations procedures using a CAD model were shown to be suitable with designs obtained from the adaptive boundary fitting method due to its smooth boundaries .", "entity": [{"entity": "CAD model", "entity_type": "enabling technology", "pos": [39, 48]}, {"entity": "be", "entity_type": "material", "pos": [63, 65]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [80, 87]}, {"entity": "boundary", "entity_type": "engineering feature", "pos": [115, 123]}, {"entity": "smooth boundaries", "entity_type": "engineering feature", "pos": [150, 167]}], "task": "NER"}
{"text": "Studies like this represent a key element in today 's research from DfAM , namely the transformation of complex AM-designs into CAD/CAM environments .", "entity": [{"entity": "element", "entity_type": "material", "pos": [34, 41]}, {"entity": "research", "entity_type": "concept or principle", "pos": [54, 62]}, {"entity": "CAD/CAM environments", "entity_type": "enabling technology", "pos": [128, 148]}], "task": "NER"}
{"text": "2 Commercial software implementations for lightweight structures Promoted by the greater application of TO in industry , an increased range of software providers have emerged , maturing and facilitating access to ready-to-use tools .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [13, 21]}, {"entity": "lightweight structures", "entity_type": "machine or equipment", "pos": [42, 64]}, {"entity": "industry", "entity_type": "application", "pos": [110, 118]}, {"entity": "range", "entity_type": "process parameter", "pos": [134, 139]}, {"entity": "software", "entity_type": "concept or principle", "pos": [143, 151]}, {"entity": "ready-to-use", "entity_type": "concept or principle", "pos": [213, 225]}], "task": "NER"}
{"text": "Particularly TO software providing greater freedom in utilizing subroutines , as recently demonstrated in , present a promising platform for further innovations in this field .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [16, 24]}, {"entity": "as", "entity_type": "material", "pos": [78, 80]}, {"entity": "platform", "entity_type": "machine or equipment", "pos": [128, 136]}], "task": "NER"}
{"text": "on automotive components like an upright .", "entity": [{"entity": "automotive", "entity_type": "application", "pos": [3, 13]}], "task": "NER"}
{"text": "In , significant weight savings of one to two-thirds were achieved while ensuring the same structural performance as the original parts .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [17, 23]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [91, 113]}, {"entity": "as", "entity_type": "material", "pos": [114, 116]}], "task": "NER"}
{"text": "In , shape controls ensured control over the member size , accounting for the minimum resolution of the electron beam melting process for a successful print .", "entity": [{"entity": "resolution", "entity_type": "process parameter", "pos": [86, 96]}, {"entity": "electron beam melting", "entity_type": "manufacturing process", "pos": [104, 125]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [151, 156]}], "task": "NER"}
{"text": "It was observed , that all considered factors were closely related to the amount of support material used , as it increased the fabrication time and cost .", "entity": [{"entity": "support material", "entity_type": "material", "pos": [84, 100]}, {"entity": "as", "entity_type": "material", "pos": [108, 110]}, {"entity": "fabrication time", "entity_type": "process parameter", "pos": [128, 144]}], "task": "NER"}
{"text": "From the above study , it can be concluded that the layout of the final design for the industrial sector will be the result of multi-objective considerations , specifically drawing attention to the performance-economy relation with the utilized print materials .", "entity": [{"entity": "be", "entity_type": "material", "pos": [30, 32]}, {"entity": "layout", "entity_type": "concept or principle", "pos": [52, 58]}, {"entity": "design", "entity_type": "engineering feature", "pos": [72, 78]}, {"entity": "industrial sector", "entity_type": "concept or principle", "pos": [87, 104]}, {"entity": "be", "entity_type": "material", "pos": [110, 112]}, {"entity": "drawing", "entity_type": "manufacturing process", "pos": [173, 180]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [245, 250]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [251, 260]}], "task": "NER"}
{"text": "This highlights the importance of a DfAM framework that assures correct weighting of the relevant parameters and provides similar to the generative design a portfolio of quantifiable geometrical solutions .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [41, 50]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [98, 108]}, {"entity": "generative design", "entity_type": "enabling technology", "pos": [137, 154]}], "task": "NER"}
{"text": "The optimisation of a heat sink design displayed the software 's capabilities to deal with multi-objective optimisation , as the design variables included friction force , thermal conductivity and out-of-plane heat transfer , besides the density of the elements .", "entity": [{"entity": "heat sink", "entity_type": "machine or equipment", "pos": [22, 31]}, {"entity": "design", "entity_type": "engineering feature", "pos": [32, 38]}, {"entity": "software", "entity_type": "concept or principle", "pos": [53, 61]}, {"entity": "as", "entity_type": "material", "pos": [122, 124]}, {"entity": "design", "entity_type": "engineering feature", "pos": [129, 135]}, {"entity": "friction force", "entity_type": "concept or principle", "pos": [155, 169]}, {"entity": "thermal conductivity", "entity_type": "machanical property", "pos": [172, 192]}, {"entity": "heat transfer", "entity_type": "concept or principle", "pos": [210, 223]}, {"entity": "density", "entity_type": "machanical property", "pos": [238, 245]}, {"entity": "elements", "entity_type": "material", "pos": [253, 261]}], "task": "NER"}
{"text": "Despite showcasing the theoretical capabilities of today 's TO-software , the above-mentioned studies commonly lack experimental verification .", "entity": [{"entity": "theoretical", "entity_type": "concept or principle", "pos": [23, 34]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [116, 128]}], "task": "NER"}
{"text": "Generally , numerical examples in TO involve either cantilever , half MBB or full MBB beams , but there is no explicit agreement by the scientific community on their aspect ratio , making comparisons difficult .", "entity": [{"entity": "cantilever", "entity_type": "engineering feature", "pos": [52, 62]}, {"entity": "half MBB", "entity_type": "engineering feature", "pos": [65, 73]}, {"entity": "MBB beams", "entity_type": "engineering feature", "pos": [82, 91]}, {"entity": "aspect ratio", "entity_type": "engineering feature", "pos": [166, 178]}], "task": "NER"}
{"text": "From a practical standpoint , standardised flexure tests would be better suited for experimental verification and therefore aid the comparison between both the TO-models and their physical counterparts .", "entity": [{"entity": "flexure tests", "entity_type": "process characterization", "pos": [43, 56]}, {"entity": "be", "entity_type": "material", "pos": [63, 65]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [84, 96]}], "task": "NER"}
{"text": "3 Advanced applications TO-designs are increasingly adopted in technologically advanced industries as AM hardware and software are maturing , making complexity and scalability of AM-parts more tangible .", "entity": [{"entity": "industries", "entity_type": "application", "pos": [88, 98]}, {"entity": "as", "entity_type": "material", "pos": [99, 101]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [102, 104]}, {"entity": "software", "entity_type": "concept or principle", "pos": [118, 126]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [149, 159]}], "task": "NER"}
{"text": "Recent case-studies on topologically optimized engine pistons or car chassis indeed showed a promising development for increased uptake of TO in the automotive sector .", "entity": [{"entity": "topologically", "entity_type": "concept or principle", "pos": [23, 36]}, {"entity": "car", "entity_type": "process characterization", "pos": [65, 68]}, {"entity": "automotive sector", "entity_type": "application", "pos": [149, 166]}], "task": "NER"}
{"text": "As an example , Aage looked into optimizing the wing structure of a Boeing 777 using high-performance computing to overcome current limitations regarding the number of resolvable voxels and representable feature size .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [53, 62]}, {"entity": "Boeing", "entity_type": "application", "pos": [68, 74]}, {"entity": "high-performance computing", "entity_type": "enabling technology", "pos": [85, 111]}, {"entity": "voxels", "entity_type": "concept or principle", "pos": [179, 185]}, {"entity": "feature size", "entity_type": "process parameter", "pos": [204, 216]}], "task": "NER"}
{"text": "However , this should not distract from the more pressing challenge the AM-community is currently faced to further exploit AM capabilities , namely the reduction of the computational cost and improvement of the resolution for standard engineering problems .", "entity": [{"entity": "pressing", "entity_type": "manufacturing process", "pos": [49, 57]}, {"entity": "faced", "entity_type": "manufacturing process", "pos": [98, 103]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [123, 125]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [152, 161]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [211, 221]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [226, 234]}, {"entity": "engineering", "entity_type": "application", "pos": [235, 246]}], "task": "NER"}
{"text": "In case of small- and mid-sized companies these are commonly solved with standard desktop machines rather than employing high-performance computing .", "entity": [{"entity": "companies", "entity_type": "application", "pos": [32, 41]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [73, 81]}, {"entity": "machines", "entity_type": "machine or equipment", "pos": [90, 98]}, {"entity": "high-performance computing", "entity_type": "enabling technology", "pos": [121, 147]}], "task": "NER"}
{"text": "the fruition of compliant mechanisms , realized by means of multi-material printers and the use of materials with greatly varying Poisson 's ratios .", "entity": [{"entity": "compliant mechanisms", "entity_type": "concept or principle", "pos": [16, 36]}, {"entity": "multi-material", "entity_type": "concept or principle", "pos": [60, 74]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [99, 108]}], "task": "NER"}
{"text": "2 AM-designs derived from evolutionary TO Evolutionary algorithms have been used and constantly improved for structural optimisation over the last two decades .", "entity": [{"entity": "algorithms", "entity_type": "concept or principle", "pos": [55, 65]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [109, 132]}], "task": "NER"}
{"text": "The most prominent representative is BESO , introduced by Yang as an extension to the Evolutionary Structural Optimisation method put forward by Xie and Stevens .", "entity": [{"entity": "BESO", "entity_type": "concept or principle", "pos": [37, 41]}, {"entity": "as", "entity_type": "material", "pos": [63, 65]}, {"entity": "Structural Optimisation method", "entity_type": "concept or principle", "pos": [99, 129]}], "task": "NER"}
{"text": "However , issues related to stepped contours i.e .", "entity": [{"entity": "contours", "entity_type": "engineering feature", "pos": [36, 44]}], "task": "NER"}
{"text": "smooth boundaries remain .", "entity": [{"entity": "smooth boundaries", "entity_type": "engineering feature", "pos": [0, 17]}], "task": "NER"}
{"text": "1 Digitally print-ready designs In light of DfAM , achieving a smooth boundary representation , especially for discrete TO-solutions , is currently a subject of intense study .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [24, 31]}, {"entity": "smooth boundary", "entity_type": "engineering feature", "pos": [63, 78]}], "task": "NER"}
{"text": "Capitalizing on the shape functions , a smoother boundary , accounting for discontinuous material distributions within single FEs , was realized .", "entity": [{"entity": "boundary", "entity_type": "engineering feature", "pos": [49, 57]}, {"entity": "material", "entity_type": "material", "pos": [89, 97]}, {"entity": "distributions", "entity_type": "concept or principle", "pos": [98, 111]}], "task": "NER"}
{"text": "Despite revealing the same overall topology , the Iso-XFEM method provided a superior structural stiffness as compared to the BESO implementation for the same amount of iterations and identical mesh-size .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [35, 43]}, {"entity": "Iso-XFEM method", "entity_type": "process characterization", "pos": [50, 65]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [97, 106]}, {"entity": "as", "entity_type": "material", "pos": [107, 109]}, {"entity": "BESO implementation", "entity_type": "concept or principle", "pos": [126, 145]}], "task": "NER"}
{"text": "BESO with a finer initial fixed mesh matched the performance but at a computational expense .", "entity": [{"entity": "BESO", "entity_type": "concept or principle", "pos": [0, 4]}, {"entity": "fixed mesh", "entity_type": "engineering feature", "pos": [26, 36]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [49, 60]}], "task": "NER"}
{"text": "As the mesh manipulation is outweighing the computational benefit of BESO , the AM-friendly Iso-XFEM method was regarded as the preferential TO method , streamlining the design process towards digitally-print-ready models and effectively tying in aspects of lightweighting and boundary representation .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "mesh manipulation", "entity_type": "concept or principle", "pos": [7, 24]}, {"entity": "BESO", "entity_type": "concept or principle", "pos": [69, 73]}, {"entity": "Iso-XFEM method", "entity_type": "process characterization", "pos": [92, 107]}, {"entity": "as", "entity_type": "material", "pos": [109, 111]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [170, 184]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [258, 272]}, {"entity": "boundary representation", "entity_type": "concept or principle", "pos": [277, 300]}], "task": "NER"}
{"text": "In a more recent study , Iso-XFEM was applied as a design-procedure to obtain a lightweight brake pedal .", "entity": [{"entity": "Iso-XFEM", "entity_type": "process characterization", "pos": [25, 33]}, {"entity": "as", "entity_type": "material", "pos": [35, 37]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [80, 91]}], "task": "NER"}
{"text": "The structure was effectively enhanced for AM , using a manual post-processing step , in which a partial cellular infill based on Body Centred Cubic unit cells was included to improve the performance under arbitrary loading and to reduce warpage arising from residual stresses in SLM .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [4, 13]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [43, 45]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [63, 78]}, {"entity": "infill", "entity_type": "process parameter", "pos": [114, 120]}, {"entity": "Body Centred Cubic", "entity_type": "concept or principle", "pos": [130, 148]}, {"entity": "cells", "entity_type": "application", "pos": [154, 159]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [188, 199]}, {"entity": "warpage", "entity_type": "concept or principle", "pos": [238, 245]}, {"entity": "residual stresses", "entity_type": "machanical property", "pos": [259, 276]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [280, 283]}], "task": "NER"}
{"text": "In , a modified BESO method was used to optimize the strut thickness of lattices used in an engine bracket , to improve the compliance over a homogenous design .", "entity": [{"entity": "BESO method", "entity_type": "concept or principle", "pos": [16, 27]}, {"entity": "strut thickness", "entity_type": "process parameter", "pos": [53, 68]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [72, 80]}, {"entity": "bracket", "entity_type": "machine or equipment", "pos": [99, 106]}, {"entity": "homogenous design", "entity_type": "engineering feature", "pos": [142, 159]}], "task": "NER"}
{"text": "The material allocation is conducted based on the ratio between the local and global stress magnitude i.e .", "entity": [{"entity": "material", "entity_type": "material", "pos": [4, 12]}, {"entity": "stress", "entity_type": "machanical property", "pos": [85, 91]}, {"entity": "magnitude", "entity_type": "process parameter", "pos": [92, 101]}], "task": "NER"}
{"text": "the stress distribution as well as the predefined strut diameter bounds .", "entity": [{"entity": "stress distribution", "entity_type": "machanical property", "pos": [4, 23]}, {"entity": "as", "entity_type": "material", "pos": [24, 26]}, {"entity": "as", "entity_type": "material", "pos": [32, 34]}, {"entity": "strut diameter", "entity_type": "process parameter", "pos": [50, 64]}], "task": "NER"}
{"text": "compliant mechanisms , a modified BESO with local displacement constraints was employed by Zuo and Xie .", "entity": [{"entity": "compliant mechanisms", "entity_type": "concept or principle", "pos": [0, 20]}, {"entity": "BESO", "entity_type": "concept or principle", "pos": [34, 38]}, {"entity": "displacement constraints", "entity_type": "concept or principle", "pos": [50, 74]}], "task": "NER"}
{"text": "Here , the standard penalization factor was introduced for the material interpolation and to ensure convergence , however , for the FEA several critical nodes were assigned to local displacement functions based on the individual virtual loads to fine-tune the topology for a specific load case .", "entity": [{"entity": "standard", "entity_type": "concept or principle", "pos": [11, 19]}, {"entity": "material interpolation", "entity_type": "concept or principle", "pos": [63, 85]}, {"entity": "displacement functions", "entity_type": "concept or principle", "pos": [182, 204]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [260, 268]}], "task": "NER"}
{"text": "Numerical examples displayed dissimilar topologies compared to the conventional compliance-driven approach and a significant reduction in the maximum vertical deflection .", "entity": [{"entity": "topologies", "entity_type": "concept or principle", "pos": [40, 50]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [125, 134]}, {"entity": "vertical deflection", "entity_type": "process parameter", "pos": [150, 169]}], "task": "NER"}
{"text": "As outlined by the authors , this method lends itself for lightweight structures such as an aircraft wing , for which awareness and control over the deformed shape are required .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "lightweight structures", "entity_type": "machine or equipment", "pos": [58, 80]}, {"entity": "as", "entity_type": "material", "pos": [86, 88]}, {"entity": "aircraft wing", "entity_type": "application", "pos": [92, 105]}, {"entity": "deformed shape", "entity_type": "machanical property", "pos": [149, 163]}], "task": "NER"}
{"text": "For the most part , TO procedures employ fixed meshes for the FEA .", "entity": [{"entity": "fixed meshes", "entity_type": "engineering feature", "pos": [41, 53]}], "task": "NER"}
{"text": "A mesh refinement captures the material behaviour more accurately , however at higher computational cost due to more degrees of freedom .", "entity": [{"entity": "mesh refinement", "entity_type": "concept or principle", "pos": [2, 17]}, {"entity": "material", "entity_type": "material", "pos": [31, 39]}, {"entity": "accurately", "entity_type": "process characterization", "pos": [55, 65]}, {"entity": "degrees of freedom", "entity_type": "concept or principle", "pos": [117, 135]}], "task": "NER"}
{"text": "A fine mesh for updating design variable and a hierarchical system for the FEA .", "entity": [{"entity": "fine mesh", "entity_type": "engineering feature", "pos": [2, 11]}, {"entity": "design", "entity_type": "engineering feature", "pos": [25, 31]}], "task": "NER"}
{"text": "This resulted in a relatively-smooth topology , due to the finer resolution representing the boundaries of the structure , whereas the size of the internal elements remained coarse .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [37, 45]}, {"entity": "finer resolution", "entity_type": "process parameter", "pos": [59, 75]}, {"entity": "boundaries", "entity_type": "engineering feature", "pos": [93, 103]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [111, 120]}, {"entity": "elements", "entity_type": "material", "pos": [156, 164]}], "task": "NER"}
{"text": "It is of note that caution must be taken in choosing an appropriate value for the maximum element size to obtain accurate FEA results .", "entity": [{"entity": "be", "entity_type": "material", "pos": [32, 34]}, {"entity": "element size", "entity_type": "process parameter", "pos": [90, 102]}, {"entity": "accurate", "entity_type": "process characterization", "pos": [113, 121]}], "task": "NER"}
{"text": "3 Level set TO for AM Level set method centre around the structural boundaries i.e .", "entity": [{"entity": "set", "entity_type": "application", "pos": [8, 11]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [19, 21]}, {"entity": "set", "entity_type": "application", "pos": [28, 31]}, {"entity": "boundaries", "entity_type": "engineering feature", "pos": [68, 78]}], "task": "NER"}
{"text": "interfaces and their implicit representation via iso-contours of the corresponding level set function .", "entity": [{"entity": "via iso-contours", "entity_type": "engineering feature", "pos": [45, 61]}, {"entity": "level set function", "entity_type": "concept or principle", "pos": [83, 101]}], "task": "NER"}
{"text": "The inherently smooth and well-defined boundaries obtained lend themselves for parameterization into geometric shapes , potentially linking aspects of manufacturing and digitalization .", "entity": [{"entity": "boundaries", "entity_type": "engineering feature", "pos": [39, 49]}, {"entity": "geometric shapes", "entity_type": "engineering feature", "pos": [101, 117]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [151, 164]}], "task": "NER"}
{"text": "However , for analysis , the geometrical model is mostly discretized and mapped onto a fixed mesh , following the density-based methods .", "entity": [{"entity": "geometrical model", "entity_type": "concept or principle", "pos": [29, 46]}, {"entity": "fixed mesh", "entity_type": "engineering feature", "pos": [87, 97]}], "task": "NER"}
{"text": "For instance , by embracing both economic and performance-driven DfAM considerations , Liu and co-workers have developed a feature-based approach as well as algorithms that take into account the deposition path/building direction and support-free manufacturing .", "entity": [{"entity": "as", "entity_type": "material", "pos": [132, 134]}, {"entity": "as", "entity_type": "material", "pos": [146, 148]}, {"entity": "algorithms", "entity_type": "concept or principle", "pos": [157, 167]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [195, 205]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [247, 260]}], "task": "NER"}
{"text": "Regarding DfAM studies have shown that gaps between paths due to sharp angle changes can be avoided and as the paths follow the principal stress trajectories , the overall performance can be increased .", "entity": [{"entity": "sharp angle", "entity_type": "engineering feature", "pos": [65, 76]}, {"entity": "be", "entity_type": "material", "pos": [89, 91]}, {"entity": "as", "entity_type": "material", "pos": [104, 106]}, {"entity": "principal stress", "entity_type": "machanical property", "pos": [128, 144]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [172, 183]}, {"entity": "be", "entity_type": "material", "pos": [188, 190]}], "task": "NER"}
{"text": "In , the contour offset method and the structural skeleton based method , including a support structure constraint , were investigated .", "entity": [{"entity": "contour offset method", "entity_type": "enabling technology", "pos": [9, 30]}, {"entity": "structural skeleton", "entity_type": "engineering feature", "pos": [39, 58]}, {"entity": "support structure", "entity_type": "engineering feature", "pos": [86, 103]}], "task": "NER"}
{"text": "It was found that the structural performance was comparable between both methods , whereas , the skeleton-based method was favourable as it avoided manufacturing irregularities .", "entity": [{"entity": "structural performance", "entity_type": "process characterization", "pos": [22, 44]}, {"entity": "as", "entity_type": "material", "pos": [46, 48]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [148, 161]}], "task": "NER"}
{"text": "The authors optimized a cantilever beam for self-supported AM , using a multi-LS interpolation approach , to illustrate their method .", "entity": [{"entity": "cantilever beam", "entity_type": "machine or equipment", "pos": [24, 39]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [59, 61]}, {"entity": "interpolation", "entity_type": "concept or principle", "pos": [81, 94]}], "task": "NER"}
{"text": "Similarly , the skeletonisation of 2D LS topologies was utilized in to constrain the minimum hole size and control the number of holes in the topology to ensure better manufacturability .", "entity": [{"entity": "skeletonisation", "entity_type": "enabling technology", "pos": [16, 31]}, {"entity": "2D", "entity_type": "concept or principle", "pos": [35, 37]}, {"entity": "topologies", "entity_type": "concept or principle", "pos": [41, 51]}, {"entity": "hole size", "entity_type": "engineering feature", "pos": [93, 102]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [142, 150]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [168, 185]}], "task": "NER"}
{"text": "In , it was applied to avoid small struts by controlling the minimum or maximum length scale of the features i.e .", "entity": [{"entity": "struts", "entity_type": "machine or equipment", "pos": [35, 41]}, {"entity": "length scale", "entity_type": "process characterization", "pos": [80, 92]}], "task": "NER"}
{"text": "the distance between skeleton and boundary .", "entity": [{"entity": "boundary", "entity_type": "engineering feature", "pos": [34, 42]}], "task": "NER"}
{"text": "8b illustrates the difference in topology between constraint and unconstraint LS TO of a cantilever beam .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [33, 41]}, {"entity": "cantilever beam", "entity_type": "machine or equipment", "pos": [89, 104]}], "task": "NER"}
{"text": "In the study of Allaire , the aspect of the overhang constraint was considered from two perspectives .", "entity": [{"entity": "overhang constraint", "entity_type": "process parameter", "pos": [44, 63]}], "task": "NER"}
{"text": "The latter has been developed in and centres on the intermediate AM stages , resulting in the continuous change in shape and boundary conditions with each consecutive layer .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [65, 67]}, {"entity": "boundary conditions", "entity_type": "concept or principle", "pos": [125, 144]}, {"entity": "layer", "entity_type": "process parameter", "pos": [167, 172]}], "task": "NER"}
{"text": "the cooling rate as another fabrication constraint for this minimum compliance problem .", "entity": [{"entity": "cooling rate", "entity_type": "process parameter", "pos": [4, 16]}, {"entity": "as", "entity_type": "material", "pos": [17, 19]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [28, 39]}, {"entity": "minimum compliance problem", "entity_type": "process parameter", "pos": [60, 86]}], "task": "NER"}
{"text": "Likewise , in , Mart accounted for procesB-induced effects , such as porosity in parts created from electron beam melting .", "entity": [{"entity": "as", "entity_type": "material", "pos": [66, 68]}, {"entity": "electron beam melting", "entity_type": "manufacturing process", "pos": [100, 121]}], "task": "NER"}
{"text": "Considering fabrication-stages and -flaws for different AM-processes is certainly representing a more interconnected and realistic application of DfAM , encompassing intrinsic and extrinsic factors , shared in the upper and middle band , and contributing to higher quality AM-parts in the future .", "entity": [{"entity": "intrinsic and extrinsic factors", "entity_type": "process parameter", "pos": [166, 197]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [265, 272]}], "task": "NER"}
{"text": "Certain design requirements like fixed passive elements or other functional affiliations often do not allow support-free angles .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [8, 14]}, {"entity": "elements", "entity_type": "material", "pos": [47, 55]}], "task": "NER"}
{"text": "Mirzendehdel and Suresh reduced the support volume of topologically optimized structures using an LS based Pareto TO , considering both support structure and topological sensitivities through dynamic weighting .", "entity": [{"entity": "support", "entity_type": "application", "pos": [36, 43]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [54, 67]}, {"entity": "Pareto", "entity_type": "concept or principle", "pos": [107, 113]}, {"entity": "support structure", "entity_type": "engineering feature", "pos": [136, 153]}, {"entity": "topological sensitivities", "entity_type": "concept or principle", "pos": [158, 183]}, {"entity": "dynamic", "entity_type": "concept or principle", "pos": [192, 199]}], "task": "NER"}
{"text": "Similar attempts to reduce support volume include tree-like and topologically optimized supports .", "entity": [{"entity": "support", "entity_type": "application", "pos": [27, 34]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [64, 77]}, {"entity": "supports", "entity_type": "application", "pos": [88, 96]}], "task": "NER"}
{"text": "2 Cellular structures in AM Cellular structures represent an important structural design feature in AM , commonly used for lightweighting .", "entity": [{"entity": "Cellular structures", "entity_type": "engineering feature", "pos": [2, 21]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [25, 27]}, {"entity": "structural design", "entity_type": "engineering feature", "pos": [71, 88]}, {"entity": "feature", "entity_type": "engineering feature", "pos": [89, 96]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [100, 102]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [123, 137]}], "task": "NER"}
{"text": "Characterized by slender/thin members , such as struts/bars or sheets/plates , these formations are increasingly utilized as an integral feature in AM-designs primarily due to material and time-/energy-saving in fabrication as well as improvements in strength-to-weight ratio , as summarized in .", "entity": [{"entity": "as", "entity_type": "material", "pos": [45, 47]}, {"entity": "as", "entity_type": "material", "pos": [105, 107]}, {"entity": "feature", "entity_type": "engineering feature", "pos": [137, 144]}, {"entity": "material", "entity_type": "material", "pos": [176, 184]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [212, 223]}, {"entity": "as", "entity_type": "material", "pos": [224, 226]}, {"entity": "as", "entity_type": "material", "pos": [232, 234]}, {"entity": "as", "entity_type": "material", "pos": [278, 280]}], "task": "NER"}
{"text": "Besides the specific strength , their ability to dissipate energy , heat and vibration add value to the design .", "entity": [{"entity": "specific strength", "entity_type": "machanical property", "pos": [12, 29]}, {"entity": "heat", "entity_type": "concept or principle", "pos": [68, 72]}, {"entity": "design", "entity_type": "engineering feature", "pos": [104, 110]}], "task": "NER"}
{"text": "Recently , a significant increase in buckling load and buckling strength have been recorded by using triangular lattice-infills or topology optimized hierarchical microstructures , respectively .", "entity": [{"entity": "buckling load", "entity_type": "process characterization", "pos": [37, 50]}, {"entity": "buckling strength", "entity_type": "machanical property", "pos": [55, 72]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [131, 139]}, {"entity": "microstructures", "entity_type": "material", "pos": [163, 178]}], "task": "NER"}
{"text": "In metal-AM , they can also help mitigate warpage , arising from procesB-induced residual stresses , however , some lattice types must be altered to accommodate for e.g .", "entity": [{"entity": "warpage", "entity_type": "concept or principle", "pos": [42, 49]}, {"entity": "residual stresses", "entity_type": "machanical property", "pos": [81, 98]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [116, 123]}, {"entity": "be", "entity_type": "material", "pos": [135, 137]}], "task": "NER"}
{"text": "The use of lattices , contrary to the common misconception , is therefore not a lightweighting approach from a pure stiffness standpoint , which needs to be considered in the design process .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [11, 19]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [80, 94]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [116, 125]}, {"entity": "be", "entity_type": "material", "pos": [154, 156]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [175, 189]}], "task": "NER"}
{"text": "An overview from design to analysis of cellular structures for AM can be extracted from .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [17, 23]}, {"entity": "cellular structures", "entity_type": "engineering feature", "pos": [39, 58]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [63, 65]}, {"entity": "be", "entity_type": "material", "pos": [70, 72]}], "task": "NER"}
{"text": "Unit cells represent the building blocks of a lattice , which is generated either from sweeping , meshing/mapping , tessellation to obtain a regular pattern or stochastically yielding unstructured formations , which is often achieved via techniques such as dithering .", "entity": [{"entity": "Unit cells", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [46, 53]}, {"entity": "tessellation", "entity_type": "engineering feature", "pos": [116, 128]}, {"entity": "pattern", "entity_type": "concept or principle", "pos": [149, 156]}, {"entity": "as", "entity_type": "material", "pos": [165, 167]}], "task": "NER"}
{"text": "Unit cells are generally classified into truss based and surface-based .", "entity": [{"entity": "Unit cells", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "truss", "entity_type": "machine or equipment", "pos": [41, 46]}], "task": "NER"}
{"text": "Numerous cell topologies were generatively developed over the years , leading to the emergence of unit cell libraries/families for AM .", "entity": [{"entity": "cell topologies", "entity_type": "concept or principle", "pos": [9, 24]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [98, 107]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [131, 133]}], "task": "NER"}
{"text": "Ground trusses , often resembling lattice-like configurations , are characterized by a freeform frame-network with locally varying strut diameters which also lends themselves well for AM .", "entity": [{"entity": "freeform", "entity_type": "concept or principle", "pos": [87, 95]}, {"entity": "strut diameters", "entity_type": "process parameter", "pos": [131, 146]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [184, 186]}], "task": "NER"}
{"text": "It is however of note , that isotropic open-cell trusB-like structures have an up to threefold inferior stiffness performance compared to their closed-cell lattice counterparts of the same relative density .", "entity": [{"entity": "isotropic", "entity_type": "machanical property", "pos": [29, 38]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [104, 113]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [114, 125]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [156, 163]}, {"entity": "relative density", "entity_type": "machanical property", "pos": [189, 205]}], "task": "NER"}
{"text": "On this account , considering that lattices are not stiffnesB-optimal and given the choice , surface-based unit cells should be favoured for lightweight designs .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [35, 43]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [107, 117]}, {"entity": "be", "entity_type": "material", "pos": [125, 127]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [141, 152]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [153, 160]}], "task": "NER"}
{"text": "Unit cell tessellation approaches often give rise to non-conformity as loose-hanging members are formed when a lattice is created , impairing the structural performance .", "entity": [{"entity": "Unit cell", "entity_type": "concept or principle", "pos": [0, 9]}, {"entity": "tessellation", "entity_type": "engineering feature", "pos": [10, 22]}, {"entity": "as", "entity_type": "material", "pos": [68, 70]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [111, 118]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [146, 168]}], "task": "NER"}
{"text": "Lattices derived from tessellated surface-based unit cells are less affected by this phenomenon .", "entity": [{"entity": "Lattices", "entity_type": "concept or principle", "pos": [0, 8]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [48, 58]}], "task": "NER"}
{"text": "On the contrary , conformal lattices were found to yield greater structural performance .", "entity": [{"entity": "conformal lattices", "entity_type": "engineering feature", "pos": [18, 36]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [65, 87]}], "task": "NER"}
{"text": "Works on graded lattices most generally focus on piecewise variation in volume fractions that change from one unit cell to another .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [16, 24]}, {"entity": "variation", "entity_type": "concept or principle", "pos": [59, 68]}, {"entity": "volume fractions", "entity_type": "process parameter", "pos": [72, 88]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [110, 119]}], "task": "NER"}
{"text": "However , due to the implicit definition of triply periodic minimal surface lattices , true functional grading is achievable with ease .", "entity": [{"entity": "triply periodic minimal surface", "entity_type": "concept or principle", "pos": [44, 75]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [76, 84]}], "task": "NER"}
{"text": "Together with the advancement in hardware technology , capable of fine- and multi-scale structures , these new lightweight lattice structures with locally changing material properties represent a unique offering of AM .", "entity": [{"entity": "technology", "entity_type": "concept or principle", "pos": [42, 52]}, {"entity": "multi-scale structures", "entity_type": "engineering feature", "pos": [76, 98]}, {"entity": "lightweight lattice", "entity_type": "concept or principle", "pos": [111, 130]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [164, 183]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [215, 217]}], "task": "NER"}
{"text": "Discrepancies between the ideal and the actual performance of lattices , reviewed in , is owed to irregularities introduced during manufacturing , which include micro-voids or the change in surface roughness , making the prediction of the mechanical performance based on the relative density and linear elastic assumptions difficult .", "entity": [{"entity": "performance", "entity_type": "concept or principle", "pos": [47, 58]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [62, 70]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [131, 144]}, {"entity": "micro-voids", "entity_type": "machanical property", "pos": [161, 172]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [190, 207]}, {"entity": "prediction", "entity_type": "concept or principle", "pos": [221, 231]}, {"entity": "mechanical", "entity_type": "application", "pos": [239, 249]}, {"entity": "relative density", "entity_type": "machanical property", "pos": [275, 291]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [303, 310]}], "task": "NER"}
{"text": "A comparison between the experimental and numerical analyses of lattices and a summary of simulation methods are summarized in .", "entity": [{"entity": "experimental", "entity_type": "concept or principle", "pos": [25, 37]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [64, 72]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [90, 100]}], "task": "NER"}
{"text": "Latticing tools are increasingly provided in today 's CAD software and are commonly used to substitute low-stress areas for weight reduction .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [10, 15]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [54, 57]}, {"entity": "areas", "entity_type": "process parameter", "pos": [114, 119]}, {"entity": "weight", "entity_type": "process parameter", "pos": [124, 130]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [131, 140]}], "task": "NER"}
{"text": "Particularly the ability to achieve a balance between robustness and compliance in tailored lattices was recently stressed .", "entity": [{"entity": "robustness", "entity_type": "machanical property", "pos": [54, 64]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [92, 100]}], "task": "NER"}
{"text": "Another emerging research field in AM , aiming - among others - at combing high strength and stiffness , is biomimicry .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [17, 25]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [35, 37]}, {"entity": "strength", "entity_type": "machanical property", "pos": [80, 88]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [93, 102]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [108, 118]}], "task": "NER"}
{"text": "Moreover , it is of note , that some software providers like ELiSE are already incorporating bionic templates into designs geared towards AM .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [37, 45]}, {"entity": "bionic templates", "entity_type": "material", "pos": [93, 109]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [115, 122]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [138, 140]}], "task": "NER"}
{"text": "1 Topologically optimized lattices based on academic codes Promising academic approaches dealing with structural optimisation of lattices for AM are on the uprise .", "entity": [{"entity": "Topologically", "entity_type": "concept or principle", "pos": [2, 15]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [26, 34]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [102, 125]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [129, 137]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [142, 144]}], "task": "NER"}
{"text": "The digitalisation of these intricate structures is a prerequisite to ensure optimisation , bridge the gap to manufacturing and ultimately improve the structural performance of lightweight AM-parts .", "entity": [{"entity": "bridge", "entity_type": "application", "pos": [92, 98]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [110, 123]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [151, 173]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [177, 188]}], "task": "NER"}
{"text": "Computationally efficient representation of lattices is as challenging as it is important for the analysis and manufacturing steps .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [44, 52]}, {"entity": "as", "entity_type": "material", "pos": [56, 58]}, {"entity": "as", "entity_type": "material", "pos": [71, 73]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [111, 124]}], "task": "NER"}
{"text": "As a consequence , research is actively looking into ways to reduce the computational expense , aiding streamline the design process and enabling geometrical layouts , such as functionally graded lattices .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "research", "entity_type": "concept or principle", "pos": [19, 27]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [118, 132]}, {"entity": "as", "entity_type": "material", "pos": [173, 175]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [196, 204]}], "task": "NER"}
{"text": "1 Structurally optimized lattices using the homogenization method To capture the heterogeneous nature of lattices , unit cells are commonly homogenized into representative volume elements .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [25, 33]}, {"entity": "homogenization method", "entity_type": "manufacturing process", "pos": [44, 65]}, {"entity": "heterogeneous", "entity_type": "concept or principle", "pos": [81, 94]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [105, 113]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [116, 126]}, {"entity": "homogenized", "entity_type": "manufacturing process", "pos": [140, 151]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [172, 178]}, {"entity": "elements", "entity_type": "material", "pos": [179, 187]}], "task": "NER"}
{"text": "Homogenization-based methods have recently been integrated into a lattice mesostructural optimisation framework for AM .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [66, 73]}, {"entity": "framework", "entity_type": "concept or principle", "pos": [102, 111]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [116, 118]}], "task": "NER"}
{"text": "In , Messner presented the inverse homogenization , in which the macrostructural material properties of a periodic lattice consisting of simple unit cells are combined with a subsequent parameterization to obtain a 3D trusB-like lattice structure with struts of round crosB-sections and isotropic material behaviour .", "entity": [{"entity": "homogenization", "entity_type": "manufacturing process", "pos": [35, 49]}, {"entity": "macrostructural material properties", "entity_type": "machanical property", "pos": [65, 100]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [115, 122]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [137, 143]}, {"entity": "cells", "entity_type": "application", "pos": [149, 154]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [215, 217]}, {"entity": "lattice structure", "entity_type": "engineering feature", "pos": [229, 246]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [252, 258]}, {"entity": "crosB-sections", "entity_type": "concept or principle", "pos": [268, 282]}, {"entity": "isotropic material", "entity_type": "material", "pos": [287, 305]}], "task": "NER"}
{"text": "In the context of digital AM , it is worth mentioning , that such a parameterization of the design space is beneficial for better control over the geometrical layout using CAD-like environments and therefore bridging the gap between important intrinsic DfAM aspects .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [26, 28]}, {"entity": "design space", "entity_type": "concept or principle", "pos": [92, 104]}, {"entity": "layout", "entity_type": "concept or principle", "pos": [159, 165]}, {"entity": "CAD-like environments", "entity_type": "enabling technology", "pos": [172, 193]}, {"entity": "bridging", "entity_type": "concept or principle", "pos": [208, 216]}], "task": "NER"}
{"text": "2 Graded lattices derived from mapping combined with density-based TO Various studies have utilized a mapping approach to update a cellular structure based on the density values obtained from unpenalized TO .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [9, 17]}, {"entity": "cellular structure", "entity_type": "engineering feature", "pos": [131, 149]}, {"entity": "density", "entity_type": "machanical property", "pos": [163, 170]}], "task": "NER"}
{"text": "Some of these use the abovementioned homogenization approach to map the unit cells achieving a more accurate mechanical response .", "entity": [{"entity": "homogenization", "entity_type": "manufacturing process", "pos": [37, 51]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [72, 82]}, {"entity": "accurate", "entity_type": "process characterization", "pos": [100, 108]}], "task": "NER"}
{"text": "In , a SIMP-solution provides the density distribution , which is mapped onto the explicit cellular structure , leading to the newly density-adjusted structure .", "entity": [{"entity": "density distribution", "entity_type": "machanical property", "pos": [34, 54]}, {"entity": "cellular structure", "entity_type": "engineering feature", "pos": [91, 109]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [150, 159]}], "task": "NER"}
{"text": "In an FEA of a beam under three-point bending it was determined that the stiffness of the explicit cellular model increased with greater gradient density and lower cell size , approaching the implicit i.e .", "entity": [{"entity": "beam", "entity_type": "machine or equipment", "pos": [15, 19]}, {"entity": "three-point bending", "entity_type": "process characterization", "pos": [26, 45]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [73, 82]}, {"entity": "model", "entity_type": "concept or principle", "pos": [108, 113]}, {"entity": "density", "entity_type": "machanical property", "pos": [146, 153]}, {"entity": "cell size", "entity_type": "machanical property", "pos": [164, 173]}], "task": "NER"}
{"text": "Great reliability of the numerical model was concluded after negligible differences in performance were obtained in comparison with the specimens created from SLA .", "entity": [{"entity": "reliability", "entity_type": "process characterization", "pos": [6, 17]}, {"entity": "model", "entity_type": "concept or principle", "pos": [35, 40]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [87, 98]}, {"entity": "SLA", "entity_type": "machine or equipment", "pos": [159, 162]}], "task": "NER"}
{"text": "An increase in stiffness by more than a third over the uniform lattice was revealed in the experiment , highlighting a viable design approach for structurally enhanced AM-parts .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [15, 24]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [63, 70]}, {"entity": "experiment", "entity_type": "concept or principle", "pos": [91, 101]}, {"entity": "design", "entity_type": "engineering feature", "pos": [126, 132]}], "task": "NER"}
{"text": "The dependence between cell size and performance elucidates the need for high-precision , fine-scale manufacturing in future work .", "entity": [{"entity": "cell size", "entity_type": "machanical property", "pos": [23, 32]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [37, 48]}, {"entity": "fine-scale manufacturing", "entity_type": "manufacturing process", "pos": [90, 114]}], "task": "NER"}
{"text": "Manufacturing of extruded 2D lattices is straightforward for most printing technologies , however , 3D cellular structures can pose a challenge for e.g .", "entity": [{"entity": "Manufacturing", "entity_type": "manufacturing process", "pos": [0, 13]}, {"entity": "extruded", "entity_type": "manufacturing process", "pos": [17, 25]}, {"entity": "2D", "entity_type": "concept or principle", "pos": [26, 28]}, {"entity": "printing technologies", "entity_type": "enabling technology", "pos": [66, 87]}, {"entity": "3D cellular structures", "entity_type": "engineering feature", "pos": [100, 122]}], "task": "NER"}
{"text": "powder-based processes , as unconsolidated material is easily encapsulated in cavities .", "entity": [{"entity": "processes", "entity_type": "concept or principle", "pos": [13, 22]}, {"entity": "as", "entity_type": "material", "pos": [25, 27]}, {"entity": "material", "entity_type": "material", "pos": [43, 51]}, {"entity": "encapsulated", "entity_type": "concept or principle", "pos": [62, 74]}], "task": "NER"}
{"text": "This was taken into consideration by Jin through manufacturing constraints such as the minimum section thickness , the minimum hole diameter and the uniformity of the section thickness i.e .", "entity": [{"entity": "manufacturing constraints", "entity_type": "concept or principle", "pos": [49, 74]}, {"entity": "as", "entity_type": "material", "pos": [80, 82]}, {"entity": "diameter", "entity_type": "concept or principle", "pos": [132, 140]}], "task": "NER"}
{"text": "The authors mapped the lattice of square cell honeycombs onto the density matrix of the TO-solution .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [23, 30]}, {"entity": "cell", "entity_type": "application", "pos": [41, 45]}, {"entity": "density matrix", "entity_type": "machanical property", "pos": [66, 80]}], "task": "NER"}
{"text": "The FEA reveals superior compressive performance of the developed graded lattice even with the manufacturing constraints over the uniform lattice .", "entity": [{"entity": "performance", "entity_type": "concept or principle", "pos": [37, 48]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [73, 80]}, {"entity": "manufacturing constraints", "entity_type": "concept or principle", "pos": [95, 120]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [138, 145]}], "task": "NER"}
{"text": "Similar to , the authors found that a decreasing cell size and an increasing gradient density has a positive effect on the structural performance .", "entity": [{"entity": "cell size", "entity_type": "machanical property", "pos": [49, 58]}, {"entity": "density", "entity_type": "machanical property", "pos": [86, 93]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [123, 145]}], "task": "NER"}
{"text": "Song expanded the concept to irregularly shaped cells for AM .", "entity": [{"entity": "cells", "entity_type": "application", "pos": [48, 53]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [58, 60]}], "task": "NER"}
{"text": "Here , a triangular mesh , obtained from a domain of unit tangent circles , is the basis for the formation of the cellular structure with predetermined cell/circle ratios .", "entity": [{"entity": "triangular mesh", "entity_type": "enabling technology", "pos": [9, 24]}, {"entity": "domain", "entity_type": "concept or principle", "pos": [43, 49]}, {"entity": "cellular structure", "entity_type": "engineering feature", "pos": [114, 132]}], "task": "NER"}
{"text": "This irregular lattice is then mapped onto the density field obtained from unpenalized SIMP .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [15, 22]}, {"entity": "density field", "entity_type": "machanical property", "pos": [47, 60]}], "task": "NER"}
{"text": "Experimental tests showed that the irregular cell structure obtained from the unpenalized SIMP outperformed those using penalization .", "entity": [{"entity": "Experimental", "entity_type": "concept or principle", "pos": [0, 12]}, {"entity": "cell", "entity_type": "application", "pos": [45, 49]}], "task": "NER"}
{"text": "Mapping strut-based unit cells with different densities into a hexahedral mesh of a topologically optimized structure enabled Robbins to create structures with an external topology based on the penalized SIMP-result filled with a conformal lattice with properties determined from the homogenization method .", "entity": [{"entity": "strut-based", "entity_type": "engineering feature", "pos": [8, 19]}, {"entity": "cells", "entity_type": "application", "pos": [25, 30]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [84, 97]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [108, 117]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [172, 180]}, {"entity": "conformal lattice", "entity_type": "engineering feature", "pos": [230, 247]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [253, 263]}, {"entity": "homogenization method", "entity_type": "manufacturing process", "pos": [284, 305]}], "task": "NER"}
{"text": "The meshing was done with the Sandia 's Sculpt tool , allowing for the adaption and smoothing of the mesh at the boundaries , aiding the creation of a flawless and print-ready STL files .", "entity": [{"entity": "tool", "entity_type": "machine or equipment", "pos": [47, 51]}, {"entity": "boundaries", "entity_type": "engineering feature", "pos": [113, 123]}, {"entity": "STL", "entity_type": "manufacturing standard", "pos": [176, 179]}, {"entity": "files", "entity_type": "manufacturing standard", "pos": [180, 185]}], "task": "NER"}
{"text": "To guarantee the same weight of structures with various unit cell densities , the external topology was adapted accordingly , revealing an improved performance for less dense lattices .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [22, 28]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [56, 65]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [91, 99]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [148, 159]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [175, 183]}], "task": "NER"}
{"text": "Even though the structure was printed using laser power bed fusion of stainless steel , no experimental verification was conducted , which is a recurring shortcoming in many of the reviewed studies on structural optimisation using either TO or lattices .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [16, 25]}, {"entity": "laser power bed fusion", "entity_type": "manufacturing process", "pos": [44, 66]}, {"entity": "stainless steel", "entity_type": "material", "pos": [70, 85]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [91, 103]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [201, 224]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [244, 252]}], "task": "NER"}
{"text": "While all the aforementioned studies solely focused on the performance aspects of the mapped structures , Panesar took also aspects of design and manufacturability into account .", "entity": [{"entity": "performance", "entity_type": "concept or principle", "pos": [59, 70]}, {"entity": "design", "entity_type": "engineering feature", "pos": [135, 141]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [146, 163]}], "task": "NER"}
{"text": "Hereby investigating intersected , scaled and graded lattices with strut- and surface-based self-supporting unit cells for design aspect like structural optimality , design effort , support requirements , robustness i.e .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [53, 61]}, {"entity": "self-supporting", "entity_type": "engineering feature", "pos": [92, 107]}, {"entity": "cells", "entity_type": "application", "pos": [113, 118]}, {"entity": "design", "entity_type": "engineering feature", "pos": [123, 129]}, {"entity": "design", "entity_type": "engineering feature", "pos": [166, 172]}, {"entity": "support", "entity_type": "application", "pos": [182, 189]}, {"entity": "robustness", "entity_type": "machanical property", "pos": [205, 215]}], "task": "NER"}
{"text": "resilience to variation in loading and design-to-manufacturing discrepancy .", "entity": [{"entity": "variation", "entity_type": "concept or principle", "pos": [14, 23]}], "task": "NER"}
{"text": "The authors used a voxel paradigm , rather than the traditional volume boundary representation via B-rep , to represent lattices and employed an iso-value matrix , similar to , for functional grading .", "entity": [{"entity": "voxel", "entity_type": "concept or principle", "pos": [19, 24]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [64, 70]}, {"entity": "boundary representation", "entity_type": "concept or principle", "pos": [71, 94]}, {"entity": "B-rep", "entity_type": "enabling technology", "pos": [99, 104]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [120, 128]}], "task": "NER"}
{"text": "purely topologically optimized result .", "entity": [{"entity": "topologically", "entity_type": "concept or principle", "pos": [7, 20]}], "task": "NER"}
{"text": "Authors highlighted the superiority of the proposed lattice types in terms of specific stiffness over the uniform lattice and the robustness of the graded lattice making it the most well-rounded performing lattice .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [52, 59]}, {"entity": "specific stiffness", "entity_type": "machanical property", "pos": [78, 96]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [114, 121]}, {"entity": "robustness", "entity_type": "machanical property", "pos": [130, 140]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [155, 162]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [206, 213]}], "task": "NER"}
{"text": "Particularly , the lattices comprised of surface-based unit cells were found to result in more resilient structures .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [19, 27]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [55, 65]}], "task": "NER"}
{"text": "However , from a performance i.e .", "entity": [{"entity": "performance", "entity_type": "concept or principle", "pos": [17, 28]}], "task": "NER"}
{"text": "stiffness perspective , all lattices perform inferior compared to the solid pendant .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [0, 9]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [28, 36]}], "task": "NER"}
{"text": "Moreover , the cellular structures reduced the support structure requirements compared to the solid design .", "entity": [{"entity": "cellular structures", "entity_type": "engineering feature", "pos": [15, 34]}, {"entity": "support structure", "entity_type": "engineering feature", "pos": [47, 64]}, {"entity": "design", "entity_type": "engineering feature", "pos": [100, 106]}], "task": "NER"}
{"text": "Similar to , the voxel-based method of Aremeu employs a net-skin approach , ensuring conformal lattices despite tessellation , through re-connecting strut-members at the boundary .", "entity": [{"entity": "conformal lattices", "entity_type": "engineering feature", "pos": [85, 103]}, {"entity": "tessellation", "entity_type": "engineering feature", "pos": [112, 124]}, {"entity": "boundary", "entity_type": "engineering feature", "pos": [170, 178]}], "task": "NER"}
{"text": "The authors believe , that due to the limited resolvable resolution of AM machines , this method would satisfy the level of detail required for the model without high computational cost and geometrical complexity , however , no numerical nor experimental verification was conducted in this study .", "entity": [{"entity": "resolution", "entity_type": "process parameter", "pos": [57, 67]}, {"entity": "AM machines", "entity_type": "machine or equipment", "pos": [71, 82]}, {"entity": "model", "entity_type": "concept or principle", "pos": [148, 153]}, {"entity": "geometrical complexity", "entity_type": "engineering feature", "pos": [190, 212]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [242, 254]}], "task": "NER"}
{"text": "More recently Wang have topologically optimized a strut-based Kagome lattice structure based on the SIMP method with direct AM considerations .", "entity": [{"entity": "topologically", "entity_type": "concept or principle", "pos": [24, 37]}, {"entity": "strut-based", "entity_type": "engineering feature", "pos": [50, 61]}, {"entity": "lattice structure", "entity_type": "engineering feature", "pos": [69, 86]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [124, 126]}], "task": "NER"}
{"text": "The novelty is that it represents a structure-based rather than a boundary-based TO and constitutes a method to increase the specific stiffness of the primitive unit cell .", "entity": [{"entity": "specific stiffness", "entity_type": "machanical property", "pos": [125, 143]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [161, 170]}], "task": "NER"}
{"text": "In an attempt to fine-tune the structural response of lattices , Maskery have recently observed a sequential failure of piece-wise graded BCC lattices in compression promoting increased energy absorption in comparison to the ungraded lattice .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [54, 62]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [109, 116]}, {"entity": "BCC", "entity_type": "concept or principle", "pos": [138, 141]}, {"entity": "compression", "entity_type": "machanical property", "pos": [154, 165]}, {"entity": "energy absorption", "entity_type": "process characterization", "pos": [186, 203]}, {"entity": "ungraded lattice", "entity_type": "engineering feature", "pos": [225, 241]}], "task": "NER"}
{"text": "Furthermore , the results indicated non-homogeneous bulk properties , making the use of Gibson-Ashby models inadequate , as they are developed for uniform density lattices .", "entity": [{"entity": "non-homogeneous bulk properties", "entity_type": "machanical property", "pos": [36, 67]}, {"entity": "Gibson-Ashby models", "entity_type": "concept or principle", "pos": [88, 107]}, {"entity": "as", "entity_type": "material", "pos": [121, 123]}, {"entity": "density", "entity_type": "machanical property", "pos": [155, 162]}], "task": "NER"}
{"text": "It is important to note however , that this model is still useful for obtaining ballpark values for lattices through simple calculations .", "entity": [{"entity": "model", "entity_type": "concept or principle", "pos": [44, 49]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [100, 108]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [117, 123]}], "task": "NER"}
{"text": "Due to the very specific failure mechanisms in graded lattices , future work ought to put more emphasis on the experimental verification in order to make more reliable predictions for their performance .", "entity": [{"entity": "failure mechanisms", "entity_type": "machanical property", "pos": [25, 43]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [54, 62]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [111, 123]}, {"entity": "predictions", "entity_type": "concept or principle", "pos": [168, 179]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [190, 201]}], "task": "NER"}
{"text": "3 Variable-density infills derived from density-based TO An emerging topic in structural optimization with a promising application for AM are TO-based compliance-driven infill strategies for porous material , which account for the principal stress directions imposed by the loading condition .", "entity": [{"entity": "structural optimization", "entity_type": "concept or principle", "pos": [78, 101]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [135, 137]}, {"entity": "infill", "entity_type": "process parameter", "pos": [169, 175]}, {"entity": "porous material", "entity_type": "material", "pos": [191, 206]}, {"entity": "principal stress", "entity_type": "machanical property", "pos": [231, 247]}], "task": "NER"}
{"text": "Infills derived from homogenization-based TO , using projection-based methods , was subject under investigation in , making designs potentially more feasible for AM through the incorporation of a minimum length scale constraint for the microstructural features matching the print-resolution .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [124, 131]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [162, 164]}, {"entity": "length scale", "entity_type": "process characterization", "pos": [204, 216]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [236, 251]}, {"entity": "print-resolution", "entity_type": "process parameter", "pos": [274, 290]}], "task": "NER"}
{"text": "In , this method was experimentally underpinned , demonstrating how self-supporting variable-density lattices can be generated .", "entity": [{"entity": "self-supporting", "entity_type": "engineering feature", "pos": [68, 83]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [101, 109]}, {"entity": "be", "entity_type": "material", "pos": [114, 116]}], "task": "NER"}
{"text": "Work by Wu centres on SIMP , whereby in , solely the infills of 3D structures were optimized and the shell was represented by passive elements , whereas the approach in demonstrated a concurrent optimisation of shell and infill for 2D structures .", "entity": [{"entity": "3D structures", "entity_type": "concept or principle", "pos": [64, 77]}, {"entity": "shell", "entity_type": "machine or equipment", "pos": [101, 106]}, {"entity": "elements", "entity_type": "material", "pos": [134, 142]}, {"entity": "shell", "entity_type": "machine or equipment", "pos": [211, 216]}, {"entity": "infill", "entity_type": "process parameter", "pos": [221, 227]}, {"entity": "2D structures", "entity_type": "engineering feature", "pos": [232, 245]}], "task": "NER"}
{"text": "In these structures were separated through multiple successive smoothing and projection steps combined with interpolations of intermediate densities to obtain discrete topologies with checkerboard-free domains and well-defined boundaries .", "entity": [{"entity": "discrete topologies", "entity_type": "engineering feature", "pos": [159, 178]}, {"entity": "boundaries", "entity_type": "engineering feature", "pos": [227, 237]}], "task": "NER"}
{"text": "In contrast to the standard objective function , a local rather than a global volume constraint was employed in both studies , meaning the density of the neighbouring elements was limited in a predefined radius , controlling the porosity locally .", "entity": [{"entity": "standard", "entity_type": "concept or principle", "pos": [19, 27]}, {"entity": "volume constraint", "entity_type": "process parameter", "pos": [78, 95]}, {"entity": "density", "entity_type": "machanical property", "pos": [139, 146]}, {"entity": "elements", "entity_type": "material", "pos": [167, 175]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [229, 237]}], "task": "NER"}
{"text": "It was found , that higher radii result in topologies with coarser pores and greater stiffness as the local volume constraint becomes less influencing .", "entity": [{"entity": "topologies", "entity_type": "concept or principle", "pos": [43, 53]}, {"entity": "pores", "entity_type": "machanical property", "pos": [67, 72]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [85, 94]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}, {"entity": "volume constraint", "entity_type": "process parameter", "pos": [108, 125]}], "task": "NER"}
{"text": "Furthermore , Wu emphasized that these control parameters are beneficial for the manufacturability of parts intended for powder-based AM-processes , as closed walls cause entrapments .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [47, 57]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [81, 98]}, {"entity": "as", "entity_type": "material", "pos": [129, 131]}], "task": "NER"}
{"text": "To avoid slender struts without infill , a length scale constraint is introduced in , which was implemented by an erosion and dilation projection before a final sensitivity analysis was conducted .", "entity": [{"entity": "slender struts", "entity_type": "engineering feature", "pos": [9, 23]}, {"entity": "infill", "entity_type": "process parameter", "pos": [32, 38]}, {"entity": "length scale", "entity_type": "process characterization", "pos": [43, 55]}, {"entity": "sensitivity analysis", "entity_type": "concept or principle", "pos": [161, 181]}], "task": "NER"}
{"text": "Conversely , in , the authors introduce an anisotropic filter , forcing the material to accumulate in preferred i.e .", "entity": [{"entity": "anisotropic filter", "entity_type": "material", "pos": [43, 61]}, {"entity": "material", "entity_type": "material", "pos": [76, 84]}], "task": "NER"}
{"text": "a prescribed direction in order to resemble bone-inspired infills , resulting in trusB-like formations .", "entity": [{"entity": "bone-inspired infills", "entity_type": "enabling technology", "pos": [44, 65]}], "task": "NER"}
{"text": "The filter , in particular , helped improve the uniaxial buckling stability .", "entity": [{"entity": "filter", "entity_type": "application", "pos": [4, 10]}, {"entity": "buckling", "entity_type": "machanical property", "pos": [57, 65]}], "task": "NER"}
{"text": "Recently , Wu have presented a computationally more efficient extension to their work that is using a simultaneous optimization of the shape and the distribution of the lattice , demonstrating a twofold increase in buckling load over the equivalent TO-solution .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [115, 127]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [149, 161]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [169, 176]}, {"entity": "buckling load", "entity_type": "process characterization", "pos": [215, 228]}], "task": "NER"}
{"text": "Besides weight reductions , improvements in damage tolerance and robustness generally illustrate greater functionality , mechanical capability and versatility of lattices , potentially outweighing the losses in stiffness for certain engineering problems compared to a solid solution .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [8, 14]}, {"entity": "damage tolerance", "entity_type": "machanical property", "pos": [44, 60]}, {"entity": "robustness", "entity_type": "machanical property", "pos": [65, 75]}, {"entity": "mechanical capability", "entity_type": "machanical property", "pos": [121, 142]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [162, 170]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [211, 220]}, {"entity": "engineering", "entity_type": "application", "pos": [233, 244]}, {"entity": "solid solution", "entity_type": "material", "pos": [268, 282]}], "task": "NER"}
{"text": "Another emerging topic for AM within topologically optimized and variable-density lattices , which will not be further discussed , are both multi-scale and multi-material structures .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [27, 29]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [37, 50]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [82, 90]}, {"entity": "be", "entity_type": "material", "pos": [108, 110]}, {"entity": "multi-material structures", "entity_type": "engineering feature", "pos": [156, 181]}], "task": "NER"}
{"text": "Primary investigations into a concurrent optimization of both macroscale and a micro-scale lattices , using two different materials , show great promise for the design-potential of AM .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [41, 53]}, {"entity": "macroscale", "entity_type": "concept or principle", "pos": [62, 72]}, {"entity": "micro-scale lattices", "entity_type": "engineering feature", "pos": [79, 99]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [122, 131]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [181, 183]}], "task": "NER"}
{"text": "4 Strut-sizing and -scaling for structurally optimized trusB-like structures Emerged from the idea to drastically decrease the computational complexity and processing time , the size matching and scaling method for mesoscale lattices , represents an alternative approach for structural optimisation .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [141, 151]}, {"entity": "mesoscale lattices", "entity_type": "engineering feature", "pos": [215, 233]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [275, 298]}], "task": "NER"}
{"text": "Besides the modification of the topology as certain struts that have a minor contribution to the structural performance are eliminated , the method mainly centres on the size optimisation of the struts .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [32, 40]}, {"entity": "as", "entity_type": "material", "pos": [41, 43]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [52, 58]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [97, 119]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [195, 201]}], "task": "NER"}
{"text": "An average stress distribution of the solid body serves as the basis upon which the unit cell topology with geometrical features is determined prior to the mapping onto the initial geometry .", "entity": [{"entity": "average", "entity_type": "concept or principle", "pos": [3, 10]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [18, 30]}, {"entity": "as", "entity_type": "material", "pos": [56, 58]}, {"entity": "unit cell topology", "entity_type": "concept or principle", "pos": [84, 102]}, {"entity": "geometrical features", "entity_type": "engineering feature", "pos": [108, 128]}, {"entity": "geometry", "entity_type": "concept or principle", "pos": [181, 189]}], "task": "NER"}
{"text": "Choosing the exact node size and thresholds for the upper and lower bounds of the strut diameter were deemed to be vital for the assurance of manufacturability with AM .", "entity": [{"entity": "strut diameter", "entity_type": "process parameter", "pos": [82, 96]}, {"entity": "be", "entity_type": "material", "pos": [112, 114]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [142, 159]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [165, 167]}], "task": "NER"}
{"text": "Overall this does not take away from its feasibility for application in large structures as shown on the basis of a light-weight micro air vehicle fuselage and is , therefore , a viable alternative to pure TO .", "entity": [{"entity": "feasibility", "entity_type": "concept or principle", "pos": [41, 52]}, {"entity": "as", "entity_type": "material", "pos": [89, 91]}, {"entity": "light-weight", "entity_type": "machanical property", "pos": [116, 128]}, {"entity": "fuselage", "entity_type": "machine or equipment", "pos": [147, 155]}], "task": "NER"}
{"text": "This method represents a lattice generation tool integrated into Siemens NX CAD software .", "entity": [{"entity": "lattice generation", "entity_type": "engineering feature", "pos": [25, 43]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [76, 79]}], "task": "NER"}
{"text": "In light of the multifunctional performance of lattices , Seepersad have demonstrated how a post-processing steps can be used to obtain lattice topologies with e.g .", "entity": [{"entity": "performance", "entity_type": "concept or principle", "pos": [32, 43]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [47, 55]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [92, 107]}, {"entity": "be", "entity_type": "material", "pos": [118, 120]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [136, 143]}], "task": "NER"}
{"text": "improved heat transfer , by effectively identifying lattice members that can be sacrificed , based on a hybrid FEA and finite difference approach .", "entity": [{"entity": "heat transfer", "entity_type": "concept or principle", "pos": [9, 22]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [52, 59]}, {"entity": "be", "entity_type": "material", "pos": [63, 65]}], "task": "NER"}
{"text": "A more recent study has demonstrated a solution for a similar multifunctional optimization for a heterogeneous cellular structures using a decision support problem formulation .", "entity": [{"entity": "solution", "entity_type": "concept or principle", "pos": [39, 47]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [78, 90]}, {"entity": "heterogeneous cellular structures", "entity_type": "engineering feature", "pos": [97, 130]}, {"entity": "support", "entity_type": "application", "pos": [148, 155]}], "task": "NER"}
{"text": "5 Evolutionary algorithms for structurally enhanced lattices Tang made use of a BESO-based approach to design a latticed engine bracket with optimal strut thicknesses , using a kernel-based algorithm .", "entity": [{"entity": "algorithms", "entity_type": "concept or principle", "pos": [15, 25]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [52, 60]}, {"entity": "design", "entity_type": "engineering feature", "pos": [103, 109]}, {"entity": "bracket", "entity_type": "machine or equipment", "pos": [128, 135]}, {"entity": "strut thicknesses", "entity_type": "process parameter", "pos": [149, 166]}, {"entity": "kernel-based algorithm", "entity_type": "enabling technology", "pos": [177, 199]}], "task": "NER"}
{"text": "Points of the boundary and internal elements are subsequently separated , and the initial wireframe is mapped onto the boundary kernel points , followed by a trimming procedure used to remove wires outside the functional volume .", "entity": [{"entity": "boundary", "entity_type": "engineering feature", "pos": [14, 22]}, {"entity": "elements", "entity_type": "material", "pos": [36, 44]}, {"entity": "boundary kernel points", "entity_type": "concept or principle", "pos": [119, 141]}, {"entity": "trimming", "entity_type": "manufacturing process", "pos": [158, 166]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [221, 227]}], "task": "NER"}
{"text": "Finally , these two sets of frames are merged together forming the final conformal lattice , which undergoes the BESO algorithm to modify the strut thickness based on the von Mises stresses obtained from the FEA of the homogenized functional volume and predetermined geometrical limits .", "entity": [{"entity": "forming", "entity_type": "manufacturing process", "pos": [55, 62]}, {"entity": "conformal lattice", "entity_type": "engineering feature", "pos": [73, 90]}, {"entity": "BESO algorithm", "entity_type": "concept or principle", "pos": [113, 127]}, {"entity": "strut thickness", "entity_type": "process parameter", "pos": [142, 157]}, {"entity": "von Mises stresses", "entity_type": "machanical property", "pos": [171, 189]}, {"entity": "homogenized", "entity_type": "manufacturing process", "pos": [219, 230]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [242, 248]}, {"entity": "geometrical limits", "entity_type": "engineering feature", "pos": [267, 285]}], "task": "NER"}
{"text": "The structural performance was improved in contrast to a homogeneous lattice and the weight reduced by up to 75 % over the original solid design .", "entity": [{"entity": "structural performance", "entity_type": "process characterization", "pos": [4, 26]}, {"entity": "homogeneous lattice", "entity_type": "engineering feature", "pos": [57, 76]}, {"entity": "weight", "entity_type": "process parameter", "pos": [85, 91]}, {"entity": "design", "entity_type": "engineering feature", "pos": [138, 144]}], "task": "NER"}
{"text": "A recent study by Tang dealt with DfAM in the context of lattices and used BESO to locally improve the size of trusB-like members , creating a heterogeneous lattice .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [57, 65]}, {"entity": "BESO", "entity_type": "concept or principle", "pos": [75, 79]}, {"entity": "heterogeneous lattice", "entity_type": "engineering feature", "pos": [143, 164]}], "task": "NER"}
{"text": "In this study , a meta-model was created , which was comprised of the geometrical manufacturing constraints regarding the deflection of horizontal struts and the thickness of struts with reference to the inclination angle .", "entity": [{"entity": "geometrical manufacturing constraints", "entity_type": "concept or principle", "pos": [70, 107]}, {"entity": "horizontal struts", "entity_type": "engineering feature", "pos": [136, 153]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [175, 181]}, {"entity": "inclination angle", "entity_type": "engineering feature", "pos": [204, 221]}], "task": "NER"}
{"text": "Additionally , the optimized lattice structure led to an increase in stiffness over the traditional homogeneous pendant .", "entity": [{"entity": "lattice structure", "entity_type": "engineering feature", "pos": [29, 46]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [69, 78]}, {"entity": "homogeneous", "entity_type": "concept or principle", "pos": [100, 111]}], "task": "NER"}
{"text": "Besides , the abovementioned more favourable examples for the use of evolutionary algorithms for the optimisation of lattices , Chu have conversely demonstrated eminent drawbacks of the PSO over the non-evolutionary LMO optimisation , due to the stochastic nature of such algorithms .", "entity": [{"entity": "algorithms", "entity_type": "concept or principle", "pos": [82, 92]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [117, 125]}, {"entity": "non-evolutionary LMO optimisation", "entity_type": "concept or principle", "pos": [199, 232]}, {"entity": "stochastic", "entity_type": "concept or principle", "pos": [246, 256]}, {"entity": "algorithms", "entity_type": "concept or principle", "pos": [272, 282]}], "task": "NER"}
{"text": "Based on ground truss structures which were optimized for a given volume fraction and a set allowable deflection , the optimal strut dimensions were obtained with both algorithms .", "entity": [{"entity": "truss", "entity_type": "machine or equipment", "pos": [16, 21]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [66, 81]}, {"entity": "set", "entity_type": "application", "pos": [88, 91]}, {"entity": "strut", "entity_type": "machine or equipment", "pos": [127, 132]}, {"entity": "dimensions", "entity_type": "engineering feature", "pos": [133, 143]}, {"entity": "algorithms", "entity_type": "concept or principle", "pos": [168, 178]}], "task": "NER"}
{"text": "Results showed comparable structural performance but the superior computational efficiency and convergence of the LMO method .", "entity": [{"entity": "structural performance", "entity_type": "process characterization", "pos": [26, 48]}, {"entity": "computational efficiency", "entity_type": "concept or principle", "pos": [66, 90]}], "task": "NER"}
{"text": "The integration of DfAM constraints into the optimisation algorithms remains a bottleneck for a streamlined design procedure , calling for benchmarking studies helping to identify more efficient approaches in digital AM in future work .", "entity": [{"entity": "algorithms", "entity_type": "concept or principle", "pos": [58, 68]}, {"entity": "bottleneck", "entity_type": "concept or principle", "pos": [79, 89]}, {"entity": "design", "entity_type": "engineering feature", "pos": [108, 114]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [217, 219]}], "task": "NER"}
{"text": "2 Topologically optimized lattices employing commercial software As the role of AM in the industry is slowly shifting towards production , ready-to-use design software capitalizing on now amenable features like lattices , are becoming more readily accessible .", "entity": [{"entity": "Topologically", "entity_type": "concept or principle", "pos": [2, 15]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [26, 34]}, {"entity": "software", "entity_type": "concept or principle", "pos": [56, 64]}, {"entity": "As", "entity_type": "material", "pos": [65, 67]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [80, 82]}, {"entity": "industry", "entity_type": "application", "pos": [90, 98]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [126, 136]}, {"entity": "ready-to-use", "entity_type": "concept or principle", "pos": [139, 151]}, {"entity": "design", "entity_type": "engineering feature", "pos": [152, 158]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [211, 219]}], "task": "NER"}
{"text": "3DXpert for Solidworks , nTopology or ANSYS which is providing a AM-specific design platforms .", "entity": [{"entity": "ANSYS", "entity_type": "application", "pos": [38, 43]}, {"entity": "design", "entity_type": "engineering feature", "pos": [77, 83]}], "task": "NER"}
{"text": "1 Modelling structurally optimized lattices for printing In the context of trusses , Gorguluarslan developed a two-phase lattice optimisation framework , specifically tackling the issue of the minimum manufacturable crosB-section .", "entity": [{"entity": "Modelling", "entity_type": "enabling technology", "pos": [2, 11]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [35, 43]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [121, 128]}, {"entity": "framework", "entity_type": "concept or principle", "pos": [142, 151]}, {"entity": "manufacturable", "entity_type": "concept or principle", "pos": [201, 215]}], "task": "NER"}
{"text": "Here a primary ground structure optimisation is followed by a rectification process in which elements falling below a certain minimum crosB-sections threshold are eliminated , before a final optimisation step is conducted , for which the method of Feasible Directions is employed .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [22, 31]}, {"entity": "process", "entity_type": "concept or principle", "pos": [76, 83]}, {"entity": "elements", "entity_type": "material", "pos": [93, 101]}, {"entity": "crosB-sections", "entity_type": "concept or principle", "pos": [134, 148]}, {"entity": "step", "entity_type": "concept or principle", "pos": [204, 208]}], "task": "NER"}
{"text": "Altair 's OptiStruct and HyperMesh were utilized for structural optimisation .", "entity": [{"entity": "HyperMesh", "entity_type": "engineering feature", "pos": [25, 34]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [53, 76]}], "task": "NER"}
{"text": "Among others , the typical cantilever beam example was used to compare the effectiveness of the framework and the MFD algorithm with Chang and Rosen 's SMS method and the Relative Density Mapping of Alzahrani , respectively .", "entity": [{"entity": "cantilever beam", "entity_type": "machine or equipment", "pos": [27, 42]}, {"entity": "effectiveness", "entity_type": "concept or principle", "pos": [75, 88]}, {"entity": "framework", "entity_type": "concept or principle", "pos": [96, 105]}, {"entity": "MFD algorithm", "entity_type": "concept or principle", "pos": [114, 127]}, {"entity": "Relative Density", "entity_type": "machanical property", "pos": [171, 187]}], "task": "NER"}
{"text": "Under restriction of the minimum feature size , MFD was identified to outperform SMS and RDM in terms of stiffness but required more computational effort .", "entity": [{"entity": "minimum feature size", "entity_type": "process parameter", "pos": [25, 45]}, {"entity": "RDM", "entity_type": "manufacturing process", "pos": [89, 92]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [105, 114]}], "task": "NER"}
{"text": "However , it was also found that designs obtained from genetic algorithms and PSO have an even superior structural performance .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [33, 40]}, {"entity": "genetic algorithms", "entity_type": "concept or principle", "pos": [55, 73]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [104, 126]}], "task": "NER"}
{"text": "In Abaqus served as a tool for the TO within the RDM method .", "entity": [{"entity": "Abaqus", "entity_type": "enabling technology", "pos": [3, 9]}, {"entity": "as", "entity_type": "material", "pos": [17, 19]}, {"entity": "tool", "entity_type": "machine or equipment", "pos": [22, 26]}, {"entity": "RDM", "entity_type": "manufacturing process", "pos": [49, 52]}], "task": "NER"}
{"text": "Compared to the SMS method , the density values of the TO are used to map the struts into the domain , making RDM less dependent on the FEA analysis .", "entity": [{"entity": "density", "entity_type": "machanical property", "pos": [33, 40]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [78, 84]}, {"entity": "domain", "entity_type": "concept or principle", "pos": [94, 100]}, {"entity": "RDM", "entity_type": "manufacturing process", "pos": [110, 113]}], "task": "NER"}
{"text": "Arisoy developed a framework for the substitution of solid parts of a CAD model with lattices , which served as the basis for a plugin in Siemens 's NX CAD software .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [19, 28]}, {"entity": "CAD model", "entity_type": "enabling technology", "pos": [70, 79]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [85, 93]}, {"entity": "as", "entity_type": "material", "pos": [109, 111]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [152, 155]}], "task": "NER"}
{"text": "boundary surface defining the layout of the lattice .", "entity": [{"entity": "boundary", "entity_type": "engineering feature", "pos": [0, 8]}, {"entity": "layout", "entity_type": "concept or principle", "pos": [30, 36]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [44, 51]}], "task": "NER"}
{"text": "During the FEA of the solid part , meshed with tetrahedral elements , a remeshing process including trimming is conducted ensuring that the elements are part of the lattice .", "entity": [{"entity": "tetrahedral elements", "entity_type": "engineering feature", "pos": [47, 67]}, {"entity": "remeshing process", "entity_type": "concept or principle", "pos": [72, 89]}, {"entity": "trimming", "entity_type": "manufacturing process", "pos": [100, 108]}, {"entity": "elements", "entity_type": "material", "pos": [140, 148]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [165, 172]}], "task": "NER"}
{"text": "Besides an improved and efficient workflow for AM , the authors concluded to have improved the boundary smoothness of the lattices with the implicit volume representation , so that the manufacturability for AM is improved .", "entity": [{"entity": "workflow", "entity_type": "concept or principle", "pos": [34, 42]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [47, 49]}, {"entity": "boundary", "entity_type": "engineering feature", "pos": [95, 103]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [122, 130]}, {"entity": "implicit volume representation", "entity_type": "engineering feature", "pos": [140, 170]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [185, 202]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [207, 209]}], "task": "NER"}
{"text": "In terms of digitalization and streamlining the design process , this study demonstrated great promise , as the lattices were modelled within the same CAD environment .", "entity": [{"entity": "design process", "entity_type": "concept or principle", "pos": [48, 62]}, {"entity": "as", "entity_type": "material", "pos": [105, 107]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [112, 120]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [151, 154]}], "task": "NER"}
{"text": "Based on the design optimisation of a missile launcher beam on a macro- and mesoscale , H exemplarily demonstrated the potential of multi-scale optimisation .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [13, 19]}, {"entity": "missile launcher beam", "entity_type": "machine or equipment", "pos": [38, 59]}, {"entity": "macro- and mesoscale", "entity_type": "engineering feature", "pos": [65, 85]}], "task": "NER"}
{"text": "They have effectively combined TO with partial substitution of solids with lattices , to design a lightweight beam using the commercial software Altair Inspire and Materialise Magics .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [75, 83]}, {"entity": "design", "entity_type": "engineering feature", "pos": [89, 95]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [98, 109]}, {"entity": "beam", "entity_type": "machine or equipment", "pos": [110, 114]}, {"entity": "software", "entity_type": "concept or principle", "pos": [136, 144]}], "task": "NER"}
{"text": "2 Experimental benchmarking of 3D-printed lattices In contrast to the previous studies , Beyer and Figueroa tested different unit cell structures experimentally and Harl even determined the performance of optimized lattice structures by comparing them to numerical results .", "entity": [{"entity": "Experimental", "entity_type": "concept or principle", "pos": [2, 14]}, {"entity": "3D-printed", "entity_type": "manufacturing process", "pos": [31, 41]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [125, 134]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [190, 201]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [215, 233]}], "task": "NER"}
{"text": "The experimental verification is vital as structural optimisation and DfAM aspects are mutually dependent .", "entity": [{"entity": "experimental", "entity_type": "concept or principle", "pos": [4, 16]}, {"entity": "as", "entity_type": "material", "pos": [39, 41]}], "task": "NER"}
{"text": "This stems from the individual characteristics and limitations of different AM processes affecting the properties .", "entity": [{"entity": "AM processes", "entity_type": "manufacturing process", "pos": [76, 88]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [103, 113]}], "task": "NER"}
{"text": "As outlined by Gibson , this is related to common meso- and microstructural features of cellular structures , affecting the structural performance , including : 1 ) material properties ; 2 ) cell topology and shape ; 3 ) relative density of structure .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [60, 75]}, {"entity": "cellular structures", "entity_type": "engineering feature", "pos": [88, 107]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [124, 146]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [165, 184]}, {"entity": "cell topology", "entity_type": "concept or principle", "pos": [191, 204]}, {"entity": "relative density", "entity_type": "machanical property", "pos": [221, 237]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [241, 250]}], "task": "NER"}
{"text": "As the procesB-parameters influence the microstructure and consequently the performance , verification with the numerical model becomes vital for estimating the actual properties and improving future models .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [40, 54]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [76, 87]}, {"entity": "verification", "entity_type": "concept or principle", "pos": [90, 102]}, {"entity": "model", "entity_type": "concept or principle", "pos": [122, 127]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [168, 178]}], "task": "NER"}
{"text": "In , Netfabb 's Selective Space Structures tool was utilized to create lattices from rectangular prisms and hexagonal geometries , which were subsequently manufactured using the PolyJet and SLM process for polymers and aluminium , respectively .", "entity": [{"entity": "tool", "entity_type": "machine or equipment", "pos": [43, 47]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [71, 79]}, {"entity": "hexagonal", "entity_type": "engineering feature", "pos": [108, 117]}, {"entity": "geometries", "entity_type": "concept or principle", "pos": [118, 128]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [155, 167]}, {"entity": "PolyJet", "entity_type": "concept or principle", "pos": [178, 185]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [190, 193]}, {"entity": "process", "entity_type": "concept or principle", "pos": [194, 201]}, {"entity": "polymers", "entity_type": "material", "pos": [206, 214]}, {"entity": "aluminium", "entity_type": "material", "pos": [219, 228]}], "task": "NER"}
{"text": "The compression and flexure tests of unit cells composed of a polymer revealed that the hexagonal unit cells show greater yield strengths and that comparable properties with the solid pendant can most likely be achieved with vertical trusses in the cell .", "entity": [{"entity": "compression", "entity_type": "machanical property", "pos": [4, 15]}, {"entity": "flexure tests", "entity_type": "process characterization", "pos": [20, 33]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [37, 47]}, {"entity": "polymer", "entity_type": "material", "pos": [62, 69]}, {"entity": "hexagonal unit cells", "entity_type": "engineering feature", "pos": [88, 108]}, {"entity": "yield strengths", "entity_type": "machanical property", "pos": [122, 137]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [158, 168]}, {"entity": "be", "entity_type": "material", "pos": [208, 210]}, {"entity": "vertical", "entity_type": "concept or principle", "pos": [225, 233]}, {"entity": "cell", "entity_type": "application", "pos": [249, 253]}], "task": "NER"}
{"text": "Within the scaled lattices fabricated from polymer and aluminium , it was found that the kagome structure displayed the best performance-to-mass ratio .", "entity": [{"entity": "lattices fabricated", "entity_type": "concept or principle", "pos": [18, 37]}, {"entity": "polymer", "entity_type": "material", "pos": [43, 50]}, {"entity": "aluminium", "entity_type": "material", "pos": [55, 64]}, {"entity": "kagome structure", "entity_type": "engineering feature", "pos": [89, 105]}], "task": "NER"}
{"text": "Moreover , it was reported that the aluminium lattice was superior to the polymer counterpart with respect to the solid structures , possibly stressing differences in manufacturing and therefore highlighting the role of DfAM .", "entity": [{"entity": "aluminium lattice", "entity_type": "engineering feature", "pos": [36, 53]}, {"entity": "polymer", "entity_type": "material", "pos": [74, 81]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [167, 180]}], "task": "NER"}
{"text": "A connection between relative cell density , unit cell structure and structural performance , was established , giving designers and engineers helpful indications for the selection of the adequate lattice configuration .", "entity": [{"entity": "cell density", "entity_type": "engineering feature", "pos": [30, 42]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [45, 54]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [55, 64]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [69, 91]}, {"entity": "lattice configuration", "entity_type": "concept or principle", "pos": [197, 218]}], "task": "NER"}
{"text": "Similarly , Harl employed the CAESS ProTOp software for both the lattice generation and the subsequent TO of the lattice .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [43, 51]}, {"entity": "lattice generation", "entity_type": "engineering feature", "pos": [65, 83]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [113, 120]}], "task": "NER"}
{"text": "The latter was conducted to improve the structural performance by lowering the local stress concentration to which cellular structures are prone to .", "entity": [{"entity": "structural performance", "entity_type": "process characterization", "pos": [40, 62]}, {"entity": "local stress concentration", "entity_type": "concept or principle", "pos": [79, 105]}, {"entity": "cellular structures", "entity_type": "engineering feature", "pos": [115, 134]}], "task": "NER"}
{"text": "Using selective laser sintering with polyamide , the designs were tested in flexure and the results clearly highlight the potential of using TO lattices in terms of weight-reduction , robustness and stiffness as well as its superiority over uniform lattices .", "entity": [{"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [6, 31]}, {"entity": "polyamide", "entity_type": "material", "pos": [37, 46]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [53, 60]}, {"entity": "flexure", "entity_type": "machine or equipment", "pos": [76, 83]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [144, 152]}, {"entity": "robustness", "entity_type": "machanical property", "pos": [184, 194]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [199, 208]}, {"entity": "as", "entity_type": "material", "pos": [209, 211]}, {"entity": "as", "entity_type": "material", "pos": [217, 219]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [249, 257]}], "task": "NER"}
{"text": "The next paragraphs build on this idea of TO cellular structures by locally changing the cell density with the use of commercial software .", "entity": [{"entity": "build", "entity_type": "process parameter", "pos": [20, 25]}, {"entity": "cellular structures", "entity_type": "engineering feature", "pos": [45, 64]}, {"entity": "cell density", "entity_type": "engineering feature", "pos": [89, 101]}, {"entity": "software", "entity_type": "concept or principle", "pos": [129, 137]}], "task": "NER"}
{"text": "In a study by Rezaie a beam under three-point bending was topologically optimized using Abaqus and subsequently manufactured in ABS using FDM .", "entity": [{"entity": "beam", "entity_type": "machine or equipment", "pos": [23, 27]}, {"entity": "three-point bending", "entity_type": "process characterization", "pos": [34, 53]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [58, 71]}, {"entity": "Abaqus", "entity_type": "enabling technology", "pos": [88, 94]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [112, 124]}, {"entity": "ABS", "entity_type": "material", "pos": [128, 131]}, {"entity": "FDM", "entity_type": "manufacturing process", "pos": [138, 141]}], "task": "NER"}
{"text": "Here , the external boundaries of the bounding box were preserved , and the lattice composed of hollow cubic unit cells was mapped onto a SIMP-result .", "entity": [{"entity": "boundaries", "entity_type": "engineering feature", "pos": [20, 30]}, {"entity": "bounding box", "entity_type": "engineering feature", "pos": [38, 50]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [76, 83]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [109, 119]}], "task": "NER"}
{"text": "Additionally , manufacturability was taken into consideration by tailoring the hole-size to match the printer 's resolution .", "entity": [{"entity": "manufacturability", "entity_type": "concept or principle", "pos": [15, 32]}, {"entity": "printer", "entity_type": "machine or equipment", "pos": [102, 109]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [113, 123]}], "task": "NER"}
{"text": "In comparison with the standard topologically optimized beam , the loss in performance turned out to be very minor .", "entity": [{"entity": "standard", "entity_type": "concept or principle", "pos": [23, 31]}, {"entity": "beam", "entity_type": "machine or equipment", "pos": [56, 60]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [75, 86]}, {"entity": "be", "entity_type": "material", "pos": [101, 103]}], "task": "NER"}
{"text": "Especially when considering the more fabrication-friendly design of the cellular lattice , this method can be a viable alternative for lightweight structures .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [58, 64]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [81, 88]}, {"entity": "be", "entity_type": "material", "pos": [107, 109]}, {"entity": "lightweight structures", "entity_type": "machine or equipment", "pos": [135, 157]}], "task": "NER"}
{"text": "The significance of the results , however , must be reviewed critically , due to insufficient batch size and the well-known and inherent quality fluctuations in AM .", "entity": [{"entity": "be", "entity_type": "material", "pos": [49, 51]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [137, 144]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [161, 163]}], "task": "NER"}
{"text": "Improved quality control measures are therefore needed form a manufacturing standpoint while an extensive data library will ease the choice in adequate lattice configurations from a design perspective .", "entity": [{"entity": "quality control", "entity_type": "concept or principle", "pos": [9, 24]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [62, 75]}, {"entity": "data", "entity_type": "concept or principle", "pos": [106, 110]}, {"entity": "lattice configurations", "entity_type": "concept or principle", "pos": [152, 174]}, {"entity": "design", "entity_type": "engineering feature", "pos": [182, 188]}], "task": "NER"}
{"text": "These aspects constitute -among others - a necessity with the increasing uptake of AM across industries .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [83, 85]}, {"entity": "industries", "entity_type": "application", "pos": [93, 103]}], "task": "NER"}
{"text": "With the combination of the density-gradients from TO with a size optimisation , Daynes derived functionally graded trusB-structures that align with the isostatic lines i.e .", "entity": [{"entity": "functionally graded trusB-structures", "entity_type": "engineering feature", "pos": [96, 132]}, {"entity": "isostatic lines", "entity_type": "concept or principle", "pos": [153, 168]}], "task": "NER"}
{"text": "the principal stresses during loading .", "entity": [{"entity": "principal stresses", "entity_type": "machanical property", "pos": [4, 22]}], "task": "NER"}
{"text": "By making use of the Altair OptiStruct software , a topologically optimized design is automatically obtained , substituted by pre-selected unit cells before a size optimisation ensures that the overall target density is achieved .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [39, 47]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [52, 65]}, {"entity": "design", "entity_type": "engineering feature", "pos": [76, 82]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [139, 149]}, {"entity": "density", "entity_type": "machanical property", "pos": [209, 216]}], "task": "NER"}
{"text": "Upon the information on in-plane stresses and orientation extracted from the software , the authors developed a MATLAB subroutine to create a functionally graded mesh , which was fed back into the software for analysis .", "entity": [{"entity": "orientation extracted", "entity_type": "concept or principle", "pos": [46, 67]}, {"entity": "software", "entity_type": "concept or principle", "pos": [77, 85]}, {"entity": "functionally graded mesh", "entity_type": "engineering feature", "pos": [142, 166]}, {"entity": "software", "entity_type": "concept or principle", "pos": [197, 205]}], "task": "NER"}
{"text": "The substitution of the domain with BCC unit cells conformal with the isostatic lines resulted in a graded lattice with improved structural performance .", "entity": [{"entity": "domain", "entity_type": "concept or principle", "pos": [24, 30]}, {"entity": "BCC", "entity_type": "concept or principle", "pos": [36, 39]}, {"entity": "cells", "entity_type": "application", "pos": [45, 50]}, {"entity": "isostatic lines", "entity_type": "concept or principle", "pos": [70, 85]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [107, 114]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [129, 151]}], "task": "NER"}
{"text": "Twice the stiffness and about 75 times greater strength were demonstrated in the experimental three-point bending tests compared to the uniform lattice design .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [10, 19]}, {"entity": "strength", "entity_type": "machanical property", "pos": [47, 55]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [81, 93]}, {"entity": "bending tests", "entity_type": "process characterization", "pos": [106, 119]}, {"entity": "lattice design", "entity_type": "engineering feature", "pos": [144, 158]}], "task": "NER"}
{"text": "These study highlights how much potential is still untapped in commercial software regarding the utilization of tailored , functionally graded lattices for enhanced specific structural performance .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [74, 82]}, {"entity": "functionally graded lattices", "entity_type": "engineering feature", "pos": [123, 151]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [174, 196]}], "task": "NER"}
{"text": "3 Commercial and academic software solutions for TO and the generation of cellular structures AM-specific design tools , incorporating TO or the implementation of lattices , are central to the greater adoption of AM .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [26, 34]}, {"entity": "cellular structures", "entity_type": "engineering feature", "pos": [74, 93]}, {"entity": "design", "entity_type": "engineering feature", "pos": [106, 112]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [163, 171]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [213, 215]}], "task": "NER"}
{"text": "Today 's software landscape for AM-specific design provides a range of features that have been summarized in the supplementary information of this review .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [9, 17]}, {"entity": "design", "entity_type": "engineering feature", "pos": [44, 50]}, {"entity": "range", "entity_type": "process parameter", "pos": [62, 67]}], "task": "NER"}
{"text": "It is important to note , that the majority of commercial software to-date solve specific problems that are common for a wide range of industrial applications .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [58, 66]}, {"entity": "range", "entity_type": "process parameter", "pos": [126, 131]}, {"entity": "industrial", "entity_type": "application", "pos": [135, 145]}], "task": "NER"}
{"text": "14a illustrates the proportionate distribution of underlying TO-methods/approaches in commercial software to-date .", "entity": [{"entity": "distribution", "entity_type": "concept or principle", "pos": [34, 46]}, {"entity": "software", "entity_type": "concept or principle", "pos": [97, 105]}], "task": "NER"}
{"text": "14b constitutes the predominant file formats available in current lattice generation software .", "entity": [{"entity": "file", "entity_type": "manufacturing standard", "pos": [32, 36]}, {"entity": "lattice generation", "entity_type": "engineering feature", "pos": [66, 84]}], "task": "NER"}
{"text": "Analogously , lattice generation software is dominated by STL file formats , however , with the emerging complexity in e.g .", "entity": [{"entity": "lattice generation", "entity_type": "engineering feature", "pos": [14, 32]}, {"entity": "STL", "entity_type": "manufacturing standard", "pos": [58, 61]}, {"entity": "file", "entity_type": "manufacturing standard", "pos": [62, 66]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [105, 115]}], "task": "NER"}
{"text": "multi-material prints we see the adoption and market share increase of 3MF and AMF file formats .", "entity": [{"entity": "multi-material", "entity_type": "concept or principle", "pos": [0, 14]}, {"entity": "3MF", "entity_type": "manufacturing standard", "pos": [71, 74]}, {"entity": "AMF", "entity_type": "concept or principle", "pos": [79, 82]}], "task": "NER"}
{"text": "To evaluate the effectiveness of the different software , more benchmarking research will be needed .", "entity": [{"entity": "effectiveness", "entity_type": "concept or principle", "pos": [16, 29]}, {"entity": "software", "entity_type": "concept or principle", "pos": [47, 55]}, {"entity": "research", "entity_type": "concept or principle", "pos": [76, 84]}, {"entity": "be", "entity_type": "material", "pos": [90, 92]}], "task": "NER"}
{"text": "A first attempt , recently published by Saadlaoui compared the performance of a topologically optimized cube under compression loading using Optistruct and Abaqus .", "entity": [{"entity": "performance", "entity_type": "concept or principle", "pos": [63, 74]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [80, 93]}, {"entity": "cube", "entity_type": "concept or principle", "pos": [104, 108]}, {"entity": "compression", "entity_type": "machanical property", "pos": [115, 126]}, {"entity": "Abaqus", "entity_type": "enabling technology", "pos": [156, 162]}], "task": "NER"}
{"text": "A stresB-constrained optimisation and a discrete-compliance optimisation were conducted in Abaqus as well as a continuous compliance optimisation in Optistruct .", "entity": [{"entity": "stresB-constrained", "entity_type": "machanical property", "pos": [2, 20]}, {"entity": "Abaqus", "entity_type": "enabling technology", "pos": [91, 97]}, {"entity": "as", "entity_type": "material", "pos": [98, 100]}, {"entity": "continuous compliance", "entity_type": "concept or principle", "pos": [111, 132]}], "task": "NER"}
{"text": "Both numerical and experimental results were obtained for the three approaches , whereby SLM was adopted for the fabrication of the specimens .", "entity": [{"entity": "experimental", "entity_type": "concept or principle", "pos": [19, 31]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [89, 92]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [113, 124]}], "task": "NER"}
{"text": "This was explained by the consideration of internal material behaviour for the numerical model rather than the external criteria in the experiment .", "entity": [{"entity": "material", "entity_type": "material", "pos": [52, 60]}, {"entity": "model", "entity_type": "concept or principle", "pos": [89, 94]}, {"entity": "experiment", "entity_type": "concept or principle", "pos": [136, 146]}], "task": "NER"}
{"text": "This aspect also includes local plastic deformations in the actual specimen , which do not necessarily affect the global elastic properties or mechanical strength and which are not accounted for in the commonly employed linear-elastic computational models , as stated by Saadlaoui .", "entity": [{"entity": "local plastic deformations", "entity_type": "concept or principle", "pos": [26, 52]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [121, 128]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [143, 162]}, {"entity": "computational models", "entity_type": "enabling technology", "pos": [235, 255]}, {"entity": "as", "entity_type": "material", "pos": [258, 260]}], "task": "NER"}
{"text": "In terms of the computational procedures , the study revealed that the stresB-constrained optimisation approach has the highest computational cost , but the corresponding specimen demonstrated the best mechanical performance with respect to the ratio of strength to weight .", "entity": [{"entity": "stresB-constrained", "entity_type": "machanical property", "pos": [71, 89]}, {"entity": "mechanical", "entity_type": "application", "pos": [202, 212]}, {"entity": "ratio of strength", "entity_type": "process characterization", "pos": [245, 262]}, {"entity": "weight", "entity_type": "process parameter", "pos": [266, 272]}], "task": "NER"}
{"text": "Computational efficiency and power are particularly important in continuum structural optimisations and will be key for viable design procedures in large-scale , multifunctional , multiscale and cellular-based TO .", "entity": [{"entity": "Computational efficiency", "entity_type": "concept or principle", "pos": [0, 24]}, {"entity": "power", "entity_type": "process parameter", "pos": [29, 34]}, {"entity": "continuum", "entity_type": "concept or principle", "pos": [65, 74]}, {"entity": "be", "entity_type": "material", "pos": [109, 111]}, {"entity": "design", "entity_type": "engineering feature", "pos": [127, 133]}], "task": "NER"}
{"text": "Recent efforts made to improve the feasibility of TO codes for machines with standard computational performance are equally important as the more salient examples , exploiting immense resources to explore what is ultimately possible .", "entity": [{"entity": "feasibility", "entity_type": "concept or principle", "pos": [35, 46]}, {"entity": "machines", "entity_type": "machine or equipment", "pos": [63, 71]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [77, 85]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [100, 111]}, {"entity": "as", "entity_type": "material", "pos": [134, 136]}], "task": "NER"}
{"text": "General conclusions , drawn from this review , can be summarized as : Superior solutions/designs for AM-parts can be obtained using structural optimization methods such as TO if DfAM considerations are included .", "entity": [{"entity": "be", "entity_type": "material", "pos": [51, 53]}, {"entity": "as", "entity_type": "material", "pos": [65, 67]}, {"entity": "be", "entity_type": "material", "pos": [114, 116]}, {"entity": "structural optimization methods", "entity_type": "concept or principle", "pos": [132, 163]}, {"entity": "as", "entity_type": "material", "pos": [169, 171]}], "task": "NER"}
{"text": "This elucidates the need for a holistic design approach , paving way for how we design for AM in the future .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [40, 46]}, {"entity": "design", "entity_type": "engineering feature", "pos": [80, 86]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [91, 93]}], "task": "NER"}
{"text": "Aspects of digitalization are still somewhat underrepresented and pose a bottleneck between design and manufacturing , including computationally inexpensive models and an entirely self-contained process from CAD file to Gcode .", "entity": [{"entity": "bottleneck", "entity_type": "concept or principle", "pos": [73, 83]}, {"entity": "design", "entity_type": "engineering feature", "pos": [92, 98]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [103, 116]}, {"entity": "process", "entity_type": "concept or principle", "pos": [195, 202]}, {"entity": "CAD file", "entity_type": "manufacturing standard", "pos": [208, 216]}], "task": "NER"}
{"text": "To bridge the gap to manufacturing , CAD/CAM software needs to be further improved , pathing among others the way for greater efficiency and compatibility when post-processing digital designs .", "entity": [{"entity": "bridge", "entity_type": "application", "pos": [3, 9]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [21, 34]}, {"entity": "CAD/CAM software", "entity_type": "enabling technology", "pos": [37, 53]}, {"entity": "be", "entity_type": "material", "pos": [63, 65]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [160, 175]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [184, 191]}], "task": "NER"}
{"text": "Both multifunctional TO-based designs , considering multiple objectives and part-integration as well as latticing were considered particularly promising for lightweight high-performance parts .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [30, 37]}, {"entity": "as", "entity_type": "material", "pos": [93, 95]}, {"entity": "as", "entity_type": "material", "pos": [101, 103]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [157, 168]}], "task": "NER"}
{"text": "Functionally graded structures , specifically those that are optimized to better conform to the load trajectories , are inciting increased research interest .", "entity": [{"entity": "Functionally graded structures", "entity_type": "engineering feature", "pos": [0, 30]}, {"entity": "research", "entity_type": "concept or principle", "pos": [139, 147]}], "task": "NER"}
{"text": "The most prominent TO method , both in academia and industry , is the density-based approach assuming isotropic material property .", "entity": [{"entity": "industry", "entity_type": "application", "pos": [52, 60]}, {"entity": "isotropic material", "entity_type": "material", "pos": [102, 120]}], "task": "NER"}
{"text": "Level set methods seem to establish themselves increasingly in the market , due to the intrinsic smooth boundary representation , which is of great benefit for a streamlined design procedure .", "entity": [{"entity": "set", "entity_type": "application", "pos": [6, 9]}, {"entity": "smooth boundary", "entity_type": "engineering feature", "pos": [97, 112]}, {"entity": "design", "entity_type": "engineering feature", "pos": [174, 180]}], "task": "NER"}
{"text": "The sheer amount of software available for both TO and latticing that includes AM-specific design constraints , clearly demonstrates the industry is gravitating towards a wide application of AM .", "entity": [{"entity": "software", "entity_type": "concept or principle", "pos": [20, 28]}, {"entity": "design", "entity_type": "engineering feature", "pos": [91, 97]}, {"entity": "industry", "entity_type": "application", "pos": [137, 145]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [191, 193]}], "task": "NER"}
{"text": "This is supported by the intensified interest in the academic community to make optimisation process more computationally efficient which is a necessity to make AM more accessible for a range of industries .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [93, 100]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [161, 163]}, {"entity": "range", "entity_type": "process parameter", "pos": [186, 191]}, {"entity": "industries", "entity_type": "application", "pos": [195, 205]}], "task": "NER"}
{"text": "As reviewed , the majority of studies concentrate on structural optimisation with the inclusion of inclination angle constraints as opposed to fabrication , materials or digitalization .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [53, 76]}, {"entity": "inclusion", "entity_type": "material", "pos": [86, 95]}, {"entity": "inclination angle", "entity_type": "engineering feature", "pos": [99, 116]}, {"entity": "as", "entity_type": "material", "pos": [129, 131]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [143, 154]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [157, 166]}], "task": "NER"}
{"text": "Aspects deemed important for future work on the design and structural optimisation in AM , are as follows : Consistency through benchmarking mathematically-driven models and confidence via experimental verification will be important as industries are on the verge of adopting AM as means of production .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [48, 54]}, {"entity": "structural optimisation", "entity_type": "concept or principle", "pos": [59, 82]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [86, 88]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}, {"entity": "Consistency", "entity_type": "concept or principle", "pos": [108, 119]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [189, 201]}, {"entity": "be", "entity_type": "material", "pos": [220, 222]}, {"entity": "as", "entity_type": "material", "pos": [233, 235]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [276, 278]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [291, 301]}], "task": "NER"}
{"text": "Structural analyses accommodating path planning i.e .", "entity": [{"entity": "Structural analyses", "entity_type": "process characterization", "pos": [0, 19]}, {"entity": "path planning", "entity_type": "enabling technology", "pos": [34, 47]}], "task": "NER"}
{"text": "tailored infills and a simultaneous optimization of process and design will constitute a central aspect to improved structural performance in the future .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [36, 48]}, {"entity": "process", "entity_type": "concept or principle", "pos": [52, 59]}, {"entity": "design", "entity_type": "engineering feature", "pos": [64, 70]}, {"entity": "structural performance", "entity_type": "process characterization", "pos": [116, 138]}], "task": "NER"}
{"text": "In conjunction with a growing interest in fibre-reinforced AM , a key challenge will be to develop TO methods that account for anisotropic material considerations , paving the way for next-generation lightweight structures .", "entity": [{"entity": "fibre-reinforced AM", "entity_type": "manufacturing process", "pos": [42, 61]}, {"entity": "be", "entity_type": "material", "pos": [85, 87]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [127, 138]}, {"entity": "lightweight structures", "entity_type": "machine or equipment", "pos": [200, 222]}], "task": "NER"}
{"text": "The digital AM-workflow for print-ready designs would immensely benefit from smooth boundary representations .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [40, 47]}, {"entity": "smooth boundary", "entity_type": "engineering feature", "pos": [77, 92]}], "task": "NER"}
{"text": "post-processing procedures for discrete solutions and more recently the intensified use of the level set method were observed .", "entity": [{"entity": "post-processing", "entity_type": "concept or principle", "pos": [0, 15]}, {"entity": "discrete solutions", "entity_type": "concept or principle", "pos": [31, 49]}, {"entity": "set", "entity_type": "application", "pos": [101, 104]}], "task": "NER"}
{"text": "Their uptake by the industry into upcoming software could potentially constitute a boost for the future of AM .", "entity": [{"entity": "industry", "entity_type": "application", "pos": [20, 28]}, {"entity": "software", "entity_type": "concept or principle", "pos": [43, 51]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [107, 109]}], "task": "NER"}
{"text": "In light of both increasing complexity through the inclusion of DfAM constraints and multi-objective optimization as well as the orientation towards large-scale designs , generating high-resolution designs efficiently , will become a key challenge across all TO methods in the future .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [28, 38]}, {"entity": "inclusion", "entity_type": "material", "pos": [51, 60]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [101, 113]}, {"entity": "as", "entity_type": "material", "pos": [114, 116]}, {"entity": "as", "entity_type": "material", "pos": [122, 124]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [129, 140]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [161, 168]}, {"entity": "high-resolution designs", "entity_type": "engineering feature", "pos": [182, 205]}], "task": "NER"}
{"text": "Contrary to previous developments , the industry pulls academia with regard to generative design , rather than taking solutions up .", "entity": [{"entity": "industry", "entity_type": "application", "pos": [40, 48]}, {"entity": "generative design", "entity_type": "enabling technology", "pos": [79, 96]}], "task": "NER"}
{"text": "Due to the feasibility of economically producing large-scale metal components with relatively high deposition rates , significant progress has been made in the understanding of the Wire Arc Additive Manufacturing process , as well as the microstructure and mechanical properties of the fabricated components .", "entity": [{"entity": "feasibility", "entity_type": "concept or principle", "pos": [11, 22]}, {"entity": "metal", "entity_type": "material", "pos": [61, 66]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [67, 77]}, {"entity": "high deposition rates", "entity_type": "process parameter", "pos": [94, 115]}, {"entity": "Wire Arc Additive Manufacturing", "entity_type": "manufacturing process", "pos": [181, 212]}, {"entity": "process", "entity_type": "concept or principle", "pos": [213, 220]}, {"entity": "as", "entity_type": "material", "pos": [223, 225]}, {"entity": "as", "entity_type": "material", "pos": [231, 233]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [238, 252]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [257, 278]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [286, 296]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [297, 307]}], "task": "NER"}
{"text": "As WAAM has evolved , a wide range of materials have become associated with the process and its applications .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "range", "entity_type": "process parameter", "pos": [29, 34]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [38, 47]}, {"entity": "process", "entity_type": "concept or principle", "pos": [80, 87]}], "task": "NER"}
{"text": "This article reviews the emerging research on WAAM techniques and the commonly used metallic feedstock materials , and also provides a comprehensive over view of the metallurgical and material properties of the deposited parts .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [34, 42]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [46, 50]}, {"entity": "metallic", "entity_type": "material", "pos": [84, 92]}, {"entity": "feedstock materials", "entity_type": "material", "pos": [93, 112]}, {"entity": "metallurgical", "entity_type": "application", "pos": [166, 179]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [184, 203]}], "task": "NER"}
{"text": "Common defects produced in WAAM components using different alloys are described , including deformation , porosity , and cracking .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [7, 14]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [27, 31]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [32, 42]}, {"entity": "alloys", "entity_type": "material", "pos": [59, 65]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [92, 103]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [106, 114]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [121, 129]}], "task": "NER"}
{"text": "Methods for improving the fabrication quality of the additively manufactured components are discussed , taking into account the requirements of the various alloys .", "entity": [{"entity": "fabrication", "entity_type": "manufacturing process", "pos": [26, 37]}, {"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [53, 76]}, {"entity": "alloys", "entity_type": "material", "pos": [156, 162]}], "task": "NER"}
{"text": "The integration of materials and manufacturing process to produce defect-free and structurally-sound deposited parts remains a crucial effort into the future .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [19, 28]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [33, 54]}], "task": "NER"}
{"text": "In recent years , wire arc additive manufacturing has increasingly attracted attention from the industrial manufacturing sector due to its ability to create large metal components with high deposition rate , low equipment cost , high material utilization , and consequent environmental friendliness .", "entity": [{"entity": "wire arc additive manufacturing", "entity_type": "manufacturing process", "pos": [18, 49]}, {"entity": "industrial", "entity_type": "application", "pos": [96, 106]}, {"entity": "metal", "entity_type": "material", "pos": [163, 168]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [169, 179]}, {"entity": "high deposition rate", "entity_type": "process parameter", "pos": [185, 205]}, {"entity": "equipment", "entity_type": "machine or equipment", "pos": [212, 221]}, {"entity": "material utilization", "entity_type": "process characterization", "pos": [234, 254]}], "task": "NER"}
{"text": "The origin of the WAAM process can be traced back to the 1925s when Baker proposed to use an electric arc as the heat source with filler wires as feedstock materials to deposit metal ornaments .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [18, 22]}, {"entity": "process", "entity_type": "concept or principle", "pos": [23, 30]}, {"entity": "be", "entity_type": "material", "pos": [35, 37]}, {"entity": "electric arc", "entity_type": "process parameter", "pos": [93, 105]}, {"entity": "as", "entity_type": "material", "pos": [106, 108]}, {"entity": "heat source", "entity_type": "concept or principle", "pos": [113, 124]}, {"entity": "as", "entity_type": "material", "pos": [143, 145]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [156, 165]}, {"entity": "metal", "entity_type": "material", "pos": [177, 182]}], "task": "NER"}
{"text": "The WAAM technique bears various nomenclatures by different research institutions worldwide , as shown in 1 .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [4, 8]}, {"entity": "research", "entity_type": "concept or principle", "pos": [60, 68]}, {"entity": "as", "entity_type": "material", "pos": [94, 96]}], "task": "NER"}
{"text": "Today , WAAM has become a promising fabrication process for various engineering materials such as titanium , aluminium , nickel alloy and steel .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [8, 12]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [36, 47]}, {"entity": "engineering materials", "entity_type": "material", "pos": [68, 89]}, {"entity": "as", "entity_type": "material", "pos": [95, 97]}, {"entity": "aluminium", "entity_type": "material", "pos": [109, 118]}, {"entity": "nickel alloy", "entity_type": "material", "pos": [121, 133]}, {"entity": "steel", "entity_type": "material", "pos": [138, 143]}], "task": "NER"}
{"text": "Compared to traditional subtractive manufacturing , the WAAM system can reduce fabrication time by 40and post-machining time by 15depending on the component size .", "entity": [{"entity": "traditional subtractive manufacturing", "entity_type": "manufacturing process", "pos": [12, 49]}, {"entity": "WAAM system", "entity_type": "machine or equipment", "pos": [56, 67]}, {"entity": "fabrication time", "entity_type": "process parameter", "pos": [79, 95]}, {"entity": "post-machining", "entity_type": "manufacturing process", "pos": [105, 119]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [147, 156]}], "task": "NER"}
{"text": "For instance , recent breakthroughs in WAAM technology have made it possible to fabricate aircraft landing gear ribs with a saving of approximately 78 % in raw material when compared with the traditional subtractive machining process .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [39, 43]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [44, 54]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [80, 89]}, {"entity": "gear", "entity_type": "machine or equipment", "pos": [107, 111]}, {"entity": "raw material", "entity_type": "material", "pos": [156, 168]}, {"entity": "traditional subtractive machining process", "entity_type": "manufacturing process", "pos": [192, 233]}], "task": "NER"}
{"text": "Due to the highly complex nature of WAAM , many different aspects of the process need to be studied , including process development , material quality and performance , path design and programming , process modelling , process monitoring and online control .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [36, 40]}, {"entity": "process", "entity_type": "concept or principle", "pos": [73, 80]}, {"entity": "be", "entity_type": "material", "pos": [89, 91]}, {"entity": "process", "entity_type": "concept or principle", "pos": [112, 119]}, {"entity": "material", "entity_type": "material", "pos": [134, 142]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [155, 166]}, {"entity": "design", "entity_type": "engineering feature", "pos": [174, 180]}, {"entity": "process", "entity_type": "concept or principle", "pos": [199, 206]}, {"entity": "modelling", "entity_type": "enabling technology", "pos": [207, 216]}, {"entity": "process monitoring", "entity_type": "concept or principle", "pos": [219, 237]}], "task": "NER"}
{"text": "Several WAAM review papers have been published by leaders in the field , covering state-of-the-art systems , design , usage , in-situ process monitoring , in-situ metrology and in-process control and sensing .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [8, 12]}, {"entity": "state-of-the-art", "entity_type": "concept or principle", "pos": [82, 98]}, {"entity": "design", "entity_type": "engineering feature", "pos": [109, 115]}, {"entity": "in-situ", "entity_type": "concept or principle", "pos": [126, 133]}, {"entity": "in-situ", "entity_type": "concept or principle", "pos": [155, 162]}, {"entity": "sensing", "entity_type": "application", "pos": [200, 207]}], "task": "NER"}
{"text": "Nevertheless , there is still a need for a systematic review of the properties of various WAAM-processed materials , the defects associated with different alloys , and a summary of current and future research directions that are aimed at quality improvements for the alloy classes of interest .", "entity": [{"entity": "properties", "entity_type": "concept or principle", "pos": [68, 78]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [105, 114]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [121, 128]}, {"entity": "alloys", "entity_type": "material", "pos": [155, 161]}, {"entity": "research", "entity_type": "concept or principle", "pos": [200, 208]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [238, 245]}, {"entity": "alloy", "entity_type": "material", "pos": [267, 272]}], "task": "NER"}
{"text": "This paper reviews the microstructure and mechanical properties of various metals , including titanium and its alloys , aluminum and its alloys , Ni-based alloy , steel and other intermetallic materials fabricated by the various WAAM processes .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [23, 37]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [42, 63]}, {"entity": "metals", "entity_type": "material", "pos": [75, 81]}, {"entity": "titanium", "entity_type": "material", "pos": [94, 102]}, {"entity": "alloys", "entity_type": "material", "pos": [111, 117]}, {"entity": "aluminum", "entity_type": "material", "pos": [120, 128]}, {"entity": "alloys", "entity_type": "material", "pos": [137, 143]}, {"entity": "Ni-based alloy", "entity_type": "material", "pos": [146, 160]}, {"entity": "steel", "entity_type": "material", "pos": [163, 168]}, {"entity": "intermetallic", "entity_type": "material", "pos": [179, 192]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [203, 213]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [229, 233]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [234, 243]}], "task": "NER"}
{"text": "The common defects that have been found to occur for different materials are also summarized .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [11, 18]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [63, 72]}], "task": "NER"}
{"text": "The current methods for both in-process and post-process quality improvement and defect reduction are introduced .", "entity": [{"entity": "post-process", "entity_type": "concept or principle", "pos": [44, 56]}, {"entity": "defect", "entity_type": "concept or principle", "pos": [81, 87]}], "task": "NER"}
{"text": "Finally , a discussion is given on improving quality of WAAM fabricated parts through process selection , feedstock optimization , process monitoring and control and post-process , including proposals for future research directions .", "entity": [{"entity": "quality", "entity_type": "concept or principle", "pos": [45, 52]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [56, 60]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [61, 71]}, {"entity": "process selection", "entity_type": "concept or principle", "pos": [86, 103]}, {"entity": "feedstock optimization", "entity_type": "machine or equipment", "pos": [106, 128]}, {"entity": "process monitoring", "entity_type": "concept or principle", "pos": [131, 149]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [166, 178]}, {"entity": "research", "entity_type": "concept or principle", "pos": [212, 220]}], "task": "NER"}
{"text": "2 Wire arc additive manufacturing systems 2.1 Classification of WAAM process Depending on the nature of the heat source , there are commonly three types of WAAM processes : Gas Metal Arc Welding -based , Gas Tungsten Arc Welding -based and Plasma Arc Welding -based .", "entity": [{"entity": "Wire arc additive manufacturing", "entity_type": "manufacturing process", "pos": [2, 33]}, {"entity": "Classification", "entity_type": "concept or principle", "pos": [46, 60]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [64, 68]}, {"entity": "process", "entity_type": "concept or principle", "pos": [69, 76]}, {"entity": "heat source", "entity_type": "concept or principle", "pos": [108, 119]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [156, 160]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [161, 170]}, {"entity": "Gas Metal Arc Welding", "entity_type": "manufacturing process", "pos": [173, 194]}, {"entity": "Gas Tungsten Arc Welding", "entity_type": "manufacturing process", "pos": [204, 228]}, {"entity": "Plasma Arc Welding", "entity_type": "manufacturing process", "pos": [240, 258]}], "task": "NER"}
{"text": "As listed in 1 , specific class of WAAM techniques exhibit specific features .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [35, 39]}], "task": "NER"}
{"text": "The deposition rate of GMAW-based WAAM is 2times higher than that of GTAW-based or PAW-based methods .", "entity": [{"entity": "deposition rate", "entity_type": "process parameter", "pos": [4, 19]}, {"entity": "GMAW-based WAAM", "entity_type": "manufacturing process", "pos": [23, 38]}], "task": "NER"}
{"text": "However , the GMAW-based WAAM is less stable and generates more weld fume and spatter due to the electric current acting directly on the feedstock .", "entity": [{"entity": "GMAW-based WAAM", "entity_type": "manufacturing process", "pos": [14, 29]}, {"entity": "weld fume", "entity_type": "process characterization", "pos": [64, 73]}, {"entity": "spatter", "entity_type": "process characterization", "pos": [78, 85]}, {"entity": "feedstock", "entity_type": "material", "pos": [137, 146]}], "task": "NER"}
{"text": "The choice of WAAM technique directly influences the processing conditions and production rate for a target component .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [14, 18]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [79, 89]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [108, 117]}], "task": "NER"}
{"text": "2.2 Robotic WAAM system Most WAAM systems use an articulated industrial robot as the motion mechanism .", "entity": [{"entity": "WAAM system", "entity_type": "machine or equipment", "pos": [12, 23]}, {"entity": "WAAM systems", "entity_type": "machine or equipment", "pos": [29, 41]}, {"entity": "articulated industrial robot", "entity_type": "application", "pos": [49, 77]}, {"entity": "mechanism", "entity_type": "concept or principle", "pos": [92, 101]}], "task": "NER"}
{"text": "Two different system designs are available .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [21, 28]}], "task": "NER"}
{"text": "The first design uses an enclosed chamber to provide a good inert gas shielding environment , similar to laser Power-Bed Fusion systems .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [10, 16]}, {"entity": "inert gas", "entity_type": "concept or principle", "pos": [60, 69]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [105, 110]}, {"entity": "Fusion", "entity_type": "concept or principle", "pos": [121, 127]}], "task": "NER"}
{"text": "The second design uses existing or specially designed local gas shielding mechanisms , with the robot positioned on a linear rail to increase the overall working envelop .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [11, 17]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [45, 53]}, {"entity": "gas", "entity_type": "concept or principle", "pos": [60, 63]}, {"entity": "robot", "entity_type": "machine or equipment", "pos": [96, 101]}], "task": "NER"}
{"text": "It is capable of fabricating very large metal structures up to several a meters in dimension .", "entity": [{"entity": "fabricating", "entity_type": "manufacturing process", "pos": [17, 28]}, {"entity": "metal", "entity_type": "material", "pos": [40, 45]}, {"entity": "dimension", "entity_type": "engineering feature", "pos": [83, 92]}], "task": "NER"}
{"text": "2 shows an example of this design of WAAM system , used for the research and development at the University of Wollongong .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [27, 33]}, {"entity": "WAAM system", "entity_type": "machine or equipment", "pos": [37, 48]}, {"entity": "research", "entity_type": "concept or principle", "pos": [64, 72]}], "task": "NER"}
{"text": "Fabricating a part using WAAM involves three main steps : process planning , deposition , and post processing .", "entity": [{"entity": "Fabricating", "entity_type": "manufacturing process", "pos": [0, 11]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [25, 29]}, {"entity": "process planning", "entity_type": "concept or principle", "pos": [58, 74]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [77, 87]}, {"entity": "post processing", "entity_type": "concept or principle", "pos": [94, 109]}], "task": "NER"}
{"text": "For a given CAD model , 3D slicing and programming software generates the desired robot motions and welding parameters for the deposition process , aimed at producing defect-free fabrication with high geometrical accuracy .", "entity": [{"entity": "CAD model", "entity_type": "enabling technology", "pos": [12, 21]}, {"entity": "3D slicing", "entity_type": "enabling technology", "pos": [24, 34]}, {"entity": "software", "entity_type": "concept or principle", "pos": [51, 59]}, {"entity": "robot", "entity_type": "machine or equipment", "pos": [82, 87]}, {"entity": "welding", "entity_type": "manufacturing process", "pos": [100, 107]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [108, 118]}, {"entity": "deposition process", "entity_type": "manufacturing process", "pos": [127, 145]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [179, 190]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [213, 221]}], "task": "NER"}
{"text": "Based on the welding deposition model for the specific material being used to fabricate the component , the 3D slicing and programming software offer automated path planning and process optimization to avoid potential procesB-induced defects .", "entity": [{"entity": "welding", "entity_type": "manufacturing process", "pos": [13, 20]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [21, 31]}, {"entity": "specific material", "entity_type": "material", "pos": [46, 63]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [78, 87]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [92, 101]}, {"entity": "3D slicing", "entity_type": "enabling technology", "pos": [108, 118]}, {"entity": "software", "entity_type": "concept or principle", "pos": [135, 143]}, {"entity": "automated path planning", "entity_type": "enabling technology", "pos": [150, 173]}, {"entity": "process optimization", "entity_type": "concept or principle", "pos": [178, 198]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [234, 241]}], "task": "NER"}
{"text": "During fabrication , the robot and external axis provide accurate motion for the welding torch to build up the component in a layer-by-layer fashion .", "entity": [{"entity": "fabrication", "entity_type": "manufacturing process", "pos": [7, 18]}, {"entity": "robot", "entity_type": "machine or equipment", "pos": [25, 30]}, {"entity": "accurate", "entity_type": "process characterization", "pos": [57, 65]}, {"entity": "welding torch", "entity_type": "machine or equipment", "pos": [81, 94]}, {"entity": "build", "entity_type": "process parameter", "pos": [98, 103]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [111, 120]}, {"entity": "layer-by-layer fashion", "entity_type": "concept or principle", "pos": [126, 148]}], "task": "NER"}
{"text": "Advanced WAAM systems can be equipped with various sensors to measure welding signals , deposited bead geometry , metal transfer behaviour and interpass temperature , thereby supporting in-process monitoring and control to achieve higher product quality .", "entity": [{"entity": "WAAM systems", "entity_type": "machine or equipment", "pos": [9, 21]}, {"entity": "be", "entity_type": "material", "pos": [26, 28]}, {"entity": "sensors", "entity_type": "machine or equipment", "pos": [51, 58]}, {"entity": "welding", "entity_type": "manufacturing process", "pos": [70, 77]}, {"entity": "deposited bead geometry", "entity_type": "process characterization", "pos": [88, 111]}, {"entity": "metal", "entity_type": "material", "pos": [114, 119]}, {"entity": "interpass temperature", "entity_type": "process parameter", "pos": [143, 164]}, {"entity": "product quality", "entity_type": "concept or principle", "pos": [238, 253]}], "task": "NER"}
{"text": "This is an area of current and future research interest , with the potential for significantly improving WAAM process performance .", "entity": [{"entity": "area", "entity_type": "process parameter", "pos": [11, 15]}, {"entity": "research", "entity_type": "concept or principle", "pos": [38, 46]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [105, 109]}, {"entity": "process performance", "entity_type": "concept or principle", "pos": [110, 129]}], "task": "NER"}
{"text": "3 Metals used in WAAM process WAAM processes use commercially available wires which are produced for the welding industry and available in spooled form and in a wide range of alloys as feedstock materials .", "entity": [{"entity": "Metals", "entity_type": "material", "pos": [2, 8]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [17, 21]}, {"entity": "process", "entity_type": "concept or principle", "pos": [22, 29]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [35, 44]}, {"entity": "welding industry", "entity_type": "application", "pos": [105, 121]}, {"entity": "range", "entity_type": "process parameter", "pos": [166, 171]}, {"entity": "alloys", "entity_type": "material", "pos": [175, 181]}, {"entity": "feedstock materials", "entity_type": "material", "pos": [185, 204]}], "task": "NER"}
{"text": "2 indicates the commonly used alloys and their various applications in WAAM .", "entity": [{"entity": "alloys", "entity_type": "material", "pos": [30, 36]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [71, 75]}], "task": "NER"}
{"text": "Manufacture of a structurally sound , defect free , reliable part requires an understanding of the available process options , their underlying physical processes , feedstock materials , process control methods and an appreciation of the causes of the various common defects and their remedies .", "entity": [{"entity": "Manufacture", "entity_type": "concept or principle", "pos": [0, 11]}, {"entity": "defect", "entity_type": "concept or principle", "pos": [38, 44]}, {"entity": "process", "entity_type": "concept or principle", "pos": [109, 116]}, {"entity": "physical processes", "entity_type": "concept or principle", "pos": [144, 162]}, {"entity": "feedstock materials", "entity_type": "material", "pos": [165, 184]}, {"entity": "process control", "entity_type": "concept or principle", "pos": [187, 202]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [267, 274]}], "task": "NER"}
{"text": "This section reviews the metals that are commonly used in WAAM , with a particular emphasis on the microstructure and mechanical properties of the additively manufactured alloys .", "entity": [{"entity": "metals", "entity_type": "material", "pos": [25, 31]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [58, 62]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [99, 113]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [118, 139]}, {"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [147, 170]}], "task": "NER"}
{"text": "3.1 Titanium alloys Titanium alloys have been widely studied for application of additive manufacturing in aerospace components due to their high strength-to-weight ratio and inherently high material cost .", "entity": [{"entity": "Titanium alloys", "entity_type": "material", "pos": [4, 19]}, {"entity": "Titanium", "entity_type": "material", "pos": [20, 28]}, {"entity": "alloys", "entity_type": "material", "pos": [29, 35]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [80, 102]}, {"entity": "aerospace components", "entity_type": "machine or equipment", "pos": [106, 126]}, {"entity": "material", "entity_type": "material", "pos": [190, 198]}], "task": "NER"}
{"text": "There are increasing demands for more efficient and lower cost alternatives to the conventional subtractive manufacturing methods , which suffer very low fly-to-buy ratios for many component designs .", "entity": [{"entity": "conventional subtractive manufacturing methods", "entity_type": "manufacturing process", "pos": [83, 129]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [181, 190]}], "task": "NER"}
{"text": "There exists many business opportunities for the WAAM process , particularly for large-sized titanium components with complex structures .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [49, 53]}, {"entity": "process", "entity_type": "concept or principle", "pos": [54, 61]}, {"entity": "titanium", "entity_type": "material", "pos": [93, 101]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [102, 112]}, {"entity": "complex structures", "entity_type": "concept or principle", "pos": [118, 136]}], "task": "NER"}
{"text": "The distinctive WAAM thermal cycle , which involves repeated heating and cooling , produces meta-stable microstructures and inhomogeneous compositions in the fabricated part .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [16, 20]}, {"entity": "thermal cycle", "entity_type": "process parameter", "pos": [21, 34]}, {"entity": "heating", "entity_type": "manufacturing process", "pos": [61, 68]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [73, 80]}, {"entity": "meta-stable microstructures", "entity_type": "machanical property", "pos": [92, 119]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [158, 168]}], "task": "NER"}
{"text": "For example , Baufeld investigated the microstructures of Ti6Al4V fabricated using a GTAW-based WAAM system , and found two distinctive regions on the aB-built wall .", "entity": [{"entity": "microstructures", "entity_type": "material", "pos": [39, 54]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [58, 65]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [66, 76]}, {"entity": "WAAM system", "entity_type": "machine or equipment", "pos": [96, 107]}], "task": "NER"}
{"text": "In the bottom region , where alternating bands are perpendicular to the build direction , a basketwave Widmanststructure with phase lamellae is present , while in the top region , where no such bands appear , needle-like precipitate is the main structure .", "entity": [{"entity": "build direction", "entity_type": "process parameter", "pos": [72, 87]}, {"entity": "phase", "entity_type": "concept or principle", "pos": [126, 131]}, {"entity": "lamellae", "entity_type": "material", "pos": [132, 140]}, {"entity": "precipitate", "entity_type": "material", "pos": [221, 232]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [245, 254]}], "task": "NER"}
{"text": "Similar microstructural evolution has also been observed in the PAW-based process .", "entity": [{"entity": "microstructural evolution", "entity_type": "concept or principle", "pos": [8, 33]}, {"entity": "process", "entity_type": "concept or principle", "pos": [74, 81]}], "task": "NER"}
{"text": "Lin reported a graded microstructure along the build direction and identified the martensite structure , Widmanststructure and basket-wave structure from the bottom to the top region of the fabricated component , as shown in 3 .", "entity": [{"entity": "graded microstructure", "entity_type": "engineering feature", "pos": [15, 36]}, {"entity": "build direction", "entity_type": "process parameter", "pos": [47, 62]}, {"entity": "martensite", "entity_type": "material", "pos": [82, 92]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [93, 102]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [190, 200]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [201, 210]}, {"entity": "as", "entity_type": "material", "pos": [213, 215]}], "task": "NER"}
{"text": "An epitaxial growth of grains with discrete direction is also observed along the build direction owing to thermal gradient , commonly seen in additively manufactured titanium alloy components .", "entity": [{"entity": "epitaxial", "entity_type": "machanical property", "pos": [3, 12]}, {"entity": "grains", "entity_type": "concept or principle", "pos": [23, 29]}, {"entity": "build direction", "entity_type": "process parameter", "pos": [81, 96]}, {"entity": "thermal gradient", "entity_type": "process parameter", "pos": [106, 122]}, {"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [142, 165]}, {"entity": "alloy", "entity_type": "material", "pos": [175, 180]}], "task": "NER"}
{"text": "3 summarizes the microstructure and mechanical property data of Ti6Al4V samples fabricated using various WAAM technologies .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [17, 31]}, {"entity": "mechanical property", "entity_type": "concept or principle", "pos": [36, 55]}, {"entity": "data", "entity_type": "concept or principle", "pos": [56, 60]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [64, 71]}, {"entity": "samples fabricated", "entity_type": "concept or principle", "pos": [72, 90]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [105, 109]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [110, 122]}], "task": "NER"}
{"text": "The aB-forged and aB-cast minimum specifications from ASTM standards are also listed for comparison .", "entity": [{"entity": "specifications", "entity_type": "process parameter", "pos": [34, 48]}, {"entity": "standards", "entity_type": "concept or principle", "pos": [59, 68]}], "task": "NER"}
{"text": "As shown in 4 , the tensile property of aB-fabricated Ti6Al4V samples is close to that of wrought Ti6Al4V and exceeds that of cast Ti6Al4V as specified by ASTM standards .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "tensile property", "entity_type": "machanical property", "pos": [20, 36]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [54, 61]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [62, 69]}, {"entity": "wrought", "entity_type": "concept or principle", "pos": [90, 97]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [98, 105]}, {"entity": "cast", "entity_type": "manufacturing process", "pos": [126, 130]}, {"entity": "as", "entity_type": "material", "pos": [139, 141]}, {"entity": "standards", "entity_type": "concept or principle", "pos": [160, 169]}], "task": "NER"}
{"text": "In addition , WAAM fabricated Ti6Al4V samples show anisotropic properties with lower strength and higher elongation values in the build direction compared to deposition direction , which is mainly attributed to the grain size of lamellae and the orientation of the elongated prior grains .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [14, 18]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [19, 29]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [38, 45]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [51, 62]}, {"entity": "strength", "entity_type": "machanical property", "pos": [85, 93]}, {"entity": "elongation values", "entity_type": "machanical property", "pos": [105, 122]}, {"entity": "build direction", "entity_type": "process parameter", "pos": [130, 145]}, {"entity": "deposition direction", "entity_type": "process parameter", "pos": [158, 178]}, {"entity": "grain size", "entity_type": "machanical property", "pos": [215, 225]}, {"entity": "lamellae", "entity_type": "material", "pos": [229, 237]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [246, 257]}, {"entity": "grains", "entity_type": "concept or principle", "pos": [281, 287]}], "task": "NER"}
{"text": "3.2 Aluminum alloys and steel Although fabrication trials for many different series of aluminum alloys , including Al-Cu , Al-Si and Al-Mg have been successfully carried out , the commercial value of WAAM is mainly justifiable for large and complex thin-walled structures , since cost of manufacturing small and simple aluminum alloy components using conventional machining processes is low .", "entity": [{"entity": "Aluminum alloys", "entity_type": "material", "pos": [4, 19]}, {"entity": "steel", "entity_type": "material", "pos": [24, 29]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [39, 50]}, {"entity": "aluminum alloys", "entity_type": "material", "pos": [87, 102]}, {"entity": "Al-Cu", "entity_type": "material", "pos": [115, 120]}, {"entity": "Al-Si", "entity_type": "material", "pos": [123, 128]}, {"entity": "Al-Mg", "entity_type": "material", "pos": [133, 138]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [200, 204]}, {"entity": "complex thin-walled structures", "entity_type": "machanical property", "pos": [241, 271]}, {"entity": "cost of manufacturing", "entity_type": "concept or principle", "pos": [280, 301]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [312, 318]}, {"entity": "aluminum alloy", "entity_type": "material", "pos": [319, 333]}, {"entity": "conventional machining", "entity_type": "manufacturing process", "pos": [351, 373]}], "task": "NER"}
{"text": "Using WAAM to fabricate steel is unpopular for the same reason although it is the most commonly used engineering material .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [6, 10]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [14, 23]}, {"entity": "engineering material", "entity_type": "material", "pos": [101, 121]}], "task": "NER"}
{"text": "Another reason for the poor commercial application of WAAM in aluminum is that some series of aluminum alloys , such as Al 7xxx and 6xxx , are challenging to weld due to turbulent melt pool and weld defects , which frequently occur during the deposition process .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [54, 58]}, {"entity": "aluminum", "entity_type": "material", "pos": [62, 70]}, {"entity": "aluminum alloys", "entity_type": "material", "pos": [94, 109]}, {"entity": "as", "entity_type": "material", "pos": [117, 119]}, {"entity": "Al", "entity_type": "material", "pos": [120, 122]}, {"entity": "weld", "entity_type": "engineering feature", "pos": [158, 162]}, {"entity": "melt pool", "entity_type": "material", "pos": [180, 189]}, {"entity": "weld", "entity_type": "engineering feature", "pos": [194, 198]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [199, 206]}, {"entity": "deposition process", "entity_type": "manufacturing process", "pos": [243, 261]}], "task": "NER"}
{"text": "In general , aB-deposited additively manufactured aluminum alloy parts have inferior mechanical properties compared to those machined from billet material .", "entity": [{"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [26, 49]}, {"entity": "alloy", "entity_type": "material", "pos": [59, 64]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [85, 106]}, {"entity": "machined", "entity_type": "manufacturing process", "pos": [125, 133]}, {"entity": "billet", "entity_type": "material", "pos": [139, 145]}], "task": "NER"}
{"text": "In order to achieve higher tensile strength , most of the aB-deposited aluminum parts undergo post-process heat treatment to refine the microstructure .", "entity": [{"entity": "tensile strength", "entity_type": "machanical property", "pos": [27, 43]}, {"entity": "aluminum", "entity_type": "material", "pos": [71, 79]}, {"entity": "post-process heat", "entity_type": "concept or principle", "pos": [94, 111]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [136, 150]}], "task": "NER"}
{"text": "4 lists the yield strength , ultimate tensile strength , and elongation of WAAM-fabricated 2219aluminium alloy samples .", "entity": [{"entity": "yield strength", "entity_type": "machanical property", "pos": [12, 26]}, {"entity": "ultimate tensile strength", "entity_type": "machanical property", "pos": [29, 54]}, {"entity": "elongation", "entity_type": "machanical property", "pos": [61, 71]}, {"entity": "alloy", "entity_type": "material", "pos": [105, 110]}], "task": "NER"}
{"text": "Due to the uniform distribution of large diamond particles within the microstructure , the sample exhibits lower UTS and YS than that of the wrought part specified by ASTM standard .", "entity": [{"entity": "distribution", "entity_type": "concept or principle", "pos": [19, 31]}, {"entity": "diamond", "entity_type": "material", "pos": [41, 48]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [70, 84]}, {"entity": "sample", "entity_type": "concept or principle", "pos": [91, 97]}, {"entity": "UTS", "entity_type": "machanical property", "pos": [113, 116]}, {"entity": "wrought", "entity_type": "concept or principle", "pos": [141, 148]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [172, 180]}], "task": "NER"}
{"text": "However , after heat treatment , significant improvement beyond ASTM standard can be observed in both strength and elongation as a consequence of the grain refinement .", "entity": [{"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [16, 30]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [69, 77]}, {"entity": "be", "entity_type": "material", "pos": [82, 84]}, {"entity": "strength", "entity_type": "machanical property", "pos": [102, 110]}, {"entity": "elongation", "entity_type": "machanical property", "pos": [115, 125]}, {"entity": "as", "entity_type": "material", "pos": [126, 128]}, {"entity": "grain refinement", "entity_type": "process characterization", "pos": [150, 166]}], "task": "NER"}
{"text": "3.3 Nickel-based superalloys Nickel-based superalloys are the second most popular material studied by the additive manufacturing research community after titanium alloys , mainly due to their high strengths at elevated temperatures and high fabrication cost using traditional methods .", "entity": [{"entity": "Nickel-based superalloys", "entity_type": "material", "pos": [4, 28]}, {"entity": "superalloys", "entity_type": "material", "pos": [42, 53]}, {"entity": "material", "entity_type": "material", "pos": [82, 90]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [106, 128]}, {"entity": "titanium alloys", "entity_type": "material", "pos": [154, 169]}, {"entity": "strengths", "entity_type": "machanical property", "pos": [197, 206]}, {"entity": "temperatures", "entity_type": "process parameter", "pos": [219, 231]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [241, 252]}], "task": "NER"}
{"text": "Nickel-based superalloys are widely applied in aerospace , aeronautical , petrochemical , chemical and marine industries due to their outstanding strength and oxidation resistance at temperatures above 550 To date , various Nickel-based superalloys , including Inconel 718 and Inconel 625 alloy have been studied after WAAM processing .", "entity": [{"entity": "Nickel-based superalloys", "entity_type": "material", "pos": [0, 24]}, {"entity": "aerospace", "entity_type": "application", "pos": [47, 56]}, {"entity": "aeronautical", "entity_type": "application", "pos": [59, 71]}, {"entity": "marine industries", "entity_type": "application", "pos": [103, 120]}, {"entity": "strength", "entity_type": "machanical property", "pos": [146, 154]}, {"entity": "oxidation resistance", "entity_type": "machanical property", "pos": [159, 179]}, {"entity": "temperatures", "entity_type": "process parameter", "pos": [183, 195]}, {"entity": "Nickel-based superalloys", "entity_type": "material", "pos": [224, 248]}, {"entity": "Inconel 718", "entity_type": "material", "pos": [261, 272]}, {"entity": "Inconel 625 alloy", "entity_type": "material", "pos": [277, 294]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [319, 323]}], "task": "NER"}
{"text": "The microstructure of WAAM fabricated Inconel 718 parts generally consists of large columnar grains with interdendritic boundaries delineated by small Laves phase precipitates and MC carbides .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [4, 18]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [22, 26]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [27, 37]}, {"entity": "columnar grains", "entity_type": "machanical property", "pos": [84, 99]}, {"entity": "boundaries", "entity_type": "engineering feature", "pos": [120, 130]}, {"entity": "Laves phase", "entity_type": "concept or principle", "pos": [151, 162]}, {"entity": "MC", "entity_type": "material", "pos": [180, 182]}, {"entity": "carbides", "entity_type": "material", "pos": [183, 191]}], "task": "NER"}
{"text": "Xu reported that columnar dendrite structures decorated with a large amount of Laves phase , MC carbides and Ni3Nb are also present in WAAM-fabricated Inconel 625 parts , as shown in 5 .", "entity": [{"entity": "columnar dendrite structures", "entity_type": "engineering feature", "pos": [17, 45]}, {"entity": "Laves phase", "entity_type": "concept or principle", "pos": [79, 90]}, {"entity": "MC", "entity_type": "material", "pos": [93, 95]}, {"entity": "carbides", "entity_type": "material", "pos": [96, 104]}, {"entity": "Ni3Nb", "entity_type": "material", "pos": [109, 114]}, {"entity": "Inconel 625", "entity_type": "material", "pos": [151, 162]}, {"entity": "as", "entity_type": "material", "pos": [171, 173]}], "task": "NER"}
{"text": "It is worth noting that the microstructure can be refined to smaller dendritic arm spacing , less niobium segregation and discontinuous Laves phase in the interdendritic regions using post-process heat treatments , which are beneficial to the mechanical properties .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [28, 42]}, {"entity": "be", "entity_type": "material", "pos": [47, 49]}, {"entity": "dendritic arm spacing", "entity_type": "biomedical", "pos": [69, 90]}, {"entity": "niobium segregation", "entity_type": "concept or principle", "pos": [98, 117]}, {"entity": "Laves phase", "entity_type": "concept or principle", "pos": [136, 147]}, {"entity": "post-process heat", "entity_type": "concept or principle", "pos": [184, 201]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [243, 264]}], "task": "NER"}
{"text": "5 lists the mechanical properties of several Nickel-based superalloys fabricated using the WAAM process .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [12, 33]}, {"entity": "Nickel-based superalloys", "entity_type": "material", "pos": [45, 69]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [70, 80]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [91, 95]}, {"entity": "process", "entity_type": "concept or principle", "pos": [96, 103]}], "task": "NER"}
{"text": "For GMAW-based WAAM-fabricated Inconel 718 alloy , the yield and ultimate tensile strength is 473 6 MPa and 828 8 MPa respectively .", "entity": [{"entity": "Inconel 718 alloy", "entity_type": "material", "pos": [31, 48]}, {"entity": "ultimate tensile strength", "entity_type": "machanical property", "pos": [65, 90]}, {"entity": "MPa", "entity_type": "concept or principle", "pos": [100, 103]}, {"entity": "MPa", "entity_type": "concept or principle", "pos": [114, 117]}], "task": "NER"}
{"text": "These values lie between the minimum values specified by ASTM for wrought and cast materials , whereas the elongation is much lower than the standards for both wrought and cast conditions .", "entity": [{"entity": "wrought", "entity_type": "concept or principle", "pos": [66, 73]}, {"entity": "cast", "entity_type": "manufacturing process", "pos": [78, 82]}, {"entity": "elongation", "entity_type": "machanical property", "pos": [107, 117]}, {"entity": "standards", "entity_type": "concept or principle", "pos": [141, 150]}, {"entity": "wrought", "entity_type": "concept or principle", "pos": [160, 167]}, {"entity": "cast", "entity_type": "manufacturing process", "pos": [172, 176]}], "task": "NER"}
{"text": "As for WAAM-fabricated Inconel 625 alloy , the YS , UTS and elongation all meet the requirement set by ASTM for cast materials , and are slightly lower than those for wrought material .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "Inconel 625 alloy", "entity_type": "material", "pos": [23, 40]}, {"entity": "UTS", "entity_type": "machanical property", "pos": [52, 55]}, {"entity": "elongation", "entity_type": "machanical property", "pos": [60, 70]}, {"entity": "set", "entity_type": "application", "pos": [96, 99]}, {"entity": "cast", "entity_type": "manufacturing process", "pos": [112, 116]}, {"entity": "wrought material", "entity_type": "material", "pos": [167, 183]}], "task": "NER"}
{"text": "3.4 Other metals Other metals have also been investigated for potential fabrication using WAAM , such as magnesium alloy AZ31 for automotive applications , Fe/Al intermetallic compounds and Al/Ti compounds , as well as bimetallic steel/nickel and steel/bronze parts for the aeronautic industry .", "entity": [{"entity": "metals", "entity_type": "material", "pos": [10, 16]}, {"entity": "metals", "entity_type": "material", "pos": [23, 29]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [72, 83]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [90, 94]}, {"entity": "as", "entity_type": "material", "pos": [102, 104]}, {"entity": "alloy", "entity_type": "material", "pos": [115, 120]}, {"entity": "automotive", "entity_type": "application", "pos": [130, 140]}, {"entity": "intermetallic compounds", "entity_type": "material", "pos": [162, 185]}, {"entity": "Al/Ti", "entity_type": "material", "pos": [190, 195]}, {"entity": "as", "entity_type": "material", "pos": [208, 210]}, {"entity": "as", "entity_type": "material", "pos": [216, 218]}, {"entity": "aeronautic industry", "entity_type": "application", "pos": [274, 293]}], "task": "NER"}
{"text": "The detailed mechanical properties of these materials fabricated using WAAM are listed in 6 .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [13, 34]}, {"entity": "materials fabricated", "entity_type": "concept or principle", "pos": [44, 64]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [71, 75]}], "task": "NER"}
{"text": "Most of this research has focused on determining the microstructural and mechanical properties of samples taken from simple straight-walled structures , rather than developing a process to fabricate functional parts .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [13, 21]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [53, 68]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [73, 94]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [98, 105]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [117, 123]}, {"entity": "process", "entity_type": "concept or principle", "pos": [178, 185]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [189, 198]}], "task": "NER"}
{"text": "Manufacturing intermetallic parts with accurate pre-designed composition still poses major challenges for the WAAM process .", "entity": [{"entity": "Manufacturing", "entity_type": "manufacturing process", "pos": [0, 13]}, {"entity": "intermetallic", "entity_type": "material", "pos": [14, 27]}, {"entity": "accurate", "entity_type": "process characterization", "pos": [39, 47]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [61, 72]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [110, 114]}, {"entity": "process", "entity_type": "concept or principle", "pos": [115, 122]}], "task": "NER"}
{"text": "4 Common defects in WAAM-fabricated component Although the mechanical properties of components fabricated by WAAM are in many cases comparable to those of their conventionally processed counterparts , there are however some AM processing defects that must be addressed for critical applications .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [9, 16]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [36, 45]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [59, 80]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [84, 94]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [109, 113]}, {"entity": "processed", "entity_type": "concept or principle", "pos": [176, 185]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [224, 226]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [238, 245]}, {"entity": "be", "entity_type": "material", "pos": [256, 258]}], "task": "NER"}
{"text": "Porosity , high residual stress levels , and cracking , must be avoided , particularly for parts exposed to extreme environments where these defects lead to failure modes such as high temperature fatigue .", "entity": [{"entity": "Porosity", "entity_type": "machanical property", "pos": [0, 8]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [16, 31]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [45, 53]}, {"entity": "be", "entity_type": "material", "pos": [61, 63]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [141, 148]}, {"entity": "failure modes", "entity_type": "machanical property", "pos": [157, 170]}, {"entity": "as", "entity_type": "material", "pos": [176, 178]}, {"entity": "temperature fatigue", "entity_type": "machanical property", "pos": [184, 203]}], "task": "NER"}
{"text": "Defects in WAAM can occur for various reasons , such as poor programming strategy , unstable weld pool dynamics due to poor parameter setup , thermal deformation associated with heat accumulation , environmental influence and other machine malfunctions .", "entity": [{"entity": "Defects", "entity_type": "concept or principle", "pos": [0, 7]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [11, 15]}, {"entity": "as", "entity_type": "material", "pos": [40, 42]}, {"entity": "weld pool", "entity_type": "concept or principle", "pos": [93, 102]}, {"entity": "parameter", "entity_type": "concept or principle", "pos": [124, 133]}, {"entity": "thermal deformation", "entity_type": "process characterization", "pos": [142, 161]}, {"entity": "heat accumulation", "entity_type": "machanical property", "pos": [178, 195]}, {"entity": "machine", "entity_type": "machine or equipment", "pos": [232, 239]}], "task": "NER"}
{"text": "As shown in 6 , certain materials tend to be vulnerable to specific defects .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [24, 33]}, {"entity": "be", "entity_type": "material", "pos": [42, 44]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [68, 75]}], "task": "NER"}
{"text": "For example , severe oxidization for titanium alloys , porosity for aluminum alloys , poor surface roughness in steel as well as severe deformation and cracks in bimetal components have been found to typically occur .", "entity": [{"entity": "titanium alloys", "entity_type": "material", "pos": [37, 52]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [55, 63]}, {"entity": "aluminum alloys", "entity_type": "material", "pos": [68, 83]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [91, 108]}, {"entity": "steel", "entity_type": "material", "pos": [112, 117]}, {"entity": "as", "entity_type": "material", "pos": [118, 120]}, {"entity": "as", "entity_type": "material", "pos": [126, 128]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [136, 147]}, {"entity": "bimetal components", "entity_type": "machine or equipment", "pos": [162, 180]}], "task": "NER"}
{"text": "7 lists the major defects that are commonly present in components fabricated using current WAAM techniques .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [18, 25]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [55, 65]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [91, 95]}], "task": "NER"}
{"text": "The details of these common defects and their relationship to the materials will be discussed this section .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [28, 35]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [66, 75]}, {"entity": "be", "entity_type": "material", "pos": [81, 83]}], "task": "NER"}
{"text": "4.1 Deformation and residual stress Like other additive manufacturing process , distortion and residual stress are inherent to the WAAM process and it is impossible to completely avoid its generation .", "entity": [{"entity": "Deformation", "entity_type": "concept or principle", "pos": [4, 15]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [20, 35]}, {"entity": "additive manufacturing process", "entity_type": "manufacturing process", "pos": [47, 77]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [80, 90]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [95, 110]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [131, 135]}, {"entity": "process", "entity_type": "concept or principle", "pos": [136, 143]}], "task": "NER"}
{"text": "The residual stress can lead to distortion of the part , loss of geometric tolerance , delamination of layers during deposition , as well as deterioration of fatigue performance and fracture resistance of the additively manufactured components .", "entity": [{"entity": "residual stress", "entity_type": "machanical property", "pos": [4, 19]}, {"entity": "lead", "entity_type": "material", "pos": [24, 28]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [32, 42]}, {"entity": "geometric tolerance", "entity_type": "engineering feature", "pos": [65, 84]}, {"entity": "delamination of layers", "entity_type": "process characterization", "pos": [87, 109]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [117, 127]}, {"entity": "as", "entity_type": "material", "pos": [130, 132]}, {"entity": "as", "entity_type": "material", "pos": [138, 140]}, {"entity": "fatigue", "entity_type": "machanical property", "pos": [158, 165]}, {"entity": "fracture resistance", "entity_type": "machanical property", "pos": [182, 201]}, {"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [209, 232]}], "task": "NER"}
{"text": "Therefore , control and minimization of deformation and residual stress is a key area if research .", "entity": [{"entity": "deformation", "entity_type": "concept or principle", "pos": [40, 51]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [56, 71]}, {"entity": "area", "entity_type": "process parameter", "pos": [81, 85]}, {"entity": "research", "entity_type": "concept or principle", "pos": [89, 97]}], "task": "NER"}
{"text": "Various types of deformation appear in WAAM fabricated parts , including longitudinal and transvers shrinkage , bending distortion , angular distortion and rotational distortion .", "entity": [{"entity": "deformation", "entity_type": "concept or principle", "pos": [17, 28]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [39, 43]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [44, 54]}, {"entity": "shrinkage", "entity_type": "concept or principle", "pos": [100, 109]}, {"entity": "bending", "entity_type": "manufacturing process", "pos": [112, 119]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [120, 130]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [141, 151]}], "task": "NER"}
{"text": "The distortions are caused by thermal expansion and shrinkage of the part during repeated melting and cooling processes , which is particularly an issue for large thin walled structures .", "entity": [{"entity": "thermal expansion", "entity_type": "concept or principle", "pos": [30, 47]}, {"entity": "shrinkage", "entity_type": "concept or principle", "pos": [52, 61]}, {"entity": "melting", "entity_type": "manufacturing process", "pos": [90, 97]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [102, 109]}, {"entity": "thin walled structures", "entity_type": "concept or principle", "pos": [163, 185]}], "task": "NER"}
{"text": "Residual stress is the stress that remains in the material when all external loading forces are removed .", "entity": [{"entity": "Residual stress", "entity_type": "machanical property", "pos": [0, 15]}, {"entity": "stress", "entity_type": "machanical property", "pos": [23, 29]}, {"entity": "material", "entity_type": "material", "pos": [50, 58]}, {"entity": "forces", "entity_type": "concept or principle", "pos": [85, 91]}], "task": "NER"}
{"text": "If the residual stress is sufficiently high , it can be a critical influential factor in the mechanical properties and fatigue performance of the fabricated component .", "entity": [{"entity": "residual stress", "entity_type": "machanical property", "pos": [7, 22]}, {"entity": "be", "entity_type": "material", "pos": [53, 55]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [93, 114]}, {"entity": "fatigue", "entity_type": "machanical property", "pos": [119, 126]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [146, 156]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [157, 166]}], "task": "NER"}
{"text": "If the residual stress exceeds the local UTS of the material , cracking will take place , while if it is higher than the local YS but lower than UTS , warping or plastic deformation will occur .", "entity": [{"entity": "residual stress", "entity_type": "machanical property", "pos": [7, 22]}, {"entity": "UTS", "entity_type": "machanical property", "pos": [41, 44]}, {"entity": "material", "entity_type": "material", "pos": [52, 60]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [63, 71]}, {"entity": "UTS", "entity_type": "machanical property", "pos": [145, 148]}, {"entity": "warping", "entity_type": "concept or principle", "pos": [151, 158]}, {"entity": "plastic deformation", "entity_type": "machanical property", "pos": [162, 181]}], "task": "NER"}
{"text": "Ding found that the residual stress uniformly distributes across the WAAM deposited wall , and the residual stress in the preceding layer has little effect on the future layers .", "entity": [{"entity": "residual stress", "entity_type": "machanical property", "pos": [20, 35]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [69, 73]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [99, 114]}, {"entity": "layer", "entity_type": "process parameter", "pos": [132, 137]}], "task": "NER"}
{"text": "After release of clamping , however , the internal stress is redistributed with a much lower value at the top of integral part than at the interface to the substrate , resulting in bending distortion of the component .", "entity": [{"entity": "internal stress", "entity_type": "machanical property", "pos": [42, 57]}, {"entity": "interface", "entity_type": "concept or principle", "pos": [139, 148]}, {"entity": "substrate", "entity_type": "material", "pos": [156, 165]}, {"entity": "bending", "entity_type": "manufacturing process", "pos": [181, 188]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [207, 216]}], "task": "NER"}
{"text": "Path planning also involves the distortion and residual stress evolution in WAAM process .", "entity": [{"entity": "Path planning", "entity_type": "enabling technology", "pos": [0, 13]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [32, 42]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [47, 62]}, {"entity": "evolution", "entity_type": "concept or principle", "pos": [63, 72]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [76, 80]}, {"entity": "process", "entity_type": "concept or principle", "pos": [81, 88]}], "task": "NER"}
{"text": "If appropriate deposition path designs , it will help in the significant improvement in these defects , especially in large metal fabrication .", "entity": [{"entity": "deposition path", "entity_type": "process parameter", "pos": [15, 30]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [94, 101]}, {"entity": "metal", "entity_type": "material", "pos": [124, 129]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [130, 141]}], "task": "NER"}
{"text": "A detailed overview of the residual stress origin would exceed the scope of this article .", "entity": [{"entity": "residual stress", "entity_type": "machanical property", "pos": [27, 42]}], "task": "NER"}
{"text": "Among all WAAM engineering materials , bimetal components exhibit high levels of residual stress and deformation due to the material thermal expansion difference .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [10, 14]}, {"entity": "engineering materials", "entity_type": "material", "pos": [15, 36]}, {"entity": "bimetal components", "entity_type": "machine or equipment", "pos": [39, 57]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [81, 96]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [101, 112]}, {"entity": "material", "entity_type": "material", "pos": [124, 132]}], "task": "NER"}
{"text": "Hence , accurate interpass temperature control is needed when bimetal materials are used .", "entity": [{"entity": "accurate", "entity_type": "process characterization", "pos": [8, 16]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [27, 38]}, {"entity": "bimetal materials", "entity_type": "material", "pos": [62, 79]}], "task": "NER"}
{"text": "WAAM-fabricated Inconel alloy has comparatively lower residual stresses levels , but it is more susceptible to process defects such as delamination , buckling and warping , since its residual stress is usually higher than the yield stress .", "entity": [{"entity": "Inconel alloy", "entity_type": "material", "pos": [16, 29]}, {"entity": "residual stresses", "entity_type": "machanical property", "pos": [54, 71]}, {"entity": "process defects", "entity_type": "concept or principle", "pos": [111, 126]}, {"entity": "as", "entity_type": "material", "pos": [132, 134]}, {"entity": "buckling", "entity_type": "machanical property", "pos": [150, 158]}, {"entity": "warping", "entity_type": "concept or principle", "pos": [163, 170]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [183, 198]}, {"entity": "yield stress", "entity_type": "machanical property", "pos": [226, 238]}], "task": "NER"}
{"text": "Other comparatively softer materials , such as aluminum alloys , easily respond to deformation defects due to their high thermal expansion coefficients .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [27, 36]}, {"entity": "as", "entity_type": "material", "pos": [44, 46]}, {"entity": "aluminum alloys", "entity_type": "material", "pos": [47, 62]}, {"entity": "deformation defects", "entity_type": "machanical property", "pos": [83, 102]}, {"entity": "thermal expansion coefficients", "entity_type": "machanical property", "pos": [121, 151]}], "task": "NER"}
{"text": "A better understanding pf the effect of material characteristics in WAAM processing is needed for controlling residual stress and deformation during deposition .", "entity": [{"entity": "material", "entity_type": "material", "pos": [40, 48]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [68, 72]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [110, 125]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [130, 141]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [149, 159]}], "task": "NER"}
{"text": "Deformation and residual stress are associated with many process parameters , such as welding current , welding voltage , feeding speed , ambient temperature , shielding gas flow rate , etc .", "entity": [{"entity": "Deformation", "entity_type": "concept or principle", "pos": [0, 11]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [16, 31]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [57, 75]}, {"entity": "as", "entity_type": "material", "pos": [83, 85]}, {"entity": "welding", "entity_type": "manufacturing process", "pos": [86, 93]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [146, 157]}, {"entity": "gas flow rate", "entity_type": "process parameter", "pos": [170, 183]}], "task": "NER"}
{"text": "Fortunately , several post-process treatments that have been proven to effectively mitigate residual stress and deformation , and these will be discussed 5 .", "entity": [{"entity": "post-process", "entity_type": "concept or principle", "pos": [22, 34]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [92, 107]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [112, 123]}, {"entity": "be", "entity_type": "material", "pos": [141, 143]}], "task": "NER"}
{"text": "4.2 Porosity Porosity is another common defect in WAAM processing that needs to be minimized due to adverse effects on mechanical properties .", "entity": [{"entity": "Porosity", "entity_type": "machanical property", "pos": [4, 12]}, {"entity": "defect", "entity_type": "concept or principle", "pos": [40, 46]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [50, 54]}, {"entity": "be", "entity_type": "material", "pos": [80, 82]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [119, 140]}], "task": "NER"}
{"text": "Firstly , porosity will lead to a component with low mechanical strength by damage from micro-cracks , and secondly , it usually brings low fatigue property to deposition via spatially with different size and shape distribution .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [10, 18]}, {"entity": "lead", "entity_type": "material", "pos": [24, 28]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [34, 43]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [53, 72]}, {"entity": "damage", "entity_type": "machanical property", "pos": [76, 82]}, {"entity": "micro-cracks", "entity_type": "concept or principle", "pos": [88, 100]}, {"entity": "fatigue", "entity_type": "machanical property", "pos": [140, 147]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [160, 170]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [215, 227]}], "task": "NER"}
{"text": "In general , this type of defects are mainly classified as either raw material-induced or procesB-induced .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [26, 33]}, {"entity": "as", "entity_type": "material", "pos": [47, 49]}], "task": "NER"}
{"text": "The WAAM raw material , including aB-received wire and substrate , often has a degree of surface contamination , such as moisture , grease and other hydrocarbon compounds that may be difficult to completely remove .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [4, 8]}, {"entity": "raw material", "entity_type": "material", "pos": [9, 21]}, {"entity": "substrate", "entity_type": "material", "pos": [55, 64]}, {"entity": "surface contamination", "entity_type": "process characterization", "pos": [89, 110]}, {"entity": "as", "entity_type": "material", "pos": [118, 120]}, {"entity": "be", "entity_type": "material", "pos": [180, 182]}], "task": "NER"}
{"text": "These contaminants can be easily absorbed into the molten pool and subsequently generate porosity after solidification .", "entity": [{"entity": "be", "entity_type": "material", "pos": [23, 25]}, {"entity": "molten pool", "entity_type": "concept or principle", "pos": [51, 62]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [89, 97]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [104, 118]}], "task": "NER"}
{"text": "Among common engineering materials , aluminum alloy is the most susceptible to this defect as the solubility of hydrogen in solid and liquid is significantly different .", "entity": [{"entity": "engineering materials", "entity_type": "material", "pos": [13, 34]}, {"entity": "aluminum alloy", "entity_type": "material", "pos": [37, 51]}, {"entity": "defect", "entity_type": "concept or principle", "pos": [84, 90]}, {"entity": "as", "entity_type": "material", "pos": [91, 93]}, {"entity": "solubility", "entity_type": "machanical property", "pos": [98, 108]}], "task": "NER"}
{"text": "Even small amounts of dissolved hydrogen in the liquid state may exceed the limit of solubility after solidification , resulting in porosity .", "entity": [{"entity": "liquid state", "entity_type": "concept or principle", "pos": [48, 60]}, {"entity": "limit", "entity_type": "concept or principle", "pos": [76, 81]}, {"entity": "solubility", "entity_type": "machanical property", "pos": [85, 95]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [102, 116]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [132, 140]}], "task": "NER"}
{"text": "Therefore , the cleanliness of raw materials is critical , especially for aluminum alloys .", "entity": [{"entity": "raw materials", "entity_type": "material", "pos": [31, 44]}, {"entity": "aluminum alloys", "entity_type": "material", "pos": [74, 89]}], "task": "NER"}
{"text": "ProcesB-induced porosity is usually non-spherical , and mainly caused by poor path planning or an unstable deposition process .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [16, 24]}, {"entity": "non-spherical", "entity_type": "concept or principle", "pos": [36, 49]}, {"entity": "path planning", "entity_type": "enabling technology", "pos": [78, 91]}, {"entity": "deposition process", "entity_type": "manufacturing process", "pos": [107, 125]}], "task": "NER"}
{"text": "When the deposition path is complex or the manufacturing process is changeable , insufficient fusion or spatter ejection is easily produced , creating gaps or voids in these influenced regions .", "entity": [{"entity": "deposition path", "entity_type": "process parameter", "pos": [9, 24]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [43, 64]}, {"entity": "insufficient fusion", "entity_type": "material", "pos": [81, 100]}, {"entity": "spatter", "entity_type": "process characterization", "pos": [104, 111]}, {"entity": "ejection", "entity_type": "concept or principle", "pos": [112, 120]}, {"entity": "voids", "entity_type": "concept or principle", "pos": [159, 164]}], "task": "NER"}
{"text": "To control porosity , the following methods can be adopted : an AC GMAW-based process or CMT-PADV based process is preferred , especially for aluminum ; the highest quality shielding gas , tight gas seals , non-organic piping and short pipe lengths are highly recommended ; the wire and substrate surfaces are as clean as possible before fabrication ; high quality feedstock should be used ; the deposited bead shape needs to be optimized ; the thermal profile during processing should be monitored and controlled ; post-deposition treatment , such as interpass rolling can be applied .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [11, 19]}, {"entity": "be", "entity_type": "material", "pos": [48, 50]}, {"entity": "process", "entity_type": "concept or principle", "pos": [78, 85]}, {"entity": "process", "entity_type": "concept or principle", "pos": [104, 111]}, {"entity": "aluminum", "entity_type": "material", "pos": [142, 150]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [165, 172]}, {"entity": "gas", "entity_type": "concept or principle", "pos": [183, 186]}, {"entity": "gas", "entity_type": "concept or principle", "pos": [195, 198]}, {"entity": "substrate", "entity_type": "material", "pos": [287, 296]}, {"entity": "as", "entity_type": "material", "pos": [310, 312]}, {"entity": "as", "entity_type": "material", "pos": [319, 321]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [338, 349]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [357, 364]}, {"entity": "feedstock", "entity_type": "material", "pos": [365, 374]}, {"entity": "be", "entity_type": "material", "pos": [382, 384]}, {"entity": "deposited bead shape", "entity_type": "process characterization", "pos": [396, 416]}, {"entity": "be", "entity_type": "material", "pos": [426, 428]}, {"entity": "thermal profile", "entity_type": "concept or principle", "pos": [445, 460]}, {"entity": "be", "entity_type": "material", "pos": [486, 488]}, {"entity": "as", "entity_type": "material", "pos": [549, 551]}, {"entity": "rolling", "entity_type": "manufacturing process", "pos": [562, 569]}, {"entity": "be", "entity_type": "material", "pos": [574, 576]}], "task": "NER"}
{"text": "4.3 Crack and delamination Similar to residual stress and deformation , cracking and delamination not only involves the thermal signature of the manufacturing process , but also relates to the material characteristics of the deposit .", "entity": [{"entity": "delamination", "entity_type": "concept or principle", "pos": [14, 26]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [38, 53]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [58, 69]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [72, 80]}, {"entity": "delamination", "entity_type": "concept or principle", "pos": [85, 97]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [145, 166]}, {"entity": "material", "entity_type": "material", "pos": [193, 201]}], "task": "NER"}
{"text": "Ordinarily , the crack is categorised as either a solidification crack or grain boundary crack within the WAAM component .", "entity": [{"entity": "as", "entity_type": "material", "pos": [38, 40]}, {"entity": "solidification crack", "entity_type": "process characterization", "pos": [50, 70]}, {"entity": "grain boundary crack", "entity_type": "machanical property", "pos": [74, 94]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [106, 110]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [111, 120]}], "task": "NER"}
{"text": "The former type of crack depends mainly on the solidification nature of the material and is usually caused by the obstruction of solidified grain flow or high strain in the melt pool .", "entity": [{"entity": "solidification", "entity_type": "concept or principle", "pos": [47, 61]}, {"entity": "material", "entity_type": "material", "pos": [76, 84]}, {"entity": "grain", "entity_type": "concept or principle", "pos": [140, 145]}, {"entity": "strain", "entity_type": "machanical property", "pos": [159, 165]}, {"entity": "melt pool", "entity_type": "material", "pos": [173, 182]}], "task": "NER"}
{"text": "Grain boundary cracking often generates along the grain boundaries due to the differences between boundary morphology and potential precipitate formation or dissolution .", "entity": [{"entity": "Grain boundary", "entity_type": "concept or principle", "pos": [0, 14]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [15, 23]}, {"entity": "grain boundaries", "entity_type": "concept or principle", "pos": [50, 66]}, {"entity": "boundary morphology", "entity_type": "process characterization", "pos": [98, 117]}, {"entity": "precipitate", "entity_type": "material", "pos": [132, 143]}], "task": "NER"}
{"text": "Generally , this deficiency is visible and can not be repaired by post-process treatment .", "entity": [{"entity": "be", "entity_type": "material", "pos": [51, 53]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [66, 78]}], "task": "NER"}
{"text": "In order to prevent this defect , pre-process treatment such as preheating of the substrate needs to be considered .", "entity": [{"entity": "defect", "entity_type": "concept or principle", "pos": [25, 31]}, {"entity": "as", "entity_type": "material", "pos": [61, 63]}, {"entity": "substrate", "entity_type": "material", "pos": [82, 91]}, {"entity": "be", "entity_type": "material", "pos": [101, 103]}], "task": "NER"}
{"text": "Bimetal material combinations , such as Al/Cu , Al/Ti and Al/Fe , are quite susceptible to cracking and delamination when fabricated with the WAAM process .", "entity": [{"entity": "Bimetal material combinations", "entity_type": "material", "pos": [0, 29]}, {"entity": "as", "entity_type": "material", "pos": [37, 39]}, {"entity": "Al/Cu", "entity_type": "material", "pos": [40, 45]}, {"entity": "Al/Ti", "entity_type": "material", "pos": [48, 53]}, {"entity": "Al/Fe", "entity_type": "material", "pos": [58, 63]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [91, 99]}, {"entity": "delamination", "entity_type": "concept or principle", "pos": [104, 116]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [122, 132]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [142, 146]}, {"entity": "process", "entity_type": "concept or principle", "pos": [147, 154]}], "task": "NER"}
{"text": "The dissimilar metals have large differences in their mutual solubility and chemical reactivity so that the intermetallic phase-equilibrium is freely broken , thus inducing crack growth along grain boundaries .", "entity": [{"entity": "metals", "entity_type": "material", "pos": [15, 21]}, {"entity": "mutual solubility", "entity_type": "machanical property", "pos": [54, 71]}, {"entity": "intermetallic", "entity_type": "material", "pos": [108, 121]}, {"entity": "crack growth", "entity_type": "concept or principle", "pos": [173, 185]}, {"entity": "grain boundaries", "entity_type": "concept or principle", "pos": [192, 208]}], "task": "NER"}
{"text": "Also , Inconel alloy readily generates solidification cracking issues due to the existence of liquid film at terminal solidification .", "entity": [{"entity": "Inconel alloy", "entity_type": "material", "pos": [7, 20]}, {"entity": "solidification cracking", "entity_type": "concept or principle", "pos": [39, 62]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [118, 132]}], "task": "NER"}
{"text": "Both of these material types should receive particular attention to avoid cracking and delamination .", "entity": [{"entity": "material", "entity_type": "material", "pos": [14, 22]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [74, 82]}, {"entity": "delamination", "entity_type": "concept or principle", "pos": [87, 99]}], "task": "NER"}
{"text": "To control crack defects , corresponding measures can be taken as follows : Mixed wires and optimization of their compositions ; Decrease the cooling rate during the deposition process Other measures to improve strength rather than solution treatment .", "entity": [{"entity": "crack defects", "entity_type": "machanical property", "pos": [11, 24]}, {"entity": "be", "entity_type": "material", "pos": [54, 56]}, {"entity": "as", "entity_type": "material", "pos": [63, 65]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [92, 104]}, {"entity": "cooling rate", "entity_type": "process parameter", "pos": [142, 154]}, {"entity": "deposition process", "entity_type": "manufacturing process", "pos": [166, 184]}, {"entity": "strength", "entity_type": "machanical property", "pos": [211, 219]}, {"entity": "solution treatment", "entity_type": "manufacturing process", "pos": [232, 250]}], "task": "NER"}
{"text": "5 Current methods for quality improvement in the WAAM process Generally , WAAM parts require post-process treatment to improve material properties , reduce surface roughness and porosity , and remove residual stress and distortions .", "entity": [{"entity": "quality", "entity_type": "concept or principle", "pos": [22, 29]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [49, 53]}, {"entity": "process", "entity_type": "concept or principle", "pos": [54, 61]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [74, 78]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [93, 105]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [127, 146]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [156, 173]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [178, 186]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [200, 215]}], "task": "NER"}
{"text": "By appropriate application of post process , the majority of issues that influence deposition quality can be mitigated or eliminated .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [35, 42]}, {"entity": "deposition quality", "entity_type": "process characterization", "pos": [83, 101]}, {"entity": "be", "entity_type": "material", "pos": [106, 108]}], "task": "NER"}
{"text": "Presently , several post-process treatment technologies have been reported to improve part quality in the WAAM process .", "entity": [{"entity": "post-process", "entity_type": "concept or principle", "pos": [20, 32]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [43, 55]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [91, 98]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [106, 110]}, {"entity": "process", "entity_type": "concept or principle", "pos": [111, 118]}], "task": "NER"}
{"text": "5.1 Post-process heat treatment Post-process heat treatment is widely used in WAAM to reduce residual stress , enhance material strength and as a method of hardness control .", "entity": [{"entity": "Post-process heat", "entity_type": "concept or principle", "pos": [4, 21]}, {"entity": "Post-process heat", "entity_type": "concept or principle", "pos": [32, 49]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [78, 82]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [93, 108]}, {"entity": "material strength", "entity_type": "machanical property", "pos": [119, 136]}, {"entity": "as", "entity_type": "material", "pos": [141, 143]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [156, 164]}], "task": "NER"}
{"text": "The selection of a suitable heat treatment process depends on the target material , additive manufacturing methods , working temperature and heat treatment conditions .", "entity": [{"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [28, 42]}, {"entity": "material", "entity_type": "material", "pos": [73, 81]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [84, 106]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [125, 136]}, {"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [141, 155]}], "task": "NER"}
{"text": "If the heat treatment state is set incorrectly , the probability of cracking will increase under mechanical loading , as the combination of existing residual stress with load stress exceeds the materialdesign limitation .", "entity": [{"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [7, 21]}, {"entity": "set", "entity_type": "application", "pos": [31, 34]}, {"entity": "probability", "entity_type": "concept or principle", "pos": [53, 64]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [68, 76]}, {"entity": "mechanical loading", "entity_type": "concept or principle", "pos": [97, 115]}, {"entity": "as", "entity_type": "material", "pos": [118, 120]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [149, 164]}, {"entity": "stress", "entity_type": "machanical property", "pos": [175, 181]}], "task": "NER"}
{"text": "As summarized s 3after heat treatment , the mechanical strength of WAAM-fabricated parts improved significantly , with increase of 4 % , 78 % , 5 % and 17 % being reported for titanium alloy , aluminum alloy , Nickel-based superalloys and intermetallic Ti/Al alloy , respectively .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "s", "entity_type": "material", "pos": [3, 4]}, {"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [23, 37]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [44, 63]}, {"entity": "titanium alloy", "entity_type": "material", "pos": [176, 190]}, {"entity": "aluminum alloy", "entity_type": "material", "pos": [193, 207]}, {"entity": "Nickel-based superalloys", "entity_type": "material", "pos": [210, 234]}, {"entity": "intermetallic", "entity_type": "material", "pos": [239, 252]}, {"entity": "alloy", "entity_type": "material", "pos": [259, 264]}], "task": "NER"}
{"text": "In addition , post-process heat treatment plays an important role in grain refinement , especially for WAAM-fabricated aluminum and Inconel alloy .", "entity": [{"entity": "post-process heat", "entity_type": "concept or principle", "pos": [14, 31]}, {"entity": "grain refinement", "entity_type": "process characterization", "pos": [69, 85]}, {"entity": "aluminum", "entity_type": "material", "pos": [119, 127]}, {"entity": "Inconel alloy", "entity_type": "material", "pos": [132, 145]}], "task": "NER"}
{"text": "The decision to use post-process heat treatment depends on the material alloying system and also the pre-heat treatment state .", "entity": [{"entity": "post-process heat", "entity_type": "concept or principle", "pos": [20, 37]}, {"entity": "material", "entity_type": "material", "pos": [63, 71]}, {"entity": "alloying", "entity_type": "engineering feature", "pos": [72, 80]}, {"entity": "pre-heat treatment", "entity_type": "manufacturing process", "pos": [101, 119]}], "task": "NER"}
{"text": "Generally , high carbon content materials must be heat treated , while a few materials can be damaged by this technique .", "entity": [{"entity": "carbon content", "entity_type": "material", "pos": [17, 31]}, {"entity": "be", "entity_type": "material", "pos": [47, 49]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [77, 86]}, {"entity": "be", "entity_type": "material", "pos": [91, 93]}], "task": "NER"}
{"text": "Therefore , the utilization of post heat treatment process to WAAM component needs to consider the specific material and its application .", "entity": [{"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [36, 50]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [62, 66]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [67, 76]}, {"entity": "specific material", "entity_type": "material", "pos": [99, 116]}], "task": "NER"}
{"text": "5.2 Interpass cold rolling Rolling of the weld bead between each deposited layer has been shown to reduce residual stresses and distortion.Interpass cold rolling not only lowers residual stress , but also brings more homogeneous material properties .", "entity": [{"entity": "Interpass cold rolling", "entity_type": "manufacturing process", "pos": [4, 26]}, {"entity": "weld bead", "entity_type": "concept or principle", "pos": [42, 51]}, {"entity": "deposited layer", "entity_type": "process characterization", "pos": [65, 80]}, {"entity": "residual stresses", "entity_type": "machanical property", "pos": [106, 123]}, {"entity": "cold rolling", "entity_type": "manufacturing process", "pos": [149, 161]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [178, 193]}, {"entity": "homogeneous material", "entity_type": "material", "pos": [217, 237]}], "task": "NER"}
{"text": "In the WAAM process , the thermal gradient with deposition layers and alternate re-heating and re-cooling process result in the target part having anisotropic microstructural evolution and mechanical properties .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [7, 11]}, {"entity": "process", "entity_type": "concept or principle", "pos": [12, 19]}, {"entity": "thermal gradient", "entity_type": "process parameter", "pos": [26, 42]}, {"entity": "deposition layers", "entity_type": "process parameter", "pos": [48, 65]}, {"entity": "process", "entity_type": "concept or principle", "pos": [106, 113]}, {"entity": "anisotropic microstructural evolution", "entity_type": "concept or principle", "pos": [147, 184]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [189, 210]}], "task": "NER"}
{"text": "The cold rolling technique significantly reduces microstructural anisotropy through plastically deforming the deposition .", "entity": [{"entity": "cold rolling", "entity_type": "manufacturing process", "pos": [4, 16]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [49, 64]}, {"entity": "anisotropy", "entity_type": "machanical property", "pos": [65, 75]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [110, 120]}], "task": "NER"}
{"text": "7 shows the schematic diagram of an interpass cold rolling system developed at Cranfield University .", "entity": [{"entity": "interpass cold rolling", "entity_type": "manufacturing process", "pos": [36, 58]}], "task": "NER"}
{"text": "A slotted roller is used to refine the microstructure and enhance tensile strength in the longitudinal direction by supporting external force .", "entity": [{"entity": "slotted roller", "entity_type": "engineering feature", "pos": [2, 16]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [39, 53]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [66, 82]}, {"entity": "force", "entity_type": "concept or principle", "pos": [136, 141]}], "task": "NER"}
{"text": "As shown in 8 , both ultimate tensile strength and yield strength in the build direction were improved through interpass cold rolling , which contributes to more homogeneous material properties in the target component .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "ultimate tensile strength", "entity_type": "machanical property", "pos": [21, 46]}, {"entity": "yield strength", "entity_type": "machanical property", "pos": [51, 65]}, {"entity": "build direction", "entity_type": "process parameter", "pos": [73, 88]}, {"entity": "interpass cold rolling", "entity_type": "manufacturing process", "pos": [111, 133]}, {"entity": "homogeneous material", "entity_type": "material", "pos": [162, 182]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [208, 217]}], "task": "NER"}
{"text": "Interpass cold rolling also can play a critical role in the healing of hydrogen porosity in WAAM-fabricated aluminum parts .", "entity": [{"entity": "Interpass cold rolling", "entity_type": "manufacturing process", "pos": [0, 22]}, {"entity": "hydrogen porosity", "entity_type": "machanical property", "pos": [71, 88]}, {"entity": "aluminum", "entity_type": "material", "pos": [108, 116]}], "task": "NER"}
{"text": "Generally , high dislocation density is produced by the rolling process .", "entity": [{"entity": "dislocation density", "entity_type": "machanical property", "pos": [17, 36]}, {"entity": "rolling process", "entity_type": "manufacturing process", "pos": [56, 71]}], "task": "NER"}
{"text": "These dislocation can act as preferential sites for atomic hydrogen absorption and as well as for the hydrogen , allowing to diffuse to the surface .", "entity": [{"entity": "dislocation", "entity_type": "concept or principle", "pos": [6, 17]}, {"entity": "as", "entity_type": "material", "pos": [26, 28]}, {"entity": "atomic hydrogen absorption", "entity_type": "concept or principle", "pos": [52, 78]}, {"entity": "as", "entity_type": "material", "pos": [83, 85]}, {"entity": "as", "entity_type": "material", "pos": [91, 93]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [140, 147]}], "task": "NER"}
{"text": "9 summarizes the outcomes documented in the literature , in terms of the pore incidence and size distribution in aluminum components fabricated using WAAM with interpass cold rolling .", "entity": [{"entity": "pore", "entity_type": "machanical property", "pos": [73, 77]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [97, 109]}, {"entity": "aluminum", "entity_type": "material", "pos": [113, 121]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [133, 143]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [150, 154]}, {"entity": "interpass cold rolling", "entity_type": "manufacturing process", "pos": [160, 182]}], "task": "NER"}
{"text": "The porosities existing in aB-fabricated component can be reduced or even eliminated when interpass cold rolling is applied .", "entity": [{"entity": "porosities", "entity_type": "machanical property", "pos": [4, 14]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [41, 50]}, {"entity": "be", "entity_type": "material", "pos": [55, 57]}, {"entity": "interpass cold rolling", "entity_type": "manufacturing process", "pos": [90, 112]}], "task": "NER"}
{"text": "This technique is only feasible for simple deposited parts , such as straight walls , due to the geometrical limitation of the rolling process .", "entity": [{"entity": "simple", "entity_type": "manufacturing process", "pos": [36, 42]}, {"entity": "as", "entity_type": "material", "pos": [66, 68]}, {"entity": "rolling process", "entity_type": "manufacturing process", "pos": [127, 142]}], "task": "NER"}
{"text": "For more complex components with curves and corners , special flexible tooling need to be developed to achieve an effective rolling process , thus limiting the range of industrial application .", "entity": [{"entity": "components", "entity_type": "machine or equipment", "pos": [17, 27]}, {"entity": "flexible tooling", "entity_type": "concept or principle", "pos": [62, 78]}, {"entity": "be", "entity_type": "material", "pos": [87, 89]}, {"entity": "rolling process", "entity_type": "manufacturing process", "pos": [124, 139]}, {"entity": "range", "entity_type": "process parameter", "pos": [160, 165]}, {"entity": "industrial", "entity_type": "application", "pos": [169, 179]}], "task": "NER"}
{"text": "Cold rolling technique will also reduce residual stress , but the ability to reduce overall part distortion is yet to be proven .", "entity": [{"entity": "Cold rolling", "entity_type": "manufacturing process", "pos": [0, 12]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [40, 55]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [97, 107]}, {"entity": "be", "entity_type": "material", "pos": [118, 120]}], "task": "NER"}
{"text": "5.3 Interpass cooling Recently , interpass cooling has been developed and evaluated at the University of Wollongong .", "entity": [{"entity": "Interpass", "entity_type": "process parameter", "pos": [4, 13]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [14, 21]}, {"entity": "interpass", "entity_type": "process parameter", "pos": [33, 42]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [43, 50]}], "task": "NER"}
{"text": "8 presents the schematic diagram of a WAAM system with interpass cooling .", "entity": [{"entity": "WAAM system", "entity_type": "machine or equipment", "pos": [38, 49]}, {"entity": "interpass", "entity_type": "process parameter", "pos": [55, 64]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [65, 72]}], "task": "NER"}
{"text": "The moveable gas nozzle , which supplies argon , nitrogen or CO2 gas , is used to provide active , or forced , cooling on the fabricated part during and/or after deposition of each layer .", "entity": [{"entity": "gas", "entity_type": "concept or principle", "pos": [13, 16]}, {"entity": "argon", "entity_type": "material", "pos": [41, 46]}, {"entity": "nitrogen", "entity_type": "material", "pos": [49, 57]}, {"entity": "CO2", "entity_type": "material", "pos": [61, 64]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [111, 118]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [126, 136]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [162, 172]}, {"entity": "layer", "entity_type": "process parameter", "pos": [181, 186]}], "task": "NER"}
{"text": "Using such rapid cooling , the in-situ layer temperature and heat cycle can be controlled within a range to obtain the desired microstructure and mechanical properties .", "entity": [{"entity": "cooling", "entity_type": "manufacturing process", "pos": [17, 24]}, {"entity": "in-situ", "entity_type": "concept or principle", "pos": [31, 38]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [45, 56]}, {"entity": "heat cycle", "entity_type": "machanical property", "pos": [61, 71]}, {"entity": "be", "entity_type": "material", "pos": [76, 78]}, {"entity": "range", "entity_type": "process parameter", "pos": [99, 104]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [127, 141]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [146, 167]}], "task": "NER"}
{"text": "This process may also potentially reduce residual stress and distortion , although this aspect has not been investigated .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [41, 56]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [61, 71]}], "task": "NER"}
{"text": "An initial feasibility study shows promising results when using forced interpass cooling with compressed CO2 to fabricate Ti6Al4V thin-walled structures , as shown in 9 .", "entity": [{"entity": "feasibility", "entity_type": "concept or principle", "pos": [11, 22]}, {"entity": "interpass", "entity_type": "process parameter", "pos": [71, 80]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [81, 88]}, {"entity": "CO2", "entity_type": "material", "pos": [105, 108]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [112, 121]}, {"entity": "as", "entity_type": "material", "pos": [155, 157]}], "task": "NER"}
{"text": "It was found that interpass cooling produces less surface oxidation , refined microstructure , improved hardness and enhanced strength .", "entity": [{"entity": "interpass", "entity_type": "process parameter", "pos": [18, 27]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [28, 35]}, {"entity": "surface oxidation", "entity_type": "manufacturing process", "pos": [50, 67]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [78, 92]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [104, 112]}, {"entity": "strength", "entity_type": "machanical property", "pos": [126, 134]}], "task": "NER"}
{"text": "In addition , manufacturing efficiency is significantly improved due to the reduction of dwell time between deposited layers .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [14, 27]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [76, 85]}, {"entity": "dwell time", "entity_type": "process parameter", "pos": [89, 99]}, {"entity": "deposited layers", "entity_type": "process characterization", "pos": [108, 124]}], "task": "NER"}
{"text": "More detailed research findings will be presented in future .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [14, 22]}, {"entity": "be", "entity_type": "material", "pos": [37, 39]}], "task": "NER"}
{"text": "5.4 Peening and ultrasonic impact treatment Peening and ultrasonic impact treatments have been used in welding applications to reduce local residual stress and improve weld mechanical properties .", "entity": [{"entity": "Peening", "entity_type": "manufacturing process", "pos": [4, 11]}, {"entity": "ultrasonic impact treatment", "entity_type": "process characterization", "pos": [16, 43]}, {"entity": "Peening", "entity_type": "manufacturing process", "pos": [44, 51]}, {"entity": "ultrasonic impact treatments", "entity_type": "process characterization", "pos": [56, 84]}, {"entity": "welding", "entity_type": "manufacturing process", "pos": [103, 110]}, {"entity": "local residual stress", "entity_type": "concept or principle", "pos": [134, 155]}, {"entity": "weld", "entity_type": "engineering feature", "pos": [168, 172]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [173, 194]}], "task": "NER"}
{"text": "Both techniques are cold mechanical treatments that impact the weld surface using high energy media to release tensile stress by imposing compressive stress at the treatment surface .", "entity": [{"entity": "cold mechanical treatments", "entity_type": "manufacturing process", "pos": [20, 46]}, {"entity": "impact", "entity_type": "concept or principle", "pos": [52, 58]}, {"entity": "weld surface", "entity_type": "process characterization", "pos": [63, 75]}, {"entity": "tensile stress", "entity_type": "machanical property", "pos": [111, 125]}, {"entity": "compressive stress", "entity_type": "machanical property", "pos": [138, 156]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [174, 181]}], "task": "NER"}
{"text": "Usually , the mechanical peening process produces compressive stresses at a limited depth below the component surface , such as around 1mm in carbon steels .", "entity": [{"entity": "mechanical peening", "entity_type": "concept or principle", "pos": [14, 32]}, {"entity": "compressive stresses", "entity_type": "machanical property", "pos": [50, 70]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [100, 109]}, {"entity": "as", "entity_type": "material", "pos": [125, 127]}, {"entity": "carbon steels", "entity_type": "material", "pos": [142, 155]}], "task": "NER"}
{"text": "Ultrasonic impact treatment produces grain refinement and randomizes orientation , thus contributing to mechanical strength improvement .", "entity": [{"entity": "Ultrasonic impact treatment", "entity_type": "process characterization", "pos": [0, 27]}, {"entity": "grain refinement", "entity_type": "process characterization", "pos": [37, 53]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [69, 80]}, {"entity": "mechanical strength", "entity_type": "machanical property", "pos": [104, 123]}], "task": "NER"}
{"text": "It is reported that after ultrasonic impact treatment , the surface residual stress of WAAM-fabricated Ti6Al4V part can be reduced to 58 % and the microhardness can be increased by 28 % compared to the aB-fabricated sample .", "entity": [{"entity": "ultrasonic impact treatment", "entity_type": "process characterization", "pos": [26, 53]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [60, 67]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [68, 83]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [103, 110]}, {"entity": "be", "entity_type": "material", "pos": [120, 122]}, {"entity": "microhardness", "entity_type": "concept or principle", "pos": [147, 160]}, {"entity": "be", "entity_type": "material", "pos": [165, 167]}, {"entity": "sample", "entity_type": "concept or principle", "pos": [216, 222]}], "task": "NER"}
{"text": "Also , the surface-modified layers undergo plastic deformation with significant grain refinement and dense dislocations .", "entity": [{"entity": "plastic deformation", "entity_type": "machanical property", "pos": [43, 62]}, {"entity": "grain refinement", "entity_type": "process characterization", "pos": [80, 96]}, {"entity": "dense dislocations", "entity_type": "engineering feature", "pos": [101, 119]}], "task": "NER"}
{"text": "The ultrasonic impact treatment is limited by penetration depth , which is up to 60 below surface .", "entity": [{"entity": "ultrasonic impact treatment", "entity_type": "process characterization", "pos": [4, 31]}, {"entity": "penetration depth", "entity_type": "process parameter", "pos": [46, 63]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [90, 97]}], "task": "NER"}
{"text": "Therefore , although both techniques are good post-process treatments , they have negligible effect on internal residual stresses of large metal part fabricated using WAAM .", "entity": [{"entity": "post-process", "entity_type": "concept or principle", "pos": [46, 58]}, {"entity": "internal residual stresses", "entity_type": "machanical property", "pos": [103, 129]}, {"entity": "metal", "entity_type": "material", "pos": [139, 144]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [150, 160]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [167, 171]}], "task": "NER"}
{"text": "6 Discussion Improving process stability , eliminating or decreasing deposition defects and producing components with high quality and mechanical performance have become major research focuses in making the WAAM process more competitive against other additive manufacturing methods .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [23, 30]}, {"entity": "deposition defects", "entity_type": "machanical property", "pos": [69, 87]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [102, 112]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [123, 130]}, {"entity": "mechanical", "entity_type": "application", "pos": [135, 145]}, {"entity": "research", "entity_type": "concept or principle", "pos": [176, 184]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [207, 211]}, {"entity": "process", "entity_type": "concept or principle", "pos": [212, 219]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [251, 273]}], "task": "NER"}
{"text": "An in-depth understanding of various materials , ideal process setup , in-process parameter control and post processing is essential for achieving such a goal .", "entity": [{"entity": "various materials", "entity_type": "material", "pos": [29, 46]}, {"entity": "process", "entity_type": "concept or principle", "pos": [55, 62]}, {"entity": "parameter", "entity_type": "concept or principle", "pos": [82, 91]}, {"entity": "post processing", "entity_type": "concept or principle", "pos": [104, 119]}], "task": "NER"}
{"text": "After a systematic review and analysis , a quality-based framework aiming to achieve high-quality and defectB-free WAAM process is proposed , as shown in 10 .", "entity": [{"entity": "framework", "entity_type": "concept or principle", "pos": [57, 66]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [115, 119]}, {"entity": "process", "entity_type": "concept or principle", "pos": [120, 127]}, {"entity": "as", "entity_type": "material", "pos": [142, 144]}], "task": "NER"}
{"text": "Three main aspects are considered : feedstock optimization , manufacturing process , and post-process treatment .", "entity": [{"entity": "feedstock optimization", "entity_type": "machine or equipment", "pos": [36, 58]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [61, 82]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [89, 101]}], "task": "NER"}
{"text": "Selection of the most suitable welding WAAM process for the deposition material can ensure manufacturing process stability and contribute to reduction of defects .", "entity": [{"entity": "welding WAAM", "entity_type": "manufacturing process", "pos": [31, 43]}, {"entity": "process", "entity_type": "concept or principle", "pos": [44, 51]}, {"entity": "deposition material", "entity_type": "material", "pos": [60, 79]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [91, 112]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [141, 150]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [154, 161]}], "task": "NER"}
{"text": "For example , if the CMT-PADV process is used for producing aluminum parts , porosity defects can be dramatically reduced when compared to other GMAW modes .", "entity": [{"entity": "CMT-PADV process", "entity_type": "manufacturing process", "pos": [21, 37]}, {"entity": "aluminum", "entity_type": "material", "pos": [60, 68]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [77, 85]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [86, 93]}, {"entity": "be", "entity_type": "material", "pos": [98, 100]}, {"entity": "GMAW", "entity_type": "manufacturing process", "pos": [145, 149]}], "task": "NER"}
{"text": "Moreover , integrated and reliable process monitoring and control systems are needed to maintain the stability of the process and ensure the quality of production .", "entity": [{"entity": "process monitoring", "entity_type": "concept or principle", "pos": [35, 53]}, {"entity": "control systems", "entity_type": "machine or equipment", "pos": [58, 73]}, {"entity": "stability", "entity_type": "machanical property", "pos": [101, 110]}, {"entity": "process", "entity_type": "concept or principle", "pos": [118, 125]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [141, 148]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [152, 162]}], "task": "NER"}
{"text": "Usually , the bead geometry , interpass temperature , arc characteristics and metal transfer behaviour are included in process monitoring and control .", "entity": [{"entity": "bead geometry", "entity_type": "process characterization", "pos": [14, 27]}, {"entity": "interpass temperature", "entity_type": "process parameter", "pos": [30, 51]}, {"entity": "arc", "entity_type": "concept or principle", "pos": [54, 57]}, {"entity": "metal", "entity_type": "material", "pos": [78, 83]}, {"entity": "process monitoring", "entity_type": "concept or principle", "pos": [119, 137]}], "task": "NER"}
{"text": "Controlling the interpass temperature within a reasonable range is beneficial to microstructural evolution and the resulting mechanical properties .", "entity": [{"entity": "interpass temperature", "entity_type": "process parameter", "pos": [16, 37]}, {"entity": "range", "entity_type": "process parameter", "pos": [58, 63]}, {"entity": "microstructural evolution", "entity_type": "concept or principle", "pos": [81, 106]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [125, 146]}], "task": "NER"}
{"text": "Further , regulating the arc characteristics and metal transfer behaviour in real time is helpful to process stability and avoidance of defects .", "entity": [{"entity": "arc", "entity_type": "concept or principle", "pos": [25, 28]}, {"entity": "metal", "entity_type": "material", "pos": [49, 54]}, {"entity": "process", "entity_type": "concept or principle", "pos": [101, 108]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [136, 143]}], "task": "NER"}
{"text": "Based on the process monitoring data that has been collected during deposition , one of several post-process treatments can be selected to mitigate defects and improve mechanical performance .", "entity": [{"entity": "process monitoring", "entity_type": "concept or principle", "pos": [13, 31]}, {"entity": "data", "entity_type": "concept or principle", "pos": [32, 36]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [68, 78]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [96, 108]}, {"entity": "be", "entity_type": "material", "pos": [124, 126]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [148, 155]}, {"entity": "mechanical", "entity_type": "application", "pos": [168, 178]}], "task": "NER"}
{"text": "Considering the material characteristics , microstructural evolution and mechanical properties can also be optimized through new feedstock composition design .", "entity": [{"entity": "material", "entity_type": "material", "pos": [16, 24]}, {"entity": "microstructural evolution", "entity_type": "concept or principle", "pos": [43, 68]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [73, 94]}, {"entity": "be", "entity_type": "material", "pos": [104, 106]}, {"entity": "feedstock", "entity_type": "material", "pos": [129, 138]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [139, 150]}], "task": "NER"}
{"text": "It is well known that different alloying elements have specific effects on material properties .", "entity": [{"entity": "alloying elements", "entity_type": "material", "pos": [32, 49]}, {"entity": "specific effects", "entity_type": "machanical property", "pos": [55, 71]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [75, 94]}], "task": "NER"}
{"text": "By referring to the phase diagram , the desired deposition microstructures can be obtained via adding specific alloying elements in the feedstock and subsequent mechanical properties improved .", "entity": [{"entity": "phase diagram", "entity_type": "concept or principle", "pos": [20, 33]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [48, 58]}, {"entity": "be", "entity_type": "material", "pos": [79, 81]}, {"entity": "alloying elements", "entity_type": "material", "pos": [111, 128]}, {"entity": "feedstock", "entity_type": "material", "pos": [136, 145]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [161, 182]}], "task": "NER"}
{"text": "For example , twin-wire GTAW-based WAAM has been successfully developed to produce intermetallic graded materials .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [35, 39]}, {"entity": "intermetallic", "entity_type": "material", "pos": [83, 96]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [104, 113]}], "task": "NER"}
{"text": "The development of new powder cored wires , will offer exciting opportunities for fabricating target components with accurate metal composition .", "entity": [{"entity": "powder", "entity_type": "material", "pos": [23, 29]}, {"entity": "fabricating", "entity_type": "manufacturing process", "pos": [82, 93]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [101, 111]}, {"entity": "accurate", "entity_type": "process characterization", "pos": [117, 125]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [132, 143]}], "task": "NER"}
{"text": "In summary , using new welding consumables brings a cost effective solution , which supports high deposition quality through obtaining the desired microstructures , lowering manufacturing costs by reducing or eliminating pre-weld cleaning and re-work , and providing safer working environments by reducing weld fumes .", "entity": [{"entity": "welding consumables", "entity_type": "machine or equipment", "pos": [23, 42]}, {"entity": "solution", "entity_type": "concept or principle", "pos": [67, 75]}, {"entity": "supports", "entity_type": "application", "pos": [84, 92]}, {"entity": "deposition quality", "entity_type": "process characterization", "pos": [98, 116]}, {"entity": "microstructures", "entity_type": "material", "pos": [147, 162]}, {"entity": "manufacturing costs", "entity_type": "concept or principle", "pos": [174, 193]}, {"entity": "pre-weld cleaning", "entity_type": "manufacturing process", "pos": [221, 238]}, {"entity": "weld fumes", "entity_type": "process characterization", "pos": [306, 316]}], "task": "NER"}
{"text": "Another essential part of WAAM processing for most materials is post-process treatment , which is used to reduce residual stresses and distortion , refine microstructures , improve microhardness and enhance material strength .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [26, 30]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [51, 60]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [64, 76]}, {"entity": "residual stresses", "entity_type": "machanical property", "pos": [113, 130]}, {"entity": "distortion", "entity_type": "concept or principle", "pos": [135, 145]}, {"entity": "microstructures", "entity_type": "material", "pos": [155, 170]}, {"entity": "microhardness", "entity_type": "concept or principle", "pos": [181, 194]}, {"entity": "material strength", "entity_type": "machanical property", "pos": [207, 224]}], "task": "NER"}
{"text": "However , post-process technologies have their own limitations , for instance , peening and ultrasonic impact treatment only improve material property and reduce defects near the part surface , while extended heat treatment of certain materials promotes grain growth rather than grain refinement .", "entity": [{"entity": "post-process", "entity_type": "concept or principle", "pos": [10, 22]}, {"entity": "peening", "entity_type": "manufacturing process", "pos": [80, 87]}, {"entity": "ultrasonic impact treatment", "entity_type": "process characterization", "pos": [92, 119]}, {"entity": "material property", "entity_type": "concept or principle", "pos": [133, 150]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [162, 169]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [184, 191]}, {"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [209, 223]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [235, 244]}, {"entity": "grain growth", "entity_type": "concept or principle", "pos": [254, 266]}, {"entity": "grain refinement", "entity_type": "process characterization", "pos": [279, 295]}], "task": "NER"}
{"text": "Currently , most WAAM fabricated parts need to be post-process treated with a selective combination of technologies to reduce the defects and improve the product quality to the greatest extent possible .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [17, 21]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [22, 32]}, {"entity": "be", "entity_type": "material", "pos": [47, 49]}, {"entity": "technologies", "entity_type": "concept or principle", "pos": [103, 115]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [130, 137]}, {"entity": "product quality", "entity_type": "concept or principle", "pos": [154, 169]}], "task": "NER"}
{"text": "7 Conclusions A detailed review of recent technological developments in WAAM process has been presented , with a focus on microstructure , mechanical properties , process defects and post-process treatment .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [72, 76]}, {"entity": "process", "entity_type": "concept or principle", "pos": [77, 84]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [122, 136]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [139, 160]}, {"entity": "process defects", "entity_type": "concept or principle", "pos": [163, 178]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [183, 195]}], "task": "NER"}
{"text": "Through matching a knowledge of material characteristics with the performance features of particular WAAM techniques , a quality-based framework is proposed , for producing high-quality and defect-free components .", "entity": [{"entity": "material", "entity_type": "material", "pos": [32, 40]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [66, 77]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [101, 105]}, {"entity": "framework", "entity_type": "concept or principle", "pos": [135, 144]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [202, 212]}], "task": "NER"}
{"text": "In WAAM of metallic materials , the fundamental interrelationships between material composition and microstructure govern the material properties and fabrication quality .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [3, 7]}, {"entity": "metallic materials", "entity_type": "material", "pos": [11, 29]}, {"entity": "material", "entity_type": "material", "pos": [75, 83]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [84, 95]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [100, 114]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [126, 145]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [150, 161]}], "task": "NER"}
{"text": "Since the WAAM process is an inherently non-equilibrium thermal process , it is challenging to predicate and control the microstructural evolution , which is responsible for the variation of mechanical properties in the deposited part .", "entity": [{"entity": "WAAM", "entity_type": "manufacturing process", "pos": [10, 14]}, {"entity": "process", "entity_type": "concept or principle", "pos": [15, 22]}, {"entity": "process", "entity_type": "concept or principle", "pos": [64, 71]}, {"entity": "microstructural evolution", "entity_type": "concept or principle", "pos": [121, 146]}, {"entity": "variation", "entity_type": "concept or principle", "pos": [178, 187]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [191, 212]}], "task": "NER"}
{"text": "Further research attention should be paid on the study of underlying physical and chemical metallurgical mechanisms in WAAM process to provide a guidance for the process optimization , improvement and control .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [8, 16]}, {"entity": "be", "entity_type": "material", "pos": [34, 36]}, {"entity": "metallurgical", "entity_type": "application", "pos": [91, 104]}, {"entity": "WAAM", "entity_type": "manufacturing process", "pos": [119, 123]}, {"entity": "process", "entity_type": "concept or principle", "pos": [124, 131]}, {"entity": "process optimization", "entity_type": "concept or principle", "pos": [162, 182]}], "task": "NER"}
{"text": "The defects generated in WAAM-produced part are closely related to the target material characteristics and process parameters .", "entity": [{"entity": "defects", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "material", "entity_type": "material", "pos": [78, 86]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [107, 125]}], "task": "NER"}
{"text": "The development of strategies or ancillary process to overcome defects generation are of prime importance .", "entity": [{"entity": "ancillary process", "entity_type": "concept or principle", "pos": [33, 50]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [63, 70]}], "task": "NER"}
{"text": "As WAAM matures as a commercial manufacturing process , development of a commercially available WAAM system for metal components is an interdisciplinary challenge , which integrates physical welding process development , materials science and thermo-mechanical engineering , and mechatronic and control system design This study presents a review on powder bed laser additive manufacturing of stainless steel .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "as", "entity_type": "material", "pos": [16, 18]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [32, 53]}, {"entity": "WAAM system", "entity_type": "machine or equipment", "pos": [96, 107]}, {"entity": "metal", "entity_type": "material", "pos": [112, 117]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [118, 128]}, {"entity": "welding", "entity_type": "manufacturing process", "pos": [191, 198]}, {"entity": "process", "entity_type": "concept or principle", "pos": [199, 206]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [221, 230]}, {"entity": "thermo-mechanical", "entity_type": "concept or principle", "pos": [243, 260]}, {"entity": "engineering", "entity_type": "application", "pos": [261, 272]}, {"entity": "control system", "entity_type": "machine or equipment", "pos": [295, 309]}, {"entity": "powder bed laser additive manufacturing", "entity_type": "manufacturing process", "pos": [349, 388]}, {"entity": "stainless steel", "entity_type": "material", "pos": [392, 407]}], "task": "NER"}
{"text": "The powder bed laser additive manufacturing processes that are presented in this paper are the selective laser sintering and selective laser melting .", "entity": [{"entity": "powder bed laser additive manufacturing", "entity_type": "manufacturing process", "pos": [4, 43]}, {"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [95, 120]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [125, 148]}], "task": "NER"}
{"text": "The powder bed laser additive manufacturing process of stainless steel are reviewed in this paper .", "entity": [{"entity": "powder bed laser additive manufacturing", "entity_type": "manufacturing process", "pos": [4, 43]}, {"entity": "stainless steel", "entity_type": "material", "pos": [55, 70]}], "task": "NER"}
{"text": "The process parameters was found to plat an important role in the evolving properties of the powder bed based laser additive manufacturing process .", "entity": [{"entity": "process parameters", "entity_type": "concept or principle", "pos": [4, 22]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [75, 85]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [93, 103]}, {"entity": "laser additive manufacturing", "entity_type": "manufacturing process", "pos": [110, 138]}], "task": "NER"}
{"text": "Selection and/or Peer-review under responsibility of Materials Processing and characterization .", "entity": [{"entity": "Materials Processing", "entity_type": "process characterization", "pos": [53, 73]}], "task": "NER"}
{"text": "Steels are important engineering material invented by mankind because of their extreme multiplicity in operties .", "entity": [{"entity": "Steels", "entity_type": "material", "pos": [0, 6]}, {"entity": "engineering material", "entity_type": "material", "pos": [21, 41]}], "task": "NER"}
{"text": "Stainless steel originated from steel as a result of the addition of chromium .", "entity": [{"entity": "Stainless steel", "entity_type": "material", "pos": [0, 15]}, {"entity": "steel", "entity_type": "material", "pos": [32, 37]}, {"entity": "as", "entity_type": "material", "pos": [38, 40]}, {"entity": "chromium", "entity_type": "material", "pos": [69, 77]}], "task": "NER"}
{"text": "The percentage composition the chromium is sufficient enough to prevent rusting in corrosive environment .", "entity": [{"entity": "composition", "entity_type": "concept or principle", "pos": [15, 26]}, {"entity": "chromium", "entity_type": "material", "pos": [31, 39]}, {"entity": "corrosive", "entity_type": "machanical property", "pos": [83, 92]}], "task": "NER"}
{"text": "Different grades of stainless stee ludes , Martensitic stainless steel , Ferritic stainless steel , Austenitic stainless steel , superferritic stainless steel plex stainless steel , precipitation hardening stainless steel and super austenitic stainless steel .", "entity": [{"entity": "Martensitic stainless steel", "entity_type": "material", "pos": [43, 70]}, {"entity": "Ferritic stainless steel", "entity_type": "material", "pos": [73, 97]}, {"entity": "Austenitic stainless steel", "entity_type": "material", "pos": [100, 126]}, {"entity": "superferritic stainless steel", "entity_type": "material", "pos": [129, 158]}, {"entity": "stainless steel", "entity_type": "material", "pos": [164, 179]}, {"entity": "precipitation hardening", "entity_type": "manufacturing process", "pos": [182, 205]}, {"entity": "steel", "entity_type": "material", "pos": [216, 221]}, {"entity": "austenitic stainless steel", "entity_type": "material", "pos": [232, 258]}], "task": "NER"}
{"text": "ection and/or Peer-review under responsibility of Materials Processing and characterization .", "entity": [{"entity": "Materials Processing", "entity_type": "process characterization", "pos": [50, 70]}], "task": "NER"}
{"text": "Asides from its high corrosion resistance property , stainless steel are malleable enough to be bent , folded , welded , machined and deep drawn , they also have a high heat conductivity and high strength .", "entity": [{"entity": "corrosion resistance", "entity_type": "concept or principle", "pos": [21, 41]}, {"entity": "stainless steel", "entity_type": "material", "pos": [53, 68]}, {"entity": "be", "entity_type": "material", "pos": [93, 95]}, {"entity": "welded", "entity_type": "manufacturing process", "pos": [112, 118]}, {"entity": "machined", "entity_type": "manufacturing process", "pos": [121, 129]}, {"entity": "heat conductivity", "entity_type": "machanical property", "pos": [169, 186]}, {"entity": "strength", "entity_type": "machanical property", "pos": [196, 204]}], "task": "NER"}
{"text": "Stainless steels find extensive applications that include : chemical equipments , food processing equipments , cryogenic vessels , X-ray tube bases , heat exchangers , cutleries , jet-engine parts , automotive fasteners , valves , brewing equipments , and aircraft fittings .", "entity": [{"entity": "Stainless steels", "entity_type": "material", "pos": [0, 16]}, {"entity": "cryogenic vessels", "entity_type": "machanical property", "pos": [111, 128]}, {"entity": "X-ray tube", "entity_type": "machine or equipment", "pos": [131, 141]}, {"entity": "heat exchangers", "entity_type": "machine or equipment", "pos": [150, 165]}, {"entity": "automotive", "entity_type": "application", "pos": [199, 209]}, {"entity": "brewing equipments", "entity_type": "machine or equipment", "pos": [231, 249]}], "task": "NER"}
{"text": "Methods of fabrication of stainless steel include hot forming processes and cold forming processes .", "entity": [{"entity": "fabrication", "entity_type": "manufacturing process", "pos": [11, 22]}, {"entity": "stainless steel", "entity_type": "material", "pos": [26, 41]}, {"entity": "hot forming processes", "entity_type": "manufacturing process", "pos": [50, 71]}, {"entity": "cold forming processes", "entity_type": "manufacturing process", "pos": [76, 98]}], "task": "NER"}
{"text": "Complex parts are broken down into smaller parts when these conventional manufacturing processes are used .", "entity": [{"entity": "conventional manufacturing", "entity_type": "manufacturing process", "pos": [60, 86]}], "task": "NER"}
{"text": "These does not only make the process to be cumbersome but also heavier because of extra materials that are used in joining the several parts together .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [29, 36]}, {"entity": "be", "entity_type": "material", "pos": [40, 42]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [88, 97]}, {"entity": "joining", "entity_type": "manufacturing process", "pos": [115, 122]}], "task": "NER"}
{"text": "Additive manufacturing processes is an advanced manufacturing process that can produce complex parts no matter the complexity as a single unit part .", "entity": [{"entity": "Additive manufacturing processes", "entity_type": "manufacturing process", "pos": [0, 32]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [48, 69]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [115, 125]}, {"entity": "as", "entity_type": "material", "pos": [126, 128]}], "task": "NER"}
{"text": "Additive manufacturing is a modern method of fabrication process which is used in producing a functional engineering metallic components one layer at a time from computer aided design model data .", "entity": [{"entity": "Additive manufacturing", "entity_type": "manufacturing process", "pos": [0, 22]}, {"entity": "fabrication", "entity_type": "manufacturing process", "pos": [45, 56]}, {"entity": "engineering", "entity_type": "application", "pos": [105, 116]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [126, 136]}, {"entity": "layer", "entity_type": "process parameter", "pos": [141, 146]}, {"entity": "computer aided design", "entity_type": "enabling technology", "pos": [162, 183]}, {"entity": "data", "entity_type": "concept or principle", "pos": [190, 194]}], "task": "NER"}
{"text": "There are various types of additive manufacturing technology , which include : vat photopolymerization , fused deposition modelling , selective laser sintering/melting , laminated object manufacturing and Laser metal deposition that is also referred to as .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [27, 49]}, {"entity": "vat photopolymerization", "entity_type": "manufacturing process", "pos": [79, 102]}, {"entity": "fused deposition", "entity_type": "concept or principle", "pos": [105, 121]}, {"entity": "selective laser", "entity_type": "manufacturing process", "pos": [134, 149]}, {"entity": "laminated object manufacturing", "entity_type": "manufacturing process", "pos": [170, 200]}, {"entity": "Laser metal deposition", "entity_type": "manufacturing process", "pos": [205, 227]}, {"entity": "as", "entity_type": "material", "pos": [253, 255]}], "task": "NER"}
{"text": "Vat photopolymerization is the first commercial additive manufacturing method that is used to create a layer of solidified material using ultraviolet radiation to selectively polymerize a curable resin until a complete part is formed .", "entity": [{"entity": "Vat photopolymerization", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [48, 70]}, {"entity": "layer", "entity_type": "process parameter", "pos": [103, 108]}, {"entity": "material", "entity_type": "material", "pos": [123, 131]}, {"entity": "ultraviolet radiation", "entity_type": "concept or principle", "pos": [138, 159]}, {"entity": "curable resin", "entity_type": "material", "pos": [188, 201]}], "task": "NER"}
{"text": "Its advantages includes high building speed and flexibility .", "entity": [{"entity": "flexibility", "entity_type": "machanical property", "pos": [48, 59]}], "task": "NER"}
{"text": "Major disadvantages are high cost of materials and process errors due to over curing .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [37, 46]}, {"entity": "process errors", "entity_type": "concept or principle", "pos": [51, 65]}, {"entity": "curing", "entity_type": "manufacturing process", "pos": [78, 84]}], "task": "NER"}
{"text": "Fused deposition modelling additive manufacturing is also referred to as material extrusion process , this process is used for fabricating 3D parts by deposition of laser heated thermoplastic filaments in a layer wise manner .", "entity": [{"entity": "Fused deposition", "entity_type": "concept or principle", "pos": [0, 16]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [27, 49]}, {"entity": "as", "entity_type": "material", "pos": [70, 72]}, {"entity": "extrusion process", "entity_type": "manufacturing process", "pos": [82, 99]}, {"entity": "process", "entity_type": "concept or principle", "pos": [107, 114]}, {"entity": "fabricating", "entity_type": "manufacturing process", "pos": [127, 138]}, {"entity": "3D parts", "entity_type": "application", "pos": [139, 147]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [151, 161]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [165, 170]}, {"entity": "thermoplastic filaments", "entity_type": "material", "pos": [178, 201]}, {"entity": "layer", "entity_type": "process parameter", "pos": [207, 212]}], "task": "NER"}
{"text": "With this method , complex durable parts can be easily manufactured with high accuracy .", "entity": [{"entity": "be", "entity_type": "material", "pos": [45, 47]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [55, 67]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [78, 86]}], "task": "NER"}
{"text": "Draw-backs of this additive manufacturing technology include poor surface finish , time consumption and high porosity of manufactured parts .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [19, 41]}, {"entity": "surface finish", "entity_type": "engineering feature", "pos": [66, 80]}, {"entity": "porosity of manufactured parts", "entity_type": "machanical property", "pos": [109, 139]}], "task": "NER"}
{"text": "This method has been applied in automotive , aerospace , medical and plastic industries .", "entity": [{"entity": "automotive", "entity_type": "application", "pos": [32, 42]}, {"entity": "aerospace", "entity_type": "application", "pos": [45, 54]}, {"entity": "medical", "entity_type": "application", "pos": [57, 64]}, {"entity": "plastic industries", "entity_type": "application", "pos": [69, 87]}], "task": "NER"}
{"text": "Selective laser sintering/malting is a powder bed additive manufacturing method that involves atomic fusion/melting of metallic powder deposited in form of layers .", "entity": [{"entity": "Selective laser", "entity_type": "manufacturing process", "pos": [0, 15]}, {"entity": "powder bed additive manufacturing", "entity_type": "manufacturing process", "pos": [39, 72]}, {"entity": "metallic powder", "entity_type": "material", "pos": [119, 134]}], "task": "NER"}
{"text": "Parts can be easily processed within a short time frame , it is flexible and accurate .", "entity": [{"entity": "be", "entity_type": "material", "pos": [10, 12]}, {"entity": "processed", "entity_type": "concept or principle", "pos": [20, 29]}, {"entity": "accurate", "entity_type": "process characterization", "pos": [77, 85]}], "task": "NER"}
{"text": "This additive manufacturing method has been mostly used with metals such as stainless steel 316L austenitic grade , precipitated hardened stainless steel .", "entity": [{"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [5, 27]}, {"entity": "metals", "entity_type": "material", "pos": [61, 67]}, {"entity": "as", "entity_type": "material", "pos": [73, 75]}, {"entity": "steel", "entity_type": "material", "pos": [86, 91]}, {"entity": "austenitic", "entity_type": "material", "pos": [97, 107]}, {"entity": "precipitated hardened", "entity_type": "machanical property", "pos": [116, 137]}, {"entity": "steel", "entity_type": "material", "pos": [148, 153]}], "task": "NER"}
{"text": "Selective laser sintering has an extensive application in the field of aerospace , medical and automotive engineering due to the ability to control the stiffness of components in a desired model .", "entity": [{"entity": "Selective laser sintering", "entity_type": "manufacturing process", "pos": [0, 25]}, {"entity": "aerospace", "entity_type": "application", "pos": [71, 80]}, {"entity": "medical", "entity_type": "application", "pos": [83, 90]}, {"entity": "automotive", "entity_type": "application", "pos": [95, 105]}, {"entity": "stiffness", "entity_type": "machanical property", "pos": [152, 161]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [165, 175]}, {"entity": "model", "entity_type": "concept or principle", "pos": [189, 194]}], "task": "NER"}
{"text": "Selective laser melting is a powder based bed fusion that is used to produce metallic components by deposition of a thin metallic powder on a substrate and using a high intensity laser beam to melt and fuse selective region of metallic powder according to the computer aided design data in a layer-wise fashion .", "entity": [{"entity": "Selective laser melting", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "powder", "entity_type": "material", "pos": [29, 35]}, {"entity": "bed fusion", "entity_type": "manufacturing process", "pos": [42, 52]}, {"entity": "metallic", "entity_type": "material", "pos": [77, 85]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [86, 96]}, {"entity": "deposition", "entity_type": "concept or principle", "pos": [100, 110]}, {"entity": "thin metallic powder", "entity_type": "material", "pos": [116, 136]}, {"entity": "substrate", "entity_type": "material", "pos": [142, 151]}, {"entity": "intensity laser beam", "entity_type": "machine or equipment", "pos": [169, 189]}, {"entity": "melt", "entity_type": "concept or principle", "pos": [193, 197]}, {"entity": "fuse", "entity_type": "manufacturing process", "pos": [202, 206]}, {"entity": "metallic powder", "entity_type": "material", "pos": [227, 242]}, {"entity": "computer aided design", "entity_type": "enabling technology", "pos": [260, 281]}, {"entity": "fashion", "entity_type": "concept or principle", "pos": [303, 310]}], "task": "NER"}
{"text": "This method has an advantage of less porosity of built parts with better mechanical property , manufacturability of complex shapes and excellent scanning efficiency .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [37, 45]}, {"entity": "mechanical property", "entity_type": "concept or principle", "pos": [73, 92]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [95, 112]}, {"entity": "complex shapes", "entity_type": "machanical property", "pos": [116, 130]}, {"entity": "scanning efficiency", "entity_type": "process characterization", "pos": [145, 164]}], "task": "NER"}
{"text": "The disadvantage is similar to that of the process discuss earlier in terms of process control challenge due to too many parameters and also there is a material wastage .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [43, 50]}, {"entity": "process control", "entity_type": "concept or principle", "pos": [79, 94]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [121, 131]}, {"entity": "material", "entity_type": "material", "pos": [152, 160]}], "task": "NER"}
{"text": "Selective laser melting has been extensively used with the employment of stainless steel .", "entity": [{"entity": "Selective laser melting", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "stainless steel", "entity_type": "material", "pos": [73, 88]}], "task": "NER"}
{"text": "Selective laser melting has an extensive application in the field of aerospace , medical , automotive engineering and medical health care sectors .", "entity": [{"entity": "Selective laser melting", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "aerospace", "entity_type": "application", "pos": [69, 78]}, {"entity": "medical", "entity_type": "application", "pos": [81, 88]}, {"entity": "automotive", "entity_type": "application", "pos": [91, 101]}, {"entity": "medical", "entity_type": "application", "pos": [118, 125]}], "task": "NER"}
{"text": "Benefits of this methods include good efficiency of material usage , parts with complicated shapes can be built , high strength material can be achieved , materials can be customized , it takes less time and it eliminated oxide impurities due to vacuum environment .", "entity": [{"entity": "material", "entity_type": "material", "pos": [52, 60]}, {"entity": "be", "entity_type": "material", "pos": [103, 105]}, {"entity": "strength", "entity_type": "machanical property", "pos": [119, 127]}, {"entity": "material", "entity_type": "material", "pos": [128, 136]}, {"entity": "be", "entity_type": "material", "pos": [141, 143]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [155, 164]}, {"entity": "be", "entity_type": "material", "pos": [169, 171]}, {"entity": "oxide impurities", "entity_type": "machanical property", "pos": [222, 238]}], "task": "NER"}
{"text": "Disadvantages of this methods are high price of set-up due to integration of vacuum with the machine for good thermal and impurity free environment , X-rays are formed during the process which is detrimental to human health .", "entity": [{"entity": "machine", "entity_type": "machine or equipment", "pos": [93, 100]}, {"entity": "impurity", "entity_type": "machanical property", "pos": [122, 130]}, {"entity": "X-rays", "entity_type": "concept or principle", "pos": [150, 156]}, {"entity": "process", "entity_type": "concept or principle", "pos": [179, 186]}], "task": "NER"}
{"text": "Laminated object additive manufacturing is an additive-subtractive rapid prototyping manufacturing process where 3D objects are manufactured by metal sheet material that are bonded together by thermally activated adhesive coating layer by layer .", "entity": [{"entity": "Laminated object additive manufacturing", "entity_type": "manufacturing process", "pos": [0, 39]}, {"entity": "rapid prototyping", "entity_type": "enabling technology", "pos": [67, 84]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [85, 106]}, {"entity": "3D objects", "entity_type": "application", "pos": [113, 123]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [128, 140]}, {"entity": "metal", "entity_type": "material", "pos": [144, 149]}, {"entity": "material", "entity_type": "material", "pos": [156, 164]}, {"entity": "thermally activated", "entity_type": "manufacturing process", "pos": [193, 212]}, {"entity": "adhesive", "entity_type": "material", "pos": [213, 221]}, {"entity": "layer by layer", "entity_type": "concept or principle", "pos": [230, 244]}], "task": "NER"}
{"text": "Each layer is formed from a sheet of paper coated with a thermoplastic adhesive and sheet is bonded together by using a heated stainless steel roller after which a CO2 laser cuts crosB-section into a layer of paper according to the information from the CAD model repeatedly until the required object is formed and lamination is actualized .", "entity": [{"entity": "layer", "entity_type": "process parameter", "pos": [5, 10]}, {"entity": "sheet", "entity_type": "material", "pos": [28, 33]}, {"entity": "coated", "entity_type": "application", "pos": [43, 49]}, {"entity": "thermoplastic adhesive", "entity_type": "material", "pos": [57, 79]}, {"entity": "sheet", "entity_type": "material", "pos": [84, 89]}, {"entity": "stainless steel", "entity_type": "material", "pos": [127, 142]}, {"entity": "roller", "entity_type": "machine or equipment", "pos": [143, 149]}, {"entity": "CO2", "entity_type": "material", "pos": [164, 167]}, {"entity": "layer", "entity_type": "process parameter", "pos": [200, 205]}, {"entity": "CAD model", "entity_type": "enabling technology", "pos": [253, 262]}], "task": "NER"}
{"text": "The process is simple and faster since the laser doesnhave to scan the entire area of the cross section .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [15, 21]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [43, 48]}, {"entity": "area", "entity_type": "process parameter", "pos": [78, 82]}, {"entity": "cross section", "entity_type": "concept or principle", "pos": [90, 103]}], "task": "NER"}
{"text": "Merits of this method includes that fact that large size parts can be built , it is cheap , no microstructural alteration during the process , and it is flexible in the sense that component does not need support structures .", "entity": [{"entity": "be", "entity_type": "material", "pos": [67, 69]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [95, 110]}, {"entity": "process", "entity_type": "concept or principle", "pos": [133, 140]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [180, 189]}, {"entity": "support structures", "entity_type": "engineering feature", "pos": [204, 222]}], "task": "NER"}
{"text": "Setbacks of this methods includes wastage of material during the subtractive process , complex internal cavities and hollow parts are difficult to build , and it has poor surface finishing .", "entity": [{"entity": "material", "entity_type": "material", "pos": [45, 53]}, {"entity": "subtractive process", "entity_type": "manufacturing process", "pos": [65, 84]}, {"entity": "build", "entity_type": "process parameter", "pos": [147, 152]}, {"entity": "surface finishing", "entity_type": "manufacturing process", "pos": [171, 188]}], "task": "NER"}
{"text": "Laminated object manufacturing has been demonstrated in aerospace and tool design industries .", "entity": [{"entity": "Laminated object manufacturing", "entity_type": "manufacturing process", "pos": [0, 30]}, {"entity": "aerospace", "entity_type": "application", "pos": [56, 65]}, {"entity": "tool design industries", "entity_type": "application", "pos": [70, 92]}], "task": "NER"}
{"text": "Laser Metal Deposition , an additive manufacturing process , is used in building parts by melting a metal powder that is injected into a specific location by mean of a high power laser beam .", "entity": [{"entity": "Laser Metal Deposition", "entity_type": "manufacturing process", "pos": [0, 22]}, {"entity": "additive manufacturing process", "entity_type": "manufacturing process", "pos": [28, 58]}, {"entity": "melting", "entity_type": "manufacturing process", "pos": [90, 97]}, {"entity": "metal powder", "entity_type": "material", "pos": [100, 112]}, {"entity": "high power laser beam", "entity_type": "machanical property", "pos": [168, 189]}], "task": "NER"}
{"text": "The process of solidification and cooling occur in a closed chamber in an argon atmosphere so as to prevent oxidation of the melt pool .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [15, 29]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [34, 41]}, {"entity": "closed chamber", "entity_type": "machine or equipment", "pos": [53, 67]}, {"entity": "argon atmosphere", "entity_type": "process parameter", "pos": [74, 90]}, {"entity": "as", "entity_type": "material", "pos": [94, 96]}, {"entity": "oxidation", "entity_type": "manufacturing process", "pos": [108, 117]}, {"entity": "melt pool", "entity_type": "material", "pos": [125, 134]}], "task": "NER"}
{"text": "This process permits the use of high variety of metals and composites such as stainless steel mostly austenitic grades , which are mainly 316 , SS 316L , SS 304L and other exotic metals such as titanium and its alloys , composites and functionally graded materials .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "metals", "entity_type": "material", "pos": [48, 54]}, {"entity": "composites", "entity_type": "material", "pos": [59, 69]}, {"entity": "as", "entity_type": "material", "pos": [75, 77]}, {"entity": "steel", "entity_type": "material", "pos": [88, 93]}, {"entity": "austenitic", "entity_type": "material", "pos": [101, 111]}, {"entity": "SS", "entity_type": "material", "pos": [144, 146]}, {"entity": "SS", "entity_type": "material", "pos": [154, 156]}, {"entity": "metals", "entity_type": "material", "pos": [179, 185]}, {"entity": "as", "entity_type": "material", "pos": [191, 193]}, {"entity": "alloys", "entity_type": "material", "pos": [211, 217]}, {"entity": "composites", "entity_type": "material", "pos": [220, 230]}, {"entity": "functionally graded materials", "entity_type": "material", "pos": [235, 264]}], "task": "NER"}
{"text": "A major benefit of laser additive manufacturing technology is that , it provide new chances for customization of metallic components in terms of material composition manipulation and properties , improvements in product performance , and lower overall manufacturing costs due to its unique capabilities .", "entity": [{"entity": "laser additive manufacturing", "entity_type": "manufacturing process", "pos": [19, 47]}, {"entity": "metallic", "entity_type": "material", "pos": [113, 121]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [122, 132]}, {"entity": "material", "entity_type": "material", "pos": [145, 153]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [154, 165]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [183, 193]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [220, 231]}, {"entity": "manufacturing costs", "entity_type": "concept or principle", "pos": [252, 271]}], "task": "NER"}
{"text": "Lots of research and discoveries has been achieved with laser metal deposition as an additive manufacturing method with the employment of stainless steel and stainless steel composite with much effort in enhancing wear resistance and strength property .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [8, 16]}, {"entity": "laser metal deposition", "entity_type": "manufacturing process", "pos": [56, 78]}, {"entity": "as", "entity_type": "material", "pos": [79, 81]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [85, 107]}, {"entity": "stainless steel", "entity_type": "material", "pos": [138, 153]}, {"entity": "stainless steel", "entity_type": "material", "pos": [158, 173]}, {"entity": "composite", "entity_type": "material", "pos": [174, 183]}, {"entity": "wear resistance", "entity_type": "machanical property", "pos": [214, 229]}, {"entity": "strength property", "entity_type": "machanical property", "pos": [234, 251]}], "task": "NER"}
{"text": "This paper presents an overview of selective laser sintering and selective laser melting process of stainless steel .", "entity": [{"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [35, 60]}, {"entity": "selective laser melting process", "entity_type": "manufacturing process", "pos": [65, 96]}, {"entity": "stainless steel", "entity_type": "material", "pos": [100, 115]}], "task": "NER"}
{"text": "Some recent research works on stainless steel using these powder bed additive manufacturing techniques are presented and future research need are also proposed .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [12, 20]}, {"entity": "stainless steel", "entity_type": "material", "pos": [30, 45]}, {"entity": "powder bed additive manufacturing", "entity_type": "manufacturing process", "pos": [58, 91]}, {"entity": "research", "entity_type": "concept or principle", "pos": [128, 136]}], "task": "NER"}
{"text": "Selective Laser Sintering of Stainless Steel This additive manufacturing process is a powder based layer-additive manufacturing process where metallic components are built section by section .", "entity": [{"entity": "Selective Laser Sintering", "entity_type": "manufacturing process", "pos": [0, 25]}, {"entity": "Stainless Steel", "entity_type": "material", "pos": [29, 44]}, {"entity": "additive manufacturing process", "entity_type": "manufacturing process", "pos": [50, 80]}, {"entity": "powder", "entity_type": "material", "pos": [86, 92]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [114, 135]}, {"entity": "metallic", "entity_type": "material", "pos": [142, 150]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [151, 161]}], "task": "NER"}
{"text": "A moderately low laser power is used in this process as metallic material never reach a liquid phase during the heating process .", "entity": [{"entity": "laser power", "entity_type": "process parameter", "pos": [17, 28]}, {"entity": "process", "entity_type": "concept or principle", "pos": [45, 52]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}, {"entity": "material", "entity_type": "material", "pos": [65, 73]}, {"entity": "liquid phase", "entity_type": "machanical property", "pos": [88, 100]}, {"entity": "heating", "entity_type": "manufacturing process", "pos": [112, 119]}], "task": "NER"}
{"text": "The process occurs at a faster rate at high temperature which is why it involves heating a powder .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [44, 55]}, {"entity": "heating", "entity_type": "manufacturing process", "pos": [81, 88]}, {"entity": "powder", "entity_type": "material", "pos": [91, 97]}], "task": "NER"}
{"text": "The process is achieved when the laser scan powder material deposited on the substrate on the 2D crosB-section of the part created in 3D geometrical shape .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "laser scan", "entity_type": "enabling technology", "pos": [33, 43]}, {"entity": "material", "entity_type": "material", "pos": [51, 59]}, {"entity": "substrate", "entity_type": "material", "pos": [77, 86]}, {"entity": "2D crosB-section", "entity_type": "engineering feature", "pos": [94, 110]}, {"entity": "3D geometrical shape", "entity_type": "engineering feature", "pos": [134, 154]}], "task": "NER"}
{"text": "The process is repeated in which after the first laser scan , the powder bed is lowered by the amount of thickness of the layer produced initially , and then a new layer of powder material is spread on the powder bed again on top of the initial scanned layer until a fully dense built part is produced .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "laser scan", "entity_type": "enabling technology", "pos": [49, 59]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [66, 76]}, {"entity": "layer", "entity_type": "process parameter", "pos": [122, 127]}, {"entity": "layer", "entity_type": "process parameter", "pos": [164, 169]}, {"entity": "powder material", "entity_type": "material", "pos": [173, 188]}, {"entity": "spread", "entity_type": "concept or principle", "pos": [192, 198]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [206, 216]}, {"entity": "layer", "entity_type": "process parameter", "pos": [253, 258]}, {"entity": "fully dense", "entity_type": "process parameter", "pos": [267, 278]}], "task": "NER"}
{"text": "Selective laser sintering process has the potential to become one of the most valuable additive manufacturing techniques , because it has potential to easily produced complex shapes .", "entity": [{"entity": "Selective laser sintering process", "entity_type": "manufacturing process", "pos": [0, 33]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [87, 109]}, {"entity": "complex shapes", "entity_type": "machanical property", "pos": [167, 181]}], "task": "NER"}
{"text": "The Figure 1 shows the schematic diagram of the SLS process .", "entity": [{"entity": "SLS process", "entity_type": "manufacturing process", "pos": [48, 59]}], "task": "NER"}
{"text": "Schematic diagram of selective laser sintering process .", "entity": [{"entity": "selective laser sintering process", "entity_type": "manufacturing process", "pos": [21, 54]}], "task": "NER"}
{"text": "Few research investigations and studies have been done in the application of selective laser sintering with stainless steels .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [4, 12]}, {"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [77, 102]}, {"entity": "stainless steels", "entity_type": "material", "pos": [108, 124]}], "task": "NER"}
{"text": "Stainless steel grades that has been involved in this process are the austenitic type mainly SS 316L and the precipitated hardened stainless steel grade PH .", "entity": [{"entity": "Stainless steel", "entity_type": "material", "pos": [0, 15]}, {"entity": "process", "entity_type": "concept or principle", "pos": [54, 61]}, {"entity": "austenitic", "entity_type": "material", "pos": [70, 80]}, {"entity": "SS", "entity_type": "material", "pos": [93, 95]}, {"entity": "precipitated hardened", "entity_type": "machanical property", "pos": [109, 130]}, {"entity": "steel", "entity_type": "material", "pos": [141, 146]}, {"entity": "PH", "entity_type": "concept or principle", "pos": [153, 155]}], "task": "NER"}
{"text": "Ibrahim studied the fabrication of a novel porous electrode scaffold made from stainless steel 316L powder using selective laser sintering by careful selection of process parameters and also how the property such as porosity , electrical conductivity and optical microscopy measurements were used to investigate the properties of the fabricated sample .", "entity": [{"entity": "fabrication", "entity_type": "manufacturing process", "pos": [20, 31]}, {"entity": "porous electrode scaffold", "entity_type": "engineering feature", "pos": [43, 68]}, {"entity": "stainless steel", "entity_type": "material", "pos": [79, 94]}, {"entity": "powder", "entity_type": "material", "pos": [100, 106]}, {"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [113, 138]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [163, 181]}, {"entity": "property", "entity_type": "concept or principle", "pos": [199, 207]}, {"entity": "as", "entity_type": "material", "pos": [213, 215]}, {"entity": "electrical conductivity", "entity_type": "machanical property", "pos": [227, 250]}, {"entity": "optical microscopy", "entity_type": "process characterization", "pos": [255, 273]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [316, 326]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [334, 344]}], "task": "NER"}
{"text": "In this investigation stainless steel , SS316L with particle size of 25 to 50 micro-meter were built with 30 W laser power and 1500 mm/s scanning speed .", "entity": [{"entity": "stainless steel", "entity_type": "material", "pos": [22, 37]}, {"entity": "particle", "entity_type": "concept or principle", "pos": [52, 60]}, {"entity": "laser power", "entity_type": "process parameter", "pos": [111, 122]}, {"entity": "scanning speed", "entity_type": "process parameter", "pos": [137, 151]}], "task": "NER"}
{"text": "Density and porosity properties were investigated and it was discovered that high porosity metal parts can be produced by using a low laser power and high scan speed .", "entity": [{"entity": "Density and porosity", "entity_type": "engineering feature", "pos": [0, 20]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [82, 90]}, {"entity": "metal", "entity_type": "material", "pos": [91, 96]}, {"entity": "be", "entity_type": "material", "pos": [107, 109]}, {"entity": "laser power", "entity_type": "process parameter", "pos": [134, 145]}, {"entity": "scan speed", "entity_type": "process parameter", "pos": [155, 165]}], "task": "NER"}
{"text": "This study also revealed the feasibility of producing porous metal sintered parts for electrochemical devices using the right processing parameters .", "entity": [{"entity": "feasibility", "entity_type": "concept or principle", "pos": [29, 40]}, {"entity": "porous metal", "entity_type": "material", "pos": [54, 66]}, {"entity": "electrochemical devices", "entity_type": "machine or equipment", "pos": [86, 109]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [137, 147]}], "task": "NER"}
{"text": "Xie studied the mechanical and structural characteristics of porous 316L stainless steel fabricated by indirect laser sintering .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [16, 26]}, {"entity": "porous", "entity_type": "machanical property", "pos": [61, 67]}, {"entity": "316L stainless steel", "entity_type": "material", "pos": [68, 88]}, {"entity": "laser sintering", "entity_type": "manufacturing process", "pos": [112, 127]}], "task": "NER"}
{"text": "In this investigation , a simple encapsulated method was developed to coat 316L SS powder fabricated by indirect SLS process , with ethylene-vinyl acetate copolymer resin .", "entity": [{"entity": "simple", "entity_type": "manufacturing process", "pos": [26, 32]}, {"entity": "encapsulated", "entity_type": "concept or principle", "pos": [33, 45]}, {"entity": "316L SS powder", "entity_type": "material", "pos": [75, 89]}, {"entity": "SLS process", "entity_type": "manufacturing process", "pos": [113, 124]}, {"entity": "ethylene-vinyl acetate copolymer resin", "entity_type": "machanical property", "pos": [132, 170]}], "task": "NER"}
{"text": "In this experiment , a water atomized 316L stainless steel powder with particle size of 45 micro-meter and ethylene-vinyl acetate copolymer resin were used to encapsulate the stainless steel metallic particle together .", "entity": [{"entity": "experiment", "entity_type": "concept or principle", "pos": [8, 18]}, {"entity": "water atomized", "entity_type": "manufacturing process", "pos": [23, 37]}, {"entity": "316L stainless steel powder", "entity_type": "material", "pos": [38, 65]}, {"entity": "particle", "entity_type": "concept or principle", "pos": [71, 79]}, {"entity": "ethylene-vinyl acetate copolymer resin", "entity_type": "machanical property", "pos": [107, 145]}, {"entity": "stainless steel", "entity_type": "material", "pos": [175, 190]}, {"entity": "metallic", "entity_type": "material", "pos": [191, 199]}], "task": "NER"}
{"text": "The selective laser sintering method was performed in a pure argon environment on a WYS600 SLS equipment with powder bed temperature 5 0 C below the melting temperature of ethylene-vinyl acetate copolymer resin .", "entity": [{"entity": "selective laser sintering", "entity_type": "manufacturing process", "pos": [4, 29]}, {"entity": "pure argon", "entity_type": "material", "pos": [56, 66]}, {"entity": "SLS", "entity_type": "manufacturing process", "pos": [91, 94]}, {"entity": "equipment", "entity_type": "machine or equipment", "pos": [95, 104]}, {"entity": "powder bed", "entity_type": "machine or equipment", "pos": [110, 120]}, {"entity": "C", "entity_type": "material", "pos": [137, 138]}, {"entity": "melting temperature", "entity_type": "process parameter", "pos": [149, 168]}, {"entity": "ethylene-vinyl acetate copolymer resin", "entity_type": "machanical property", "pos": [172, 210]}], "task": "NER"}
{"text": "The processing parameters employed were scan spacing of 0.10 , 0.15 and 0.20 mm , laser power ranges between 10 and 35 W at interval of 5 W , scanning speed was set between 1000 and 2000 mm/s at difference of 200 mm/s and layer thickness was set at 0.15 mm .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [15, 25]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [77, 79]}, {"entity": "laser power", "entity_type": "process parameter", "pos": [82, 93]}, {"entity": "scanning speed", "entity_type": "process parameter", "pos": [142, 156]}, {"entity": "set", "entity_type": "application", "pos": [161, 164]}, {"entity": "layer thickness", "entity_type": "process parameter", "pos": [222, 237]}, {"entity": "set", "entity_type": "application", "pos": [242, 245]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [254, 256]}], "task": "NER"}
{"text": "Before characterization of the EVA resin , post-processing was carried out in pure hydrogen contained furnace .", "entity": [{"entity": "resin", "entity_type": "material", "pos": [35, 40]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [43, 58]}, {"entity": "pure hydrogen", "entity_type": "material", "pos": [78, 91]}, {"entity": "furnace", "entity_type": "machine or equipment", "pos": [102, 109]}], "task": "NER"}
{"text": "The EVA resin was then characterized in terms of its thermal behaviour , density , porosity , average pore size .", "entity": [{"entity": "resin", "entity_type": "material", "pos": [8, 13]}, {"entity": "density", "entity_type": "machanical property", "pos": [73, 80]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [83, 91]}, {"entity": "average", "entity_type": "concept or principle", "pos": [94, 101]}], "task": "NER"}
{"text": "Mechanical test was performed on a CMT4305 electronic testing universal testing machine with a purpose of investigating the yield strength and young modulus .", "entity": [{"entity": "Mechanical test", "entity_type": "process characterization", "pos": [0, 15]}, {"entity": "electronic testing", "entity_type": "process characterization", "pos": [43, 61]}, {"entity": "testing", "entity_type": "process characterization", "pos": [72, 79]}, {"entity": "machine", "entity_type": "machine or equipment", "pos": [80, 87]}, {"entity": "yield strength", "entity_type": "machanical property", "pos": [124, 138]}, {"entity": "young modulus", "entity_type": "machanical property", "pos": [143, 156]}], "task": "NER"}
{"text": "It was discovered that the laser power and the sintering temperature are determining factor on the reduction in the porosity of the material .", "entity": [{"entity": "laser power", "entity_type": "process parameter", "pos": [27, 38]}, {"entity": "sintering", "entity_type": "manufacturing process", "pos": [47, 56]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [99, 108]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [116, 124]}, {"entity": "material", "entity_type": "material", "pos": [132, 140]}], "task": "NER"}
{"text": "It was concluded that the characteristics of the sintered porous stainless steel 316 L produced can be use as a substitute for bones in biomedical applications .", "entity": [{"entity": "sintered", "entity_type": "manufacturing process", "pos": [49, 57]}, {"entity": "porous", "entity_type": "machanical property", "pos": [58, 64]}, {"entity": "steel", "entity_type": "material", "pos": [75, 80]}, {"entity": "be", "entity_type": "material", "pos": [100, 102]}, {"entity": "as", "entity_type": "material", "pos": [107, 109]}, {"entity": "biomedical applications", "entity_type": "application", "pos": [136, 159]}], "task": "NER"}
{"text": "Pal investigated the effect of post-processing and machining process parameters on the mechanical properties of stainless steel product produced by direct laser sintering .", "entity": [{"entity": "post-processing", "entity_type": "concept or principle", "pos": [31, 46]}, {"entity": "machining", "entity_type": "manufacturing process", "pos": [51, 60]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [69, 79]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [87, 108]}, {"entity": "stainless steel", "entity_type": "material", "pos": [112, 127]}, {"entity": "laser sintering", "entity_type": "manufacturing process", "pos": [155, 170]}], "task": "NER"}
{"text": "A sample of stainless steel was fabricated in an argon atmosphere in a 40 degree centigrade pre-heating machining chamber with a fibre laser system having beam diameter of 0.1 mm .", "entity": [{"entity": "sample", "entity_type": "concept or principle", "pos": [2, 8]}, {"entity": "stainless steel", "entity_type": "material", "pos": [12, 27]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [32, 42]}, {"entity": "argon atmosphere", "entity_type": "process parameter", "pos": [49, 65]}, {"entity": "machining chamber", "entity_type": "machine or equipment", "pos": [104, 121]}, {"entity": "fibre laser system", "entity_type": "machine or equipment", "pos": [129, 147]}, {"entity": "beam diameter", "entity_type": "process parameter", "pos": [155, 168]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [176, 178]}], "task": "NER"}
{"text": "Processing parameters of tensile specimens were 195 W laser power , scan speed of 900 mm/s with 40 micro-meter thickness layer .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [11, 21]}, {"entity": "tensile specimens", "entity_type": "machine or equipment", "pos": [25, 42]}, {"entity": "laser power", "entity_type": "process parameter", "pos": [54, 65]}, {"entity": "scan speed", "entity_type": "process parameter", "pos": [68, 78]}, {"entity": "layer", "entity_type": "process parameter", "pos": [121, 126]}], "task": "NER"}
{"text": "Tensile test was then performed with specimen dimensions 80 mm in total length , 40 mm gauge length , 5 mm gauge diameter , length of holding part was set at 20 mm and diameter 6 mm .", "entity": [{"entity": "Tensile test", "entity_type": "process characterization", "pos": [0, 12]}, {"entity": "dimensions", "entity_type": "engineering feature", "pos": [46, 56]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [60, 62]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [84, 86]}, {"entity": "mm gauge diameter", "entity_type": "process parameter", "pos": [104, 121]}, {"entity": "set", "entity_type": "application", "pos": [151, 154]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [161, 163]}, {"entity": "diameter", "entity_type": "concept or principle", "pos": [168, 176]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [179, 181]}], "task": "NER"}
{"text": "It was discovered that the tensile strength of the DLMS part increased after heat treatment .", "entity": [{"entity": "tensile strength", "entity_type": "machanical property", "pos": [27, 43]}, {"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [77, 91]}], "task": "NER"}
{"text": "Residual stresses remain in the het treated part with increased tensile strength due to rapid cooling without undergoing any post-processing stage .", "entity": [{"entity": "Residual stresses", "entity_type": "machanical property", "pos": [0, 17]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [64, 80]}, {"entity": "cooling", "entity_type": "manufacturing process", "pos": [94, 101]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [125, 140]}], "task": "NER"}
{"text": "It was discovered after the analysis that the energy density will determine the mechanical property which implies that tensile strength of the stainless steel can be controlled by the combination of the machining parameters and energy density .", "entity": [{"entity": "energy density", "entity_type": "process parameter", "pos": [46, 60]}, {"entity": "mechanical property", "entity_type": "concept or principle", "pos": [80, 99]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [119, 135]}, {"entity": "stainless steel", "entity_type": "material", "pos": [143, 158]}, {"entity": "be", "entity_type": "material", "pos": [163, 165]}, {"entity": "machining", "entity_type": "manufacturing process", "pos": [203, 212]}, {"entity": "energy density", "entity_type": "process parameter", "pos": [228, 242]}], "task": "NER"}
{"text": "Laser power and scanning speed will also determine the extent of surface roughness of the stainless steel .", "entity": [{"entity": "Laser power", "entity_type": "process parameter", "pos": [0, 11]}, {"entity": "scanning speed", "entity_type": "process parameter", "pos": [16, 30]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [65, 82]}, {"entity": "stainless steel", "entity_type": "material", "pos": [90, 105]}], "task": "NER"}
{"text": "studied the deformation mechanism of 17-4 precipitated hardened stainless steel fabricated by direct metal laser sintering using micro pillar compression testing and transmission electron microscopy .", "entity": [{"entity": "deformation", "entity_type": "concept or principle", "pos": [12, 23]}, {"entity": "precipitated hardened", "entity_type": "machanical property", "pos": [42, 63]}, {"entity": "steel", "entity_type": "material", "pos": [74, 79]}, {"entity": "fabricated", "entity_type": "concept or principle", "pos": [80, 90]}, {"entity": "direct metal laser sintering", "entity_type": "manufacturing process", "pos": [94, 122]}, {"entity": "micro pillar compression testing", "entity_type": "process characterization", "pos": [129, 161]}, {"entity": "transmission electron microscopy", "entity_type": "process characterization", "pos": [166, 198]}], "task": "NER"}
{"text": "17- 4 stainless steel were first produced using direct metal laser sintering system in an argon atmosphere with spherical size of approximately 15 45 micro-meter in diameter .", "entity": [{"entity": "stainless steel", "entity_type": "material", "pos": [6, 21]}, {"entity": "direct metal laser sintering system", "entity_type": "machine or equipment", "pos": [48, 83]}, {"entity": "argon atmosphere", "entity_type": "process parameter", "pos": [90, 106]}, {"entity": "spherical", "entity_type": "concept or principle", "pos": [112, 121]}, {"entity": "diameter", "entity_type": "concept or principle", "pos": [165, 173]}], "task": "NER"}
{"text": "Scanning speed was 750 mm/s with scanning direction made 67 degrees between successive building layers with hatch spacing was 0.11 mm .", "entity": [{"entity": "Scanning speed", "entity_type": "process parameter", "pos": [0, 14]}, {"entity": "scanning", "entity_type": "concept or principle", "pos": [33, 41]}, {"entity": "hatch spacing", "entity_type": "process parameter", "pos": [108, 121]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [131, 133]}], "task": "NER"}
{"text": "micro compression properties of the 17-4 precipitation hardened stainless steel was evaluated .", "entity": [{"entity": "compression", "entity_type": "machanical property", "pos": [6, 17]}, {"entity": "precipitation hardened", "entity_type": "manufacturing process", "pos": [41, 63]}, {"entity": "steel", "entity_type": "material", "pos": [74, 79]}], "task": "NER"}
{"text": "Outcome revealed that the microstructure and properties of the 17-4 stainless steel stainless steel specimens vary significantly from those produced by conventional manufacturing methods because of fine grain evolution that emerged .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [26, 40]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [45, 55]}, {"entity": "17-4 stainless steel", "entity_type": "material", "pos": [63, 83]}, {"entity": "steel", "entity_type": "material", "pos": [94, 99]}, {"entity": "conventional manufacturing", "entity_type": "manufacturing process", "pos": [152, 178]}, {"entity": "grain evolution", "entity_type": "concept or principle", "pos": [203, 218]}], "task": "NER"}
{"text": "Selective Laser Melting of Stainless Steel Selective Laser Melting process is an additive manufacturing technology that can be used to produce solid metallic components from metallic powder by using a high intensity laser to melt and fuse selective region of the metallic powder layer by layer according to the computer aided design data .", "entity": [{"entity": "Selective Laser Melting", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "Stainless Steel", "entity_type": "material", "pos": [27, 42]}, {"entity": "Selective Laser Melting process", "entity_type": "manufacturing process", "pos": [43, 74]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [81, 103]}, {"entity": "be", "entity_type": "material", "pos": [124, 126]}, {"entity": "metallic", "entity_type": "material", "pos": [149, 157]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [158, 168]}, {"entity": "metallic powder", "entity_type": "material", "pos": [174, 189]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [216, 221]}, {"entity": "melt", "entity_type": "concept or principle", "pos": [225, 229]}, {"entity": "fuse", "entity_type": "manufacturing process", "pos": [234, 238]}, {"entity": "metallic powder", "entity_type": "material", "pos": [263, 278]}, {"entity": "layer by layer", "entity_type": "concept or principle", "pos": [279, 293]}, {"entity": "computer aided design", "entity_type": "enabling technology", "pos": [311, 332]}], "task": "NER"}
{"text": "A new layer of metal powder is applied and the build platform is being lowered by the amount of thickness of one layer .", "entity": [{"entity": "layer", "entity_type": "process parameter", "pos": [6, 11]}, {"entity": "metal powder", "entity_type": "material", "pos": [15, 27]}, {"entity": "build platform", "entity_type": "machine or equipment", "pos": [47, 61]}, {"entity": "layer", "entity_type": "process parameter", "pos": [113, 118]}], "task": "NER"}
{"text": "The process involves building of component layer by layer by depositing a thin metallic powder on a substrate .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [4, 11]}, {"entity": "building of component layer", "entity_type": "process parameter", "pos": [21, 48]}, {"entity": "layer", "entity_type": "process parameter", "pos": [52, 57]}, {"entity": "thin metallic powder", "entity_type": "material", "pos": [74, 94]}, {"entity": "substrate", "entity_type": "material", "pos": [100, 109]}], "task": "NER"}
{"text": "A high intensity power laser is then used to melt and fuse together a specific area of the metallic powder according to the data from the 3D CAD .", "entity": [{"entity": "power", "entity_type": "process parameter", "pos": [17, 22]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [23, 28]}, {"entity": "melt", "entity_type": "concept or principle", "pos": [45, 49]}, {"entity": "fuse", "entity_type": "manufacturing process", "pos": [54, 58]}, {"entity": "area", "entity_type": "process parameter", "pos": [79, 83]}, {"entity": "metallic powder", "entity_type": "material", "pos": [91, 106]}, {"entity": "data", "entity_type": "concept or principle", "pos": [124, 128]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [138, 140]}], "task": "NER"}
{"text": "Once the laser scanning is completed , succeeding layer of metallic powder is deposited on top and laser scans another new layer until the required component is completely built after repeated successive layer of metallic powder is deposited .", "entity": [{"entity": "laser", "entity_type": "enabling technology", "pos": [9, 14]}, {"entity": "layer", "entity_type": "process parameter", "pos": [50, 55]}, {"entity": "metallic powder", "entity_type": "material", "pos": [59, 74]}, {"entity": "laser scans", "entity_type": "enabling technology", "pos": [99, 110]}, {"entity": "layer", "entity_type": "process parameter", "pos": [123, 128]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [148, 157]}, {"entity": "layer", "entity_type": "process parameter", "pos": [204, 209]}, {"entity": "metallic powder", "entity_type": "material", "pos": [213, 228]}], "task": "NER"}
{"text": "Once the laser scanning processes completed , loose powders are removed from the building chamber and the component can be separated from the substrate plate manually or by electrical discharge machining .", "entity": [{"entity": "laser scanning processes", "entity_type": "enabling technology", "pos": [9, 33]}, {"entity": "powders", "entity_type": "material", "pos": [52, 59]}, {"entity": "building chamber", "entity_type": "process parameter", "pos": [81, 97]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [106, 115]}, {"entity": "be", "entity_type": "material", "pos": [120, 122]}, {"entity": "substrate plate", "entity_type": "machine or equipment", "pos": [142, 157]}, {"entity": "electrical discharge machining", "entity_type": "manufacturing process", "pos": [173, 203]}], "task": "NER"}
{"text": "Schematic diagram describing the SLM process is shown in Figure 2 .", "entity": [{"entity": "SLM", "entity_type": "manufacturing process", "pos": [33, 36]}, {"entity": "process", "entity_type": "concept or principle", "pos": [37, 44]}], "task": "NER"}
{"text": "Figure 2 : Schematic diagram selective laser melting process Numerous research has been conducted with the application of selective laser melting of stainless steel in the literature .", "entity": [{"entity": "selective laser melting process", "entity_type": "manufacturing process", "pos": [29, 60]}, {"entity": "research", "entity_type": "concept or principle", "pos": [70, 78]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [122, 145]}, {"entity": "stainless steel", "entity_type": "material", "pos": [149, 164]}], "task": "NER"}
{"text": "Jandin 2005 investigated the influence of laser power strength on the porosity of component built .", "entity": [{"entity": "laser power strength", "entity_type": "process parameter", "pos": [42, 62]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [70, 78]}, {"entity": "component", "entity_type": "machine or equipment", "pos": [82, 91]}], "task": "NER"}
{"text": "In their study , ytterbium fibre laser with a wavelength of 1065 nm was used to process the 316L stainless steel powder .", "entity": [{"entity": "fibre laser", "entity_type": "concept or principle", "pos": [27, 38]}, {"entity": "wavelength", "entity_type": "concept or principle", "pos": [46, 56]}, {"entity": "process", "entity_type": "concept or principle", "pos": [80, 87]}, {"entity": "316L stainless steel powder", "entity_type": "material", "pos": [92, 119]}], "task": "NER"}
{"text": "The experiment showed that low laser power and high scanning speed caused incomplete melting of the powder material and resulted in high porosity in the components .", "entity": [{"entity": "experiment", "entity_type": "concept or principle", "pos": [4, 14]}, {"entity": "laser power", "entity_type": "process parameter", "pos": [31, 42]}, {"entity": "scanning speed", "entity_type": "process parameter", "pos": [52, 66]}, {"entity": "melting", "entity_type": "manufacturing process", "pos": [85, 92]}, {"entity": "powder material", "entity_type": "material", "pos": [100, 115]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [137, 145]}, {"entity": "components", "entity_type": "machine or equipment", "pos": [153, 163]}], "task": "NER"}
{"text": "This can be improved by increasing the laser power , and decreasing the scanning speed .", "entity": [{"entity": "be", "entity_type": "material", "pos": [9, 11]}, {"entity": "laser power", "entity_type": "process parameter", "pos": [39, 50]}, {"entity": "scanning speed", "entity_type": "process parameter", "pos": [72, 86]}], "task": "NER"}
{"text": "Wang investigated selective laser melting of stainless steel 316L with low porosity and high build rates by employing fast scanning speeds to fabricate high-density stainless steel 316L parts .", "entity": [{"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [18, 41]}, {"entity": "stainless steel", "entity_type": "material", "pos": [45, 60]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [75, 83]}, {"entity": "build rates", "entity_type": "process characterization", "pos": [93, 104]}, {"entity": "scanning speeds", "entity_type": "process parameter", "pos": [123, 138]}, {"entity": "fabricate", "entity_type": "manufacturing process", "pos": [142, 151]}, {"entity": "stainless steel", "entity_type": "material", "pos": [165, 180]}], "task": "NER"}
{"text": "The aim of the study was to improve the production rate while maintaining a low porosity for the selective laser melting-built parts .", "entity": [{"entity": "production", "entity_type": "manufacturing process", "pos": [40, 50]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [80, 88]}, {"entity": "selective laser", "entity_type": "manufacturing process", "pos": [97, 112]}], "task": "NER"}
{"text": "The study shed light on the improvement of selective laser melting build rates without any decrease in the mechanical properties or any loss of parts density of stainless steel 316L .", "entity": [{"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [43, 66]}, {"entity": "build rates", "entity_type": "process characterization", "pos": [67, 78]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [107, 128]}, {"entity": "density", "entity_type": "machanical property", "pos": [150, 157]}, {"entity": "stainless steel", "entity_type": "material", "pos": [161, 176]}], "task": "NER"}
{"text": "Miranda investigated and developed models for predicting the physical and mechanical properties of 316L stainless steel produced by selective laser melting .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [74, 95]}, {"entity": "316L stainless steel", "entity_type": "material", "pos": [99, 119]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [132, 155]}], "task": "NER"}
{"text": "The influence of various processing parameters on density , hardness and shear strength of 316L stainless steel were studied using statistical analysis in order to significantly determine main factors and their interactions .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [36, 46]}, {"entity": "density", "entity_type": "machanical property", "pos": [50, 57]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [60, 68]}, {"entity": "shear strength", "entity_type": "machanical property", "pos": [73, 87]}, {"entity": "316L stainless steel", "entity_type": "material", "pos": [91, 111]}], "task": "NER"}
{"text": "Six different models were developed as a predictive design tool to determine the influence of these processing parameters on the shear strength , hardness and density .", "entity": [{"entity": "as", "entity_type": "material", "pos": [36, 38]}, {"entity": "design", "entity_type": "engineering feature", "pos": [52, 58]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [111, 121]}, {"entity": "shear strength", "entity_type": "machanical property", "pos": [129, 143]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [146, 154]}, {"entity": "density", "entity_type": "machanical property", "pos": [159, 166]}], "task": "NER"}
{"text": "Wang investigated the development of grain structure mechanism of 316L stainless steel fabricated by selective laser melting and mechanical property characterization .", "entity": [{"entity": "grain structure", "entity_type": "concept or principle", "pos": [37, 52]}, {"entity": "316L stainless steel", "entity_type": "material", "pos": [66, 86]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [101, 124]}, {"entity": "mechanical property characterization", "entity_type": "process characterization", "pos": [129, 165]}], "task": "NER"}
{"text": "The grain structure mechanism was studied using finite element analysis in order to reveal the growth mechanism of grains under rapid solidification condition .", "entity": [{"entity": "grain structure", "entity_type": "concept or principle", "pos": [4, 19]}, {"entity": "finite element analysis", "entity_type": "concept or principle", "pos": [48, 71]}, {"entity": "mechanism", "entity_type": "concept or principle", "pos": [102, 111]}, {"entity": "grains", "entity_type": "concept or principle", "pos": [115, 121]}, {"entity": "rapid solidification", "entity_type": "manufacturing process", "pos": [128, 148]}], "task": "NER"}
{"text": "A detailed analysis of crystal orientation of formed dendrite was performed using geometrical analysis in collaboration with experimental findings .", "entity": [{"entity": "crystal orientation", "entity_type": "machanical property", "pos": [23, 42]}, {"entity": "dendrite", "entity_type": "biomedical", "pos": [53, 61]}, {"entity": "geometrical analysis", "entity_type": "engineering feature", "pos": [82, 102]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [125, 137]}], "task": "NER"}
{"text": "It was discovered that rapid solidification caused by high-speed scanning resulted into sub-micron grains within the final solidified microstructure .", "entity": [{"entity": "rapid solidification", "entity_type": "manufacturing process", "pos": [23, 43]}, {"entity": "high-speed scanning", "entity_type": "enabling technology", "pos": [54, 73]}, {"entity": "sub-micron", "entity_type": "engineering feature", "pos": [88, 98]}, {"entity": "grains", "entity_type": "concept or principle", "pos": [99, 105]}, {"entity": "solidified microstructure", "entity_type": "machanical property", "pos": [123, 148]}], "task": "NER"}
{"text": "It was also detected that grain size and densification was a dependant on high volume energy density of the laser which will significantly affect the mechanical properties of the final product formed after solidification .", "entity": [{"entity": "grain size", "entity_type": "machanical property", "pos": [26, 36]}, {"entity": "densification", "entity_type": "manufacturing process", "pos": [41, 54]}, {"entity": "volume", "entity_type": "concept or principle", "pos": [79, 85]}, {"entity": "energy density", "entity_type": "process parameter", "pos": [86, 100]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [108, 113]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [150, 171]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [206, 220]}], "task": "NER"}
{"text": "Casati studied the microstructure and fracture behaviour of 316L austenitic stainless steel produced by selective laser melting and discovered that severe thermal gradients and high cooling rates affects the crystal growth and orientation of grain structure after solidification .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [19, 33]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [38, 46]}, {"entity": "316L austenitic stainless steel", "entity_type": "material", "pos": [60, 91]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [104, 127]}, {"entity": "thermal gradients", "entity_type": "process parameter", "pos": [155, 172]}, {"entity": "cooling rates", "entity_type": "process parameter", "pos": [182, 195]}, {"entity": "crystal growth", "entity_type": "machanical property", "pos": [208, 222]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [227, 238]}, {"entity": "grain structure", "entity_type": "concept or principle", "pos": [242, 257]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [264, 278]}], "task": "NER"}
{"text": "This causes material spattering and microstructure defects like pores and incomplete melted particles .", "entity": [{"entity": "material", "entity_type": "material", "pos": [12, 20]}, {"entity": "microstructure defects", "entity_type": "concept or principle", "pos": [36, 58]}, {"entity": "pores", "entity_type": "machanical property", "pos": [64, 69]}, {"entity": "melted", "entity_type": "concept or principle", "pos": [85, 91]}], "task": "NER"}
{"text": "The influence of effect of different distribution of defects on mechanical response and failure mechanism were investigated using 316L bars with microstructure and texture built along two different orientations .", "entity": [{"entity": "distribution", "entity_type": "concept or principle", "pos": [37, 49]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [53, 60]}, {"entity": "mechanical response", "entity_type": "concept or principle", "pos": [64, 83]}, {"entity": "failure mechanism", "entity_type": "machanical property", "pos": [88, 105]}, {"entity": "316L bars", "entity_type": "material", "pos": [130, 139]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [145, 159]}, {"entity": "texture", "entity_type": "engineering feature", "pos": [164, 171]}, {"entity": "orientations", "entity_type": "concept or principle", "pos": [198, 210]}], "task": "NER"}
{"text": "It was concluded that semi-molten metallic powder particles of stainless steel 316L were responsible for the scattering and reduced strength of the material after solidification .", "entity": [{"entity": "semi-molten", "entity_type": "machanical property", "pos": [22, 33]}, {"entity": "metallic powder", "entity_type": "material", "pos": [34, 49]}, {"entity": "stainless steel", "entity_type": "material", "pos": [63, 78]}, {"entity": "strength", "entity_type": "machanical property", "pos": [132, 140]}, {"entity": "material", "entity_type": "material", "pos": [148, 156]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [163, 177]}], "task": "NER"}
{"text": "Liu investigated the spatter behaviour of stainless steel 316L during selective laser melting process .", "entity": [{"entity": "spatter", "entity_type": "process characterization", "pos": [21, 28]}, {"entity": "stainless steel", "entity_type": "material", "pos": [42, 57]}, {"entity": "selective laser melting process", "entity_type": "manufacturing process", "pos": [70, 101]}], "task": "NER"}
{"text": "It was discovered that spatter is caused as a result of negative impact of laser on the building of parts in successive layers during selective laser melting process .", "entity": [{"entity": "spatter", "entity_type": "process characterization", "pos": [23, 30]}, {"entity": "as", "entity_type": "material", "pos": [41, 43]}, {"entity": "impact", "entity_type": "concept or principle", "pos": [65, 71]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [75, 80]}, {"entity": "building of parts", "entity_type": "process characterization", "pos": [88, 105]}, {"entity": "selective laser melting process", "entity_type": "manufacturing process", "pos": [134, 165]}], "task": "NER"}
{"text": "Two types of spatter were identified which were droplet spatter , generated by the tearing behaviour of molten metal and powder spatter , which are produced when non-metallic powder particles around the molten pool are blown away as a result of metallic vapour impact .", "entity": [{"entity": "spatter", "entity_type": "process characterization", "pos": [13, 20]}, {"entity": "droplet spatter", "entity_type": "process characterization", "pos": [48, 63]}, {"entity": "molten metal", "entity_type": "material", "pos": [104, 116]}, {"entity": "powder spatter", "entity_type": "process characterization", "pos": [121, 135]}, {"entity": "powder particles", "entity_type": "material", "pos": [175, 191]}, {"entity": "molten pool", "entity_type": "concept or principle", "pos": [203, 214]}, {"entity": "as", "entity_type": "material", "pos": [230, 232]}, {"entity": "metallic", "entity_type": "material", "pos": [245, 253]}, {"entity": "impact", "entity_type": "concept or principle", "pos": [261, 267]}], "task": "NER"}
{"text": "It was discovered that oxygen composition increase during spatter and X-ray diffraction shows that diffraction peaks of austenite content and ferrite are low due to the formation of iron oxides .", "entity": [{"entity": "oxygen", "entity_type": "material", "pos": [23, 29]}, {"entity": "composition", "entity_type": "concept or principle", "pos": [30, 41]}, {"entity": "spatter", "entity_type": "process characterization", "pos": [58, 65]}, {"entity": "X-ray diffraction", "entity_type": "process characterization", "pos": [70, 87]}, {"entity": "diffraction", "entity_type": "process characterization", "pos": [99, 110]}, {"entity": "austenite", "entity_type": "material", "pos": [120, 129]}, {"entity": "ferrite", "entity_type": "material", "pos": [142, 149]}, {"entity": "iron oxides", "entity_type": "material", "pos": [182, 193]}], "task": "NER"}
{"text": "Li investigated the deformation behaviour of stainless steel micro-lattice structures produced by selective laser melting .", "entity": [{"entity": "Li", "entity_type": "material", "pos": [0, 2]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [20, 31]}, {"entity": "stainless steel", "entity_type": "material", "pos": [45, 60]}, {"entity": "micro-lattice structures", "entity_type": "engineering feature", "pos": [61, 85]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [98, 121]}], "task": "NER"}
{"text": "Macroscopic deformation of micro-lattice structures and microscopic stress and strain evolution were studied using a full scale 3D finite element model .", "entity": [{"entity": "Macroscopic deformation", "entity_type": "machanical property", "pos": [0, 23]}, {"entity": "micro-lattice structures", "entity_type": "engineering feature", "pos": [27, 51]}, {"entity": "microscopic stress", "entity_type": "machanical property", "pos": [56, 74]}, {"entity": "strain", "entity_type": "machanical property", "pos": [79, 85]}, {"entity": "evolution", "entity_type": "concept or principle", "pos": [86, 95]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [128, 130]}, {"entity": "element", "entity_type": "material", "pos": [138, 145]}], "task": "NER"}
{"text": "The finite element prediction revealed that deformation of micro-lattice is significantly affected by applied boundary conditions and constitutive properties of the selective laser melted parent material .", "entity": [{"entity": "finite element", "entity_type": "concept or principle", "pos": [4, 18]}, {"entity": "deformation", "entity_type": "concept or principle", "pos": [44, 55]}, {"entity": "micro-lattice", "entity_type": "engineering feature", "pos": [59, 72]}, {"entity": "boundary conditions", "entity_type": "concept or principle", "pos": [110, 129]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [147, 157]}, {"entity": "selective laser melted", "entity_type": "manufacturing process", "pos": [165, 187]}, {"entity": "material", "entity_type": "material", "pos": [195, 203]}], "task": "NER"}
{"text": "Zhao studied the influence of stainless steel decarburization on its youngmodulus hardness and tensile strength during selective laser melting process .", "entity": [{"entity": "stainless steel", "entity_type": "material", "pos": [30, 45]}, {"entity": "decarburization", "entity_type": "manufacturing process", "pos": [46, 61]}, {"entity": "youngmodulus", "entity_type": "machanical property", "pos": [69, 81]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [82, 90]}, {"entity": "tensile strength", "entity_type": "machanical property", "pos": [95, 111]}, {"entity": "selective laser melting process", "entity_type": "manufacturing process", "pos": [119, 150]}], "task": "NER"}
{"text": "The study was investigated using evolution mechanism of the chemical element during SLM .", "entity": [{"entity": "evolution", "entity_type": "concept or principle", "pos": [33, 42]}, {"entity": "element", "entity_type": "material", "pos": [69, 76]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [84, 87]}], "task": "NER"}
{"text": "It was discovered that during decarburization process 21 % of carbon composition was lost and as a result , it reduces the young modulus and hardness of the molten pool boundary as well as the tensile property of the stainless steel .", "entity": [{"entity": "decarburization", "entity_type": "manufacturing process", "pos": [30, 45]}, {"entity": "carbon", "entity_type": "material", "pos": [62, 68]}, {"entity": "as", "entity_type": "material", "pos": [82, 84]}, {"entity": "young modulus", "entity_type": "machanical property", "pos": [123, 136]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [141, 149]}, {"entity": "molten pool", "entity_type": "concept or principle", "pos": [157, 168]}, {"entity": "boundary", "entity_type": "engineering feature", "pos": [169, 177]}, {"entity": "as", "entity_type": "material", "pos": [178, 180]}, {"entity": "as", "entity_type": "material", "pos": [186, 188]}, {"entity": "tensile property", "entity_type": "machanical property", "pos": [193, 209]}, {"entity": "stainless steel", "entity_type": "material", "pos": [217, 232]}], "task": "NER"}
{"text": "Selective laser melting also been used to process martensitic grade of stainless steel .", "entity": [{"entity": "Selective laser melting", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "process", "entity_type": "concept or principle", "pos": [42, 49]}, {"entity": "martensitic grade", "entity_type": "machanical property", "pos": [50, 67]}, {"entity": "stainless steel", "entity_type": "material", "pos": [71, 86]}], "task": "NER"}
{"text": "Krakhmalev investigated the evolution of microstructure in AISI 420 martensitic stainless steel during selective laser melting .", "entity": [{"entity": "evolution", "entity_type": "concept or principle", "pos": [28, 37]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [41, 55]}, {"entity": "AISI 420", "entity_type": "material", "pos": [59, 67]}, {"entity": "stainless steel", "entity_type": "material", "pos": [80, 95]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [103, 126]}], "task": "NER"}
{"text": "It was discovered that several upper layers which are in austenite phase posses hardness value higher than the final bulk microstructure of thermally decomposited martensite .", "entity": [{"entity": "austenite phase", "entity_type": "process characterization", "pos": [57, 72]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [80, 88]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [122, 136]}, {"entity": "thermally decomposited martensite", "entity_type": "material", "pos": [140, 173]}], "task": "NER"}
{"text": "Also , numerical simulation results of thermal cycles discovered that thermal process can be controlled by variation of laser energy input .", "entity": [{"entity": "numerical simulation", "entity_type": "enabling technology", "pos": [7, 27]}, {"entity": "thermal cycles", "entity_type": "process parameter", "pos": [39, 53]}, {"entity": "process", "entity_type": "concept or principle", "pos": [78, 85]}, {"entity": "be", "entity_type": "material", "pos": [90, 92]}, {"entity": "variation", "entity_type": "concept or principle", "pos": [107, 116]}, {"entity": "laser energy", "entity_type": "concept or principle", "pos": [120, 132]}], "task": "NER"}
{"text": "The tribology of selective laser melting of 316Lstainless steel as a processed part under lubricated conditions was studied by Zhu .", "entity": [{"entity": "tribology", "entity_type": "concept or principle", "pos": [4, 13]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [17, 40]}, {"entity": "steel", "entity_type": "material", "pos": [58, 63]}, {"entity": "as", "entity_type": "material", "pos": [64, 66]}, {"entity": "processed", "entity_type": "concept or principle", "pos": [69, 78]}], "task": "NER"}
{"text": "The friction and wear behaviours of 316L stainless steel produced both by selective laser melting and traditional methods were studied using a ring on-disc rig under lubricated conditions .", "entity": [{"entity": "friction", "entity_type": "concept or principle", "pos": [4, 12]}, {"entity": "wear", "entity_type": "concept or principle", "pos": [17, 21]}, {"entity": "316L stainless steel", "entity_type": "material", "pos": [36, 56]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [74, 97]}], "task": "NER"}
{"text": "It was discovered that the tribological performance of SLM stainless steel sample will be better if the pores can be drastically reduced with refined grains .", "entity": [{"entity": "tribological performance", "entity_type": "concept or principle", "pos": [27, 51]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [55, 58]}, {"entity": "steel", "entity_type": "material", "pos": [69, 74]}, {"entity": "sample", "entity_type": "concept or principle", "pos": [75, 81]}, {"entity": "be", "entity_type": "material", "pos": [87, 89]}, {"entity": "pores", "entity_type": "machanical property", "pos": [104, 109]}, {"entity": "be", "entity_type": "material", "pos": [114, 116]}, {"entity": "grains", "entity_type": "concept or principle", "pos": [150, 156]}], "task": "NER"}
{"text": "Cherry investigated how processing parameters affects the microstructural and physical properties of 316L stainless steel by selective laser melting .", "entity": [{"entity": "parameters", "entity_type": "concept or principle", "pos": [35, 45]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [58, 73]}, {"entity": "physical properties", "entity_type": "machanical property", "pos": [78, 97]}, {"entity": "316L stainless steel", "entity_type": "material", "pos": [101, 121]}, {"entity": "selective laser melting", "entity_type": "manufacturing process", "pos": [125, 148]}], "task": "NER"}
{"text": "After systematic characterization of porosity and microstructure , it was discovered that porosity is highest at lower laser energy and decreases at higher laser energy and also laser energy density alteration resulted in production of dense parts .", "entity": [{"entity": "porosity", "entity_type": "machanical property", "pos": [37, 45]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [50, 64]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [90, 98]}, {"entity": "laser energy", "entity_type": "concept or principle", "pos": [119, 131]}, {"entity": "laser energy", "entity_type": "concept or principle", "pos": [156, 168]}, {"entity": "laser energy density", "entity_type": "process parameter", "pos": [178, 198]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [222, 232]}], "task": "NER"}
{"text": "Material hardness was also increased due to reduction in porosity .", "entity": [{"entity": "Material", "entity_type": "material", "pos": [0, 8]}, {"entity": "hardness", "entity_type": "machanical property", "pos": [9, 17]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [44, 53]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [57, 65]}], "task": "NER"}
{"text": "Most of the research that has been done focused mostly on austenitic stainless steel grade , 316L and also on martensitic grade AISI 420 .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [12, 20]}, {"entity": "austenitic stainless steel", "entity_type": "material", "pos": [58, 84]}, {"entity": "martensitic grade", "entity_type": "machanical property", "pos": [110, 127]}, {"entity": "AISI 420", "entity_type": "material", "pos": [128, 136]}], "task": "NER"}
{"text": "Selective laser melting has been extensively explored with stainless steel but further study need to be done with the employment of other grades of stainless steel This review article summarizes the current state-of-the-art for biomimicry in additive manufacturing .", "entity": [{"entity": "Selective laser melting", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "stainless steel", "entity_type": "material", "pos": [59, 74]}, {"entity": "be", "entity_type": "material", "pos": [101, 103]}, {"entity": "stainless steel", "entity_type": "material", "pos": [148, 163]}, {"entity": "state-of-the-art", "entity_type": "concept or principle", "pos": [207, 223]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [228, 238]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [242, 264]}], "task": "NER"}
{"text": "Biomimicry is the practice of learning from and emulating nature - which can be increasingly realized in engineering applications due to progress in additive manufacturing .", "entity": [{"entity": "Biomimicry", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "be", "entity_type": "material", "pos": [77, 79]}, {"entity": "engineering", "entity_type": "application", "pos": [105, 116]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [149, 171]}], "task": "NER"}
{"text": "AM has grown tremendously in recent years , with improvements in technology and resulting material properties sometimes exceeding those of equivalent parts produced by traditional production processes .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [65, 75]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [90, 109]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [180, 190]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [191, 200]}], "task": "NER"}
{"text": "This has led to the industrial use of AM parts even in highly critical applications , most notably in aerospace , automotive and medical applications .", "entity": [{"entity": "led", "entity_type": "application", "pos": [9, 12]}, {"entity": "industrial", "entity_type": "application", "pos": [20, 30]}, {"entity": "AM parts", "entity_type": "machine or equipment", "pos": [38, 46]}, {"entity": "aerospace", "entity_type": "application", "pos": [102, 111]}, {"entity": "automotive", "entity_type": "application", "pos": [114, 124]}, {"entity": "medical applications", "entity_type": "application", "pos": [129, 149]}], "task": "NER"}
{"text": "The ability to create parts with complex geometries is one of the most important advantages of this technology , allowing the production of complex functional objects from various materials including plastics and metals that can not be easily produced by any other means .", "entity": [{"entity": "complex geometries", "entity_type": "concept or principle", "pos": [33, 51]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [100, 110]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [126, 136]}, {"entity": "complex functional objects", "entity_type": "machine or equipment", "pos": [140, 166]}, {"entity": "various materials", "entity_type": "material", "pos": [172, 189]}, {"entity": "plastics", "entity_type": "material", "pos": [200, 208]}, {"entity": "metals", "entity_type": "material", "pos": [213, 219]}, {"entity": "be", "entity_type": "material", "pos": [233, 235]}], "task": "NER"}
{"text": "Utilizing the full complexity allowed by AM is the key to unlocking the huge potential of this technology for real world applications and biomimicry might be pivotal in this regard .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [19, 29]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [41, 43]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [95, 105]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [138, 148]}, {"entity": "be", "entity_type": "material", "pos": [155, 157]}], "task": "NER"}
{"text": "Biomimicry may take different forms in AM , including customization of parts for individuals , or optimization for specific properties such as stiffness and light-weighting .", "entity": [{"entity": "Biomimicry", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [39, 41]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [98, 110]}, {"entity": "specific properties", "entity_type": "machanical property", "pos": [115, 134]}, {"entity": "as", "entity_type": "material", "pos": [140, 142]}], "task": "NER"}
{"text": "The optimization process often uses an iterative simulation-driven process analogous to biological evolution with an improvement in every iteration .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [4, 16]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [49, 66]}, {"entity": "process", "entity_type": "concept or principle", "pos": [67, 74]}, {"entity": "biological evolution", "entity_type": "concept or principle", "pos": [88, 108]}], "task": "NER"}
{"text": "Other forms of biomimicry in AM include the incorporation of real biological inputs into designs ; the use of cellular or lattice structures for various applications and customized to the application ; incorporating multi-functionality into designs ; the consolidation of numerous parts into one and the reduction of waste , amongst others .", "entity": [{"entity": "biomimicry", "entity_type": "concept or principle", "pos": [15, 25]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [29, 31]}, {"entity": "biological inputs", "entity_type": "biomedical", "pos": [66, 83]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [89, 96]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [122, 140]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [241, 248]}, {"entity": "consolidation", "entity_type": "concept or principle", "pos": [255, 268]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [304, 313]}], "task": "NER"}
{"text": "Numerous biomimetic design approaches may be used broadly categorized into customized/freeform , simulation-driven and lattice designs .", "entity": [{"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [9, 26]}, {"entity": "be", "entity_type": "material", "pos": [42, 44]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [97, 114]}, {"entity": "lattice designs", "entity_type": "engineering feature", "pos": [119, 134]}], "task": "NER"}
{"text": "not for prototyping .", "entity": [{"entity": "prototyping", "entity_type": "concept or principle", "pos": [8, 19]}], "task": "NER"}
{"text": "The current limits of each design approach are discussed and the most exciting future opportunities for biomimetic AM applications are highlighted .", "entity": [{"entity": "limits", "entity_type": "concept or principle", "pos": [12, 18]}, {"entity": "design", "entity_type": "engineering feature", "pos": [27, 33]}, {"entity": "biomimetic AM applications", "entity_type": "application", "pos": [104, 130]}], "task": "NER"}
{"text": "The beauty found in nature is often inspirational - and this inspiration has found its way into functional mechanical engineering through the latest developments in additive manufacturing .", "entity": [{"entity": "mechanical engineering", "entity_type": "application", "pos": [107, 129]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [165, 187]}], "task": "NER"}
{"text": "Other forms of engineering beauty are structural hierarchy , order or lack of order , and combinations with other structures .", "entity": [{"entity": "engineering", "entity_type": "application", "pos": [15, 26]}, {"entity": "structural hierarchy", "entity_type": "concept or principle", "pos": [38, 58]}], "task": "NER"}
{"text": "Learning from these biological structures may advance our use of efficient structures in engineering applications and may even help to provide new solutions to engineering problems , in a sustainable way .", "entity": [{"entity": "biological structures", "entity_type": "engineering feature", "pos": [20, 41]}, {"entity": "engineering", "entity_type": "application", "pos": [89, 100]}, {"entity": "engineering", "entity_type": "application", "pos": [160, 171]}, {"entity": "sustainable", "entity_type": "concept or principle", "pos": [188, 199]}], "task": "NER"}
{"text": "Biomimicry in engineering involves the study of biological systems specifically with the aim to use information learned in solving engineering problems , or for use in engineering applications .", "entity": [{"entity": "Biomimicry", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "engineering", "entity_type": "application", "pos": [14, 25]}, {"entity": "biological systems", "entity_type": "concept or principle", "pos": [48, 66]}, {"entity": "engineering", "entity_type": "application", "pos": [131, 142]}, {"entity": "engineering", "entity_type": "application", "pos": [168, 179]}], "task": "NER"}
{"text": "In nature , structural features from nano to micro to macro scale define an objectproperties and functionalities and vice versa .", "entity": [{"entity": "nano", "entity_type": "engineering feature", "pos": [37, 41]}, {"entity": "macro scale", "entity_type": "concept or principle", "pos": [54, 65]}], "task": "NER"}
{"text": "Modern engineering design has the possibility to change the structural features and properties of the objects while maintaining functionality or to apply simulation to find a design for specific required properties .", "entity": [{"entity": "engineering", "entity_type": "application", "pos": [7, 18]}, {"entity": "design", "entity_type": "engineering feature", "pos": [19, 25]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [84, 94]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [154, 164]}, {"entity": "design", "entity_type": "engineering feature", "pos": [175, 181]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [204, 214]}], "task": "NER"}
{"text": "In an ideal case , AM is able to translate innovative biomimetic design into physical objects with the desired properties and functionality .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [19, 21]}, {"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [54, 71]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [111, 121]}], "task": "NER"}
{"text": "Much of this potential has particularly realistic prospects when using AM , with its freedom of design and complex production capabilities .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [71, 73]}, {"entity": "design", "entity_type": "engineering feature", "pos": [96, 102]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [115, 125]}], "task": "NER"}
{"text": "The capability to emulate the complex structures and hence the properties of biological materials is the aim of biomimicry .", "entity": [{"entity": "complex structures", "entity_type": "concept or principle", "pos": [30, 48]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [63, 73]}, {"entity": "biological materials", "entity_type": "material", "pos": [77, 97]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [112, 122]}], "task": "NER"}
{"text": "For example , failure of a specific design that is claimed to be biomimetic but uses no input from nature , might undermine the credibility of biomimicry .", "entity": [{"entity": "failure", "entity_type": "concept or principle", "pos": [14, 21]}, {"entity": "design", "entity_type": "engineering feature", "pos": [36, 42]}, {"entity": "be", "entity_type": "material", "pos": [62, 64]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [143, 153]}], "task": "NER"}
{"text": "Often structures with curves and rounded edges in any way resembling something in nature are referred to as or This is not incorrect but it must be kept in mind that no biological input is present , and as such is not truly biomimetic or bio-inspired .", "entity": [{"entity": "rounded edges", "entity_type": "engineering feature", "pos": [33, 46]}, {"entity": "as", "entity_type": "material", "pos": [105, 107]}, {"entity": "be", "entity_type": "material", "pos": [145, 147]}, {"entity": "biological input", "entity_type": "biomedical", "pos": [169, 185]}, {"entity": "as", "entity_type": "material", "pos": [203, 205]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [224, 234]}, {"entity": "bio-inspired", "entity_type": "concept or principle", "pos": [238, 250]}], "task": "NER"}
{"text": "Additionally , when a structure is designed for a biological application it may be termed biomimetic or bionic simply due to its intended biological role .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [22, 31]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [35, 43]}, {"entity": "be", "entity_type": "material", "pos": [80, 82]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [90, 100]}], "task": "NER"}
{"text": "Topology optimization , generative design and simulation-driven design tools used to create optimized designs using simulation often create unconventional and complex shapes and forms .", "entity": [{"entity": "Topology optimization", "entity_type": "engineering feature", "pos": [0, 21]}, {"entity": "generative design", "entity_type": "enabling technology", "pos": [24, 41]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [46, 63]}, {"entity": "design", "entity_type": "engineering feature", "pos": [64, 70]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [102, 109]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [116, 126]}, {"entity": "complex shapes", "entity_type": "machanical property", "pos": [159, 173]}], "task": "NER"}
{"text": "The simulation-driven design process is in reality also biomimetic or bio-inspired in the sense that it is iterative and therefore mimics aspects of natural evolutionary strategies in a short timeframe .", "entity": [{"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [4, 21]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [22, 36]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [56, 66]}, {"entity": "bio-inspired", "entity_type": "concept or principle", "pos": [70, 82]}], "task": "NER"}
{"text": "In the area of cellular or lattice structure design , some engineers refer to all porous engineered structures as biomimetic simply due to their resemblance to natural porous materials , or their similarity to the biological equivalent .", "entity": [{"entity": "area", "entity_type": "process parameter", "pos": [7, 11]}, {"entity": "lattice structure design", "entity_type": "engineering feature", "pos": [27, 51]}, {"entity": "porous", "entity_type": "machanical property", "pos": [82, 88]}, {"entity": "as", "entity_type": "material", "pos": [111, 113]}, {"entity": "porous materials", "entity_type": "material", "pos": [168, 184]}, {"entity": "biological equivalent", "entity_type": "concept or principle", "pos": [214, 235]}], "task": "NER"}
{"text": "However , cellular and lattice designs have unlimited design permutations and can therefore be tailored to the application .", "entity": [{"entity": "lattice designs", "entity_type": "engineering feature", "pos": [23, 38]}, {"entity": "design", "entity_type": "engineering feature", "pos": [54, 60]}, {"entity": "be", "entity_type": "material", "pos": [92, 94]}], "task": "NER"}
{"text": "Currently , the most important application for these porous engineered structures is in dental and bone implants .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [53, 59]}, {"entity": "dental and bone implants", "entity_type": "application", "pos": [88, 112]}], "task": "NER"}
{"text": "The latter is a biomimetic application in the sense that the structure should emulate bone for best results , in terms of mechanical properties and permeability .", "entity": [{"entity": "biomimetic application", "entity_type": "application", "pos": [16, 38]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [61, 70]}, {"entity": "bone", "entity_type": "biomedical", "pos": [86, 90]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [122, 143]}, {"entity": "permeability", "entity_type": "machanical property", "pos": [148, 160]}], "task": "NER"}
{"text": "Finally , biomimetic lattice structures may also specifically refer to stochastic design strategies which create structures with a random distribution of strut thicknesses and lengths the randomness emulates nature .", "entity": [{"entity": "biomimetic", "entity_type": "concept or principle", "pos": [10, 20]}, {"entity": "stochastic design", "entity_type": "engineering feature", "pos": [71, 88]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [138, 150]}, {"entity": "strut thicknesses", "entity_type": "process parameter", "pos": [154, 171]}], "task": "NER"}
{"text": "A biomimetic and bio-inspired approach to materials design has attracted great interest from scientists in diverse areas : biophysics and biomaterials , sensors and chemistry , materials science and engineering , to name a few .", "entity": [{"entity": "biomimetic", "entity_type": "concept or principle", "pos": [2, 12]}, {"entity": "bio-inspired", "entity_type": "concept or principle", "pos": [17, 29]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [42, 51]}, {"entity": "design", "entity_type": "engineering feature", "pos": [52, 58]}, {"entity": "areas", "entity_type": "process parameter", "pos": [115, 120]}, {"entity": "biophysics", "entity_type": "concept or principle", "pos": [123, 133]}, {"entity": "biomaterials", "entity_type": "material", "pos": [138, 150]}, {"entity": "sensors", "entity_type": "machine or equipment", "pos": [153, 160]}, {"entity": "chemistry", "entity_type": "concept or principle", "pos": [165, 174]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [177, 186]}, {"entity": "engineering", "entity_type": "application", "pos": [199, 210]}], "task": "NER"}
{"text": "From 2016 , with the progress in AM technology and wider understanding of the fact that complex designs can be realized in real AM products , biomimetic approaches began to be the subject of research in more than 150 papers per year .", "entity": [{"entity": "AM technology", "entity_type": "manufacturing process", "pos": [33, 46]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [96, 103]}, {"entity": "be", "entity_type": "material", "pos": [108, 110]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [128, 130]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [142, 152]}, {"entity": "be", "entity_type": "material", "pos": [164, 166]}, {"entity": "research", "entity_type": "concept or principle", "pos": [191, 199]}], "task": "NER"}
{"text": "Interest in lattice structures produced by AM also increased year by year .", "entity": [{"entity": "lattice structures", "entity_type": "engineering feature", "pos": [12, 30]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [43, 45]}], "task": "NER"}
{"text": "In recent years AM has grown from a prototyping technology to a reliable direct production technique .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [16, 18]}, {"entity": "prototyping", "entity_type": "concept or principle", "pos": [36, 47]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [80, 90]}], "task": "NER"}
{"text": "In particular , metal AM has developed tremendously , up to the point where it is now possible to produce functional metal parts for critical applications in medical and aerospace industries .", "entity": [{"entity": "metal AM", "entity_type": "manufacturing process", "pos": [16, 24]}, {"entity": "metal", "entity_type": "material", "pos": [117, 122]}, {"entity": "medical", "entity_type": "application", "pos": [158, 165]}, {"entity": "aerospace industries", "entity_type": "application", "pos": [170, 190]}], "task": "NER"}
{"text": "Powder bed fusion is the term used to specifically describe metal AM using a laser or electron beam to melt tracks and layers for the manufacture of detailed and complex shaped parts .", "entity": [{"entity": "Powder bed fusion", "entity_type": "manufacturing process", "pos": [0, 17]}, {"entity": "metal AM", "entity_type": "manufacturing process", "pos": [60, 68]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [77, 82]}, {"entity": "electron beam", "entity_type": "concept or principle", "pos": [86, 99]}, {"entity": "melt", "entity_type": "concept or principle", "pos": [103, 107]}, {"entity": "manufacture", "entity_type": "concept or principle", "pos": [134, 145]}], "task": "NER"}
{"text": "The track-by-track and layer-by-layer PBF process allows the manufacturing of parts with intricate , complex designs .", "entity": [{"entity": "layer-by-layer", "entity_type": "concept or principle", "pos": [23, 37]}, {"entity": "process", "entity_type": "concept or principle", "pos": [42, 49]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [61, 74]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [109, 116]}], "task": "NER"}
{"text": "Part complexity allows designs to be optimized for specific applications such as light-weighting in aerospace parts or improving bone growth and implant success in bone implants .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [5, 15]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [23, 30]}, {"entity": "be", "entity_type": "material", "pos": [34, 36]}, {"entity": "as", "entity_type": "material", "pos": [78, 80]}, {"entity": "aerospace", "entity_type": "application", "pos": [100, 109]}, {"entity": "bone growth", "entity_type": "concept or principle", "pos": [129, 140]}, {"entity": "implant", "entity_type": "application", "pos": [145, 152]}, {"entity": "bone implants", "entity_type": "application", "pos": [164, 177]}], "task": "NER"}
{"text": "It has been demonstrated that the mechanical performance of PBF parts can be superior to traditionally manufactured equivalents and lots of work has been done in particular in Ti6Al4V as shown in .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [34, 44]}, {"entity": "PBF", "entity_type": "manufacturing process", "pos": [60, 63]}, {"entity": "be", "entity_type": "material", "pos": [74, 76]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [103, 115]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [176, 183]}, {"entity": "as", "entity_type": "material", "pos": [184, 186]}], "task": "NER"}
{"text": "Laser powder bed fusion is limited to intricate parts typically smaller than 300 mm for larger metal parts it is possible to use wire and arc AM with a reduction in detail possible .", "entity": [{"entity": "Laser powder bed fusion", "entity_type": "manufacturing process", "pos": [0, 23]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [81, 83]}, {"entity": "metal", "entity_type": "material", "pos": [95, 100]}, {"entity": "wire and arc AM", "entity_type": "manufacturing process", "pos": [129, 144]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [152, 161]}], "task": "NER"}
{"text": "In addition to metals , various other materials can be reliably processed using AM including polymers , ceramics and various types of composites , as is discussed in more detail in .", "entity": [{"entity": "metals", "entity_type": "material", "pos": [15, 21]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [38, 47]}, {"entity": "be", "entity_type": "material", "pos": [52, 54]}, {"entity": "processed", "entity_type": "concept or principle", "pos": [64, 73]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [80, 82]}, {"entity": "polymers", "entity_type": "material", "pos": [93, 101]}, {"entity": "ceramics", "entity_type": "material", "pos": [104, 112]}, {"entity": "composites", "entity_type": "material", "pos": [134, 144]}, {"entity": "as", "entity_type": "material", "pos": [147, 149]}], "task": "NER"}
{"text": "Metals are highly likely to have practical uses in biomimetic structural applications in military , aerospace and automotive industries due to the light-weight and strong parts that can be produced , and hence much effort has been aimed in this direction .", "entity": [{"entity": "Metals", "entity_type": "material", "pos": [0, 6]}, {"entity": "biomimetic structural applications", "entity_type": "application", "pos": [51, 85]}, {"entity": "military", "entity_type": "application", "pos": [89, 97]}, {"entity": "aerospace", "entity_type": "application", "pos": [100, 109]}, {"entity": "automotive industries", "entity_type": "application", "pos": [114, 135]}, {"entity": "light-weight", "entity_type": "machanical property", "pos": [147, 159]}, {"entity": "be", "entity_type": "material", "pos": [186, 188]}], "task": "NER"}
{"text": "However , many biological systems are based on combinations of stiff and softer materials , and often have mechanical properties more like polymers and composite materials .", "entity": [{"entity": "biological systems", "entity_type": "concept or principle", "pos": [15, 33]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [80, 89]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [107, 128]}, {"entity": "polymers", "entity_type": "material", "pos": [139, 147]}, {"entity": "composite materials", "entity_type": "material", "pos": [152, 171]}], "task": "NER"}
{"text": "Therefore , many applications also exist for nature-inspired designs in materials other than metals .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [61, 68]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [72, 81]}, {"entity": "metals", "entity_type": "material", "pos": [93, 99]}], "task": "NER"}
{"text": "Many of the examples presented in this review focus specifically on metal AM , due to their relevance for high-value functional end-use parts , but the same principles apply to all other additively manufactured materials .", "entity": [{"entity": "metal AM", "entity_type": "manufacturing process", "pos": [68, 76]}, {"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [187, 210]}], "task": "NER"}
{"text": "For products designed by biomimicry , it has been proposed that two broad approaches exist : the approach and the approach as outlined in .", "entity": [{"entity": "designed", "entity_type": "engineering feature", "pos": [13, 21]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [25, 35]}, {"entity": "as", "entity_type": "material", "pos": [42, 44]}], "task": "NER"}
{"text": "In the first case , the designer/engineer is inspired by a biological concept or model and applies this to a new design idea .", "entity": [{"entity": "biological concept", "entity_type": "concept or principle", "pos": [59, 77]}, {"entity": "model", "entity_type": "concept or principle", "pos": [81, 86]}, {"entity": "design", "entity_type": "engineering feature", "pos": [113, 119]}], "task": "NER"}
{"text": "In addition to these approaches , three major ways of obtaining a designed biomimetic model in practice exist : customized/freeform design , simulation-driven design and lattice design .", "entity": [{"entity": "designed", "entity_type": "engineering feature", "pos": [66, 74]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [75, 85]}, {"entity": "design", "entity_type": "engineering feature", "pos": [132, 138]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [141, 158]}, {"entity": "design", "entity_type": "engineering feature", "pos": [159, 165]}, {"entity": "lattice design", "entity_type": "engineering feature", "pos": [170, 184]}], "task": "NER"}
{"text": "For example , lattices may be incorporated in a freeform design process or in a simulation-design process .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [14, 22]}, {"entity": "be", "entity_type": "material", "pos": [27, 29]}, {"entity": "freeform design", "entity_type": "engineering feature", "pos": [48, 63]}, {"entity": "process", "entity_type": "concept or principle", "pos": [64, 71]}], "task": "NER"}
{"text": "All these approaches may also be used with or without direct input from nature , with varying levels of biological input or bio-inspiration possible .", "entity": [{"entity": "be", "entity_type": "material", "pos": [30, 32]}, {"entity": "biological input", "entity_type": "biomedical", "pos": [104, 120]}, {"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [124, 139]}], "task": "NER"}
{"text": "Customized and freeform design involves manipulation with curved surfaces and is typically used to create custom and unique designs fit for a particular application while maintaining functionality .", "entity": [{"entity": "Customized and freeform design", "entity_type": "engineering feature", "pos": [0, 30]}, {"entity": "curved surfaces", "entity_type": "concept or principle", "pos": [58, 73]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [124, 131]}], "task": "NER"}
{"text": "For instance , customized implants aimed at directly replicating the bone shape for replacement , tree-like support structures , nervouB-system-inspired shade or hierarchical networks where nodes constantly branch and merge .", "entity": [{"entity": "implants", "entity_type": "application", "pos": [26, 34]}, {"entity": "bone shape", "entity_type": "process parameter", "pos": [69, 79]}, {"entity": "tree-like support structures", "entity_type": "machanical property", "pos": [98, 126]}, {"entity": "hierarchical networks", "entity_type": "concept or principle", "pos": [162, 183]}], "task": "NER"}
{"text": "This process is the simplest of the biomimetic design methods , particularly useful for customization such as in prosthetics or implants , and is also used in artistic design .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [36, 53]}, {"entity": "as", "entity_type": "material", "pos": [107, 109]}, {"entity": "prosthetics", "entity_type": "application", "pos": [113, 124]}, {"entity": "implants", "entity_type": "application", "pos": [128, 136]}, {"entity": "design", "entity_type": "engineering feature", "pos": [168, 174]}], "task": "NER"}
{"text": "With reference to prosthetics and implants , the design requirement is taken from a biological shape , hence the biomimetic description .", "entity": [{"entity": "prosthetics", "entity_type": "application", "pos": [18, 29]}, {"entity": "implants", "entity_type": "application", "pos": [34, 42]}, {"entity": "design", "entity_type": "engineering feature", "pos": [49, 55]}, {"entity": "biological shape", "entity_type": "engineering feature", "pos": [84, 100]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [113, 123]}], "task": "NER"}
{"text": "In addition , freeform design results in organic shapes which can often resemble natural structures .", "entity": [{"entity": "freeform design", "entity_type": "engineering feature", "pos": [14, 29]}], "task": "NER"}
{"text": "Simulation-driven design is a very promising approach which has emerged in recent years and is especially useful for light-weight design for engineering applications .", "entity": [{"entity": "Simulation-driven", "entity_type": "enabling technology", "pos": [0, 17]}, {"entity": "design", "entity_type": "engineering feature", "pos": [18, 24]}, {"entity": "light-weight", "entity_type": "machanical property", "pos": [117, 129]}, {"entity": "design", "entity_type": "engineering feature", "pos": [130, 136]}, {"entity": "engineering", "entity_type": "application", "pos": [141, 152]}], "task": "NER"}
{"text": "This involves structural optimization and uses an iterative process of simulation and material removal to optimize the required material distribution or material stiffness for a given set of expected load cases .", "entity": [{"entity": "structural optimization", "entity_type": "concept or principle", "pos": [14, 37]}, {"entity": "process", "entity_type": "concept or principle", "pos": [60, 67]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [71, 81]}, {"entity": "material", "entity_type": "material", "pos": [86, 94]}, {"entity": "material", "entity_type": "material", "pos": [128, 136]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [137, 149]}, {"entity": "material stiffness", "entity_type": "engineering feature", "pos": [153, 171]}, {"entity": "set", "entity_type": "application", "pos": [184, 187]}], "task": "NER"}
{"text": "This process of stepwise optimization is similar to most evolutionary processes in nature , and removal of material in areas of low stress is a similar optimization strategy as is used in natural systems , hence the motivation to categorize this process as biomimetic .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [25, 37]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [70, 79]}, {"entity": "material", "entity_type": "material", "pos": [107, 115]}, {"entity": "areas", "entity_type": "process parameter", "pos": [119, 124]}, {"entity": "stress", "entity_type": "machanical property", "pos": [132, 138]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [152, 164]}, {"entity": "as", "entity_type": "material", "pos": [174, 176]}, {"entity": "process", "entity_type": "concept or principle", "pos": [246, 253]}, {"entity": "as", "entity_type": "material", "pos": [254, 256]}], "task": "NER"}
{"text": "The field of topology optimization in AM was reviewed recently in , where the current limits of the practical use of this technique was discussed in detail , especially with regards to overhang angle , support removal , residual stress , build quality including challenges in software tools that need to be solved for its more widespread adoption .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [13, 34]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [38, 40]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [86, 92]}, {"entity": "overhang angle", "entity_type": "process parameter", "pos": [185, 199]}, {"entity": "support", "entity_type": "application", "pos": [202, 209]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [220, 235]}, {"entity": "build", "entity_type": "process parameter", "pos": [238, 243]}, {"entity": "software", "entity_type": "concept or principle", "pos": [276, 284]}, {"entity": "be", "entity_type": "material", "pos": [304, 306]}], "task": "NER"}
{"text": "The use of additively-manufactured lattice or cellular structures is a highly relevant approach which is often combined with the former methods , i.e .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [35, 42]}, {"entity": "cellular structures", "entity_type": "engineering feature", "pos": [46, 65]}], "task": "NER"}
{"text": "the incorporation of lattices or cellular designs into optimized organic or topology optimized designs .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [21, 29]}, {"entity": "cellular designs", "entity_type": "engineering feature", "pos": [33, 49]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [76, 84]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [95, 102]}], "task": "NER"}
{"text": "Natural systems often use cellular structures and these are widely used in bio-inspiration for the use of lattices in engineering parts , hence the categorization as biomimetic .", "entity": [{"entity": "cellular structures", "entity_type": "engineering feature", "pos": [26, 45]}, {"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [75, 90]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [106, 114]}, {"entity": "engineering", "entity_type": "application", "pos": [118, 129]}, {"entity": "as", "entity_type": "material", "pos": [163, 165]}], "task": "NER"}
{"text": "Lattices have obvious light-weighting advantages , high specific stiffness , fracture toughness , crack growth arresting , amongst other desirable and tailorable properties .", "entity": [{"entity": "Lattices", "entity_type": "concept or principle", "pos": [0, 8]}, {"entity": "specific stiffness", "entity_type": "machanical property", "pos": [56, 74]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [77, 85]}, {"entity": "crack growth", "entity_type": "concept or principle", "pos": [98, 110]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [162, 172]}], "task": "NER"}
{"text": "One major application of cellular structures is their use in bone implants , to improve osseointegration .", "entity": [{"entity": "cellular structures", "entity_type": "engineering feature", "pos": [25, 44]}, {"entity": "bone implants", "entity_type": "application", "pos": [61, 74]}, {"entity": "osseointegration", "entity_type": "machanical property", "pos": [88, 104]}], "task": "NER"}
{"text": "The design theory for present-day AM in general was reviewed and limitations discussed in .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [4, 10]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [34, 36]}], "task": "NER"}
{"text": "On the topic of biomimetic 3D printing , the review gives a detailed overview of the use of biological inputs into the design process , discusses biological study systems used in biomimicry and focusses on applications of polymer and multi-material 3D printing , but does not discuss metal AM or simulation-driven design .", "entity": [{"entity": "biomimetic", "entity_type": "concept or principle", "pos": [16, 26]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [27, 38]}, {"entity": "biological inputs", "entity_type": "biomedical", "pos": [92, 109]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [119, 133]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [179, 189]}, {"entity": "polymer", "entity_type": "material", "pos": [222, 229]}, {"entity": "multi-material 3D printing", "entity_type": "manufacturing process", "pos": [234, 260]}, {"entity": "metal AM", "entity_type": "manufacturing process", "pos": [284, 292]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [296, 313]}, {"entity": "design", "entity_type": "engineering feature", "pos": [314, 320]}], "task": "NER"}
{"text": "Biomimetic approaches for AM include the design of innovative materials and systems .", "entity": [{"entity": "Biomimetic", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [26, 28]}, {"entity": "design", "entity_type": "engineering feature", "pos": [41, 47]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [62, 71]}], "task": "NER"}
{"text": "In addition to simulation-driven design of single-material parts , fracture-resistant composite materials could be designed using simulation-driven design and validated by multi-material 3D printing as demonstrated in .", "entity": [{"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [15, 32]}, {"entity": "design", "entity_type": "engineering feature", "pos": [33, 39]}, {"entity": "fracture-resistant composite", "entity_type": "material", "pos": [67, 95]}, {"entity": "be", "entity_type": "material", "pos": [112, 114]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [130, 147]}, {"entity": "design", "entity_type": "engineering feature", "pos": [148, 154]}, {"entity": "multi-material 3D printing", "entity_type": "manufacturing process", "pos": [172, 198]}, {"entity": "as", "entity_type": "material", "pos": [199, 201]}], "task": "NER"}
{"text": "Multi-material biomimetic design for medical purposes has been demonstrated in .", "entity": [{"entity": "Multi-material", "entity_type": "concept or principle", "pos": [0, 14]}, {"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [15, 32]}, {"entity": "medical", "entity_type": "application", "pos": [37, 44]}], "task": "NER"}
{"text": "Not all freeform designs , lattice designs or topology optimized designs include biological input , but they are still referred to as biomimetic in a broader sense .", "entity": [{"entity": "freeform designs", "entity_type": "engineering feature", "pos": [8, 24]}, {"entity": "lattice designs", "entity_type": "engineering feature", "pos": [27, 42]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [46, 54]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [65, 72]}, {"entity": "biological input", "entity_type": "biomedical", "pos": [81, 97]}, {"entity": "as", "entity_type": "material", "pos": [131, 133]}], "task": "NER"}
{"text": "True biological input in the AM design process is still rare in engineering due to the lack of biologists involved in engineering design in general .", "entity": [{"entity": "biological input", "entity_type": "biomedical", "pos": [5, 21]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [29, 31]}, {"entity": "process", "entity_type": "concept or principle", "pos": [39, 46]}, {"entity": "engineering", "entity_type": "application", "pos": [64, 75]}, {"entity": "engineering", "entity_type": "application", "pos": [118, 129]}, {"entity": "design", "entity_type": "engineering feature", "pos": [130, 136]}], "task": "NER"}
{"text": "Nevertheless , biological materials science is a mature field which focuses on studying biological systems to understand their properties and potentially employ these designs in engineering systems .", "entity": [{"entity": "biological materials", "entity_type": "material", "pos": [15, 35]}, {"entity": "biological systems", "entity_type": "concept or principle", "pos": [88, 106]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [127, 137]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [167, 174]}, {"entity": "engineering", "entity_type": "application", "pos": [178, 189]}], "task": "NER"}
{"text": "Biological materials often possess superior mechanical properties due to unique combinations of hard and soft materials and gradients between them .", "entity": [{"entity": "Biological materials", "entity_type": "material", "pos": [0, 20]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [44, 65]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [110, 119]}], "task": "NER"}
{"text": "Biologically inspired design principles have been categorized recently into fibrous , helical , gradient , layered , tubular , cellular , suture and overlapping structures .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [22, 28]}, {"entity": "fibrous", "entity_type": "machanical property", "pos": [76, 83]}, {"entity": "tubular", "entity_type": "engineering feature", "pos": [117, 124]}, {"entity": "suture", "entity_type": "material", "pos": [138, 144]}], "task": "NER"}
{"text": "Besides broad design categories or guidelines , the use of X-ray tomography to study intricate details of individual biological structures in 3D for biomimetic applications is also a promising strategy to learn from nature .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [14, 20]}, {"entity": "X-ray tomography", "entity_type": "process characterization", "pos": [59, 75]}, {"entity": "biological structures", "entity_type": "engineering feature", "pos": [117, 138]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [142, 144]}, {"entity": "biomimetic applications", "entity_type": "application", "pos": [149, 172]}], "task": "NER"}
{"text": "Incorporating biological inputs into engineering design is a topic of continued effort and includes the development of biomimicry design databases .", "entity": [{"entity": "biological inputs", "entity_type": "biomedical", "pos": [14, 31]}, {"entity": "engineering", "entity_type": "application", "pos": [37, 48]}, {"entity": "design", "entity_type": "engineering feature", "pos": [49, 55]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [119, 129]}, {"entity": "databases", "entity_type": "enabling technology", "pos": [137, 146]}], "task": "NER"}
{"text": "Biomimetic design has also been named as it has been suggested that these approaches may lead to the use of the minimum required materials , which is most environmentally sustainable .", "entity": [{"entity": "Biomimetic design", "entity_type": "engineering feature", "pos": [0, 17]}, {"entity": "as", "entity_type": "material", "pos": [19, 21]}, {"entity": "lead", "entity_type": "material", "pos": [89, 93]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [129, 138]}, {"entity": "sustainable", "entity_type": "concept or principle", "pos": [171, 182]}], "task": "NER"}
{"text": "Despite the access to complexity and freedom of design , which is often cited for AM , all the biomimetic approaches discussed here have practical manufacturability limits in the context of present-day AM systems .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [22, 32]}, {"entity": "design", "entity_type": "engineering feature", "pos": [48, 54]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [82, 84]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [95, 105]}, {"entity": "manufacturability limits", "entity_type": "concept or principle", "pos": [147, 171]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [202, 204]}], "task": "NER"}
{"text": "A recent review paper covers the use of AM to produce bio-inspired structures with the main aim to learn about and optimize the biological structures themselves .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [40, 42]}, {"entity": "bio-inspired structures", "entity_type": "engineering feature", "pos": [54, 77]}, {"entity": "biological structures", "entity_type": "engineering feature", "pos": [128, 149]}], "task": "NER"}
{"text": "In the area of biomimetic cellular design , various recent reviews are useful and relevant to bone implant applications in particular , and are more generally discussed for various applications in .", "entity": [{"entity": "area", "entity_type": "process parameter", "pos": [7, 11]}, {"entity": "biomimetic cellular design", "entity_type": "engineering feature", "pos": [15, 41]}, {"entity": "bone implant applications", "entity_type": "application", "pos": [94, 119]}], "task": "NER"}
{"text": "It is therefore the aim of this present review paper to fill the gaps between these areas and address all the above biomimetic approaches in one cohesive framework .", "entity": [{"entity": "areas", "entity_type": "process parameter", "pos": [84, 89]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [116, 126]}, {"entity": "framework", "entity_type": "concept or principle", "pos": [154, 163]}], "task": "NER"}
{"text": "Most examples used in this paper are focused on metal AM due to its ability to produce functional end-use parts , but the principles are broadly applicable to all additively manufactured materials .", "entity": [{"entity": "metal AM", "entity_type": "manufacturing process", "pos": [48, 56]}, {"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [163, 186]}], "task": "NER"}
{"text": "While most of the discussion and examples are using laser powder bed fusion , other AM technologies are equally applicable and the design and challenges vary slightly with each technology .", "entity": [{"entity": "laser powder bed fusion", "entity_type": "manufacturing process", "pos": [52, 75]}, {"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [84, 99]}, {"entity": "design", "entity_type": "engineering feature", "pos": [131, 137]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [177, 187]}], "task": "NER"}
{"text": "For example , binder jetting has shown some promise for realization of complex designs cost effectively , but the obtained material properties require investigation .", "entity": [{"entity": "binder jetting", "entity_type": "manufacturing process", "pos": [14, 28]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [79, 86]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [123, 142]}], "task": "NER"}
{"text": "The fields of biomimicry and AM hold a unique synergy and inter-dependence on one another .", "entity": [{"entity": "biomimicry", "entity_type": "concept or principle", "pos": [14, 24]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [29, 31]}], "task": "NER"}
{"text": "2 True biomimicry True biomimicry of natural form , involves the purposeful emulation of structure-function relationships in biological entities to solve engineering challenges , or to apply these to advanced engineering systems .", "entity": [{"entity": "biomimicry", "entity_type": "concept or principle", "pos": [7, 17]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [23, 33]}, {"entity": "biological entities", "entity_type": "material", "pos": [125, 144]}, {"entity": "engineering", "entity_type": "application", "pos": [154, 165]}, {"entity": "engineering", "entity_type": "application", "pos": [209, 220]}], "task": "NER"}
{"text": "A review on biomimicry and bio-inspiration in the field of AM and 3D printing is provided in and focuses on explaining different potential biological study organisms and associated applications with specific biological input , mostly by polymer AM .", "entity": [{"entity": "biomimicry", "entity_type": "concept or principle", "pos": [12, 22]}, {"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [27, 42]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [59, 61]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [66, 77]}, {"entity": "biological input", "entity_type": "biomedical", "pos": [208, 224]}, {"entity": "polymer", "entity_type": "material", "pos": [237, 244]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [245, 247]}], "task": "NER"}
{"text": "In addition , the review highlights the potential for different forms of AM technologies to mimic nature .", "entity": [{"entity": "AM technologies", "entity_type": "manufacturing process", "pos": [73, 88]}, {"entity": "mimic", "entity_type": "machine or equipment", "pos": [92, 97]}], "task": "NER"}
{"text": "As mentioned above , the goal of biomimetic research is to learn generic design rules from natural systems to assist the development of optimized biomimetic materials which can be used widely in engineering systems .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [33, 43]}, {"entity": "design rules", "entity_type": "concept or principle", "pos": [73, 85]}, {"entity": "biomimetic materials", "entity_type": "material", "pos": [146, 166]}, {"entity": "be", "entity_type": "material", "pos": [177, 179]}, {"entity": "engineering", "entity_type": "application", "pos": [195, 206]}], "task": "NER"}
{"text": "To illustrate , osteoderms thin plates of dermal bone that form protective natural body armour in various animal species not only play a defensive role , but might also be involved in physiological processes such as thermoregulation .", "entity": [{"entity": "osteoderms", "entity_type": "biomedical", "pos": [16, 26]}, {"entity": "dermal bone", "entity_type": "biomedical", "pos": [42, 53]}, {"entity": "be", "entity_type": "material", "pos": [169, 171]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [198, 207]}, {"entity": "as", "entity_type": "material", "pos": [213, 215]}], "task": "NER"}
{"text": "The structural changes required for a physiological capacity might decrease the strength of osteoderms , rendering the structure less optimally adapted for protection than what would be expected .", "entity": [{"entity": "capacity", "entity_type": "concept or principle", "pos": [52, 60]}, {"entity": "strength", "entity_type": "machanical property", "pos": [80, 88]}, {"entity": "osteoderms", "entity_type": "biomedical", "pos": [92, 102]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [119, 128]}, {"entity": "be", "entity_type": "material", "pos": [183, 185]}], "task": "NER"}
{"text": "Alternatively , a bio-inspiration approach can be employed to alter specific properties of the natural structure resulting in an optimal design .", "entity": [{"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [18, 33]}, {"entity": "be", "entity_type": "material", "pos": [47, 49]}, {"entity": "specific properties", "entity_type": "machanical property", "pos": [68, 87]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [103, 112]}, {"entity": "design", "entity_type": "engineering feature", "pos": [137, 143]}], "task": "NER"}
{"text": "Glyptodon osteoderms consists of a lattice core sandwiched between two compact layers that form a shell .", "entity": [{"entity": "osteoderms", "entity_type": "biomedical", "pos": [10, 20]}, {"entity": "lattice core", "entity_type": "engineering feature", "pos": [35, 47]}, {"entity": "compact", "entity_type": "manufacturing process", "pos": [71, 78]}, {"entity": "shell", "entity_type": "machine or equipment", "pos": [98, 103]}], "task": "NER"}
{"text": "By printing and testing 3D models with varying lattice and shell parameters , the optimized shell thickness compared to lattice density and lattice strut thickness was revealed .", "entity": [{"entity": "testing", "entity_type": "process characterization", "pos": [16, 23]}, {"entity": "3D models", "entity_type": "application", "pos": [24, 33]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [47, 54]}, {"entity": "shell", "entity_type": "machine or equipment", "pos": [59, 64]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [65, 75]}, {"entity": "shell", "entity_type": "machine or equipment", "pos": [92, 97]}, {"entity": "lattice density", "entity_type": "engineering feature", "pos": [120, 135]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [140, 147]}], "task": "NER"}
{"text": "Similar procedures have been used to reverse-engineer a natural structure for application as a gripping device the Aristotlelantern structure as described in .", "entity": [{"entity": "structure", "entity_type": "concept or principle", "pos": [64, 73]}, {"entity": "as", "entity_type": "material", "pos": [90, 92]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [132, 141]}, {"entity": "as", "entity_type": "material", "pos": [142, 144]}], "task": "NER"}
{"text": "The mechanical properties of natural materials , particularly the superior fracture toughness , make biological structures highly suitable for biomimetic studies .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [4, 25]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [37, 46]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [75, 83]}, {"entity": "biological structures", "entity_type": "engineering feature", "pos": [101, 122]}, {"entity": "biomimetic studies", "entity_type": "concept or principle", "pos": [143, 161]}], "task": "NER"}
{"text": "Nevertheless , a major advantage of AM is that a structure of interest can be further optimized by using materials that do not occur naturally in biological systems .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [36, 38]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [49, 58]}, {"entity": "be", "entity_type": "material", "pos": [75, 77]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [105, 114]}, {"entity": "biological systems", "entity_type": "concept or principle", "pos": [146, 164]}], "task": "NER"}
{"text": "In the case of glyptodont osteoderms , the use of biomimetic reverse-engineered metal models show remarkable strength and energy absorption capacity .", "entity": [{"entity": "osteoderms", "entity_type": "biomedical", "pos": [26, 36]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [50, 60]}, {"entity": "metal", "entity_type": "material", "pos": [80, 85]}, {"entity": "strength", "entity_type": "machanical property", "pos": [109, 117]}, {"entity": "energy absorption capacity", "entity_type": "process characterization", "pos": [122, 148]}], "task": "NER"}
{"text": "Besides material properties , the combination of hard and soft materials has been studied for improved fracture toughness properties using simulation-driven design tools .", "entity": [{"entity": "material properties", "entity_type": "concept or principle", "pos": [8, 27]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [63, 72]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [103, 111]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [122, 132]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [139, 156]}, {"entity": "design", "entity_type": "engineering feature", "pos": [157, 163]}], "task": "NER"}
{"text": "In a recent study , pangolin scales were used as inspiration for bendable protective material for aerospace applications different combinations of hard plates and soft connecting material were 3D printed and mechanically tested .", "entity": [{"entity": "as", "entity_type": "material", "pos": [46, 48]}, {"entity": "bendable protective material", "entity_type": "material", "pos": [65, 93]}, {"entity": "aerospace", "entity_type": "application", "pos": [98, 107]}, {"entity": "material", "entity_type": "material", "pos": [179, 187]}, {"entity": "3D printed", "entity_type": "manufacturing process", "pos": [193, 203]}], "task": "NER"}
{"text": "Lastly , the microarchitecture of biological structures , which can be categorized as one of eight forms : fibrous , helical , gradient , layered , tubular , cellular , suture and overlapping , plays an important role in determining the mechanical properties of biological materials .", "entity": [{"entity": "microarchitecture", "entity_type": "concept or principle", "pos": [13, 30]}, {"entity": "biological structures", "entity_type": "engineering feature", "pos": [34, 55]}, {"entity": "be", "entity_type": "material", "pos": [68, 70]}, {"entity": "as", "entity_type": "material", "pos": [83, 85]}, {"entity": "fibrous", "entity_type": "machanical property", "pos": [107, 114]}, {"entity": "tubular", "entity_type": "engineering feature", "pos": [148, 155]}, {"entity": "suture", "entity_type": "material", "pos": [169, 175]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [237, 258]}, {"entity": "biological materials", "entity_type": "material", "pos": [262, 282]}], "task": "NER"}
{"text": "These structural organizations can be replicated by AM to study and optimize the arrangement of biological materials as discussed in .", "entity": [{"entity": "be", "entity_type": "material", "pos": [35, 37]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [52, 54]}, {"entity": "biological materials", "entity_type": "material", "pos": [96, 116]}, {"entity": "as", "entity_type": "material", "pos": [117, 119]}], "task": "NER"}
{"text": "Hierarchical structures such as functional graded materials , structures and surfaces can be produced directly by AM or in combination with other methods .", "entity": [{"entity": "Hierarchical structures", "entity_type": "engineering feature", "pos": [0, 23]}, {"entity": "as", "entity_type": "material", "pos": [29, 31]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [50, 59]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [77, 85]}, {"entity": "be", "entity_type": "material", "pos": [90, 92]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [114, 116]}], "task": "NER"}
{"text": "For example , LPBF and femtosecond laser surface modification makes it possible to produce complex hierarchical structures for wettability applications .", "entity": [{"entity": "LPBF", "entity_type": "manufacturing process", "pos": [14, 18]}, {"entity": "femtosecond laser", "entity_type": "concept or principle", "pos": [23, 40]}, {"entity": "hierarchical structures", "entity_type": "engineering feature", "pos": [99, 122]}, {"entity": "wettability", "entity_type": "concept or principle", "pos": [127, 138]}], "task": "NER"}
{"text": "Stereolithography and LPBF was applied for manufacturing of a multi-material arm orthosis ; this approach can be used for manufacturing implants where the strength varies throughout the implant .", "entity": [{"entity": "Stereolithography", "entity_type": "manufacturing process", "pos": [0, 17]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [22, 26]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [43, 56]}, {"entity": "multi-material", "entity_type": "concept or principle", "pos": [62, 76]}, {"entity": "be", "entity_type": "material", "pos": [110, 112]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [122, 135]}, {"entity": "implants", "entity_type": "application", "pos": [136, 144]}, {"entity": "strength", "entity_type": "machanical property", "pos": [155, 163]}, {"entity": "implant", "entity_type": "application", "pos": [186, 193]}], "task": "NER"}
{"text": "In general , AM of in-situ LPBF sintered composite objects also is a form of biomimicry since biological tissues are composite materials with stiff reinforcing elements and binding medium .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [13, 15]}, {"entity": "in-situ", "entity_type": "concept or principle", "pos": [19, 26]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [32, 40]}, {"entity": "composite", "entity_type": "material", "pos": [41, 50]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [77, 87]}, {"entity": "biological tissues", "entity_type": "material", "pos": [94, 112]}, {"entity": "composite materials", "entity_type": "material", "pos": [117, 136]}, {"entity": "reinforcing elements", "entity_type": "engineering feature", "pos": [148, 168]}], "task": "NER"}
{"text": "A pivotal tool to characterize structures for biomimicry or bio-inspiration is X-ray micro-computed tomography , as reviewed in .", "entity": [{"entity": "tool", "entity_type": "machine or equipment", "pos": [10, 14]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [46, 56]}, {"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [60, 75]}, {"entity": "X-ray micro-computed tomography", "entity_type": "process characterization", "pos": [79, 110]}, {"entity": "as", "entity_type": "material", "pos": [113, 115]}], "task": "NER"}
{"text": "MicroCT is ideally suited to obtain detailed microstructural information of natural structures in 3D , which can be used to directly replicate natural structures , measure 3D design values and implement these in engineering structures as bio-inspiration , or in a broader sense to create a design principle without using any measurements .", "entity": [{"entity": "MicroCT", "entity_type": "process characterization", "pos": [0, 7]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [45, 60]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [98, 100]}, {"entity": "be", "entity_type": "material", "pos": [113, 115]}, {"entity": "3D design values", "entity_type": "engineering feature", "pos": [172, 188]}, {"entity": "engineering", "entity_type": "application", "pos": [212, 223]}, {"entity": "as", "entity_type": "material", "pos": [235, 237]}, {"entity": "design", "entity_type": "engineering feature", "pos": [290, 296]}], "task": "NER"}
{"text": "These three are shown in 3 , using the examples of a direct replication of a structure printed on an entry-level FDM printer , a reverse-engineered design based on measurements taken from a natural structure and a generic bio-inspiration example in which honeycomb structures are used as light-weight design .", "entity": [{"entity": "direct replication", "entity_type": "concept or principle", "pos": [53, 71]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [77, 86]}, {"entity": "FDM printer", "entity_type": "machine or equipment", "pos": [113, 124]}, {"entity": "design", "entity_type": "engineering feature", "pos": [148, 154]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [198, 207]}, {"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [222, 237]}, {"entity": "honeycomb structures", "entity_type": "engineering feature", "pos": [255, 275]}, {"entity": "as", "entity_type": "material", "pos": [285, 287]}, {"entity": "design", "entity_type": "engineering feature", "pos": [301, 307]}], "task": "NER"}
{"text": "The main aim of direct replication is to investigate the structure of interest .", "entity": [{"entity": "direct replication", "entity_type": "concept or principle", "pos": [16, 34]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [57, 66]}], "task": "NER"}
{"text": "For reverse-engineering , the goal is similar to that of direct replication , but the techniques make the structure more practical for direct engineering applications .", "entity": [{"entity": "direct replication", "entity_type": "concept or principle", "pos": [57, 75]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [106, 115]}, {"entity": "engineering", "entity_type": "application", "pos": [142, 153]}], "task": "NER"}
{"text": "The generic bio-inspiration involves using design or guidelines from nature , which might be more beneficial when limits are imposed on the structure .", "entity": [{"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [12, 27]}, {"entity": "design", "entity_type": "engineering feature", "pos": [43, 49]}, {"entity": "be", "entity_type": "material", "pos": [90, 92]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [114, 120]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [140, 149]}], "task": "NER"}
{"text": "One biological structure that is of particular interest to biomimetic studies , and which has been studied extensively using microCT , is the lightweight structure of bird feathers and bones .", "entity": [{"entity": "biological structure", "entity_type": "engineering feature", "pos": [4, 24]}, {"entity": "biomimetic studies", "entity_type": "concept or principle", "pos": [59, 77]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [125, 132]}, {"entity": "lightweight structure", "entity_type": "machine or equipment", "pos": [142, 163]}, {"entity": "bird feathers", "entity_type": "material", "pos": [167, 180]}], "task": "NER"}
{"text": "Here , bio-inspiration and design rules might be applied in engineering designs for aerospace applications .", "entity": [{"entity": "bio-inspiration", "entity_type": "concept or principle", "pos": [7, 22]}, {"entity": "design rules", "entity_type": "concept or principle", "pos": [27, 39]}, {"entity": "be", "entity_type": "material", "pos": [46, 48]}, {"entity": "engineering", "entity_type": "application", "pos": [60, 71]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [72, 79]}, {"entity": "aerospace", "entity_type": "application", "pos": [84, 93]}], "task": "NER"}
{"text": "In recent work using topology optimization techniques , an optimized light-weight structure for an airplane wing was demonstrated through simulation and optimization , with the obtained structure having a strong resemblance to the structure of bird wing bones , i.e. , a solid shell and connecting rods at angles inside the hollow structure .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [21, 42]}, {"entity": "light-weight", "entity_type": "machanical property", "pos": [69, 81]}, {"entity": "airplane wing", "entity_type": "application", "pos": [99, 112]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [138, 148]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [153, 165]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [186, 195]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [231, 240]}, {"entity": "shell", "entity_type": "machine or equipment", "pos": [277, 282]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [331, 340]}], "task": "NER"}
{"text": "While the optimality of bone design had been well described analytically , this was the first example of large-scale computational structure design : the rapid increase in computing power over the last years now allows for obtaining detailed structures from simulation-driven design tools , which for the first time nears the complexity of natural systems .", "entity": [{"entity": "bone", "entity_type": "biomedical", "pos": [24, 28]}, {"entity": "computational structure design", "entity_type": "engineering feature", "pos": [117, 147]}, {"entity": "power", "entity_type": "process parameter", "pos": [182, 187]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [258, 275]}, {"entity": "design", "entity_type": "engineering feature", "pos": [276, 282]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [326, 336]}], "task": "NER"}
{"text": "In conclusion , the complexity that AM allows makes it possible to manufacture true biomimetic structures , yet , knowledge of the biological structure is necessary .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [20, 30]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [36, 38]}, {"entity": "manufacture", "entity_type": "concept or principle", "pos": [67, 78]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [84, 94]}, {"entity": "biological structure", "entity_type": "engineering feature", "pos": [131, 151]}], "task": "NER"}
{"text": "3 Customized and freeform design Traditional design for engineering involves individual part design in computer-aided design tools , with engineering expertise and intuition required to understand the limits of traditional subtractive manufacturing .", "entity": [{"entity": "Customized and freeform design", "entity_type": "engineering feature", "pos": [2, 32]}, {"entity": "design", "entity_type": "engineering feature", "pos": [45, 51]}, {"entity": "engineering", "entity_type": "application", "pos": [56, 67]}, {"entity": "design", "entity_type": "engineering feature", "pos": [93, 99]}, {"entity": "computer-aided design", "entity_type": "enabling technology", "pos": [103, 124]}, {"entity": "engineering", "entity_type": "application", "pos": [138, 149]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [201, 207]}, {"entity": "traditional subtractive manufacturing", "entity_type": "manufacturing process", "pos": [211, 248]}], "task": "NER"}
{"text": "This most often results in traditional designs with right angles and flat surfaces due to the simplicity for subtractive manufacturing of such designs .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [39, 46]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [74, 82]}, {"entity": "subtractive manufacturing", "entity_type": "manufacturing process", "pos": [109, 134]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [143, 150]}], "task": "NER"}
{"text": "Over the last few years , advanced manufacturing techniques have become available and viable which allows the design engineer more freedom to create parts with more complex designs .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [35, 48]}, {"entity": "design", "entity_type": "engineering feature", "pos": [110, 116]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [173, 180]}], "task": "NER"}
{"text": "These new design capabilities allow organic shapes and freeform designs , which are often also termed biomimetic due to their organic shapes resembling natural structures and sometimes , in the case of medical devices in particular , the forms are shaped to fit natural materials such as bone implants .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [10, 16]}, {"entity": "freeform designs", "entity_type": "engineering feature", "pos": [55, 71]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [102, 112]}, {"entity": "medical devices", "entity_type": "application", "pos": [202, 217]}, {"entity": "fit", "entity_type": "concept or principle", "pos": [258, 261]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [270, 279]}, {"entity": "as", "entity_type": "material", "pos": [285, 287]}, {"entity": "implants", "entity_type": "application", "pos": [293, 301]}], "task": "NER"}
{"text": "Natural structures tend to comprise of curves and organic shapes as they represent a balance between minimal energy expenditure and material used on the one hand , and maximal return of work on the other hand , all within the organismdevelopmental limits .", "entity": [{"entity": "as", "entity_type": "material", "pos": [65, 67]}, {"entity": "energy expenditure", "entity_type": "machanical property", "pos": [109, 127]}, {"entity": "material", "entity_type": "material", "pos": [132, 140]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [248, 254]}], "task": "NER"}
{"text": "Freeform and custom designs may be termed biomimetic as they resemble natural structures in these aspects , but without the constraints imposed by the organism itself .", "entity": [{"entity": "Freeform", "entity_type": "concept or principle", "pos": [0, 8]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [20, 27]}, {"entity": "be", "entity_type": "material", "pos": [32, 34]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [42, 52]}, {"entity": "as", "entity_type": "material", "pos": [53, 55]}], "task": "NER"}
{"text": "Despite this freedom of design , traditional engineering thinking is often limited to experience of using right angles and flat surfaces .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [24, 30]}, {"entity": "engineering", "entity_type": "application", "pos": [45, 56]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [128, 136]}], "task": "NER"}
{"text": "In order to optimally use this new design freedom , additional tools are needed .", "entity": [{"entity": "design freedom", "entity_type": "concept or principle", "pos": [35, 49]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [63, 68]}], "task": "NER"}
{"text": "The most important contributing tools for freeform design are discussed here .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [32, 37]}, {"entity": "freeform design", "entity_type": "engineering feature", "pos": [42, 57]}], "task": "NER"}
{"text": "One of these is the shaping of curved and organic surfaces by the use of T-splines and more recently polygonal non-uniform rational B-spline .", "entity": [{"entity": "shaping", "entity_type": "manufacturing process", "pos": [20, 27]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [50, 58]}, {"entity": "T-splines", "entity_type": "engineering feature", "pos": [73, 82]}, {"entity": "non-uniform rational B-spline", "entity_type": "concept or principle", "pos": [111, 140]}], "task": "NER"}
{"text": "These tools allow organic designs with curved surfaces that often resemble natural structures .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [6, 11]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [26, 33]}, {"entity": "curved surfaces", "entity_type": "concept or principle", "pos": [39, 54]}], "task": "NER"}
{"text": "These are also critical tools in final steps of topology optimization and even true biomimetic reverse engineering structures , ultimately allowing for watertight models with curved geometries .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [24, 29]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [48, 69]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [84, 94]}, {"entity": "engineering", "entity_type": "application", "pos": [103, 114]}, {"entity": "watertight models", "entity_type": "concept or principle", "pos": [152, 169]}, {"entity": "geometries", "entity_type": "concept or principle", "pos": [182, 192]}], "task": "NER"}
{"text": "Not only do these tools make custom curved shapes possible in a relevant workspace , but they are also effectively translated into geometries suitable for simulation and/or AM .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [18, 23]}, {"entity": "geometries", "entity_type": "concept or principle", "pos": [131, 141]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [155, 165]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [173, 175]}], "task": "NER"}
{"text": "In terms of custom design especially for implants patient-specific implants are a special category and require a particular workflow involving the processing of medical image data , the use of CAD tools and design for AM knowledge to yield a good resulting implant as discussed in .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [19, 25]}, {"entity": "implants", "entity_type": "application", "pos": [41, 49]}, {"entity": "implants", "entity_type": "application", "pos": [67, 75]}, {"entity": "workflow", "entity_type": "concept or principle", "pos": [124, 132]}, {"entity": "medical", "entity_type": "application", "pos": [161, 168]}, {"entity": "image data", "entity_type": "concept or principle", "pos": [169, 179]}, {"entity": "CAD", "entity_type": "enabling technology", "pos": [193, 196]}, {"entity": "design", "entity_type": "engineering feature", "pos": [207, 213]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [218, 220]}, {"entity": "implant", "entity_type": "application", "pos": [257, 264]}, {"entity": "as", "entity_type": "material", "pos": [265, 267]}], "task": "NER"}
{"text": "An example is shown in 4 where a patient-specific facial implant was produced in Ti6Al4V .", "entity": [{"entity": "implant", "entity_type": "application", "pos": [57, 64]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [81, 88]}], "task": "NER"}
{"text": "Increases in computing power , the availability of cloud computing and the wider availability of CAE tools all led to the sharp increase in advanced and complex design capability .", "entity": [{"entity": "power", "entity_type": "process parameter", "pos": [23, 28]}, {"entity": "cloud computing", "entity_type": "enabling technology", "pos": [51, 66]}, {"entity": "CAE", "entity_type": "enabling technology", "pos": [97, 100]}, {"entity": "led", "entity_type": "application", "pos": [111, 114]}, {"entity": "design", "entity_type": "engineering feature", "pos": [161, 167]}], "task": "NER"}
{"text": "One of the first examples was the Insight Plotfrom Solidworks , which demonstrates the main load paths in a designed part , as calculated from one or more applied loads by finite element modelling .", "entity": [{"entity": "designed", "entity_type": "engineering feature", "pos": [108, 116]}, {"entity": "as", "entity_type": "material", "pos": [124, 126]}, {"entity": "finite element modelling", "entity_type": "process characterization", "pos": [172, 196]}], "task": "NER"}
{"text": "This was a forerunner of topology optimization tools which will be discussed in more detail in the next section .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [25, 46]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [47, 52]}, {"entity": "be", "entity_type": "material", "pos": [64, 66]}], "task": "NER"}
{"text": "As mentioned above , AM releases much of the traditional limits of subtractive manufacturing allowing much wider allowed manufacturing complexity .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [21, 23]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [57, 63]}, {"entity": "subtractive manufacturing", "entity_type": "manufacturing process", "pos": [67, 92]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [121, 134]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [135, 145]}], "task": "NER"}
{"text": "This is already broadly acknowledged , and new design rules for reliable manufacturing in all forms of AM are emerging and in many cases are already mature and well-defined .", "entity": [{"entity": "design rules", "entity_type": "concept or principle", "pos": [47, 59]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [73, 86]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [103, 105]}], "task": "NER"}
{"text": "The design for AM rules and practical issues are discussed in detail in and more recently in the context of topology optimization in .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [4, 10]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [15, 17]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [108, 129]}], "task": "NER"}
{"text": "One major advantage of these new design tools for creating manually organic and curved surfaces and shapes is the ability to create artistic features the resemblance to biological/natural and organic structures brings a new dimension to artistic designs for end-use products .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [33, 39]}, {"entity": "curved surfaces", "entity_type": "concept or principle", "pos": [80, 95]}, {"entity": "biological/natural", "entity_type": "biomedical", "pos": [169, 187]}, {"entity": "organic structures", "entity_type": "engineering feature", "pos": [192, 210]}, {"entity": "dimension", "entity_type": "engineering feature", "pos": [224, 233]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [246, 253]}], "task": "NER"}
{"text": "The use of 3D printing in arts , fashion and jewelry is growing as is shown in and artistic design is easily achieved by AM , without significantly adding to the cost of the product .", "entity": [{"entity": "3D printing", "entity_type": "manufacturing process", "pos": [11, 22]}, {"entity": "fashion", "entity_type": "concept or principle", "pos": [33, 40]}, {"entity": "as", "entity_type": "material", "pos": [64, 66]}, {"entity": "design", "entity_type": "engineering feature", "pos": [92, 98]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [121, 123]}], "task": "NER"}
{"text": "Freeform design tools can be used to shape custom-fit sportswear or footwear , with the first fully-AM footwear being produced by Adidas Futurecraft .", "entity": [{"entity": "Freeform design", "entity_type": "engineering feature", "pos": [0, 15]}, {"entity": "be", "entity_type": "material", "pos": [26, 28]}, {"entity": "footwear", "entity_type": "machine or equipment", "pos": [68, 76]}, {"entity": "footwear", "entity_type": "machine or equipment", "pos": [103, 111]}], "task": "NER"}
{"text": "The design of this shoe is entirely latticed giving a futuristic and biomimetic visual appeal .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [4, 10]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [69, 79]}], "task": "NER"}
{"text": "These are two examples of mass production and mass customization by AM .", "entity": [{"entity": "mass production", "entity_type": "concept or principle", "pos": [26, 41]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [68, 70]}], "task": "NER"}
{"text": "Aspects of importance besides personal/custom design for fit , is the incorporation of logos or names , and the ability for the customer to take part in the design process giving them some options making their product unique .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [46, 52]}, {"entity": "fit", "entity_type": "concept or principle", "pos": [57, 60]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [157, 171]}], "task": "NER"}
{"text": "4 Simulation-driven biomimetic design One of the first drivers of the concepts behind simulation-driven design was from the ideas of Julius Wolff , the 19th Century Orthopedic surgeon , who first suggested that , a consequence of primary shape variations and continuous loading , or even due to loading alone , bone changes its inner architecture according to mathematical rules and , as a secondary effect and governed by the same mathematical rules , also changes its shape .", "entity": [{"entity": "Simulation-driven", "entity_type": "enabling technology", "pos": [2, 19]}, {"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [20, 37]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [86, 103]}, {"entity": "design", "entity_type": "engineering feature", "pos": [104, 110]}, {"entity": "variations", "entity_type": "concept or principle", "pos": [244, 254]}, {"entity": "bone", "entity_type": "biomedical", "pos": [311, 315]}, {"entity": "architecture", "entity_type": "application", "pos": [334, 346]}, {"entity": "mathematical", "entity_type": "concept or principle", "pos": [360, 372]}, {"entity": "as", "entity_type": "material", "pos": [385, 387]}, {"entity": "mathematical", "entity_type": "concept or principle", "pos": [432, 444]}], "task": "NER"}
{"text": "The concept of topology optimization sprung from here from the concept that a structure can be optimized by following load paths and be modified to fit the particular mechanical requirement .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [15, 36]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [78, 87]}, {"entity": "be", "entity_type": "material", "pos": [92, 94]}, {"entity": "be", "entity_type": "material", "pos": [133, 135]}, {"entity": "fit", "entity_type": "concept or principle", "pos": [148, 151]}, {"entity": "mechanical", "entity_type": "application", "pos": [167, 177]}], "task": "NER"}
{"text": "The first industrial class software solutions incorporating the rules of design along with the ability to capture the along with the constraints to automatically generate design was released in the early 1990This was primarily the beginning of CAE simulation driving inspirational designs .", "entity": [{"entity": "industrial", "entity_type": "application", "pos": [10, 20]}, {"entity": "software", "entity_type": "concept or principle", "pos": [27, 35]}, {"entity": "design", "entity_type": "engineering feature", "pos": [73, 79]}, {"entity": "design", "entity_type": "engineering feature", "pos": [171, 177]}, {"entity": "CAE simulation", "entity_type": "enabling technology", "pos": [244, 258]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [281, 288]}], "task": "NER"}
{"text": "Over the years many manufacturing constraints have also been added to shape these designs to be cognizant of the downstream manufacturing , and is relevant to different manufacturing processes .", "entity": [{"entity": "manufacturing constraints", "entity_type": "concept or principle", "pos": [20, 45]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [82, 89]}, {"entity": "be", "entity_type": "material", "pos": [93, 95]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [124, 137]}, {"entity": "manufacturing processes", "entity_type": "manufacturing process", "pos": [169, 192]}], "task": "NER"}
{"text": "If the part is produced by an extrusion process , then using the extrusion constraints will generate a shape that is extrudable across the defined design space .", "entity": [{"entity": "extrusion process", "entity_type": "manufacturing process", "pos": [30, 47]}, {"entity": "extrusion", "entity_type": "manufacturing process", "pos": [65, 74]}, {"entity": "design space", "entity_type": "concept or principle", "pos": [147, 159]}], "task": "NER"}
{"text": "Likewise , on specifying a casting constraint , the bionic shape that is generated will be free of undercuts for easy extraction from the casting molds .", "entity": [{"entity": "casting", "entity_type": "manufacturing process", "pos": [27, 34]}, {"entity": "be", "entity_type": "material", "pos": [88, 90]}, {"entity": "undercuts", "entity_type": "engineering feature", "pos": [99, 108]}, {"entity": "casting molds", "entity_type": "machine or equipment", "pos": [138, 151]}], "task": "NER"}
{"text": "For AM , overhang constraints generate shapes that have minimal support requirement during build in a given print direction , with less horizontal sections , for example .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [4, 6]}, {"entity": "overhang constraints", "entity_type": "process parameter", "pos": [9, 29]}, {"entity": "support", "entity_type": "application", "pos": [64, 71]}, {"entity": "build", "entity_type": "process parameter", "pos": [91, 96]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [108, 113]}], "task": "NER"}
{"text": "There are various manufacturing constraints in AM that can be incorporated into the design optimization process and it is the incorporation of these into the topology optimization process which will create designs ready for production .", "entity": [{"entity": "manufacturing constraints", "entity_type": "concept or principle", "pos": [18, 43]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [47, 49]}, {"entity": "be", "entity_type": "material", "pos": [59, 61]}, {"entity": "design optimization process", "entity_type": "concept or principle", "pos": [84, 111]}, {"entity": "topology optimization process", "entity_type": "engineering feature", "pos": [158, 187]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [206, 213]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [224, 234]}], "task": "NER"}
{"text": "Shown in 5 are selected examples from Altair covering a variety of parts that illustrate the power of simulation in mimicking nature for product design that outperform conventional designs and are manufacturable and lightweight .", "entity": [{"entity": "power", "entity_type": "process parameter", "pos": [93, 98]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [102, 112]}, {"entity": "product design", "entity_type": "engineering feature", "pos": [137, 151]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [181, 188]}, {"entity": "manufacturable", "entity_type": "concept or principle", "pos": [197, 211]}, {"entity": "lightweight", "entity_type": "concept or principle", "pos": [216, 227]}], "task": "NER"}
{"text": "The first example is the HardMarque automotive piston which was designed and optimized for production by additive manufacturing in titanium the end result is reported to be 25 % lighter and equally strong compared to the original aluminium part .", "entity": [{"entity": "automotive", "entity_type": "application", "pos": [36, 46]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [64, 72]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [91, 101]}, {"entity": "additive manufacturing", "entity_type": "manufacturing process", "pos": [105, 127]}, {"entity": "titanium", "entity_type": "material", "pos": [131, 139]}, {"entity": "be", "entity_type": "material", "pos": [170, 172]}, {"entity": "aluminium", "entity_type": "material", "pos": [230, 239]}], "task": "NER"}
{"text": "The second example from Renishaw is a seat post bracket of a mountain bike , meant to replace a cast aluminium part with additively manufactured titanium : the mass reduction was reported at 40 % .", "entity": [{"entity": "bracket", "entity_type": "machine or equipment", "pos": [48, 55]}, {"entity": "cast", "entity_type": "manufacturing process", "pos": [96, 100]}, {"entity": "aluminium", "entity_type": "material", "pos": [101, 110]}, {"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [121, 144]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [165, 174]}], "task": "NER"}
{"text": "The third example is a case study from the aerospace industry , in particular the optimization of a mechanical hinge for an Airbus A320 by the European Aeronautic Defence and Space Innovation Works in this case a 75 % mass reduction was realized .", "entity": [{"entity": "case study", "entity_type": "concept or principle", "pos": [23, 33]}, {"entity": "aerospace industry", "entity_type": "application", "pos": [43, 61]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [82, 94]}, {"entity": "mechanical", "entity_type": "application", "pos": [100, 110]}, {"entity": "Airbus A320", "entity_type": "application", "pos": [124, 135]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [223, 232]}], "task": "NER"}
{"text": "The last example is a research project with Laser Zentrum Nord focusing on lightweighting of aircraft cabin brackets .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [22, 30]}, {"entity": "Laser", "entity_type": "enabling technology", "pos": [44, 49]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [75, 89]}], "task": "NER"}
{"text": "Simulation-driven design in the context of AM refers to the use of simulation to numerically and a given space to meet some desired performance criteria under a defined set of constraints .", "entity": [{"entity": "Simulation-driven", "entity_type": "enabling technology", "pos": [0, 17]}, {"entity": "design", "entity_type": "engineering feature", "pos": [18, 24]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [43, 45]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [67, 77]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [132, 143]}, {"entity": "set", "entity_type": "application", "pos": [169, 172]}], "task": "NER"}
{"text": "This currently refers to either of topology optimization or generative design , which can often be used interchangeably in the context of AM both involve the use of simulation .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [35, 56]}, {"entity": "generative design", "entity_type": "enabling technology", "pos": [60, 77]}, {"entity": "be", "entity_type": "material", "pos": [96, 98]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [138, 140]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [165, 175]}], "task": "NER"}
{"text": "Topology optimization refers to optimizing an existing shape or design space .", "entity": [{"entity": "Topology optimization", "entity_type": "engineering feature", "pos": [0, 21]}, {"entity": "design space", "entity_type": "concept or principle", "pos": [64, 76]}], "task": "NER"}
{"text": "Generative design is a broader definition of exploring a variety of possible designs within a given space with a desire to identify an optimal solution from various possible solutions meeting the same performance criteria .", "entity": [{"entity": "Generative design", "entity_type": "enabling technology", "pos": [0, 17]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [77, 84]}, {"entity": "solution", "entity_type": "concept or principle", "pos": [143, 151]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [201, 212]}], "task": "NER"}
{"text": "In the context of design for AM , both the approaches are aimed at creating light-weight parts which mostly contain material in areas were load is experienced and material is removed in areas which do not require it .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [18, 24]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [29, 31]}, {"entity": "light-weight", "entity_type": "machanical property", "pos": [76, 88]}, {"entity": "material", "entity_type": "material", "pos": [116, 124]}, {"entity": "areas", "entity_type": "process parameter", "pos": [128, 133]}, {"entity": "material", "entity_type": "material", "pos": [163, 171]}, {"entity": "areas", "entity_type": "process parameter", "pos": [186, 191]}], "task": "NER"}
{"text": "This process of simulation and material-removal or addition is repeated iteratively until an optimization goal is achieved , and this iterative process may be seen analogous to the process of evolution .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [16, 26]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [93, 105]}, {"entity": "process", "entity_type": "concept or principle", "pos": [144, 151]}, {"entity": "be", "entity_type": "material", "pos": [156, 158]}, {"entity": "process", "entity_type": "concept or principle", "pos": [181, 188]}, {"entity": "evolution", "entity_type": "concept or principle", "pos": [192, 201]}], "task": "NER"}
{"text": "In fact , these simulations sometimes make use of genetic and evolutionary algorithms .", "entity": [{"entity": "simulations", "entity_type": "enabling technology", "pos": [16, 27]}, {"entity": "genetic and evolutionary algorithms", "entity_type": "concept or principle", "pos": [50, 85]}], "task": "NER"}
{"text": "Effectively , these algorithms incorporate rules like in nature to mathematically disallow weaklings to proliferate , but in an accelerated fashion using clever computational methods .", "entity": [{"entity": "algorithms", "entity_type": "concept or principle", "pos": [20, 30]}, {"entity": "fashion", "entity_type": "concept or principle", "pos": [140, 147]}, {"entity": "clever computational methods", "entity_type": "enabling technology", "pos": [154, 182]}], "task": "NER"}
{"text": "More recently this was also described in terms of manufacturing challenges in and in terms of available software tools and their differences and limits in .", "entity": [{"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [50, 63]}, {"entity": "software", "entity_type": "concept or principle", "pos": [104, 112]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [145, 151]}], "task": "NER"}
{"text": "A good example of topology optimization , applied to an extreme lightweighting requirement is the design of a titanium alloy drone frame , with larger dimensions than can be produced on typical powder bed fusion systems .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [18, 39]}, {"entity": "lightweighting", "entity_type": "machanical property", "pos": [64, 78]}, {"entity": "design", "entity_type": "engineering feature", "pos": [98, 104]}, {"entity": "titanium alloy", "entity_type": "material", "pos": [110, 124]}, {"entity": "dimensions", "entity_type": "engineering feature", "pos": [151, 161]}, {"entity": "be", "entity_type": "material", "pos": [171, 173]}, {"entity": "powder bed fusion", "entity_type": "manufacturing process", "pos": [194, 211]}], "task": "NER"}
{"text": "This was produced on the large-scale laser powder bed fusion system called Aeroswift and the design done in collaboration with Altair .", "entity": [{"entity": "laser powder bed fusion system", "entity_type": "machine or equipment", "pos": [37, 67]}, {"entity": "design", "entity_type": "engineering feature", "pos": [93, 99]}], "task": "NER"}
{"text": "The design iteration process is shown in 6 , done in Altair Inspire .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [4, 10]}, {"entity": "process", "entity_type": "concept or principle", "pos": [21, 28]}], "task": "NER"}
{"text": "Another example of a topology optimized part a load bearing bracket is shown in 7 , which is taken from .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [21, 29]}, {"entity": "bearing bracket", "entity_type": "application", "pos": [52, 67]}], "task": "NER"}
{"text": "This titanium alloy bracket was designed to replace a traditional composite bracket in an experimental vehicle for the Shell eco-challenge .", "entity": [{"entity": "titanium alloy", "entity_type": "material", "pos": [5, 19]}, {"entity": "bracket", "entity_type": "machine or equipment", "pos": [20, 27]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [32, 40]}, {"entity": "composite", "entity_type": "material", "pos": [66, 75]}, {"entity": "bracket", "entity_type": "machine or equipment", "pos": [76, 83]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [90, 102]}, {"entity": "Shell", "entity_type": "machine or equipment", "pos": [119, 124]}], "task": "NER"}
{"text": "The design process schematic here shows the original composite part , the design space , the optimized solution and the final smoothed solution , after application of connections and polyNURBS to the surfaces .", "entity": [{"entity": "design process", "entity_type": "concept or principle", "pos": [4, 18]}, {"entity": "composite", "entity_type": "material", "pos": [53, 62]}, {"entity": "design space", "entity_type": "concept or principle", "pos": [74, 86]}, {"entity": "solution", "entity_type": "concept or principle", "pos": [103, 111]}, {"entity": "smoothed solution", "entity_type": "concept or principle", "pos": [126, 143]}, {"entity": "polyNURBS", "entity_type": "enabling technology", "pos": [183, 192]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [200, 208]}], "task": "NER"}
{"text": "This part was also used in a round robin test whereby the same bracket was produced at various commercial laser powder bed fusion systems and detailed analysis performed using microCT .", "entity": [{"entity": "round robin test", "entity_type": "process characterization", "pos": [29, 45]}, {"entity": "bracket", "entity_type": "machine or equipment", "pos": [63, 70]}, {"entity": "laser powder bed fusion systems", "entity_type": "machine or equipment", "pos": [106, 137]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [176, 183]}], "task": "NER"}
{"text": "The study highlighted the need for testing AM parts to ensure structural integrity .", "entity": [{"entity": "testing", "entity_type": "process characterization", "pos": [35, 42]}, {"entity": "AM parts", "entity_type": "machine or equipment", "pos": [43, 51]}, {"entity": "structural integrity", "entity_type": "machanical property", "pos": [62, 82]}], "task": "NER"}
{"text": "Another example is the design for a large bracket for the same vehicle related to the above-mentioned example .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [23, 29]}, {"entity": "bracket", "entity_type": "machine or equipment", "pos": [42, 49]}], "task": "NER"}
{"text": "8 shows the optimized topology itself which is also latticed : this is a sequential process in most software packages and the area to be latticed and the lattice parameters are selected by the user .", "entity": [{"entity": "topology", "entity_type": "concept or principle", "pos": [22, 30]}, {"entity": "process", "entity_type": "concept or principle", "pos": [84, 91]}, {"entity": "software", "entity_type": "concept or principle", "pos": [100, 108]}, {"entity": "area", "entity_type": "process parameter", "pos": [126, 130]}, {"entity": "be", "entity_type": "material", "pos": [134, 136]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [137, 144]}], "task": "NER"}
{"text": "Latticing will be discussed in the next section and holds many advantages but must be carefully implemented in a design , due to issues such as requirement for supports inside the lattice region , and struts which are potentially too thin .", "entity": [{"entity": "be", "entity_type": "material", "pos": [15, 17]}, {"entity": "be", "entity_type": "material", "pos": [83, 85]}, {"entity": "design", "entity_type": "engineering feature", "pos": [113, 119]}, {"entity": "as", "entity_type": "material", "pos": [141, 143]}, {"entity": "supports", "entity_type": "application", "pos": [160, 168]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [180, 187]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [201, 207]}], "task": "NER"}
{"text": "The first is the Bugatti brake caliper which is shown in 9 , and which is currently the worldlargest functional part produced in titanium by AM .", "entity": [{"entity": "caliper", "entity_type": "machine or equipment", "pos": [31, 38]}, {"entity": "titanium", "entity_type": "material", "pos": [129, 137]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [141, 143]}], "task": "NER"}
{"text": "In this case the use of Ti6Al4V titanium alloy is especially useful for light-weighting , as this material is already strong and relatively light .", "entity": [{"entity": "Ti6Al4V", "entity_type": "material", "pos": [24, 31]}, {"entity": "alloy", "entity_type": "material", "pos": [41, 46]}, {"entity": "as", "entity_type": "material", "pos": [90, 92]}, {"entity": "material", "entity_type": "material", "pos": [98, 106]}], "task": "NER"}
{"text": "Its use for automotive and aerospace applications is well known , but manufacturing complex designs by traditional manufacturing methods in this material is extremely challenging .", "entity": [{"entity": "automotive", "entity_type": "application", "pos": [12, 22]}, {"entity": "aerospace", "entity_type": "application", "pos": [27, 36]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [70, 83]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [92, 99]}, {"entity": "traditional manufacturing", "entity_type": "manufacturing process", "pos": [103, 128]}, {"entity": "material", "entity_type": "material", "pos": [145, 153]}], "task": "NER"}
{"text": "The topology optimization result is visually impressive , the performance of this caliper has been validated in various tests and is used in production vehicles , with a 40 % mass reduction compared to the previous version made of aluminium .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [4, 25]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [62, 73]}, {"entity": "caliper", "entity_type": "machine or equipment", "pos": [82, 89]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [141, 151]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [180, 189]}, {"entity": "aluminium", "entity_type": "material", "pos": [231, 240]}], "task": "NER"}
{"text": "5 Cellular and lattice design Cellular structures exist in nature in numerous shapes , sizes and packing arrangements some of the most well-known examples are the beehoneycomb , wood cells and spongy bone , all of which are discussed in a book by Gibson .", "entity": [{"entity": "lattice design", "entity_type": "engineering feature", "pos": [15, 29]}, {"entity": "Cellular structures", "entity_type": "engineering feature", "pos": [30, 49]}, {"entity": "beehoneycomb", "entity_type": "engineering feature", "pos": [163, 175]}, {"entity": "wood cells", "entity_type": "material", "pos": [178, 188]}, {"entity": "spongy bone", "entity_type": "biomedical", "pos": [193, 204]}], "task": "NER"}
{"text": "MicroCT scans of some natural cellular materials are shown in 11 .", "entity": [{"entity": "MicroCT", "entity_type": "process characterization", "pos": [0, 7]}, {"entity": "cellular materials", "entity_type": "material", "pos": [30, 48]}], "task": "NER"}
{"text": "In fact , one of the first true observations of cellular structures in nature can be traced back to 1665 , when Robert Hooke published his observation of the cellularity in cork and suggested that the unique behavior of cork was attributable to its underlying cellular structure .", "entity": [{"entity": "cellular structures", "entity_type": "engineering feature", "pos": [48, 67]}, {"entity": "be", "entity_type": "material", "pos": [82, 84]}, {"entity": "cork", "entity_type": "material", "pos": [173, 177]}, {"entity": "cork", "entity_type": "material", "pos": [220, 224]}, {"entity": "cellular structure", "entity_type": "engineering feature", "pos": [260, 278]}], "task": "NER"}
{"text": "Humans have been using cellular materials such as wood , cork and bamboo , several millennia before we realized the underlying structural basis for their interesting behaviour .", "entity": [{"entity": "cellular materials", "entity_type": "material", "pos": [23, 41]}, {"entity": "as", "entity_type": "material", "pos": [47, 49]}, {"entity": "cork", "entity_type": "material", "pos": [57, 61]}], "task": "NER"}
{"text": "Lattices today owe much of their origins and design selection to mathematics and crystallography , as well as following Maxwellstability criterion , which was primarily developed in the context of large engineering structures .", "entity": [{"entity": "Lattices", "entity_type": "concept or principle", "pos": [0, 8]}, {"entity": "design", "entity_type": "engineering feature", "pos": [45, 51]}, {"entity": "crystallography", "entity_type": "manufacturing process", "pos": [81, 96]}, {"entity": "as", "entity_type": "material", "pos": [99, 101]}, {"entity": "as", "entity_type": "material", "pos": [107, 109]}, {"entity": "engineering", "entity_type": "application", "pos": [203, 214]}], "task": "NER"}
{"text": "The main utility of cellular or lattice structures lies in their ability to meet performance targets while enabling significant mass reduction , something that is a principle commonly embodied in nature .", "entity": [{"entity": "lattice structures", "entity_type": "engineering feature", "pos": [32, 50]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [81, 92]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [133, 142]}], "task": "NER"}
{"text": "While cellular materials do tend to have lower effective material stiffness and strength properties , this reduction is often acceptable and can be tailored to the application , as well as varied locally .", "entity": [{"entity": "cellular materials", "entity_type": "material", "pos": [6, 24]}, {"entity": "effective material stiffness", "entity_type": "process characterization", "pos": [47, 75]}, {"entity": "strength properties", "entity_type": "machanical property", "pos": [80, 99]}, {"entity": "reduction", "entity_type": "concept or principle", "pos": [107, 116]}, {"entity": "be", "entity_type": "material", "pos": [145, 147]}, {"entity": "as", "entity_type": "material", "pos": [178, 180]}, {"entity": "as", "entity_type": "material", "pos": [186, 188]}], "task": "NER"}
{"text": "Lattices may also be useful for other purposes besides light-weighting : they have interesting thermal , acoustic properties and energy absorbing properties under compressive loading they perform a crucial protection role in nature .", "entity": [{"entity": "Lattices", "entity_type": "concept or principle", "pos": [0, 8]}, {"entity": "be", "entity_type": "material", "pos": [18, 20]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [114, 124]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [146, 156]}, {"entity": "compressive loading", "entity_type": "machanical property", "pos": [163, 182]}], "task": "NER"}
{"text": "Cellular materials have also been seen as a crucial enabler for large system-level multi-functional design optimization , such as in an aircraft wing .", "entity": [{"entity": "Cellular materials", "entity_type": "material", "pos": [0, 18]}, {"entity": "as", "entity_type": "material", "pos": [39, 41]}, {"entity": "multi-functional design optimization", "entity_type": "concept or principle", "pos": [83, 119]}, {"entity": "as", "entity_type": "material", "pos": [127, 129]}, {"entity": "aircraft wing", "entity_type": "application", "pos": [136, 149]}], "task": "NER"}
{"text": "The categorization of natural cellular structures is discussed in more detail in a recent review article which focuses on biomimetic design of cellular materials utilizing cellular designs in engineering systems .", "entity": [{"entity": "cellular structures", "entity_type": "engineering feature", "pos": [30, 49]}, {"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [122, 139]}, {"entity": "cellular materials", "entity_type": "material", "pos": [143, 161]}, {"entity": "cellular designs", "entity_type": "engineering feature", "pos": [172, 188]}, {"entity": "engineering", "entity_type": "application", "pos": [192, 203]}], "task": "NER"}
{"text": "Perhaps the most commonly used , and well-known bio-inspired cellular material is the honeycomb , which has found a wide range of applications in architecture , transportation , chemical engineering and more , as compiled in a review article .", "entity": [{"entity": "bio-inspired", "entity_type": "concept or principle", "pos": [48, 60]}, {"entity": "material", "entity_type": "material", "pos": [70, 78]}, {"entity": "honeycomb", "entity_type": "concept or principle", "pos": [86, 95]}, {"entity": "range", "entity_type": "process parameter", "pos": [121, 126]}, {"entity": "architecture", "entity_type": "application", "pos": [146, 158]}, {"entity": "engineering", "entity_type": "application", "pos": [187, 198]}, {"entity": "as", "entity_type": "material", "pos": [210, 212]}], "task": "NER"}
{"text": "With regard to additively manufactured cellular materials , the emphasis in the past decade has been on lattice structures , and their use for medical bone-replacement implant applications .", "entity": [{"entity": "additively manufactured", "entity_type": "manufacturing process", "pos": [15, 38]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [48, 57]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [104, 122]}, {"entity": "medical", "entity_type": "application", "pos": [143, 150]}, {"entity": "implant", "entity_type": "application", "pos": [168, 175]}], "task": "NER"}
{"text": "In this application , the primary role of the lattice is to allow for osseointegration of bone into the implant , thereby causing better fixation .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [46, 53]}, {"entity": "osseointegration", "entity_type": "machanical property", "pos": [70, 86]}, {"entity": "bone", "entity_type": "biomedical", "pos": [90, 94]}, {"entity": "implant", "entity_type": "application", "pos": [104, 111]}], "task": "NER"}
{"text": "A recent book chapter describes the most important criteria for bone regeneration in titanium implants produced by powder bed fusion and the production of topologically designed and otherwise designed porous lattices for this application was also reviewed in .", "entity": [{"entity": "bone regeneration", "entity_type": "concept or principle", "pos": [64, 81]}, {"entity": "titanium implants", "entity_type": "application", "pos": [85, 102]}, {"entity": "powder bed fusion", "entity_type": "manufacturing process", "pos": [115, 132]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [141, 151]}, {"entity": "topologically", "entity_type": "concept or principle", "pos": [155, 168]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [169, 177]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [192, 200]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [208, 216]}], "task": "NER"}
{"text": "From an engineering standpoint , cellular materials are realized practically in commercial software packages using different approaches .", "entity": [{"entity": "engineering", "entity_type": "application", "pos": [8, 19]}, {"entity": "cellular materials", "entity_type": "material", "pos": [33, 51]}, {"entity": "software", "entity_type": "concept or principle", "pos": [91, 99]}], "task": "NER"}
{"text": "Traditional CAD software uses mesh-based representation , but recent developments in software are exploring the use of volumetric object representation to generate surfaces , and in at least one case , the use of implicit modeling via the definition of fields that then generate cellular structures .", "entity": [{"entity": "CAD", "entity_type": "enabling technology", "pos": [12, 15]}, {"entity": "software", "entity_type": "concept or principle", "pos": [16, 24]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [164, 172]}, {"entity": "modeling", "entity_type": "enabling technology", "pos": [222, 230]}, {"entity": "cellular structures", "entity_type": "engineering feature", "pos": [279, 298]}], "task": "NER"}
{"text": "Mesh-based approaches can generate visually impressive lattices which conform well to the original surface design , and is relatively easily implemented for complex part geometries .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [55, 63]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [99, 106]}, {"entity": "design", "entity_type": "engineering feature", "pos": [107, 113]}, {"entity": "geometries", "entity_type": "concept or principle", "pos": [170, 180]}], "task": "NER"}
{"text": "The volumetric object representation approach allows for the user to select a unit cell from a wider variety of cellular designs .", "entity": [{"entity": "unit cell", "entity_type": "concept or principle", "pos": [78, 87]}, {"entity": "cellular designs", "entity_type": "engineering feature", "pos": [112, 128]}], "task": "NER"}
{"text": "The repeated unit cell approach also allows relatively easy prediction of mechanical properties of the structure , easing the design process .", "entity": [{"entity": "unit cell", "entity_type": "concept or principle", "pos": [13, 22]}, {"entity": "prediction", "entity_type": "concept or principle", "pos": [60, 70]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [74, 95]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [103, 112]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [126, 140]}], "task": "NER"}
{"text": "A series of unit cells and corresponding repeated lattice structures are shown in 12 .", "entity": [{"entity": "unit cells", "entity_type": "concept or principle", "pos": [12, 22]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [50, 68]}], "task": "NER"}
{"text": "These are all designed with the same total density , but the different designs result in different minimum feature thickness and pore sizes .", "entity": [{"entity": "designed", "entity_type": "engineering feature", "pos": [14, 22]}, {"entity": "density", "entity_type": "machanical property", "pos": [43, 50]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [71, 78]}, {"entity": "minimum feature thickness", "entity_type": "engineering feature", "pos": [99, 124]}, {"entity": "pore sizes", "entity_type": "process parameter", "pos": [129, 139]}], "task": "NER"}
{"text": "The first four are strut-based and the next four are minimal surface designs .", "entity": [{"entity": "strut-based", "entity_type": "engineering feature", "pos": [19, 30]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [61, 68]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [69, 76]}], "task": "NER"}
{"text": "The latter are found in nature , and have been shown to have good properties for bone implant applications .", "entity": [{"entity": "properties", "entity_type": "concept or principle", "pos": [66, 76]}, {"entity": "bone implant applications", "entity_type": "application", "pos": [81, 106]}], "task": "NER"}
{"text": "These minimal surfaces are sheet-based designs which are often self-supporting and tend to have zero average curvature at every point on the surface , which makes for a more even distribution of stresses within these structures .", "entity": [{"entity": "surfaces", "entity_type": "concept or principle", "pos": [14, 22]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [39, 46]}, {"entity": "self-supporting", "entity_type": "engineering feature", "pos": [63, 78]}, {"entity": "zero average curvature", "entity_type": "engineering feature", "pos": [96, 118]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [141, 148]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [179, 191]}], "task": "NER"}
{"text": "Despite the growing prevalence of design software capable of generating cellular structure designs , it is not always apparent what the best unit cell for a specific application is and this becomes even more challenging in the context of multi-functional design .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [34, 40]}, {"entity": "cellular structure", "entity_type": "engineering feature", "pos": [72, 90]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [141, 150]}, {"entity": "design", "entity_type": "engineering feature", "pos": [255, 261]}], "task": "NER"}
{"text": "It is in such a context that biomimetic design can play a key role , in helping develop structure-function relationships based on observations of cellular materials in nature , and using these to guide selection of cellular materials .", "entity": [{"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [29, 46]}, {"entity": "cellular materials", "entity_type": "material", "pos": [146, 164]}, {"entity": "cellular materials", "entity_type": "material", "pos": [215, 233]}], "task": "NER"}
{"text": "Natural cellular materials span the range of parameter space used in design , from beam or strut-based materials to surface based ones , including structures that combine both types , as shown in 13 .", "entity": [{"entity": "cellular materials", "entity_type": "material", "pos": [8, 26]}, {"entity": "range", "entity_type": "process parameter", "pos": [36, 41]}, {"entity": "parameter", "entity_type": "concept or principle", "pos": [45, 54]}, {"entity": "design", "entity_type": "engineering feature", "pos": [69, 75]}, {"entity": "beam", "entity_type": "machine or equipment", "pos": [83, 87]}, {"entity": "strut-based", "entity_type": "engineering feature", "pos": [91, 102]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [103, 112]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [116, 123]}, {"entity": "as", "entity_type": "material", "pos": [125, 127]}], "task": "NER"}
{"text": "These cellular materials occur in nature both internal to a form , as well as externally on the surface .", "entity": [{"entity": "cellular materials", "entity_type": "material", "pos": [6, 24]}, {"entity": "as", "entity_type": "material", "pos": [67, 69]}, {"entity": "as", "entity_type": "material", "pos": [75, 77]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [96, 103]}], "task": "NER"}
{"text": "The main application of lattice structures , which has resulted in considerable research efforts , is their use in medical implants .", "entity": [{"entity": "lattice structures", "entity_type": "engineering feature", "pos": [24, 42]}, {"entity": "research", "entity_type": "concept or principle", "pos": [80, 88]}, {"entity": "medical implants", "entity_type": "application", "pos": [115, 131]}], "task": "NER"}
{"text": "For this application the pore sizes required are typically small , requiring small feature sizes in general .", "entity": [{"entity": "pore sizes", "entity_type": "process parameter", "pos": [25, 35]}, {"entity": "feature sizes", "entity_type": "process parameter", "pos": [83, 96]}], "task": "NER"}
{"text": "Other applications than medical , such as in light-weight structures for aerospace or automotive parts , might prefer thicker lattices to focus on mechanical reliability and strength .", "entity": [{"entity": "medical", "entity_type": "application", "pos": [24, 31]}, {"entity": "as", "entity_type": "material", "pos": [39, 41]}, {"entity": "light-weight", "entity_type": "machanical property", "pos": [45, 57]}, {"entity": "aerospace", "entity_type": "application", "pos": [73, 82]}, {"entity": "automotive", "entity_type": "application", "pos": [86, 96]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [126, 134]}, {"entity": "mechanical reliability", "entity_type": "concept or principle", "pos": [147, 169]}, {"entity": "strength", "entity_type": "machanical property", "pos": [174, 182]}], "task": "NER"}
{"text": "Experimental work with lattices with thick struts show excellent strength properties as shown in for 50 % density Ti6Al4V lattices of two strut-based designs .", "entity": [{"entity": "Experimental", "entity_type": "concept or principle", "pos": [0, 12]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [23, 31]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [43, 49]}, {"entity": "strength properties", "entity_type": "machanical property", "pos": [65, 84]}, {"entity": "as", "entity_type": "material", "pos": [85, 87]}, {"entity": "density", "entity_type": "machanical property", "pos": [106, 113]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [122, 130]}, {"entity": "strut-based designs", "entity_type": "engineering feature", "pos": [138, 157]}], "task": "NER"}
{"text": "Simple strut-based lattice designs can be classified according to the Maxwell criterion as either bending-dominated or stretch-dominated as illustrated schematically and by a few examples in 14 .", "entity": [{"entity": "Simple", "entity_type": "manufacturing process", "pos": [0, 6]}, {"entity": "lattice designs", "entity_type": "engineering feature", "pos": [19, 34]}, {"entity": "be", "entity_type": "material", "pos": [39, 41]}, {"entity": "Maxwell criterion", "entity_type": "concept or principle", "pos": [70, 87]}, {"entity": "as", "entity_type": "material", "pos": [88, 90]}, {"entity": "as", "entity_type": "material", "pos": [137, 139]}], "task": "NER"}
{"text": "The Maxwell criterion for simple strut-based 3D structures is : M = b 3j + 6 Where b = the number of struts , and j = the number of joints When M < 0 the structure is bending-dominated When M 0 the structure is stretch-dominated and When M > 0 the structure is over-rigid Bending-dominated refers to the struts which tend to bend under compression of the lattice resulting in shear failure , while stretch-dominated structures are stiffer and fail in a layer-by-layer mechanism .", "entity": [{"entity": "Maxwell criterion", "entity_type": "concept or principle", "pos": [4, 21]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [26, 32]}, {"entity": "3D structures", "entity_type": "concept or principle", "pos": [45, 58]}, {"entity": "b", "entity_type": "material", "pos": [68, 69]}, {"entity": "b", "entity_type": "material", "pos": [83, 84]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [101, 107]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [154, 163]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [198, 207]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [248, 257]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [304, 310]}, {"entity": "compression", "entity_type": "machanical property", "pos": [336, 347]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [355, 362]}, {"entity": "shear failure", "entity_type": "machanical property", "pos": [376, 389]}, {"entity": "stretch-dominated structures", "entity_type": "machanical property", "pos": [398, 426]}, {"entity": "layer-by-layer", "entity_type": "concept or principle", "pos": [453, 467]}], "task": "NER"}
{"text": "These failure modes have been observed in relatively thick-strut lattices and imaged by microCT in their initial failure locations .", "entity": [{"entity": "failure modes", "entity_type": "machanical property", "pos": [6, 19]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [65, 73]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [88, 95]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [113, 120]}], "task": "NER"}
{"text": "The mechanical response of lattice structures in general follows a linear elastic response up to the first point of buckling or failure , followed by a plateau region , followed by final densification .", "entity": [{"entity": "mechanical response", "entity_type": "concept or principle", "pos": [4, 23]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [27, 45]}, {"entity": "elastic", "entity_type": "machanical property", "pos": [74, 81]}, {"entity": "first point of buckling", "entity_type": "machanical property", "pos": [101, 124]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [128, 135]}, {"entity": "densification", "entity_type": "manufacturing process", "pos": [187, 200]}], "task": "NER"}
{"text": "This is shown in the example in 15 , which also shows why cellular materials are useful for energy absorption as they can handle significant yielding without catastrophic failure , under most circumstances .", "entity": [{"entity": "cellular materials", "entity_type": "material", "pos": [58, 76]}, {"entity": "energy absorption", "entity_type": "process characterization", "pos": [92, 109]}, {"entity": "as", "entity_type": "material", "pos": [110, 112]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [171, 178]}], "task": "NER"}
{"text": "A lattice structure can be approximated as an open-cell foam , with effective elastic modulus E of the lattice related to the density of the structure and the elastic modulus of the bulk material - solid as follows : E = 2 E s o l i d s o l i d 2 In this relationship , the constant depends on the manufacturing accuracy and material properties and varies between 0.1 and 4 but is a constant for a specific material and process .", "entity": [{"entity": "lattice structure", "entity_type": "engineering feature", "pos": [2, 19]}, {"entity": "be", "entity_type": "material", "pos": [24, 26]}, {"entity": "as", "entity_type": "material", "pos": [40, 42]}, {"entity": "foam", "entity_type": "material", "pos": [56, 60]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [78, 93]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [103, 110]}, {"entity": "density", "entity_type": "machanical property", "pos": [126, 133]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [141, 150]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [159, 174]}, {"entity": "material", "entity_type": "material", "pos": [187, 195]}, {"entity": "as", "entity_type": "material", "pos": [204, 206]}, {"entity": "s", "entity_type": "material", "pos": [213, 214]}, {"entity": "o", "entity_type": "material", "pos": [227, 228]}, {"entity": "s", "entity_type": "material", "pos": [235, 236]}, {"entity": "o", "entity_type": "material", "pos": [237, 238]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [298, 311]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [312, 320]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [325, 344]}, {"entity": "specific material", "entity_type": "material", "pos": [398, 415]}, {"entity": "process", "entity_type": "concept or principle", "pos": [420, 427]}], "task": "NER"}
{"text": "What this relationship shows is that the effective elastic modulus can be controlled by the density alone this means that a lattice with unit cell design of 50 % density may use any unit cell size as long as the total space filled contains at least six unit cells in each direction then the material stiffness will be the same .", "entity": [{"entity": "elastic modulus", "entity_type": "machanical property", "pos": [51, 66]}, {"entity": "be", "entity_type": "material", "pos": [71, 73]}, {"entity": "density", "entity_type": "machanical property", "pos": [92, 99]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [124, 131]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [137, 146]}, {"entity": "design", "entity_type": "engineering feature", "pos": [147, 153]}, {"entity": "density", "entity_type": "machanical property", "pos": [162, 169]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [182, 191]}, {"entity": "as", "entity_type": "material", "pos": [197, 199]}, {"entity": "as", "entity_type": "material", "pos": [205, 207]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [253, 263]}, {"entity": "material stiffness", "entity_type": "engineering feature", "pos": [291, 309]}, {"entity": "be", "entity_type": "material", "pos": [315, 317]}], "task": "NER"}
{"text": "This means lattices with many thin struts might perform the same as lattices with less thick struts , an interesting design aspect which can be varied by application requirement .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [11, 19]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [35, 41]}, {"entity": "as", "entity_type": "material", "pos": [65, 67]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [93, 99]}, {"entity": "design", "entity_type": "engineering feature", "pos": [117, 123]}, {"entity": "be", "entity_type": "material", "pos": [141, 143]}], "task": "NER"}
{"text": "It is also important to note that the exponent refers to ideal bending-dominated lattice while an ideal stretch-dominated lattice has exponent This is illustrated in 16 , for a range of lattice types clearly this exponent may vary somewhat depending on the lattice design selected .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [81, 88]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [122, 129]}, {"entity": "range", "entity_type": "process parameter", "pos": [177, 182]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [186, 193]}, {"entity": "lattice design", "entity_type": "engineering feature", "pos": [257, 271]}], "task": "NER"}
{"text": "Besides the relationships mentioned above , lattice designs must also be considered relative to manufacturing limits .", "entity": [{"entity": "lattice designs", "entity_type": "engineering feature", "pos": [44, 59]}, {"entity": "be", "entity_type": "material", "pos": [70, 72]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [96, 109]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [110, 116]}], "task": "NER"}
{"text": "For example , sheet-based designs can typically print without supports , and strut-based designs can print without supports up to a certain strut length for horizontal struts .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [26, 33]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [48, 53]}, {"entity": "supports", "entity_type": "application", "pos": [62, 70]}, {"entity": "strut-based designs", "entity_type": "engineering feature", "pos": [77, 96]}, {"entity": "print", "entity_type": "manufacturing process", "pos": [101, 106]}, {"entity": "supports", "entity_type": "application", "pos": [115, 123]}, {"entity": "certain strut length", "entity_type": "engineering feature", "pos": [132, 152]}, {"entity": "horizontal struts", "entity_type": "engineering feature", "pos": [157, 174]}], "task": "NER"}
{"text": "Therefore , manufacturing constraints are imposed on the design possibilities .", "entity": [{"entity": "manufacturing constraints", "entity_type": "concept or principle", "pos": [12, 37]}, {"entity": "design", "entity_type": "engineering feature", "pos": [57, 63]}], "task": "NER"}
{"text": "The most important limits are the minimum feature size , which , in practice , is limited not only by the powder size and laser spot size , but also by the 3D model slicing accuracy and the resulting hatch and contour scanning employed .", "entity": [{"entity": "limits", "entity_type": "concept or principle", "pos": [19, 25]}, {"entity": "minimum feature size", "entity_type": "process parameter", "pos": [34, 54]}, {"entity": "powder", "entity_type": "material", "pos": [106, 112]}, {"entity": "laser spot size", "entity_type": "process parameter", "pos": [122, 137]}, {"entity": "3D model slicing", "entity_type": "engineering feature", "pos": [156, 172]}, {"entity": "contour scanning", "entity_type": "process parameter", "pos": [210, 226]}], "task": "NER"}
{"text": "For example , in a recent study of thin-strut lattices , the standard processing parameters resulted in the inability to produce struts varying gradually from 0.2 to 0.4 mm .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [46, 54]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [61, 69]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [81, 91]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [129, 135]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [170, 172]}], "task": "NER"}
{"text": "Here , different designs were produced with approximately the same strut dimensions despite differences in design .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [17, 24]}, {"entity": "strut", "entity_type": "machine or equipment", "pos": [67, 72]}, {"entity": "dimensions", "entity_type": "engineering feature", "pos": [73, 83]}, {"entity": "design", "entity_type": "engineering feature", "pos": [107, 113]}], "task": "NER"}
{"text": "These thin-strut lattices also have relatively large surface roughness values compared to the strut thickness , which understandably affects the mechanical properties more than would be expected for a thicker-strut version .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [17, 25]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [53, 70]}, {"entity": "strut thickness", "entity_type": "process parameter", "pos": [94, 109]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [145, 166]}, {"entity": "be", "entity_type": "material", "pos": [183, 185]}], "task": "NER"}
{"text": "In this above-mentioned study the experimental elastic modulus values were significantly lower than predicted mostly attributed to surface roughness and irregularity which creates stress concentrations in notches and in locations of very thin wall thickness .", "entity": [{"entity": "experimental", "entity_type": "concept or principle", "pos": [34, 46]}, {"entity": "elastic modulus", "entity_type": "machanical property", "pos": [47, 62]}, {"entity": "predicted", "entity_type": "concept or principle", "pos": [100, 109]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [131, 148]}, {"entity": "stress concentrations", "entity_type": "process characterization", "pos": [180, 201]}, {"entity": "notches", "entity_type": "engineering feature", "pos": [205, 212]}, {"entity": "wall thickness", "entity_type": "engineering feature", "pos": [243, 257]}], "task": "NER"}
{"text": "Effectively for a metal laser powder bed fusion system with about 100 spot size , the minimum reliable wall thickness should be 0.3-0.4 mm if no special precautions or optimization for strut manufacturing is done to enhance the manufacturability .", "entity": [{"entity": "metal", "entity_type": "material", "pos": [18, 23]}, {"entity": "laser powder bed fusion system", "entity_type": "machine or equipment", "pos": [24, 54]}, {"entity": "spot size", "entity_type": "process parameter", "pos": [70, 79]}, {"entity": "wall thickness", "entity_type": "engineering feature", "pos": [103, 117]}, {"entity": "be", "entity_type": "material", "pos": [125, 127]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [136, 138]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [168, 180]}, {"entity": "strut", "entity_type": "machine or equipment", "pos": [185, 190]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [191, 204]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [228, 245]}], "task": "NER"}
{"text": "The next section discusses material properties and will specifically mention limits with regards to lattice manufacturability .", "entity": [{"entity": "material properties", "entity_type": "concept or principle", "pos": [27, 46]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [77, 83]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [100, 107]}], "task": "NER"}
{"text": "6 Material properties of AM biomimetic parts Biomimetic-designed and produced parts are visually so vastly different from traditional manufactured parts , that it causes mistrust and resistance to acceptance of this new technology , especially by engineers .", "entity": [{"entity": "Material properties", "entity_type": "concept or principle", "pos": [2, 21]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [25, 27]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [134, 146]}, {"entity": "resistance", "entity_type": "machanical property", "pos": [183, 193]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [220, 230]}], "task": "NER"}
{"text": "In some ways this is to be expected , as AM has a history of over-hype and under-delivery in the past .", "entity": [{"entity": "be", "entity_type": "material", "pos": [24, 26]}, {"entity": "as", "entity_type": "material", "pos": [38, 40]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [41, 43]}], "task": "NER"}
{"text": "In the qualification process , mechanical properties of the optimized process can be tested and validated as demonstrated for Ti6Al4V in .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [21, 28]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [31, 52]}, {"entity": "process", "entity_type": "concept or principle", "pos": [70, 77]}, {"entity": "be", "entity_type": "material", "pos": [82, 84]}, {"entity": "as", "entity_type": "material", "pos": [106, 108]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [126, 133]}], "task": "NER"}
{"text": "In order to obtain defect-free and accurately produced parts , X-ray tomography can be used as outlined in .", "entity": [{"entity": "accurately", "entity_type": "process characterization", "pos": [35, 45]}, {"entity": "X-ray tomography", "entity_type": "process characterization", "pos": [63, 79]}, {"entity": "be", "entity_type": "material", "pos": [84, 86]}, {"entity": "as", "entity_type": "material", "pos": [92, 94]}], "task": "NER"}
{"text": "The specific process parameters which combine to create an object in AM all have an influence on the subsequent material properties and the manufacturing process of the object as a whole .", "entity": [{"entity": "process parameters", "entity_type": "concept or principle", "pos": [13, 31]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [69, 71]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [112, 131]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [140, 161]}, {"entity": "as", "entity_type": "material", "pos": [176, 178]}], "task": "NER"}
{"text": "This is true not only for fully dense objects , but also for complex or lattice design with biomimetic features such as custom or complex shapes , inner structures or surface modifications .", "entity": [{"entity": "fully dense", "entity_type": "process parameter", "pos": [26, 37]}, {"entity": "lattice design", "entity_type": "engineering feature", "pos": [72, 86]}, {"entity": "biomimetic features", "entity_type": "engineering feature", "pos": [92, 111]}, {"entity": "as", "entity_type": "material", "pos": [117, 119]}, {"entity": "complex shapes", "entity_type": "machanical property", "pos": [130, 144]}, {"entity": "surface modifications", "entity_type": "manufacturing process", "pos": [167, 188]}], "task": "NER"}
{"text": "In this case , material properties and the properties of i.e .", "entity": [{"entity": "material properties", "entity_type": "concept or principle", "pos": [15, 34]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [43, 53]}], "task": "NER"}
{"text": "single building blocks and joints between them also influence the properties of the LPBF object .", "entity": [{"entity": "properties", "entity_type": "concept or principle", "pos": [66, 76]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [84, 88]}], "task": "NER"}
{"text": "Defects and flaws such as porosity occurs in the LPBF process due to various reasons and this can influence the mechanical properties of the final parts .", "entity": [{"entity": "Defects", "entity_type": "concept or principle", "pos": [0, 7]}, {"entity": "flaws", "entity_type": "concept or principle", "pos": [12, 17]}, {"entity": "as", "entity_type": "material", "pos": [23, 25]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [49, 53]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [112, 133]}], "task": "NER"}
{"text": "There are many process parameters the laser power , laser spot size and scanning speed , hatch distance , material properties , powder particle size distribution and powder layer thickness , the strategy , design and orientation of the 3D part and its supports , the scanning and building strategy , etc .", "entity": [{"entity": "process parameters", "entity_type": "concept or principle", "pos": [15, 33]}, {"entity": "laser power", "entity_type": "process parameter", "pos": [38, 49]}, {"entity": "laser spot size", "entity_type": "process parameter", "pos": [52, 67]}, {"entity": "scanning speed", "entity_type": "process parameter", "pos": [72, 86]}, {"entity": "hatch distance", "entity_type": "process parameter", "pos": [89, 103]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [106, 125]}, {"entity": "powder particle", "entity_type": "material", "pos": [128, 143]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [149, 161]}, {"entity": "powder", "entity_type": "material", "pos": [166, 172]}, {"entity": "layer thickness", "entity_type": "process parameter", "pos": [173, 188]}, {"entity": "design", "entity_type": "engineering feature", "pos": [206, 212]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [217, 228]}, {"entity": "3D part", "entity_type": "application", "pos": [236, 243]}, {"entity": "supports", "entity_type": "application", "pos": [252, 260]}, {"entity": "scanning", "entity_type": "concept or principle", "pos": [267, 275]}], "task": "NER"}
{"text": "which all may influence the molten pool size , further solidification , microstructural grain growth and eventually the mechanical properties , lifetime and performance of LPBF parts .", "entity": [{"entity": "molten pool", "entity_type": "concept or principle", "pos": [28, 39]}, {"entity": "solidification", "entity_type": "concept or principle", "pos": [55, 69]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [72, 87]}, {"entity": "grain growth", "entity_type": "concept or principle", "pos": [88, 100]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [120, 141]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [157, 168]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [172, 176]}], "task": "NER"}
{"text": "The details of the AM process are discussed in the comprehensive review paper .", "entity": [{"entity": "AM process", "entity_type": "manufacturing process", "pos": [19, 29]}], "task": "NER"}
{"text": "It is already well known that variation of process parameters may influence the formation of porosity and may lead to extensive flaws and build imperfections , as is shown for example in a round robin test recently .", "entity": [{"entity": "variation", "entity_type": "concept or principle", "pos": [30, 39]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [43, 61]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [93, 101]}, {"entity": "lead", "entity_type": "material", "pos": [110, 114]}, {"entity": "flaws", "entity_type": "concept or principle", "pos": [128, 133]}, {"entity": "build", "entity_type": "process parameter", "pos": [138, 143]}, {"entity": "as", "entity_type": "material", "pos": [160, 162]}, {"entity": "round robin test", "entity_type": "process characterization", "pos": [189, 205]}], "task": "NER"}
{"text": "This highlights the need for process optimization .", "entity": [{"entity": "process optimization", "entity_type": "concept or principle", "pos": [29, 49]}], "task": "NER"}
{"text": "Other properties such as corrosion are also strongly affected by processing conditions and are important for biomimetic applications , especially medical applications .", "entity": [{"entity": "properties", "entity_type": "concept or principle", "pos": [6, 16]}, {"entity": "as", "entity_type": "material", "pos": [22, 24]}, {"entity": "biomimetic applications", "entity_type": "application", "pos": [109, 132]}, {"entity": "medical applications", "entity_type": "application", "pos": [146, 166]}], "task": "NER"}
{"text": "For example , it was shown that a higher corrosion resistance of Co-Cr dental alloy was obtained by Selective Laser Melting in comparison with the Selective Laser Sintering process , due to a passive oxide protecting layer which formed on the surface of the SLM sample .", "entity": [{"entity": "corrosion resistance", "entity_type": "concept or principle", "pos": [41, 61]}, {"entity": "Co-Cr dental alloy", "entity_type": "material", "pos": [65, 83]}, {"entity": "Selective Laser Melting", "entity_type": "manufacturing process", "pos": [100, 123]}, {"entity": "Selective Laser Sintering process", "entity_type": "manufacturing process", "pos": [147, 180]}, {"entity": "oxide", "entity_type": "material", "pos": [200, 205]}, {"entity": "layer", "entity_type": "process parameter", "pos": [217, 222]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [243, 250]}, {"entity": "SLM", "entity_type": "manufacturing process", "pos": [258, 261]}, {"entity": "sample", "entity_type": "concept or principle", "pos": [262, 268]}], "task": "NER"}
{"text": "Takaichi found that metal elution from the LPBF dental implants was smaller than that of the aB-cast Co-Cr alloy .", "entity": [{"entity": "metal", "entity_type": "material", "pos": [20, 25]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [43, 47]}, {"entity": "dental", "entity_type": "application", "pos": [48, 54]}, {"entity": "alloy", "entity_type": "material", "pos": [107, 112]}], "task": "NER"}
{"text": "Thus , it could be said that LPBF materials have superior corrosion properties .", "entity": [{"entity": "be", "entity_type": "material", "pos": [16, 18]}, {"entity": "LPBF materials", "entity_type": "material", "pos": [29, 43]}, {"entity": "corrosion properties", "entity_type": "machanical property", "pos": [58, 78]}], "task": "NER"}
{"text": "However , procesB-parameters can influence the corrosion behavior of samples produced with different procesB-parameters .", "entity": [{"entity": "corrosion behavior", "entity_type": "machanical property", "pos": [47, 65]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [69, 76]}], "task": "NER"}
{"text": "It is already known that the level of microporosity affects the corrosion behavior as shown in .", "entity": [{"entity": "microporosity", "entity_type": "machanical property", "pos": [38, 51]}, {"entity": "corrosion behavior", "entity_type": "machanical property", "pos": [64, 82]}, {"entity": "as", "entity_type": "material", "pos": [83, 85]}], "task": "NER"}
{"text": "Micro-segregation of elements under specific LPBF procesB-parameters can occur causing different corrosion behavior at materials processed under different parameters .", "entity": [{"entity": "Micro-segregation", "entity_type": "concept or principle", "pos": [0, 17]}, {"entity": "elements", "entity_type": "material", "pos": [21, 29]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [45, 49]}, {"entity": "corrosion behavior", "entity_type": "machanical property", "pos": [97, 115]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [119, 128]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [155, 165]}], "task": "NER"}
{"text": "Since melt pool boundaries may differ in corrosion resistance compared to the center of the meltpool , more melt pool boundaries imply different corrosion resistance of LPBF material .", "entity": [{"entity": "melt pool boundaries", "entity_type": "concept or principle", "pos": [6, 26]}, {"entity": "corrosion resistance", "entity_type": "concept or principle", "pos": [41, 61]}, {"entity": "meltpool", "entity_type": "process characterization", "pos": [92, 100]}, {"entity": "melt pool boundaries", "entity_type": "concept or principle", "pos": [108, 128]}, {"entity": "corrosion resistance", "entity_type": "concept or principle", "pos": [145, 165]}, {"entity": "LPBF material", "entity_type": "material", "pos": [169, 182]}], "task": "NER"}
{"text": "These statements have to be taken into account especially for smart AM advanced biodegradable implants that should degrade with spatial and temporal controllability to meet the requirements of different bone regeneration stages .", "entity": [{"entity": "be", "entity_type": "material", "pos": [25, 27]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [68, 70]}, {"entity": "implants", "entity_type": "application", "pos": [94, 102]}, {"entity": "bone regeneration", "entity_type": "concept or principle", "pos": [203, 220]}], "task": "NER"}
{"text": "LPBF samples have varying surface roughness on side , top and bottom surfaces .", "entity": [{"entity": "LPBF", "entity_type": "manufacturing process", "pos": [0, 4]}, {"entity": "surface roughness", "entity_type": "machanical property", "pos": [26, 43]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [69, 77]}], "task": "NER"}
{"text": "Attached powder particles can be eliminated by post-process mechanical or chemical procedures .", "entity": [{"entity": "powder particles", "entity_type": "material", "pos": [9, 25]}, {"entity": "be", "entity_type": "material", "pos": [30, 32]}, {"entity": "post-process", "entity_type": "concept or principle", "pos": [47, 59]}, {"entity": "mechanical", "entity_type": "application", "pos": [60, 70]}], "task": "NER"}
{"text": "However , for LPBF parts with complex shapes and fine features or lattice structures , full powder evacuation and targeted accuracy and roughness values can be quite difficult to obtain .", "entity": [{"entity": "LPBF", "entity_type": "manufacturing process", "pos": [14, 18]}, {"entity": "complex shapes", "entity_type": "machanical property", "pos": [30, 44]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [66, 84]}, {"entity": "powder", "entity_type": "material", "pos": [92, 98]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [123, 131]}, {"entity": "roughness values", "entity_type": "machanical property", "pos": [136, 152]}, {"entity": "be", "entity_type": "material", "pos": [157, 159]}], "task": "NER"}
{"text": "The surface roughness is dependent on the building and scanning strategy , material properties , powder size , layer thickness , etc .", "entity": [{"entity": "surface roughness", "entity_type": "machanical property", "pos": [4, 21]}, {"entity": "scanning strategy", "entity_type": "concept or principle", "pos": [55, 72]}, {"entity": "material properties", "entity_type": "concept or principle", "pos": [75, 94]}, {"entity": "powder", "entity_type": "material", "pos": [97, 103]}, {"entity": "layer thickness", "entity_type": "process parameter", "pos": [111, 126]}], "task": "NER"}
{"text": "This can influence not only the mechanical properties but also the biological response of bone cells or soft tissues when such an object is implanted .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [32, 53]}, {"entity": "bone cells", "entity_type": "biomedical", "pos": [90, 100]}, {"entity": "implanted", "entity_type": "manufacturing process", "pos": [140, 149]}], "task": "NER"}
{"text": "Moreover , there is currently no general approach and agreement about preferred roughness values or surface micron-scale features and pore size for effective bone cell growth and functioning of implants .", "entity": [{"entity": "roughness values", "entity_type": "machanical property", "pos": [80, 96]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [100, 107]}, {"entity": "micron-scale", "entity_type": "engineering feature", "pos": [108, 120]}, {"entity": "pore size", "entity_type": "process parameter", "pos": [134, 143]}, {"entity": "bone cell", "entity_type": "biomedical", "pos": [158, 167]}, {"entity": "implants", "entity_type": "application", "pos": [194, 202]}], "task": "NER"}
{"text": "For lattice structures , the geometrical characteristics of unit cells , the building direction , overhang angles , hatch and contour scanning strategy may all influence the obtained roughness in the scaffolds and may cause deviations from designed sizes .", "entity": [{"entity": "lattice structures", "entity_type": "engineering feature", "pos": [4, 22]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [60, 70]}, {"entity": "building direction", "entity_type": "process parameter", "pos": [77, 95]}, {"entity": "overhang angles", "entity_type": "process parameter", "pos": [98, 113]}, {"entity": "contour scanning", "entity_type": "process parameter", "pos": [126, 142]}, {"entity": "roughness", "entity_type": "machanical property", "pos": [183, 192]}, {"entity": "scaffolds", "entity_type": "engineering feature", "pos": [200, 209]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [240, 248]}], "task": "NER"}
{"text": "For example , in du Plessis , the elemental cubic lattice was designed with a total 15 mm width , 0.75 mm strut thickness and 8 struts across one direction in total , resulting in 1.28 mm distance between struts and total 65 % porosity .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [50, 57]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [62, 70]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [87, 89]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [103, 105]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [128, 134]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [185, 187]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [205, 211]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [227, 235]}], "task": "NER"}
{"text": "One set of samples was built at standard procesB-parameters recommended for EOS Ti6Al4V in vertical direction , other ones at 45angle .", "entity": [{"entity": "set", "entity_type": "application", "pos": [4, 7]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [11, 18]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [32, 40]}, {"entity": "EOS", "entity_type": "application", "pos": [76, 79]}, {"entity": "vertical", "entity_type": "concept or principle", "pos": [91, 99]}], "task": "NER"}
{"text": "Samples were heat-treated for stresB-relieving as indicated in .", "entity": [{"entity": "Samples", "entity_type": "concept or principle", "pos": [0, 7]}, {"entity": "heat-treated", "entity_type": "manufacturing process", "pos": [13, 25]}, {"entity": "as", "entity_type": "material", "pos": [47, 49]}], "task": "NER"}
{"text": "The differences in strut thickness , roughness and microstructure is clearly visible by crosB-sections and also different columnar prior beta-grain orientations are clearly present .", "entity": [{"entity": "strut thickness", "entity_type": "process parameter", "pos": [19, 34]}, {"entity": "roughness", "entity_type": "machanical property", "pos": [37, 46]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [51, 65]}, {"entity": "crosB-sections", "entity_type": "concept or principle", "pos": [88, 102]}, {"entity": "orientations", "entity_type": "concept or principle", "pos": [148, 160]}], "task": "NER"}
{"text": "Samples that were produced at 45 degrees , had 25 % lower ultimate compression strength in comparison with vertical samples .", "entity": [{"entity": "Samples", "entity_type": "concept or principle", "pos": [0, 7]}, {"entity": "compression strength", "entity_type": "machanical property", "pos": [67, 87]}, {"entity": "vertical samples", "entity_type": "concept or principle", "pos": [107, 123]}], "task": "NER"}
{"text": "Bending and stretch-dominated lattices fail respectively in shear and layer-by-layer failure modes , and this might depend somewhat on the material ductility .", "entity": [{"entity": "Bending", "entity_type": "manufacturing process", "pos": [0, 7]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [30, 38]}, {"entity": "layer-by-layer", "entity_type": "concept or principle", "pos": [70, 84]}, {"entity": "failure modes", "entity_type": "machanical property", "pos": [85, 98]}, {"entity": "material", "entity_type": "material", "pos": [139, 147]}, {"entity": "ductility", "entity_type": "machanical property", "pos": [148, 157]}], "task": "NER"}
{"text": "For a brittle material , shear failure is not desirable and layer-by-layer can be much preferred and even might act as protective mechanism .", "entity": [{"entity": "brittle material", "entity_type": "material", "pos": [6, 22]}, {"entity": "shear failure", "entity_type": "machanical property", "pos": [25, 38]}, {"entity": "layer-by-layer", "entity_type": "concept or principle", "pos": [60, 74]}, {"entity": "be", "entity_type": "material", "pos": [79, 81]}, {"entity": "as", "entity_type": "material", "pos": [116, 118]}, {"entity": "mechanism", "entity_type": "concept or principle", "pos": [130, 139]}], "task": "NER"}
{"text": "The layer-by-layer mechanism is more predictable as it is known where the next failure will occur .", "entity": [{"entity": "layer-by-layer", "entity_type": "concept or principle", "pos": [4, 18]}, {"entity": "predictable", "entity_type": "concept or principle", "pos": [37, 48]}, {"entity": "as", "entity_type": "material", "pos": [49, 51]}, {"entity": "failure", "entity_type": "concept or principle", "pos": [79, 86]}], "task": "NER"}
{"text": "In general , manufacturing imperfections might affect thin features more than thick features , hence thin struts should be thickened or well-designed with sufficient safety margin .", "entity": [{"entity": "manufacturing imperfections", "entity_type": "concept or principle", "pos": [13, 40]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [106, 112]}, {"entity": "be", "entity_type": "material", "pos": [120, 122]}, {"entity": "safety", "entity_type": "concept or principle", "pos": [166, 172]}], "task": "NER"}
{"text": "The obtained texturization in LPBF materials - grain and sub-grain sizes - depend on the procesB-parameters used and scanning strategy in LPBF materials as shown by .", "entity": [{"entity": "LPBF materials", "entity_type": "material", "pos": [30, 44]}, {"entity": "grain", "entity_type": "concept or principle", "pos": [47, 52]}, {"entity": "sub-grain sizes", "entity_type": "process parameter", "pos": [57, 72]}, {"entity": "scanning strategy", "entity_type": "concept or principle", "pos": [117, 134]}, {"entity": "LPBF materials", "entity_type": "material", "pos": [138, 152]}, {"entity": "as", "entity_type": "material", "pos": [153, 155]}], "task": "NER"}
{"text": "The microstructure of LPBF solid samples and their mechanical properties , fracture and fatigue behavior have some peculiarities in aB-built and heat-treated AM parts , which have been widely studied .", "entity": [{"entity": "microstructure", "entity_type": "concept or principle", "pos": [4, 18]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [22, 26]}, {"entity": "samples", "entity_type": "concept or principle", "pos": [33, 40]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [51, 72]}, {"entity": "fracture", "entity_type": "concept or principle", "pos": [75, 83]}, {"entity": "fatigue", "entity_type": "machanical property", "pos": [88, 95]}, {"entity": "heat-treated", "entity_type": "manufacturing process", "pos": [145, 157]}, {"entity": "AM parts", "entity_type": "machine or equipment", "pos": [158, 166]}], "task": "NER"}
{"text": "For example , the columnar boundaries of prior beta-phase were observed in aB-built Ti6Al4V ELI specimens and remain even after heat treatment of 950 for 2 hours .", "entity": [{"entity": "boundaries", "entity_type": "engineering feature", "pos": [27, 37]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [84, 91]}, {"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [128, 142]}], "task": "NER"}
{"text": "Anisotropy in AM is often mentioned .", "entity": [{"entity": "Anisotropy", "entity_type": "machanical property", "pos": [0, 10]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [14, 16]}], "task": "NER"}
{"text": "For example , the mechanical properties of LPBF Ti6Al4V ELI was found to be strongly anisotropic where three-point bending fatigue tests were used with parts produced in different orientations .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [18, 39]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [43, 47]}, {"entity": "be", "entity_type": "material", "pos": [73, 75]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [85, 96]}, {"entity": "three-point bending fatigue tests", "entity_type": "process characterization", "pos": [103, 136]}, {"entity": "orientations", "entity_type": "concept or principle", "pos": [180, 192]}], "task": "NER"}
{"text": "The crack propagation rate and fatigue life of aB-built and heat-treated samples correlated with column boundaries and orientation of the layers , i.e .", "entity": [{"entity": "crack propagation rate", "entity_type": "concept or principle", "pos": [4, 26]}, {"entity": "fatigue life", "entity_type": "machanical property", "pos": [31, 43]}, {"entity": "heat-treated", "entity_type": "manufacturing process", "pos": [60, 72]}, {"entity": "correlated", "entity_type": "concept or principle", "pos": [81, 91]}, {"entity": "column boundaries", "entity_type": "engineering feature", "pos": [97, 114]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [119, 130]}], "task": "NER"}
{"text": "correlated with the building direction .", "entity": [{"entity": "correlated", "entity_type": "concept or principle", "pos": [0, 10]}, {"entity": "building direction", "entity_type": "process parameter", "pos": [20, 38]}], "task": "NER"}
{"text": "For static tensile tests , lower ductility was observed experimentally for the horizontal specimens in comparison with vertical samples this could be attributed to long prior beta-grain boundaries in Ti6Al4V which grow in the build direction and are hence perpendicular to the loading direction in horizontal specimens .", "entity": [{"entity": "tensile tests", "entity_type": "process characterization", "pos": [11, 24]}, {"entity": "ductility", "entity_type": "machanical property", "pos": [33, 42]}, {"entity": "horizontal specimens", "entity_type": "biomedical", "pos": [79, 99]}, {"entity": "vertical samples", "entity_type": "concept or principle", "pos": [119, 135]}, {"entity": "be", "entity_type": "material", "pos": [147, 149]}, {"entity": "boundaries", "entity_type": "engineering feature", "pos": [186, 196]}, {"entity": "Ti6Al4V", "entity_type": "material", "pos": [200, 207]}, {"entity": "build direction", "entity_type": "process parameter", "pos": [226, 241]}, {"entity": "horizontal specimens", "entity_type": "biomedical", "pos": [298, 318]}], "task": "NER"}
{"text": "As it was noted in , the orientation dependency of the ductility in AM is not yet clear and further in-depth investigations need to be done .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "orientation", "entity_type": "concept or principle", "pos": [25, 36]}, {"entity": "ductility", "entity_type": "machanical property", "pos": [55, 64]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [68, 70]}, {"entity": "be", "entity_type": "material", "pos": [132, 134]}], "task": "NER"}
{"text": "Mechanical properties are dependent on building and scanning strategies and these vary for different materials .", "entity": [{"entity": "Mechanical properties", "entity_type": "concept or principle", "pos": [0, 21]}, {"entity": "scanning strategies", "entity_type": "concept or principle", "pos": [52, 71]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [101, 110]}], "task": "NER"}
{"text": "For example , LPBF 316 L stainless steel had maximum strength and Youngmodulus under a 45 degree offset between the layer and loading direction , whereas AlSi10Mg revealed the lowest strength in this case .", "entity": [{"entity": "LPBF", "entity_type": "manufacturing process", "pos": [14, 18]}, {"entity": "stainless steel", "entity_type": "material", "pos": [25, 40]}, {"entity": "strength", "entity_type": "machanical property", "pos": [53, 61]}, {"entity": "Youngmodulus", "entity_type": "machanical property", "pos": [66, 78]}, {"entity": "offset", "entity_type": "concept or principle", "pos": [97, 103]}, {"entity": "layer", "entity_type": "process parameter", "pos": [116, 121]}, {"entity": "AlSi10Mg", "entity_type": "material", "pos": [154, 162]}, {"entity": "strength", "entity_type": "machanical property", "pos": [183, 191]}], "task": "NER"}
{"text": "In samples manufactured by LPBF from a nickel-based alloy , strong crystallographic texture resulting in anisotropic properties was found in creep behavior : specimens with loading parallel to the building direction were superior compared to specimens with loading axis normal to the building direction .", "entity": [{"entity": "samples manufactured", "entity_type": "concept or principle", "pos": [3, 23]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [27, 31]}, {"entity": "nickel-based alloy", "entity_type": "material", "pos": [39, 57]}, {"entity": "texture", "entity_type": "engineering feature", "pos": [84, 91]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [105, 116]}, {"entity": "creep behavior", "entity_type": "machanical property", "pos": [141, 155]}, {"entity": "building direction", "entity_type": "process parameter", "pos": [197, 215]}, {"entity": "building direction", "entity_type": "process parameter", "pos": [284, 302]}], "task": "NER"}
{"text": "The Young 's modulus determined in measurements at room and elevated temperature was different during tensile testing parallel or perpendicular to the building direction .", "entity": [{"entity": "temperature", "entity_type": "process parameter", "pos": [69, 80]}, {"entity": "tensile testing", "entity_type": "process characterization", "pos": [102, 117]}, {"entity": "building direction", "entity_type": "process parameter", "pos": [151, 169]}], "task": "NER"}
{"text": "The building direction and laser scanning direction / scanning strategy are important for the mechanical integrity and this adds complexity to the optimal processing protocol for parts of complex shape .", "entity": [{"entity": "building direction", "entity_type": "process parameter", "pos": [4, 22]}, {"entity": "laser", "entity_type": "enabling technology", "pos": [27, 32]}, {"entity": "scanning strategy", "entity_type": "concept or principle", "pos": [54, 71]}, {"entity": "mechanical integrity", "entity_type": "machanical property", "pos": [94, 114]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [129, 139]}, {"entity": "protocol", "entity_type": "concept or principle", "pos": [166, 174]}, {"entity": "complex shape", "entity_type": "machanical property", "pos": [188, 201]}], "task": "NER"}
{"text": "Material type , particle size distribution and particle shape , procesB-parameters , protective atmosphere , building and scanning strategies , post-processing , etc .", "entity": [{"entity": "Material", "entity_type": "material", "pos": [0, 8]}, {"entity": "particle size distribution", "entity_type": "concept or principle", "pos": [16, 42]}, {"entity": "particle", "entity_type": "concept or principle", "pos": [47, 55]}, {"entity": "scanning strategies", "entity_type": "concept or principle", "pos": [122, 141]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [144, 159]}], "task": "NER"}
{"text": "should all be optimized according to the specific LPBF process so that biomimetic objects can be produced with the desired properties .", "entity": [{"entity": "be", "entity_type": "material", "pos": [11, 13]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [50, 54]}, {"entity": "biomimetic objects", "entity_type": "concept or principle", "pos": [71, 89]}, {"entity": "be", "entity_type": "material", "pos": [94, 96]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [123, 133]}], "task": "NER"}
{"text": "Once material properties and structural integrity have been assessed , the parts produced can be trusted , especially when suitable design safety margins have been incorporated .", "entity": [{"entity": "material properties", "entity_type": "concept or principle", "pos": [5, 24]}, {"entity": "structural integrity", "entity_type": "machanical property", "pos": [29, 49]}, {"entity": "be", "entity_type": "material", "pos": [55, 57]}, {"entity": "design", "entity_type": "engineering feature", "pos": [132, 138]}], "task": "NER"}
{"text": "There are some general suggested guidelines based on the experiences of the authors which can be used in addition to ensure safety and reliability of biomimetic parts in real world applications : 1 For lattices , thin struts might contain micro-porosity , rough surfaces and manufacturing imperfections which affect the mechanical properties sometimes more strongly than thicker features .", "entity": [{"entity": "be", "entity_type": "material", "pos": [94, 96]}, {"entity": "safety", "entity_type": "concept or principle", "pos": [124, 130]}, {"entity": "reliability", "entity_type": "process characterization", "pos": [135, 146]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [150, 160]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [202, 210]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [218, 224]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [262, 270]}, {"entity": "manufacturing imperfections", "entity_type": "concept or principle", "pos": [275, 302]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [320, 341]}], "task": "NER"}
{"text": "It was found that the cyclic response of lattices depend not only on the type of bulk material , but also on the roughness of the outer surface of the struts and the distribution of the micro-pores inside the struts which can both affect the crack initiation and crack propagation .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [41, 49]}, {"entity": "material", "entity_type": "material", "pos": [86, 94]}, {"entity": "roughness", "entity_type": "machanical property", "pos": [113, 122]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [136, 143]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [151, 157]}, {"entity": "distribution", "entity_type": "concept or principle", "pos": [166, 178]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [209, 215]}, {"entity": "crack propagation", "entity_type": "concept or principle", "pos": [263, 280]}], "task": "NER"}
{"text": "Post processing chemical cleaning to decrease strut roughness can be used to minimize this .", "entity": [{"entity": "Post processing chemical cleaning", "entity_type": "concept or principle", "pos": [0, 33]}, {"entity": "strut", "entity_type": "machine or equipment", "pos": [46, 51]}, {"entity": "roughness", "entity_type": "machanical property", "pos": [52, 61]}, {"entity": "be", "entity_type": "material", "pos": [66, 68]}], "task": "NER"}
{"text": "The accuracy of various AM techniques are different since different laser spot size , powder layer thickness , procesB-parameters as well as powder material are used .", "entity": [{"entity": "accuracy", "entity_type": "process characterization", "pos": [4, 12]}, {"entity": "AM techniques", "entity_type": "manufacturing process", "pos": [24, 37]}, {"entity": "laser spot size", "entity_type": "process parameter", "pos": [68, 83]}, {"entity": "powder", "entity_type": "material", "pos": [86, 92]}, {"entity": "layer thickness", "entity_type": "process parameter", "pos": [93, 108]}, {"entity": "as", "entity_type": "material", "pos": [130, 132]}, {"entity": "as", "entity_type": "material", "pos": [138, 140]}, {"entity": "material", "entity_type": "material", "pos": [148, 156]}], "task": "NER"}
{"text": "Therefore , for a particular purpose where mechanical properties are critical , AM lattices should be tested stringently .", "entity": [{"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [43, 64]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [80, 82]}, {"entity": "be", "entity_type": "material", "pos": [99, 101]}], "task": "NER"}
{"text": "To improve mechanical performance of lattice structures for load bearing applications they must be well-designed .", "entity": [{"entity": "mechanical", "entity_type": "application", "pos": [11, 21]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [37, 55]}, {"entity": "be", "entity_type": "material", "pos": [65, 67]}], "task": "NER"}
{"text": "Van Bael showed that stiffness and compressive strength of lattice structures correlate well with volume fraction .", "entity": [{"entity": "stiffness", "entity_type": "machanical property", "pos": [21, 30]}, {"entity": "compressive strength", "entity_type": "machanical property", "pos": [35, 55]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [59, 77]}, {"entity": "volume fraction", "entity_type": "process parameter", "pos": [98, 113]}], "task": "NER"}
{"text": "Contuzzi proposed to use solid reinforcements in fine lattice structures that increase load carrying capability of the structure almost linearly with the number of the reinforcements .", "entity": [{"entity": "lattice structures", "entity_type": "engineering feature", "pos": [54, 72]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [119, 128]}], "task": "NER"}
{"text": "Bobbert proposed to use in these applications continuous sheet-based porous structures because they are expected to be less sensitive to such imperfections than beam-based porous structures , to improve fatigue resistance .", "entity": [{"entity": "porous", "entity_type": "machanical property", "pos": [69, 75]}, {"entity": "be", "entity_type": "material", "pos": [87, 89]}, {"entity": "imperfections", "entity_type": "concept or principle", "pos": [142, 155]}, {"entity": "porous", "entity_type": "machanical property", "pos": [172, 178]}, {"entity": "fatigue", "entity_type": "machanical property", "pos": [203, 210]}], "task": "NER"}
{"text": "2 For lattices , selecting lattice parameters to ensure no supports are required on the lattice or inside the lattice area is critical .", "entity": [{"entity": "lattices", "entity_type": "concept or principle", "pos": [6, 14]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [27, 34]}, {"entity": "supports", "entity_type": "application", "pos": [59, 67]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [88, 95]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [110, 117]}, {"entity": "area", "entity_type": "process parameter", "pos": [118, 122]}], "task": "NER"}
{"text": "Here , strut angles and/or length is important .", "entity": [{"entity": "strut", "entity_type": "machine or equipment", "pos": [7, 12]}], "task": "NER"}
{"text": "3 For irregular geometries from topology optimization and freeform design , it is advisable to perform build-simulation to ensure no local heat accumulation occurs which might lead to residual stress and warping .", "entity": [{"entity": "geometries", "entity_type": "concept or principle", "pos": [16, 26]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [32, 53]}, {"entity": "freeform design", "entity_type": "engineering feature", "pos": [58, 73]}, {"entity": "heat accumulation", "entity_type": "machanical property", "pos": [139, 156]}, {"entity": "lead", "entity_type": "material", "pos": [176, 180]}, {"entity": "residual stress", "entity_type": "machanical property", "pos": [184, 199]}, {"entity": "warping", "entity_type": "concept or principle", "pos": [204, 211]}], "task": "NER"}
{"text": "In this process , the optimal build angle and supports should be selected .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [8, 15]}, {"entity": "build", "entity_type": "process parameter", "pos": [30, 35]}, {"entity": "supports", "entity_type": "application", "pos": [46, 54]}, {"entity": "be", "entity_type": "material", "pos": [62, 64]}], "task": "NER"}
{"text": "4 Residual stress can be minimized by design as mentioned above , and can be further improved by stresB-relief heat treatment a relatively simple recommended solution .", "entity": [{"entity": "Residual stress", "entity_type": "machanical property", "pos": [2, 17]}, {"entity": "be", "entity_type": "material", "pos": [22, 24]}, {"entity": "design", "entity_type": "engineering feature", "pos": [38, 44]}, {"entity": "as", "entity_type": "material", "pos": [45, 47]}, {"entity": "be", "entity_type": "material", "pos": [74, 76]}, {"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [111, 125]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [139, 145]}, {"entity": "solution", "entity_type": "concept or principle", "pos": [158, 166]}], "task": "NER"}
{"text": "Heat treatment can have a decisive role on higher ductility and load bearing capacity of lattice structures and might increase fatigue life .", "entity": [{"entity": "Heat treatment", "entity_type": "manufacturing process", "pos": [0, 14]}, {"entity": "ductility", "entity_type": "machanical property", "pos": [50, 59]}, {"entity": "capacity", "entity_type": "concept or principle", "pos": [77, 85]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [89, 107]}, {"entity": "fatigue life", "entity_type": "machanical property", "pos": [127, 139]}], "task": "NER"}
{"text": "5 Special attention must be given to the loading direction during use , because anisotropic mechanical properties of LPBF objects exists .", "entity": [{"entity": "be", "entity_type": "material", "pos": [25, 27]}, {"entity": "anisotropic", "entity_type": "machanical property", "pos": [80, 91]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [103, 113]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [117, 121]}], "task": "NER"}
{"text": "This anisotropy might not only result from the material and its specific microstructure , but also from scanning and building strategies used for LPBF manufacturing , which might vary with different systems .", "entity": [{"entity": "anisotropy", "entity_type": "machanical property", "pos": [5, 15]}, {"entity": "material", "entity_type": "material", "pos": [47, 55]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [73, 87]}, {"entity": "scanning", "entity_type": "concept or principle", "pos": [104, 112]}, {"entity": "LPBF", "entity_type": "manufacturing process", "pos": [146, 150]}], "task": "NER"}
{"text": "Lattice structures built in different directions have non-identical mechanical properties .", "entity": [{"entity": "Lattice structures", "entity_type": "engineering feature", "pos": [0, 18]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [68, 89]}], "task": "NER"}
{"text": "7 Challenges in biomimetic AM Despite all the potential for biomimicry in AM in its various forms , there are some challenges to its practical implementation .", "entity": [{"entity": "biomimetic AM", "entity_type": "application", "pos": [16, 29]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [60, 70]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [74, 76]}], "task": "NER"}
{"text": "Most importantly , all forms of biomimetic design for AM involves complexity in various forms not previously encountered .", "entity": [{"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [32, 49]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [54, 56]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [66, 76]}], "task": "NER"}
{"text": "While AM relaxes the traditional manufacturing rules , not any geometry or structure can be produced easily or reliably .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [6, 8]}, {"entity": "traditional manufacturing", "entity_type": "manufacturing process", "pos": [21, 46]}, {"entity": "geometry", "entity_type": "concept or principle", "pos": [63, 71]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [75, 84]}, {"entity": "be", "entity_type": "material", "pos": [89, 91]}], "task": "NER"}
{"text": "Due to the complexity of design , design for AM becomes even more crucial to ensure manufacturability and might involve re-design in cases of difficult geometries .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [11, 21]}, {"entity": "design", "entity_type": "engineering feature", "pos": [25, 31]}, {"entity": "design", "entity_type": "engineering feature", "pos": [34, 40]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [45, 47]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [84, 101]}, {"entity": "geometries", "entity_type": "concept or principle", "pos": [152, 162]}], "task": "NER"}
{"text": "Metal AM and its limits in general are discussed in more detail in .", "entity": [{"entity": "Metal AM", "entity_type": "manufacturing process", "pos": [0, 8]}, {"entity": "limits", "entity_type": "concept or principle", "pos": [17, 23]}], "task": "NER"}
{"text": "AM is still a relatively new manufacturing process which requires process optimization and quality control to ensure accuracy and reliability .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [0, 2]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [29, 50]}, {"entity": "process optimization", "entity_type": "concept or principle", "pos": [66, 86]}, {"entity": "quality control", "entity_type": "concept or principle", "pos": [91, 106]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [117, 125]}, {"entity": "reliability", "entity_type": "process characterization", "pos": [130, 141]}], "task": "NER"}
{"text": "This requirement is critically important for parts with complex geometries which include curved surfaces , thin connecting features , hidden features and lattice structures .", "entity": [{"entity": "complex geometries", "entity_type": "concept or principle", "pos": [56, 74]}, {"entity": "curved surfaces", "entity_type": "concept or principle", "pos": [89, 104]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [154, 172]}], "task": "NER"}
{"text": "There are also many varieties of AM with different trade names , processes and differences in quality obtained .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [33, 35]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [65, 74]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [94, 101]}], "task": "NER"}
{"text": "This quality refers in particular to material density and process induced pores , inherent process surface roughness , build errors such as uneven powder spreading or scan track errors leading to critical flaws , residual stresses and associated warping and cracking and microstructural inhomogeneity .", "entity": [{"entity": "quality", "entity_type": "concept or principle", "pos": [5, 12]}, {"entity": "material", "entity_type": "material", "pos": [37, 45]}, {"entity": "density", "entity_type": "machanical property", "pos": [46, 53]}, {"entity": "process", "entity_type": "concept or principle", "pos": [58, 65]}, {"entity": "pores", "entity_type": "machanical property", "pos": [74, 79]}, {"entity": "process", "entity_type": "concept or principle", "pos": [91, 98]}, {"entity": "roughness", "entity_type": "machanical property", "pos": [107, 116]}, {"entity": "build", "entity_type": "process parameter", "pos": [119, 124]}, {"entity": "as", "entity_type": "material", "pos": [137, 139]}, {"entity": "powder", "entity_type": "material", "pos": [147, 153]}, {"entity": "errors", "entity_type": "concept or principle", "pos": [178, 184]}, {"entity": "flaws", "entity_type": "concept or principle", "pos": [205, 210]}, {"entity": "residual stresses", "entity_type": "machanical property", "pos": [213, 230]}, {"entity": "warping", "entity_type": "concept or principle", "pos": [246, 253]}, {"entity": "cracking", "entity_type": "concept or principle", "pos": [258, 266]}, {"entity": "microstructural", "entity_type": "concept or principle", "pos": [271, 286]}], "task": "NER"}
{"text": "A major limitation is the minimum feature size for the AM system used .", "entity": [{"entity": "minimum feature size", "entity_type": "process parameter", "pos": [26, 46]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [55, 57]}], "task": "NER"}
{"text": "Some additional limitations are placed on the part designs , most notably the build angles .", "entity": [{"entity": "designs", "entity_type": "engineering feature", "pos": [51, 58]}, {"entity": "build", "entity_type": "process parameter", "pos": [78, 83]}], "task": "NER"}
{"text": "All down-facing surfaces have typically rougher surfaces than upwardB-facing surfaces , thin angled features suffer from stair-step effects , and small angles require supports .", "entity": [{"entity": "surfaces", "entity_type": "concept or principle", "pos": [16, 24]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [48, 56]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [77, 85]}, {"entity": "supports", "entity_type": "application", "pos": [167, 175]}], "task": "NER"}
{"text": "Support removal is not a simple process : this post-processing is time consuming and may also affect the dimensional accuracy and quality of the resulting part .", "entity": [{"entity": "Support", "entity_type": "application", "pos": [0, 7]}, {"entity": "simple", "entity_type": "manufacturing process", "pos": [25, 31]}, {"entity": "process", "entity_type": "concept or principle", "pos": [32, 39]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [47, 62]}, {"entity": "dimensional accuracy", "entity_type": "process characterization", "pos": [105, 125]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [130, 137]}], "task": "NER"}
{"text": "When supports are needed inside a complex part , these supports might not be physically removable at all as shown in the example in 18 .", "entity": [{"entity": "supports", "entity_type": "application", "pos": [5, 13]}, {"entity": "supports", "entity_type": "application", "pos": [55, 63]}, {"entity": "be", "entity_type": "material", "pos": [74, 76]}, {"entity": "as", "entity_type": "material", "pos": [105, 107]}], "task": "NER"}
{"text": "In this figure , two topology-optimized bracket designs were almost entirely latticed but the build process required incorporation of supports also inside the lattice region .", "entity": [{"entity": "bracket", "entity_type": "machine or equipment", "pos": [40, 47]}, {"entity": "build", "entity_type": "process parameter", "pos": [94, 99]}, {"entity": "supports", "entity_type": "application", "pos": [134, 142]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [159, 166]}], "task": "NER"}
{"text": "Removing supports from lattice regions on the exterior can cause damage to the lattice struts , and removing them from inside the lattice region is entirely impossible .", "entity": [{"entity": "supports", "entity_type": "application", "pos": [9, 17]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [23, 30]}, {"entity": "damage", "entity_type": "machanical property", "pos": [65, 71]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [79, 86]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [130, 137]}], "task": "NER"}
{"text": "In this case , the brackets still met the mass target despite internal supports , but the aesthetic value is not as visually impressive as could have been achieved by appropriate design to eliminate supports .", "entity": [{"entity": "supports", "entity_type": "application", "pos": [71, 79]}, {"entity": "aesthetic", "entity_type": "concept or principle", "pos": [90, 99]}, {"entity": "as", "entity_type": "material", "pos": [113, 115]}, {"entity": "as", "entity_type": "material", "pos": [136, 138]}, {"entity": "design", "entity_type": "engineering feature", "pos": [179, 185]}, {"entity": "supports", "entity_type": "application", "pos": [199, 207]}], "task": "NER"}
{"text": "Detailed inspection of these complex parts ensures their structural integrity and accuracy of production .", "entity": [{"entity": "inspection", "entity_type": "process characterization", "pos": [9, 19]}, {"entity": "structural integrity", "entity_type": "machanical property", "pos": [57, 77]}, {"entity": "accuracy", "entity_type": "process characterization", "pos": [82, 90]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [94, 104]}], "task": "NER"}
{"text": "Due to the expense involved in AM , non-destructive tools are especially useful to analyze parts without destroying them : the most widely used are X-ray techniques such as 2D digital radiography and 3D micro-computed tomography .", "entity": [{"entity": "AM", "entity_type": "manufacturing process", "pos": [31, 33]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [52, 57]}, {"entity": "X-ray", "entity_type": "process characterization", "pos": [148, 153]}, {"entity": "as", "entity_type": "material", "pos": [170, 172]}, {"entity": "2D", "entity_type": "concept or principle", "pos": [173, 175]}, {"entity": "radiography", "entity_type": "enabling technology", "pos": [184, 195]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [200, 202]}], "task": "NER"}
{"text": "Due to the complexity of the parts 2D X-ray images are difficult to interpret and smaller flaws which are typical to AM may be missed .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [11, 21]}, {"entity": "2D", "entity_type": "concept or principle", "pos": [35, 37]}, {"entity": "images", "entity_type": "concept or principle", "pos": [44, 50]}, {"entity": "flaws", "entity_type": "concept or principle", "pos": [90, 95]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [117, 119]}, {"entity": "be", "entity_type": "material", "pos": [124, 126]}], "task": "NER"}
{"text": "As a result , microCT is often the preferred method of choice .", "entity": [{"entity": "As", "entity_type": "material", "pos": [0, 2]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [14, 21]}], "task": "NER"}
{"text": "This technique works by acquisition of X-ray absorption images from many angles around the object , followed by reconstruction to produce a 3D representation of the object , including its interior .", "entity": [{"entity": "X-ray absorption", "entity_type": "process characterization", "pos": [39, 55]}, {"entity": "images", "entity_type": "concept or principle", "pos": [56, 62]}, {"entity": "reconstruction", "entity_type": "concept or principle", "pos": [112, 126]}, {"entity": "3D", "entity_type": "concept or principle", "pos": [140, 142]}], "task": "NER"}
{"text": "It is also known as X-ray tomography , CT scanning or X-ray microscopy .", "entity": [{"entity": "as", "entity_type": "material", "pos": [17, 19]}, {"entity": "CT", "entity_type": "enabling technology", "pos": [39, 41]}, {"entity": "X-ray", "entity_type": "process characterization", "pos": [54, 59]}, {"entity": "microscopy", "entity_type": "process characterization", "pos": [60, 70]}], "task": "NER"}
{"text": "The most important issues that can be identified by microCT and which are relevant to biomimetic AM are : - Powder can get stuck in complex areas , especially inside lattices , and when heat-treated they become stuck .", "entity": [{"entity": "be", "entity_type": "material", "pos": [35, 37]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [52, 59]}, {"entity": "biomimetic AM", "entity_type": "application", "pos": [86, 99]}, {"entity": "Powder", "entity_type": "material", "pos": [108, 114]}, {"entity": "areas", "entity_type": "process parameter", "pos": [140, 145]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [166, 174]}, {"entity": "heat-treated", "entity_type": "manufacturing process", "pos": [186, 198]}], "task": "NER"}
{"text": "This adds weight and might be unsafe .", "entity": [{"entity": "weight", "entity_type": "process parameter", "pos": [10, 16]}, {"entity": "be", "entity_type": "material", "pos": [27, 29]}], "task": "NER"}
{"text": "- Rough surfaces which depend on build angle might affect mechanical properties , with rough surfaces in inaccessible areas being unable to be processed .", "entity": [{"entity": "surfaces", "entity_type": "concept or principle", "pos": [8, 16]}, {"entity": "build", "entity_type": "process parameter", "pos": [33, 38]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [58, 79]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [93, 101]}, {"entity": "areas", "entity_type": "process parameter", "pos": [118, 123]}, {"entity": "be", "entity_type": "material", "pos": [124, 126]}], "task": "NER"}
{"text": "Roughness can be measured quantitatively or assessed visually .", "entity": [{"entity": "Roughness", "entity_type": "machanical property", "pos": [0, 9]}, {"entity": "be", "entity_type": "material", "pos": [14, 16]}, {"entity": "quantitatively", "entity_type": "concept or principle", "pos": [26, 40]}], "task": "NER"}
{"text": "- Manufacturing flaws such as porosity might also occur despite process parameter optimization and this may affect the mechanical properties .", "entity": [{"entity": "Manufacturing", "entity_type": "manufacturing process", "pos": [2, 15]}, {"entity": "flaws", "entity_type": "concept or principle", "pos": [16, 21]}, {"entity": "as", "entity_type": "material", "pos": [27, 29]}, {"entity": "process parameter", "entity_type": "concept or principle", "pos": [64, 81]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [82, 94]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [119, 140]}], "task": "NER"}
{"text": "It is important to note here that process parameter optimization prior to building a part can limit procesB-induced porosity and this microporosity is expected to be the same in a test coupon than in a complex part .", "entity": [{"entity": "process parameter", "entity_type": "concept or principle", "pos": [34, 51]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [52, 64]}, {"entity": "limit", "entity_type": "concept or principle", "pos": [94, 99]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [116, 124]}, {"entity": "microporosity", "entity_type": "machanical property", "pos": [134, 147]}, {"entity": "be", "entity_type": "material", "pos": [163, 165]}], "task": "NER"}
{"text": "- Residual stress can not directly be seen in microCT images but can be seen indirectly in the form of warping and cracks .", "entity": [{"entity": "Residual stress", "entity_type": "machanical property", "pos": [2, 17]}, {"entity": "be", "entity_type": "material", "pos": [35, 37]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [46, 53]}, {"entity": "images", "entity_type": "concept or principle", "pos": [54, 60]}, {"entity": "be", "entity_type": "material", "pos": [69, 71]}, {"entity": "warping", "entity_type": "concept or principle", "pos": [103, 110]}], "task": "NER"}
{"text": "Unnoticed residual stress in a part might affect its mechanical properties .", "entity": [{"entity": "residual stress", "entity_type": "machanical property", "pos": [10, 25]}, {"entity": "mechanical properties", "entity_type": "concept or principle", "pos": [53, 74]}], "task": "NER"}
{"text": "StresB-relief heat treatment is therefore highly recommended .", "entity": [{"entity": "heat treatment", "entity_type": "manufacturing process", "pos": [14, 28]}], "task": "NER"}
{"text": "The above issues can be partially improved or solved by using AM simulations to highlight where thermal hotspots might be formed .", "entity": [{"entity": "be", "entity_type": "material", "pos": [21, 23]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [62, 64]}, {"entity": "be", "entity_type": "material", "pos": [119, 121]}], "task": "NER"}
{"text": "A change in the build angle or design itself can contribute to eliminate these .", "entity": [{"entity": "build", "entity_type": "process parameter", "pos": [16, 21]}, {"entity": "design", "entity_type": "engineering feature", "pos": [31, 37]}], "task": "NER"}
{"text": "Changing the lattice design or parameters can improve the requirement for supports and self-supporting lattice designs can be selected in some cases .", "entity": [{"entity": "lattice design", "entity_type": "engineering feature", "pos": [13, 27]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [31, 41]}, {"entity": "supports", "entity_type": "application", "pos": [74, 82]}, {"entity": "self-supporting", "entity_type": "engineering feature", "pos": [87, 102]}, {"entity": "lattice designs", "entity_type": "engineering feature", "pos": [103, 118]}, {"entity": "be", "entity_type": "material", "pos": [123, 125]}], "task": "NER"}
{"text": "Besides build orientation planning and simulation , the manufacturing process can be optimized to ensure high quality production on test cubes , which can be subjected to detailed analysis by sectioning , or preferably by microCT .", "entity": [{"entity": "build orientation", "entity_type": "process parameter", "pos": [8, 25]}, {"entity": "simulation", "entity_type": "enabling technology", "pos": [39, 49]}, {"entity": "manufacturing process", "entity_type": "manufacturing process", "pos": [56, 77]}, {"entity": "be", "entity_type": "material", "pos": [82, 84]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [110, 117]}, {"entity": "production", "entity_type": "manufacturing process", "pos": [118, 128]}, {"entity": "be", "entity_type": "material", "pos": [139, 141]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [222, 229]}], "task": "NER"}
{"text": "When using microCT , however , it is also important to realize that while small porosity is acceptable when well distributed , only major flaws or those with specific location-specific clustering are important , as well as those in critical regions of the part .", "entity": [{"entity": "microCT", "entity_type": "process characterization", "pos": [11, 18]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [80, 88]}, {"entity": "flaws", "entity_type": "concept or principle", "pos": [138, 143]}, {"entity": "as", "entity_type": "material", "pos": [212, 214]}, {"entity": "as", "entity_type": "material", "pos": [220, 222]}], "task": "NER"}
{"text": "Optimization of processes using test cubes and microCT may assist in identifying the root cause of some types of defects which allows to improve the process .", "entity": [{"entity": "Optimization", "entity_type": "concept or principle", "pos": [0, 12]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [16, 25]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [47, 54]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [113, 120]}, {"entity": "process", "entity_type": "concept or principle", "pos": [149, 156]}], "task": "NER"}
{"text": "Simulations and experimental work done on lattice structures with artificially induced porosity in individual struts showed that this did not affect the yield strength of the lattice for up to 0.5 mm pores .", "entity": [{"entity": "Simulations", "entity_type": "enabling technology", "pos": [0, 11]}, {"entity": "experimental", "entity_type": "concept or principle", "pos": [16, 28]}, {"entity": "lattice structures", "entity_type": "engineering feature", "pos": [42, 60]}, {"entity": "porosity", "entity_type": "machanical property", "pos": [87, 95]}, {"entity": "struts", "entity_type": "machine or equipment", "pos": [110, 116]}, {"entity": "yield strength", "entity_type": "machanical property", "pos": [153, 167]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [175, 182]}, {"entity": "mm", "entity_type": "manufacturing process", "pos": [197, 199]}], "task": "NER"}
{"text": "8 New trends in biomimetic AM This section mentions some current interesting trends in biomimetic design for AM , with new developments expected in the next few years as the techniques are refined and new tools become available .", "entity": [{"entity": "trends", "entity_type": "concept or principle", "pos": [6, 12]}, {"entity": "biomimetic AM", "entity_type": "application", "pos": [16, 29]}, {"entity": "trends", "entity_type": "concept or principle", "pos": [77, 83]}, {"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [87, 104]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [109, 111]}, {"entity": "as", "entity_type": "material", "pos": [167, 169]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [205, 210]}], "task": "NER"}
{"text": "The first worth mentioning is that most topology optimization software at present operates on the topology itself and subsequently certain areas can be selected for latticing , i.e .", "entity": [{"entity": "topology optimization", "entity_type": "engineering feature", "pos": [40, 61]}, {"entity": "software", "entity_type": "concept or principle", "pos": [62, 70]}, {"entity": "topology", "entity_type": "concept or principle", "pos": [98, 106]}, {"entity": "areas", "entity_type": "process parameter", "pos": [139, 144]}, {"entity": "be", "entity_type": "material", "pos": [149, 151]}], "task": "NER"}
{"text": "the latticing is not part of the simulation-driven design process .", "entity": [{"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [33, 50]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [51, 65]}], "task": "NER"}
{"text": "This latticing is incorporated into the simulation-driven design process and will find application especially in light-weighting applications .", "entity": [{"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [40, 57]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [58, 72]}], "task": "NER"}
{"text": "The other useful development is the optimization of repeated lattices gradient lattices and variations of strut thickness or unit cell size across a part , and conformal lattices to the surfaces of a part .", "entity": [{"entity": "optimization", "entity_type": "concept or principle", "pos": [36, 48]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [61, 69]}, {"entity": "lattices", "entity_type": "concept or principle", "pos": [79, 87]}, {"entity": "variations", "entity_type": "concept or principle", "pos": [92, 102]}, {"entity": "strut thickness", "entity_type": "process parameter", "pos": [106, 121]}, {"entity": "unit cell", "entity_type": "concept or principle", "pos": [125, 134]}, {"entity": "conformal lattices", "entity_type": "engineering feature", "pos": [160, 178]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [186, 194]}], "task": "NER"}
{"text": "In other words , the lattice is not simply cut off on the edge of the part but unit cells are stretched to fit the surface topology .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [21, 28]}, {"entity": "unit cells", "entity_type": "concept or principle", "pos": [79, 89]}, {"entity": "fit", "entity_type": "concept or principle", "pos": [107, 110]}, {"entity": "surface topology", "entity_type": "engineering feature", "pos": [115, 131]}], "task": "NER"}
{"text": "An example hereof is shown in 21 where the lattice is conformal to two opposing surfaces and the lattice density varies to allow denser lattice in areas where simulations show higher stress will be experienced .", "entity": [{"entity": "lattice", "entity_type": "concept or principle", "pos": [43, 50]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [80, 88]}, {"entity": "lattice density", "entity_type": "engineering feature", "pos": [97, 112]}, {"entity": "lattice", "entity_type": "concept or principle", "pos": [136, 143]}, {"entity": "areas", "entity_type": "process parameter", "pos": [147, 152]}, {"entity": "simulations", "entity_type": "enabling technology", "pos": [159, 170]}, {"entity": "stress", "entity_type": "machanical property", "pos": [183, 189]}, {"entity": "be", "entity_type": "material", "pos": [195, 197]}], "task": "NER"}
{"text": "Recent research approaches for cellular material design have included the development of multi-scale optimization approaches as described by Osanov and Guest and Cadman .", "entity": [{"entity": "research", "entity_type": "concept or principle", "pos": [7, 15]}, {"entity": "cellular material", "entity_type": "material", "pos": [31, 48]}, {"entity": "optimization", "entity_type": "concept or principle", "pos": [101, 113]}, {"entity": "as", "entity_type": "material", "pos": [125, 127]}], "task": "NER"}
{"text": "In this approach , the unit cell domain is discretized into elements which are then themselves optimized using topology optimization methods , similar to discussions in the previous section .", "entity": [{"entity": "unit cell", "entity_type": "concept or principle", "pos": [23, 32]}, {"entity": "domain", "entity_type": "concept or principle", "pos": [33, 39]}, {"entity": "elements", "entity_type": "material", "pos": [60, 68]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [111, 132]}], "task": "NER"}
{"text": "A unit cell so designed can then be used to compute effective properties , after which inverse homogenization is used to upscale the cellular geometry to the level of the larger structure .", "entity": [{"entity": "unit cell", "entity_type": "concept or principle", "pos": [2, 11]}, {"entity": "designed", "entity_type": "engineering feature", "pos": [15, 23]}, {"entity": "be", "entity_type": "material", "pos": [33, 35]}, {"entity": "properties", "entity_type": "concept or principle", "pos": [62, 72]}, {"entity": "homogenization", "entity_type": "manufacturing process", "pos": [95, 109]}, {"entity": "geometry", "entity_type": "concept or principle", "pos": [142, 150]}, {"entity": "structure", "entity_type": "concept or principle", "pos": [178, 187]}], "task": "NER"}
{"text": "These ideas have been recently extended to multi-material cellular structure optimization .", "entity": [{"entity": "multi-material", "entity_type": "concept or principle", "pos": [43, 57]}, {"entity": "cellular structure", "entity_type": "engineering feature", "pos": [58, 76]}], "task": "NER"}
{"text": "Cellular automata methods have also been developed to design materials and microstructures , and machine learning methods are beginning to be applied to materials design .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [54, 60]}, {"entity": "microstructures", "entity_type": "material", "pos": [75, 90]}, {"entity": "machine", "entity_type": "machine or equipment", "pos": [97, 104]}, {"entity": "be", "entity_type": "material", "pos": [126, 128]}, {"entity": "materials", "entity_type": "concept or principle", "pos": [153, 162]}, {"entity": "design", "entity_type": "engineering feature", "pos": [163, 169]}], "task": "NER"}
{"text": "Because of the very complex shapes of the parts having a biomimetic or bionic design , it is often necessary to use support structures for overhanging areas .", "entity": [{"entity": "complex shapes", "entity_type": "machanical property", "pos": [20, 34]}, {"entity": "biomimetic", "entity_type": "concept or principle", "pos": [57, 67]}, {"entity": "design", "entity_type": "engineering feature", "pos": [78, 84]}, {"entity": "support structures", "entity_type": "engineering feature", "pos": [116, 134]}, {"entity": "areas", "entity_type": "process parameter", "pos": [151, 156]}], "task": "NER"}
{"text": "This can be a big problem in the post processing of these parts for removing the supports and surface finishing .", "entity": [{"entity": "be", "entity_type": "material", "pos": [9, 11]}, {"entity": "post processing", "entity_type": "concept or principle", "pos": [33, 48]}, {"entity": "supports", "entity_type": "application", "pos": [81, 89]}, {"entity": "surface finishing", "entity_type": "manufacturing process", "pos": [94, 111]}], "task": "NER"}
{"text": "On the other hand , internal complexity and small features are limited in this process , since with constant preheating of each layer to a high temperature , the powder is partially sintered and later can not be removed from the manufactured part .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [29, 39]}, {"entity": "process", "entity_type": "concept or principle", "pos": [79, 86]}, {"entity": "preheating", "entity_type": "manufacturing process", "pos": [109, 119]}, {"entity": "layer", "entity_type": "process parameter", "pos": [128, 133]}, {"entity": "temperature", "entity_type": "process parameter", "pos": [144, 155]}, {"entity": "powder", "entity_type": "material", "pos": [162, 168]}, {"entity": "sintered", "entity_type": "manufacturing process", "pos": [182, 190]}, {"entity": "be", "entity_type": "material", "pos": [209, 211]}, {"entity": "manufactured", "entity_type": "concept or principle", "pos": [229, 241]}], "task": "NER"}
{"text": "There are also quite serious limitations on materials for EBM technology .", "entity": [{"entity": "materials", "entity_type": "concept or principle", "pos": [44, 53]}, {"entity": "EBM", "entity_type": "manufacturing process", "pos": [58, 61]}], "task": "NER"}
{"text": "Also recently , companies such as EOS and Velo3D have improved their softwares , scanning strategies and process control parameters , which allowed to realize designs with overhangs lower than 15and large inner diameters without supports .", "entity": [{"entity": "companies", "entity_type": "application", "pos": [16, 25]}, {"entity": "as", "entity_type": "material", "pos": [31, 33]}, {"entity": "scanning strategies", "entity_type": "concept or principle", "pos": [81, 100]}, {"entity": "process control", "entity_type": "concept or principle", "pos": [105, 120]}, {"entity": "parameters", "entity_type": "concept or principle", "pos": [121, 131]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [159, 166]}, {"entity": "overhangs", "entity_type": "process parameter", "pos": [172, 181]}, {"entity": "supports", "entity_type": "application", "pos": [229, 237]}], "task": "NER"}
{"text": "These developments are all very promising for the realization of increasingly complex biomimetic designs with improved structural integrity and surface quality .", "entity": [{"entity": "biomimetic designs", "entity_type": "engineering feature", "pos": [86, 104]}, {"entity": "structural integrity", "entity_type": "machanical property", "pos": [119, 139]}, {"entity": "surface quality", "entity_type": "process parameter", "pos": [144, 159]}], "task": "NER"}
{"text": "An emerging trend is the development of software packages incorporating the entire workflow for advanced design for AM , including freeform design , topology optimization , latticing and more recently also build simulation and even support generation and slicing for build preparation .", "entity": [{"entity": "trend", "entity_type": "concept or principle", "pos": [12, 17]}, {"entity": "software", "entity_type": "concept or principle", "pos": [40, 48]}, {"entity": "workflow", "entity_type": "concept or principle", "pos": [83, 91]}, {"entity": "design", "entity_type": "engineering feature", "pos": [105, 111]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [116, 118]}, {"entity": "freeform design", "entity_type": "engineering feature", "pos": [131, 146]}, {"entity": "topology optimization", "entity_type": "engineering feature", "pos": [149, 170]}, {"entity": "build", "entity_type": "process parameter", "pos": [206, 211]}, {"entity": "support generation", "entity_type": "engineering feature", "pos": [232, 250]}, {"entity": "slicing", "entity_type": "concept or principle", "pos": [255, 262]}, {"entity": "build preparation", "entity_type": "process parameter", "pos": [267, 284]}], "task": "NER"}
{"text": "When all this is combined in one workspace the entire design process is simplified and this allows more frequent and improved biomimetic designs to be realized in practice .", "entity": [{"entity": "design process", "entity_type": "concept or principle", "pos": [54, 68]}, {"entity": "biomimetic designs", "entity_type": "engineering feature", "pos": [126, 144]}, {"entity": "be", "entity_type": "material", "pos": [148, 150]}], "task": "NER"}
{"text": "The development of standards for AM and non-destructive testing in AM is emerging as an important aspect in the qualification of processes and ensuring reliability in AM processes .", "entity": [{"entity": "standards", "entity_type": "concept or principle", "pos": [19, 28]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [33, 35]}, {"entity": "non-destructive testing", "entity_type": "process characterization", "pos": [40, 63]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [67, 69]}, {"entity": "as", "entity_type": "material", "pos": [82, 84]}, {"entity": "processes", "entity_type": "concept or principle", "pos": [129, 138]}, {"entity": "reliability", "entity_type": "process characterization", "pos": [152, 163]}, {"entity": "AM processes", "entity_type": "manufacturing process", "pos": [167, 179]}], "task": "NER"}
{"text": "This is especially applicable to biomimetic designs and it holds the most advantage in optimizing process parameters prior to building complex parts - using microCT test methods .", "entity": [{"entity": "biomimetic designs", "entity_type": "engineering feature", "pos": [33, 51]}, {"entity": "process parameters", "entity_type": "concept or principle", "pos": [98, 116]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [157, 164]}], "task": "NER"}
{"text": "Inspecting complex parts is also valuable in critical parts such as for aerospace , and microCT is the best method to do this .", "entity": [{"entity": "as", "entity_type": "material", "pos": [65, 67]}, {"entity": "aerospace", "entity_type": "application", "pos": [72, 81]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [88, 95]}], "task": "NER"}
{"text": "It is worth mentioning that besides complex part inspections , which are limited in resolution by field of view , it is becoming standard practice to inspect witness specimens of smaller diameter built alongside complex parts .", "entity": [{"entity": "inspections", "entity_type": "process characterization", "pos": [49, 60]}, {"entity": "resolution", "entity_type": "process parameter", "pos": [84, 94]}, {"entity": "standard", "entity_type": "concept or principle", "pos": [129, 137]}, {"entity": "diameter", "entity_type": "concept or principle", "pos": [187, 195]}], "task": "NER"}
{"text": "This allows for high resolution CT analysis with defects found in these specimens being indicative of problems encountered during the build .", "entity": [{"entity": "high resolution", "entity_type": "process parameter", "pos": [16, 31]}, {"entity": "CT", "entity_type": "enabling technology", "pos": [32, 34]}, {"entity": "defects", "entity_type": "concept or principle", "pos": [49, 56]}, {"entity": "build", "entity_type": "process parameter", "pos": [134, 139]}], "task": "NER"}
{"text": "Something that is becoming increasingly popular for improving part density is the use of hot isostatic pressing , especially for additively-manufactured metal parts for aerospace it is a requirement that all parts are HIPped .", "entity": [{"entity": "density", "entity_type": "machanical property", "pos": [67, 74]}, {"entity": "hot isostatic pressing", "entity_type": "manufacturing process", "pos": [89, 111]}, {"entity": "metal", "entity_type": "material", "pos": [153, 158]}, {"entity": "aerospace", "entity_type": "application", "pos": [169, 178]}], "task": "NER"}
{"text": "The HIP process closes pores and improves the microstructure , but it is important to realize that not all pores are necessarily closed by HIP : it has been shown that pores connected to the surface do not close properly , and is detectable by microCT .", "entity": [{"entity": "HIP", "entity_type": "manufacturing process", "pos": [4, 7]}, {"entity": "pores", "entity_type": "machanical property", "pos": [23, 28]}, {"entity": "microstructure", "entity_type": "concept or principle", "pos": [46, 60]}, {"entity": "pores", "entity_type": "machanical property", "pos": [107, 112]}, {"entity": "HIP", "entity_type": "manufacturing process", "pos": [139, 142]}, {"entity": "pores", "entity_type": "machanical property", "pos": [168, 173]}, {"entity": "surface", "entity_type": "concept or principle", "pos": [191, 198]}, {"entity": "microCT", "entity_type": "process characterization", "pos": [244, 251]}], "task": "NER"}
{"text": "The important point is that HIP should not be used as a blind solution its performance especially in thin walled parts should be checked .", "entity": [{"entity": "HIP", "entity_type": "manufacturing process", "pos": [28, 31]}, {"entity": "be", "entity_type": "material", "pos": [43, 45]}, {"entity": "as", "entity_type": "material", "pos": [51, 53]}, {"entity": "solution", "entity_type": "concept or principle", "pos": [62, 70]}, {"entity": "performance", "entity_type": "concept or principle", "pos": [75, 86]}, {"entity": "be", "entity_type": "material", "pos": [126, 128]}], "task": "NER"}
{"text": "In general , the use of biomimetic AM is growing at a very fast rate , with practical engineering applications emerging almost daily .", "entity": [{"entity": "biomimetic AM", "entity_type": "application", "pos": [24, 37]}, {"entity": "engineering", "entity_type": "application", "pos": [86, 97]}], "task": "NER"}
{"text": "This is driven by the maturation of metal powder bed fusion AM , the development of appropriate software tools , and the huge interest from companies in investing in a technology with clear potential to disrupt various industries .", "entity": [{"entity": "metal powder bed fusion", "entity_type": "manufacturing process", "pos": [36, 59]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [60, 62]}, {"entity": "software", "entity_type": "concept or principle", "pos": [96, 104]}, {"entity": "companies", "entity_type": "application", "pos": [140, 149]}, {"entity": "technology", "entity_type": "concept or principle", "pos": [168, 178]}, {"entity": "industries", "entity_type": "application", "pos": [219, 229]}], "task": "NER"}
{"text": "The key to disrupting existing products is in significant advantages in the new design which is possible by AM and biomimicry is key to unlocking this potential .", "entity": [{"entity": "design", "entity_type": "engineering feature", "pos": [80, 86]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [108, 110]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [115, 125]}], "task": "NER"}
{"text": "Besides aesthetic appeal , actual light-weight advantage is likely the biggest drawcard in automotive and aerospace industries .", "entity": [{"entity": "aesthetic", "entity_type": "concept or principle", "pos": [8, 17]}, {"entity": "light-weight", "entity_type": "machanical property", "pos": [34, 46]}, {"entity": "automotive", "entity_type": "application", "pos": [91, 101]}, {"entity": "aerospace industries", "entity_type": "application", "pos": [106, 126]}], "task": "NER"}
{"text": "In other industries the combination of multiple parts into one might be a significant advantage and it is expected that the multi-functionality of designs might be one of the big future growth areas .", "entity": [{"entity": "industries", "entity_type": "application", "pos": [9, 19]}, {"entity": "be", "entity_type": "material", "pos": [69, 71]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [147, 154]}, {"entity": "be", "entity_type": "material", "pos": [161, 163]}, {"entity": "areas", "entity_type": "process parameter", "pos": [193, 198]}], "task": "NER"}
{"text": "9 Conclusions It is clear that biomimicry in AM allows complex functional designs and various tools are currently available to easily achieve such designs .", "entity": [{"entity": "biomimicry", "entity_type": "concept or principle", "pos": [31, 41]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [45, 47]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [74, 81]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [94, 99]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [147, 154]}], "task": "NER"}
{"text": "Biomimetic designs are therefore both beautiful and functional .", "entity": [{"entity": "Biomimetic designs", "entity_type": "engineering feature", "pos": [0, 18]}], "task": "NER"}
{"text": "Despite the high possible complexity , some design for AM rules have emerged which improve the manufacturability and reliability of these types of parts and these should be incorporated into the design process .", "entity": [{"entity": "complexity", "entity_type": "concept or principle", "pos": [26, 36]}, {"entity": "design", "entity_type": "engineering feature", "pos": [44, 50]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [55, 57]}, {"entity": "manufacturability", "entity_type": "concept or principle", "pos": [95, 112]}, {"entity": "reliability", "entity_type": "process characterization", "pos": [117, 128]}, {"entity": "be", "entity_type": "material", "pos": [170, 172]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [195, 209]}], "task": "NER"}
{"text": "It is especially important that process parameters are optimized to ensure structural integrity and ensure high quality manufacturing , as manufacturing errors might affect these parts more than traditional parts this requires an additional safety factor to be built into designs , and inspection is critical .", "entity": [{"entity": "process parameters", "entity_type": "concept or principle", "pos": [32, 50]}, {"entity": "structural integrity", "entity_type": "machanical property", "pos": [75, 95]}, {"entity": "quality", "entity_type": "concept or principle", "pos": [112, 119]}, {"entity": "manufacturing", "entity_type": "manufacturing process", "pos": [120, 133]}, {"entity": "as", "entity_type": "material", "pos": [136, 138]}, {"entity": "errors", "entity_type": "concept or principle", "pos": [153, 159]}, {"entity": "safety factor", "entity_type": "engineering feature", "pos": [241, 254]}, {"entity": "be", "entity_type": "material", "pos": [258, 260]}, {"entity": "designs", "entity_type": "engineering feature", "pos": [272, 279]}, {"entity": "inspection", "entity_type": "process characterization", "pos": [286, 296]}], "task": "NER"}
{"text": "Post-processing of parts is also a challenge , and the options are limited therefore depending on the application the complexity of the design might need to be constrained to ensure all surfaces are accessible by required post-processing techniques .", "entity": [{"entity": "Post-processing", "entity_type": "concept or principle", "pos": [0, 15]}, {"entity": "complexity", "entity_type": "concept or principle", "pos": [118, 128]}, {"entity": "design", "entity_type": "engineering feature", "pos": [136, 142]}, {"entity": "be", "entity_type": "material", "pos": [157, 159]}, {"entity": "surfaces", "entity_type": "concept or principle", "pos": [186, 194]}, {"entity": "post-processing", "entity_type": "concept or principle", "pos": [222, 237]}], "task": "NER"}
{"text": "One of the most widely used applications of biomimetic design in AM is light-weighting , but many other opportunities exist including parts customized for acoustic , thermal , optical or other applications , especially in combination with surface modification techniques .", "entity": [{"entity": "biomimetic design", "entity_type": "engineering feature", "pos": [44, 61]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [65, 67]}, {"entity": "optical", "entity_type": "process characterization", "pos": [176, 183]}, {"entity": "surface modification", "entity_type": "manufacturing process", "pos": [239, 259]}], "task": "NER"}
{"text": "Most importantly , all examples in this work clearly demonstrate that biomimetic designs can be trusted and should be used more widely .", "entity": [{"entity": "biomimetic designs", "entity_type": "engineering feature", "pos": [70, 88]}, {"entity": "be", "entity_type": "material", "pos": [93, 95]}, {"entity": "be", "entity_type": "material", "pos": [115, 117]}], "task": "NER"}
{"text": "Biomimetic designs are crucial for fully unlocking the power of metal AM in particular .", "entity": [{"entity": "Biomimetic designs", "entity_type": "engineering feature", "pos": [0, 18]}, {"entity": "power", "entity_type": "process parameter", "pos": [55, 60]}, {"entity": "metal AM", "entity_type": "manufacturing process", "pos": [64, 72]}], "task": "NER"}
{"text": "In conclusion , biomimicry in AM has been shown to be possible in various ways , with the most accessible tools currently being freeform design and simulation-driven design .", "entity": [{"entity": "biomimicry", "entity_type": "concept or principle", "pos": [16, 26]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [30, 32]}, {"entity": "be", "entity_type": "material", "pos": [37, 39]}, {"entity": "tools", "entity_type": "machine or equipment", "pos": [106, 111]}, {"entity": "freeform design", "entity_type": "engineering feature", "pos": [128, 143]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [148, 165]}, {"entity": "design", "entity_type": "engineering feature", "pos": [166, 172]}], "task": "NER"}
{"text": "These tools allow complex forms to be created which often resemble natural structures , and the design engineer may incorporate from naturein this design process .", "entity": [{"entity": "tools", "entity_type": "machine or equipment", "pos": [6, 11]}, {"entity": "be", "entity_type": "material", "pos": [35, 37]}, {"entity": "design", "entity_type": "engineering feature", "pos": [96, 102]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [147, 161]}], "task": "NER"}
{"text": "For example , in simulation-driven design , various outcomes are possible and selection of the design outcome most similar to a biological structure is most likely the best solution .", "entity": [{"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [17, 34]}, {"entity": "design", "entity_type": "engineering feature", "pos": [35, 41]}, {"entity": "design", "entity_type": "engineering feature", "pos": [95, 101]}, {"entity": "biological structure", "entity_type": "engineering feature", "pos": [128, 148]}, {"entity": "solution", "entity_type": "concept or principle", "pos": [173, 181]}], "task": "NER"}
{"text": "The greatest future potential for biomimicry in AM lies in incorporating real biological input in some ways in the design process and here biological materials science is crucial in providing from naturewhich can be incorporated easily .", "entity": [{"entity": "biomimicry", "entity_type": "concept or principle", "pos": [34, 44]}, {"entity": "AM", "entity_type": "manufacturing process", "pos": [48, 50]}, {"entity": "biological input", "entity_type": "biomedical", "pos": [78, 94]}, {"entity": "design process", "entity_type": "concept or principle", "pos": [115, 129]}, {"entity": "biological materials", "entity_type": "material", "pos": [139, 159]}, {"entity": "be", "entity_type": "material", "pos": [213, 215]}], "task": "NER"}
{"text": "It is not only in the design process where biomimicry can be employed .", "entity": [{"entity": "design process", "entity_type": "concept or principle", "pos": [22, 36]}, {"entity": "biomimicry", "entity_type": "concept or principle", "pos": [43, 53]}, {"entity": "be", "entity_type": "material", "pos": [58, 60]}], "task": "NER"}
{"text": "The entire process of 3D printing may follow biological principles , including sustainability .", "entity": [{"entity": "process", "entity_type": "concept or principle", "pos": [11, 18]}, {"entity": "3D printing", "entity_type": "manufacturing process", "pos": [22, 33]}, {"entity": "sustainability", "entity_type": "concept or principle", "pos": [79, 93]}], "task": "NER"}
{"text": "Biomimetic design therefore forms part of and drives the bio-industrial revolution which will become known as Industry 5.0 .", "entity": [{"entity": "Biomimetic design", "entity_type": "engineering feature", "pos": [0, 17]}, {"entity": "as", "entity_type": "material", "pos": [107, 109]}], "task": "NER"}
{"text": "Conflict of interest One author is the Senior VP Business Development & Strategy Simulation Driven Design at Altair Engineering Inc , a provider of software for simulation-driven design amongst others .", "entity": [{"entity": "Simulation", "entity_type": "enabling technology", "pos": [81, 91]}, {"entity": "Design", "entity_type": "engineering feature", "pos": [99, 105]}, {"entity": "Altair Engineering", "entity_type": "application", "pos": [109, 127]}, {"entity": "software", "entity_type": "concept or principle", "pos": [148, 156]}, {"entity": "simulation-driven", "entity_type": "enabling technology", "pos": [161, 178]}], "task": "NER"}