Ultrahigh-strength titanium gyroid scaffolds manufactured by selective laser melting (SLM) for bone implant applications
Ultrahigh-strength titanium gyroid scaffolds manufactured by selective laser melting (SLM) for bone implant applications
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DOI：
10.1016/j.actamat.2018.08.005
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发表时间：
2018-10-01
期刊：
影响因子：
9.4
通讯作者：
Wen, Cuie
中科院分区：
文献类型：
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作者：
Ataee, Arash;Li, Yuncang;Wen, Cuie
采用选择性激光熔化(SLM)技术制备了具有68-73%的高孔率、2 mm、2.5 mm和3 mm三种不同单元尺寸的商业纯钛(Cp-Ti)人工骨支架。对不同晶胞尺寸和不同样品取向的支架的微观结构和力学性能进行了评价。铸态支承的显微组织以块状马氏体为主，平均显微硬度为2.27 GPA，与致密铸造CP-Ti相比提高了50%左右。支架的弹性模量值为1465~2676 Mpa，屈服强度为44.9~56.5 Mpa，接近骨小梁的弹性模量值，可以承受种植体的生理载荷。预制支架在50%应变范围内表现出良好的延展性，在20%~30%应变范围内无断裂迹象。支架的主要压缩响应是通过形成塑性铰，导致支架绕塑性铰旋转，然后在长高原地区的支架中形成局部剪切带。这些SLM制备的回旋状Cp-Ti支架的硬度和抗压强度显著提高，其弹性模量接近于骨小梁的弹性模量值，有望在骨植入应用中改进Cp-Ti支架。(C)2018 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
Commercially pure titanium (CP-Ti) gyroid scaffolds with interconnected pores and high porosities in the range of 68-73% and three different unit cell sizes of 2, 2.5, and 3 mm were manufactured by selective laser melting (SLM) for bone implant applications. The microstructure and mechanical properties of the scaffolds with different unit cell sizes and sample orientations were evaluated. The microstructure of as-built struts was dominated by massive martensite and the average microhardness of the struts was 2.27 GPa, which is similar to 50% higher than that of dense cast CP-Ti. The elastic modulus and yield strength of the as-built scaffolds ranged from 1465 to 2676 MPa and from 44.9 to 56.5 MPa, respectively, values which are close to the elastic modulus of trabecular bone and presumably strong enough to bear the physiological loading of implants. The as-built scaffolds exhibited excellent ductility up to 50% strain and no sign of fracture up to 20-30% strain under compression. The dominant compressive response of the scaffolds was observed by formation of a plastic hinge which led to rotation of the struts about the plastic hinges followed by development of local shear bands in struts in the long plateau region. These SLM-manufactured gyroid CP-Ti scaffolds with significantly enhanced hardness and compressive strength exhibited an elastic modulus close to that of trabecular bone and offer a promising improvement on CP-Ti scaffolds for bone implant applications. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.