3D打印医用钛合金多孔材料力学性能研究进展

Research Progress on the Mechanical Properties of the Biomedical Titanium Alloy Porous Structures Fabricated by 3D Printing Technique

钛合金多孔材料具有与人体骨匹配的弹性模量,可有效解决金属植入物与人体骨弹性错配;其内部存在的大量孔隙有利于周围细胞的长入和新骨的生长,从而促进骨组织形成。近年来,增材制造(3D打印)技术被用于钛合金多孔材料制备,该方法可以精确控制孔隙参数,并且克服了因金属高熔点造成的制备困难。本文综述了作者团队在3D打印医用Ti-6Al-4V、纯Ti以及低模量钛合金多孔材料组织及力学性能的研究结果。对于Ti-6Al-4V两相合金,其疲劳性能受多孔结构设计和多种后处理的影响。纯Ti多孔材料较Ti-6Al-4V更优的疲劳寿命源于其更好的塑性和形变孪晶的应变硬化效应。低模量Ti2448合金的优异疲劳寿命则源于其超弹性提高裂纹萌生寿命,高韧性提高裂纹扩展寿命。最后展望了复杂生理环境腐蚀疲劳性能、多孔材料表面生物活化处理和新型医用金属体系多孔材料等发展方向。

Porous titanium alloys have been used for biomedical implants owing to their low-modulus matching with that of human bones and interconnecting pores with suitable size,which facilitates bone ingrowth and satisfies the requirement of a successful implant.Recently,additive manufacturing(3D printing) has emerged as an excellent technology for manufacturing porous implants with accurate designed pore parameters and overcoming processing difficulties caused by high melting temperatures of metals.In this paper,the microstructure and mechanical properties of porous Ti-6Al-4V,commercial pure titanium(CP-Ti),and low-modulus Ti2448 alloys produced by 3D printing,obtained mainly by the authors 'group,are reviewed.For Ti-6Al-4V,its fatigue properties are affected by the type of mesh struts and post processing.The better fatigue life of CP-Ti compared to that of Ti-6Al-4V derives from its superior ductility and the strain hardening effect caused by deformation twins.The excellent fatigue life of the lowmodulus Ti2448 alloy results from its superelasticity and the high toughness,which increases the crack nucleation life and fatigue crack propagation life,respectively.Future directions of corrosion-fatigue properties of materials in complex physiological environments,surface biological functionalization,and porous material of new metallic alloy systems are discussed.