多孔Ti-6Al-4V合金在模拟体液中的力-电化学有限元分析  

Finite element analysis of mechanical-electrochemical behavior of porous Ti-6Al-4V alloy in simulated body fluids

作　　者：战楠 宋振兴 张晓川[4] ZHAN Nan;SONG Zhenxing;ZHANG Xiaochuan(Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control,Tianjin University of Technology,Tianjin 300384,China;National Demonstration Center for Experimental Mechanical and Electrical Engineering Education,Tianjin University of Technology,Tianjin 300384,China;Tianjin RuiSaiKe New Material Technology Co.,Ltd.,Tianjin 300457,China;School of Mechanical Engineering,Tianjin University of Commerce,Tianjin 300134,China)

机构地区：[1]天津理工大学天津市先进机电系统设计与智能控制重点实验室,天津300384 [2]天津理工大学机电工程国家级实验教学示范中心,天津300384 [3]天津瑞赛可新材料科技有限公司,天津300457 [4]天津商业大学机械工程学院,天津300134

出　　处：《材料科学与工艺》2025年第2期35-42,共8页Materials Science and Technology

基　　金：国家自然科学基金资助项目(11872275)。

摘　　要：多孔Ti-6Al-4V合金植入人体内将长期处于体液腐蚀环境中,且不可避免地承受人体自重和运动产生的载荷,易引发应力腐蚀,增加无菌失败和严重并发症的风险。为了明确载荷水平及孔隙特性对多孔Ti-6Al-4V合金应力腐蚀性能的影响,本文通过数值仿真方法研究其力-电化学响应规律。基于应力腐蚀理论,将由孔隙特性引发的结构应力耦合到电极反应的平衡电位和交换电流密度表达式,建立了力-电化学耦合有限元模型,通过数值仿真方法分析了植入物试样承受弯曲载荷时,应力、电流密度以及电极腐蚀厚度等的力-电化学响应规律。结果表明:随着承载水平增加,应力集中明显的孔隙边缘区域腐蚀更为剧烈,最大腐蚀厚度均出现在孔梁边缘处。与无应力试样相比,超过屈服应力试样的5年腐蚀厚度增加了22%。孔隙尺寸显著影响应力分布、电化学腐蚀速率及最终的电极腐蚀厚度,随着孔隙的增大,电极5年腐蚀厚度逐渐减小,且大孔应力腐蚀速率低于小孔。Porous Ti-6Al-4V alloy,when implanted in the human body,is exposed to body fluid corrosion environment and inevitably experiences loads generated by human weight and movement.This can lead to stress corrosion,increasing the risk of sterility failure and serious complications.In order to clarify the influence of load level and pore size on the stress corrosion performance of porous Ti-6Al-4V alloy,this paper studies the mechanical electrochemical response through numerical methods.Based on stress corrosion theory,the equilibrium potential and exchange current density expressions of electrode reactions are coupled with the structural stresses induced by pore characteristics.A coupled mechanical-electrochemical finite element model is established.When the implant specimen is subjected to bending loads,the mechanical electrochemical responses,such as stress,current density and electrode corrosion thickness,are analyzed by numerical simulation.The calculation results show that with the increase of load level,the corrosion is more severe in the pore edge area with significant stress concentration.The maximum corrosion thickness occurs at the edges of the pore.Compared to specimens without stress,the corrosion thickness of specimens with stress after 5 years increases by 22%for specimens exceeding the yield stress.The pore size significantly affects the stress distribution,electrochemical corrosion rate and the final electrode corrosion thickness.With the increase of the pore size,the 5 year corrosion thickness of the electrode gradually decreases,and the stress corrosion rate of the large pore is lower than that of the small pore.

关 键 词：钛合金 多孔材料 应力腐蚀 力-电化学耦合 应力集中 

分 类 号：TB31[一般工业技术—材料科学与工程]