干态及小牛血清环境下超声滚压对Ti6Al7Nb合金微动磨损行为的影响研究  

Effect of Ultrasonic Surface Rolling Process on the Fretting Wear Behavior of Ti6Al7Nb Alloy in Air and Bovine Serum

作　　者：黄奕博 贺继樊 李洪洋 刘建华 彭金方[3] 朱旻昊 HUANG Yibo;HE Jifan;LI Hongyang;LIU Jianhua;PENG Jinfang;ZHU Minhao(School of Materials Science and Engineering,Southwest Jiaotong University,Sichuan Chengdu 610031,China;School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Sichuan Chengdu 610031,China;State Key Laboratory of Rail Transit Vehicle System,Southwest Jiaotong University,Sichuan Chengdu 610031,China)

机构地区：[1]西南交通大学材料科学与工程学院,四川成都610031 [2]西南交通大学力学与航空航天学院,四川成都610031 [3]西南交通大学轨道交通运载系统全国重点实验室,四川成都610031

出　　处：《摩擦学学报(中英文)》2025年第3期351-362,共12页Tribology

基　　金：国家自然科学基金项目(52305215,U2141212)资助.

摘　　要：为提高人工植入件的抗微动磨损性能,采用超声表面滚压技术(USRP)对其典型材料(Ti6Al7Nb合金)进行表面强化处理.在此基础上,研究并揭示了表面改性层在干态及小牛血清环境下的微动磨损行为和损伤机理.结果表明:USRP使基材表面形成约33μm的晶粒细化层,表面硬度提升约28.1%.USRP处理并未显著改变基材的微动运行区域特性,在损伤严重的滑移区损伤机制主要为磨粒磨损、疲劳磨损和氧化磨损.USRP强化处理改变了表层材料的晶界取向,减轻了接触区材料的剥落磨损程度,但增加的晶界通道可能加剧氧化磨损.不同微动工况下,USRP强化表面均具有较好的减摩效果,尤其在小牛血清环境中其磨损率较基材可降低约28%.研究结果可为人工关节材料的抗微动损伤表面工程防护提供理论数据和应用参考.Artificial hip joints are often subjected to cyclic alternating or impact loads during long-term service in the human body,and the friction interface is inevitably subjected to sustained multi axial composite stresses such as torsion,slip and compression,resulting in a large number of fretting wear problems.In order to improve the fretting wear resistance of artificial implants,ultrasonic surface rolling process(USRP)was used to strengthen the Ti6Al7Nb alloy.On this basis,the fretting wear behavior and damage mechanism of the modified material in air and bovine serum were studied.Before conducting the experiment,the material hardness improvement was characterized,and the experiment was conducted on a indigenously developed fretting wear testing machine,which could provide real-time feedback on the dynamic response of the contact interface.After completing the experiment,SEM with EDS function and white-light interferometer was used to analyze the damage mechanism of the worn area.The results indicated that a grain refinement layer of about 33μm was formed on the USRP treated surface.Through SEM analysis,it could be observed that the microstructure of the substrate after USRP surface treatment exhibited grain refinement and plastic flow,and the surface hardness measured by micro-hardness tester increased by about 28.1%.The fretting wear resistance performance of USRP samples had been improved to a certain extent,but the fretting running regime of the USRP treated surface had no significant changes.The failure mechanism were mainly adhesion wear and slight fatigue wear in fretting partial slip regime,abrasive wear,fatigue wear and oxidation wear in fretting slip regime,and the mixed regime was dominated by fatigue wear and oxidation wear.It was worth noting that in partial slip regime,bovine serum might exacerbate the wear degree.But in the mixed zone and slip zone,due to the boundary lubrication effect of the bovine serum,the wear degree was reduced compared with air condition.Besides,the damage degree of delamina

关 键 词：Ti6Al7Nb合金 超声滚压表面强化 切向微动磨损 小牛血清环境 损伤机理 

分 类 号：TH117.1[机械工程—机械设计及理论]