NiTi合金表面改性及其微动磨损性能研究

Study on Surface Modification and Fretting Wear Properties of NiTi Alloy

采用多弧离子镀技术在NiTi形状记忆合金表面制备TiN涂层。利用SRVⅢ摩擦磨损试验机研究NiTi合金表面改性后在37℃Hank’s模拟体液中微动磨损性能,分析法向载荷对TiN合金磨损机制的影响规律。利用SEM扫描电镜及能谱考察磨损表面形貌,结果表明:制备的TiN涂层表面致密均匀,无明显缺陷。说明TiN涂层可有效提高基体的耐磨性能,其磨损机制主要表现为剥落损伤与磨粒磨损并存。TiN涂层显微硬度为784 HV,远高于基体,TiN/NiTi膜基硬度比缓慢下降,涂层与基体结合强度高。

TiN coating is prepared on the surface of NiTi shape memory alloy by multi-arc ion plating technology.The SRVIII friction and wear tester is used to study the surface modification of NiTi alloy and simulate the fretting wear performance in Hank's body fluid at 37°C,and the influence of normal load on the wear mechanism of TiN alloy is analyzed.SEM scanning electron microscopy and energy spectrum are used to investigate the morphology of the wear surface,and the results show that the surface of the TiN coating is dense and uniform without obvious defects,TiN coating can effectively improve the wear resistance of the matrix,and its wear mechanism is mainly manifested as spalling damage and abrasive wear.The microhardness of TiN coating is 784 HV,which is much higher than that of the matrix,and the hardness ratio of TiN/NiTi film is slowly reduced,and the bonding strength between the coating and the matrix is high.