TiNi 系形状记忆合金两体磨粒磨损机制研究

Two body abrasive wear mechanism of TiNi SMA

研究了硬度较低的ＮｉＴｉ系形状记忆合金的两体磨粒磨损行为，其耐磨性明显高于硬度较高的３８ＣｒＭｏＡｌ（氮化）合金．认为形状记忆合金（ＳＭＡ）的超弹性、弹性模量非线性、高强度及良好的耐疲劳性等因素的综合作用构成了ＳＭＡ的“自适应”磨损机制，这种“自适应”机制是ＮｉＴｉ系形状记忆合金具有极好耐磨性的根本原因．

? The NiTi and Ti 50 Ni 25 Cu 25 alloy were tested for two body abrasive wear against quench hardening 45 # steel and 600 # abrasive paper on pin on disk test configuration respectively. The nitriding 38CrMoAl alloy as the compared alloy was tested on the same condition. The NiTi and Ti 50 Ni 25 Cu 25 alloy demonstrated excellent wear resistance whether against quench hardening 45 # steel or against 600 # abrasive paper in the load range 40 100 N and in the sliding distance range 0 5000 m which was investigated in this study. The wear rates of the Ti 50 Ni 25 Cu 25 were found to be 30% 50% of that of the nitriding 38CrMoAl despite of the greatly lower hardness of the SMA. The plough track of the Ti 50 Ni 25 Cu 25 alloy against 600 # abrasive paper was more clear than that against quench hardening 45 # steel. The metallographic characterization of the cross section along the wear track indicated no obvious plastic deformation in the tribolayer. The wear resistance of SMA is discussed in terms of self adaptable wear mechanism which is the interaction result of super elasticity, non linear elastic module, high yield and fatigue strength.