Chen Zihan, Li Xuanpeng, Li Yong, Wang Yu, Jian Yongxin
State Key Laboratory of Oil and Gas Equipment, CNPC Tubular Goods Research Institute, Xi'an 710077, China.
Xi'an Thermal Power Research Institute Co., Ltd., Xi'an 710032, China.
Materials (Basel). 2024 May 30;17(11):2644. doi: 10.3390/ma17112644.
To explore a new method to improve the wear resistance of TiNi shape memory alloy (SMA), Ti-50.8Ni alloy was treated by the method of ultrasonic surface shot peening. The microstructure evolution, hardness, and tribological behaviors have been further investigated to evaluate the effect of ultrasonic surface shot peening (USSP). The surface microstructure can be refined to some extent while the basic phase composition has little change. USSP can facilitate the martensitic transformation in the surface layer, which benefits improving the surface hardness. Additionally, the hardness of Ti-50.8Ni alloy increases first and then decreases with the increase of applied load, but the USSP-treated alloy tends to be more sensitive to load. USSP treatment can improve the wear resistance and reduce the coefficient of friction (COF) in case of a low sliding wear speed of 5 mm/s. However, the tribological properties of USSP-treated alloy are reversely worse in the case of 10 mm/s. This is mainly attributed to the combined effect of stress-induced martensite transformation and degeneration resulting from the frictional heating during the dry sliding wear process.
为探索一种提高TiNi形状记忆合金（SMA）耐磨性的新方法，采用超声表面喷丸处理方法对Ti-50.8Ni合金进行处理。通过进一步研究其微观结构演变、硬度和摩擦学行为来评估超声表面喷丸（USSP）的效果。表面微观结构可在一定程度上细化，而基本相组成变化不大。USSP可促进表层的马氏体转变，这有利于提高表面硬度。此外，Ti-50.8Ni合金的硬度随加载载荷的增加先增大后减小，但经USSP处理的合金对载荷更敏感。在滑动磨损速度为5 mm/s较低时，USSP处理可提高耐磨性并降低摩擦系数（COF）。然而，在10 mm/s时，经USSP处理合金的摩擦学性能反而变差。这主要归因于干滑动磨损过程中应力诱发马氏体转变和摩擦热导致的退化的综合作用。
