Fabrication self-recovery bulge textures on TiNi shape memory alloy and its tribological properties in lubricated sliding

Effect of self-recovery bulge texture on tribological properties of TiNi under oil-lubricated condition was investigated. Fabrication of bulge textures on TiNi alloy was performed by a method with a sequence of indentation-polishing-heating. Due to the different levels of transformation of martensite to austenite, XRD pattern for the bulged TiNi was different after process of indentation-polishing-heating. Friction coefficient of the bulged TiNi was obviously lower than that of non-bulged counterpart. Study illustrated test conditions and height of bulges effectively varied the tribological behaviors of TiNi specimens. SEM analysis indicated that scratches produced by abrasive and oxidation wear were the major wear mechanisms of the bulged TiNi specimens. Furthermore, the implementation of bulge textures significantly improved the tribological properties of TiNi alloy.