Research combining experiment and FEM analysis on sliding wear behaviors and mechanisms of TiNi alloy

Abstract

TiNi alloy has recently been demonstrated to possess superior wear resistance compared to conventional wear-resistant materials. Hence, TiNi alloy may become a potential candidate for tribological applications. In order to exploit tribological applications of TiNi alloy, the thorough understanding of its wear behaviors and mechanisms is essential. In this paper, the sliding wear behaviors of TiNi alloy with three different phase structure have been investigated using CFT-1 tribo-tester. The wear mechanisms and factors affecting the wear resistance of TiNi alloy were discussed based on results of X-ray diffraction, scanning electronic microscope and surface hardness test. Moreover, a finite element analysis based on bilinear kinematic hardening model was conducted to simulate the contact mechanical behaviors of TiNi alloy during sliding wear. The experimental results showed that austenitic TiNi alloy exhibited the highest wear resistance whereas martensitic TiNi alloy showed the lowest and the high wear resistance of TiNi alloy greatly benefits from its pseudoelasticity. The analytical results indicated that the pseudoelastic deformation behaviors of TiNi alloy can effectively enhance its elastic contact area and diminish maximum Von Mises stress during contact process, thus diminish the plastic damage during sliding wear. Both the results of experiment and finite element analysis demonstrated that the pseudoelasticity is the greatest contributing factor for superior wear resistance of TiNi alloy.