LAUSR

Abstract The difference in wear behavior of superelastic NiTi and conventional Ti6Al4V alloys with similar elastic limits was investigated. Reciprocating dry sliding wear tests were performed with a ball-on-plate tribometer at different normal loads and sliding times. Mechanical properties were also examined using different microindentation tests, and wear track morphologies and chemical compositions in the scar area were characterized by scanning electron microscopy (SEM) and energy-dispersive spectrometry. Superelasticity of the NiTi alloy was significantly beneficial to its tribological properties, and the wear resistance of the NiTi alloy was up to 40 times higher than that of the Ti6Al4V alloy. Such a significant difference cannot be attributed only to the relatively small difference in hardness (H) or H/E ratios (E = elastic modulus) of the materials but, rather, to a difference in strain energy, which dissipates in the material and results from normal load of the sliding ball. To estimate this energy, spherical microindentation tests in the wear scar were carried out. Understanding the difference between the tribological behavior of the NiTi shape memory alloy and conventional Ti6Al4V material provides insight into wear progression, and an investigation of its mechanisms can effectively prevent the destruction of components, prolonging their safe service life.