The mechanism responsible for high wear resistance of Pseudo-elastic TiNi alloy - a novel tribo-material

Recent studies show that pseudo-elastic TiNi alloy exhibits high resistance to wear, compared to many conventional wear-resistant materials. It is demonstrated that hardness is not crucial to the wear resistance of this alloy, since its hardness is lower than those of conventional wear-resistant materials. In order to understand the excellent wear behaviour of TiNi alloy and determine the factors responsible for wear resistance of the alloy, the performance of Ti-50.3 at.% Ni alloy during a dry sliding wear process was investigated and compared to a 2Cr13 steel. It was demonstrated that the TiNi alloy performed much better than the 2Cr13 steel, although the latter has a higher hardness. It is expected that the high wear resistance of TiNi alloy is attributable to its special mechanical behaviour, in particular its so-called pseudo-elasticity, caused by reversible martensitic transformation. Mechanical and thermal properties of Ti-50.3 at.% Ni alloy were studied and a FEM analysis was made to investigate the plastic strain in the contact region and to correlate the wear behaviour of TiNi alloy to its pseudo-elastic and thermal properties that are influenced by the martensitic transformation. (C) 1999 Elsevier Science S.A. All rights reserved.