Research On Sliding Wear Behavior And Finite Element Analysis Of TiNi Alloy

TiNi alloy is a typical temperature controlled shape memory alloy,it has attracted much attention in the field of material science and industry because of its unique shape memory effect and pseudo-elasticity due to the thermo-elastic martensitic transformation.TiNi alloy has excellent friction and wear resistance,and is expected to become an ideal material for friction and wear parts in practical engineering applications.So far,the friction and wear mechanism and the decisive factors that affect the friction and wear resistance of TiNi alloy have not yet formed a unified and definite conclusion.In this study,the TiNi alloys comprised of different phases were taken as the research object,the wear mechanism and wear resistance of TiNi alloy were studied by combining the friction experiment and finite element method.The wear behavior and wear resistance of TiNi alloys comprised of three different phases were studied through sliding wear experiment.The wear mechanism and main factors that affect the wear resistance of TiNi alloy were discussed with the help of surface hardness tester,X-ray diffraction and scanning electron microscope(SEM).It was found that the main wear mechanism of TiNi alloy was adhesive wear and abrasive wear,the main reason of wear was its pseudo-elasticity.To clarify the pseudoelastic deformation characteristics of TiNi alloy,the tensile mechanical tests of TiNi alloy were carried on.The present common constitutive relations of TiNi alloy were compared by the stress-strain curve of the tensile tests,and the pseudo-elasticity constitutive model of contact mechanical behavior analysis were determined.Finally,the simulation analysis of contact mechanics was carried on.The influences of relevant characteristic parameters on the contact stress and strain distribution of TiNi alloy were systematically discussed.The wear resistance of TiNi alloy could be improved by reducing its elastic modulus,critical stress of phase transformation and pseudo-elastic modulus.It was provided some guidance for practical application and material selection of TiNi alloy in friction engineering.