Microstructure and Properties of the New-typed TiNi-based Shape Memory Alloy for Micro Electro Mechanical System

The new-typed TiNi-based shape memory alloy TiNi45V8In0.2 for micro electro mechanical system was successfully prepared by the method of two-step.The alloy was analyzed by XRD,SEM and so on.And the mechanical properties,stress relaxation resistance and corrosion resistance were tested and analyzed.The results show that the new-typed alloy was composed of the mesh TiNi base phase and dispersive distributed V3Ni phase,which is with better mechanical properties,stress relaxation resistance and corrosion resistance.Compared with common TiNi alloy,the tensile strength of the new-typed alloy at the temperature of -40℃,25℃ and 150℃ could increase by 47.1%,39.4% and 123.9%,respectively.The yield strength of the new-typed alloy at the temperature of -40℃,25℃ and 150℃ could increase by 110.3%、92.5%、263.8%,respectively.Moreover,the corrosion potential of the new-typed alloy could shift positively by 267 mV.The stress relaxation of the new-typed alloy after 50 h could decrease from 16% to 0.5%.