Research Progress in Studies on Characteristics of Transformation and Deformation in Ti-Ni Shape Memory Alloys Fabricated under Various Processes

In this article the research progressing about the influence of the chemical composition and the heat treatment processes on the transformation and deformation characteristics of Ti-Ni base shape memory alloys (SMA) in recent years.The development state of shape memory materials fabricated under various processes,such as SMA spring,thin film,porous,composite,and single crystal,and their properties are introduced.The development direction for this study field is forecasted.It can effectively change the transformation temperature and improve the tempe-rature hysteresis,and get shape memory effect or superelasticity needed through adding suitable alloy elements and selecting reasonable heat treatment processes in Ti-Ni base SMA.Fibrous,filmy,porosity,and compositize are the developing tendency of Ti-Ni base SMA in future.