Review on the β-Ti Based High Temperature Shape Memory Alloys

High temperature shape memory alloys are used as intelligent driving, connecting and fastening components in the fire alarms, nuclear reactors, Mars detectors and other high temperature environments. It is an important metal intelligent material serving the development of science and technology. Compared with other high temperature memory alloys, b-Ti based high temperature shape memory alloys have attracted much more attention due to their high transformation temperature, large theoretical transformation strain, excellent cold and hot processing ability and low cost. However, some problems are existed to limit the application, such as poor thermal cycling stability and low shape memory effect. In recent years, researchers have designed and developed a series of new alloy systems. The properties are improved by means of composition optimization, thermomechanical treatment and so on. In this work, the recent development of some typical b-Ti based high temperature shape memory alloys are presented, including Ti-Nb based alloys with large strain recover characteristic, Ti-Ta based alloys with high thermal cycle stability and light weight Ti-V-Al based alloys. The microstructure, martensitic transformation behavior and functional properties of the alloy are summarized.