Effect of Cold Work and Partial Anneal on Thermomechanical Behaviour of Ti-50.5at%Ni

This study investigated the effect of cold work and partial annealing on the thermal and mechanical behaviour of NiTi. It is well understood that the thermomechanical properties of near-equiatomic NiTi are highly dependent on the microstructure, hence the history of thermomechanical treatments it has undergone through. It has been generally accepted that a sufficiently high cold work is necessary prior to annealing but detailed knowledge of the influence of the level of prior cold work on annealing is unclear. This study determined the threshold effective levels of cold work required for annealing and demonstrated that the thermal and mechanical properties of Ti-50.5at%Ni are sensitive to the level of cold work as well as temperature of partial annealing.