Influence of Thermo mechanical Training on the Transformation Characteristic of TiNi Shape Memory Alloy

Two way shape memory effect (TWSME) is introduced in the TiNi shape memory alloys (SMAs) spring by thermonechnical training after annealing heat treatment, which has promising application in microactuator. During the training procedure the transformation temperatures and hysteresis are measured by differential scanning calorimetry (DSC). The results show that the martnsitic transformation temperatuers increase and the reverse martensitic transformation temperatuers decrease with increasing training cycles. The change trend of A s and A f is very similar to that of TWSME recovery rate during training. The authors conclude that the dislocation induced during training plays an important role in the introducing TWSME and the shift of transformation temperatuers.