Abstract
A shape memory alloy (SMA) is generally used under cyclic phase transformation condition. In this paper, phase transformation fatigue strength of SMA tape is investigated experimentally. It is found that cyclic number at fracture due to cyclic M-phase - P-phase transformation is very small even for rather small load. This is because internal stress is generated by uneven phase transformation due to uneven temperature distribution R-phase transformation does not require wide range of Temperature. The transformation between R-phase and P-phase is superior to M-P phase transformation for prolonging SMA's life and having a larger SMA's total work up to fracture.
