Effects of thermomechanical cycling on the shape memory behavior and transformation temperatures of a Ni50.2Ti49.8 alloy

The effects of thermomechanical cycling on the shape memory behavior and transformation temperatures of a Ni50.2Ti49.8 alloy under a constant applied stress of 300 MPa were investigated.It is believed that thermomechanical cycling induces defects such as dislocations,which evidently affect the shape memory behavior and transformation temperatures.The recovery strain decreases with increasing number of thermomechanical cycles,whereas the irreversible plastic strain increases,especially in the initial few cycles.The stored elastic strain energy has an important influence on transformation temperatures,the Aso decreases and the Mso increases with increasing number of thermornechanical cycles.The recovery strain,irreversible plastic strain,Aso,and Mso reach a saturation value after several cycles.