Constitutive Equation with Consideration of Slip-Deformed Martensite in the Deforming of Ti–Ni Shape Memory Alloy

The modeling of the transformation and deformation behavior of a shape memory alloy has been investigated by many researchers. However, there are few reports that investigate plastic deformation of shape memory alloys. To design an actual product, the modeling in consideration of plastic deformation is indispensable. In this work, plastic deformation after pre-deformation is investigated using the volume fraction of slip-deformed martensite. New kinetics and constitutive equations are proposed for the reverse transformation process. The material constants in the proposed equations are determined from the results of tensile and heating/cooling tests on Ti–50 at%Ni alloy. The calculated results describe well the deformation and transformation behavior affected by pre-strain.