Kinetics of the Forward and Reverse Martensitic Transformations in Titanium Nickelide during Deformation and Shape Memory Effect

Abstract—The athermal and deformation-induced martensitic transformations in a titanium nickelide-based alloy are considered. For this purpose, specimens are subjected to tensile deformation at various degrees and then heated to measure their sizes and to perform X-ray diffraction analysis of the phase composition and microstresses in the B2 phase. The martensitic transformation is found to be thermoelastic during deformation up to the first critical degree. Above this deformation, an intensive increase in microstresses occurs, which is associated with shape changes in the material due to dislocation formation and slip. This mechanism competes with and begins to suppress the martensitic transformation mechanism above the second critical strain. Here, the martensitic transformation acquires characteristics of an explosive transformation mechanism.