The martensitic transformation in the Cu–Zn based shape memory alloys as a tool for the evaluation of transformation mechanisms and phase stabilities

Three aspects related to the martensitic transformation are discussed, using the Cu–Zn based alloys as prototypes. The first is concerned with the similarities to the plastic deformation by dislocations, since both proceed by coordinated atom movements. In the second, the changes in stability due to long-range order are compared with reference to the disordered high temperature equilibrium phases. Finally, the ordering and annealing behavior of the vacancies, which control the time dependent aging in the martensite, are related to their ordered arrangement in the high temperature cubic equilibrium γ phases.