A phase field model and computer simulation of martensitic transformations in polyerystalline materials

A three dimensional phase field model of the martensitic transformation in polycrystalline materials is presented. The model describes the system evolution by a kinetic equation of the Ginzburg-Landau type which explicitly takes into account the contribution of the transformation-induced coherency strain by using the phase field micromechanics theory. The model was used to simulate the martensitic transformation in single-crystals and polycrystals of Fe-Ni and Au-Cd alloys. Simulations performed for a wide range of undercoolings demonstrated that the volume fraction of the residual parent phase in the Fe-Ni system depended on the undercooling and a large undercooling was required for a complete transformation. Simulations showed that the crystallographic texture affected the development of the transformation. The effect of applied stress on the transformation was studied. The stress vs. strain curves with the hysteresis effect were obtained by the simulation of the structure evolution under applied stress.