Phase-Field Study of Microstructure and Plasticity in Polycrystalline MnNi Shape Memory Alloys

The evolution of microstructure and plasticity in polycrystalline MnNi shape memory alloys was simulated by a phase-field method considering plastic deformation. Plastic strain was found to occur around grain boundaries and intersections between martensitic bands. In addition, the accumulation of plastic strain would keep on continuously occurring during the thermal or stress cycling process. The occurring of plastic strain could be caused by the lattice incompatibility between austenite and martensite near the tip of martensite plate.