Phase field simulation of heterogeneous cubic → tetragonal martensite nucleation

The mechanisms for heterogeneous cubic → tetragonal martensite nucleation due to different types of microscopic defects (voids, stress-concentration site, inertial inclusion and pre-existing nucleus) and the temporal evolution of martensite morphology are monitored with finite element simulation of phase filed model. The results demonstrate that the nucleation prefers to occur around void and stress-concentration site initially; high residual stress exists around inertial inclusion; pre-existing nucleus promotes nearby martensite phase to develop on it. The effects of various defects on heterogeneous nucleation are different, and stress relaxation behavior is the dominant factor which characterizes the whole microstructure evolution process.