Rotation induced grain growth and stagnation in phase field crystal models

We consider the grain growth and stagnation in polycrystalline microstructures. From the phase field crystal modelling of the coarsening dynamics, we identify a transition from a grain-growth stagnation upon deep quenching below the melting temperature $T_m$ to a continuous coarsening at shallower quenching near $T_m$. The grain evolution is mediated by local grain rotations. In the deep quenching regime, the grain assembly typically reaches a metastable state where the kinetic barrier for recrystallization across boundaries is too large and grain rotation with subsequent coalescence is infeasible. For quenching near $T_m$, we find that the grain growth depends on the average rate of grain rotation, and follows a power law behavior with time with a scaling exponent that depends on the quenching depth.

No reviews yet.

No comments yet.