  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.
