On the nucleation of recrystallization by a bulging mechanism: A two-dimensional vertex simulation

The nucleation of grains by subgrain growth has been investigated using a two-dimensional vertex model. The initial geometry has an on average flat grain boundary, separating two populations of subgrains. The phenomenon has been studied using (i) a constant ratio between the subgrain and the grain boundary mobility or energy and (ii) simple relations for the misorientation dependencies of these two quantities. Bulging of grain boundaries owing to subgrain growth at topologically favoured sites has been observed. A subgrain size gradient at the grain boundary reduces the bulging frequency and leads to a general drift of the grain boundary.