Transformation kinetics and microstructure for grain boundary nucleated recrystallization in two dimensions

Site saturation recrystallization nucleated from grain boundaries and grain boundary corners (triple junctions) in pre-existing two-dimensional grain structures have been investigated by computer simulations. For grain corner nucleation it is found that both the kinetics and the resulting grain size distribution are very close to the corresponding results for randomly distributed sites, which demonstrates that grain boundary corners in two-dimensional grain structures are close to, although not completely, randomly distributed. For grain boundary nucleation both the kinetics and the resulting size distributions are in general considerably affected, and the effects increase with increasing density of grain boundary sites. However, for a very low density of sites the kinetics approach the kinetics for randomly distributed sites. For the size distribution of recrystallized grains, on the other hand, some differences still remain even when the density of sites becomes very low, which demonstrates that grain boundary sites can never be considered completely randomly distributed, even at very low density. This result also demonstrates that the size distribution of recrystallized grains is more sensitive to the spatial distribution of the sites than the kinetics.