Simulation of effect of nucleation mechanism on dynamic recrystallization process

In order to study the effect of nucleation mechanism on the hot working process of polycrystalline metals, the evolvement of dynamic recrystallization microstructure under three nucleation mechanisms was simulated by developing a two-dimension cellular automaton model. The variation of the mean size of recrystallization grains (R-grains) and the characteristics of growth kinetics during the hot working process were obtained. The simulated results of the three models were discussed and compared together. It is found that the variation of the mean size of recrystallization grains is decided by the nucleation mechanism and the growth mode. However, the steady mean size only depends on the total number of nuclei. The curve of the growth kinetics looks like the shape of 'S' and its variation follows the JMAK theory. The Avrami exponent is decided by the spatial distribution of nuclei.