Generalized vertex model of recrystallization – Application to polycrystalline copper

The vertex model is first extended in order to take into account the influence of the stored energy on the recrystallization processes. Some phenomenological laws describing the evolution of grain boundary energy and mobility versus misorientation are used. Nucleation is considered to be site-saturated and no specific misorientation is taken into account in the law describing the grain boundary mobility. The experimentally determined stored energy values, crystallographic orientations and boundary misorientation distributions are used in order to characterize the initial microstructure. The vertex model is then tested to study the recrystallization of 70% and 90% cold rolled polycrystalline copper during annealing treatment. In order to explain the texture evolution in both cases, it is necessary to introduce an energy threshold for grain boundary movement, i.e. a minimal value of the stored energy difference between neighboring grains necessary to cause the grain boundary motion. With both improvements (incorporation of the stored energy and of its threshold), the developed model is shown to predict texture evolutions in good agreement with experimental data.