Mean-field criteria for the onset of discontinuous recrystallization in cold rolled aluminum alloys

Discontinuous subgrain growth is an important mechanism for the formation of recrystallization nuclei during annealing after cold rolling of aluminum alloys. Based on the analytical textbook theory for continuous and discontinuous growth of cellular microstructures, we derive and validate simple mean-field criteria for the onset of discontinuous recrystallization in aluminum alloys. The determining factors in the criteria are the stored energy after deformation, the rate of recovery and the mobility of large angle grain boundaries. The criteria are successfully applied to isothermal annealings and annealings at constant heating rates. They can be combined with arbitrary mean-field recovery models, including the widely used phenomenological softening laws.