Simulation of softening kinetics and microstructural events in aluminum alloy subjected to single and multi-pass rolling operations

In this study, a multi-scale model is proposed to assess softening kinetics and microstructural changes during isothermal annealing within an aluminum alloy. In the first stage, an elastic-plastic finite element analysis is performed for computing the distributions of effective plastic strain and stress while the stored energy after cold rolling is defined based on the predicted data and then utilized for generation of the initial conditions in the microstructural analysis. In the next stage, an algorithm based on cellular automata coupled with a first order rate equation is used to determine the progress of softening behavior at elevated temperatures while both recrystallization and recovery processes are taken into account. The model is examined on single and multi-pass rolling of AA1050 during which the softening progress is measured at temperature varying between 160 °C and 360 °C. The changes in microstructures and mechanical properties are determined by means of microstructural observations, tensile testing and hardness measurements. Finally, the experimental and the predicted results are compared and a reasonable consistency is observed between the two sets of data indicating the validity of the developed algorithm.