Thermal stability of aluminum cold rolled to large strain

Common to metals deformed to high strains is a very fine microstructure, high strength, and limited ductility. Structure and property optimization by annealing after deformation must, therefore, be explored. In the present study, commercial purity aluminum has been annealed after cold rolling to ultrahigh strains up to evM ¼ 6:2 and annealing processes have been studied in terms of recovery and conventional recrystallization. These processes have been analyzed by isochronal and isothermal annealing in the temperature range 140–420 C. It has been found that the recrystallization temperature is a little affected by the rolling strain, whereas the rate of recovery and the temperature range over which recovery takes place increase significantly as the strain is increased. These observations are discussed as to how they can guide studies of nanostructured metals processed by plastic deformation.