Evolution of recrystallization and recrystallization texture in continuous-cast AA 3015 aluminum alloy

Abstract

The evolution of recrystallization and recrystallization texture during annealing after cold rolling of a continuous-cast (CC) AA 3015 aluminum alloy with and without pretreatment was investigated in detail. It was found that the preheat treatment prior to cold rolling significantly affected the recrystallization kinetics, the shape and size of recrystallized grains, and the resulting texture of the CC AA 3015 aluminum alloy. In the case of the alloy without pretreatment, annealing at low temperatures resulted in coarse elongated recrystallized grains and a very strong P texture. As the annealing temperature increased, the size of the recrystallized grains dramatically decreased, the recrystallized grains became equiaxed, and the strength of the P texture decreased. The transition behavior could be attributed to the effect of Zener-particle pinning caused by concurrent precipitation. In contrast, the recrystallization texture of the CC AA 3015 aluminum alloy with pretreatment was characterized by a major cube component and a minor R component, and the annealing temperature did not affect the recrystallization texture. Moreover, concurrent precipitation retarded markedly the recrystallization of the CC AA 3015 aluminum alloy, decreased the Johnson-Mehl-Avrami-Kolmogorov (JMAK) exponent from 2.0 to 0.5, and increased the activation energy for recrystallization from 225 to 539 kJ/mol.