Softening behaviour of cold rolled continuous cast and ingot cast aluminum alloy AA5754

The recovery and recrystallization behaviour of ingot cast (IC) and continuous cast (CC) AA5754 cold rolled material has been compared. Included in the comparison was the effect of a homogenization treatment as well as hot rolling prior to cold rolling for the CC material. Without the homogenization process, the softening kinetics between the CC and IC material were significantly different with the CC material exhibiting considerably slower softening kinetics. However, when the CC material was homogenized prior to cold rolling, the softening kinetics were similar to that of ingot cast (IC) material. The differences in the softening behaviour between the CC material without a homogenization treatment and IC material can be related to solute drag and concurrent precipitation which occurred during annealing of the CC material resulting in the retarded growth of recrystallized grains. This was supported by measuring the evolution in the resistivity and microstructure during the annealing heat treatment. Differences in the recrystallized texture between the CC and IC material were also made during this investigation and the results indicated that although overall the textures were weak, the IC material consistently had a higher cube texture volume fraction.