Two-stage annealing of a cold-rolled Al-Mn-Fe-Si alloy with different microchemistry states

A detailed investigation of an Al-Mn-Fe-Si model alloy during two-stage annealing after cold rolling has been carried out. Two homogenized variants, one with a high supersaturation of Mn and fine dispersoids and another with a much coarser dispersoid structure together with less Mn content in solid solution, were cold rolled to different strains before subsequent annealing. The effect of pre-existing dispersoids, introduced prior to cold rolling through homogenization, and concurrent precipitation during annealing on the softening behaviour are both discussed in terms of grain structure and texture evolution. The results show that more and finer dispersoids together with strong concurrent precipitation lead to a coarser and pan-cake shaped grain structure with strong P {0 1 1}〈5 6 6〉 and medium strength ND-rotated cube {0 0 1}〈3 1 0〉 texture components regardless of the target temperature. On the other hand, a refined grain structure and medium strength P and Cube {0 0 1}〈1 0 0〉 were obtained when the pre-existing dispersoids are coarser and fewer, and concurrent precipitation is limited. However, even though significant differences were observed during the two-stage annealing in terms of recrystallization microstructure and texture brought about by the different microchemistries, the stress-strain behaviour of the respective as-recrystallized states exhibited negligible differences.