Structure transformations during annealing of twin-roll cast Al-Fe-Mn-Si (AA 8006) alloy sheets II.: Effect of homogenization and heating rate

The kinetics and temperature range of structure transformations during annealing of twin-roll cast AlFeMnSi (AA 8006) alloy sheets were studied using electrical resistometry, light metallography and transmission electron microscopy. The effects of homogenization and heating rate were investigated, as well. Recrystallization response curves were determined by Vickers microhardness measurements. It was found that recrystallization starts and is completed at much lower temperatures in the homogenized material than in the non-homogenized one. Coarse grained heterogeneous structure is formed in the non-homogenized material, while fine grain homogeneous structure is typical for the homogenized alloy. The heating rate of the final annealing affects the temperature range of structure transformations and the resulting strip grain structure. The grains are more homogeneous in quickly heated samples, particularly in the homogenized material.