INFLUENCE OF THE CAST STRUCTURE ON THE RECRYSTALLIZATION BEHAVIOUR OF AN Al-Zn-Mg ALLOY.

In the present work on a medium-strength Al-Zn-Mg alloy containing additions of Zr and Mn in addition to Fe and Si impurities was studied in both the as-cast and wrought conditions. The character and dispersion of inclusions were carefully quantified, using microprobe analyses and electron metallography, and related to both the solute redistribution during casting and to the use of thermal mechanical working procedure applied to the as-cast material. The recrystallization behavior of the material was then related to the local size and dispersion of inclusions after a variety of working and annealing procedures.