The influence of dispersoids on the recrystallization of aluminium alloys

Abstract

Abstract The influence of dispersoids on the softening processes in twin-roll cast and cold-rolled Al – Fe – Mn – Si aluminium alloy was studied. Before rolling, the specimens were thermo-mechanically pre-treated in order to create a different second-phase dispersion. The influence of the initial microstructure was studied by means of electrical resistivity, light and electron microscopy. The evolution of softening was monitored by microhardness measurements. The depletion of the Al matrix from solutes connected with formation of a dense dispersion of precipitates results in the enhancement of (sub)grain-boundary mobility. As a consequence, full recrystallization occurs at lower temperatures in pre-annealed specimens with low solute concentrations. The presence of coarser precipitates formed during the pre-treatment results in the formation of a fine-grained microstructure.