Characterization of a thermomechanically processed powder metallurgy Al–5wt.% Mg–1.2wt.% Cr alloy

Abstract

A thermomechanical processing (TMP) was carried out in a powder metallurgy extruded Al–5wt.% Mg–1.2wt.% Cr alloy to obtain a fine-grained material. The extruded billets showed elongated (sub)grains, oriented towards the β-fiber orientations, where the intensity maximum was located at the brass component (Bs). After annealing at 550 °C for 48 h, the (sub)grains remained elongated toward the extrusion direction, whereas the intensity of the Bs component increased. After TMP which consisted of various reductions by cold rolling up to 90% with intermediate annealing, the microstructure developed a banded structure, composed of elongated (sub)grains of size 0.5–1 μm, and the intensity of orientations along the β-fiber decreased considerably. After annealing at 500 °C for 48 h, the TMP material showed recrystallized grains 5–8 μm in size with a weak rotated cube texture.