The Microstructure Evolution of Al-Mg-Sc-Zr Alloy after Deformation by Equal Channel Angular Pressing

Abstract

Equal-channel angular pressing is a method of severe plastic deformation, which implies high deformation into the material and leads to grain size reduction and strength increase. It was applied on a twin-roll cast Al-Mg-Sc alloy, which contained Al3(Sc,Zr) particles formed during annealing at 300 °C for 8 hours. The evolution of the microstructure and mechanical properties after deformation was studied during isochronal heating 50 K/50 min. Strengthening occurred during annealing at lower temperatures and was followed by prominent microhardness drop, which was connected with formation of new grains and recrystallization. The presence of Al3(Sc,Zr) particles in the matrix is accounted for the high temperature stability.