The influence of thermomechanical treatment and chemical composition on recrystallization of Al-Mg alloys

Abstract

Recrystallization behaviour of AlMg3, AlMg4.5Mn and AlMg6Mn alloy plates subjected to different thermomechanical treatments (TMTs), has been studied by means of optical microscopy and hardness measurements. Applied two-stage annealing at 565°C/6h + 450°C/4h simulated homogenization and heterogenization processes, respectively, and was followed by cold rolling with 20, 40 and 60%. Final annealing was performed for 3h at 250, 280 and 350°C, with slow and rapid heating rates (0.6 and 25°C/min). Increase of rolling reduction and temperature, either individually or in combination, promotes recrystallization during final annealing. The recrystallization process was found non-simply related to the chemical composition, but a rather complex recrystallization behaviour of these alloys is attributed to the effect of the size and distribution of the second phase particles formed during the thermomechanical treatment. .