Effect of High-Pressure Torsion and Subsequent Annealing on the Mechanical Properties of the Al–4% Cu–3% Mn Alloy

Abstract—The thermal stability of the Al–4 wt % Cu–3 wt % Mn experimental alloy at temperatures to 400°C and its standard mechanical properties and microhardness are studied. The alloy composition is chosen so that more than 10 vol % fine Al₂₀Cu₂Mn₃ particles are formed in it. The alloy is prepared by electromagnetic casting followed by working, which includes upsetting and subsequent high-pressure torsion (HPT). HPT is found to result in an almost threefold increase in the hardness as compared to that of the cast ingot (250 and 90 HV, respectively). The strength of the alloy subjected to HPT increases by 1.2 to 1.4 and 1.6 to 1.8 times as compared to that observed after upsetting at 20 and 400°C, respectively. The strain hardening is found to be retained after annealing at up to 250°C for 5 h; in this case, plasticity increases substantially.