Influence of retrogression and re-ageing on the mechanical and corrosion properties of 7039 aluminium alloy

Abstract

The effect of T6 and retrogression and re-ageing (RRA) treatments on the corrosion and mechanical properties of a 7039 Al alloy was examined. T6- and RRA-tempered alloys exhibited a similar intergranular corrosion resistance for a retrogression time of 3 min at 220 °C. The results revealed that an RRA-tempered alloy (3 min retrogression at 220 °C followed by re-ageing) exhibited a higher hardness and strength and a lower ductility and toughness than a T6-tempered alloy with a significant improvement in the stress corrosion cracking resistance.