Influence of cold pre-deformation on the microstructure, mechanical properties and corrosion resistance of Zn-bearing 5xxx aluminum alloy

Abstract

The effect of cold pre-deformation combined with ageing treatment on age hardening behavior and associated intergranular corrosion (IGC) resistance of an Zn-bearing 5xxx aluminum alloy is investigated in this study. Results reveal that the strength of the alloy is improved greatly by the prior cold deformation basing on the synergistic effect of work hardening and ageing strengthening. With the combination of cold pre-deformation and ageing treatment, the peak yield strength of the alloy is 314.7 MPa, which increases by 110% than that of the T6 treated alloy. Moreover, the intergranular microstructure such as grain boundary precipitates can be optimized by coordinating the pre-deformation and ageing treatment. Hence, Al–Mg–Zn alloy with high strength and excellent IGC resistance can be obtained by combining the prior cold deformation and ageing treatment.

Keywords

• Aluminum alloy
• Pre-deformation
• Zn-bearing
• Yield strength
• Intergranular corrosion