Superplasticity of High-Strength Submicrocrystalline Al–0.5Mg–Sc Aluminum Alloys

The effect of scandium on the superplasticity characteristics of Al–0.5Mg–Sc conductor aluminum alloys with a submicrocrystalline (SMC) structure is investigated. Large elongation to failure (~1060%) is achieved in the SMC alloys with 0.4 and 0.5% Sc at a deformation temperature of 500°C and a strain rate of 1 × 10–1 s–1. Intense pore formation is shown to occur during the superplasticity of the Al–0.5Mg–Sc SMC alloys. The kinetics of deformation-stimulated grain growth in the Al–0.5Mg–Sc SMC alloys is found to be determined by the mobility of junction disclinations and orientation-misfit dislocations.