Superplastic Response of an Advanced Al-Li-Mg-Cu-Sc Alloy Subjected to Intense Plastic Deformation

Abstract

A novel commercial Al–Li–Mg–Cu–Sc alloy was fabricated by casting and subjected to intense plastic deformation through equal-channel angular extrusion at 598 K to a total strain of ∼16. Superplastic properties of this alloy were studied in the temperature range of 623–773 K and at strain rates of 1.4×10⁻³–1.4×10⁻¹ s⁻¹. The highest elongation-to-failure of 650% appeared at 723 K and a strain rate of 1.4×10⁻³ s⁻¹ with corresponding coefficient of strain rate sensitivity of 0.42. The microstructure evolution and cavitation during superplastic deformation were examined.