Microstructure and mechanical properties of rolled Mg–Gd–Zn–Zr–Ag–Al–Li alloys

Abstract

Abstract The microstructural evolution and mechanical properties of hot rolled Mg-12Gd-1Zn-0.5Zr-0.5Ag (in wt.%) (MGZKA) alloys, with and without Al and Li additions, were investigated in this study. The Al and Li-containing alloys achieved excellent overall mechanical properties, especially MGZKA-6Al5Li alloy with a high elastic modulus of 52.2 GPa and a good plasticity of 15%. Compared with Al and Li-free MGZKA alloy, the fragmented Al2Gd and nanoscale Al2Li3 phases with high modulus are observed in Al and Li-containing MGZKA-4Al3Li and MGZKA-6Al5Li alloys, which contribute to the overall elastic modulus of the alloys. The dynamic recrystallization regions of Al and Li-containing alloys increased while c/a ratio reduced, leading to the weakened texture. The activation of non-basal slip in Al and Li-containing alloys is closely related to the fine grains and weakened texture, which jointly promote the plasticity of Al and Li-containing alloys.