Evolution of Microstructure, Texture, and Tensile Properties in Two-Phase Mg-Li Alloys: Effect of Zn Addition

The effect of ternary zinc (Zn) addition to two-phase magnesium-lithium alloys on the evolution of their microstructure, texture and tensile properties has been investigated. It was observed that the volume fraction of hexagonal close-packed α phase increased with increase in the Zn content. The size of α lamellae reduced with increase in the Zn content. The strength of the alloys in as-cast condition increased with the Zn content due to solid-solution strengthening without compromising the ductility. The tensile properties of these two-phase alloys were found to be strongly dependent on the volume fraction and size of the α phase. Zn addition led to enhancement of the {200} || normal direction (ND) component but weakening of {110} || ND components in the β phase, while increase in the Zn content had a minor effect on the texture of the α phase in cold-rolled condition. The specific strength of the alloy with 2 wt.% Zn was found to be comparable to, while the ductility was higher than, the highest-strength 7075-T73 Al alloy.