A comparative study on the effect of 0.5 wt% Ca or Ce on the microstructure, texture, and mechanical properties of the hot-rolled Mg-4Li alloy

The microstructure, texture, and mechanical properties of the hot-rolled Mg-4Li, Mg-4Li-0.5Ca and Mg-4Li-0.5Ce alloy were examined. The results indicated that the addition of either Ca or Ce significantly refined the microstructure and largely randomized the texture distribution of as-rolled Mg-4Li. Meanwhile, Mg-4Li-0.5Ca exhibited a relatively smaller grain size and a more scattered texture distribution compared to Mg-4Li-0.5Ce, probably attributed to the more prominent recrystallization in Mg-4Li-0.5Ca. Additionally, owing to the more refined microstructure and dispersed Mg2Ca, the strength of Mg-4Li-0.5Ca is much higher than that of Mg-4Li0.5Ce, while both of them are superior to the counterpart of Mg-4Li. Moreover, by benefiting from the enhanced activation of non-basal slip, Mg-4Li-0.5Ce exhibits a much larger elongation compared to Mg-4Li. However, the elongation of Mg-4Li-0.5Ca is slightly lower than that of Mg-4Li, potentially ascribed to the occurrence of preferred cracking within the eutectic-like Mg2Ca.