Influence of Strain Path Change on the Microstructure and Mechanical Properties of Duplex Mg–Li Alloy

The microstructures, texture evolution, and mechanical properties of unidirectionally-rolled and cross-rolled Mg–9Li–6Er alloy were investigated in this paper. The results show that the Mg–9Li–6Er alloy mainly consists of α phase and β phase along with Er₅Mg₂₄ eutectic. The strain path was changed between rolling passes during the cross-rolling process, which led to a weaker texture development compared to the conventional unidirectional-rolling method. At the same time, cross-rolling process makes the alloys have a much significant deformation strengthening effect than that of the unidirectionally-rolling process, which can be mainly attributed to the change in strain path, making the α phase distributes disorderly in the β phase and interacts with each other into a network. On the other hand, due to the disordered distribution of matrix phases, uniform plastic deformation is blocked, and thus the ductility is greatly lowered.