Effect of deformation processing on microstructure evolution and mechanical properties of Mg-Li alloys: A review

As the lightest structural metal, Mg-Li alloys, possessing the advantages of high specific strength, high specific stiffness, good electromagnetic shielding, and damping properties, have a bright application prospect in automotive, aerospace, transportation, medical and other fields. However, the strength of Mg-Li alloys is lower when compared to other structural metals, which requires alloying or deformation treatment to enhance mechanical properties. The research progress of deformation processing of Mg-Li alloys is summarized, including the effect of conventional plastic deformation and severe plastic deformation on the microstructure and mechanical properties of Mg-Li alloys, the effect of strain and temperature in the deformation process on their microstructure and mechanical properties, and several grain refinement mechanisms of Mg-Li alloys. The problems encountered during the industrial application of Mg-Li alloys are discussed. Grain refinement and enhanced work hardening are still the primary means to improve the comprehensive performance. Several structural design strategies (heterogeneous structured materials) are highlightened, which will be helpful for the guidance of future innovations for Mg-Li alloys to reach high strength.