Study on Strengthening and Toughening of Mechanical Properties of Mg-Li Alloy by Adding Non-Rare-Earth Elements Al and Si

As the lightest class of structural alloys, Mg-Li alloy plays an important role in the automotive and energy sectors for vehicle weight reduction, energy-saving, and emission reduction. Numerous studies have shown that adding rare earth elements to Mg-Li alloy could significantly improve the toughness of alloys, but it is important to study Mg-Li alloy’s non-rare-earth reinforcement since rare earth elements are limited in supply. The influence of alloying with Al-Si intermediate alloy on the mechanical properties of Mg-Li alloy is reviewed in this paper. Many techniques, such as SEM, EBSD, and TEM were employed to study the rolled and extrusion formed Mg-Li alloy after annealing. According to the analysis of composition, phases, microstructure orientation, and second phase reinforcement mechanism, the Al-Si eutectic strengthening effect worked better than adding Al alone. Additionally, aided by the EBSD technique, the importance of grain size, crystallography, and texture were revealed in the ultralight Mg-Li alloy strengthening mechanism. Strengthening methods such as deformation hardening and crystalline refinement remain dominant at the present, owing to their low cost, and high efficiency.