Abstract: In response to the urgent demand for lightweight, magnesium (Mg) alloys have garnered considerable attention owing to their low density. Nonetheless, the intrinsic poor room-temperature formability of Mg alloys remains a major obstacle in shaping precise complex components, necessitating the development of superplastic Mg alloys. Excellent superplasticity is usually acquired in high-alloyed Mg alloys with enhanced microstructural thermal stability facilitated by abundant optimized second-phase particles. While for cost-effective low-alloyed Mg alloys lacking particles, regulating solute segregation has emerged as a promising approach to achieve superplasticity recently. Moreover, the potential of bimodal-grained Mg alloys for superplastic deformation has been revealed, expanding the options for designing superplastic materials beyond the conventional approach of fine-grained microstructures. This study reviews significant developments in superplastic Mg alloys from the view of alloying strategies, grain structure control and deformation mechanisms, with potential implications for future research and industrial applications of superplastic Mg alloys.

Key words: Mg alloys, Superplasticity, Second-phase particles, Solute segregation, Microstructure control