Corrosion resistant and high-strength dual-phase Mg-Li-Al-Zn alloy by friction stir processing

Magnesium (Mg) alloys are attractive for lightweighting applications due to their low density and high specific strength. However, poor formability and rapid degradation limit their use. Alloying with lithium (Li) improves formability, but introduces rapid corrosion and age-softening. This work demonstrates that friction stir processing (FSP) followed by liquid CO2 quenching enhances the durability of a dual-phase Mg-Li-Al alloy. The resulting alloy exhibits a low electrochemical degradation rate (0.72 mg·cm⁻²·day⁻¹) and high specific strength (209 kN·m·kg⁻¹), attributed to a refined microstructure with dense nanoprecipitates that suppress the formation of detrimental AlLi phase and an aluminum-rich protective surface layer.

Zhuoran Zeng, Mengran Zhou, Marco Esmaily, Yuman Zhu, Sanjay Choudhary, James C. Griffith, Jisheng Ma, Yvonne Hora, Yu Chen, Alessio Gullino, Qingyu Shi, Hidetoshi Fujii, Nick Birbilis