Enhancing corrosion resistance of Mg-Zn-Ca alloys via constrained friction processing

Magnesium (Mg) alloys are promising lightweight structural materials due to their excellent mechanical properties and high specific strength. However, their relatively high corrosion rates, susceptibility to localized corrosion, and potential for stress corrosion cracking pose significant challenges for engineering applications. This study investigates the corrosion resistance of Mg-Zn-Ca (ZX) alloys processed by a constrained friction processing (CFP) technique. CFP significantly refines the microstructure, reduces the size and volume of secondary phases, and enhances the mechanical properties of ZX alloys. The results show that CFP ZX alloys exhibit improved corrosion resistance in NaCl solution, with ZX10 alloy demonstrating the best performance due to the formation of a dense corrosion product and a protective Zn-rich layer on the surface. The study reveals that the severe shear deformation and extensive recrystallization during CFP accelerate the dissolution of secondary phases into the matrix, leading to a more homogeneous microstructure and reduced localized micro-galvanic corrosion. These findings highlight the potential of CFP for producing high-performance Mg alloys with enhanced corrosion resistance for structural applications.