Microstructure and corrosion resistance of ultrahigh pressure Mg-8Li based alloys

High anti-corrosion Mg alloys is desirable to expand their industrial applications. Herein we report an outstanding corrosion resistance of dual-phase Mg-8Li-Y alloy using ultrahigh pressure (UHP) technology. The average corrosion rate is ∼0.47 mm/y, overwhelming the majority of Mg-Li alloys reported hitherto. In-situ X-ray diffraction and scanning electron microscope observation demonstrate that a unique multiple-film on UHPed Mg-8Li-Y alloy attributes to the excellent corrosion resistance, which origins from the dynamic dissolution/regeneration of Li2CO3-rich composite film, thus effectively prohibiting corrosion solution permeation. These results provide some implications to design good anti-corrosion coating for Mg, ever stainless Mg alloys.