Nature of Surface Film on Matrix Phase of Mg Alloy AZ80 Formed in Water

The nature of the surface film formed on the α-Mg matrix phase of AZ80 in pure H2O was investigated using scanning transmission electron microscopy–energy-dispersive spectroscopy (STEM-EDS). Thin foil cross sections of the film/substrate interface were prepared using focused ion beam (FIB) milling. The film formed consists of a diffuse bilayer structure. A relatively thick, more-hydrated outer layer is found to form on a thinner, less-hydrated …