Oxidation studies of Al alloys: Part II Al-Mg alloy

The oxidation behaviour of molten Al-Mg alloys has been investigated. The oxides formed were extracted from the alloys using a novel extraction method and the oxidation mechanisms are discussed with reference to the growth behaviour of the oxides. The oxides formed in Al-Mg alloys were explored by scanning electron microscopy, X-ray diffraction and photoelectron spectroscopy. Thermodynamic calculations were performed to predict the feasibility of the reactions giving rise to oxides and to explain the oxide formation under various experimental conditions. The formation of MgAl2O4 was followed by formation of MgO as a function of time leading to depletion of Mg.