Foaming behavior of Al-Mg alloy melts with and without a thickening step was studied. Stable foams were obtained in both the cases. Oxides formed in Al-Mg melts were studied using XRD, SEM and TEM. These studies revealed the formation of MgAl2O4, MgO and transition oxides in Al-Mg melts. The stabilization of Al-Mg foams was attributed to the formation of MgAl2O4 and transition oxides. © 2017 Elsevier B.V.