Oxidation behavior and incombustibility of molten Mg-Zn-Y alloys with Ca and Be addition

By addition of Ca or Be, non-flammable high strength Mg97Zn1Y2 (at%) alloys are developed. The addition of Ca results in the formation of a thin and continuous CaO and MgO outermost layer above Y2O3 inner layer, what helps to prevent the internal oxidation of Y and an increased ignition temperature can be achieved. The addition of a small amount of Be also helps to suppress the internal oxidation of Y. The most likely explanation for the enhancement of incombustibility is that the segregation of Be along the grain boundaries in the Y2O3 layer impedes the grain boundary diffusion of oxygen and cations.