2001 Volume 42 Issue 6 Pages 1139-1141
Microstructural and compositional changes of oxide films were investigated in pure magnesium and Mg–1.51 mass%Ca alloy oxidized at high temperature. The oxide films of pure magnesium formed at high temperature above 500°C were porous, whereas those of Ca-containing alloy were compact, thin and dense. It was found that the oxide films of Ca-containing alloy were basically in the amorphous state containing a high volume fraction of CaO, while those of liquid oxidation were identified as a mixture of amorphous and microcrystalline structure. The retardation and suppression of solid and liquid oxidation at high temperature in Ca-containing magnesium alloy was caused by the formation of compact amorphous oxide films.