Morphology of oxide films of Al-5Mg alloy in dynamic conditions in casting

Al-Mg alloys are reported to be sensitive to turbulence during casting, creating plentiful drosslike defects. New oxide films that form very quickly during casting seem to be one of the main reasons. The characteristics of these new films were studied. Samples for the study were prepared based on a technique in which an oxide-metal sandwich was made by the bubble impingement technique. Features of the oxide film such as thickness, morphology, rigidity and presence of nuclei in the matrix alloy have been examined by SEM. Possible consequences of the morphology of the oxide film are discussed.