Surface chemistry of water atomised aluminium alloy powders

This paper focuses on the characterisation of chemical composition and morphology of the surface oxide film in water atomised (WA) aluminium powders as a function of technological regimes (atomisation temperature and water pressure) by AES. The surface film mainly consists of aluminium oxides. However, magnesium is enriched and oxidised on the powder surface. Powders atomised at a higher water pressure are usually less oxidised than those atomised at a lower pressure. The surface of powders is covered by surface oxides of non-uniform thickness. Rather high oxide islands cover 30-70% of the surface. The rest is covered with a thin oxide film of three to maximal eight monolayers.