Characterisation of Oxide Coatings Produced on Aluminum Alloys by MAO and Chemical Methods

The study compared the properties of oxide coatings formed on aluminium alloys produced by: MAO (micro – arc oxidation), and the chemical method (oxidation in acid). Morphology, microstructure and of the coatings was analysed with a scanning electron microscope SEM. Corrosion resistance were tested in potentiometer – dynamic. The layers produced by MAO significantly improved corrosion resistance. Coatings produced after 3 minutes of oxidation had better corrosion resistance than the coatings after 5 minutes of oxidation. The layers produced by chemical method didn’t improve corrosion resistance of aluminium alloy.