anodizing

Method of coating metal for corrosion resistance, electrical insulation, thermal control, abrasion resistance, sealing, improving paint adhesion, and decorative finishing. Anodizing consists of electrically depositing an oxide film from aqueous solution onto the surface of a metal, often aluminum, which serves as the anode in an electrolytic cell. In the most common type of anodizing, which uses a 15 sulfuric acid bath, dyes can be introduced into the oxidation process to achieve a coloured surface. Aluminum thus anodized and coloured is used widely in giftware, home appliances, and architectural decoration.