ANODIC ALUMINIUM OXIDE FILM AND METHOD OF FORMING IT

摘要

ANODIC ALUMINIUM OXIDE FILM AND METHOD OF FORMING IT An anodic oxide film is formed on aluminium strip by continuously passing the strip through a phosphoric acid electrolyte at from 25.degree.C to 80.degree.C, the contact time between the strip and the electrolyte being not more than 15 seconds during which time the strip is anodized at a current density of at least 250 A/m2. In the resulting film, the pores are enlarged so that the effected surface area is increased. The film forms an excellent substrate for lacquer, paint, or adhesive.