Anodic aluminium oxide film and method of forming it.

摘要

An anodic oxide film is formed on aluminium strip by continuously passing the strip through a phosphoric acid electrolyte at from 25°C to 80°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/m<Sup>2</Sup>. 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 aluminium.