The Gaseous Anodization of Aluminum

Gaseous anodization of aluminum has been investigated as an alternative procedure to forming thin oxide films by such standard techniques as electrolytic anodization and air oxidation. Oxide films are formed on an aluminum surface when positioned in the plateau region of a glow discharge of oxygen. Process variables such as the oxygen pressure and the applied voltage are found to affect the time for film formation. The films are further evaluated on the basis of capacitance and breakdown voltage measurements as well as breakdown pattern observations. Some information as to the rate and nature of film formation is deduced from probe current versus time measurements.