Effect of Sulfuric Acid Anodized Aluminum Alloy Components on Oxide Films

The chemical composition of aluminum alloys has an effect on the thickness of the oxide film formed, in addition to the resistance to the formation of oxide films. As in the same oxidation treatment conditions, the pure aluminum oxide film is thicker than the aluminum alloy. Aluminum-silicon alloys are more difficult to oxidize and the oxide film is dark gray. Therefore, sheet metal parts with and without an aluminum layer are anodized. Because the oxide film of pure aluminum is formed quickly and thickly in the same tank oxidation process, the oxide film of bare aluminum is generated slowly and thinly.