What is the difference between aluminum and aluminum alloy in corrosion resistance characteristics

Anodic oxidation is generally used. The thickness of anodic oxide film obtained by anodic oxidation treatment is generally 5-20V m, and the thickness of hard anodic oxide film can reach 60-2500m. It has high corrosion resistance. This is due to the higher chemical stability of anodized films

The characteristics of aluminum and aluminum alloy corrosion resistance: after testing, the anodic oxide film of pure aluminum than aluminum alloy anodic oxide film corrosion resistance is better. This is due to the alloy composition

Inclusion or metal compounds can not be oxidized or dissolved, so that the oxide film is discontinuous or void, so that the corrosion resistance of the oxide film is greatly reduced. Therefore, generally after anodic oxidation of the film must be closed treatment, to improve its corrosion resistance.

So the anodic oxidation of aluminum is stronger than the corrosion resistance of aluminum alloy, aluminum and aluminum alloy in the atmosphere can naturally form a layer of oxidation film, but the film is thin (40-50a) and loose porous, amorphous, uneven and discontinuous film layer, can not be used as a reliable protection of a decorative film layer. With the continuous development of aluminum products processing industry, the method of anodic oxidation or chemical oxidation is more and more widely used in industry to generate a layer of oxide film on the surface of aluminum and aluminum alloy parts, so as to achieve the purpose of protection and decoration. The thickness of the oxide film obtained by chemical oxygen durli is generally 0.3 ~ 4um, and its soft, wear and corrosion resistance are lower than that of the anodic oxide film. Therefore, except for special purposes, it is rarely used alone. But it has a good adsorption capacity, on its surface again painted, can effectively improve the aluminum products

Corrosion resistance and decorative.