Aluminum Anodized Layer
The aluminum anodized layer is a thin, porous oxide layer on the surface of aluminum, produced by electrolytic anodizing. It protects against corrosion and can be colored.
Physical-Chemical Mechanism
The aluminum anodized layer is formed by electrolytic anodizing of aluminum in a sulfuric acid bath. This oxidizes the surface of the aluminum, producing a thin, porous oxide layer.
Metallurgical Relevance & Welding Risks
The anodized layer can break down under high temperature and pressure during welding. This can lead to corrosion and loss of the protective layer, affecting the lifespan of the components. It is important to remove or protect the anodized layer before welding.
Workshop Practice & Action Items
Before welding aluminum, the anodized layer should be removed. This can be done by mechanical polishing or chemical removal. When selecting the welding process, note that certain processes (like TIG welding) generate higher temperatures and can affect the anodized layer more. It is advisable to run a test before welding to ensure the anodized layer is not destroyed.