1. The oxidized aluminum forms a dense oxide film on the outer surface, so that the corrosion resistance is increased, and the melting point is also increased, and it can be used as a heat-resistant material, and aluminum which is not oxidized does not have these properties. 2 Oxidized aluminum has corrosion resistance and is more chemically stable than aluminum due to a layer of trioxide. There is also aluminum and acid-base reverberation to release hydrogen, and alumina has no gas. 3 After oxidation, the surface will form a dense oxide film, so that the aluminum inside will not continue to oxidize.