Replaces plastic, reusable, environmentally friendly, significantly reduces overall weight while maintaining structural strength.Aluminum spontaneously forms a dense oxide film (Al₂O₃) in the air, approximately [thickness missing]. With a thickness of 0.01-0.1 μm, this film adheres tightly to the aluminum surface, preventing the internal metal from reacting further with oxygen, water, or acidic and alkaline substances.Through processes such as anodizing and electrophoretic coating, the oxide film can be thickened or a protective layer can be applied, further enhancing corrosion resistance.