5052 aluminum plate contains copper, brick, iron and other impurities that affect the surface appearance of the oxide film: copper will make the oxide film turn red, damage the quality of the electrolyte, and increase oxidation defects; silicon will make the oxide film gray, especially when the content When it exceeds 4.5%, the impact is more obvious.
Due to its own characteristics, iron will exist in the form of black spots after anodization. In addition, there are other impurities in the 5052 aluminum plate that affect the appearance of the oxide film: 1-2% aluminum alloy turns brown-blue after oxidation. As the manganese content in the aluminum increases, the surface color after oxidation changes from brown to blue. Converts color to dark brown. Aluminum alloys containing 0.6-1.5% silicon turn gray after oxidation, and when containing 3-6% silicon, they turn white-gray.