The anodized aluminum plate is to place the aluminum plate in the corresponding electrolyte (such as sulfuric acid, chromic acid, oxalic acid, etc.) as the anode, and perform electrolysis under specific conditions and an applied current. The aluminum plate of the anode is oxidized, and a thin layer of aluminum oxide is formed on the surface, the thickness of which is 5-20 microns, and the hard anodized film can reach 60-200 microns.
The anodized aluminum plate improves its hardness and wear resistance, which can reach 250-500 kg/mm2, good heat resistance, the melting point of the hard anodized film is as high as 2320K, excellent insulation, and the breakdown voltage is as high as 2000V, enhanced corrosion resistance, at ω=0. No corrosion after thousands of hours in NaCl salt spray. There are a large number of micropores in the thin layer of oxide film, which can absorb various lubricants, and is suitable for manufacturing engine cylinders or other wear-resistant parts; the film micropores have strong adsorption capacity and can be colored into various beautiful and bright colors.
Non-ferrous metals or their alloys (such as aluminum, magnesium and their alloys, etc.) can be anodized.
Chemical alumina plate is the treatment process in which part of the base metal of the aluminum plate reacts in a weakly alkaline or weakly acidic solution to thicken the natural oxide film on the surface or produce other passivation films. The commonly used chemical oxide film is chromic acid film and phosphoric acid membranes, which are both thin and absorbent, and can be colored and sealed.