Anodized aluminum plate is placed in the corresponding electrolyte (such as sulfuric acid, chromic acid, oxalic acid, etc.) as the anode, under the specific conditions and the effect of external current, electrolysis. The anodized aluminum plate forms a thin layer of alumina on its surface, with a thickness of 5-20 μ M. the hard anodized film can reach 60-200 μ M. After anodizing, the hardness and wear resistance of the aluminum plate are improved, which can reach 250-500kg / mm2. It has 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 , which enhances the corrosion resistance. It does not corrode in ω = 0.03nacl salt fog for thousands of hours. There are a lot of micropores in the thin layer of oxide film, which can absorb all kinds of lubricants. It is suitable for making engine cylinder or other wear-resistant parts. The micropores of oxide film have strong adsorption capacity and can be colored into various beautiful and gorgeous colors. Non ferrous metals or their alloys (such as aluminum, magnesium and their alloys) can be anodized.
Introduction to chemical aluminum oxide plate
Chemical aluminum oxide plate is the treatment process that part of the base metal reacts in the weak alkaline or weak acid solution to make the natural oxide film on its surface thicken or produce some other passivation films. The commonly used chemical oxide films are chromic acid film and phosphoric acid film, which are thin in absorption and good in pore sealing.
Comparison between chemical oxide film and anode oxide film of aluminum plate
3. Compared with the anodizing film of aluminum plate, the chemical oxidation film of aluminum plate is much thinner, with lower corrosion resistance and hardness, and is not easy to be colored, and the light resistance after coloring is poor, so the anodizing treatment is only introduced in the coloring and color matching of aluminum plate.