Analysis of the reasons for the most widely used aluminum hard anodized surface treatment process
August 17, 2023
1, prevent corrosion of aluminum products
Because the film obtained by hard anodizing aluminum has sufficient stability in the atmosphere, the oxide film on the surface of aluminum can be used as a protective layer. The film obtained by anodizing aluminum in chromic acid solution is compact and has good corrosion resistance. The pores of the oxide film obtained from the sulfuric acid solution are larger than the former, but the industrial aluminum profile has a thicker film layer and strong adsorption capacity, and its corrosion resistance is also very good if it is properly filled and closed. In particular, the chromic acid anodizing method is particularly suitable for the hard anodizing of aluminum in riveted and welded parts.
2, protection - decorative products
For most aluminum and its alloy products requiring surface finishing, after chemical or electrochemical polishing, anodizing surface treatment and then anodizing with sulfuric acid solution can obtain high transparency oxide film. This oxide film can absorb many kinds of organic dyes and inorganic dyes, so that it has a variety of bright colors. This layer of color film is both an anti-corrosion layer and a decorative layer. Under some special technological conditions, protective and decorative oxide film similar in appearance to porcelain can also be obtained.
3, as an electrical insulation layer
Aluminum hard anodized aluminum oxide and aluminum alloy products after anodizing the oxide film has a large resistance, so it has a certain effect on improving the electrical insulation of some products, can be anodized to prepare the dielectric layer of capacitance, can also be prepared with aluminum oxide for its surface insulation layer.