Several characteristics of anodic oxidation
Posted: Jan 25, 2017 Hits: 1105
Anodic oxidation has a wide range of applications in industry. It can be used to prevent products from corrosion, such as abrasion resistant layer, electrical insulation layer, paint bottom layer and bottom layer, etc. Here are some characteristics of anodic oxidation.
1. Prevent corrosion of aluminum product
Through anodic oxidation, aluminum in chromic acid solution would produce oxidation film, which is compaction and good corrosion resistance. On the contrary, the oxidation film from sulfuric acid solution has larger holes. But it has thicker film and strong adsorptivity. With proper filling and sealing treatment, it would have good corrosion resistance. Especially, chromic acid anodizing is suitable for anodic oxidation treatment of riveted and welded parts.
2. Protection and decoration of products
Most aluminum alloy products require surface polish treatment. After chemical or electrochemical polishing and anodic treatment in the sulfuric acid solution, there would be a oxide film with high transparency. This oxide film can absorb a wide range of organic and inorganic dyes so that it has a variety of bright colors.
3.Hard wear layer
After hard anodizing, the aluminum alloy would have thick and hard Al2O3 layer on the surface. This layer also has low harshness. Through anodic treatment, we can also get thick and hard oxidation film on the aluminum products in the sulfuric acid or oxalic acid solution.
4.Insulating layer
Through anodic oxidation, the layer has strong electric resistance so that it can improve the electrical insulation for some products. We can use anodic oxidation to make the dielectric layer of electric capacity or use alumina to make insulating layer for its surface.
5.The bottom of the spray paint
Because the layer of anodic oxidation has advantages of porosity and good adsorption capacity, it can be used as the bottom of spray paint and other organic films. It can improve the corrosion resistance by combining the paint film or organic film with products.
6. The bottom of electroplate
Before electroplating the aluminum products, we need to add the bottom. There are many ways to add bottom to the surface of stroma, in addition to zinc plating, zinc dipping and electroless nickel plating, anodic oxidation is also one of the important methods.
