In recent years, the surface treatment technology of aluminum honeycomb panels has a tendency to develop anodizing treatment technology. For the anodizing treatment of the honeycomb panel, attention should be paid to the uniformity of the thickness of the anodized film, the uniformity of the color, and the reproducibility. To ensure the uniformity of the thickness of the anodized film, the uniformity of the color and the reproducibility, the chemical composition of the aluminum alloy and the production process of the anodization must be strictly controlled.
1. Strictly control the production process of the casting. The chemical composition of the ingot must be controlled as small as possible and the chemical composition must be uniform. In addition, the smelting process, the casting process, and the homogenization process must be strictly performed.
2. Select the appropriate fixture. The fixture material must ensure good electrical conductivity. Copper or copper alloy fixtures are generally used. Dedicated or general-purpose jigs that have been used, such as anodizing, are used again, and the surface oxide film must be removed to ensure good contact.
3. Strictly control the anodization temperature. From the anodic oxidation film formation mechanism, when the anodic oxidation temperature is low, the formed oxide film is dense and the porosity is small. As the anodization temperature increases, the oxide film gradually becomes loose, the porosity gradually becomes larger, and the color of the film layer is gradually increased. It gradually darkens as the temperature rises. Therefore, the anodization temperature is an important factor determining the density of the oxide film and an important factor determining the color uniformity of the oxide film.
4. Strictly control the anodizing current density. As the current density increases, the color of the oxide film gradually becomes deeper, and the thickness of the film layer first becomes thicker and then becomes thinner. The reason is that the current density increases, the film pores increase, and it is easy to color; the current density decreases, the film The growth rate is reduced and the film layer is dense, so as the current density increases, the color of the oxide film gradually becomes deeper. Under other conditions, the current density is increased, the growth rate of the oxide film is increased, the oxidation time can be shortened, the chemical dissolution amount of the film layer is reduced, the film is hard, and the wear resistance is good. However, the current density cannot rise too high, otherwise the heat effect in the pores of the membrane will increase due to the influence of Joule heat, the local temperature rise will be significant, the dissolution rate of the oxide film will increase, and the film formation speed will decrease. That is to say, the current density is increased, and the film formation rate can be increased within a certain range, but after reaching a certain value, the film formation speed is decreased. The magnitude of the current density directly affects the uniformity of the color of the oxide film.
