来源：http://www.jndclyyxgs.com 发布时间：2021-08-26 19:01:16
Electrolytic coloring of aluminum alloy plate has good decoration, so it is widely used at home and abroad, especially in the surface treatment production of architectural aluminum profiles. At present, the main process is electrolytic coloring with tin nickel mixed salt. The color of the product is mainly champagne. Compared with single nickel salt coloring, the color of electrolytic coloring with tin nickel mixed salt is bright and full; The main problem is the color difference of the product. The unreasonable extrusion process and oxidation coloring process in the production of aluminum profile will lead to the color difference of the product.
The influence of extrusion process on the oxidation coloring of alloy aluminum plate is mainly the influence of die design, 5052 aluminum plate extrusion temperature, extrusion speed and cooling mode on the surface state and microstructure uniformity of extruded profile. The mold design shall be able to make the feed fully knead, otherwise it is easy to have bright (dark) band defects, and color separation may occur on the same profile; At the same time, the die state and the extrusion lines on the profile surface also affect the oxidation coloring. Different extrusion temperature, speed, cooling mode and cooling time will lead to uneven structure and color difference.
Anodizing has a very important impact on the color difference of electrolytic coloring of alloy aluminum plate, especially in the production process of vertical oxidation line, it is easy to have two colors. The vertical oxidation tank is 7.5m deep, and the temperature difference between upper and lower tank liquid is easy to occur. Temperature has an important impact on anodizing. High temperature intensifies the dissolution of oxidation film by oxidation tank liquid, and the pore diameter of porous anodic oxidation film surface will increase, On the contrary, the pore size of porous anodic oxide film is small. In addition, the porosity of anodic oxide film is higher at high temperature, and vice versa.
Electrolytic coloring of alloy aluminum plate is mainly to make the metal ions in the coloring solution carry out electrochemical reduction reaction on the surface of the barrier layer in the micropores of the oxide film, so that the metal ions in the coloring solution are deposited at the bottom of the anodic oxide film hole, scattering the incident light and showing different colors. The more substances deposited in the micropores, the darker the color. Under the condition of passing the same electric quantity, the same amount of metal or metal compound is deposited on the parts with high and low temperature. For the parts with high porosity and large surface pore diameter, the average sediment per hole is less. The color of 5052 aluminum plate is relatively light, on the contrary, the color is darker, resulting in two colors of coloring material. In the anodizing process of alloy aluminum plate, the conductivity has an impact on the oxide film and will also cause the color difference of coloring materials. This problem is mainly prone to occur in the horizontal production line. It is mainly due to the loose clamping during the upper row of oxidized blank before oxidation, resulting in poor conductivity of individual materials, which makes the oxide film relatively different. After coloring, the color difference will occur.