The anodized film of aluminum alloy in sulfuric acid solution is colorless and porous, so it is most suitable for dyeing. However, when alternating current anodizing, a series of chemical reactions often occur because the film contains sulfur, although it is easy to dye. However, since the dyeing and the sulfur in the film layer form sulfides, even in the copper color liquid, the direct current and the alternating current treatment are different from the anodized film color gamma, so the appropriate process and operating conditions must be selected during the anodization. A group of good quality films.
Other anodized films, such as the oxalate oxide film itself, appear yellow and can only be dyed dark. Oxidation at 35 degrees Celsius, an almost colorless film is obtained, which is very low as a dyed underlayer, and the chromic oxide film layer is generally not suitable for dyeing because the film is thin and the void ratio is low, and on the other hand, the film color is gray, It can only be dark, and has been studied intensively. It is believed that the film obtained can only be colored with an equal voltage or high concentration of chromic acid anodization. In addition, porcelain oxide film and some chemical oxide film layers can be dyed.
The aluminum oxide film layer must have a certain thickness and should be larger than 7 μm. The film of the sacrificial bag can only be dyed with a very light color.
The aluminum oxide film should have certain loose pores and adsorptivity, so the hard anodized film layer and the conventional oxidized oxide layer are not suitable for dyeing.
The aluminum oxide film layer should be complete and uniform, and should not have scratches, trachoma, pitting corrosion and other defects.
The aluminum alloy film itself has a suitable color, and there is no difference in gold structure, such as grain size or severe segregation. Therefore, there are certain requirements for aluminum alloy materials. When the content of silicon, magnesium, manganese, iron, and the like in the alloy composition is too high, the oxide film is dark, and the color tone changes in the dyeing.