The natural color of die-cast aluminum anodizing is the electrochemical oxidation of metals or alloys. Aluminum and its alloys form a layer of oxide film on aluminum products (anode) under the action of applied current under corresponding electrolyte and specific process conditions. Different from other chemical oxidation processes, first, it has the effect of reducing the natural color. If not specified, it usually refers to sulfuric acid anodizing.
Anodizing uses metal or alloy parts as anodes and uses electrolysis to form oxide films on the surface. The metal oxide film changes the surface state and properties, such as surface coloring, improving corrosion resistance, enhancing wear resistance and hardness, and protecting metal surfaces. The natural color of die-cast aluminum anodized, aluminum and its alloys are placed in the corresponding electrolyte (such as sulfuric acid, chromic acid, oxalic acid, etc.) as the anode, and electrolysis is carried out under specific conditions and applied current. The aluminum or its alloy of the anode is oxidized to form a thin layer of aluminum oxide on the surface, the thickness of which is 5-20 microns, and the hard anodized film can reach 60-200 microns.
The anodized aluminum or its alloy improves its hardness and wear resistance to 250～500kg/mm2, good heat resistance, the melting point of hard anodized film is as high as 2320K, excellent insulation, shock resistance The breakdown voltage is as high as 2000V, which enhances the corrosion resistance and does not corrode in ω=0.03NaCl salt spray for thousands of hours. There are a large number of micropores in the thin oxide film, which can absorb various lubricants, which is suitable for manufacturing engine cylinders or other wear-resistant parts; the film has a strong adsorption capacity and can be colored into various beautiful and gorgeous colors. Non-ferrous metals or their alloys (such as aluminum, magnesium and their alloys, etc.) can be anodized. This method is widely used in mechanical parts, aircraft and automobile parts, precision instruments and radio equipment, daily necessities and architectural decoration.
In addition to metals, the oxidation caused by other substances as anodes is also called "anodization". In the actual process, there are more anodic oxidations for aluminum alloys, which can be applied in daily life. It is considered that the characteristics of this process, A hard protective layer is produced on the surface of aluminum parts, which can be used to produce kitchen utensils and other daily necessities. However, the anodizing effect of cast aluminum is not good, and the surface is not shiny, it can only be black. The color of die-cast aluminum anodized aluminum alloy profile is better.