Aluminum plates can be seen everywhere in our lives. Aluminum plates are used in automobiles, construction, home improvement, electronic appliances, and other fields. In particular, most of the mobile phones we use every day are packaged in metal shells, and this metal shell is aluminum alloys. They are smooth, bright, and mirror-like. An important process that makes aluminum alloys have these characteristics is anodizing.
What is anodized aluminum?
An anodized aluminum plate is placed the aluminum plate in the corresponding electrolyte (such as sulfuric acid, chromic acid, oxalic acid, etc.) as an anode, and conducts electrolysis under specific conditions and the action of an applied current.
A dense oxide film is formed on the surface of the aluminum plate, and the colorless and porous nature of the anodic oxide film is used to achieve the purpose of dyeing and protecting the aluminum matrix.
Anodizing process of aluminum plate
In simple terms, the anodizing process is mainly from degreasing → etching → neutralization → anodizing → coloring → sealing.
A metal or alloy product is used as an anode, and an oxide film is formed on the surface by electrolysis. Metal oxide films change the surface state and properties, such as surface coloration, improve corrosion resistance, enhance wear resistance and hardness, and protect metal surfaces. For example, in aluminum anodization, aluminum, and its alloys are placed in a corresponding electrolyte (such as sulfuric acid, chromic acid, oxalic acid, etc.) as an anode, and electrolysis is carried out under specific conditions, and the action of an applied current.
The aluminum or its alloy of the anode is oxidized, and a thin layer of aluminum oxide is formed on the surface, the thickness of which is 5-30 microns, and the hard anodic oxide film can reach 25-150 microns. Anodized aluminum or its alloy improves its hardness and wear resistance, up to 250-500 kg/mm2, good heat resistance, hard-anodized film melting point up to 2320K, excellent insulation, shock resistance. The breakdown voltage is as high as 2000V, which enhances the corrosion resistance and does not corrode for thousands of hours in ω=0.03NaCl salt spray.
There are a lot of micropores in the thin oxide film layer, which can adsorb various lubricants, suitable for the manufacture of engine cylinders or other wear-resistant parts; the film micropores have strong adsorption capacity and can be colored into various beautiful and bright colors.
Generally speaking, the anode is made of aluminum or aluminum alloy, and the cathode is made of a lead plate. The aluminum plate and the lead plate are put together in an aqueous solution containing sulfuric acid, oxalic acid, and chromic acid. An oxide film is formed on the surface. Of these acids, the most common is anodizing with sulfuric acid.
Characteristics of anodized aluminum
1. Flatness Ordinary aluminum plates are prone to unevenness. The anodized aluminum plate has a great improvement in the surface production process, and its production process is more high-quality. Therefore, both the smoothness and flatness of the surface are better than ordinary aluminum plates.
2. The appearance is gorgeous We all know that the appearance of ordinary aluminum plates is mostly gray, and the color is single. The anodized aluminum plate is rich in color choices, not just a single gray. The well-known Apple Gold, Space Gray, and Rose Gold are formed by the anodizing process.
3. Anti-corrosion and anti-wear Because the coating is added, the coating undoubtedly acts as a protective layer that isolates the metal from the outside world. Therefore, the anti-rust performance of the anodized aluminum plate is particularly good, and the service life of the surface metal can be extended. At the same time, adding a coating also makes the surface of the material more wear-resistant.
4. The use of excellent performance Anodized aluminum plate not only has excellent bendability but also its machinability is particularly good. Different sizes can be made according to different needs. And its weather resistance is also very good, no matter what kind of weather conditions it can be used normally, and it can also stand upright in the face of saline-alkali acid rain.
The above information is the detailed information of the alumina board organized by CHAL. It is precisely because of the excellent performance of anodized aluminum that it is favored by mobile phone manufacturers. As a professional aluminum plate manufacturer, we have been providing high-quality aluminum sheets to customers all over the world. If you are also interested in a cost-effective aluminum plate, we will be your best choice.