Anodizing process is a metal surface treatment technology, especially for aluminum and aluminum alloys
The main principle of the process is that aluminum or aluminum alloy products are used as an anode and put into a specific electrolyte to form an oxide film on the surface of the product through electrolysis, so as to give it protection, beauty and other characteristics.
The specific steps of the anodizing process includes
- Preliminary treatment: polishing and chemical treatment of aluminum or aluminum alloy products to remove oil, fingerprints and other impurities on the surface of the product. This process usually requires certain conditions such as time and voltage.
- Electrolyte preparation: Select the appropriate electrolyte, such as sulfuric acid solution, and prepare enough electrolyte to ensure that the product is immersed in it.
- Anodizing treatment: Put the treated aluminum or aluminum alloy products into the electrolyte as the anode, and set the corresponding process conditions, such as voltage and current density.
- Oxide film formation: Through electrolysis, a layer of oxide film is formed on the surface of the product.
- Post-treatment: Clean the products formed by oxide film. After drying and other external treatment, to remove the residual electrolyte and impurities on the surface.
- Quality inspection: Quality inspection of the processed products, such as film thickness, hardness, adhesion and other indicators, to ensure that the quality meets the requirements.
The advantages of anodizing process includes
- Wear resistance and corrosion resistance: The formed oxide film has high hardness and good wear resistance, which can effectively resist wear and corrosion.
- Enhance aesthetics: by choosing different electrolytes and treatment methods, oxide films of various colors and textures can be formed on the surface of products to enhance the aesthetics of products.
- Improve adhesion: oxidation, film and substrate material has good adhesion, can effectively improve the corrosion resistance and wear resistance of products.
- Low cost, simple process: Compared with other surface treatment technology, anodizing process cost is low, and the process is relatively simple.
Anodizing process limitations include
- Limited scope of application: Anodizing process is mainly applicable to aluminum and aluminum alloy products, and may not be applicable to products of other materials
- Poor high temperature resistance: the formed oxide film is prone to discoloration and shedding at high temperatures, so it is not suitable for high temperature environment.
- Poor environmental protection: Some harmful substances are used in the electrolyte, which is harmful to the environment and the human body, so corresponding environmental protection measures need to be taken.
In short, the anodizing process is a surface treatment technology suitable for aluminum and aluminum alloy products, which has the advantages of wear resistance, corrosion resistance, and enhanced aesthetics, but at the same time, there are some limitations. In practical applications, such as the selection of packaging surface treatment process for revolving doors and automatic doors, the appropriate surface treatment technology and program need to be selected according to the specific situation.
Anodizing can also be performed in a borate or tartrate bath that is insoluble in alumina. In these processes, the coating stops growing when the part is fully covered, and the thickness is linear to the applied voltage. Widely used in the manufacture of electrolytic capacitors for environmental impact anodizing is a more environmentally friendly metal finishing process. Usually, by-products contain only small amounts of heavy metals.
The most common anodizing wastewater, aluminum hydroxide and aluminum sulfate can be recycled or used in industrial wastewater treatment systems.
