Aluminum alloy is a common lightweight metal material with excellent thermal conductivity and excellent mechanical properties, and is widely used in industrial manufacturing and daily life. However, the surface of aluminum alloys is susceptible to oxidation, reducing its corrosion resistance and aesthetics. In order to improve the surface properties of aluminum alloys, a surface treatment technology called micro-arc oxidation has been developed.

Micro-arc oxidation, also known as electrolytic micro-arc oxidation, electrolytic oxidation, anodizing, etc., is a process that uses the micro-arc discharge phenomenon generated in the electrolyte to generate a dense oxide film on the surface of aluminum alloys. This oxide film has high hardness, good wear resistance and corrosion resistance, and can effectively improve the surface properties of aluminum alloys.

The process of micro-arc oxidation is relatively complex, mainly including several steps such as pre-treatment, electrolyte formula, micro-arc oxidation equipment and post-processing. First, the aluminum alloy surface needs to be cleaned and degreased to ensure the adhesion of the oxide film. Then, select an appropriate electrolyte for formulation. Commonly used electrolytes include sulfuric acid, chromium sulfate, tartaric sulfate, etc. Next, an aluminum alloy product is used as an anode and placed in an electrolytic cell. A certain voltage and current are applied to cause micro-arc discharge in the electrolyte. Under the action of micro-arc discharge, an oxidation reaction occurs on the surface of the aluminum alloy, forming a dense oxide film. Finally, the oxide film is sealed to increase its corrosion resistance and hardness.

The oxide film of micro-arc oxidation is mainly composed of alumina and silicate and has a porous structure. This porous structure not only increases the surface area of the oxide film, but also improves its adhesion and wear resistance. In addition, the aluminum oxide particles in the oxide film also have good corrosion resistance and can effectively protect the aluminum alloy substrate from corrosion. Therefore, the aluminum alloy treated by micro-arc oxidation has high corrosion resistance, hardness and wear resistance.

Micro-arc oxidation technology is widely used in aerospace, automobile manufacturing, building materials and other fields. In the aerospace field, micro-arc oxidation technology can be used to manufacture aerospace engine parts and aircraft casings to improve their high temperature resistance and corrosion resistance. In the field of automobile manufacturing, micro-arc oxidation technology can be used to manufacture automobile engine blocks, body structural parts, etc., to improve their wear resistance and corrosion resistance. In the field of building materials, micro-arc oxidation technology can be used to manufacture aluminum alloy doors, windows, curtain walls, etc. to improve their weather resistance and corrosion resistance.

Micro-arc oxidation of aluminum alloy surfaces is an effective surface treatment technology that can significantly improve the surface properties of aluminum alloys. Through micro-arc oxidation treatment, aluminum alloys can obtain higher hardness, wear resistance and corrosion resistance, making them suitable for applications in various fields. With the advancement of science and technology and the improvement of processes, micro-arc oxidation technology will be more widely used and developed in the future.