1. Material and Surface Condition of Workpiece

(1) Micro-arc oxidation has low requirements for aluminum materials, whether copper or silicon-containing aluminum alloys that are difficult to anodize. As long as the valve metal ratio exceeds 40%, they can be used for micro-arc oxidation, and ideal coatings can be obtained.

(2) Surface conditions typically do not require polishing. For rough surfaces, micro-arc oxidation can restore them to a smooth finish; for surfaces with low roughness (i.e., smooth), the roughness will increase.

2. The Impact of Liquid Components on Oxidation

Electrolyte composition is a crucial factor in achieving a qualified film layer. The micro-arc oxidation solution typically employs alkaline salt solutions containing certain metal or non-metal oxides, such as silicates, phosphates, and borates. Under the same micro-arc electrolytic voltage, the higher the concentration of the electrolyte, the faster the film formation rate, and the slower the temperature rise of the solution. Conversely, a slower film formation rate and a faster temperature rise of the solution are observed.

3. The Impact of Temperature on Micro-Arc Oxidation

Micro-arc oxidation differs from anodizing in that it requires a wider temperature range, typically between 10-90 degrees Celsius. The higher the temperature, the faster the film forms, but the roughness also increases. Additionally, higher temperatures can lead to the formation of water vapor. Generally, it is recommended to operate between 20-60 degrees Celsius. Since micro-arc oxidation releases heat energy, the liquid temperature rises quickly, necessitating a larger heat exchange and refrigeration system for the process to control the tank liquid temperature.

4. The Impact of Time on Micro-Arc Oxidation

Micro-arc oxidation typically lasts between 10 to 60 minutes. The longer the oxidation time, the higher the denseness of the film, but its roughness also increases.

5. Cathode Materials

Cathode materials can be selected from stainless steel, carbon steel, nickel, etc., which can be suspended or used to form cathode cells.

6. The Impact of Post-Treatment on Micro-Arc Oxidation

After micro-arc oxidation, the workpiece can be used directly without any further treatment, or it can undergo subsequent processes such as sealing, electro-phoresis, polishing, etc.