Anodizing is a commonly used metal surface treatment process, mainly used for surface protection and decoration of aluminum and its alloys. The following is the basic operation process of anodizing:
Pre-processing
Cleaning: Use degreasers, acidic cleaning agents, etc. to remove oil, dust and other impurities on the metal surface.
Acid etching: Etching the surface with an acid solution (such as dilute sulfuric acid) to remove the oxide layer and surface defects.
Water washing: Rinse thoroughly with clean water to remove residual cleaning agent and acid.
Anodizing
Electrolytic tank preparation: Place the cleaned metal parts into the electrolytic tank and add electrolyte into the tank.
Power supply connection: The metal piece serves as the anode and is connected to the positive pole of the power supply. The lead or aluminum plate in the tank serves as the cathode and is connected to the negative pole of the power supply.
Applying current: After energizing, the current passes through the electrolyte and forms an aluminum oxide film on the metal surface.
Dyeing
After anodizing, the aluminum material is immersed in a dye solution, and the dye molecules will penetrate into the micropores of the oxide film. Dyeing time and temperature will affect the shade and uniformity of dyeing.
Post-processing
Sealing treatment: After anodizing, the oxide film is sealed by water vapor, hot water or chemicals (such as chromate) to improve the corrosion resistance of the film.
Water washing: Rinse again with water to remove residual sealer.
Drying: Use drying equipment or natural air drying to dry the workpiece.
Test
Check the thickness, uniformity, appearance and adhesion of the oxide film to ensure that quality standards are met.
