The general process of anodizing aluminum sheet

The main process is:
(1) Surface pretreatment: The surface of the profile is cleaned by chemical or physical methods to expose the pure substrate, so as to facilitate the acquisition of a complete and dense artificial oxide film. Mirror or matt (matt) surfaces can also be obtained by mechanical means.
(2) Anodizing: Under certain process conditions, the surface of the pretreated profile will undergo anodization on the surface of the substrate to form a dense, porous, and strong AL203 film layer. (3) Sealing: The pores of the porous oxide film formed after anodization are sealed, so that the anti-pollution, corrosion resistance and wear resistance of the oxide film are enhanced.

The oxide film is colorless and transparent. Using the strong adsorption of the oxide film before sealing, some metal salts are adsorbed and deposited in the film pores, so that the surface of the profile can show many colors other than the original color (silver white), such as: black, bronze, Gold and stainless steel.