(1) Surface pretreatment: Use chemical or physical methods to clean the surface of the profile and expose the pure matrix to facilitate obtaining a complete and dense artificial oxide film. It is also possible to obtain a mirror or matte (matt) surface by mechanical means.
(2) Anodizing: The surface of the pretreated profiles will undergo anodization on the surface of the substrate under certain process conditions to form a dense, porous, and strong adsorption Al2O3 film.
(3) Sealing: The pores of the porous oxide film formed after anodization are closed to enhance the anti-pollution, corrosion resistance and wear resistance of the oxide film. The oxide film is colorless and transparent. Using the strong adsorption of the oxide film before sealing, some metal salts can be adsorbed and deposited in the film pores, which can make the appearance of the profile show many colors other than the natural color (silver white), such as: black, bronze, Golden yellow and stainless steel color, etc.
