1) Surface pretreatment: clean the profile surface by chemical or physical method, expose the pure matrix, in order to obtain a complete and dense artificial oxide film. Specular or matte (matte) surfaces can also be obtained mechanically.
2) Anodic oxidation: For the surface pretreated profiles, under certain technological conditions, the substrate surface will be anodized to form a dense, porous and strongly adsorbed Al203 film.
3) Hole sealing: seal the pores of the porous oxide film formed after anodic oxidation to enhance the anti-pollution and anti-corrosion wear resistance of the oxide film.