Extrusion profile forming process
Extrusion is the means of profile forming. Firstly, the mold is designed and manufactured according to the section of the profile product, and the heated round cast rod is extruded from the mold by an extruder. The commonly used grade 6063 alloy is also subjected to an air-cooling quenching process and an artificial aging process after extrusion to complete the heat treatment strengthening. Different grades of heat treatable reinforced alloys have different heat treatment regimes.
Coloring (here mainly on the oxidation process)
Oxidation: The extruded aluminum alloy profile has low surface corrosion resistance and must be surface treated by anodizing to increase the corrosion resistance, wear resistance and appearance of the aluminum.
The main process is:
(1) Surface pretreatment: The surface of the profile is cleaned by chemical or physical means to expose a pure matrix to facilitate the obtaining of a complete and dense artificial oxide film. It is also possible to obtain a specular or matt (matte) surface by mechanical means.
(2) Anodizing: After surface pretreatment, under certain process conditions, the surface of the substrate is anodized to form a dense, porous, strong adsorption Al2O3 film.
(3) Sealing: The pores of the pores of the porous oxide film formed by anodization are closed, so that the oxide film is prevented from being contaminated, and the corrosion resistance and wear resistance are enhanced. The oxide film is colorless and transparent. By using the strong adsorption property of the oxide film before sealing, some metal salts are adsorbed and deposited in the pores of the film, so that the appearance of the profile shows many colors other than the natural color (silver white), such as black, bronze, Gold and stainless steel.