Aluminum alloy dies casting after treatment, beautiful color, corrosion resistance, wear resistance, and insulation higher than ordinary aluminum castings placed in an appropriate electrolyte solution, using this as an anode for electrolysis In the process of electrolysis, the hydroxide ion in water releases electrons at the anode to become water and new ecological hydrogen, which makes aluminum oxide thicker alumina film, because this process is metal products as the anode is oxidized, so it is called anodic oxidation, process.
1. Pretreatment: aluminum alloy die casting in many mechanical processing processes, stained with more grease, a small amount of abrasive, dust and defective oxide film, etc., these substances have poor conductivity, and can not be anodized, so it needs to be treated in advance Method is to use carbon tetrachloride, trichloroethylene, do cleaner gasoline or toluene, dip aluminum alloy die casting, brush with wool washing, then dried, immersed in the water again, after multiple oils to do clean, immediately wash with hot water If generated on the surface of a layer of black film, but also in 32% nitric acid solution soak for 20 seconds, in order to remove the black film, the final rinse in cold water Immerse in distilled water for use as an oxide film.
2. Anodic oxidation (1) Preparation of sulfuric acid electrolyte: it is mixed with sulfuric acid and deionized water, and the specific gravity of the solution is about 1.125-1.140. Sometimes in order to obtain a good protective performance of anodic oxidation film, usually add a small amount of oxalic acid to the sulfuric acid electrolyte. (2) oxidation process: the line meter is installed, will be processed aluminum alloy die casting anode and all immersed in the electrolyte, and then switch on the power supply, according to the following process conditions control.