1. Aluminum parts as the anode, lead plate as the cathode
2.Put the aluminum and lead plates together in the aqueous solution, which contains sulfuric acid, oxalic acid, chromic acid, etc.
4. An oxide film is formed on the surface of aluminum and lead plates. thickness is 5-30 microns
5. Coloring, such as Black Anodize. anodic oxidation is great performance on aluminium Extrusion parts