Pulse Current Hard Anodic Oxidation Technology for Aluminum Alloy 2A12 in Sulfuric Acid of Low Concentration

The hard anodic oxidation coating of aluminum alloy 2A12 was prepared in sulfuric acid solutions of different low concentrations with special apparatus.The effects of solution concentration,oxidation temperature,oxidized time,current density and pulse period on the micro-hardness,oxidation voltage,film thickness and film quality were studied.The optimum technology of pulse anodic oxidation for 2A12 was obtained.The problem of surface quality could be solved by controlling the temperature at -2~0 ℃ and the solution concentration at 2%.