Study on Corrosion Behavior of Anodic Oxide Film on 7075 Aluminum Alloy

In this paper,the 7075 aluminum alloy was taken as research object.The method of sulfuric acid DC anodic oxidation was used to products oxide film and the corrosion behavior of 7075 aluminum alloy under the condition of copper accelerated acetic acid salt spray corrosion was investigated.It is shown from the range analysis that time is the biggest influencing factor to the corrosion behavior of this alloy,followed by the temperature and then the concentration of the etching solution under the condition of salt spray corrosion.The main corrosion feature of this alloy after anodizing is pitting and the deepest pitting is 112.6 μm under the condition of 72 h、35℃、3% etching solution concentration.The corrosion resistance of aluminum alloy after anodizing is strongly improved.The improvement to uniform corrosion is much more than that to pitting corrosion by anodic oxidation.