Investigation on Corrosion Behavior of Anodic Oxide Film on 2024 Aluminum Alloy

Anodic oxidation in sulfuric acid electrolyte was used in the surface modification of 2024 aluminum alloy.An orthogonal test was made on the processed alloy under the condition of copper accelerated salt spray corrosion.The corrosion rates of the experimental group and the control group in salt fog environment were examined with the method of the weight gain.The corrosion features of 2024 aluminum alloy was studied by SEM and PDS.The results show that under the present experimental conditions,the highest corrosion weight gain of the alloy after anodizing is 20.1 g/m2.It is shown from the range analysis that time is the biggest influencing factor on the corrosion behavior of this alloy,followed by the temperature and then the concentration of the etching solution.Anodic oxidation can improve the uniform corrosion resistance of 2024 aluminum alloy,but the improvement of the pitting corrosion is limited.