7075铝合金阳极氧化膜腐蚀性能研究

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

本文以7075铝合金为研究对象,采用硫酸直流电阳极氧化法制备氧化膜,并通过正交试验研究了合金在铜加速乙酸盐雾腐蚀条件下的腐蚀性能。由极差分析可知:在盐雾腐蚀条件下,时间是最大的影响因素,其次是温度对合金的影响,最小的是腐蚀液浓度。阳极氧化后的合金主要以点蚀为主,在72 h、35℃、3%腐蚀液浓度条件下,蚀坑最深值可达112.6μm,阳极氧化对均匀腐蚀的改善作用明显大于点腐蚀。

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.