摘要
以锰酸盐和锆盐为主盐,在铝合金表面化学氧化得到耐蚀性能良好的化学氧化膜,采用正交试验优化溶液的配方与工艺条件,采用极化曲线及交流阻抗测量分析其耐蚀性。铝合金化学氧化膜的腐蚀电位比铝合金试样的腐蚀电位正0.45 V左右,腐蚀电流密度仅0.286μA/cm2。交流阻抗谱图低频端的阻抗值比铝合金试样的值大一个数量级。铝合金化学氧化膜外观呈金黄色,具有规则排列的柱状生长结构。
A process with permanganate salt and zirconate as the oxidants in the treating solution has been studied, high corrosion resistance Cr-free coversion coatings were formed on the surface of LY12 allumi-nium alloy with chemical oxidation method. Solution components and preparing parameters were optimized with the orthogonal test method. The corrosion resistance of the conversion film was evaluated with anodic polarization curves and AC impedance method. The corrosion potential of the conversion film is 0.45 V higher than that on a blank sample. Corrosion current density is 0. 286 μA/cm^2. The impedance of the conversion film on low frequency end of the EIS spectra is higher than that on blank sample by one order of magnitude. The results show that the appearance of the coating is golden yellow and its micro-morphology is uniform and regular columnar structure under the SEM.
出处
《电镀与精饰》
CAS
2008年第9期20-24,共5页
Plating & Finishing
关键词
铝合金
化学氧化膜
正交试验
耐蚀性
aluminum alloy
chemical conversion film
orthogonal test
corrosion resistance
