(中国科学院金属研究所 金属腐蚀与防护国家重点实验室，沈阳 110016)
摘 要: 利用浸渍法在LY12铝合金表面获得了金黄色的铈转化膜，确定了常温稀土(铈)化学转化膜成膜工艺。应用电化学方法和浸泡试验研究了铝合金铈化学转化膜的成膜动力学及转化膜在3.5%NaCl溶液中的耐蚀性能，并与传统的Alodine处理工艺进行了比较。采用表面分析技术分析了膜的成分并观察了膜的微观形貌。结果表明，本稀土处理工艺成膜工艺简单，成膜速度快，耐蚀性能略优于Alodine转化膜，能有效地抑制铝合金的点腐蚀。SEM表明铝合金铈转化膜由许多球形颗粒和块状膜构成。EDAX能谱表明，铈转化膜主要含有铈、氧和铝3种元素，球形颗粒含有较高浓度的氧和铈。
关键字: 铝合金； 转化膜； 稀土； 耐蚀性
alloy in trivalent cerium solution
（State Key Laboratory for Corrosion and Protection, Institute of Metal Research,
The Chinese Academy of Sciences, Shenyang 110016, P.R.China）
Abstract:A golden yellow coating was obtained by immersion process on LY12 aluminum alloy surface. The process of cerium conversion coating at normal temperature was developed. The dynamics of coatings formation and its corrosion resistance in 3.5% NaCl solution were studied by electrochemical methods and immersion test, which was compared with traditional Alodine process. The microstructure of the coatings were investigated by scanning electronic microscopy (SEM), and the chemical composition of the coatings was analyzed. Experimental results show that the conversion process is simple and the speed of coatings formation is fast, and the corrosion resistance in 3.5%NaCl solution is sufficient, which is slightly superior to the coatings obtained by Alodine process and effectively inhibites the pitting corrosion of the aluminum alloy. SEM experiment shows that the coatings consist of lots of spherical particles and amounts of lumpish matrix. EDAX results show that the coatings consist of oxygen, cerium and aluminum, and the spherical particles contain higher concentration of cerium and oxygen than the other parts.
Key words: aluminum alloy; conversion coatings; rare earth metal; corrosion resistance
