LY12铝合金钼酸盐转化膜研究

利用浸渍法在LY12铝合金表面获得了深黄色的钼酸盐耐蚀转化膜。结果表明，本处理工艺简单，成膜速率快，铝合金的耐蚀性大为提高，具有较好的抗点腐蚀性能。扫描电镜（SEM）分析表明，膜的微观形态由大小不一的球形颗粒构成。X射线光电子能谱（XPS）实验表明，转化膜表层中钼主要以MoO2形式存在，并含有少量的MoO3，在膜的内层钼以正4价形式存在。并讨论了钼酸盐转化膜的成膜机理及耐蚀机理。

The Molybdate Conversion Coatings on LY12 Aluminum Alloy

A deep yellow-color molybdate conversion coating on LY12 aluminum alloy surface was obtained by immersion process. The experimental results showed that the treating process was simple and the speed of formation of the coatings was fast, and the corrosion resistance of aluminum alloy greatly increased. The treated sample had a good pitting corrosion resistance in 3.5%NaCl solution. SEM experimental results show that the conversion coatings consist of spherical particles differing in size. XPS analysis indicates that the composition of outer layer of the coatings consist of MoO2 and a spot of MoO3.The molybdenum exist in the inner layer of conversion coating in the form of tetravalent status. The mechanisms of coatings formation and corrosion resistance are discussed.