镀锌层无铬钼酸盐钝化液的研究进展及思考

镀锌层无铬钼酸盐钝化液的研究进程经历了由钼酸盐+磷酸盐体系发展到该体系加添加剂(无机或有机化合物)的钝化液体系的过程.为了增加钝化膜的膜厚,封闭微裂纹,达到高耐蚀的目的,列举了将无机盐和有机化合物复配以获得复合钝化膜的钝化工艺.其中较为成功的钝化液是钼酸盐与硅烷的复配体系,所获得的钝化膜的性能已接近、达到或超过了铬酸盐钝化膜的耐蚀水平.最后提出了一些尚待解决的问题.

Research Progress in Chromium-Free Molybdate Passivation Solution for Electroplated Zinc and Zinc Alloy Coatings

The passivation technologies for preparing composite passivation films on electroplated Zn and Zn alloy coatings from Cr-free molybdate solution containing formulated inorganic salts and organic compounds were introduced in relation to increasing thickness of the passivation film, sealing micro-cracks and improving corrosion resistance of the film. It was pointed out in the history of study on Cr-free molybdate passivation solution, a transition from molybdate plus phosphate systems to the same systems doped with inorganic and/or organic additives had been involved.One of the most successful passivation solution was molybdate-silane combinatory system, which could be used to prepare passivation films with nearly the same, comparable or better corrosion resistanee as compared with chromate passivation film. Finally,some problems along with Cr-free passivation solution for electroplated Zn and Zn alloy coatings were suggested.