变形铝合金表面锆基化学转化膜的研究现状

化学转化膜是金属表面主要的处理方法之一，具备良好的附着力和耐蚀性，能为铝合金提供一定的临时防护。传统的六价铬酸盐化学转化膜在日渐严苛的环保压力下已经逐渐淘汰，取而代之的是近几年发展迅猛的三价铬及无铬锆基化学转化膜。铝合金可分为铸造铝合金和变形铝合金，按照所含主要合金元素和热处理状态可分为若干个系列和型号。本文选取几种典型的变形铝合金，综述了不同铝合金微观组织对转化膜成膜过程的影响，化学转化液添加剂、预处理和后处理工艺对转化膜性能的调控及作用机理，以及几种典型商业钝化剂在变形铝合金表面的应用。总结了目前变形铝合金表面锆基化学转化膜仍面临的问题和发展趋势，未来化学转化膜需在满足新型铝合金发展要求的基础上，通过不同有机、无机添加剂以及外场作用对转化膜的成膜均一性、完整性进行调控，以提高转化膜的综合性能。

Research progress of zirconium-based chemical conversion coatings on typical wrought aluminum alloys

Chemical conversion coating is an important surface treatment method of aluminum alloy, which has good adhesion and corrosion resistance and can provide temporary protection for aluminum alloy surface. The traditional hexavalent chromate chemical conversion coatings has been gradually eliminated under the increasingly severe environmental pressure and replaced by the rapid development of zirconium-based chemical conversion coating in recent years. Aluminum alloy can be divided into cast aluminum alloy and wrought aluminum alloy. According to the main alloy elements and heat treatment status, it can be divided into several series and models. In this paper, the influence of the microstructure of several typical wrought aluminum alloys on the conversion coating forming process, the regulation of passivation solution additives, pretreatment and post-treatment process on the corrosion resistance of the conversion coating and the application of several typical commercial passivators on the surface of the aluminum alloy were reviewed. Finally, the problems and development trend of zirconium-based chemical conversion coating on aluminum alloy surface were summarized. On the basis of meeting the requirements of the development of new aluminum alloy, the uniformity and integrity of the conversion coating should be regulated by different organic and inorganic additives and field effect, so as to improve the comprehensive performance of the conversion coating.