表面硅烷预处理/环氧镁铝复合涂层体系对铝合金的保护性能

摘要

在 LY12铝合金表面制备了一层硅烷膜，研究了硅烷膜对铝合金表面富镁铝环氧涂层性能的影响。硅烷处理后，形成了硅烷膜与基体之间Si-O-Al共价键以及硅烷膜内部的Si-O-Si 结构，而硅烷膜中未成键的硅醇基团-OH 以及 R-的环氧基团与涂层中的有机组分反应成键或通过范德华力发生交联互穿，使铝合金基体与环氧镁铝复合涂层之间形成更加牢固的交联互穿网络结构（IPN），镁铝复合涂层在LY12铝合金基体上的附着力明显提高。马丘测试和电化学阻抗测试结果表明，硅烷处理改善了LY12铝合金表面镁铝复合涂层的整体屏蔽性能，使涂层体系的保护效果显著提高，保护时间延长。%A silane film was formed on LY12 aluminum alloy and the effect of silane pretreatment on the performance of a Mg-Al rich primer on LY12 alloy were studied. After silane treatment, Si-O-Al covalent bonds were formed between aluminum alloy substrate and silane film and Si-O-Si structure was formed in silane film. In addition, silanol groups-OH in free form and epoxy groups from silane film might react with organic fractions in epoxy coating to form cross-linked bonding, and these two types of groups were bonded through van de Waals force, forming an interpenetrating polymer network (IPN) across the interface and providing improved adhesion between aluminum substrate and silane film. Machu test and electrochemical measurements indicated that silane pre-treatment significantly improved the performance of the Mg-Al rich primer on LY12 alloy, which was attributed to strengthened barrier effect of the coating system.