A silane film was formed on LY12 aluminum alloy and the effect of silane pretreatment on the performance of a Mγ-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 Mγ-Al rich primer on LY12 alloy
which was attributed to strengthened barrier effect of the coating system.