Silane Treatment And Corrosion Studies On Metal Surface

LY12aluminum alloy is widely used in aerospace industry due to its highstrength, but the problem of the existence of high alloy elements, such as Cu cause theworldwide attention, because these elements can decrease the corrosion resistance anddo harm to the substrates. Silane treatment is considered as environmental friendlyreplacements for the existing chromate and phosphate processes. It attracts theattention of many industries because silanes are known as good coupling agents,conferring in addition, corrosion protection. Moreover they seem to comply withenvironmental issues.The primary focus of our research is to prepare BTSE silane films andKH69/KH170mixture silane films on LY12aluminum alloy using silane treatment.The FTIR analysis showed the presence of Si-OH and Si-O-Si, which was inconsistent with the chemical bonding theory.The BTSE films thickness increased withBTSE concentration,but increasing immersion time was useless.The electrochemicalanalysis showed that the corrosion resistence of BTSE films would decrease when itsurpassed the critical concentration, since the highly BTSE concentration would causeflocculation. The7%BTSE film possessed the best corrosion resistence in ourresearch.In this research, we also incorporated KH560silane directly intoepoxy/polyamide systems and then applied onto tinplate to reinforce the surface. Wefound that the water absorption in epoxy coatings decreased drastically afterincorporated with silane component compared to the untreated coating. With theincrease of silane content, water absorption of epoxy coatings passed through aminimum, corresponding to9%of silane incorporation. The self-repairing effect dueto the hydrolysis and condensation of silane agents is proposed to explain thisphenomenon.