Silane-incorporated epoxy coatings on aluminum alloy (AA2024). Part 1: Improved corrosion performance

• SECM was used for corrosion performance evaluation of silane-incorporated superprimers.
• Organosilanes dramatically improve corrosion performance of epoxy coatings.
• Silane incorporation reduces water and ions uptake and swelling of epoxy coatings.
• Silane incorporation improves adhesion of organic coatings.

This work consists of two parts. In the first part, adhesion property and corrosion performance of silane-incorporated epoxy coatings were systematically studied by pull-off test, salt spray test, electrochemical impedance spectroscopy and scanning electrochemical microscopy. The results showed that the silane agents, both the “active” γ-aminopropyltrimethoxy silane and the “non-active” bis-1,2-[triethoxysilyl]ethane not only reinforce the cross-linking of epoxy coatings but also strengthen the bonding at the coating/metal interface. These lead to better adhesion, less water uptake and swelling, and enhanced corrosion resistance of the coatings.