Adaptability of sol-gel anti-corrosion coating on different metallic substrates

Abstract

In this paper, the adaptability of sol-gel anti-corrosion coating applied in space station on different metal substrates, such as aluminium, titanium, steel and copper, has been analysed, and anti-corrosion performances of the sol-gel coating have been evaluated here. The electro-chemical properties of the coating on different substrates are tested by potentiodynamic polarization curves and AC impedance spectroscopy. The results show that the anticorrosive effect of the sol-gel coating on titanium, steel and copper substrate is obviously better than that of aluminium alloy. For different designations of aluminium alloy, the anti-corrosion effect of 2A12 Al alloy is better than that of 5A06 Al alloy, which may be related to the metal composition in the substrate. The corrosion resistance of 2A12 containing Cu is better than that of 5A06 series containing Mg. This study will provide references for the application of sol-gel anticorrosion coating and surface anticorrosion of aerospace products.