Composite triazole-containing PEO-coatings for effective corrosion protection of AlMg3 aluminum alloy

The study considers composite coatings formed on the AlMg3 aluminum alloy, consisting of PEO-coatings impregnated with corrosion inhibitors, 1,2,4-triazole and benzotriazole, in various concentrations. The morphology and composition of the resulting coatings were studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The increase in the protective properties of composite coatings was studied by electrochemical impedance spectroscopy (EIS). SEM-images showed that the coatings have a self-assembled microtubular structure with a tube diameter varying from 300 to 500 nm and average tube height of 9 µm. EIS results showed that samples with composite inhibitor containing PEO-coatings have better protective properties compared to pure aluminum alloy and base PEO-layer. An increase in the concentration of inhibitors of the triazole group from 0.05 M to 0.1 M during impregnation into a PEO-coating leads to a decrease in the corrosion resistance of the samples with composite coatings.