Corrosion behavior of microarc oxidized CeO₂-Al₂O₃ composite coatings on 2A12 Al alloy Available to Purchase

Ceramic oxide ceramic coatings was fabricated on the surface of 2A12 aluminum alloy by microarc oxidation technology with different cerium tartrate contents (0, 0.75, 1.50, 2.25, 3.00 g/l) in the compound electrolyte. To analyze the microstructure and elemental composition of the MAO oxide ceramic coatings, scanning electron microscopy, X-ray diffraction, and energy dispersive spectroscopy were applied. The thickness of the coatings was measured by a coating thickness gauge. The influence of cerium tartrate addition on the cavitation erosion resistance of the samples was studied by measuring the weight change of the sample in the cavitation experiments. The effect of cerium tartrate addition on the corrosion resistance of microarc oxidation ceramic coating was studied through the electrochemical workstation, using two detection methods of the Tafel curve and electrochemical impedance spectroscopy curve and using an equivalent circuit to fit the impedance data. The results show that with the increase of cerium tartrate, the thickness of the ceramic coatings increased and the cavitation erosion resistance occurred fluctuations. The optimal corrosion resistance was obtained when the concentration of cerium tartrate was 1.5 g/l in electrochemical and cavitation erosion tests.