High-temperature oxidation behavior of CeO₂-doped MAO coatings on TC4 titanium alloy

Abstract

To improve the surface micropores and high-temperature oxidation resistance of micro-arc oxidation (MAO) coating on TC4 titanium alloy, cerium dioxide (CeO2) particles were introduced into the electrolyte to prepare MAO composite coatings with different CeO2 content. X-ray diffractometer, scanning electron microscope and multifunctional material surface performance tester were used to analyze the phase composition, surface morphology and bonding force of the samples. TC4 substrate, undoped MAO sample and optimally doped MAO sample were oxidized at 650°C, 750°C and 850°C respectively. The results show that the best doped MAO samples show excellent high-temperature oxidation resistance at three temperatures. Compared with the undoped MAO sample, the maximum oxidation weight gain per unit area of the optimally doped MAO sample decreased by 10.8%, 19.6% and 22.1%, respectively. This is mainly because the thickness, hardness and adhesion of MAO coating are all increased by doping CeO2 particles, and a dense protective layer can also be formed on the surface of TC4 substrate. The invasion of oxygen medium is effectively prevented. In this research work, the optimal addition amount of CeO2 is 6 g/L.

Study on the structure and corrosion resistance of MoS2/MgO micro-arc oxidation composite ceramic coating on the surface of ZK60 magnesium alloy

“…Micro-arc oxidation (MAO) is the process of forming ceramic coatings on metal surfaces by electrochemical methods. Due to its excellent bonding with the base metal, high hardness, good insulating properties and high resistance to high temperatures, corrosion and friction damage, it has garnered significant attention (Chen et al , 2023).…”