Oxidation and Corrosion Resistance of Graphene-modified Silicon Oxide Coating

Abstract

Abstract The thermal corrosion resistance of nickel-based GH4413 alloy at the service temperature of 660 °C and the oxidation behavior at 600–700 °C after graphene modified silicon coating were studied. The morphologies and types of corrosion and oxidation products after thermal salt corrosion and constant temperature oxidation were analyzed by scanning electron microscopy, energy spectrum, X-ray diffraction, and X-ray photo electron spectroscopy. The resistance of thermal corrosion and oxidation of graphene-modified silicon coating was evaluated. The results show that compared with the uncoated sample, the weight loss during thermal corrosion of the coated sample at 660 °C is lower than that of the uncoated sample. The coating partially peels off after salt corrosion up to 500 h at 660 °C. The O element diffuses into the matrix to form fine oxides, and the coating still plays a protective role on the matrix. After oxidation at 600–700 °C to 3000 h, the dense layer of Al2O3 and TiO2 and a small amount of Cr2O3 appear at the interface between the coating and the matrix without loose harmful oxidation product. The addition of graphene reduces the chemical activity of the silicon coating and makes the coating denser. Therefore, the GH4413 alloy after the graphene-modified coating has excellent resistance to thermal corrosion and oxidation at its service temperature.