Studies on solution-derived ceramic coatings for oxidation protection of carbon-carbon composites Original Research Article

Carbon-carbon composites have been coated with silica and zircon prepared by sol-gel technique and with methylsilsesquioxane, a preceramic polymer. The effect of processing parameters for preparation of the sols and coating procedure on coating morphology has been studied. Oxidation behaviour of uncoated and coated carbon-carbon composites has been studied. Coatings with continuous and uniform structure, obtained by controlled processing, have been found to give effective oxidation protection. Zircon coatings are found to have better oxidation resistance than silica coatings. Coating of the composites with methylsilsesquioxane and subsequent pyrolysis results in the formation of silicon-oxy-carbide coatings. These coatings are found to provide very effective oxidation resistance at high temperature up to 1200 °C.