A method for preparing a diamond high-temperature oxidation-resistant silicon-based coating

Abstract

The application discloses a preparation method of a diamond high-temperature oxidation-resistant silicon-based coating, and relates to the technical field of coating preparation.The method comprises the following steps: after diamond powder is activated, the diamond powder is soaked through a dispersion liquid, a composite sol and a protective sol respectively, and then is treated through a muffle furnace and a high-pressure atmosphere furnace to obtain the diamond high-temperature oxidation-resistant silicon-based coating.In the application, the soaking through the composite sol relies on a three-dimensional interpenetrating network structure constructed by multi-walled carbon nanotubes to play a toughening effect of bridging, pulling out and crack deflection, and meanwhile, the nano-rivet effect of silicon carbide nanocrystals is used to pin the internal micro-cracks of the coating, so that the fracture toughness and the impact resistance of the coating are significantly improved.In addition, a firm chemical bond is formed between the inner silicon carbide transition layer and the outer yttrium oxide-silicon nitride protective layer, the interface integrity of the gradient coating is strengthened, the oxygen permeation is blocked by the outer layer, the volatilization loss of the coating components at high temperature is reduced, and the high-temperature oxidation resistance and the structural stability of the coating are comprehensively ensured.

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