Preparation method of ceramic matrix composite surface priming coat

Abstract

The invention relates to a preparation method of a ceramic matrix composite surface priming coat. A combined method of combining a slurry method with a silicon carbide in-situ reaction process is utilized to realize surface leveling of a composite material, and then a low-pressure chemical vapor deposition process is matched to prepare a silicon-rich silicon carbide priming coat of the environmental barrier coating for SiC / SiC and C / SiC composite materials. The method has the advantages that 1) the proportion of each component in a slurry precursor can be adjusted according to the characteristics of different surface defects to obtain proper viscosity, so that a better defect filling effect is achieved; 2) an integrated reaction of the repair slurry and the composite material through a high-temperature cracking process is realized; 3) a silicon-rich silicon carbide priming coat is obtained on the surface of a composite material by adopting a low-pressure chemical vapor deposition process, so that the quality of the environmental barrier coating is improved, and the service life of the environmental barrier coating is prolonged; and (4) the silicon-rich silicon carbide coating is deposited on the surface of the composite material, so that the temperature resistance and the high-temperature oxidation resistance of the composite material are improved, the bonding strength of the environmental barrier coating and the composite material matrix is enhanced, and the thermal expansion matching of the environmental barrier coating and the composite material matrix is improved.

Description

technical field [0001] The invention relates to a method for preparing a primer layer on the surface of a ceramic matrix composite material. The method uses a combined method of a slurry method combined with a silicon carbide in-situ reaction process to further smooth the surface of SiC / SiC and C / SiC composite materials, and then cooperates with low pressure The chemical vapor deposition process prepares SiC / SiC and C / SiC composite materials with silicon-rich silicon carbide primer layer, which is used as the basis of environmental barrier coating spraying, and belongs to the coating field. Background technique [0002] At present, the service temperature and service performance of traditional superalloy materials are close to the limit, and it is difficult to meet the design requirements of a new generation of advanced aero-engines with high thrust-to-weight ratio and high efficiency. The temperature at the front inlet of the new generation of advanced aero-engine turbine r...

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Problems solved by technology

[0007] Based on the above problems, the purpose of the present invention is to provide a method for preparing a primer layer on the surface of a ceramic matrix composite material, which solves the problems of low bonding strength, short service life, and easy peeling of the coating after spraying the environmental barrier directly on the surface of the composite material. The surface of the composite material is smooth after processing, which improves the coating quality of the environmental barrier coating and realizes integrated design and molding, increases the life of the SiC / SiC and C / SiC composite surface coating system, and has high engineering application value

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