Repairing method of SiC/SiC ceramic-based composite material

Abstract

A repairing method of a SiC / SiC ceramic-based composite material comprises the following steps: polishing the surface of a test sample, cleaning and drying, corroding the test sample by HF, cleaning and drying, ultrasonically cleaning, drying and soaking into a catalyst solution prepared from iron, cobalt or nickel, performing vacuum drying, wrapping the test sample with graphite paper and only exposing a fracture; and putting the test sample into a vacuum furnace, introducing methyltrichlorosilane, H2 and Ar, preserving heat for 5 to 20 hours, closing methyltrichlorosilane and H2, preservingheat for 10 to 100 minutes, closing Ar, introducing NH3, BCl3, H2 and N2, preserving heat for 5 to 20 hours, closing NH3 and BCl3, introducing methyltrichlorosilane and H2, preserving heat for 50 to 300 hours, taking out the test sample, removing the graphite paper, polishing and repairing the surface, putting the treated sample into the vacuum furnace, introducing methyltrichlorosilane, H2 and Ar, preserving heat for 5 to 30 hours, and spray-coating a composite coating consisting of yttrium silicate and mullite by a plasma spray-coating method. Main injury that the SiC / SiC composite materialis liable to generate can be repaired, the material composition is not changed after repairing, and the anti-oxidation property of the material under the high-temperature environment is improved.

Description

technical field [0001] The invention relates to a repair method of a ceramic matrix composite material, in particular to a repair method of a SiC / SiC ceramic matrix composite material. Background technique [0002] SiC / SiC ceramics are the most ideal new-generation high-temperature structural materials in the fields of aerospace and atomic energy. It is applied to the structural components of aerospace engines, can be used at ultra-high temperatures, has low density and high strength, and can significantly increase the thrust-to-weight ratio of the engine. It is used as a reactor wall material for atomic energy reactors, which has good stability, easy maintenance, safety and reliability. high. Therefore, many countries have carried out research on the application of materials to high-temperature thermal structural components, and achieved fruitful results. [0003] The main application fields of SiC / SiC are often related to high-temperature environment, which may affect th...

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Problems solved by technology

[0003] The main application fields of SiC / SiC are often related to high-temperature environment, which may affect the occurrence and evolution of subsequent oxidation damage. In addition to the thermal mismatch cracks generated during the preparation process, SiC / SiC will also suffer from high-temperature oxidation during service. Thermal damage cracks are generated due to the mismatch of thermal expansion coefficients. These cracks will lead to a decrease in the high-temperature oxidation resistance of ceramic matrix composites, which will cause premature failure and even catastrophic failure of components during repeated use.