SiC/SiC composite material wide temperature range thermal protective coating and preparation method thereof

Abstract

The invention relates to a SiC / SiC composite material wide temperature range thermal protective coating. The coating is composed of a transition layer, a hole-sealing layer and an anti-washout layer.The transition layer is made of SiC and SiBCN ceramic prepared through a polymer precursor infiltration and pyrolysis (PIP) technology. The hole-sealing layer is made of SiBCN ceramic prepared througha slurry method and CVD-SiC prepared through a chemical vapor deposition technology. The anti-washout layer is made of a yttrium silicate coating prepared through a molten-salt growth method. The invention further relates to a preparation method of the SiC / SiC composite material wide temperature range thermal protective coating. The coating has excellent thermal shock resistance and antioxidant property in the wide temperature range of 800-1300 DEG C, and has wide application prospects in hot end parts such as aero-engine exhaust nozzles, heat shields and turbine outer rings and thermal protective structures of aircrafts with high Mach number such as leading edges and rudders.

Description

technical field [0001] The invention belongs to the technical field of preparation of thermal protection coatings, and in particular relates to a SiC / SiC composite material wide temperature range thermal protection coating and a preparation method thereof. Background technique [0002] SiC / SiC composite materials have the characteristics of low density, high temperature resistance, high hardness, oxidation resistance, and excellent mechanical properties. It is an ideal material for thermal protection structure of high Mach number aircraft. [0003] However, the current engineering production of raw material SiC fibers has a high carbon content or oxygen content, which limits the oxidation resistance of SiC / SiC composites. In addition, the porosity of SiC / SiC composites prepared by traditional preparation processes (such as chemical vapor deposition process and polymer precursor impregnation cracking process) is relatively high, reaching 5% to 15%, and the oxidation media ox...

AI Technical Summary

Problems solved by technology

Traditional thermal protection coatings are mainly SiC coatings (CVD-SiC coatings) prepared by chemical vapor deposition processes. CVD-SiC coatings are generally used to fill small gaps inside SiC / SiC composite materials, and their oxidation products are at 800 The temperature range of ℃~1000℃ has a loose structure, and it is difficult to seal the penetration path of the oxidizing medium; at the same time, the coating has weak erosion resistance, and it is difficult to maintain structural stability under the impact of gas particles, thermal shock and load shock

SiC / SiC composite aero-engine hot-end components and high-Mach number aircraft thermal protection structures are subjected to gas particle impact, thermal shock and load impact under different working conditions during service, and weak bonding strength and thermal shock resistance can easily lead to thermal shocks. The protective coating has structural defects or even falls off, which loses its protective effect on ceramic matrix composites and seriously affects the performance of materials and components, especially high temperature stability.