SiCf/SiC ceramic-based composite material with composite interfaces

Abstract

A SiCf / SiC ceramic-based composite material with composite interfaces is characterized by comprising CVD-SiC coating, a PIP-SiC matrix, the composite interfaces and SiC fiber, wherein the CVD-SiC coating is silicon carbide coating prepared through a chemical vapor deposition method, and has the thickness of 100-500 microns; the composite interfaces are formed by alternately and periodically overlapping any two or three of a BN interface, a ZrO2 interface, an LaPO4 interface and an SiC interface, and the cycle period frequency is 3-5 times; the PIP-SiC matrix is silicon carbide formed through in-situ pyrolysis of polycarbosilane; the SiC fiber accounts for 40-60% of the composite material by volume, a pyrolytic carbon layer with the thickness of 5-20 nanometers is formed on the surface thereof. A preparation method comprises the following steps: preparing multiple layers of composite interfaces on the surface of the silicon carbide fiber by different preparation processes, then fillingthe SiC matrix by a PIP method, and finally preparing the surface SiC coating by a CVD method. The SiCf / SiC ceramic-based composite material prepared through the preparation method provided by the invention is high in toughness and strong in antioxidant capacity, and the preparation process is simple.

Description

technical field [0001] The invention relates to a ceramic matrix composite material and a preparation method thereof, in particular to a SiC composite interface f / SiC ceramic matrix composite material and preparation method thereof. Background technique [0002] SiC ceramics have the potential to replace metals as a new generation of high-temperature structural materials because of their excellent properties such as high temperature resistance, low density, high specific strength, high specific modulus, oxidation resistance and corrosion resistance. In addition, due to its excellent semiconductor characteristics and relatively stable dielectric properties at high temperatures, SiC also has a good application prospect in microwave absorbing materials. However, due to the low fracture toughness of SiC single material, which manifests as brittle fracture, its application is limited. At present, it has been gradually adopted by SiC f / SiC composite material replaced. Contin...

AI Technical Summary

Problems solved by technology

[0009] Although the BN interface, ZrO 2 The interface can improve the oxidation resistance of the composite material to a certain extent, but the use temperature of the pure BN interface is still low, and the pure ZrO 2 Interfacial phase transformation toughening is limited and cannot play the role of deflecting cracks