Method for preparing multiphase ceramics by introducing zirconium carbide by using sol-gel method

Abstract

The invention provides a method for preparing silicon boron carbon nitrogen-zirconium carbide multiphase ceramics by introducing second phase zirconium carbide at high temperature by using a sol-gel method, belonging to the technical field of silicon boron carbon nitrogen ceramic-based composite materials. According to the method, zirconium n-propoxide, furfuryl alcohol, hydrochloric acid, acetylacetone and ethanol are taken as raw materials; a mass ratio of the second phase, introduced by the sol-gel method, to silicon boron carbon nitrogen is equal to (5 to 20): 100; a molar ratio of the zirconium n-propoxide to the furfuryl alcohol to the hydrochloric acid is equal to 1 to 2 to 1; a mass ratio of silica powder to hexagonal boron nitride powder is equal to 1: (0.1 to 1.2). The method comprises the steps of preparing a zirconium carbide precursor solution; preparing silicon boron carbon nitrogen ceramic composite powder; preparing a powder precursor; preparing powder; finally, putting the powder into a hot-press and carrying out hot pressed sintering, wherein the sintering temperature is 1900 DEG C, the sintering time is 60min, the sintering pressure is 60MPa, and the sintering atmosphere is argon. The precursor introduced by the sol-gel method is subjected to a carbothermal reduction reaction so as to generate zirconium carbide, so that the whole performance of a silicon boron carbon nitrogen matrix is maintained.

Description

technical field [0001] The invention relates to a method for preparing a silicon-boron-carbon-nitrogen ceramic-based composite material by introducing ultra-high-temperature second-phase zirconium carbide through a sol-gel method, and belongs to the technical field of silicon-boron-carbon-nitrogen ceramic-based composite materials. Background technique [0002] The covalent bond structure of the silicon-boron-carbon-nitrogen ceramic material itself endows it with high thermal stability, high temperature oxidation resistance, high temperature creep resistance, etc., and it has the advantages of low density and low elastic modulus. It is a new type of Multi-functional high-temperature heat-resistant material, used for nose cone cap, wing leading edge, rudder surface, cover plate and nozzle of spacecraft, etc. However, in practical applications, there is room and demand for further improvement of its high temperature performance. Zirconium carbide ceramics have the advantages ...

AI Technical Summary

Problems solved by technology

However, in practical applications, there is room and demand for further improvement of its high temperature performance.

Zirconium carbide ceramics have the advantages of high melting point, high strength, high hardness, etc., but their sinterability is poor

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