A treatment method for improving the service temperature and performance of silicon carbide fiber

Abstract

The invention relates to a treatment method for improving the use temperature and performance of SiC fibers, which is characterized in that two treatment methods are used, one of which is to immerse commercially available SiC fibers in a 15-35vol% organic polymer solution and dry After winding on the graphite tube, heat treatment in a high-temperature furnace at 30-200Mpa, 1600-2000°C in an argon atmosphere, so that the carbon formed by the pyrolysis of the organic polymer and the SiO decomposed by the SiC fiber under high temperature and low pressure are in situ Reaction to generate SiC; another method is to directly wind SiC on the graphite cylinder, and use the same heat treatment conditions as described in the first method to make free carbon in the fiber react with SiO in situ to generate SiC. The characteristics of the present invention avoid SiC fiber Degradation at high temperature leads to performance attenuation, and the oxygen content of the SiC fiber drops from 21wt% to 5wt% after being treated by the method provided by the invention.

Description

A treatment method for improving the service temperature and performance of silicon carbide fiber technical field The invention relates to a treatment method for improving the properties of ordinary SiC fibers, increasing their use temperature and performance, more precisely, relates to a treatment process for ordinary SiC fibers to avoid degradation at high temperatures, and belongs to the field of preparation technology of ceramic matrix composite materials. Background technique High-performance silicon carbide ceramics have high strength and high hardness, and the strength can be maintained up to 1600 ° C. It has good oxidation resistance, high thermal conductivity, acid and alkali corrosion resistance, low thermal expansion coefficient and good thermal shock resistance, etc. , Widely used in industry and national defense military industry. By reinforcing SiC ceramics with fibers, the fracture toughness of SiC ceramics can be improved, so that the composite material has...

AI Technical Summary

Problems solved by technology

In addition, the amorphous microstructure makes it unstable at high temperature. As the temperature increases, crystallization and grain growth will also destroy the microstructure of the fiber and cause fiber degradation.

This non-stoichiometric, oxygen-containing amorphous fiber greatly limits the application of SiC fibers

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