Beta-type silicon carbide protective layer coated RB-SiC composite material and preparation method thereof

Abstract

The invention relates to the technical field of preparation of silicon carbide composite materials, in particular to a beta-type silicon carbide protective layer coated RB-SiC composite material and a preparation method. Comprising the following steps: preparing a silicon carbide preform from silicon carbide powder; carrying out high-temperature degreasing and degumming treatment on the silicon carbide preform at 600-1000 DEG C to obtain a porous silicon carbide preform; placing the porous silicon carbide preform in a cracking furnace, and carrying out chemical vapor infiltration in a flowable mixed gas atmosphere to obtain a beta-type silicon carbide protective layer; selectively processing a siliconizing channel with the depth of 50-200 microns on the non-service surface of the preform; the prefabricated body is subjected to reactive sintering densification treatment, the sintering temperature ranges from 1420 DEG C to 1700 DEG C, and the heat preservation time ranges from 3 h to 24 h; and cooling to room temperature after sintering. The method has the advantages that silicon in RB-SiC is prevented from being exposed to a service environment, and material failure is avoided; and the dimensional precision of the component structure is not reduced while the high-performance protective layer is prepared.

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