Carbon/carbon/silicon carbide composite material and preparation method

Abstract

The invention discloses a carbon / carbon / silicon carbide composite material with a simple preparation technology and silicon steam corrosion resistance, and a preparation method. The carbon / carbon / silicon carbide composite material is characterized by being prepared by a process that a carbon fiber prefabricated body is machined and purified after being subjected to pyrolytic carbon and silicon carbide alternating densification or pyrolytic carbon and silicon carbide mixing densification with a chemical vapor infiltration method. The density of the carbon / carbon / silicon carbide composite material is 1.3-2.5g.cm<3>, the flexural strength is more than or equal to 300MPa, and the fracture toughness is more than or equal to 15MPa.m<1 / 2>. According to the carbon / carbon / silicon carbide composite material disclosed by the invention, corrosion on the core part carbon fiber of the carbon / carbon / silicon carbide composite material by silicon steam can be effectively inhibited. The flexural strength of the prepared carbon / carbon / silicon carbide composite material is more than 300MPa which is 2-5 times of that of carbon / carbon composite material, the fracture toughness is more than or equal to 15MPa.m<1 / 2>, the silicon steam corrosion resistance capability is improved by 5-10 times in comparison with that of the carbon / carbon composite material, and the service life of the carbon / carbon / silicon carbide composite material is drastically prolonged. Meanwhile, the higher strength of the carbon / carbon / silicon carbide composite material is favorable for improving the safety of a thermal field.

Description

technical field [0001] The invention relates to a composite material and a preparation method, in particular to a carbon / carbon / silicon carbide composite material and a preparation method, in particular to a carbon / carbon / silicon carbide composite material for high-temperature furnaces and a preparation method. Background technique [0002] Carbon / carbon composite material is one of the advanced composite materials widely used at present. It is a composite material formed by carbon fiber or various carbon fabrics to reinforce the carbon matrix. It has low density, high specific strength, wear resistance, high temperature resistance, and thermal expansion. Excellent performance such as small coefficient. The material is usually made of carbon fiber mesh tire and mesh tire, or carbon cloth and carbon cloth, or mesh tire and carbon cloth are composited into a carbon fiber prefabricated body by alternately stacking needle punching, and then the prefabricated body is put into a c...

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Problems solved by technology

The literature points out that it is difficult to prepare high-density C / SiC or C / C-SiC composite materials by using a single CVI method, but it is possible to prepare high-density C / SiC or C / C-SiC composite materials by using a single PIP method or CVI+PIP method. For C-SiC composite materials, however, a certain amount of Si will remain in the PIP process, and the free Si will inevitably react with the carbon fibers, causing damage to the carbon fibers in the reinforcing phase, resulting in a decrease in the toughening and reinforcing effect of the carbon fibers, thereby improving the overall performance of the material. Decrease, especially the substantial reduction in mechanical strength, leading to catastrophic fracture of the material

At the same time, its process is complex and requires repeated dipping

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