Preparation method of HfC-SiC modified carbon/carbon composite material

Abstract

The invention discloses a preparation method of an HfC-SiC modified carbon / carbon composite material and can be used for solving the technical problem that a composite material prepared by adopting the existing carbon / carbon composite material preparation method has poor mechanical properties. According to the technical scheme, an organic precursor solution containing hafnium and silicon is utilized, a porous carbon / carbon composite material is impregnated under the vacuum condition at normal temperature, then heat treatment is carried out at a high temperature, a series of chemical reactions are carried out, so that a carbon / carbon composite material containing HfC and SiC is obtained, and finally a high density HfC-SiC modified carbon / carbon composite material is obtained after cyclic impregnation and heat treatment is carried out. The preparation method of the HfC-SiC modified carbon / carbon composite material has the advantages that the porous carbon / carbon composite material is prepared by adopting a thermal gradient chemical vapour deposition method, and a thermolysis carbon layer is formed on carbon fibers, so that the carbon fibers are protected and can not be damaged; and a polycarbosilane precursor liquid phase impregnation pyrolysis method is adopted, SiC can be doped into a material, wettability between HfC ceramic and a matrix is improved, density is increased, and erosion resistance of the composite material is further improved.

Description

technical field [0001] The invention relates to a preparation method of carbon / carbon composite material, in particular to a preparation method of HfC-SiC modified carbon / carbon composite material. Background technique [0002] Carbon / carbon composite materials have a series of advantages such as low density, high specific strength, high modulus and low thermal expansion coefficient. They are widely used in aerospace high-temperature components. They have the ability to resist erosion, high temperature and oxidation, and can reduce the weight of components. With the rapid development of new aircraft, the requirements for solid rocket motors are more stringent, and the ablation resistance of carbon / carbon composites needs to be further improved. Relevant studies have shown that introducing refractory metal carbide HfC into carbon / carbon composites can Improving its anti-ablation performance, while introducing SiC can improve the wettability of HfC and the substrate, and furth...

AI Technical Summary

Problems solved by technology

However, in this method, because the precursor is directly added to the carbon fiber prefabricated body, the carbon fiber is seriously damaged during the heat treatment process, and at the same time, due to the poor wettability of HfC and the matrix, the pyrolytic carbon peels off seriously during the ablation process.

[0005] In the process of preparing HfC modified carbon / carbon composite materials in the prior art, the introduction of HfC is mainly to soak the carbon fiber prefabricated body directly in the metal salt solution containing Hf. This kind of method seriously damages the carbon fiber, resulting in The mechanical properties of HfC ceramics are greatly reduced, and because of the poor wettability of HfC itself and the substrate, the bonding strength between HfC and carbon is weak, and the high temperature ablation resistance of HfC ceramics cannot be fully utilized.

Moreover, due to the thermal expansion mismatch between the matrix material and the fiber, the residual thermal stress of the composite material is relatively large, which affects the ablative performance of the material

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