Tool for compacting thick-walled hollow carbon/carbon (C/C) composite product

Abstract

The invention discloses a tool for compacting a thick-walled hollow carbon / carbon (C / C) composite product, which comprises an outer barrel, a gas inlet substrate and a gas guide device, wherein the interior of the outer barrel is provided with a gas inlet basal plate; a cavity I is formed between the gas inlet substrate and the gas inlet basal plate; the gas inlet substrate is provided with a gas inlet; the top face of the gas inlet basal plate is provided with an inner barrel; a to-be-compacted thick-walled hollow C / C composite preform is sheathed onto the inner barrel; a gap I for the circulation of gas is formed between the outer surface of the C / C composite preform and the inner surface of the outer barrel; a gap II for the circulation of the gas is formed between the inner surface of the C / C composite preform and the outer surface of the inner barrel; and the gas inlet basal plate is provided with a plurality of diversion passages II and diversion passages III, wherein the diversion passages II are used for communicating the cavity I with the gap I, and the diversion passages III are used for communicating the cavity I and the gap II. According to the tool for compacting the thick-walled hollow C / C composite product, gas diversion can be performed, and thereby, the retention period of pyrolysis gas in a depositing space is shortened, and the C / C composite preform is rapidly and evenly compacted.

Description

technical field [0001] The invention relates to a dense tooling, in particular to a dense tooling for thick-walled hollow C / C composite material products. Background technique [0002] C / C composite material, that is, carbon fiber reinforced carbon-based composite material, is a high-performance material with the characteristics of light weight, high strength, high modulus, high dimensional stability, high chemical stability and high temperature resistance. It is widely used in high-tech fields such as aerospace, high-speed trains, and thermal field materials. Studies have shown that the mechanical / ablative properties of C / C composites vary with the amount of pyrolytic carbon they contain. With the increase of pyrolytic carbon content, the compression, shear and ablation resistance properties of the material are greatly improved. [0003] Chemical vapor infiltration (CVI) is a traditional method for preparing pyrolytic carbon. Due to the low decomposition temperature of c...

AI Technical Summary

Problems solved by technology

Due to the low decomposition temperature of conventional cracked gas (such as propylene) and its large molecular weight, it is easier to deposit on the outside of the C / C composite material preform in the soaking deposition process, thereby affecting the flow of cracked gas to the C / C composite material preform. Further diffusion inside, eventually leading to the inability to achieve rapid and uniform densification

[0004] In the traditional soaking CVI densification process, there are few special designs for the deposition space, which can easily cause the gas flow state to be disordered, and the reaction gas cannot flow out of this space immediately, thus forming a large hydrocarbon gas intermediate product. The product is more likely to produce by-products such as carbon black, and the density difference between the inside and outside of the product is large, which prolongs the densification cycle of pyrolytic carbon and affects the uniformity of its distribution state

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