Technology and equipment for preparing C/C composite

Abstract

The invention discloses a technology and equipment for preparing a C / C (carbon / carbon) composite. The technology for rapidly preparing the C / C composite comprises the following steps that (1) a preform is pretreated; (2) tools are prepared; (3) furnace loading is conducted; (4) temperature gradient differential CVI (chemical vapor infiltration) treatment is conducted; (5) heating of a heating element and input of mixed gas are stopped sequentially after 100-300h; and (6) a cover plate, the outer tool, the preform and the inner tool are taken out to form the C / C composite with density of 1.4-1.7g / cm<3>. The invention further discloses the equipment for preparing the C / C composite. According to the technology and the equipment, the operation is simple; the densification period is short; the industrial difficulty is small; the densification rate is high; ineffective reaction can be avoided; the carbon yield can be increased; and pollution of a vacuum system can be prevented.

Description

technical field [0001] The invention relates to a process and equipment for rapidly preparing carbon / carbon (C / C) composite material parts by using a temperature gradient pressure difference chemical vapor phase infiltration method (CVI). Background technique [0002] The current main process for preparing C / C composites is the isothermal CVI process, which is simple and easy to operate, and can simultaneously densify multiple prefabricated bodies of different sizes and shapes. / C composites have potential. However, during the preparation process using the isothermal CVI process, pyrolytic carbon will be preferentially deposited on the surface of the preform, which will prematurely close the pores on the surface of the preform and affect its internal densification. Usually, it is necessary to use low temperature and low gas concentration to reduce the reaction speed. And multiple mechanical processing to remove the surface crust to open the pores, so the preparation cycle o...

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Problems solved by technology

However, the material from the precursor to the preform still mainly depends on its diffusion, the gas transmission is slow, and the densification rate of the material is low.

[0004] The confined variable temperature and pressure difference chemical vapor infiltration process disclosed in Chinese patent 00113718.2 and the method for rapidly preparing C / C composite materials disclosed by temperature gradient chemical vapor infiltration in Chinese patent 200510096306.2 both involve the temperature gradient and pressure difference chemical vapor infiltration process, but they are High equipment requirements and difficult industrialization

Chinese patent 200310115118.0 discloses a carbon brake disc negative pressure directional flow out temperature gradient chemical vapor infiltration method, but this method is only suitable for the preparation of carbon brake discs and not for the preparation of cylindrical parts, and the scope of application is small

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