Highly-oriented highly-heat-conducting carbon/carbon composite material and preparation method thereof

Abstract

The invention relates to a highly-oriented highly-heat-conducting carbon / carbon composite material and a preparation method thereof. The technical scheme is as follows: the method comprises the following steps of: oxidizing and stabilizing large-section strip-shaped intermediate phase pitch fiber which serves as a raw material; uniformly coating an adhesive on the surface of the oxidized and stabilized strip-shaped intermediate phase pitch fiber, wherein the adhesive accounts for 4 to 20wt% of raw materials; tiling the strip-shaped intermediate phase pitch fiber coated with the adhesive is coated in a mold in a unidirectional mode and performing hot-forming; and finally, carbonizing at the temperature of between 1,000 and 1,600 DEG C and graphitizing at the temperature of between 2,800 and 3,100 DEG C, so as to obtain the highly-oriented highly-heat-conducting carbon / carbon composite material. In the scheme, the cross section of the large-section strip-shaped intermediate phase pitch fiber has a shape of an approximate rectangle which has the width of 1 to 2 millimeters and the thickness of 8 to 20 microns; the hot-forming temperature is 300 to 700 DEG C; the hot-forming pressure is 5 to 20MPa, and the temperature and the pressure are kept for 1 to 24 hours. The method has the advantages of being simple in preparation process, low in cost, high in repeatability and short in production cycle, and the composite material prepared by using the method has the highly-oriented and highly-heat-conducting characteristics.

Description

technical field [0001] The invention belongs to the technical field of carbon / carbon composite materials. In particular, it relates to a carbon / carbon composite material with high orientation and high thermal conductivity and a preparation method thereof. Background technique [0002] With the rapid development of science and technology, efficient heat conduction and heat dissipation have become key issues in the field of thermal management. For example, if a hypersonic vehicle flies at an altitude of 20-100 km above the ground, in order to reduce the difficulty of heat protection of the vehicle, it is necessary to conduct or absorb the heat generated during the flight as soon as possible to improve the heat dissipation efficiency of the vehicle; communication satellites use high power density Plasma materials used in devices and nuclear fusion devices will generate and accumulate a large amount of heat during operation. In order to ensure the stable operation of the equipm...

AI Technical Summary

Problems solved by technology

In terms of heat conduction efficiency, preparation process simplicity and production cost, one-dimensional carbon / carbon composite materials are undoubtedly the most advantageous. The commonly used preparation method is to use circular cross-section mesophase pitch continuous carbon fibers as raw materials, and use pitch as a binder. And through preforming, impregnation, carbonization, densification and graphitization (Qiu Haipeng, Song Yongzhong, Guo Quangui, etc. High thermal conductivity carbon fiber and its carbon-based composite [J]. Functional Materials, 33, 5), but the The thermal conductivity of the prepared material is greatly affected by factors such as the crystal structure, filling rate (40~65%), distribution and orientation of the round fiber

"A preparation method of high thermal conductivity mesophase pitch-based carbon material" (CN200410064588.3) patented technology, in order to solve the influence of matrix carbon (pitch binder) on heat conduction, moderate pre-oxidation (that is, incomplete oxidation, retaining part The mesophase pitch fibers of bonding components) are directly subjected to hot molding, and then carbonized and graphitized to obtain high thermal conductivity carbon materials. Although the use of pitch binders is avoided, the pitch fibers are moderately pre-oxidized and maintain a certain degree of self-bonding Formability is very difficult to control, and the density of the resulting material (1.4~1.7g / cm 3 ) and thermal conductivity (250~500W / m.K) are not high

[0005] To sum up, the above methods have more or less disadvantages such as long production cycle, high cost, complicated preparation process and strict requirements on equipment, and the thermal conductivity of the prepared carbon / carbon composite material needs to be further improved.

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