A kind of porous c/c composite material and its preparation method

Abstract

The present invention proposes a porous C / C composite material and a preparation method thereof, which are obtained through a precursor impregnation-curing-cracking process, and the precursor is composed of resorcinol, formaldehyde and water. Under the action of saturated vapor pressure, the present invention forms pores by occupying water in the phenolic resin, and finally obtains a porous resin carbon matrix suitable for reactive infiltration with high porosity, uniform pore distribution and adjustable pore size distribution.

Description

technical field [0001] The invention relates to a porous C / C composite material and a preparation method, belonging to the technical field of C / C composite material preparation. Background technique [0002] Developed countries such as the United States, France, Germany, and Japan have carried out extensive research on the preparation technology and application of C / SiC composite materials in the past 30 years. At present, C / SiC composite materials have been used as heat-resistant materials in reusable spacecraft and rocket engine systems, such as fuselage flaps, nose cone caps, wing leading edges of the US X-38 aircraft, and French SNECMA's The nozzle diffuser section of the HM7 large rocket engine. In addition, C / SiC composite materials also have broad application prospects in rocket engine combustion chambers, space mirrors, turbine engines, armor plates, and braking materials for aircraft and racing cars. [0003] The main preparation processes of C / SiC composite mater...

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Problems solved by technology

However, this process still has the following disadvantages: (1) the densification speed of the matrix is ​​low, the production cycle is long, and the preparation cost is high; (2) the prepared composite material inevitably has 10% to 15% of pores as a by-product of high molecular weight deposition. (3) The reaction gas concentration near the pore entrance of the preform is high, and the deposition rate is greater than the internal deposition rate, which easily leads to the closure of the entrance (that is, the "bottleneck effect") and the Generate a density gradient; (4) In the process of preparing SiC, strong corrosive products are produced, which have a strong corrosion and damage effect on equipment

First of all, the matrix carbon prepared by these methods is basically amorphous carbon, which has poor reactivity with molten silicon and is not conducive to the infiltration of liquid silicon.

[0009] In order to solve the problem of low reactivity between matrix carbon and liquid-phase silicon in the existing RMI process, the Institute of Metal Research, Chinese Academy of Sciences, based on the liquid-phase silicon reaction infiltration mechanism, started by improving the microscopic morphology, porosity and pore surface area of ​​matrix carbon. Invented the active liquid phase siliconizing technology based on the high-reactivity active carbon filling technology in the carbon fiber prefabricated body, which changed the matrix carbon from dense amorphous carbon to nano-scale granular carbon with abundant pores, thus greatly improving the matrix carbon reactivity active

However, since this process uses a large amount of alcohols as precursor solvents, special treatment is required for storage and preparation, and industrial production cannot be realized due to potential safety hazards.