Preparation method of C / C-SiC composite material

Abstract

According to the preparation method of the C / C-SiC composite material, the preparation efficiency of C / C-SiC can be effectively improved, and the C / C-SiC composite material with good mechanical properties and excellent oxidation resistance and friction performance is obtained. The process method comprises the following steps: carrying out heat treatment and degumming on a preform, preparing a SiC-containing C matrix through slurry impregnation and cracking, and reacting the C matrix into the SiC matrix through a liquid siliconizing process. The slurry is prepared by dispersing SiC micro powder in medium-temperature coal pitch, and after the slurry is impregnated and cracked to a certain density, the liquid siliconizing process is utilized to partially react a carbon matrix generated by impregnating and cracking the pitch into a SiC matrix. The method is suitable for preparing components with high requirements on oxidation resistance and friction performance of materials.

Description

Technical Field

[0001] The invention belongs to the field of composite materials, and in particular relates to a method for preparing a wear-resistant and oxidation-resistant C / C-SiC composite material. Background Art

[0002] Continuous carbon fiber reinforced silicon carbide (C / C-SiC) composite materials have a series of excellent properties such as low density, high temperature resistance, high strength and toughness, thermal shock resistance, high chemical stability, low thermal expansion coefficient and high design tolerance. They are excellent candidate materials for rocket engine nozzles. In the 1970s, the French European Power Society (SEP) successfully developed the C / C-SiC composite nozzle for the first time. After that, the material has gradually been widely used in the aerospace field. For example, the European Ariane upper stage HM7 cryogenic engine uses this material as the nozzle extension section. my country has also successfully applied this material nozzle to various rocket engines represented by the "Expedition III".

[0003] At the same time, C / C-SiC composite materials have a series of excellent properties such as good friction thermal stability, low wear, small braking system size and environmental adaptability, which make up for the shortcomings of thermal cracks and high-temperature deformation of steel brake discs at high temperatures and the low wet friction coefficient of C / C composite brake materials. It is a highly competitive new generation of friction materials with broad application prospects in high-speed trains, automobiles, aircraft and other fields.

[0004] At present, the main methods for preparing C / C-SiC at home and abroad include chemical vapor deposition (CVI), precursor impregnation cracking (PIP) and reactive melt infiltration (RMI). The comprehensive performance of C / C-SiC composites prepared by chemical vapor deposition and precursor pyrolysis methods is relatively high, but the long preparation cycle and high cost limit the wide application of C / C-SiC in aviation and civil applications. The preparation of C / C-SiC composites by reactive melt infiltration has the advantages of simple process, low cost, high density, and convenience for near-net size molding. It is a process route with outstanding advantages. The inventors have found that in order to convert the C matrix into SiC as much as possible, a sufficient amount of silicon material needs to be added in the RMI process, but a certain amount of Si will remain in the prepared C / C-SiC friction material. The high temperature stability of Si is poor, which will reduce the working temperature and creep resistance of the material. The hardness of the residual Si is high, which is easy to produce cutting action on the friction surface, forming the plowing action of micro-convex bodies. At the same time, Si has a low melting point (about 1411°C), and is prone to plastic deformation during friction, causing adhesive wear on the surface of the friction object, resulting in unstable friction coefficient, which has an adverse effect on the performance of C / C-SiC friction materials. Excessive or partially excessive addition of silicon can also cause silicification corrosion to carbon fibers. Therefore, the inventors believe that the reasonable control of the content and distribution of residual Si is the key to the preparation of C / C-SiC friction materials by the RMI method, and reducing the addition of silicon material is an effective way to control the residual silicon content. Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide a method for preparing a C / C-SiC composite material, which can significantly improve the efficiency of material preparation, while effectively avoiding the problem of residual silicon caused by excessive Si material and siliconization corrosion of carbon fiber leading to performance degradation.

[0006] The present invention proposes a method for quickly preparing C / C-SiC composite materials by combining slurry impregnation and pyrolysis with RMI. SiC powder is added to molten asphalt and stirred to prepare a slurry, and a C matrix containing a certain amount of SiC is prepared outside the preform fiber through a slurry impregnation and pyrolysis process; in the subsequent RMI process, a small amount of silicon material is added to participate in the reaction to prepare the SiC matrix. The slurry impregnation and pyrolysis combined with the RMI process can significantly shorten the production cycle. At the same time, reducing the amount of silicon material added in the RMI process can effectively avoid the problem of residual silicon caused by excessive Si material and siliconized corrosion of carbon fiber, resulting in performance degradation.

[0007] The object of the present invention is achieved through the following technical scheme: A method for quickly preparing a C / C-SiC composite material, characterized in that it comprises the following steps: A method for rapidly preparing a C / C-SiC composite material, characterized in that it comprises the following steps: S1: performing a degumming treatment on a carbon fiber preform to obtain a degummed preform; S2: Mix SiC powder into asphalt, heat and melt, and stir thoroughly to obtain slurry; S3: placing the debonded preform in S1 into the slurry in S2 for vacuum impregnation for 2-3 hours, and cooling and curing the excess slurry after recovery; S4: carbonizing the solidified preform, and removing the excess carbon layer on the surface and cleaning it up after carbonization; S5: Repeat S3~S4 3~4 times until the density reaches 1.3~1.45g / cm 3 , obtaining a sample, subjecting the sample to heat treatment, and obtaining a sample after heat treatment; S6: The heat-treated sample is placed in a tooling, covered with silicon material, and siliconized to obtain a C / C-SiC composite material.

[0008] Furthermore, in S1, the degumming treatment is carried out in a heat treatment furnace, the carbon fiber preform is placed in the heat treatment furnace, N2 is continuously passed for 3 to 5 hours to fill the interior of the cracking furnace with an inert atmosphere, the temperature is increased to 750 to 850°C at a heating rate of 20 to 25°C / h and kept warm for 2 to 4 hours, and then cooled to room temperature along with the furnace.

[0009] Furthermore, in S2, the particle size of the SiC powder is 200-500 nm.

[0010] Furthermore, in S2, the asphalt softening point temperature is between 80 and 100°C.

[0011] Furthermore, in S2, the SiC powder and asphalt are mixed in a mass ratio of 1:3 to 1:4.

[0012] Furthermore, in S2, the slurry needs to be stirred for 2 to 3 hours.

[0013] Furthermore, in S3, the vacuum impregnation is carried out in a vertical impregnation tank with a storage tank, and a material delivery pipeline is provided between the storage tank and the impregnation tank for feeding and returning materials, and the asphalt slurry is stored in the storage tank; Furthermore, in S3, the process parameters of the vacuum impregnation are: evacuating the impregnation tank to 100~200Pa, heating to 200~220℃, and keeping the temperature and pressure for 30~90min, while heating the storage tank to 200~220℃, stirring continuously for 30~90min, and then sucking the slurry in the storage tank into the impregnation tank. After vacuum impregnation for 2~4h, pressurizing the impregnation tank to 0.8~1MPa to allow the slurry to flow back into the storage tank, and the impregnation tank is naturally cooled to solidify the preform impregnated with the slurry.

[0014] Further, in S4, the carbonization is carried out in a cracking furnace, and the process parameters of the carbonization are: continuously passing N2 for 3 to 5 hours to fill the cracking furnace with an inert atmosphere, heating the temperature to 400 to 450°C at a heating rate of 20 to 25°C / h and keeping it warm for 3 hours, then heating the temperature to 850 to 900°C at a heating rate of 20 to 25°C / h and keeping it warm for 4 hours, and cooling to room temperature along with the furnace.

[0015] Further, in S4, the heat treatment is completed in a high-temperature heat treatment furnace, and the process parameters of the heat treatment are: evacuating to below 100 Pa, heating to 900-950°C at a heating rate of 25-30°C / h and keeping warm for 2-3h, then heating to 2100-2200°C at a heating rate of 35-40°C / h and keeping warm for 2-3h, then cooling to 1500-1600°C at a rate of 70-80°C / h and cooling naturally; Furthermore, when the temperature rises to 1050~1100℃, argon gas needs to be introduced to 101~102kPa as a protective gas and this pressure should be maintained until the temperature drops to 300~350℃; Further, in S6, the siliconizing is performed in a high-temperature heat treatment furnace, and the process parameters of the siliconizing are: heating to 1600-1650°C at a heating rate of 300-360°C / h and keeping the temperature for 2-3h, and then cooling to room temperature with the furnace; Furthermore, in S6, the amount of silicon material used is 1 / 5 to 1 / 3 of the mass of the sample after the heat treatment.

[0016] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: (1) In view of the long preparation cycle of traditional CVI and PIP of antioxidant and wear-resistant C / C-SiC and the possible performance damage of RMI, the present invention proposes a preparation process of slurry impregnation and cracking combined with RMI. SiC micropowder is added to molten asphalt to prepare a slurry for impregnation and cracking. The density of the C / C blank containing SiC can be increased to 1.3-1.45 within 3-5 cycles. After heat treatment, only one RMI process is required to obtain the antioxidant and wear-resistant C / C-SiC composite material, which significantly improves the preparation efficiency of antioxidant and wear-resistant C / C-SiC.

[0017] (2) The amount of silicon material used in the RMI process of the present invention is reduced by 1 / 6 to 1 / 2 compared with the traditional PIP+RMI process, which can effectively avoid the degradation of friction performance caused by residual silicon and the damage to mechanical properties caused by siliconized corrosion of carbon fiber. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without carrying out creative work are within the scope of protection of the present invention.

[0019] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0020] The experimental methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are obtained from conventional commercial channels or prepared by conventional methods unless otherwise specified. Example 1

[0021] A rapid preparation method for a C / C-SiC plate comprises the following steps: The density of the non-woven fabric and the ultra-thin mesh was obtained by alternately stacking and needle punching to obtain a density of 0.45g / cm 3 The carbon fiber sheet needle-punched preform is placed in a heat treatment furnace, and N2 is continuously passed for 3 hours to fill the interior of the cracking furnace with an inert atmosphere. The temperature is raised to 750°C at a heating rate of 20°C / h and kept warm for 3 hours, and then cooled to room temperature with the furnace to obtain a degummed preform; the degummed preform is placed in an impregnation tank, evacuated to below 200Pa, heated to 200°C, and kept warm and pressurized for 1.5 hours; SiC micropowder with a particle size of 500nm and solid asphalt are added to the storage tank at a mass ratio of 1:4, heated to melt the asphalt, and fully stirred for 2 hours to obtain a slurry, and the slurry is further heated to 200°C and stirred for 30 minutes. n; open the feed valve to allow the slurry to enter the impregnation tank and vacuum impregnate for 3 hours; after the impregnation is completed, recover the excess slurry and cool and solidify naturally; take out the solidified preform and put it into the carbonization furnace, continue to pass N2 for 3 hours to make the inside of the cracking furnace full of inert atmosphere, increase the temperature to 400℃ at a rate of 20℃ / h and keep it warm for 3 hours, then increase the temperature to 900℃ at a rate of 20℃ / h and keep it warm for 4 hours, and cool it with the furnace; take it out after cooling to room temperature, remove the surface carbon layer and clean it up; repeat the above impregnation and cracking process 3 times, and the density reaches 1.32g / cm 3, and obtain the sample; put the sample into a high-temperature heat treatment furnace, evacuate to below 100Pa, heat it to 900℃ at a heating rate of 25℃ / h and keep it warm for 3h, then heat it to 2100℃ at a heating rate of 35℃ / h, and when it is heated to 1100℃, introduce argon to 101kPa as a protective gas and maintain this pressure for 3h, then cool it to 1500℃ at a rate of 80℃ / h, then naturally cool it to room temperature and take it out for cleaning to obtain the heat-treated sample; put the heat-treated sample into a graphite tooling, cover it with silicon material of 1 / 3 of the mass of the heat-treated sample, put it into a high-temperature heat treatment furnace, evacuate to below 200Pa, heat it to 1650℃ at a heating rate of 300℃ / h and keep it warm for 3h, then cool it to room temperature with the furnace, and obtain a density of 1.72g / cm 3 C / C-SiC composites. Example 2

[0022] A rapid preparation method for a C / C-SiC plate comprises the following steps: The density of the non-woven fabric and the ultra-thin mesh was obtained by alternately stacking and needle punching to obtain a density of 0.42g / cm 3 The carbon fiber sheet needle-punched preform is placed in a heat treatment furnace, and N2 is continuously passed for 3 hours to fill the inside of the cracking furnace with an inert atmosphere. The temperature is raised to 800°C at a heating rate of 25°C / h and kept warm for 4 hours, and then cooled to room temperature with the furnace to obtain a degummed preform; the degummed preform is placed in an impregnation tank, evacuated to below 200Pa, heated to 200°C, and kept warm and pressurized for 30 minutes; SiC micropowder with a particle size of 200nm and solid asphalt are added to the storage tank at a mass ratio of 1:3, heated to melt the asphalt, and fully stirred for 3 hours to obtain a slurry, and the slurry is further heated to 220°C and continuously stirred for 1 hour; the feed valve is opened to allow the slurry to enter the impregnation tank and vacuum impregnated for 3 hours; after the impregnation is completed, the excess slurry is recovered, and naturally cooled and solidified; the solidified preform is taken out and placed in a carbonization furnace, and N2 is continuously passed. 3h to fill the cracking furnace with inert atmosphere, heat up to 400℃ at a heating rate of 20℃ / h and keep it for 3h, then heat up to 900℃ at a heating rate of 20℃ / h and keep it for 4h, and cool it with the furnace; take it out after cooling to room temperature, remove the surface carbon layer and clean it; repeat the above impregnation cracking process 4 times, and the density reaches 1.44g / cm 3, and obtain the sample; put the sample into a high-temperature heat treatment furnace, evacuate to below 100Pa, heat up to 900℃ at a heating rate of 25℃ / h and keep it warm for 3h, then heat up to 2200℃ at a heating rate of 35℃ / h, and introduce argon to 100kPa as a protective gas when the temperature reaches 1100℃ and maintain this pressure for 3h, then cool down to 1600℃ at a rate of 80℃ / h, then naturally cool down to room temperature and take out for cleaning to obtain the heat-treated sample; put the heat-treated sample into a graphite tooling, cover it with silicon material of 1 / 5 of the mass of the heat-treated sample, put it into a high-temperature heat treatment furnace, evacuate to below 200Pa, heat up to 1600℃ at a heating rate of 330℃ / h and keep it warm for 2h, then cool to room temperature with the furnace, and obtain a density of 1.71g / cm 3 C / C-SiC composites. Example 3

[0023] A rapid preparation method for a C / C-SiC plate comprises the following steps: The density of the non-woven fabric and the ultra-thin mesh was obtained by alternately stacking and needle punching to obtain a density of 0.42g / cm 3 The carbon fiber sheet needle-punched preform is placed in a heat treatment furnace, and N2 is continuously passed for 3 hours to fill the inside of the cracking furnace with an inert atmosphere. The temperature is raised to 800°C at a heating rate of 25°C / h and kept warm for 4 hours, and then cooled to room temperature with the furnace to obtain a degummed preform; the degummed preform is placed in an impregnation tank, evacuated to below 200Pa, heated to 200°C, and kept warm and pressurized for 1 hour; SiC micropowder with a particle size of 300nm and solid asphalt are added to the storage tank at a mass ratio of 1:3, heated to melt the asphalt, and fully stirred for 3 hours to obtain a slurry, and the slurry is further heated to 220°C and continuously stirred for 90 minutes; the feed valve is opened to allow the slurry to enter the impregnation tank and vacuum impregnated for 3 hours; after the impregnation is completed, the excess slurry is recovered, and naturally cooled and solidified; the solidified preform is taken out and placed in a carbonization furnace, and N2 is continuously passed. 3h to fill the cracking furnace with inert atmosphere, heat up to 400℃ at a heating rate of 20℃ / h and keep it for 3h, then heat up to 900℃ at a heating rate of 20℃ / h and keep it for 4h, and cool it with the furnace; take it out after cooling to room temperature, remove the surface carbon layer and clean it up; repeat the above impregnation cracking process 3 times, and the density reaches 1.36g / cm 3, get the sample; put the sample into a high-temperature heat treatment furnace, evacuate to below 100Pa, heat up to 900℃ at a heating rate of 25℃ / h and keep it warm for 3h, then heat up to 2200℃ at a heating rate of 35℃ / h, introduce argon to 100kPa as a protective gas when the temperature reaches 1100℃ and maintain this pressure for 3h, then cool down to 1600℃ at a rate of 70℃ / h, then naturally cool down to room temperature and take out for cleaning to get the heat-treated sample; put the heat-treated sample into a graphite tooling, cover it with silicon material of 1 / 3 of the mass of the heat-treated sample, put it into a high-temperature heat treatment furnace, evacuate to below 200Pa, heat up to 1600℃ at a heating rate of 330℃ / h and keep it warm for 2h, then cool to room temperature with the furnace, and get a density of 1.75g / cm 3 C / C-SiC composites.

[0024] Comparative Example 1: C / C-SiC composites were prepared by traditional CVI+PIP process.

[0025] The density of the non-woven fabric and the ultra-thin mesh was obtained by alternately stacking and needle punching to obtain a density of 0.45g / cm 3 A carbon fiber sheet needle-punched preform is prepared, the preform is placed in a vapor deposition furnace, N2 is continuously passed for 3 hours to fill the interior of the cracking furnace with an inert atmosphere, the temperature is raised to 700°C at a heating rate of 20°C / h and kept warm for 3 hours; then the temperature is continued to be raised to 900°C, natural gas and nitrogen are passed at a gas volume of 30L / min, the pressure in the furnace is maintained at 5kPa, and deposition is performed for 20 hours. After the deposition is completed, the temperature is naturally lowered to room temperature and taken out; the deposited preform is placed in a tooling barrel, placed in a vacuum impregnation tank, evacuated to below 200Pa, 50wt% polysilicon carbane xylene solution is added, and impregnated for 3 hours; the impregnated blank is placed in a 130°C oven for drying and curing for 6 hours, and then placed in a cracking furnace for cracking, and the cracking parameters are: continuous N2 The pyrolysis furnace was filled with an inert atmosphere for 3 hours, and the temperature was raised to 1100°C at a rate of 20°C / h and kept at that temperature for 3 hours, and then cooled to room temperature with the furnace; the immersion pyrolysis process was repeated 24 times, and the density reached 1.72g / cm 3 .

[0026] Comparative Example 2: Preparation of C / C-SiC composites by asphalt PIP+RMI process.

[0027] The density of the non-woven fabric and the ultra-thin mesh was obtained by alternately stacking and needle punching to obtain a density of 0.42g / cm 3The carbon fiber sheet needle-punched preform is placed in a heat treatment furnace, and N2 is continuously passed for 3 hours to fill the inside of the cracking furnace with an inert atmosphere. The temperature is raised to 800°C at a heating rate of 25°C / h and kept warm for 4 hours, and then cooled to room temperature with the furnace to obtain a degummed preform; the degummed preform is placed in an impregnation tank, evacuated to below 200Pa, heated to 200°C, and kept warm and pressurized for 1 hour; solid asphalt is added to the storage tank, heated to 220°C to melt the asphalt, and stirred continuously for 2 hours; the feed valve is opened to allow the asphalt to enter the impregnation tank, and vacuum impregnation is performed for 3 hours; after the impregnation is completed, the excess asphalt is recovered, and it is naturally cooled and solidified; the solidified preform is taken out and placed in a carbonization furnace, and N2 is continuously passed. 3h to fill the cracking furnace with inert atmosphere, heat up to 400℃ at a heating rate of 20℃ / h and keep it for 3h, then heat up to 900℃ at a heating rate of 20℃ / h and keep it for 4h, and cool it with the furnace; take it out after cooling to room temperature, remove the surface carbon layer and clean it up; repeat the above impregnation cracking process 5 times, and the density reaches 1.34g / cm 3 , and obtain the sample; put the sample into a high-temperature heat treatment furnace, evacuate to below 100Pa, heat up to 900℃ at a heating rate of 25℃ / h and keep it warm for 3h, then heat up to 2200℃ at a heating rate of 35℃ / h, and introduce argon to 100kPa as a protective gas when the temperature reaches 1100℃ and maintain this pressure for 3h, then cool down to 1600℃ at a rate of 80℃ / h, then naturally cool down to room temperature and take out for cleaning to obtain the heat-treated sample; put the heat-treated sample into a graphite tooling, cover it with 2 / 5 of the mass of the heat-treated sample with silicon material, put it into a high-temperature heat treatment furnace, evacuate to below 200Pa, heat up to 1600℃ at a heating rate of 330℃ / h and keep it warm for 2h, then cool to room temperature with the furnace, and obtain a density of 1.76g / cm 3 C / C-SiC composites.

[0028] The C / C-SiC composite material was prepared according to the process of the embodiment. After 3-4 times of asphalt slurry impregnation and cracking, the density could reach 1.3-1.45 g / cm 3 After another siliconization, the density reaches 1.7 g / cm 3 The C / C-SiC composite material was prepared according to the process of Comparative Example 1. After 24 PIPs, the density reached 1.72 g / cm 3 The present invention can significantly improve the preparation efficiency of C / C-SiC. According to the process of comparative example 2, the C / C-SiC composite material is prepared, and the silicon material used is 1 / 6 to 1 / 2 more than that of the embodiment. The present invention can effectively reduce the amount of silicon material used in the RMI process, effectively avoid the reduction of friction performance caused by residual silicon, and avoid the mechanical performance damage caused by carbon fiber silicification corrosion.

[0029] The protection scope of the present invention is not limited to the above embodiments. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a C / C-SiC composite material, It is characterized in that The following steps are involved: S1: performing a degumming treatment on a carbon fiber preform to obtain a degummed preform; S2: Mix SiC powder into asphalt, heat and melt, and stir thoroughly to obtain slurry; S3: placing the degummed preform obtained in S1 in the slurry obtained in S2 for vacuum impregnation for 2-3 hours, recovering the excess slurry and cooling it to solidify the preform; S4: carbonizing the solidified preform, and removing the excess carbon layer on the surface and cleaning it up after carbonization; S5: Repeat S3~S4 3~4 times until the density reaches 1.3~1.45g / cm 3 , obtaining a sample, subjecting the sample to heat treatment, and obtaining a sample after heat treatment; S6: Cover the heat-treated sample with silicon material and perform siliconization to obtain a C / C-SiC composite material.

2. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S1, the degumming treatment is carried out in a heat treatment furnace. The carbon fiber preform is placed in the heat treatment furnace and continuously heated by N 2 Fill the cracking furnace with inert atmosphere for 3 to 5 hours, raise the temperature to 750 to 850°C at a heating rate of 20 to 25°C / h and keep it at that temperature for 2 to 4 hours, and then cool to room temperature along with the furnace.

3. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S2, the particle size of the SiC powder is 200~500nm.

4. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S2, the asphalt softening point temperature is 80-100°C; the SiC micropowder and asphalt are mixed in a mass ratio of 1:3-1:4; and the stirring time is 2-3h.

5. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S3, the vacuum impregnation is carried out in a vertical impregnation tank with a storage tank, and a feeding pipeline is provided between the storage tank and the impregnation tank for feeding and returning materials, and the asphalt slurry is stored in the storage tank; the process parameters of the vacuum impregnation are: the impregnation tank is evacuated to 100~200Pa, heated to 200~220℃, and kept warm and pressurized for 30~90min, and the storage tank is heated to 200~220℃ at the same time, and stirred continuously for 30~90min, and then the slurry in the storage tank is sucked into the impregnation tank, and after vacuum impregnation for 2~4h, the impregnation tank is pressurized to 0.8~1MPa to make the slurry flow back to the storage tank, and the impregnation tank is naturally cooled to solidify the preform impregnated with the slurry.

6. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S4, the carbonization is carried out in a cracking furnace, and the process parameters of the carbonization are: continuous flow of N 2 Fill the cracking furnace with inert atmosphere for 3 to 5 hours, heat the temperature to 400 to 450°C at a heating rate of 20 to 25°C / h and keep it warm for 3 hours, then heat the temperature to 850 to 900°C at a heating rate of 20 to 25°C / h and keep it warm for 4 hours, and then cool to room temperature along with the furnace.

7. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S4, the heat treatment is completed in a high-temperature heat treatment furnace, and the process parameters of the heat treatment are: evacuating to below 100 Pa, heating to 900~950℃ at a heating rate of 25~30℃ / h and keeping warm for 2~3h, then heating to 2100~2200℃ at a heating rate of 35~40℃ / h and keeping warm for 2~3h, then cooling to 1500~1600℃ at a rate of 70~80℃ / h and then cooling naturally.

8. A method for preparing a C / C-SiC composite material according to claim 7, It is characterized in that When the temperature rises to 1050~1100℃, argon gas needs to be introduced to 101~102kPa as a protective gas and this pressure should be maintained until the temperature drops to 300~350℃.

9. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S6, the siliconizing is carried out in a high-temperature heat treatment furnace, and the process parameters of the siliconizing are: heating to 1600-1650°C at a heating rate of 300-360°C / h and keeping the temperature for 2-3h, and then cooling to room temperature with the furnace.

10. A method for preparing a C / C-SiC composite material according to claim 1, It is characterized in that In S6, the amount of silicon material used is 1 / 5 to 1 / 3 of the mass of the sample after the heat treatment.