Rapid preparation method of carbon / carbon brake disc

Abstract

The invention provides a rapid preparation method of a carbon / carbon brake disc, which comprises the following steps: in a chemical vapor infiltration stage, alternately placing inner graphite backing rings and outer graphite backing rings between carbon / carbon brake disc preforms, and changing a carbon source gas flow path, so that the brake disc forms a pressure difference in the thickness direction and the radial direction; meanwhile, by controlling the temperature of a carbon source gas inlet, adjusting the internal and external pressure difference of the stock columns and controlling the time of each disc surface of the brake disc in the cavities of the internal and external stock columns, the densification time of the brake disc prefabricated body is effectively shortened, the uniformity of the carbon / carbon brake disc in the thickness direction and the radial direction is improved, and rapid and high-quality densification of the carbon / carbon composite material brake disc is achieved. The surface of the prepared carbon / carbon brake disc is not prone to crusting, the preparation efficiency is high, and the density of the brake disc is uniform.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft brake devices, and in particular relates to a rapid preparation method of a carbon / carbon brake disc. Background Art

[0002] Carbon / carbon composite materials have a series of advantages such as low density, high specific strength, high specific heat capacity, and high temperature resistance. In addition, their excellent friction, wear and thermal physical properties make them the first choice for brake materials. Carbon / carbon brake discs can not only avoid the problems of easy deformation, cracking, unstable braking torque, short service life and large maintenance workload that occur during the use of traditional powder metallurgy steel brake discs, but also because carbon / carbon composite materials are chemically inert and are not corroded by acid mist and seawater, they can be used in various climatic conditions, greatly improving the safety and reliability of aircraft brake devices. After more than half a century of development, carbon / carbon composite materials have been used in almost all aircraft brake materials.

[0003] The main production process of carbon / carbon brake discs is chemical vapor infiltration (CVI), which is to place a preform made of carbon fiber in a CVI furnace, heat it to the required temperature, and introduce a gaseous carbon source gas. The carbon source gas undergoes a cracking reaction during diffusion into the preform to produce pyrolytic carbon and fills the pores of the preform to form a carbon / carbon composite material. This method can obtain a rough layer structure with good friction and wear performance, but there are problems such as long production cycle, low precursor utilization, high energy consumption, poor product consistency and stability, which greatly restricts its use in the brake field.

[0004] The patent application with publication number CN1291174C provides a method for preparing aircraft carbon brake discs by slit directional flow. By placing graphite gaskets between each preform, the carbon source gas is directed to flow through the equidistant slits between the preforms, thereby improving the effective utilization rate of the carbon source gas and preventing the formation of harmful substance carbon black. However, this method can only obtain directional flow of gas between preforms, and cannot achieve directional flow of gas inside the preform. It is difficult to make the carbon source gas penetrate evenly in the thickness direction and radial direction to ensure the overall uniformity of the carbon-carbon brake disc.

[0005] The patent with publication number CN111348931A provides a gas phase infiltration method for annular carbon / carbon composite materials. In the segmented deposition process, two material columns with different gas flow directions are used alternately to stack the preforms. By controlling and changing the direction of the gaseous precursor reaction gas flow, the uniformity of the density of the carbon / carbon brake disc in the radial direction is improved to a certain extent and the densification time is shortened. However, although the method provided by the patent can avoid the probability of carbon black generation by changing the gas flow direction and setting the direction of the pressure-adjusting air outlet, it cannot solve the problem of high surface density and low center density of the carbon / carbon brake disc in the thickness direction. Summary of the invention

[0006] The purpose of the present invention is to solve the problems of long preparation cycle, poor radial uniformity of the brake disc and axial density gradient of the brake disc in the existing carbon / carbon brake disc preparation method, and to provide a rapid preparation method for a carbon / carbon brake disc.

[0007] To achieve the above purpose, the technical solution provided by the present invention is:

[0008] A rapid preparation method for a carbon / carbon brake disc, which is special in that it comprises the following steps:

[0009] Step 1, preparing a carbon / carbon brake disc preform:

[0010] The carbon fiber mesh and carbon cloth are laminated and needle-punched to form a 2.5D carbon fiber preform, and the fiber structure is cut into a plurality of ring structures to form a carbon / carbon brake disc preform; the carbon / carbon brake disc preform has a density of 0.50-0.70 g / cm 3 ;

[0011] Step 2, pre-deposition and shaping treatment of the carbon / carbon brake disc preform:

[0012] The carbon / carbon brake disc preforms prepared in step 1 are stacked in sequence to form a material column, and placed in a chemical vapor infiltration furnace; the furnace chamber is evacuated and heated, the carbon source gas flow rate is adjusted, and the material column is pre-deposited and shaped to form a carbon / carbon brake disc porous body; the carbon / carbon brake disc porous body has a density of 0.85±0.1g / cm 3 ;

[0013] During the pre-deposition shaping process, after the carbon source gas is introduced, the pressure inside and outside the material column cavity is adjusted to form a pressure difference inside and outside the material column cavity, and the carbon source gas flows from the inner cavity of the material column along the radial direction of the material column to the outside of the material column, and then discharged from the gas outlet of the chemical vapor infiltration furnace;

[0014] The air inlet of the chemical vapor infiltration furnace is located at the center of the material column; the temperature in the chemical vapor infiltration furnace is 880-1100° C.; the pre-deposition shaping time is 30-100 hours;

[0015] Step 3, subjecting the carbon / carbon brake disc porous body obtained in step 2 to chemical vapor infiltration densification treatment:

[0016] Inner graphite gaskets and outer graphite gaskets are alternately laid between adjacent carbon / carbon brake disc porous blanks, the furnace chamber is vacuumed and then heated, the carbon source gas flow rate and the pressure inside and outside the cavity of the carbon / carbon brake disc porous blank are adjusted to form a pressure difference in the axial and radial directions of the carbon / carbon brake disc porous blank, and chemical vapor infiltration densification treatment is performed. After the treatment, the density of the carbon / carbon brake disc is 1.70-1.85g / cm 3 ;

[0017] The temperature in the chemical vapor infiltration furnace is 880-1100°C;

[0018] The inner diameter of the inner graphite gasket is equal to the inner diameter of the carbon / carbon brake disc preform, and the outer diameter of the outer graphite gasket is equal to the outer diameter of the carbon / carbon brake disc preform;

[0019] Step 4, placing the carbon / carbon brake disc porous body densified in step 3 in a graphitization furnace, graphitizing it at a temperature of 1800-2400° C., and keeping the temperature for 1-4 hours; the vacuum degree in the furnace chamber is not greater than 1 kPa;

[0020] Step 5, performing fine processing and anti-oxidation coating treatment on the graphitized carbon / carbon brake disc according to design requirements to obtain a carbon / carbon brake disc.

[0021] Furthermore, in step 1, the carbon cloth is a carbon fiber cloth, and the carbon fiber mesh is a dense planar mesh structure formed by overlapping short carbon fiber filaments.

[0022] Furthermore, the specific process of laminating and needling the carbon fiber web and the carbon cloth to form a 2.5D carbon fiber preform in step 1 is as follows:

[0023] First, the carbon fiber mesh and carbon cloth are alternately stacked to form a multi-layer structure, and then the barbs on the needle are vertically inserted into the multi-layer structure, so that the carbon fiber short fibers of some mesh layers are brought into and remain in the multi-layer mesh and carbon cloth, and the layers of the multi-layer structure are connected to form a 2.5D carbon fiber preform.

[0024] Furthermore, in step 2, the chamber of the chemical vapor infiltration furnace is first evacuated to a temperature below 1 kPa, and then the furnace is heated to 880-1100°C.

[0025] Furthermore, in the step 2, the carbon source gas is preheated to 500-900° C. by a preheating device located at the bottom of the chemical vapor infiltration furnace chamber, and then fed into the furnace chamber at a speed of 0.7-3 m / s.

[0026] Furthermore, in step 2, the pressure outside the material column is adjusted by extracting gas outside the material column, so that a pressure difference is formed inside and outside the material column cavity;

[0027] The pressure in the material column cavity is greater than 1 kPa and less than or equal to 5 kPa, and the pressure difference between the inside and outside of the material column is not greater than 1 kPa.

[0028] Furthermore, in step 3, the chamber of the chemical vapor infiltration furnace is first evacuated to less than 1 kPa, and then the temperature in the furnace is heated to 880-1100° C.;

[0029] Then, the carbon source gas is preheated to 300-800° C. by a preheating device located at the bottom of the chemical vapor infiltration furnace chamber, and then fed into the furnace chamber at a speed of 0.7-3 m / s;

[0030] After the carbon source gas is introduced, the gas outside the carbon / carbon brake disc porous blank is extracted to form a pressure difference inside and outside the cavity of the carbon / carbon brake disc porous blank along the thickness direction and the radial direction; the pressure inside the porous cavity of the carbon / carbon brake disc blank is greater than 1kPa and less than or equal to 5kPa, and the pressure difference inside and outside the cavity of the material column is not greater than 1kPa.

[0031] Furthermore, in step 3, one side of the carbon / carbon brake disc porous body is first subjected to densification treatment for 100-400 hours, and then the carbon / carbon brake disc porous body is turned over and further subjected to densification treatment for 100-300 hours.

[0032] Furthermore, in step 3, the thickness of the inner graphite gasket ring and the outer graphite gasket ring is 3-8 mm, and the ring band width is 5%-10% of the ring band width of the carbon / carbon brake disc preform.

[0033] Furthermore, in step 2 and step 3, the carbon source gas includes one or more of natural gas, propane, propylene and acetylene, and nitrogen, hydrogen or a mixture thereof is used as a diluent gas.

[0034] The advantages of the present invention are:

[0035] 1. In the chemical vapor infiltration stage, the method of the present invention changes the flow route of the carbon source gas by alternately placing inner graphite gaskets and outer graphite gaskets between the carbon / carbon brake disc preforms, so that a pressure difference is formed in the thickness direction and radial direction of the brake disc; at the same time, by controlling the inlet temperature of the carbon source gas, adjusting the pressure difference between the inside and outside of the material column, and controlling the time that each disc surface of the brake disc is in the inner and outer material column cavities, the densification time of the brake disc preform is effectively shortened, the uniformity of the carbon / carbon brake disc in the thickness direction and radial direction is improved, and the rapid and high-quality densification of the carbon / carbon composite brake disc is achieved.

[0036] 2. In the method of the present invention, the inlet gas flow rate and temperature are reasonably set according to the thickness and porosity of the carbon / carbon brake disc preform, and the pressure difference between the inside and outside of the material column is adjusted, which can effectively avoid crusting on the surface of the brake disc preform.

[0037] 3. The preparation method provided by the present invention is simple to operate. Compared with the existing isothermal method, the production cycle of the method of the present invention is shortened by 20%-30%, the production cost is reduced by 10%-20%, and it is suitable for large-scale industrial production.

[0038] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0040] Figure 1 : is a schematic diagram of the gas flow direction in the pre-deposition shaping treatment stage of the present invention;

[0041] Figure 2 : is a schematic diagram of the gas flow direction in the furnace chamber during the gas phase infiltration densification stage of the present invention;

[0042] Figure 3 : A schematic diagram of the gas flow direction in the porous green body of the brake disc material in the gas phase infiltration densification stage of the present invention;

[0043] Figure 4 : Schematic diagram of sample preparation for density uniformity characterization;

[0044] Figure 5 : It is a test comparison of the density in the axial direction (thickness direction) of the examples 1, 2, and 3 of the embodiments of the present invention and the conventional brake disc;

[0045] Figure 6 : Comparison of radial density of embodiments 1, 2, 3 of the present invention and conventional brake discs;

[0046] In the figure: 1-induction coil, 2-graphite cover plate, 3-insulation structure, 4-graphite heater, 5-carbon / carbon brake disc preform, 6-thermocouple device, 7-preheating device, 8-insulation device, 9-double-layer water-cooled furnace shell, 10-carbon / carbon brake disc porous blank, 11-outer graphite gasket, 12-inner graphite gasket. DETAILED DESCRIPTION

[0047] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0048] Example 1

[0049] In this embodiment, propylene is used as the carbon source gas and nitrogen is used as the diluent gas to prepare a carbon / carbon brake disc. The specific steps are as follows:

[0050] Step 1: preparing a carbon / carbon brake disc preform.

[0051] The carbon cloth is made of carbon fiber flat cloth. First, the carbon fiber flat cloth and carbon fiber mesh tire are alternately stacked to form a multi-layer structure, in which the carbon fiber flat cloth layer is alternately laid at 0° and 90°; then, the carbon fiber mesh tire short fibers are brought into the multi-layer carbon fiber mesh tire and carbon fiber flat cloth through the barbs on the needle by needle punching to form Z-direction fibers; finally, according to the size of the prepared carbon / carbon brake disc, the multi-layer structure after needle punching is cut into an annular preform with a density of 0.60g / cm 3 .

[0052] Step 2, stack the carbon / carbon brake disc preforms 5 in sequence to form a material column, place the material column in a chemical vapor infiltration furnace, ensure that the air inlet is at the center of the material column, and set a graphite cover plate 2 on the top of the material column. Turn on the vacuum pump to evacuate the gas in the furnace chamber to a vacuum of 0.8kPa, then heat the furnace to 900°C, and then introduce a mixed gas of propylene and nitrogen at a speed of 1m / s, wherein the mixing ratio of propylene and nitrogen in the mixed gas is 80:20; control the gas inlet temperature to 650°C, turn on the vacuum pump to extract the gas outside the material column, that is, the gas in the chemical vapor infiltration furnace chamber, so that a pressure difference is formed between the inner and outer cavities of the material column, the pressure inside the material column is 1.3±0.2kPa, and the pressure difference between the inner and outer cavities of the material column is 0.5±0.1kPa; after running for 50h, a density of 0.85±0.1g / cm 3 Carbon / carbon porous green body.

[0053] Reference Figure 1 The chemical vapor infiltration furnace includes a double-layer water-cooled furnace shell 9, and a heat preservation structure 3 is arranged between the inner cavity of the chemical vapor infiltration furnace and the double-layer water-cooled furnace shell 9. The outer wall of the heat preservation structure 3 is wound with an induction coil 1, and the inner wall of the heat preservation structure 3 is provided with a graphite heater 4, and the graphite heater 4 is used to heat the chemical vapor infiltration furnace. The bottom of the chemical vapor infiltration furnace cavity is provided with a heat insulation device 8 and a preheating device 7 from bottom to top, and the preheating device is used to preheat the carbon source gas before the carbon source gas is introduced. The thermocouple device 6 is inserted into the central cavity of the material column along the central hole of the heat insulation device and the preheating device.

[0054] Step 3, alternately place outer graphite gaskets 11 and inner graphite gaskets 12 between adjacent carbon / carbon porous blanks, turn on the vacuum pump to evacuate the gas in the furnace chamber to a vacuum of 0.8 kPa, raise the temperature in the furnace to 900°C, and then introduce a mixed gas of propylene gas and nitrogen at a speed of 1 m / s, wherein the mixing ratio of propylene gas and nitrogen is 80:20; control the gas inlet temperature to 650°C, fill the gas into the inner cavity of the material column, turn on the vacuum pump to extract the gas outside the material column, the pressure inside the material column is 1.3±0.1 kPa, and the pressure difference between the inside and outside of the material column is 0.3±0.1 kPa; after running for 300 hours, turn over the carbon / carbon porous blanks one by one and continue running for 200 hours to obtain a density of 1.72-1.78 g / cm 3 Carbon / carbon brake discs.

[0055] The outer diameter of the outer graphite gasket ring 11 is the same as the outer diameter of the carbon fiber preform, the thickness is 5 mm, and the ring width is 5%-10% of the ring width of the carbon / carbon brake disc preform;

[0056] The inner diameter of the inner graphite gasket ring 12 is the same as that of the carbon fiber preform, the thickness is 5 mm, and the ring band width is 5%-10% of the ring band width of the carbon / carbon brake disc preform.

[0057] Step 4, placing the carbon / carbon brake disc porous body with qualified density in a graphitization furnace for graphitization treatment, turning on the vacuum pump to evacuate the gas in the furnace chamber to 0.5 kPa, raising the temperature in the furnace to 2000° C., and keeping it warm for 2 hours.

[0058] Step 5, the carbon / carbon brake disc that has completed the graphitization treatment is subjected to mechanical processing and anti-oxidation coating treatment according to the requirements of the model drawing to obtain the final carbon / carbon brake disc.

[0059] Example 2

[0060] In this embodiment, natural gas and propane are used as carbon source gases to prepare carbon / carbon brake discs. The specific steps are as follows:

[0061] Step 1: The carbon / carbon brake disc preform is an alternately stacked carbon fiber non-woven fabric and mesh tire, wherein the non-woven fabric layer is alternately laid at 0° and 90°, and then the mesh tire short fibers are brought into the multi-layer mesh tire and carbon cloth by needle punching to form Z-direction fibers. The preform is cut into a ring-shaped preform according to the size of the prepared carbon / carbon brake disc, and the density of the preform is 0.50g / cm 3 .

[0062] Step 2, stack the carbon / carbon brake disc preforms in sequence to form a material column, place the material column in a chemical vapor infiltration furnace, ensure that the air inlet is at the center of the material column, and set a graphite cover plate on the carbon / carbon brake disc preform at the top of the material column. Turn on the vacuum pump to evacuate the gas in the furnace chamber to a vacuum of 0.8kPa, then heat the furnace to 1050°C, and then introduce a mixture of natural gas and propane at a speed of 0.7m / s. The mixing ratio of natural gas and propane in the mixed gas is 85:15. The gas inlet temperature is controlled at 600°C, the pressure in the material column is 2±0.2kPa, and the pressure difference between the inside and outside of the material column is 0.8±0.1kPa. After running for 30 hours, a density of 0.85±0.1g / cm 3 Carbon / carbon porous green body.

[0063] Step 3, alternately place inner graphite gaskets and outer graphite gaskets between adjacent carbon / carbon porous green bodies, turn on the vacuum pump to evacuate the gas in the furnace chamber to a vacuum of 0.8 kPa, raise the temperature in the furnace to 1050°C, and then introduce a mixture of natural gas and propane at a speed of 0.7 m / s, with a mixing ratio of 85:15; control the gas inlet temperature to 600°C, turn on the vacuum pump to extract the gas outside the material column, the pressure inside the material column is 2±0.2 kPa, and the pressure difference between the inside and outside of the material column is 0.5±0.1 kPa. ; After running for 250 hours, turn over the carbon / carbon porous green bodies one by one and continue running for 200 hours to obtain a density of 1.70-1.76 g / cm 3 Carbon / carbon brake discs.

[0064] Step 4, placing the carbon / carbon brake disc with qualified density in a graphitization treatment furnace for graphitization treatment, turning on the vacuum pump to evacuate the gas in the furnace chamber to 0.5 kPa, raising the temperature in the furnace to 1800° C., and keeping it warm for 2 hours.

[0065] Step 5, the carbon / carbon brake disc that has completed the graphitization treatment is subjected to mechanical processing and anti-oxidation coating treatment according to the requirements of the model drawing to obtain the final carbon / carbon brake disc.

[0066] Example 3

[0067] A method for rapidly preparing a carbon / carbon composite brake disc solves the problems of long preparation cycle and poor radial uniformity of existing carbon / carbon brake discs. In this embodiment, natural gas and propane are used as carbon source gases to prepare carbon / carbon brake discs. The specific steps are as follows:

[0068] Step 1: The carbon / carbon brake disc preform is an alternately stacked carbon fiber non-woven fabric and mesh tire, wherein the non-woven fabric layer is alternately laid at 0° and 90°, and then the mesh tire short fibers are brought into the multi-layer mesh tire and carbon cloth by needle punching to form Z-direction fibers. The preform is cut into a ring-shaped preform according to the size of the prepared carbon / carbon brake disc, and the density of the preform is 0.70g / cm 3 .

[0069] Step 2, stack the carbon / carbon brake disc preforms in sequence to form a material column, place the material column in a chemical vapor infiltration furnace, ensure that the air inlet is at the center of the material column, and set a graphite cover plate on the carbon / carbon brake disc preform at the top of the material column. Turn on the vacuum pump to evacuate the gas in the furnace chamber to a vacuum of 0.8kPa, then heat the furnace to 1000°C, and then introduce a mixture of natural gas and propane at a speed of 1m / s, with a mixing ratio of 90:10; control the gas inlet temperature to 700°C, turn on the vacuum pump to extract the gas outside the material column, so that a pressure difference is formed inside and outside the material column cavity, the pressure inside the material column is 2.5±0.2kPa, and the pressure difference between the inside and outside of the material column is 0.8±0.1kPa; after running for 50 hours, a density of 0.85±0.1g / cm 3 Carbon / carbon porous green body.

[0070] Step 3, alternately place inner graphite gaskets 12 and outer graphite gaskets 11 between adjacent carbon / carbon porous blanks, turn on the vacuum pump to evacuate the gas in the furnace chamber to a vacuum of 0.8 kPa, heat the furnace to 1000°C, and then introduce a mixture of natural gas and propane at a speed of 1 m / s, with a mixing ratio of 90:10; control the gas inlet temperature to 700°C, turn on the vacuum pump to extract the gas outside the material column, and form a pressure difference in the thickness direction and radial direction of the carbon / carbon brake disc preform. The pressure in the material column is 2.5±0.2 kPa, and the pressure difference between the inside and outside of the material column is 0.5±0.1 kPa; after running for 300 hours, turn over the carbon / carbon porous blanks one by one and continue running for 200 hours to obtain a density of 1.72-1.78 g / cm 3 Carbon / carbon brake discs.

[0071] Step 4, placing the densified carbon / carbon brake disc in a graphitization furnace for graphitization treatment, turning on the vacuum pump to evacuate the gas in the furnace chamber to 0.5 kPa, raising the temperature in the furnace to 2100° C., and keeping it warm for 1.5 hours.

[0072] Step 5, the carbon / carbon brake disc that has completed the graphitization treatment is subjected to mechanical processing and anti-oxidation coating treatment according to the requirements of the model drawing to obtain the final carbon / carbon brake disc.

[0073] Performance Testing

[0074] In order to illustrate the performance of the carbon / carbon brake disc prepared by the method of the present invention, the carbon / carbon brake disc prepared in Examples 1, 2, and 3 was characterized for density uniformity and compared with the carbon / carbon brake disc prepared by the traditional method. Figure 4 , take two square block samples from each carbon / carbon brake disc, ensure that the sample length is more than 80% of the annular band width, the sample thickness is the thickness of the carbon / carbon brake disc, and mark the inner diameter and outer diameter directions on the sample.

[0075] Density uniformity test in thickness direction: Measure the density of sample 1 by volume weight method, and then symmetrically grind the sample 1mm thinner from two symmetrical planes along the thickness direction and measure the density. Repeat 9 times to obtain the density of test blocks 2#, 3#, ..., 10# with successively thinner thickness. The test results are shown in Figure 5 .

[0076] Conduct a radial density uniformity test: Sample 2 is processed into 10 slices with the same width and thickness as the sample at equal distances in the length direction. The slices are numbered 1#, 2#, 3#...10# from the inner diameter to the outer diameter. The test results are shown in Figure 6 .

[0077] It can be seen that compared with the carbon / carbon brake discs prepared by the traditional process, the density uniformity of Examples 1, 2, and 3 is greatly improved. The problem of high surface density and low center density in the thickness direction of the brake discs prepared by the traditional process is improved, and the problem of large fluctuations in density distribution in the radial direction is alleviated.

[0078] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A rapid preparation method of a carbon / carbon brake disc, characterized in that: The following steps are involved: Step 1, preparing a carbon / carbon brake disc preform: The carbon fiber mesh and carbon cloth are laminated and needle-punched to form a 2.5D carbon fiber preform, and the carbon fiber preform is cut into a plurality of ring structures to form a carbon / carbon brake disc preform; the carbon / carbon brake disc preform has a density of 0.50-0.70 g / cm 3 ; Step 2: Pre-deposition and shaping the carbon / carbon brake disc preform: The carbon / carbon brake disc preforms prepared in step 1 are stacked in sequence to form a material column, which is placed in a chemical vapor infiltration furnace; the furnace chamber is evacuated and then heated to increase the temperature, the carbon source gas flow rate is adjusted, and the material column is pre-deposited and shaped to form a carbon / carbon brake disc porous body; the carbon / carbon brake disc porous body has a density of 0.85±0.1g / cm 3 ; During the pre-deposition shaping process, after the carbon source gas is introduced, the pressure inside and outside the material column cavity is adjusted to form a pressure difference inside and outside the material column cavity, and the carbon source gas flows from the inner cavity of the material column along the radial direction of the material column to the outside of the material column, and then discharged from the gas outlet of the chemical vapor infiltration furnace; The air inlet of the chemical vapor infiltration furnace is located at the center of the material column; the temperature in the chemical vapor infiltration furnace is 880-1100° C.; the pre-deposition shaping time is 30-100 hours; Step 3, subjecting the carbon / carbon brake disc porous body obtained in step 2 to chemical vapor infiltration densification treatment: Inner graphite gaskets and outer graphite gaskets are alternately laid between adjacent carbon / carbon brake disc porous blanks, the furnace chamber is vacuumed and then heated, the carbon source gas flow rate and the pressure inside and outside the carbon / carbon brake disc porous blank cavity are adjusted to form a pressure difference in the axial and radial directions of the carbon / carbon brake disc porous blank, and chemical vapor infiltration densification treatment is performed. After the treatment, the density of the carbon / carbon brake disc porous blank is 1.70-1.85g / cm 3 ; The temperature in the chemical vapor infiltration furnace is 880-1100°C; The inner diameter of the inner graphite gasket is equal to the inner diameter of the carbon / carbon brake disc preform, and the outer diameter of the outer graphite gasket is equal to the outer diameter of the carbon / carbon brake disc preform; Step 4, placing the carbon / carbon brake disc porous body densified in step 3 in a graphitization furnace, graphitizing it at a temperature of 1800-2400° C., and keeping the temperature for 1-4 hours; the vacuum degree in the furnace chamber is not greater than 1 kPa; Step 5, performing fine processing and anti-oxidation coating treatment on the graphitized carbon / carbon brake disc according to design requirements to obtain a carbon / carbon brake disc.

2. The rapid preparation method of carbon / carbon brake disc according to claim 1, characterized in that: In step 1, the carbon cloth is a carbon fiber cloth, and the carbon fiber mesh is a dense plane mesh structure formed by overlapping short carbon fiber filaments; The length of the carbon fiber short filaments is 5-8 mm.

3. The rapid preparation method of carbon / carbon brake disc according to claim 2, characterized in that: The specific process of forming a 2.5D carbon fiber preform by laminating and needle-punching the carbon fiber web and the carbon cloth in step 1 is as follows: First, the carbon fiber mesh and carbon cloth are alternately stacked to form a multi-layer structure, and then the barbs on the needle are vertically inserted into the multi-layer structure, so that the carbon fiber short fibers of some mesh layers are brought into and remain in the multi-layer mesh and carbon cloth, and the layers of the multi-layer structure are connected to form a 2.5D carbon fiber preform.

4. The rapid preparation method of carbon / carbon brake disc according to claim 1, characterized in that: In the step 2, the chamber of the chemical vapor infiltration furnace is first evacuated to a pressure of less than or equal to 1 kPa, and then the furnace is heated to 880-1100° C.

5. The rapid preparation method of carbon / carbon brake disc according to claim 4, characterized in that: In the step 2, the carbon source gas is preheated to 300-800° C. by a preheating device located at the bottom of the chemical vapor infiltration furnace chamber, and then fed into the furnace chamber at a speed of 0.7-3 m / s.

6. The rapid preparation method of carbon / carbon brake disc according to claim 5, characterized in that: In step 2, the pressure outside the material column is adjusted by extracting gas outside the material column, so that a pressure difference is formed inside and outside the material column cavity; The pressure in the material column cavity is greater than 1 kPa and less than or equal to 5 kPa, and the pressure difference between the inside and outside of the material column is not greater than 1 kPa.

7. The rapid preparation method of carbon / carbon brake disc according to claim 6, characterized in that: In the step 3, the chamber of the chemical vapor infiltration furnace is first evacuated to less than 1 kPa, and then the temperature in the furnace is raised to 880-1100° C.; then the carbon source gas is preheated to 500-900° C. by a preheating device located at the bottom of the chamber of the chemical vapor infiltration furnace, and then fed into the chamber at a speed of 0.7-3 m / s; After the carbon source gas is introduced, the gas outside the carbon / carbon brake disc porous blank is extracted to form a pressure difference inside and outside the cavity of the carbon / carbon brake disc porous blank along the thickness direction and the radial direction; the pressure inside the porous cavity of the carbon / carbon brake disc blank is greater than 1kPa and less than or equal to 5kPa, and the pressure difference inside and outside the cavity of the material column is not greater than 1kPa.

8. The rapid preparation method of carbon / carbon brake disc according to claim 7, characterized in that: In the step 3, one side of the carbon / carbon brake disc porous body is first subjected to a densification treatment for 100-400 hours, and then the carbon / carbon brake disc porous body is turned over and further subjected to a densification treatment for 100-300 hours.

9. The rapid preparation method of carbon / carbon brake disc according to claim 8, characterized in that: In step 3, the thickness of the inner graphite gasket ring and the outer graphite gasket ring is 3-8 mm, and the ring band width is 5%-10% of the ring band width of the carbon / carbon brake disc preform.

10. The rapid preparation method of carbon / carbon brake disc according to any one of claims 1 to 9, characterized in that: In step 2 and step 3, the carbon source gas includes one or more of natural gas, propane, propylene and acetylene, and a diluent gas, and the diluent gas is nitrogen, hydrogen or a mixture thereof.

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