Aerospace carbon ceramic brake material and method of making same

Abstract

The application discloses an aviation carbon ceramic brake material and a preparation method thereof. The aviation carbon ceramic brake material is prepared by the following steps: alternately stacking no-woven cloth and thin net felt, and layer by layer performing first needle punching to respectively obtain an upper layer preform and a lower layer preform; then placing flexible graphite paper in the middle of the upper layer preform and the lower layer preform, and performing second needle punching to obtain a carbon fiber preform; performing resin carbon densification on the carbon fiber preform to obtain a C / C blank; performing chemical vapor deposition carbon densification on the C / C blank to obtain a C / C porous body; performing reaction infiltration silicon on the C / C porous body to obtain a carbon ceramic composite material; arranging a coating on the surface of the carbon ceramic composite material to obtain a carbon ceramic composite material containing a coating; and machining the carbon ceramic composite material containing the coating to obtain the aviation carbon ceramic brake material. The aviation carbon ceramic brake material provided by the application has high heat conductivity, no howling, and stable brake performance.

Description

Technical Field

[0001] This invention relates to an aerospace carbon-ceramic brake material and its preparation method, belonging to the technical field of brake carbon-ceramic composite material preparation. Background Technology

[0002] Currently, there are many methods for preparing C / SiC brake materials, including precursor impregnation pyrolysis, plasma spraying, vapor deposition, and reactive infiltration. These methods can basically solve the braking problems of most aircraft, high-speed trains, and automobiles. However, carbon-ceramic brake materials exhibit significant squealing and high temperatures during braking. Current carbon-ceramic material preparation technologies struggle to completely resolve these issues, hindering the large-scale application of aerospace carbon-ceramic brake materials. The high hardness of carbon-ceramic materials, coupled with significant self-excited vibration and poor thermal conductivity during braking, are the main causes of squealing and high temperatures. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the first objective of this invention is to provide a method for preparing aerospace carbon-ceramic brake materials. This invention utilizes a designed sandwich-structured carbon fiber preform, which undergoes impregnation densification and CVD deposition densification, followed by a reactive melting process. The resulting carbon-ceramic brake material not only exhibits excellent performance but also solves the problems of squealing and high temperatures during braking, making the large-scale application of carbon-ceramic brake materials possible.

[0004] The second objective of this invention is to provide an aerospace carbon-ceramic brake material prepared by the above-mentioned preparation method. The aerospace carbon-ceramic brake material provided by this invention has high thermal conductivity, no whistling, and stable braking performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention discloses a method for preparing an aerospace carbon-ceramic brake material. The method involves alternately layering non-woven fabric and thin mesh felt, and then performing a first needle punch on each layer to obtain an upper preform and a lower preform. Flexible graphite paper is then placed between the upper and lower preforms, and a second needle punch or puncture is performed to obtain a carbon fiber preform. The carbon fiber preform is first densified with resin carbon to obtain a C / C preform. The C / C preform is then densified with carbon through chemical vapor deposition to obtain a C / C porous body. The C / C porous body is then subjected to reactive melting and infiltration with silicon to obtain a carbon-ceramic composite material. A coating is applied to the surface of the carbon-ceramic composite material to obtain a coated carbon-ceramic composite material. Finally, the coated carbon-ceramic composite material is machined to obtain the aerospace carbon-ceramic brake material.

[0007] The preparation method of this invention involves introducing flexible graphite paper into the middle of the carbon fiber preform during preparation, ultimately obtaining an aerospace carbon-ceramic brake material with graphite paper in the center. Graphite paper has excellent thermal conductivity, which can quickly dissipate the heat of the carbon-ceramic brake material during braking, thereby reducing the surface temperature rise of the carbon-ceramic brake material. In addition, during the carbon densification process, this invention first performs resin carbon densification and then chemical vapor deposition carbon densification. The inventors have found that resin carbon densification can effectively fill the large pores generated during the needle punching process, thereby avoiding the enrichment of silicon carbide in the needle holes after melting and infiltration, obtaining uniformly distributed silicon carbide, and finally obtaining a carbon-ceramic brake material with stable braking performance and low squeal.

[0008] In a preferred embodiment, the thickness of the non-woven fabric is ≥1.5mm, and the thickness of the thin mesh is <0.5mm, preferably 0.3-0.4mm.

[0009] In this invention, the non-woven fabric used is made of non-twisted continuous carbon fiber, and the carbon content of the non-twisted PAN carbon fiber should not be less than 92%.

[0010] In a preferred embodiment, the upper precast body and the lower precast body have the same structure, wherein the number of non-woven fabric layers is 7 to 9, and the uppermost and lowermost layers of both the upper and lower precast bodies are non-woven fabric.

[0011] The inventors discovered that if the content of the thin mesh layer is high, silicon will accumulate in the needle holes and mesh layer during the melting process, resulting in the formation of a large amount of silicon carbide. In this invention, by using the above-mentioned method to stack the non-woven fabric and the thin mesh layer, and controlling that the top and bottom layers of the upper and lower preforms are both non-woven fabric, the mesh layer can be appropriately reduced, effectively solving the problem of silicon carbide accumulation in the mesh layer. During the needle punching process, a small amount of mesh is pulled and broken vertically by the hook needle, making the non-woven fabric adhere more tightly and increasing the interlayer shear strength. Therefore, if the thin mesh is too small, it will also cause the graphite paper and the non-woven fabric to not adhere tightly, easily resulting in large gaps and a significant reduction in shear strength.

[0012] In a preferred embodiment, during the first acupuncture session, the row spacing and inter-row spacing are ≤1mm; the density of the first acupuncture session is 30-50 needles / cm. 2 The diameter of the needle should be ≤0.5mm.

[0013] In a preferred embodiment, the non-woven fabric, thin mesh, and flexible graphite paper are all circular.

[0014] In a preferred embodiment, the thickness of the flexible graphite paper is 0.6-2.5 mm, more preferably 1-2.5 mm, and even more preferably 1-1.5 mm.

[0015] The inventors discovered that the thicker the graphite paper, the better its thermal conductivity. However, graphite paper that is too thin is prone to breakage during the preparation of carbon fiber preforms, which prevents it from effectively utilizing its excellent thermal conductivity. On the other hand, excessively thick graphite paper will also result in a decrease in shear strength because the vertical fibers are too short during the needle punching process, making it difficult to stitch the preform together. While a thicker graphite paper can be used with the piercing process, the cost of the piercing process is three times higher than that of the needle punching process. Therefore, this invention optimizes the second needle punching process, which allows for the use of a thicker graphite paper compared to the conventional needle punching method, thereby further improving the thermal conductivity of the carbon ceramic brake material.

[0016] In a preferred embodiment, the second needling is performed inward along a position 10-12 mm larger than the inner diameter of the flexible graphite paper and outward along a position 10-12 mm smaller than the outer diameter of the flexible graphite paper.

[0017] The inventors discovered that by using the above-mentioned needle punching method for the second needle punching, on the one hand, a higher graphite paper thickness can be used, and on the other hand, the carbon fiber content in the vertical direction can be increased, thereby improving the interlaminar shear strength. This allows the interlaminar shear strength to reach the level that can be achieved by the puncture method, but at a lower cost. If the needle punching is not performed as described above, large gaps will appear between the non-woven fabrics of the preform and between the non-woven fabrics and the graphite paper, resulting in lower interlaminar shear strength.

[0018] In the preferred embodiment, the second acupuncture session has a row spacing and inter-row spacing of ≤1mm; the density of the second acupuncture session is 30-50 needles / cm. 2 .

[0019] In a preferred embodiment, the density of the carbon fiber preform is 0.6–0.7 g / cm³. 3 .

[0020] In a preferred embodiment, the carbon fiber preform resin carbon densification process is as follows: the carbon fiber preform is impregnated in an impregnating agent, then cured to obtain a cured preform, and then carbonized and heat-treated to obtain a C / C preform. The impregnating agent is composed of furfuryl ketone resin, phosphoric acid solution, and toluene, with a mass ratio of furfuryl ketone resin: phosphoric acid: toluene = 1:0.05~0.08:0.03~0.06.

[0021] In this invention, the viscosity (25°C) of the furfuryl ketone resin used is 40-100s, the ash content (w / %) is ≤3.0, and the moisture content (w / %) is ≤1.0; the phosphoric acid is commercially available 85% phosphoric acid, and the purity of the toluene is 99%. In actual operation, the furfuryl ketone resin, phosphoric acid, and toluene are mixed and stirred for about 30 minutes.

[0022] In a further preferred embodiment, the impregnation process is as follows: the C / C blank is placed in an impregnation kettle, a vacuum is drawn to a pressure of <100 Pa, then the impregnation agent is drawn into the impregnation kettle, and after impregnation for 1 to 2 hours, nitrogen gas is used to pressurize the pressure to 2 to 5 MPa, and impregnation is continued for 1 to 2 hours.

[0023] In a preferred embodiment, the curing temperature is 180–200°C, the curing time is 8–10 h, and the curing pressure is 2–5 MPa.

[0024] In actual operation, curing can be carried out directly in the impregnation tank. That is, after impregnation, the impregnating agent is released and the temperature is raised directly for curing.

[0025] In a preferred embodiment, the carbonization temperature is 800–820°C and the carbonization time is 8–10 hours.

[0026] In a preferred embodiment, the heat treatment temperature is 1500℃~1800℃, and the heat treatment time is 2~3h. By controlling the heat treatment temperature within the above range, the resin carbon can be thoroughly purified. If the heat treatment temperature is too low, the resin carbon will not be thoroughly purified, and during the subsequent melting and infiltration process, the resin carbon will continue to release small molecule substances, increasing the internal pressure of the matrix, affecting the infiltration of silicon, and resulting in uneven melting and infiltration.

[0027] In a preferred embodiment, the density of the char / char blank is 1.10–1.15 g / cm³. 3 .

[0028] In this invention, a single resin impregnation-curing densification process is performed to fill the needle-punched large pores with resin carbon. This process can reduce the size of the large pores and prevent the small pores from being blocked due to volume shrinkage. If multiple layers of impregnation are performed, the small pores will be blocked by the resin carbon, affecting the subsequent infiltration of silicon and resulting in uneven melting and infiltration.

[0029] In a preferred embodiment, during the chemical vapor deposition furnace, acetylene gas is used as the carbon source, and nitrogen is used as the dilution gas, with a volume ratio of acetylene gas to nitrogen of 1:1.2 to 1.3. In this invention, using acetylene gas as the carbon source is advantageous because acetylene gas is low in cost, and the carbon structure formed by acetylene gas deposition is primarily a rough layer structure, which exhibits better thermal conductivity.

[0030] In a preferred embodiment, the chemical vapor deposition is carried out at a pressure of 0.7–0.9 kPa, a temperature of 1000–1050 °C, and a time of 110–300 h.

[0031] In a preferred embodiment, carbon densification is carried out by chemical vapor deposition, followed by heat treatment to obtain C / C porous bodies. The heat treatment temperature is 1500℃~1600℃ and the time is 2~3h.

[0032] In a preferred embodiment, the silicon used in the reaction melting process has a purity of ≥99.0% and a particle size of ≤400 mesh.

[0033] In a preferred embodiment, the reactive melting infiltration of silicon is carried out under a nitrogen atmosphere, the temperature of the reactive melting infiltration of silicon is 1900℃~2100℃, the reaction time is 2~3h, and the pressure is 1000~2000Pa.

[0034] The inventors discovered that the reaction melting temperature has a significant impact on the friction coefficient of carbon-ceramic brake materials. The higher the reaction melting temperature of silicon, the higher the friction coefficient. Therefore, an appropriate melting temperature can be selected according to the needs of actual applications.

[0035] In a preferred embodiment, the process of applying a coating to the surface of the carbon-ceramic composite material is as follows: the carbon-ceramic composite material is placed in a coating impregnating agent and vacuum impregnated for 1 to 2 hours, followed by curing treatment. The vacuum degree during vacuum impregnation is 10 Pa, the temperature of the curing treatment is 350 to 420°C, and the curing time is 3 to 5 hours.

[0036] In a further preferred embodiment, the coating impregnating agent is obtained by mixing solution A and solution B at a mass ratio of (4-4.5):1, wherein in solution A, the molar ratio of aluminum isopropoxide (Al(C3H7O)3): tetraethyl orthosilicate (Si(OC2H5)4): water (H2O): ethanol (C2H5OH) is 1:(1-1.5):(4-4.5):(10-12), and in solution B, the mass ratio of ceramic powder to hydrochloric acid ethanol solution is 1:4; wherein the concentration of hydrochloric acid in the hydrochloric acid ethanol solution is 0.2-0.3 mol / L, and the ceramic powder is obtained by mixing silica powder (SiO2) and alumina powder (Al2O3) at a mass ratio of 1:1-1.2 and then grinding them, wherein both silica powder and alumina powder are 500-600 mesh.

[0037] After the surface of the carbon-ceramic composite material is coated, it undergoes a grinding process to remove the anti-oxidation coating on the friction surface. The designed machining allowance is less than 0.2 mm per side. After machining, the carbon-ceramic brake material is obtained.

[0038] The present invention also provides a carbon-ceramic brake material prepared by the above preparation method.

[0039] Principles and advantages

[0040] The squealing problem during braking with aerospace carbon-ceramic brake materials is mainly caused by the uneven distribution of silicon carbide components within the material. The inventors discovered that the primary cause of this uneven silicon carbide distribution is the inability to fill the large pores formed during the needle-punching process in the preform fabrication stage, coupled with a high content of thin mesh layers. This leads to silicon enrichment in the needle-punched pores and mesh layers during the melting and infiltration process, resulting in a large amount of silicon carbide. During friction, the areas rich in silicon carbide have higher hardness, increased local roughness, and increased vibration, thus producing squealing. Furthermore, because carbon-ceramic materials have low thermal diffusivity and poor thermal conductivity, the brake disc surface temperature is high, which not only increases wear but also makes the fusible plug more prone to melting, posing a safety risk. Moreover, the higher temperature increases thermal vibration on the friction surface, making the squealing even louder.

[0041] The inventors discovered that the main solutions to the vibration and howling problem are to fill the large needle-punched gaps and reduce the content of thin mesh. Resin impregnation can effectively fill the large pores and solve the problem of silicon carbide accumulation in the needle holes, while reducing the content of thin mesh can effectively solve the problem of silicon carbide accumulation in the mesh layer.

[0042] The inventors discovered that the main solution to the high temperature problem of the friction surface is to increase the heat storage capacity of the brake disc and improve the thermal conductivity of the material. Encasing flexible graphite paper within the material structure achieves both the goal of increasing the heat storage capacity and the ability of graphite's excellent thermal conductivity to quickly dissipate heat, thereby reducing the brake disc temperature.

[0043] The aerospace carbon-ceramic brake prepared by this invention has a density of 1.98–2.1 g / cm³. 3 The friction coefficient is 0.3±0.02, the whistling frequency is less than 1200 Hz, the brake temperature is less than 480℃, and the braking performance is stable. Attached Figure Description

[0044] Figure 1 A schematic diagram of the anatomical structure of the carbon fiber preform of this invention.

[0045] Figure 2 Cross-sectional anatomical diagram of the carbon-ceramic brake material prepared in Example 1 of this invention. Detailed Implementation

[0046] Example 1

[0047] Step 1: Preparation of the preform

[0048] The prefabricated structure is made of untwisted continuous carbon fiber woven into a non-woven carbon cloth. The carbon content of the untwisted PAN carbon fiber should be no less than 92%, and the thickness should be 1.5 mm. The prefabricated structure is composed of multiple layers of PAN carbon fiber non-woven cloth, multiple layers of PAN carbon fiber thin mesh, and a layer of flexible graphite paper. The thin mesh is 0.3 mm thick, and the flexible graphite paper is 1.5 mm thick. The non-woven cloth is laid in alternating layers at 0° / 90° angles. Two prefabricated structures are first prepared, with 8 layers of non-woven cloth laid in each structure, and a thin mesh sandwiched between every two layers of non-woven cloth. The upper and lower prefabricated structures are then needle-punched separately, with a needle spacing and line spacing ≤ 1 mm; the needle density is controlled at 40 needles / cm². 2 Within the specified range, the needle diameter is 0.5 mm. Then, a layer of flexible graphite paper is sandwiched between the upper and lower prefabricated layers and joined together. Needling operations are performed inwards along positions 10 mm larger than the inner diameter of the interlayer graphite paper and outwards along positions 10 mm smaller than the outer diameter of the interlayer graphite paper. The needle spacing and interval are ≤1 mm; the needle density is controlled at 40 needles / cm². 2 Within the scope (see appendix for details) Figure 1 The bulk density of the prepared preform was 0.65 g / cm³. 3 .

[0049] Step 2: Impregnation and densification

[0050] The preform from step one was placed in an impregnation and curing furnace, and a vacuum was applied (vacuum degree ≤10 Pa). Then, a mixing solution of furfuryl ketone resin, phosphoric acid, and toluene in a ratio of 1:0.05:0.03 was prepared and drawn into the furnace to immerse the C / C matrix. Vacuum impregnation was performed for 1 hour, followed by pressure impregnation for another hour. The impregnation solution was then released, the pressure was increased to 5 MPa, and the furnace was heated to 200℃ for curing for 8 hours. After curing, the preform was cooled to room temperature and transferred to a carbonization furnace. The furnace was evacuated twice to purge with nitrogen, and then purged with nitrogen to a slightly positive pressure. The temperature was raised to 820℃ for carbonization. After carbonization, the preform was transferred to a high-temperature heat treatment furnace for heat treatment at 1600℃ for 2 hours, yielding a density of 1.12 g / cm³. 3 C / C blank.

[0051] Step 3: CVD Densification

[0052] The preform from step two was transferred to a chemical vapor deposition (CVD) furnace for densification, using acetylene gas as the carbon source and nitrogen gas as the dilution gas. During CVD, the furnace pressure was controlled at 0.7–0.9 kPa and the temperature at 1050 °C; the volume ratio of acetylene gas to nitrogen gas was 1:1.2; after 240 hours of deposition, the density reached 1.45 g / cm³. 3 Then it is transferred to a high-temperature heat treatment furnace for heat treatment at 1600℃ for 2 hours.

[0053] Step 4: Reactive Melting

[0054] The preform from step three is then subjected to melt infiltration of silicon. The silicon purity is greater than 99%, and the particle size is less than 400 mesh; the infiltration temperature is 1900℃; the infiltration time is 2 hours; the atmosphere is nitrogen; and the furnace pressure is 1000-2000 Pa.

[0055] Step 5: Coating Impregnation

[0056] The blank from step four is transferred into an impregnation curing oven, and a vacuum is applied (vacuum degree ≤10 Pa). The coating liquid is then drawn into the impregnation vessel to immerse the brake disc. After vacuum impregnation for 1 hour, the pressure is released to drain the coating liquid, and then the temperature is slowly raised to 350℃ for curing treatment, with a curing time of 3 hours.

[0057] Step Six: Machining of C / SiC Brake Discs

[0058] The blank from step five is then transferred to the grinding process to remove the anti-oxidation coating on the friction surface. The designed machining allowance is less than 0.2 mm per surface. After machining, the C / SiC brake disc is obtained.

[0059] The prepared material has the following properties: density 1.98 g / cm³. 3 The coefficient of friction is 0.3, the whistling frequency is 1100 Hz, and the braking temperature is 467℃. The shear strength is 30 MPa, the wear rate is 0.63 μm / cycle·surface, and the braking performance is stable.

[0060] Example 2

[0061] The other steps are the same as in Example 1, except that the thickness of the flexible graphite paper used to prepare the preform is 1.0 mm.

[0062] The prepared material has the following properties: density 1.98 g / cm³. 3 The coefficient of friction is 0.28, the whistling frequency is 1100 Hz, and the braking temperature is 503℃. The shear strength is 30 MPa, the wear rate is 0.71 μm / cycle·surface, and the braking performance is stable.

[0063] Example 3

[0064] The other steps are the same as in Example 1, except that the thickness of the flexible graphite paper used to prepare the preform is 2.5 mm, and the secondary needle punching process is changed to fiber puncture.

[0065] The prepared material has the following properties: density 1.98 g / cm³. 3 The coefficient of friction is 0.3, the whistling frequency is 1100 Hz, and the braking temperature is 432℃. The shear strength is 45 MPa, the wear rate is 0.60 μm / cycle·surface, and the braking performance is stable.

[0066] Comparative Example 1

[0067] The other steps are the same as in Example 1, except that the felt layer is omitted in the preparation of the preform.

[0068] Delamination occurred after impregnation and carbonization of the precast body, leading to its failure. Removing the mesh layer resulted in a decrease in the vertical fiber mechanical properties and interlaminar shear strength during the needle-punching and stitching process of the upper and lower precast bodies.

[0069] Comparative Example 2

[0070] The other steps are the same as in Example 1, except that the thickness of the flexible graphite paper used to prepare the preform is 2.5 mm.

[0071] After impregnation and carbonization, the preform exhibits delamination, leading to preform failure. During the needle-punching process, when the graphite paper thickness reaches 2.5 mm, the vertical fiber mechanical properties decrease and the interlaminar shear strength diminishes during the needle-punching and stitching of the upper and lower preforms.

[0072] Comparative Example 3

[0073] The other steps are the same as in Example 1, except that the thickness of the felt layer in the preform preparation is 1.0 mm.

[0074] The prepared material has the following properties: density 1.99 g / cm³. 3 It has a friction coefficient of 0.3, a whistling frequency of 1280 Hz, and a braking temperature of 470℃. Its shear strength is 35 MPa, wear rate is 0.61 μm / cycle·surface, and its braking performance is stable.

[0075] In Comparative Example 3, increasing the thickness of the felt layer increased the whistling frequency and the brake temperature rose.

[0076] Comparative Example 4

[0077] The other steps are the same as in Example 1, except that the graphite paper is omitted in the preparation of the preform, and the mesh layer and the non-woven fabric are stacked at intervals with the same thickness.

[0078] The prepared material has the following properties: density 2.2 g / cm³. 3 It has a friction coefficient of 0.4, a whistling frequency of 1440 Hz, and a braking temperature of 798℃. Its shear strength is 33 MPa, wear rate is 1.47 μm / cycle / surface, and its braking performance is stable.

[0079] In Comparative Example 4, the removal of graphite paper and the equal-ratio superposition of non-woven fabric and felt resulted in the highest frequency of whistling during braking, increased brake temperature, and increased wear.

[0080] Comparative Example 5

[0081] The other steps are the same as in Example 1, except that graphite paper is omitted in the preparation of the preform.

[0082] The prepared material has the following properties: density 2.05 g / cm³. 3 The coefficient of friction is 0.28, the whistling frequency is 1250 Hz, and the braking temperature is 710℃. The shear strength is 25 MPa, the wear rate is 1.44 μm / cycle·surface, and the braking performance is stable.

[0083] In Comparative Example 5, the removal of graphite paper reduced thermal conductivity, increased brake temperature, increased wear, and increased whistling frequency.

[0084] Comparative Example 6

[0085] The other steps are the same as in Example 1, except that the thickness of the flexible graphite paper used to prepare the preform is 0.5 mm.

[0086] The prepared material has the following properties: density 1.98 g / cm³. 3 The coefficient of friction is 0.28, the whistling frequency is 1150 Hz, and the braking temperature is 547℃. The shear strength is 30 MPa, the wear rate is 0.94 μm / cycle·surface, and the braking performance is stable.

[0087] The performance of the embodiments is shown in Table 1:

[0088] Performance Comparison Example 1 Example 2 Example 3 <![CDATA[Density (g / cm 3 )]]> 1.98 1.98 1.98 Shear strength (MPa) 30 30 45 Whistling frequency (Hz) 1100 1100 1100 Brake temperature (°C) 467 503 432 coefficient of friction 0.3 0.3 0.3 Wear rate μm / time·area 0.63 0.71 0.60

[0089] The performance of the comparative examples is shown in Table 2:

[0090] Performance Comparison Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 <![CDATA[Density (g / cm 3 )]]> 1.99 2.2 2.05 1.98 Shear strength (MPa) 35 33 25 30 Whistling frequency (Hz) 1280 1440 1250 1150 Brake temperature (°C) 470 798 710 547 coefficient of friction 0.3 0.4 0.28 0.3 Wear rate μm / time·area 0.61 1.47 1.44 0.94

Claims

1. A method for preparing an aeronautical carbon-carbon brake material, characterized in that: The non-woven cloth and the thin net felt are alternately stacked and first needled layer by layer to obtain an upper layer preform and a lower layer preform respectively; then the flexible graphite paper is placed in the middle of the upper layer preform and the lower layer preform, and then a second needling or puncture is performed to obtain a carbon fiber preform; the carbon fiber preform is first densified by resin carbon to obtain a C / C blank, the C / C blank is densified by chemical vapor deposition carbon to obtain a C / C porous body, the C / C porous body is obtained by reaction infiltration of silicon to obtain a carbon ceramic composite material, a coating is arranged on the surface of the carbon ceramic composite material to obtain a carbon ceramic composite material with a coating, and the carbon ceramic composite material with the coating is machined to obtain an aviation carbon ceramic brake material. The upper layer preform and the lower layer preform have the same structure, wherein the number of layers of the non-woven cloth is 7-9 layers, and the uppermost layer and the lowermost layer of the upper layer preform and the lower layer preform are both non-woven cloth. The thickness of the thin net felt is <0.5mm. The thickness of the flexible graphite paper is 0.6-2.5 mm. The second needling is performed inward along a position greater than the inner diameter of the flexible graphite paper by 10-12 mm and outward along a position less than the outer diameter of the flexible graphite paper by 10-12 mm.

2. The method for preparing an aerospace carbon-ceramic brake material according to claim 1, characterized in that: The thickness of the non-woven fabric is greater than or equal to 1.5 mm, the line spacing and the interval spacing are less than or equal to 1 mm during the first needling, the density of the first needling is 30-50 needles per cm 2 , and the diameter of the needle is less than or equal to 0.5 mm.

3. The method for preparing an aviation carbon-carbon brake material according to claim 1 or 2, characterized in that: The non-woven cloth, the thin net felt, and the flexible graphite paper are all circular rings.

4. The preparation method of the aviation carbon ceramic brake material according to claim 1 or 2, characterized in that: The second needling has a line distance and a space distance of less than or equal to 1 mm, and a density of 30-50 needles per cm 2 ; The carbon fiber prepreg has a density of 0.6-0.7 g / cm 3 .

5. The method of claim 1, wherein the carbon-carbon brake material is an aircraft carbon-carbon brake material. The process of resin carbon densification of the carbon fiber preform is: the carbon fiber preform is impregnated in an impregnating agent, then a cured preform is obtained after curing, and then a C / C blank is obtained after carbonization treatment and heat treatment, the impregnating agent is composed of furfural resin, phosphoric acid solution, and toluene, and the mass ratio of furfural resin: phosphoric acid: toluene is 1: 0.05-0.08: 0.03-0.06; The impregnation process is: the C / C blank is placed in an impregnation kettle, vacuumized to a pressure <100 Pa, then the impregnating agent is sucked into the impregnation kettle, impregnated for 1-2 h, then pressurized to 2-5 MPa with nitrogen, and impregnated for 1-2 h; The curing temperature is 180-200℃, the curing time is 8-10 h, and the curing pressure is 2-5 MPa; The carbonization treatment temperature is 800-820℃, and the carbonization treatment time is 8-10 h.

6. The method of claim 5, wherein the carbon-carbon brake material is an aircraft carbon-carbon brake material. The heat treatment temperature is 1500℃-1800℃, and the heat treatment time is 2-3 h; The density of the C / C green body is 1.10-1.15 g / cm 3 .

7. The method of claim 1, wherein the carbon-carbon brake material is an aircraft carbon-carbon brake material. The chemical vapor deposition uses acetylene gas as a carbon source and nitrogen gas as a dilution gas, and the volume ratio of acetylene gas to nitrogen gas is 1: 1.2-1.3; The chemical vapor deposition pressure is 0.7-0.9 kPa, the temperature is 1000-1050℃, and the time is 110-300 h; After the chemical vapor deposition carbon densification, the C / C porous body is obtained by heat treatment, and the heat treatment temperature is 1500℃-1600℃, and the time is 2-3 h.

8. The method of claim 1, wherein the carbon-carbon brake material is an aircraft carbon-carbon brake material. The purity of the silicon used in the reaction infiltration of silicon is ≥99.0%, and the particle size is ≤400 mesh; The reaction infiltration of silicon is carried out in a nitrogen atmosphere, the reaction infiltration of silicon temperature is 1900℃-2100℃, the reaction infiltration of silicon time is 2-3 h, and the pressure is 1000-2000 Pa.

9. The method of claim 1, wherein the carbon-carbon brake material is an aircraft carbon-carbon brake material. The process for coating the surface of the carbon ceramic composite material is as follows: the carbon ceramic composite material is vacuum impregnated in a coating impregnant for 1-2 hours, and then solidified to obtain the coating, wherein the vacuum degree during the vacuum impregnation is 10 Pa, the solidification temperature is 350-420 DEG C, and the solidification time is 3-5 hours; The coating impregnant is obtained by mixing A liquid and B liquid in a mass ratio of 4-4.5:1, wherein in the A liquid, the molar ratio of aluminum isopropoxide, tetraethyl orthosilicate, water and ethanol is 1:1-1.5:4-4.5:10-12, and in the B liquid, the mass ratio of ceramic powder and hydrochloric acid ethanol solution is 1:4; wherein the concentration of hydrochloric acid in the hydrochloric acid ethanol solution is 0.2-0.3 mol / L, the ceramic powder is obtained by mixing silica powder and alumina powder in a mass ratio of 1:1-1.2 and then grinding, and the silica powder and the alumina powder are both 500-600 mesh.

10. The carbon ceramic brake material prepared by the preparation method of any one of claims 1-9.

Images