Carbon fiber reinforced ceramic material with near-zero expansion characteristic and preparation method thereof

Abstract

The invention relates to a carbon fiber reinforced ceramic material with near-zero expansion characteristic and a preparation method thereof, and belongs to the field of ceramic matrix composite materials. Comprising the following steps: obtaining a pyrolytic carbon interface layer on the surface of a fiber bundle through a chemical vapor deposition method; the preparation method comprises the following steps: ball-milling and uniformly mixing low-expansion ceramic powder, a monomer, a cross-linking agent and a dispersing agent, adding an initiator and a catalyst, stirring, and carrying out vacuum defoaming; soaking the carbon fiber woven body in the ceramic slurry, curing the slurry into a wet blank, drying, repeatedly soaking and circulating until the weight is not increased any more, and drying to constant weight; densification is achieved through precursor impregnation and pyrolysis, and the carbon fiber reinforced ceramic material is obtained. According to the preparation method, a composite process of pressure-assisted gel casting and ultrasonic vibration-assisted pressurized impregnation-cracking is utilized, so that the introduction amount and uniformity of a low-expansion or negative-expansion ceramic phase in a fiber woven body are improved, and the problems of low impregnation efficiency, multiple cycle periods and the like of a ceramic precursor in a traditional PIP process are solved; the thermal expansion coefficient of the ceramic-based composite material can be greatly reduced, the overall strength is high, and the fracture toughness resistance is good.

Description

Technical Field

[0001] The present invention belongs to the field of ceramic matrix composites, and particularly relates to a carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof. Background Art

[0002] With the development of space remote sensing technology, higher requirements are put forward for space optical systems. As the mounting platform for optical elements, the change of the position tolerance of the space opto-mechanical structure is mainly affected by the structural stiffness of the camera frame, the stiffness of the support structure, and the thermal adaptability. In addition, the working environment temperature of the space opto-mechanical structure changes violently, space radiation, space debris impact, as well as space atomic oxygen impact and vibration during rocket launch will all affect the precision structure of the camera optical system, becoming the key factors determining the service life of space cameras. Therefore, extremely stringent requirements are put forward for the material selection and preparation of the space opto-mechanical structure. Lightweight materials with high specific strength, high specific stiffness, and low thermal expansion coefficient are one of the key technologies for the space opto-mechanical structure. Among them, the thermal expansion performance of the space opto-mechanical structure material needs to meet the requirement of near-zero expansion within the service temperature range, and the absolute value of its thermal expansion coefficient is less than 0.4×10 -6 / K.

[0003] Currently, the materials used for space opto-mechanical structure parts mainly include alloy materials, resin matrix composites, and ceramic matrix composites. Among them, C / SiC composites integrate the excellent mechanical properties, high temperature resistance, and low thermal expansion coefficient of carbon fibers, as well as the low density, oxidation resistance, and ablation resistance of the silicon carbide matrix, and are ideal materials for making space opto-mechanical structure materials. However, the thermal expansion coefficient of the C / SiC composites prepared by the existing technology is about 1-2×10 -6 / K, still having a gap with the performance requirements of future space structure materials. Currently, in the research and development of near-zero expansion ceramic matrix composites for space opto-mechanical structure parts, there are still significant challenges in the existing preparation technologies.

[0004] Considering the high thermal expansion coefficient of SiC matrix, it is difficult to meet the requirements of near-zero expansion by using a single SiC phase as the matrix of carbon fiber reinforced ceramic matrix composites. On the other hand, the preparation processes of carbon fiber composites mainly include chemical vapor infiltration (CVI), precursor pyrolysis (PIP) and reactive melt infiltration (RMI), but these methods generally have the disadvantages of long process cycle and high preparation cost. The slurry impregnation method has low cost and short process cycle, which can reduce the time of subsequent PIP impregnation and pyrolysis densification, but due to the interlaced structure of the braid and the friction between the particles, it is easy to cause blockage on the surface of the carbon fiber braid, resulting in insufficient ceramic content and uneven distribution inside the braid. Therefore, it is urgent to study and invent a new method that can uniformly introduce a high content of low expansion or negative expansion particles into a three-dimensional carbon fiber braid, and it is low cost and short process cycle, so as to prepare carbon fiber reinforced ceramic materials with near-zero expansion characteristics. Summary of the invention

[0005] In order to solve the deficiencies in the above-mentioned background technology, the present invention provides a carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof. A low expansion or negative expansion second phase is introduced into a C / SiC composite material by pressure-assisted gel injection molding, the amount and uniformity of ceramic powder introduced into the fiber braid are improved, and the thermal expansion performance is achieved by controlling the amount of addition to achieve an adjustable and controllable state; and combined with ultrasonic vibration-assisted pressurized impregnation-cracking, the problems of low impregnation efficiency and multiple cycles of ceramic precursors in the traditional PIP process are overcome. The material prepared by the PIP process has the advantages of low density, high rigidity and good thermal conductivity. The converted SiC is an amorphous structure with a lower expansion coefficient than that of crystalline SiC. The multi-level pore structure in the material can also offset thermal expansion, thereby realizing the preparation of carbon fiber reinforced ceramic materials with near-zero expansion characteristics. Compared with the traditional preparation process, the present invention can greatly reduce the thermal expansion coefficient of ceramic-based composite materials, and the process cycle is short and the preparation cost is low.

[0006] Furthermore, the method for preparing the carbon fiber reinforced ceramic material with near-zero expansion characteristics comprises the following steps:

[0007] Step 1: Soak the carbon fiber braid in acetone, wash it with distilled water and place it in an oven until it is completely dry;

[0008] Step 2: Place the carbon fiber braid in a high-temperature vacuum furnace and obtain a pyrolytic carbon interface layer on the fiber bundle surface by chemical vapor deposition;

[0009] Step 3: The low expansion ceramic powder, organic monomer, crosslinking agent and dispersant are ball-milled to obtain a uniformly dispersed ceramic slurry, followed by adding an initiator and a catalyst, and vacuum degassing after sufficient stirring;

[0010] Step 4: Immerse the carbon fiber preform in the ceramic slurry, transfer it into an autoclave, evacuate the air and fill it with gas to high pressure, and then cure the slurry into a green body by heating or standing at room temperature.

[0011] Step 5: Dry the wet carbon fiber preform in an incubator, repeat the impregnation cycle until the weight no longer increases, and dry it to a constant weight after impregnation is completed to obtain a carbon fiber reinforced ceramic green body after impregnation molding.

[0012] Step 6: Immerse the carbon fiber reinforced ceramic green body in a ceramic precursor, perform pressure impregnation and apply ultrasonic vibration, and then perform curing and pyrolysis to obtain a carbon fiber reinforced ceramic material with near-zero expansion characteristics.

[0013] Further, the carbon fiber preform in the first step is one or several of various commonly used carbon fiber fabrics, including 2.5D weaving, 3D needling, 3D three-dimensional weaving, etc., and the fiber volume fraction of the fiber preform is 10-60%.

[0014] Further, in the second step, the pyrolytic carbon interface layer is prepared by chemical vapor deposition. The raw materials used in the chemical vapor infiltration method are methane, natural gas, propane or propylene, the gas flow rate is 1.0-10.0 L / min, the deposition temperature is 950-1200 °C, the deposition pressure is 3-25 kPa, the deposition time is 10-100 h, and the thickness of the carbon interface layer is 50-600 nm.

[0015] Further, the low-expansion ceramic powder in the third step is one or several of NZP group compounds, quartz, cordierite, zirconium tungstate, β-spodumene, aluminum titanate, with an average particle size of 50 nm-5 μm. The organic monomer is at least one of acrylamide, methacrylamide, hydroxymethylacrylamide, polyethylene glycol diacrylate, sodium alginate, and gelatin. The content of the organic monomer is 5-20% of the mass of the slurry. The cross-linking agent is at least one of N,N'-methylenebisacrylamide, polyethylene glycol dimethacrylate, and pentaerythritol triacrylate. The content of the cross-linking agent is 1 / 10-1 / 5 of the mass of the monomer. The dispersant is at least one of polyethylene glycol, tetramethylammonium hydroxide, sodium carboxymethylcellulose, sodium tripolyphosphate, and polymethacrylate. The mass of the dispersant is 0.2-5% of the mass of the ceramic powder. The volume fraction of the ceramic slurry is 15-55%, the rotation speed of the ball mill is 100-300 r / min, and the ball milling time is 1-12 h.

[0016] Further, the initiator in the third step is at least one of ammonium persulfate, potassium persulfate, and azobisisobutyronitrile. The mass of the initiator is 0.1-1% of the mass of the monomer. The catalyst is at least one of tetramethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, and triethanolamine. The mass of the catalyst is 0.1-5% of the mass of the monomer.

[0017] Further, the vacuum degree in the fourth step is 1 Pa - 10 Pa, the impregnation pressure is 2 - 10 MPa, the curing temperature is 25 - 80 °C, and the curing time is 10 min - 10 h.

[0018] Further, the drying temperature in the fifth step is 25 - 80 °C, and the drying time is 2 - 24 h.

[0019] Further, the ceramic precursor in the sixth step is one or more of polycarbosilane, polymethylsilane, polyvinylsilane or polycarbosilylmethane. The vacuum degree is 1 Pa - 10 Pa, the vibration frequency is 100 - 600 kHz, the impregnation pressure is 2 - 10 MPa, the curing temperature is 100 - 250 °C, the time is 6 - 24 h, the high-temperature pyrolysis temperature is 1100 - 1500 °C, the protective gas is an inert gas, the heat preservation time is 1 - 5 h, and the number of impregnation and pyrolysis times is 2 - 12 times.

[0020] Advantages of the present invention:

[0021] The carbon fiber reinforced ceramic material with near-zero expansion characteristics provided by the present invention and its preparation method have the following advantages compared with the prior art:

[0022] 1. The carbon fiber reinforced ceramic material with near-zero expansion characteristics provided by the present invention and its preparation method use the pressure-assisted gel casting method to introduce a low-expansion or negative-expansion second phase into the C / SiC composite material, improve the introduction amount and uniformity of ceramic powder in the fiber woven body, and realize the controllability of the thermal expansion coefficient of the composite material by controlling the addition amount. In addition, the material prepared by the PIP process has the advantages of low density, high stiffness and good thermal conductivity. The converted SiC is an amorphous structure, and its expansion coefficient is lower than that of crystalline SiC. The multi-level pore structure existing in the material can also offset thermal expansion. The measured average thermal expansion coefficient of the composite material is 1 - 5×10 -7 / °C at -100 - 150 °C, achieving the goal of near-zero expansion and meeting the stringent requirements of future space optical-mechanical systems for structural materials.

[0023] 2. Compared with the traditional composite material preparation process, the present invention adopts the pressure-assisted gel casting method combined with ultrasonic vibration-assisted pressure impregnation-pyrolysis method, breaking through the problems of insufficient ceramic content and uneven distribution inside the carbon fiber woven body prepared by the traditional slurry impregnation method, as well as low impregnation efficiency and many cycle periods of the ceramic precursor in the PIP process. The process cycle is short and the preparation cost is low. Description of the drawings

[0024] Figure 1 It is a solid diagram of the carbon fiber reinforced ceramic material with near-zero expansion characteristics prepared in Example 1.

[0025] Figure 2 SEM image of the fracture surface of the carbon fiber reinforced ceramic material with near-zero expansion characteristics prepared in Example 1.

[0026] Figure 3 SEM image of crack propagation of the carbon fiber reinforced ceramic material with near-zero expansion characteristics prepared in Example 1. Specific implementation manners

[0027] Next, the technical solutions in the embodiments of the present invention will be described more clearly with reference to the accompanying drawings in the embodiments of the present invention. The following descriptions are only preferred embodiments of the present invention, but not limited to the following embodiments. The present invention is not limited thereto. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0028] Example 1

[0029] A carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof, comprising the following steps:

[0030] Immerse a 3D needle-punched structure carbon fiber fabric with a fiber volume fraction of 40% in acetone, wash it with distilled water, and place it in an oven until completely dry;

[0031] Place the carbon fiber fabric in a high-temperature vacuum furnace. The raw materials used are methane, natural gas, propane, or propylene. The gas flow rate is 5 L / min, the deposition temperature is 1100 °C, the deposition pressure is 10 kPa, the deposition time is 60 h, and the thickness of the carbon interface layer is 200 nm;

[0032] Weigh CaZr4(PO4)6 ceramic powder with an average particle size of 1 μm and add it to deionized water. The volume fraction of the ceramic slurry is 38%. Add tetramethylammonium hydroxide with a mass of 1.5 wt% of the ceramic powder, acrylamide with a mass of 10% of the slurry, N,N'-methylenebisacrylamide with a mass of 1 / 10 of the monomer, ammonium persulfate with a mass of 0.5% of the monomer, and tetramethylethylenediamine with a mass of 0.2% of the monomer. The rotation speed of the ball mill is 200 r / min, and the ball milling time is 6 h. Then, perform vacuum degassing;

[0033] Immerse the carbon fiber fabric in the ceramic slurry, perform pressure impregnation in an autoclave. The vacuum degree is 5 Pa, the impregnation pressure is 8 MPa, cure the slurry. The curing temperature is 50 °C, and the curing time is 30 min to obtain a carbon fiber reinforced ceramic green body;

[0034] Place the wet carbon fiber fabric green body in an incubator for drying. The drying temperature is 50 °C, and the drying time is 4 h. Repeat the impregnation cycle until the weight no longer increases. After impregnation is completed, dry it to a constant weight to obtain a carbon fiber reinforced ceramic green body after impregnation molding;

[0035] The green body of carbon fiber reinforced ceramic is immersed in polycarbosilane, then transferred into an autoclave for pressure impregnation with ultrasonic vibration applied. The vacuum degree is 5 Pa, the vibration frequency is 500 kHz, the impregnation pressure is 8 MPa. Then it is cured and pyrolyzed. The curing temperature is 200 °C and the time is 12 h. The high-temperature pyrolysis temperature is 120 °C, the protective gas is argon, and the heat preservation time is 2 h. The number of impregnation and pyrolysis times is 5 times, obtaining a carbon fiber reinforced ceramic material with near-zero expansion characteristics. The density of the carbon fiber reinforced ceramic material with near-zero expansion characteristics obtained in Example 1 is 2.2 g / cm 3 , the porosity is 14%; the flexural strength is 184 MPa, and the fracture toughness is 7.5 MPa·m 1 / 2 ; The solid diagram of the near-zero expansion fiber reinforced ceramic matrix composite obtained in Example 1 is as shown in Figure 1 , the SEM diagram of the fracture surface is as shown in Figure 2 , the average coefficient of thermal expansion is 3×10 -7 / °C (-100 - 150 °C), and the SEM diagram of crack propagation is as shown in Figure 3 .

[0036] Example 2

[0037] A carbon fiber reinforced ceramic material with near-zero expansion characteristics and its preparation method, including the following steps:

[0038] The 3D needle-punched structure carbon fiber fabric with a fiber volume fraction of 35% is immersed in acetone, washed with distilled water, and placed in an oven until completely dry;

[0039] The carbon fiber fabric is placed in a high-temperature vacuum furnace. The raw materials used are methane, natural gas, propane or propylene, the gas flow rate is 3 L / min, the deposition temperature is 1000 °C, the deposition pressure is 5 kPa, the deposition time is 50 h, and the thickness of the carbon interface layer is 150 nm;

[0040] Weigh cordierite ceramic powder with an average particle size of 0.8 μm and add it to deionized water. The volume fraction of the ceramic slurry is 30%. Add polyethylene glycol with a mass of 1 wt% of the ceramic powder, acrylamide with a mass of 10% of the slurry, N,N'-methylenebisacrylamide with a mass of 1 / 8 of the monomer, ammonium persulfate with a mass of 1% of the monomer, and tetramethylethylenediamine with a mass of 0.5% of the monomer. The rotation speed of the ball mill is 250 r / min, the ball milling time is 4 h, and then vacuum degassing is carried out;

[0041] The carbon fiber fabric is immersed in the ceramic slurry and subjected to pressure impregnation in an autoclave. The vacuum degree is 10 Pa, the impregnation pressure is 5 MPa, and the slurry is cured. The curing temperature is 60 °C and the curing time is 50 min, obtaining a green body of carbon fiber reinforced ceramic;

[0042] The wet blank of the carbon fiber woven body is placed in an incubator for drying. The drying temperature is 60°C and the drying time is 6 hours. The impregnation cycle is repeated until the weight no longer increases. After impregnation is completed, it is dried to a constant weight to obtain a carbon fiber reinforced ceramic green body after impregnation molding;

[0043] The carbon fiber reinforced ceramic green body is soaked in polycarbosilane, then transferred to an autoclave for pressure impregnation and ultrasonic vibration is applied. The vacuum degree is 8 Pa, the vibration frequency is 400 kHz, the impregnation pressure is 8 MPa, and then curing and pyrolysis are carried out. The curing temperature is 200°C and the time is 8 hours. The high-temperature pyrolysis temperature is 1200°C, the protective gas is argon, and the heat preservation time is 1 hour. The number of impregnation pyrolysis times is 4 times to obtain a carbon fiber reinforced ceramic material with near-zero expansion characteristics. The density of the carbon fiber reinforced ceramic material with near-zero expansion characteristics obtained in Example 2 is 2.1 g / cm 3 , the porosity is 16%; the flexural strength is 150 MPa, and the fracture toughness is 5 MPa·m 1 / 2 , and the average coefficient of thermal expansion is 2×10 -7 / °C (-100 - 150°C).

[0044] Example 3

[0045] A carbon fiber reinforced ceramic material with near-zero expansion characteristics and its preparation method include the following steps:

[0046] The 3D three-dimensional woven structure carbon fiber woven body with a fiber volume fraction of 40% is soaked in acetone, washed with distilled water and placed in an oven until completely dry;

[0047] The carbon fiber woven body is placed in a high-temperature vacuum furnace. The raw materials used are methane, natural gas, propane or propylene. The gas flow rate is 8 L / min, the deposition temperature is 1100°C, the deposition pressure is 10 kPa, the deposition time is 80 hours, and the thickness of the carbon interface layer is 300 nm;

[0048] Weigh the NaZr4(PO4)6 ceramic powder with an average particle size of 0.5 μm and add it to deionized water. The volume fraction of the ceramic slurry is 35%. Add sodium carboxymethyl cellulose accounting for 0.8 wt% of the mass of the ceramic powder, 15% of the mass of the slurry of methylacrylamide, polyethylene glycol dimethacrylate accounting for 1 / 5 of the mass of the monomer, potassium persulfate accounting for 0.5% of the mass of the monomer, and tetramethylethylenediamine accounting for 2% of the mass of the monomer. The rotation speed of the ball mill is 300 r / min and the ball milling time is 3 hours. Then vacuum degassing is carried out;

[0049] The carbon fiber woven body is soaked in the ceramic slurry and pressure impregnation is carried out in an autoclave. The vacuum degree is 5 Pa and the impregnation pressure is 10 MPa. The slurry is cured. The curing temperature is 80°C and the curing time is 20 minutes to obtain a wet blank of carbon fiber reinforced ceramic;

[0050] Place the wet blank of the carbon fiber woven body in an incubator for drying. The drying temperature is 70 °C and the drying time is 10 h. Repeat the impregnation cycle until the weight no longer increases. After impregnation is completed, dry to a constant weight to obtain a carbon fiber reinforced ceramic green body after impregnation molding;

[0051] Immerse the carbon fiber reinforced ceramic green body in polymethylsilane, then transfer it to an autoclave, perform pressure impregnation and apply ultrasonic vibration. The vacuum degree is 5 Pa, the vibration frequency is 300 kHz, the impregnation pressure is 5 MPa, and then carry out curing and pyrolysis. The curing temperature is 220 °C and the time is 6 h. The high-temperature pyrolysis temperature is 1250 °C, the protective gas is argon, and the heat preservation time is 2 h. The number of impregnation pyrolysis times is 5 times to obtain a carbon fiber reinforced ceramic material with near-zero expansion characteristics. The density of the carbon fiber reinforced ceramic material with near-zero expansion characteristics obtained in Example 3 is 2.3 g / cm 3 , the porosity is 12%; the flexural strength is 158 MPa, and the fracture toughness is 5.8 MPa·m 1 / 2 , and the average coefficient of thermal expansion is 1×10 -7 / °C (-100 - 150 °C).

Claims

1. A carbon fiber reinforced ceramic material with near-zero expansion characteristics and its preparation method, characterized in that, The preparation method includes the following steps: First step: Immerse the carbon fiber woven body in acetone, wash it with distilled water and then place it in an oven until it is completely dry; Second step: Place the carbon fiber woven body in a high-temperature vacuum furnace, and obtain a pyrolytic carbon interface layer on the surface of the fiber bundle by chemical vapor deposition; Third step: Ball-mill and mix low-expansion ceramic powder, organic monomer, cross-linking agent, and dispersant to obtain a uniformly dispersed ceramic slurry. Then add an initiator and a catalyst, and perform vacuum degassing after sufficient stirring; Fourth step: Immerse the carbon fiber woven body in the ceramic slurry, transfer it to an autoclave, evacuate and fill it with gas to high pressure, and then through heating or standing at room temperature, the slurry is solidified into a green body; Fifth step: Dry the wet green body of the carbon fiber woven body in an incubator, repeat the impregnation cycle until the weight no longer increases, and dry it to a constant weight after impregnation is completed to obtain a carbon fiber reinforced ceramic green body after impregnation molding; Sixth step: Immerse the carbon fiber reinforced ceramic green body in a ceramic precursor, perform pressure impregnation and apply ultrasonic vibration, and then perform curing and pyrolysis to obtain a carbon fiber reinforced ceramic material with near-zero expansion characteristics.

2. The carbon fiber reinforced ceramic material with near-zero expansion characteristics according to claim 1 and its preparation method, characterized in that, The carbon fiber woven body in the first step is one or more of various commonly used carbon fiber fabrics, including 2.5D weaving, 3D needling, 3D three-dimensional weaving, etc., and the fiber volume fraction of the fiber woven body is 10-60%.

3. A carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof according to claim 1, characterized in that, In the second step, the pyrolytic carbon interface layer is prepared by chemical vapor deposition. The raw materials used in the chemical vapor infiltration method are methane, natural gas, propane or propylene, the gas flow rate is 1.0-10.0 L / min, the deposition temperature is 950-1200 °C, the deposition pressure is 3-25 kPa, the deposition time is 10-100 h, and the thickness of the carbon interface layer is 50-600 nm.

4. A carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof according to claim 1, characterized in that, The low-expansion ceramic powder in the third step is one or more of NZP group compounds, quartz, cordierite, zirconium tungstate, β-spodumene, aluminum titanate, with an average particle size of 50 nm-5 μm. The organic monomer is at least one of acrylamide, methacrylamide, hydroxymethylacrylamide, polyethylene glycol diacrylate, sodium alginate, gelatin. The content of the organic monomer is 5-20% of the mass of the slurry. The cross-linking agent is at least one of N,N'-methylenebisacrylamide, polyethylene glycol dimethacrylate, pentaerythritol triacrylate. The content of the cross-linking agent is 1 / 10-1 / 5 of the mass of the monomer. The dispersant is at least one of polyethylene glycol, tetramethylammonium hydroxide, sodium carboxymethyl cellulose, sodium tripolyphosphate, and polymethacrylate. The mass of the dispersant is 0.2-5% of the mass of the ceramic powder. The volume fraction of the ceramic slurry is 15-55%. The rotation speed of the ball mill is 100-300 r / min, and the ball milling time is 1-12 h.

5. A carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof according to claim 1, characterized in that, The initiator in the third step is at least one of ammonium persulfate, potassium persulfate, azobisisobutyronitrile. The mass of the initiator is 0.1-1% of the mass of the monomer. The catalyst is at least one of tetramethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, triethanolamine. The mass of the catalyst is 0.1-5% of the mass of the monomer.

6. The carbon fiber reinforced ceramic material with near-zero expansion characteristics and its preparation method according to claim 1, characterized in that, The vacuum degree described in the fourth step is 1 Pa - 10 Pa, the impregnation pressure is 2 - 10 MPa, the curing temperature is 25 - 80 °C, and the curing time is 10 min - 10 h.

7. A carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof according to claim 1, characterized in that, The drying temperature described in the fifth step is 25 - 80 °C, and the drying time is 2 - 24 h.

8. A carbon fiber reinforced ceramic material with near-zero expansion characteristics and a preparation method thereof according to claim 1, characterized in that, The ceramic precursor described in the sixth step is one or more of polycarbosilane, polymethylsilane, polyvinylsilane, or polycarbosilylmethylsilane. The vacuum degree is 1 Pa - 10 Pa, the vibration frequency is 100 - 600 kHz, the impregnation pressure is 2 - 10 MPa, the curing temperature is 100 - 250 °C, the time is 6 - 24 h, the high-temperature pyrolysis temperature is 1100 - 1500 °C, the protective gas is an inert gas, the heat preservation time is 1 - 5 h, and the number of impregnation and pyrolysis times is 2 - 12 times.

9. A carbon fiber reinforced ceramic material with near-zero expansion characteristics and its preparation method, characterized in that, Prepared from the carbon fiber reinforced ceramic material with near-zero expansion characteristics and its preparation method according to any one of claims 1 to 8.

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