High thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure and its preparation method

Abstract

This invention relates to a method for preparing composite materials, specifically a method for preparing a high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure, and the high thermal conductivity C / SiC-ZrB2 composite material itself. This invention addresses the shortcomings of existing technologies, such as the high difficulty in weaving mesophase pitch-based fiber preforms, which makes it difficult to obtain high thermal conductivity triaxial orthogonal preforms. The method of this invention utilizes a hybrid fiber formed by weaving pitch-based carbonized fibers and aramid fibers to prepare a first high thermal conductivity fiber preform. High thermal conductivity carbon nanotubes are then introduced, and a three-dimensional CNT@PyC@SiC matrix is ​​constructed by depositing a PyC pyrolytic carbon layer and a SiC layer. Finally, multi-component ZrB2 particles and SiC particles are used to regulate the stress compatibility between the matrix, resulting in a high thermal conductivity C / SiC-ZrB2 composite material with excellent thermal conductivity and mechanical properties.

Description

Technical Field

[0001] This invention relates to a method for preparing composite materials, specifically to a method for preparing a high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure and the high thermal conductivity C / SiC-ZrB2 composite material. Background Technology

[0002] With the increasing demands for lightweight structures, efficient heat transfer and dissipation, and thermal dimensional stability in hypersonic vehicles, expanding the extreme environmental resistance of existing thermal protection systems and materials, and exploring new thermal protection material systems, has become an urgent need to promote the development of hypersonic and aerospace vehicle technologies. Traditional ceramic-based materials, due to their relatively low thermal conductivity, are prone to thermal stress concentration at high temperatures, leading to material cracking or failure, thus limiting their application in high-temperature environments. High thermal conductivity mesophase pitch-based carbon fibers possess advantages such as high thermal conductivity, ultra-high modulus, low density, and low coefficient of thermal expansion; however, the influence of their modulus makes the weaving process of mesophase pitch-based fiber preforms difficult. When preparing triaxial orthogonal preforms, Li Baoliu et al. from Hunan University used high thermal conductivity pitch-based fibers in the X and Y directions, and low-modulus PAN-based fibers in the Z direction. PAN-based fibers have poor thermal conductivity, thus limiting the thermal conductivity of the triaxial orthogonal preform structure in the Z direction. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies, such as the high difficulty in weaving mesophase pitch-based fiber preforms and the difficulty in obtaining high thermal conductivity triaxial orthogonal preforms. The invention provides a method for preparing high thermal conductivity C / SiC-ZrB2 composite materials with three-dimensional interpenetrating network structure and the high thermal conductivity C / SiC-ZrB2 composite material.

[0004] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0005] A method for preparing a high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure, characterized by the following steps:

[0006] S1, using pitch-based carbonized fiber and aramid fiber to form a mixed fiber, and using the mixed fiber to prepare the first high thermal conductivity fiber preform;

[0007] S2, the first high thermal conductivity fiber preform is heat-treated to obtain the second high thermal conductivity fiber preform;

[0008] S3, deposit a PyC pyrolytic carbon layer on the second high thermal conductivity fiber preform to obtain the third high thermal conductivity fiber preform;

[0009] S4, carbon nanotube interfaces are grown on the third high thermal conductivity fiber preform to obtain the fourth high thermal conductivity fiber preform.

[0010] S5, PyC pyrolytic carbon layer and SiC layer are deposited sequentially on the fourth high thermal conductivity fiber preform to obtain high thermal conductivity C / SiC composite material;

[0011] S6, ZrB2 particles and SiC particles are added to a phenolic resin solution with a mass fraction of 10%~20%, and ball milling is performed to obtain the first slurry;

[0012] S7. The high thermal conductivity C / SiC composite material obtained in step S5 is modified at ultra-high temperature using the first slurry to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material.

[0013] S8. After subjecting the high thermal conductivity C / SiC-ZrB2 composite material obtained in step S7 to a liquid silicon melt infiltration reaction, a densified high thermal conductivity C / SiC-ZrB2 composite material is obtained, thus completing the preparation.

[0014] Furthermore, step S7 specifically includes:

[0015] S7.1. Under vacuum conditions, the high thermal conductivity C / SiC composite material is immersed in the first slurry for impregnation;

[0016] S7.2. Curing and pyrolysis treatment of the high thermal conductivity C / SiC composite material;

[0017] S7.3. Under vacuum conditions, the high thermal conductivity C / SiC composite material is immersed in a phenolic resin solution with a mass fraction of 20%~30%, and then cured and pyrolyzed to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material.

[0018] Further, in step S1, the density of the mixed fibers is 0.7~0.9 g / cm³. 3 The porosity is 55%~75%;

[0019] In step S3, the thickness of the PyC pyrolysis carbon layer is 500~1000 nm;

[0020] In step S5, the thickness of the PyC pyrolytic carbon layer is 1000~2000 nm.

[0021] Furthermore, step S7.1 specifically includes:

[0022] The first slurry is added to the pressure impregnation tank. The high thermal conductivity C / SiC composite material obtained in step S5 is hung above the first slurry. After sealing the pressure impregnation tank and evacuating it, the high thermal conductivity C / SiC composite material is immersed in the first slurry for impregnation.

[0023] Further, in step S7.1, the impregnation specifically involves: maintaining a vacuum condition for 0.5 to 1 hour, then pressurizing to 0.5 MPa to 1.4 MPa, holding the pressure for 0.5 to 1 hour, and then removing the product.

[0024] Step S7.2 specifically involves curing the high thermal conductivity C / SiC composite material at 50~150℃ for 2~6 hours, then holding it at 900~1200℃ in a vacuum environment for 1~3 hours for pyrolysis treatment, and then cooling it to room temperature.

[0025] Furthermore, step S7.3 specifically includes:

[0026] A phenolic resin solution with a mass fraction of 20%~30% was added to a pressure impregnation tank. The high thermal conductivity C / SiC-ZrB2 composite material was suspended above the phenolic resin solution. The pressure impregnation tank was sealed and a vacuum was drawn to immerse the high thermal conductivity C / SiC-ZrB2 composite material in the phenolic resin solution. The vacuum condition was maintained for 0.5~1 hour. Then, the pressure was increased to 0.5MPa~1.4MPa and held for 0.5~1 hour before being removed. The material was cured at 50~150℃ for 2~6 hours. Then, it was subjected to pyrolysis treatment at 900~1200℃ in a vacuum environment for 1~3 hours. Finally, it was cooled to room temperature to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material.

[0027] Furthermore, step S2 specifically includes:

[0028] S2.1. In a protective atmosphere, the temperature is raised to 900-1000℃ at a heating rate of 3-5℃ / min, and held for 1-2 hours to heat treat the first high thermal conductivity fiber preform, and then cooled to room temperature; the flow rate of the protective atmosphere is 10-100mL / min.

[0029] S2.2. In a protective atmosphere, the temperature is raised to 2600~3000℃ at a heating rate of 3~5℃ / min and held for 1~2h to heat-treat the first high thermal conductivity fiber preform, and then cooled to room temperature to obtain the second high thermal conductivity fiber preform; the flow rate of the protective atmosphere is 10~100mL / min.

[0030] Furthermore, step S4 specifically includes:

[0031] In a protective atmosphere, the temperature is raised to 1000-1200℃ at a heating rate of 3-5℃ / min, held for 1-3 hours, and then cooled to room temperature, thereby growing a carbon nanotube interface on the third high thermal conductivity fiber preform to obtain the fourth high thermal conductivity fiber preform; the flow rate of the protective atmosphere is 10-100mL / min.

[0032] In steps S2.1, S2.2, and S4, the protective atmosphere is nitrogen.

[0033] In step S6, the particle size of the ZrB2 particles and SiC particles is 1~5μm, the total integral is 5%~15% of the phenolic resin solution, and the ball milling time is 12~15 hours.

[0034] Step S8 specifically involves: coating the porous, high thermal conductivity C / SiC-ZrB2 composite material obtained in step S7.3 with Si powder, placing it in a silicon infiltration furnace, and performing a liquid silicon infiltration reaction at a vacuum environment of 1430~1550℃ for 1~3 hours to obtain a densified, high thermal conductivity C / SiC-ZrB2 composite material.

[0035] Further, in step S2.1, the temperature is raised to 940℃ at a heating rate of 3℃ / min and held for 1.5h, with a protective atmosphere flow rate of 80mL / min;

[0036] In step S2.2, the temperature is raised to 2800℃ at a heating rate of 5℃ / min and held for 1.5h. The flow rate of the protective atmosphere is 80mL / min.

[0037] In step S4, the temperature is raised to 1000℃ at a heating rate of 5℃ / min, held for 2 hours, and the protective atmosphere flow rate is 100mL / min.

[0038] In step S6, the ZrB2 particles and SiC particles have a particle size of 3 μm, the total integral is 12% of the phenolic resin solution, and the ball milling time is 12 hours.

[0039] In step S7.1, maintain the vacuum condition for 0.5 hours, then pressurize to 0.8 MPa, hold the pressure for 0.5 hours, and then remove.

[0040] In step S7.2, the high thermal conductivity C / SiC composite material is cured at 90°C for 4 hours, and then kept at 1000°C in a vacuum environment for 2 hours for pyrolysis treatment.

[0041] In step S7.3, the mass fraction of the phenolic resin solution is 24%; the high thermal conductivity C / SiC-ZrB2 composite material is immersed in the phenolic resin solution, and the vacuum condition is maintained for 1 hour. Then, the pressure is increased to 1.2 MPa and held for 1 hour before being taken out. It is cured at 90°C for 3 hours, and then subjected to pyrolysis treatment at 1000°C in a vacuum environment for 2 hours.

[0042] In step S8, the liquid silicon melting reaction is carried out in a vacuum environment at 1500℃ for 2 hours.

[0043] Meanwhile, the present invention also provides a method for preparing a high thermal conductivity C / SiC-ZrB2 composite material with the above-mentioned three-dimensional interpenetrating network structure.

[0044] The beneficial effects of this invention are:

[0045] 1. This invention relates to a method for preparing a high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure. The pitch-based carbonized fiber in the mixed fibers exhibits strong thermal stability, maintaining good structural and performance stability at high temperatures. After graphitization through heat treatment, a highly ordered graphite structure is formed, creating a high thermal conductivity fiber framework. Following heat treatment of the first high thermal conductivity fiber preform, firstly, high thermal conductivity carbon nanotubes are introduced to improve the thermal conductivity of the ceramic matrix composite interface. Secondly, a three-dimensional CNT@PyC@SiC matrix is ​​constructed by depositing a PyC pyrolytic carbon layer and a SiC layer to adjust the pore size within the preform. Finally, the stress compatibility between the matrix and multi-component ZrB2 particles and SiC particles is controlled, further improving the ablation resistance of the ceramic matrix composite at higher temperatures.

[0046] 2. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure of the present invention involves the vapor-phase growth of carbon nanotube interfaces on the fiber surface, constructing a highly interconnected thermally conductive network between the fiber and the matrix. This method can improve the bonding performance between the interface and the fiber, enhance the interfacial bonding between the fiber and the matrix, strengthen the structural stability of the composite material, optimize the thermal conduction path, thereby improving the heat conduction channel, reducing thermal resistance, and forming a three-dimensional thermally conductive network between the fiber and the matrix material.

[0047] 3. The preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention introduces multi-element ultra-high temperature materials such as ZrB2 and SiC, which can not only improve the high temperature resistance and ablation resistance under extreme environments, but also effectively improve the thermal expansion matching between particles and reduce the thermal stress of the matrix at high temperatures.

[0048] 4. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention can effectively divide the large pores between the bundles and form a strong interface with the matrix formed by ZrB2 particles and SiC particles, effectively preventing crack propagation and improving the flexural strength of the material.

[0049] 5. The preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention, from preform forming, ultra-high temperature modification to the final liquid silicon infiltration reaction, can further adjust the density of mixed fibers, the growth conditions of carbon nanotube interfaces, the ratio of ultra-high temperature ceramic phases formed by ZrB2 particles and SiC particles in ultra-high temperature modification, and other process parameters. Through combination technology, the uniformity and continuity of the material at both the macroscopic and microscopic scales are ensured, and the material properties are precisely controlled, making the composite material preparation process flexible and efficient.

[0050] 6. The high thermal conductivity C / SiC-ZrB2 composite material of the present invention has excellent thermal conductivity and mechanical properties. The out-of-plane thermal conductivity can reach 103.46 W / (Km), and the bending mechanical properties can reach 199.50 MPa, which is significantly improved compared with the existing C / SiC-ZrB2 composite material. It is suitable for heat dissipation, thermal management and aerospace fields in high-temperature environments. Attached Figure Description

[0051] Figure 1 This is a flowchart of Example 1 of the preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention;

[0052] Figure 2 This is a macroscopic view of the first high thermal conductivity fiber preform in Example 1 of the preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention;

[0053] Figure 3 This is a microscopic morphology diagram of the fiber cross-section of the second high thermal conductivity fiber preform in Example 1 of the preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention.

[0054] Figure 4 This is a microscopic morphology diagram of carbon nanotubes on the fourth high thermal conductivity fiber preform in Example 1 of the preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention.

[0055] Figure 5 This is a magnified 100x microscopic morphology image of the three-dimensional CNTs@PyC@SiC matrix structure in Example 1 of the preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention.

[0056] Figure 6 This is a magnified 150x microscopic morphology image of the three-dimensional CNTs@PyC@SiC matrix structure in Example 1 of the preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention.

[0057] Figure 7 The figure shows the test results of the three-point bending mechanical properties of the high thermal conductivity C / SiC-ZrB2 composite material of the present invention in Example 1. Detailed Implementation

[0058] Example 1

[0059] To fully utilize the electrical and thermal conductivity of mesophase pitch-based carbon fibers while overcoming their drawbacks of high modulus and poor weaving properties, this invention employs a hybrid weaving method, combining low-modulus, high-strength carbonized pitch-based fibers with high-strength, highly flexible aramid fibers. After over-carbonization and graphitization, a triaxial orthogonal pitch-based carbon fiber preform with high thermal conductivity in both the X, Y, and Z directions is ultimately formed. This structure is expected to meet the stringent requirements of hypersonic vehicles for the mechanical and thermal properties of composite materials while maintaining high performance.

[0060] The preparation method of the high thermal conductivity C / SiC-ZrB2 composite material with three-dimensional interpenetrating network structure of the present invention is as follows: Figure 1 As shown, the specific steps include:

[0061] Step 1: A 2K hybrid fiber is formed by weaving pitch-based carbonized fiber and aramid fiber, with a density of approximately 0.82 g / cm³. 3 With a porosity of 62%, the first high thermal conductivity fiber preform was prepared using mixed fibers according to design requirements, such as... Figure 2 As shown.

[0062] Step 2: The first high thermal conductivity fiber preform is heat-treated in a nitrogen protective atmosphere. The heat treatment parameters are as follows: the temperature is raised to 940℃ at a heating rate of 3℃ / min, held at that temperature for 1.5h, and then cooled to room temperature. The flow rate of the protective atmosphere is 80mL / min.

[0063] Step 3: The first high thermal conductivity fiber preform is heat-treated in a nitrogen protective atmosphere to obtain the second high thermal conductivity fiber preform, such as... Figure 3 As shown. The heat treatment parameters are: the temperature is raised to 2800℃ at a heating rate of 5℃ / min, held at that temperature for 1.5h, and then cooled to room temperature. The flow rate of the protective atmosphere is 80mL / min.

[0064] Step 4: A 700 nm thick PyC pyrolytic carbon layer is deposited on the second high thermal conductivity fiber preform using a chemical vapor infiltration (CVI) process to obtain the third high thermal conductivity fiber preform.

[0065] Step 5: Under a nitrogen protective atmosphere, carbon nanotube interfaces are grown on the third high thermal conductivity fiber preform using chemical vapor deposition (CVD) to obtain the fourth high thermal conductivity fiber preform, as shown below. Figure 4As shown, the specific parameters for growing carbon nanotube interfaces are as follows: the temperature is raised to 1000℃ at a heating rate of 5℃ / min, held for 2 hours, and then lowered to room temperature, with a protective atmosphere flow rate of 100mL / min.

[0066] Step 6: A 1600 nm thick PyC pyrolytic carbon layer is deposited on the fourth high thermal conductivity fiber preform using the CVI process. Then, a SiC layer is deposited on the PyC pyrolytic carbon layer using the CVI process to form a three-dimensional CNTs@PyC@SiC substrate. Figure 5 and Figure 6 As shown, a C / SiC composite material with high thermal conductivity was obtained.

[0067] Step 7: Weigh the phenolic resin powder and solvent according to the ratio, prepare a phenolic resin solution with a mass fraction of 15%, add ZrB2 particles with a particle size of 3μm and a volume fraction of 12% and SiC particles to the phenolic resin solution, ball mill for 12-15 hours to prepare the first slurry.

[0068] Step 8: Hang the high thermal conductivity C / SiC composite material prepared in step 6 above the first slurry in a pressure impregnation tank and evacuate to ensure that the air in the high thermal conductivity C / SiC composite material is completely extracted. Then immerse it in the first slurry and maintain the vacuum condition for 0.5 hours. Then pressurize it to 0.8 MPa and hold the pressure for 0.5 hours before taking out the high thermal conductivity C / SiC composite material.

[0069] Step 9: The impregnated high thermal conductivity C / SiC composite material is cured at 90°C for 4 hours, then kept at 1000°C in a vacuum environment for 2 hours for pyrolysis treatment, and then cooled to room temperature.

[0070] Step 10: The high thermal conductivity C / SiC composite material that has undergone curing and pyrolysis treatment is suspended above a 24% (w / w) phenolic resin solution in a pressure impregnation tank and a vacuum is drawn. Then it is immersed in the phenolic resin solution and the vacuum condition is maintained for 1 hour. Then it is pressurized to 1.2 MPa and held for 1 hour before being taken out. It is cured at 90°C for 3 hours, and then pyrolyzed at 1000°C in a vacuum environment for 2 hours. Finally, it is cooled to room temperature to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material.

[0071] Step 11: The porous, high thermal conductivity C / SiC-ZrB2 composite material obtained in Step 10 is coated with Si powder and placed in a silicon infiltration furnace. Liquid silicon infiltration (RMI) is then performed at 1500℃ under vacuum for 2 hours, followed by cooling to room temperature to obtain a densified, high thermal conductivity C / SiC-ZrB2 composite material. The results of its mechanical property testing are as follows... Figure 7As shown in Table 1, the thermal diffusivity and thermal conductivity of the C / SiC-ZrB2 composite material were tested at three points on its surface (denoted as Spot1, Spot2, and Spot3, respectively). The thermal conductivity of the existing C / SiC-ZrB2 composite material is usually 10-20 W / (mK). It can be seen that the thermal conductivity of the high thermal conductivity C / SiC-ZrB2 composite material of the present invention is significantly improved compared with the existing C / SiC-ZrB2 composite material.

[0072] Table 1 Thermal diffusivity and thermal conductivity of composite materials at room temperature

[0073]

[0074] Steps 7-9 above constitute the ultra-high temperature modification process. In this invention, a phenolic resin solution is used as a solvent to dissolve ZrB2 and SiC particles, forming a first slurry with high viscosity. This facilitates increasing the residence time of the first slurry on the high thermal conductivity C / SiC composite material in subsequent steps, thereby improving the retention rate of ZrB2 and SiC, reducing the number of impregnation cycles, and increasing preparation efficiency. Simultaneously, the phenolic resin is converted into carbon during the pyrolysis process, avoiding the need for subsequent carbon matrix preparation and simplifying the preparation process. In this invention, the negative pressure after vacuuming is typically -0.1 MPa.

[0075] Example 2

[0076] The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure of the present invention includes the following steps:

[0077] Step 1: A 2K hybrid fiber is formed by weaving pitch-based carbonized fiber and aramid fiber, with a density of approximately 0.7 g / cm³. 3 With a porosity of 75%, the first high thermal conductivity fiber preform was prepared using mixed fibers according to design requirements.

[0078] Step 2: The first high thermal conductivity fiber preform is heat-treated in a nitrogen protective atmosphere. The heat treatment parameters are as follows: the temperature is raised to 900℃ at a heating rate of 5℃ / min, held at that temperature for 2 hours, and then cooled to room temperature. The flow rate of the protective atmosphere is 10mL / min.

[0079] Step 3: The first high thermal conductivity fiber preform is heat-treated in a nitrogen protective atmosphere to obtain the second high thermal conductivity fiber preform. The heat treatment parameters are as follows: the temperature is raised to 3000℃ at a heating rate of 4℃ / min, held at that temperature for 1 hour, and then cooled to room temperature. The flow rate of the protective atmosphere is 10mL / min.

[0080] Step 4: A 500 nm thick PyC pyrolytic carbon layer is deposited on the second high thermal conductivity fiber preform using the CVI process to obtain the third high thermal conductivity fiber preform.

[0081] Step 5: Under a nitrogen protective atmosphere, carbon nanotube interfaces are grown on the third high thermal conductivity fiber preform by CVD process to obtain the fourth high thermal conductivity fiber preform. The specific parameters for growing the carbon nanotube interface are as follows: the temperature is raised to 1100℃ at a heating rate of 3℃ / min, held for 1h, and then cooled to room temperature. The flow rate of the protective atmosphere is 10mL / min.

[0082] Step 6: A 2000 nm thick PyC pyrolytic carbon layer is deposited on the fourth high thermal conductivity fiber preform using the CVI process. Then, a SiC layer is deposited on the PyC pyrolytic carbon layer using the CVI process to form a three-dimensional CNTs@PyC@SiC matrix, thus obtaining a high thermal conductivity C / SiC composite material.

[0083] Step 7: Weigh the phenolic resin powder and solvent according to the ratio to prepare a phenolic resin solution with a mass fraction of 10%. Add ZrB2 particles with a particle size of 5μm and a volume fraction of 15% and SiC particles to the phenolic resin solution, and ball mill for 12 hours to prepare the first slurry.

[0084] Step 8: Hang the high thermal conductivity C / SiC composite material prepared in step 6 above the first slurry in a pressure impregnation tank and evacuate to ensure that the air in the high thermal conductivity C / SiC composite material is completely extracted. Then immerse it in the first slurry and maintain the vacuum condition for 0.5 hours. Then pressurize it to 0.5 MPa and hold the pressure for 1 hour before taking out the high thermal conductivity C / SiC composite material.

[0085] Step 9: The impregnated high thermal conductivity C / SiC composite material is cured at 50°C for 6 hours, then kept at 900°C in a vacuum environment for 1 hour for pyrolysis treatment, and then cooled to room temperature.

[0086] Step 10: The high thermal conductivity C / SiC composite material, which has undergone curing and pyrolysis treatment, is suspended above a 20% (w / w) phenolic resin solution in a pressure impregnation tank and then vacuumed. It is then immersed in the phenolic resin solution and the vacuum condition is maintained for 1 hour. After that, the pressure is increased to 0.5 MPa and held for 0.5 hours before being removed. It is then cured at 150°C for 2 hours, followed by pyrolysis treatment at 900°C in a vacuum environment for 1 hour. Finally, it is cooled to room temperature to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material.

[0087] Step 11: The porous high thermal conductivity C / SiC-ZrB2 composite material obtained in Step 10 is coated with Si powder and placed in a silicon infiltration furnace. The liquid silicon infiltration reaction is carried out in a vacuum environment at 1430℃ for 1 hour, and then cooled to room temperature to obtain a densified high thermal conductivity C / SiC-ZrB2 composite material.

[0088] Example 3

[0089] The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure of the present invention includes the following steps:

[0090] Step 1: A 2K hybrid fiber is formed by weaving pitch-based carbonized fiber and aramid fiber, with a density of approximately 0.9 g / cm³. 3 With a porosity of 55%, the first high thermal conductivity fiber preform was prepared using mixed fibers according to design requirements.

[0091] Step 2: The first high thermal conductivity fiber preform is heat-treated in a nitrogen protective atmosphere. The heat treatment parameters are as follows: the temperature is raised to 1000℃ at a heating rate of 4℃ / min, held at that temperature for 1 hour, and then cooled to room temperature. The flow rate of the protective atmosphere is 50mL / min.

[0092] Step 3: The first high thermal conductivity fiber preform is heat-treated in a nitrogen protective atmosphere to obtain the second high thermal conductivity fiber preform. The heat treatment parameters are as follows: the temperature is raised to 2600℃ at a heating rate of 3℃ / min, held at that temperature for 2 hours, and then cooled to room temperature. The flow rate of the protective atmosphere is 100mL / min.

[0093] Step 4: A 1000 nm thick PyC pyrolytic carbon layer is deposited on the second high thermal conductivity fiber preform using the CVI process to obtain the third high thermal conductivity fiber preform.

[0094] Step 5: Under a nitrogen protective atmosphere, carbon nanotube interfaces are grown on the third high thermal conductivity fiber preform by CVD process to obtain the fourth high thermal conductivity fiber preform. The specific parameters for growing the carbon nanotube interface are as follows: the temperature is raised to 1200℃ at a heating rate of 4℃ / min, held for 3h, and then cooled to room temperature. The flow rate of the protective atmosphere is 50mL / min.

[0095] Step 6: A 1000 nm thick PyC pyrolytic carbon layer is deposited on the fourth high thermal conductivity fiber preform using the CVI process. Then, a SiC layer is deposited on the PyC pyrolytic carbon layer using the CVI process to form a three-dimensional CNTs@PyC@SiC matrix, thus obtaining a high thermal conductivity C / SiC composite material.

[0096] Step 7: Weigh the phenolic resin powder and solvent according to the ratio to prepare a phenolic resin solution with a mass fraction of 20%. Add ZrB2 particles with a particle size of 1μm and a volume fraction of 5% and SiC particles to the phenolic resin solution, and ball mill for 12 hours to prepare the first slurry.

[0097] Step 8: Hang the high thermal conductivity C / SiC composite material prepared in step 6 above the first slurry in a pressure impregnation tank and evacuate to ensure that the air in the high thermal conductivity C / SiC composite material is completely extracted. Then immerse it in the first slurry and maintain the vacuum condition for 1 hour. Then pressurize it to 1.4 MPa and hold the pressure for 0.5 hours before taking out the high thermal conductivity C / SiC composite material.

[0098] Step 9: The impregnated high thermal conductivity C / SiC composite material is cured at 150°C for 2 hours, then kept at 1200°C in a vacuum environment for 3 hours for pyrolysis treatment, and then cooled to room temperature.

[0099] Step 10: The high thermal conductivity C / SiC composite material that has undergone curing and pyrolysis treatment is suspended above a 30% (w / w) phenolic resin solution in a pressure impregnation tank and a vacuum is drawn. Then, it is immersed in the phenolic resin solution and the vacuum condition is maintained for 0.5 hours. Then, the pressure is increased to 1.4 MPa and held for 0.5 hours before being removed. It is then cured at 50°C for 6 hours, followed by pyrolysis treatment at 1200°C in a vacuum environment for 3 hours. Finally, it is cooled to room temperature to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material.

[0100] Step 11: The porous high thermal conductivity C / SiC-ZrB2 composite material obtained in Step 10 is coated with Si powder and placed in a silicon infiltration furnace. The liquid silicon infiltration reaction is carried out in a vacuum environment at 1550℃ for 3 hours, and then cooled to room temperature to obtain a densified high thermal conductivity C / SiC-ZrB2 composite material.

Claims

1. A method for preparing a high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure, characterized in that, Includes the following steps: S1, using pitch-based carbon fiber and aramid fiber to form a mixed fiber, and using the mixed fiber to prepare the first high thermal conductivity fiber preform; S2, the first high thermal conductivity fiber preform is heat-treated to obtain the second high thermal conductivity fiber preform; S3, deposit a PyC pyrolytic carbon layer on the second high thermal conductivity fiber preform to obtain the third high thermal conductivity fiber preform; S4, carbon nanotube interfaces are grown on the third high thermal conductivity fiber preform to obtain the fourth high thermal conductivity fiber preform. S5, PyC pyrolytic carbon layer and SiC layer are deposited sequentially on the fourth high thermal conductivity fiber preform to obtain high thermal conductivity C / SiC composite material; S6, ZrB2 particles and SiC particles are added to a phenolic resin solution with a mass fraction of 10%~20%, and ball milling is performed to obtain the first slurry; S7, the high thermal conductivity C / SiC composite material obtained in step S5 is modified at ultra-high temperature using the first slurry to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material; specifically: S7.

1. Under vacuum conditions, the high thermal conductivity C / SiC composite material is immersed in the first slurry for impregnation; S7.

2. Curing and pyrolysis treatment of the high thermal conductivity C / SiC composite material; S7.

3. Under vacuum conditions, the high thermal conductivity C / SiC composite material is immersed in a phenolic resin solution with a mass fraction of 20%~30%, and then cured and pyrolyzed to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material. S8. After the high thermal conductivity C / SiC-ZrB2 composite material obtained in step S7 is subjected to liquid silicon infiltration reaction, a densified high thermal conductivity C / SiC-ZrB2 composite material is obtained, and the preparation is completed.

2. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure according to claim 1, characterized in that: In step S1, the density of the mixed fibers is 0.7~0.9 g / cm³. 3 The porosity is 55%~75%; In step S3, the thickness of the PyC pyrolysis carbon layer is 500~1000 nm; In step S5, the thickness of the PyC pyrolytic carbon layer is 1000~2000 nm.

3. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure according to claim 1, characterized in that, Step S7.1 is as follows: The first slurry is added to the pressure impregnation tank. The high thermal conductivity C / SiC composite material obtained in step S5 is hung above the first slurry. After sealing the pressure impregnation tank and evacuating it, the high thermal conductivity C / SiC composite material is immersed in the first slurry for impregnation.

4. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure according to claim 3, characterized in that: In step S7.1, the impregnation specifically involves: maintaining a vacuum condition for 0.5 to 1 hour, then pressurizing to 0.5 MPa to 1.4 MPa, holding the pressure for 0.5 to 1 hour, and then removing the product. Step S7.2 specifically involves curing the high thermal conductivity C / SiC composite material at 50~150℃ for 2~6 hours, then holding it at 900~1200℃ in a vacuum environment for 1~3 hours for pyrolysis treatment, and then cooling it to room temperature.

5. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure according to claim 4, characterized in that, Step S7.3 specifically includes: A phenolic resin solution with a mass fraction of 20%~30% was added to a pressure impregnation tank. The high thermal conductivity C / SiC-ZrB2 composite material was suspended above the phenolic resin solution. The pressure impregnation tank was sealed and a vacuum was drawn to immerse the high thermal conductivity C / SiC-ZrB2 composite material in the phenolic resin solution. The vacuum condition was maintained for 0.5~1 hour. Then, the pressure was increased to 0.5MPa~1.4MPa and held for 0.5~1 hour before being removed. The material was cured at 50~150℃ for 2~6 hours. Then, it was subjected to pyrolysis treatment at 900~1200℃ in a vacuum environment for 1~3 hours. Finally, it was cooled to room temperature to obtain a porous high thermal conductivity C / SiC-ZrB2 composite material.

6. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure according to claim 5, characterized in that, Step S2 is as follows: S2.

1. In a protective atmosphere, the temperature is raised to 900-1000℃ at a heating rate of 3-5℃ / min, and held for 1-2 hours to heat treat the first high thermal conductivity fiber preform, and then cooled to room temperature; the flow rate of the protective atmosphere is 10-100mL / min. S2.

2. In a protective atmosphere, the temperature is raised to 2600~3000℃ at a heating rate of 3~5℃ / min and held for 1~2h to heat-treat the first high thermal conductivity fiber preform, and then cooled to room temperature to obtain the second high thermal conductivity fiber preform; the flow rate of the protective atmosphere is 10~100mL / min.

7. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure according to claim 6, characterized in that, Step S4 is as follows: In a protective atmosphere, the temperature is raised to 1000-1200℃ at a heating rate of 3-5℃ / min, held for 1-3 hours, and then cooled to room temperature, thereby growing a carbon nanotube interface on the third high thermal conductivity fiber preform to obtain the fourth high thermal conductivity fiber preform; the flow rate of the protective atmosphere is 10-100mL / min. In steps S2.1, S2.2, and S4, the protective atmosphere is nitrogen. In step S6, the particle size of the ZrB2 particles and SiC particles is 1~5μm, the total integral is 5%~15% of the phenolic resin solution, and the ball milling time is 12~15 hours. Step S8 specifically involves: coating the porous, high thermal conductivity C / SiC-ZrB2 composite material obtained in step S7.3 with Si powder, placing it in a silicon infiltration furnace, and performing a liquid silicon infiltration reaction at a vacuum environment of 1430~1550℃ for 1~3 hours to obtain a densified, high thermal conductivity C / SiC-ZrB2 composite material.

8. The method for preparing the high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure according to claim 7, characterized in that: In step S2.1, the temperature is raised to 940℃ at a heating rate of 3℃ / min and held for 1.5h. The flow rate of the protective atmosphere is 80mL / min. In step S2.2, the temperature is raised to 2800℃ at a heating rate of 5℃ / min and held for 1.5h. The flow rate of the protective atmosphere is 80mL / min. In step S4, the temperature is raised to 1000℃ at a heating rate of 5℃ / min, held for 2 hours, and the protective atmosphere flow rate is 100mL / min. In step S6, the ZrB2 particles and SiC particles have a particle size of 3 μm, the total integral is 12% of the phenolic resin solution, and the ball milling time is 12 hours. In step S7.1, maintain the vacuum condition for 0.5 hours, then pressurize to 0.8 MPa, hold the pressure for 0.5 hours, and then remove. In step S7.2, the high thermal conductivity C / SiC composite material is cured at 90°C for 4 hours, and then kept at 1000°C in a vacuum environment for 2 hours for pyrolysis treatment. In step S7.3, the mass fraction of the phenolic resin solution is 24%; the high thermal conductivity C / SiC-ZrB2 composite material is immersed in the phenolic resin solution, and the vacuum condition is maintained for 1 hour. Then, the pressure is increased to 1.2MPa and held for 1 hour before being taken out. It is cured at 90°C for 3 hours, and then subjected to pyrolysis treatment at 1000°C in a vacuum environment for 2 hours. In step S8, the liquid silicon melting reaction is carried out in a vacuum environment at 1500℃ for 2 hours.

9. A high thermal conductivity C / SiC-ZrB2 composite material prepared by a method for preparing a high thermal conductivity C / SiC-ZrB2 composite material with a three-dimensional interpenetrating network structure as described in any one of claims 1-8.

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