Preparation method of ceramic-based composite material
By using an impregnation process to prepare multilayer carbon fiber matrix and ceramic precursor, the problem of uneven internal structure of ceramic matrix composites was solved, resulting in high-strength, lightweight ceramic matrix composites that are resistant to ablation and thermal shock, making them suitable for the aerospace field.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2026-04-14
AI Technical Summary
Traditional ceramic matrix composites suffer from difficulties in impregnating the filler slurry into the middle part of the matrix during the preparation process, resulting in uneven internal structure, low thermal shock resistance and strength, which cannot meet the harsh thermal and mechanical oxygen coupling environment requirements of new hypersonic aircraft.
By preparing a carbon fiber matrix and performing multiple treatments, combined with the impregnation process of ceramic precursors and powders, a multilayer composite material preform is formed. High-temperature pyrolysis and vapor deposition technology are used to ensure that the material is uniformly filled with ceramic structure, thereby improving its strength and thermal shock resistance.
It achieves uniformity of the internal structure of ceramic matrix composites, improves ablation resistance, thermal shock resistance and high-temperature oxidation resistance, while the material is lightweight, meeting the harsh environmental requirements of the aerospace field.
Abstract
Description
Technical Field
[0001] This invention relates to the field of ceramic composite materials, and more specifically to a method for preparing ceramic matrix composite materials. Background Technology
[0002] Ceramic materials, while possessing inherent insulation and temperature resistance, can be further enhanced in ceramic composites by improving their thermal shock resistance, ablation resistance, and high mechanical properties, leading to their application in the aerospace field. Currently, new hypersonic aircraft face extremely harsh thermal, mechanical, and oxygen coupling environments, requiring them to be as lightweight as possible. Traditional composite materials struggle to meet these requirements and suffer from several issues during the preparation of ceramic matrix composites. For example, the filling slurry is difficult to impregnate into the central part of the ceramic matrix, resulting in uneven internal structure, reduced thermal shock resistance, and low strength. Furthermore, the uneven internal structure of ceramic matrix composites prevents them from being cut and processed for use.
[0003] Therefore, how to achieve ceramic materials that can be bonded or filled throughout the interior of ceramic matrix composites, so as to achieve a uniform internal structure, good ablation resistance, good thermal shock resistance, good high-temperature oxidation resistance, high mechanical properties, and light weight, has become an urgent problem to be solved in this field. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing ceramic matrix composites, which enables ceramic materials to be bonded or filled throughout the ceramic matrix composite, resulting in a uniform internal structure, good ablation resistance, good thermal shock resistance, good high-temperature oxidation resistance, high mechanical properties, and light weight.
[0005] One aspect of the present invention provides a method for preparing a ceramic matrix composite material, comprising the following steps:
[0006] A primary intermediate layer carbon fiber matrix is prepared by means of a first carbon fiber, wherein the first carbon fiber includes carbon fiber A; the aspect ratio of carbon fiber A is 10-50.
[0007] A first precursor slurry is prepared, the first precursor slurry comprising a ceramic precursor;
[0008] Prepare a ceramic slurry, wherein the ceramic slurry comprises ceramic powder and ceramic precursor;
[0009] The primary intermediate layer carbon fiber matrix is subjected to the first intermediate layer treatment to obtain the secondary intermediate layer carbon fiber matrix;
[0010] The secondary intermediate layer carbon fiber matrix is subjected to a second intermediate layer treatment to obtain a tertiary intermediate layer carbon fiber matrix.
[0011] The intermediate layer carbon fiber matrix is impregnated and dried with the first precursor slurry to obtain the intermediate layer carbon fiber preform.
[0012] A primary composite material preform is prepared based on an intermediate carbon fiber preform;
[0013] The process for preparing the composite material preform includes the following steps:
[0014] A primary upper carbon fiber matrix and a primary lower carbon fiber matrix are prepared by means of a second carbon fiber on the upper and lower surfaces of an intermediate carbon fiber preform; the second carbon fiber includes carbon fiber A and carbon fiber B; the aspect ratio of carbon fiber B is 20-100.
[0015] The primary upper carbon fiber matrix and the primary lower carbon fiber matrix are subjected to the first upper layer treatment and the first lower layer treatment, respectively, to obtain the secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix.
[0016] The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix are subjected to a second upper layer treatment and a second lower layer treatment, respectively, to obtain a tertiary upper carbon fiber matrix and a tertiary lower carbon fiber matrix.
[0017] The three-level upper carbon fiber matrix and the three-level lower carbon fiber matrix are impregnated and dried with ceramic slurry. The upper carbon fiber preform and the lower carbon fiber preform are connected on the upper and lower surfaces of the middle carbon fiber preform to obtain the primary composite material preform.
[0018] The primary composite material preform is cured to obtain a secondary composite material preform;
[0019] The secondary composite preform is subjected to high-temperature pyrolysis under nitrogen or an inert atmosphere to obtain the ceramic matrix composite material.
[0020] The ceramic precursor includes one of silicon carbide precursor, zirconium carbide precursor, and zirconium silicon precursor; preferably, the silicon carbide precursor includes one of liquid polycarbosilane and solid polycarbosilane / xylene.
[0021] The ceramic powder includes carbides and / or borides;
[0022] The prepared ceramic matrix composite material includes an upper surface layer, a middle layer, and a lower surface layer.
[0023] The upper surface layer of the composite material includes upper surface mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles that are sequentially attached to the surface of the upper surface fibers and the fiber intersections.
[0024] The composite material intermediate layer includes intermediate layer mesh fibers, silicon boron compound and silicon carbide sequentially attached to the surface and intersections of the intermediate layer mesh fibers;
[0025] The lower surface layer of the composite material includes lower surface layer mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles filling the pores of the lower surface layer mesh fibers in sequence attached to the surface and intersections of the lower surface layer fibers.
[0026] The density of the upper surface layer, middle layer, and lower surface layer of the composite material is 0.25-0.3 g / cm³. 3 ;
[0027] The porosity of the upper and lower surface fibers is greater than that of the intermediate mesh fiber.
[0028] The advantages of this invention over the prior art are as follows: a primary intermediate carbon fiber matrix is prepared by using a first carbon fiber, wherein the first carbon fiber includes carbon fiber A; the aspect ratio of carbon fiber A is 10-50; a primary upper carbon fiber matrix and a primary lower carbon fiber matrix are prepared on the upper and lower surfaces of the intermediate carbon fiber preform by using a second carbon fiber; the second carbon fiber includes carbon fiber A and carbon fiber B; the aspect ratio of carbon fiber B is 20-100; the composite material preform is divided into an upper preform, a middle preform, and a lower preform, and the substrate porosity in the middle preform is small, while the substrate porosity in the upper and lower preforms is large, and the grid surface of the matrix of the middle preform is uniformly coated with ceramic precursors, while the matrix grids of the upper and lower preforms are filled with ceramic particles and the grid surface is coated with ceramic precursors;
[0029] This achieves the integral sintering of ceramic matrix composite materials, which includes three parts: an upper surface layer, a middle layer, and a lower surface layer. The upper surface layer is uniformly filled with a ceramic precursor sintered to obtain a ceramic structure, and the upper, middle, and lower surface layers are uniformly filled with a ceramic precursor and a ceramic powder sintered to obtain a ceramic structure.
[0030] This achieves the goal of reducing the density of ceramic matrix composites while ensuring that the entire interior of the ceramic matrix composite is filled with ceramic structures, the internal porosity of the ceramic matrix composite is uniform, and the overall density is high.
[0031] The upper surface layer of the composite material includes upper surface mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles that are sequentially attached to the surface of the upper surface fibers and the fiber intersections.
[0032] The composite material intermediate layer includes intermediate layer mesh fibers, silicon boron compound and silicon carbide sequentially attached to the surface and intersections of the intermediate layer mesh fibers;
[0033] The lower surface layer of the composite material includes lower surface layer mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles filling the pores of the lower surface layer mesh fibers in sequence attached to the surface and intersections of the lower surface layer fibers.
[0034] Achieving high internal mesh strength in ceramic matrix composites is beneficial for achieving high strength in ceramic matrix composites.
[0035] The density of the upper and lower surface layers of the composite material is 0.25-0.3 g / cm³. 3 The density of the composite material's intermediate layer is 0.2-0.24 g / cm³. 3 The porosity of the upper and lower surface fibers is greater than that of the intermediate mesh fibers, which enables the intermediate layer to form a ceramic structure by combining the matrix pores of the internal mesh fibers with the precursor ceramic, thereby achieving high strength and light weight of the composite material intermediate layer.
[0036] Ultimately, the ceramic matrix composite material exhibits a uniform internal structure, excellent ablation resistance, thermal shock resistance, high-temperature oxidation resistance, and high mechanical properties, while also being lightweight.
[0037] Furthermore, the method for preparing the primary intermediate layer carbon fiber matrix includes the following: dispersing the first carbon fiber in a first solvent to prepare a first carbon fiber slurry;
[0038] The first carbon fiber slurry is poured into a porous mold with a screen at the bottom, and then the first solvent in the first carbon fiber slurry is filtered out to obtain the primary intermediate layer carbon fiber matrix.
[0039] The aspect ratio of the carbon fiber A is 10-50, and the first solvent is water or alcohol;
[0040] The mass ratio of carbon fiber A to solvent in the first carbon fiber slurry is 0.9%-1.2%.
[0041] The beneficial effect of the previous step is that, by having the aspect ratio of the carbon fiber A to be 10-50 and the mass ratio of carbon fiber A to solvent in the first carbon fiber slurry to be 0.9%-1.2%, the pores inside the prepared carbon fiber matrix are small.
[0042] Furthermore, the process of preparing the secondary intermediate layer carbon fiber matrix includes the following steps:
[0043] The primary intermediate layer of the porous mold, which is placed on a screen at the bottom, is impregnated with silica sol, and then the excess silica sol is filtered out; the mass ratio of the first carbon fiber to the silica sol is (55-65):1.
[0044] A first matrix reinforcement solution is prepared by mixing a first matrix reinforcement agent with a second solvent at a mass ratio of 1:(15-25) to obtain the first matrix reinforcement solution; the first matrix reinforcement agent includes one or two of boron nitride and boron carbide; the particle size of the first matrix reinforcement agent is 50-100 nm.
[0045] The first matrix reinforcement solution is used to impregnate the primary intermediate carbon fiber matrix after it has been impregnated with silica sol, and then the second solvent in the first matrix reinforcement solution is filtered out.
[0046] Then, the material is dried at a temperature of 20-40℃ to obtain the secondary intermediate layer carbon fiber matrix.
[0047] The beneficial effect of the previous step is that the primary intermediate carbon fiber matrix of the porous mold with a screen at the bottom is impregnated with the silica sol, thereby shaping the primary intermediate carbon fiber matrix built by the first carbon fiber.
[0048] The first matrix reinforcing agent includes one or two of boron nitride and boron carbide; the particle size of the first matrix reinforcing agent is 50-100nm, and the first matrix reinforcing agent is deposited at the fiber intersections of the mesh in the secondary intermediate carbon fiber matrix. During the subsequent sintering process, the first matrix reinforcing agent reacts with the silica sol on the surface of the intersections to generate silicon nitride compounds, thereby improving the strength of the intermediate carbon fiber matrix.
[0049] Furthermore, the process for preparing the tertiary intermediate layer carbon fiber matrix includes the following steps:
[0050] The secondary intermediate layer fiber matrix is placed in a vapor deposition apparatus;
[0051] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 620-720℃.
[0052] Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus into a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus.
[0053] The temperature is raised again, and when it reaches 900-950℃, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 0.9-1.2L / min.
[0054] After deposition for 20-30 minutes, a carbon source mixed gas is introduced at a flow rate of 0.9-1.2 L / min; the temperature is then increased to 1050-1350℃, and the deposition reaction is carried out for 2-3 hours to obtain the tertiary intermediate layer carbon fiber matrix.
[0055] Furthermore, the atomized silicon source liquid is one of hexamethyldisiloxane, tetramethyldisiloxane, and hexamethyldisilazane;
[0056] The carbon source gas mixture is a mixture of propane and argon, with a propane to argon ratio of 1:1 to 1:4.
[0057] The beneficial effect of the previous step is that it achieves a carbon interface on the surface of the intermediate carbon fiber matrix, thereby enabling the intermediate carbon fiber matrix to resist high-temperature oxidation.
[0058] Furthermore, the tertiary intermediate layer carbon fiber matrix is placed in an impregnation device containing the first precursor slurry for impregnation. The impregnation device includes a box body with a receiving space. The receiving space is divided into a first receiving cavity, a second receiving cavity, and a third receiving cavity by a first filter plate and a second filter plate arranged in parallel. The first receiving cavity is located between the first filter plate and the second filter plate, the second receiving cavity is located above the first filter plate, and the third receiving cavity is located below the second filter plate.
[0059] Both the first filter plate and the second filter plate are provided with a number of filter holes;
[0060] The first filter plate and the second filter plate are detachably connected to the inside of the housing;
[0061] A gasket is provided between the first filter plate and the second filter plate;
[0062] Preferably, the gasket has an elastic structure connected to the side near the inner wall of the box;
[0063] Preferably, the upper or lower end of the gasket is slidably connected to the first or second filter plate;
[0064] There are no filter holes between the position where the gasket contacts the first or second filter plate and the end of the first or second filter plate near the inner wall of the box.
[0065] Furthermore, the preparation process of the intermediate carbon fiber preform includes the following steps:
[0066] The three-stage intermediate carbon fiber matrix is placed between the first filter plate or the second filter plate, and the three-stage intermediate carbon fiber matrix is limited by a gasket and the two ends of the three-stage intermediate carbon fiber matrix are sealed.
[0067] Then, the first precursor slurry is added to the first accommodating cavity of the box;
[0068] Then, the first precursor slurry in the first accommodating cavity is squeezed, or the third accommodating cavity is evacuated; the first precursor slurry is then introduced into the second accommodating cavity to impregnate the tertiary intermediate layer carbon fiber matrix, and the excess first precursor slurry is introduced into the third accommodating cavity.
[0069] Then, the impregnated three-stage intermediate carbon fiber matrix is removed and dried to obtain the intermediate carbon fiber preform.
[0070] The beneficial effect of the previous step is that the first precursor slurry is attached to the surface of the matrix mesh in the intermediate carbon fiber preform, thereby realizing that the mesh structure inside the composite material intermediate layer is combined with a ceramic structure.
[0071] Furthermore, the process of preparing the primary upper carbon fiber matrix and the primary lower carbon fiber matrix on the upper and lower surfaces of the intermediate carbon fiber preform is as follows:
[0072] To prepare a second carbon fiber slurry, carbon fiber A and carbon fiber B are dispersed in a first solvent at a volume ratio of (65-85):(25-35) to obtain the second carbon fiber slurry.
[0073] The intermediate carbon fiber preform is placed in a porous mold with a screen at the bottom. Then, an upper carbon fiber limiting plate is horizontally set above the upper surface of the intermediate carbon fiber preform. The upper carbon fiber limiting plate is provided with a first slurry inlet. The distance between the upper carbon fiber limiting plate and the intermediate carbon fiber preform is set according to the thickness of the primary upper carbon fiber matrix.
[0074] Then the second carbon fiber slurry enters between the upper carbon fiber limiting plate and the upper surface of the middle carbon fiber blank through the first slurry inlet opening;
[0075] The first solvent in the second carbon fiber slurry is then filtered out, and the second carbon fiber is laid in an interlaced manner on the upper surface of the intermediate carbon fiber preform to prepare the upper carbon fiber matrix on the upper surface of the intermediate carbon fiber preform; a screen is installed on the surface of the upper carbon fiber limiting plate.
[0076] Then, flip the porous mold, remove the screen that is in contact with the lower surface of the intermediate carbon fiber preform, and then horizontally set the lower carbon fiber limiting plate above the lower surface of the intermediate carbon fiber preform. The lower carbon fiber limiting plate is provided with a second slurry inlet. The distance between the lower carbon fiber limiting plate and the intermediate carbon fiber preform is set according to the thickness of the primary lower carbon fiber matrix.
[0077] Then the second carbon fiber slurry enters between the lower carbon fiber limiting plate and the lower surface of the middle carbon fiber blank through the second slurry inlet opening;
[0078] The first solvent in the second carbon fiber slurry is then filtered out, and the second carbon fiber is laid in an interleaved manner on the lower surface of the intermediate carbon fiber preform; thus, a lower carbon fiber matrix is prepared on the lower surface of the intermediate carbon fiber preform.
[0079] Furthermore, the primary upper carbon fiber matrix and the primary lower carbon fiber matrix undergo the following steps: the first treatment of the upper layer and the first treatment of the lower layer, respectively.
[0080] The primary upper carbon fiber matrix and the primary lower carbon fiber matrix, which are connected to the upper and lower surfaces of the intermediate carbon fiber preform, are immersed in silica sol for impregnation, and then the excess silica sol is filtered out.
[0081] A second matrix reinforcement solution is prepared by mixing a second matrix reinforcement agent and a second solvent at a mass ratio of 1:(35-45) to obtain the second matrix reinforcement solution; the second matrix reinforcement agent includes one or both of boron nitride and boron carbide; the particle size of the second matrix reinforcement agent is larger than that of the first matrix reinforcement agent, and the particle size of the second matrix reinforcement agent is 0.1-1 μm.
[0082] The second matrix reinforcement solution is used to impregnate the primary upper carbon fiber matrix and the primary lower carbon fiber matrix after impregnation with silica sol, and then the second solvent in the second matrix reinforcement solution is filtered out.
[0083] Then, drying is carried out at a temperature of 20-40℃ to obtain a secondary upper carbon fiber matrix and a secondary lower carbon fiber matrix that are connected to the upper and lower surfaces of the intermediate carbon fiber preform.
[0084] The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix undergo a second treatment for the upper layer and a second treatment for the lower layer, respectively, including the following steps:
[0085] The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix, which are connected to the upper and lower surfaces of the intermediate carbon fiber preform, are placed in a vapor deposition apparatus with the upper carbon fiber matrix facing upwards.
[0086] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 620-720℃.
[0087] Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus into a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus.
[0088] The temperature is raised again, and when it reaches 900-950℃, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 0.9-1.2L / min.
[0089] After deposition for 20-30 minutes, a carbon source mixed gas is introduced at a flow rate of 0.9-1.2 L / min; the temperature is then increased to 1050-1350℃, and the deposition reaction is carried out for 2-3 hours.
[0090] Then, the lower carbon fiber matrix is turned upwards, and a vacuum is drawn to put the inside of the vapor deposition device under negative pressure. Inert gas is then introduced to replace the air in the vapor deposition device.
[0091] The temperature is raised again, and when it reaches 900-950℃, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 0.9-1.2L / min.
[0092] After deposition for 5-15 minutes, a carbon source mixed gas is introduced at a flow rate of 0.9-1.2 L / min; the temperature is then increased to 1050-1350℃, and the deposition reaction is allowed to proceed for 0.5-1.5 hours.
[0093] The beneficial effect of the previous step is that it achieves the initial shaping of the secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix by attaching silica sol to the fiber surface inside the upper carbon fiber preform and the lower carbon fiber preform, and the accumulation of two matrix reinforcing agents on the surface of the fiber intersection point. This ensures that the matrix grid intersection points inside the upper surface layer and the lower surface layer of the composite material prepared by subsequent sintering are coated with carbonitride compounds, which increases the matrix strength inside the upper surface layer and the lower surface layer of the composite material.
[0094] This method enables the formation of an interface between the carbon fiber surfaces of the upper and lower layers of the composite material matrix, thereby improving its resistance to high-temperature oxidation under high-temperature conditions.
[0095] Furthermore, the process of impregnating the tertiary upper carbon fiber matrix and the tertiary lower carbon fiber matrix with ceramic slurry includes the following steps:
[0096] Ceramic powder, ceramic precursor, and binder are mixed in a ratio of (75-85):(10-20):(2-5), and then the pH value is adjusted to 6-8 by adding ammonia or hydrochloric acid to obtain the ceramic slurry.
[0097] The adhesive comprises a thermosetting resin and a solvent in a mass ratio of 1:(450-550):(1.8-3.3);
[0098] The thermosetting resin includes one of phenolic resin and epoxy resin; the dispersant includes one or more of sodium dodecyl sulfate, polyethylene glycol, sodium polyacrylate, and polyvinylpyrrolidone.
[0099] The curing temperature of the primary composite preform is 180℃-240℃, and the curing time is 2h-4h.
[0100] The secondary composite preform is subjected to high-temperature pyrolysis under nitrogen or inert atmosphere, with a pyrolysis temperature of 1000℃-1400℃ and a time of 0.5h-1.5h.
[0101] The beneficial effect of the previous step is that it enables the attachment and filling of ceramic structures within the matrix mesh of the upper and lower surface layers of the composite material, thereby improving the thermal shock resistance, high-temperature oxidation resistance, and mechanical properties of the ceramic matrix composite material. Detailed Implementation
[0102] To better understand the technical solution of the present invention, the present invention will be further described below with reference to specific embodiments.
[0103] Example 1:
[0104] This embodiment provides a method for preparing a ceramic matrix composite material, characterized by comprising the following steps:
[0105] A primary intermediate layer carbon fiber matrix is prepared by means of a first carbon fiber, wherein the first carbon fiber comprises carbon fiber A; the aspect ratio of carbon fiber A is 30; the method for preparing the primary intermediate layer carbon fiber matrix includes the following:
[0106] The first carbon fiber is dispersed in the first solvent to prepare the first carbon fiber slurry;
[0107] The first carbon fiber slurry is poured into a porous mold with a screen at the bottom, and then the first solvent in the first carbon fiber slurry is filtered out to obtain the primary intermediate layer carbon fiber matrix.
[0108] The first solvent is water or alcohol;
[0109] The mass ratio of carbon fiber A to solvent in the first carbon fiber slurry is 1.05%.
[0110] A first precursor slurry is prepared, the first precursor slurry comprising a ceramic precursor;
[0111] The ceramic precursor includes a silicon carbide precursor; the ceramic powder includes a carbide.
[0112] Prepare a ceramic slurry, wherein the ceramic slurry comprises ceramic powder and ceramic precursor;
[0113] The primary intermediate layer carbon fiber matrix undergoes a first intermediate layer treatment to obtain a secondary intermediate layer carbon fiber matrix. The process for preparing the secondary intermediate layer carbon fiber matrix includes the following steps:
[0114] The primary intermediate layer of the porous mold, which is placed on a screen at the bottom, is impregnated with silica sol, and then excess silica sol is filtered out; the mass ratio of the first carbon fiber to silica sol is 60:1.
[0115] A first matrix reinforcement solution is prepared by mixing a first matrix reinforcement agent with a second solvent at a mass ratio of 1:20; the first matrix reinforcement agent includes boron nitride; the particle size of the first matrix reinforcement agent is 75 nm.
[0116] The first matrix reinforcement solution is used to impregnate the primary intermediate carbon fiber matrix after it has been impregnated with silica sol, and then the second solvent in the first matrix reinforcement solution is filtered out.
[0117] Then, the material is dried at a temperature of 20-40℃ to obtain the secondary intermediate layer carbon fiber matrix.
[0118] The secondary intermediate layer carbon fiber matrix is subjected to a second intermediate layer treatment to obtain a tertiary intermediate layer carbon fiber matrix; the process of preparing the tertiary intermediate layer carbon fiber matrix includes the following steps:
[0119] The secondary intermediate layer fiber matrix is placed in a vapor deposition apparatus;
[0120] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 670℃.
[0121] Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus to a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus; the atomized silicon source liquid is hexamethyldisiloxane;
[0122] The carbon source gas mixture is a mixture of propane and argon, with a propane to argon ratio of 1:2.5;
[0123] The temperature is raised again, and when it reaches 925°C, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 1.05 L / min.
[0124] After deposition for 25 minutes, a carbon source mixed gas was introduced at a flow rate of 1.05 L / min; the temperature was then raised to 1200 °C and the deposition reaction was carried out for 2.5 hours to obtain the tertiary intermediate layer carbon fiber matrix.
[0125] The intermediate layer carbon fiber matrix is impregnated and dried with the first precursor slurry to obtain the intermediate layer carbon fiber preform.
[0126] The three-stage intermediate carbon fiber matrix is impregnated in an impregnation device containing a first precursor slurry. The impregnation device includes a housing with a receiving space. The receiving space is divided into a first receiving cavity, a second receiving cavity, and a third receiving cavity by a first filter plate and a second filter plate arranged in parallel. The first receiving cavity is located between the first and second filter plates, the second receiving cavity is located above the first filter plate, and the third receiving cavity is located below the second filter plate. Both the first and second filter plates have a plurality of filter holes. The first and second filter plates are detachably connected to the inside of the housing. A gasket is provided between the first and second filter plates.
[0127] The preparation process of the intermediate layer carbon fiber preform includes the following steps:
[0128] The three-stage intermediate carbon fiber matrix is placed between the first filter plate or the second filter plate, and the three-stage intermediate carbon fiber matrix is limited by a gasket and the two ends of the three-stage intermediate carbon fiber matrix are sealed.
[0129] Then, the first precursor slurry is added to the first accommodating cavity of the box;
[0130] Then, the first precursor slurry in the first accommodating cavity is squeezed, or the third accommodating cavity is evacuated; the first precursor slurry is then introduced into the second accommodating cavity to impregnate the tertiary intermediate layer carbon fiber matrix, and the excess first precursor slurry is introduced into the third accommodating cavity.
[0131] Then, the impregnated three-stage intermediate carbon fiber matrix is removed and dried to obtain the intermediate carbon fiber preform.
[0132] The gasket is connected to an elastic structure on the side near the inner wall of the box; the upper or lower end of the gasket is slidably connected to the first filter plate or the second filter plate.
[0133] There are no filter holes between the position where the gasket contacts the first or second filter plate and the end of the first or second filter plate near the inner wall of the box.
[0134] The process for preparing the composite material preform includes the following steps:
[0135] A primary upper carbon fiber matrix and a primary lower carbon fiber matrix are prepared by means of a second carbon fiber on the upper and lower surfaces of an intermediate carbon fiber preform; the second carbon fiber includes carbon fiber A and carbon fiber B; the aspect ratio of carbon fiber B is 60;
[0136] The process of preparing the primary upper carbon fiber matrix and the primary lower carbon fiber matrix on the upper and lower surfaces of the intermediate carbon fiber preform is as follows:
[0137] To prepare a second carbon fiber slurry, carbon fiber A and carbon fiber B are dispersed in a first solvent at a volume ratio of 75:30 to obtain the second carbon fiber slurry.
[0138] The intermediate carbon fiber preform is placed in a porous mold with a screen at the bottom. Then, an upper carbon fiber limiting plate is horizontally set above the upper surface of the intermediate carbon fiber preform. The upper carbon fiber limiting plate is provided with a first slurry inlet. The distance between the upper carbon fiber limiting plate and the intermediate carbon fiber preform is set according to the thickness of the primary upper carbon fiber matrix.
[0139] Then the second carbon fiber slurry enters between the upper carbon fiber limiting plate and the upper surface of the middle carbon fiber blank through the first slurry inlet opening;
[0140] The first solvent in the second carbon fiber slurry is then filtered out, and the second carbon fiber is laid in an interlaced manner on the upper surface of the intermediate carbon fiber preform to prepare the upper carbon fiber matrix on the upper surface of the intermediate carbon fiber preform; a screen is installed on the surface of the upper carbon fiber limiting plate.
[0141] Then, flip the porous mold, remove the screen that is in contact with the lower surface of the intermediate carbon fiber preform, and then horizontally set the lower carbon fiber limiting plate above the lower surface of the intermediate carbon fiber preform. The lower carbon fiber limiting plate is provided with a second slurry inlet. The distance between the lower carbon fiber limiting plate and the intermediate carbon fiber preform is set according to the thickness of the primary lower carbon fiber matrix.
[0142] Then the second carbon fiber slurry enters between the lower carbon fiber limiting plate and the lower surface of the middle carbon fiber blank through the second slurry inlet opening;
[0143] The first solvent in the second carbon fiber slurry is then filtered out, and the second carbon fiber is laid in an interleaved manner on the lower surface of the intermediate carbon fiber preform; thus, a lower carbon fiber matrix is prepared on the lower surface of the intermediate carbon fiber preform.
[0144] The primary upper carbon fiber matrix and the primary lower carbon fiber matrix are subjected to the first upper layer treatment and the first lower layer treatment, respectively, to obtain the secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix.
[0145] The primary upper carbon fiber matrix and the primary lower carbon fiber matrix undergo the following steps for the first treatment of the upper layer and the first treatment of the lower layer, respectively:
[0146] The primary upper carbon fiber matrix and the primary lower carbon fiber matrix, which are connected to the upper and lower surfaces of the intermediate carbon fiber preform, are immersed in silica sol for impregnation, and then the excess silica sol is filtered out.
[0147] A second matrix reinforcement solution is prepared by mixing a second matrix reinforcement agent and a second solvent at a mass ratio of 1:40. The second matrix reinforcement agent includes boron nitride. The particle size of the second matrix reinforcement agent is larger than that of the first matrix reinforcement agent, and the particle size of the second matrix reinforcement agent is 1.05 μm.
[0148] The second matrix reinforcement solution is used to impregnate the primary upper carbon fiber matrix and the primary lower carbon fiber matrix after impregnation with silica sol, and then the second solvent in the second matrix reinforcement solution is filtered out.
[0149] Then, drying is carried out at a temperature of 30°C to obtain a secondary upper carbon fiber matrix and a secondary lower carbon fiber matrix that are connected to the upper and lower surfaces of the intermediate carbon fiber preform.
[0150] The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix are subjected to a second upper layer treatment and a second lower layer treatment, respectively, to obtain a tertiary upper carbon fiber matrix and a tertiary lower carbon fiber matrix.
[0151] The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix undergo a second treatment for the upper layer and a second treatment for the lower layer, respectively, including the following steps:
[0152] The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix, which are connected to the upper and lower surfaces of the intermediate carbon fiber preform, are placed in a vapor deposition apparatus with the upper carbon fiber matrix facing upwards.
[0153] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 660℃.
[0154] Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus into a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus.
[0155] The temperature is raised again, and when it reaches 925°C, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 1.05 L / min.
[0156] After 25 minutes of deposition, a carbon source mixed gas was introduced at a flow rate of 1.05 L / min; the temperature was then increased to 1200 °C, and the deposition reaction was carried out for 2.5 hours.
[0157] Then, the lower carbon fiber matrix is turned upwards, and a vacuum is drawn to put the inside of the vapor deposition device under negative pressure. Inert gas is then introduced to replace the air in the vapor deposition device.
[0158] The temperature is raised again, and when it reaches 925°C, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 1.05 L / min.
[0159] After 10 minutes of deposition, a carbon source gas mixture was introduced at a flow rate of 1.05 L / min; the temperature was then increased to 1200 °C, and the deposition reaction was carried out for 1 hour.
[0160] The three-level upper carbon fiber matrix and the three-level lower carbon fiber matrix are impregnated and dried with ceramic slurry. The upper carbon fiber preform and the lower carbon fiber preform are connected on the upper and lower surfaces of the middle carbon fiber preform to obtain the primary composite material preform.
[0161] The process of impregnating ceramic slurry with a three-stage upper carbon fiber matrix and a three-stage lower carbon fiber matrix includes the following steps:
[0162] Ceramic powder, ceramic precursor, and binder are mixed in a ratio of 80:15:3.5, and then the pH value is adjusted to 7 by adding ammonia or hydrochloric acid to obtain the ceramic slurry.
[0163] The adhesive comprises a thermosetting resin and a solvent in a mass ratio of 1:500:2.6;
[0164] The thermosetting resin includes phenolic resin; the dispersant includes sodium dodecyl sulfate.
[0165] The primary composite material preform is cured to obtain a secondary composite material preform; the curing temperature of the primary composite material preform is 210℃ and the curing time is 3h.
[0166] The secondary composite preform is subjected to high-temperature pyrolysis under nitrogen or an inert atmosphere to obtain the ceramic matrix composite material; the secondary composite preform is subjected to high-temperature pyrolysis under nitrogen or an inert atmosphere at a temperature of 1200°C for 1 hour.
[0167] The prepared ceramic matrix composite material includes an upper surface layer, a middle layer, and a lower surface layer.
[0168] The upper surface layer of the composite material includes upper surface mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles that are sequentially attached to the surface of the upper surface fibers and the fiber intersections.
[0169] The composite material intermediate layer includes intermediate layer mesh fibers, silicon boron compound and silicon carbide sequentially attached to the surface and intersections of the intermediate layer mesh fibers;
[0170] The lower surface layer of the composite material includes lower surface layer mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles filling the pores of the lower surface layer mesh fibers in sequence attached to the surface and intersections of the lower surface layer fibers.
[0171] The density of the upper and lower surface layers of the composite material is 0.27 g / cm³. 3 The density of the composite material interlayer is 0.22 g / cm³. 3 ;
[0172] The porosity of the upper and lower surface fibers is greater than that of the intermediate mesh fiber.
[0173] Example 2:
[0174] The same content as in Example 1 will not be repeated here; the different aspects of this embodiment compared to Example 1 are as follows:
[0175] One aspect of this embodiment provides a method for preparing a ceramic matrix composite material, which further includes the following steps:
[0176] A primary intermediate layer carbon fiber matrix is prepared by means of a first carbon fiber, wherein the first carbon fiber comprises carbon fiber A; the aspect ratio of carbon fiber A is 40; and the first solvent is water or alcohol.
[0177] The mass ratio of carbon fiber A to solvent in the first carbon fiber slurry is 1.1%.
[0178] The ceramic precursor includes a zirconium carbide precursor; the ceramic powder includes a boride.
[0179] The mass ratio of the first carbon fiber to silica sol is 63:1;
[0180] A first matrix reinforcement solution is prepared by mixing a first matrix reinforcement agent with a second solvent at a mass ratio of 1:23. The first matrix reinforcement agent includes one or both of boron nitride and boron carbide. The particle size of the first matrix reinforcement agent is 95 nm.
[0181] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 710℃;
[0182] The atomized silicon source liquid is tetramethyldisiloxane;
[0183] The carbon source gas mixture is a mixture of propane and argon, with a propane to argon ratio of 1:3.5;
[0184] The temperature is raised again, and when it reaches 945°C, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 1.15 L / min.
[0185] After deposition for 28 minutes, a carbon source mixed gas was introduced at a flow rate of 1.15 L / min; the temperature was then raised to 1330 °C and the deposition reaction was carried out for 2.8 hours to obtain the tertiary intermediate layer carbon fiber matrix.
[0186] Preferably, the gasket has an elastic structure connected to the side near the inner wall of the box;
[0187] Preferably, the upper or lower end of the gasket is slidably connected to the first or second filter plate;
[0188] There are no filter holes between the position where the gasket contacts the first or second filter plate and the end of the first or second filter plate near the inner wall of the box.
[0189] The second carbon fiber includes carbon fiber A and carbon fiber B; the aspect ratio of carbon fiber B is 60.
[0190] To prepare a second carbon fiber slurry, carbon fiber A and carbon fiber B are dispersed in a first solvent at a volume ratio of 83:33 to obtain the second carbon fiber slurry.
[0191] A second matrix reinforcement solution is prepared by mixing a second matrix reinforcement agent and a second solvent at a mass ratio of 1:43. The second matrix reinforcement agent includes one or both of boron nitride and boron carbide. The particle size of the second matrix reinforcement agent is larger than that of the first matrix reinforcement agent, and the particle size of the second matrix reinforcement agent is 0.9 μm.
[0192] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 710℃;
[0193] Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus into a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus.
[0194] The temperature is raised again, and when it reaches 945°C, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 1.15 L / min.
[0195] After deposition for 28 minutes, a carbon source mixed gas was introduced at a flow rate of 1.15 L / min; the temperature was then increased to 1330 °C, and the deposition reaction was carried out for 2.8 hours.
[0196] Then, the lower carbon fiber matrix is turned upwards, and a vacuum is drawn to put the inside of the vapor deposition device under negative pressure. Inert gas is then introduced to replace the air in the vapor deposition device.
[0197] The temperature is raised again, and when it reaches 945°C, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 1.15 L / min.
[0198] After 13 minutes of deposition, a carbon source mixed gas was introduced at a flow rate of 1.18 L / min; the temperature was then increased to 1330 °C, and the deposition reaction was carried out for 1.25 hours.
[0199] The process of impregnating ceramic slurry with a three-stage upper carbon fiber matrix and a three-stage lower carbon fiber matrix includes the following steps:
[0200] Ceramic powder, ceramic precursor, and binder are mixed in a ratio of 83:18:4.5, and then the pH value is adjusted to 7.6 by adding ammonia or hydrochloric acid to obtain the ceramic slurry.
[0201] The adhesive comprises a thermosetting resin and a solvent in a mass ratio of 1:530:3.1;
[0202] The thermosetting resin includes one of phenolic resin and epoxy resin; the dispersant includes one or more of sodium dodecyl sulfate, polyethylene glycol, sodium polyacrylate, and polyvinylpyrrolidone.
[0203] The primary composite material preform is cured to obtain a secondary composite material preform; the curing temperature of the primary composite material preform is 238℃ and the curing time is 2.3h.
[0204] The secondary composite preform was subjected to high-temperature pyrolysis under nitrogen or inert atmosphere at a temperature of 1380℃ for 0.6h.
[0205] The density of the upper and lower surface layers of the composite material is 0.29 g / cm³. 3 The density of the composite material's intermediate layer is 0.23 g / cm³. 3 .
[0206] Example 3:
[0207] The same content as in Example 1 will not be repeated here; the different aspects of this embodiment compared to Example 1 are as follows:
[0208] One aspect of this embodiment provides a method for preparing a ceramic matrix composite material, which further includes the following steps:
[0209] A primary intermediate layer carbon fiber matrix is prepared by means of a first carbon fiber, wherein the first carbon fiber comprises carbon fiber A; the aspect ratio of carbon fiber A is 15; and the first solvent is water or alcohol.
[0210] The mass ratio of carbon fiber A to solvent in the first carbon fiber slurry is 0.95.
[0211] The ceramic precursor includes one of silicon carbide precursor, zirconium carbide precursor, and zirconium silicon precursor; the ceramic powder includes carbides and / or borides.
[0212] The mass ratio of the first carbon fiber to the silica sol is 59:1;
[0213] A first matrix reinforcement solution is prepared by mixing a first matrix reinforcement agent with a second solvent at a mass ratio of 1:18. The first matrix reinforcement agent includes boron nitride and boron carbide. The particle size of the first matrix reinforcement agent is 52 nm.
[0214] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 640℃.
[0215] The atomized silicon source liquid is one of hexamethyldisilazane;
[0216] The carbon source gas mixture is a mixture of propane and argon, with a propane to argon ratio of 1:1.5;
[0217] The temperature is raised again, and when it reaches 910°C, atomized silicon source liquid and argon gas are introduced, with the silicon source liquid flow rate being 0.5 L / min.
[0218] After deposition for 22 minutes, a carbon source mixed gas was introduced at a flow rate of 0.92 L / min; the temperature was then increased to 1080 °C and the deposition reaction was carried out for 2.2 hours to obtain the tertiary intermediate layer carbon fiber matrix.
[0219] Preferably, the gasket has an elastic structure connected to the side near the inner wall of the box;
[0220] Preferably, the upper or lower end of the gasket is slidably connected to the first or second filter plate;
[0221] There are no filter holes between the position where the gasket contacts the first or second filter plate and the end of the first or second filter plate near the inner wall of the box.
[0222] The second carbon fiber includes carbon fiber A and carbon fiber B; the aspect ratio of carbon fiber B is 30.
[0223] To prepare a second carbon fiber slurry, carbon fiber A and carbon fiber B are dispersed in a first solvent at a volume ratio of 68:26 to obtain the second carbon fiber slurry.
[0224] A second matrix reinforcement solution is prepared by mixing a second matrix reinforcement agent and a second solvent at a mass ratio of 1:38. The second matrix reinforcement agent includes boron nitride and boron carbide. The particle size of the second matrix reinforcement agent is larger than that of the first matrix reinforcement agent, and the particle size of the second matrix reinforcement agent is 0.18 μm.
[0225] The secondary intermediate layer fiber matrix is heated to a maximum temperature of 640℃.
[0226] Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus into a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus.
[0227] The temperature is raised again, and when it reaches 910°C, atomized silicon source liquid and argon gas are introduced, with the silicon source liquid flow rate being 0.95 L / min;
[0228] After deposition for 202 min, a carbon source mixed gas was introduced at a flow rate of 0.95 L / min; the temperature was then increased to 1080 °C, and the deposition reaction was carried out for 2.8 hours.
[0229] Then, the lower carbon fiber matrix is turned upwards, and a vacuum is drawn to put the inside of the vapor deposition device under negative pressure. Inert gas is then introduced to replace the air in the vapor deposition device.
[0230] The temperature is raised again, and when it reaches 910°C, atomized silicon source liquid and argon gas are introduced, with the silicon source liquid flow rate being 0.95 L / min;
[0231] After 6 minutes of deposition, a carbon source mixed gas was introduced at a flow rate of 0.95 L / min; the temperature was then increased to 1060 °C, and the deposition reaction was carried out for 1.3 hours.
[0232] The process of impregnating ceramic slurry with a three-stage upper carbon fiber matrix and a three-stage lower carbon fiber matrix includes the following steps:
[0233] Ceramic powder, ceramic precursor, and binder are mixed in a ratio of 78:12:2.5, and then the pH value is adjusted to 6.2 by adding ammonia or hydrochloric acid to obtain the ceramic slurry.
[0234] The adhesive comprises a thermosetting resin and a solvent in a mass ratio of 1:460:2;
[0235] The thermosetting resin includes epoxy resin; the dispersant includes sodium polyacrylate and polyvinylpyrrolidone.
[0236] The primary composite material preform is cured to obtain a secondary composite material preform; the curing temperature of the primary composite material preform is 189℃ and the curing time is 2.3h.
[0237] The secondary composite preform was subjected to high-temperature pyrolysis under nitrogen or inert atmosphere at a temperature of 1010℃ for 0.6h.
[0238] The density of the upper and lower surface layers of the composite material is 0.26 g / cm³. 3 The density of the composite material's intermediate layer is 0.21 g / cm³. 3 .
[0239] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, the above-described features have similar functions to (but are not limited to) those disclosed in this application.
Claims
1. A method for preparing a ceramic matrix composite material, characterized in that, Includes the following steps: A primary intermediate layer carbon fiber matrix is prepared by means of a first carbon fiber, wherein the first carbon fiber includes carbon fiber A; the aspect ratio of carbon fiber A is 10-50. A first precursor slurry is prepared, the first precursor slurry comprising a ceramic precursor; Prepare a ceramic slurry, wherein the ceramic slurry comprises ceramic powder and ceramic precursor; The primary intermediate layer carbon fiber matrix is subjected to the first intermediate layer treatment to obtain the secondary intermediate layer carbon fiber matrix; The secondary intermediate layer carbon fiber matrix is subjected to a second intermediate layer treatment to obtain a tertiary intermediate layer carbon fiber matrix. The intermediate layer carbon fiber matrix is impregnated and dried with the first precursor slurry to obtain the intermediate layer carbon fiber preform. A primary composite material preform is prepared based on an intermediate carbon fiber preform; The process for preparing the composite material preform includes the following steps: A primary upper carbon fiber matrix and a primary lower carbon fiber matrix are prepared by means of a second carbon fiber on the upper and lower surfaces of an intermediate carbon fiber preform; the second carbon fiber includes carbon fiber A and carbon fiber B; the aspect ratio of carbon fiber B is 20-100. The primary upper carbon fiber matrix and the primary lower carbon fiber matrix are subjected to the first upper layer treatment and the first lower layer treatment, respectively, to obtain the secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix. The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix are subjected to a second upper layer treatment and a second lower layer treatment, respectively, to obtain a tertiary upper carbon fiber matrix and a tertiary lower carbon fiber matrix. The three-level upper carbon fiber matrix and the three-level lower carbon fiber matrix are impregnated and dried with ceramic slurry. The upper carbon fiber preform and the lower carbon fiber preform are connected on the upper and lower surfaces of the middle carbon fiber preform to obtain the primary composite material preform. The primary composite material preform is cured to obtain a secondary composite material preform; The secondary composite preform is subjected to high-temperature pyrolysis under nitrogen or an inert atmosphere to obtain the ceramic matrix composite material. The ceramic precursor includes one of silicon carbide precursor, zirconium carbide precursor, and zirconium silicon precursor; The ceramic powder includes carbides and / or borides; The prepared ceramic matrix composite material includes an upper surface layer, a middle layer, and a lower surface layer. The upper surface layer of the composite material includes upper surface mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles that are sequentially attached to the surface of the upper surface fibers and the fiber intersections. The composite material intermediate layer includes intermediate layer mesh fibers, silicon boron compound and silicon carbide sequentially attached to the surface and intersections of the intermediate layer mesh fibers; The lower surface layer of the composite material includes lower surface layer mesh fibers, silicon boron compounds, silicon carbide, and ceramic particles filling the pores of the lower surface layer mesh fibers in sequence attached to the surface and intersections of the lower surface layer fibers. The density of the upper and lower surface layers of the composite material is 0.25-0.3 g / cm³. 3 The density of the composite material's intermediate layer is 0.2-0.24 g / cm³. 3 ; The porosity of the upper and lower surface fibers is greater than that of the intermediate mesh fiber.
2. The method for preparing a ceramic matrix composite material according to claim 1, characterized in that, The preparation method of the primary intermediate layer carbon fiber matrix includes the following: The first carbon fiber is dispersed in the first solvent to prepare the first carbon fiber slurry; The first carbon fiber slurry is poured into a porous mold with a screen at the bottom, and then the first solvent in the first carbon fiber slurry is filtered out to obtain the primary intermediate layer carbon fiber matrix. The aspect ratio of the carbon fiber A is 10-50, and the first solvent is water or alcohol; The mass ratio of carbon fiber A to solvent in the first carbon fiber slurry is 0.9%-1.2%.
3. The method for preparing a ceramic matrix composite material according to claim 1, characterized in that, The process of preparing the secondary intermediate layer carbon fiber matrix includes the following steps: The primary intermediate layer of the porous mold, which is placed on a screen at the bottom, is impregnated with silica sol, and then the excess silica sol is filtered out; the mass ratio of the first carbon fiber to the silica sol is (55-65):
1. A first matrix reinforcement solution is prepared by mixing a first matrix reinforcement agent with a second solvent at a mass ratio of 1:(15-25) to obtain the first matrix reinforcement solution; the first matrix reinforcement agent includes one or two of boron nitride and boron carbide; the particle size of the first matrix reinforcement agent is 50-100 nm. The first matrix reinforcement solution is used to impregnate the primary intermediate carbon fiber matrix after it has been impregnated with silica sol, and then the second solvent in the first matrix reinforcement solution is filtered out. Then, the material is dried at a temperature of 20-40℃ to obtain the secondary intermediate layer carbon fiber matrix.
4. The method for preparing a ceramic matrix composite material according to claim 1, characterized in that, The process of preparing a tertiary intermediate layer carbon fiber matrix includes the following steps: The secondary intermediate layer fiber matrix is placed in a vapor deposition apparatus; The secondary intermediate layer fiber matrix is heated to a maximum temperature of 620-720℃. Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus into a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus. The temperature is raised again, and when it reaches 900-950℃, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 0.9-1.2L / min. After deposition for 20-30 minutes, a carbon source mixed gas is introduced at a flow rate of 0.9-1.2 L / min; the temperature is then increased to 1050-1350℃, and the deposition reaction is carried out for 2-3 hours to obtain the tertiary intermediate layer carbon fiber matrix.
5. The method for preparing a ceramic matrix composite material according to claim 4, characterized in that, The atomized silicon source liquid is one of hexamethyldisiloxane, tetramethyldisiloxane, and hexamethyldisilazane; The carbon source gas mixture is a mixture of propane and argon, with a propane to argon ratio of 1:1 to 1:
4.
6. The method for preparing a ceramic matrix composite material according to claim 4, characterized in that, The three-stage intermediate layer carbon fiber matrix is placed into an impregnation device containing a first precursor slurry for impregnation. The impregnation device includes a box body with a receiving space. The receiving space is divided into a first receiving cavity, a second receiving cavity, and a third receiving cavity by a first filter plate and a second filter plate arranged in parallel. The first receiving cavity is located between the first filter plate and the second filter plate, the second receiving cavity is located above the first filter plate, and the third receiving cavity is located below the second filter plate. Both the first filter plate and the second filter plate are provided with a number of filter holes; The first filter plate and the second filter plate are detachably connected to the inside of the housing; A gasket is provided between the first filter plate and the second filter plate.
7. The method for preparing a ceramic matrix composite material according to claim 6, characterized in that, The preparation process of the intermediate layer carbon fiber preform includes the following steps: The three-stage intermediate carbon fiber matrix is placed between the first filter plate or the second filter plate, and the three-stage intermediate carbon fiber matrix is limited by a gasket and the two ends of the three-stage intermediate carbon fiber matrix are sealed. Then, the first precursor slurry is added to the first accommodating cavity of the box; Then, the first precursor slurry in the first accommodating cavity is squeezed, or the third accommodating cavity is evacuated; the first precursor slurry is then introduced into the second accommodating cavity to impregnate the tertiary intermediate layer carbon fiber matrix, and the excess first precursor slurry is introduced into the third accommodating cavity. Then, the impregnated three-stage intermediate carbon fiber matrix is removed and dried to obtain the intermediate carbon fiber preform.
8. The method for preparing a ceramic matrix composite material according to claim 1, characterized in that, The process of preparing the primary upper carbon fiber matrix and the primary lower carbon fiber matrix on the upper and lower surfaces of the intermediate carbon fiber preform is as follows: To prepare a second carbon fiber slurry, carbon fiber A and carbon fiber B are dispersed in a first solvent at a volume ratio of (65-85):(25-35) to obtain the second carbon fiber slurry. The intermediate carbon fiber preform is placed in a porous mold with a screen at the bottom. Then, an upper carbon fiber limiting plate is horizontally set above the upper surface of the intermediate carbon fiber preform. The upper carbon fiber limiting plate is provided with a first slurry inlet. The distance between the upper carbon fiber limiting plate and the intermediate carbon fiber preform is set according to the thickness of the primary upper carbon fiber matrix. Then the second carbon fiber slurry enters between the upper carbon fiber limiting plate and the upper surface of the middle carbon fiber blank through the first slurry inlet opening; By filtering out the first solvent in the second carbon fiber slurry, the second carbon fiber is laid interlaced on the upper surface of the intermediate carbon fiber preform, thereby preparing the upper carbon fiber matrix on the upper surface of the intermediate carbon fiber preform. A screen is installed on the surface of the upper carbon fiber limiting plate; Then, flip the porous mold, remove the screen that is in contact with the lower surface of the intermediate carbon fiber preform, and then horizontally set the lower carbon fiber limiting plate above the lower surface of the intermediate carbon fiber preform. The lower carbon fiber limiting plate is provided with a second slurry inlet. The distance between the lower carbon fiber limiting plate and the intermediate carbon fiber preform is set according to the thickness of the primary lower carbon fiber matrix. Then the second carbon fiber slurry enters between the lower carbon fiber limiting plate and the lower surface of the middle carbon fiber blank through the second slurry inlet opening; The first solvent in the second carbon fiber slurry is then filtered out, and the second carbon fiber is laid in an interlaced manner on the lower surface of the intermediate layer carbon fiber preform. A lower carbon fiber matrix is prepared on the lower surface of the intermediate carbon fiber preform.
9. The method for preparing a ceramic matrix composite material according to claim 1, characterized in that, The primary upper carbon fiber matrix and the primary lower carbon fiber matrix undergo the following steps for the first treatment of the upper layer and the first treatment of the lower layer, respectively: The primary upper carbon fiber matrix and the primary lower carbon fiber matrix, which are connected to the upper and lower surfaces of the intermediate carbon fiber preform, are immersed in silica sol for impregnation, and then the excess silica sol is filtered out. A second matrix reinforcement solution is prepared by mixing a second matrix reinforcement agent and a second solvent at a mass ratio of 1:(35-45) to obtain the second matrix reinforcement solution; the second matrix reinforcement agent includes one or both of boron nitride and boron carbide; the particle size of the second matrix reinforcement agent is larger than that of the first matrix reinforcement agent, and the particle size of the second matrix reinforcement agent is 0.1-1 μm. The second matrix reinforcement solution is used to impregnate the primary upper carbon fiber matrix and the primary lower carbon fiber matrix after impregnation with silica sol, and then the second solvent in the second matrix reinforcement solution is filtered out. Then, drying is carried out at a temperature of 20-40℃ to obtain a secondary upper carbon fiber matrix and a secondary lower carbon fiber matrix that are connected to the upper and lower surfaces of the intermediate carbon fiber preform. The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix undergo a second treatment for the upper layer and a second treatment for the lower layer, respectively, including the following steps: The secondary upper carbon fiber matrix and the secondary lower carbon fiber matrix, which are connected to the upper and lower surfaces of the intermediate carbon fiber preform, are placed in a vapor deposition apparatus with the upper carbon fiber matrix facing upwards. The secondary intermediate layer fiber matrix is heated to a maximum temperature of 620-720℃. Then, a vacuum is drawn to bring the inside of the vapor deposition apparatus into a negative pressure state, and then an inert gas is introduced to replace the air in the vapor deposition apparatus. The temperature is raised again, and when it reaches 900-950℃, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 0.9-1.2L / min. After deposition for 20-30 minutes, a carbon source mixed gas is introduced at a flow rate of 0.9-1.2 L / min; the temperature is then increased to 1050-1350℃, and the deposition reaction is carried out for 2-3 hours. Then, the lower carbon fiber matrix is turned upwards, and a vacuum is drawn to put the inside of the vapor deposition device under negative pressure. Inert gas is then introduced to replace the air in the vapor deposition device. The temperature is raised again, and when it reaches 900-950℃, atomized silicon source liquid and argon gas are introduced. The flow rate of the silicon source liquid is 0.9-1.2L / min. After deposition for 5-15 minutes, a carbon source mixed gas is introduced at a flow rate of 0.9-1.2 L / min; the temperature is then increased to 1050-1350℃, and the deposition reaction is allowed to proceed for 0.5-1.5 hours.
10. The method for preparing a ceramic matrix composite material according to claim 1, characterized in that, The process of impregnating ceramic slurry with a three-stage upper carbon fiber matrix and a three-stage lower carbon fiber matrix includes the following steps: Ceramic powder, ceramic precursor, and binder are mixed in a ratio of (75-85):(10-20):(2-5), and then the pH value is adjusted to 6-8 by adding ammonia or hydrochloric acid to obtain the ceramic slurry. The adhesive comprises a thermosetting resin and a solvent in a mass ratio of 1:(450-550):(1.8-3.3); The thermosetting resin includes one of phenolic resin and epoxy resin; the dispersant includes one or more of sodium dodecyl sulfate, polyethylene glycol, sodium polyacrylate, and polyvinylpyrrolidone. The curing temperature of the primary composite preform is 180℃-240℃, and the curing time is 2h-4h. The secondary composite preform is subjected to high-temperature pyrolysis under nitrogen or inert atmosphere, with a pyrolysis temperature of 1000℃-1400℃ and a time of 0.5h-1.5h.