A method for manufacturing a high-density carbon fiber cloth bearing plate

Abstract

A method for preparing a high-density carbon fiber cloth support plate involves formulating a composite resin impregnation solution composed of phenolic resin, epoxy resin, curing agent, and coupling agent in a specific mass ratio. A preform is constructed using an alternating cycle of resin spraying and carbon cloth laying, followed by multi-stage stepped pressurization and heating curing. In the composite resin system, the rapid gelation of the epoxy resin in the initial stage of hot pressing complements the viscosity decrease of the phenolic resin. Combined with the multi-stage stepped pressurization and heating regime, impregnation is performed during the optimal resin flow period, and compaction is carried out during the gelation period. This effectively controls resin flow, preventing loss and layup misalignment, resulting in a high-density preform. This method eliminates the need for multiple independent carbon cloth pretreatment steps in traditional methods, simplifying the process and eliminating the inherent defect of resin loss caused by remelting of dried prepreg.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber cloth support plate technology, and in particular to a method for preparing a high-density carbon fiber cloth support plate. Background Technology

[0002] Carbon-carbon composites are multiphase materials composed of carbon fiber reinforcement and a carbon matrix. They inherit a series of excellent properties from carbon materials, including extremely high temperature resistance (above 2000℃ in an inert atmosphere), low density and high specific strength far lower than metals, as well as low coefficient of thermal expansion and good thermal shock resistance. Therefore, this material is widely used in high-end fields such as aerospace, photovoltaic industry, and high-performance braking systems.

[0003] Despite its superior performance, the preparation process of carbon fiber reinforced carbon-carbon composites is complex, time-consuming, and costly. Furthermore, traditional methods have several inherent drawbacks, hindering further improvements in production efficiency and performance. Currently, the industry commonly employs a prepreg-hot pressing-multiple densification process when preparing carbon fiber reinforced carbon-carbon composites. For example, the carbon / carbon composite material and its preparation method disclosed in application number CN202511364695.6 involves first surface-treating the carbon fiber cloth to improve its surface activity and wettability. Then, it is immersed in a solution of pure phenolic resin, and the resin is forced to penetrate the fiber bundles using external forces such as filtration, ultrasound, or high pressure to produce a prepreg with a certain resin content. The prepreg is then dried to obtain a solid or semi-solid intermediate product for storage and layup. After layup, the prepreg layers are placed in a hot press mold for hot pressing and curing, causing the resin to crosslink and bonding the fibers into a whole. The cured preform then undergoes carbonization and multiple liquid-phase densification steps under an inert atmosphere.

[0004] The existing technical solutions have the following prominent technical drawbacks: 1. Severe resin loss and insufficient matrix content: Traditional processes use phenolic resin pre-impregnated carbon cloth, requiring multiple independent steps such as carbon cloth pretreatment, overall impregnation, drying, and pre-impregnated material storage. However, during the hot-pressing curing stage, the dried pre-impregnated material is remelted. As the temperature rises, the viscosity of pure phenolic resin drops sharply. Under pressure, a large amount of low-viscosity resin is lost from the carbon cloth layers, resulting in low resin carbon content, high porosity, and uneven component distribution in the final composite material. Figure 2 As shown.

[0005] 2. Low initial density and extremely complicated densification process: Due to resin loss, the density of the preform obtained after the first curing and carbonization is very low and the porosity is very high. It is necessary to rely on multiple cycles of liquefaction densification to increase the density to the application requirements. Each cycle includes a long impregnation, curing and carbonization process, resulting in extremely low production efficiency and high cost.

[0006] 3. Defects in mechanical properties and reliability: Resin loss and uneven distribution lead to defects such as pores within the material, which become stress concentration points. Simultaneously, the interfacial bonding between carbon fibers and the pure resin matrix is ​​weak. These problems collectively result in low interlaminar shear strength, making the material prone to cracking and delamination during use. Summary of the Invention

[0007] In view of this, the present invention provides a method for preparing a high-density carbon fiber cloth support plate to solve the above-mentioned technical problems.

[0008] A method for preparing a high-density carbon fiber cloth support plate includes the following steps: Step S1: A composite resin impregnation solution is prepared by compounding 60-70% phenolic resin, 15-25% epoxy resin, 6-18% curing agent, and 2-6% coupling agent by mass percentage; Step S2: Provide carbon fiber fabric and cut it to the required size; Step S3: Lay a piece of carbon fiber cloth flat on the workbench, then evenly apply the composite resin impregnation liquid to the surface of the carbon fiber cloth through atomized spraying to form a resin layer. Then, lay another piece of carbon fiber cloth on the resin layer and alternately cycle spraying and laying until the stacked layers reach the predetermined thickness, finally forming a preform; Step S4: Place the preform into a preheated hot press mold, and then perform multi-stage stepped pressure and temperature increase curing to obtain a preform. The multi-stage stepped pressure and temperature increase curing includes at least an initial flow and heat preservation stage, a gradual gelation and compression stage, and a final curing stage. The gradual gelation and compression stage goes through at least two sub-stages of stepped pressure and temperature increase in sequence, and each sub-stage increases the pressure and temperature higher than the previous sub-stage and holds it at that temperature. Step S5: The preform is placed in a vacuum carbonization furnace for carbonization treatment, so that the resin matrix is ​​converted into a carbon matrix. The carbonized preform is subjected to at least two rounds of liquid phase densification and at least one round of gas phase densification to obtain a densified blank. Step S6: Perform surface treatment on the blank to obtain the carbon fiber cloth support plate.

[0009] Further, in step S1 above, specifically, the weighed raw materials are placed in a stirrer and stirred at 400-600 rpm for 10-20 minutes at 25-30°C. Then, the mixture is transferred to an ultrasonic disperser and ultrasonically dispersed at a frequency of 35-45 kHz for 15-20 minutes to ensure that all components are fully mixed and uniform without agglomeration, thereby obtaining a composite resin impregnation liquid with stable viscosity suitable for atomization spraying.

[0010] Furthermore, in step S3 above, the table surface temperature is maintained at 20~25℃, the nozzle moves at a speed of 2~3 mm / s and is 10~15 mm away from the carbon cloth surface, and the spraying time for each layer is controlled at 30~50 seconds, forming a resin layer with a single layer thickness of 0.15~0.20 mm.

[0011] Further, in step S4 above, the initial gel flow and heat preservation stage involves increasing the pressure to 2-4 MPa at a rate of 2-3 MPa / h and holding it at 85-105℃ for 1-3 hours; the gradual gel compression stage involves a final temperature of 110℃ to 130℃, a heating time of 1-2 hours, a final pressure of 5 MPa to 10 MPa, and a pressure increase time of 1-2 hours; and the final curing stage involves increasing the pressure to a final pressure of 8-10 MPa and a temperature of 165-185℃ and holding it at that temperature for 9-12 hours.

[0012] Furthermore, in step S5 above, in at least two rounds of liquid phase densification, the first impregnation temperature is 50-70℃, the carbonization temperature is 60-80℃, and the carbonization time is 2-3h; the second impregnation temperature is 30-50℃, the carbonization temperature is 70-90℃, and the carbonization time is 3-4h.

[0013] Furthermore, in step S5 above, in at least one phase densification process, the preform after liquid phase densification is placed in a chemical vapor deposition furnace at 2100~2300℃, and a carbon-containing gas such as methane is introduced and kept at this temperature for 2~3 hours.

[0014] Furthermore, in step S6 above, the surface treatment includes at least precision milling, cutting, and surface polishing.

[0015] A method for preparing a high-density carbon fiber cloth support plate. The high-density carbon fiber cloth support plate has a density of not less than 1.55 g / cm³.

[0016] Compared with existing technologies, the method for preparing high-density carbon fiber cloth support plates provided by this invention solves the problems of easy resin loss, high porosity, cumbersome processes, and insufficient performance in the preparation of traditional carbon-carbon composite materials through the synergistic innovation of composite resin system, integrated layup spraying process, and multi-stage stepped hot-pressing curing. Specifically, the rapid gelation of epoxy resin in the initial stage of hot pressing in the composite resin system complements the viscosity decrease of phenolic resin. Combined with a multi-stage stepped pressurization and heating regime, wetting is achieved during the optimal resin flow period and compaction is performed during the gelation period, thereby effectively controlling resin flow, preventing loss and layup misalignment, and obtaining a high-density preform. Since a high-density preform is obtained in the initial hot-pressing curing stage, subsequent densification only requires two liquid-phase impregnations and one vapor-phase deposition, significantly reducing the traditional 4-6 or even more densification processes and shortening the entire production cycle. In addition, the traditional method eliminates the need for multiple independent processes such as carbon cloth pretreatment, overall impregnation, drying, and prepreg storage. This not only simplifies the process but also eliminates the inherent defect of resin loss caused by the remelting of dried prepreg. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a method for preparing a high-density carbon fiber cloth support plate provided by the present invention.

[0018] Figure 2 This is a schematic diagram of a carbon fiber cloth support plate prepared by a method in the prior art.

[0019] Figure 3 This is a schematic diagram of the carbon fiber cloth support plate prepared by the method for preparing a high-density carbon fiber cloth support plate provided by the present invention.

[0020] Figure 4 This invention provides a table of mechanical parameter test data for a method of preparing a high-density carbon fiber cloth support plate under different conditions. Detailed Implementation

[0021] The following provides a more detailed description of specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the scope of protection of the present invention.

[0022] like Figure 1The diagram shows a flowchart of a method for preparing a high-density carbon fiber cloth support plate according to the present invention. Existing carbon fiber cloth support plates mostly use carbon fiber cloth impregnated with pure phenolic resin solution to form a prepreg, which is then dried and stored. After layup, it is hot-pressed and cured under a simple one-time pressurization and heating regime. During this process, the dried prepreg remelts, leading to significant resin loss. Subsequently, carbonization is performed, and the liquid-phase densification process needs to be repeated up to 4 to 6 times to achieve densification. Pure phenolic resin is easily lost during hot pressing, resulting in low matrix content. The simple curing regime cannot suppress resin loss and interlayer slippage, and the lengthy multiple densification cycles lead to long production cycles and high costs.

[0023] Based on this, the present invention provides a method for preparing a high-density carbon fiber cloth support plate, comprising the following steps: Step S1: A composite resin impregnation solution is prepared by compounding 60-70% phenolic resin, 15-25% epoxy resin, 6-18% curing agent, and 2-6% coupling agent by mass ratio. Specifically, the weighed raw materials are placed in a stirrer and stirred at 400-600 rpm for 10-20 minutes at 25-30°C. Subsequently, the mixture is transferred to an ultrasonic disperser and ultrasonically dispersed at a frequency of 35-45 kHz for 15-20 minutes to ensure that all components are fully mixed and uniform without agglomeration, resulting in a composite resin impregnation solution with stable viscosity suitable for atomized spraying.

[0024] By introducing multiple functional components, a synergistic resin system was constructed. Phenolic resin, as the main matrix, provides a high carbon retention rate, which is the basis for forming the final carbon matrix. Epoxy resin, as a key modifying component, addresses the problem of severe resin loss due to viscosity reduction in the initial stage of hot pressing. In the initial stage of hot pressing curing, the viscosity of pure phenolic resin decreases significantly with increasing temperature, easily flowing out in large quantities from the carbon cloth pores under pressure, resulting in low carbon content in the matrix resin. Therefore, the viscosity decrease of phenolic resin in the initial heating stage is the main cause of resin impregnation loss. By introducing epoxy resin and its matching curing agent, the epoxy resin undergoes a rapid cross-linking and curing reaction under the action of the curing agent, and its viscosity increases sharply and gels. Therefore, in the initial stage of hot pressing, while the viscosity of the phenolic resin decreases and attempts to flow, the epoxy resin system simultaneously gels, and its viscosity increases. This opposite trend of decreasing and increasing viscosity effectively curbs the loss of phenolic resin, ensuring a high retention rate and uniform distribution of resin content within the preform.

[0025] Curing agents are used to trigger and promote the cross-linking and curing reaction of epoxy resins. Coupling agents, such as silane or titanate coupling agents, are used to address the problem of weak interfacial bonding between carbon fibers and the resin matrix, which easily leads to delamination. The chemical inertness of carbon fiber surfaces and limited physical adhesion to organic resins result in insufficient interfacial shear strength and delamination. Coupling agents are bifunctional molecules; one end has an organophilic functional group such as amino or epoxy, which can chemically react with epoxy or phenolic resins. The other end has an inorganic functional group such as alkoxy, which can form strong chemical bonds or strong physical adsorption with trace amounts of hydroxyl groups on the carbon fiber surface. This constructs a strong molecular bridge between the fiber and the matrix, greatly improving interfacial wettability, enhancing interfacial bond strength, and significantly strengthening the interfacial shear strength and anti-delamination ability of the composite material.

[0026] After high-temperature carbonization, phenolic resin transforms into carbon, which constitutes the composite material. Therefore, it needs to occupy the largest proportion to ensure that the final material has sufficient carbon matrix to achieve high density and high strength. Epoxy resin is used to prevent the loss of phenolic resin. Its dosage is crucial during the critical temperature range when gelation occurs. Both excessively high and low epoxy resin proportions have an impact. For example, if the proportion is close to or exceeds that of phenolic resin, premature and excessive gelation will severely hinder the overall flow and wetting of the resin, leading to insufficient wetting of the carbon fibers and the creation of new defects. Simultaneously, the carbonization residue rate of epoxy resin is generally lower than that of phenolic resin. An excessively high epoxy proportion may reduce the overall carbon yield and affect the final density. This proportion, obtained experimentally, ensures that the reaction kinetics, viscosity changes, and interface modification effects of each component during the curing process are optimally balanced, thereby maximizing overall performance.

[0027] Step S2: Provide carbon fiber cloth and cut it to the required size.

[0028] The preferred material is plain-weave carbon fabric woven from T700 grade carbon fiber, which is precisely cut to the required size using a CNC cutting machine. T700 grade carbon fiber is an industry-standard carbon fiber grade with a tensile strength of approximately 4900 MPa and a tensile modulus of approximately 230 GPa. The plain-weave carbon fabric is a conventional carbon fiber fabric where the warp and weft yarns interweave every other yarn.

[0029] Step S3: First, lay a piece of carbon fiber cloth flat on the workbench. Then, apply the composite resin impregnation liquid evenly to the surface of the carbon fiber cloth through atomized spraying to form a resin layer. Then, lay another piece of carbon fiber cloth on the resin layer and alternately spray and lay it up until the layer reaches the predetermined thickness, and finally form a preform with alternating carbon fiber cloth-resin layer-carbon fiber cloth.

[0030] Specifically, carbon fiber cloth is laid flat on a temperature-adjustable worktable, with the table surface temperature maintained at 20-25°C. This temperature helps the resin maintain its optimal working viscosity. The prepared composite resin impregnation solution is atomized into micron-sized droplets through an atomizing nozzle. The nozzle is moved at a speed of 2-3 mm / s, keeping it 10-15 mm away from the carbon cloth surface, for uniform scanning spraying. This speed and distance ensure uniform spray coverage, preventing omissions due to excessive speed and excessive resin application in certain areas due to insufficient speed. Each layer is sprayed for 30-50 seconds, forming a resin layer with a thickness of approximately 0.15-0.20 mm. After one layer is sprayed, the robotic arm automatically lays down the next layer of carbon cloth, repeating the process until the predetermined thickness is achieved. This ensures that the resin is retained to the maximum extent between each fiber layer, laying the foundation for subsequent hot pressing, and also avoiding the uneven resin distribution and loss problems associated with traditional integral impregnation.

[0031] Existing technologies generally employ a method of overall impregnation followed by drying and then lamination. Specifically, before impregnation, the carbon fiber cloth needs to undergo treatments such as low-temperature plasma oxidation to improve the surface activity of the carbon fibers. Then, impregnation methods such as filtration, ultrasound, and high pressure are used to force the resin solution to penetrate the carbon cloth, ensuring that the resin can enter the interior of the fiber bundle. Finally, drying is performed to obtain pre-impregnated carbon cloth. This results in the need for independent impregnation and drying processes to produce these intermediate semi-finished products, with numerous overall process steps and a long cycle time. Moreover, the dried pre-impregnated carbon cloth is in a solid or semi-solid state for easy storage and lamination. However, the dried prepreg will remelt in the initial stage of hot pressing in subsequent processes. At this time, the resin viscosity is extremely low, and a large amount will be lost from the interlayer under pressure, leading to problems such as insufficient matrix content and high porosity in the final cured product.

[0032] This application improves the resin impregnation solution by incorporating highly active functional groups. These functional groups can directly chemically bond or strongly physically adsorb onto the carbon fiber surface during impregnation. Simultaneously, the resin impregnation solution is atomized using a nozzle, allowing it to effectively cover the carbon fiber fabric and its internal pores. This eliminates the need for pretreatment such as plasma bombardment to create oxygen-containing functional groups and grooves, and also eliminates the impregnation, drying, and pre-impregnation of carbon fiber fabric preparation steps. Furthermore, the synergistic effect of the resin impregnation solution and the subsequent multi-step hot-pressing curing process ensures sufficient resin flow and impregnation while preventing resin loss, guaranteeing a high and uniform matrix content. Detailed explanations will follow in conjunction with the hot-pressing steps.

[0033] Step S4: Place the preform into a hot press mold preheated to 85-105℃, and then perform multi-stage stepped pressure and temperature increase curing to obtain the preform. The multi-stage stepped pressure and temperature increase curing includes at least an initial flow and heat preservation stage, a gradual gelation and compression stage, and a final curing stage performed sequentially.

[0034] The initial resin flow and heat preservation stage involves slowly increasing the pressure to 2-4 MPa at a rate of 2-3 MPa / h and holding at 85-105℃ for 1-3 hours. During this initial stage, the pressure is low and the temperature is above the melting temperature of phenolic resin and below the rapid curing temperature of epoxy resin. At this point, the phenolic resin melts and its viscosity significantly decreases, transforming into a easily flowing liquid, while the epoxy resin has not yet begun rapid curing, resulting in good overall fluidity. Subsequently, the low-viscosity resin begins to flow under low pressure, penetrating deep into the carbon fiber bundles and interlayers, allowing the resin to fully flow and wet the carbon fibers. Simultaneously, it slowly expels air from the interlayers and fiber bundles. The low pressure and heat preservation time provide sufficient driving force and ample time to fully complete resin flow and air removal.

[0035] The progressive gel compression stage sequentially involves at least two sub-stages of stepped pressure and temperature increases. Each sub-stage raises the pressure and temperature to a higher set point and holds it at that temperature for a certain time. The final temperature is 110°C to 130°C, with a heating time of 1-2 hours, and the final pressure is 5 MPa to 10 MPa, with a pressurization time of 1-2 hours. During the progressive gel compression stage, as the temperature gradually increases, the epoxy resin begins and accelerates its cross-linking reaction under the action of the curing agent, causing a sharp increase in system viscosity. At this point, the increased resin viscosity makes it less prone to loss but has not yet completely lost its fluidity. Simultaneously, the pressure is also increased stepwise. This simultaneous stepwise pressurization is to compact the preform structure step by step during the stage when the resin viscosity increases, fluidity decreases, but curing is not yet complete. The heat preservation at the end of each sub-stage ensures that the resin reaction is sufficient and the structure is stable at that pressure and temperature point, preparing for the next higher pressure step. This achieves the purpose of removing air bubbles and increasing density while preventing resin loss, significantly increasing the density of the preform.

[0036] The final curing stage involves raising the pressure to a final pressure of 8-10 MPa and the temperature to 165-185°C, and holding at that temperature for 9-12 hours. During this final curing stage, by ensuring tight interlayer contact under the highest pressure and complete resin curing at high temperature, extremely high initial strength and density are achieved. Simultaneously, the coupling agent functions fully under high pressure, greatly enhancing the interfacial bonding between the fiber and the matrix, fundamentally preventing delamination and cracking.

[0037] Compared to existing technologies that involve reheating and melting dried pre-impregnated carbon cloth, this method directly applies the resin to the carbon cloth in a liquid or flowable state, completely eliminating the need for a dried pre-impregnated carbon cloth. Using a specially formulated composite resin impregnation solution addresses the main reason why the viscosity of traditional pure phenolic resin continuously decreases upon heating. The epoxy resin added to the composite resin impregnation solution undergoes a cross-linking reaction with the curing agent during the gradual gelation and compression stage, causing a sharp increase in system viscosity and gelation. This achieves thorough wetting while effectively preventing interlayer slippage, thereby producing a preform with high initial density and strong interlayer bonding.

[0038] Step S5: Place the preform into a vacuum carbonization furnace for carbonization treatment to convert the resin matrix into a carbon matrix. Perform at least two rounds of liquid phase densification and at least one round of gas phase densification on the carbonized preform to obtain a densified blank.

[0039] Specifically, the preform is placed in a vacuum carbonization furnace and evacuated to 1×10⁻³ Pa. The temperature is then increased to 1100~1300℃ at a rate of 10~50℃ / min and held for 2~4 hours. During this process, non-carbon elements in the resin decompose and escape, leaving glassy carbon to form a carbon matrix. Simultaneously, shrinkage and micropores are generated.

[0040] Two rounds of resin impregnation and re-carbonization are performed. The first impregnation temperature is 50-70 ℃, the carbonization temperature is 60-80 ℃, and the carbonization time is 2-3 h. The second impregnation temperature is 30-50 ℃, the carbonization temperature is 70-90 ℃, and the carbonization time is 3-4 h.

[0041] The preform after liquid phase densification is subjected to chemical vapor deposition treatment. The preform after liquid phase densification is placed in a chemical vapor deposition furnace at 2100~2300℃, and carbon-containing gas such as methane is introduced. The temperature is maintained for 2~3 hours, so that the pyrolytic carbon produced by its pyrolysis is deposited in the finest pores inside the material, achieving final pore sealing and densification, and finally obtaining a carbon fiber cloth support plate with a density of not less than 1.5g / cm³.

[0042] Because the pre-processing of layer spraying and the step-by-step hot-pressing curing combined with the composite resin impregnation solution prevent resin loss to the greatest extent, the traditional process will not suffer from problems such as low resin matrix content and high porosity in the cured green body due to the large amount of resin loss in the early stage of hot pressing. As a result, the total volume of pores that need to be filled after carbonization is significantly less than that of the traditional process. Therefore, only two liquid phase impregnations are needed to fill the main pores, and then one vapor phase deposition is used to seal the residual micropores, so that the target density can be achieved with the fewest number of cycles.

[0043] Step S6: Perform surface treatment on the blank to obtain the carbon fiber cloth support plate. Specifically, CNC machine tools are used for machining, and coated tools are used for precision milling and cutting to ensure dimensional accuracy and no chipping at the edges. Finally, a polishing machine is used for surface polishing.

[0044] Compared with existing technologies, the method for preparing high-density carbon fiber cloth support plates provided by this invention solves the problems of easy resin loss, high porosity, cumbersome processes, and insufficient performance in the preparation of traditional carbon-carbon composite materials through the synergistic innovation of composite resin system, integrated layup spraying process, and multi-stage stepped hot-pressing curing. Specifically, the rapid gelation of epoxy resin in the initial stage of hot pressing in the composite resin system complements the viscosity decrease of phenolic resin. Combined with a multi-stage stepped pressurization and heating regime, wetting is achieved during the optimal resin flow period and compaction is performed during the gelation period, thereby effectively controlling resin flow, preventing loss and layup misalignment, and obtaining a high-density preform. Since a high-density preform is obtained in the initial hot-pressing curing stage, subsequent densification only requires two liquid-phase impregnations and one vapor-phase deposition, significantly reducing the traditional 4-6 or even more densification processes and shortening the entire production cycle. In addition, the traditional method eliminates the need for multiple independent processes such as carbon cloth pretreatment, overall impregnation, drying, and prepreg storage. This not only simplifies the process but also eliminates the inherent defect of resin loss caused by the remelting of dried prepreg.

[0045] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions or improvements within the spirit of the present invention are covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a high-density carbon fiber cloth support plate, comprising the following steps: Step S1: A composite resin impregnation solution is prepared by compounding 60-70% phenolic resin, 15-25% epoxy resin, 6-18% curing agent, and 2-6% coupling agent by mass percentage; Step S2: Provide carbon fiber fabric and cut it to the required size; Step S3: Lay a piece of carbon fiber cloth flat on the workbench, then evenly apply the composite resin impregnation liquid to the surface of the carbon fiber cloth through atomized spraying to form a resin layer. Then, lay another piece of carbon fiber cloth on the resin layer and alternately cycle spraying and laying until the stacked layers reach the predetermined thickness, finally forming a preform; Step S4: Place the preform into a preheated hot press mold, and then perform multi-stage stepped pressure and temperature increase curing to obtain a preform. The multi-stage stepped pressure and temperature increase curing includes at least an initial flow and heat preservation stage, a gradual gelation and compression stage, and a final curing stage. The gradual gelation and compression stage goes through at least two sub-stages of stepped pressure and temperature increase in sequence, and each sub-stage increases the pressure and temperature higher than the previous sub-stage and holds it at that temperature. Step S5: The preform is placed in a vacuum carbonization furnace for carbonization treatment, so that the resin matrix is ​​converted into a carbon matrix. The carbonized preform is subjected to at least two rounds of liquid phase densification and at least one round of gas phase densification to obtain a densified blank. Step S6: Perform surface treatment on the blank to obtain the carbon fiber cloth support plate.

2. The method for preparing the high-density carbon fiber cloth support plate as described in claim 1, characterized in that: In step S1 above, specifically, the weighed raw materials are placed in a stirrer and stirred at 400-600 rpm for 10-20 minutes at 25-30°C. Then, the mixture is transferred to an ultrasonic disperser and ultrasonically dispersed at a frequency of 35-45 kHz for 15-20 minutes to ensure that all components are fully mixed and uniform without agglomeration, thereby obtaining a composite resin impregnation liquid with stable viscosity suitable for atomization spraying.

3. The method for preparing the high-density carbon fiber cloth support plate as described in claim 1, characterized in that: In step S3 above, the table surface temperature is maintained at 20~25℃, the nozzle moves at a speed of 2~3 mm / s and is 10~15 mm away from the carbon cloth surface, and the spraying time for each layer is controlled at 30~50 seconds, forming a resin layer with a single layer thickness of 0.15~0.20 mm.

4. The method for preparing the high-density carbon fiber cloth support plate as described in claim 1, characterized in that: In step S4 above, the initial gel flow and heat preservation stage involves increasing the pressure to 2-4 MPa at a rate of 2-3 MPa / h and holding it at 85-105℃ for 1-3 hours. The gradual gel compression stage has a final temperature of 110℃ to 130℃, a heating time of 1-2 hours, a final pressure of 5 MPa to 10 MPa, and a pressure increase time of 1-2 hours. The final curing stage involves increasing the pressure to a final pressure of 8-10 MPa and a temperature of 165-185℃ and holding it at that temperature for 9-12 hours.

5. The method for preparing the high-density carbon fiber cloth support plate as described in claim 1, characterized in that: In step S5 above, in at least two rounds of liquid phase densification, the first impregnation temperature is 50-70 ℃, the carbonization temperature is 60-80 ℃, and the carbonization time is 2-3 h; the second impregnation temperature is 30-50 ℃, the carbonization temperature is 70-90 ℃, and the carbonization time is 3-4 h.

6. The method for preparing the high-density carbon fiber cloth support plate as described in claim 1, characterized in that: In step S5 above, in at least one phase densification process, the preform after liquid phase densification is placed in a chemical vapor deposition furnace at 2100~2300℃, and a carbon-containing gas such as methane is introduced and kept at this temperature for 2~3 hours.

7. The method for preparing the high-density carbon fiber cloth support plate as described in claim 1, characterized in that: In step S6 above, the surface treatment includes at least precision milling, cutting, and surface polishing.

8. A high-density carbon fiber cloth support plate prepared by the method according to any one of claims 1 to 7, characterized in that: The density of the high-density carbon fiber cloth support plate is not less than 1.55 g / cm³.

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