Winding, dipping and forming method of ultrathin carbon-carbon screen blank

Abstract

The invention discloses a winding and dipping forming method of an ultrathin carbon-carbon screen blank, which is characterized by comprising the following steps: selecting a reinforcement fiber material and a matrix material; determining a winding system; based on the selected reinforcement fiber material and the selected matrix material, a composite material body is prepared through a winding tool by adopting a fiber wet-method winding process; performing first high-temperature treatment on the composite material body to obtain a porous preform; performing asphalt impregnation on the porous preform; and after the asphalt impregnation is completed, carrying out second high-temperature treatment to obtain an ultrathin carbon-carbon screen blank. According to the method disclosed by the invention, through two high-temperature treatment processes and an asphalt impregnation process, the prepared green body has a relatively low percentage of close area, the subsequent CVD (Chemical Vapor Deposition) carbonization process is facilitated, and the ultrathin carbon-carbon screen with qualified density is finally obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a winding and impregnation molding method for an ultra-thin carbon-carbon screen blank. Background Art

[0002] The working principle of the electric propulsion ion engine is to first use electrical energy to ionize the propellant, and the ionized ions are accelerated and drawn out in the process of passing through the grid assembly with an ultra-thin mesh structure, thereby generating long-term stable thrust. Among them, the grid assembly is the core component of the electric propulsion ion engine, and its design and manufacturing level directly determines the performance and life of the propulsion system.

[0003] The life of conventional metal molybdenum grids is only 14,000 hours, which is still a huge gap from the 40,000 hours required for deep space exploration. In order to improve the structural performance of ultra-thin mesh structure grid components, further research on the application of advanced materials must be carried out. Carbon-carbon composite materials have the advantages of light weight, high strength, low expansion, high temperature resistance and ion sputtering resistance, and have been widely used in high-end equipment such as aviation and aerospace. It is an ideal choice to replace metal molybdenum to make electric propulsion ion engine grids. Moreover, in order to make deep space exploration spacecraft have sufficient thrust, it is necessary to carry out research on the design and manufacturing process of large-caliber ultra-thin carbon-carbon mesh grids with a diameter of more than 300 mm.

[0004] The process flow for preparing ultra-thin carbon-carbon mesh grid is roughly divided into three steps: blank forming, CVD deposition carbonization and finishing. Among them, blank forming is particularly critical as the first step, which generally includes two processes: fiber wet winding and pressurized curing. The quality of the blank also determines the difficulty of subsequent processes and the forming effect of the final product.

[0005] During the green body forming process, if a resin with a high carbon content is directly used as the wet winding matrix material, the prepared green body can easily obtain a higher residual carbon rate that meets the technical indicators in the subsequent process, but there is also a problem of high closed porosity, which makes it difficult to CVD dense carbon deposition in some closed pores during the carbonization process. Summary of the invention

[0006] The technology of the present invention solves the problem: overcomes the shortcomings of the prior art, provides a winding and impregnation molding method for an ultra-thin carbon-carbon screen blank, selects epoxy resin or polyvinyl alcohol as the matrix material for wet winding of fibers in the blank molding process, and after curing, a first high-temperature treatment is performed to remove most of the non-carbon elements in the matrix material, so that the reinforcement fibers have porous characteristics while maintaining adhesion and not falling apart, and then asphalt impregnation is used to fill the pores of the preform, and finally a second high-temperature treatment is performed to obtain the ultra-thin carbon-carbon screen blank.

[0007] In order to solve the above technical problems, the present invention discloses a winding and impregnation molding method for an ultra-thin carbon-carbon screen blank, comprising:

[0008] Select reinforcement fiber material and matrix material;

[0009] Determine the winding system;

[0010] Based on the selected reinforcement fiber material and matrix material, a composite material body is prepared by winding tooling, adopting a fiber wet winding process and curing;

[0011] Performing a first high temperature treatment on the composite body to obtain a porous preform;

[0012] Asphalt impregnation of the porous preform;

[0013] After the asphalt impregnation is completed, a second high-temperature treatment is carried out to obtain an ultra-thin carbon-carbon screen blank.

[0014] In the winding and impregnation molding method of the ultra-thin carbon-carbon screen blank, the reinforcement fiber material is selected according to the following principles:

[0015] According to the thickness h, porosity w, outer diameter d and maximum allowable weight m of the ultra-thin carbon-carbon screen blank to be prepared, the minimum multifilament strength σ is calculated:

[0016]

[0017] Among them, k1 represents the strength empirical parameter, g represents the standard gravitational acceleration;

[0018] The material whose average value of multifilament strength test is greater than σ is selected as the reinforcement fiber material.

[0019] In the winding and infusion molding method of the ultra-thin carbon-carbon screen blank, the matrix material is selected according to the following principle: a material that can ensure that the reinforcement fibers remain adhered and not fall apart after the first high-temperature treatment and has porous characteristics is selected as the matrix material.

[0020] In the winding and infusion molding method of the ultra-thin carbon-carbon mesh blank, the winding system is determined, including: determining the number of winding layers n, the winding sequence and the winding tape distance b of the reinforcement fiber.

[0021] In the winding and impregnation molding method of the ultra-thin carbon-carbon screen blank, the winding tape distance b is determined by the following formula:

[0022]

[0023] Wherein, k2 represents the winding empirical parameter, l represents the unfolding bandwidth of the reinforcement fiber material during the winding process, and t represents the linear density value of the reinforcement fiber material.

[0024] In the winding and impregnation molding method of the ultra-thin carbon-carbon screen blank, the winding tooling includes: a metal frame a, a metal frame b and a graphite core mold;

[0025] The metal frame a and the metal frame b are overlapped to form a regular hexagonal metal frame; wherein,

[0026] The metal frame a and the metal frame b are both processed with overlapping steps at two overlapping positions, and are provided with screw holes a and screw holes b for connecting and fixing the metal frame a and the metal frame b;

[0027] The graphite core mold is located in a regular hexagonal metal frame;

[0028] A cutting groove is provided on each side of the regular hexagonal metal frame;

[0029] The six corners of the regular hexagonal metal frame are processed with a top tightening hole a, a top tightening hole b, a top tightening hole c, a fixing screw hole a, a fixing screw hole b and a fixing screw hole c in sequence.

[0030] In the winding and infusion molding method of the ultra-thin carbon-carbon screen blank, the composite material body is subjected to a first high-temperature treatment to obtain a porous preform, including:

[0031] Use metal tooling to clamp the composite material body together with the winding tooling in the middle and fix it with screws;

[0032] Put the assembled composite material body together with the winding tooling and the metal tooling into an oven, and cure it according to the curing process parameters of the selected matrix material; wherein the surface where the metal tooling contacts the composite material body is flat, without obvious protrusions or pits;

[0033] After curing is completed, wait for the temperature to drop naturally, take the composite material body together with the winding tooling and the metal tooling out of the oven, remove the metal tooling, and replace it with a graphite plate tooling a, sandwich the composite material body together with the winding tooling in the middle, and fix it with screws; wherein the graphite plate tooling a includes: two graphite plates a with flat surfaces;

[0034] Put the assembled composite material body together with the winding tooling and the graphite plate tooling a into a high-temperature box furnace, gradually increase the temperature of the high-temperature box furnace to a temperature range of 950°C±50°C, and maintain the temperature range of 950°C±50°C for no less than 6 hours to perform the first high-temperature treatment; during the first high-temperature treatment, the high-temperature box furnace is always kept in an inert atmosphere;

[0035] After waiting for natural cooling, the composite material body together with the winding tooling and the graphite plate tooling a are taken out from the high-temperature box furnace, and the graphite plate tooling a is removed to obtain a porous preform together with the winding tooling.

[0036] In the winding and impregnation molding method of the ultra-thin carbon-carbon screen blank, the porous preform is impregnated with asphalt, including:

[0037] Use graphite plate fixture b to clamp the porous preform with the winding fixture in the middle and fix it with screws; wherein the graphite plate fixture b comprises: two graphite plates b with one side having a flat surface and the other side having grid-like fine grooves; one side of the graphite plate b having the grid-like fine grooves is in contact with the porous preform;

[0038] Put the assembled porous preform together with the winding tooling and graphite plate tooling b into a container filled with solid asphalt, then put the container into an oven, adjust the oven temperature to be higher than the melting temperature of the asphalt and keep it warm for at least 24 hours to allow the asphalt to fully impregnate the porous preform.

[0039] In the winding and impregnation molding method of the ultra-thin carbon-carbon screen blank, after the asphalt impregnation is completed, a second high-temperature treatment is performed to obtain the ultra-thin carbon-carbon screen blank, including:

[0040] After waiting for the temperature to drop naturally, the porous preform together with the winding tooling and the graphite plate tooling b are taken out of the oven, and then put into a high-temperature box furnace together;

[0041] The temperature of the high-temperature box furnace is gradually increased to a temperature range of 950°C ± 50°C, and the temperature range of 950°C ± 50°C is maintained for no less than 12 hours to perform the second high-temperature treatment; during the second high-temperature treatment, the high-temperature box furnace is always kept in an inert atmosphere;

[0042] After waiting for natural cooling, the porous preform together with the winding tooling and the graphite plate tooling b are taken out from the high-temperature box furnace, and the graphite plate tooling b and the winding tooling are removed to obtain the ultra-thin carbon-carbon screen blank.

[0043] In the winding and infusion molding method of the ultra-thin carbon-carbon screen blank,

[0044] The first high temperature treatment is used to remove non-carbon elements in the matrix material and to keep the reinforcement fibers adhered and not falling apart within the specified high temperature treatment temperature range and time;

[0045] Asphalt impregnation, a process of asphalt impregnation specified for increasing the density of porous preforms;

[0046] The second high temperature treatment is used to remove non-carbon elements in the impregnated asphalt and maintain the high temperature treatment temperature range and time specified by the ultra-thin carbon-carbon screen blank.

[0047] The present invention has the following advantages:

[0048] The present invention discloses a winding and impregnation molding method for an ultra-thin carbon-carbon screen blank. Through two high-temperature treatment processes and an asphalt impregnation process, the prepared blank has a lower closed porosity, which is conducive to the subsequent CVD deposition carbonization process and ultimately obtains an ultra-thin carbon-carbon screen with a qualified density. The ultra-thin carbon-carbon screen blank designed and manufactured using the method of the present invention can meet the index requirements of the subsequent ultra-thin carbon-carbon screen preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a front view of a winding tool in an embodiment of the present invention;

[0050] Figure 2 It is a left side view of a winding tool in an embodiment of the present invention;

[0051] Figure 3 yes Figure 2 AA view. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0053] In this embodiment, the winding and dipping molding method of the ultra-thin carbon-carbon screen blank comprises:

[0054] Step 1: Select reinforcement fiber material and matrix material.

[0055] In this embodiment, the reinforcement fiber material can be selected according to the following principles:

[0056] According to the thickness h, the porosity w (i.e. the ratio of the opening area to the opening region area), the outer diameter d and the maximum allowable weight m of the ultra-thin carbon-carbon screen blank to be prepared, the minimum multifilament strength σ is calculated:

[0057]

[0058] Among them, k1 represents the empirical parameter of fiber strength, which is generally 5 to 8; g represents the standard gravitational acceleration.

[0059] The material with the average value of the multifilament strength test greater than σ is selected as the reinforcement fiber material. In order to obtain a green body with the highest possible carbon content, it is generally preferred to select the reinforcement fiber material from the carbon fiber material series.

[0060] Furthermore, the base material can be selected according to the following principles:

[0061] Select a material that can ensure that the reinforcement fibers remain adhered and have porous characteristics after the first high-temperature treatment as the matrix material. According to process verification, epoxy resin or polyvinyl alcohol can be used as the matrix material of the fiber wet winding process, which can ensure that the reinforcement fibers remain adhered and have porous characteristics after the first high-temperature treatment. Of course, other materials that can ensure that the reinforcement fibers remain adhered and have porous characteristics after the first high-temperature treatment can also be used as the matrix material of the wet winding process.

[0062] Step 2, determine the winding system.

[0063] In this embodiment, determining the winding system mainly includes: determining the number of winding layers n, the winding order and the winding tape distance b of the reinforcement fiber. Take an ultra-thin carbon-carbon screen blank containing single-layer fiber winding angles of 0°, 60° and 120° as an example. First, determine the number of winding layers. Since the ultra-thin carbon-carbon screen blank is designed with 3 winding angles of 0°, 60° and 120°, and considering that the number of cycles is not less than 2, the number of winding layers is determined to be 6. Furthermore, for the design of the winding order of each winding layer, it is not recommended to wind the winding layers in the same direction together, so the winding order is set to 0°, 60°, 120°, 60°, 120°, 0°. Furthermore, the winding tape distance b can be determined by the following formula: Wherein, k2 represents the empirical parameter of fiber winding, which is generally 0.75 to 0.95, l represents the unfolding bandwidth of the reinforcement fiber material during the winding process, and t represents the linear density value of the reinforcement fiber material.

[0064] Step 3: Based on the selected reinforcement fiber material and matrix material, a composite material body is prepared by winding a tool, adopting a fiber wet winding process and curing.

[0065] In this embodiment, the fiber wet winding process requires the use of winding tooling. Taking the ultra-thin carbon-carbon screen blank containing single-layer fiber winding angles of 0°, 60° and 120° as an example, the following is designed: Figures 1 to 3The hexagonal winding tool shown in the figure mainly comprises: a metal frame a3, a metal frame b9 and a graphite core mold 6. The metal frame a3 and the metal frame b9 are overlapped to form a regular hexagonal metal frame; the metal frame a3 and the metal frame b9 are both processed with overlapping steps at two overlapping positions, and are provided with screw holes a4 and screw holes b8 for connecting and fixing the metal frame a3 and the metal frame b9; the graphite core mold 6 is located in the regular hexagonal metal frame. A cutting groove 1 is provided on each side of the regular hexagonal metal frame for cutting the fiber winding layer from the side after the fiber wet winding; the six corners of the regular hexagonal metal frame are processed with tightening holes a10, tightening holes b11, tightening holes c12, fixing screw holes a13, fixing screw holes b14 and fixing screw holes c15 in sequence, and the winding tooling is fixed by switching different fixing screw holes and corresponding tightening holes to complete the layered winding of the reinforcement fibers in different winding directions, and then cured according to the curing system of the selected matrix material to obtain a molded composite material body.

[0066] Step 4: performing a first high temperature treatment on the composite material body to obtain a porous preform.

[0067] In this embodiment, the first high temperature treatment process is as follows:

[0068] The composite material body and the wrapping tool are clamped in the middle using a metal tool and fixed with screws.

[0069] The assembled composite material body, winding tooling and metal tooling are placed in an oven together and cured according to the selected curing process parameters of the matrix material. The surface of the metal tooling in contact with the composite material body is flat without obvious protrusions or pits.

[0070] After curing is completed, wait for the temperature to drop naturally and then take the composite material body, the winding tooling and the metal tooling out of the oven. Remove the metal tooling and replace it with the graphite plate tooling a, sandwich the composite material body and the winding tooling in the middle and fix it with screws. The graphite plate tooling a includes: two graphite plates a with flat surfaces.

[0071] Put the assembled composite material body together with the winding tooling and the graphite plate tooling a into a high-temperature box furnace, gradually increase the temperature of the high-temperature box furnace to a temperature range of 950℃±50℃, and maintain the temperature range of 950℃±50℃ for no less than 6 hours to perform the first high-temperature treatment. During the first high-temperature treatment, the high-temperature box furnace is always kept in an inert atmosphere, and nitrogen can be selected as the inert gas.

[0072] After waiting for natural cooling, the composite material body together with the winding tooling and the graphite plate tooling a are taken out from the high-temperature box furnace, and the graphite plate tooling a is removed to obtain a porous preform together with the winding tooling.

[0073] Step 5: impregnating the porous preform with asphalt.

[0074] In this embodiment, the asphalt impregnation process is as follows:

[0075] The porous preform is clamped in the middle with the winding tooling using a graphite plate tooling b and fixed with screws. The graphite plate tooling b includes: two graphite plates b with a flat surface on one side and a grid-like fine groove processed on the other side; the surface of the graphite plate b with the grid-like fine grooves on one side is in contact with the porous preform, and the grid-like fine grooves are used to facilitate the asphalt to enter at high temperature so as to fully impregnate the porous preform.

[0076] Place the assembled porous preform together with the winding tooling and graphite plate tooling b into a container containing a sufficient amount of solid asphalt, then place the container into an oven, adjust the oven temperature to be higher than the melting temperature of the asphalt and keep it warm for at least 24 hours to allow the asphalt to fully impregnate the porous preform.

[0077] Step 6: After the asphalt impregnation is completed, a second high-temperature treatment is performed to obtain an ultra-thin carbon-carbon screen blank.

[0078] In this embodiment, the second high temperature treatment process is as follows:

[0079] After waiting for natural cooling, the porous preform together with the winding tooling and the graphite plate tooling b are taken out of the oven, and then put into a high-temperature box furnace together.

[0080] The temperature of the high-temperature box furnace is gradually increased to a temperature range of 950°C±50°C, and the temperature range of 950°C±50°C is maintained for no less than 12 hours to carry out a second high-temperature treatment; wherein, during the second high-temperature treatment, the high-temperature box furnace is always kept in an inert atmosphere.

[0081] After waiting for natural cooling, the porous preform together with the winding tooling and the graphite plate tooling b are taken out from the high-temperature box furnace, and the graphite plate tooling b and the winding tooling are removed to obtain the ultra-thin carbon-carbon screen blank.

[0082] In this embodiment, the above step 4, the first high temperature treatment, is mainly used to remove non-carbon elements in the matrix material and maintain the high temperature treatment temperature range and time specified for the adhesion of the reinforcement fibers. The above step 5, asphalt impregnation, is mainly used to increase the density of the porous preform. The above step 6, the second high temperature treatment, is mainly used to remove non-carbon elements in the impregnated asphalt and maintain the high temperature treatment temperature range and time specified for the ultra-thin carbon-carbon screen blank.

[0083] Based on the above embodiment, a specific example is described below.

[0084] According to the minimum multifilament strength calculated by the empirical formula of the minimum multifilament strength, a certain brand of domestic T800 grade carbon fiber was selected as the reinforcement fiber material; the selected matrix material was polyvinyl alcohol; the designed ultra-thin carbon-carbon screen blank had 6 winding layers and a thickness of 0.75mm; according to the winding angles of different winding layers, the designed winding sequence was 0°, 60°, 120°, 60°, 120°, 0°; according to the empirical formula of winding tape distance, the winding tape distance was calculated to be 0.65mm; according to the relevant process parameters of the selected matrix material, the determined curing system was: room temperature → 80℃ / 1.5h → 100℃ / 12h → 135℃ / 6h → natural cooling with the furnace; after curing, the composite material body and tooling were taken out, and two special graphite plates with flat surfaces were used to fix the composite material The material body together with the winding tooling is clamped in the middle and fixed with screws, then put into a high-temperature box furnace for the first high-temperature treatment, and the system is as follows: room temperature→950℃ / 8h→natural cooling with the furnace, and the high-temperature box furnace is in a nitrogen atmosphere during the high-temperature treatment; the first high-temperature treatment produces a porous preform, and a special graphite plate with a flat surface on one side and a grid-like fine groove on the other side is used to clamp the porous preform together with the winding tooling, and fixed with screws and put into an oven at 200℃ for 24h to allow the asphalt to fully impregnate the porous preform; after the asphalt impregnation is completed, the porous preform together with the graphite tooling is taken out and transferred to the high-temperature box furnace for the second high-temperature treatment, and the system is as follows: room temperature→950℃ / 12h→natural cooling with the furnace, and the high-temperature box furnace is in a nitrogen atmosphere during the high-temperature treatment. A total of 6 ultra-thin carbon-carbon screen blanks were prepared using this process. After subsequent CVD deposition carbonization and finishing steps, the final ultra-thin carbon-carbon screens all passed the thermal environment test and mechanical properties test.

[0085] In summary, the present invention discloses a winding and dipping molding method for an ultra-thin carbon-carbon screen mesh blank, which can be used to prepare an ultra-thin carbon-carbon screen mesh blank that can meet the requirements of mechanical properties, density and other indicators.

[0086] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0087] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A winding and impregnation molding method for an ultra-thin carbon-carbon screen blank, characterized in that: include: Select reinforcement fiber material and matrix material; Determine the winding system; Based on the selected reinforcement fiber material and matrix material, a composite material body is prepared by winding tooling, adopting a fiber wet winding process and curing; Performing a first high temperature treatment on the composite body to obtain a porous preform; Asphalt impregnation of the porous preform; After the asphalt impregnation is completed, a second high-temperature treatment is carried out to obtain an ultra-thin carbon-carbon screen blank.

2. The winding and infusion molding method of the ultra-thin carbon-carbon screen blank according to claim 1 is characterized in that: Select the reinforcement fiber material according to the following principles: According to the thickness h, porosity w, outer diameter d and maximum allowable weight m of the ultra-thin carbon-carbon screen blank to be prepared, the minimum multifilament strength σ is calculated: Among them, k1 represents the strength empirical parameter, and g represents the standard gravitational acceleration; The material whose average value of multifilament strength test is greater than σ is selected as the reinforcement fiber material.

3. The winding and impregnation molding method of the ultra-thin carbon-carbon screen blank according to claim 2 is characterized in that: The matrix material is selected according to the following principle: a material which can ensure that the reinforcement fibers remain adhered and not fall apart after the first high temperature treatment and has porous characteristics is selected as the matrix material.

4. The winding and infusion molding method of the ultra-thin carbon-carbon screen blank according to claim 3 is characterized in that: Determine the winding system, including: determine the number of winding layers n, the winding sequence and the winding tape distance b of the reinforcement fiber.

5. The winding and infusion molding method of the ultra-thin carbon-carbon screen blank according to claim 4 is characterized in that: The winding tape distance b is determined by the following formula: Wherein, k2 represents the winding empirical parameter, l represents the unfolding bandwidth of the reinforcement fiber material during the winding process, and t represents the linear density value of the reinforcement fiber material.

6. The winding and infusion molding method of the ultra-thin carbon-carbon screen blank according to claim 1 is characterized in that: A winding tool, comprising: a metal frame a (3), a metal frame b (9) and a graphite core mold (6); The metal frame a (3) and the metal frame b (9) are overlapped to form a regular hexagonal metal frame; wherein, The metal frame a (3) and the metal frame b (9) are both processed with overlapping steps at two overlapping positions, and are provided with screw holes a (4) and screw holes b (8) for connecting and fixing the metal frame a (3) and the metal frame b (9); The graphite core mold (6) is located in a regular hexagonal metal frame; A cutting groove (1) is provided on each side of the regular hexagonal metal frame; The six corners of the regular hexagonal metal frame are processed with a tightening hole a (10), a tightening hole b (11), a tightening hole c (12), a fixing screw hole a (13), a fixing screw hole b (14) and a fixing screw hole c (15) in sequence.

7. The winding and infusion molding method of the ultra-thin carbon-carbon screen blank according to claim 1 is characterized in that: The composite body is subjected to a first high temperature treatment to obtain a porous preform, comprising: Use metal tooling to clamp the composite material body together with the winding tooling in the middle and fix it with screws; Put the assembled composite material body together with the winding tooling and the metal tooling into an oven, and cure it according to the curing process parameters of the selected matrix material; wherein the surface where the metal tooling contacts the composite material body is flat, without obvious protrusions or pits; After curing is completed, wait for the temperature to drop naturally, take the composite material body together with the winding tooling and the metal tooling out of the oven, remove the metal tooling, and replace it with a graphite plate tooling a, sandwich the composite material body together with the winding tooling in the middle, and fix it with screws; wherein the graphite plate tooling a includes: two graphite plates a with flat surfaces; Put the assembled composite material body together with the winding tooling and the graphite plate tooling a into a high-temperature box furnace, gradually increase the temperature of the high-temperature box furnace to a temperature range of 950°C±50°C, and maintain the temperature range of 950°C±50°C for no less than 6 hours to perform the first high-temperature treatment; during the first high-temperature treatment, the high-temperature box furnace is always kept in an inert atmosphere; After waiting for natural cooling, the composite material body together with the winding tooling and the graphite plate tooling a are taken out from the high-temperature box furnace, and the graphite plate tooling a is removed to obtain a porous preform together with the winding tooling.

8. The winding and infusion molding method of the ultra-thin carbon-carbon screen blank according to claim 7 is characterized in that: Asphalt impregnation of porous preforms, including: Use graphite plate fixture b to clamp the porous preform with the winding fixture in the middle and fix it with screws; wherein the graphite plate fixture b comprises: two graphite plates b with one side having a flat surface and the other side having grid-like fine grooves; one side of the graphite plate b having the grid-like fine grooves is in contact with the porous preform; Put the assembled porous preform together with the winding tooling and graphite plate tooling b into a container filled with solid asphalt, then put the container into an oven, adjust the oven temperature to be higher than the melting temperature of the asphalt and keep it warm for at least 24 hours to allow the asphalt to fully impregnate the porous preform.

9. The winding and impregnation molding method of the ultra-thin carbon-carbon screen blank according to claim 8, characterized in that the asphalt After impregnation, a second high temperature treatment is performed to obtain an ultra-thin carbon-carbon screen blank, including: After waiting for the temperature to drop naturally, the porous preform together with the winding tooling and the graphite plate tooling b are taken out of the oven, and then put into a high-temperature box furnace together; The temperature of the high-temperature box furnace is gradually increased to a temperature range of 950°C ± 50°C, and the temperature range of 950°C ± 50°C is maintained for no less than 12 hours to perform the second high-temperature treatment; during the second high-temperature treatment, the high-temperature box furnace is always kept in an inert atmosphere; After waiting for natural cooling, the porous preform together with the winding tooling and the graphite plate tooling b are taken out from the high-temperature box furnace, and the graphite plate tooling b and the winding tooling are removed to obtain the ultra-thin carbon-carbon screen blank.

10. The winding and infusion molding method of the ultra-thin carbon-carbon screen blank according to claim 1, characterized in that: The first high temperature treatment is used to remove non-carbon elements in the matrix material and to keep the reinforcement fibers adhered and not falling apart within the specified high temperature treatment temperature range and time; Asphalt impregnation, a process of asphalt impregnation specified for increasing the density of porous preforms; The second high temperature treatment is used to remove non-carbon elements in the impregnated asphalt and maintain the high temperature treatment temperature range and time specified by the ultra-thin carbon-carbon screen blank.

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