A method for high-throughput preparation and rapid screening of multilayer structural ceramic matrix composites

Abstract

The application discloses a kind of multilayer structure ceramic matrix composite high-throughput preparation and rapid screening method.First, different types of fiber preform are used to prepare ceramic matrix composite, and after simple polishing, the specified thickness ceramic matrix composite sheet is formed, and the sheet is pressed into a multilayer structure according to different order with adhesive, and the electromagnetic wave reflectivity test is carried out.After testing, the sheet can be separated and reused after dissolving the multilayer structure with anhydrous ethanol solution.A small amount of different types of fiber preform is used to prepare ceramic matrix composite sheet, and a variety of different multilayer structures can be tested, and the multilayer structure meeting the wideband wave absorption performance is screened out.The high-throughput test method of structure wave-absorbing ceramic matrix composite designed by the application solves the technical problem that ceramic matrix composite material in the prior art is difficult to quickly screen out wideband structure wave-absorbing ceramic matrix composite due to long preparation cycle and high cost.

Description

Technical Field

[0001] This invention relates to the field of high-temperature microwave absorbing composite materials, and in particular to a high-throughput preparation and rapid screening method for multilayer ceramic matrix composite materials. Background Technology

[0002] With the continuous advancement of radar detection technology, the stealth performance of aircraft is increasingly becoming a crucial factor affecting their safety and reliability. Material stealth, fundamentally speaking, is the most effective method to improve the stealth performance of aircraft. Ceramic matrix composites, with their excellent mechanical properties, thermal stability, and chemical stability, have significant application prospects in the field of high-temperature load-bearing and radar-absorbing materials for aerospace. In particular, multi-layered ceramic matrix composites, with matching layers, loss layers, and reflective layers, each with its own functional layer, possess the characteristics of "thinness, light weight, wide bandwidth, and frequency tunability," making them the most common and effective method for preparing broadband radar-absorbing, high-temperature resistant aircraft components.

[0003] Most reported multilayer ceramic matrix composites involve pre-designing prefabricated structures by stacking different types of fibers or according to corresponding layup structures, with one fiber prefabricated structure for each multilayer structure. The fiber prefabricated structure is then densified, and finally, the reflectivity of the ceramic matrix composite is tested. If the reflectivity of this multilayer structure is unsatisfactory, a new prefabricated structure and multilayer structure need to be designed. This method of preparing and screening one multilayer structure for one fiber layup significantly limits the feasible application of multilayer ceramic matrix composites. Furthermore, the preparation of one multilayer structure for one fiber prefabricated structure is time-consuming, and the cost of the composite material is constantly increasing. The preparation cycle becomes longer with the increasing number of multilayer structures requiring screening, which greatly restricts the development of multilayer ceramic matrix composites in the field of high-temperature broadband microwave absorption.

[0004] If the preparation cycle and cost can be reduced, and different multilayer structures can be tested quickly, and a suitable multilayer structure can be selected and its broadband absorption performance tested, it will be beneficial to promote the application of ceramic matrix composites in the field of high-temperature microwave absorption. Summary of the Invention

[0005] The technical problem this invention aims to solve is that existing multilayer ceramic matrix composite materials require multiple molding processes, resulting in complex processes, long cycles, and high preparation costs. This ultimately leads to difficulties in rapidly screening multilayer structures that meet broadband microwave absorption performance requirements, resulting in high costs and long cycles. To address the shortcomings of existing technologies, this invention provides a high-throughput preparation and rapid screening method for multilayer ceramic matrix composite materials. The overall idea of ​​this method is to prepare ceramic matrix composite thin plates using a small number of different types of fiber preforms, prepare different multilayer structures through different layup sequences, test various multilayer structures, and finally screen out multilayer structures that meet broadband microwave absorption performance.

[0006] To solve the above technical problems, the present application provides a high-throughput preparation and rapid screening method of multi-layer structure ceramic matrix composite materials.

[0007] The preparation and rapid screening method comprises the following steps:

[0008] Step 1: Preparation of ceramic matrix composite material sheets of different fiber types.

[0009] Degumming: 1-3 fibers in carbon fibers, silicon carbide fibers, and alumina fibers are woven into a fiber preform by two-dimensional weaving, 2.5-dimensional weaving, or three-dimensional weaving, with a volume fraction of 30%-60%.

[0010] Put the fiber preform into a muffle furnace, and raise the temperature from room temperature to 500-800℃ in 3-6 hours, keep the temperature for 1-2 hours, and then cool to room temperature in 5-10 hours, and take out the fiber preform.

[0011] First, densification is performed by chemical vapor deposition and then by precursor impregnation and pyrolysis, and the densification process is as follows:

[0012] CVI process (chemical vapor deposition): the fiber preform is clamped with a porous graphite mold with a pore size of 2-8 mm, and is tightened with carbon-carbon bolts. The fiber preform with the porous graphite mold is placed in a high-temperature deposition furnace, and NH3, BCl3, Ar, and H2 gas flow ratios of 60:(5-20):60:60 are introduced, the temperature is controlled at 1000-1200℃, the pressure is controlled at 1KPa-5KPa, the deposition time is 6-12 hours, and after the deposition is completed, it is taken out, and the preparation process needs to use a porous graphite mold to prevent the preform from deforming.

[0013] PIP process (precursor impregnation and pyrolysis): the fiber preform is placed in a vacuum impregnation tank, and then the vacuum impregnation tank is vacuumed, and the vacuuming time is 10-30 minutes, and the pressure is maintained below 1KPa.

[0014] Further, the precursor solution is poured into the vacuum impregnation tank, so that the fiber preform is fully impregnated with the precursor solution, and the vacuum impregnation time is 1-3 hours. The precursor solution is one of polycarbosilane solution, polysilazane solution, polysilazane solution, polysiloxane solution, and polyborazane solution.

[0015] Then, nitrogen protective gas is filled in the vacuum impregnation tank for pressure impregnation, and the pressure is maintained at 1-10MPa, and the pressure impregnation time is 2-4 hours.

[0016] After pressure impregnation, the nitrogen gas inside is released, and the fiber preform is taken out.

[0017] Drying: The fiber preform after taking out is put into a blast drying oven, and dried for 6-12 hours under the condition of constant temperature and constant pressure of 80-300℃.

[0018] High temperature pyrolysis: The dried fiber preform is put into a vacuum pyrolysis furnace, and heated from room temperature to 300℃ for 3-5 hours; at 300℃, heat preservation for 1-2 hours; after 3-5 hours from 300℃ to 500-1200℃, and heat preservation for 1-3 hours, and then cooled to room temperature for 5-10 hours.

[0019] After cooling, the prepared composite material is weighed and the density is calculated, and the density calculation refers to the density after removing the surface impurities of the fiber preform.

[0020] Repeat the steps of impregnation, drying, high temperature pyrolysis and cooling until the density difference between adjacent two times is not more than 0.05g / cm 3 , which indicates that the pores in the fiber preform have been basically filled completely, and the porous graphite mold needs to be used throughout the preparation process to prevent deformation.

[0021] The density of the adjacent two times refers to the density of the fiber preform after the last high temperature pyrolysis and the density of the fiber preform after this high temperature pyrolysis.

[0022] Second step: polishing and processing of the thin plate

[0023] The ceramic matrix composite plate after CVI process and PIP process is polished, and the thickness is polished to one of 0.5, 1, 1.5, 2, 2.5, 3mm, wherein the parallelism of the thin plate is less than or equal to 0.1, and the thin plate can be bonded only after the surface is polished flat.

[0024] Third step: preparation of adhesive.

[0025] The dispersant and the resin are stirred according to a certain proportion, and then ultrasonic for 1-2 hours for standby. The mass ratio of resin and dispersant in the adhesive is (10-50):(1-5). The resin is methylphenyl silicone resin or general silicone resin; the dispersant is sodium hydroxymethyl cellulose or sodium alkyl benzene sulfonate.

[0026] Fourth step: one-step forming of multi-layer structure.

[0027] The adhesive is applied on the ceramic matrix composite sheets of different fiber types, the sheets are laid in a multilayer structure ceramic matrix composite flat plate according to the order of a multilayer structure, the ceramic matrix composite is pressed to a thickness of 3-6 mm by a metal flat plate, and then the ceramic matrix composite is heated in an oven at 150-250 DEG C for 2 hours, and finally cooled to room temperature for 2-5 hours. The number of layers of the multilayer structure ceramic matrix composite is one of 2-12 layers, and each layer is combined in different orders to form a multilayer structure.

[0028] Step 5: test and reuse.

[0029] During the test of the reflectivity of the ceramic matrix composite in the corresponding frequency band by the bow method or the waveguide method, the front and back surfaces of the ceramic matrix composite need to be tested.

[0030] After the test is completed, the multilayer structure ceramic matrix composite flat plate is placed in an ultrasonic device containing anhydrous ethanol solution, and ultrasonic is performed at 30-50 DEG C for 1-2 hours, and then different types of ceramic matrix composite sheets are taken out to prepare for the test of other multilayer structures.

[0031] The dissolved ceramic matrix composite sheets of different fiber types are laid according to the order of another multilayer structure, the multilayer structure one-step forming step of step 4 is repeated, and the reflectivity of the multilayer structure ceramic matrix composite flat plate is further tested by the bow method or the waveguide method until all the multilayer structures are tested, the multilayer structure with the lowest reflectivity and the widest frequency band below-10 dB is selected as the required multilayer structure.

[0032] Another object of the present application is to provide a multilayer structure ceramic matrix composite obtained by the method of the above claims.

[0033] The ceramic matrix composite prepared by the present application has many advantages such as thin thickness, light weight, fast test speed, and reusability.

[0034] The present application can effectively solve the problems of the existing multilayer structure ceramic matrix composite, which needs multiple forming, complex process, long cycle, complex preparation and test, and long test cycle of the structure of the broadband wave-absorbing ceramic matrix composite. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0036] Figure 1 The flow chart for preparation. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, but cannot limit the protection scope of the present application.

[0038] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present application should be the general meanings understood by the skilled in the art to which the present application belongs.

[0039] The experimental methods in the following embodiments are all conventional methods unless otherwise specified. The test materials used in the following embodiments are all commercially available unless otherwise specified.

[0040] Example 1

[0041] The present application provides a high-throughput preparation and rapid screening method for a multilayer structure ceramic matrix composite material, and the specific steps are as follows.

[0042] Step 1: Preparation of ceramic matrix composite material sheets of different fiber types.

[0043] Degumming: carbon fibers and silicon carbide fibers are respectively woven into fiber preforms by two-dimensional weaving method, and the volume fraction is 40%.

[0044] The fiber preform is placed in a muffle furnace, and the temperature is raised from room temperature to 800℃ in 5 hours, and then cooled to room temperature in 5 hours. The fiber preform is taken out.

[0045] CVI process (chemical vapor deposition method): the fiber preform is clamped with a 4mm pore size porous graphite mold, and is tightened with carbon carbon bolts. The fiber preform with the porous graphite mold is placed in a high temperature deposition furnace, and NH3, BCl3, Ar, H2 are introduced in a ratio of 60:10:60:60, the temperature is controlled at 1000℃, the pressure is controlled at 1KPa, the deposition time is 6 hours, and the deposition process needs to be prevented from deforming the preform by using the porous graphite mold.

[0046] PIP process (precursor impregnation and pyrolysis method): then the fiber preform is placed in a vacuum impregnation tank, and then the vacuum impregnation tank is vacuumed, and the vacuum time is 10 minutes, and the pressure is kept below 1KPa.

[0047] Further, the precursor solution is poured into the vacuum impregnation tank, so that the fiber preform is fully impregnated with the precursor solution, and the vacuum impregnation time is 1 hour. The precursor solution is polycarbosilane solution.

[0048] Subsequently, nitrogen gas is filled into the vacuum impregnation tank to protect the gas and pressurize the impregnation, the pressure is maintained at 2 MPa, and the pressurized impregnation time is 2 hours.

[0049] After pressurized impregnation, the nitrogen gas inside is released, and the fiber preform is taken out.

[0050] Drying: The fiber preform taken out is placed in a forced air drying oven, and dried at a constant temperature and pressure of 150°C for 6 hours.

[0051] High temperature pyrolysis: The dried fiber preform is placed in a vacuum pyrolysis furnace, and heated from room temperature to 300°C for 4 hours; at 300°C, heat for 1 hour; heat from 300°C to 1000°C for 3 hours, and heat for 2 hours; then cool to room temperature for 6 hours.

[0052] After cooling, the prepared composite material is weighed and the density is calculated, and the density calculation refers to the density of the fiber preform after removing surface impurities.

[0053] Repeat the steps of impregnation, drying, high temperature pyrolysis and cooling until the density difference between adjacent two times is not more than 0.05 g / cm 3 , indicating that the pores inside the fiber preform have been basically filled completely, and the porous graphite mold needs to be used throughout the preparation process to prevent deformation.

[0054] The density of the fiber preform after the last high temperature pyrolysis and the density of the fiber preform after this high temperature pyrolysis are referred to as the density of the fiber preform after the last high temperature pyrolysis and the density of the fiber preform after this high temperature pyrolysis.

[0055] Second step: polishing and processing of the thin plate

[0056] The ceramic matrix composite plate after CVI and PIP processes is polished to a thickness of 1 mm, and the surface parallelism of the thin plate is 0.1. After the surface is polished, the thin plate can be bonded

[0057] Third step: preparation of the adhesive.

[0058] The dispersant and the resin are stirred in a mass ratio of 10:5 and then ultrasonic for 1 hour for standby. The resin is methylphenyl silicone resin or general silicone resin; the dispersant is sodium hydroxymethyl cellulose or sodium alkyl benzene sulfonate.

[0059] Fourth step: one-step forming of the multi-layer structure.

[0060] The number of thin plates of the multilayer structure ceramic matrix composite material is 3, and each layer is combined in different orders to form a multilayer structure. The adhesive is brushed on the ceramic matrix composite material thin plates of different fiber types, 3 ceramic matrix composite material thin plates are laid to form a multilayer structure plate, a metal plate is used to compress the multilayer structure plate to a thickness of 3 mm, and the multilayer structure plate is placed in an oven for heat treatment at 200°C for 2 hours, and finally cooled to room temperature for 5 hours.

[0061] Step 5: Test and reuse.

[0062] During the test of the reflectivity of the ceramic matrix composite material on the corresponding frequency band by the bow method or the waveguide method, the front and back surfaces of the ceramic matrix composite material need to be tested.

[0063] After the test is completed, the multilayer structure ceramic matrix composite material plate is placed in an ultrasonic device containing anhydrous ethanol solution, ultrasonic treatment is performed at 30°C for 1 hour, and different types of ceramic matrix composite material thin plates are taken out to prepare for the test of other multilayer structures.

[0064] After dissolution, the ceramic matrix composite material thin plates of different fiber types are brushed with adhesive, 3 thin plates are laid to form another multilayer structure ceramic matrix composite material plate, a metal plate is used to compress the multilayer structure ceramic matrix composite material plate to a thickness of 3 mm, and the multilayer structure ceramic matrix composite material plate is placed in an oven for heat treatment at 200°C for 2 hours, and finally cooled to room temperature for 5 hours.

[0065] Step 5 is repeated until all combination orders are tested. Table 1 is the test results of Example 1 of the present application

[0066] Table 1 Reflectivity of three-layer thin plate structure at 2-18 GHz (thin plate thickness is 1 mm)

[0067]

[0068] Note: RLmin represents the minimum reflection loss, EAB represents the effective absorption bandwidth with a reflection less than -10 dB; fiber type A is carbon fiber, and B is silicon carbide fiber.

[0069] Example 2:

[0070] The present application provides a high-throughput preparation and rapid screening method for multilayer structure ceramic matrix composite materials, and the specific steps are as follows.

[0071] Step 1: Preparation of ceramic matrix composite material thin plates of different fiber types.

[0072] Degumming: The silicon carbide fibers and alumina fibers are respectively woven into fiber preforms by two-dimensional weaving method, and the volume fraction is 40%.

[0073] Put the fiber preform into the muffle furnace, 5 hours from room temperature to 800℃, keep 1 hour, then cool to room temperature for 5 hours, take out the fiber preform.

[0074] CVI process (chemical vapor deposition method): the fiber preform is clamped with a porous graphite mold with a pore size of 4 mm, and is tightened with carbon-carbon bolts. The fiber preform with the porous graphite mold is placed in a high-temperature deposition furnace, and the gas flow ratio of NH3, BCl3, Ar, H2 is 60:10:60:60, the temperature is controlled at 1000℃, the pressure is controlled at 1KPa, the deposition time is 6 hours, after deposition, take out, the preparation process needs to use the porous graphite mold to prevent the preform from deforming.

[0075] PIP process (precursor impregnation pyrolysis method): the fiber preform is placed in a vacuum impregnation tank, then the vacuum impregnation tank is vacuumized, the vacuumization time is 10 minutes, and the pressure is kept below 1KPa.

[0076] Further, the precursor solution is poured into the vacuum impregnation tank, so that the fiber preform is fully impregnated with the precursor solution, and the vacuum impregnation time is 1 hour. The precursor solution is polycarbosilane solution.

[0077] Then pressurized impregnation is carried out in the vacuum impregnation tank with nitrogen protection gas, the pressure is kept at 2MPa, and the pressurized impregnation time is 2 hours.

[0078] After pressurized impregnation, the nitrogen gas inside is released, and the fiber preform is taken out.

[0079] Drying: the fiber preform taken out is placed in a forced air drying oven, and dried at a constant temperature and pressure of 150℃ for 6 hours.

[0080] High temperature pyrolysis: the dried fiber preform is placed in a vacuum pyrolysis furnace, 4 hours from room temperature to 300℃; at 300℃, keep 1 hour; 3 hours from 300℃ to 1000℃, and keep 2 hours, then cool to room temperature for 6 hours.

[0081] After cooling, the prepared composite material is weighed and the density is calculated, and the density calculation refers to the density of the fiber preform after removing surface impurities.

[0082] Repeat the steps of impregnation, drying, high temperature pyrolysis and cooling until the density difference between adjacent two times is not more than 0.05g / cm 3 , which indicates that the pores inside the fiber preform have been basically filled completely, and the preparation process needs to use the porous graphite mold to prevent deformation.

[0083] The adjacent two densities refer to the density of the fiber preform after the last high-temperature pyrolysis and the density of the fiber preform after this high-temperature pyrolysis.

[0084] Second step: polishing and processing of the thin plate

[0085] The ceramic matrix composite plate subjected to the CVI process and the PIP process is polished to a thickness of 1 mm, wherein the parallelism of the surface of the thin plate is equal to 0.1, and the thin plate can be bonded after the surface is polished flat

[0086] Third step: preparation of the adhesive.

[0087] The mass ratio of the resin in the adhesive to the dispersant is 10:5. The resin is methylphenyl silicone resin or general silicone resin; the dispersant is sodium hydroxymethyl cellulose or sodium alkyl benzene sulfonate. The dispersant and the resin are stirred according to a certain proportion and then ultrasonically treated for 1 hour for standby.

[0088] Fourth step: one-step forming of the multi-layer structure.

[0089] The number of layers of the multi-layer structure ceramic matrix composite thin plate is 3, and the ceramic matrix composite thin sheets of each layer are combined in different orders to form a multi-layer structure. The adhesive is brushed on the ceramic matrix composite thin plates of different fiber types, and the three ceramic matrix composite thin plates are laid into a multi-layer structure flat plate. A metal flat plate is used to press the multi-layer structure flat plate to a thickness of 3 mm, and the multi-layer structure flat plate is placed in an oven for heat treatment at 200℃ for 2 hours, and finally cooled to room temperature for 5 hours.

[0090] Fifth step: testing and reuse.

[0091] During the testing of the reflectivity of the ceramic matrix composite in the corresponding frequency band by the bow method or the waveguide method, the front and back surfaces of the ceramic matrix composite need to be tested.

[0092] After the test is completed, the multi-layer structure ceramic matrix composite flat plate is placed in an ultrasonic device containing anhydrous ethanol solution, ultrasonically treated at 30℃ for 1 hour, and different types of ceramic matrix composite thin sheets are taken out to prepare for the testing of other multi-layer structures.

[0093] After dissolution, the ceramic matrix composite thin plates of different fiber types are brushed with adhesive, and the three thin plates are laid into another multi-layer structure ceramic matrix composite flat plate. A metal flat plate is used to press the multi-layer structure ceramic matrix composite flat plate to a thickness of 3 mm, and the multi-layer structure ceramic matrix composite flat plate is placed in an oven for heat treatment at 200℃ for 2 hours, and finally cooled to room temperature for 5 hours.

[0094] Repeat the fifth step until all the combination orders are tested.

[0095] Example 3:

[0096] The application provides a high-throughput preparation and rapid screening method for a multilayer structure ceramic matrix composite material, and specific steps are as follows.

[0097] Step 1: Preparation of ceramic matrix composite material sheets of different fiber types.

[0098] Degumming: carbon fibers and alumina fibers are respectively woven into a fiber preform by a two-dimensional weaving method, and the volume fraction is 40%.

[0099] The fiber preform is placed in a muffle furnace, and the temperature is raised from room temperature to 800 DEG C in 5 hours, and then cooled to room temperature in 5 hours.

[0100] CVI process (chemical vapor deposition method): the fiber preform is clamped with a 4mm aperture porous graphite mold, and is tightened with a carbon-carbon bolt. The fiber preform with the porous graphite mold is placed in a high-temperature deposition furnace, and the gas flow ratio of NH3, BCl3, Ar and H2 is 60:10:60:60, the temperature is controlled at 1000 DEG C, the pressure is controlled at 1KPa, the deposition time is 6 hours, and the deposition is completed. The preparation process needs to use a porous graphite mold to prevent the preform from deforming.

[0101] PIP process (precursor impregnation and pyrolysis method): the fiber preform is placed in a vacuum impregnation tank, and then the vacuum impregnation tank is vacuumized, and the vacuumization time is 10 minutes, and the pressure is kept below 1KPa.

[0102] Further, the precursor solution is poured into the vacuum impregnation tank, so that the fiber preform is fully impregnated with the precursor solution, and the vacuum impregnation time is 1 hour. The precursor solution is a polycarbosilane solution.

[0103] Then, nitrogen protection gas is filled in the vacuum impregnation tank for pressure impregnation, the pressure is kept at 2MPa, and the pressure impregnation time is 2 hours.

[0104] After pressure impregnation, the nitrogen gas in the tank is released, and the fiber preform is taken out.

[0105] Drying: the taken-out fiber preform is placed in a blow drying oven, and dried at a constant temperature and pressure of 150 DEG C for 6 hours.

[0106] High-temperature pyrolysis: the dried fiber preform is placed in a vacuum pyrolysis furnace, and the temperature is raised from room temperature to 300 DEG C in 4 hours; at 300 DEG C, the temperature is kept for 1 hour; the temperature is raised from 300 DEG C to 1000 DEG C in 3 hours, and kept for 2 hours, and then cooled to room temperature in 6 hours.

[0107] After cooling, the prepared composite material is weighed and the density is calculated, which refers to the density of the fiber preform after removing surface impurities.

[0108] The impregnation-drying-high temperature pyrolysis-cooling steps are repeated until the density difference between adjacent two times is not more than 0.05 g / cm 3 , indicating that the pores in the fiber preform have been substantially filled, and the preparation process needs to use a porous graphite mold to prevent deformation.

[0109] The density of the adjacent two times refers to the density of the fiber preform after the last high temperature pyrolysis and the density of the fiber preform after this high temperature pyrolysis.

[0110] Second step: polishing and processing of the thin plate

[0111] The ceramic matrix composite plate after CVI and PIP processes is polished to a thickness of 1 mm, and the surface parallelism of the thin plate is equal to 0.1. After the surface is polished, the thin plate can be bonded

[0112] Third step: preparation of the adhesive.

[0113] The dispersant and the resin are stirred in a mass ratio of 10:5 and then ultrasonically treated for 1 hour for standby. The resin is methylphenyl silicone resin or general silicone resin; the dispersant is sodium hydroxymethyl cellulose or sodium alkyl benzene sulfonate.

[0114] Fourth step: one-step forming of the multi-layer structure.

[0115] The number of layers of the multi-layer structure ceramic matrix composite thin plate is 3, and each layer is combined in different order to form a multi-layer structure. The adhesive is applied on the ceramic matrix composite thin plate of different fiber types, and the three ceramic matrix composite thin plates are laid into a multi-layer structure flat plate. A metal flat plate is used to press the multi-layer structure flat plate to a thickness of 3 mm, and then placed in an oven for heat treatment at 200°C for 2 hours, and finally cooled to room temperature for 5 hours.

[0116] Fifth step: testing and reuse.

[0117] During the testing of the reflectivity of the ceramic matrix composite material in the corresponding frequency band by the bow method or waveguide method, the front and back surfaces of the ceramic matrix composite material need to be tested.

[0118] After the test is completed, the multi-layer structure ceramic matrix composite flat plate is placed in an ultrasonic device containing anhydrous ethanol solution, and ultrasonically treated at 30°C for 1 hour. Different types of ceramic matrix composite thin slices are taken out for the preparation of other multi-layer structure tests.

[0119] After the different fiber types of ceramic matrix composite thin plates are dissolved, the adhesive is brushed, three thin plates are laid into another multi-layer structure ceramic matrix composite flat plate, the multi-layer structure ceramic matrix composite flat plate is pressed to 3mm thickness by a metal flat plate, and is placed into an oven for heat treatment at 200℃ for 2 hours, and finally is cooled to room temperature for 5 hours.

[0120] The fifth step is repeated until all the combination sequences are tested.

[0121] It should be noted that, unless otherwise specified, technical terms or scientific terms used in the present application should be understood as their common meanings to those skilled in the art to which the present application pertains. Unless otherwise specified, the relative steps, numerical expressions and values of the components and steps set forth in these examples do not limit the scope of the present application. In all the examples shown and described herein, unless otherwise specified, any specific value should be interpreted as merely exemplary, and not as a limitation, therefore, other examples of the exemplary embodiments can have different values.

[0122] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; the present application has been described in detail with reference to the foregoing embodiments, and those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered in the protection scope of the present application.

[0123] The present application designs a multi-layer structure ceramic matrix composite high-throughput preparation and rapid screening method. The method uses different fiber types of ceramic matrix composite thin sheets to bond into one body with adhesive according to different sequences, the present application can use limited materials to comprehensively analyze and screen the performance of the existing possible multi-layer structure, which can effectively solve the problems of existing multi-layer structure ceramic matrix composite which needs multiple molding, complex process, long cycle, complex preparation and testing, and long testing cycle of broadband wave absorbing ceramic matrix composite structure. At the same time, the ceramic matrix composite prepared by the present application has many advantages such as "thin thickness, light weight, fast testing speed, and reusability".

Claims

1. A method for high-throughput preparation and rapid screening of multilayer structure ceramic matrix composites, characterized in that: Step 1: preparation of a ceramic matrix composite plate; Step 2: polishing and processing of the thin plate; polishing the ceramic matrix composite treated in Step 1 to a thickness of one of 0.5, 1, 1.5, 2, 2.5, and 3 mm, and a surface parallelism of less than or equal to 0.1, to obtain a ceramic matrix composite thin plate; Step 3: preparation of an adhesive; stirring the dispersant and the resin in a certain proportion and then ultrasonicating for 1-2 hours for standby; Step 4: one-step forming of the multilayer structure ceramic matrix composite; laying up a plurality of ceramic matrix composite thin plates into a multilayer structure flat plate with the adhesive, and then pressing the thickness to 3-6 mm with a metal flat plate, and then placing into an oven for heat treatment at 150-250℃ for 2 hours, and then naturally cooling to room temperature before taking out, to obtain a multilayer structure ceramic matrix composite; Step 5: testing and reuse; testing the front and back surfaces of the multilayer structure ceramic matrix composite obtained in Step 4 for electromagnetic wave reflectivity by the bow method or the waveguide method; after the testing, dissolving the multilayer structure ceramic matrix composite with anhydrous ethanol, and then taking out each layer of the ceramic matrix composite thin plate for standby; changing the laying-up order of the plurality of ceramic matrix composite thin plates after dissolution, and then repeating Step 4 and Step 5 until the desired multilayer structure ceramic matrix composite is screened out. The ceramic matrix composite plate in Step 1 adopts different types of fibers, and the fibers are one to three of carbon fibers, silicon carbide fibers, and alumina fibers; the weaving structure of the ceramic matrix composite plate is any one of two-dimensional weaving, 2.5-dimensional weaving, and three-dimensional weaving, and the volume fraction of the fibers of the ceramic matrix composite is 30%-60%. The chemical vapor deposition method is as follows: clamping the fiber preform with a porous graphite mold with a pore size of 2-8 mm, controlling the thickness of the fiber preform to be 0.5 or 1 mm, placing the fiber preform with the porous graphite mold into a high-temperature deposition furnace while introducing NH3, BCl3, Ar, and H2 gases, controlling the gas flow ratio of NH3, BCl3, Ar, and H2 to be 60: (5-20): 60: 60, controlling the temperature of the deposition furnace to be 1000-1200℃, controlling the pressure to be 1 KPa-5 KPa, and controlling the deposition time to be 6-12 hours, and then taking out after the deposition is completed. The precursor impregnation and pyrolysis method is as follows: vacuum impregnating the fiber preform prepared by the chemical vapor deposition method with a precursor solution for 1-3 hours, then performing pressure impregnation with a pressure of 1-10 MPa for 2-4 hours, and then taking out for drying and high-temperature pyrolysis; the high-temperature pyrolysis step is as follows: first increasing the temperature from room temperature to 300℃ over 3-5 hours; keeping the temperature at 300℃ for 1-2 hours; increasing the temperature from 300℃ to 500-1200℃ over 3-5 hours and keeping the temperature for 1-3 hours, and then cooling to room temperature over 5-10 hours; the precursor solution is one of polycarbosilane solution, polysilazane solution, and polysilazaborane solution. ​ ​ ​ ​ ​ ​ 2. The method of claim 1, wherein the method is characterized by: ​ 3. The method for high-throughput fabrication and rapid screening of multilayer structural ceramic matrix composites according to claim 1 or 2, characterized in that: In step 1, the fiber preform of the ceramic matrix composite of different fiber types is subjected to a degumming heat treatment, and the fiber preform after the degumming heat treatment is densified by a chemical vapor deposition method and then by a precursor impregnation and pyrolysis method, and the precursor impregnation and pyrolysis method is repeatedly used until the density difference of the fiber preform after adjacent two times of densification is not more than 0.05 g / cm 3 .

4. The method of claim 3, wherein the method is characterized by: ​ 5. The method of claim 3, wherein the method is characterized by: ​ 6. The method of claim 1, wherein the method is characterized by: The mass ratio of the resin and dispersant in step 3 is (10-50):(1-5); the resin is methyl phenyl silicone resin or general silicone resin; and the dispersant is sodium hydroxymethyl cellulose or sodium alkyl benzene sulfonate.

7. The method of claim 1, wherein the method is characterized by: In step 4, the required multilayer structure ceramic matrix composite material is the one with the lowest reflectivity of less than -10 dB and the widest frequency band.

8. The method of claim 1, wherein the method is characterized by: In step 4, 2-12 pieces of ceramic matrix composite material thin plates are laid in different orders to form a multilayer structure flat plate by using an adhesive.

9. The method of claim 1, wherein the method is characterized by: In step 5, the specific steps of dissolving the multilayer structure ceramic matrix composite material by using anhydrous ethanol are as follows: the multilayer structure ceramic matrix composite material is placed in an ultrasonic device containing an anhydrous ethanol solution, and ultrasonic treatment is carried out at 30-50 ℃ for 1-2 hours. 10.A multilayer structure ceramic matrix composite material obtained by the method of any one of claims 1-9.

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