2.5 D woven ceramic-based composite material based on C / C composite material and preparation method of 2.5 D woven ceramic-based composite material

Abstract

The invention discloses a 2.5 D woven ceramic-based composite material based on a C / C composite material and a preparation method of the 2.5 D woven ceramic-based composite material, and belongs to the technical field of ceramic-based composite material preparation. According to the method, C / C waste scraps are introduced into a low-density 2.5 D woven composite material, resin carbon serves as a binder to form a three-dimensional network structure, a carbon skeleton of the formed three-dimensional network structure contains carbon fibers and carbon particles, the carbon fibers and the carbon particles are in lap joint to provide more sites for reaction of alloy melt, full reaction of the melt is promoted, the content of residual metal is reduced, and the mechanical property of the composite material is improved. According to the method disclosed by the invention, large-size pores between warp yarns and weft yarns of the 2.5 D woven preform are reduced, meanwhile, the recycling of the waste C / C composite material is realized, the pollution of wastes to the environment is reduced, and the green sustainable development is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic-based composite material preparation, and particularly relates to a 2.5D woven ceramic-based composite material based on C / C composite material and a preparation method thereof. Background Art

[0002] As high-performance aircraft evolve toward faster speeds, longer endurance, and greater stability, key components such as nose cones, leading edges, engine combustion chambers, and nozzle / throat liners for next-generation high-specific-impulse orbital control engines and advanced aerospace vehicles place higher demands on the performance of related thermal protection materials. Ultra-high-temperature ceramics (UHTCs) refer to a series of high-temperature-resistant ceramic compounds, such as transition metal borides, carbides, and nitrides, with melting points above 3000°C, including ZrB2, HfB2, ZrC, HfC, and TaC. Due to their excellent high-temperature resistance and resistance to oxidation and ablation, these ceramics are considered to have great potential for application in extreme high-temperature environments. However, the inherent brittleness and poor thermal shock resistance of ceramics limit their engineering applications. Combining UHTCs with continuous carbon fibers, which offer excellent strength and toughness, as reinforcements to create highly reliable ceramic-based composites is a key technology to overcome inherent brittleness and thermal shock failure, thereby achieving high-strength, toughness, and excellent ablation resistance.

[0003] At present, the commonly used carbon fiber preform structures mainly include needle-punched preforms, three-dimensional braided preforms and three-dimensional woven preforms. The 2.5D woven preform is a special structure of the three-dimensional woven preform. By interlocking the weft yarns and the warp yarns, the fiber bundles are interwoven at a certain angle in the thickness direction, so that the material has better integrity, improves the weak interlayer performance of planar laminated composites, enhances the impact impedance of composites, reduces the delamination damage of composites, and has good shear performance and good designability. 2.5D woven composites avoid the shortcomings of poor interlayer performance of needle-punched composites and complex processes of three-dimensional braided composites, reduce manufacturing costs, shorten production cycles, and are easy to prepare rotating components such as nose cones, shells and other complex structural parts. It is an important candidate material for thermal structure components of high-speed aircraft.

[0004] Common methods for preparing ceramic-based composites include chemical vapor infiltration, precursor impregnation and cracking, slurry impregnation, reactive infiltration, and the like. Reactive infiltration refers to a preparation method in which a metal or alloy melt infiltrates into a porous preform due to capillary forces at high temperatures, and chemically reacts with the matrix to simultaneously generate a ceramic phase. Compared with the previous processes, it has the advantages of a short preparation cycle, high density, and the ability to achieve near-net-size molding. However, there are many factors that affect reactive infiltration, including process parameters, carbon matrix type, preform structure, preform density, pore structure, and the like. The weaving method of the carbon fiber preform determines the internal pore structure and porosity of the low-density composite material, which in turn affects subsequent melt infiltration and chemical reactions. Due to the unique spatial distribution of yarns during the weaving process, 2.5D woven preforms have a large and unevenly distributed complex pore structure between the warp and weft yarns, which has become the key restricting the densification of 2.5D woven ceramic-based composites. Currently, there are few studies on the preparation of 2.5D woven ceramic-based composites by reactive infiltration and the research is still in the exploratory stage.

[0005] Chinese patent publication number CN119372567A discloses a 2.5D woven carbon fiber preform-reinforced Zr-based composite material and its preparation method. This method uses a 2.5D woven carbon fiber preform as reinforcement, prepares a solution using ceramic particles and resin as raw materials, then impregnates a low-density C / PyC composite with the resin / ceramic solution. A dense Zr-based composite material is prepared through impregnation, carbonization, and reactive infiltration. However, the composite material prepared by this method has a high residual metal content, which affects the high-temperature performance of the composite material.

[0006] Chinese patent publication number CN119263864A discloses a multi-scale three-dimensional network carbon skeleton structure-assisted composite material and its preparation method. This method involves impregnating a low-density needle-punched fiber preform composite material in a precursor solution, followed by a curing-carbonization-reaction infiltration process to produce a ceramic-modified composite material. The precursor solution is a mixture of resorcinol, formaldehyde solution, distilled water, and hexadecyltrimethylammonium bromide. This method can reduce residual metal in the composite material, but it is relatively expensive and requires the use of a toxic precursor solution during the preparation process, which pollutes the environment and poses safety risks. Summary of the Invention

[0007] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a 2.5D woven ceramic-based composite material based on C / C composite material and a preparation method thereof, so as to solve the problem of large-sized and unevenly distributed complex pore structure between the warp and weft yarns of the 2.5D woven preform in the prior art.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: S1, sieving C / C composite waste chips to obtain sieved C / C waste chips, wherein the C / C waste chips contain carbon fibers and pyrolytic carbon particles; S2, mixing the sieved C / C waste chips, phenolic resin and anhydrous ethanol and stirring them ultrasonically to obtain a waste chip-resin mixed solution; S3, introducing the pyrolytic carbon interfacial phase into the 2.5D woven carbon fiber preform by chemical vapor infiltration to obtain a low-density 2.5D woven C / C composite; S4, low-density 2.5D woven C / C composites were immersed in waste scrap-resin mixed solution and impregnated under vacuum environment; S5, drying the impregnated low-density 2.5D woven C / C composite material and carbonizing it to obtain a carbonized low-density 2.5D woven C / C w Composite materials; S6, carbonized low-density 2.5D woven C / C w After reactive infiltration of the composite material, a 2.5D woven ceramic matrix composite material was obtained.

[0009] A further improvement of the present invention is: Preferably, in S1, the mesh size of the sieve used in the screening process is 20 to 300 meshes.

[0010] Preferably, in S2, the mixing mass ratio of the C / C waste chips, phenolic resin and anhydrous ethanol is (1-2):1:10.

[0011] Preferably, in S3, the 2.5D woven carbon fiber preform is a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure, the number of warp yarns is 2, the number of weft yarns is 4, the weft density is 3.3 strands / cm, the warp density is 12 strands / cm, and the density is 0.8 g / cm 3 , the volume fraction is 45.8%.

[0012] Preferably, in S3, the density of the low-density 2.5D woven C / C composite material is 1.3-1.5 g / cm 3 .

[0013] Preferably, in S4, the vacuum degree during the impregnation process is 5-7 kPa, and the impregnation time is 30-60 min; in S5, the drying temperature is 70-120°C, and the drying time is 20-30 h; the carbonization temperature is 900-1000°C, and the carbonization time is 2-3 h.

[0014] Preferably, the impregnation, drying and carbonization processes under vacuum environment in S4 and S5 are repeated several times.

[0015] Preferably, in S6, reactive infiltration is performed using ZrSi2 alloy powder.

[0016] Preferably, in S6, the temperature of the reactive infiltration is 1700-1900° C., the vacuum degree is 0.026-0.1 Pa, and the holding time is 0.5-2 h.

[0017] A 2.5D woven ceramic matrix composite material based on a C / C composite material prepared by any of the above preparation methods, comprising a 2.5D woven carbon fiber preform, wherein ZrC-SiC ceramics and residual metal are distributed in the 2.5D woven carbon fiber preform; the density of the 2.5D woven ceramic matrix composite material is 2.28 to 3.09 g / cm 3 , the porosity is 10.05~17.54%.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a method for preparing a 2.5D woven ceramic-based composite material based on a carbon / carbon composite material. This method introduces waste carbon / carbon scraps into a low-density 2.5D woven composite material, forming a three-dimensional carbon skeleton within the low-density composite material. This method also divides the large (>1 mm) pores between fiber bundles filled with pyrolytic carbon in the low-density 2.5D woven composite material, which are difficult to introduce via chemical vapor infiltration, into smaller pores. This enhances capillary forces during the infiltration process, facilitating the infiltration of the melt. This method enables the recycling of waste carbon / carbon composite materials, reduces environmental pollution, and promotes green and sustainable development. The C / C scrap introduced by the present invention uses resin carbon as a binder to form a three-dimensional network structure of carbon skeletons present in large-sized pores. It has a high specific surface area and can provide a carbon source for the infiltrated alloy melt, reducing melt loss. The formed three-dimensional network structure of the carbon skeleton contains carbon fibers and carbon particles, which overlap with each other to provide more sites for the reaction of the alloy melt, promote the full reaction of the melt, and reduce the residual metal content. The method of the present invention can not only reduce the adverse effects of large-sized pores on the infiltration process, significantly improve the densification efficiency, promote the full reaction of the melt and matrix, and reduce the residual metal content, but also solve the resource waste and environmental pollution problems caused by the discarding of scraps generated during processing, reduce production costs, increase the utilization rate of materials, and promote sustainable development. The present invention transforms waste C / C composite materials into valuables and reuses them at a high value. The preparation process is simple and easy to scale up, and is not limited by the size and shape of the composite materials, and has good industrial application prospects.

[0019] Furthermore, by screening C / C waste chips, C / C waste chips of different sizes can be introduced into the composite material, and the size of the formed carbon skeleton structure can be adjusted to meet the application requirements of different pore sizes, different melt properties, and different preform structures.

[0020] The present invention also provides a 2.5D woven ceramic matrix composite material prepared by the above preparation method, which has a density of 2.28 to 3.09 g / cm 3 The porosity ranged from 10.05% to 17.54%. Compared to 2.5D woven ceramic-based composites prepared without the aid of waste C / C composites, the density increased by 61.78% and the porosity decreased by 56.29%. The melt infiltrated the composite under capillary forces and reacted in situ to form a dense ceramic matrix with a uniform distribution of the ceramic phase, improving the mechanical and ablation resistance of the composite. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The SEM images of C / C waste chips of different sizes after screening; Among them: Figures (a) and (e) are enlarged schematic diagrams of 200μm and 20μm of 20-80 mesh respectively; Figures (b) and (f) - 80-200 mesh; Figures (c), (g) - 200-300 mesh; Figures (d), (h) - less than 300 mesh; Figure 2 For the low density 2.D woven C / C in Example 4 w SEM images of composite materials; Among them: Figure (a) - low magnification SEM image; Figure (b) - high magnification SEM image; Figure 3 The cross-sectional SEM image and EDS spectrum of the 2.5D ceramic matrix composite material prepared in Example 4; Among them: Figure (a) - low magnification SEM image; Figure (b) - high magnification SEM image; Figure (c) - EDS spectrum of Figure (b).

[0022] Figure 4 The cross-sectional SEM image and EDS spectrum of the 2.5D ceramic matrix composite material obtained in Example 5; Among them: Figure (a) - low magnification SEM image; Figure (b) - high magnification SEM image; Figure (c) - EDS spectrum of Figure (b).

[0023] Figure 5 This is a cross-sectional SEM image of the 2.5D ceramic matrix composite material prepared in Comparative Example 1; Among them: Figure (a) - low magnification SEM image; Figure (b) - high magnification SEM image.

[0024] Figure 6 This is the X-ray diffraction pattern of the 2.5D ceramic-based composite material obtained in Example 5.

[0025] Figure 7 This is the X-ray diffraction pattern of the 2.5D ceramic-based composite material prepared in Comparative Example 1.

[0026] Figure 8This is a flow chart of a method for preparing 2.5D woven ceramic-based composite materials using waste C / C composite materials as an aid in one embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in further detail below with reference to the accompanying drawings: To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0028] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0029] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0030] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0031] C / C composites are composite materials with carbon fibers as reinforcement and carbonaceous materials such as pyrolytic carbon or pitch carbon as the matrix. The preparation of C / C composites requires multiple mechanical processes, which generate a large amount of waste chips containing carbon fibers and carbon particles. Currently, the common industrial practice is to discard or bury these waste chips, causing environmental pollution and waste of resources. Therefore, adopting a green and sustainable method to achieve internal pore control of 2.5D woven composites, reduce large-sized pores, reduce the residual metal content in the composites obtained by melt infiltration, and improve the densification of the material remains one of the current issues that need to be addressed in the preparation of 2.5D woven ceramic-based composites by reactive infiltration.

[0032] See also Figure 8The present invention discloses a method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material, comprising the following steps: S1, sieving C / C composite waste scraps to obtain sieved C / C waste scraps, wherein the C / C waste scraps are in a granular form; S2, preparing a mixed solution by using the sieved C / C waste chips, phenolic resin and anhydrous ethanol as raw materials and ultrasonically stirring the solution to obtain a waste chip-resin mixed solution; S3, introducing the pyrolytic carbon matrix into the 2.5D woven carbon fiber preform by chemical vapor infiltration to obtain a low-density 2.5D woven C / C composite; S4, low-density 2.5D woven C / C composites were immersed in the waste chips-resin mixed solution and impregnated under vacuum; S5, drying the impregnated low-density 2.5D woven C / C composite material and carbonizing it to obtain a carbonized low-density 2.5D woven C / C w Composite materials; S6, using the reaction infiltration method, after cleaning and drying C / C w The composite material is surrounded by ZrSi2 alloy powder and subjected to high-temperature heat treatment under vacuum to obtain a 2.5D woven ceramic matrix composite material, which is a C / C-ZrC-SiC composite material.

[0033] The method of the present invention first obtains C / C scraps of different mesh sizes by screening, then prepares a C / C scrap-phenolic resin mixed solution, deposits a pyrolytic carbon interface phase inside a 2.5D woven carbon fiber preform by chemical vapor infiltration, and then introduces the C / C composite material scraps into the matrix to fill part of the pores by vacuum impregnation-drying-carbonization; finally, a reactive infiltration process is used to react ZrSi2 alloy with the C / C scraps and the carbon matrix to form ceramics, ultimately preparing a 2.5D woven ceramic-based composite material. The present invention adopts a vacuum impregnation-drying-carbonization process to introduce granular C / C scraps into the large-sized pores of the 2.5D woven carbon fiber preform to form a three-dimensional network carbon skeleton; using a reactive infiltration process, the melt infiltrates into the three-dimensional network carbon skeleton at high temperature to react in situ to generate a ceramic phase, thereby preparing a dense 2.5D woven ceramic-based composite material.

[0034] In some embodiments of the present invention, in S1, the C / C waste chips are chips generated during the C / C processing process, and the chips contain carbon fibers and pyrolytic carbon particles. The screen used is 20 to 300 mesh. The screening process of S1 is classified and recovered according to the screening results.

[0035] In some embodiments of the present invention, in S2, the process of preparing the mixed solution of the screened C / C waste chips, phenolic resin and anhydrous ethanol to obtain the waste chips-resin mixed solution is as follows: first, the phenolic resin is dissolved in anhydrous ethanol, and then the C / C waste chips are added and stirred evenly to obtain a C / C waste chips-resin mixed solution; wherein the mass ratio of the C / C waste chips: phenolic resin: anhydrous ethanol is (1-2): 1:10.

[0036] Furthermore, in S2, the ultrasonic time is 20 to 30 minutes, and the magnetic stirring time is 30 to 60 minutes.

[0037] In some embodiments of the present invention, in S3, the 2.5D woven carbon fiber preform is a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure, the number of warp yarns is 2, the number of weft yarns is 4, the weft density is 3.3 strands / cm, the warp density is 12 strands / cm, and the density is 0.8 g / cm 3 , the volume fraction is 45.8%.

[0038] In some embodiments of the present invention, in step S3, the pyrolytic carbon interface phase is introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration to obtain the low-density 2.5D woven C / C composite material with a density of 1.3 to 1.5 g / cm 3 .

[0039] In some embodiments of the present invention, in S4, the 2.5D woven carbon fiber preform is vacuum impregnated in the mixed solution at a vacuum degree of 5 to 7 kPa for a time of 30 to 60 min.

[0040] In some embodiments of the present invention, in S5, the drying temperature is 70-120° C., and the drying time is 20-30 hours.

[0041] In some embodiments of the present invention, in S5, the process parameters of the high-temperature carbonization are: under an argon protective atmosphere, heating to 900-1000° C. at a rate of 3-7° C. / min and keeping warm for 2-3 hours; during the high-temperature carbonization process, the resin is cracked into carbon.

[0042] In some embodiments of the present invention, in the processes of S4 and S5, the vacuum impregnation-drying-carbonization process is repeated 1 to 3 times to obtain a low-density 2.5D woven C / C with a weight gain of 6 to 20%. w Composite materials, where w stands for waste.

[0043] In some embodiments of the present invention, in S6, the 2.5D woven ceramic-based composite material is prepared by a reactive infiltration process using ZrSi2 alloy powder as an infiltrant; wherein the particle size of the ZrSi2 alloy powder is 1 to 50 μm and the purity is 99.5%.

[0044] In S6, the low density 2.5D woven C / C w After cleaning and drying, the composite material is placed in a graphite crucible, ZrSi2 alloy powder is embedded around it, the crucible is sealed, and the crucible is placed in a high-temperature furnace for heat treatment to obtain a 2.5D woven ceramic-based composite material; during the vacuum infiltration process, the heating rate of the high-temperature heat treatment is 7-10℃ / min, the temperature is raised to 1700-1900℃, the vacuum degree is 0.026-0.1 Pa, and the holding time is 0.5-2h.

[0045] On the other hand, the present invention also provides a 2.5D woven ceramic-based composite material obtained by the above-mentioned preparation method, which comprises a 2.5D woven carbon fiber preform, ZrC-SiC ceramic and a small amount of residual metal, wherein the ZrC-SiC ceramic and the residual metal are distributed in the 2.5D woven carbon fiber preform.

[0046] The 2.5D woven ceramic-based composite material prepared using the above-mentioned method has the advantages of high density and low residual metal content. This method introduces waste C / C composite material into the large pores of the 2.5D woven preform, forming a three-dimensional carbon network. During the reactive infiltration process, capillary forces cause the melt to enter the carbon network and form a Zr-based ceramic in situ. The ceramic matrix is ​​evenly distributed, improving the mechanical and ablation resistance of the composite material. Ultimately, the introduced waste material and pyrolytic carbon react with the ZrSi2 alloy to form a ZrC-SiC ceramic.

[0047] One embodiment of the present invention provides a method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material, comprising the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips are passed through a 20-300 mesh sieve and classified and recycled according to the screening results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is (1-2): 1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The 2.5D woven carbon fiber preform used is a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns is 2, the number of weft yarns is 4, the weft density is 3.3 strands / cm, the warp density is 12 strands / cm, and the density is 0.8 g / cm 3, the volume fraction is 45.8%.

[0048] Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 is immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 30 minutes at a vacuum pressure of 5 to 7 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in an oven at 80°C for 24 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. Under an argon protective atmosphere, the temperature was raised to 900°C at 5°C / min and kept warm for 2 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C with a weight gain of 6-20%. w Composite material low density 2.5D woven C / C w Composite materials.

[0049] Step 6: Reaction Infiltration The low-density 2.5D woven C / C w After cleaning and drying, the composite material was placed in a graphite crucible, and ZrSi2 alloy powder (particle size of 1 to 50 μm, purity of 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace for heat treatment to obtain a 2.5D woven ceramic-based composite material. The reactive infiltration process used was: heating rate of 10°C / min, heating to 1800°C, vacuum degree of 0.026 to 0.1 Pa, holding time of 2h, and then power off to cool down.

[0050] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0051] The following examples utilize conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or as recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art.

[0052] Example 1 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through 20-mesh and 80-mesh sieves and classified and recycled according to the screening results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 1:1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 30 minutes under a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in an 80°C oven for 24 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 900°C at 5°C / min under an argon protective atmosphere and kept warm for 2 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 6.43%.

[0053] Step 6: Reaction Infiltration The low-density 2.5D woven C / C w After cleaning and drying the composite material, it was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1800°C at a rate of 10°C / min, the vacuum was 0.1 Pa, and the temperature was kept at this temperature for 2 hours. The power was then turned off and the temperature was cooled. The density after heat treatment was 2.28 g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 17.54%; Example 2 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through 80-mesh and 200-mesh sieves and classified and recycled according to the screening results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 1:1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 30 minutes under a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in an 80°C oven for 24 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 900°C at 5°C / min under an argon protective atmosphere and kept warm for 2 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 10.70%.

[0054] Step 6: Reaction Infiltration The low-density 2.5D woven C / C wAfter cleaning and drying the composite material, it was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1800°C at a rate of 10°C / min, the vacuum was 0.1 Pa, and the temperature was kept at this temperature for 2 hours. The power was then turned off and the temperature was cooled. The density after heat treatment was 2.56 g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 12.56%; Example 3 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through 200-mesh and 300-mesh sieves and classified and recycled according to the screening results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 1:1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 30 minutes under a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in an 80°C oven for 24 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 900°C at 5°C / min under an argon protective atmosphere and kept warm for 2 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 10.52%.

[0055] Step 6: Reaction Infiltration The low-density 2.5D woven C / C w After cleaning and drying, the composite material was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1800°C at a rate of 10°C / min, the vacuum was 0.1 Pa, and the temperature was kept at this temperature for 2 hours. The power was then turned off and the temperature was cooled. The density after heat treatment was 2.57 g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 12.36%; Example 4 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through a 300-mesh sieve and classified and recycled according to the screening results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 1:1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 30 minutes under a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in an 80°C oven for drying for 24 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 900°C at 5°C / min under an argon protective atmosphere and kept warm for 2 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 20.67%.

[0056] Step 6: Reaction Infiltration The low-density 2.5D woven C / C w After cleaning and drying the composite material, it was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1800°C at a rate of 10°C / min, the vacuum was 0.1 Pa, and the temperature was kept at this temperature for 2 hours. The power was then turned off and the temperature was cooled. The density after heat treatment was 2.63 g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 12.14%; Example 5 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through a 300-mesh sieve and recycled according to the sieving results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 1:1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 30 minutes under a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in an 80°C oven for 24 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 900°C at 5°C / min under an argon protective atmosphere and kept warm for 2 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 20.67%.

[0057] Step 6: Reaction Infiltration The low-density 2.5D woven C / C w After cleaning and drying the composite material, it was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1800°C at a rate of 10°C / min, the vacuum was 0.026 Pa, and the temperature was kept at this temperature for 2 hours. The power was then turned off and the temperature was cooled. The density after heat treatment was 3.09 g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 10.05%.

[0058] Example 6 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through a 300-mesh sieve and classified and recycled according to the screening results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 2:1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 60 minutes under a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in a 70°C oven for drying for 30 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 1000°C at 5°C / min under an argon protective atmosphere and kept warm for 3 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 20.67%.

[0059] Step 6: Reaction Infiltration The low-density 2.5D woven C / C w After cleaning and drying the composite material, it was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1700°C at a rate of 10°C / min, the vacuum was 0.026 Pa, and the temperature was kept at this temperature for 2 hours. The power was then turned off and the temperature was cooled. The density after heat treatment was 2.33 g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 12.37%.

[0060] Example 7 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through a 300-mesh sieve and recycled according to the sieving results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 2:1:10. Magnetic stirring is performed on the suspension for 40 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 40 minutes at a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in a 100°C oven for drying for 25 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 950°C at 7°C / min under an argon protective atmosphere and kept warm for 2.5 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 20.67%.

[0061] Step 6: Reaction Infiltration The low-density 2.5D woven C / C w After cleaning and drying, the composite material was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1900°C at a rate of 8°C / min, the vacuum was 0.05 Pa, and the temperature was kept at this temperature for 0.5 h. The power was then turned off and the temperature was cooled. The density after heat treatment was 2.31 g / cm 3 , a 2.5D woven ceramic matrix composite with a porosity of 13.59%.

[0062] Example 8 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1: Screening of C / C composite waste chips The C / C composite waste chips were passed through a 300-mesh sieve and classified and recycled according to the screening results; Step 2: Preparation of C / C composite waste scrap-resin mixed solution Dissolve phenolic resin in anhydrous ethanol and sonicate for 30 minutes to obtain a phenolic resin solution. Add the C / C composite scraps obtained in step 1 to the phenolic resin solution. The mass ratio of C / C scraps: phenolic resin: anhydrous ethanol is 1:1:10. Magnetic stirring is performed on the suspension for 30 minutes to obtain a mixed solution. Step 3, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 4: Dipping of mixed solution The low-density 2.5D woven C / C composite material obtained in step 3 was immersed in the mixed solution obtained in step 2, placed in a vacuum box, and immersed for 5 minutes under a vacuum pressure of 6 kPa; Step 5: Drying and carbonization The low-density 2.5D woven C / C composite material in step 4 was taken out after impregnation and placed in a 120°C oven for drying for 20 hours; after repeating the impregnation and drying three times, the composite material was subjected to high-temperature carbonization. The composite material was placed in a heat treatment furnace and heated to 900°C at 3°C / min under an argon protective atmosphere and kept warm for 2 hours to crack the resin into carbon. The vacuum impregnation-drying-carbonization process was repeated three times to obtain a low-density 2.5D woven C / C w Composite material, weight gain rate is 20.67%.

[0063] Step 6: Reaction Infiltration The low-density 2.5D woven C / C wAfter cleaning and drying the composite material, it was placed in a graphite crucible, and ZrSi2 alloy powder (particle size 1-50μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1800℃ at a rate of 7℃ / min, the vacuum was 0.1 Pa, and the temperature was kept at this temperature for 1 hour. The power was then turned off and the temperature was cooled. The density after heat treatment was 2.55g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 10.57%.

[0064] Comparative Example 1 A method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material comprises the following steps: Step 1, Preparation of low-density 2.5D woven C / C composites The pyrolytic carbon interfacial phase was introduced into the 2.5D woven carbon fiber preform by chemical vapor infiltration. The 2.5D woven carbon fiber preform was a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure. The number of warp yarns was 2, the number of weft yarns was 4, the weft density was 3.3 strands / cm, the warp density was 12 strands / cm, and the density was 0.8 g / cm 3 , with a volume fraction of 45.8%. After chemical vapor infiltration, a pyrolytic carbon interface layer was deposited to obtain a density of 1.4 g / cm 3 Low-density 2.5D woven C / C composite materials; Step 2: Reaction Infiltration The low-density 2.5D woven C / C composite material obtained in step 1 was cleaned and dried, then placed in a graphite crucible. ZrSi2 alloy powder (particle size 1-50 μm, purity 99.5%) was embedded around it. The crucible was sealed and placed in a high-temperature furnace. The temperature was raised to 1800°C at a rate of 10°C / min, the vacuum was 0.026 Pa, and the temperature was kept at this temperature for 2 hours. The temperature was then turned off and cooled. The density after heat treatment was 1.91 g / cm 3 , 2.5D woven ceramic matrix composite with a porosity of 22.99%; Compared with Comparative Example 1, the density of the 2.5D woven ceramic-based composite material prepared in Example 1 was increased by 19.37%, and the porosity was reduced by 23.71%. The density of the 2.5D woven ceramic-based composite material prepared in Example 2 was increased by 34.03%, and the porosity was reduced by 45.37%. The density of the 2.5D woven ceramic-based composite material prepared in Example 3 was increased by 34.55%, and the porosity was reduced by 46.24%. The density of the 2.5D woven ceramic-based composite material prepared in Example 4 was increased by 37.70%, and the porosity was reduced by 47.1 9%, the density of the 2.5D woven ceramic-based composite material prepared in Example 5 increased by 61.78%, and the porosity decreased by 56.29%, the density of the 2.5D woven ceramic-based composite material prepared in Example 6 increased by 21.99%, and the porosity decreased by 46.19%, the density of the 2.5D woven ceramic-based composite material prepared in Example 7 increased by 20.94%, and the porosity decreased by 40.88%, and the density of the 2.5D woven ceramic-based composite material prepared in Example 8 increased by 33.51%, and the porosity decreased by 54.02%.

[0065] Figure 1 Figures (a) to (h) are SEM images of the C / C composite waste chips of 20-80 mesh, 80-200 mesh, 200-300 mesh and <300 mesh obtained by sieving in Examples 1 to 5. Figure 1 It can be seen that the C / C waste chips are mainly composed of carbon fibers and pyrolytic carbon, and the carbon fibers and pyrolytic carbon are combined together without separation.

[0066] Figure 2 Figures (a) and (b) in the middle show the low-density 2.D woven C / C obtained by introducing C / C waste chips with a mesh size of less than 300 into the 2.5D woven carbon fiber preform in Example 4. w SEM images of composite materials, from Figure 2 It can be seen that there are "oblong" large-sized pores (length > 1 mm) between the warp and weft yarns. The introduced C / C waste chips exist in the large-sized pores under the bonding effect of resin carbon to form a three-dimensional network carbon skeleton, which is conducive to the subsequent infiltration of the melt.

[0067] Figure 3 Figures (a) to (c) are cross-sectional SEM images and EDS spectra of the 2.5D ceramic matrix composite material obtained in Example 4. Figure 3 It can be seen that the three-dimensional network carbon skeleton between the pores reacts with the melt to in situ generate a dense ceramic phase and a small amount of residual metal.

[0068] Figure 4 Figures (a) to (c) are cross-sectional SEM images and EDS spectra of the 2.5D ceramic matrix composite material obtained in Example 5. Figure 4 It can be seen that the three-dimensional network carbon skeleton between the pores reacts with the melt to in situ generate a dense ceramic phase.

[0069] Figure 5 Figures (a) and (b) are cross-sectional SEM images of the 2.5D ceramic matrix composite material obtained in Comparative Example 1. Figure 5 It can be seen from the figure that the melt loses from the macropores during the reactive infiltration process, resulting in a large number of large-sized pores remaining in the composite material.

[0070] Figure 6 The X-ray diffraction pattern of the 2.5D woven ceramic matrix composite material obtained in Example 5 is shown in FIG. Figure 6 It can be seen that the XRD peaks are C peak, ZrC peak, SiC peak, and a small amount of ZrSi peak, which proves that a high-density 2.5D woven ceramic-based composite material was successfully prepared, effectively reducing the residual metal content.

[0071] Figure 7 The X-ray diffraction pattern of the 2.5D woven ceramic matrix composite material prepared in Comparative Example 1 is shown in FIG. Figure 7 It can be seen that the XRD peaks are C peak, ZrC peak, SiC peak, ZrSi peak, and ZrSi2 peak. The presence of residual metal peaks indicates that there is a lot of residual metal in the composite material prepared without adding C / C waste.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a 2.5D woven ceramic matrix composite material based on C / C composite material, characterized in that: The following steps are involved: S1, sieving C / C composite waste chips to obtain sieved C / C waste chips, wherein the C / C waste chips contain carbon fibers and pyrolytic carbon particles; S2, mixing the sieved C / C waste chips, phenolic resin and anhydrous ethanol and stirring them ultrasonically to obtain a waste chip-resin mixed solution; S3, introducing the pyrolytic carbon interfacial phase into the 2.5D woven carbon fiber preform by chemical vapor infiltration to obtain a low-density 2.5D woven C / C composite; S4, low-density 2.5D woven C / C composites were immersed in waste scrap-resin mixed solution and impregnated under vacuum environment; S5, drying the impregnated low-density 2.5D woven C / C composite material and carbonizing it to obtain a carbonized low-density 2.5D woven C / C w Composite materials; S6, carbonized low-density 2.5D woven C / C w After reactive infiltration of the composite material, a 2.5D woven ceramic matrix composite material was obtained.

2. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 1, characterized in that: In S1, the mesh size of the sieve used in the screening process is 20 to 300 meshes.

3. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 1, characterized in that: In S2, the mixing mass ratio of the C / C waste chips, phenolic resin and anhydrous ethanol is (1-2):1:

10.

4. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 1, characterized in that: The 2.5D woven carbon fiber preform described in S3 is a 2.5D layer-layer angle interlocking woven preform with a shallow cross-link structure, with a warp yarn number of 2, a weft yarn number of 4, a weft density of 3.3 strands / cm, a warp density of 12 strands / cm, and a density of 0.8 g / cm 3 , the volume fraction is 45.8%.

5. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 1, characterized in that: In S3, the density of the low-density 2.5D woven C / C composite material is 1.3-1.5 g / cm 3 .

6. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 1, characterized in that: In S4, the vacuum degree during the impregnation process is 5-7 kPa, and the impregnation time is 30-60 min; in S5, the drying temperature is 70-120°C, and the drying time is 20-30 h; the carbonization temperature is 900-1000°C, and the carbonization time is 2-3 h.

7. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 1, characterized in that: The impregnation, drying and carbonization processes under vacuum conditions of S4 and S5 were repeated several times.

8. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 1, characterized in that: In S6, reactive infiltration is performed using ZrSi2 alloy powder.

9. The method for preparing a 2.5D woven ceramic matrix composite material based on a C / C composite material according to claim 8, characterized in that: In S6, the temperature of the reactive infiltration is 1700-1900°C, the vacuum degree is 0.026-0.1 Pa, and the holding time is 0.5-2 h.

10. A 2.5D woven ceramic matrix composite material based on a C / C composite material prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The invention comprises a 2.5D woven carbon fiber preform, wherein ZrC-SiC ceramics and residual metal are distributed in the 2.5D woven carbon fiber preform; the density of the 2.5D woven ceramic matrix composite material is 2.28-3.09 g / cm 3 , the porosity is 10.05~17.54%.

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