Microwave absorbing ceramic composite material with broadband and high temperature oxidation resistance and preparation method thereof

Abstract

The application discloses a kind of wave-absorbing ceramic composite material with broadband and high temperature antioxidation and preparation method thereof, comprising: 1) zirconium source, boric acid and auxiliary spinning agent are added to organic solvent, stirring is uniform, and spinning solution is obtained;2) the spinning solution is electrostatically spun, and the preform fiber is obtained;3) the preform fiber is shaped and treated, and inorganic chemical fiber cloth is obtained;4) PSNB, PZO and PZC liquid precursor are stirred uniformly, and mixed impregnant is obtained;5) inorganic chemical fiber cloth is stacked into several layers, then placed in mixed impregnant, and then treated by vacuum impregnation method, and preform composite material is obtained;6) the preform composite material is treated by low-temperature crosslinking, and the cured preform composite material is obtained;7) the cured preform composite material is pyrolyzed, and wave-absorbing ceramic composite material is obtained, and the wave-absorbing ceramic composite material prepared by the method has broadband electromagnetic wave absorption and high temperature antioxidation performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of wave-absorbing materials, and relates to a wave-absorbing ceramic composite material with broadband and high-temperature oxidation resistance, and a preparation method thereof. Background Art

[0002] Composite materials with both radar-absorbing and high-temperature oxidation resistance are essential for the stealth of modern high-speed aircraft. With the rapid advancement of military technology, aircraft design requirements have expanded beyond speed and maneuverability to include stealth performance to meet the demands of increasingly complex and advanced radar detection. Absorbing materials must combine the high heat resistance and excellent wave-absorbing properties of ceramic matrix materials to ensure structural integrity and functional stability in extreme environments. This allows them to efficiently absorb electromagnetic waves, significantly reducing the aircraft's radar cross section (RCS) and minimizing the risk of detection. Furthermore, absorbing materials must be highly designable and customizable for specific application scenarios, optimizing their absorption of electromagnetic waves across different frequency bands to provide comprehensive stealth protection. In summary, composite materials with both radar-absorbing and high-temperature oxidation resistance not only enhance aircraft survivability in complex environments but also provide strong technical support for the future development of aerospace engineering, with far-reaching implications for national security and scientific and technological advancement.

[0003] Electrospinning is a process for manufacturing nanofibers that uses electric field forces to stretch liquid polymer solutions or melts to form extremely fine fibers. Electrospinning technology provides new possibilities for the preparation of high-performance ceramic fibers, making the developed fibers exhibit unparalleled advantages in the aerospace field. First, the ceramic fibers obtained by electrospinning have extremely high specific surface area and low density, making them ideal lightweight and high-strength composite material reinforcements, which can significantly improve the strength and stiffness of aircraft structural parts without adding extra weight. Secondly, the excellent high-temperature resistance of ceramic fibers ensures their stability in extreme temperature environments, making them suitable for the hot end parts of aircraft and their power systems, ensuring the safety of spacecraft during high-speed flight or re-entry into the atmosphere. Reference 1, "Wang Q, Qi L, Jia Y, et al. Flexible ZrO2 / ZrC / ZrB2 ceramic nanofiber mats by electrospinning with broadband electromagnetic absorption and high-temperature oxidation resistance [J]. Materials Letters, 2024, 365:136442," describes a ZrO2 / ZrC / ZrB2 fiber fabric prepared by electrospinning combined with high-temperature pyrolysis. This ceramic fiber exhibits high conductivity and dielectric constant, and when mixed with paraffin wax, it exhibits an effective absorption bandwidth of 8.64 GHz. However, this composite ceramic fiber is not suitable for use as a microwave absorber alone and must be combined with a microwave-transmitting ceramic matrix to prepare a fiber-reinforced ceramic composite.

[0004] Silicon-boron-carbon-nitrogen composite ceramics (SiBCN) obtained by the PDC method combine the advantages of four elements: silicon (Si), boron (B), carbon (C) and nitrogen (N), and exhibit a series of excellent physical, chemical and mechanical properties. They have excellent high-temperature stability, low density, high hardness, good oxidation resistance and wear resistance, while maintaining structural integrity and functional effectiveness under extreme conditions. Reference 2 "Luo C, Tang Y, Jiao T, et al. High-temperature stable and metal-free electromagnetic wave-absorbing SiBCN ceramics derived from carbon-rich hyperbranched polyborosilazanes [J]. ACS applied materials & interfaces, 2018, 10 (33): 28051-28061." mentions that SiBCN is an ideal wave-transmitting material due to its low dielectric constant and tangent loss. However, when used alone, carbon-rich SiBCN only has an effective absorption bandwidth of 3.65 GHz. Therefore, in order to improve its absorbing performance, SiBCN is usually used as an impedance matching wave-transmitting material and combined with an electromagnetic loss absorber with good absorbing ability to form a composite absorbing material to obtain broadband absorbing ability. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance and a preparation method thereof. The microwave-absorbing ceramic composite material prepared by this method has broadband electromagnetic wave absorption and high-temperature oxidation resistance.

[0006] To achieve the above objectives, the present invention discloses a method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance, comprising:

[0007] 1) adding a zirconium source, boric acid and a spinning aid into an organic solvent and stirring uniformly to obtain a spinning solution;

[0008] 2) electrospinning the spinning solution to obtain a preformed fiber;

[0009] 3) performing shaping treatment on the preform fiber to obtain an inorganic fiber cloth;

[0010] 4) Stirring the liquid precursors of PSNB, PZO and PZC uniformly to obtain a mixed impregnant;

[0011] 5) stacking the inorganic fiber cloth obtained in step 3) into several layers, and then placing the inorganic fiber cloth into the mixed impregnating agent obtained in step 4) to obtain a preform composite material by vacuum impregnation;

[0012] 6) performing low-temperature crosslinking treatment on the preform composite material to obtain a cured preform composite material;

[0013] 7) performing high-temperature pyrolysis on the cured preform composite material to obtain a wave-absorbing ceramic composite material with wide frequency and high-temperature oxidation resistance.

[0014] The preparation method of the wave-absorbing ceramic composite material with wide frequency and high-temperature oxidation resistance according to the application is further improved in that:

[0015] Further, in step 1), the mass ratio of the zirconium source, boric acid and the spinning aid is 1.0:0.2-0.5:0.5-1.0.

[0016] Further, in step 1), the zirconium source is a high polymer precursor containing zirconium.

[0017] Further, in step 1), the spinning aid is polyvinylpyrrolidone.

[0018] Further, in step 1), the organic solvent is one of N,N-dimethylformamide and ethanol or a mixture of the two.

[0019] Further, in step 2), in the electrospinning process, a needle with an inner diameter of 0.5-1.0 mm is used, the spinning voltage is 10-15 kV, the fiber collection distance is 10-30 cm, the liquid pushing rate is 0.002-0.01 mm·s -1 , the spinning temperature is 20-30℃, and the air relative humidity is 20-40 RH%.

[0020] Further, the operation process of step 3) is as follows:

[0021] The preform body fiber is heated to 220-300℃ at a heating rate of 2℃ / min under an air atmosphere, and then heat-treated at normal pressure for 2-3 h to obtain the inorganic fiber cloth.

[0022] Further, in step 4), the mass ratio of the PSNB, PZO and PZC liquid phase precursors is 1.0-1.5:1.0:1.0.

[0023] Further, the operation process of step 7) is as follows:

[0024] The cured preform composite material is heated to 1100-1500℃ at a heating rate of 2-5℃ / min under an argon atmosphere, and then heat-treated for 1-2 h to obtain the wave-absorbing ceramic composite material with wide frequency and high-temperature oxidation resistance.

[0025] The invention discloses a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance, which is prepared based on a method for preparing the microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0026] The present invention has the following beneficial effects:

[0027] The broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material and its preparation method described in the present invention are specifically operated by using a zirconium-containing precursor electrospinning slurry to prepare a pre-ceramic fiber cloth by an electrospinning method, which is then converted into a ZrO2 / ZrC / ZrB2 fiber cloth precursor through low-temperature pre-oxidation and shaping. Subsequently, the PSNB / PZO / PZC liquid phase mixed precursor is uniformly mixed by magnetic stirring, and the ZrO2 / ZrC / ZrB2 fiber cloth precursor is introduced by impregnation. After low-temperature crosslinking and high-temperature pyrolysis, a SiBCN / ZrO2 / ZrC / ZrB2 microwave-absorbing ceramic composite material reinforced with ZrO2 / ZrC / ZrB2 composite ceramic fibers is finally obtained. In the obtained composite material, SiBCN serves as a wave-transmitting phase, which can improve the impedance matching between the composite material and free space. At the same time, the in-situ formation of ZrO2 / ZrC / ZrB2 nanoparticles and ZrO2 / ZrC / ZrB2 fiber cloth gives the composite material a good dispersion effect, forming a microscopic three-dimensional conductive network within the composite. This not only improves the composite's conductivity loss capacity but also generates additional interfacial polarization losses through the rich heterogeneous interfaces. In addition, the fiber cloth within the composite has a layered structure, and the electromagnetic wave reflection between layers further enhances the material's absorption effect. These synergistic effects significantly improve the composite's broadband absorption performance and high-temperature oxidation resistance.

[0028] In addition, it needs to be explained that the material has the advantages of light weight, high temperature resistance, wide frequency wave absorption and simple preparation process, and is an ideal wave absorbing material suitable for high temperature extreme environment. Specifically, the effective wave absorbing bandwidth of the composite material can reach 11.52 GHz, and when the thickness is 3.8 mm, it can cover the entire X- and Ku- wave bands, and partially cover the C- wave band. In this composite material, SiBCN as a wave-transparent matrix shows excellent wave-transparent performance at room temperature and high temperature conditions, ensuring that the incident electromagnetic wave can enter the interior of the composite material. In addition, the in-situ formed ZrO2 / ZrC / ZrB2 nanoparticles fill the gaps between the ZrO2 / ZrC / ZrB2 fibers, increase the hetero-interface, and enhance the interface polarization loss. The ZrO2 / ZrC / ZrB2 multi-layer fiber cloth with a three-dimensional network structure enhances the electrical conductivity loss capability of the composite material, and the multi-element nano-phase also increases the dispersion effect of the composite material, and the layered structure of the multi-layer fiber cloth provides an ideal path for multiple reflections of electromagnetic waves in the interior of the composite material. The above characteristics synergistically improve the wide-band wave absorbing performance of the composite material. By controlling the pyrolysis temperature of the composite material, the impedance matching between the whole composite material and the free space can be adjusted, and the wide-band wave absorbing performance is further optimized. This preparation method not only simplifies the process flow, but also ensures the consistency and repeatability of the material performance, providing a solid foundation for the preparation of high-performance wave absorbing materials. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which form a part of the present description, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve to explain the present application. The accompanying drawings do not constitute an improper limitation of the present application. In the drawings:

[0030] Figure 1 Scanning electron microscope image of the ZrO2 / ZrC / ZrB2 composite ceramic fiber reinforced SiBCN / ZrO2 / ZrC / ZrB2 wave absorbing ceramic composite material prepared by the present application;

[0031] Figure 2 RL two-dimensional graph of ZrO2 / ZrC / ZrB2 composite ceramic fiber reinforced SiBCN / ZrO2 / ZrC / ZrB2 wave absorbing ceramic composite material under different pyrolysis temperature conditions;

[0032] Figure 3 Mass change curve of ZrO2 / ZrC / ZrB2 composite ceramic fiber reinforced SiBCN / ZrO2 / ZrC / ZrB2 wave absorbing ceramic composite material in an oxidizing environment. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] In the description of the present invention, it is to be understood that the terms “include” and “comprise” indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0035] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0036] It should be further understood that the term "and / or" as used in the present specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0037] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0038] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0041] The method for preparing the broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0042] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.2-0.5:0.5-1.0, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinylpyrrolidone (PVP) having a molecular weight of 130,000; and the organic solvent is one of N,N-dimethylformamide and ethanol, or a mixture thereof;

[0043] 2) electrospinning the spinning solution to obtain a preformed fiber, wherein a needle with an inner diameter of 0.5 to 1.0 mm, a spinning voltage of 10 to 15 kV, a spinning distance of 10 to 30 cm, and a liquid pushing rate of 0.002 to 0.01 mm·s is used during the electrospinning process. -1 , the spinning temperature is 20-30°C, and the relative humidity of the air is 20-40RH%;

[0044] 3) performing a shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically: heating the preform fiber to 220-300° C. at a heating rate of 2° C. / min in an air atmosphere, and then maintaining the temperature for 2-3 hours at normal pressure to obtain the inorganic fiber cloth;

[0045] 4) Weighing PSNB, PZO, and PZC liquid precursors in a mass ratio of 1.0-1.5:1.0:1.0 and stirring evenly to obtain a mixed impregnating agent;

[0046] 5) stacking the inorganic fiber cloth obtained in step 3) into 16-32 layers, placing the layers in the mixed impregnating agent obtained in step 4), and treating the layers by vacuum impregnation to obtain a prefabricated composite material, wherein the vacuum degree during the vacuum impregnation treatment is 3-5 MPa and the impregnation time is 0.5-1 hour;

[0047] 6) subjecting the prefabricated composite material to a low-temperature crosslinking treatment to obtain a cured prefabricated composite material, specifically: heating the prefabricated composite material to 220-300° C. at a heating rate of 2-5° C. / min, and then keeping the temperature at room temperature for 2-3 hours to obtain a cured prefabricated composite material.

[0048] 7) In an argon atmosphere, the cured prefabricated composite material is subjected to high-temperature cracking to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance. Specifically, in an argon atmosphere, the cured prefabricated composite material is heated to 1100-1500°C at a heating rate of 2-5°C / min and kept warm for 1-2 hours to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0049] Example 1

[0050] The method for preparing the broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0051] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.5:0.5, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinylpyrrolidone (PVP) having a molecular weight of 130,000; and the organic solvent is N,N-dimethylformamide;

[0052] 2) Electrospinning the spinning solution to obtain a preformed fiber. During the electrospinning process, a needle with an inner diameter of 0.8 mm, a spinning voltage of 12 kV, a spinning distance of 20 cm, and a liquid pushing rate of 0.005 mm·s was used. -1 , the spinning temperature is 25℃, and the relative humidity of air is 35RH%;

[0053] 3) performing a shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically, heating the preform fiber to 260° C. at a heating rate of 2° C. / min in an air atmosphere, and then maintaining the temperature for 3 hours at normal pressure to obtain the inorganic fiber cloth;

[0054] 4) Weigh PSNB, PZO, and PZC liquid precursors in a mass ratio of 1.0:1.0:1.0 and stir evenly to obtain a mixed impregnating agent;

[0055] 5) stacking the inorganic fiber cloth obtained in step 3) into 16 layers, placing the layers in the mixed impregnating agent obtained in step 4), and treating the layers by vacuum impregnation to obtain a prefabricated composite material, wherein the vacuum degree during the vacuum impregnation treatment is 3 MPa and the impregnation time is 1 hour;

[0056] 6) subjecting the prefabricated composite material to a low-temperature crosslinking treatment to obtain a cured prefabricated composite material, specifically: heating the prefabricated composite material to 280° C. at a heating rate of 5° C. / min, and then maintaining the temperature at normal pressure for 2.3 hours to obtain a cured prefabricated composite material;

[0057] 7) In an argon atmosphere, the cured prefabricated composite material is subjected to high-temperature cracking to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance. Specifically, in an argon atmosphere, the cured prefabricated composite material is heated to 1400°C at a heating rate of 2°C / min and kept warm for 1 hour to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0058] Example 2

[0059] The method for preparing the broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0060] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.5:1.0, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP) having a molecular weight of 130,000; and the organic solvent is ethanol;

[0061] 2) Electrospinning the spinning solution to obtain a preformed fiber. During the electrospinning process, a needle with an inner diameter of 0.5 mm, a spinning voltage of 15 kV, a spinning distance of 10 cm, and a liquid pushing rate of 0.01 mm·s was used. -1 , the spinning temperature is 20℃, and the relative humidity of the air is 25RH%;

[0062] 3) performing a shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically, heating the preform fiber to 240° C. at a heating rate of 2° C. / min in an air atmosphere, and then maintaining the temperature for 3 hours at normal pressure to obtain the inorganic fiber cloth;

[0063] 4) Weigh PSNB, PZO, and PZC liquid precursors in a mass ratio of 1.5:1.0:1.0 and stir evenly to obtain a mixed impregnating agent;

[0064] 5) stacking the inorganic fiber cloth obtained in step 3) into 24 layers, placing the layers in the mixed impregnating agent obtained in step 4), and treating the layers by vacuum impregnation to obtain a prefabricated composite material, wherein the vacuum degree during the vacuum impregnation treatment is 5 MPa and the impregnation time is 0.5 h;

[0065] 6) subjecting the prefabricated composite material to a low-temperature crosslinking treatment to obtain a cured prefabricated composite material, specifically: heating the prefabricated composite material to 240° C. at a heating rate of 5° C. / min, and then maintaining the temperature at normal pressure for 3 hours to obtain a cured prefabricated composite material;

[0066] 7) In an argon atmosphere, the cured prefabricated composite material is subjected to high-temperature cracking to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance. Specifically, in an argon atmosphere, the cured prefabricated composite material is heated to 1300°C at a heating rate of 5°C / min and kept warm for 2 hours to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0067] Example 3

[0068] The method for preparing the broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0069] 1) weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.4:1.0, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinylpyrrolidone (PVP) having a molecular weight of 130,000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

[0070] 2) Electrospinning the spinning solution to obtain a preformed fiber. During the electrospinning process, a needle with an inner diameter of 1.0 mm, a spinning voltage of 10 kV, a spinning distance of 25 cm, and a liquid pushing rate of 0.008 mm·s was used. -1 , the spinning temperature is 30℃, and the relative humidity of the air is 40RH%;

[0071] 3) performing a shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically, heating the preform fiber to 300° C. at a heating rate of 2° C. / min in an air atmosphere, and then maintaining the temperature for 2 hours at normal pressure to obtain the inorganic fiber cloth;

[0072] 4) Weigh PSNB, PZO, and PZC liquid precursors in a mass ratio of 1.0:1.0:1.0 and stir evenly to obtain a mixed impregnating agent;

[0073] 5) stacking the inorganic fiber cloth obtained in step 3) into 32 layers, placing the layers in the mixed impregnating agent obtained in step 4), and treating the layers by vacuum impregnation to obtain a prefabricated composite material, wherein the vacuum degree during the vacuum impregnation treatment is 5 MPa and the impregnation time is 0.5 h;

[0074] 6) subjecting the prefabricated composite material to a low-temperature crosslinking treatment to obtain a cured prefabricated composite material, specifically: heating the prefabricated composite material to 300° C. at a heating rate of 5° C. / min, and then maintaining the temperature at normal pressure for 2 hours to obtain a cured prefabricated composite material;

[0075] 7) In an argon atmosphere, the cured prefabricated composite material is subjected to high-temperature cracking to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance. Specifically, in an argon atmosphere, the cured prefabricated composite material is heated to 1500°C at a heating rate of 2°C / min and kept warm for 1 hour to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0076] Example 4

[0077] The method for preparing the broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0078] 1) weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.4:0.7, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinylpyrrolidone (PVP) having a molecular weight of 130,000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

[0079] 2) Electrospinning the spinning solution to obtain a preformed fiber. During the electrospinning process, a needle with an inner diameter of 0.6 mm, a spinning voltage of 13 kV, a spinning distance of 20 cm, and a liquid pushing rate of 0.006 mm·s was used. -1 , the spinning temperature is 25℃, and the relative humidity of the air is 30RH%;

[0080] 3) performing a shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically, heating the preform fiber to 260° C. at a heating rate of 2° C. / min in an air atmosphere, and then maintaining the temperature for 2.5 hours at normal pressure to obtain the inorganic fiber cloth;

[0081] 4) Weigh PSNB, PZO, and PZC liquid precursors in a mass ratio of 1.3:1.0:1.0 and stir evenly to obtain a mixed impregnating agent;

[0082] 5) stacking the inorganic fiber cloth obtained in step 3) into 25 layers, placing the layers in the mixed impregnating agent obtained in step 4), and treating the layers by vacuum impregnation to obtain a prefabricated composite material, wherein the vacuum degree during the vacuum impregnation treatment is 4 MPa and the impregnation time is 0.75 h;

[0083] 6) subjecting the prefabricated composite material to a low-temperature crosslinking treatment to obtain a cured prefabricated composite material, specifically: heating the prefabricated composite material to 260° C. at a heating rate of 3.5° C. / min, and then maintaining the temperature at normal pressure for 2.5 hours to obtain a cured prefabricated composite material;

[0084] 7) In an argon atmosphere, the cured prefabricated composite material is subjected to high-temperature cracking to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance. Specifically, in an argon atmosphere, the cured prefabricated composite material is heated to 1200°C at a heating rate of 3°C / min and kept warm for 1 to 2 hours to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0085] Example 5

[0086] The method for preparing the broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0087] 1) weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.5:1.0, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinylpyrrolidone (PVP) having a molecular weight of 130,000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

[0088] 2) Electrospinning the spinning solution to obtain a preformed fiber. During the electrospinning process, a needle with an inner diameter of 1.0 mm, a spinning voltage of 15 kV, a spinning distance of 30 cm, and a liquid pushing rate of 0.01 mm·s was used. -1 , the spinning temperature is 30℃, and the relative humidity of the air is 40RH%;

[0089] 3) performing a shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically, heating the preform fiber to 300° C. at a heating rate of 2° C. / min in an air atmosphere, and then maintaining the temperature for 3 hours at normal pressure to obtain the inorganic fiber cloth;

[0090] 4) Weigh PSNB, PZO, and PZC liquid precursors in a mass ratio of 1.5:1.0:1.0 and stir evenly to obtain a mixed impregnating agent;

[0091] 5) stacking the inorganic fiber cloth obtained in step 3) into 32 layers, placing the layers in the mixed impregnating agent obtained in step 4), and treating the layers by vacuum impregnation to obtain a prefabricated composite material, wherein the vacuum degree during the vacuum impregnation treatment is 5 MPa and the impregnation time is 1 hour;

[0092] 6) subjecting the prefabricated composite material to a low-temperature crosslinking treatment to obtain a cured prefabricated composite material, specifically: heating the prefabricated composite material to 300° C. at a heating rate of 5° C. / min, and then maintaining the temperature at normal pressure for 3 hours to obtain a cured prefabricated composite material;

[0093] 7) In an argon atmosphere, the cured prefabricated composite material is subjected to high-temperature cracking to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance. Specifically, in an argon atmosphere, the cured prefabricated composite material is heated to 1500°C at a heating rate of 5°C / min and kept warm for 2 hours to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0094] Example 6

[0095] The method for preparing the broadband and high-temperature oxidation-resistant microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0096] 1) weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.2:0.5, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinylpyrrolidone (PVP) having a molecular weight of 130,000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

[0097] 2) Electrospinning the spinning solution to obtain a preformed fiber. During the electrospinning process, a needle with an inner diameter of 0.5 mm, a spinning voltage of 10 kV, a spinning distance of 10 cm, and a liquid pushing rate of 0.002 mm·s was used. -1 , the spinning temperature is 20℃, and the relative humidity of the air is 20RH%;

[0098] 3) performing a shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically, heating the preform fiber to 220° C. at a heating rate of 2° C. / min in an air atmosphere, and then maintaining the temperature for 2 hours at normal pressure to obtain the inorganic fiber cloth;

[0099] 4) Weigh PSNB, PZO, and PZC liquid precursors in a mass ratio of 1.0:1.0:1.0 and stir evenly to obtain a mixed impregnating agent;

[0100] 5) stacking the inorganic fiber cloth obtained in step 3) into 16 layers, placing the layers in the mixed impregnating agent obtained in step 4), and treating the layers by vacuum impregnation to obtain a prefabricated composite material, wherein the vacuum degree during the vacuum impregnation treatment is 3 MPa and the impregnation time is 0.5 h;

[0101] 6) subjecting the prefabricated composite material to a low-temperature crosslinking treatment to obtain a cured prefabricated composite material, specifically: heating the prefabricated composite material to 220° C. at a heating rate of 2° C. / min, and then maintaining the temperature at normal pressure for 2 hours to obtain a cured prefabricated composite material;

[0102] 7) In an argon atmosphere, the cured prefabricated composite material is subjected to high-temperature cracking to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance. Specifically, in an argon atmosphere, the cured prefabricated composite material is heated to 1100°C at a heating rate of 2°C / min and kept warm for 1 hour to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

[0103] The preparation method and resulting composite material provided by this invention open up new avenues for the development of novel stealth materials, particularly suitable for applications requiring efficient electromagnetic wave absorption and structural stability in extreme environments, such as modern high-speed aircraft stealth technology. This method not only optimizes the material's overall dielectric properties but also significantly enhances its electromagnetic wave absorption capacity across a wide frequency range and its stability in high-temperature environments, providing strong technical support for the future development of aerospace engineering.

[0104] Those skilled in the art will readily identify other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0105] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0106] The above is only the preferred embodiment of the present application, and does not limit the present application, and any simple modification, change and equivalent structure change of the above embodiment according to the technical essence of the present application are still within the protection scope of the technical scheme of the present application.

Claims

1. A method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance, characterized in that: include: 1) Add the zirconium source, boric acid and spinning aid into the organic solvent and stir evenly to obtain a spinning solution; 2) electrospinning the spinning solution to obtain a preformed fiber; 3) performing shaping treatment on the preformed fibers to obtain an inorganic fiber cloth; 4) Stirring the liquid precursors of PSNB, PZO, and PZC uniformly to obtain a mixed impregnant, wherein PZO is polyzirconoxane and PZC is a zirconium-containing polymer precursor; 5) stacking the inorganic fiber cloth obtained in step 3) into several layers, placing the layers in the mixed impregnating agent obtained in step 4), and then treating the layers by vacuum impregnation to obtain a prefabricated composite material; 6) performing a low-temperature cross-linking treatment on the prefabricated composite material to obtain a cured prefabricated composite material; 7) The cured prefabricated composite material is subjected to high-temperature cracking to obtain a ZrO2 / ZrC / ZrB2 composite ceramic fiber reinforced SiBCN / ZrO2 / ZrC / ZrB2 microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance.

2. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, characterized in that: In step 1), the mass ratio of the zirconium source, boric acid and spinning aid is 1.0:0.2~0.5:0.5~1.

0.

3. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, characterized in that: In step 1), the zirconium source is a zirconium-containing polymer precursor.

4. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, wherein: In step 1), the spinning aid is polyvinyl pyrrolidone.

5. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, characterized in that: In step 1), the organic solvent is one of N,N-dimethylformamide and ethanol or a mixture of the two.

6. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, characterized in that: In step 2), during the electrospinning process, a needle with an inner diameter of 0.5-1.0 mm was used, the spinning voltage was 10-15 kV, the winding distance was 10-30 cm, and the liquid pushing rate was 0.002-0.01 mm·s -1 , the spinning temperature is 20~30 ℃, and the relative humidity of the air is 20~40 RH%.

7. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, characterized in that: The operation process of step 3) is: In an air atmosphere, the preform fiber is heated to 220~300℃ at a heating rate of 2℃ / min, and then kept at normal pressure for 2~3 hours to obtain an inorganic fiber cloth.

8. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, characterized in that: In step 4), the mass ratio of the liquid precursors of PSNB, PZO, and PZC is 1.0-1.5:1.0:1.

0.

9. The method for preparing a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance according to claim 1, characterized in that: The operation process of step 7) is: In an argon atmosphere, the cured prefabricated composite material is heated to 1100-1500° C. at a heating rate of 2-5° C. / min and kept at this temperature for 1-2 hours to obtain a microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance.

10. A microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance, characterized in that: The microwave-absorbing ceramic composite material is prepared based on the preparation method of any one of claims 1-9 having both broadband and high-temperature oxidation resistance.

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