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

Abstract

The preparation method comprises the following steps: (1) adding a zirconium source, boric acid and a spinning aid into an organic solvent, and uniformly stirring to obtain a spinning solution; 2) performing electrostatic spinning on the spinning solution to obtain preform fibers; (3) carrying out shaping treatment on the preform fiber to obtain inorganic fiber cloth; (4) uniformly stirring the PSNB liquid-phase precursor, the PZO liquid-phase precursor and the PZC liquid-phase precursor to obtain a mixed impregnant; (5) stacking the inorganic fiber cloth into a plurality of layers, putting the inorganic fiber cloth into the mixed impregnant, and then treating the inorganic fiber cloth by a vacuum impregnation method to obtain a prefabricated composite material; 6) performing low-temperature crosslinking 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, and the wave-absorbing ceramic composite material is obtained. The wave-absorbing ceramic composite material prepared through the method has broadband electromagnetic wave absorption and high-temperature oxidation resistance.

Description

Technical Field

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

[0002] Composite materials with both wave-absorbing and high-temperature oxidation resistance are indispensable materials for the stealth of modern high-speed aircraft. With the rapid development of military technology, in order to cope with increasingly complex and advanced radar detection, the design requirements of aircraft are no longer limited to speed and maneuverability, but have been further extended to stealth performance. It is required that the wave-absorbing material can integrate the high heat resistance and excellent wave-absorbing properties of the ceramic matrix material to ensure that it can maintain structural integrity and functional stability in extreme environments, so that it can efficiently absorb electromagnetic waves, significantly reduce the radar cross section (RCS) of the aircraft, and reduce the risk of detection. In addition, the wave-absorbing material must also have a high degree of designability, and can be customized according to the needs of specific application scenarios. Development, optimize its absorption of electromagnetic waves in different frequency bands, and provide all-round stealth protection. In summary, composite materials with both wave-absorbing and high-temperature oxidation resistance can not only improve the survivability of aircraft in complex environments, but also provide strong technical support for the development of future aerospace engineering, which has far-reaching significance for national security and scientific and technological progress.

[0003] Electrospinning is a process for making 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 show unparalleled advantages in the aerospace field. First, the ceramic fibers obtained by electrospinning have extremely high specific surface area and low density, and are ideal lightweight and high-strength composite material reinforcements. They 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. They are 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 ZrO 2 / ZrC / ZrB 2 ceramic nanofiber mats by electrospinning with broadbandelectromagnetic absorption and high-temperature oxidation resistance[J].Materials Letters,2024,365:136442." mentioned a ZrO prepared by electrospinning combined with high-temperature pyrolysis.2 / ZrC / ZrB 2 Fiber cloth, the ceramic fiber has high conductivity and dielectric constant, and has an effective absorption bandwidth of 8.64GHz after being mixed with paraffin in proportion. However, the composite ceramic fiber is not suitable for use as a wave absorbing material alone, and needs to be combined with a wave-transmitting ceramic matrix to prepare a fiber-reinforced ceramic composite material for application.

[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. It has 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 wave-absorbing bandwidth of 3.65 GHz. Therefore, in order to improve its wave absorbing performance, SiBCN is usually used as an impedance matching wave-transmitting material combined with an electromagnetic loss absorber with good wave absorbing ability to form a composite wave absorbing material to obtain broadband wave 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 the method has broadband electromagnetic wave absorption and high-temperature oxidation resistance.

[0006] To achieve the above object, 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 the mixture to obtain a spinning solution;

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

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

[0010] 4) Stir the liquid precursors of PSNB, PZO and PZC evenly to obtain a mixed impregnating agent;

[0011] 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;

[0012] 6) subjecting the prefabricated composite material to low-temperature cross-linking treatment to obtain a cured prefabricated composite material;

[0013] 7) The cured prefabricated composite material is subjected to high-temperature pyrolysis to obtain a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance.

[0014] The further improvement of the preparation method of the microwave-absorbing ceramic composite material with both broadband and high-temperature oxidation resistance of the present invention is:

[0015] Furthermore, 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.

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

[0017] Furthermore, in step 1), the spinning aid is polyvinyl pyrrolidone.

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

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

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

[0021] In an air atmosphere, the preform fiber is heated to 220-300° C. at a heating rate of 2° C. / min, and then kept at this temperature for 2-3 hours at normal pressure to obtain an inorganic fiber cloth.

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

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

[0024] 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 broadband 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 preparation method of 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 microwave-absorbing ceramic composite material with broadband and high-temperature oxidation resistance and the preparation method thereof of 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, and then pre-oxidizing and shaping at a low temperature to convert it into ZrO 2 / ZrC / ZrB 2 The PSNB / PZO / PZC liquid phase mixed precursor was then evenly mixed by magnetic stirring and ZrO was introduced by impregnation. 2 / ZrC / ZrB 2 The fiber cloth precursor is then cross-linked at low temperature and pyrolyzed at high temperature to obtain ZrO 2 / ZrC / ZrB 2 Composite ceramic fiber reinforced SiBCN / ZrO 2 / ZrC / ZrB 2 The wave-absorbing ceramic composite material, in which SiBCN is used as a wave-transmitting phase, can improve the impedance matching between the composite material and free space. 2 / ZrC / ZrB 2 Nanoparticles and ZrO 2 / ZrC / ZrB 2 The fiber cloth makes the composite material have a good dispersion effect and forms a microscopic three-dimensional conductive network in the composite material, which can not only improve the conductivity loss capacity of the composite material, but also generate additional interface polarization loss through rich heterogeneous interfaces. In addition, the fiber cloth in the composite material has a layered structure, and the electromagnetic wave reflection between layers further enhances the absorption effect of the material. The above synergistic effect greatly improves the broadband absorption performance and high-temperature oxidation resistance of the composite material.

[0028] In addition, it should be noted that this material has the advantages of light weight, high temperature resistance, broadband absorption and simple preparation process. It is an ideal absorbing material for high temperature extreme environments. Specifically, the effective absorption bandwidth of the composite material can reach 11.52GHz. When the thickness is 3.8mm, it can cover the entire X- and Ku-bands, and partially cover the C-band. In this composite material, SiBCN acts as a wave-transmitting matrix, which exhibits excellent wave-transmitting properties at both room temperature and high temperature conditions, ensuring that the incident electromagnetic waves can enter the interior of the composite material. In addition, the in-situ formed ZrO 2 / ZrC / ZrB 2 Nanoparticles filled with ZrO 2 / ZrC / ZrB 2 The gaps between the fibers increase the heterogeneous interface and enhance the interface polarization loss. ZrO with a three-dimensional network structure 2 / ZrC / ZrB 2 Multilayer fiber cloth improves the conductivity loss capacity of the composite material. The multi-element nanophase also increases the dispersion effect of the composite material. The layered structure of the multilayer fiber cloth provides an ideal path for multiple reflections of electromagnetic waves inside the composite material. The above characteristics work together to improve the broadband absorption performance of the composite material. By controlling the pyrolysis temperature of the composite material, the impedance matching between the composite material as a whole and the free space can be regulated to further optimize its broadband absorption performance. This preparation method not only simplifies the process, but also ensures the consistency and repeatability of material performance, providing a solid foundation for the preparation of high-performance absorbing materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 The ZrO prepared by the present invention 2 / ZrC / ZrB 2 Composite ceramic fiber reinforced SiBCN / ZrO 2 / ZrC / ZrB 2 Scanning electron microscope image of the microwave-absorbing ceramic composite;

[0031] Figure 2 ZrO under different pyrolysis temperatures 2 / ZrC / ZrB 2 Composite ceramic fiber reinforced SiBCN / ZrO 2 / ZrC / ZrB 2 RL 2D plot of the microwave absorbing ceramic composite;

[0032] Figure 3 for ZrO 2 / ZrC / ZrB 2 Composite ceramic fiber reinforced SiBCN / ZrO 2 / ZrC / ZrB 2 Mass change curve of absorbing ceramic composite material in oxidizing environment. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of 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 specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0036] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, 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, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the 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 determining" 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, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually 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 in 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] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0041] The method for preparing the microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance 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 them to an organic solvent, stirring evenly, and obtaining a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130000; the organic solvent is one of N, N-dimethylformamide and ethanol or a mixture of the two;

[0043] 2) electrospinning the spinning solution to obtain a preform fiber, wherein a needle with an inner diameter of 0.5 to 1.0 mm is used, 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) Under air atmosphere, the preform fiber is subjected to a shaping treatment to obtain an inorganic fiber cloth, specifically: under air atmosphere, the preform fiber is heated to 220-300° C. at a heating rate of 2° C. / min, and then kept at this temperature for 2-3 hours under normal pressure to obtain an 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, stirring evenly to obtain a mixed impregnating agent;

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

[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 normal pressure 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 wide-band and high-temperature anti-oxidation absorbing ceramic composite material. 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 1-2h to obtain a wide-band and high-temperature anti-oxidation absorbing ceramic composite material.

[0049] Embodiment 1

[0050] The method for preparing the microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance 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 them to an organic solvent, and stirring them evenly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130000; and the organic solvent is N,N-dimethylformamide;

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

[0053] 3) Under an air atmosphere, the preform fiber is subjected to a shaping treatment to obtain an inorganic fiber cloth, specifically, under an air atmosphere, the preform fiber is heated to 260° C. at a heating rate of 2° C. / min, and then kept at this temperature for 3 hours under normal pressure to obtain an inorganic fiber cloth;

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

[0055] 5) stacking the inorganic fiber cloth obtained in step 3) into 16 layers, and then placing it in the mixed impregnating agent obtained in step 4), and treating it 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 for 2.3 hours at normal pressure 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] Embodiment 2

[0059] The method for preparing the microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance 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 them to an organic solvent, and stirring them evenly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is ethanol;

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

[0062] 3) Under air atmosphere, the preform fiber is subjected to a shaping treatment to obtain an inorganic fiber cloth, specifically: under air atmosphere, the preform fiber is heated to 240° C. at a heating rate of 2° C. / min, and then kept at this temperature for 3 hours under normal pressure to obtain an inorganic fiber cloth;

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

[0064] 5) stacking the inorganic fiber cloth obtained in step 3) into 24 layers, and then placing it in the mixed impregnating agent obtained in step 4), and treating it 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 for 3 hours at normal pressure 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] Embodiment 3

[0068] The method for preparing the microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance 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 them to an organic solvent, and stirring them evenly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

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

[0071] 3) Under air atmosphere, the preform fiber is subjected to a shaping treatment to obtain an inorganic fiber cloth, specifically: under air atmosphere, the preform fiber is heated to 300° C. at a heating rate of 2° C. / min, and then kept at this temperature for 2 hours under normal pressure to obtain an inorganic fiber cloth;

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

[0073] 5) stacking the inorganic fiber cloth obtained in step 3) into 32 layers, and then placing it in the mixed impregnating agent obtained in step 4), and treating it 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 keeping 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 wide-band and high-temperature anti-oxidation absorbing ceramic composite material. 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 wide-band and high-temperature anti-oxidation absorbing ceramic composite material.

[0076] Embodiment 4

[0077] The method for preparing the microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance 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 them to an organic solvent, and stirring them evenly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

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

[0080] 3) Under air atmosphere, the preform fiber is subjected to a shaping treatment to obtain an inorganic fiber cloth, specifically: under air atmosphere, the preform fiber is heated to 260° C. at a heating rate of 2° C. / min, and then kept at this temperature for 2.5 hours under normal pressure to obtain an inorganic fiber cloth;

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

[0082] 5) stacking the inorganic fiber cloth obtained in step 3) into 25 layers, and then placing it in the mixed impregnating agent obtained in step 4), and treating it 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 for 2.5 hours at normal pressure 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 wide-band and high-temperature anti-oxidation absorbing ceramic composite material. 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 wide-band and high-temperature anti-oxidation absorbing ceramic composite material.

[0085] Embodiment 5

[0086] The method for preparing the microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance 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 them to an organic solvent, and stirring them evenly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

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

[0089] 3) Under an air atmosphere, the preform fiber is subjected to a shaping treatment to obtain an inorganic fiber cloth, specifically: under an air atmosphere, the preform fiber is heated to 300° C. at a heating rate of 2° C. / min, and then kept at this temperature for 3 hours under normal pressure to obtain an inorganic fiber cloth;

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

[0091] 5) stacking the inorganic fiber cloth obtained in step 3) into 32 layers, and then placing it in the mixed impregnating agent obtained in step 4), and treating it 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 keeping 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] Embodiment 6

[0095] The method for preparing the microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance 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 them to an organic solvent, and stirring them evenly to obtain a spinning solution, wherein the zirconium source is a zirconium-containing polymer precursor (PZC); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

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

[0098] 3) Under an air atmosphere, the preform fiber is subjected to a shaping treatment to obtain an inorganic fiber cloth, specifically, under an air atmosphere, the preform fiber is heated to 220° C. at a heating rate of 2° C. / min, and then kept at this temperature for 2 hours under normal pressure to obtain an inorganic fiber cloth;

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

[0100] 5) stacking the inorganic fiber cloth obtained in step 3) into 16 layers, and then placing it in the mixed impregnating agent obtained in step 4), and treating it 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 for 2 hours at normal pressure 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 wide-band and high-temperature anti-oxidation absorbing ceramic composite material. 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 wide-band and high-temperature anti-oxidation absorbing ceramic composite material.

[0103] The preparation method provided by the present invention and the composite material obtained therefrom have opened up a new path for the development of new stealth materials, and are particularly suitable for application scenarios that require high-efficiency electromagnetic wave absorption and structural stability in extreme environments, such as modern high-speed aircraft stealth technology. This method not only optimizes the overall dielectric properties of the material, but also greatly improves its electromagnetic wave absorption capacity in a wide frequency range and stability in high-temperature environments, providing strong technical support for the development of future aerospace engineering.

[0104] Those skilled in the art will readily appreciate 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 present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0105] It should be understood that the present invention is not limited to the exact construction that has been 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 description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

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) adding a zirconium source, boric acid and a spinning aid into an organic solvent and stirring the mixture to obtain a spinning solution; 2) electrospinning the spinning solution to obtain a preform fiber; 3) performing shaping treatment on the preform fiber to obtain an inorganic fiber cloth; 4) Stir the liquid precursors of PSNB, PZO and PZC evenly to obtain a mixed impregnating agent; 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) subjecting the prefabricated composite material to low-temperature cross-linking treatment to obtain a cured prefabricated composite material; 7) The cured prefabricated composite material is subjected to high-temperature pyrolysis to obtain a microwave-absorbing ceramic composite material having both broadband and high-temperature oxidation resistance.

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

5. The method for preparing the 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 the 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 to 1.0 mm is used, a spinning voltage of 10 to 15 kV, a collection distance of 10 to 30 cm, and a liquid pushing rate of 0.002 to 0.01 mm·s -1 , the spinning temperature is 20-30°C, and the relative humidity of the air is 20-40RH%.

7. The method for preparing the 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° C. at a heating rate of 2° C. / min, and then kept at this temperature for 2-3 hours at normal pressure to obtain an inorganic fiber cloth.

8. The method for preparing the 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 the 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 warm for 1-2 hours to obtain a microwave-absorbing ceramic composite material with broadband and high-temperature oxidation resistance.

10. A microwave absorbing ceramic composite material having 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 to 9 having both broadband and high-temperature oxidation resistance.

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