Flexible broadband multilayer absorbing ceramic composite material and preparation method thereof

Abstract

The application discloses a kind of flexible broadband multilayer wave-absorbing ceramic composite material 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 electrospun, and the preform fiber is obtained;3) the preform fiber is treated, and the inorganic fiber cloth is obtained;4) the inorganic fiber cloth is pyrolyzed, and ZrO2-ZrC-ZrB2 fiber cloth is obtained;5) Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth are pasted by high temperature glue, and Al2O3 fiber cloth / multilayer ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth is pasted layer by layer;6) the product obtained in step 5) is hot-pressed by hot-pressing method, and the flexible broadband multilayer wave-absorbing ceramic composite material is obtained, and the material prepared by the method has broadband electromagnetic wave absorption performance.

Description

Technical Field

[0001] The invention belongs to the technical field of wave-absorbing materials, and relates to a broadband multi-layer wave-absorbing ceramic composite material that is adhesive and flexible, and a preparation method thereof. Background Art

[0002] The rapid development of modern technology requires aircraft to possess higher performance, more advanced functions, and stronger stealth capabilities. In this context, electromagnetic compatibility and radar stealth have become important indicators for measuring the level of equipment modernization. To cope with complex and changing battlefield environments and improve the survivability and penetration probability of combat platforms, the development of high-temperature resistant materials with excellent wave-absorbing properties is particularly critical. Wave-absorbing ceramic composites are a class of special functional materials that maintain structural stability under extreme temperature conditions and effectively absorb electromagnetic wave energy over a wide bandwidth, converting it into heat or other forms of energy without significant reflection. The application of these materials is of great significance for reducing target signatures and minimizing the probability of detection. This is particularly true in the aerospace field, where surfaces of high-speed aircraft, aircraft engine inlets, and tail nozzles must not only withstand the intense frictional heat generated by high-speed flight but also maintain excellent wave-absorbing properties in high-temperature environments to achieve stealth or anti-interference purposes.

[0003] Electrospinning technology is a technology that uses high-voltage electrostatic fields to produce ultrafine fibers. It can generate continuous fibers with diameters ranging from a few nanometers to a few microns from a variety of polymer solutions or melts. Ceramic fibers prepared by electrospinning not only inherit the excellent high-temperature resistance, oxidation resistance, and corrosion resistance of traditional ceramic materials, but also maintain the softness and processability of the material. These properties ensure the stability of the physical and chemical properties of the material under extreme environmental conditions, and are particularly suitable for temperature-sensitive applications in the aerospace field. In addition, by adjusting the component ratio of the precursor solution or introducing functional fillers, the electromagnetic parameters of the fiber can also be customized to achieve effective absorption of electromagnetic waves in specific frequency bands to meet the needs of different application scenarios. 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 ceramic fiber cloth prepared by electrospinning combined with high-temperature pyrolysis. This ceramic fiber cloth exhibits an effective absorption bandwidth of 8.64 GHz. However, due to its high dielectric constant and conductivity, this ceramic fiber cloth, when used alone as an absorber, suffers from poor impedance matching with free space, limiting further improvement in its absorption performance. Therefore, exploring methods to improve the absorption capabilities of ZrO2-ZrC-ZrB2 ceramic fiber cloth has important theoretical and practical significance for the development of high-temperature stealth materials suitable for extreme environments. Breakthroughs in this area will provide new insights and technical support for the design and development of high-performance absorbers, promoting the advancement of related technologies.

[0004] Alumina (Al2O3) fiber cloth, a high-performance inorganic non-metallic material, exhibits significant advantages in applications as a wave-transmitting material, particularly in environments requiring high-temperature resistance, corrosion resistance, and high stability. Reference 2, "Mei, Hui, et al. "3D-printed oblique honeycomb Al2O3 / SiCw structure for electromagnetic wave absorption," Chemical Engineering Journal 372(2019):940-945," notes that Al2O3's low dielectric constant and loss tangent make it an ideal wave-transmitting material. However, due to its limited electromagnetic loss capacity, Al2O3 alone is not suitable as an efficient wave-absorbing material. 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 broadband multi-layer absorbing ceramic composite material that is adhesive and flexible and a preparation method thereof. The material prepared by this method has broadband electromagnetic wave absorption performance.

[0006] To achieve the above-mentioned object, the present invention discloses a method for preparing a broadband multilayer wave-absorbing ceramic composite material that is adhesive and flexible, 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 a shaping treatment on the preformed fibers to obtain an inorganic fiber cloth;

[0010] 4) pyrolyzing the inorganic fiber cloth at high temperature to obtain a ZrO2-ZrC-ZrB2 fiber cloth;

[0011] 5) Paste the Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high temperature glue in the order of Al2O3 fiber cloth / multi-layer ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth;

[0012] 6) hot pressing the product obtained in step 5) to obtain a broadband multilayer microwave-absorbing ceramic composite material that is adhesive and flexible.

[0013] The further improvement of the method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention is as follows:

[0014] Furthermore, in step 1), the mass ratio of the zirconium source, boric acid and spinning aid is 1.0:0.2-0.3:0.5-1.0.

[0015] Furthermore, in step 1), the zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate.

[0016] Furthermore, in step 1), the spinning aid is polyvinyl pyrrolidone.

[0017] Furthermore, in step 1), the organic solvent is one of N,N-dimethylformamide and ethanol or a mixture of the two.

[0018] Furthermore, in step 2), during the electrospinning process, a needle with an inner diameter of 0.5 to 1.0 mm, a spinning voltage of 10 to 15 kV, a winding distance of 10 to 30 cm, and a liquid pushing rate of 0.002 to 0.01 mm·s is used. -1 , the spinning temperature is 20-30°C, and the relative humidity of the air is 20-40RH%.

[0019] Furthermore, the specific operations of step 3) are:

[0020] In an air atmosphere, the preform fiber is heated to 220-300° C. at a heating rate of 2° C. / min, and then kept warm for 2-3 hours under normal pressure to obtain an inorganic fiber cloth.

[0021] Furthermore, the operation process of step 4) is as follows:

[0022] In an argon atmosphere, the inorganic fiber cloth 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 flexible ZrO2-ZrC-ZrB2 fiber cloth.

[0023] Furthermore, in step 6), during hot pressing, the temperature is raised to 150-180° C. at a heating rate of 5° C. / min, kept at that temperature for 1 hour, and then naturally cooled to room temperature.

[0024] The invention discloses a broadband multi-layer wave-absorbing ceramic composite material that is both adhesive and flexible. The composite material is prepared based on a method for preparing the broadband multi-layer wave-absorbing ceramic composite material that is both adhesive and flexible.

[0025] The present invention has the following beneficial effects:

[0026] The present invention describes a flexible, adhesive, broadband, multi-layered ceramic composite material and its preparation method. In practice, ZrO2-ZrC-ZrB2 fiber cloth and Al2O3 fiber cloth are bonded layer by layer using high-temperature adhesive, in the order of Al2O3 fiber cloth / multi-layer ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth. This ultimately forms a ceramic composite material with broadband absorbing properties. This composite material exhibits advantages such as high-temperature resistance, oxidation resistance, broadband absorption, excellent conformability to special-shaped and curved parts, and a simple preparation process, making it an ideal absorbing material for high-temperature environments. The "Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth" composite material has an effective absorption bandwidth of up to 10 GHz, covering the entire X- and Ku-bands. In this composite structure, the outer Al2O3 fiber cloth acts as an impedance matching layer, ensuring efficient electromagnetic wave penetration into the composite. The ZrO2-ZrC-ZrB2 fiber cloth layer provides efficient electrical conductivity loss through its three-dimensional network structure. At the same time, the large number of heterogeneous interfaces between the nanoparticles of each phase on the fiber produces significant interfacial polarization loss, thereby enhancing the overall electromagnetic loss capability of the composite material. In addition, by optimizing and adjusting the number of layers of the intermediate ZrO2-ZrC-ZrB2 fiber cloth, fine control of the dielectric constant is achieved, further improving the broadband absorption performance of the composite material. Finally, it should be noted that the material described in the present invention has a high absorption efficiency in the X- and Ku-bands, providing new design ideas and technical approaches for the development of high-performance absorbing materials suitable for extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 The scanning electron microscope image and the physical image of the ZrO2-ZrC-ZrB2 fiber cloth prepared by the present invention;

[0029] Figure 2 This is a physical picture of the Al2O3 fiber cloth / 24-layer ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth composite material;

[0030] Figure 3 RL two-dimensional map of Al2O3 fiber cloth / 16-layer ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth composite material;

[0031] Figure 4 RL two-dimensional diagram of Al2O3 fiber cloth / 24 layers of ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth composite material. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0041] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.2-0.3:0.5-1.0, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution;

[0042] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; 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 preformed fiber, wherein, 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 winding distance of 10 to 30 cm, and a liquid pushing rate of 0.002 to 0.01 mm·s is used. -1 , the spinning temperature is 20-30°C, and the relative humidity of the air is 20-40RH%;

[0044] 3) performing a fiber 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 under normal pressure to obtain the inorganic fiber cloth;

[0045] 4) in an argon atmosphere, pyrolyzing the inorganic fiber cloth to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1100-1500°C at a heating rate of 2-5°C / min and keeping the temperature for 1-2 hours to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0046] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0047] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 150-180° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0048] Example 1

[0049] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0050] 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;

[0051] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is ethanol.

[0052] 2) electrospinning the spinning solution to obtain a preform fiber, wherein, during the electrospinning process, a needle with an inner diameter of 0.8 mm, a spinning voltage of 14 kV, a winding distance of 15 cm, and a liquid pushing rate of 0.002 mm·s -1 , the spinning temperature is 25℃, and the relative humidity of the air is 20RH%;

[0053] 3) performing a fiber shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically: heating the preform fiber to 280° 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;

[0054] 4) pyrolyzing the inorganic fiber cloth in an argon atmosphere to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1400°C at a heating rate of 5°C / min and holding the temperature for 1 hour to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0055] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0056] 6) hot pressing the product obtained in step 5) by hot pressing, wherein the temperature is raised to 150° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0057] Example 2

[0058] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0059] 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;

[0060] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is N,N-dimethylformamide.

[0061] 2) electrospinning the spinning solution to obtain a preform fiber, wherein, during the electrospinning process, a needle with an inner diameter of 0.5 mm, a spinning voltage of 15 kV, a winding distance of 10 cm, and a liquid pushing rate of 0.008 mm·s -1 , the spinning temperature is 30℃, and the relative humidity of the air is 40RH%;

[0062] 3) performing a fiber 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 under normal pressure to obtain the inorganic fiber cloth;

[0063] 4) pyrolyzing the inorganic fiber cloth in an argon atmosphere to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1200°C at a heating rate of 5°C / min and holding the temperature for 2 hours to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0064] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0065] 6) hot pressing the product obtained in step 5) by hot pressing, wherein the temperature is raised to 180° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0066] Example 3

[0067] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0068] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.3:0.8, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution;

[0069] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

[0070] 2) electrospinning the spinning solution to obtain a preform fiber, wherein, during the electrospinning process, a needle with an inner diameter of 0.5 mm, a spinning voltage of 12 kV, a winding distance of 25 cm, and a liquid pushing rate of 0.01 mm·s -1 , the spinning temperature is 20℃, and the relative humidity of the air is 20RH%;

[0071] 3) performing a fiber 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 3 hours at normal pressure to obtain the inorganic fiber cloth;

[0072] 4) in an argon atmosphere, pyrolyzing the inorganic fiber cloth to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1500°C at a heating rate of 2°C / min and holding the temperature for 1 hour to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0073] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0074] 6) hot pressing the product obtained in step 5) by hot pressing, wherein the temperature is raised to 180° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0075] Example 4

[0076] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0077] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.2:1.0, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution;

[0078] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; the organic solvent is a mixture of N,N-dimethylformamide and ethanol;

[0079] 2) electrospinning the spinning solution to obtain a preform fiber, wherein, during the electrospinning process, a needle with an inner diameter of 0.6 mm, a spinning voltage of 10 kV, a winding distance of 10 cm, and a liquid pushing rate of 0.0055 mm·s -1 , the spinning temperature is 25℃, and the relative humidity of the air is 30RH%;

[0080] 3) performing a fiber 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;

[0081] 4) pyrolyzing the inorganic fiber cloth in an argon atmosphere to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1300°C at a heating rate of 5°C / min and holding the temperature for 1 hour to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0082] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0083] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 160° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0084] Example 5

[0085] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0086] 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;

[0087] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is N,N-dimethylformamide.

[0088] 2) electrospinning the spinning solution to obtain a preform fiber, wherein, during the electrospinning process, a needle with an inner diameter of 0.5 mm, a spinning voltage of 10 kV, a winding distance of 10 cm, and a liquid pushing rate of 0.002 mm·s -1 , the spinning temperature is 20℃, and the relative humidity of the air is 20RH%;

[0089] 3) performing a fiber 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;

[0090] 4) pyrolyzing the inorganic fiber cloth in an argon atmosphere to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1100°C at a heating rate of 2°C / min and holding the temperature for 1 hour to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0091] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0092] 6) hot pressing the product obtained in step 5) by hot pressing, wherein the temperature is raised to 150° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0093] Example 6

[0094] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0095] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.3:1.0, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution;

[0096] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is N,N-dimethylformamide.

[0097] 2) electrospinning the spinning solution to obtain a preform fiber, wherein, 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 -1 , the spinning temperature is 30℃, and the relative humidity of the air is 40RH%;

[0098] 3) performing a fiber 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;

[0099] 4) in an argon atmosphere, pyrolyzing the inorganic fiber cloth to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1500°C at a heating rate of 5°C / min and holding the temperature for 2 hours to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0100] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0101] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 80° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0102] Example 7

[0103] The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material of the present invention comprises the following steps:

[0104] 1) Weighing a zirconium source, boric acid, and a spinning aid in a mass ratio of 1.0:0.25:0.8, adding the mixture to an organic solvent, and stirring uniformly to obtain a spinning solution;

[0105] The zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate (PZO); the spinning aid is polyvinyl pyrrolidone (PVP), and the molecular weight of the spinning aid is 130,000; and the organic solvent is ethanol.

[0106] 2) electrospinning the spinning solution to obtain a preform fiber, wherein, during the electrospinning process, a needle with an inner diameter of 0.6 mm, a spinning voltage of 13 kV, a winding distance of 20 cm, and a liquid pushing rate of 0.008 mm·s -1 , the spinning temperature is 25℃, and the relative humidity of air is 35RH%;

[0107] 3) performing a fiber shaping treatment on the preform fiber in an air atmosphere to obtain an inorganic fiber cloth, specifically: heating the preform fiber to 280° 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;

[0108] 4) pyrolyzing the inorganic fiber cloth in an argon atmosphere to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth, specifically: heating the inorganic fiber cloth to 1300°C at a heating rate of 3°C / min and holding the temperature for 1.2 hours to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth;

[0109] 5) Pasting Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high-temperature adhesive (mainly composed of Al2O3) in the order of Al2O3 fiber cloth / ZrO2-ZrC-ZrB2 fiber cloth (multi-layer) / Al2O3 fiber cloth, wherein the high-temperature adhesive is Al2O3;

[0110] 6) hot pressing the product obtained in step 5) by hot pressing, wherein the temperature is raised to 170° C. at a rate of 5° C. / min and kept at that temperature for 1 hour; and then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is both adhesive and flexible.

[0111] 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.

[0112] 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.

[0113] 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 shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing a broadband multi-layer microwave-absorbing ceramic composite material that is both adhesive and flexible, 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 a shaping treatment on the preformed fibers to obtain an inorganic fiber cloth; 4) pyrolyzing the inorganic fiber cloth at high temperature to obtain a ZrO2-ZrC-ZrB2 fiber cloth; 5) Paste the Al2O3 fiber cloth and ZrO2-ZrC-ZrB2 fiber cloth layer by layer using high temperature glue in the order of Al2O3 fiber cloth / multi-layer ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth; 6) hot pressing the product obtained in step 5) to obtain a broadband multilayer microwave-absorbing ceramic composite material that is adhesive and flexible; In step 1), the spinning aid is polyvinyl pyrrolidone; The specific operations of step 3) are: 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. The operation process of step 4) is: In an argon atmosphere, the inorganic fiber cloth was heated to 1100~1500℃ at a heating rate of 2~5℃ / min and kept at this temperature for 1~2 hours to obtain a flexible ZrO2-ZrC-ZrB2 fiber cloth.

2. The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material according to claim 1, characterized in that: In step 1), the mass ratio of the zirconium source, boric acid and spinning aid is 1.0:0.2~0.3:0.5~1.

0.

3. The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material according to claim 1, characterized in that: In step 1), the zirconium source is a zirconium-containing polymer precursor zirconium acetylacetonate.

4. The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material according to claim 1, wherein: In step 1), the organic solvent is one of N,N-dimethylformamide and ethanol or a mixture of the two.

5. The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material 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%.

6. The method for preparing the adhesive and flexible broadband multi-layered microwave-absorbing ceramic composite material according to claim 1, characterized in that: In step 6), during hot pressing, the temperature is raised to 150-180°C at a rate of 5°C / min, kept at that temperature for 1 hour, and then naturally cooled to room temperature.

7. A broadband multi-layer microwave-absorbing ceramic composite material that is adhesive and flexible, characterized in that: The invention is prepared based on the preparation method of the adhesive and flexible broadband multi-layered wave-absorbing ceramic composite material according to any one of claims 1 to 6.

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