Broadband multilayer wave-absorbing ceramic composite material capable of being pasted and flexible and preparation method of broadband multilayer wave-absorbing ceramic composite material

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, so as to obtain a spinning solution; 2) performing electrostatic spinning on the spinning solution to obtain preform fibers; 3) performing fiber shaping treatment on the preform fiber to obtain inorganic fiber cloth; (4) carrying out high-temperature cracking on the inorganic fiber cloth, so as to obtain ZrO2-ZrC-ZrB2 fiber cloth; (5) the Al2O3 fiber cloth and the ZrO2-ZrC-ZrB2 fiber cloth are pasted layer by layer according to the proportion that the Al2O3 fiber cloth / the multiple layers of ZrO2-ZrC-ZrB2 fiber cloth / the Al2O3 fiber cloth is pasted layer by layer through high-temperature glue; and 6) carrying out hot pressing on the product obtained in the step 5) by a hot pressing method to obtain the adhesive broadband multilayer wave-absorbing ceramic composite material with flexibility, and the material prepared by the method has broadband electromagnetic wave absorbing 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 which is adhesive and flexible, and a preparation method thereof. Background Art

[0002] The rapid development of modern science and technology requires aircraft to have higher performance, more advanced functions and stronger stealth capabilities. In this context, electromagnetic compatibility and radar stealth have become one of the important indicators for measuring the level of equipment modernization. In order to cope with the complex and changing battlefield environment and improve the survivability and penetration probability of combat platforms, it is particularly important to develop high-temperature resistant materials with excellent wave-absorbing properties. Wave-absorbing ceramic composite materials are a type of special functional material that can maintain structural stability under extreme temperature conditions and effectively absorb electromagnetic wave energy in a wide bandwidth range, converting it into heat energy or other forms of energy without obvious reflection. The application of such materials is of great significance for reducing target characteristic signals and reducing the probability of detection. Especially in the field of aerospace, such as the surface of high-speed aircraft, the air inlet and tail nozzle of aircraft engines, not only need to withstand the intense friction and heat generated by high-speed flight, but also need to maintain good wave-absorbing effects in high-temperature environments to achieve the purpose of stealth or anti-interference.

[0003] Electrospinning 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 a specific frequency band to meet the needs of different application scenarios. Reference 1 "Wang Q, Qi L, Jia Y, et al. Flexible ZrO 2 / ZrC / ZrB 2 ceramic nanofiber mats by electrospinning with broadband electromagnetic absorption and high-temperature oxidation resistance[J].Materials Letters,2024,365:136442." mentioned a ZrO prepared by electrospinning technology combined with high-temperature pyrolysis. 2 -ZrC-ZrB2 Ceramic fiber cloth has an effective absorption bandwidth of 8.64 GHz. However, due to its high dielectric constant and conductivity, it faces the problem of poor impedance matching with free space when used alone as an absorbing material, which limits the further improvement of its absorbing performance. Therefore, it is necessary to explore ways to improve the ZrO 2 -ZrC-ZrB 2 The method of studying the microwave absorption capacity of ceramic fiber cloth has important theoretical value and practical significance for the research and development of high-temperature stealth materials suitable for extreme environments. Breakthroughs in this field will provide new ideas and technical support for the design and development of high-performance microwave absorbing materials and promote the development of related technologies.

[0004] Alumina (Al 2 O 3 ) fiber cloth, as a high-performance inorganic non-metallic material, has shown significant advantages in the application of wave-transmitting materials, and is particularly suitable for working environments that require high temperature resistance, corrosion resistance and high stability. Reference 2 "Mei, Hui, et al." 3D-printed oblique honeycomb Al 2 O 3 / SiCw structure for electromagneticwave absorption."Chemical Engineering Journal 372(2019):940-945." mentioned Al 2 O 3 Due to its low dielectric constant and loss tangent, it is an ideal wave-transmitting material. 2 O 3 Its electromagnetic loss capacity is limited and it is not suitable as an efficient absorbing material when used alone. Summary of the invention

[0005] The purpose of the present invention is to overcome the disadvantages of the prior art and provide a wide-band multilayer absorbing ceramic composite material that is adhesive and flexible and a preparation method thereof. The material prepared by the method has wide-band electromagnetic wave absorption performance.

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

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

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

[0010] 4) The inorganic fiber cloth is subjected to high temperature pyrolysis to obtain ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0011] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through high temperature glue and pressed by Al 2 O 3 Fiber cloth / multilayer ZrO 2 -ZrC-ZrB 2 Fiber cloth / Al 2 O 3 The fiber cloth is pasted layer by layer;

[0012] 6) The product obtained in step 5) is hot pressed by a hot pressing method 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 broadband multi-layer microwave-absorbing ceramic composite material that can be bonded and is flexible according to the present invention is:

[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 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%.

[0019] Furthermore, the specific operation of step 3) is:

[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 at this temperature for 2-3 hours at normal pressure to obtain an inorganic fiber cloth.

[0021] Further, the operation process of step 4) is:

[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 at this temperature for 1-2 hours to obtain a flexible ZrO 2 -ZrC-ZrB 2 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 multilayer wave-absorbing ceramic composite material which is both pastable and flexible. The composite material is prepared based on a method for preparing the broadband multilayer wave-absorbing ceramic composite material which is both pastable and flexible.

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

[0026] The invention discloses a wide-band multi-layered microwave-absorbing ceramic composite material that is both adhesive and flexible and a method for preparing the same. In specific operation, high-temperature glue is used to bond ZrO 2 -ZrC-ZrB 2 Fiber cloth and Al 2 O 3 Fiber cloth, according to Al 2 O 3 Fiber cloth / Multilayer ZrO 2 -ZrC-ZrB 2 Fiber cloth / Al 2 O 3 The structural order of the fiber cloth is pasted layer by layer, and finally a ceramic composite material with broadband absorbing performance is formed. The composite material has the advantages of high temperature resistance, oxidation resistance, broadband absorbing, excellent adhesion to special-shaped parts and curved parts, and simple preparation process. It is an ideal absorbing material for high temperature environments. 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The effective absorption bandwidth of the "fiber cloth" composite material can reach 10GHz, covering the entire X- and Ku-bands. In this composite structure, the outer layer of Al 2 O 3 The fiber cloth acts as an impedance matching layer to ensure that electromagnetic waves can efficiently enter the composite material.2 -ZrC-ZrB 2 The fiber cloth layer provides efficient electrical conductivity loss through its three-dimensional network structure, while the large number of heterogeneous interfaces between the nanoparticles of each phase on the fiber produce significant interface polarization loss, thereby enhancing the overall electromagnetic loss capacity of the composite material. 2 -ZrC-ZrB 2 The optimization adjustment of the number of fiber cloth layers can achieve fine control of the dielectric constant and further improve the broadband absorbing performance of the composite material. Finally, it should be noted that the material of the present invention has a high absorbing efficiency in the X- and Ku-bands, which provides a new design idea and technical approach for the development of high-performance absorbing materials suitable for extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 The ZrO prepared by the present invention 2 -ZrC-ZrB 2 Scanning electron microscope image and physical image of the fiber cloth;

[0029] Figure 2 For Al 2 O 3 Fiber cloth / 24 layers of ZrO 2 -ZrC-ZrB 2 Fiber cloth / Al 2 O 3 Physical picture of fiber cloth composite material;

[0030] Figure 3 For Al 2 O 3 Fiber cloth / 16 layers of ZrO 2 -ZrC-ZrB 2 Fiber cloth / Al 2 O 3 RL 2D plot of fiber cloth composite;

[0031] Figure 4 For Al 2 O 3 Fiber cloth / 24 layers of ZrO 2 -ZrC-ZrB 2 Fiber cloth / Al 2 O 3 RL 2D plot of the fiber cloth composite. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[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 determining" 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, 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.

[0039] 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.

[0040] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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 preform fiber, wherein in 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 spinning 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%;

[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 keeping the temperature at normal pressure for 2-3 hours to obtain an inorganic fiber cloth;

[0045] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB 2 The inorganic fiber cloth is heated to 1100-1500°C at a heating rate of 2-5°C / min and kept at this temperature for 1-2h to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0046] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[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 heating rate of 5° C. / min and kept warm for 1 hour; then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is adhesive and flexible.

[0048] Embodiment 1

[0049] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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; the organic solvent is ethanol;

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

[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 280° C. at a heating rate of 2° C. / min in an air atmosphere, and then keeping the temperature at normal pressure for 2 hours to obtain an inorganic fiber cloth;

[0054] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB 2 The inorganic fiber cloth is heated to 1400°C at a heating rate of 5°C / min and kept at this temperature for 1h to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0055] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[0056] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 150° C. at a heating 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 adhesive and flexible.

[0057] Embodiment 2

[0058] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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; the organic solvent is N,N-dimethylformamide;

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

[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 260° C. at a heating rate of 2° C. / min in an air atmosphere, and then keeping the temperature at normal pressure for 3 hours to obtain an inorganic fiber cloth;

[0063] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB 2 The inorganic fiber cloth is heated to 1200°C at a heating rate of 5°C / min and kept at this temperature for 2 hours to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0064] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[0065] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 180° C. at a heating 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 adhesive and flexible.

[0066] Embodiment 3

[0067] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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 in the electrospinning process, a needle with an inner diameter of 0.5 mm is used, a spinning voltage of 12 kV, a spinning distance of 25 cm, and a liquid pushing rate of 0.01 mm·s -1 , spinning temperature is 20℃, relative humidity of air is 20RH%;

[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 220° C. at a heating rate of 2° C. / min in an air atmosphere, and then keeping the temperature at normal pressure for 3 hours to obtain an inorganic fiber cloth;

[0072] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB 2 The inorganic fiber cloth is heated to 1500°C at a heating rate of 2°C / min and kept at this temperature for 1 hour to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0073] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[0074] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 180° C. at a heating 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 adhesive and flexible.

[0075] Embodiment 4

[0076] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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 in the electrospinning process, a needle with an inner diameter of 0.6 mm is used, a spinning voltage of 10 kV, a spinning distance of 10 cm, and a liquid pushing rate of 0.0055 mm·s -1 , spinning temperature is 25℃, relative humidity of 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 300° C. at a heating rate of 2° C. / min in an air atmosphere, and then keeping the temperature at normal pressure for 2 hours to obtain an inorganic fiber cloth;

[0081] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB 2 The inorganic fiber cloth is heated to 1300°C at a heating rate of 5°C / min and kept at this temperature for 1h to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0082] 5) Al2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[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 heating 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 adhesive and flexible.

[0084] Embodiment 5

[0085] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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; the organic solvent is N,N-dimethylformamide;

[0088] 2) electrospinning the spinning solution to obtain a preform fiber, wherein in the electrospinning process, a needle with an inner diameter of 0.5 mm is 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%;

[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 220° C. at a heating rate of 2° C. / min in an air atmosphere, and then keeping the temperature at normal pressure for 2 hours to obtain an inorganic fiber cloth;

[0090] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB2 The inorganic fiber cloth is heated to 1100°C at a heating rate of 2°C / min and kept at this temperature for 1h to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0091] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[0092] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 150° C. at a heating 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 adhesive and flexible.

[0093] Embodiment 6

[0094] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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; the organic solvent is N,N-dimethylformamide;

[0097] 2) electrospinning the spinning solution to obtain a preform fiber, wherein in the electrospinning process, a needle with an inner diameter of 1.0 mm is 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%;

[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 300° C. at a heating rate of 2° C. / min in an air atmosphere, and then keeping the temperature at normal pressure for 3 hours to obtain an inorganic fiber cloth;

[0099] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB 2 The inorganic fiber cloth is heated to 1500°C at a heating rate of 5°C / min and kept at this temperature for 2 hours to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0100] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[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 heating rate of 5° C. / min and kept warm for 1 hour; then naturally cooled to room temperature to obtain a broadband multilayer absorbing ceramic composite material that is adhesive and flexible.

[0102] Embodiment 7

[0103] The method for preparing the broadband multi-layer wave-absorbing ceramic composite material that can be bonded and is flexible according to 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 them to an organic solvent, stirring evenly, and obtaining 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; the organic solvent is ethanol;

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

[0107] 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 280° C. at a heating rate of 2° C. / min in an air atmosphere, and then keeping the temperature at normal pressure for 2.5 hours to obtain an inorganic fiber cloth;

[0108] 4) In an argon atmosphere, the inorganic fiber cloth is subjected to high temperature pyrolysis to obtain a flexible ZrO 2 -ZrC-ZrB 2 The inorganic fiber cloth is heated to 1300°C at a heating rate of 3°C / min and kept at this temperature for 1.2 hours to obtain a flexible ZrO 2 -ZrC-ZrB 2 Fiber cloth;

[0109] 5) Al 2 O 3 Fiber cloth and ZrO 2 -ZrC-ZrB 2 The fiber cloth is passed through a high temperature glue (the main component is Al 2 O 3 ), press Al 2 O 3 Fiber cloth / ZrO 2 -ZrC-ZrB 2 Fiber cloth (multi-layer) / Al 2 O 3 The fiber cloth is pasted layer by layer, wherein the high temperature glue is Al 2 O 3 ;

[0110] 6) hot pressing the product obtained in step 5) by hot pressing, wherein during hot pressing, the temperature is raised to 170° C. at a heating 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 adhesive and flexible.

[0111] 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 is indicated by the following claims.

[0112] 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.

[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 still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a broadband multilayer microwave-absorbing ceramic composite material that is adhesive and flexible, 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 a shaping treatment on the preform fiber to obtain an inorganic fiber cloth; 4) performing high temperature pyrolysis on the inorganic fiber cloth to obtain a ZrO2-ZrC-ZrB2 fiber cloth; 5) Paste the Al2O3 fiber cloth and the ZrO2-ZrC-ZrB2 fiber cloth layer by layer through high temperature glue in the order of Al2O3 fiber cloth / multi-layer ZrO2-ZrC-ZrB2 fiber cloth / Al2O3 fiber cloth; 6) The product obtained in step 5) is hot pressed by a hot pressing method to obtain a broadband multilayer microwave absorbing ceramic composite material that is adhesive and flexible.

2. The method for preparing the adhesive and flexible broadband multi-layer 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-layer 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-layer microwave-absorbing ceramic composite material according to claim 1, characterized in that: In step 1), the spinning aid is polyvinyl pyrrolidone.

5. The method for preparing the adhesive and flexible broadband multi-layer microwave-absorbing ceramic composite material 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 adhesive and flexible broadband multi-layer 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 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 adhesive and flexible broadband multi-layer microwave-absorbing ceramic composite material according to claim 1, characterized in that: 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.

8. The method for preparing the adhesive and flexible broadband multi-layer microwave-absorbing ceramic composite material according to claim 1, characterized in that: The operation process of step 4) is: 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.

9. The method for preparing the adhesive and flexible broadband multi-layer 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 heating rate of 5° C. / min, kept at that temperature for 1 hour, and then naturally cooled to room temperature.

10. A broadband multi-layer microwave-absorbing ceramic composite material that is adhesive and flexible, characterized in that: The invention is prepared based on the method for preparing the broadband multilayer wave-absorbing ceramic composite material which is adhesive and flexible as described in any one of claims 1 to 9.

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