Ablation-resistant, heat-proof, heat-insulating and wave-absorbing integrated fiber-reinforced silicon resin composite material

Abstract

The invention relates to an ablation-resistant, heat-insulation and wave-absorbing integrated fiber-reinforced silicon resin composite material, which belongs to the technical field of wave-absorbing materials, and comprises a heat-insulation area and a wave-absorbing area which are sequentially arranged from top to bottom, the wave absorbing area comprises a magnetic modified fiber single sheet and / or an electric modified fiber single sheet; each electrically-modified fiber single sheet comprises electrically-modified fibers and matrix resin, wherein the peripheries of the electrically-modified fibers are coated with electrically-coated modified layers, and gaps of the electrically-modified fibers are filled with the matrix resin; each magnetic modified fiber single sheet comprises a magnetic modified fiber and matrix resin, wherein the periphery of the magnetic modified fiber is coated with a magnetic coating modified layer, and gaps of the magnetic modified fiber are filled with the matrix resin. The modified layer is coated on the periphery of the fiber to form regular and ordered wave-absorbing areas, regular and ordered refraction and reflection areas are formed in gaps among the fibers, interfaces with different absorptivity are formed between the wave-absorbing areas and the refraction and reflection areas due to different materials, the absorption effect is improved, the absorptivity and the absorption bandwidth are improved, and the service life of the fiber is prolonged. And meanwhile, the problems of poor dispersion uniformity and low production efficiency of the wave-absorbing material are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wave - absorbing materials, and particularly to a fiber - reinforced silicone resin composite material with ablation resistance, heat insulation, and wave - absorption integration. Background Art

[0002] During the flight of hypersonic aircraft, they face a high - temperature aerodynamic heat environment with a surface temperature exceeding 800 °C, and need the protection of heat - insulation materials. However, these materials often do not have wave - absorbing properties. Although carbon - based, magnetic, and polymer wave - absorbing materials used in wave - absorbing coatings exhibit good electromagnetic wave absorption properties at room temperature, they will undergo decomposition, oxidation, demagnetization, etc. in high - temperature environments, resulting in the failure of stealth performance. Existing heat - insulation / stealth materials have disadvantages such as high density, high thermal conductivity, and narrow wave - absorbing frequency bands. The step - by - step processing and forming of the heat - insulation layer and the wave - absorbing layer increase the difficulty of the preparation process and reduce the overall reliability of the structure. Therefore, it is necessary to develop an integrated composite material with a simple preparation process, low cost, and excellent heat - insulation and wave - absorbing properties.

[0003] In addition, according to the forming process and load - bearing capacity, wave - absorbing materials in the prior art can be divided into two types: coating type and structural type, which have the following defects respectively: The wave - absorbing coating is to disperse conductive carbon - based materials in a polymer material matrix or binder and directly coat it on the surface of an object. Although this method has a simple preparation process, it has disadvantages such as a large overall mass, a narrow effective absorption frequency band, and easy shedding. The structural wave - absorbing material is a multi - functional composite material that can meet the requirements of wave - absorption and load - bearing at the same time, and has good mechanical properties, thermal stability, and chemical stability. It has strong designability and has important application value for realizing structure - function integration. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a fiber - reinforced silicone resin composite material with ablation resistance, heat insulation, and wave - absorption integration, so as to solve at least one of the technical problems existing in the existing structural wave - absorbing composite materials, such as poor stability of step - by - step processing of the heat - insulation layer and the wave - absorbing layer, poor dispersion uniformity of the wave - absorbing material, low production efficiency, narrow absorption bandwidth, and poor wave - absorption effect.

[0005] The present invention discloses a fiber - reinforced silicone resin composite material with ablation resistance, heat insulation, and wave - absorption integration, including: A heat - insulation area and a wave - absorption area arranged in sequence from top to bottom; The wave - absorption area includes magnetically modified fiber single chips, and / or, electrically modified fiber single chips; The electrically modified fiber single chip includes electrically modified fibers with an electrically coated modification layer on the outer periphery and a matrix resin filled in the gaps between the electrically modified fibers; The magnetically modified fiber single chip includes magnetically modified fibers with a magnetically coated modification layer on the outer periphery and a matrix resin filled in the gaps between the magnetically modified fibers.

[0006] Preferably, the wave-absorbing region includes one or more magnetically modified fiber single sheets, and / or one or more electrically modified fiber single sheets.

[0007] Preferably, the wave-absorbing region includes a plurality of magnetically modified fiber single sheets and a plurality of electrically modified fiber single sheets; the magnetically modified fiber single sheets and the electrically modified fiber single sheets are arranged at intervals in the order from the electromagnetic wave incident surface to the exit surface, and a magnetically modified fiber single sheet is provided between adjacent electrically modified fiber single sheets.

[0008] Preferably, a magnetically modified fiber single sheet is provided on the incident surface of the electrically modified fiber single sheet, and the incident electromagnetic wave enters the electrically modified fiber single sheet after passing through at least one layer of magnetically modified fiber single sheets.

[0009] Preferably, when the wave-absorbing region includes a plurality of magnetically modified fiber single sheets, the content of the magnetic wave-absorbing agent in the plurality of magnetically modified fiber single sheets arranged in the order from the electromagnetic wave incident surface to the exit surface increases.

[0010] Preferably, the increase in the content of the magnetic wave-absorbing agent in adjacent magnetically modified fiber single sheets satisfies that the mass percentage of the magnetic wave-absorbing agent in adjacent magnetically modified fiber single sheets increases by 3% to 5%.

[0011] Preferably, when the wave-absorbing region includes a plurality of electrically modified fiber single sheets, the content of the electrical wave-absorbing agent in the plurality of electrically modified fiber single sheets arranged in the order from the electromagnetic wave incident surface to the exit surface increases.

[0012] Preferably, the increase in the content of the electrical wave-absorbing agent in adjacent electrically modified fiber single sheets satisfies that the mass percentage of the electrical wave-absorbing agent in adjacent electrically modified fiber single sheets increases by 0.5% to 2%.

[0013] A preparation method of a fiber-reinforced silicone resin composite material with integrated ablation resistance, heat insulation and wave absorption, which is used to prepare the above-mentioned fiber-reinforced silicone resin composite material with integrated ablation resistance, heat insulation and wave absorption, includes: Preparing electrically modified fiber single sheets by modifying raw fibers with an electrically modified wave-absorbing agent; Preparing magnetically modified fiber single sheets by modifying raw fibers with a magnetically modified wave-absorbing agent; Stacking the electrically modified fiber single sheets, the magnetically modified fiber single sheets and the high-temperature ablation-resistant reinforcing fibers according to the design goal to prepare a composite material preform; Pouring the composite material preform into a matrix resin to form a fiber-reinforced silicone resin composite material with integrated ablation resistance, heat insulation and wave absorption.

[0014] Application of an ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material, the ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material prepared by using the above ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material or the method is used for the stealth of aircrafts and ships and the electromagnetic radiation and interference prevention of buildings and equipment.

[0015] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects: (1) The modified fiber with a coated and modified layer on the outer periphery of the fiber prepared by the present invention has good process compatibility during preparation compared with the conventional method of laying wave-absorbing materials on the fiber surface, is not easy to delaminate, has strong designability, has the advantage of one-piece molding, and has high mechanical strength; compared with the conventional technology of dissolving wave-absorbing materials in matrix resin and reinforcing fibers to construct a relatively uniform wave-absorbing material, the present invention coats a coated and modified layer on the outer periphery of the fiber to form a regular and ordered wave-absorbing area, and at the same time forms regular and ordered refraction and reflection areas in the gaps between the fibers. Due to the different materials between the wave-absorbing area and the refraction and reflection areas, interfaces with different absorption rates are formed, which helps to improve the absorption effect, increase the absorption rate and absorption bandwidth, and at the same time improves the problems of poor dispersion uniformity and low production efficiency of wave-absorbing materials.

[0016] (2) By sequentially and alternately arranging electrically modified fiber single pieces and magnetically modified fiber single pieces and filling matrix resin between multiple modified fiber single pieces and between each modified fiber single piece, the present invention helps to form interfaces with different absorption rates and form ordered refraction, reflection areas and wave-absorbing areas. Due to the different materials between the refraction and reflection areas, interfaces with different absorption rates are formed, which helps to improve the absorption effect, increase the absorption rate and effective absorption bandwidth.

[0017] (3) By arranging a magnetically modified fiber single piece on the incident surface of the electrically modified fiber single piece, the present invention improves the impedance matching of the composite material, enables more electromagnetic waves to enter the material interior as much as possible, and increases the electromagnetic wave absorption rate.

[0018] (4) By dissolving the wave-absorbing material in a polar solvent to prepare a slurry and coating it on the outer surface of the fiber, the present invention improves the problem of poor dispersion uniformity of the wave-absorbing material in non-polar resin, and at the same time avoids the defect that the increase in the viscosity of the polymer resin makes it difficult to apply manufacturing processes such as resin transfer molding and impregnation, and improves the production efficiency and wave-absorbing effect.

[0019] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification, and some advantages can be made obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained from the content specifically pointed out in the specification and the drawings. Description of the Drawings

[0020] The accompanying drawings are only for the purpose of showing specific embodiments, and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference numerals denote the same components; Figure 1 It is a schematic structural diagram of a fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption prepared according to the present invention; Figure 2 It is a front physical diagram of a fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption prepared in Example 1; Figure 3 It is a test diagram of the initial reflectivity of the fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption in Example 1; Figure 4 It is a test diagram of the reflectivity of the fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption in Example 2 before and after the ablation test; Figure 5 It is a test diagram of the initial reflectivity of the fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption in Example 3; Figure 6 It is a test diagram of the reflectivity of the fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption in Example 4 before and after the ablation test; Figure 7 It is a test diagram of the initial reflectivity of the fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption in Example 1; Figure 8 It is a reverse physical diagram of a fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption prepared in Example 1.

[0021] Reference numerals 001 - Heat insulation area; 002 - Wave absorption area. Detailed embodiments

[0022] The following will specifically describe the preferred embodiments of the present invention with reference to the accompanying drawings, in which the accompanying drawings form a part of the present invention and are used together with the embodiments of the present invention to explain the principle of the present invention, and are not used to limit the scope of the present invention.

[0023] Term definition In the present invention, up and down refer to taking the incident direction of electromagnetic waves of the composite material as up, and stacking from top to bottom means stacking in sequence according to the incident direction of electromagnetic waves.

[0024] In the first aspect, the present invention provides a fiber-reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption integrated, as Figure 1 , Figure 2 and Figure 8 shown, including: a heat insulation area 001 and a wave absorption area 002 arranged in sequence from top to bottom; The wave-absorbing region includes magnetic modified fiber single sheets, and / or, electrically modified fiber single sheets; The electrically modified fiber single sheet includes electrically modified fibers with an electrically coated modification layer on the outer periphery and a matrix resin filled in the gaps between the electrically modified fibers; The magnetic modified fiber single sheet includes magnetic modified fibers with a magnetically coated modification layer on the outer periphery and a matrix resin filled in the gaps between the magnetic modified fibers.

[0025] During implementation, in the present invention, a coated modification layer is coated on the outer periphery of the fiber to form a regular and orderly wave-absorbing region, and at the same time, a regular and orderly refraction and reflection region is formed in the gaps between the fibers. Due to the different materials between the wave-absorbing region and the refraction and reflection region, an interface with different absorption rates is formed, which helps to improve the absorption effect, the absorption rate and the absorption bandwidth.

[0026] Compared with the prior art, the modified fibers with a coated modification layer coated on the outer periphery of the fibers prepared in the present invention have good process compatibility during preparation compared with the conventional laying of wave-absorbing materials on the fiber surface, are not easy to delaminate, have strong designability, have the advantage of integral molding, and have high mechanical strength; compared with the conventional technology of dissolving wave-absorbing materials in matrix resin and reinforcing fibers to construct a relatively uniform wave-absorbing material, in the present invention, a coated modification layer is coated on the outer periphery of the fiber to form a regular and orderly wave-absorbing region, and at the same time, a regular and orderly refraction and reflection region is formed in the gaps between the fibers. Due to the different materials between the wave-absorbing region and the refraction and reflection region, an interface with different absorption rates is formed, which helps to improve the absorption effect, the absorption rate and the absorption bandwidth, and at the same time improves the problems of poor dispersion uniformity and low production efficiency of the wave-absorbing material.

[0027] Preferably, the wave-absorbing region includes one or more magnetic modified fiber single sheets, and / or, one or more electrically modified fiber single sheets.

[0028] More preferably, the wave-absorbing region includes a plurality of magnetic modified fiber single sheets and a plurality of electrically modified fiber single sheets; the magnetic modified fiber single sheets and the electrically modified fiber single sheets are arranged at intervals in the order from the electromagnetic wave incident surface to the exit surface, and a magnetic modified fiber single sheet is provided between adjacent electrically modified fiber single sheets.

[0029] It should be noted that the applicant's research found that filling the matrix resin between each modified fiber single sheet and increasing the number of modified fiber single sheets in the electrically modified fiber single sheet and the magnetic modified fiber single sheet can increase the absolute value of the minimum reflection loss and the effective absorption bandwidth. This is because similar to filling the matrix resin in the gaps between the fibers, the stacking of multiple modified fiber single sheets and the filling of the matrix resin between each modified fiber single sheet both help to form regular and orderly refraction and reflection regions and wave-absorbing regions, and due to the different materials between the refraction and reflection regions, an interface with different absorption rates is formed, which helps to improve the absorption effect, the absorption rate and the effective absorption bandwidth.

[0030] Compared with the prior art, in the present invention, by sequentially and alternately arranging the electrically modified fiber single sheets and the magnetically modified fiber single sheets, and filling matrix resin between multiple modified fiber single sheets and between each modified fiber single sheet, it helps to form interfaces with different absorption rates and form ordered refraction and reflection regions and absorption regions. Due to different materials between the refraction and reflection regions, interfaces with different absorption rates are formed, which helps to improve the absorption effect, increase the absorption rate and the effective absorption bandwidth.

[0031] Specifically, the electrically coated modification layer includes an electrically modified wave-absorbing agent and necessary adhesives; the magnetically coated modification layer includes a magnetically modified wave-absorbing agent and necessary adhesives.

[0032] Specifically, the electrically modified wave-absorbing agent includes one or more of multi-walled carbon nanotubes (MWCNT), activated carbon (CB), highly conductive carbon black (Super P), reduced graphene oxide (RGO), or vapor-grown carbon fiber (VGCF).

[0033] Preferably, the electrically modified wave-absorbing agent is multi-walled carbon nanotubes (MWCNT), reduced graphene oxide (RGO), or a mixture of multi-walled carbon nanotubes (MWCNT) and vapor-grown carbon fiber (VGCF).

[0034] Further preferably, the electrically modified wave-absorbing agent is a mixture of multi-walled carbon nanotubes (MWCNT) and reduced graphene oxide (RGO).

[0035] Specifically, the mass ratio of the mixture of multi-walled carbon nanotubes (MWCNT) and reduced graphene oxide (RGO) is 0.8~1.2:1, and it can be 0.8:1, 0.82:1, 0.84:1, 0.85:1, 0.88:1, 0.9:1, 0.92:1, 0.94:1, 0.95:1, 0.96:1, 0.98:1, 1:1, 1.04:1, 1.05:1, 1.06:1, 1.08:1, 1.10:1, 1.12:1, 1.14:1, 1.15:1, 1.18:1, or 1.20:1.

[0036] Preferably, the mass ratio of the mixture of multi-walled carbon nanotubes (MWCNT) and reduced graphene oxide (RGO) is 1:1.

[0037] Specifically, the magnetically modified wave-absorbing agent includes metal oxides composed of one or more of iron, cobalt, and nickel, or alloys composed of two or more of iron, cobalt, and nickel.

[0038] Specifically, the average particle size of the magnetic modified wave-absorbing agent is 1 μm to 10 μm, which can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm; the average particle size of the electrically modified wave-absorbing agent is 20 nm to 100 μm (for irregularly shaped particles, the particle size is taken as the diameter of the circumscribed sphere).

[0039] Preferably, the average particle size of the magnetic modified wave-absorbing agent is 3 μm to 5 μm; the average particle size of the electrically modified wave-absorbing agent is 50 nm to 50 μm.

[0040] Specifically, the average particle sizes of the magnetic modified wave-absorbing agent and the electrically modified wave-absorbing agent are within the above ranges, are evenly dispersed, and are not prone to agglomeration.

[0041] The described binder includes one or more of polyacrylonitrile or methyl methacrylate.

[0042] Specifically, the mass percentage of the magnetic modified wave-absorbing agent in the magnetic modified fiber single sheet is 20 - 50%, the mass percentage of the fiber is 20% to 30%, and the rest is the binder and the matrix resin.

[0043] Preferably, when the wave-absorbing area includes multiple magnetic modified fiber single sheets, the content of the magnetic modified wave-absorbing agent in the multiple magnetic modified fiber single sheets arranged in the order from the electromagnetic wave incident surface to the outgoing surface increases.

[0044] Further preferably, the increase in the content of the magnetic modified wave-absorbing agent in adjacent magnetic modified fiber single sheets satisfies: the mass percentage of the magnetic modified wave-absorbing agent in adjacent magnetic modified fiber single sheets increases by 3% to 5%.

[0045] Specifically, the mass percentage of the electrically modified wave-absorbing agent in the electrically modified fiber single sheet is 1% to 8%, the mass percentage of the fiber is 20% to 30%, and the rest is the matrix resin and the binder.

[0046] Preferably, when the wave-absorbing area includes multiple electrically modified fiber single sheets, the content of the electrically modified wave-absorbing agent in the multiple electrically modified fiber single sheets arranged in the order from the electromagnetic wave incident surface to the outgoing surface increases.

[0047] Further preferably, the increase in the content of the electrically modified wave-absorbing agent in adjacent electrically modified fiber single sheets satisfies: the mass percentage of the electrically modified wave-absorbing agent in adjacent electrically modified fiber single sheets increases by 0.5% to 2%.

[0048] Specifically, the thickness of the single piece of electrically modified fiber is 2 mm to 5 mm, and it can be 2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 4.0 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm or 5.0 mm; the thickness of the single piece of magnetically modified fiber is 1 mm to 5 mm, and it can be 1 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 4.0 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm or 5.0 mm.

[0049] Preferably, a single piece of magnetically modified fiber is provided on the incident surface of the single piece of electrically modified fiber, and the incident electromagnetic wave enters the single piece of electrically modified fiber after passing through at least one layer of magnetically modified fiber.

[0050] It should be noted that providing a single piece of magnetically modified fiber on the incident surface of the single piece of electrically modified fiber can effectively improve the impedance matching of the material, enabling as much electromagnetic wave as possible to enter the interior of the material.

[0051] Compared with the prior art, in the present invention, by providing a single piece of magnetically modified fiber on the incident surface of the single piece of electrically modified fiber, the impedance matching of the composite material is improved, enabling as much electromagnetic wave as possible to enter the interior of the material, and the electromagnetic wave absorption rate is increased.

[0052] Preferably, the electrically absorbing layer has 1 to 3 layers, and the magnetically absorbing layer has 1 to 3 layers; More preferably, when the single piece of electrically modified fiber and the single piece of magnetically modified fiber exist simultaneously, the total number of the single piece of electrically modified fiber and the single piece of magnetically modified fiber ≤ 3.

[0053] More preferably, when the single piece of electrically modified fiber and the single piece of magnetically modified fiber exist simultaneously, the single piece of magnetically modified fiber has 1 layer, and the single piece of electrically modified fiber has two layers.

[0054] It should be noted that the multi-layer structure in which the single piece of electrically modified fiber and the single piece of magnetically modified fiber are arranged at intervals can have multiple interfaces with different electromagnetic parameters inside the material, forming multiple interfacial polarizations. At the same time, it can also cause multiple reflections of the electromagnetic wave, increasing the dissipation path of the electromagnetic wave in the wave-absorbing body, thereby enhancing the absorption of the electromagnetic wave; however, the number of layers of the single piece of electrically modified fiber and the single piece of magnetically modified fiber is not the more the better. When the electrically modified fiber has 1 to 3 layers; the magnetically modified fiber has 1 to 3 layers, it has a better effect; when the single piece of electrically modified fiber and the single piece of magnetically modified fiber exist simultaneously, the single piece of magnetically modified fiber has 1 layer, and the single piece of electrically modified fiber has two layers, which is conducive to obtaining a larger effective absorption bandwidth.

[0055] Specifically, the heat insulation layer is composed of high-temperature ablation-resistant reinforcing fibers and a matrix resin filled in the gaps between the high-temperature ablation-resistant reinforcing fibers.

[0056] Preferably, a transition medium layer is provided between the heat insulation area and the wave absorption area, and between adjacent electrically modified fiber single sheets and magnetically modified fiber single sheets.

[0057] Specifically, the transition medium layer is composed of reinforcing fibers and a matrix resin filled in the gaps between the reinforcing fibers.

[0058] Specifically, the heat insulation area, the electrically modified fiber single sheet, the magnetically modified fiber single sheet, and the transition medium layer can use the same matrix resin as the filling and molding resin.

[0059] Specifically, the matrix resin is a nanoporous silicone resin.

[0060] Specifically, the raw materials of the nanoporous silicone resin include polysiloxane, silane monomer / silane prepolymer, and an alkaline catalyst, and are prepared under the conditions of a curing temperature of 80°C to 100°C and a time of 24 h to 48 h.

[0061] Specifically, the high-temperature ablation-resistant reinforcing fibers, reinforcing fibers, and modified fiber single sheets can be in the form of fiber cloth or fiber web; the areal density of the fiber web is 0.40 g / cm 2 ~0.85 g / cm 2 , and can be 0.40 g / cm 2 , 0.42 g / cm 2 , 0.43g / cm 2 , 0.46 g / cm 2 , 0.48 g / cm 2 , 0.50 g / cm 2 , 0.52 g / cm 2 , 0.55 g / cm 2 , 0.56 g / cm 2 , 0.58 g / cm 2 , 0.60 g / cm 2 , 0.64g / cm 2 , 0.66g / cm 2 , 0.68 g / cm 2 , 0.70 g / cm 2 , 0.74g / cm 2 , 0.76g / cm 2 , 0.78 g / cm 2 , 0.80 g / cm 2 or 0.84 g / cm 2 .

[0062] The areal density of the fiber cloth is 0.9 g / cm 2 ~1.5 g / cm 2 , and can be 0.9 g / cm2 、1.0 g / cm 2 、1.1 g / cm 2 、1.2 g / cm 2 、1.3 g / cm 2 、1.4 g / cm 2 or 1.5 g / cm 2 。

[0063] Preferably, the areal density of the fibrous web tread is 0.50 g / cm 2 ~0.70 g / cm 2 , and the areal density of the fibrous cloth is 0.9 g / cm 2 ~1.2 g / cm 2 。

[0064] It should be noted that if the areal density is too large, the voids between the fibers will decrease, reducing the reflection and absorption of electromagnetic waves in the material; if the areal density is too small, it will be difficult to meet the strength requirements.

[0065] Specifically, the thickness range of the modified fiber single sheet in the electrically modified fiber single sheet and the magnetically modified fiber single sheet is 0.2 mm to 0.5 mm, and it can be 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm; the amount of coating slurry on the modified fiber single sheet is 400 g / m 2 ~900 g / m 2 , and it can be 400 g / m 2 , 420 g / m 2 , 480 g / m 2 , 500 g / m 2 , 510 g / m 2 , 560 g / m 2 , 580 g / m 2 , 600 g / m 2 , 620 g / m 2 , 640 g / m 2 , 660 g / m 2 , 680 g / m 2 , 700 g / m 2 , 720 g / m 2 , 740 g / m 2 , 790 g / m 2 , 800 g / m 2 , 820 g / m 2 , 840 g / m 2 , 860 g / m 2 , 880 g / m 2 or 900 g / m 2 。

[0066] The diameter range of the original fibers in the modified fibers is 5 μm to 10 μm, and it can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

[0067] Specifically, the fibers in the high-temperature ablation-resistant reinforcing fibers, reinforcing fibers, and modified fiber single sheets can be any one of quartz fibers, silicon carbide fibers, glass fibers, and high-silica fibers.

[0068] Preferably, each fiber layer is connected by knitting. The knitting material is quartz fiber, and the knitting density is 10 stitches / cm 2 ~20 stitches / cm 2 , which can provide sufficient connection strength for each fiber layer.

[0069] It should be noted that when the amount of the slurry coated on the modified fiber single sheet is within the above range, it helps to form regular and orderly refraction and reflection regions with appropriate sizes in the gaps between the fiber surface density matches, which helps to improve the absorption effect, absorption rate, and absorption bandwidth.

[0070] Specifically, the mass percentage of the magnetic modification wave-absorbing agent in the magnetic modified fiber single sheet is 20 - 50%, the mass percentage of the fiber is 20% - 30%, and the rest is the matrix resin.

[0071] Preferably, the thickness ratio of the electrically modified fiber single sheet to the magnetic modified fiber single sheet is (1 - 2):1.5.

[0072] It should be noted that the electrically modified fiber single sheet and the magnetic modified fiber single sheet within this thickness range improve the impedance matching of the composite material, enable as much electromagnetic wave as possible to enter the material interior, and improve the electromagnetic wave absorption rate and absorption bandwidth.

[0073] Specifically, the thickness of the transition medium layer is 2 mm to 10 mm, and the thickness of the heat insulation region is 10 mm to 15 mm; the thickness of the wave absorption region varies according to the number of magnetic modified fiber single sheets and electrically modified fiber single sheets.

[0074] On the other hand, the present invention provides a preparation method for an ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material, including: Preparing an electrically modified fiber single sheet by modifying the original fibers with an electrically modified wave-absorbing agent; Preparing a magnetic modified fiber single sheet by modifying the original fibers with a magnetic modified wave-absorbing agent; Stacking the electrically modified fiber single sheet, the magnetic modified fiber single sheet, and the high-temperature ablation-resistant reinforcing fibers according to the design target to prepare a composite material preform; Pouring the composite material preform into the matrix resin for molding to prepare an ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material.

[0075] Specifically, a preparation method of an ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material includes: S1: Weigh an appropriate amount of electrically modified wave-absorbing agent and binder according to the ratio, add a solvent and mix to form an electrically modified wave-absorbing slurry; weigh an appropriate amount of magnetically modified wave-absorbing agent and binder according to the ratio, add a solvent and mix to form a magnetically modified wave-absorbing slurry; S2: Coating the electrically modified wave-absorbing slurry on a single fiber sheet by spraying or brushing process, and drying to obtain an electrically modified single fiber sheet; coating the magnetically modified wave-absorbing slurry on a single fiber sheet, and drying to obtain a magnetically modified single fiber sheet; S3: Arrange and stack the electrically modified single fiber sheet, magnetically modified single fiber sheet and high-temperature ablation-resistant reinforcing fiber in S2, and pour in the matrix resin to mold and prepare the ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material.

[0076] During implementation, step S3 includes: S301: Vertically stitch the electrically modified single fiber sheet, magnetically modified single fiber sheet and high-temperature ablation-resistant reinforcing fiber in the plane of the single fiber sheet to form a fiber preform; S302: Place the fiber preform in a mold, pressurize and pour the matrix resin into the mold, cure and dry in a high-temperature environment to obtain the ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material.

[0077] During implementation, the mass ratio of the electrically modified wave-absorbing agent to the binder in the electrically modified wave-absorbing slurry is (4~20):1; the mass ratio of the magnetically modified wave-absorbing agent to the binder in the magnetically modified wave-absorbing slurry is (30~50):1; the usage amount of the solvent relative to the solid components in the electrically modified wave-absorbing agent slurry and the magnetically modified wave-absorbing agent slurry is 300 ml / kg ~500 ml / kg.

[0078] Compared with the prior art, the present invention improves the problem of poor dispersion uniformity of the wave-absorbing material in the non-polar resin by dissolving the wave-absorbing material in a polar solvent to prepare a slurry and coating it on the outer surface of the fiber, and at the same time avoids the defect that the increase in the viscosity of the polymer resin makes it difficult to apply manufacturing processes such as resin transfer molding and impregnation, and improves the production efficiency and wave-absorbing effect.

[0079] The binder includes one or more of polyacrylonitrile or methyl methacrylate.

[0080] It should be noted that the mass ratio of the electrically modified wave-absorbing agent to the binder, the mass ratio of the magnetically modified wave-absorbing agent to the binder, and the usage amount of the solvent relative to the solid components in the electrically modified wave-absorbing agent slurry and the magnetically modified wave-absorbing agent slurry within the above ranges help to form regular and orderly refraction and reflection regions with appropriate sizes in the gaps between the fibers, which helps to improve the absorption effect, absorption rate and absorption bandwidth.

[0081] The solvent described above includes one of N,N-dimethylformamide, N-methylpyrrolidone, or N-ethylpyrrolidone.

[0082] Furthermore, in step S302, the curing temperature and time in the high-temperature environment are 60°C to 100°C and 12 h to 48 h respectively.

[0083] Thirdly, an application of the ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material as described above. This composite material is applied in the field of electromagnetic wave absorption and can be specifically used for the stealth of aircrafts, ships, etc. and the prevention of electromagnetic radiation and interference in buildings and equipment.

[0084] To better illustrate the present invention, the following examples and comparative examples are set:

[0085] Example 1 This example discloses an ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material and its preparation method. The specific preparation steps are as follows: S1: Weigh 1 g of methyl methacrylate and add it to 400 ml of N,N-dimethylformamide. Stir it fully at room temperature to dissolve. Weigh 2.5 g of a mixture of multi-walled carbon nanotubes (MWCNT) and reduced graphene oxide (RGO) with a mass ratio of 1:1 and add it to the above solution in portions. Ultrasonic for 10 - 15 min to disperse it evenly, and stir fully until a suspension is formed to obtain an electrically modified wave-absorbing slurry; the average particle size of the electrically modified wave-absorbing agent is 100 nm.

[0086] S2: Weigh 25 g of the above slurry each time and evenly disperse it onto a single-piece quartz fiber web through a spraying process. Change the addition amount of the mixture of multi-walled carbon nanotubes (MWCNT) and reduced graphene oxide (RGO) with a mass ratio of 1:1 to prepare a series of electrically modified fiber single-pieces, electrically modified fiber single-piece 1, electrically modified fiber single-piece 2, and electrically modified fiber single-piece 3. The mass percentages of the electrically modified wave-absorbing agent in the electrically modified fiber single-pieces are 1%, 2%, and 3% respectively, the fiber mass percentage is 20%, and the rest are the binder methyl methacrylate and silicone resin; then put the above electrically modified fiber single-pieces into an 80°C oven and dry for 10 h to obtain electrically modified quartz fibers; the average diameter of the original fibers in the modified fibers is 10 μm, the areal density of the quartz fiber single-piece is 0.27 g / cm 3 , the thickness of the electrically modified fiber single-piece is 0.2 mm, and the amount of the slurry coated on the modified fiber single-piece is 500 g / m 2 .

[0087] S3: Take the above electrically modified quartz fiber single-pieces and lay them in layers in turn with a thickness of 8 mm and an areal density of 0.27 g / cm 3Stacked in the order of a quartz fiber layer (heat insulation area), a 6-mm-thick quartz fiber needled web layer (transition medium layer), electro-modified fiber single sheet 1, electro-modified fiber single sheet 2, and electro-modified fiber single sheet 3, with the thickness of the electro-modified fiber single sheet being 2 mm; connected into a fiber preform through a stitching process, and the knitting density is 20 stitches / cm 2 Lay the fiber preform in a mold of 330 mm×330 mm×5 mm, pressurize and pour silicone resin until the fiber preform is completely impregnated with the silicone resin solution, and then seal the mold. Place the above-mentioned poured mold in an oven at 100 °C for curing for 24 h, and then dry it in an environment at 80 °C for 12 h; the silicone resin is nano-porous silicone resin; the nano-porous silicone resin is prepared from a polysiloxane with a polymerization degree of 1000 and a silane monomer according to a molar ratio of 1:100 and an appropriate amount of alkaline catalyst, and is prepared under the conditions of a curing temperature of 80 °C to 100 °C and a curing time of 24 h to 48 h.

[0088] Figure 2 Figure of the ablative-resistant, heat-insulating / wave-absorbing integrated fiber-reinforced silicone resin composite prepared in this example, with the material density being 0.54 kg / m 3 , and the room-temperature thermal conductivity being 0.048 .

[0089] According to GB / T 42741-2023, the complex conductivity constant and complex permeability of the ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite prepared in this example were tested in the range of 2 GHz to 18 GHz by the free space method; the material was cut into a flat plate of 300 mm×300 mm×5 mm; according to the transmission line theory, the reflection loss of the wave-absorbing composite material at different thicknesses can be calculated using formulas (1) and (2).

[0090] Formula (1): , where is the self-space impedance, approximately 377 Ω, is the input impedance.

[0091] Formula (2): , where is the complex conductivity constant, is the complex permeability, j represents the imaginary part, f is the frequency, d is the sample thickness, and c is the speed of light.

[0092] According to the calculation, the reflectivity curve is shown in Figure 3 , with the minimum reflectivity of -43.8 dB and the effective absorption bandwidth of 11.0 GHz, having excellent wave-absorbing performance. After the material is ablated at 800 °C for 1 h, the minimum reflectivity is -38.1 dB and the effective absorption bandwidth is 8.2 GHz, still having excellent wave-absorbing performance.

[0093] Example 2 This example discloses an ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material and its preparation method. The specific preparation steps are as follows: The difference from Example 1 is that in S3, according to the incident direction of electromagnetic waves, a 10 mm thick 2.5D woven quartz fiber layer (heat-insulating area), a 10 mm thick quartz fiber needle-punched web layer (transition medium layer), electro-modified fiber single piece 1, a 2 mm thick quartz fiber needle-punched web layer (transition medium layer), electro-modified fiber single piece 2, a 2 mm thick quartz fiber needle-punched web layer (transition medium layer), electro-modified fiber single piece 3, and a 5 mm thick quartz fiber needle-punched web layer (transition medium layer) are sequentially laid. The fiber layers are connected by a layer-by-layer needle-punching process to obtain a fiber preform with a total thickness of 35 mm. The fiber preform is laid in a mold of 330mm×330mm×5mm, and organosilicon resin is pressure-impregnated until the fiber preform is completely impregnated with the organosilicon resin solution, and then the mold is sealed. The above-mentioned impregnated mold is placed in an oven at 100°C for curing for 24 h, and then dried in an environment at 80°C for 12 h; the organosilicon resin is the same nanoporous organosilicon resin as in Example 1, and the rest is the same as in Example 1.

[0094] Performance test: The density of the prepared ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material is 0.62 g / cm 3 , and the room-temperature thermal conductivity is 0.050 , calculated according to the method in Example 1, the reflectivity curve is shown in Figure 4 , the minimum reflectivity is -28.2 dB, the effective absorption bandwidth is 12.7 GHz, and it has excellent wave-absorbing performance.

[0095] The material is treated by ablation at 800°C for 1 h, and the reflectivity curve after ablation is shown in Figure 4 , the minimum reflectivity is -28.1 dB, the effective absorption bandwidth is 9.3 GHz, and it still has excellent wave-absorbing performance.

[0096] Example 3 This example discloses an ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material and its preparation method. The specific preparation steps are as follows: S1: Weigh 1 g of methyl methacrylate and add it to 400 ml of N,N-dimethylformamide, and stir it fully at room temperature to dissolve it. Weigh 95 g of carbonyl iron magnetic alloy powder and add it to the above solution in portions, and mechanically stir until a suspension is formed to obtain a magnetically modified wave-absorbing slurry; the average particle size of the magnetically modified wave-absorbing agent is 5 μm.

[0097] S2: Weigh 25 g of the above-mentioned slurry each time, and evenly disperse it onto a single-piece quartz fiber web through a spraying process. By changing the addition amount of the magnetic-modified wave-absorbing slurry, a series of magnetic-modified fiber single pieces, namely magnetic-modified fiber single piece 1 and magnetic-modified fiber single piece 2, are prepared. The mass percentages of the magnetic-modified wave-absorbing agent in the electrically modified fiber single pieces are 20% and 25% respectively, the fiber mass percentage is 20%, and the rest are the binder methyl methacrylate and silicone resin. Then, place the above-mentioned magnetic-modified fiber single pieces in an 80°C oven and dry them for 10 h to obtain magnetic-modified quartz fibers. The average diameter of the original fibers in the modified fibers is 10 μm, the surface density of the quartz fiber single piece is 0.27 g / cm 3 , the thickness of the magnetic-modified fiber single piece is 0.2 mm, and the amount of the coated slurry on the modified fiber single piece is 600 g / m 2 .

[0098] S3: Take the above-mentioned electrically modified quartz fiber single pieces, and lay a 10-mm-thick 2.5D braided quartz fiber layer (heat insulation area), a 9-mm-thick quartz fiber needle-punched web layer (transition medium layer), magnetic-modified fiber single piece 1, and magnetic-modified fiber single piece 2 in sequence and stack them. The thickness of the magnetic-modified fiber single piece is 2 mm. Connect them into a 25-mm fiber preform through a stitching process, and the knitting density is 10 stitches / cm 3 . Place the fiber preform in a mold of 330 mm × 330 mm × 5 mm, and pressure-impregnate it with silicone resin until the fiber preform is completely impregnated with the silicone resin solution, and then seal the mold. Place the above-mentioned impregnated mold in a 100°C oven and cure it for 24 h, and then dry it in an 80°C environment for 12 h; the silicone resin is nanoporous silicone resin; the nanoporous silicone resin is prepared from a polysiloxane with a polymerization degree of 1000 and a silane monomer in a molar ratio of 1:100 and an appropriate amount of alkaline catalyst, and is prepared under the conditions of a curing temperature of 80°C to 100°C and a curing time of 24 h to 48 h. 2 Figure

[0099] Figure 2 is a physical picture of the ablative-resistant, heat-insulating / wave-absorbing integrated fiber-reinforced silicone resin composite prepared in this example, and the material density is 0.54 kg / m 3 , and the room-temperature thermal conductivity is 0.048 .

[0100] According to GB / T 42741-2023, the complex conductivity constant and complex permeability of the ablative-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite prepared in this example were tested in the range of 2 GHz to 18 GHz by the free space method.

[0101] Calculated according to the method of Example 1, the reflectivity curve is shown in Figure 5, the density of the prepared ablative-resistant, heat-insulating / electromagnetic wave absorbing integrated fiber-reinforced silicone resin composite is 0.66 g / cm 3 , and the thermal conductivity at room temperature is 0.068 , the minimum reflectivity is -29.0 dB, and the effective absorption bandwidth is 8.5 GHz. After the material is treated at 800 °C for 1 h, the minimum reflectivity is -26.1 dB, and the effective absorption bandwidth is 6.2 GHz, still having excellent electromagnetic wave absorbing performance.

[0102] Example 4 This example discloses an ablative-resistant, heat-insulating and electromagnetic wave absorbing integrated fiber-reinforced silicone resin composite and its preparation method. The difference from Example 3 is that in step S3, in the direction of electromagnetic wave incidence, a 10 mm thick 2.5D braided quartz fiber layer (heat-insulating area), an 8 mm thick quartz fiber needle punched web layer (transition medium layer), magnetic modified fiber single sheet 1, a 2 mm thick quartz fiber needle punched web layer (transition medium layer), magnetic modified fiber single sheet 2, a 2 mm thick quartz fiber needle punched web layer (transition medium layer), electrically modified fiber single sheet 1 (prepared in Example 1), and a 2 mm thick quartz fiber needle punched web layer (transition medium layer) are sequentially laid. The fiber layers are connected by the same stitching process as in Example 3 to obtain a fiber preform with a total thickness of 30 mm, and the rest is the same as in Example 3.

[0103] Performance test: The density of the prepared ablative-resistant, heat-insulating / electromagnetic wave absorbing integrated fiber-reinforced silicone resin composite is 0.65 g / cm 3 , and the thermal conductivity at room temperature is 0.063 , calculating the minimum reflectivity -27.2 dB and the effective absorption bandwidth 11.4 GHz according to the method in Example 1. The reflectivity curve is shown in Figure 6 .

[0104] After the composite material is ablated at 800 °C for 1 h, the reflectivity curve after ablation is shown in Figure 6 , the minimum reflectivity is -27.3 dB, and the effective absorption bandwidth is 6.9 GHz, still having good electromagnetic wave absorbing performance.

[0105] Example 5 This example discloses an ablative-resistant, heat-insulating and electromagnetic wave absorbing integrated fiber-reinforced silicone resin composite and its preparation method. The difference from Example 3 is that in step S3, in the direction of electromagnetic wave incidence, Layering in sequence a 15-mm-thick 2.5D braided quartz fiber layer (heat insulation area), a 10-mm-thick quartz fiber needle-punched web layer (transition medium layer), magnetic modified fiber single sheet 2, a 2-mm-thick quartz fiber needle-punched web layer (transition medium layer), electrically modified fiber single sheet 1, a 2-mm-thick quartz fiber needle-punched web layer (transition medium layer), electrically modified fiber single sheet 2, and a 2-mm-thick quartz fiber needle-punched web layer (transition medium layer), and connecting each fiber layer through a stitching process to obtain a fiber preform with a total thickness of 35 mm, and the rest is the same as in Example 3.

[0106] Performance test: The density of the prepared ablation-resistant, heat-insulating / absorbing-wave integrated fiber-reinforced silicone resin composite material is 0.68 g / cm 3 , and the room-temperature thermal conductivity is 0.059 , the minimum reflectivity is -35.4 dB, the effective absorption bandwidth is 12.6 GHz, and the reflectivity curve is shown in Figure 7 .

[0107] The composite material is subjected to ablation treatment at 800 °C for 1 h, the minimum reflectivity is -30.3 dB, the effective absorption bandwidth is 10.9 GHz, and it still has excellent wave-absorbing performance and thermal stability.

[0108] Example 6 This example discloses an ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material and its preparation method. The difference from Example 5 is that: the average particle size of the magnetic modified wave-absorbing agent is 5 μm; the average particle size of the electrically modified wave-absorbing agent is 150 nm; the mass percentage of the magnetic modified wave-absorbing agent in the magnetic modified fiber single sheet is 50%; the mass percentages of the electrically modified wave-absorbing agent in the two electrically modified fiber single sheets used are 2% and 6% respectively, and the rest is the same as in Example 5.

[0109] Performance test: The density of the prepared ablation-resistant, heat-insulating / absorbing-wave integrated fiber-reinforced silicone resin composite material is 0.69 g / cm 3 , and the room-temperature thermal conductivity is 0.058 , the minimum reflectivity is -35.1 dB, the effective absorption bandwidth is 12.4 GHz, and the reflectivity curve is shown in Figure 7 .

[0110] The composite material is subjected to ablation treatment at 800 °C for 1 h, the minimum reflectivity is -30.1 dB, the effective absorption bandwidth is 10.5 GHz, and it still has excellent wave-absorbing performance and thermal stability.

[0111] Example 7 This embodiment discloses a fiber - reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption integration and its preparation method. The difference from Embodiment 5 is that only one electrically modified fiber single - sheet is used, the electrically modified fiber single - sheet 2 is removed, and only the electrically modified fiber single - sheet 1 is retained, so that the thickness of the transition dielectric layer below the electrically modified fiber single - sheet 1 increases, while the total thickness of the composite material remains unchanged.

[0112] Performance test: The density of the prepared ablation - resistant, heat - insulating / wave - absorbing integrated fiber - reinforced silicone resin composite material is 0.69 g / cm 3 , and the room - temperature thermal conductivity is 0.058 , the minimum reflectivity is - 32.0 dB, the effective absorption bandwidth is 10.9 GHz, and the reflectivity curve is shown in Figure 7 .

[0113] The composite material is subjected to ablation treatment at 800 °C for 1 h. The minimum reflectivity is - 28.1 dB, and the effective absorption bandwidth is 9.5 GHz. The wave - absorbing performance and thermal stability are significantly reduced compared with Embodiment 5.

[0114] Embodiment 8 This embodiment discloses a fiber - reinforced silicone resin composite material with ablation resistance, heat insulation and wave absorption integration and its preparation method. The difference from Embodiment 5 is that the electrically modified fiber single - sheet uses conductive graphite; the magnetically modified fiber single - sheet uses an iron - cobalt alloy with a mass ratio of 1:1.

[0115] Performance test: The density of the prepared ablation - resistant, heat - insulating / wave - absorbing integrated fiber - reinforced silicone resin composite material is 0.69 g / cm 3 , and the room - temperature thermal conductivity is 0.058 , the minimum reflectivity is - 34.2 dB, the effective absorption bandwidth is 12.4 GHz, and the reflectivity curve is shown in Figure 7 .

[0116] The composite material is subjected to ablation treatment at 800 °C for 1 h. The minimum reflectivity is - 28.6 dB, and the effective absorption bandwidth is 10.2 GHz. It still has excellent wave - absorbing performance and thermal stability.

[0117] Comparing Examples 1 - 8, it can be seen that the ablation - resistant, heat - insulating and wave - absorbing integrated fiber - reinforced silicone resin composite material prepared by the present invention uses electrically modified fiber single - sheets in the electric wave - absorbing layer and magnetically modified fiber single - sheets in the magnetic wave - absorbing layer, which are arranged in an alternating laminated manner. The number of electrically modified fiber single - sheets in the electric wave - absorbing layer and magnetically modified fiber single - sheets in the magnetic wave - absorbing layer is 1 - 2. The thickness of the electrically modified fiber single - sheets in the electric wave - absorbing layer is 2 mm - 3 mm, and the thickness of the magnetically modified fiber single - sheets in the magnetic wave - absorbing layer is 2 mm - 3 mm. The initial minimum reflectivity ≤ - 29.0 dB, and the initial effective absorption bandwidth ≥ 8.5 GHz; preferably, the initial minimum reflectivity ≤ - 30.1 dB, and the initial effective absorption bandwidth ≥ 10.5 GHz.

[0118] After ablation treatment at 800 °C for 1 h, the minimum reflectivity ≤ -26.1 dB and the effective absorption bandwidth ≥ 6.2 GHz; preferably, the initial minimum reflectivity ≤ -30.1 dB and the initial effective absorption bandwidth ≥ 10.5 GHz.

[0119] Comparing with Comparative Examples 1-4, it can be seen that adding a transition dielectric layer between each absorbing layer can increase multiple interfaces inside the material, causing multiple reflections of electromagnetic waves, thereby effectively enhancing the absorption of electromagnetic waves and broadening the absorption frequency band.

[0120] Comparing with Comparative Examples 1-8, by setting a magnetically modified fiber single sheet on the incident surface of the electrically modified fiber single sheet, the impedance matching of the composite material is improved, enabling as much electromagnetic wave as possible to enter the material interior, and enhancing the electromagnetic wave absorption rate; increasing the number of modified fiber single sheets in the electrically modified fiber single sheet and the magnetically modified fiber single sheet can increase the absolute value of the minimum reflection loss and the effective absorption bandwidth.

[0121] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material, characterized in that: include: The heat insulation area and the wave absorbing area are arranged sequentially from top to bottom; The wave absorbing region includes a magnetically modified fiber monolith and / or an electrically modified fiber monolith; The electrically modified fiber monolith comprises an electrically modified fiber coated with an electrically coated modified layer on the periphery and a matrix resin filled in the gaps between the electrically modified fibers; The magnetic modified fiber monolith comprises magnetic modified fibers with a magnetic coating modification layer coated on the periphery and a matrix resin filled in the gaps of the magnetic modified fibers.

2. The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to claim 1, characterized in that: The absorbing region includes one or more magnetically modified fiber monoliths, and / or one or more electrically modified fiber monoliths.

3. The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to claim 2, characterized in that: The wave absorbing region includes a plurality of magnetically modified fiber monoliths and a plurality of electrically modified fiber monoliths; The magnetically modified fiber sheets and the electrically modified fiber sheets are arranged in sequence from the electromagnetic wave incident surface to the emitting surface, and the magnetically modified fiber sheets are arranged between adjacent electrically modified fiber sheets.

4. The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to claim 3, characterized in that: The incident surface of the electrically modified fiber monolith is provided with a magnetically modified fiber monolith, and the incident electromagnetic wave is incident into the electrically modified fiber monolith after passing through at least one layer of the magnetically modified fiber monolith.

5. The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to claim 3 or 4, characterized in that: When the wave absorbing region includes a plurality of magnetically modified fiber monoliths, the content of the magnetically modified wave absorbing agent in the plurality of magnetically modified fiber monoliths sequentially arranged from the electromagnetic wave incident surface to the emitting surface increases gradually.

6. The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to claim 5, characterized in that: The increasing content of the magnetically modified absorber in adjacent magnetically modified fiber sheets satisfies: the mass percentage of the magnetically modified absorber in adjacent magnetically modified fiber sheets increases by 3% to 5%.

7. The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to claim 3 or 4, characterized in that: When the wave absorbing zone includes a plurality of electrically modified fiber monoliths, the content of the electrically modified wave absorbing agent in the plurality of electrically modified fiber monoliths sequentially arranged from the electromagnetic wave incident surface to the emitting surface increases gradually.

8. The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to claim 7, characterized in that: The increasing content of the electrically modified absorber in adjacent electrically modified fiber monoliths satisfies: the mass percentage of the electrically modified absorber in adjacent electrically modified fiber monoliths increases by 0.5% to 2%.

9. A method for preparing an ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material, characterized in that: Used to prepare the ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material according to any one of claims 1 to 8, comprising: Using an electrically modified absorber to modify the original fiber to prepare an electrically modified fiber monolith; Using magnetically modified absorbent to modify original fibers to prepare magnetically modified fiber monoliths; The electrically modified fiber monolith, the magnetically modified fiber monolith and the high temperature resistant ablation reinforced fiber are stacked according to the design target to prepare a composite material preform; The composite material preform is poured into the matrix resin for molding to prepare the ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material.

10. An application of an ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material, characterized in that: The ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material described in any one of claims 1 to 8 or the ablation-resistant, heat-insulating and wave-absorbing integrated fiber-reinforced silicone resin composite material prepared by the preparation method described in claim 9 is used for stealth of aircraft and ships and for protection of buildings and equipment from electromagnetic radiation and interference.

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