Broadband stealth shielding composite, method of making and use

Abstract

The embodiment of the application discloses a broadband stealth shielding composite material, a preparation method and application; the composite material is an integrated structure material formed by sequentially compositing a metasurface layer, a magnetized carbon fiber wave absorbing layer and a reflection layer; wherein, the metasurface layer comprises periodic metal structure units; the magnetized carbon fiber wave absorbing layer is prepared from magnetized carbon fibers and has a gradient porous structure in the thickness direction; and the reflection layer is a polymer fiber layer formed by polymer fibers plated with a metal layer. The metasurface layer of the composite material can reduce reflected energy through a phase cancellation mechanism, can adjust the reflection amplitude and phase of the metasurface to enhance scattering and expand the wave absorbing bandwidth; the magnetized carbon fiber wave absorbing layer with the gradient porous structure can effectively dissipate electromagnetic waves propagating in the structure, and has good wave absorbing effect; and the composite material can be used to manufacture a stealth shielding structure unit, and has good application prospect in improving the stealth shielding performance of weapon equipment.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to broadband stealth shielding composite materials and their preparation methods. Background Technology

[0002] With the rapid development of communication and detection technologies in the ground-to-air, air-to-air, and sea-to-air domains, stealth is of paramount importance to the combat capabilities and battlefield survivability of weapons and equipment. There is an urgent need for broadband stealth materials with good practical value; broadband refers to frequencies in the 2-18 GHz range. Summary of the Invention

[0003] In view of this, some embodiments disclose broadband stealth shielding composite materials, which are integrated structural materials formed by sequentially compositing a metasurface layer, a magnetized carbon fiber absorbing layer, and a reflective layer; wherein, the metasurface layer contains periodic metal structural units; the magnetized carbon fiber absorbing layer is made of magnetized carbon fibers and has a gradient porous structure in its thickness direction; the reflective layer is a polymer fiber layer made of polymer fibers with a metal layer coated on the surface.

[0004] Furthermore, some embodiments disclose broadband stealth shielding composite materials, in which the magnetized carbon fiber absorbing layer includes multiple magnetized carbon fiber meshes stacked sequentially, each magnetized carbon fiber mesh having a porous array, and the porous arrays of the sequentially stacked magnetized carbon fiber meshes being arranged in a gradient with each other to form a gradient porous structure.

[0005] Some embodiments disclose a broadband stealth shielding composite material in which the magnetized carbon fiber mesh is made of a magnetized carbon fiber prepreg, the cross-section of which is multifaceted and irregular.

[0006] Some embodiments disclose broadband stealth shielding composite materials with multifaceted irregular shapes including triangles, quadrilaterals, rhombuses, crosses, and corrugations.

[0007] Some embodiments disclose broadband stealth shielding composite materials in which the magnetized carbon fiber prepreg is made of carbon fiber prepreg tape coated with magnetic material.

[0008] Some embodiments disclose broadband stealth shielding composite materials, in which the metasurface layer is a PEEK thin film with a square metal ring array loaded on its surface.

[0009] Some embodiments disclose broadband stealth shielding composite materials in which polymer fibers with metal layers on the surface are nickel-plated carbon fiber, copper-plated carbon fiber, or nano-silicon carbide-plated carbon fiber, wherein the coating thickness of copper, nickel, or nano-silicon carbide is 0.2 to 0.3 μm.

[0010] On the other hand, some embodiments disclose the application of broadband stealth shielding composite materials for fabricating stealth shielding structural units.

[0011] On the other hand, some embodiments disclose the application of broadband stealth shielding composite materials, wherein the stealth shielding structural unit includes a structure formed by a regular combination of composite materials.

[0012] On another front, some embodiments disclose methods for preparing broadband stealth shielding composite materials, including:

[0013] Magnetized carbon fiber prepreg tape is fabricated, in which the surface of the carbon fibers in the resulting magnetized carbon fiber prepreg tape is coated with a magnetic material.

[0014] Magnetized carbon fiber prepreg is fabricated using magnetized carbon fiber prepreg tape;

[0015] A magnetized carbon fiber mesh is fabricated using a magnetized carbon fiber prepreg, wherein a porous array structure is formed in the magnetized carbon fiber mesh.

[0016] Magnetized carbon fiber meshes with porous array structures of different apertures are stacked sequentially, with the porous structures corresponding to each other, to form a magnetized carbon fiber absorbing layer with a gradient porous structure.

[0017] A metal layer is deposited on a PEEK film, and the metal layer is etched to obtain periodic metal structural units, forming a metasurface layer.

[0018] A polymer fiber layer is made using polymer fibers with a metal coating on the surface, serving as a reflective layer;

[0019] By sequentially stacking a metasurface layer, a magnetized carbon fiber absorbing layer, and a reflective layer, and then bonding them together with an adhesive film, a broadband stealth shielding composite material with an integrated structure is obtained.

[0020] The broadband stealth shielding composite material prepared by the method disclosed in this invention has the following characteristics: the metasurface layer of the composite material can reduce reflection energy through a phase cancellation mechanism, and can adjust the reflection amplitude and phase of the metasurface to enhance scattering and expand the absorption bandwidth; the magnetized carbon fiber absorbing layer with a gradient porous structure can effectively dissipate electromagnetic waves propagating within its structure, exhibiting excellent absorption performance; the composite material can be used to fabricate stealth shielding structural units, and further can be used to prepare stealth shielding structural components, showing good application prospects in improving the stealth shielding performance of weapon systems. Attached Figure Description

[0021] Figure 1 Schematic diagrams of metamaterial structures for metasurface layers disclosed in some embodiments;

[0022] Figure 2 Schematic diagrams of magnetized carbon fiber mesh structures disclosed in some embodiments;

[0023] Figure 3Schematic diagrams of magnetized carbon fiber absorbing layer structures disclosed in some embodiments;

[0024] Figure 4 Some embodiments disclose schematic diagrams of broadband stealth shielding composite material structures;

[0025] Figure 5 Performance test results of broadband stealth shielding composite materials disclosed in some embodiments;

[0026] Figure 6 Some embodiments disclose schematic diagrams of stealth shielding plate-like components.

[0027] Figure Labels

[0028] 1. Magnetic carbon fiber absorbing layer; 2. Reflective layer

[0029] 3. Metasurface layer D. Square metal ring

[0030] L1 First magnetized carbon fiber layer L5 Fifth magnetized carbon fiber layer

[0031] E, E1, E2 square holes

[0032] 100 Magnetic Absorption Structure Plate 101 First Support Frame

[0033] 102 Second support frame 103 Rotatable assembly Detailed Implementation

[0034] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in these embodiments of the invention, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in these embodiments is merely for describing particular implementations and is not intended to limit the scope of the disclosure of these embodiments.

[0035] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this invention pertain; other experimental methods and technical means not specifically noted in the embodiments of this invention refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0036] The terms “basic” and “approximately” used in this document are to describe small fluctuations. For example, they can mean less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Numerical data presented or expressed in range format in this document are used for convenience and brevity only, and should therefore be flexibly interpreted to include not only the explicitly listed values ​​that define the range, but also all independent values ​​or subranges contained within that range. For example, a numerical range of “1–5%” should be interpreted to include not only the explicitly listed values ​​from 1% to 5%, but also the independent values ​​and subranges within the indicated range. Thus, this numerical range includes independent values ​​such as 2%, 3.5%, and 4%, and subranges such as 1%–3%, 2%–4%, and 3%–5%, etc. This principle also applies to ranges that list only one value. Furthermore, this interpretation applies regardless of the width of the range or the characteristics described.

[0037] In this document, including in the claims, conjunctions such as "comprising," "including," "with," "having," "containing," "involving," and "accommodating" are understood to be open-ended, meaning "including but not limited to." Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0038] To better illustrate the content of this invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that the invention can be practiced even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail, in order to highlight the spirit of the invention.

[0039] Without conflict, the technical features disclosed in the embodiments of the present invention can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of the present invention.

[0040] In some embodiments, the broadband stealth shielding composite material is an integrated structural material formed by sequentially combining a metasurface layer, a magnetized carbon fiber absorbing layer, and a reflective layer. Typically, this integrated structural material has a complete shape and a stable structure, and can serve as a basic structural component of the composite material to prepare structural units. The integrated structure is composed of three layered materials stacked together, wherein the metasurface layer contains periodic metal structural units; the magnetized carbon fiber absorbing layer is made of magnetized carbon fibers and has a gradient porous structure in its thickness direction; the reflective layer is a polymer fiber layer, formed by polymer fibers with a metal layer coated on the surface.

[0041] Typically, metasurface layers, as functional structural layers, can reduce reflected energy through phase cancellation mechanisms, while simultaneously adjusting the reflection amplitude and phase of the metasurface to enhance scattering and expand the absorption bandwidth.

[0042] Typically, metasurface layers possess metamaterial structures, which are frequency-selective two-dimensional metamaterials. By printing or etching periodic metallic patterns on the metamaterial surface, broadband absorption can be achieved. Metamaterials are usually structural materials composed of subwavelength structural units. These subwavelength structural units can be arranged in a periodic, quasi-periodic, or disordered manner. Metamaterials can typically exhibit artificially customized dielectric constants and permeabilities according to a predetermined spatial distribution, thereby achieving complete control over the amplitude, phase, and polarization of electromagnetic waves.

[0043] Figure 1 These are schematic diagrams of metamaterial structures disclosed in some embodiments; wherein the metamaterial has a thickness of 2 mm and can be fabricated into periodic patterns using the phase gradient principle. For example, firstly, a thin copper layer is deposited on a PEEK film by magnetron sputtering, and then periodic metal units are fabricated by wet etching according to the designed pattern to obtain the metamaterial layer. Figure 1 As shown, the metamaterial layer is formed on the PEEK film by an array of square metal rings D. These metal rings are designed according to the phase gradient principle. The outer dimension a of the square metal ring D is 25 mm, the distance between the square metal ring D and the edge of the PEEK film is 25 mm, and the distance between adjacent square metal rings D is 45 mm. The distance between adjacent metal rings refers to the distance between the centers of adjacent metal rings. The width of the metal rings is 2 to 4 mm. The metal ring array formed by these anisotropic metal rings arranged at uniform intervals can effectively resonate in the electromagnetic field at a specific wavelength, causing a phase shift of the incident radar wave and generating a phase gradient on the surface.

[0044] Some embodiments disclose a broadband stealth shielding composite material, in which the magnetized carbon fiber absorbing layer includes a plurality of magnetized carbon fiber meshes arranged and stacked sequentially. Each magnetized carbon fiber mesh is provided with a porous array, and the porous arrays of the sequentially arranged magnetized carbon fiber meshes are arranged in a gradient with each other to form a gradient porous structure.

[0045] In some embodiments, such as Figure 2 As shown, the magnetized carbon fiber mesh 100 has regularly arranged square holes E; as Figure 3As shown, the magnetized carbon fiber absorbing layer is composed of five layers of magnetized fiber mesh stacked sequentially. The bottom layer, the first magnetized carbon fiber layer L1, has square holes E1, which is the smallest. Four layers of magnetized carbon fiber are stacked sequentially on the first layer L1, each of which has a square hole structure, and the square holes correspond to each other. The top layer, the fifth magnetized carbon fiber layer L5, has the largest square hole E5. The final magnetized carbon fiber absorbing layer with a five-layer structure forms an array of holes, which are arranged in a gradient from bottom to top.

[0046] Typically, aperture structures exhibiting a stepped increase in size possess excellent wave absorption performance. This superior absorption performance is usually the result of combining the aperture structure's shape with a magnetized carbon fiber mesh conductive layer. As the square aperture of the upper structure increases, the contact area between the upper structure and the air increases. When electromagnetic waves are emitted from the upper layer, reflection decreases, allowing more electromagnetic waves to penetrate to the lower layer. During the process of electromagnetic waves entering the lower layer, as the square aperture of the aperture decreases, the contact area between the electromagnetic waves and the conductive layer increases, causing the conductive layer to absorb even more electromagnetic waves. Furthermore, some reflected electromagnetic waves come into contact with the conductive layer again within the structure and are absorbed two or more times, further increasing the loss of electromagnetic waves within the structure, thus achieving a good wave absorption effect.

[0047] Some embodiments disclose a broadband stealth shielding composite material in which the magnetized carbon fiber mesh is made of a magnetized carbon fiber prepreg, the cross-section of which is multifaceted and irregular.

[0048] Some embodiments disclose broadband stealth shielding composite materials with multifaceted irregular shapes including triangles, quadrilaterals, rhombuses, crosses, and corrugations.

[0049] Some embodiments disclose broadband stealth shielding composite materials in which the magnetized carbon fiber prepreg is made of carbon fiber prepreg tape coated with magnetic material.

[0050] Typically, carbon fiber prepreg tape coated with magnetic materials is obtained by combining carbon fiber bundles and magnetic materials; for example, the carbon fiber bundles can be modified with magnetic materials, coating the surface of the carbon fibers within the bundles with the magnetic material. Modification methods can include coating, spraying, etc. Magnetic materials include ferrite, carbonyl iron powder, and Co30. 4， Magnetic materials such as Fe4O3.

[0051] In some embodiments, a coating method is used to prepare carbon fiber prepreg tape coated with magnetic materials. First, carbonyl iron powder is added to an aqueous epoxy resin and stirred to mix evenly to obtain a microwave absorbing slurry containing magnetic materials. The mass of carbonyl iron powder in the microwave absorbing slurry accounts for 35-45%. Then, an integrated process of carbon fiber tow spreading and sizing is used to coat the surface of the carbon fiber with magnetic materials during the process of spreading the carbon fiber tow to obtain the carbon fiber prepreg tape, and finally, a carbon fiber prepreg tape coated with magnetic materials is obtained.

[0052] Typically, carbon fiber prepreg tape coated with magnetic materials exhibits a certain degree of flexibility and can be bent and shaped as needed. Therefore, carbon fiber prepreg tape coated with magnetic materials can be used to construct carbon fiber prepregs of different shapes to obtain structures with specific three-dimensional shapes and structures, such as structures with cross-sections of triangles, quadrilaterals, corrugations, crosses, Y-shapes, rhombuses, etc.

[0053] Generally, irregularly shaped magnetized carbon fiber prepregs are obtained from magnetized carbon fiber as raw material through further processing. The irregular cross-section can be completed using a matching mold. Furthermore, using the irregularly shaped prepreg as a reinforcement, a super-mechanical structural laminate can be prepared as a magnetized carbon fiber mesh.

[0054] Some embodiments disclose broadband stealth shielding composite materials, in which the metasurface layer is a PEEK thin film with a square metal ring array loaded on its surface.

[0055] Some embodiments disclose broadband stealth shielding composite materials in which polymer fibers with metal layers on the surface are nickel-plated carbon fiber, copper-plated carbon fiber, or nano-silicon carbide-plated carbon fiber, wherein the coating thickness of copper, nickel, or nano-silicon carbide is 0.2 to 0.3 μm.

[0056] In some embodiments, such as Figure 4 As shown, the broadband stealth shielding composite material is composed of a reflective layer 2, a magnetized carbon fiber absorbing layer 1, and a metasurface layer 3 stacked together. In some embodiments, the reflective layer 2, the magnetized carbon fiber absorbing layer 1, and the metasurface layer 3 are stacked sequentially, and a J-116 adhesive film is placed between the layers. They are then hot-pressed and bonded together at 180°C and 0.5MPa to form an integrated composite material.

[0057] Some embodiments disclose the application of broadband stealth shielding composite materials for fabricating stealth shielding structural units. Typically, broadband stealth shielding composite materials can be used as structural units, combined according to a predetermined method to obtain structural units with stealth shielding effects. These structural units are usually sheet materials and can serve as surface structural components of stealth shielding equipment or devices; when used as structural components, they typically need to be molded and shaped according to a predetermined form.

[0058] Some embodiments disclose the application of broadband stealth shielding composite materials, wherein the stealth shielding structural unit comprises a structure formed by a regular combination of composite materials.

[0059] In some embodiments, multiple stealth shielding composite materials are arranged sequentially as multiple magnetic absorbing structural plates to form a stealth shielding plate-like component. A certain angle is formed between the magnetic absorbing structural plates and the surface of the stealth shielding plate-like component; this angle can be adjusted according to the requirements of the stealth shielding effect. The magnetic absorbing structural plates are parallel to each other, and the spacing between adjacent magnetic absorbing structural plates is equal.

[0060] Some embodiments disclose a method for preparing a broadband stealth shielding composite material, including:

[0061] Magnetized carbon fiber prepreg tape is fabricated, in which the surface of the carbon fibers in the resulting magnetized carbon fiber prepreg tape is coated with a magnetic material.

[0062] Magnetized carbon fiber prepreg is fabricated using magnetized carbon fiber prepreg tape;

[0063] A magnetized carbon fiber mesh is fabricated using a magnetized carbon fiber prepreg, wherein a porous array structure is formed in the magnetized carbon fiber mesh.

[0064] Magnetized carbon fiber meshes with porous array structures of different apertures are stacked sequentially, with the porous structures corresponding to each other, to form a magnetized carbon fiber absorbing layer with a gradient porous structure.

[0065] A metal layer is deposited on a PEEK film, and the metal layer is etched to obtain periodic metal structural units, forming a metasurface layer.

[0066] A polymer fiber layer is made using polymer fibers with a metal coating on the surface, serving as a reflective layer;

[0067] By sequentially stacking a metasurface layer, a magnetized carbon fiber absorbing layer, and a reflective layer, and then bonding them together with an adhesive film, a broadband stealth shielding composite material with an integrated structure is obtained.

[0068] In some embodiments, the performance of broadband stealth shielding composite materials with an integrated structure was tested, and the results are as follows: Figure 5 As shown, the effective absorption bandwidth with a reflectivity of less than -10dB in the frequency range of 2-18GHz is approximately 14.7GHz (2.1-3.8GHz, 5-18GHz), and the maximum absorption intensity is -27dB.

[0069] In some embodiments, such as Figure 6As shown, the stealth shielding plate-like component includes multiple parallel and equally spaced magnetic absorption structure plates 100. The lower end of each magnetic absorption structure plate 100 is mounted on a first support frame 101, and the upper end of each magnetic absorption structure plate 100 is mounted on a second support frame 102. The magnetic absorption structure plates 100 are connected to the first support frame 101 and the second support frame 102 via a rotatable assembly 103. An angle α is formed between the plane containing the magnetic absorption structure plates 100 and the first support frame 101. This angle α is the setting angle of the magnetic absorption structure plates 100; typically, α is between 0° and 90°.

[0070] The rotatable component includes a support, a flipping arm, and a drive device. The drive device drives the flipping arm to drive the support, which in turn drives the magnetic absorption structure plate 100, thereby changing the setting angle of the magnetic absorption structure plate 100 and achieving the flipping of the object. Simply put, when the drive device is activated, the flipping arm begins to rotate, bringing the stealth shielding composite material to a flipped position between 0 and 90 degrees.

[0071] The broadband stealth shielding composite material prepared by the method disclosed in this invention has the following characteristics: the metasurface layer of the composite material can reduce reflection energy through a phase cancellation mechanism, and can adjust the reflection amplitude and phase of the metasurface to enhance scattering and expand the absorption bandwidth; the magnetized carbon fiber absorbing layer with a gradient porous structure can effectively dissipate electromagnetic waves propagating within its structure, exhibiting excellent absorption performance; the composite material can be used to fabricate stealth shielding structural units, and further can be used to prepare stealth shielding structural components, showing good application prospects in improving the stealth shielding performance of weapon systems.

[0072] The technical solutions and technical details disclosed in the embodiments of this invention are merely illustrative of the inventive concept of this invention and do not constitute a limitation on the technical solutions of the embodiments of this invention. Any conventional changes, substitutions, or combinations made to the technical details disclosed in the embodiments of this invention have the same inventive concept as this invention and are within the protection scope of the claims of this invention.

Claims

1. A broadband stealth shielding composite material, characterized in that, The composite material is an integrated structure material formed by sequentially compounding a metasurface layer, a magnetized carbon fiber wave-absorbing layer, and a reflection layer. The metasurface layer comprises periodic metal structure units; the reflection energy is reduced through a phase cancellation mechanism, and the reflection amplitude and phase of the metasurface are adjusted to enhance scattering and expand the wave-absorbing bandwidth; the metasurface layer is a PEEK film with a square metal ring array loaded on the surface; the outer dimension of the square metal ring is 25 mm, the distance between the square metal ring and the edge of the PEEK film is 25 mm, and the distance between adjacent square metal rings is 45 mm; the width of the square metal ring is 2-4 mm. The magnetized carbon fiber wave-absorbing layer is prepared from magnetized carbon fibers; the magnetized carbon fiber wave-absorbing layer comprises a plurality of magnetized carbon fiber meshes that are sequentially arranged and stacked; each magnetized carbon fiber mesh is provided with a plurality of porous arrays; the porous arrays of the sequentially arranged magnetized carbon fiber meshes are correspondingly arranged in a gradient and form a gradient porous structure in the thickness direction; the magnetized carbon fiber mesh is made of a magnetized carbon fiber prepreg; the cross section of the magnetized carbon fiber prepreg is a multi-faceted special shape; the multi-faceted special shape comprises a triangle, a quadrilateral, a rhombus, a cross, and a corrugated shape. The magnetized carbon fiber prepreg is made of a carbon fiber prepreg tape coated with a magnetic material; the carbon fiber prepreg tape coated with the magnetic material is obtained by compounding carbon fiber tows and the magnetic material. The reflection layer is a fiber layer made of fibers coated with a metal layer; the fibers coated with the metal layer are nickel-coated carbon fibers, copper-coated carbon fibers, and nano-silicon carbide-coated carbon fibers; the coating thickness of copper, nickel, and nano-silicon carbide is 0.2-0.3 µm.

2. Use of the broadband stealth shielding composite material according to claim 1, characterized in that, A stealth shielding structure unit is prepared.

3. Use of a broadband stealth shielding composite material according to claim 1, characterized in that, The stealth shielding structure unit comprises a structure formed by regularly combining the composite material.

4. The method of making a broadband stealth shielding composite of claim 1, wherein, The method comprises: A magnetized carbon fiber prepreg tape is prepared, and the carbon fibers in the obtained magnetized carbon fiber prepreg tape are coated with a magnetic material; The magnetized carbon fiber prepreg tape is used to prepare a magnetized carbon fiber prepreg; The magnetized carbon fiber prepreg is used to prepare a magnetized carbon fiber mesh, and a porous array structure is formed in the magnetized carbon fiber mesh; Magnetized carbon fiber meshes with different porous array structures are sequentially stacked, and the porous structures correspond to each other to form a magnetized carbon fiber wave-absorbing layer with a gradient porous structure; A metal layer is coated on a PEEK film, and periodic metal structure units are obtained by etching the metal layer to form a metasurface layer; Fibers coated with a metal layer are used to prepare a fiber layer as a reflection layer; The metasurface layer, the magnetized carbon fiber wave-absorbing layer, and the reflection layer are sequentially stacked and bonded by an adhesive film to obtain a wideband stealth shielding composite material with an integrated structure.

Images