Three-dimensional-configuration wide-incidence-angle light wave-absorbing material

Abstract

The invention relates to an electromagnetic wave absorbing material, in particular to a three-dimensional wide-incidence-angle lightweight wave-absorbing material, which comprises a wave-transparent layer, a wave-absorbing layer and a reflecting layer, the wave-transparent layer is a limited array randomly combined by a plurality of cell elements with different heights and different shapes, each cell element is divided into multiple layers of gradients, and the gradient of each cell element is larger than that of the reflecting layer. Filling spaces in every two adjacent cell elements are mutually independent, the cell elements of the wave-transparent layer are filled with the wave-absorbing layer, the reflecting layer is connected to the bottom faces of the cell elements of the wave-transparent layer and blocks the wave-absorbing layer in the cell elements, and the wave-transparent layer is formed by 3D printing of a nylon PA12 material. The wave-absorbing layer is formed by mixing 5% of solids and 95% of water in a container, magnetically stirring, filling a filling space in the cell element with the mixture, and freeze-drying, and the solids comprise 80% of graphene and 20% of cellulose. According to the invention, a very good absorption effect can be achieved on electromagnetic waves incident from different directions.

Description

Technical Field

[0001] The invention relates to an electromagnetic wave absorbing material, in particular to a three-dimensional configuration, wide incident angle, and light-weight absorbing material. Background Art

[0002] With the continuous development of advanced detection technology, all kinds of weapons and equipment, especially large-sized vehicle equipment, are facing increasingly severe electromagnetic environment situations, and their survivability and strike capabilities are seriously threatened. The foam and foam sandwich absorbing materials currently used have good performance in the vertical incident direction, but they cannot provide all-round and effective protection against electromagnetic detection threats from different directions (0°-60°), especially when the absorbing performance decays faster at large angles, and cannot meet the requirements of lightweight absorbing materials with wide incident angles. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a three-dimensional structured light-weight absorbing material with a wide incident angle, which can have a good absorption effect on electromagnetic waves incident from different directions.

[0004] In order to solve the above technical problems, this application provides the following technical solutions:

[0005] The present invention discloses a three-dimensional light-weight absorbing material with a wide incident angle, comprising a wave-transmitting layer, a wave-absorbing layer and a reflecting layer. The wave-transmitting layer is a finite array formed by randomly combining a plurality of cells of different heights and shapes, two adjacent cells are connected to each other, each of the cells is divided into a multi-layer gradient, and the filling spaces inside two adjacent cells are independent of each other. The wave-absorbing layer is filled in the cells of the wave-transmitting layer, the reflecting layer is in the shape of a plate, the reflecting layer is connected to the bottom surface of the cells of the wave-transmitting layer, and the reflecting layer seals the wave-absorbing layer in the cells.

[0006] Furthermore, the wave-transmitting layer is made of nylon PA12 material by 3D printing.

[0007] Furthermore, the cell shape is an equilateral triangle, a quadrilateral, a hexagon, a circle or other randomly combined configurations.

[0008] Furthermore, the heights of the plurality of cells are all between 15 mm and 23 mm, and the gradient levels of the plurality of cells are all between 4 and 6 layers.

[0009] Furthermore, the thickness of the wave-transmitting layer is 0.6 mm.

[0010] Furthermore, the absorbing layer is formed by mixing 5% of solid matter and 95% of water in a container, adding a magnetic stirrer into the container, placing the container on a magnetic stirrer, and driving the magnetic stirrer to move in a circular motion for 2 to 3 hours by a magnetic field to mix the solid matter and water evenly, and then filling the mixture into the filling space and freeze-drying the mixture, wherein the solid matter includes 80% of graphene and 20% of cellulose, and the above percentages are all mass percentages.

[0011] Furthermore, the freeze-drying process includes freezing at -60°C for 24 hours and low-temperature drying in a freeze drying oven for 48 hours.

[0012] Furthermore, the flake size of the graphene is less than 20 μm, the average thickness of the graphene is less than 4 nm, the specific surface area of ​​the graphene is greater than 50 m2 / g, and the purity of the graphene is greater than 99.5%.

[0013] Furthermore, the reflective layer is a carbon fiber plate, and the reflective layer is bonded to the bottom surface of the cell.

[0014] Furthermore, the thickness of the carbon fiber plate is 0.2 mm.

[0015] Compared with the prior art, the three-dimensional structured wide incident angle lightweight absorbing material of the present invention has at least the following beneficial effects:

[0016] The invention discloses a three-dimensional light-weight absorbing material with a wide incident angle. The material comprises a wave-transmitting layer, a wave-absorbing layer and a reflecting layer. The incident electromagnetic waves are reflected and scattered multiple times by the reflecting layer, thereby increasing the transmission paths of electromagnetic waves at different angles after entering the material, enhancing the impedance matching characteristics of the material, and effectively accelerating the attenuation of electromagnetic energy. At the same time, since the wave-transmitting layer is a finite array formed by randomly combining multiple cells of different heights and shapes, and each cell is divided into multiple layers of gradients, the material not only has good absorbing performance for electromagnetic waves in a vertical incident direction, but also has good absorbing effects for electromagnetic waves incident in different directions to match the requirements of wide-angle incident wave absorption.

[0017] The three-dimensional wide-incident-angle lightweight wave-absorbing material of the present invention will be further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1a It is a schematic diagram of the three-dimensional structure of the wide-incident-angle lightweight absorbing material of the present invention;

[0019] Figure 1b It is a schematic diagram of the three-dimensional structure of the wide-incident-angle lightweight wave-absorbing material of the three-dimensional configuration of the present invention in another direction;

[0020] Figure 1c It is a cross-sectional view of a cell in the wide incident angle lightweight wave absorbing material of the three-dimensional configuration of the present invention;

[0021] Figure 2 It is a diagram showing the formation process of the wave absorbing layer in the wide incident angle lightweight wave absorbing material of the three-dimensional configuration of the present invention;

[0022] Figure 3 The graph is a test result of the real part and imaginary part of the relative complex dielectric constant of the absorbing material with a composition ratio of 5%-80% prepared three times in the wide-incident-angle lightweight absorbing material with a three-dimensional configuration of the present invention;

[0023] Figure 4 A schematic diagram of the random hierarchical structure of cells in the wide-incident-angle lightweight absorbing material of the present invention;

[0024] Figure 5 A schematic diagram of the random height structure of a cell in the wide-incident-angle lightweight absorbing material of the three-dimensional configuration of the present invention;

[0025] Figure 6 The test results of the electromagnetic performance of the wide-incident-angle reflectivity of the three-dimensionally configured wide-incident-angle lightweight absorbing material of the present invention are shown. DETAILED DESCRIPTION

[0026] like Figure 1a , Figure 1b , Figure 1c As shown, the present invention is a three-dimensional structure with a wide incident angle lightweight absorbing material, comprising a wave-transmitting layer 11, a wave-absorbing layer 12, and a reflecting layer 13. The wave-transmitting layer 11 is a finite array formed by a random combination of multiple cells 111 of different heights and shapes. Two adjacent cells 111 are connected to each other, and each cell 111 is divided into multiple layers of gradient. The filling spaces inside two adjacent cells 111 are independent of each other. The wave-absorbing layer 12 is filled in the cells of the wave-transmitting layer 11. The reflecting layer 13 is in the shape of a plate. The reflecting layer 13 is connected to the bottom surface of the cells 111 of the wave-transmitting layer 11, and the reflecting layer 13 blocks the wave-absorbing layer 12 in the cells 111. After the electromagnetic wave is incident, it penetrates the wave-transmitting layer 11 and reaches the wave-absorbing layer 12. The electromagnetic wave energy is absorbed and attenuated inside the wave-absorbing layer 12. The electromagnetic wave that is not absorbed is reflected by the reflecting layer 13 and further absorbed and attenuated repeatedly inside the wave-absorbing layer 12. The electromagnetic performance test results of the three-dimensional structure with a wide incident angle lightweight absorbing material of the present invention are shown as follows. Figure 6As shown. The three-dimensional structure of the wide incident angle lightweight absorbing material of the present invention comprises a wave-transmitting layer 11, a wave-absorbing layer 12, and a reflective layer 13. The incident electromagnetic wave is reflected and scattered multiple times by the reflective layer 13, which increases the transmission path of electromagnetic waves at different angles after entering the material, enhances the impedance matching characteristics of the material, and effectively accelerates the attenuation of electromagnetic energy. At the same time, since the wave-transmitting layer 11 is a finite array formed by randomly combining multiple cells 111 of different heights and shapes, and each cell 111 is divided into multiple layers of gradient, it not only has good absorbing performance for electromagnetic waves in the vertical incident direction, but also has good absorbing effect for electromagnetic waves incident in different directions to match the requirements of wide-angle incident wave absorption.

[0027] Optionally, the wave-transmitting layer 11 is made of nylon PA12 material by 3D printing. The wave-transmitting layer is made of nylon PA12 material, so that the three-dimensional configuration of the wide incident angle lightweight absorbing material of the present invention not only has excellent wave-transmitting performance but also has reliable bearing performance, and can better meet the use requirements.

[0028] Optional, such as Figure 5 As shown, the shape of the cell 111 is an equilateral triangle, a quadrilateral, a hexagon, a circle or other randomly combined configurations, which further enhances the absorption effect of electromagnetic waves incident from different directions.

[0029] Optional, such as Figure 4 As shown, the heights of the plurality of cells 111 are all between 15 mm and 23 mm, and the gradient levels of the plurality of cells 111 are all between 4 and 6 layers.

[0030] Optionally, the thickness of the wave-transmitting layer 11 is 0.6 mm, so that the three-dimensional configuration of the wide-incident-angle lightweight wave-absorbing material of the present invention not only has good wave-transmitting performance and reliable mechanical properties but also meets the demand for lightweight.

[0031] Optional, such as Figure 2 As shown, the wave absorbing layer 12 is formed by mixing 5% of solid matter and 95% of water in a container, adding a magnetic stirrer to the container, placing it on a magnetic stirrer, using a magnetic field to drive the stirrer in the container to move in a circular motion for 2 to 3 hours, and then filling the solution into the filling space inside the cell after mixing it evenly and freeze-drying it. The solid matter includes 80% of graphene and 20% of cellulose by mass. In the above-mentioned magnetic stirring process, the principle of like charges repel each other and opposite charges attract each other is utilized, and the magnetic field generated by the magnetic stirrer is used to drive the magnetic stirrer placed in the container to move in a circular motion, thereby achieving the purpose of stirring the liquid or solid-liquid mixture. The wave absorbing layer 12 is formed into a porous wave absorbing structure by a freeze-drying process of graphene, cellulose and water, and has a high dielectric constant, such as Figure 3As shown in the test results of the real and imaginary parts of the relative complex dielectric constant of the absorbing materials prepared three times, it also has an extremely low density (60-70 mg / cm3) and good mechanical properties. It can absorb wide-angle incident electromagnetic waves with better absorbing performance, and is more adaptable to cells of different heights and shapes randomly combined, and has a better degree of integration with the cells.

[0032] Optionally, the freeze-drying process includes freezing at -60°C for 24 hours and low-temperature drying in a freeze drying oven for 48 hours.

[0033] Optionally, the flake size of graphene is less than 20 μm, the average thickness of graphene is less than 4 nm, the specific surface area of ​​graphene is greater than 50 m 2 / g, and the purity of graphene is greater than 99.5%.

[0034] Optionally, the reflective layer 13 is a carbon fiber board, and the reflective layer 13 is epoxy-bonded to the bottom surface of the cell. The reflective layer 13 is a carbon fiber board, so that the three-dimensional configuration of the light-weight absorbing material with a wide incident angle has good wave transmission performance and load-bearing performance.

[0035] Optionally, the thickness of the carbon fiber plate is 0.2 mm, which further enables the three-dimensional configuration of the wide incident angle lightweight absorbing material of the present invention to not only have good wave transmission performance and reliable mechanical properties but also meet the demand for lightweight.

[0036] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A three-dimensional light-weight absorbing material with a wide incident angle, characterized in that: The invention comprises a wave-transmitting layer (11), a wave-absorbing layer (12), and a reflecting layer (13); the wave-transmitting layer (11) is a finite array formed by randomly combining a plurality of cells (111) of different heights and shapes; two adjacent cells (111) are connected to each other; each cell (111) is divided into a multi-layer gradient; the filling spaces inside two adjacent cells (111) are independent of each other; the wave-absorbing layer (12) is filled in the cells (111) of the wave-transmitting layer (11); the reflecting layer (13) is in the shape of a plate; the reflecting layer (13) is connected to the bottom surface of the cells (111) of the wave-transmitting layer (11); and the reflecting layer (13) seals the wave-absorbing layer (12) in the cells (111).

2. The three-dimensional wide-incident-angle lightweight absorbing material according to claim 1, characterized in that: The wave-transmitting layer (11) is made of nylon PA12 material by 3D printing.

3. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 2, characterized in that: The shape of the cell (111) is a regular triangle, a quadrilateral, a hexagon, a circle or other randomly combined configurations.

4. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 3, characterized in that: The heights of the plurality of cells (111) are all between 15 mm and 23 mm, and the gradient levels of the plurality of cells (111) are all between 4 and 6 layers.

5. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 4, characterized in that: The thickness of the wave-transmitting layer (11) is 0.6 mm.

6. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 1, characterized in that: The wave absorbing layer (12) is formed by mixing 5% of solid matter and 95% of water in a container, adding a magnetic stirrer into the container, placing the container on a magnetic stirrer, and driving the magnetic stirrer to move in a circular motion for 2 to 3 hours by a magnetic field to mix the solid matter and water evenly, and then filling the mixture into the filling space and freeze-drying the mixture, wherein the solid matter comprises 80% of graphene and 20% of cellulose, and the above percentages are all percentages by mass.

7. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 6, characterized in that: The freeze drying process includes freezing at -60°C for 24 hours and low-temperature drying in a freeze drying oven for 48 hours.

8. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 7, characterized in that: The flake size of the graphene is less than 20 μm, the average thickness of the graphene is less than 4 nm, the specific surface area of ​​the graphene is greater than 50 m2 / g, and the purity of the graphene is greater than 99.5%.

9. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 3, characterized in that: The reflective layer (13) is a carbon fiber plate, and the reflective layer (13) is bonded to the bottom surface of the cell.

10. The three-dimensional light-weight absorbing material with a wide incident angle according to claim 9, characterized in that: The thickness of the carbon fiber plate is 0.2 mm.

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