High-strength electromagnetic wave absorbing composite material and preparation method thereof

Abstract

The application belongs to the technical field of electromagnetic wave absorbing composite materials, and discloses a high-strength electromagnetic wave absorbing composite material and a preparation method thereof.The high-strength electromagnetic wave absorbing composite material is composed of a wave-transparent layer, a loss layer and a reflection layer, wherein the wave-transparent layer is prepared from glass fiber cloth, quartz fiber cloth, epoxy resin, wave-absorbing polyurethane foam and ultraviolet absorber, the loss layer is prepared from silicon carbide, graphite, conductive fiber, corrosion inhibitor and antioxidant, and the reflection layer is prepared from carbon fiber, graphite, copper powder and preservative.The wave-transparent layer obtained by adding ultraviolet absorber and epoxy resin can enhance the corrosion resistance and light resistance of the wave-transparent layer, the loss layer obtained by adding corrosion inhibitor and antioxidant can enhance the corrosion resistance of the loss layer, and the reflection layer obtained by adding preservative can resist corrosion at the connection between the electromagnetic wave absorbing composite material and other articles, so as to enhance the comprehensive strength of the electromagnetic wave absorbing composite material.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic wave absorbing composite materials technology, specifically to a high-strength electromagnetic wave absorbing composite material and its preparation method. Background Technology

[0002] Under radar electromagnetic wave illumination, in order to reduce the scattering characteristics of the target wing, in addition to adjusting the sweep angle to eliminate the backscattering characteristics caused by specular reflection, it is also of paramount importance to eliminate the traveling wave scattering emitted from the wing root to the wingtip. The generation of traveling wave scattering is mainly due to a current traveling wave propagating along the length of the conductor on the smooth skin. Since one component of the electric field is tangent to the surface, it excites a surface current traveling wave, which propagates laterally along the conductor strip and is reflected at the end of the strip, forming a reverse traveling wave. Under small angle of incidence, this reverse traveling wave can produce strong scattering in the echo direction. Under normal circumstances, traveling wave scattering has a significant impact on the overall RCS of the target wing.

[0003] In related technologies, an effective method to suppress such scattering sources is to coat the metal surface with a magnetic absorbing material, so that the surface wave is weakened to a very small extent before it reaches the abrupt change. However, the weather resistance of the coated absorbing material is relatively poor, and long-term exposure to the outdoors or harsh environments may cause its performance to degrade, requiring regular maintenance or replacement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-strength electromagnetic wave absorbing composite material and its preparation method, thus solving the problems mentioned in the background section.

[0005] To solve the above-mentioned technical problems, according to one aspect of the present invention, more specifically, a high-strength electromagnetic wave absorbing composite material and its preparation method, the high-strength electromagnetic wave absorbing composite material is composed of a wave-transmitting layer, a loss layer and a reflective layer, wherein the wave-transmitting layer is prepared from glass fiber cloth, quartz fiber cloth, epoxy resin, wave-absorbing polyurethane foam and ultraviolet absorber, the loss layer is prepared from silicon carbide, graphite, conductive fiber, corrosion inhibitor and antioxidant, and the reflective layer is prepared from carbon fiber, graphite, copper powder and corrosion inhibitor.

[0006] Furthermore, the wave-transparent layer material comprises the following components by percentage: glass fiber cloth: 50-70%, quartz fiber cloth: 20-30%, epoxy resin: 10-20%, wave-absorbing polyurethane foam: 5%, and ultraviolet absorber: 5%.

[0007] Furthermore, the raw material of the loss layer comprises the following components by percentage: silicon carbide: 60-80%, graphite: 10-20%, conductive fiber: 10-20%, corrosion inhibitor: 8%, and antioxidant: 7%.

[0008] Furthermore, the reflective layer material comprises the following components by percentage: carbon fiber: 50-70%, graphite: 20-40%, copper powder: 20-30%, and preservative: 5-10%.

[0009] Furthermore, this includes the following steps:

[0010] S1. Preparation of the wave-transparent layer

[0011] S1.1. Place 50-70% of glass fiber cloth, 20-30% of quartz fiber cloth, 10-20% of epoxy resin and 5% of microwave absorbing polyurethane foam into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0012] S1.2. Place 5% of the ultraviolet absorber into the mixing equipment and mix for 20 minutes until the ultraviolet absorber is fully mixed into the composite material.

[0013] S1.3. The mixed material is molded into the desired shape of the wave-transparent layer using a mold;

[0014] S1.4 Place the formed wave-transparent layer inside the dryer and dry it for 30 minutes at a temperature of 120℃;

[0015] S2, Preparation of loss layer

[0016] S2.1. Place 60-80% silicon carbide, 10-20% graphite and 10-20% conductive fiber into a mixing device and mix for 30 minutes until the raw materials are evenly mixed.

[0017] S2.2. Place 8% of corrosion inhibitor and 7% of antioxidant into a mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0018] S2.3. The mixed material is molded into the required shape of the loss layer using a mold;

[0019] S2.4 Place the formed wave-transparent layer inside the dryer and dry it for 20 minutes at a temperature of 100℃;

[0020] S3. Prepare the reflective layer

[0021] S3.1. Place 50-70% carbon fiber, 20-40% graphite and 20-30% copper powder into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0022] S3.2. Place 5-10% of the corrosion inhibitor into the mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0023] S3.3. The mixed material is molded into the desired reflective layer shape using a mold;

[0024] S3.4 Place the formed reflective layer inside the dryer and dry it for 20 minutes at a temperature of 110℃;

[0025] S4. The wave-transmitting layer, loss layer and reflective layer are fused together to form an electromagnetic wave-absorbing composite material, and the electromagnetic wave-absorbing composite material is placed into the testing equipment for testing.

[0026] Furthermore, in S4, the testing equipment detects the electromagnetic absorbing composite material's indicators of absorption performance, thermal stability, environmental adaptability, mechanical properties, and acoustic impedance difference with air.

[0027] Furthermore, in step S4, the formula for calculating the acoustic impedance difference between the electromagnetic wave-absorbing composite material and air is as follows:

[0028]

[0029] In the formula, S k The acoustic impedance difference between the electromagnetic absorbing composite material and air; ρ c The density of the electromagnetic wave absorbing composite material is expressed in kg / m³. 3 c is the sound velocity of the electromagnetic absorbing composite material, in m / s; m is the mass of the electromagnetic absorbing composite material, in kg; f is the coefficient of friction of the electromagnetic absorbing material; ρ0 is the density of air, taken as 1.2 kg / m³. 3 C0 is the speed of sound in air, with a value of 340 m / s;

[0030] Among them, the acoustic impedance difference between the electromagnetic wave absorbing composite material and air is between -1 and 1, and the electromagnetic wave absorbing composite material is qualified.

[0031] If the acoustic impedance difference between the electromagnetic absorbing composite material and the air is outside the range of -1 to 1, the electromagnetic absorbing composite material is considered unqualified.

[0032] Furthermore, the electromagnetic absorbing composite material inside the detection device is if:

[0033] By: transferring the electromagnetic absorbing composite material to a storage warehouse for later use;

[0034] Failed; transfer the electromagnetic absorbing composite material to the processing equipment.

[0035] The beneficial effects of the high-strength electromagnetic wave absorbing composite material and its preparation method of the present invention are as follows:

[0036] This invention prepares an electromagnetic absorbing composite material comprising a wave-transmitting layer, a loss layer, and a reflective layer, and fuses the wave-transmitting layer, the loss layer, and the reflective layer to form the electromagnetic absorbing composite material. Specifically, the wave-transmitting layer is enhanced in corrosion resistance and lightfastness by adding ultraviolet absorbers and epoxy resin; the loss layer is enhanced in corrosion resistance by adding corrosion inhibitors and antioxidants; and the reflective layer is enhanced in corrosion-resistant by adding preservatives to resist corrosion at the junction of the electromagnetic absorbing composite material with other materials, thereby enhancing the overall strength of the electromagnetic absorbing composite material. Attached Figure Description

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0038] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0039] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0040] like Figure 1 As shown, according to one aspect of the present invention, a high-strength electromagnetic absorbing composite material and its preparation method are provided. The high-strength electromagnetic absorbing composite material is composed of a wave-transmitting layer, a loss layer and a reflective layer. The wave-transmitting layer is prepared from glass fiber cloth, quartz fiber cloth, epoxy resin, wave-absorbing polyurethane foam and ultraviolet absorber. The loss layer is prepared from silicon carbide, graphite, conductive fiber, corrosion inhibitor and antioxidant. The reflective layer is prepared from carbon fiber, graphite, copper powder and corrosion inhibitor.

[0041] In this embodiment, the wave-transparent layer material comprises the following components by percentage: glass fiber cloth: 50-70%, quartz fiber cloth: 20-30%, epoxy resin: 10-20%, wave-absorbing polyurethane foam: 5%, and ultraviolet absorber: 5%.

[0042] In this embodiment, the raw material of the loss layer comprises the following components by percentage: silicon carbide: 60-80%, graphite: 10-20%, conductive fiber: 10-20%, corrosion inhibitor: 8%, and antioxidant: 7%.

[0043] In this embodiment, the reflective layer material comprises the following components by percentage: carbon fiber: 50-70%, graphite: 20-40%, copper powder: 20-30%, and preservative: 5-10%.

[0044] In this embodiment, the following steps are included:

[0045] S1. Preparation of the wave-transparent layer

[0046] S1.1. Place 50-70% of glass fiber cloth, 20-30% of quartz fiber cloth, 10-20% of epoxy resin and 5% of microwave absorbing polyurethane foam into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0047] S1.2. Place 5% of the ultraviolet absorber into the mixing equipment and mix for 20 minutes until the ultraviolet absorber is fully mixed into the composite material.

[0048] S1.3. The mixed material is molded into the desired shape of the wave-transparent layer using a mold;

[0049] S1.4 Place the formed wave-transparent layer inside the dryer and dry it for 30 minutes at a temperature of 120℃;

[0050] S2, Preparation of loss layer

[0051] S2.1. Place 60-80% silicon carbide, 10-20% graphite and 10-20% conductive fiber into a mixing device and mix for 30 minutes until the raw materials are evenly mixed.

[0052] S2.2. Place 8% of corrosion inhibitor and 7% of antioxidant into a mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0053] S2.3. The mixed material is molded into the required shape of the loss layer using a mold;

[0054] S2.4 Place the formed wave-transparent layer inside the dryer and dry it for 20 minutes at a temperature of 100℃;

[0055] S3. Prepare the reflective layer

[0056] S3.1. Place 50-70% carbon fiber, 20-40% graphite and 20-30% copper powder into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0057] S3.2. Place 5-10% of the corrosion inhibitor into the mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0058] S3.3. The mixed material is molded into the desired reflective layer shape using a mold;

[0059] S3.4 Place the formed reflective layer inside the dryer and dry it for 20 minutes at a temperature of 110℃;

[0060] S4. The wave-transmitting layer, loss layer and reflective layer are fused together to form an electromagnetic wave-absorbing composite material, and the electromagnetic wave-absorbing composite material is placed into the testing equipment for testing.

[0061] In this embodiment, in step S4, the testing equipment detects the electromagnetic absorbing composite material's indicators of absorption performance, thermal stability, environmental adaptability, mechanical properties, and acoustic impedance difference with air. Furthermore, the method for testing the absorption performance of the electromagnetic absorbing composite material is as follows: a vector network analyzer (VNA) is used for testing, the absorbing material is made into a certain shape (such as sheet or block), and placed in a standard waveguide or free space for measurement.

[0062] The thermal stability testing method for electromagnetic absorbing composite materials is as follows: thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are used to measure the mass change and heat flow change of the material at different temperatures, and to evaluate its thermal stability and decomposition temperature.

[0063] The environmental adaptability testing method for electromagnetic absorbing composite materials is as follows: the durability and reliability of the materials are evaluated through accelerated aging tests, salt spray tests, and damp heat tests to ensure that they still have good wave absorption performance in harsh environments.

[0064] The mechanical properties of electromagnetic wave absorbing composite materials are tested using a tensile testing machine and a bending testing machine.

[0065] In this embodiment, in step S4, the formula for calculating the acoustic impedance difference between the electromagnetic wave absorbing composite material and air is as follows:

[0066]

[0067] In the formula, S k The acoustic impedance difference between the electromagnetic absorbing composite material and air; ρ c The density of the electromagnetic wave absorbing composite material is expressed in kg / m³. 3 c is the sound velocity of the electromagnetic absorbing composite material, in m / s; m is the mass of the electromagnetic absorbing composite material, in kg; f is the coefficient of friction of the electromagnetic absorbing material; ρ0 is the density of air, taken as 1.2 kg / m³. 3 C0 is the speed of sound in air, with a value of 340 m / s;

[0068] Among them, the acoustic impedance difference between the electromagnetic wave absorbing composite material and air is between -1 and 1, and the electromagnetic wave absorbing composite material is qualified.

[0069] If the acoustic impedance difference between the electromagnetic absorbing composite material and the air is outside the range of -1 to 1, the electromagnetic absorbing composite material is considered unqualified.

[0070] In this embodiment, the electromagnetic absorbing composite material inside the detection device is:

[0071] By: transferring the electromagnetic absorbing composite material to a storage warehouse for later use;

[0072] Failed; transfer the electromagnetic absorbing composite material to the processing equipment.

[0073] Example 1

[0074] S1. Preparation of the wave-transparent layer

[0075] S1.1. Place 60% of glass fiber cloth, 20% of quartz fiber cloth, 10% of epoxy resin and 5% of microwave absorbing polyurethane foam into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0076] S1.2. Place 5% of the ultraviolet absorber into the mixing equipment and mix for 20 minutes until the ultraviolet absorber is fully mixed into the composite material.

[0077] S1.3. The mixed material is molded into the desired shape of the wave-transparent layer using a mold;

[0078] S1.4 Place the formed wave-transparent layer inside the dryer and dry it for 30 minutes at a temperature of 120℃;

[0079] S2, Preparation of loss layer

[0080] S2.1. Place 60% silicon carbide, 15% graphite and 10% conductive fiber into a mixing device and mix for 30 minutes until the raw materials are evenly mixed.

[0081] S2.2. Place 8% of corrosion inhibitor and 7% of antioxidant into a mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0082] S2.3. The mixed material is molded into the required shape of the loss layer using a mold;

[0083] S2.4 Place the formed wave-transparent layer inside the dryer and dry it for 20 minutes at a temperature of 100℃;

[0084] S3. Prepare the reflective layer

[0085] S3.1. Place 50% carbon fiber, 25% graphite and 20% copper powder into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0086] S3.2. Place 5% of the corrosion inhibitor into the mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0087] S3.3. The mixed material is molded into the desired reflective layer shape using a mold;

[0088] S3.4 Place the formed reflective layer inside the dryer and dry it for 20 minutes at a temperature of 110℃;

[0089] S4. The wave-transmitting layer, the loss layer and the reflective layer are fused together to form an electromagnetic wave-absorbing composite material.

[0090] The data obtained for the electromagnetic absorbing composite material are as follows: the density of the electromagnetic absorbing composite material is 1.36 kg / m³. 3 The sound velocity of the electromagnetic wave absorbing composite material is 300 m / s, the mass of the electromagnetic wave absorbing composite material is 0.05 kg, and the coefficient of friction of the electromagnetic wave absorbing composite material is 0.42.

[0091] Substituting the data of the electromagnetic absorbing composite material into the calculation formula for the acoustic impedance difference between the electromagnetic absorbing composite material and air, we obtain the following:

[0092] [(1.36×300)+0.05+0.42]-(1.2×340)=0.47

[0093] Since 0.47 is within the range of -1 to 1, the acoustic impedance difference between the electromagnetic wave absorbing composite material and air obtained in this embodiment is qualified.

[0094] Example 2

[0095] S1. Preparation of the wave-transparent layer

[0096] S1.1. Place 50% of glass fiber cloth, 30% of quartz fiber cloth, 10% of epoxy resin and 5% of microwave absorbing polyurethane foam into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0097] S1.2. Place 5% of the ultraviolet absorber into the mixing equipment and mix for 20 minutes until the ultraviolet absorber is fully mixed into the composite material.

[0098] S1.3. The mixed material is molded into the desired shape of the wave-transparent layer using a mold;

[0099] S1.4 Place the formed wave-transparent layer inside the dryer and dry it for 30 minutes at a temperature of 120℃;

[0100] S2, Preparation of loss layer

[0101] S2.1. Place 60% silicon carbide, 15% graphite and 10% conductive fiber into a mixing device and mix for 30 minutes until the raw materials are evenly mixed.

[0102] S2.2. Place 8% of corrosion inhibitor and 7% of antioxidant into a mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0103] S2.3. The mixed material is molded into the required shape of the loss layer using a mold;

[0104] S2.4 Place the formed wave-transparent layer inside the dryer and dry it for 20 minutes at a temperature of 100℃;

[0105] S3. Prepare the reflective layer

[0106] S3.1. Place 50% carbon fiber, 20% graphite and 25% copper powder into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed.

[0107] S3.2. Place 5% of the corrosion inhibitor into the mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material.

[0108] S3.3. The mixed material is molded into the desired reflective layer shape using a mold;

[0109] S3.4 Place the formed reflective layer inside the dryer and dry it for 20 minutes at a temperature of 110℃;

[0110] S4. The wave-transmitting layer, the loss layer and the reflective layer are fused together to form an electromagnetic wave-absorbing composite material.

[0111] The data obtained for the electromagnetic absorbing composite material are as follows: the density of the electromagnetic absorbing composite material is 1.37 kg / m³. 3 The sound velocity of the electromagnetic wave absorbing composite material is 298 m / s, the mass of the electromagnetic wave absorbing composite material is 0.05 kg, and the coefficient of friction of the electromagnetic wave absorbing composite material is 0.42.

[0112] Substituting the data of the electromagnetic absorbing composite material into the calculation formula for the acoustic impedance difference between the electromagnetic absorbing composite material and air, we obtain the following:

[0113] [(1.37×298)+0.05+0.42]-(1.2×340)=0.73

[0114] Since 0.73 is within the range of -1 to 1, the acoustic impedance difference between the electromagnetic wave absorbing composite material and air obtained in this embodiment is qualified.

[0115] Comparative Example 1

[0116] S1. Mix the magnetic absorber, binder, solvent, composite additive and curing agent to obtain the microwave absorbing slurry;

[0117] S2. The microwave absorbing fiber is immersed in the microwave absorbing slurry, and then stirred, dried and disassembled in sequence to obtain microwave absorbing fiber with microwave absorbing slurry on the surface.

[0118] S3. The microwave-absorbing fibers with microwave-absorbing paste on their surface are stirred and mixed with the composite adhesive to obtain several layers of composite microwave-absorbing prepreg.

[0119] S4. The microwave absorbing prepreg is cut and then laminated sequentially to obtain a composite microwave absorbing layer. A skin layer and a reflective layer are laminated on the upper and lower surfaces of the composite microwave absorbing layer, respectively. After curing, the high-strength microwave absorbing composite material is obtained.

[0120] Comparative Example 2

[0121] S1. Weaving silicon carbide fibers into corrugated fiber preforms: Continuous silicon carbide fiber bundles are woven into plain-weave silicon carbide fiber cloth. Then, according to the size of the corrugated board mold, the silicon carbide fiber cloth is cut into the corresponding size and stacked layer by layer. The number of stacked layers is determined by the thickness of the honeycomb wall. Then, continuous glass fibers are sewn along the thickness direction to obtain corrugated silicon carbide fiber preforms. The width of the fiber cloth is 10-30 mm, and the number of stacked layers is 4-8.

[0122] S2. Preparation of boron nitride interface layer by chemical vapor infiltration process: The silicon carbide fiber preform in S1 is placed in a vacuum furnace, and argon, hydrogen, boron trichloride and ammonia are introduced. The reaction is carried out under high temperature and high pressure to generate boron nitride, and a boron nitride interface layer is deposited on the surface of the silicon carbide fiber preform. The pressure in the vacuum furnace is 100-400 Pa and the temperature is 600-800 °C. Argon is used as a dilution gas, hydrogen is used as a carrier gas, boron trichloride provides the boron source, and ammonia provides the nitrogen source. Boron trichloride and ammonia react to deposit a boron nitride interface layer on the surface of the silicon carbide fiber preform. The deposition time is 20-50 h and the thickness of the boron nitride interface layer is 200-600 nm.

[0123] S3. Preparation of composite matrix by chemical vapor infiltration process: The preform with boron nitride interface layer deposited in S2 is placed in a deposition furnace. Argon, hydrogen and gases corresponding to different matrices are introduced into the deposition furnace and reacted under high temperature and high pressure to deposit the matrix on the surface of boron nitride interface layer, thus obtaining silicon carbide ceramic matrix composite corrugated plate; the pressure in the deposition furnace is 100-400 Pa, the temperature is 700-1000℃, argon is used as dilution gas, hydrogen is used as carrier gas, the matrix is ​​silicon nitride or silicon carbide, and the deposition time is 100-150 h;

[0124] S4. The corrugated plates of silicon carbide ceramic matrix composite material obtained in S3 are connected together with ceramic slurry adhesive, and then the matrix is ​​deposited under the same deposition conditions as in S2 to obtain silicon carbide ceramic matrix composite absorbing honeycomb. The ceramic slurry adhesive is composed of ceramic powder and ceramic precursor solution in a mass ratio of 1:5-1:10.

[0125] The electromagnetic absorbing composite materials prepared in the examples and comparative examples were tested for their absorption performance, thermal stability, environmental adaptability, mechanical properties, and acoustic impedance difference with air. Specific data are shown in Table 1.

[0126]

[0127]

[0128] As shown in Table 1, the electromagnetic absorbing composite materials obtained through Examples 1 and 2 have better thermal stability, environmental adaptability, and acoustic impedance difference with air than Comparative Examples 1 and 2. Furthermore, the electromagnetic absorbing composite materials obtained through Examples 1 and 2 have much better environmental adaptability than those obtained through Comparative Examples 1 and 2. This results in the electromagnetic absorbing composite materials obtained in this application having higher strength and environmental adaptability, and being able to maintain stable performance even after long-term exposure to outdoor or harsh environments.

[0129] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention are also within the protection scope of the present invention.

Claims

1. A high-strength electromagnetic wave absorbing composite material, characterized in that: The high-strength electromagnetic wave-absorbing composite material is composed of a wave-transmitting layer, a loss layer, and a reflective layer. The wave-transmitting layer is made of glass fiber cloth, quartz fiber cloth, epoxy resin, wave-absorbing polyurethane foam, and ultraviolet absorber. The loss layer is made of silicon carbide, graphite, conductive fiber, corrosion inhibitor, and antioxidant. The reflective layer is made of carbon fiber, graphite, copper powder, and corrosion inhibitor.

2. The high-strength electromagnetic wave absorbing composite material according to claim 1, characterized in that: The wave-transparent layer material comprises the following components by percentage: glass fiber cloth: 50-70%, quartz fiber cloth: 20-30%, epoxy resin: 10-20%, wave-absorbing polyurethane foam: 5%, and ultraviolet absorber: 5%.

3. The high-strength electromagnetic wave absorbing composite material according to claim 1, characterized in that: The raw material of the loss layer comprises the following components by percentage: silicon carbide: 60-80%, graphite: 10-20%, conductive fiber: 10-20%, corrosion inhibitor: 8%, and antioxidant: 7%.

4. The high-strength electromagnetic wave absorbing composite material according to claim 1, characterized in that: The reflective layer material comprises the following components by percentage: carbon fiber: 50-70%, graphite: 20-40%, copper powder: 20-30%, and preservative: 5-10%.

5. The method for preparing a high-strength electromagnetic wave absorbing composite material according to claim 1, characterized in that: Includes the following steps: S1. Preparation of the wave-transparent layer S1.

1. Place 50-70% of glass fiber cloth, 20-30% of quartz fiber cloth, 10-20% of epoxy resin and 5% of microwave absorbing polyurethane foam into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed. S1.

2. Place 5% of the ultraviolet absorber into the mixing equipment and mix for 20 minutes until the ultraviolet absorber is fully mixed into the composite material. S1.

3. The mixed material is molded into the desired shape of the wave-transparent layer using a mold; S1.4 Place the formed wave-transparent layer inside the dryer and dry it for 30 minutes at a temperature of 120℃; S2, Preparation of loss layer S2.

1. Place 60-80% silicon carbide, 10-20% graphite and 10-20% conductive fiber into a mixing device and mix for 30 minutes until the raw materials are evenly mixed. S2.

2. Place 8% of corrosion inhibitor and 7% of antioxidant into a mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material. S2.

3. The mixed material is molded into the required shape of the loss layer using a mold; S2.4 Place the formed wave-transparent layer inside the dryer and dry it for 20 minutes at a temperature of 100℃; S3. Prepare the reflective layer S3.

1. Place 50-70% carbon fiber, 20-40% graphite and 20-30% copper powder into a mixing equipment and mix for 30 minutes until the raw materials are evenly mixed. S3.

2. Place 5-10% of the corrosion inhibitor into the mixing equipment and mix for 20 minutes until the corrosion inhibitor and antioxidant are fully mixed inside the composite material. S3.

3. The mixed material is molded into the desired reflective layer shape using a mold; S3.4 Place the formed reflective layer inside the dryer and dry it for 20 minutes at a temperature of 110℃; S4. The wave-transmitting layer, loss layer and reflective layer are fused together to form an electromagnetic wave-absorbing composite material, and the electromagnetic wave-absorbing composite material is placed into the testing equipment for testing.

6. The method for preparing a high-strength electromagnetic wave absorbing composite material according to claim 4, characterized in that: In step S4, the testing equipment detects the electromagnetic absorbing composite material's indicators of absorption performance, thermal stability, environmental adaptability, mechanical properties, and acoustic impedance difference with air.

7. The high-strength electromagnetic wave absorbing composite material and its preparation method according to claim 6, characterized in that: In step S4, the formula for calculating the acoustic impedance difference between the electromagnetic wave absorbing composite material and air is as follows: In the formula, S k The acoustic impedance difference between the electromagnetic absorbing composite material and air; ρ c The density of the electromagnetic wave absorbing composite material is expressed in kg / m³. 3 c is the sound velocity of the electromagnetic absorbing composite material, in m / s; m is the mass of the electromagnetic absorbing composite material, in kg; f is the coefficient of friction of the electromagnetic absorbing material; ρ0 is the density of air, taken as 1.2 kg / m³. 3 C0 is the speed of sound in air, with a value of 340 m / s; Among them, the acoustic impedance difference between the electromagnetic wave absorbing composite material and air is between -1 and 1, and the electromagnetic wave absorbing composite material is qualified. If the acoustic impedance difference between the electromagnetic absorbing composite material and the air is outside the range of -1 to 1, the electromagnetic absorbing composite material is considered unqualified.

8. The high-strength electromagnetic wave absorbing composite material and its preparation method according to claim 6, characterized in that: If the electromagnetic absorbing composite material inside the detection equipment is: By: transferring the electromagnetic absorbing composite material to a storage warehouse for later use; Failed; transfer the electromagnetic absorbing composite material to the processing equipment.

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