阅读说明：本技术 耐高温宽频吸波/承载复合材料及其制备方法 (High-temperature-resistant broadband wave-absorbing/bearing composite material and preparation method thereof ) 是由 邹如荣 危伟 阮东升 李雷雷 雷志鹏 彭潺 于 2021-08-20 设计创作，主要内容包括：本发明提供了一种耐高温宽频吸波/承载复合材料及其制备方法,该材料包括依次设置的透波层、阻抗匹配层、电损耗吸波层、磁损耗吸波层和反射层,其中透波层、阻抗匹配层、电损耗吸波层、磁损耗吸波层和反射层均为纤维增强树脂基复合材料,且透波层掺杂有空心玻璃微珠。本发明提供耐高温宽频吸波/承载复合材料材料,具有吸波频带宽、耐高温、质轻、力学性能优异的特点,该制备方法工艺可靠,易于操作。(The invention provides a high-temperature-resistant broadband wave-absorbing/bearing composite material and a preparation method thereof. The high-temperature-resistant broadband wave-absorbing/bearing composite material provided by the invention has the characteristics of wide wave-absorbing frequency band, high temperature resistance, light weight and excellent mechanical property, and the preparation method is reliable in process and easy to operate.)

1. A high-temperature-resistant broadband wave-absorbing/bearing composite material is characterized in that: the thickness of the material is 3 mm-10 mm, and the material comprises a wave-transmitting layer, an impedance matching layer, an electrical loss wave-absorbing layer, a magnetic loss wave-absorbing layer and a reflecting layer which are sequentially arranged, wherein the wave-transmitting layer, the impedance matching layer, the electrical loss wave-absorbing layer, the magnetic loss wave-absorbing layer and the reflecting layer are all made of fiber reinforced resin matrix composite materials, and the wave-transmitting layer is doped with hollow glass beads.

2. The high-temperature-resistant broadband wave-absorbing/load-bearing composite material according to claim 1, wherein: the thickness of wave-transparent layer is 0.2mm ~3mm, and the thickness of impedance matching layer is 0.2mm ~1mm, and the thickness of electric loss absorbing layer is 0.2mm ~4mm, and the thickness of magnetic loss absorbing layer is 0.6mm ~6mm, and the thickness of reflection stratum is 0.2mm ~1 mm.

3. The high-temperature-resistant broadband wave-absorbing/load-bearing composite material according to claim 1, wherein: the wave-transmitting layer is prepared by attaching a blend of resin and hollow glass beads on fiber cloth; in the blend, the weight percentage of the hollow glass beads is 2-5%.

4. The high-temperature-resistant broadband wave-absorbing/load-bearing composite material according to claim 1, wherein: the impedance matching layer is made by attaching a blend of resin and conductive carbon black to a fiber cloth; in the blend, the weight percentage of the conductive carbon black is 3% -10%.

5. The high-temperature-resistant broadband wave-absorbing/load-bearing composite material according to claim 1, wherein: the electric loss wave-absorbing layer is prepared by attaching a blend of resin and an electric loss absorbent on fiber cloth; in the blend, the weight percentage of the electrical loss absorbent is 15-35%; the electrical loss absorbent is one or more of graphene, conductive carbon black, chopped carbon fiber or other carbon powder.

6. The high-temperature-resistant broadband wave-absorbing/load-bearing composite material according to claim 1, wherein: the magnetic loss wave absorbing layer is prepared by attaching a blend of resin and a magnetic loss absorbent on fiber cloth; in the blend, the weight percentage content of the magnetic loss absorbent is 50% -80%; the magnetic loss absorbent is one or more of iron-silicon-chromium, iron-silicon-aluminum and iron-nickel alloy powder.

7. The high-temperature-resistant broadband wave-absorbing/load-bearing composite material according to any one of claims 1 to 6, wherein: in the wave-transparent layer, the impedance matching layer, the electric loss wave-absorbing layer and the magnetic loss wave-absorbing layer, the fiber is one or more of quartz fiber, low-dielectric glass fiber and high-silica fiber; the resin is one or more of high-temperature-resistant modified organic silicon resin, modified phenolic resin, modified epoxy resin, cyanate ester, bismaleimide resin and polyimide resin; the reflecting layer is made of carbon fiber reinforced resin matrix composite.

8. The preparation method of the high-temperature-resistant broadband wave-absorbing/load-bearing composite material according to any one of claims 1 to 7, characterized by comprising the following steps:

s1, uniformly mixing the hollow glass beads with resin, coating the mixture on fiber cloth, and drying the fiber cloth until the surface is dry to serve as a wave-transmitting layer for later use;

s2, uniformly mixing the conductive carbon black and the resin, coating the mixture on fiber cloth, heating the mixture at a low temperature to be surface dry, heating the mixture for curing, and repeating the heating and curing for multiple times until the sheet resistance meets the requirements to obtain impedance matching cloth for later use;

s3, uniformly mixing the electrical loss absorbent with resin, coating the mixture on fiber cloth, heating the mixture at a low temperature to be surface dry, heating the mixture to be cured, and repeating the heating and curing for multiple times until the square resistance of the electrical loss wave-absorbing cloth meets the requirement to obtain the electrical loss wave-absorbing cloth for later use;

s4, uniformly mixing the magnetic loss absorbent with resin, coating the mixture on fiber cloth, heating the fiber cloth to be surface-dry at low temperature, heating the fiber cloth to be solidified, and repeating the steps for multiple times until the density of the surface of the magnetic loss wave-absorbing cloth meets the requirement to obtain the magnetic loss wave-absorbing cloth for later use;

s5, coating resin on the carbon fiber cloth, and drying to be surface dry to be used as a reflecting layer for standby;

s6, performing resin pre-dipping treatment on the electric loss wave absorption cloth obtained in the step S3 and the magnetic loss wave absorption cloth obtained in the step S4, respectively coating resin on two surfaces of the wave absorption cloth, heating and drying the wave absorption cloth until the surface is dry, and using the wave absorption cloth as an electric loss wave absorption layer and a magnetic loss wave absorption layer for later use;

s7, stacking and laying the layers of cloth according to the sequence of the wave-transmitting layer, the impedance matching layer, the electric loss wave-absorbing layer, the magnetic loss wave-absorbing layer and the reflecting layer, and then molding by adopting a prepreg molding process of the composite material to obtain the high-temperature-resistant broadband wave-absorbing/bearing composite material.

9. The method of claim 8, wherein: the sheet resistance in S2 is 2000 omega/□ -9000 omega/□; the square resistance of S3 is 40 Ω/□ -1500 Ω/□.

10. The method of claim 8, wherein: the density of the magnetic loss wave-absorbing cloth surface in S4 is 0.8kg/m²~1.3kg/m²。

Technical Field

The invention belongs to the technical field of materials, and particularly relates to a high-temperature-resistant broadband wave-absorbing/load-bearing composite material and a preparation method thereof.

Background

The electromagnetic wave absorber is a functional composite material which can effectively absorb incident electromagnetic waves and remarkably reduce the echo intensity, and has important application in the fields of military stealth, civil electromagnetic protection and electromagnetic interference resistance. The structural wave-absorbing composite material adopts a fiber reinforcement to carry out comprehensive integrated design of wave-absorbing performance and mechanical property, thereby having double functions of wave absorption and bearing, avoiding the defects of easy falling off, poor weather resistance and the like of a coating type wave-absorbing material coating, and becoming an important direction in the field of wave-absorbing material research.

201610975918.7 discloses a method for preparing carbon fiber/glass fiber hybrid stealth composite material, which adopts two-dimensional weaving technology to weave glass fiber for wave transmission and carbon fiber for wave absorption into a whole and then forms the product by resin transfer molding process, thus greatly improving the interlayer strength of the product, but only the processed carbon fiber layer is used as a wave absorption layer, the wave absorption frequency band is narrow, and the equipment development requirement is difficult to meet.

200810240990.0 discloses a broadband multilayer wave-absorbing composite material and its preparation method, which adopts a multilayer structure form of combining an electric loss type carbon nanotube composite layer and a magnetic loss type carbonyl iron powder composite layer to achieve the broadband wave-absorbing effect. However, the oxidation resistance of the carbonyl iron powder at high temperature is poor, so that the stealth requirements of high-speed aircrafts or special parts needing high-temperature resistance, high-speed hot air impact resistance and the like cannot be met.

CN 112644103A discloses a broadband wave-absorbing force-bearing composite material and a preparation method thereof, and the purpose of broadband wave absorption is achieved by adopting a mode of a wave-transmitting foam layer, a wave-transmitting mask layer, an electric loss wave-absorbing composite material layer, a magnetic loss wave-absorbing patch layer and a reflection layer. The wave-transparent foam material adopts the characteristic of low dielectric of the wave-transparent foam layer as the outermost layer to carry out impedance characteristic matching to obtain excellent wave-absorbing performance, but the foam material adopted as the surface layer has the defects of insufficient mechanical strength, easy breakage and no salt spray acid-base resistance. In addition, the rubber patch is used as a magnetic loss layer, and the rubber substrate has the defects of poor temperature resistance and high bulk density because the temperature resistance is lower than 200 ℃ generally and the density is higher.

Disclosure of Invention

The invention provides a high-temperature-resistant broadband wave-absorbing/bearing composite material and a preparation method thereof.

The technical scheme includes that the high-temperature-resistant broadband wave-absorbing/bearing composite material is 3-10 mm thick and comprises a wave-transmitting layer, an impedance matching layer, an electrical loss wave-absorbing layer, a magnetic loss wave-absorbing layer and a reflecting layer which are sequentially arranged, wherein the wave-transmitting layer, the impedance matching layer, the electrical loss wave-absorbing layer, the magnetic loss wave-absorbing layer and the reflecting layer are all made of fiber reinforced resin matrix composite materials, and the wave-transmitting layer is doped with hollow glass beads.

Furthermore, the thickness of the wave-transmitting layer is 0.2 mm-3 mm, the thickness of the impedance matching layer is 0.2 mm-1 mm, the thickness of the electric loss wave-absorbing layer is 0.2 mm-4 mm, the thickness of the magnetic loss wave-absorbing layer is 0.6 mm-6 mm, and the thickness of the reflecting layer is 0.2 mm-1 mm.

Further, the wave-transmitting layer is made by attaching a blend of resin and hollow glass beads on the fiber cloth; in the blend, the weight percentage of the hollow glass beads is 2-5%.

Further, the impedance matching layer is made by attaching a blend of resin and conductive carbon black to the fiber cloth; in the blend, the weight percentage of the conductive carbon black is 3% -10%.

Further, the electric loss wave absorbing layer is prepared by attaching a blend of resin and an electric loss absorbent on the fiber cloth; in the blend, the weight percentage of the electrical loss absorbent is 15-35%; the electrical loss absorbent is one or more of graphene, conductive carbon black, chopped carbon fiber or other carbon powder.

Furthermore, the magnetic loss wave absorption layer is prepared by attaching a blend of resin and a magnetic loss absorbent on fiber cloth; in the blend, the weight percentage content of the magnetic loss absorbent is 50% -80%; the magnetic loss absorbent is one or more of iron-silicon-chromium, iron-silicon-aluminum, iron-nickel and other alloy powder.

Furthermore, in the fiber reinforced resin matrix composite material of the wave-transparent layer, the impedance matching layer, the electric loss wave-absorbing layer and the magnetic loss wave-absorbing layer, the fiber is one or more of quartz fiber, low-dielectric glass fiber and high-silica fiber; the resin is one or more of high-temperature-resistant modified organic silicon resin, modified phenolic resin, modified epoxy resin, cyanate ester, bismaleimide resin and polyimide resin; the reflecting layer is made of carbon fiber reinforced resin matrix composite.

The invention also relates to a method for preparing the high-temperature-resistant broadband wave-absorbing/bearing composite material, which comprises the following steps:

s1, uniformly mixing the hollow glass beads with resin, coating the mixture on fiber cloth, and drying the fiber cloth until the surface is dry to serve as a wave-transmitting layer for later use;

s2, uniformly mixing the conductive carbon black and the resin, coating the mixture on fiber cloth, heating the mixture at a low temperature to be surface dry, heating the mixture for curing, and repeating the heating and curing for multiple times until the sheet resistance meets the requirements to obtain impedance matching cloth for later use;

s3, uniformly mixing the electrical loss absorbent with resin, coating the mixture on fiber cloth, heating the mixture at a low temperature to be surface dry, heating the mixture to be cured, and repeating the heating and curing for multiple times until the square resistance of the electrical loss wave-absorbing cloth meets the requirement to obtain the electrical loss wave-absorbing cloth for later use;

s4, uniformly mixing the magnetic loss absorbent with resin, coating the mixture on fiber cloth, heating the fiber cloth to be surface-dry at low temperature, heating the fiber cloth to be solidified, and repeating the steps for multiple times until the density of the surface of the magnetic loss wave-absorbing cloth meets the requirement to obtain the magnetic loss wave-absorbing cloth for later use;

s5, coating resin on the carbon fiber cloth, and drying to be surface dry to be used as a reflecting layer for standby;

s6, performing resin pre-dipping treatment on the electric loss wave absorption cloth obtained in the step S3 and the magnetic loss wave absorption cloth obtained in the step S4, respectively coating resin on two surfaces of the wave absorption cloth, heating and drying the wave absorption cloth until the surface is dry, and using the wave absorption cloth as an electric loss wave absorption layer and a magnetic loss wave absorption layer for later use;

s7, stacking and laying the layers of cloth according to the sequence of the wave-transmitting layer, the impedance matching layer, the electric loss wave-absorbing layer, the magnetic loss wave-absorbing layer and the reflecting layer, and then molding by adopting a prepreg molding process of the composite material to obtain the high-temperature-resistant broadband wave-absorbing/bearing composite material.

Furthermore, the sheet resistance in S2 is 2000 Ω/□ -9000 Ω/□. The square resistance of S3 is 40 Ω/□ -1500 Ω/□.

Further, the density of the magnetic loss wave-absorbing cloth cover in S4 is 0.8kg/m²~1.3kg/m²。

The invention has the following beneficial effects:

1. according to the invention, the hollow glass beads are doped in the wave-transmitting layer resin, so that the wave-transmitting layer resin has an ultralow dielectric property, the dielectric and loss of the wave-transmitting layer can be further reduced, the impedance of the wave-transmitting layer is closer to that of an air layer, and electromagnetic waves can penetrate through the wave-transmitting layer from the air layer into the material more easily to obtain the maximum loss. In addition, the electric loss wave-absorbing layer adopts a carbon-based wave-absorbing material, the electric loss wave-absorbing layer has large dielectric and small impedance, the problem of large impedance span between the wave-transmitting layer and the electric loss wave-absorbing layer exists, and if electromagnetic waves directly enter the electric loss wave-absorbing layer from the wave-transmitting layer, larger echo reflection can be generated.

2. Due to the frequency dispersion characteristic of the wave-absorbing material, the single wave-absorbing layer structure has the defect of narrow wave-absorbing frequency band, the invention adopts a multilayer structure form of compounding an electric loss wave-absorbing layer with better high-frequency wave-absorbing effect and a magnetic loss wave-absorbing layer with better low-frequency wave-absorbing effect to widen the wave-absorbing frequency band, thereby having the effect of wave-absorbing frequency bandwidth, and the effective frequency bandwidth exceeds 8 GHz.

3. The invention adopts carbon materials and alloy materials with excellent temperature resistance as absorbents of the electric loss wave-absorbing layer and the magnetic loss wave-absorbing layer respectively. The invention adopts modified organic silicon resin, modified phenolic resin, cyanate ester, bismaleimide resin and polyimide resin with excellent high temperature resistance as the absorbent adhesive matrix. The whole structure system has excellent temperature resistance and can adapt to a high-temperature environment of more than 200 ℃.

4. The invention adopts the low-density carbon absorbent in the electric loss wave-absorbing layer, so that the structural surface density can be greatly reduced, and the surface density can be reduced by 1-2 kg/m by taking a material with the thickness of 5mm as an example²。

5. During specific molding, if the resin and the fiber are directly compounded and then pressurized and cured for molding, under the action of high pressure, micromolecules in the resin in the multilayer structure are heated and volatilized to be difficult to discharge out of the material, and a large number of air holes are formed in the interior. According to the invention, the small molecular solvent in the resin is discharged before curing and pressurizing by adopting a pre-drying surface drying and gradient temperature raising process mode during preparation, the porosity of a material system after composite molding is greatly reduced, and the wave-absorbing load-bearing composite material with excellent mechanical property is obtained, and compared with the process mode which is not adopted, the process mode can improve the tensile strength and the bending strength by 30-50%, and the interlaminar shear strength by 60-100%.

Drawings

FIG. 1 is a schematic structural view of a material provided by the present invention; wherein, 1-wave-transparent layer; 2-an impedance matching layer; 3-an electrical loss wave-absorbing layer; 4-magnetic loss wave-absorbing layer; 5-a reflective layer.

FIG. 2 is a photograph of a high temperature resistant broadband absorbing/supporting composite product of example 1.

Fig. 3 is a test result of the stealth material of the high-temperature-resistant broadband wave-absorbing/load-bearing composite material product in embodiment 1 of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

Example 1:

1) structural design of wave-absorbing structural plate

According to the required performance requirements of the wave-absorbing structure plate, the specific structure is shown in figure 1, the total thickness of the designed structure wave-absorbing material is 5.2mm, wherein the thickness of the wave-transmitting layer is 2.5mm, the thickness of the impedance matching layer is 0.2mm, the thickness of the electric loss wave-absorbing layer is 0.5mm, the thickness of the magnetic loss wave-absorbing layer is 1.8mm, and the thickness of the reflecting layer is 0.2 mm.

Wherein the wave-transmitting layer is a quartz fiber reinforced composite material sprayed by 5 parts by mass of hollow glass microspheres and 95 parts by mass of modified phenolic resin blend; the impedance matching layer is a quartz fiber reinforced composite material sprayed by 8 parts by mass of conductive carbon black and 92 parts by mass of modified organic silicon resin blend; the electric loss wave absorbing layer is a quartz fiber reinforced composite material sprayed with 20 parts by mass of conductive carbon black and 80 parts by mass of modified organic silicon resin blend and 30 parts by mass of conductive carbon black and 70 parts by mass of modified organic silicon resin blend respectively; the magnetic loss wave absorbing layer is a quartz fiber reinforced composite material sprayed by 50 parts by mass of iron-silicon-aluminum alloy powder and 50 parts by mass of modified organic silicon resin; the reflecting layer is made of carbon fiber reinforced modified phenolic resin matrix composite.

2) Preparation of wave-permeable cloth

Fully mixing hollow glass microspheres and a modified phenolic resin adhesive according to a designed mass ratio, weighing a proper amount of the mixed adhesive, uniformly coating the adhesive on quartz fiber cloth with the thickness of 0.12mm in a hand-pasting and blade-coating mode, putting the quartz fiber cloth into an oven after multilayer combined spraying, heating to 80 ℃ for 2h, and drying to obtain 2.5mm transparent wave cloth.

3) Impedance matching cloth preparation

Fully mixing and uniformly stirring the conductive carbon black and the modified organic silicon resin adhesive according to the designed mass ratio, uniformly spraying the mixed coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed coating in an oven for 2h at 60 ℃, heating the coating for surface drying, heating the coating to 180 ℃ for 2h, curing, and repeating the steps for many times until the impedance matching cloth square resistance reaches 3.6k omega/□.

4) Preparation of electric loss wave absorption cloth

Fully mixing the conductive carbon black and the modified organic silicon resin adhesive according to the designed mass ratio, uniformly stirring to prepare the wave-absorbing coating, uniformly spraying the wave-absorbing coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed wave-absorbing coating into an oven for heating at 60 ℃ for 2h, drying the surface of the coated wave-absorbing coating, heating to 180 ℃ for 2h, and curing, wherein the steps are repeated for a plurality of times until 20wt% of electric loss wave-absorbing square resistance reaches 900 omega/□ and 30wt% of electric loss wave-absorbing square resistance reaches 260 omega/□.

5) Preparation of magnetic loss wave absorption cloth

Fully mixing the iron-silicon-aluminum powder with the modified organic silicon resin adhesive according to the designed mass ratio, uniformly stirring to prepare the wave-absorbing coating, uniformly spraying the wave-absorbing coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed wave-absorbing coating into a drying oven for heating at 60 ℃ for 2h, drying the surface of the coated wave-absorbing coating, heating to 180 ℃ for 2h, curing, and repeating for multiple times until the density of the magnetic loss wave-absorbing cloth surface reaches 1.2kg/m²。

6) Preparation of reflective cloth

The modified phenolic resin is uniformly coated on carbon fiber cloth with the thickness of 0.2mm by adopting a hand-pasting and blade-coating mode, and the carbon fiber cloth is put into an oven after being coated for 2 hours at the temperature of 60 ℃ and then is heated to 80 ℃ for 2 hours and then is dried.

7) Pre-dipping treatment for electric loss wave absorbing cloth and magnetic loss wave absorbing cloth

The modified phenolic resin is respectively coated on two sides of the electric loss wave absorbing cloth and the magnetic loss wave absorbing cloth by a spraying or coating process, and the electric loss wave absorbing cloth and the magnetic loss wave absorbing cloth are placed in an oven for 2 hours at 60 ℃ and then heated to 80 ℃ for 2 hours for surface drying.

8) And (4) stacking and laying each layer of cloth according to a preset laying mode, and integrally forming by adopting a composite material mould pressing process. The pressure is 1MPa, and the temperature is 120 ℃ for 2 h; the pressure of the second section is 3MPa, and the temperature is 180 ℃ for 2 h. A photograph of the product is shown in figure 2.

The wave-absorbing material with the structure is baked for 20min at 350 ℃, and has no cracking and no foaming. The results of the test using the product obtained in this example as a stealth material are shown in FIG. 3. The reflectivity is less than or equal to-8 dB in the frequency range of 2GHz to 4GHz, and the reflectivity is less than or equal to-6 dB in the frequency range of 4GHz to 18 GHz. The tensile strength of the wave-absorbing material with the structure is 166.2MPa, the bending strength is 115.2MPa, and the interlaminar shear strength is 12.3 MPa.

Example 2:

1) structural design of wave-absorbing structural plate

According to the required performance requirements of the wave-absorbing structure plate, the total thickness of the wave-absorbing material of the designed structure is 3.5mm, wherein the thickness of the wave-transmitting layer is 2mm, the thickness of the impedance matching layer is 0.2mm, the thickness of the electric loss wave-absorbing layer is 0.5mm, the thickness of the magnetic loss wave-absorbing layer is 0.6mm, and the thickness of the reflecting layer is 0.2 mm. Wherein the wave-transmitting layer is a quartz fiber reinforced composite material sprayed by 3 parts by mass of hollow glass microspheres and 97 parts by mass of modified organic silicon resin blend; the impedance matching layer is a quartz fiber reinforced composite material sprayed by 5 parts by mass of conductive carbon black and 95 parts by mass of modified organic silicon resin blend; the electric loss wave absorbing layer is a quartz fiber reinforced composite material sprayed with 15 parts by mass of conductive carbon black and 85 parts by mass of modified organic silicon resin blend and 25 parts by mass of conductive carbon black and 75 parts by mass of modified organic silicon resin blend respectively; the magnetic loss wave absorbing layer is a quartz fiber reinforced composite material sprayed by 60 parts by mass of iron-silicon-chromium alloy powder and 40 parts by mass of modified organic silicon resin blend; the reflecting layer is made of carbon fiber reinforced modified organic silicon resin matrix composite.

2) Preparation of wave-permeable cloth

Fully mixing the hollow glass beads with the modified organic silicon resin adhesive according to the designed mass ratio, weighing a proper amount of the mixed adhesive, uniformly coating the adhesive on quartz fiber cloth with the thickness of 0.12mm in a hand-pasting and blade-coating mode, putting the quartz fiber cloth into an oven after spraying, heating the quartz fiber cloth to 80 ℃ for 2 hours, and drying the quartz fiber cloth.

3) Impedance matching cloth preparation

Fully mixing and uniformly stirring the conductive carbon black and the modified organic silicon resin adhesive according to the designed mass ratio, uniformly spraying the mixed coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed coating in an oven at 40 ℃ for 4h, at 80 ℃ for 2h, at 120 ℃ for 2h, heating, surface-drying, heating to 180 ℃ for 4h, curing, and repeating for many times until the square resistance of the impedance matching cloth reaches 4.5k omega/□.

4) Preparation of electric loss wave absorption cloth

Fully mixing the conductive carbon black and the modified organic silicon resin adhesive according to the designed mass ratio, uniformly stirring to prepare the wave-absorbing coating, uniformly spraying the wave-absorbing coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed mixture into a drying oven, heating the mixture for surface drying at 40 ℃ for 4h, at 80 ℃ for 2h and at 120 ℃ for 2h, heating the mixture to 180 ℃ for 4h, curing the mixture, and repeating the steps for a plurality of times until the 15wt% electric loss wave-absorbing square resistance reaches 1300 omega/□, and the 25wt% electric loss wave-absorbing square resistance reaches 360 omega/□.

5) Preparation of magnetic loss wave absorption cloth

Fully mixing the ferrosilicon aluminum powder and the modified organic silicon resin adhesive according to the designed mass ratio, uniformly stirring to prepare the wave-absorbing coating, uniformly spraying the wave-absorbing coating on 0.12mm thick quartz fiber cloth by using a spray gun, putting the sprayed mixture into a drying oven for heating and surface drying at 40 ℃ for 4h, at 80 ℃ for 2h and at 120 ℃ for 2h, heating to 180 ℃ for 4h, curing, and repeating for multiple times until the density of the magnetic loss wave-absorbing cloth surface reaches 0.96kg/m²。

6) Preparation of reflective cloth

The modified phenolic resin is uniformly coated on carbon fiber cloth with the thickness of 0.2mm by adopting a hand-pasting and blade-coating mode, and the carbon fiber cloth is put into an oven after being coated for 4 hours at the temperature of 60 ℃ and then is heated to 80 ℃ for 2 hours and then is dried.

7) Pre-dipping treatment for electric loss wave absorbing cloth and magnetic loss wave absorbing cloth

The modified phenolic resin is respectively coated on two sides of the electric loss wave absorbing cloth and the magnetic loss wave absorbing cloth by a spraying or coating process, and the electric loss wave absorbing cloth and the magnetic loss wave absorbing cloth are placed in an oven for 2 hours at 60 ℃ and then heated to 80 ℃ for 2 hours for surface drying.

8) And (4) stacking and laying the cloth layers according to a preset laying mode, and integrally forming by adopting a composite material bag pressing process. The first-stage curing temperature is 120 ℃ for 2h, and the second-stage curing temperature is 180 ℃ for 4 h.

The wave-absorbing material with the structure is baked for 3min at 450 ℃, and has no cracking and no foaming. The reflectivity is less than or equal to-3 dB in the frequency range of 4GHz to 8GHz, and the reflectivity is less than or equal to-6 dB in the frequency range of 8GHz to 18 GHz. The tensile strength of the wave-absorbing material with the structure is 143.6MPa, the bending strength is 96.7MPa, and the interlaminar shear strength is 10.2 MPa.

Example 3:

1) structural design of wave-absorbing structural plate

According to the required performance requirements of the wave-absorbing structure plate, the total thickness of the wave-absorbing material of the designed structure is 6mm, wherein the thickness of the wave-transmitting layer is 2.5mm, the thickness of the impedance matching layer is 0.5mm, the thickness of the electric loss wave-absorbing layer is 1mm, the thickness of the magnetic loss wave-absorbing layer is 1.8mm, and the thickness of the reflecting layer is 0.2 mm. Wherein the wave-transmitting layer is a quartz fiber reinforced composite material sprayed by 5 parts by mass of hollow glass microspheres and 95 parts by mass of modified epoxy resin blend; the impedance matching layer is a quartz fiber reinforced composite material sprayed by 8 parts by mass of conductive carbon black and 92 parts by mass of modified epoxy resin blend; the electric loss wave absorbing layer is a quartz fiber reinforced composite material sprayed by 20 parts by mass of conductive carbon black and 80 parts by mass of modified epoxy resin blend and 30 parts by mass of conductive carbon black and 70 parts by mass of modified epoxy resin blend respectively; the magnetic loss wave absorbing layer is a quartz fiber reinforced composite material sprayed by 30 parts by mass of iron-silicon-aluminum alloy powder, 30 parts by mass of iron-silicon-chromium alloy powder and 40 parts by mass of modified epoxy resin blend; the reflecting layer is made of carbon fiber reinforced modified epoxy resin matrix composite.

2) Preparation of wave-permeable cloth

Fully mixing the hollow glass beads with the modified epoxy resin adhesive according to the designed mass ratio, weighing a proper amount of the mixed adhesive, uniformly coating the adhesive on quartz fiber cloth with the thickness of 0.12mm in a hand-pasting and blade-coating mode, and placing the quartz fiber cloth in an oven for surface drying at the temperature of 80 ℃ for 2 hours after the coating.

3) Impedance matching cloth preparation

Fully mixing and uniformly stirring the conductive carbon black and the modified epoxy resin adhesive according to the designed mass ratio, uniformly spraying the mixed coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the quartz fiber cloth into an oven after spraying for 2 hours at 80 ℃, heating for 4 hours at 120 ℃, drying the surface of the quartz fiber cloth, heating to 160 ℃ for 2 hours, curing, and repeating the steps for many times until the impedance matching cloth square resistance reaches 3.6 komega/□.

4) Preparation of electric loss wave absorption cloth

Fully mixing conductive carbon black and a modified epoxy resin adhesive according to a designed mass ratio, uniformly stirring to prepare a wave-absorbing coating, uniformly spraying the wave-absorbing coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed wave-absorbing coating into a drying oven for 2 hours at 80 ℃, heating the surface for 4 hours at 120 ℃, then heating the surface to be dried, raising the temperature to 160 ℃ for 2 hours, curing, repeating the steps for a plurality of times until 20wt% of electric loss wave-absorbing square resistance reaches 760 omega/□, and 30wt% of electric loss wave-absorbing square resistance reaches 260 omega/□ and 80 omega/□ respectively.

5) Preparation of magnetic loss wave absorption cloth

Fully mixing iron-silicon-aluminum powder, iron-silicon-chromium powder and a modified epoxy resin adhesive according to the designed mass ratio, uniformly stirring to prepare a wave-absorbing coating, uniformly spraying the wave-absorbing coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the coated quartz fiber cloth into a drying oven for 2 hours at the temperature of 80 ℃, heating the quartz fiber cloth for 4 hours at the temperature of 120 ℃, drying the quartz fiber cloth, heating the quartz fiber cloth to the temperature of 160 ℃ for 2 hours, curing, and repeating the steps for multiple times until the density of the magnetic loss wave-absorbing cloth surface reaches 0.96kg/m²。

6) Preparation of reflective cloth

The modified epoxy resin is uniformly coated on carbon fiber cloth with the thickness of 0.2mm by adopting a hand-pasting and blade-coating mode, and the carbon fiber cloth is placed in an oven for surface drying at the temperature of 80 ℃ for 2h after being coated.

7) Pre-dipping treatment for electric loss wave absorbing cloth and magnetic loss wave absorbing cloth

The modified phenolic resin is respectively coated on the two sides of the electric loss wave-absorbing cloth and the magnetic loss wave-absorbing cloth by a spraying or coating process, and the electric loss wave-absorbing cloth and the magnetic loss wave-absorbing cloth are placed in an oven for surface drying at 80 ℃ for 2 hours.

8) And (4) stacking and laying each layer of cloth according to a preset laying mode, and integrally forming by adopting a composite material mould pressing process. The pressure is 3MPa, and the temperature is 120 ℃ for 4 h; the pressure of the second section is 3MPa, and the temperature is 160 ℃ for 2 h.

The wave-absorbing material with the structure is baked for 4 hours at 250 ℃, and has no cracking and no foaming. The reflectivity is less than or equal to-8 dB within the frequency range of 4 GHz-18 GHz. The tensile strength of the wave-absorbing material with the structure is 201.3MPa, the bending strength is 153.6MPa, and the interlaminar shear strength is 19.8 MPa.

Example 4

1) Structural design of wave-absorbing structural plate

According to the required performance requirements of the wave-absorbing structure plate, the total thickness of the wave-absorbing material of the designed structure is 3.9mm, wherein the thickness of the wave-transmitting layer is 2mm, the thickness of the impedance matching layer is 0.2mm, the thickness of the electric loss wave-absorbing layer is 0.3mm, the thickness of the magnetic loss wave-absorbing layer is 1.2mm, and the thickness of the reflecting layer is 0.2 mm. Wherein the wave-transmitting layer is a quartz fiber reinforced composite material sprayed by 2 parts by mass of hollow glass microspheres and 98 parts by mass of modified epoxy resin blend; the impedance matching layer is a quartz fiber reinforced composite material sprayed by 10 parts by mass of conductive carbon black and 90 parts by mass of modified epoxy resin blend; the electric loss wave absorbing layer is a quartz fiber reinforced composite material sprayed by 20 parts by mass of conductive carbon black and 80 parts by mass of modified epoxy resin blend; the magnetic loss wave absorbing layer is a quartz fiber reinforced composite material sprayed by 30 parts by mass of iron-silicon-aluminum alloy powder, 30 parts by mass of iron-silicon-chromium alloy powder and 40 parts by mass of modified epoxy resin blend; the reflecting layer is made of carbon fiber reinforced modified epoxy resin matrix composite.

2) Preparation of wave-permeable cloth

Fully mixing the hollow glass beads with the modified epoxy resin adhesive according to the designed mass ratio, weighing a proper amount of the mixed adhesive, uniformly coating the adhesive on quartz fiber cloth with the thickness of 0.12mm in a hand-pasting and blade-coating mode, and placing the quartz fiber cloth in an oven for surface drying at the temperature of 80 ℃ for 2 hours after the coating.

3) Impedance matching cloth preparation

Fully mixing and uniformly stirring the conductive carbon black and the modified epoxy resin adhesive according to the designed mass ratio, uniformly spraying the mixed coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the quartz fiber cloth into an oven after spraying for 2 hours at 80 ℃, heating for 4 hours at 120 ℃, drying the surface of the quartz fiber cloth, heating to 160 ℃ for 2 hours, curing, and repeating the steps for many times until the impedance matching cloth square resistance reaches 2.4 kOmega/□.

4) Preparation of electric loss wave absorption cloth

Fully mixing the conductive carbon black and the modified epoxy resin adhesive according to the designed mass ratio, uniformly stirring to prepare the wave-absorbing coating, uniformly spraying the wave-absorbing coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed mixture into a drying oven for 2 hours at the temperature of 80 ℃, heating the mixture for 4 hours at the temperature of 120 ℃, drying the mixture, heating the mixture to the temperature of 160 ℃ for 2 hours, curing the mixture, and repeating the steps for a plurality of times until the square resistance of 20wt% of the electric loss wave-absorbing cloth reaches 540 omega/□

5) Preparation of magnetic loss wave absorption cloth

Mixing the ferrosilicon aluminum powder, the ferrosilicon chromium powder and the modified epoxy resin adhesive according to the designed mass ratioFully mixing, stirring uniformly to prepare a wave-absorbing coating, uniformly spraying the wave-absorbing coating on quartz fiber cloth with the thickness of 0.12mm by using a spray gun, putting the sprayed coating into a drying oven for 2 hours at the temperature of 80 ℃, heating the surface for 4 hours at the temperature of 120 ℃, drying the surface, heating the surface to 160 ℃ for 2 hours, curing, and repeating the steps for multiple times until the density of the magnetic loss wave-absorbing cloth surface reaches 0.96kg/m²。

6) Preparation of reflective cloth

The modified epoxy resin is uniformly coated on carbon fiber cloth with the thickness of 0.2mm by adopting a hand-pasting and blade-coating mode, and the carbon fiber cloth is placed in an oven for surface drying at the temperature of 80 ℃ for 2h after being coated.

7) Pre-dipping treatment for electric loss wave absorbing cloth and magnetic loss wave absorbing cloth

The modified phenolic resin is respectively coated on the two sides of the electric loss wave-absorbing cloth and the magnetic loss wave-absorbing cloth by a spraying or coating process, and the electric loss wave-absorbing cloth and the magnetic loss wave-absorbing cloth are placed in an oven for surface drying at 80 ℃ for 2 hours.

8) And (4) stacking and laying each layer of cloth according to a preset laying mode, and integrally forming by adopting a composite material mould pressing process. The pressure is 3MPa, and the temperature is 120 ℃ for 4 h; the pressure of the second section is 3MPa, and the temperature is 160 ℃ for 2 h.

The wave-absorbing material with the structure is baked for 4 hours at 250 ℃, and has no cracking and no foaming. The reflectivity is less than or equal to-6 dB within the frequency range of 4 GHz-18 GHz. The tensile strength of the wave-absorbing material with the structure is 221.7MPa, the bending strength is 169.6MPa, and the interlaminar shear strength is 20.2 MPa.

In the above examples, all the resins used were high temperature resistant modified resins.

Wherein the modified phenolic resin can be THC-400 boron phenolic resin of Shaanxi Taihang fire retardant polymer Co Ltd; the modified organic silicon resin can be SH-9601 organic silicon resin of chemical industry Co., Ltd in New four seas in Hubei; the modified epoxy resin can be EPU polyurethane modified epoxy resin of the company Limited responsibility of the institute of oceanic chemical industry.