阅读说明：本技术 一种共固化吸波复合材料及其制备方法 (Co-curing wave-absorbing composite material and preparation method thereof ) 是由 李阳 吕通 李旻 闫丽生 李洋 宫元勋 于 2021-08-24 设计创作，主要内容包括：本发明提供了一种共固化吸波复合材料及其制备方法,该制备方法包括如下步骤：(1)在成型模具上铺覆至少一层第一预浸料,然后进行预压实,得到复合材料基体；(2)在所述复合材料基体上铺覆至少一层用作反射层的第二预浸料,然后进行预压实,得到包含反射层的复合材料基体；(3)在所述包含反射层的复合材料基体上铺覆至少一层吸波胶膜,得到吸波复合材料基体；其中,所述吸波胶膜包含：吸波剂和吸波树脂；(4)在所述吸波复合材料基体上铺覆至少一层用作阻抗匹配层的第三预浸料,然后进行固化处理,得到所述共固化吸波复合材料。本方案提供的共固化吸波复合材料的制备工序简单,且具有优异的力学性能。(The invention provides a co-curing wave-absorbing composite material and a preparation method thereof, wherein the preparation method comprises the following steps: (1) paving at least one layer of first prepreg on a forming die, and then performing pre-compaction to obtain a composite material matrix; (2) paving at least one layer of second prepreg used as a reflecting layer on the composite material matrix, and then performing pre-compaction to obtain the composite material matrix containing the reflecting layer; (3) paving at least one wave-absorbing adhesive film layer on the composite material matrix containing the reflecting layer to obtain a wave-absorbing composite material matrix; wherein, the ripples glued membrane that absorbs water contains: wave absorbing agent and wave absorbing resin; (4) and paving at least one layer of third prepreg used as an impedance matching layer on the wave-absorbing composite material matrix, and then carrying out curing treatment to obtain the co-cured wave-absorbing composite material. The co-curing wave-absorbing composite material provided by the scheme is simple in preparation process and has excellent mechanical properties.)

1. A preparation method of a co-cured wave-absorbing composite material is characterized by comprising the following steps:

(1) paving at least one layer of first prepreg on a forming die, and then performing pre-compaction to obtain a composite material matrix;

(2) paving at least one layer of second prepreg used as a reflecting layer on the composite material matrix, and then performing pre-compaction to obtain the composite material matrix containing the reflecting layer;

(3) paving at least one wave-absorbing adhesive film layer on the composite material matrix containing the reflecting layer to obtain a wave-absorbing composite material matrix; wherein, the ripples glued membrane that absorbs water contains: wave absorbing agent and wave absorbing resin;

(4) and paving at least one layer of third prepreg used as an impedance matching layer on the wave-absorbing composite material matrix to obtain the wave-absorbing composite material matrix containing the impedance matching layer, and then carrying out curing treatment to obtain the co-cured wave-absorbing composite material.

2. The production method according to claim 1, wherein in step (1):

the first prepreg is formed by compounding fiber cloth and prepreg resin;

the fiber cloth is at least one selected from quartz fiber cloth, glass fiber cloth, boron fiber cloth and carbon fiber cloth;

the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin;

the thickness of the first prepreg is 0.15-0.25 mm; and/or

And pre-compacting after two or three layers of the prepreg are paved.

3. The production method according to claim 1, wherein in step (2):

the second prepreg is a carbon fiber prepreg formed by compounding carbon fiber cloth and prepreg resin; wherein the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin;

the thickness of the reflecting layer is more than or equal to 0.2 mm; and/or

And pre-compacting after each layer or two layers of the second prepreg are laid.

4. The method of claim 1, wherein:

in the step (1) and the step (2), the pre-compaction temperature is 25-40 ℃, the pressure is 0.8-3MPa, and the pre-compaction time is 10-15 min.

5. The production method according to claim 1, wherein in step (3):

the wave absorbing agent is at least one selected from ferrite powder, carbonyl iron powder, conductive carbon black, carbon fiber, silicon carbide fiber, carbon nano tube and graphene;

the wave-absorbing resin is at least one selected from epoxy resin, polyurethane resin, cyanate resin and polyimide resin.

6. The production method according to claim 1, wherein in step (3):

the thickness of the wave-absorbing adhesive film is 0.1-5 mm;

the mass ratio of the wave absorbing agent to the wave absorbing resin in the wave absorbing adhesive film is 1-17: 20.

7. The production method according to claim 1, wherein in step (3):

when the mass fraction of the wave absorbing agent in the wave absorbing adhesive film is more than or equal to 75 percent, the method also comprises the step of laying a layer of resin film after laying each layer of the wave absorbing adhesive film; wherein the resin film is at least one selected from the group consisting of a cyanate resin film, a urethane resin film, an epoxy resin film, a phenol resin film, a polyimide resin film, and a bismaleimide resin; and/or;

and pre-compacting after one or two layers of the wave-absorbing adhesive films are paved.

8. The production method according to claim 1, wherein in step (4):

the third prepreg is formed by compounding prepreg resin and glass fiber cloth or quartz fiber cloth; wherein the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin; and/or

And pre-compacting after each layer or two layers of the third prepreg are laid.

9. The production method according to any one of claims 1 to 8, characterized in that:

in the step (4), the curing temperature of the curing treatment is 90-350 ℃, the curing time is 100-.

10. A co-cured wave-absorbing composite material, characterized in that it is prepared by the preparation method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of wave-absorbing materials, in particular to a co-curing wave-absorbing composite material and a preparation method thereof.

Background

The wave-absorbing material is a functional material which can be used for attenuating incident radar waves so as to reduce the radar scattering cross section, and is widely applied to the fields of airplane stealth, ship stealth, flying missile stealth, tank stealth and the like.

At present, the existing wave-absorbing composite material is usually prepared by spraying a wave-absorbing coating on the surface of the composite material or sticking a wave-absorbing patch, and an obvious interface exists between a wave-absorbing layer of the obtained wave-absorbing composite material and the composite material, so that debonding and layering are easily caused between the wave-absorbing coating or the wave-absorbing patch and the composite material, the mechanical property and the service life of the wave-absorbing composite material are influenced, and the maintenance cost is increased; meanwhile, when the wave-absorbing composite material is prepared by adopting the method, the composite material is prepared in advance, and then the wave-absorbing coating is sprayed or the wave-absorbing patch is pasted, so that the preparation process of the wave-absorbing composite material is increased, and the production cost is increased.

Therefore, a wave-absorbing composite material with simple preparation process and excellent mechanical property is urgently needed.

Disclosure of Invention

The invention provides a co-curing wave-absorbing composite material and a preparation method thereof.

In a first aspect, the invention provides a preparation method of a co-cured wave-absorbing composite material, which comprises the following steps:

(1) paving at least one layer of first prepreg on a forming die, and then performing pre-compaction to obtain a composite material matrix;

(2) paving at least one layer of second prepreg used as a reflecting layer on the composite material matrix, and then performing pre-compaction to obtain the composite material matrix containing the reflecting layer;

(3) paving at least one wave-absorbing adhesive film layer on the composite material matrix containing the reflecting layer to obtain a wave-absorbing composite material matrix; wherein, the ripples glued membrane that absorbs water contains: wave absorbing agent and wave absorbing resin;

(4) and paving at least one layer of third prepreg used as an impedance matching layer on the wave-absorbing composite material matrix to obtain the wave-absorbing composite material matrix containing the impedance matching layer, and then carrying out curing treatment to obtain the co-cured wave-absorbing composite material.

Preferably, in the step (1), the first prepreg is compounded by fiber cloth and prepreg resin;

the fiber cloth is at least one selected from quartz fiber cloth, glass fiber cloth, boron fiber cloth and carbon fiber cloth;

the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin;

the thickness of the first prepreg is 0.15-0.25 mm.

Preferably, in step (1), pre-compaction is performed after each lay-up of two or three layers of the prepreg.

Preferably, in the step (2), the second prepreg is a carbon fiber prepreg formed by compounding carbon fiber cloth and prepreg resin; wherein the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin;

the thickness of the reflecting layer is more than or equal to 0.2 mm.

Preferably, in step (2), pre-compaction is performed after each lay-up of one or two layers of the second prepreg.

Preferably, in the step (1) and the step (2), the pre-compaction temperature is 25-40 ℃, the pressure is 0.8-3MPa, and the pre-compaction time is 10-15 min.

Preferably, in the step (3), the wave absorbing agent is at least one selected from ferrite powder, carbonyl iron powder, conductive carbon black, carbon fiber, silicon carbide fiber, carbon nanotube and graphene;

the wave-absorbing resin is at least one selected from epoxy resin, polyurethane resin, cyanate resin and polyimide resin.

Preferably, in the step (3), the thickness of the wave-absorbing glue film is 0.1-5 mm;

the mass ratio of the wave absorbing agent to the wave absorbing resin in the wave absorbing adhesive film is 1-17: 20.

Preferably, in the step (3), when the mass fraction of the wave absorbing agent in the wave absorbing adhesive film is more than or equal to 75%, the method further comprises the step of paving a resin film after paving one layer of the wave absorbing adhesive film; wherein the resin film is at least one selected from the group consisting of cyanate resin film, urethane resin film, epoxy resin film, phenol resin film, polyimide resin film and bismaleimide resin.

Preferably, in the step (3), pre-compaction is performed after at least one or two layers of the wave-absorbing adhesive films are laid.

Preferably, in the step (4), the third prepreg is formed by compounding prepreg resin and glass fiber cloth or quartz fiber cloth; wherein the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin.

Preferably, in step (4), pre-compaction is performed after each lay-up of one or two layers of the third prepreg.

Preferably, in the step (4), the curing temperature of the curing treatment is 90-350 ℃, the curing time is 100-240min, and the curing pressure is 0.075-0.7 MPa.

In a second aspect, the invention provides a co-cured wave-absorbing composite material prepared by the preparation method of the first aspect of the invention.

Compared with the prior art, the invention at least has the following beneficial effects:

the co-curing wave-absorbing composite material prepared by the invention comprises a reflecting layer, a wave-absorbing layer and an impedance matching layer, wherein carbon fiber prepreg serving as the reflecting layer, a wave-absorbing adhesive film serving as the wave-absorbing layer and glass fiber prepreg serving as the impedance matching layer are sequentially paved on a composite material substrate, and then co-curing is carried out to form the wave-absorbing composite material integrally. Therefore, the wave-absorbing layer and the composite material matrix are directly solidified into a whole, and no obvious interface is generated between the wave-absorbing layer and the composite material matrix, so that the phenomena of layering and debonding are not easy to generate, the co-solidified wave-absorbing composite material has excellent mechanical property and wave-absorbing property, the service life of the co-solidified wave-absorbing composite material is prolonged, and the maintenance cost is reduced. Meanwhile, the co-curing wave-absorbing composite material prepared based on the co-curing method also reduces the production and preparation procedures and reduces the production cost.

Drawings

FIG. 1 is a schematic structural view of a co-cured wave-absorbing composite material prepared according to the present invention;

FIG. 2 is a reflectivity curve diagram of a co-cured wave-absorbing composite material prepared in example 2 of the present invention;

FIG. 3 is a reflectivity curve diagram of the co-cured wave-absorbing composite material prepared in example 3 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.

The invention provides a preparation method of a co-curing wave-absorbing composite material, which comprises the following steps:

(1) paving at least one layer of first prepreg on a forming die, and then performing pre-compaction to obtain a composite material matrix;

(2) paving at least one layer of second prepreg used as a reflecting layer on the composite material matrix, and then performing pre-compaction to obtain the composite material matrix containing the reflecting layer;

(3) paving at least one wave-absorbing adhesive film layer on the composite material matrix containing the reflecting layer to obtain a wave-absorbing composite material matrix; wherein, the ripples glued membrane that absorbs water contains: wave absorbing agent and wave absorbing resin;

(4) and paving at least one layer of third prepreg used as an impedance matching layer on the wave-absorbing composite material matrix to obtain the wave-absorbing composite material matrix containing the impedance matching layer, and then carrying out curing treatment to obtain the co-cured wave-absorbing composite material.

The forming mold may be made of a material such as metal (e.g., carbon steel, invar steel, etc.), a composite material (e.g., carbon fiber composite material, glass fiber composite material, etc.), wood, etc. For a newly processed forming die, the forming die needs to be cleaned for 2-3 times by gasoline to remove oil stains on the surface; then cleaning for 2-3 times by using acetone to remove gasoline and other impurities; finally, a release agent or release wax is coated on the molding surface of the molding die. For non-newly processed forming dies, gasoline cleaning is not required.

It should be noted that when the release agent or the release wax is coated, clean and dry dust-free cloth or cotton cloth is needed to be wiped, and at the same time, the interval is 10-15min when the release agent or the release wax is coated each time, so that the release agent can be better coated on the surface of the forming mold. More preferably, the release agent or release wax is brushed a total of 3 times.

According to some preferred embodiments, in step (1), the first prepreg is compounded by a fiber cloth and a prepreg resin;

the fiber cloth is at least one selected from quartz fiber cloth, glass fiber cloth, boron fiber cloth and carbon fiber cloth;

the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin;

the first prepreg has a thickness of 0.15 to 0.25mm (e.g. may be 0.15mm, 0.2mm, 0.22mm or 0.25 mm).

According to some more preferred embodiments, the first prepreg has a thickness of 0.2 mm.

At least one of them is a mixture of any one or any several of them mixed in any ratio.

According to some preferred embodiments, in step (1), pre-compaction is performed after each two or three plies of the prepreg have been laid down.

According to some preferred embodiments, in the step (2), the second prepreg is a carbon fiber prepreg compounded by carbon fiber cloth and prepreg resin; wherein the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin;

the thickness of the reflective layer is 0.2mm or more (for example, 0.2mm, 0.4mm, 1mm, 1.5mm or 2 mm).

In the invention, the carbon fiber has good dielectric and conductive capacities and is a dielectric loss type wave-absorbing material. When electromagnetic waves propagate among the carbon fibers, in addition to electromagnetic energy loss caused by the skin effect, part of the electromagnetic waves are scattered among the carbon fiber bundles to generate a phase cancellation-like phenomenon, so that the reflection of the electromagnetic waves can be reduced, and part of the energy of the electromagnetic waves can be consumed. Meanwhile, the continuous carbon fiber cloth has good conductivity and can generate strong reflection effect on electromagnetic waves, so that the continuous carbon fiber cloth can be used as a reflection layer to reflect the electromagnetic waves and be secondarily lost, and the wave absorbing performance of the co-curing wave absorbing composite material is further improved.

According to some preferred embodiments, in step (2), pre-compaction is performed after each laying of one or two layers of the second prepreg.

According to some preferred embodiments, in the step (1) and the step (2), the pre-compaction temperature of the pre-compaction is 25 to 40 ℃ (for example, 25 ℃, 30 ℃, 35 ℃ or 40 ℃), the pressure is 0.8 to 3MPa (for example, 0.8MPa, 1MPa, 1.5MPa, 2MPa, 2.5MPa or 3MPa may be used), and the pre-compaction time is 10 to 15min (for example, 10min, 11min, 12min, 13min, 14min or 15min may be used).

According to some preferred embodiments, in the step (3), the wave absorbing agent is at least one selected from ferrite powder, carbonyl iron powder, conductive carbon black, carbon fiber, silicon carbide fiber, carbon nanotube and graphene;

the wave-absorbing resin is at least one selected from epoxy resin, polyurethane resin, cyanate resin and polyimide resin.

According to some preferred embodiments, in step (3), the thickness of the wave-absorbing adhesive film is 0.1-5mm (for example, it may be 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5 mm);

the mass ratio of the wave absorbing agent to the wave absorbing resin in the wave absorbing adhesive film is 1-17:20 (for example, 1:20, 2:20, 5:20, 10:20, 15:20 or 17: 20).

In the invention, the wave-absorbing adhesive film can be obtained according to the wave-absorbing adhesive film material with the application number of CN202010950674.3 and the preparation method disclosed by the preparation method, the wave-absorbing adhesive film material produced by the mixing and calendering method has no problem of wave-absorbing agent sedimentation, the interior of the adhesive film is compact and uniform, the stability of batch production is improved, an organic solvent is not used in the whole production process, and the production cost is effectively reduced while the problem of environmental protection is solved.

According to some preferred embodiments, in the step (3), when the mass fraction of the wave-absorbing agent in the wave-absorbing adhesive film is greater than or equal to 75% (for example, it may be 75%, 80%, 85%, or 90%), the method further comprises the step of laying a resin film after each layer of the wave-absorbing adhesive film is laid; wherein the resin film is at least one selected from the group consisting of a cyanate resin film, a urethane resin film, an epoxy resin film, a phenol resin film, a polyimide resin film, and a bismaleimide resin.

In the invention, when the content of the wave absorbing agent in the wave absorbing adhesive films is more than or equal to 75 percent, a layer of resin film is required to be laid between each layer of wave absorbing adhesive film to increase the bonding strength between the wave absorbing adhesive films and avoid layering and debonding between the wave absorbing adhesive films, thereby ensuring the mechanical property of the co-cured wave absorbing composite material.

According to some preferred embodiments, in step (3), pre-compaction is performed after each one or two layers of the wave-absorbing adhesive film are laid. And when the mass fraction of the wave absorbing agent in the wave absorbing adhesive film is more than or equal to 75%, pre-compacting after the wave absorbing adhesive film and the resin film are sequentially paved.

According to some more preferred embodiments, in step (3), the pre-compaction temperature for pre-compaction is 25 to 40 ℃ (e.g., may be 25 ℃, 30 ℃, 35 ℃ or 40 ℃), the pressure is 0.8 to 3MPa (e.g., may be 0.8MPa, 1MPa, 1.5MPa, 2MPa, 2.5MPa or 3MPa), and the pre-compaction time is 10 to 15min (e.g., may be 10min, 11min, 12min, 13min, 14min or 15 min).

Specifically, when the size of the wave-absorbing adhesive film is less than or equal to 500mm multiplied by 500mm, pre-compaction can be performed after 2 layers of wave-absorbing adhesive films are laid; when the size of the wave-absorbing adhesive film is more than 500mm multiplied by 500mm, 1 layer of wave-absorbing adhesive film needs to be paved for one-time pre-compaction so as to completely discharge gas between layers during paving and avoid bubbles, bulges and the like from influencing the mechanical property of the co-curing wave-absorbing composite material. More specifically, the thickness of the paved wave-absorbing adhesive film can be calculated according to the requirement on the wave-absorbing performance of the composite material.

In the invention, the paving manufacturability of the wave-absorbing adhesive film is not influenced by the thickness of the wave-absorbing adhesive film and the paving curved surface, is suitable for paving various curved surfaces, has higher technological operability than the wave-absorbing paster, and is more convenient to operate. And the wave-absorbing adhesive film with the same thickness have better wave-absorbing performance than the wave-absorbing adhesive film, so that when the wave-absorbing adhesive film is paved on a composite material with specific wave-absorbing performance requirements, multiple layers of the wave-absorbing adhesive film need to be paved, the composite material is too thick, the paving manufacturability is further influenced, and the mechanical property of the obtained composite material is also influenced due to the lower adhesive force.

According to some more preferred embodiments, in the step (4), the third prepreg is formed by compounding prepreg resin with glass fiber cloth or quartz fiber cloth; wherein the prepreg resin is at least one selected from cyanate ester resin, epoxy resin, polyurethane resin, phenolic resin, polyimide resin and bismaleimide resin.

According to some preferred embodiments, in step (4), pre-compaction is performed after each application of one or two layers of the third prepreg.

According to some more preferred embodiments, in step (4), pre-compaction is performed after each layer or two layers of the third prepreg are laid, wherein the pre-compaction temperature is 25 to 40 ℃ (for example, 25 ℃, 30 ℃, 35 ℃ or 40 ℃), the pressure is 0.8 to 3MPa (for example, 0.8MPa, 1MPa, 1.5MPa, 2MPa, 2.5MPa or 3MPa), and the pre-compaction time is 10 to 15min (for example, 10min, 11min, 12min, 13min, 14min or 15 min).

In the invention, the impedance matching layer is added on the surface of the wave-absorbing adhesive film and is used for impedance matching between the wave-absorbing adhesive film and air so as to improve the absorption efficiency of the wave-absorbing layer on electromagnetic waves and provide good impedance matching performance for the co-curing wave-absorbing composite material.

According to some preferred embodiments, in the step (4), the curing temperature of the curing treatment is 90 to 350 ℃ (for example, may be 90 ℃, 100 ℃, 150 ℃, 200 ℃, 250 ℃, 300 ℃ or 350 ℃), the curing time is 100-.

In the curing treatment, the temperature rise rate is 0.15 to 2 ℃/min (for example, 0.15 ℃/min, 0.2 ℃/min, 0.5 ℃/min, 0.75 ℃/min, 1 ℃/min, 1.5 ℃/min or 2 ℃/min), and the temperature fall rate is not more than 3 ℃/min (for example, 0.15 ℃/min, 0.2 ℃/min, 0.5 ℃/min, 0.75 ℃/min, 1 ℃/min, 1.5 ℃/min, 2 ℃/min, 2.5 ℃/min or 3 ℃/min).

In the invention, fig. 1 shows a schematic structural diagram of a co-cured wave-absorbing composite material, wherein 1 is used for representing the surface of a forming mold; 2 is used for representing the composite material matrix obtained in the step (1); 3 is used to denote a reflective layer; 4, the wave-absorbing layer obtained after the wave-absorbing adhesive film is laid in the step (3) is used for representing, and the wave-absorbing composite material matrix is obtained by forming 2 and 3 in the figure 1; and 5, paving a third prepreg on the wave-absorbing composite material matrix in the step (4) to obtain the impedance matching layer.

It should be noted that the thicknesses of the composite material substrate, the reflective layer, the wave-absorbing layer and the impedance matching layer can be designed according to the mechanical property and the wave-absorbing property of the composite material.

The invention also provides a co-curing wave-absorbing composite material, which is prepared by the preparation method of the co-curing wave-absorbing composite material.

In order to more clearly illustrate the technical scheme and the advantages of the invention, the following describes in detail a preparation method of the co-cured wave-absorbing composite material by using several embodiments.

In the following embodiments, the preparation method of the wave-absorbing adhesive film comprises the following steps: the preparation method disclosed by CN202010950674.3 (a wave-absorbing adhesive film material and a preparation method thereof) is adopted:

firstly, putting wave-absorbing resin and a wave-absorbing agent into an internal mixer for banburying and rough mixing to obtain rough-mixed wave-absorbing resin; the technological conditions of banburying and coarse mixing are as follows: the temperature of the banburying and rough mixing is 150 ℃, the time of the banburying and rough mixing is 45min, and the rotating speed of a rotor of the banburying and rough mixing is 200 r/min;

secondly, putting the rough mixed wave-absorbing resin obtained in the first step into a resin open mill for refining and fine mixing to obtain a wave-absorbing resin blank which is uniformly mixed; the technological conditions for refining and mixing are as follows: the temperature of the starting and refining mixture is 180 ℃, the time of the starting and refining mixture is 45min, and the roller speed of the starting and refining mixture is 12 m/min;

placing the wave-absorbing resin blank obtained in the step two into a precision calender for precision calendering of the wave-absorbing adhesive film, and obtaining the wave-absorbing resin adhesive film after calendering; the process conditions of calendering are as follows: the temperature of the rolling is 150 ℃, the pressure of the rolling is 1000N, and the speed of the rolling is 4 m/s;

and fourthly, pasting the base cloth and the release film on the wave-absorbing resin adhesive film obtained in the third step through a thermal pasting machine, cutting and then rolling to complete the preparation of the wave-absorbing adhesive film material.

Example 1

(1) Cleaning the molding surface of the molding die by using gasoline and acetone respectively, and brushing a release agent for 3 times, wherein the time interval of brushing the release agent for each time is 10 min; then, paving a first layer of first prepreg (which is formed by compounding carbon fiber cloth and epoxy resin and has the thickness of 0.2mm) on the forming die, performing pre-compaction for 10min, then, paving 2 layers of first prepreg for each time, performing pre-compaction for 15min, and paving 10 layers of first prepreg in total to obtain a composite material matrix;

(2) paving a second prepreg (which is formed by compounding carbon fiber cloth and epoxy resin and has the thickness of 0.2mm) on the composite material matrix obtained in the step (1), pre-compacting for 15min by paving 2 layers of the second prepreg, and paving 6 layers of the second prepreg in total to obtain the composite material matrix containing the reflecting layer;

(3) paving wave-absorbing adhesive films (wherein the mass fraction of the wave-absorbing agent is 70% and the thickness is 0.2mm) on the composite material substrate containing the reflecting layer obtained in the step (2), pre-compacting for 15min after paving 1 layer of wave-absorbing adhesive film, and paving 7 layers of wave-absorbing adhesive films in total to obtain the wave-absorbing composite material substrate; wherein, inhale ripples glued membrane contains: carbonyl iron powder and epoxy resin;

(4) paving a third prepreg (which is formed by compounding quartz fiber cloth and epoxy resin and has the thickness of 0.1mm) on the wave-absorbing composite material substrate obtained in the step (3), pre-compacting for 15min by paving 2 layers of the third prepreg every time, paving 9 layers of the third prepregs in total, then carrying out bag-making packaging on the paved wave-absorbing composite material substrate, and placing the packaged wave-absorbing composite material substrate in an autoclave for curing treatment to obtain a co-cured wave-absorbing composite material; vacuumizing the whole curing process, keeping the pressure of an autoclave at 0.3MPa at the heating rate of 0.15 ℃/min, preserving the heat for 120min when the temperature is raised to 130 ℃, reducing the temperature of a forming die to 60 ℃ at the cooling rate of 0.5 ℃/min after the heat preservation is finished, releasing the pressure, taking out of the autoclave, and demolding when the forming die is restored to the room temperature (25 ℃) to obtain the co-curing wave-absorbing composite material;

wherein the prepressing temperature of the prepressing in the steps is 25 ℃, and the pressure is 1.5 MPa.

Example 2

(1) Cleaning the molding surface of the air inlet channel molding mold by acetone respectively, and brushing a release agent for 3 times, wherein the time interval of brushing the release agent every time is 10 min; then, paving a first layer of first prepreg (which is formed by compounding carbon fiber cloth and cyanate ester resin and has the thickness of 0.2mm) on the forming die, performing pre-compaction for 10min, then, paving 2 layers of first prepreg for each time, performing pre-compaction for 15min, and paving 15 layers of first prepreg in total to obtain a composite material matrix;

(2) paving a second prepreg (which is formed by compounding carbon fiber cloth and epoxy resin and has the thickness of 0.2mm) on the composite material matrix obtained in the step (1), pre-compacting for 15min by paving 2 layers of the second prepreg, and paving 2 layers of the second prepreg in total to obtain the composite material matrix containing the reflecting layer;

(3) paving wave-absorbing adhesive films (wherein the mass fraction of the wave-absorbing agent is 60% and the thickness is 0.2mm) on the composite material substrate containing the reflecting layer obtained in the step (2), pre-compacting for 15min after paving 1 layer of wave-absorbing adhesive film, and paving 9 layers of wave-absorbing adhesive films in total to obtain the wave-absorbing composite material substrate; wherein, inhale ripples glued membrane contains: ferrite powder and cyanate resin;

(4) paving a third prepreg (which is formed by compounding glass fiber cloth and epoxy resin and has the thickness of 0.1mm) on the wave-absorbing composite material matrix obtained in the step (3), pre-compacting for 15min by paving 2 layers of the third prepreg every time, paving 12 layers of the third prepregs in total, then carrying out bag-making packaging on the paved wave-absorbing composite material matrix, and placing the packaged wave-absorbing composite material matrix in an autoclave for curing treatment to obtain a co-cured wave-absorbing composite material; vacuumizing the whole curing process, wherein the heating rate is 1 ℃/min, and when the temperature is raised to 110 ℃, the heat preservation is started for 150min, and after the heat preservation is finished; then applying the tank pressure and continuing to heat up, wherein the pressure of the autoclave is 0.2MPa, the temperature is raised to 180 ℃ at the heating rate of 0.5 ℃/min, then the heat preservation is started for 150min, and the heat preservation is finished; reducing the temperature of the forming die to 60 ℃ at a cooling rate of 1 ℃/min, then releasing the pressure and taking out of the tank, and demolding when the forming die is recovered to room temperature (25 ℃) to obtain the co-cured wave-absorbing composite material;

wherein the prepressing temperature of the prepressing in the steps is 30 ℃, and the pressure is 2 MPa.

Example 3

(1) Cleaning the molding surface of the antenna opening cover molding mold with acetone respectively, and brushing a release agent for 3 times, wherein the time interval of brushing the release agent for each time is 10 min; then, paving a first layer of first prepreg (which is formed by compounding carbon fiber cloth and epoxy resin and has the thickness of 0.2mm) on the forming die, performing pre-compaction for 10min, then, paving 2 layers of first prepreg for each time, performing pre-compaction for 15min, and paving 5 layers of first prepreg in total to obtain a composite material matrix;

(2) paving a second prepreg (which is formed by compounding carbon fiber cloth and epoxy resin and has the thickness of 0.2mm) on the composite material matrix obtained in the step (1), pre-compacting for 15min by paving 2 layers of the second prepreg, and paving 2 layers of the second prepreg in total to obtain the composite material matrix containing the reflecting layer;

(3) paving wave-absorbing glue films (wherein the mass fraction of the wave-absorbing agent is 80% and the thickness is 0.2mm) on the composite material substrate containing the reflecting layer obtained in the step (2), pre-compacting for 15min by paving 1 layer of wave-absorbing glue film, paving one layer of resin film (epoxy resin film) between every two layers of wave-absorbing glue films, and paving 6 layers of wave-absorbing glue films in total to obtain the wave-absorbing composite material substrate; wherein, inhale ripples glued membrane contains: carbonyl iron powder and epoxy resin;

(4) paving a third prepreg (which is formed by compounding glass fiber cloth and epoxy resin and has the thickness of 0.1mm) on the wave-absorbing composite material matrix obtained in the step (3), pre-compacting for 15min by paving 2 layers of the third prepreg every time, paving 9 layers of the third prepregs in total, then carrying out bag-making packaging on the paved wave-absorbing composite material matrix, and placing the packaged wave-absorbing composite material matrix in an autoclave for curing treatment to obtain a co-cured wave-absorbing composite material; vacuumizing the whole curing process, wherein the heating rate is 2 ℃/min, and when the temperature is raised to 110 ℃, starting to preserve heat for 120min, and after the heat preservation is finished; then applying the tank pressure and continuing to heat up, wherein the pressure of the autoclave is 0.2MPa, the temperature is raised to 180 ℃ at the heating rate of 2 ℃/min, then the heat preservation is started for 120min, and the heat preservation is finished; reducing the temperature of the forming die to 60 ℃ at a cooling rate of 2 ℃/min, then releasing the pressure and taking out of the tank, and demolding when the forming die is recovered to room temperature (25 ℃) to obtain the co-cured wave-absorbing composite material;

wherein the prepressing temperature of the prepressing in the steps is 40 ℃, and the pressure is 2.5 MPa.

Example 4

Example 4 is essentially the same as example 1, except that: the first prepreg is formed by compounding boron fiber cloth and phenolic resin; the second prepreg is formed by compounding carbon fiber cloth and bismaleimide resin; the third prepreg is formed by compounding glass fiber cloth and polyimide resin.

Example 5

Example 5 is essentially the same as example 1, except that: the first prepreg is formed by compounding quartz fiber cloth and polyurethane resin; the second prepreg is formed by compounding carbon fiber cloth and polyimide resin; the third prepreg is formed by compounding glass fiber cloth and phenolic resin.

Comparative example 1

Comparative example 1 is substantially the same as example 1 except that: and (3): curing the composite material matrix containing the reflecting layer obtained in the step (2) in the step (4), then paving wave-absorbing patches on the cured composite material matrix containing the reflecting layer (wherein the mass fraction of the wave-absorbing agent is 70%), pre-compacting 1 layer of wave-absorbing patches for each paving for 15min, and paving 7 layers of wave-absorbing patches in total to obtain the wave-absorbing composite material matrix; wherein, inhale ripples paster contains: carbonyl iron powder and nitrile rubber;

the curing treatment in the step (4) comprises the following steps: and (3) keeping the forming pressure in a vacuum bag at 0.3MPa and at room temperature (25 ℃) for 120min, and demolding to obtain the co-curing wave-absorbing composite material.

Comparative example 2

Comparative example 2 is substantially the same as example 1 except that: and (3) lacking the step (3), after the co-cured composite material is obtained in the step (4), spreading 7 layers of wave-absorbing patches on the surface of the composite material, making bags, packaging, placing in an oven for curing, keeping the forming pressure in a vacuum bag at 0.3MPa and at room temperature (25 ℃) for 120min, and demolding to obtain the co-cured wave-absorbing composite material. The wave absorbing patch comprises carbonyl iron powder and nitrile rubber, and the mass fraction of the wave absorbing agent is 70%.

The co-cured wave-absorbing composite materials obtained in examples 1 to 5 and comparative examples 1 to 2 were respectively tested for mechanical properties such as tensile, compressive and flexural properties and reflectivity to obtain the mechanical property data shown in table 1 and the wave-absorbing property data shown in table 2. Wherein, the reflection curves of the co-cured wave-absorbing composite material prepared in the embodiment 2 under different testing frequencies are shown in fig. 2, and the reflection curves of the co-cured wave-absorbing composite material prepared in the embodiment 3 under different testing frequencies are shown in fig. 3.

TABLE 1

TABLE 2

As can be seen from tables 1 and 2, the wave-absorbing patch spread on the surface of the cured composite material has low bonding strength (i.e., poor adhesion) and is easy to crack, while the bonding strength between the wave-absorbing adhesive film and the composite material is higher; secondly, the wave-absorbing patch is composed of an absorbent and rubber, so that the wave-absorbing patch is low in corrosion resistance and ageing resistance, and the co-cured wave-absorbing adhesive film has an impedance matching layer as a protective layer and has more excellent corrosion resistance and ageing resistance; and the wave-absorbing patch has no mechanical property, so the mechanical properties measured in comparative examples 1 and 2 are poor.

From table 1, it can be seen that all the mechanical properties of the co-cured wave-absorbing composite material obtained in examples 1 to 5 are superior to those of the wave-absorbing composite material obtained in comparative examples 1 to 2, and obviously, an obvious interface is easy to exist between the wave-absorbing layer of the wave-absorbing composite material prepared by adopting the wave-absorbing patch in comparative example 2 and the composite material, so that the mechanical properties are poor. As can be seen from Table 2, compared with comparative examples 1 and 2, the co-cured wave-absorbing composite material prepared by the integrated molding method provided by the invention comprises the reflecting layer, the wave-absorbing layer and the impedance matching layer, and has more excellent wave-absorbing performance.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.