Wave-absorbing laminate with electrical performance damage tolerance and angle tolerance and preparation method thereof

Abstract

The present invention discloses an absorbing laminate with electrical damage tolerance and angle tolerance, and a method for preparing the same. The absorbing laminate comprises, from top to bottom, a first magnetic prepreg layer, a first quartz fiber prepreg layer, a second magnetic prepreg layer, a second quartz fiber prepreg layer, a first magnetic resin film layer, a third magnetic prepreg layer, and a second magnetic resin film layer. The first and second magnetic resin film layers are each formed by applying a magnetic resin slurry, which is a mixture of an absorbent and a resin, to a carrier. The first, second, and third magnetic prepreg layers are each formed by applying a magnetic resin film, which is formed by applying a magnetic resin slurry to the upper and lower surfaces of a quartz fiber cloth. The magnetic resin film is formed by applying a magnetic resin slurry to the carrier. The absorbing laminate of the present invention achieves, for the first time, effective absorption of electromagnetic wave energy within the 6 GHz to 18 GHz frequency band when the damage area of ​​the absorbing laminate is 20%.

Description

Technical Field

[0001] The present invention belongs to the field of aviation equipment design and manufacturing, and particularly relates to a wave-absorbing laminate with electrical performance damage tolerance and angle tolerance and a preparation method thereof. Background Art

[0002] As a typical structure that plays a vital role in integrating load-bearing and stealth in next-generation aviation equipment, radar-absorbing laminates are often subjected to harsh environments such as aerodynamic loads and aerodynamic heat. This can lead to structural damage and electrical performance degradation, severely reducing the survivability of this new generation of aviation equipment in complex electromagnetic environments. Therefore, achieving excellent electrical performance with damage tolerance and angular tolerance through composition, structure, and process design is a major challenge facing the design and manufacturing of aviation equipment.

[0003] To address these issues, current researchers are working to design mechanical properties that make laminated structures resistant to external damage, thereby reducing the probability of damage and improving damage tolerance. For example, Ahmed et al. summarized novel technologies for improving damage tolerance and impact resistance in natural fiber composites; Plocher et al. summarized design strategies and damage evolution mechanisms for composite material damage tolerance; Selver et al. proposed an intra-beam micro-wrapping process to improve impact damage tolerance through fiber buffering and intra-beam crack dispersion mechanisms; Mencattelli et al. introduced interlaminar discontinuities through laser cutting to improve impact damage tolerance and thus enhance energy dissipation capabilities; and Raney et al. used a rotational 3D printing method with enhanced damage tolerance to fabricate carbon fiber-epoxy composites composed of volumetric elements with programmable, defined fiber arrangements. However, existing literature and patents rarely address how to suppress electrical performance degradation after material damage. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an absorbing laminate with electrical performance damage tolerance and angle tolerance and a preparation method thereof.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A wave-absorbing laminate with electrical performance damage tolerance and angle tolerance, wherein the wave-absorbing laminate is layered from top to bottom with a first magnetic prepreg layer, a first quartz fiber prepreg layer, a second magnetic prepreg layer, a second quartz fiber prepreg layer, a first magnetic resin film layer, a third magnetic prepreg layer, and a second magnetic resin film layer; the first magnetic resin film layer and the second magnetic resin film layer are both formed by coating a magnetic resin slurry on a carrier, the magnetic resin slurry being a mixture of an absorbent and a resin, the absorbent including one or more of FeCo alloy powder, conductive carbon black, carbonyl iron, and ferrite; the first magnetic prepreg layer, the second magnetic prepreg layer, and the third magnetic prepreg layer are all obtained by laying a magnetic resin film on the upper and lower surfaces of a quartz fiber cloth, and the magnetic resin film is formed by coating a magnetic resin slurry on a carrier.

[0007] The above-mentioned absorbing laminate is preferably configured such that the thickness of the first magnetic prepreg layer is 0.3 mm to 0.4 mm, the thickness of the first quartz fiber prepreg layer is 0.1 mm to 0.2 mm, the thickness of the second magnetic prepreg layer is 0.3 mm to 0.4 mm, the thickness of the second quartz fiber prepreg layer is 0.3 mm to 0.4 mm, the thickness of the first magnetic resin film layer is 0.5 mm to 0.6 mm, the thickness of the third magnetic prepreg layer is 3 mm to 3.1 mm, and the thickness of the second magnetic resin film layer is 0.2 mm to 0.3 mm.

[0008] The above-mentioned absorbing laminate is preferably such that the mass fraction of the absorbent in the magnetic resin slurry is 40% to 70%, the particle size of the absorbent is 30 μm to 100 μm, the resin includes one or more of epoxy resin, bismaleimide resin, cyanate ester and polyimide resin, and the carrier is release paper.

[0009] In the above-mentioned absorbing laminate, preferably, the quartz fiber cloth is composed of fiber bundles, the diameter of the fiber bundles is 1.5mm to 2.5mm, the size of the inter-bundle holes between the fiber bundles is 500μm to 800μm, the diameter of a single quartz fiber in the fiber bundle is 10μm to 15μm; the thickness of the quartz fiber cloth is 0.15mm.

[0010] The above-mentioned absorbing laminate is preferably such that, within the frequency band of 6 GHz to 18 GHz, when the damaged area of ​​the absorbing laminate accounts for ≤20%, the reflection loss is <-10 dB.

[0011] As a general technical concept, the present invention also provides a method for preparing the above-mentioned absorbing laminate with electrical damage tolerance and angle tolerance, comprising the following steps:

[0012] (1) Preparation of magnetic resin slurry: mixing the absorbent and the resin to obtain magnetic resin slurry;

[0013] (2) Preparation of magnetic resin film: coating the magnetic resin slurry obtained in step (1) on a carrier according to a preset thickness, and pre-treating the carrier to obtain a first magnetic resin film, a second magnetic resin film, and a third magnetic resin film;

[0014] (3) Preparation of magnetic prepreg: Laying the third magnetic resin film obtained in step (2) on the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth with the magnetic resin film, stacking multiple pieces of the quartz fiber cloth with the magnetic resin film to a preset thickness, and processing them using a vacuum bag-autoclave process to obtain the first magnetic prepreg, the second magnetic prepreg, and the third magnetic prepreg;

[0015] (4) Layer design: Lay out the first magnetic prepreg, the first quartz fiber prepreg, the second magnetic prepreg, the second quartz fiber prepreg, the first magnetic resin film, the third magnetic prepreg, and the second magnetic resin film in sequence from top to bottom to obtain a layer structure;

[0016] (5) Preparation of a laminate: The laminate structure obtained in step (4) is cured to form a structure in which the laminate layers from top to bottom are the first magnetic prepreg layer, the first quartz fiber prepreg layer, the second magnetic prepreg layer, the second quartz fiber prepreg layer, the first magnetic resin film layer, the third magnetic prepreg layer, and the second magnetic resin film layer, thereby obtaining an absorbing laminate with electrical performance damage tolerance and angle tolerance.

[0017] In the above-mentioned preparation method, preferably, in step (5), the specific process of the curing treatment is: keeping warm at 100°C to 150°C for 20min to 40min, keeping warm at 220°C to 250°C for 10min to 30min, keeping warm at 300°C to 340°C for 10min to 30min, keeping warm at 370°C for 2h to 3h, and then cooling to room temperature at a cooling rate of 1.5°C / min to 3°C / min; the curing treatment is carried out using a vacuum bag-autoclave process.

[0018] In the above preparation method, preferably, in step (1), the mixing is carried out under stirring conditions, and the stirring speed is 1000r / min to 2000r / min.

[0019] In the above preparation method, preferably, in step (2), the thickness of the third magnetic resin film is 60 μm to 120 μm, the pretreatment temperature is 60° C. to 120° C., and the pretreatment time is 10 min to 25 min.

[0020] In the above preparation method, preferably, in step (3), the pressure of the vacuum bag-autoclave process is 0.3 MPa to 0.6 MPa, the temperature is 120° C. to 260° C., and the time is ≤2 h.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] The present invention provides an absorbing laminate with electrical damage tolerance and angle tolerance. Compared with the traditional idea of ​​improving damage tolerance through mechanical performance design, the present invention suppresses the degradation of electrical performance of the absorbing laminate after damage through the "gradient absorption-transmission-absorption layer" structural design, and for the first time achieves effective absorption of electromagnetic wave energy (i.e., reflection loss <-10dB) when the damage area of ​​the absorbing laminate is 20% in the 6GHz to 18GHz frequency band. This is of great significance for improving the survivability of aviation equipment in complex electromagnetic environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a low-magnification scanning electron microscope image of the entire magnetic prepreg in Example 1 of the present invention.

[0024] Figure 2 This is a contour map of the quartz fiber cloth in Example 1 of the present invention.

[0025] Figure 3 This is a scanning electron microscope image of the pores between the magnetic prepreg bundles in Example 1 of the present invention.

[0026] Figure 4 This is a scanning electron microscope image of the inner hole position of the magnetic prepreg bundle in Example 1 of the present invention.

[0027] Figure 5 1 and 2 are electromagnetic parameter diagrams of the magnetic resin film and the magnetic prepreg in Example 1 of the present invention, wherein (a) is the magnetic resin film and (b) is the magnetic prepreg.

[0028] Figure 6 1 is a Cole-Cole plot of the magnetic resin film and the magnetic prepreg in Example 1 of the present invention.

[0029] Figure 7 Graph showing the eddy current loss coefficient of the magnetic resin film and the magnetic prepreg in Example 1 of the present invention.

[0030] Figure 8 The reflectivity and Smith chart of the absorbing laminate with electrical damage tolerance and angle tolerance at different incident angles in Example 1 of the present invention are shown, where (a) is the reflectivity and (b) is the Smith chart.

[0031] Figure 9 Graphs showing the reflectivity and impedance of the absorbing laminate with electrical damage tolerance and angle tolerance at different damage areas in Example 1 of the present invention, where (a) is the reflectivity and (b) is the impedance.

[0032] Figure 10Graphs of reflectivity and impedance at different incident angles when the damage area of ​​the absorbing laminate with electrical damage tolerance and angle tolerance in Example 1 of the present invention is 20% are shown, where (a) is reflectivity and (b) is impedance. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but the scope of protection of the present invention is not limited thereby. The materials and instruments used in the following examples are all commercially available.

[0034] Example 1:

[0035] A method for preparing an absorbing laminate with electrical damage tolerance and angle tolerance according to the present invention, wherein the layers laid out from top to bottom are a first magnetic prepreg layer, a first quartz fiber prepreg layer, a second magnetic prepreg layer, a second quartz fiber prepreg layer, a first magnetic resin film layer, a third magnetic prepreg layer, and a second magnetic resin film layer; wherein the first magnetic resin film layer and the second magnetic resin film layer are both formed by coating a magnetic resin slurry on release paper, and the magnetic resin slurry is a mixture of FeCo alloy powder and polyimide resin; the first magnetic prepreg layer, the second magnetic prepreg layer, and the third magnetic prepreg layer are all obtained by laying a magnetic resin film on the upper and lower surfaces of a quartz fiber cloth, and the magnetic resin film is formed by coating the magnetic resin slurry on a carrier.

[0036] In this embodiment, the thickness of the first magnetic prepreg layer is d1 = 0.4 mm, the thickness of the first quartz fiber prepreg layer is d2 = 0.15 mm, the thickness of the second magnetic prepreg layer is d3 = 0.35 mm, the thickness of the second quartz fiber prepreg layer is d4 = 0.4 mm, the thickness of the first magnetic resin film layer is d5 = 0.6 mm, the thickness of the third magnetic prepreg layer is d6 = 3.1 mm, and the thickness of the second magnetic resin film layer is d7 = 0.3 mm.

[0037] In this embodiment, the quartz fiber cloth is composed of fiber bundles. The diameter of the fiber bundles is 2 mm. The size of the inter-bundle holes between the fiber bundles is 700 μm. The diameter of a single quartz fiber in the fiber bundle is 12 μm. The thickness of the quartz fiber cloth is 0.15 mm.

[0038] In this embodiment, the particle size of the FeCo alloy powder is 30-40 μm.

[0039] A method for preparing an absorbing laminate with electrical damage tolerance and angle tolerance of the present invention comprises the following steps:

[0040] (1) Preparation of magnetic absorbent slurry: FeCo alloy powder and polyimide resin were mixed in a mass ratio of 3:2 and stirred in a high-speed stirrer at a speed of 1200 rpm to obtain magnetic absorbent slurry.

[0041] (2) Preparation of magnetic resin film: The magnetic absorbent slurry obtained in step (1) was scraped onto release paper using an automatic coating machine, and a predetermined thickness was achieved by varying the gap between the scraper and the release paper. Subsequently, the film was dried in a 70°C oven for 15 minutes to obtain a first magnetic resin film, a second magnetic resin film, and a third magnetic resin film. The thickness of the third magnetic resin film was controlled to be 80 μm.

[0042] (3) Preparation of magnetic prepreg: The third magnetic resin film obtained in step (2) is applied to the upper and lower surfaces of a quartz fiber cloth to obtain a quartz fiber cloth with a magnetic resin film; multiple pieces of quartz fiber cloth with a magnetic resin film are stacked to a predetermined thickness and processed using a vacuum bag-autoclave process, i.e., heat preservation at 240°C for 50 minutes at a pressure of 0.3 MPa, to remove excess solvent from the prepreg to obtain a first magnetic prepreg, a second magnetic prepreg, and a third magnetic prepreg. The thickness of the quartz fiber cloth is 0.15 mm.

[0043] (4) Layer design: From top to bottom, the first magnetic prepreg, the first quartz fiber prepreg, the second magnetic prepreg, the second quartz fiber prepreg, the first magnetic resin film, the third magnetic prepreg, and the second magnetic resin film are laid in order to obtain a layer structure. The layer structure has a total of seven representative intermediate layers. Among them, the first quartz fiber prepreg and the second quartz fiber prepreg were purchased from Guangwei Composite Materials Co., Ltd. and the brand is S4.

[0044] (5) Preparation of laminates: The laminate structure obtained in step (4) is treated using a vacuum bag-autoclave curing process, specifically: first, it is kept at 120°C for 30 minutes, then kept at 240°C for 20 minutes, then kept at 340°C for 30 minutes, and then kept at 370°C for 2.5 hours, and then cooled to room temperature at a cooling rate of 3°C / min; a structure is formed in which the laminates from top to bottom are the first magnetic prepreg layer, the first quartz fiber prepreg layer, the second magnetic prepreg layer, the second quartz fiber prepreg layer, the first magnetic resin film layer, the third magnetic prepreg layer, and the second magnetic resin film layer, thereby obtaining an absorbing laminate with electrical performance damage tolerance and angle tolerance.

[0045] Figure 1 This is a low-magnification scanning electron microscope image of the entire magnetic prepreg in Example 1 of the present invention. Figure 2 This is a contour map of the quartz fiber cloth in Example 1 of the present invention. Figure 3 This is a scanning electron microscope image of the pores between the magnetic prepreg bundles in Example 1 of the present invention. Figure 4 This is a scanning electron microscope image of the inner hole position of the magnetic prepreg bundle in Example 1 of the present invention. Figures 1 to 4It can be seen that the absorbent filler magnetic FeCo alloy is evenly distributed on the surface of the quartz fiber cloth. Since the size of the FeCo alloy particles is 30-40μm, the diameter of a single quartz fiber of the quartz fiber cloth is 12μm, the diameter of the fiber bundle is 2mm, and the size of the inter-bundle hole is 700μm, the FeCo alloy particles can easily enter the inter-bundle hole to form a periodic absorption pattern (see Figure 2 ), and it is difficult for FeCo alloy particles to enter the inner pores of the quartz fiber bundle, thus forming a typical absorption (magnetic resin film)-transmission (quartz fiber prepreg)-absorption (magnetic resin film) structure.

[0046] Figure 5 1 and 2 are electromagnetic parameter diagrams of the magnetic resin film and the magnetic prepreg in Example 1 of the present invention, wherein (a) is the magnetic resin film and (b) is the magnetic prepreg. Figure 6 1 is a Cole-Cole plot of the magnetic resin film and the magnetic prepreg in Example 1 of the present invention. Figure 7 Eddy current loss coefficient diagram of magnetic resin film and magnetic prepreg in Example 1 of the present invention. Figures 5 to 7 It can be seen that the typical absorption-transmission-absorption microstructure of the present invention is easy to achieve adjustable electrical properties, and at the same time enriches the electromagnetic energy loss mechanism, changing the two Debye polarization and relaxation loss behaviors in the magnetic electromagnetic film into three. In addition, according to Figure 7 According to the calculation results of the eddy current loss coefficient, this typical absorb-through-absorb microstructure can realize the transformation from the exchange resonance loss mechanism to the eddy current loss mechanism.

[0047] The prepared absorbing laminate with electrical damage tolerance and angle tolerance was processed into a size of 300×300mm. The electromagnetic reflectivity test at an incident angle of 0-40° in the 6-18GHz frequency band was carried out using a bow frame according to GJB-2038A, and the electromagnetic reflectivity test results and Smith circle diagram were obtained. Figure 8 The reflectivity and Smith chart of the absorbing laminate with electrical damage tolerance and angle tolerance in Example 1 of the present invention at different incident angles, where (a) is the reflectivity and (b) is the Smith chart. Figure 8 It can be seen that within the 6-18 GHz frequency band, the absorbing laminate of the present invention with electrical damage tolerance and angle tolerance has a reflectivity of <-10 dB at an incident angle of 0-40°, and a corresponding absorptivity of >90%, indicating that the absorbing laminate prepared by the present invention has excellent angle tolerance.

[0048] Figure 9 The reflectivity and impedance diagrams of the absorbing laminate with electrical damage tolerance and angle tolerance in Example 1 of the present invention at different damage areas are shown, where (a) is the reflectivity and (b) is the impedance. Figure 9It can be seen that the absorbing laminate with electrical damage tolerance and angle tolerance of the present invention has a damage area ratio of less than 20% and a reflection loss of less than -10dB, which can effectively absorb electromagnetic wave energy, that is, has excellent electrical damage tolerance.

[0049] Figure 10 The reflectivity and impedance diagrams of the absorbing laminate with electrical damage tolerance and angle tolerance in Example 1 of the present invention at different incident angles when the damage area is 20%, where (a) is the reflectivity and (b) is the impedance. Figure 10 It can be seen that when the damage area of ​​the absorbing laminate with electrical damage tolerance and angle tolerance of the present invention accounts for 20%, the absorbing laminate still has excellent angle tolerance and can effectively absorb electromagnetic wave energy.

[0050] The above description is only a preferred embodiment of the present invention and does not constitute any formal limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A microwave absorbing laminate with electrical damage tolerance and angle tolerance, characterized in that: The absorbing laminate is layered from top to bottom in the order of a first magnetic prepreg layer, a first quartz fiber prepreg layer, a second magnetic prepreg layer, a second quartz fiber prepreg layer, a first magnetic resin film layer, a third magnetic prepreg layer, and a second magnetic resin film layer; the first magnetic resin film layer and the second magnetic resin film layer are both formed by coating a magnetic resin slurry on a carrier, the magnetic resin slurry is a mixture of an absorbent and a resin, and the absorbent includes one or more of FeCo alloy powder, carbonyl iron, and ferrite; the first magnetic prepreg layer, the second magnetic prepreg layer, and the third magnetic prepreg layer are all obtained by laying a third magnetic resin film on the upper and lower surfaces of a quartz fiber cloth, and the third magnetic resin film is formed by coating a magnetic resin slurry on a carrier.

2. The microwave absorbing laminate with electrical damage tolerance and angle tolerance according to claim 1, characterized in that: The thickness of the first magnetic prepreg layer is 0.3mm~0.4mm, the thickness of the first quartz fiber prepreg layer is 0.1mm~0.2mm, the thickness of the second magnetic prepreg layer is 0.3mm~0.4mm, the thickness of the second quartz fiber prepreg layer is 0.3mm~0.4mm, the thickness of the first magnetic resin film layer is 0.5mm~0.6mm, the thickness of the third magnetic prepreg layer is 3mm~3.1mm, and the thickness of the second magnetic resin film layer is 0.2mm~0.3mm.

3. The microwave absorbing laminate with electrical damage tolerance and angle tolerance according to claim 2, characterized in that: The mass fraction of the absorbent in the magnetic resin slurry is 40% to 70%, the particle size of the absorbent is 30 μm to 100 μm, the resin includes one or more of epoxy resin, bismaleimide resin, cyanate ester and polyimide resin, and the carrier is release paper.

4. The microwave absorbing laminate with electrical damage tolerance and angle tolerance according to claim 3, characterized in that: The quartz fiber cloth is composed of fiber bundles, the diameter of the fiber bundles is 1.5mm to 2.5mm, the size of the inter-bundle holes between the fiber bundles is 500μm to 800μm, the diameter of a single quartz fiber in the fiber bundle is 10μm to 15μm; the thickness of the quartz fiber cloth is 0.15mm.

5. The microwave absorbing laminate with electrical damage tolerance and angle tolerance according to any one of claims 1 to 4, characterized in that: In the frequency band of 6 GHz to 18 GHz, when the damaged area of ​​the absorbing laminate accounts for ≤20%, the reflection loss is less than -10 dB.

6. A method for preparing an absorbing laminate with electrical damage tolerance and angle tolerance according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Preparation of magnetic resin slurry: mixing the absorbent and the resin to obtain magnetic resin slurry; (2) Preparation of magnetic resin film: coating the magnetic resin slurry obtained in step (1) on a carrier according to a preset thickness, and pre-treating the carrier to obtain a first magnetic resin film, a second magnetic resin film, and a third magnetic resin film; (3) Preparation of magnetic prepreg: Laying the third magnetic resin film obtained in step (2) on the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth with the magnetic resin film, stacking multiple pieces of the quartz fiber cloth with the magnetic resin film to a preset thickness, and processing them using a vacuum bag-autoclave process to obtain the first magnetic prepreg, the second magnetic prepreg, and the third magnetic prepreg; (4) Layer design: Lay out the first magnetic prepreg, the first quartz fiber prepreg, the second magnetic prepreg, the second quartz fiber prepreg, the first magnetic resin film, the third magnetic prepreg, and the second magnetic resin film from top to bottom to obtain a layer structure; (5) Preparation of laminated boards: The laminated structure obtained in step (4) is cured to form a structure in which the laminated layers from top to bottom are the first magnetic prepreg layer, the first quartz fiber prepreg layer, the second magnetic prepreg layer, the second quartz fiber prepreg layer, the first magnetic resin film layer, the third magnetic prepreg layer, and the second magnetic resin film layer, thereby obtaining an absorbing laminated board having electrical performance damage tolerance and angle tolerance.

7. The method for preparing the microwave-absorbing laminate with electrical damage tolerance and angle tolerance according to claim 6, wherein: In step (5), the specific process of the curing treatment is: keeping warm at 100°C to 150°C for 20min to 40min, keeping warm at 220°C to 250°C for 10min to 30min, keeping warm at 300°C to 340°C for 10min to 30min, keeping warm at 370°C for 2h to 3h, and then cooling to room temperature at a cooling rate of 1.5°C / min to 3°C / min; the curing treatment is carried out using a vacuum bag-autoclave process.

8. The method for preparing the microwave-absorbing laminate with electrical damage tolerance and angle tolerance according to claim 6 or 7, wherein: In step (1), the mixing is carried out under stirring conditions, and the stirring speed is 1000 r / min to 2000 r / min.

9. The method for preparing the microwave-absorbing laminate with electrical damage tolerance and angle tolerance according to claim 6 or 7, characterized in that: In step (2), the thickness of the third magnetic resin film is 60 μm to 120 μm, the pretreatment temperature is 60° C. to 120° C., and the pretreatment time is 10 min to 25 min.

10. The method for preparing the microwave-absorbing laminate with electrical damage tolerance and angle tolerance according to claim 6 or 7, characterized in that: In step (3), the pressure of the vacuum bag-autoclave process is 0.3 MPa to 0.6 MPa, the temperature is 120° C. to 260° C., and the time is ≤ 2 h.

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