Composite material with high electromagnetic shielding and low lightning stroke damage and preparation method thereof

Abstract

The invention provides a high-electromagnetic-shielding low-lightning-damage composite material and a preparation method thereof.The composite material is provided with a connecting side used for being connected with an aircraft and an anti-lightning side deviating from the aircraft, the composite material comprises a resin matrix, continuous carbon fiber layers and an insertion layer, and the multiple continuous carbon fiber layers are sequentially stacked in the thickness direction; an intercalation layer is arranged between every two adjacent continuous carbon fiber layers, the resin matrix fills the continuous carbon fiber layers and the interlayers containing the intercalation layers, and the volume fraction of carbon fibers in the continuous carbon fiber layers is 64-73%; wherein the intercalation layers among the first 3-7 layers, close to the anti-lightning stroke side, of the composite material are first carbon nanotube film materials, and the intercalation layers among the other layers are micron conductive materials. The composite material provided by the invention is low in damage after lightning stroke, and has high electromagnetic shielding effectiveness, interlayer performance, interlayer shear strength and thickness-direction conductivity.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and more specifically to a composite material with high electromagnetic shielding and low lightning damage and a preparation method thereof. Background Art

[0002] Continuous carbon fiber reinforced resin-based composite materials (hereinafter referred to as composite materials) are increasingly widely used in new generation aircraft due to their high specific strength and specific modulus. However, the intrinsic insulation of the resin matrix of this type of material makes it have low conductivity, which brings several safety risks. Among them, lightning strikes are one of the main safety risks encountered by aircraft that use a large number of composite materials during flight. Lightning strikes can cause serious delamination damage and fiber breakage damage to composite materials, resulting in a significant decrease in the compressive strength of the material. At present, lightning protection mainly uses metal mesh, highly conductive non-woven fabrics, etc. as surface sacrificial layer materials, but these materials require additional paving, and new composite materials with high lightning resistance are increasingly valued. On the other hand, as the degree of intelligence of aircraft becomes higher and higher, electromagnetic wave pollution becomes serious, and electronic components are easily affected by interfering electromagnetic waves and fail. Therefore, high electromagnetic shielding is also one of the current material requirements. In addition, composite materials for aircraft also require composite materials to have higher conductivity in terms of static electricity conduction and electrical connection.

[0003] In the prior art, the improvement of composite materials is generally only aimed at improving a specific function. For example, the lightning protection of aircraft structure composite materials generally adopts the copper mesh protection method. However, the electromagnetic shielding efficiency brought by the copper mesh protection method is not high, usually 40 to 60dB, and the weight is increased, generally higher than 180g / m 2 Electromagnetic shielding of materials or parts generally adopts the method of adding an external electromagnetic shielding layer. The main electromagnetic shielding materials are: metal mesh, carbon conductive film, silver-plated fabric, etc., but their lightning resistance is not high.

[0004] Therefore, composite materials for aircraft have requirements for electromagnetic shielding, lightning protection, and conductivity. However, current technologies are mostly targeted at a certain function, and the functional integration of a single composite material is low. When multiple composite materials with single functions are superimposed and used, the weight of the corresponding aircraft structure will inevitably increase, affecting the flight performance of the aircraft. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The technical problem to be solved by the present invention is that the functional integration of composite materials used in current aircraft is low. When multiple composite materials with single functions are stacked for use, the weight of the corresponding aircraft structure will inevitably increase, affecting the flight performance of the aircraft.

[0007] (II) Technical solution

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] The present invention provides a composite material with high electromagnetic shielding and low lightning damage. The composite material is a continuous carbon fiber reinforced resin-based composite material, which has a connection side for connecting to an aircraft and a lightning protection side away from the aircraft. The composite material comprises a resin matrix, a continuous carbon fiber layer and an intercalation layer. Multiple continuous carbon fiber layers are stacked in sequence along the thickness direction, and the intercalation layers are provided between two adjacent continuous carbon fiber layers. The intercalation layers between the continuous carbon fiber layers and the intercalation layers between the continuous carbon fiber layers are filled with a resin matrix, and the volume fraction of the carbon fiber in the continuous carbon fiber layer accounts for 64-73%; wherein the intercalation layers between the first 3-7 intercalation layers of the composite material close to the lightning protection side are a first carbon nanotube film material, and the intercalation layers between the remaining intercalation layers are micron conductive materials, and the thickness of the first carbon nanotube film material is 5-20 μm, and the surface density is 2-10 g / m 2 The resistivity of the micron conductive material is 0.1-30Ω / sq., and the thickness is 15-50μm.

[0010] Preferably, it also includes a surface layer, which is arranged on the surface of the lightning-resistant side, and the surface layer is a second carbon nanotube film material filled with a resin matrix and co-cured on the surface of the lightning-resistant side of the composite material, and the thickness of the second carbon nanotube film material is 14 to 100 μm, and the surface density is 6 to 42 g / m 2 .

[0011] Preferably, the micron conductive material includes at least one of nickel-plated carbon fiber felt, metal-plated non-woven fabric, and metal-plated gauze.

[0012] Preferably, the surface density of the micron conductive material is 8 to 25 g / m 2 , surface resistivity is 0.1~10Ω / sq., and thickness is 15~50μm.

[0013] Preferably, the micron conductive material is carbon fiber felt.

[0014] Preferably, the surface density of the carbon fiber felt is 5 to 15 g / m 2 , surface resistivity is 5~28Ω / sq., and thickness is 15~35μm.

[0015] Preferably, the resin matrix is ​​epoxy resin or bismaleimide resin.

[0016] Preferably, the content of insoluble particles in the resin matrix is ​​not greater than 5 wt %.

[0017] In a second aspect, the present invention further provides a method for preparing the composite material with high electromagnetic shielding and low lightning damage, comprising the following steps:

[0018] Separately preparing a continuous resin prepreg, an intercalation layer of a first carbon nanotube film material, and an intercalation layer of a micron conductive material, wherein the continuous carbon fiber layer is a resin-based prepreg whose reinforcing material is carbon fiber;

[0019] The continuous resin prepreg layers and the intercalation layers are stacked in sequence along the thickness direction in a preset order to form a composite material preform;

[0020] The composite material preform is heated and cured, and the mold is removed after cooling to obtain the high electromagnetic shielding and low lightning damage composite material.

[0021] (III) Beneficial effects

[0022] The above technical solution of the present invention has at least the following advantages:

[0023] In the present invention, by controlling the volume fraction of carbon fiber in the continuous carbon fiber layer to be 64-73%, it can be ensured that the continuous carbon fiber layer and the interlayer intercalation layer of the first carbon nanotube film material and the intercalation layer of the micron conductive material can form a good conductive contact, so that the composite material finally prepared has a higher thickness conductivity, thereby avoiding the lightning current from penetrating the insulating resin layer of a larger area to cause stratification, the stratification ability of the composite material is enhanced, and the composite material is not easy to produce a high porosity under the volume fraction condition. The intercalation layer of the first 3-7 layers of the composite material close to the lightning protection side is the first carbon nanotube film material, and the intercalation layer of the remaining layers is the micron conductive material. The intercalation layer of the carbon nanotube film material is used for the main evacuation of lightning current, and the intercalation layer of the micron conductive material is used for the auxiliary evacuation of lightning current. The composite material finally formed has good lightning protection performance; the carbon nanotube film material is used as the main electromagnetic shielding material, and the micron conductive material and the carbon fiber layer are used as auxiliary electromagnetic shielding materials, so that the high electromagnetic shielding efficiency and low lightning damage of the composite material are achieved at the same time, and the adverse effect of the carbon nanotube film on the interface is eliminated. In summary, the high electromagnetic shielding and low lightning damage composite material provided by the present invention has good lightning resistance and can withstand lightning strikes in zone 2A without delamination damage, and also has high electromagnetic shielding effectiveness and high electrical conductivity, and the interlaminar shear strength of the composite material hardly decreases.

[0024] 2. The composite material provided by the present invention has multiple functions under the premise of controlling the total weight of the composite material. When the composite material provided by the present invention is applied to aircraft manufacturing, it can ensure that the corresponding aircraft structure is integrated with multiple functions without increasing the weight of the corresponding aircraft structure too much.

[0025] 3. In the present invention, based on the composite material system provided by the present invention, a surface layer of a second carbon nanotube film material is arranged on the surface of the lightning strike resistant side, which can achieve almost no damage to the shallow surface layer, thereby reducing the fiber fuzzing and fracture damage of the shallow surface layer of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a schematic structural diagram of a composite material with high electromagnetic shielding and low lightning damage provided by an embodiment of the present invention. Figure 2 This is a scan of the damaged area of ​​zone 2A of the composite material plate provided in Example 1 of the present invention after being struck by lightning and the test plate C. Figure 3 It is a scan of the damaged area of ​​zone 2A of the composite material plate provided in comparative example 4 of the present invention after lightning strike and the test plate C. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly located on the other element or indirectly located on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0030] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate that a device or element must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating relative importance or indicating the number of technical features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The specific implementation of the present invention is described in more detail below in conjunction with specific embodiments:

[0032] Continuous carbon fiber reinforced resin matrix composite materials are usually made by laying multiple layers of continuous carbon fiber resin prepreg into a preform, and then curing it by heating and pressurizing. The structure formed generally includes carbon fiber layers with higher carbon fiber content and interlayer areas with higher resin content between different layers. Figure 1 As shown, an embodiment of the present invention provides a high electromagnetic shielding and low lightning damage composite material, which is a continuous carbon fiber reinforced resin-based composite material, the composite material has a connection side for connecting to an aircraft and a lightning protection side away from the aircraft (it should be noted that the lightning protection side in this application refers to the side of the composite material that is subject to the risk of lightning strike in actual use), the composite material includes a resin matrix, a continuous carbon fiber layer 1 and an intercalation layer, multiple continuous carbon fiber layers 1 are stacked in sequence along the thickness direction, and intercalation layers are provided between adjacent two continuous carbon fiber layers 1. The resin matrix covers the multiple continuous carbon fiber layers 1 and the intercalation layers, and fills the gaps in each continuous carbon fiber layer 1 and the intercalation layers. The resin matrix is ​​filled between adjacent continuous carbon fiber layers 1 and the intercalation layers. The volume fraction of carbon fiber in the continuous carbon fiber layer 1 accounts for 64-73%, which can be controlled by conventionally adjusting the resin content in the prepreg and the glue absorption process according to the intercalation characteristics; wherein, the intercalation layers (i.e., the first 3-7 intercalation layers of the composite material close to the lightning protection side) Figure 1 The first intercalation layer shown in the figure is the first carbon nanotube film material, and the intercalation layers between the remaining layers (i.e. Figure 1 The second intercalation layer shown in the figure is a micron conductive material, the thickness of the first carbon nanotube film material is 5 to 20 μm, and the surface density is 2 to 10 g / m 2 The resistivity of the micron conductive material is 0.1-30Ω / sq., and the thickness is 15-50μm. Specifically, the resin matrix impregnated with the whole body fills both the fiber gaps of the carbon fiber layer and the gaps between the entire layers including the intercalation layer, making the composite material an integral structure with low porosity.

[0033] In one embodiment, the high electromagnetic shielding and low lightning damage composite material further includes a surface layer, which is arranged on the surface of the lightning resistance side, and the surface layer is a second carbon nanotube film material, and the thickness of the second carbon nanotube film material is 14 to 100 μm, and the surface density is 6 to 42 g / m 2 For the system of the present invention, this solution can achieve almost no damage to the shallow surface layer, but this solution is not universally applicable to other composite material systems. For conventional composite material systems, the surface carbon nanotube film thickness needs to reach more than 300 μm to achieve this goal.

[0034] In one embodiment, the micron conductive material includes at least one of nickel-plated carbon fiber felt, metal-plated non-woven fabric, and metal-plated gauze. The surface density of the micron conductive material is 8 to 25 g / m 2 , surface resistivity is 0.1~10Ω / sq., thickness is 15~50μm. When the above materials are selected as micron conductive materials, the composite material has a higher thickness conductivity (σ z ), usually σ z ≥1.0S / cm, suitable for certain occasions with higher requirements on conductivity.

[0035] In one embodiment, the micron conductive material is carbon fiber felt. The surface density of the carbon fiber felt is 5 to 15 g / m 2 , surface resistivity is 5-28Ω / sq., thickness is 15-35μm. When carbon fiber felt is used as micron conductive material, the composite material formed has less weight gain and is lighter.

[0036] In one embodiment, the resin matrix is ​​epoxy resin or bismaleimide resin. The content of insoluble particles in the resin matrix is ​​not more than 5wt%. When the content of insoluble particles is low, the composite material can maintain a high thickness-directed conductivity σ z .

[0037] The embodiment of the present invention further provides a method for preparing a composite material with high electromagnetic shielding and low lightning damage, comprising the following steps:

[0038] Separately preparing a continuous carbon fiber resin prepreg (for forming a continuous carbon fiber layer), an intercalation layer of a first carbon nanotube film material, and an intercalation layer of a micron conductive material, wherein the continuous carbon fiber layer is a resin-based prepreg whose reinforcing material is carbon fiber;

[0039] The layers of continuous carbon fiber resin prepreg and the layers of intercalation are sequentially stacked in a preset order along the thickness direction to form a composite material preform;

[0040] The composite material preform is heated and solidified, and the mold is removed after cooling to obtain a composite material with high electromagnetic shielding and low lightning damage.

[0041] The following are several specific embodiments and comparative examples provided in this application:

[0042] Embodiment 1:

[0043] (1-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2, the resin content is 32.4wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 prepregs have a fiber orientation of 0° and 16 prepregs have a fiber orientation of 45°.

[0044] (1-2) Cut 6 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 7 μm and the surface density is 3 g / m 2 .

[0045] (1-3) Cut 26 sheets of 300 mm × 300 mm carbon fiber felt as the second intercalation layer 3. The carbon fiber is T700 with a surface density of 10 g / m 2 , the surface resistance is 8Ω / sq., and the single layer thickness is about 30μm.

[0046] (1-4) The above materials are laid on two plates in the following order: for lightning strike experiments, electromagnetic shielding and interlaminar shear strength tests, the plies are ([45,I1,0,I1,-45,I1,])([90,I2,][45,I2,0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); I1 of the first group is the carbon nanotube film in (1-2), and I2 of the second group is the carbon fiber felt in (1-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply sequence, respectively.

[0047] (1-5) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, electrical conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0048] The material data and performance data of this embodiment 1 are shown in Table 1 and Table 2.

[0049] Embodiment 2:

[0050] The implementation process of the technical solution of the present invention is as follows:

[0051] The technical solution of this embodiment is the same as that of embodiment 1, and the difference from embodiment 1 is that 8 layers of 3g / m are additionally laid on the surface of the lightning-struck side. 2 The total surface density of the carbon nanotube film is 24g / m 2 The thickness is about 56 μm. The lightning strike performance, electrical conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite material laminate prepared in this embodiment were tested.

[0052] The material data and performance data of this embodiment 2 are shown in Tables 1 and 2.

[0053] Embodiment 3:

[0054] (3-1) Take unidirectional carbon fiber reinforced bismaleimide resin prepreg T700 / 6421, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 33.2wt%. 48 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 24 prepregs have a fiber orientation of 0° and 24 prepregs have a fiber orientation of 45°.

[0055] (3-2) Cut 12 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 7 μm and the surface density is 3 g / m 2 .

[0056] (3-3) Cut 36 pieces of 300 mm × 300 mm carbon fiber felt as the second intercalation layer 3. The carbon fiber is T700 with a surface density of 6 g / m 2 , the surface resistance is 14Ω / sq., and the single layer thickness is about 26μm.

[0057] (3-4) The prepreg of the above materials is laid on two boards in the following order: (1) For lightning strike test and conductivity test, the total number of layers is 32, and the ply is: ([45,I1,0,I1,-45,I1,90,I1][45,I1,0,I1])([-45,I2,90,I2,][45,I2,0,I2,-45,I2,90,I2]2[90,I2,-45,I2,0,I2,45,I2]4); (2) For electromagnetic shielding and In the interlaminar shear strength test, the plies are ([45,I1,0,I1,-45,I1,90,I1][45,I1,0,I1])([-45,I2,90,I2,][90,I2,-45,I2,0,I2,45,I2]2); I1 of the first group is the carbon nanotube film in (3-2), I2 of the second group is the carbon fiber felt in (3-3), and the first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply sequence, respectively.

[0058] (3-5) The preform obtained by the above paving is cured according to the curing process of T800 / 6421 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 200℃ / 4h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0059] The material data and performance data of this embodiment 3 are shown in Tables 1 and 2.

[0060] Embodiment 4:

[0061] The implementation process of the technical solution of the present invention is as follows:

[0062] (4-1) Take unidirectional carbon fiber reinforced bismaleimide resin prepreg T700 / 6421, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 33.2wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 32 have a fiber orientation of 0° and 24 have a fiber orientation of 45°.

[0063] (4-2) Cut 8 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 20 μm and the surface density is 9 g / m 2 .

[0064] (4-3) Cut 24 sheets of 300 mm × 300 mm carbon fiber felt as the second intercalation layer 3. The carbon fiber is T700 with a surface density of 6 g / m 2 , the surface resistance is 14Ω / sq., and the single layer thickness is about 26μm.

[0065] (4-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply layup is: ([45,I1,0,I1,-45,I1,90,I1])([45,I2,0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlaminar shear strength test, the ply layup and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (4-2), and I2 of the second group is the carbon fiber felt in (4-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply layup sequence, respectively.

[0066] (4-5) The preform obtained by the above paving is cured according to the curing process of T800 / 6421 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 200℃ / 4h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0067] The material data and performance data of this embodiment 4 are shown in Tables 1 and 2.

[0068] Embodiment 5:

[0069] The implementation process of the technical solution of the present invention is as follows:

[0070] (5-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 32.4wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 prepregs have a fiber orientation of 0° and 16 prepregs have a fiber orientation of 45°.

[0071] (5-2) Ten sheets of 300 mm × 300 mm carbon nanotube film were cut as the first intercalation layer 2. The single layer thickness of the carbon nanotube film was 14 μm and the surface density was 6 g / m 2 .

[0072] (5-3) Cut 22 sheets of 300 mm × 300 mm nickel-plated carbon fiber felt as the second intercalation layer 3. The carbon fiber is T800 with a surface density of 14 g / m 2 , the surface resistance is 4Ω / sq., and the single layer thickness is about 30μm.

[0073] (5-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply layup is: ([45,I1,0,I1,-45,I1,90,I1][45,I1])([0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlaminar shear strength test, the ply layup and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (5-2), and I2 of the second group is the nickel-plated carbon fiber felt in (5-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply layup sequence, respectively.

[0074] (5-5) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, with a curing pressure of 0.6 MPa and a curing temperature of 180°C / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, electrical conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0075] The material data and performance data of this embodiment 5 are shown in Tables 1 and 2.

[0076] Embodiment 6:

[0077] The implementation process of the technical solution of the present invention is as follows:

[0078] (6-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 32.4wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 prepregs have a fiber orientation of 0° and 16 prepregs have a fiber orientation of 45°.

[0079] (6-2) 14 sheets of 300 mm × 300 mm carbon nanotube film were cut as the first intercalation layer 2. The single layer thickness of the carbon nanotube film was 14 μm and the surface density was 6 g / m 2 .

[0080] (6-3) Cut 18 sheets of 300 mm × 300 mm nickel-plated carbon fiber felt as the second intercalation layer 3. The carbon fiber is T800 with a surface density of 18 g / m 2 , the surface resistance is 2.1Ω / sq., and the single layer thickness is about 30μm.

[0081] (6-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply layup is: ([45,I1,0,I1,-45,I1,90,I1][45,I1,0,I1,-45,I1])([90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlaminar shear strength test, the ply layup and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (6-2), and I2 of the second group is the nickel-plated carbon fiber felt in (6-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply layup sequence, respectively.

[0082] (6-5) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, with a curing pressure of 0.6MPa and a curing temperature of 180°C / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, electrical conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0083] The material data and performance data of this Example 6 are shown in Tables 1 and 2.

[0084] Embodiment 7:

[0085] The implementation process of the technical solution of the present invention is as follows:

[0086] (7-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T700 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 31.9wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 prepregs have a fiber orientation of 0° and 16 prepregs have a fiber orientation of 45°.

[0087] (7-2) Cut 6 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 20 μm and the surface density is 9 g / m 2 .

[0088] (7-3) Cut 26 sheets of 300 mm × 300 mm nickel-plated nylon nonwoven fabric as the second intercalation layer 3, of which 6 sheets have a surface density of 24 g / m 2 , surface resistance is 1.5Ω / sq., surface density of 10 sheets is 16g / m 2 , surface resistance is 6Ω / sq., surface density of 10 sheets is 12g / m 2 The surface resistance is 8Ω / sq., the single layer thickness is about 42μm, and the surface density of the nylon non-woven fabric substrate is 9g / m 2 .

[0089] (7-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply is: ([45,I1,0,I1,-45,I1,])([90,I2,][45,I2,0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlayer shear strength test, the ply and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (7-2), and I2 of the second group is the nickel-plated nylon non-woven fabric in (7-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply order, respectively. The ply order of various nickel-plated nylon non-woven fabrics in the second group is 24g / m 2 ×3, 18g / m 2 ×5, 12g / m 2 ×5.

[0090] (7-5) The preform obtained by the above paving is cured according to the curing process of T700 / 5228 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0091] The material data and performance data of this embodiment 7 are shown in Tables 1 and 2.

[0092] Embodiment 8:

[0093] The implementation process of the technical solution of the present invention is as follows:

[0094] (8-1) Take the self-made unidirectional carbon fiber reinforced high temperature curing epoxy resin prepreg T800 / AED, 4.2% insoluble thermoplastic resin particles are added to the AED resin, the single layer curing thickness is 0.125mm, and the single layer fiber surface density is 135g / m 2 , the resin content is 33.1wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0095] (8-2) Cut 6 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 7 μm and the surface density is 3 g / m 2 .

[0096] (8-3) Cut 6 sheets of 300 mm × 300 mm nickel-plated nylon nonwoven fabric as the second intercalation layer 3, with a surface density of 12 g / m 2The surface resistance is 8Ω / sq., the single layer thickness is about 42μm, and the surface density of the nylon non-woven fabric substrate is 9g / m 2 ; Cut 20 pieces of 300mm×300mm silver-plated nylon non-woven fabric with a surface density of 14g / m 2 The surface resistance is 0.22Ω / sq., the single layer thickness is about 42μm, and the surface density of the nylon non-woven fabric substrate is 9g / m 2 .

[0097] (8-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply is: ([45,I1,0,I1,-45,I1,90,I1][45,I1])([0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlayer shear strength test, the ply and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (8-2), and I2 of the second group is the nickel-plated nylon non-woven fabric in (8-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply order, respectively. The ply order of the metal-plated nylon non-woven fabric in the second group is silver-plated non-woven fabric × 3, nickel-plated non-woven fabric × 10.

[0098] (8-5) The preform obtained by the above paving is cured according to the curing process of T800 / AED prepreg, the curing pressure is 0.6MPa, and the curing temperature is 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0099] The material data and performance data of this Example 8 are shown in Tables 1 and 2.

[0100] Embodiment 9:

[0101] The implementation process of the technical solution of the present invention is as follows:

[0102] (9-1) Take the self-made unidirectional carbon fiber reinforced high temperature curing epoxy resin prepreg T800 / AED, 4.2% insoluble thermoplastic resin particles are added to the AED resin, the single layer curing thickness is 0.125mm, and the single layer fiber surface density is 135g / m 2 , the resin content is 33.1wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0103] (9-2) Cut 12 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 7 μm and the surface density is 3 g / m 2 .

[0104] (9-3) Cut 20 sheets of 300 mm × 300 mm silver-coated nylon mesh as the second intercalation layer 3, with a surface density of 18 g / m 2 The surface resistance is 0.42Ω / sq. and the single layer thickness is about 50μm.

[0105] (9-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply layup is: ([45,I1,0,I1,-45,I1,90,I1][45,I1,0,I1])([-45,I2,90,I2,][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlayer shear strength test, the ply layup and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (9-2), and I2 of the second group is the silver-plated nylon mesh in (9-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply layup sequence, respectively.

[0106] (9-5) A carbon nanotube film is laid on the surface of the preform laid above. The single layer thickness of the carbon nanotube film is 56 μm and the surface density is 24 g / m 2 .

[0107] (9-6) The preform obtained by the above paving is cured according to the curing process of T800 / AED prepreg, the curing pressure is 0.6MPa, and the curing temperature is 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0108] The material data and performance data of this Example 9 are shown in Tables 1 and 2.

[0109] Embodiment 10:

[0110] The implementation process of the technical solution of the present invention is as follows:

[0111] (10-1) Take unidirectional carbon fiber reinforced bismaleimide resin prepreg CCF800 / 6421, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2, the resin content is 32.6wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0112] (10-2) Cut 10 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 14 μm and the surface density is 6 g / m 2 .

[0113] (10-3) Cut 22 sheets of 300 mm × 300 mm nickel-plated carbon fiber felt as the second intercalation layer 3. The carbon fiber is T800 with a surface density of 14 g / m 2 , the surface resistance is 4Ω / sq., and the single layer thickness is about 30μm.

[0114] (10-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply layup is: ([45,I1,0,I1,-45,I1,90,I1][45,I1])([0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlaminar shear strength test, the ply layup and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (10-2), and I2 of the second group is the nickel-plated carbon fiber felt in (10-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply layup sequence, respectively.

[0115] (10-5) The preform obtained by the above paving is cured according to the curing process of CCF800 / 6421 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 200℃ / 4h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0116] The material data and performance data of this embodiment 10 are shown in Tables 1 and 2.

[0117] Embodiment 11:

[0118] The implementation process of the technical solution of the present invention is as follows:

[0119] In the implementation process of this embodiment 11, in addition to laying a layer of carbon nanotube film (single layer thickness of 28 μm, surface density of 12 g / m 2), and the remaining steps are the same as those in Example 10. The lightning strike performance, electrical conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite material laminate prepared in this example are tested.

[0120] The material data and performance data of this embodiment 11 are shown in Tables 1 and 2.

[0121] Embodiment 12:

[0122] The implementation process of the technical solution of the present invention is as follows:

[0123] (12-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / BA9916, the single layer cured thickness is 0.167mm, and the single layer fiber surface density is 180g / m 2 , the resin content is 31.0wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 prepregs have a fiber orientation of 0° and 16 prepregs have a fiber orientation of 45°.

[0124] (12-2) Cut 10 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 5 μm and the surface density is 2 g / m 2 .

[0125] (12-3) Cut 22 sheets of 300 mm × 300 mm carbon fiber felt as the second intercalation layer 3. The carbon fiber is T800 with a surface density of 5 g / m 2 , the surface resistance is 19Ω / sq., and the single layer thickness is about 20μm.

[0126] (12-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply layup is: ([45,I1,0,I1,-45,I1,90,I1][45,I1])([0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlaminar shear strength test, the ply layup and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (12-2), and I2 of the second group is the carbon fiber felt in (12-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply layup sequence, respectively.

[0127] (12-5) The preform obtained by the above paving is cured according to the curing process of T800 / BA9916 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 180℃ / 3h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0128] The material data and performance data of this Example 12 are shown in Tables 1 and 2.

[0129] Embodiment 13:

[0130] The implementation process of the technical solution of the present invention is as follows:

[0131] (13-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / BA9916, the single layer cured thickness is 0.167mm, and the single layer fiber surface density is 180g / m 2 , the resin content is 36.6wt%. 32 prepregs of 300mm×300mm are cut as the continuous carbon fiber layer 1, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0132] (13-2) Cut 10 sheets of 300 mm × 300 mm carbon nanotube film as the first intercalation layer 2. The single layer thickness of the carbon nanotube film is 20 μm and the surface density is 9 g / m 2 .

[0133] (13-3) Cut 22 sheets of 300 mm × 300 mm silver-coated melt-blown nylon non-woven fabric as the second intercalation layer 3. The fiber diameter of the silver-coated melt-blown nylon non-woven fabric is 3 μm and the surface density is 12 g / m 2 (The density of nylon non-woven fabric is 4.5g / m 2 , silver plating density is 7.5g / m 2 ), the surface resistance is 0.11Ω / sq., and the single layer thickness is about 15μm.

[0134] (13-4) The prepregs of the above materials are laid on two boards in the following order: (1) for lightning strike test and conductivity test, the total number of layers is 16, and the ply layup is: ([45,I1,0,I1,-45,I1,90,I1][45,I1])([0,I2,-45,I2,90,I2][90,I2,-45,I2,0,I2,45,I2]2); (2) for electromagnetic shielding and interlayer shear strength test, the ply layup and number of layers are the same as (1); I1 of the first group is the carbon nanotube film in (13-2), and I2 of the second group is the silver-coated melt-blown nylon non-woven fabric in (13-3). The first group of plies and the second group of plies refer to the plies in the first bracket and the plies in the second bracket of the ply layup sequence, respectively.

[0135] (13-5) The preform obtained by the above paving is cured according to the curing process of T800 / BA9916 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 180℃ / 3h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this embodiment are tested.

[0136] The material data and performance data of this Example 13 are shown in Tables 1 and 2.

[0137] Comparative Example 1:

[0138] The implementation process of the technical solution of the present invention is as follows:

[0139] (D1-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 32.4wt%. 32 prepregs of 300mm×300mm are cut, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0140] (D1-2) The prepreg of the above materials is laid on 2 boards in the following order: for lightning strike test, electromagnetic shielding and interlayer shear strength test, the ply is [45,0,-45,90] 2s .

[0141] (1-5) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, the curing pressure is 0.6MPa, and the curing temperature is 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this comparative example are tested.

[0142] The material data and performance data of this comparative example 1 are shown in Table 1 and Table 2.

[0143] Comparative Example 2:

[0144] The implementation process of the technical solution of the present invention is as follows:

[0145] (D2-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 32.4wt%. 32 prepregs of 300mm×300mm are cut, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0146] (D2-2) 32 sheets of 300 mm × 300 mm carbon nanotube film were cut. The single layer thickness of the carbon nanotube film was 7 μm and the surface density was 3 g / m 2 .

[0147] (D2-3) The prepreg of the above materials is laid on two boards in the following order: for lightning strike test, electromagnetic shielding and interlayer shear strength test, the ply is ([45,I1,0,I1,-45,I1,90,I1] 2s , where I1 is the carbon nanotube film in (D2-2).

[0148] (D2-4) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, with a curing pressure of 0.6MPa and a curing temperature of 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this comparative example are tested.

[0149] The material data and performance data of this comparative example 2 are shown in Tables 1 and 2.

[0150] Comparative Example 3:

[0151] The implementation process of the technical solution of the present invention is as follows:

[0152] (D3-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 34.7wt%. 32 prepregs of 300mm×300mm are cut, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0153] (D3-2) 32 sheets of 300 mm × 300 mm carbon nanotube film were cut. The single layer thickness of the carbon nanotube film was 7 μm and the surface density was 3 g / m 2 .

[0154] (D3-3) The prepreg of the above materials is laid on two boards in the following order: for lightning strike test, electromagnetic shielding and interlayer shear strength test, the ply is ([45,I1,0,I1,-45,I1,90,I1] 2s , where I1 is the carbon nanotube film in (D3-2).

[0155] (D3-4) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, with a curing pressure of 0.4MPa and a curing temperature of 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this comparative example are tested.

[0156] The material data and performance data of this comparative example 3 are shown in Tables 1 and 2.

[0157] Comparative Example 4:

[0158] The implementation process of the technical solution of the present invention is as follows:

[0159] (D4-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 34.7wt%. 32 prepregs of 300mm×300mm are cut, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0160] (D4-2) Cut 32 pieces of 300mm×300mm carbon fiber felt, the carbon fiber is T700, and the surface density is 10g / m 2 , the surface resistance is 8Ω / sq., and the single layer thickness is about 30μm.

[0161] (D4-3) The prepreg of the above materials is laid on two boards in the following order: for lightning strike test, electromagnetic shielding and interlayer shear strength test, the ply is ([45,I1,0,I1,-45,I1,90,I1] 2s , wherein I1 is the carbon fiber felt in (D4-2).

[0162] (D4-4) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, the curing pressure is 0.4MPa, and the curing temperature is 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this comparative example are tested.

[0163] The material data and performance data of this comparative example 4 are shown in Tables 1 and 2.

[0164] Comparative Example 5:

[0165] The implementation process of the technical solution of the present invention is as follows:

[0166] (D5-1) Take unidirectional carbon fiber reinforced epoxy resin prepreg T800 / 5228, a product of AVIC Composite Materials Co., Ltd., with a single-layer cured thickness of 0.125 mm and a single-layer fiber surface density of 135 g / m 2 , the resin content is 34.7wt%. 32 prepregs of 300mm×300mm are cut, of which 16 have a fiber orientation of 0° and 16 have a fiber orientation of 45°.

[0167] (D5-2) 16 sheets of 300 mm × 300 mm carbon nanotube film were cut. The single layer thickness of the carbon nanotube film was 7 μm and the surface density was 3 g / m 2 .

[0168] (D5-3) The prepreg of the above materials is laid on two boards in the following order: for lightning strike test, electromagnetic shielding and interlaminar shear strength test, the ply laying is [45,I1,0,I1,-45,I1,90,I1]2[90,-45,0,45]2, where I1 is the carbon nanotube film in (D5-2).

[0169] (D5-4) The preform obtained by the above paving is cured according to the curing process of T800 / 5228 prepreg, with a curing pressure of 0.4MPa and a curing temperature of 180℃ / 2h. After the curing is completed, the preform is cooled out of the can and the mold is removed to obtain the corresponding quasi-isotropic composite laminate. The lightning strike performance, conductivity, electromagnetic shielding performance and main mechanical properties (mainly interlaminar shear strength) of the composite laminate prepared in this comparative example are tested.

[0170] The material data and performance data of this comparative example 5 are shown in Tables 1 and 2.

[0171] Comparative Example 6:

[0172] The implementation process of the technical solution of the present invention is as follows:

[0173] The implementation process of this comparative example 6 is the same as that of example 1 except that the resin content of the prepreg T800 / 5228 is changed from 32.4wt% to 30.5wt%.

[0174] The material data and performance data of this comparative example 6 are shown in Tables 1 and 2.

[0175] Table 1 summarizes the material parameters and composite material properties of the above examples and comparisons. The volume fraction of carbon fibers in the fiber layer (V f ) refers to the V in the fiber layer after deducting the resin-rich interlayer area of ​​the composite material. f This parameter is used because the intercalation layer has a large thickness, resulting in the V f The reference significance is invalid.

[0176] It should be noted that the definition standard of fiber fuzzing and fracture in Table 2 refers to the fiber on the surface of the composite board after lightning strike, due to the disappearance of resin in the resin vaporization area and the thermal effect of the current, which exists in the form of fiber filaments (broken or unbroken) that lack resin wrapping or are not completely wrapped by resin. After fully scraping them off, the damaged area of ​​each fiber layer is analyzed visually and microscopically; the definition standard of delamination area in Table 2 refers to the fiber and coked resin in the resin vaporization and coking area on the surface of the composite board after lightning strike are fully scraped off, and then analyzed jointly by non-destructive C-scan detection and destructive cross-sectional microscopic analysis. According to the observation of the fiber fuzzing and fracture and delamination area of ​​the composite material after lightning strike, the lightning resistance of the composite material can be characterized.

[0177] Table 1. Material parameters of each embodiment and comparative example (plate for lightning strike test)

[0178]

[0179]

[0180] Table 2 summarizes the material parameters and composite material properties of the above examples and comparisons.

[0181] Table 2. Electromagnetic shielding effectiveness, conductivity, and interlayer shear strength of each embodiment and comparative example

[0182]

[0183]

[0184] When testing the lightning strike performance of composite materials, the main reference indicators for judging the lightning strike resistance of composite materials are the superficial fiber fuzzing and breakage conditions and area after lightning strike, and the internal delamination damage (delamination area) after lightning strike. It should be noted that in this application, internal delamination damage refers to the main delamination damage area with a certain area, excluding the tiny damage similar to defects caused by current penetration (usually ≤1mm). 2 Studies have shown that internal delamination damage can lead to a significant decrease in the compressive strength of the composite material, even in the case of a small damage area (typically a delamination area of ​​500mm 2 ), the compression strength will also drop significantly by more than half; the main reason for the superficial fiber fuzzing and fracture damage is the vaporization of the resin at the lightning attachment point and the internal pressure, but it has little effect on the mechanical properties. Therefore, in order to ensure that the mechanical properties of the composite material structure meet the use requirements, it is necessary to strictly control the internal delamination damage degree (i.e., delamination area) of the composite material, and the superficial fiber fuzzing and fracture damage can be used as the preferred index of the material.

[0185] The carbon nanotube film has good electrical conductivity. When it is applied to a composite material, such as paving it on the surface of a composite material or inserting it into a composite material, the lightning resistance of the composite material is significantly improved. The high electrical conductivity of the carbon nanotube film also makes it have a very high electromagnetic shielding performance, which can reach -90dB. However, the dense carbon nanotubes in the carbon nanotube film are poorly combined with the resin matrix, resulting in deterioration of the interface performance. Typically, the interlaminar shear strength of the composite material modified by its insertion is significantly reduced (measured data are shown in Comparative Examples 2 and 3), resulting in the composite material being easy to crack when subjected to impact and compression. The method of inserting a carbon nanotube film between the layers of the composite material simultaneously achieves lightning resistance and electromagnetic shielding. Since the carbon nanotube film will seriously deteriorate the interface of the composite material, the method of punching the carbon nanotube film can be used to improve the interface, but punching will obviously lead to a decrease in electromagnetic shielding effectiveness, and the interlayer interface is still dominated by the poor interface of the carbon nanotube film / resin, which causes the electromagnetic shielding effectiveness to decrease while not fundamentally solving the problem of interface performance degradation.

[0186] Specifically, in the present invention, the control of internal delamination damage is achieved by the following technical means:

[0187] 1. Control the volume fraction of carbon fibers in the continuous carbon fiber layer in the composite material. In order to ensure that the composite material finally prepared has a higher thickness conductivity, the volume fraction of carbon fibers in the continuous carbon fiber layer should be controlled to be not less than 64%. When the volume fraction of carbon fibers in the continuous carbon fiber layer is higher than 73%, the improvement of thickness conductivity is no longer obvious, and the mechanical properties of the composite material will be reduced (see Comparative Example 6). Therefore, when the volume fraction of carbon fibers in the continuous carbon fiber layer is controlled to be not higher than 73%. By controlling the volume fraction of carbon fibers in the continuous carbon fiber layer to be 64-73%, it can be ensured that the continuous carbon fiber layer and the interlayer material set as the first carbon nanotube film material and the interlayer material are interlayered with micron conductive materials to form a good conductive contact, so that the composite material finally prepared has a higher thickness conductivity, thereby avoiding the lightning current from penetrating a larger area of ​​the insulating resin layer to cause stratification, the stratification ability of the composite material is enhanced, and the composite material is not easy to produce high porosity under this volume fraction condition. In the present invention, two intercalation layers of different materials are respectively arranged between the layers of two adjacent continuous carbon fiber layers. The intercalation layers between the first 3 to 7 layers of the composite material close to the lightning protection side are the first carbon nanotube film material, and the intercalation layers between the remaining layers are micron conductive materials. The intercalation layers of the carbon nanotube film material are used for the main evacuation of lightning current, and the intercalation layers of the micron conductive material are used for the auxiliary evacuation of lightning current. From the comparison between comparative example 5 and each embodiment, it can be seen that only the carbon nanotube film material is arranged between some layers, which still leads to serious internal stratification after the lightning test. After adding the micron conductive material as an intercalation layer to assist in the evacuation of lightning current, the stratification damage is completely suppressed. Similarly, from comparative example 4, it can be seen that when only the micron conductive material is used as an intercalation layer, the lightning damage of the composite material finally formed is still relatively serious, especially reflected in the interlayer stratification between the first layer-the second layer and the second layer-the third layer.

[0188] Furthermore, the number of intercalation layers and thickness of the carbon nanotube film material are key factors affecting the size of the delamination damage area. For the system of the present invention, the thickness of the carbon nanotube film material is preferably 5 to 20 μm, the surface resistance of the micron intercalation layer is controlled to be 0.1 to 30 Ω / sq., and the thickness is 10 to 50 μm. When the thickness of the composite material is σz ≥ 0.4, the carbon nanotube film material needs to be set at least 3 to 7 layers to effectively resist the internal delamination caused by lightning strikes, and generally does not exceed 5 layers (for systems with thickness conductivity σz ≥ 0.8 S / cm). For systems with 0.8 ≥ σz ≥ 0.4 S / cm, 4 to 8 layers are required for complete suppression. The damaged area of ​​the 2A area of ​​the composite material plate after lightning strike and the scanned image of the test plate C of Example 1 and Comparative Example 4 are shown in Figure 2 and Figure 3 , it can be seen that the effect of the present invention is remarkable.

[0189] Furthermore, in order to reduce the fuzzing and breakage of the superficial fibers and the area thereof, the present invention provides a method of laying a layer of carbon nanotube film (second carbon nanotube film material) on the surface of the composite material, controlling the thickness of the second carbon nanotube film material to be 14 to 100 μm and the surface density to be 6 to 42 g / m 2 For the system of the present invention, almost no damage to the shallow surface layer can be achieved, but this solution is not universally applicable to other composite material systems. For conventional composite material systems, the thickness of the surface carbon nanotube film needs to reach more than 300μm to achieve this goal.

[0190] When testing the electromagnetic shielding performance of composite materials, the main reference indicator for judging the electromagnetic shielding performance of composite materials is: total electromagnetic shielding effectiveness (X-band); in the present application, carbon nanotube film material is used as the main electromagnetic shielding material, and micron conductive material and carbon fiber ply are used as auxiliary electromagnetic shielding materials. From the test data, the solution provided in the present application can achieve better electromagnetic shielding performance; thereby achieving high electromagnetic shielding effectiveness and low lightning damage of the composite material at the same time, and eliminating the adverse effects of the carbon nanotube film on the interface.

[0191] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite material with high electromagnetic shielding and low lightning damage, characterized in that: The composite material has a connection side for connecting to an aircraft and a lightning strike resistant side facing away from the aircraft. The composite material is a continuous carbon fiber reinforced resin-based composite material, including a resin matrix, a continuous carbon fiber layer and an intercalation layer. Multiple continuous carbon fiber layers are stacked in sequence along the thickness direction, and the intercalation layer is provided between two adjacent continuous carbon fiber layers. The continuous carbon fiber layers and the intercalation layers between the continuous carbon fiber layers are filled with a resin matrix, and the volume fraction of the carbon fiber in the continuous carbon fiber layer is 64-73%; The first 3 to 7 interlayers of the composite material close to the lightning protection side are intercalated with a first carbon nanotube film material, and the intercalated layers of the remaining layers are micron conductive materials. The thickness of the first carbon nanotube film material is 5 to 20 μm, and the surface density is 2 to 10 g / m 2 The resistivity of the micron conductive material is 0.1-30Ω / sq., and the thickness is 15-50μm.

2. The high electromagnetic shielding and low lightning damage composite material according to claim 1, characterized in that: The composite material further comprises a surface layer, the surface layer being arranged on the surface of the lightning-resistant side, the surface layer being a second carbon nanotube film material filled with a resin matrix and co-cured on the surface of the lightning-resistant side of the composite material, the second carbon nanotube film material having a thickness of 14 to 100 μm and a surface density of 6 to 42 g / m 2 .

3. The high electromagnetic shielding and low lightning damage composite material according to claim 1, characterized in that: The micron conductive material includes at least one of nickel-plated carbon fiber felt, metal-plated non-woven fabric, and metal-plated gauze.

4. The high electromagnetic shielding and low lightning damage composite material according to claim 3, characterized in that: The surface density of the micron conductive material is 8 to 25 g / m 2 , surface resistivity is 0.1~10Ω / sq., and thickness is 15~50μm.

5. The high electromagnetic shielding and low lightning damage composite material according to claim 1, characterized in that: The micron conductive material is carbon fiber felt.

6. The high electromagnetic shielding and low lightning damage composite material according to claim 5, characterized in that: The surface density of the carbon fiber felt is 5 to 15 g / m 2 , surface resistivity is 5~28Ω / sq., and thickness is 15~35μm.

7. The high electromagnetic shielding and low lightning damage composite material according to claim 1, characterized in that: The resin matrix is ​​epoxy resin or bismaleimide resin.

8. The high electromagnetic shielding and low lightning damage composite material according to claim 1, characterized in that: The content of the insoluble particles in the resin matrix is ​​not more than 5wt%.

9. A method for preparing a composite material with high electromagnetic shielding and low lightning damage according to any one of claims 1 to 8, characterized in that: The following steps are involved: preparing a continuous carbon fiber resin prepreg, an intercalation layer of a first carbon nanotube film material, and an intercalation layer of a micron conductive material respectively; The layers of continuous carbon fiber resin prepreg and the layers of intercalation are sequentially stacked in a preset order along the thickness direction to form a composite material preform; The composite material preform is heated and cured, and the mold is removed after cooling to obtain the high electromagnetic shielding and low lightning damage composite material.

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