Wide-temperature-range bearing-shielding-lightning stroke protection integrated composite material, preparation method and application

Abstract

The invention discloses a wide-temperature-range bearing-shielding-lightning stroke protection integrated composite material, a preparation method and application. The preparation method of the wide-temperature-range bearing-shielding-lightning stroke protection integrated composite material comprises the following steps: winding a continuous metallized carbon fiber prepreg to form a prepreg cloth belt; the n prepreg cloth belts are stacked and laid in the radial direction of the prepreg cloth belts, a composite material prefabricated body is obtained, and n is larger than or equal to 2; and hot-pressing and curing the composite material prefabricated body to form the wide-temperature-range bearing-shielding-lightning stroke protection integrated composite material. The prepared wide-temperature-range bearing-shielding-lightning stroke protection integrated composite material has the advantages of being good in mechanical performance (the bending stress is 601.2 MPa, and the bending modulus is 70.71 GPa), good in electromagnetic shielding effect (the average EMI SE value of 8.2-12.4 GHz is 81.48 dB), resistant to lightning stroke, wide in temperature range (room temperature to 400 DEG C), resistant to impact and the like, and especially the lightning stroke effect is obviously better than that of a traditional copper net composite film; and the structure function integration of wide temperature range bearing, shielding and lightning protection is realized.

Description

TECHNICAL FIELD

[0001] The present application particularly relates to a wide-temperature-range load-shielding-lightning-protection integrated composite material, a preparation method and an application, and belongs to the technical field of aerospace, new energy devices, rail transit, electromagnetic shielding and lightning protection composite materials. BACKGROUND

[0002] Carbon fiber is a high-performance fiber material with carbon element as the main component, and its microstructure is composed of highly oriented graphite crystallites arranged along the fiber axis to endow it with excellent mechanical and physical properties. The typical diameter of carbon fiber ranges from 5 to 10 microns, and its density is only 1.7 to 2.1 g / cm 3 However, it exhibits amazing strength and rigidity, with tensile strength up to 5000-7000 MPa and elastic modulus up to 200-900 GPa, far exceeding traditional metal materials (such as steel with density of 7.8 g / cm 3 , strength of 500 MPa, and modulus of 200 GPa), and at the same time, it has excellent high-temperature resistance (resistant to 3000℃ in inert atmosphere), chemical corrosion resistance, low thermal expansion coefficient and electrical conductivity (electrical conductivity of 10 4 -10 6 S / m), making it an ideal material for high electromagnetic shielding performance, heat resistance and lightning protection. Carbon fiber composite material is currently a hot research topic in this field.

[0003] Carbon fiber reinforced resin matrix composite (CFRP) is a material composed of fiber as reinforcement and resin as matrix through advanced preparation technology. It has the advantages of low density, high strength, high stiffness, high temperature resistance, fatigue resistance, vibration reduction and strong designability. It has wide application prospects in aerospace, new energy devices, rail transportation, electromagnetic shielding and lightning protection. It is of great application value to develop electromagnetic shielding composite materials with high strength, high temperature resistance and lightning protection. So far, the preparation methods of carbon fiber composite materials with electromagnetic shielding, lightning protection, high strength and high temperature resistance are as follows:(1) After electroplating nickel metal on carbon fiber, three-dimensional four-way braiding is carried out, then the braided body of plated nickel carbon fiber is combined with polyether ether ketone resin, thus preparing a composite material of plated nickel carbon fiber and polyether ether ketone resin.(CN1 14561080A);(2) The non-woven fabric composite material made of plated nickel carbon fiber is fixed on the surface as a lightning protection layer.(Literature 1: Yunli Guo, Yongzheng Xu, Qinglin Wang, Qi Dong, Xiaosu Yi, Yuxi Jia, Eliminating lightning strike damage to carbon fiber composite structures in Zone 2 of aircraft by Ni-coated carbon fiber nonwoven veils. Composites Science and Technology 2019, 169.)(3) Ag / T-ZNO particles are filled between carbon fibers to build a three-dimensional conductive network to improve lightning protection, electromagnetic shielding effect and interlayer toughness.(Literature 2: Zhu H, Fu K, Huang T, et al. Highly conductive CFRP composite with Ag-coated T-ZnO interlayers for excellent lightning strike protection, EMI shielding and interlayer toughness[J]. Composites Part B, 2024, 279111448-.)(4) Non-woven carbon fiber / polypropylene / polyethylene (CEF-NF) fabric, catalytic inoculation and sensitization, chemical nickel plating and lamination with polycarbonate are manufactured. The prepared composite material has the properties of flexibility, mechanical strength and electrical performance of electromagnetic shielding materials.(Document 3: Xing D, Lu L, Teh S K, et al. Highly flexible and ultra-thin Ni-plated carbon-fabric / polycarbonate film for enhanced electromagnetic interference shielding [J]. Carbon, 2018, 13232-41.).

[0004] Traditional metal-made electromagnetic shielding and lightning protection materials, such materials can easily achieve shielding effectiveness of more than 80 dB in high frequency band (such as 1-10 GHz) through strong reflection of electromagnetic waves by free electrons, and can quickly discharge the instantaneous large current generated by lightning through high current-carrying capacity. However, the densities of copper and aluminum are 8.96 g / cm 3 and 2.7 g / cm 3 , respectively, which significantly increases the structural weight when used in aircraft or satellites, and the problem of easy oxidation of metal surface may cause the grounding resistance to rise, weakening the long-term lightning protection effect. In addition, due to the smooth micro-morphology of the metal wire surface of metal mesh (such as copper mesh and steel mesh), it is difficult to form mechanical interlocking effect with the resin matrix, resulting in poor interfacial bonding with the carbon fiber resin matrix (Hansong L, Jinsong S, Ziqi D, et al. Study on properties influence of carbon fiber reinforced polyimide composites via surface modification using metal mesh [J]. Polymer Composites, 2022, 44(2): 971-979.).

[0005] Short fiber reinforced composites have good design flexibility, retaining the high strength and high modulus characteristics of the fibers, but the uniformity of the dispersion of the fibers in the matrix is difficult to accurately control, and agglomeration is prone to occur during processing, resulting in local fiber density being too high or too low, forming conductive "island" phenomenon, and the overall mechanical properties are significantly lower than continuous fiber reinforced materials. The length of the chopped fiber is usually tens of microns to several millimeters, which is much lower than that of continuous fibers (several meters or more). When the fiber length is less than the critical value (i.e. "percolation threshold"), the fibers are difficult to effectively contact, and a continuous conductive path cannot be formed (K.H. Wong, S.J. Pickering, C.D. Rudd, et al. Recycled carbon fibre reinforced polymer composite for electromagnetic interference shielding [J] Composites Part A, 2010, 41(6): 693-702.). In the electromagnetic shielding structure of directional conduction or heat conduction, it is difficult to achieve the functional requirements through fiber arrangement optimization. In order to achieve a specific electromagnetic shielding effectiveness, the amount of fiber added is often increased, which not only increases the brittleness of the material and reduces the toughness, but also may cause the matrix to flow difficultly due to too many interfaces, resulting in rough surface or increased internal porosity of the formed part. In addition, the electromagnetic shielding composite prepared by conductive fillers has outstanding advantages in flexible electronics and lightweight devices, but the dispersion of conductive nanofillers in the matrix is poor, and agglomeration is prone to occur, resulting in discontinuous conductive network and weakened electromagnetic shielding effectiveness.

[0006] In summary, the preparation of electromagnetic shielding composites with high strength, heat resistance and lightning protection is the key to realizing their application. At present, the preparation of composites still has the following shortcomings: (1) Short fiber reinforced composites have good design flexibility, retaining the high strength and high modulus characteristics of the fibers, but the uniformity of the dispersion of the fibers in the matrix is difficult to accurately control, and agglomeration is prone to occur during processing, resulting in local fiber density being too high or too low, forming conductive "island" phenomenon, and the overall mechanical properties are significantly lower than continuous fiber reinforced materials. (2) The electromagnetic shielding composite prepared by conductive fillers has outstanding advantages in flexible electronics and lightweight devices, but the dispersion of conductive nanofillers in the matrix is poor, and agglomeration is prone to occur, resulting in discontinuous conductive network and weakened electromagnetic shielding effectiveness. SUMMARY

[0007] The main purpose of the present application is to provide a wide temperature range bearing-shielding-lightning protection integrated composite material, a preparation method and an application, so as to overcome the shortcomings in the prior art.

[0008] In order to achieve the above-mentioned purpose of the application, the technical scheme adopted by the present application comprises:

[0009] The first aspect of the embodiment of the present application provides a preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, which comprises the following steps:

[0010] winding the continuous metalized carbon fiber prepreg into a prepreg tape;

[0011] stacking and laying the n prepreg tapes along the radial direction of the prepreg tapes to obtain a composite material preform, and n is greater than or equal to 2;

[0012] thermally pressing and curing the composite material preform to form the wide-temperature-range bearing-shielding-lightning-protection integrated composite material.

[0013] The second aspect of the embodiment of the present application provides a wide-temperature-range bearing-shielding-lightning-protection integrated composite material obtained by the preparation method of the wide-temperature-range bearing-shielding-lightning-protection integrated composite material.

[0014] The third aspect of the embodiment of the present application provides an application of the wide-temperature-range bearing-shielding-lightning-protection integrated composite material in the fields of aerospace, new energy devices, rail transit, electromagnetic shielding or lightning protection.

[0015] Compared with the prior art, the advantages of the present application include:

[0016] The continuous batch production metalized carbon fiber used in the present application is used as a reinforcing material, and polyimide or the like is used as a resin matrix. The continuous metalized carbon fiber is spread to ensure high conductivity while reducing weight. Meanwhile, the composite material is structurally designed. By changing the number of layers, fiber orientation and layer angle structure of the metalized carbon fiber, the balance between performance, function, lightweight and cost is achieved. The composite material is prepared by the winding-laying-thermal pressing process.

[0017] The wide-temperature-range bearing-shielding-lightning-protection integrated composite material prepared by the present application has good mechanical properties (bending stress of 601.2 MPa, bending modulus of 70.71 GPa), electromagnetic shielding effect (average EMI SE value of 8.2-12.4 GHz is 81.48 dB), lightning protection and heat resistance, etc. The structure and function integration of the wide-temperature-range bearing-shielding-lightning-protection is realized. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a photo of a prepreg tape formed by winding the continuous metalized carbon fiber prepreg in a winding mold in a typical embodiment of the present application;

[0019] Figure 2 is a photo of a 12K T700 continuous nickel-plated carbon fiber prepreg tape obtained in the embodiment 1 of the present application;

[0020] Figure 3is a photo of the 12K T700 continuous carbon fiber prepreg fabric tape obtained in Comparative Example 1;

[0021] Figure 4 is a thermal condition curve used in a typical embodiment of the present application;

[0022] Figure 5 is a cross-sectional structure morphology diagram of the 12K T700 continuous nickel-coated carbon fiber composite material obtained in Embodiment 1 of the present application;

[0023] Figure 6 is an electromagnetic shielding performance curve of the 12K T700 continuous nickel-coated carbon fiber composite material obtained in Embodiment 1 of the present application;

[0024] Figure 7 is an electromagnetic shielding performance of the 12K T700 continuous carbon fiber composite material obtained in Comparative Example 1,

[0025] Figure 8 is the three-point bending performance of the 12K T700 continuous nickel-coated carbon fiber composite material obtained in Embodiment 1 of the present application in the fiber direction;

[0026] Figure 9 is the three-point bending performance of the 12K T700 continuous nickel-coated carbon fiber composite material obtained in Embodiment 1 of the present application in the direction perpendicular to the fiber direction;

[0027] Figure 10 is a TG curve of the 12K T700 continuous carbon fiber composite material obtained in Comparative Example 1 and the 12K T700 continuous nickel-coated carbon fiber composite material obtained in Embodiment 1 of the present application;

[0028] Figure 11 is a photo of the 12K T700 continuous carbon fiber composite material obtained in Comparative Example 1 after lightning strike;

[0029] Figure 12 is a photo of the 12K T700 continuous nickel-coated carbon fiber composite material obtained in Embodiment 1 of the present application after lightning strike.

[0030] Figure 13 is a photo of the copper mesh composite material after lightning strike under the same conditions. DETAILED DESCRIPTION

[0031] In view of the deficiencies in the prior art, the present inventors have obtained the technical solution of the present application through long-term research and a large number of practices. The technical solution, its implementation process and principles will be further explained as follows.

[0032] The first aspect of the embodiment of the present application provides a preparation method of a wide-temperature-range bearing-shielding-lightning strike protection integrated composite material, which comprises:

[0033] winding the continuous metalized carbon fiber prepreg to form a prepreg tape;

[0034] stacking n prepreg tapes along the radial direction of the prepreg tapes to obtain a composite material preform, n≥2;

[0035] thermally pressing and curing the composite material preform to form a wide-temperature-range load-shielding-lightning-protection integrated composite material.

[0036] Further, the preparation method of the wide-temperature-range load-shielding-lightning-protection integrated composite material specifically comprises: winding the continuous metalized carbon fiber prepreg on a winding mold to form the prepreg tape.

[0037] Further, the winding speed of the continuous metalized carbon fiber prepreg is 1 m / min-50 m / min, and the winding angle is that the fiber direction is parallel to the main shaft of the winding mold, and the deviation needs to be <±0.5°.

[0038] Further, the continuous metalized carbon fiber comprises nickel-plated or copper-plated carbon fiber or nickel-copper-plated carbon fiber.

[0039] Further, the continuous metalized carbon fiber prepreg is in a fibrous shape, and the diameter of the continuous metalized carbon fiber prepreg ranges from 0.1 mm to 5 mm.

[0040] Further, the number of yarns in the continuous metalized carbon fiber prepreg is 1, and the fiber volume fraction in the continuous metalized carbon fiber prepreg is 50%-65%.

[0041] Further, the spacing between the tows in the continuous metalized carbon fiber prepreg is the width of the tows±0.5 mm. Taking 12K tows as an example, the width of the 12K tows is 3 mm, and thus the spacing between the tows is 3 mm±0.5 mm.

[0042] Further, the tows contained in the prepreg tape are tightly combined with each other, which facilitates subsequent removal from the mold.

[0043] Further, the preparation method of the wide-temperature-range load-shielding-lightning-protection integrated composite material specifically comprises: first, performing spread yarn treatment on the continuous metalized carbon fiber, and then immersing the continuous metalized carbon fiber after the spread yarn treatment in a resin solution to form a continuous metalized carbon fiber prepreg.

[0044] Further, after the spread yarn treatment, the width of the continuous metalized carbon fiber is expanded to 1.5-2.5 times the initial width. The spread yarn treatment first expands the fiber tows into thinner and wider strips, reduces local aggregation of the fibers, reduces the porosity, increases the spacing between the filaments, and makes the resin more permeable (especially for high-viscosity resins such as epoxy), thereby shortening the infiltration time.

[0045] Further, the resin solution comprises resin and N-N dimethylacetamide, wherein a mass ratio of the resin and the N-N dimethylacetamide is 1:2 or 1:3, and the resin comprises at least one of thermoplastic polyimide resin, epoxy resin, polyether ether ketone resin, phenolic resin, bismaleimide resin, phthalonitrile resin, cyanate ester resin.

[0046] In a more specific embodiment, the method for preparing the wide-temperature-range load-shielding-lightning-protection integrated composite material further comprises: changing at least one of the performance, function, density / mass and cost of the wide-temperature-range load-shielding-lightning-protection integrated composite material by changing the number n of layers and / or the ply angle and / or the fiber orientation of the prepreg tape.

[0047] Further, the number n of layers of the prepreg tape can affect the mechanical properties of the wide-temperature-range load-shielding-lightning-protection integrated composite material: stiffness and strength, increasing the number n of layers can improve the overall stiffness and strength (such as tensile, compressive, bending performance) of the wide-temperature-range load-shielding-lightning-protection integrated composite material, but the interfacial effect (interlaminar stress may cause delamination) needs to be considered. Impact resistance: increasing the number n of layers can improve the energy absorption capacity of the wide-temperature-range load-shielding-lightning-protection integrated composite material, but excessive thickness may cause brittle failure. Stability: the resistance to buckling load (such as thin plate under compression) is significantly enhanced.

[0048] Further, the ply angle refers to the angle (such as 0°, ±45°, 90°) of a single layer of fibers relative to a reference axis (such as the loading direction), which directly affects anisotropy. Specifically, the ply angle can affect the in-plane performance of the wide-temperature-range load-shielding-lightning-protection integrated composite material, 0° direction: the fiber axial direction provides the highest tensile / compressive strength and stiffness (such as the modulus of carbon fibers in the 0° direction can reach more than 200 GPa). ±45° direction: enhances shear performance, improves torsional and in-plane shear strength (helicopter rotor often uses ±45° ply). 90° direction: resists transverse loads, but the performance is usually the weakest (matrix dominated).

[0049] Further, the fiber orientation can achieve local performance regulation of the wide-temperature-range load-shielding-lightning-protection integrated composite material, for example, unidirectional fibers (UD) have high strength along the fiber direction and are weak in the transverse direction; fabrics (such as plain weave, twill weave): balance in-plane performance, but sacrifice part of the unidirectional performance; random orientation (short-cut fibers): isotropic, but with lower strength (such as SMC materials). Special functions: electrical conductivity: directional arrangement of fibers can form a high-efficiency conduction network.

[0050] Further, the number of layers n of the prepreg tape is 4, the ply angles of the four layers of the prepreg tape are [0° / 0° / 90° / 90°] respectively, or the number of layers n of the prepreg tape is 4, the ply angles of the four layers of the prepreg tape are [0° / 45° / -45° / 0°] respectively, or the number of layers n of the prepreg tape is 4, the ply angles of the four layers of the prepreg tape are [0° / 90° / 45° / -45°] respectively, and the fiber orientation is determined by the ply angle.

[0051] Further, the preparation method of the wide-temperature-range bearing-shielding-lightning-protection integrated composite material specifically comprises: performing heat pressing and curing on the composite material preform in a stepwise heating and stepwise pressing manner.

[0052] Further, the temperature of the heat pressing and curing is 100℃-380℃, the pressure is 0MP-3MPa, and the total time of the heat pressing and curing is 450min-650min. Specifically, when the temperature of the heat pressing and curing is 100℃-180℃, the volatile components can be removed and the resin can be fully infiltrated; when the temperature of the heat pressing and curing is 180℃-300℃, pre-curing can be achieved and the resin flow can be reduced; and when the temperature of the heat pressing and curing is 300℃-380℃, complete imidization and densification can be achieved.

[0053] Further, the process of the heat pressing and curing specifically comprises a first heat pressing and curing stage, a second heat pressing and curing stage, a third heat pressing and curing stage, a fourth heat pressing and curing stage, a fifth heat pressing and curing stage, a sixth heat pressing and curing stage, a seventh heat pressing and curing stage, and an eighth heat pressing and curing stage,

[0054] The first heat pressing and curing stage adopts a first temperature and a first pressure, the second heat pressing and curing stage adopts a second temperature and a second pressure, the third heat pressing and curing stage adopts a third temperature and a third pressure, the fourth heat pressing and curing stage adopts a fourth temperature and a fourth pressure, the fifth heat pressing and curing stage adopts a fifth temperature and a fifth pressure, the sixth heat pressing and curing stage adopts a sixth temperature and a sixth pressure, the seventh heat pressing and curing stage adopts a seventh temperature and a seventh pressure, and the eighth heat pressing and curing stage adopts an eighth temperature and an eighth pressure, wherein the first temperature<the second temperature<the third temperature<the fourth temperature<the fifth temperature<the sixth temperature<the seventh temperature<the eighth temperature, and the first pressure = the second pressure = the third pressure = the fourth pressure≤the fifth pressure = the sixth pressure<the seventh pressure = the eighth pressure.

[0055] Further, the first temperature of the first hot-pressing and curing stage is 100-120 DEG C, the first pressure is 0-0.5 MPa, the duration is 30-60 min, the second temperature of the second hot-pressing and curing stage is 150-170 DEG C, the second pressure is 0-0.5 MPa, the duration is 30-60 min, the third temperature of the third hot-pressing and curing stage is 200-220 DEG C, the third pressure is 0-0.5 MPa, the duration is 30-60 min, the fourth temperature of the fourth hot-pressing and curing stage is 240-260 DEG C, the fourth pressure is 0-0.5 MPa, the duration is 120-180 min,

[0056] the fifth temperature of the fifth hot-pressing and curing stage is 280-300 DEG C, the fifth pressure is 0-0.5 MPa, the duration is 5-10 min, the sixth temperature of the sixth hot-pressing and curing stage is 300-330 DEG C, the sixth pressure is 0-0.5 MPa, the duration is 3-5 min,

[0057] the seventh temperature of the seventh hot-pressing and curing stage is 370 DEG C, the seventh pressure is 2-3 MPa, the duration is 120 min, the eighth temperature of the eighth hot-pressing and curing stage is 380 DEG C, the eighth pressure is 2-3 MPa, the duration is 120 min.

[0058] In a more specific embodiment, the method for preparing the wide-temperature-range bearing-shielding-lightning-protection integrated composite material further comprises: after the hot-pressing and curing is completed, the hot-pressing temperature is first lowered to below 200 DEG C, and then pressure relief and demolding are performed.

[0059] The second aspect of the embodiment of the application provides a wide-temperature-range bearing-shielding-lightning-protection integrated composite material obtained by the method for preparing the wide-temperature-range bearing-shielding-lightning-protection integrated composite material.

[0060] Further, the wide-temperature-range bearing-shielding-lightning-protection integrated composite material has a bending stress of 601.2 MPa, a bending modulus of 70.71 GPa, and an average EMISE value of 81.48 dB in the range of 8.2-12.4 GHz.

[0061] The third aspect of the embodiment of the application provides a use of the wide-temperature-range bearing-shielding-lightning-protection integrated composite material in the fields of aerospace, new energy devices, rail transit, electromagnetic shielding or lightning protection.

[0062] Further, the wide-temperature-range load-shielding-lightning-protection integrated composite material is used to make an outer shell of an aircraft or a vehicle body, and / or the wide-temperature-range load-shielding-lightning-protection integrated composite material is used to make an electromagnetic interference shielding structure or a lightning protection structure.

[0063] Further, in the field of aerospace, the wide-temperature-range load-shielding-lightning-protection integrated composite material can be used to make structural components of an aircraft (such as an airplane, a drone), a satellite, and the like. In the field of new energy devices, the wide-temperature-range load-shielding-lightning-protection integrated composite material can be used to make structural components and electromagnetic shielding components of new energy equipment (such as a power battery shell, an energy storage device). In the field of rail transit, the wide-temperature-range load-shielding-lightning-protection integrated composite material can be used to make a vehicle body structure or an electrical equipment protection component of a high-speed train or a subway. In the field of electromagnetic shielding and lightning protection, the wide-temperature-range load-shielding-lightning-protection integrated composite material can be used to make equipment that needs electromagnetic interference shielding (such as a precision instrument shell) or lightning protection (such as a communication base station, a radar cover).

[0064] The technical solution, the implementation process and the principles thereof will be further explained in the following with reference to the accompanying drawings and specific implementation cases.

[0065] In a more typical implementation, a method for preparing a wide-temperature-range load-shielding-lightning-protection integrated composite material specifically includes the following steps:

[0066] 1) Configure a resin solution.

[0067] The resin and N-N dimethylacetamide are mixed in a mass ratio of 1:3 or 1:2 to form a resin solution, and the resin solution is used as a glue solution. According to different requirements, resins with different properties and different types can be selected. For example, the resin can be a thermoplastic polyimide resin, an epoxy resin, a polyether ether ketone resin, a phenolic resin or a bismaleimide resin, etc. These resins can be obtained from the market, and specific product models are not limited herein.

[0068] 2) Place the continuous metalized carbon fiber on a unwinding device, and place the glue solution in a glue tank. The continuous metalized carbon fiber tows are immersed in the resin solution and placed on a fiber roller to form a continuous metalized carbon fiber prepreg. The continuous metalized carbon fiber prepreg is wound on a winding mold to form a prepreg tape, as shown in Figure 1

[0069] Specifically, the continuous metalized carbon fiber includes a nickel-plated or copper-plated carbon fiber or a nickel-copper-plated carbon fiber. The carbon fiber used in the continuous metalized carbon fiber can be T300, T700, T800, etc. (a more suitable type of carbon fiber is used in different scenarios). ​

[0070] Specifically, to achieve the lightweight of the composite material, the continuous metalized carbon fiber can be subjected to a spreading treatment. After the spreading treatment, the width of the continuous metalized carbon fiber is widened to 1.5-2.5 times of the initial width, for example, from 3 mm to 6 mm. The specific spreading treatment process can be realized in a manner known in the art, which is not specifically limited here.

[0071] 3) The prepreg tape formed by winding is dried at 40-80°C, and then taken out from the winding mold after drying.

[0072] 4) The prepared n prepreg tapes are sequentially stacked in the mold, and during the sequential stacking, the resin solution in step 1) is brushed on the surface of each prepreg tape. During the stacking process, the orientation of the fibers in the composite material can be precisely controlled, and the sequence of stacking can be used to realize the directional regulation and multifunctional optimization of the material performance.

[0073] Specifically, the number of layers n of the prepreg tape is 4, and the ply angle is [0° / 0° / 90° / 90°], which can realize the transverse electromagnetic shielding performance. Alternatively, the number of layers n of the prepreg tape is 4, and the ply angle is [0° / 45° / -45° / 0°], which can realize high axial stiffness (0° layer accounts for 50%), and also has partial shear resistance. Alternatively, the number of layers n of the prepreg tape is 4, and the ply angle is [0° / 90° / 45° / -45°], which can realize the construction of a three-dimensional conductive network by orthogonal + diagonal layers.

[0074] 5) The prepreg tape is placed in a flat vulcanization instrument together with the mold for hot pressing. Please refer to Figure 4 , the hot pressing process includes:

[0075] The first hot pressing and curing stage adopts a first temperature of 100-120°C, a first pressure of 0-0.5 MPa, and a duration of 30-60 min. The second hot pressing and curing stage adopts a second temperature of 150-170°C, a second pressure of 0-0.5 MPa, and a duration of 30-60 min. The third hot pressing and curing stage adopts a third temperature of 200-220°C, a third pressure of 0-0.5 MPa, and a duration of 30-60 min. The fourth hot pressing and curing stage adopts a fourth temperature of 240-260°C, a fourth pressure of 0-0.5 MPa, and a duration of 120-180 min.

[0076] The fifth hot-pressing and curing stage adopts a fifth temperature of 280-300°C, a fifth pressure of 0-0.5 MPa, and a duration of 5-10 min; the sixth hot-pressing and curing stage adopts a sixth temperature of 300-330°C, a sixth pressure of 0-0.5 MPa, and a duration of 3-5 min; when the temperature approaches 340-360°C, the resin viscosity is observed, and the resin viscosity is felt to be large, and the pressure is increased to 2-3 MPa;

[0077] The seventh hot-pressing and curing stage adopts a seventh temperature of 370°C, a seventh pressure of 2-3 MPa, and a duration of 120 min; the eighth hot-pressing and curing stage adopts an eighth temperature of 380°C, an eighth pressure of 2-3 MPa, and a duration of 120 min.

[0078] After the hot-pressing and curing is completed, the hot-pressing temperature is first lowered to below 200°C, and then the pressure is released and the mold is demolded.

[0079] Example 1

[0080] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material specifically comprises the following steps:

[0081] 1) A resin solution is prepared.

[0082] The thermoplastic polyimide resin and N-N dimethylacetamide are mixed in a ratio of 1:3 to form the resin solution.

[0083] 2) The 12K T700 continuous nickel-plated carbon fiber is placed on a unwinding device, the thickness of the nickel-plated layer is 0.6±0.05 μm, the glue solution is placed in a glue tank, the continuous nickel-plated carbon fiber tows are immersed in the resin solution and placed on a fiber roller to form a continuous nickel-plated carbon fiber prepreg, and the continuous nickel-plated carbon fiber prepreg is wound on a winding mold, and the specific winding parameters are as follows: winding speed: 20 m / min; number of yarns: 1; fiber volume fraction: 60%; winding angle: the fiber direction is completely parallel to the main shaft of the winding mold, and the deviation needs to be <±0.5°; tow spacing: 3 mm, to form a prepreg tape, as shown in FIG. 1. Figure 2

[0084] 3) The prepreg tape wound is dried at 60°C, and then taken off from the winding mold after drying.

[0085] 4) The four prepared prepreg tapes are sequentially stacked in the mold, and the resin solution in step 1) is brushed on the surface of each prepreg tape during the sequential stacking, and specifically, the prepreg tape laying angle of the four prepreg tapes is [0° / 0° / 90° / 90°].​

[0086] 5) Put the prepreg tape together with the mold into the flat vulcanization instrument for hot pressing, and the hot pressing process includes:

[0087] The first hot pressing and curing stage adopts a first temperature of 100°C, a first pressure of 0.5 MPa, and a duration of 60 min; the second hot pressing and curing stage adopts a second temperature of 150°C, a second pressure of 0.5 MPa, and a duration of 60 min; the third hot pressing and curing stage adopts a third temperature of 200°C, a third pressure of 0.5 MPa, and a duration of 60 min; the fourth hot pressing and curing stage adopts a fourth temperature of 240°C, a fourth pressure of 0.5 MPa, and a duration of 120 min;

[0088] The fifth hot pressing and curing stage adopts a fifth temperature of 300°C, a fifth pressure of 0.5 MPa, and a duration of 10 min; the sixth hot pressing and curing stage adopts a sixth temperature of 330°C, a sixth pressure of 0.5 MPa, and a duration of 3 min;

[0089] The seventh hot pressing and curing stage adopts a seventh temperature of 370°C, a seventh pressure of 3 MPa, and a duration of 120 min; the eighth hot pressing and curing stage adopts an eighth temperature of 380°C, an eighth pressure of 3 MPa, and a duration of 120 min.

[0090] After completing the hot pressing and curing, the hot pressing temperature is first lowered to below 200°C, and then the pressure is released, the mold is removed, and the composite material is taken out.

[0091] Figure 5 For the cross-sectional morphology of the composite material obtained after hot pressing, it can be seen that the polyimide resin (corresponding to the circular part in the figure) enters the nickel-plated carbon fiber (corresponding to the square part in the figure) and forms an effective composite, and there are no defects in the whole interior, which is conducive to the test of electromagnetic shielding performance.

[0092] Example 2

[0093] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0094] 1) Configure a resin solution.

[0095] Mix the thermoplastic polyimide resin and N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0096] 2) Place the 12K T700 continuous nickel-coated carbon fiber on a unwinding device, the thickness of the nickel-coated layer is 0.6±0.05 μm, and the glue solution is placed in the glue tank. The continuous nickel-coated carbon fiber tows are immersed in the resin solution and placed on the fiber roller to form a continuous nickel-coated carbon fiber prepreg. The continuous nickel-coated carbon fiber prepreg is wound on a winding mold for winding. The specific winding feature parameters are winding speed: 1-50 m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tow has a width of 3 mm, so the tow spacing is set to 3 mm±0.5 mm, forming a prepreg tape, as shown in FIG. 2. Figure 2

[0097] 3) Dry the wound prepreg tape at 40-80°C, and then take it off the winding mold after drying.

[0098] 4) Stack the four prepared prepreg tapes in the mold in turn, and brush the resin solution in step 1) on the surface of each prepreg tape during the stacking process. The ply angles of the four prepreg tapes are [0° / 45° / -45° / 0°] respectively.

[0099] 5) Put the prepreg tape together with the mold into a flat vulcanization instrument for hot pressing. The hot pressing process includes:

[0100] First hot pressing and curing stage: the first temperature used in the first hot pressing and curing stage is 100°C, the first pressure is 0.5 MPa, and the duration is 60 min; second hot pressing and curing stage: the second temperature used in the second hot pressing and curing stage is 150°C, the second pressure is 0.5 MPa, and the duration is 60 min; third hot pressing and curing stage: the third temperature used in the third hot pressing and curing stage is 200°C, the third pressure is 0.5 MPa, and the duration is 60 min; fourth hot pressing and curing stage: the fourth temperature used in the fourth hot pressing and curing stage is 240°C, the fourth pressure is 0.5 MPa, and the duration is 120 min;

[0101] Fifth hot pressing and curing stage: the fifth temperature used in the fifth hot pressing and curing stage is 300°C, the fifth pressure is 0.5 MPa, and the duration is 10 min; sixth hot pressing and curing stage: the sixth temperature used in the sixth hot pressing and curing stage is 330°C, the sixth pressure is 0.5 MPa, and the duration is 3 min;

[0102] ​The seventh hot-pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 3MPa, and a duration of 120min; and the eighth hot-pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 3MPa, and a duration of 120min.

[0103] After the hot-pressing and curing is completed, the hot-pressing temperature is first lowered to below 200℃, and then the pressure is released and the composite material is demolded and taken out.

[0104] Example 3

[0105] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0106] 1) Configure a resin solution.

[0107] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0108] 2) Place the 12K T700 continuous nickel-coated carbon fiber on a unwinding device, the thickness of the nickel-coated layer is 0.6±0.05μm, and the glue solution is placed in a glue tank. The continuous nickel-coated carbon fiber tows are immersed in the resin solution and placed on a fiber roller to form a continuous nickel-coated carbon fiber prepreg. The continuous nickel-coated carbon fiber prepreg is wound on a winding mold for winding. The specific winding characteristic parameters are as follows: winding speed: 1-50m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tow, the width is 3mm, so the tow spacing is set to 3mm±0.5mm, forming a prepreg tape, as shown in Figure 2 .

[0109] 3) Dry the prepreg tape formed by winding at 40℃-80℃, and then take it off from the winding mold after drying.

[0110] 4) Stack the four prepared prepreg tapes in the mold in turn, and brush the resin solution in step 1) on the surface of each prepreg tape during the stacking process. The laying angles of the four prepreg tapes are [0° / 90° / 45° / -45°] respectively.

[0111] 5) Put the prepreg tape together with the mold into a flat plate vulcanizing instrument for hot pressing. The hot pressing process includes:

[0112] The first heat-pressing and curing stage adopts a first temperature of 100℃, a first pressure of 0.5MPa, and a duration of 60min; the second heat-pressing and curing stage adopts a second temperature of 150℃, a second pressure of 0.5MPa, and a duration of 60min; the third heat-pressing and curing stage adopts a third temperature of 200℃, a third pressure of 0.5MPa, and a duration of 60min; the fourth heat-pressing and curing stage adopts a fourth temperature of 240℃, a fourth pressure of 0.5MPa, and a duration of 120min;

[0113] The fifth heat-pressing and curing stage adopts a fifth temperature of 300℃, a fifth pressure of 0.5MPa, and a duration of 10min; the sixth heat-pressing and curing stage adopts a sixth temperature of 330℃, a sixth pressure of 0.5MPa, and a duration of 3min.

[0114] The seventh heat-pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 3MPa, and a duration of 120min; the eighth heat-pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 3MPa, and a duration of 120min.

[0115] After the heat-pressing and curing is completed, the heat-pressing temperature is first lowered to below 200℃, and then the pressure is released, the composite material is demolded and taken out.

[0116] Example 4

[0117] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0118] 1) Configuring a resin solution.

[0119] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0120] 2) Place the 12K T700 continuous nickel-coated carbon fiber on a unwinding device, the thickness of the nickel-coated layer is 0.6±0.05 μm, and the glue solution is placed in the glue tank. The continuous nickel-coated carbon fiber tows are immersed in the resin solution and placed on the fiber roller to form a continuous nickel-coated carbon fiber prepreg. The continuous nickel-coated carbon fiber prepreg is wound on a winding mold for winding. The specific winding feature parameters are: winding speed: 1-50 m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tow has a width of 3 mm, so the tow spacing is set to 3 mm±0.5 mm, forming a prepreg tape, as shown in Figure 2 .

[0121] 3) Dry the wound prepreg tape at 40-80°C, and then take it off the winding mold after drying.

[0122] 4) Place the prepared four prepreg tapes in the mold in turn, and brush the resin solution in step 1) on the surface of each prepreg tape during the placement process. Specifically, the four prepreg tapes have a layup angle of [0° / 0° / 90° / 90°].

[0123] 5) Place the prepreg tape together with the mold in a flat vulcanization instrument for hot pressing. The hot pressing process includes:

[0124] First hot pressing and curing stage: the first temperature used in the first hot pressing and curing stage is 110°C, the first pressure is 0.5 MPa, and the duration is 50 min; second hot pressing and curing stage: the second temperature used in the second hot pressing and curing stage is 160°C, the second pressure is 0.5 MPa, and the duration is 50 min; third hot pressing and curing stage: the third temperature used in the third hot pressing and curing stage is 210°C, the third pressure is 0.5 MPa, and the duration is 40 min; fourth hot pressing and curing stage: the fourth temperature used in the fourth hot pressing and curing stage is 250°C, the fourth pressure is 0.5 MPa, and the duration is 150 min;

[0125] Fifth hot pressing and curing stage: the fifth temperature used in the fifth hot pressing and curing stage is 290°C, the fifth pressure is 0.5 MPa, and the duration is 6 min; sixth hot pressing and curing stage: the sixth temperature used in the sixth hot pressing and curing stage is 310°C, the sixth pressure is 0.5 MPa, and the duration is 4 min;

[0126] The seventh hot-pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 3MPa, and a duration of 120min; and the eighth hot-pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 3MPa, and a duration of 120min.

[0127] After the hot-pressing and curing is completed, the hot-pressing temperature is first lowered to below 200℃, and then the pressure is released and the composite material is demolded and taken out.

[0128] Example 5

[0129] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0130] 1) Configure a resin solution.

[0131] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0132] 2) Place the 12K T700 continuous nickel-coated carbon fiber on a unwinding device, the thickness of the nickel-coated layer is 0.6±0.05μm, and the glue solution is placed in a glue tank. The continuous nickel-coated carbon fiber tows are immersed in the resin solution and placed on a fiber roller to form a continuous nickel-coated carbon fiber prepreg. The continuous nickel-coated carbon fiber prepreg is wound on a winding mold for winding. The specific winding feature parameters are: winding speed: 1-50m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft of the winding mold, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tow, the width is 3mm, so the tow spacing is set to 3mm±0.5mm, forming a prepreg tape, as shown in Figure 2 .

[0133] 3) Dry the prepreg tape formed by winding at 40℃-80℃, and then take it off from the winding mold after drying.

[0134] 4) Stack the four prepared prepreg tapes in the mold in turn, and brush the resin solution in step 1) on the surface of each prepreg tape during the stacking process. Specifically, the four prepreg tapes are laid in the angle of [0° / 0° / 90° / 90°].

[0135] 5) Put the prepreg tape together with the mold into a flat plate vulcanizing instrument for hot pressing. The hot pressing process includes:

[0136] The first hot-pressing and curing stage adopts a first temperature of 100℃, a first pressure of 0.2MPa, and a duration of 60min; the second hot-pressing and curing stage adopts a second temperature of 150℃, a second pressure of 0.2MPa, and a duration of 60min; the third hot-pressing and curing stage adopts a third temperature of 200℃, a third pressure of 0.2MPa, and a duration of 60min; and the fourth hot-pressing and curing stage adopts a fourth temperature of 240℃, a fourth pressure of 0.2MPa, and a duration of 120min.

[0137] The fifth hot-pressing and curing stage adopts a fifth temperature of 300℃, a fifth pressure of 0.2MPa, and a duration of 10min; and the sixth hot-pressing and curing stage adopts a sixth temperature of 330℃, a sixth pressure of 0.2MPa, and a duration of 3min to 5min.

[0138] The seventh hot-pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 2MPa, and a duration of 120min; and the eighth hot-pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 2MPa, and a duration of 120min.

[0139] After the hot-pressing and curing is completed, the hot-pressing temperature is first lowered to below 200℃, and then the pressure is released and the composite material is demolded and taken out.

[0140] Example 6

[0141] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0142] 1) Configuring a resin solution.

[0143] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0144] 2) Place the 12K T700 continuous nickel-coated carbon fiber on a unwinding device, the thickness of the nickel-coated layer is 0.6±0.05 μm, and the glue solution is placed in the glue tank. The continuous nickel-coated carbon fiber tows are immersed in the resin solution and placed on the fiber roller to form a continuous nickel-coated carbon fiber prepreg. The continuous nickel-coated carbon fiber prepreg is wound on a winding mold for winding. The specific winding feature parameters are: winding speed: 1-50 m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tow has a width of 3 mm, so the tow spacing is set to 3 mm±0.5 mm, forming a prepreg tape, as shown in FIG. 2. Figure 2

[0145] 3) Dry the wound prepreg tape at 40-80°C, and then take it off the winding mold after drying.

[0146] 4) Place the prepared four prepreg tapes in the mold in turn, and brush the resin solution in step 1) on the surface of each prepreg tape during the placement process. Specifically, the four prepreg tapes have a layup angle of [0° / 0° / 90° / 90°].

[0147] 5) Place the prepreg tape together with the mold in a flat vulcanization instrument for hot pressing, and the hot pressing process includes:

[0148] First hot pressing and curing stage: the first temperature used in the first hot pressing and curing stage is 120°C, the first pressure is 0.5 MPa, and the duration is 30 min; second hot pressing and curing stage: the second temperature used in the second hot pressing and curing stage is 170°C, the second pressure is 0.5 MPa, and the duration is 30 min; third hot pressing and curing stage: the third temperature used in the third hot pressing and curing stage is 220°C, the third pressure is 0.5 MPa, and the duration is 30 min; fourth hot pressing and curing stage: the fourth temperature used in the fourth hot pressing and curing stage is 260°C, the fourth pressure is 0.5 MPa, and the duration is 120 min;

[0149] Fifth hot pressing and curing stage: the fifth temperature used in the fifth hot pressing and curing stage is 300°C, the fifth pressure is 0.5 MPa, and the duration is 5 min; sixth hot pressing and curing stage: the sixth temperature used in the sixth hot pressing and curing stage is 300°C, the sixth pressure is 0.5 MPa, and the duration is 5 min;

[0150] ​The seventh hot-pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 3MPa, and a duration of 120min; and the eighth hot-pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 3MPa, and a duration of 120min.

[0151] After the hot-pressing and curing is completed, the hot-pressing temperature is first lowered to below 200℃, and then the pressure is released and the composite material is demolded and taken out.

[0152] Example 7

[0153] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0154] 1) Configure a resin solution.

[0155] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0156] 2) The continuous nickel-plated carbon fiber is subjected to yarn spreading treatment, and the width of the continuous nickel-plated carbon fiber is expanded from 3mm to 6mm. The 12K T700 continuous nickel-plated carbon fiber is placed on a unwinding device, the thickness of the nickel-plated layer is 0.6±0.05μm, and the glue solution is placed in a glue tank. The continuous nickel-plated carbon fiber tows are immersed in the resin solution and placed on a fiber roller to form a continuous nickel-plated carbon fiber prepreg. The continuous nickel-plated carbon fiber prepreg is wound on a winding mold for winding. The specific winding characteristic parameters are as follows: winding speed: 1-50m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft of the winding mold, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tow has a width of 3mm, so the tow spacing is set to 3mm±0.5mm, forming a prepreg tape, as shown in Figure 2 .

[0157] 3) The prepreg tape formed by winding is dried at a temperature of 40℃-80℃, and then taken out from the winding mold after drying.

[0158] 4) The four prepared prepreg tapes are sequentially stacked in the mold, and during the sequential stacking process, the resin solution in step 1) is brushed on the surface of each prepreg tape. Specifically, the four prepreg tapes have a layup angle of [0° / 0° / 90° / 90°].

[0159] 5) The prepreg tape together with the mold is placed in a flat vulcanization instrument for hot-pressing. The hot-pressing process includes:

[0160] The first heat pressing and curing stage adopts a first temperature of 100℃, a first pressure of 0.5MPa, and a duration of 60min; the second heat pressing and curing stage adopts a second temperature of 150℃, a second pressure of 0.5MPa, and a duration of 60min; the third heat pressing and curing stage adopts a third temperature of 200℃, a third pressure of 0.5MPa, and a duration of 60min; the fourth heat pressing and curing stage adopts a fourth temperature of 240℃, a fourth pressure of 0.5MPa, and a duration of 120min;

[0161] The fifth heat pressing and curing stage adopts a fifth temperature of 300℃, a fifth pressure of 0.5MPa, and a duration of 10min; the sixth heat pressing and curing stage adopts a sixth temperature of 330℃, a sixth pressure of 0.5MPa, and a duration of 3min;

[0162] The seventh heat pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 3MPa, and a duration of 120min; the eighth heat pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 3MPa, and a duration of 120min.

[0163] After the heat pressing and curing is completed, the heat pressing temperature is first lowered to below 200℃, and then the pressure is released, the mold is removed, and the composite material is taken out.

[0164] Example 8

[0165] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0166] 1) Configuring a resin solution.

[0167] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0168] 2) Place the 12K T700 continuous copper-coated carbon fiber on the unwinding device, the copper-coated layer has a thickness of 1-2 μm, and the glue solution is placed in the glue tank. The continuous copper-coated carbon fiber tows are immersed in the resin solution and placed on the fiber roller to form a continuous copper-coated carbon fiber prepreg. The continuous copper-coated carbon fiber prepreg is wound on a winding mold for winding. The specific winding feature parameters are as follows: winding speed: 1-50 m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft of the winding mold, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tow has a width of 3 mm, so the tow spacing is set to 3 mm±0.5 mm, forming a prepreg tape, as shown in FIG. 2. Figure 2

[0169] 3) Dry the wound prepreg tape at 40-80°C, and then take it off the winding mold after drying.

[0170] 4) Stack the four prepared prepreg tapes in the mold in turn, and brush the resin solution in step 1) on the surface of each prepreg tape during the stacking process. Specifically, the four prepreg tapes have a layup angle of [0° / 0° / 90° / 90°].

[0171] 5) Put the prepreg tape together with the mold into a flat plate curing instrument for hot pressing. The hot pressing process includes:

[0172] a first hot pressing and curing stage, wherein the first temperature is 100°C, the first pressure is 0.5 MPa, and the duration is 60 min; a second hot pressing and curing stage, wherein the second temperature is 150°C, the second pressure is 0.5 MPa, and the duration is 60 min; a third hot pressing and curing stage, wherein the third temperature is 200°C, the third pressure is 0.5 MPa, and the duration is 60 min; a fourth hot pressing and curing stage, wherein the fourth temperature is 240°C, the fourth pressure is 0.5 MPa, and the duration is 120 min;

[0173] a fifth hot pressing and curing stage, wherein the fifth temperature is 300°C, the fifth pressure is 0.5 MPa, and the duration is 10 min; and a sixth hot pressing and curing stage, wherein the sixth temperature is 330°C, the sixth pressure is 0.5 MPa, and the duration is 3 min.

[0174] ​The seventh hot-pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 3MPa, and a duration of 120min; and the eighth hot-pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 3MPa, and a duration of 120min.

[0175] After the hot-pressing and curing is completed, the hot-pressing temperature is first lowered to below 200℃, and then the pressure is released and the composite material is demolded and taken out.

[0176] Comparative Example 1

[0177] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0178] 1) Configure a resin solution.

[0179] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0180] 2) Place the 12K T700 continuous carbon fiber on the unwinding device, and place the glue solution in the glue tank. The continuous carbon fiber tows are immersed in the resin solution and placed on the fiber roller to form continuous carbon fiber prepreg. The continuous carbon fiber prepreg is wound on the winding mold for winding. The specific winding characteristic parameters are as follows: winding speed: 1-50m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft of the winding mold, and the deviation needs to be <±0.5°; tow spacing: for example, the 12K tows have a width of 3mm, so the tow spacing is set to 3mm±0.5mm, forming a prepreg tape, as shown in Figure 3 .

[0181] 3) The prepreg tape formed by winding is dried at 40℃-80℃, and then taken off from the winding mold after drying.

[0182] 4) The four prepared prepreg tapes are sequentially stacked in the mold, and during the sequential stacking process, the resin solution in step 1) is brushed on the surface of each prepreg tape. Specifically, the four prepreg tapes have a layup angle of [0° / 0° / 90° / 90°].

[0183] 5) The prepreg tape is placed in a flat vulcanization instrument together with the mold for hot pressing. The hot pressing process includes:

[0184] The first heat-pressing and curing stage adopts a first temperature of 100℃, a first pressure of 0.5MPa, and a duration of 60min; the second heat-pressing and curing stage adopts a second temperature of 150℃, a second pressure of 0.5MPa, and a duration of 60min; the third heat-pressing and curing stage adopts a third temperature of 200℃, a third pressure of 0.5MPa, and a duration of 60min; and the fourth heat-pressing and curing stage adopts a fourth temperature of 240℃, a fourth pressure of 0.5MPa, and a duration of 120min.

[0185] The fifth heat-pressing and curing stage adopts a fifth temperature of 300℃, a fifth pressure of 0.5MPa, and a duration of 10min; and the sixth heat-pressing and curing stage adopts a sixth temperature of 330℃, a sixth pressure of 0.5MPa, and a duration of 3min.

[0186] The seventh heat-pressing and curing stage adopts a seventh temperature of 370℃, a seventh pressure of 3MPa, and a duration of 120min; and the eighth heat-pressing and curing stage adopts an eighth temperature of 380℃, an eighth pressure of 3MPa, and a duration of 120min.

[0187] After the heat-pressing and curing is completed, the heat-pressing temperature is first lowered to below 200℃, and then the pressure is released and the composite material is demolded and taken out.

[0188] Comparative Example 2

[0189] A preparation method of a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0190] 1) Configuring a resin solution.

[0191] The thermoplastic polyimide resin is mixed with N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0192] 2) Place the 12K T700 continuous nickel-plated carbon fiber on the unwinding device, with a nickel plating thickness of 0.6±0.05 μm, and place the glue solution in the glue tank. Dip the continuous nickel-plated carbon fiber tows into the resin solution and place them on the fiber roller to form a continuous nickel-plated carbon fiber prepreg. Wind the continuous nickel-plated carbon fiber prepreg on a winding mold for winding. The specific winding parameters are: winding speed: 1-50 m / min; number of yarns: 1; fiber volume fraction: 50%-65%; winding angle: the fiber direction is completely parallel to the main shaft of the winding mold, with a deviation of <±0.5°; tow spacing: for example, for a 12K tow, the width is 3 mm, so the tow spacing is set to 3 mm±0.5 mm, forming a prepreg tape, as shown in FIG. 2. Figure 2

[0193] 3) Dry the wound prepreg tape at 40-80°C, and then remove it from the winding mold after drying.

[0194] 4) Stack the four prepared prepreg tapes in the mold in sequence, and brush the resin solution in step 1 on the surface of each prepreg tape during the stacking process. Specifically, the four prepreg tapes have a layup angle of [0° / 0° / 90° / 90°].

[0195] 5) Place the prepreg tape together with the mold in a flat press vulcanizer for hot pressing at a temperature of 380°C for 4 hours and a pressure of 3 MPa. After hot pressing and curing, first reduce the hot pressing temperature to below 200°C, and then perform pressure relief and demolding to remove the composite material.

[0196] Comparative Example 3

[0197] A method for preparing a wide-temperature-range bearing-shielding-lightning-protection integrated composite material, specifically comprising the following steps:

[0198] 1) Prepare a resin solution.

[0199] Mix the thermoplastic polyimide resin and N-N dimethylacetamide at a ratio of 1:3 to form a resin solution.

[0200] 2) Form a plain weave fabric by alternately interweaving the nickel-plated carbon fiber tows in the warp and weft directions, and brush the resin solution on the woven plain weave fabric at a fiber resin mass fraction ratio of 6:4. Dry the brushed woven fabric at 40-80°C.

[0201] 3) Stack the four prepared prepreg tapes in the mold in sequence, and brush the resin solution in step 1 on the surface of each prepreg tape during the stacking process. Specifically, the four prepreg tapes have a layup angle of [0° / 0° / 90° / 90°]. ​

[0202] 4) Put the prepreg tape together with the mold into a flat vulcanization instrument for hot pressing, and the hot pressing process comprises:

[0203] The first hot pressing and curing stage adopts a first temperature of 100°C, a first pressure of 0.5 MPa, and a duration of 60 min; the second hot pressing and curing stage adopts a second temperature of 150°C, a second pressure of 0.5 MPa, and a duration of 60 min; the third hot pressing and curing stage adopts a third temperature of 200°C, a third pressure of 0.5 MPa, and a duration of 60 min; and the fourth hot pressing and curing stage adopts a fourth temperature of 240°C, a fourth pressure of 0.5 MPa, and a duration of 120 min;

[0204] The fifth hot pressing and curing stage adopts a fifth temperature of 300°C, a fifth pressure of 0.5 MPa, and a duration of 10 min; and the sixth hot pressing and curing stage adopts a sixth temperature of 330°C, a sixth pressure of 0.5 MPa, and a duration of 3 min to 5 min.

[0205] The seventh hot pressing and curing stage adopts a seventh temperature of 370°C, a seventh pressure of 3 MPa, and a duration of 120 min; and the eighth hot pressing and curing stage adopts an eighth temperature of 380°C, an eighth pressure of 3 MPa, and a duration of 120 min.

[0206] After the hot pressing and curing is completed, the hot pressing temperature is first lowered to below 200°C, and then the pressure is released, the mold is removed, and the composite material is taken out.

[0207] The composite material obtained in the example is subjected to electromagnetic shielding test, mechanical property test, heat resistance test, and lightning strike test.

[0208] The electromagnetic shielding performance test results of the nickel-plated carbon fiber composite material obtained in Example 1 are shown in Table 1, and the electromagnetic shielding performance test results of the carbon fiber composite material obtained in Comparative Example 1 are shown in Table 2. Figure 6 As shown in Table 1, the average EMI SE value of the nickel-plated carbon fiber composite material obtained in Example 1 in the wave band of 8.2 GHz-12.4 GHz reached 81.48 dB, and the electromagnetic shielding performance test results of the carbon fiber composite material obtained in Comparative Example 1 are shown in Table 2. Figure 7 As shown in Table 2, the average EMI SE value of the carbon fiber composite material obtained in Comparative Example 1 in the wave band of 8.2 GHz-12.4 GHz was 72.06 dB, and thus it is known that the material with excellent electrical conductivity and / or magnetic property helps to improve the electromagnetic shielding performance.

[0209] The three-point bending performance of the nickel-plated carbon fiber composite material of Example 1 along the direction of the nickel-plated carbon fiber is shown in Fig. 4, wherein the bending stress of the nickel-plated carbon fiber composite material of Example 1 is 601.2 MPa, and the bending modulus is 70.71 GPa. Figure 8 The three-point bending performance of the nickel-plated carbon fiber composite material of Example 1 perpendicular to the direction of the nickel-plated carbon fiber is shown in Fig. 5, wherein the bending stress of the nickel-plated carbon fiber composite material of Example 1 is 44.5 MPa, and the bending modulus is 7.85 GPa. Figure 9 The three-point bending performance of the nickel-plated carbon fiber composite material of Example 1 along the direction of the nickel-plated carbon fiber is shown in Fig. 4, wherein the bending stress of the nickel-plated carbon fiber composite material of Example 1 is 601.2 MPa, and the bending modulus is 70.71 GPa.

[0210] Figure 10 The thermal gravimetric curves of the carbon fiber composite material obtained in Comparative Example 1 and the nickel-plated carbon fiber composite material obtained in Example 1 are shown in Fig. 6, wherein the temperature at which the mass of the carbon fiber composite material obtained in Comparative Example 1 is 95% is 577.9°C, the temperature at which the mass is 90% is 611.2°C, and the final residual mass at 900°C is 55.46%. The temperature at which the mass of the nickel-plated carbon fiber composite material obtained in Example 1 is 95% is 617.0°C, the temperature at which the mass is 90% is 736.2°C, and the final residual mass at 900°C is 87.4%. It can be easily seen that the heat resistance of the nickel-plated carbon fiber composite material is significantly improved.

[0211] Figure 11 , Figure 12 The lightning protection effects of the carbon fiber composite material obtained in Comparative Example 1 and the nickel-plated carbon fiber composite material obtained in Example 1 under a lightning current with a peak of 200 kA are shown in Figs. 7 and 8, respectively. It can be obviously seen from the figures that the damage area and depth of the nickel-plated carbon fiber composite material are obviously smaller than those of the carbon fiber composite material, and lightning protection is achieved. Figure 13 is a photo of a copper mesh composite material after lightning strike under the same conditions.

[0212] The performance test results of the composite materials in Examples 2-6 and Examples 7-8 are basically consistent with the performance test results of the composite material in Example 1. The PI resin precursor (polyamide acid PAA) in Comparative Example 2 usually contains high-boiling-point solvents (such as NMP / DMAC). The purpose of the first platform of the stepwise heating (usually 100-150°C) is to slowly and gently remove these solvents. If the temperature is raised quickly, the solvents will instantaneously vaporize, generating extremely high vapor pressure at the interface between the nickel-plated fiber and the PI matrix, forming a large number of micro-bubbles and defects, and seriously damaging the interface bonding. Comparative Example 3 provides basically balanced stiffness and strength in the 0° and 90° directions in the fabric plane due to the up-and-down interlacing of the fiber bundles (warp and weft). If extremely directional performance is required (such as the highest stiffness and strength in one direction), unidirectional weaving is selected. If balanced bidirectional performance, better damage tolerance, and formability are required, plain weaving is selected.

[0213] It is found by testing that, in terms of electromagnetic shielding performance: the resistivity of nickel is significantly lower than that of carbon fiber, and the plating layer forms a continuous metal conductive path on the fiber surface, which can improve the electromagnetic wave reflection performance. Copper is an excellent conductor, and a continuous metal layer can be formed on its surface to reflect electromagnetic waves very effectively.

[0214] In terms of mechanical properties: the copper / nickel plating layer forms a coordination bond with the resin matrix, which can improve the interfacial shear strength (IFSS increases by 15-30%).

[0215] In terms of fiber damage suppression: the nickel / copper plating layer can fill the surface defects of carbon fiber, reduce stress concentration, and delay crack propagation. Heat resistance: nickel forms a dense oxide layer (NiO) at high temperatures, which slows down the oxidation rate of carbon fiber above 400℃ (weight loss rate decreases by 30-50%). The high thermal conductivity of copper helps to quickly disperse local hot spots and avoid heat accumulation. Lightning protection performance: the copper / nickel plating layer provides a low impedance path, allowing lightning current (100kA level) to quickly spread along the surface and avoid internal carbon fiber ablation. Arc erosion resistance: the melting points of nickel (1455℃) and copper (1085℃) are much higher than the instantaneous high temperature (up to 30000℃, but very short) generated by lightning, which can maintain the physical integrity of the structure to some extent, rather than directly decomposing and vaporizing like resin, protecting the integrity of the fiber structure. Damage tolerance improves the plated nickel layer can maintain part of the conductive network after lightning strike, preventing the structure from failing instantly (compared to the brittle peeling of ordinary carbon fiber).

[0216] By comparing Example 1 and Example 6, the plated nickel carbon fiber of 12K T700 expands from a width of 3mm to 6mm, and the surface density of the plated nickel carbon fiber composite material is reduced by 144g / m 2 .

[0217] The plated nickel or plated copper carbon fiber used in the present application is used as a reinforcing material, and polyimide is used as a resin matrix. The continuous metalized carbon fiber is subjected to spreading treatment, and the width of the continuous metalized carbon fiber after spreading is expanded to 1.5-2.5 times the initial width, achieving lightweight of the composite material, and the surface density of the composite material is reduced by 144g / m 2 At the same time, the structure of the composite material is designed, the number of layers of the metalized carbon fiber, the fiber orientation, and the layup angle are changed to balance the performance, function, lightweight, and cost, and a wide temperature range bearing-electromagnetic shielding-lightning protection structure function integrated composite material is prepared by winding-pasting-heat pressing process.

[0218] It should be understood that the above-described embodiments are merely intended to illustrate the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for preparing a wide temperature range load-shielding-lightning strike protection integrated composite material, characterized in that, The application relates to a wide-temperature-range load-shielding-lightning-protection integrated composite material and a preparation method thereof. The continuous metalized carbon fiber prepreg is wound to form a prepreg tape; n pieces of the prepreg tapes are stacked along the radial direction of the prepreg tapes to obtain a composite material preform, and n is greater than or equal to 2; The composite material preform is heat-pressed and cured to form the wide-temperature-range load-shielding-lightning-protection integrated composite material.

2. The method of making a wide temperature range load-shield-lightning strike protection integrated composite material according to claim 1, wherein, The application further provides a preparation method of the wide-temperature-range load-shielding-lightning-protection integrated composite material. The continuous metalized carbon fiber prepreg is wound on a winding mold to form the prepreg tape; Preferably, the winding speed of the continuous metalized carbon fiber prepreg is 1 m / min to 50 m / min, and the spacing between the filaments is 3 mm plus or minus 0.5 mm; Preferably, the fiber volume fraction of the continuous metalized carbon fiber prepreg is 50% to 65%; Preferably, the continuous metalized carbon fiber comprises nickel-plated or copper-plated carbon fiber or nickel-copper-plated carbon fiber; Preferably, the continuous metalized carbon fiber prepreg is in a fiber shape, and the width of the continuous metalized carbon fiber prepreg ranges from 0.1 to 5 mm; Preferably, when the continuous metalized carbon fiber prepreg is wound on the winding mold, the fiber direction of the continuous metalized carbon fiber prepreg is parallel to the main shaft of the winding mold.

3. The method of making a wide temperature range load-shield-lightning strike protection integrated composite material according to claim 1 or 2, wherein, The application further provides a preparation method of the wide-temperature-range load-shielding-lightning-protection integrated composite material. Preferably, after the unwinding treatment, the width of the continuous metalized carbon fiber is expanded to 1.5 to 2.5 times of the initial width; Preferably, the resin solution comprises resin and N-N dimethylacetamide, and the resin comprises at least one of thermoplastic polyimide resin, epoxy resin, polyether ether ketone resin, phenolic resin and bismaleimide resin. The application further provides a preparation method of the wide-temperature-range load-shielding-lightning-protection integrated composite material.

4. The method of making a wide temperature range load-shield- lightning strike protection integrated composite material according to claim 1, wherein, The number n of the prepreg tapes is 4, the layer angles of the four layers of the prepreg tapes are [0 DEG / 0 DEG / 90 DEG / 90 DEG ], or the number n of the prepreg tapes is 4, the layer angles of the four layers of the prepreg tapes are [0 DEG / 45 DEG / -45 DEG / 0 DEG ], or the number n of the prepreg tapes is 4, the layer angles of the four layers of the prepreg tapes are [0 DEG / 90 DEG / 45 DEG / -45 DEG ]. The application further provides a preparation method of the wide-temperature-range load-shielding-lightning-protection integrated composite material.

5. The method of making a wide temperature range load-shield- lightning strike protection integrated composite material according to claim 4, wherein: Preferably, the temperature of the heat pressing and curing is 100 DEG C to 380 DEG C, the pressure is 0 MP to 3 MPa, and the total time of the heat pressing and curing is 450 min to 650 min; 6. The method of making a wide temperature range load-shield-lightning strike protection integrated composite material according to claim 1 or 4, wherein, Preferably, the process of the heat pressing and curing comprises a first heat pressing and curing stage, a second heat pressing and curing stage, a third heat pressing and curing stage, a fourth heat pressing and curing stage, a fifth heat pressing and curing stage, a sixth heat pressing and curing stage, a seventh heat pressing and curing stage and an eighth heat pressing and curing stage. ​ ​ ​ The first heat-pressing curing stage adopts a first temperature and a first pressure, the second heat-pressing curing stage adopts a second temperature and a second pressure, the third heat-pressing curing stage adopts a third temperature and a third pressure, the fourth heat-pressing curing stage adopts a fourth temperature and a fourth pressure, the fifth heat-pressing curing stage adopts a fifth temperature and a fifth pressure, the sixth heat-pressing curing stage adopts a sixth temperature and a sixth pressure, the seventh heat-pressing curing stage adopts a seventh temperature and a seventh pressure, and the eighth heat-pressing curing stage adopts an eighth temperature and an eighth pressure, wherein the first temperature < the second temperature < the third temperature < the fourth temperature < the fifth temperature < the sixth temperature < the seventh temperature < the eighth temperature, and the first pressure = the second pressure = the third pressure = the fourth pressure = the fifth pressure = the sixth pressure < the seventh pressure = the eighth pressure; Preferably, the first heat-pressing curing stage adopts a first temperature of 100-120℃ and a first pressure of 0-0.5MPa, and the duration is 30-60min; the second heat-pressing curing stage adopts a second temperature of 150-170℃ and a second pressure of 0-0.5MPa, and the duration is 30-60min; the third heat-pressing curing stage adopts a third temperature of 200-220℃ and a third pressure of 0-0.5MPa, and the duration is 30-60min; the fourth heat-pressing curing stage adopts a fourth temperature of 240-260℃ and a fourth pressure of 0-0.5MPa, and the duration is 120-180min, the fifth heat-pressing curing stage adopts a fifth temperature of 280-300℃ and a fifth pressure of 0-0.5MPa, and the duration is 5-10min; the sixth heat-pressing curing stage adopts a sixth temperature of 300-330℃ and a sixth pressure of 0-0.5MPa, and the duration is 3-5min, the seventh heat-pressing curing stage adopts a seventh temperature of 370℃ and a seventh pressure of 2-3MPa, and the duration is 120min; and the eighth heat-pressing curing stage adopts an eighth temperature of 380℃ and an eighth pressure of 2-3MPa, and the duration is 120min.

7. The method of making a wide temperature range load-shield- lightning strike protection integrated composite material according to claim 6, wherein, Further comprising: After the heat-pressing curing is completed, the heat-pressing temperature is first lowered to below 200℃, and then the pressure is released and the mold is demolded.

8. The wide-temperature-range load-shielding-lightning-protection integrated composite material obtained by the method for preparing the wide-temperature-range load-shielding-lightning-protection integrated composite material according to any one of claims 1-7.

9. The wide temperature range load-shielding-lightning strike protection integrated composite material according to claim 8, characterized in that: The wide-temperature-range load-shielding-lightning-protection integrated composite material has a bending stress of 601.2MPa and a bending modulus of 70.71GPa, and the average EMISE value of the wide-temperature-range load-shielding-lightning-protection integrated composite material in the range of 8.2GHz-12.4GHz is 81.48dB.

10. The use of the wide-temperature-range load-shielding-lightning-protection integrated composite material according to claim 8 or 9 in the fields of aerospace, new energy devices, rail transit, electromagnetic shielding, and lightning protection. Preferably, the wide-temperature-range load-shielding-lightning-protection integrated composite material is used to make the outer shell of an aircraft or vehicle body, and / or the wide-temperature-range load-shielding-lightning-protection integrated composite material is used to make an electromagnetic interference shielding structure or a lightning protection structure.

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