Composite material component manufactured based on 2.5 D weaving and RTM injection and manufacturing method

Abstract

The invention discloses a composite material component manufactured based on 2.5 D weaving and RTM injection and a manufacturing method, belongs to the technical field of composite materials, and solves the problems that in an existing method, 2.5 D woven fabric is not sufficiently soaked, bubbles in fiber bundles are left, and materials and interface bonding strength and stability are affected. The composite material component comprises a fiber preform, injection resin, a binder and a curing agent; according to the invention, the composite material component is composed of a fiber preform and injection resin, the fiber preform is prefabricated and molded based on a 2.5 D weaving technology, and the fiber preform is prepared by synergistically matching silicon carbide fibers, glass fibers and modified graphene and fully impregnating the silicon carbide fibers, the glass fibers and the modified graphene based on steam explosion. The fiber dispersity is optimized, meanwhile, it is ensured that follow-up injection resin is fully infiltrated, and the prepared composite material component has excellent mechanical performance and thermal stability and further has good electromagnetic shielding performance and weather resistance.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to composite material components and manufacturing methods based on 2.5D braiding and RTM injection. Background Technology

[0002] In the field of composite material manufacturing, resin transfer molding (RTM) injection molding is widely used in industries such as aerospace, automotive, and construction due to its high efficiency and applicability. The core of this process involves laying fiber-reinforced materials in a mold, injecting resin, and allowing it to cure. However, traditional RTM processes have a series of inherent drawbacks that limit their reliability and efficiency in manufacturing complex components.

[0003] Traditional RTM (Regenerative Thermal Mold) processes employ multi-layered woven fabric lay-up. Specifically, during lay-up, operators must lay single layers of woven fabric one by one onto a tooling, designing the number of layers based on the component thickness. Subsequently, the mold is closed and resin is injected. While this method is theoretically feasible, it faces significant challenges in practical applications. Because woven fabric is soft and lacks rigidity in its dry state, it is highly susceptible to displacement or deformation during lay-up. This is especially true when manufacturing components with complex geometries, such as curved surfaces or irregular structures, where lay-up operations become extremely difficult, requiring high-precision adjustments and increasing production time and labor costs. Furthermore, the actual thickness of dry fibers is often greater than their nominal thickness (i.e., design thickness). If the number of layers is strictly calculated according to the nominal thickness during layup, the fibers in the mold cavity will become too compact due to excessive compression after mold closing. This directly hinders the uniform flow of resin and easily produces "dry spots" (i.e. areas where the resin is not fully impregnated), which seriously affects the mechanical properties and appearance quality of the component. Conversely, if the number of layup layers is reduced to avoid compression problems, the interlaminar shear strength of the molded component will be significantly reduced, weakening the overall structural integrity and damage resistance of the composite material.

[0004] To address the problems inherent in traditional RTM injection molding processes, 2.5D weaving technology has emerged. 2.5D weaving is an advanced fiber preform processing technology that, through specific weaving equipment and processes, can process preforms according to the desired shape and thickness of the component. This technology ensures fiber continuity and makes the fiber state more stable, including consistent shape and thickness.

[0005] Chinese patent CN116065285B discloses a method for preparing a 2.5D woven fabric composite material, the obtained material, and its applications. The preparation method uses a woven fabric prepreg with a 2.5D interlayer interlocking structure as a reinforcing material, followed by cutting, laying, and hot pressing. However, in existing methods, when the 2.5D woven fabric is impregnated in a mold to obtain a fabric blank, the impregnation of the 2.5D woven fabric is insufficient, resulting in residual air bubbles inside the fiber bundles, causing a dry spot effect and affecting the interfacial bonding strength and stability of the material. To address these issues, we propose a composite material component based on 2.5D weaving and RTM injection molding, and its manufacturing method. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing composite material components and manufacturing methods based on 2.5D weaving and RTM injection molding. This solves the problem that in existing methods, when injecting glue into a mold to impregnate 2.5D woven fabric to obtain a fabric blank, the 2.5D woven fabric is not sufficiently impregnated, resulting in residual air bubbles inside the fiber bundles, which causes dry spot effect and affects the interfacial bonding strength and stability of the material.

[0007] The present invention is achieved by manufacturing a composite material component based on 2.5D braiding and RTM injection. The composite material component includes a fiber preform, injection resin, binder, and curing agent. The fiber preform is preformed based on 2.5D braiding technology, and the injection resin, binder, and curing agent are injected into an injection mold containing the fiber preform using RTM injection technology and cured to form the composite material component.

[0008] Preferably, the fiber preform comprises the following raw materials in parts by weight: 50-80 parts silicon carbide fiber, 10-20 parts glass fiber, 2-10 parts modified graphene, 100-200 parts soaking solution, 2-15 parts sizing agent, and 10-15 parts polylactic acid.

[0009] Preferably, the soaking solution comprises silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent, with a volume ratio of silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent of 1:2:3:1; the sizing agent comprises epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester, with a volume ratio of epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester of 5:1:6:4:5.

[0010] The method for preparing the sizing agent includes:

[0011] Take polyimide and polycarbosilane solutions and place them in a reaction vessel and stir for 10-15 minutes at a mixing temperature of 60-70℃. After stirring, let stand for 20 minutes to obtain the solution before sizing.

[0012] Anhydrous ethanol and tetrabutyl titanate were mixed in a volume ratio of 5:1 and stirred in a magnetic stirrer for 10 min at a stirring speed of 200-250 rpm to obtain a tetrabutyl titanate solution. At the same time, deionized water, glacial acetic acid and anhydrous ethanol were mixed in a volume ratio of 4:1:10 to obtain a sizing drop solution. The sizing drop solution and tetrabutyl titanate solution were taken in a volume ratio of 1:2. The sizing drop solution was added dropwise to the tetrabutyl titanate solution at a drop rate of 2 mL / min while maintaining the temperature at 4-5℃. After the addition was completed, the mixture was stirred for 1 h. Then, 0.01 times the volume of the sizing drop solution of acetylacetone was added to the tetrabutyl titanate solution, and the mixture was stirred for another 2 h to obtain a tetrabutyl titanate modified solution.

[0013] Epoxy-modified silicone oil and organoboroester were mixed and stirred at 45°C for 10-15 minutes. Then, the pre-sizing solution and tetrabutyl titanate modified liquid were added. The mixture was ultrasonically treated with a 300W ultrasonic generator for 10-12 minutes, stirred for 30 minutes, and cooled to room temperature to obtain the sizing agent.

[0014] Preferably, the method for preparing the fiber preform includes:

[0015] Silicon carbide fiber and glass fiber were immersed in soaking solution and treated at 55-65℃ for 40-45 min. Then, 0.05 times the volume of soaking solution of 0.3 mol / L triethanolamine was added dropwise to the soaking solution and stirred in a water bath at 55℃ for 2 h to obtain fiber premix.

[0016] The fiber premix was pre-oxidized at 120-150℃ for 3 hours, and then ultrasonically treated for 20-25 minutes.

[0017] Modified graphene and fiber premix are loaded into a blasting vessel, saturated steam at 180°C is introduced into the blasting vessel, and then the blasting vessel is pressurized to 0.7 MPa. After steam blasting treatment for 10-12 minutes, the blasting vessel is depressurized within 0.1-0.5 seconds.

[0018] Remove silicon carbide fibers and glass fibers, place them in a vacuum drying oven at 50-55℃ and dry for 20-25 minutes, then immerse them in a polylactic acid and acetone solution for 20 minutes to set the shape. The volume ratio of polylactic acid and acetone solution is 1:10-15.

[0019] The sizing agent was sprayed onto the surface of silicon carbide fiber and glass fiber using a spinneret. The spraying was repeated three times, with an interval of 10-15 minutes between each spraying. Using silicon carbide fiber as warp and glass fiber as weft, finite element analysis was performed on the fiber preform. The unit cell structure of the fiber preform was subjected to three-directional periodic boundary conditions through the finite element model to simulate and predict the mechanical behavior of the material and determine the warp and weft yarn arrangement paths. The warp density was 50-60 yarns / cm and the weft density was 40-50 yarns / cm.

[0020] The weft yarn is laid along the bottom plate of the multi-harness loom, and the warp yarn passes through the weft yarn in the Z direction. The yarns are hooked together in a figure-eight shape and stacked repeatedly to obtain a fiber preform for later use.

[0021] Preferably, the modified graphene comprises the following raw materials in weight percentage: 70% graphene oxide; 2% nano zinc oxide; 3% gelatin; 2% citric acid; 15% epoxidized soybean oil; and 8% ammonium tripolyphosphate.

[0022] The method for preparing the modified graphene includes:

[0023] A zinc acetate to ethylene glycol solution with a mass ratio of 0.8:1 was taken and stirred in a water bath at 75°C for 1.2 h. Then, a sodium hydroxide aqueous solution with a mass ratio of 0.2 times that of ethylene glycol was added dropwise to the zinc acetate to ethylene glycol solution. The mixture was stirred at 75°C for 3 h. The mixture was then placed in a reaction vessel and hydrothermally mixed at 160°C for 18 h. The mixture was washed three times with anhydrous ethanol, dried in a vacuum drying oven, ground and sieved to obtain nano zinc oxide.

[0024] Graphene oxide was dispersed in 7 times its volume of deionized water and ultrasonically treated for 25-30 min to obtain a graphene dispersion. Citric acid and epoxidized soybean oil were then added to the graphene dispersion. The graphene dispersion containing citric acid and epoxidized soybean oil was stirred at 75°C for 1.5 h to obtain a soybean oil-graphene mixture.

[0025] Place ammonium tripolyphosphate in deionized water at 50℃ and stir at 100-120 rpm for 10 minutes. Then add gelatin and mix. Continue heating for 10 minutes to obtain a gelatin solution. Mix the soybean oil-graphene mixture with the gelatin solution at 200-220 rpm for 2 hours to obtain a gelatin-graphene mixture.

[0026] Nano-zinc oxide was dispersed in 20 times its volume of ethanol and stirred for 15 min. Then it was mixed with a gelatin-graphene mixture, ultrasonicated for 20 min, and dried in a vacuum drying oven at 55℃ for 2 h to obtain modified graphene.

[0027] Preferably, the injection resin comprises the following raw materials in parts by weight: 40-50 parts of polyurethane acrylate, 10-15 parts of epoxy acrylate, 2-6 parts of ammonium tripolyphosphate, 2-5 parts of hollow glass microspheres, 2-5 parts of ultraviolet absorber, and 2-8 parts of photoinitiator.

[0028] Preferably, the method for preparing the injection resin includes:

[0029] Mix ammonium tripolyphosphate with 5 times its volume of anhydrous ethanol, stir for 10 minutes, then ball mill the mixture. Finally, dry the milled liquid in a vacuum drying oven at 60°C for later use.

[0030] Hollow glass microspheres were placed in a round-bottom flask, and anhydrous ethanol with a volume 10 times that of the hollow glass microspheres was added to the flask. The mixture was stirred for 5 minutes at a speed of 200-240 rpm. Then, 0.2 times the volume of anhydrous ethanol was added to the silane coupling agent KH-570. The temperature was raised to 50-55℃. The hollow glass microspheres were then removed and placed in an oven and dried with warm air at 45℃ for 20 minutes to obtain activated hollow glass microspheres.

[0031] Polyurethane acrylate and epoxy acrylate were placed in a vacuum drying oven and dried at 40°C for 4 hours to obtain the mixed resin matrix.

[0032] The resin matrix was placed in a 60℃ water bath and stirred for 20 minutes. Then, hollow glass microspheres, ammonium tripolyphosphate, and the resin matrix were stirred and mixed in a mixer at a speed of 2000-2200 rpm for 20 minutes. Ultraviolet absorber and photoinitiator were then added to the mixer. The mixer speed was adjusted to 100 rpm and the temperature was 90℃. After vacuum degassing, the composite melt was cooled to room temperature. The composite melt was pulverized into particles and dried in a 50℃ vacuum drying oven for 2 hours to obtain the injection resin.

[0033] Preferably, the photoinitiator includes photoinitiator TPO and hindered amine light stabilizer HALS.

[0034] On the other hand, the present invention also provides a method for manufacturing composite material components based on 2.5D braiding and RTM injection molding, the method comprising:

[0035] After polishing the surface of the injection mold, a release agent is applied. The injection mold is then preheated to 50-60℃. An adhesive is applied to the surface of the fiber preform, and the fiber preform is pre-laid inside the injection mold, ensuring that the fiber preform remains flat.

[0036] A vacuum pump is used to connect the resin tank and the curing agent tank respectively. The injection resin and curing agent are simultaneously pumped into the injection mold at an injection pressure of 0.8-1.0MPa and an injection speed of 8-10mL / min. The injection resin and curing agent mixture in the injection cavity is pre-irradiated with UV, and the injection mold temperature is maintained at 80℃ for 10min.

[0037] The mold cavity of the injection mold is heated to 95°C, and the fiber preform and injection resin are pre-cured for 20 minutes under nitrogen atmosphere. The mold cavity is then heated to 120°C and held for 40 minutes to obtain the composite material component.

[0038] After the mold cavity cools naturally to room temperature, the injection mold is opened, and compressed air is used to blow the mold for 5 minutes. The composite material component is then laser-cut to remove burrs, resulting in the finished composite material component.

[0039] Preferably, the curing agent is methyltetrahydrophthalic anhydride, and the binder is a mixture of KH-570 and epoxy resin E-51, with a volume ratio of KH-570 to epoxy resin E-51 of 2:1.

[0040] Compared with the prior art, the embodiments of this application have the following main advantages:

[0041] In this embodiment of the invention, the composite material component is composed of a fiber preform and injection resin. The fiber preform is preformed based on 2.5D weaving technology. The fiber preform is formed by the synergistic combination of silicon carbide fiber, glass fiber, and modified graphene. Based on steam explosion, the silicon carbide fiber, glass fiber, and modified graphene are fully impregnated, which optimizes the fiber dispersion and ensures that the subsequent injection resin is fully impregnated. This effectively overcomes the problem in the prior art where the 2.5D woven fabric is not fully impregnated when the glue is injected into the mold to obtain the fabric blank, resulting in residual air bubbles inside the fiber bundle, which causes dry spot effect and affects the interfacial bonding strength and stability of the material. The fiber preform and injection resin are based on RTM injection process to realize the manufacturing of high-performance composite material components. Moreover, the prepared composite material components not only have excellent mechanical properties and thermal stability, but also have good electromagnetic shielding performance and weather resistance.

[0042] In this embodiment of the invention, a method for preparing a sizing agent is provided. During the preparation of the sizing agent, epoxy-modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboroester are synergistically combined. The tetrabutyl titanate modified liquid synergistically combines with polyimide and polycarbosilane, thereby enabling the composite material component to have a good electromagnetic shielding effect and improving the heat resistance and interfacial bonding strength of the sizing agent. The improvement of interfacial bonding strength reduces fiber debonding during the preparation of the fiber preform and can reduce the porosity of the fiber preform.

[0043] In this embodiment of the invention, during the preparation of the fiber preform, the pre-oxidation treatment of the fiber premix can break the agglomeration inside the fiber bundle through the cavitation effect, making the fibers more uniformly dispersed and avoiding gaps between bundles during subsequent weaving. The soaking solution, based on steam explosion treatment, can penetrate into the gaps of the fiber premix, removing dust, grease and processing residues from the fiber surface while ensuring that the sizing agent fully penetrates into the fiber gaps, avoiding missed coating or glue accumulation. This results in strong interfacial bonding in the fiber preform and improves the weather resistance and corrosion resistance of the fiber preform.

[0044] In this embodiment of the invention, to address the shortcomings of poor dispersibility, weak interfacial bonding, and limited functionality of raw graphene oxide, nano-zinc oxide is used to modify graphene oxide by providing functional active sites. Nano-zinc oxide has the advantage of small particle size, thus avoiding agglomeration when combined with graphene oxide. Furthermore, the graphene oxide is modified with citric acid and epoxidized soybean oil, enhancing its interfacial bonding with the injection resin. Finally, the addition of gelatin further improves the dispersibility of the modified graphene in the resin, preventing uneven dispersion during injection. The flame-retardant functional groups of ammonium tripolyphosphate synergistically work with the modified graphene, ensuring the flame retardancy of the fiber preform.

[0045] In this embodiment of the invention, the injection resin is composed of polyurethane acrylate, epoxy acrylate, ammonium tripolyphosphate, hollow glass microspheres, ultraviolet absorber, and photoinitiator. Mixing the hollow glass microspheres, ammonium tripolyphosphate, and resin matrix in a mixer ensures the uniform distribution of each component, improves the uniformity and stability of the composite melt, and the addition of ammonium tripolyphosphate improves the thermal stability and flame retardancy of the injection resin, enabling it to maintain good performance even at high temperatures. The addition of ultraviolet absorber improves the light stability of the injection resin, making it less prone to degradation under ultraviolet irradiation and extending the service life of the composite material. Attached Figure Description

[0046] Figure 1 A schematic diagram of the unit cell geometric model of the composite material component in Embodiment 1 of the present invention is shown.

[0047] Figure 2 A schematic diagram of the unit cell finite element model of the composite material component in Embodiment 1 of the present invention is shown.

[0048] Figure 3 The composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of the present invention are shown, as well as the flame retardant performance test results of Comparative Example 4.

[0049] Figure 4 The mechanical property test results of the composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of the present invention and Comparative Example 4 are shown.

[0050] Figure 5The composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of the present invention are shown, and the electromagnetic shielding performance test results of Comparative Example 4 are also shown. Detailed Implementation

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0052] Example 1

[0053] This invention provides a composite material component based on 2.5D braiding and RTM injection manufacturing. The composite material component includes a fiber preform, injection resin, binder, and curing agent. The fiber preform is preformed based on 2.5D braiding technology. The injection resin, binder, and curing agent are injected into an injection mold containing the fiber preform using RTM injection technology and cured to form the composite material component. The weight ratio of the injection resin to the curing agent can be 1:1.

[0054] In this embodiment, the fiber preform comprises the following raw materials in parts by weight: 50 parts silicon carbide fiber, 10 parts glass fiber, 2 parts modified graphene, 100 parts soaking solution, 2 parts sizing agent, and 10 parts polylactic acid.

[0055] In this embodiment of the invention, the injection resin comprises the following raw materials in parts by weight: 40 parts polyurethane acrylate, 10 parts epoxy acrylate, 2 parts ammonium tripolyphosphate, 2 parts hollow glass microspheres, 2 parts ultraviolet absorber, and 2 parts photoinitiator.

[0056] In this embodiment of the invention, the composite material component is composed of a fiber preform and injection resin. The fiber preform is preformed based on 2.5D weaving technology. The fiber preform is formed by the synergistic combination of silicon carbide fiber, glass fiber, and modified graphene. Based on steam explosion, the silicon carbide fiber, glass fiber, and modified graphene are fully impregnated, which optimizes the fiber dispersion and ensures that the subsequent injection resin is fully impregnated. This effectively overcomes the problem in the prior art where the 2.5D woven fabric is not fully impregnated when the glue is injected into the mold to obtain the fabric blank, resulting in residual air bubbles inside the fiber bundle, which causes dry spot effect and affects the interfacial bonding strength and stability of the material. The fiber preform and injection resin are based on RTM injection process to realize the manufacturing of high-performance composite material components. Moreover, the prepared composite material components not only have excellent mechanical properties and thermal stability, but also have good electromagnetic shielding performance and weather resistance.

[0057] The soaking solution comprises silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent, with a volume ratio of silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent of 1:2:3:1. The sizing agent comprises epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester, with a volume ratio of epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester of 5:1:6:4:5.

[0058] In this embodiment of the invention, the method for preparing the sizing agent includes:

[0059] S101, take polyimide and polycarbosilane solution and place them in a reaction vessel and stir for 10 minutes. The mixing temperature is 60℃. After stirring, let stand for 20 minutes to obtain the solution before sizing. It should be noted that the mixture of polyimide and polycarbosilane can ensure that the sizing agent has heat resistance and rigidity while also having flexibility, thereby ensuring the stability of the composite material component.

[0060] S102, anhydrous ethanol and tetrabutyl titanate were mixed in a volume ratio of 5:1 and stirred in a magnetic stirrer for 10 min at a stirring speed of 200 rpm to obtain a tetrabutyl titanate solution. At the same time, deionized water, glacial acetic acid and anhydrous ethanol were mixed in a volume ratio of 4:1:10 to obtain a sizing drop solution. The sizing drop solution and tetrabutyl titanate solution were taken in a volume ratio of 1:2. The sizing drop solution was added dropwise to the tetrabutyl titanate solution at a drop rate of 2 mL / min and the temperature was maintained at 4℃. After the drop was completed, the mixture was stirred for 1 h. Then, acetylacetone with a volume of 0.01 times that of the sizing drop solution was added to the tetrabutyl titanate solution and the mixture was stirred for another 2 h to obtain a tetrabutyl titanate modified solution. The tetrabutyl titanate modified solution, in combination with polyimide and polycarbosilane, gives the composite material component a good electromagnetic shielding effect.

[0061] S103 involves mixing epoxy-modified silicone oil and organoboroester at 45°C for 10 minutes, then adding a pre-sizing solution and tetrabutyl titanate modified solution. The mixture is then ultrasonically treated with a 300W ultrasonic generator for 10 minutes, stirred for 30 minutes, and cooled to room temperature to obtain a sizing agent. The 300W ultrasonic treatment for 10 minutes breaks up agglomerates through cavitation, ensuring thorough mixing of all components and resulting in a sizing agent without significant stratification.

[0062] In this embodiment of the invention, a method for preparing a sizing agent is provided. During the preparation of the sizing agent, epoxy-modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboroester are synergistically combined. The tetrabutyl titanate modified liquid synergistically combines with polyimide and polycarbosilane, thereby enabling the composite material component to have a good electromagnetic shielding effect and improving the heat resistance and interfacial bonding strength of the sizing agent. The improvement of interfacial bonding strength reduces fiber debonding during the preparation of the fiber preform and can reduce the porosity of the fiber preform.

[0063] In this embodiment of the invention, the method for preparing the fiber preform includes:

[0064] S201, take silicon carbide fiber and glass fiber, immerse them in soaking solution, treat them at 65℃ for 40 min, then add 0.05 times the volume of soaking solution of 0.3 mol / L triethanolamine dropwise into soaking solution, stir in water bath at 55℃ for 2 h to obtain fiber premix;

[0065] S202, the fiber premix is ​​pre-oxidized at 120℃ for 3 hours, and then the pre-oxidized fiber premix is ​​ultrasonically treated for 20 minutes.

[0066] S203, modified graphene and fiber premix are loaded into a rupture container, saturated steam at 180°C is introduced into the rupture container, the rupture container is then pressurized to 0.7MPa, steam rupture is performed for 10 minutes, and the rupture container is depressurized within 0.1 seconds.

[0067] S204, take out silicon carbide fiber and glass fiber, put the silicon carbide fiber and glass fiber in a vacuum drying oven at 51℃ for 21 min, and then immerse them in polylactic acid and acetone solution for 20 min for shaping, wherein the volume ratio of polylactic acid and acetone solution is 1:15.

[0068] S205 uses a spinneret to spray sizing agent onto the surface of silicon carbide fiber and glass fiber, spraying three times with a 12-minute interval between each spray. Using silicon carbide fiber as warp and glass fiber as weft, finite element analysis is performed on the fiber preform. The unit cell structure of the fiber preform is subjected to three-directional periodic boundary conditions through the finite element model to simulate and predict the mechanical behavior of the material and determine the warp and weft arrangement paths. The warp density is 50 yarns / cm and the weft density is 40 yarns / cm.

[0069] In this embodiment of the invention, when the unit cell structure of the fiber preform is simulated using a finite element model with three-directional periodic boundary conditions, the smallest periodic representative unit cell model is selected from the 2.5D woven composite material component to predict its mechanical properties. Figure 1 A schematic diagram of the unit cell geometric model of the composite material component in Embodiment 1 of the present invention is shown, wherein, Figure 1 (a), (b), (c), and (d) represent the unit cell model, weft model, matrix model, and warp model of the unit cell geometric model, respectively. Figure 2 A schematic diagram of the unit cell finite element model of the composite material component in Embodiment 1 of the present invention is shown, while Figure 2 (a), (b), (c), and (d) represent the unit cell model, weft model, matrix model, and warp model of the unit cell finite element model, respectively. The matrix is ​​a mixture of injection resin, binder, and curing agent. Numerical simulations of the 2.5D woven composite material component in multiple directions show that the tensile properties and in-plane shear strength of the 2.5D woven composite material component are significantly improved.

[0070] S206: Lay the weft yarn along the bottom plate of the multi-harness loom, and pass the warp yarn through the weft yarn in the Z direction. Hook and stack the yarns in a figure-eight pattern to obtain a fiber preform for later use.

[0071] In this embodiment of the invention, during the preparation of the fiber preform, the pre-oxidation treatment of the fiber premix can break the agglomeration inside the fiber bundle through the cavitation effect, making the fibers more uniformly dispersed and avoiding gaps between bundles during subsequent weaving. The soaking solution, based on steam explosion treatment, can penetrate into the gaps of the fiber premix, removing dust, grease and processing residues from the fiber surface while ensuring that the sizing agent fully penetrates into the fiber gaps, avoiding missed coating or glue accumulation. This results in strong interfacial bonding in the fiber preform and improves the weather resistance and corrosion resistance of the fiber preform.

[0072] The modified graphene comprises the following raw materials by weight percentage: 70% graphene oxide; 2% nano zinc oxide; 3% gelatin; 2% citric acid; 15% epoxidized soybean oil; and 8% ammonium tripolyphosphate.

[0073] In this embodiment of the invention, the method for preparing the modified graphene includes:

[0074] S301, take a zinc acetate and ethylene glycol solution with a mass ratio of 0.8:1, stir in a water bath at 75℃ for 1.2h, then add 0.2 times the mass of sodium hydroxide aqueous solution in ethylene glycol dropwise to the zinc acetate and ethylene glycol solution, stir at 75℃ for 3h, then place the mixture in a reaction vessel and hydrothermally mix at 160℃ for 18h, wash the mixture three times with anhydrous ethanol, dry it in a vacuum drying oven, grind and sieve to obtain nano zinc oxide;

[0075] S302, dispersing graphene oxide in 7 times its volume of deionized water, ultrasonically treating the graphene oxide for 26 min to obtain a graphene dispersion, then adding citric acid and epoxidized soybean oil to the graphene dispersion, stirring the graphene dispersion with added citric acid and epoxidized soybean oil at 75℃ for 1.5 h to obtain a soybean oil-graphene mixture.

[0076] S303, take ammonium tripolyphosphate and place it in deionized water at 50℃, stir at 102 rpm for 10 min, then add gelatin and mix, continue heating for 10 min to obtain gelatin solution, stir and mix soybean oil graphene mixture with gelatin solution at 202 rpm for 2 h to obtain gelatin-graphene mixture.

[0077] S304: Nano zinc oxide was dispersed in 20 times its volume of ethanol and stirred for 15 min. Then it was mixed with a gelatin-graphene mixture, ultrasonicated for 20 min, and dried in a vacuum drying oven at 55℃ for 2 h to obtain modified graphene.

[0078] In this embodiment of the invention, to address the shortcomings of poor dispersibility, weak interfacial bonding, and limited functionality of raw graphene oxide, nano-zinc oxide is used to modify graphene oxide by providing functional active sites. Nano-zinc oxide has the advantage of small particle size, thus avoiding agglomeration when combined with graphene oxide. Furthermore, the graphene oxide is modified with citric acid and epoxidized soybean oil, enhancing its interfacial bonding with the injection resin. Finally, the addition of gelatin further improves the dispersibility of the modified graphene in the resin, preventing uneven dispersion during injection. The flame-retardant functional groups of ammonium tripolyphosphate synergistically work with the modified graphene, ensuring the flame retardancy of the fiber preform.

[0079] The method for preparing the injection resin includes:

[0080] S401: Mix ammonium tripolyphosphate with 5 times its volume of anhydrous ethanol, stir for 10 minutes, and then ball mill. The milled liquid is then dried in a vacuum drying oven at 60°C for later use. The ball milling process, involving mixing ammonium tripolyphosphate with anhydrous ethanol, refines the ammonium tripolyphosphate particles to submicron level using mechanical force. Vacuum drying at 60°C removes residual ethanol, preventing the ammonium tripolyphosphate from agglomerating due to moisture absorption. Simultaneously, the refined ammonium tripolyphosphate particles have a larger specific surface area, increasing the contact area with subsequent resins and resulting in a more complete flame-retardant reaction.

[0081] S402: Hollow glass microspheres are placed in a round-bottom flask, and anhydrous ethanol (10 times the volume of the hollow glass microspheres) is added to the flask. The mixture is stirred for 5 minutes at a stirring speed of 210 rpm. Then, 0.2 times the volume of anhydrous ethanol is added to the silane coupling agent KH-570. The temperature is raised to 51°C, and the hollow glass microspheres are removed and placed in an oven. They are dried at 45°C with warm air for 20 minutes to obtain activated hollow glass microspheres. After activation treatment, the interfacial bonding force between the hollow glass microspheres and PUA / EA resin is significantly improved, and their dispersibility is also significantly improved, thus avoiding the problem of nozzle clogging caused by the aggregation of hollow glass microspheres during injection. At the same time, the low density of the hollow glass microspheres reduces the overall density of the resin, meeting the lightweight requirements of the material components.

[0082] S403, polyurethane acrylate and epoxy acrylate are placed in a vacuum drying oven and dried at 40°C for 4 hours to obtain a mixed resin matrix;

[0083] S404: The resin matrix is ​​placed in a 60℃ water bath and stirred for 20 minutes. Then, hollow glass microspheres, ammonium tripolyphosphate, and the resin matrix are stirred and mixed in a mixer at a speed of 2000 rpm for 20 minutes. Then, ultraviolet absorber and photoinitiator are added to the mixer. The speed of the mixer is adjusted to 100 rpm and the temperature is 90℃. After vacuum degassing, the composite melt is cooled to room temperature. The composite melt is crushed into particles and dried in a 50℃ vacuum drying oven for 2 hours to obtain injection resin.

[0084] In this embodiment of the invention, the photoinitiator includes photoinitiator TPO and hindered amine light stabilizer HALS.

[0085] In this embodiment of the invention, the injection resin is composed of polyurethane acrylate, epoxy acrylate, ammonium tripolyphosphate, hollow glass microspheres, ultraviolet absorber, and photoinitiator. Mixing the hollow glass microspheres, ammonium tripolyphosphate, and resin matrix in a mixer ensures the uniform distribution of each component, improves the uniformity and stability of the composite melt, and the addition of ammonium tripolyphosphate improves the thermal stability and flame retardancy of the injection resin, enabling it to maintain good performance even at high temperatures. The addition of ultraviolet absorber improves the light stability of the injection resin, making it less prone to degradation under ultraviolet irradiation and extending the service life of the composite material.

[0086] In this embodiment of the invention, the method for manufacturing composite material components based on 2.5D braiding and RTM injection molding includes:

[0087] S10, after polishing the surface of the injection mold, apply a release agent, preheat the injection mold to 54°C, apply an adhesive to the surface of the fiber preform, pre-lay the fiber preform in the injection mold, and keep the fiber preform flat.

[0088] S20 uses a vacuum pump connected to the resin tank and the curing agent tank respectively. The injection resin and curing agent are simultaneously pumped into the injection mold at an injection pressure of 0.8MPa and an injection speed of 8mL / min. The injection resin and curing agent mixture in the injection cavity is pre-irradiated with UV, and the injection mold temperature is maintained at 80℃ for 10min.

[0089] S30, the inner cavity of the injection mold is heated to 95°C, and the fiber preform and injection resin are pre-cured for 20 minutes under nitrogen atmosphere. The mold cavity is then heated to 120°C and held for 40 minutes to obtain a composite material component.

[0090] S40: After the mold cavity cools naturally to room temperature, the injection mold is opened, and compressed air is used to blow the mold for 5 minutes. The composite material component is then laser-cut to remove burrs, resulting in the finished composite material component.

[0091] In this embodiment of the invention, the method for manufacturing composite components based on 2.5D braiding and RTM injection molding optimizes mold pretreatment, fiber preform pretreatment, injection and curing processes, and post-treatment to ensure fiber continuity and stability. Besides maintaining the advantages of the composite laminate structure, it effectively eliminates the disadvantages of the original process, such as low interlaminar shear strength and poor damage resistance due to weak interlaminar layers. Furthermore, this method reduces layup difficulties, ensures uniform resin injection, and increases the interlaminar shear strength of the molded component, significantly improving the performance of the composite component and enhancing its mechanical properties, thermal stability, and electromagnetic shielding performance. Simultaneously, this method is environmentally friendly and energy-efficient, making it suitable for various high-performance composite material applications.

[0092] The curing agent is methyltetrahydrophthalic anhydride, and the binder is a mixture of KH-570 and epoxy resin E-51, with a volume ratio of 2:1 between KH-570 and epoxy resin E-51.

[0093] Example 2

[0094] In this embodiment, the fiber preform comprises the following raw materials in parts by weight: 80 parts silicon carbide fiber, 20 parts glass fiber, 10 parts modified graphene, 200 parts soaking solution, 15 parts sizing agent, and 15 parts polylactic acid.

[0095] In this embodiment of the invention, the injection resin comprises the following raw materials in parts by weight: 50 parts polyurethane acrylate, 15 parts epoxy acrylate, 6 parts ammonium tripolyphosphate, 5 parts hollow glass microspheres, 5 parts ultraviolet absorber, and 8 parts photoinitiator.

[0096] The soaking solution comprises silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent, with a volume ratio of silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent of 1:2:3:1. The sizing agent comprises epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester, with a volume ratio of epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester of 5:1:6:4:5.

[0097] In this embodiment of the invention, the method for preparing the sizing agent includes:

[0098] S101, take polyimide and polycarbosilane solutions and place them in a reaction vessel and stir for 12 minutes at a mixing temperature of 70°C. After stirring, let stand for 20 minutes to obtain the solution before sizing.

[0099] S102, anhydrous ethanol and tetrabutyl titanate were mixed in a volume ratio of 5:1 and stirred in a magnetic stirrer for 10 min at a stirring speed of 250 rpm to obtain a tetrabutyl titanate solution. At the same time, deionized water, glacial acetic acid and anhydrous ethanol were mixed in a volume ratio of 4:1:10 to obtain a sizing drop solution. The sizing drop solution and tetrabutyl titanate solution were taken in a volume ratio of 1:2. The sizing drop solution was added dropwise to the tetrabutyl titanate solution at a drop rate of 2 mL / min and the temperature was maintained at 5℃. After the drop was completed, the mixture was stirred for 1 h. Then, 0.01 times the volume of the sizing drop solution of acetylacetone was added to the tetrabutyl titanate solution and the mixture was stirred for another 2 h to obtain a tetrabutyl titanate modified solution.

[0100] S103: Epoxy modified silicone oil and organoboroate are mixed and stirred at 45°C for 15 min. Then, the pre-sizing solution and tetrabutyl titanate modified liquid are added. The mixture is ultrasonically treated with a 300W ultrasonic generator for 12 min, then stirred for 30 min, and cooled to room temperature to obtain the sizing agent.

[0101] In this embodiment of the invention, the method for preparing the fiber preform includes:

[0102] S201, take silicon carbide fiber and glass fiber, immerse them in soaking solution, treat them at 65℃ for 45 min, then add 0.05 times the volume of soaking solution of 0.3 mol / L triethanolamine dropwise into soaking solution, stir in water bath at 55℃ for 2 h to obtain fiber premix;

[0103] S202, the fiber premix is ​​pre-oxidized at 150℃ for 3 hours, and then the pre-oxidized fiber premix is ​​ultrasonically treated for 25 minutes.

[0104] S203, modified graphene and fiber premix are loaded into a blasting vessel, saturated steam at 180°C is introduced into the blasting vessel, the blasting vessel is then pressurized to 0.7MPa, steam blasting is performed for 10-12 minutes, and the blasting vessel is depressurized within 0.5 seconds.

[0105] S204, take out silicon carbide fiber and glass fiber, place silicon carbide fiber and glass fiber in a vacuum drying oven at 55℃ for 25 minutes, and then immerse them in polylactic acid and acetone solution for 20 minutes for shaping, wherein the volume ratio of polylactic acid and acetone solution is 1:15.

[0106] S205 uses a spinneret to spray sizing agent onto the surface of silicon carbide fiber and glass fiber, spraying three times with a 15-minute interval between each spray. Using silicon carbide fiber as warp and glass fiber as weft, finite element analysis is performed on the fiber preform. The unit cell structure of the fiber preform is subjected to three-directional periodic boundary conditions through the finite element model to simulate and predict the mechanical behavior of the material and determine the warp and weft arrangement paths. The warp density is 60 yarns / cm and the weft density is 50 yarns / cm.

[0107] S206: Lay the weft yarn along the bottom plate of the multi-harness loom, and pass the warp yarn through the weft yarn in the Z direction. Hook and stack the yarns in a figure-eight pattern to obtain a fiber preform for later use.

[0108] The modified graphene comprises the following raw materials by weight percentage: 70% graphene oxide; 2% nano zinc oxide; 3% gelatin; 2% citric acid; 15% epoxidized soybean oil; and 8% ammonium tripolyphosphate.

[0109] In this embodiment of the invention, the method for preparing the modified graphene includes:

[0110] S301, take a zinc acetate and ethylene glycol solution with a mass ratio of 0.8:1, stir in a water bath at 75℃ for 1.2h, then add 0.2 times the mass of sodium hydroxide aqueous solution in ethylene glycol dropwise to the zinc acetate and ethylene glycol solution, stir at 75℃ for 3h, then place the mixture in a reaction vessel and hydrothermally mix at 160℃ for 18h, wash the mixture three times with anhydrous ethanol, dry it in a vacuum drying oven, grind and sieve to obtain nano zinc oxide;

[0111] S302, dispersing graphene oxide in 7 times its volume of deionized water, ultrasonically treating the graphene oxide for 30 min to obtain a graphene dispersion, then adding citric acid and epoxidized soybean oil to the graphene dispersion, stirring the graphene dispersion with added citric acid and epoxidized soybean oil at 75℃ for 1.5 h to obtain a soybean oil-graphene mixture.

[0112] S303, take ammonium tripolyphosphate and place it in deionized water at 50℃, stir at 120 rpm for 10 min, then add gelatin and mix, continue heating for 10 min to obtain gelatin solution, stir and mix soybean oil graphene mixture with gelatin solution at 220 rpm for 2 h to obtain gelatin-graphene mixture.

[0113] S304: Nano zinc oxide was dispersed in 20 times its volume of ethanol and stirred for 15 min. Then it was mixed with a gelatin-graphene mixture, ultrasonicated for 20 min, and dried in a vacuum drying oven at 55℃ for 2 h to obtain modified graphene.

[0114] The method for preparing the injection resin includes:

[0115] S401, mix ammonium tripolyphosphate with 5 times the volume of anhydrous ethanol, stir for 10 minutes, then ball mill the mixture, and then dry the ball milling liquid in a vacuum drying oven at 60℃ for later use.

[0116] S402: Place hollow glass microspheres in a round-bottom flask, add 10 times the volume of anhydrous ethanol to the flask, stir for 5 minutes at a stirring speed of 240 rpm, then add 0.2 times the volume of anhydrous ethanol of silane coupling agent KH-570, heat to 50-55℃, remove the hollow glass microspheres and place them in an oven, dry them at 45℃ with warm air for 20 minutes to obtain activated hollow glass microspheres;

[0117] S403, polyurethane acrylate and epoxy acrylate are placed in a vacuum drying oven and dried at 40°C for 4 hours to obtain a mixed resin matrix;

[0118] S404: The resin matrix is ​​placed in a 60℃ water bath and stirred for 20 minutes. Then, hollow glass microspheres, ammonium tripolyphosphate, and the resin matrix are stirred and mixed in a mixer at a speed of 2200 rpm for 20 minutes. Then, ultraviolet absorber and photoinitiator are added to the mixer. The speed of the mixer is adjusted to 100 rpm and the temperature is 90℃. After vacuum degassing, the composite melt is cooled to room temperature. The composite melt is crushed into particles and dried in a 50℃ vacuum drying oven for 2 hours to obtain injection resin.

[0119] In this embodiment of the invention, the method for manufacturing composite material components based on 2.5D braiding and RTM injection molding includes:

[0120] S10, after polishing the surface of the injection mold, apply a release agent, preheat the injection mold to 60°C, apply an adhesive to the surface of the fiber preform, pre-lay the fiber preform in the injection mold, and keep the fiber preform flat.

[0121] S20 uses a vacuum pump connected to the resin tank and the curing agent tank respectively. The injection resin and curing agent are simultaneously pumped into the injection mold at an injection pressure of 1.0MPa and an injection speed of 10mL / min. The injection resin and curing agent mixture in the injection cavity is pre-irradiated with UV, and the injection mold temperature is maintained at 80℃ for 10min.

[0122] S30, the inner cavity of the injection mold is heated to 95°C, and the fiber preform and injection resin are pre-cured for 20 minutes under nitrogen atmosphere. The mold cavity is then heated to 120°C and held for 40 minutes to obtain a composite material component.

[0123] S40: After the mold cavity cools naturally to room temperature, the injection mold is opened, and compressed air is used to blow the mold for 5 minutes. The composite material component is then laser-cut to remove burrs, resulting in the finished composite material component.

[0124] Example 3

[0125] In this embodiment, the fiber preform comprises the following raw materials in parts by weight: 55 parts silicon carbide fiber, 12 parts glass fiber, 4 parts modified graphene, 110 parts soaking solution, 4 parts sizing agent, and 11 parts polylactic acid.

[0126] In this embodiment of the invention, the injection resin comprises the following raw materials in parts by weight: 45 parts polyurethane acrylate, 11 parts epoxy acrylate, 3 parts ammonium tripolyphosphate, 3 parts hollow glass microspheres, 3 parts ultraviolet absorber, and 4 parts photoinitiator.

[0127] The soaking solution comprises silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent, with a volume ratio of silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent of 1:2:3:1. The sizing agent comprises epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester, with a volume ratio of epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester of 5:1:6:4:5.

[0128] In this embodiment of the invention, the method for preparing the sizing agent includes:

[0129] S101, take polyimide and polycarbosilane solutions and place them in a reaction vessel and stir for 11 min at a mixing temperature of 62℃. After stirring, let stand for 20 min to obtain the solution before sizing.

[0130] S102, anhydrous ethanol and tetrabutyl titanate were mixed in a volume ratio of 5:1 and stirred in a magnetic stirrer for 10 min at a stirring speed of 210 rpm to obtain a tetrabutyl titanate solution. At the same time, deionized water, glacial acetic acid and anhydrous ethanol were mixed in a volume ratio of 4:1:10 to obtain a sizing drop solution. The sizing drop solution and tetrabutyl titanate solution were taken in a volume ratio of 1:2. The sizing drop solution was added dropwise to the tetrabutyl titanate solution at a drop rate of 2 mL / min and the temperature was maintained at 4℃. After the drop was completed, the mixture was stirred for 1 h. Then, acetylacetone with a volume of 0.01 times that of the sizing drop solution was added to the tetrabutyl titanate solution and the mixture was stirred for another 2 h to obtain a tetrabutyl titanate modified solution.

[0131] S103: Epoxy modified silicone oil and organoboroate are mixed and stirred at 45°C for 11 min. Then, the pre-sizing solution and tetrabutyl titanate modified liquid are added. The mixture is ultrasonically treated with a 300W ultrasonic generator for 11 min, then stirred for 30 min, and cooled to room temperature to obtain the sizing agent.

[0132] In this embodiment of the invention, the method for preparing the fiber preform includes:

[0133] S201, take silicon carbide fiber and glass fiber, immerse them in soaking solution, treat them at 55-65℃ for 40-45 min, then add 0.05 times the volume of soaking solution of 0.3 mol / L triethanolamine dropwise into soaking solution, stir in water bath at 55℃ for 2 h to obtain fiber premix;

[0134] S202, the fiber premix is ​​pre-oxidized at 125℃ for 3 hours, and then the pre-oxidized fiber premix is ​​ultrasonically treated for 21 minutes.

[0135] S203, modified graphene and fiber premix are loaded into a rupture container, saturated steam at 180°C is introduced into the rupture container, the rupture container is then pressurized to 0.7MPa, steam rupture is performed for 11 minutes, and the rupture container is depressurized within 0.2 seconds.

[0136] S204, take out silicon carbide fiber and glass fiber, place silicon carbide fiber and glass fiber in a vacuum drying oven at 51℃ for 21 min, and then immerse them in polylactic acid and acetone solution for 20 min for shaping, wherein the volume ratio of polylactic acid and acetone solution is 1:12.

[0137] S205 uses a spinneret to spray sizing agent onto the surface of silicon carbide fiber and glass fiber, spraying three times with an interval of 11 minutes between each spraying. Using silicon carbide fiber as warp and glass fiber as weft, finite element analysis is performed on the fiber preform. The unit cell structure of the fiber preform is subjected to three-directional periodic boundary conditions through the finite element model to simulate and predict the mechanical behavior of the material and determine the warp and weft arrangement paths. The warp density is 52 yarns / cm and the weft density is 43 yarns / cm.

[0138] S206: Lay the weft yarn along the bottom plate of the multi-harness loom, and pass the warp yarn through the weft yarn in the Z direction. Hook and stack the yarns in a figure-eight pattern to obtain a fiber preform for later use.

[0139] The modified graphene comprises the following raw materials by weight percentage: 70% graphene oxide; 2% nano zinc oxide; 3% gelatin; 2% citric acid; 15% epoxidized soybean oil; and 8% ammonium tripolyphosphate.

[0140] In this embodiment of the invention, the method for preparing the modified graphene includes:

[0141] S301, take a zinc acetate and ethylene glycol solution with a mass ratio of 0.8:1, stir in a water bath at 75℃ for 1.2h, then add 0.2 times the mass of sodium hydroxide aqueous solution in ethylene glycol dropwise to the zinc acetate and ethylene glycol solution, stir at 75℃ for 3h, then place the mixture in a reaction vessel and hydrothermally mix at 160℃ for 18h, wash the mixture three times with anhydrous ethanol, dry it in a vacuum drying oven, grind and sieve to obtain nano zinc oxide;

[0142] S302, dispersing graphene oxide in 7 times its volume of deionized water, ultrasonically treating the graphene oxide for 26 min to obtain a graphene dispersion, then adding citric acid and epoxidized soybean oil to the graphene dispersion, stirring the graphene dispersion with added citric acid and epoxidized soybean oil at 75℃ for 1.5 h to obtain a soybean oil-graphene mixture.

[0143] S303, take ammonium tripolyphosphate and place it in deionized water at 50℃, stir at 108 rpm for 10 min, then add gelatin and mix, continue heating for 10 min to obtain gelatin solution, stir and mix soybean oil graphene mixture with gelatin solution at 210 rpm for 2 h to obtain gelatin-graphene mixture.

[0144] S304: Nano zinc oxide was dispersed in 20 times its volume of ethanol and stirred for 15 min. Then it was mixed with a gelatin-graphene mixture, ultrasonicated for 20 min, and dried in a vacuum drying oven at 55℃ for 2 h to obtain modified graphene.

[0145] The method for preparing the injection resin includes:

[0146] S401, mix ammonium tripolyphosphate with 5 times the volume of anhydrous ethanol, stir for 10 minutes, then ball mill the mixture, and then dry the ball milling liquid in a vacuum drying oven at 60℃ for later use.

[0147] S402: Place hollow glass microspheres in a round-bottom flask, add 10 times the volume of anhydrous ethanol to the flask, stir for 5 minutes at a stirring speed of 210 rpm, then add 0.2 times the volume of anhydrous ethanol of silane coupling agent KH-570, heat to 51°C, remove the hollow glass microspheres and place them in an oven, dry them at 45°C with warm air for 20 minutes to obtain activated hollow glass microspheres;

[0148] S403, polyurethane acrylate and epoxy acrylate are placed in a vacuum drying oven and dried at 40°C for 4 hours to obtain a mixed resin matrix;

[0149] S404: The resin matrix is ​​placed in a 60℃ water bath and stirred for 20 minutes. Then, hollow glass microspheres, ammonium tripolyphosphate, and the resin matrix are stirred and mixed in a mixer at a speed of 2200 rpm for 20 minutes. Then, ultraviolet absorber and photoinitiator are added to the mixer. The speed of the mixer is adjusted to 100 rpm and the temperature is 90℃. After vacuum degassing, the composite melt is cooled to room temperature. The composite melt is crushed into particles and dried in a 50℃ vacuum drying oven for 2 hours to obtain injection resin.

[0150] In this embodiment of the invention, the method for manufacturing composite material components based on 2.5D braiding and RTM injection molding includes:

[0151] S10: After polishing the surface of the injection mold, apply a release agent, preheat the injection mold to a temperature of 50-60℃, apply an adhesive to the surface of the fiber preform, pre-lay the fiber preform in the injection mold, and keep the fiber preform flat.

[0152] S20 uses a vacuum pump connected to the resin tank and the curing agent tank respectively. The injection resin and curing agent are simultaneously pumped into the injection mold at an injection pressure of 0.85MPa and an injection speed of 9mL / min. The injection resin and curing agent mixture in the injection cavity is pre-irradiated with UV, and the injection mold temperature is maintained at 80℃ for 10min.

[0153] S30, the inner cavity of the injection mold is heated to 95°C, and the fiber preform and injection resin are pre-cured for 20 minutes under nitrogen atmosphere. The mold cavity is then heated to 120°C and held for 40 minutes to obtain a composite material component.

[0154] S40: After the mold cavity cools naturally to room temperature, the injection mold is opened, and compressed air is used to blow the mold for 5 minutes. The composite material component is then laser-cut to remove burrs, resulting in the finished composite material component.

[0155] Example 4

[0156] In this embodiment, the fiber preform comprises the following raw materials in parts by weight: 70 parts silicon carbide fiber, 18 parts glass fiber, 10 parts modified graphene, 190 parts soaking solution, 12 parts sizing agent, and 14 parts polylactic acid.

[0157] In this embodiment of the invention, the injection resin comprises the following raw materials in parts by weight: 48 parts polyurethane acrylate, 14 parts epoxy acrylate, 5 parts ammonium tripolyphosphate, 4 parts hollow glass microspheres, 5 parts ultraviolet absorber, and 7 parts photoinitiator.

[0158] The soaking solution comprises silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent, with a volume ratio of silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent of 1:2:3:1. The sizing agent comprises epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester, with a volume ratio of epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester of 5:1:6:4:5.

[0159] In this embodiment of the invention, the method for preparing the sizing agent includes:

[0160] S101, take polyimide and polycarbosilane solutions and place them in a reaction vessel and stir for 14 minutes at a mixing temperature of 67°C. After stirring, let stand for 20 minutes to obtain the solution before sizing.

[0161] S102, anhydrous ethanol and tetrabutyl titanate were mixed in a volume ratio of 5:1 and stirred in a magnetic stirrer for 10 min at a stirring speed of 240 rpm to obtain a tetrabutyl titanate solution. At the same time, deionized water, glacial acetic acid and anhydrous ethanol were mixed in a volume ratio of 4:1:10 to obtain a sizing drop solution. The sizing drop solution and tetrabutyl titanate solution were taken in a volume ratio of 1:2. The sizing drop solution was added dropwise to the tetrabutyl titanate solution at a drop rate of 2 mL / min and the temperature was maintained at 5℃. After the addition was completed, the mixture was stirred for 1 h. Then, 0.01 times the volume of the sizing drop solution of acetylacetone was added to the tetrabutyl titanate solution and the mixture was stirred for another 2 h to obtain a tetrabutyl titanate modified solution.

[0162] S103: Epoxy modified silicone oil and organoboroate are mixed and stirred at 45°C for 14 min. Then, the pre-sizing solution and tetrabutyl titanate modified liquid are added. The mixture is ultrasonically treated with a 300W ultrasonic generator for 11 min, stirred for 30 min, and cooled to room temperature to obtain the sizing agent.

[0163] In this embodiment of the invention, the method for preparing the fiber preform includes:

[0164] S201, take silicon carbide fiber and glass fiber, immerse them in soaking solution, treat them at 62℃ for 44 min, then add 0.05 times the volume of soaking solution of 0.3 mol / L triethanolamine dropwise into soaking solution, stir in water bath at 55℃ for 2 h to obtain fiber premix;

[0165] S202, the fiber premix is ​​pre-oxidized at 145℃ for 3 hours, and then the pre-oxidized fiber premix is ​​ultrasonically treated for 24 minutes.

[0166] S203, modified graphene and fiber premix are loaded into a rupture container, saturated steam at 180°C is introduced into the rupture container, the rupture container is then pressurized to 0.7MPa, steam rupture is performed for 11 minutes, and the rupture container is depressurized within 0.5 seconds.

[0167] S204, take out silicon carbide fiber and glass fiber, place silicon carbide fiber and glass fiber in a vacuum drying oven at 54℃ for 24 min, and then immerse them in polylactic acid and acetone solution for 20 min for shaping, wherein the volume ratio of polylactic acid and acetone solution is 1:13.

[0168] S205 uses a spinneret to spray sizing agent onto the surface of silicon carbide fiber and glass fiber, spraying three times with a 14-minute interval between each spray. Using silicon carbide fiber as warp and glass fiber as weft, finite element analysis is performed on the fiber preform. The unit cell structure of the fiber preform is subjected to three-directional periodic boundary conditions through the finite element model to simulate and predict the mechanical behavior of the material and determine the warp and weft arrangement paths. The warp density is 58 yarns / cm and the weft density is 47 yarns / cm.

[0169] S206: Lay the weft yarn along the bottom plate of the multi-harness loom, and pass the warp yarn through the weft yarn in the Z direction. Hook and stack the yarns in a figure-eight pattern to obtain a fiber preform for later use.

[0170] The modified graphene comprises the following raw materials by weight percentage: 70% graphene oxide; 2% nano zinc oxide; 3% gelatin; 2% citric acid; 15% epoxidized soybean oil; and 8% ammonium tripolyphosphate.

[0171] In this embodiment of the invention, the method for preparing the modified graphene includes:

[0172] S301, take a zinc acetate and ethylene glycol solution with a mass ratio of 0.8:1, stir in a water bath at 75℃ for 1.2h, then add 0.2 times the mass of sodium hydroxide aqueous solution in ethylene glycol dropwise to the zinc acetate and ethylene glycol solution, stir at 75℃ for 3h, then place the mixture in a reaction vessel and hydrothermally mix at 160℃ for 18h, wash the mixture three times with anhydrous ethanol, dry it in a vacuum drying oven, grind and sieve to obtain nano zinc oxide;

[0173] S302, dispersing graphene oxide in 7 times its volume of deionized water, ultrasonically treating the graphene oxide for 27 min to obtain a graphene dispersion, then adding citric acid and epoxidized soybean oil to the graphene dispersion, stirring the graphene dispersion with added citric acid and epoxidized soybean oil at 75°C for 1.5 h to obtain a soybean oil-graphene mixture.

[0174] S303, take ammonium tripolyphosphate and place it in deionized water at 50℃, stir at 120 rpm for 10 min, then add gelatin and mix, continue heating for 10 min to obtain gelatin solution, stir and mix soybean oil graphene mixture with gelatin solution at 220 rpm for 2 h to obtain gelatin-graphene mixture.

[0175] S304: Nano zinc oxide was dispersed in 20 times its volume of ethanol and stirred for 15 min. Then it was mixed with a gelatin-graphene mixture, ultrasonicated for 20 min, and dried in a vacuum drying oven at 55℃ for 2 h to obtain modified graphene.

[0176] The method for preparing the injection resin includes:

[0177] S401, mix ammonium tripolyphosphate with 5 times the volume of anhydrous ethanol, stir for 10 minutes, then ball mill the mixture, and then dry the ball milling liquid in a vacuum drying oven at 60℃ for later use.

[0178] S402: Place hollow glass microspheres in a round-bottom flask, add 10 times the volume of anhydrous ethanol to the flask, stir for 5 minutes at a stirring speed of 240 rpm, then add 0.2 times the volume of anhydrous ethanol of silane coupling agent KH-570, heat to 50-55℃, remove the hollow glass microspheres and place them in an oven, dry them at 45℃ with warm air for 20 minutes to obtain activated hollow glass microspheres;

[0179] S403, polyurethane acrylate and epoxy acrylate are placed in a vacuum drying oven and dried at 40°C for 4 hours to obtain a mixed resin matrix;

[0180] S404: The resin matrix is ​​placed in a 60℃ water bath and stirred for 20 minutes. Then, hollow glass microspheres, ammonium tripolyphosphate, and the resin matrix are stirred and mixed in a mixer at a speed of 2200 rpm for 20 minutes. Then, ultraviolet absorber and photoinitiator are added to the mixer. The speed of the mixer is adjusted to 100 rpm and the temperature is 90℃. After vacuum degassing, the composite melt is cooled to room temperature. The composite melt is crushed into particles and dried in a 50℃ vacuum drying oven for 2 hours to obtain injection resin.

[0181] In this embodiment of the invention, the method for manufacturing composite material components based on 2.5D braiding and RTM injection molding includes:

[0182] S10, after polishing the surface of the injection mold, apply a release agent, preheat the injection mold to 60°C, apply an adhesive to the surface of the fiber preform, pre-lay the fiber preform in the injection mold, and keep the fiber preform flat.

[0183] S20 uses a vacuum pump connected to the resin tank and the curing agent tank respectively. The injection resin and curing agent are simultaneously pumped into the injection mold at an injection pressure of 0.8-1.0MPa and an injection speed of 9.5mL / min. The injection resin and curing agent mixture in the injection cavity is pre-irradiated with UV, and the injection mold temperature is maintained at 80℃ for 10min.

[0184] S30, the inner cavity of the injection mold is heated to 95°C, and the fiber preform and injection resin are pre-cured for 20 minutes under nitrogen atmosphere. The mold cavity is then heated to 120°C and held for 40 minutes to obtain a composite material component.

[0185] S40: After the mold cavity cools naturally to room temperature, the injection mold is opened, and compressed air is used to blow the mold for 5 minutes. The composite material component is then laser-cut to remove burrs, resulting in the finished composite material component.

[0186] Example 5

[0187] In this embodiment, the fiber preform comprises the following raw materials in parts by weight: 60 parts silicon carbide fiber, 15 parts glass fiber, 6 parts modified graphene, 150 parts soaking solution, 8 parts sizing agent, and 12 parts polylactic acid.

[0188] In this embodiment of the invention, the injection resin comprises the following raw materials in parts by weight: 45 parts polyurethane acrylate, 12 parts epoxy acrylate, 4 parts ammonium tripolyphosphate, 3 parts hollow glass microspheres, 3 parts ultraviolet absorber, and 3 parts photoinitiator.

[0189] The soaking solution comprises silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent, with a volume ratio of silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent of 1:2:3:1. The sizing agent comprises epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester, with a volume ratio of epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester of 5:1:6:4:5.

[0190] In this embodiment of the invention, the method for preparing the sizing agent includes:

[0191] S101, take polyimide and polycarbosilane solutions and place them in a reaction vessel and stir for 12 minutes at a mixing temperature of 65℃. After stirring, let stand for 20 minutes to obtain the solution before sizing.

[0192] S102, anhydrous ethanol and tetrabutyl titanate were mixed in a volume ratio of 5:1 and stirred in a magnetic stirrer for 10 min at a stirring speed of 220 rpm to obtain a tetrabutyl titanate solution. At the same time, deionized water, glacial acetic acid and anhydrous ethanol were mixed in a volume ratio of 4:1:10 to obtain a sizing drop solution. The sizing drop solution and tetrabutyl titanate solution were taken in a volume ratio of 1:2. The sizing drop solution was added dropwise to the tetrabutyl titanate solution at a drop rate of 2 mL / min and the temperature was maintained at 4-5℃. After the addition was completed, the mixture was stirred for 1 h. Then, acetylacetone was added to the tetrabutyl titanate solution at a volume ratio of 0.01 times that of the sizing drop solution, and the mixture was stirred for another 2 h to obtain a tetrabutyl titanate modified solution.

[0193] S103: Epoxy modified silicone oil and organoboroate are mixed and stirred at 45°C for 10-15 minutes. Then, the pre-sizing solution and tetrabutyl titanate modified liquid are added. The mixture is ultrasonically treated with a 300W ultrasonic generator for 12 minutes, then stirred for 30 minutes and cooled to room temperature to obtain the sizing agent.

[0194] In this embodiment of the invention, the method for preparing the fiber preform includes:

[0195] S201, take silicon carbide fiber and glass fiber, immerse them in soaking solution, treat them at 65℃ for 45 min, then add 0.05 times the volume of soaking solution of 0.3 mol / L triethanolamine dropwise into soaking solution, stir in water bath at 55℃ for 2 h to obtain fiber premix;

[0196] S202, the fiber premix is ​​pre-oxidized at 150℃ for 3 hours, and then the pre-oxidized fiber premix is ​​ultrasonically treated for 25 minutes.

[0197] S203, modified graphene and fiber premix are loaded into a rupture container, saturated steam at 180°C is introduced into the rupture container, the rupture container is then pressurized to 0.7MPa, steam rupture is performed for 12 minutes, and the rupture container is depressurized within 0.5 seconds.

[0198] S204, take out silicon carbide fiber and glass fiber, place silicon carbide fiber and glass fiber in a vacuum drying oven at 55℃ for 25 minutes, and then immerse them in polylactic acid and acetone solution for 20 minutes for shaping, wherein the volume ratio of polylactic acid and acetone solution is 1:15.

[0199] S205 uses a spinneret to spray sizing agent onto the surface of silicon carbide fiber and glass fiber, spraying three times with a 15-minute interval between each spray. Using silicon carbide fiber as warp and glass fiber as weft, finite element analysis is performed on the fiber preform. The unit cell structure of the fiber preform is subjected to three-directional periodic boundary conditions through the finite element model to simulate and predict the mechanical behavior of the material and determine the warp and weft arrangement paths. The warp density is 60 yarns / cm and the weft density is 50 yarns / cm.

[0200] S206: Lay the weft yarn along the bottom plate of the multi-harness loom, and pass the warp yarn through the weft yarn in the Z direction. Hook and stack the yarns in a figure-eight pattern to obtain a fiber preform for later use.

[0201] The modified graphene comprises the following raw materials by weight percentage: 70% graphene oxide; 2% nano zinc oxide; 3% gelatin; 2% citric acid; 15% epoxidized soybean oil; and 8% ammonium tripolyphosphate.

[0202] In this embodiment of the invention, the method for preparing the modified graphene includes:

[0203] S301, take a zinc acetate and ethylene glycol solution with a mass ratio of 0.8:1, stir in a water bath at 75℃ for 1.2h, then add 0.2 times the mass of sodium hydroxide aqueous solution in ethylene glycol dropwise to the zinc acetate and ethylene glycol solution, stir at 75℃ for 3h, then place the mixture in a reaction vessel and hydrothermally mix at 160℃ for 18h, wash the mixture three times with anhydrous ethanol, dry it in a vacuum drying oven, grind and sieve to obtain nano zinc oxide;

[0204] S302, dispersing graphene oxide in 7 times its volume of deionized water, ultrasonically treating the graphene oxide for 30 min to obtain a graphene dispersion, then adding citric acid and epoxidized soybean oil to the graphene dispersion, stirring the graphene dispersion with added citric acid and epoxidized soybean oil at 75℃ for 1.5 h to obtain a soybean oil-graphene mixture.

[0205] S303, take ammonium tripolyphosphate and place it in deionized water at 50℃, stir at 120 rpm for 10 min, then add gelatin and mix, continue heating for 10 min to obtain gelatin solution, stir and mix soybean oil graphene mixture with gelatin solution at 220 rpm for 2 h to obtain gelatin-graphene mixture.

[0206] S304: Nano zinc oxide was dispersed in 20 times its volume of ethanol and stirred for 15 min. Then it was mixed with a gelatin-graphene mixture, ultrasonicated for 20 min, and dried in a vacuum drying oven at 55℃ for 2 h to obtain modified graphene.

[0207] The method for preparing the injection resin includes:

[0208] S401, mix ammonium tripolyphosphate with 5 times the volume of anhydrous ethanol, stir for 10 minutes, then ball mill the mixture, and then dry the ball milling liquid in a vacuum drying oven at 60℃ for later use.

[0209] S402: Place hollow glass microspheres in a round-bottom flask, add 10 times the volume of anhydrous ethanol to the flask, stir for 5 minutes at a stirring speed of 240 rpm, then add 0.2 times the volume of anhydrous ethanol of silane coupling agent KH-570, heat to 55°C, remove the hollow glass microspheres and place them in an oven, dry them at 45°C with warm air for 20 minutes to obtain activated hollow glass microspheres;

[0210] S403, polyurethane acrylate and epoxy acrylate are placed in a vacuum drying oven and dried at 40°C for 4 hours to obtain a mixed resin matrix;

[0211] S404: The resin matrix is ​​placed in a 60℃ water bath and stirred for 20 minutes. Then, hollow glass microspheres, ammonium tripolyphosphate, and the resin matrix are stirred and mixed in a mixer at a speed of 2200 rpm for 20 minutes. Then, ultraviolet absorber and photoinitiator are added to the mixer. The speed of the mixer is adjusted to 100 rpm and the temperature is 90℃. After vacuum degassing, the composite melt is cooled to room temperature. The composite melt is crushed into particles and dried in a 50℃ vacuum drying oven for 2 hours to obtain injection resin.

[0212] In this embodiment of the invention, the method for manufacturing composite material components based on 2.5D braiding and RTM injection molding includes:

[0213] S10: After polishing the surface of the injection mold, apply a release agent, preheat the injection mold to a temperature of 50-60℃, apply an adhesive to the surface of the fiber preform, pre-lay the fiber preform in the injection mold, and keep the fiber preform flat.

[0214] S20 uses a vacuum pump connected to the resin tank and the curing agent tank respectively. The injection resin and curing agent are simultaneously pumped into the injection mold at an injection pressure of 1.0MPa and an injection speed of 10mL / min. The injection resin and curing agent mixture in the injection cavity is pre-irradiated with UV, and the injection mold temperature is maintained at 80℃ for 10min.

[0215] S30, the inner cavity of the injection mold is heated to 95°C, and the fiber preform and injection resin are pre-cured for 20 minutes under nitrogen atmosphere. The mold cavity is then heated to 120°C and held for 40 minutes to obtain a composite material component.

[0216] S40: After the mold cavity cools naturally to room temperature, the injection mold is opened, and compressed air is used to blow the mold for 5 minutes. The composite material component is then laser-cut to remove burrs, resulting in the finished composite material component.

[0217] Comparative Example 1

[0218] The manufacturing method of the composite material component based on 2.5D braiding and RTM injection in this comparative example and the raw material composition of the composite material component are similar to those in Example 5. The difference from Example 5 is that the fiber preform is a woven fiber fabric.

[0219] Comparative Example 2

[0220] The manufacturing method of the composite material component based on 2.5D braiding and RTM injection molding in this comparative example, as well as the raw material composition of the composite material component, are similar to those in Example 5. The difference from Example 5 is that the injection resin is epoxy resin.

[0221] Comparative Example 3

[0222] The manufacturing method of the composite material component based on 2.5D braiding and RTM injection in this comparative example and the raw material composition of the composite material component are similar to those in Example 5. The difference from Example 5 is that the fiber preform is a woven fiber fabric and the injection resin is epoxy resin.

[0223] Comparative Example 4

[0224] This comparative example is a commercially available product manufactured using a 2.5D braiding process combined with RTM technology.

[0225] Performance testing:

[0226] The composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of this invention, as well as Comparative Example 4, were subjected to flame retardant performance tests. During the flame retardant test, the sample dimensions were 100mm × 50mm × 2mm. The sample was clamped in an iron frame using a small-plate burning method, with liquefied petroleum gas (LPG) as fuel. The sample was burned using an LPG spray gun at a distance of 10cm from the sample. The average burning time of the sample was recorded. (Table 1 and...) Figure 3 The composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of the present invention are shown, as well as the flame retardant performance test results of Comparative Example 4.

[0227] Table 1

[0228]

[0229] As can be seen from Table 1, compared with the composite material components prepared in Comparative Examples 1-3 and Comparative Example 4, the composite material components prepared in Examples 1-5 of the present invention achieve interlocking between fiber preform layers through a 2.5D braided structure, and achieve rapid cross-linking with injection resin through RTM injection process. The flame retardant effect is significantly better than that of the composite material components prepared in Comparative Examples 1-3 and Comparative Example 4. It can be seen that the synergistic combination of fiber preform and injection resin can effectively provide flame retardancy and thermal stability of the material.

[0230] The composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of this invention, as well as Comparative Example 4, were subjected to mechanical property testing. The sample dimensions for the mechanical property testing were 100mm × 40mm × 3mm. A universal tensile testing machine was used to test the shear strength and tensile strength of the samples. (Table 2 and...) Figure 4 The mechanical property test results of the composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of the present invention and Comparative Example 4 are shown.

[0231] Table 2

[0232]

[0233] As can be seen from Table 2, compared with the composite material components prepared in Comparative Examples 1-3 and Comparative Example 4, the composite material components prepared in Examples 1-5 of the present invention can better eliminate the disadvantages such as low interlaminar shear strength and poor damage resistance caused by interlaminar weakness. It can be seen that the 2.5D braided interlaminar interlocking structure significantly improves the interlaminar shear strength and tensile strength of the material.

[0234] The composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of this invention, as well as Comparative Example 4, were subjected to electromagnetic shielding performance tests. The sample dimensions for the electromagnetic shielding performance test were 100mm × 100mm × 2mm, the shielding cavity size was 1.5m × 1.5m × 1.5m, and the frequency was 10-18GHz. (Table 3 and...) Figure 5 The composite material components prepared in Examples 1-5 and Comparative Examples 1-3 of the present invention are shown, and the electromagnetic shielding performance test results of Comparative Example 4 are also shown.

[0235] Table 3

[0236]

[0237]

[0238] As can be seen from Table 3, compared with the composite material components prepared in Comparative Examples 1-3 and Comparative Example 4, the composite material components prepared in Examples 1-5 of this invention contain highly conductive fibers and modified graphene in the fiber preform, resulting in significantly higher electromagnetic shielding effectiveness than the comparative examples. Therefore, this invention is applicable to scenarios such as 5G communication equipment.

[0239] In summary, this invention provides a composite material component and manufacturing method based on 2.5D weaving and RTM injection molding. In the embodiments of this invention, the composite material component consists of a fiber preform and injection resin. The fiber preform is preformed based on 2.5D weaving technology. The fiber preform is synergistically formed by silicon carbide fiber, glass fiber, and modified graphene, and is fully impregnated with silicon carbide fiber, glass fiber, and modified graphene based on steam explosion. This optimizes fiber dispersion while ensuring sufficient impregnation of the subsequent injection resin. This effectively overcomes the problem in the prior art where the 2.5D woven fabric is not fully impregnated when the glue is injected into the mold to obtain the fabric blank, resulting in residual air bubbles inside the fiber bundle, causing dry spot effect and affecting the interfacial bonding strength and stability of the material. The fiber preform and injection resin based on RTM injection molding process realize the manufacturing of high-performance composite material components. Moreover, the prepared composite material components not only have excellent mechanical properties and thermal stability, but also good electromagnetic shielding performance and weather resistance.

[0240] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0241] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A composite material component based on 2.5D braiding and RTM injection molding, characterized in that, The composite material component includes a fiber preform, injection resin, binder, and curing agent. The fiber preform is preformed based on 2.5D weaving technology, and the injection resin, binder, and curing agent are injected into an injection mold containing the fiber preform using RTM injection technology and cured to form the composite material component.

2. The composite material component based on 2.5D braiding and RTM injection manufacturing as described in claim 1, characterized in that: The fiber preform comprises the following raw materials in parts by weight: 50-80 parts silicon carbide fiber, 10-20 parts glass fiber, 2-10 parts modified graphene, 100-200 parts soaking solution, 2-15 parts sizing agent, and 10-15 parts polylactic acid.

3. The composite material component based on 2.5D braiding and RTM injection manufacturing as described in claim 2, characterized in that: The soaking solution comprises silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent, with a volume ratio of silica sol, epoxy emulsion, anhydrous ethanol, and silane coupling agent of 1:2:3:

1. The sizing agent comprises epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester, with a volume ratio of epoxy modified silicone oil, tetrabutyl titanate, polyimide, polycarbosilane, and organoboronic acid ester of 5:1:6:4:

5. The method for preparing the sizing agent includes: Take polyimide and polycarbosilane solutions and place them in a reaction vessel and stir for 10-15 minutes at a mixing temperature of 60-70℃. After stirring, let stand for 20 minutes to obtain the solution before sizing. Anhydrous ethanol and tetrabutyl titanate were mixed in a volume ratio of 5:1 and stirred in a magnetic stirrer for 10 min at a stirring speed of 200-250 rpm to obtain a tetrabutyl titanate solution. At the same time, deionized water, glacial acetic acid and anhydrous ethanol were mixed in a volume ratio of 4:1:10 to obtain a sizing drop solution. The sizing drop solution and tetrabutyl titanate solution were taken in a volume ratio of 1:

2. The sizing drop solution was added dropwise to the tetrabutyl titanate solution at a drop rate of 2 mL / min while maintaining the temperature at 4-5℃. After the addition was completed, the mixture was stirred for 1 h. Then, 0.01 times the volume of the sizing drop solution of acetylacetone was added to the tetrabutyl titanate solution, and the mixture was stirred for another 2 h to obtain a tetrabutyl titanate modified solution. Epoxy-modified silicone oil and organoboroester were mixed and stirred at 45°C for 10-15 minutes. Then, the pre-sizing solution and tetrabutyl titanate modified liquid were added. The mixture was ultrasonically treated with a 300W ultrasonic generator for 10-12 minutes, stirred for 30 minutes, and cooled to room temperature to obtain the sizing agent.

4. The composite material component based on 2.5D braiding and RTM injection manufacturing as described in claim 2, characterized in that: The method for preparing the fiber preform includes: Silicon carbide fiber and glass fiber were immersed in soaking solution and treated at 55-65℃ for 40-45 min. Then, 0.05 times the volume of soaking solution of 0.3 mol / L triethanolamine was added dropwise to the soaking solution and stirred in a water bath at 55℃ for 2 h to obtain fiber premix. The fiber premix was pre-oxidized at 120-150℃ for 3 hours, and then ultrasonically treated for 20-25 minutes. Modified graphene and fiber premix are loaded into a blasting vessel, saturated steam at 180°C is introduced into the blasting vessel, and then the blasting vessel is pressurized to 0.7 MPa. After steam blasting treatment for 10-12 minutes, the blasting vessel is depressurized within 0.1-0.5 seconds. Remove silicon carbide fibers and glass fibers, place them in a vacuum drying oven at 50-55℃ and dry for 20-25 minutes, then immerse them in a polylactic acid and acetone solution for 20 minutes to set the shape. The volume ratio of polylactic acid and acetone solution is 1:10-15. The sizing agent was sprayed onto the surface of silicon carbide fiber and glass fiber using a spinneret. The spraying was repeated three times, with an interval of 10-15 minutes between each spraying. Using silicon carbide fiber as warp and glass fiber as weft, finite element analysis was performed on the fiber preform. The unit cell structure of the fiber preform was subjected to three-directional periodic boundary conditions through the finite element model to simulate and predict the mechanical behavior of the material and determine the warp and weft yarn arrangement paths. The warp density was 50-60 yarns / cm and the weft density was 40-50 yarns / cm. The weft yarn is laid along the bottom plate of the multi-harness loom, and the warp yarn passes through the weft yarn in the Z direction. The yarns are hooked together in a figure-eight pattern and stacked repeatedly to obtain a fiber preform for later use.

5. The composite material component based on 2.5D braiding and RTM injection manufacturing as described in claim 4, characterized in that: The modified graphene comprises the following raw materials by weight percentage: 70% graphene oxide; Nano zinc oxide: 2%; Gelatin: 3%; Citric acid: 2%; Epoxidized soybean oil: 15%; Ammonium tripolyphosphate: 8%; The method for preparing the modified graphene includes: A zinc acetate to ethylene glycol solution with a mass ratio of 0.8:1 was taken and stirred in a water bath at 75°C for 1.2 h. Then, a sodium hydroxide aqueous solution with a mass ratio of 0.2 times that of ethylene glycol was added dropwise to the zinc acetate to ethylene glycol solution. The mixture was stirred at 75°C for 3 h. The mixture was then placed in a reaction vessel and hydrothermally mixed at 160°C for 18 h. The mixture was washed three times with anhydrous ethanol, dried in a vacuum drying oven, ground and sieved to obtain nano zinc oxide. Graphene oxide was dispersed in 7 times its volume of deionized water and ultrasonically treated for 25-30 min to obtain a graphene dispersion. Citric acid and epoxidized soybean oil were then added to the graphene dispersion. The graphene dispersion containing citric acid and epoxidized soybean oil was stirred at 75°C for 1.5 h to obtain a soybean oil-graphene mixture. Place ammonium tripolyphosphate in deionized water at 50℃ and stir at 100-120 rpm for 10 minutes. Then add gelatin and mix. Continue heating for 10 minutes to obtain a gelatin solution. Mix the soybean oil-graphene mixture with the gelatin solution at 200-220 rpm for 2 hours to obtain a gelatin-graphene mixture. Nano-zinc oxide was dispersed in 20 times its volume of ethanol and stirred for 15 min. Then it was mixed with a gelatin-graphene mixture, ultrasonicated for 20 min, and dried in a vacuum drying oven at 55℃ for 2 h to obtain modified graphene.

6. The composite material component based on 2.5D braiding and RTM injection manufacturing as described in claim 1, characterized in that: The injection resin comprises the following raw materials in parts by weight: 40-50 parts polyurethane acrylate, 10-15 parts epoxy acrylate, 2-6 parts ammonium tripolyphosphate, 2-5 parts hollow glass microspheres, 2-5 parts ultraviolet absorber, and 2-8 parts photoinitiator.

7. The composite material component based on 2.5D braiding and RTM injection manufacturing as described in claim 6, characterized in that: The method for preparing the injection resin includes: Mix ammonium tripolyphosphate with 5 times its volume of anhydrous ethanol, stir for 10 minutes, then ball mill the mixture. Finally, dry the milled liquid in a vacuum drying oven at 60°C for later use. Hollow glass microspheres were placed in a round-bottom flask, and anhydrous ethanol with a volume 10 times that of the hollow glass microspheres was added to the flask. The mixture was stirred for 5 minutes at a speed of 200-240 rpm. Then, 0.2 times the volume of anhydrous ethanol was added to the silane coupling agent KH-570. The temperature was raised to 50-55℃. The hollow glass microspheres were then removed and placed in an oven and dried with warm air at 45℃ for 20 minutes to obtain activated hollow glass microspheres. Polyurethane acrylate and epoxy acrylate were placed in a vacuum drying oven and dried at 40°C for 4 hours to obtain the mixed resin matrix. The resin matrix was placed in a 60℃ water bath and stirred for 20 minutes. Then, hollow glass microspheres, ammonium tripolyphosphate, and the resin matrix were stirred and mixed in a mixer at a speed of 2000-2200 rpm for 20 minutes. Ultraviolet absorber and photoinitiator were then added to the mixer. The mixer speed was adjusted to 100 rpm and the temperature was 90℃. After vacuum degassing, the composite melt was cooled to room temperature. The composite melt was pulverized into particles and dried in a 50℃ vacuum drying oven for 2 hours to obtain the injection resin.

8. The composite material component based on 2.5D braiding and RTM injection manufacturing as described in claim 7, characterized in that: The photoinitiator includes photoinitiator TPO and hindered amine light stabilizer HALS.

9. A method for manufacturing composite material components based on 2.5D braiding and RTM injection as described in any one of claims 1-8, characterized in that: The method for manufacturing composite material components based on 2.5D braiding and RTM injection molding includes: After polishing the surface of the injection mold, a release agent is applied. The injection mold is then preheated to 50-60℃. An adhesive is applied to the surface of the fiber preform, and the fiber preform is pre-laid inside the injection mold, ensuring that the fiber preform remains flat. A vacuum pump is used to connect the resin tank and the curing agent tank respectively. The injection resin and curing agent are simultaneously pumped into the injection mold at an injection pressure of 0.8-1.0MPa and an injection speed of 8-10mL / min. The injection resin and curing agent mixture in the injection cavity is pre-irradiated with UV, and the injection mold temperature is maintained at 80℃ for 10min. The mold cavity of the injection mold is heated to 95°C, and the fiber preform and injection resin are pre-cured for 20 minutes under nitrogen atmosphere. The mold cavity is then heated to 120°C and held for 40 minutes to obtain the composite material component. After the mold cavity cools naturally to room temperature, the injection mold is opened, and compressed air is used to blow the mold for 5 minutes. The composite material component is then laser-cut to remove burrs, resulting in the finished composite material component.

10. The method for manufacturing composite material components based on 2.5D braiding and RTM injection molding as described in claim 9, characterized in that: The curing agent is methyltetrahydrophthalic anhydride, and the adhesive is a mixture of KH-570 and epoxy resin E-51, with a volume ratio of KH-570 to epoxy resin E-51 of 2:1.

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