A boron carbide-modified epoxy resin composite material and its preparation method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-13
- Publication Date
- 2026-08-14
AI Technical Summary
[0004]针对现有技术的不足，本发明提供了一种碳化硼改性环氧树脂复合材料及其制备方法，解决了现有技术中存在的碳化硼与环氧树脂界面相容性差、填料团聚严重、体系黏度过高的问题
1、本发明通过对碳化硼填料依次进行表面活化、聚多巴胺沉积和硅烷偶联二次接枝改性，在碳化硼颗粒表面构建了具有较强附着能力和反应活性的多级界面层。其中，表面活化处理能够去除颗粒表面杂质并提高表面活性，聚多巴胺层能够在碳化硼表面形成稳定包覆并提供丰富官能团，硅烷偶联层则进一步增强无机填料与有机环氧基体之间的界面结合，可显著改善碳化硼与环氧树脂之间的相容性和界面结合强度，减少界面脱粘和填料脱落现象，提高复合材料的结构稳定性、耐磨性能及长期服役可靠性。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer composite materials technology, specifically to a boron carbide modified epoxy resin composite material and its preparation method. Background Technology
[0002] Epoxy resins are a widely used class of thermosetting resin materials, possessing high adhesive strength, good mechanical properties, excellent electrical insulation properties, and good chemical corrosion resistance. They have significant application value in adhesives, coatings, electronic packaging, structural composite materials, potting materials, and functional protective materials. With the development of high-end equipment, special protection, wear-resistant components, and functionalized resin-based materials, single epoxy resin systems are no longer sufficient to meet higher-level application requirements in terms of hardness, wear resistance, scratch resistance, thermal stability, and specific functionalities. Therefore, modifying epoxy resins with high-performance inorganic fillers has become an important technological direction in this field.
[0003] In existing technologies, boron carbide is considered an ideal inorganic functional filler for epoxy resin modification due to its high hardness, low density, excellent wear resistance, good thermal stability, and strong neutron absorption capacity. Existing techniques typically involve directly adding boron carbide powder to epoxy resin via mechanical stirring, or first subjecting boron carbide to simple acid washing and coupling agent surface treatment before compounding with the resin, aiming to improve the material's hardness, wear resistance, and functional protective capabilities. However, in practical applications, boron carbide has a strong chemical inertness and limited interfacial compatibility with organic resins, resulting in weak interfacial bonding. Simultaneously, fine particles, especially nano-sized boron carbide, are prone to agglomeration, making it difficult to achieve stable and uniform dispersion when mixed into high-viscosity epoxy systems. As the filler content increases, the system viscosity increases significantly, easily introducing air bubbles and affecting degassing and molding. Boron carbide has a relatively high density, which may lead to sedimentation and stratification before curing. Furthermore, simply introducing rigid inorganic fillers often increases the material's brittleness, making it difficult to achieve a balance between hardness, wear resistance, and toughness in the composite system. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a boron carbide-modified epoxy resin composite material and its preparation method, which solves the problems of poor interfacial compatibility between boron carbide and epoxy resin, severe filler agglomeration, and excessively high system viscosity in existing technologies.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a boron carbide modified epoxy resin composite material, comprising the following raw materials by weight percentage: epoxy resin 45-75%, modified boron carbide composite filler 10-30%, reactive diluent 2-8%, toughening agent 3-10%, thixotropic anti-settling agent 0.2-1.5%, dispersant 0.1-2%, and curing agent and curing accelerator added according to the stoichiometric ratio of epoxy resin; The modified boron carbide composite filler is composed of micron-sized boron carbide and nano-sized boron carbide, and the surface of the modified boron carbide composite filler is sequentially provided with a polydopamine layer and a silane coupling modification layer.
[0006] Preferably, in the modified boron carbide composite filler, micron-sized boron carbide accounts for 80-95% of the total mass of the modified boron carbide composite filler, and nano-sized boron carbide accounts for 5-20% of the total mass of the modified boron carbide composite filler; the average particle size of the micron-sized boron carbide is 1-10 μm, and the average particle size of the nano-sized boron carbide is 50-200 nm.
[0007] Preferably, the epoxy resin is any one or a combination of bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin, or alicyclic epoxy resin; the reactive diluent is any one or a combination of butyl glycidyl ether, phenyl glycidyl ether, or C12-C14 alkyl glycidyl ether; the toughening agent is any one or a combination of carboxyl-terminated liquid nitrile rubber, core-shell rubber particles, or polyurethane toughening agent; and the thixotropic anti-settling agent is any one or a combination of fumed silica, organobentonite, or modified urea rheology modifiers.
[0008] Preferably, the silane coupling modified layer is formed of γ-glycidoxypropyltrimethoxysilane and / or γ-aminopropyltriethoxysilane; the curing agent is any one or more combinations of aliphatic amine curing agents, alicyclic amine curing agents, acid anhydride curing agents, or polyamide curing agents; and the curing accelerator is any one or more combinations of imidazole accelerators, tertiary amine accelerators, or organophosphorus accelerators.
[0009] This invention also provides a method for preparing boron carbide-modified epoxy resin composite material, comprising the following steps: S1. Mix micron-sized boron carbide and nano-sized boron carbide and dry them to obtain composite boron carbide filler; S2. The composite boron carbide filler is placed in an activation solution for surface activation treatment, and then washed until neutral and dried. S3. The activated composite boron carbide filler is added to a dopamine solution to carry out a self-polymerization reaction, so that a polydopamine layer is formed on its surface, followed by washing and drying. S4. The composite boron carbide filler treated with polydopamine is added to a pre-hydrolyzed silane coupling agent solution for secondary grafting modification. After treatment, it is dried to obtain the modified boron carbide composite filler. S5. The modified boron carbide composite filler is added to a low-viscosity medium containing an active diluent and / or a dispersant, and pre-wetting and dispersion treatment is performed to obtain a filler dispersion slurry. S6. Mix epoxy resin, reactive diluent, toughening agent and thixotropic anti-settling agent to obtain epoxy premix system; S7. The filler dispersion slurry is added to the epoxy premix system, and the mixture is mixed, dispersed and degassed under vacuum conditions to obtain a composite slurry; S8. Add curing agent and curing accelerator to the composite slurry, mix and then perform secondary vacuum degassing; S9. The degassed material is molded and cured by stepwise heating to obtain boron carbide modified epoxy resin composite material.
[0010] Preferably, in step S1, the drying temperature is 80-110°C and the drying time is 4-8 hours.
[0011] Preferably, in step S2, the activation solution is a dilute hydrochloric acid solution, a dilute nitric acid solution, or an aqueous hydrogen peroxide solution, the activation temperature is room temperature to 50°C, and the activation time is 0.5 to 2 hours; in step S3, the dopamine solution is prepared using Tris buffer solution, the solution pH is 8.0 to 8.8, the dopamine concentration is 1 to 5 g / L, and the self-polymerization reaction time is 2 to 8 hours.
[0012] Preferably, in step S4, the silane coupling agent solution is prepared using an ethanol / water mixed solution, with a volume ratio of ethanol to water of (80-95):(5-20), the amount of silane coupling agent used is 1-4% of the mass of the composite boron carbide filler, the pH of the pre-hydrolyzed solution is 4-5, the pre-hydrolyzed time is 20-40 min, the secondary grafting modification time is 1-3 h, and the drying temperature is 100-110℃.
[0013] Preferably, in step S5, the low-viscosity medium includes any one or more combinations of an active diluent, a dispersant, and an organic solvent, wherein the organic solvent is ethanol, acetone, or isopropanol; the pre-wetting time is 10–20 min; the dispersion treatment employs high-speed shear dispersion combined with ultrasonic-assisted dispersion, with the high-speed shear dispersion time being 20–60 min and the ultrasonic-assisted dispersion time being 5–20 min; in step S7, the vacuum mixing dispersion employs a vacuum planetary mixer, with a mixing time of 20–60 min, a vacuum degree of -0.08 to -0.098 MPa, and the system temperature not exceeding 65°C during the mixing process.
[0014] Preferably, in step S6, the preheating temperature of the epoxy resin is 40-60℃, the amount of toughening agent added is 3-12% of the mass of the epoxy resin, and the amount of thixotropic anti-settling agent added is 0.2-2% of the total mass of the epoxy premix system; in step S8, after adding the curing agent and curing accelerator, the mixture is mixed at low speed and low shear for 5-15 minutes, the secondary vacuum degassing time is 5-20 minutes, and the temperature of the composite slurry before mixing is controlled at 35-45℃; the stepwise temperature-increasing curing in step S9 includes the following stages: holding at 50-60℃ for 1-3 hours, holding at 70-90℃ for 1-3 hours, and holding at 100-130℃ for 2-4 hours.
[0015] This invention provides a boron carbide-modified epoxy resin composite material and its preparation method. It has the following beneficial effects: 1. This invention constructs a multi-level interfacial layer with strong adhesion and reactivity on the surface of boron carbide particles by sequentially performing surface activation, polydopamine deposition, and silane coupling secondary grafting modification on the boron carbide filler. Specifically, the surface activation treatment removes impurities from the particle surface and improves surface activity; the polydopamine layer forms a stable coating on the boron carbide surface and provides abundant functional groups; and the silane coupling layer further enhances the interfacial bonding between the inorganic filler and the organic epoxy matrix. This significantly improves the compatibility and interfacial bonding strength between boron carbide and epoxy resin, reduces interfacial debonding and filler detachment, and enhances the structural stability, wear resistance, and long-term service reliability of the composite material.
[0016] 2. This invention employs a dual-scale blend of micron-sized and nano-sized boron carbide, combined with low-viscosity medium pre-wetting, high-speed shear dispersion, resin transfer dispersion, and vacuum mixing and degassing processes. This ensures that the boron carbide filler possesses good wettability and initial dispersion before entering the epoxy system. Simultaneously, the synergistic filling effect between particles of different sizes reduces the agglomeration tendency of a single fine-particle system. This effectively improves the uniformity of filler dispersion in epoxy resin, reducing internal defects and localized stress concentrations within the system.
[0017] 3. This invention improves the system's fluidity, formability, and curing stability by introducing reactive diluents, toughening agents, and thixotropic anti-settling agents into the epoxy system, combined with a stepwise temperature-curing process, while ensuring a high filler content. The reactive diluent reduces the viscosity of the composite system, facilitating mixing, transport, and molding; the toughening agent helps absorb crack propagation energy, mitigating the embrittlement tendency caused by rigid fillers; and the thixotropic anti-settling agent, working in conjunction with the stepwise curing process, inhibits the settling and delamination of boron carbide before curing. This allows for improvements in material hardness, wear resistance, and modulus while maintaining toughness, processability, and uniformity in thick parts. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the preparation process of the present invention. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1
[0020] like Figure 1 As shown, this embodiment of the invention provides a method for preparing boron carbide-modified epoxy resin composite material, comprising the following steps: S1. Preparation of modified boron carbide composite filler Take 90g of micron-sized boron carbide with an average particle size of 5μm and 10g of nano-sized boron carbide with an average particle size of 100nm. Place the two in a clean mixing container and premix for 10min. Then transfer them to a forced-air drying oven and dry at 100℃ for 6h to remove surface adsorbed water and ambient moisture, thus obtaining pretreated composite boron carbide filler.
[0021] Prepare 500 mL of a 3 wt% hydrogen peroxide aqueous solution, add the pretreated composite boron carbide filler to the solution, and mechanically stir at 40 °C for 1 h to perform surface activation treatment. After treatment, separate the solid by vacuum filtration, and then wash repeatedly with deionized water until the pH of the filtrate is close to neutral. The washed powder is then dried in a 90 °C oven for 4 h to obtain the activated composite boron carbide filler.
[0022] Tris buffer solution was prepared and the pH was adjusted to 8.5. Dopamine hydrochloride was added to the buffer solution to prepare 500 mL of a 2 g / L dopamine solution. The activated composite boron carbide filler was added to the dopamine solution and stirred continuously at room temperature for 4 h to allow dopamine to self-polymerize and deposit on the boron carbide surface, forming a polydopamine layer. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried at 80 °C for 4 h to obtain a composite boron carbide filler coated with polydopamine.
[0023] Prepare 400 mL of a mixed solution of ethanol / water at a volume ratio of 90:10. Add KH-560 to the solution at a concentration of 2.5 wt% of the composite boron carbide filler. Adjust the pH of the system to 4.5 with glacial acetic acid and allow it to stand for hydrolysis for 30 min to obtain a pre-hydrolyzed silane coupling agent solution. Add the polydopamine-treated composite boron carbide filler to this solution and stir at room temperature for 2 h for secondary grafting modification. After the reaction is complete, filter the solution and dry the solid at 105 °C for 3 h to obtain the modified boron carbide composite filler.
[0024] S2. Preparation of epoxy premixed system Take 60 parts of E-51 bisphenol A type epoxy resin and add it to a reaction vessel equipped with a stirrer. Preheat the mixture at 50°C. Add 5 parts of butyl glycidyl ether as an active diluent, 6 parts of carboxyl-terminated liquid nitrile rubber as a toughening agent, 0.8 parts of fumed silica as a thixotropic anti-settling agent, and 0.5 parts of dispersant. Stir at low speed for 15 minutes and then at medium speed for 20 minutes to obtain a homogeneous epoxy premix system.
[0025] S3. Preparation and composite mixing of filler dispersion slurry Take 20 parts of the above modified boron carbide composite filler and add them to a low-viscosity medium composed of a portion of active diluent and dispersant. First, pre-wet at low speed for 15 minutes, and then disperse at a suitable speed for 30 minutes using a high-speed shear machine to form a uniform filler dispersion slurry.
[0026] The filler dispersion slurry was slowly added to the epoxy premix system, and a vacuum planetary mixer was used for mixing, dispersion and degassing. The vacuum degree was controlled at -0.095MPa, the mixing time was 40min, and the system temperature was controlled not to exceed 60℃ to obtain a uniform composite slurry.
[0027] S4. Curing and Molding Cool the composite slurry to 40°C, add an alicyclic amine curing agent that matches the epoxy equivalent, and add 0.3 parts of imidazole curing accelerator. Stir at low speed for 10 minutes to ensure uniform dispersion of the curing components.
[0028] After adding the slurry to the curing system, vacuum degassing was performed again for 10 minutes. Then, the slurry was poured into a mold that had been cleaned and coated with a release agent.
[0029] Curing was performed according to the following procedure: holding at 60℃ for 2 hours, holding at 80℃ for 2 hours, and holding at 120℃ for 3 hours. After curing, the mixture was cooled to room temperature in the oven and demolded to obtain the boron carbide modified epoxy resin composite material.
[0030] The composite material prepared using this embodiment has a uniform appearance and no obvious bubbles, delamination, or filler sedimentation. Cross-sectional observation shows that boron carbide is evenly distributed and the interface is tightly bonded. The material has good hardness, wear resistance, and comprehensive mechanical properties. Example 2
[0031] This invention provides a method for preparing boron carbide modified epoxy resin composite material. This embodiment is basically the same as Example 1, except that the filler ratio, modification conditions, and the amount of some components are adjusted as follows: Take 85g of micron-sized boron carbide with an average particle size of 3μm and 15g of nano-sized boron carbide with an average particle size of 80nm, and dry them at 90℃ for 6h.
[0032] The activation solution used was 0.5 mol / L dilute nitric acid solution, the treatment temperature was room temperature, and the treatment time was 1.5 h; after washing until neutral, it was dried at 85℃ for 5 h.
[0033] The dopamine solution concentration was 3 g / L, the pH was 8.3, the self-polymerization reaction time was 6 h, and the drying temperature was 75 °C.
[0034] The silane coupling agent used was a mixture of KH-560 and KH-550, with a total addition amount of 3 wt% of the composite boron carbide filler. The ethanol / water volume ratio was 85:15, the pH of the pre-hydrolyzed solution was 4.2, the pre-hydrolyzed time was 35 min, the grafting reaction time was 2.5 h, and the drying temperature was 105 ℃.
[0035] The epoxy resin is a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, totaling 58 parts; 6 parts of reactive diluent are added; 8 parts of core-shell rubber particles are used as toughening agent; 0.6 parts of organic bentonite are used as thixotropic anti-settling agent; and 0.8 parts of dispersant are used.
[0036] The modified boron carbide composite filler was added in an amount of 25 parts, pre-wetted for 20 min, high-speed sheared dispersion for 40 min, and then ultrasonically dispersed for 10 min.
[0037] The vacuum mixing time was 50 min, the vacuum degree was -0.09 MPa, and the system temperature was controlled below 65℃.
[0038] The curing agent is an acid anhydride-based curing agent, and the accelerator is a tertiary amine-based accelerator; the curing process is to keep the temperature at 50℃ for 3 hours, at 85℃ for 2 hours, and at 125℃ for 3 hours.
[0039] The composite material obtained in this embodiment also has good molding quality and uniform filler distribution, making it suitable for thick parts and potting applications. Example 3
[0040] This invention provides a method for preparing boron carbide modified epoxy resin composite material. The process of this embodiment is basically the same as that of Embodiment 1, with the following specific differences: The mass ratio of micron-sized boron carbide to nano-sized boron carbide was set to 95:5, wherein the average particle size of the micron-sized boron carbide was 8 μm and the average particle size of the nano-sized boron carbide was 150 nm. After mixing, the mixture was dried at 110 °C for 4 h.
[0041] The activation solution was prepared by using a 2wt% dilute hydrochloric acid solution, treated at 30℃ for 1 hour, washed until neutral, and then dried at 100℃ for 3 hours.
[0042] The dopamine solution was prepared using a Tris buffer system with a pH of 8.8, a dopamine concentration of 1 g / L, a self-polymerization reaction time of 2 h, and a drying temperature of 60 °C.
[0043] The silane coupling agent used was KH-550, and the amount added was 1.5 wt% of the composite boron carbide filler. The ethanol / water volume ratio was 95:5, the pH of the pre-hydrolysis solution was 4.8, the pre-hydrolysis was carried out for 20 min, the grafting reaction was carried out for 1 h, and the drying temperature was 100℃.
[0044] Take 65 parts of alicyclic epoxy resin, add 4 parts of phenyl glycidyl ether, 5 parts of polyurethane toughening agent, 1.0 part of modified urea rheology modifier, and 0.4 parts of dispersant. Mix at 50℃ for 30 min to obtain an epoxy premix system.
[0045] Add 15 parts of modified boron carbide composite filler to a low-viscosity medium, pre-wet for 10 min, and shear at high speed for 20 min to prepare a filler dispersion slurry.
[0046] The mixture was mixed for 30 minutes at -0.085 MPa using a dual planetary mixer and then degassed. The temperature was controlled below 55°C during the mixing process.
[0047] Add polyamide curing agent and organophosphorus accelerator, stir at low speed for 8 minutes, then degas for 8 minutes; pour into mold and cure according to the program of 55℃ / 2h, 75℃ / 2h, 110℃ / 4h, cool and demold.
[0048] The material obtained in this embodiment has good surface integrity and molding stability, indicating that the process parameters of the present invention have a good applicability range.
[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A boron carbide-modified epoxy resin composite material, characterized in that, The raw materials include the following by weight percentage: epoxy resin 45-75%, modified boron carbide composite filler 10-30%, reactive diluent 2-8%, toughening agent 3-10%, thixotropic anti-settling agent 0.2-1.5%, dispersant 0.1-2%, and curing agent and curing accelerator added according to the stoichiometric ratio of epoxy resin; The modified boron carbide composite filler is composed of micron-sized boron carbide and nano-sized boron carbide, and the surface of the modified boron carbide composite filler is sequentially provided with a polydopamine layer and a silane coupling modification layer.
2. The boron carbide-modified epoxy resin composite material according to claim 1, characterized in that, In the modified boron carbide composite filler, micron-sized boron carbide accounts for 80-95% of the total mass of the modified boron carbide composite filler, and nano-sized boron carbide accounts for 5-20% of the total mass of the modified boron carbide composite filler; the average particle size of the micron-sized boron carbide is 1-10 μm, and the average particle size of the nano-sized boron carbide is 50-200 nm.
3. The boron carbide-modified epoxy resin composite material according to claim 1, characterized in that, The epoxy resin is any one or a combination of bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin, or alicyclic epoxy resin; the reactive diluent is any one or a combination of butyl glycidyl ether, phenyl glycidyl ether, or C12-C14 alkyl glycidyl ether; the toughening agent is any one or a combination of carboxyl-terminated liquid nitrile rubber, core-shell rubber particles, or polyurethane toughening agent; the thixotropic anti-settling agent is any one or a combination of fumed silica, organobentonite, or modified urea rheology modifier.
4. The boron carbide-modified epoxy resin composite material according to claim 1, characterized in that, The silane coupling modified layer is formed of γ-glycidoxypropyltrimethoxysilane and / or γ-aminopropyltriethoxysilane; the curing agent is any one or more combinations of aliphatic amine curing agents, alicyclic amine curing agents, acid anhydride curing agents or polyamide curing agents; the curing accelerator is any one or more combinations of imidazole accelerators, tertiary amine accelerators or organophosphorus accelerators.
5. A method for preparing a boron carbide-modified epoxy resin composite material according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Mix micron-sized boron carbide and nano-sized boron carbide and dry them to obtain composite boron carbide filler; S2. The composite boron carbide filler is placed in an activation solution for surface activation treatment, and then washed until neutral and dried. S3. The activated composite boron carbide filler is added to a dopamine solution to carry out a self-polymerization reaction, so that a polydopamine layer is formed on its surface, followed by washing and drying. S4. The composite boron carbide filler treated with polydopamine is added to a pre-hydrolyzed silane coupling agent solution for secondary grafting modification. After treatment, it is dried to obtain the modified boron carbide composite filler. S5. The modified boron carbide composite filler is added to a low-viscosity medium containing an active diluent and / or a dispersant, and pre-wetting and dispersion treatment is performed to obtain a filler dispersion slurry. S6. Mix epoxy resin, reactive diluent, toughening agent and thixotropic anti-settling agent to obtain epoxy premix system; S7. The filler dispersion slurry is added to the epoxy premix system, and the mixture is mixed, dispersed and degassed under vacuum conditions to obtain a composite slurry; S8. Add curing agent and curing accelerator to the composite slurry, mix and then perform secondary vacuum degassing; S9. The degassed material is molded and cured by stepwise heating to obtain boron carbide modified epoxy resin composite material.
6. The method for preparing a boron carbide-modified epoxy resin composite material according to claim 5, characterized in that, In step S1, the drying temperature is 80–110℃ and the drying time is 4–8 hours.
7. The method for preparing a boron carbide-modified epoxy resin composite material according to claim 5, characterized in that, In step S2, the activation solution is a dilute hydrochloric acid solution, a dilute nitric acid solution, or an aqueous hydrogen peroxide solution, the activation temperature is room temperature to 50°C, and the activation time is 0.5 to 2 hours. In step S3, the dopamine solution is prepared using Tris buffer solution, the solution pH is 8.0 to 8.8, the dopamine concentration is 1 to 5 g / L, and the self-polymerization reaction time is 2 to 8 hours.
8. The method for preparing a boron carbide-modified epoxy resin composite material according to claim 5, characterized in that, In step S4, the silane coupling agent solution is prepared using an ethanol / water mixed solution with a volume ratio of ethanol to water of (80-95):(5-20). The amount of silane coupling agent used is 1-4% of the mass of the composite boron carbide filler. The pH of the pre-hydrolyzed solution is 4-5, the pre-hydrolyzed time is 20-40 min, the secondary grafting modification time is 1-3 h, and the drying temperature is 100-110℃.
9. The method for preparing a boron carbide-modified epoxy resin composite material according to claim 5, characterized in that, In step S5, the low-viscosity medium includes any one or more combinations of an active diluent, a dispersant, and an organic solvent, wherein the organic solvent is ethanol, acetone, or isopropanol; the pre-wetting time is 10–20 min; the dispersion treatment employs high-speed shear dispersion combined with ultrasonic-assisted dispersion, with the high-speed shear dispersion time being 20–60 min and the ultrasonic-assisted dispersion time being 5–20 min; in step S7, the vacuum mixing dispersion employs a vacuum planetary mixer, with a mixing time of 20–60 min and a vacuum degree of -0.08 to -0.098 MPa, and the system temperature during the mixing process does not exceed 65°C.
10. The method for preparing a boron carbide-modified epoxy resin composite material according to claim 5, characterized in that, In step S6, the preheating temperature of the epoxy resin is 40-60℃, the toughening agent is added at 3-12% of the epoxy resin mass, and the thixotropic anti-settling agent is added at 0.2-2% of the total mass of the epoxy premix system. In step S8, after adding the curing agent and curing accelerator, the mixture is mixed at low speed and low shear for 5-15 minutes, the secondary vacuum degassing time is 5-20 minutes, and the temperature of the composite slurry before mixing is controlled at 35-45℃. The stepwise temperature rise curing in step S9 includes the following stages: holding at 50-60℃ for 1-3 hours, holding at 70-90℃ for 1-3 hours, and holding at 100-130℃ for 2-4 hours.