Three-dimensional carbon fiber-reinforced resin-based composite material and preparation method therefor

Abstract

Disclosed in the present invention is a preparation method for a three-dimensional carbon fiber-reinforced resin-based composite material, comprising: by using a mesophase pitch carbon fiber cloth as an XY-direction reinforcement body and polyacrylonitrile-based carbon fibers as Z-direction reinforcement fibers to prepare a three-dimensional carbon fiber fabric reinforcement body; sequentially subjecting the three-dimensional carbon fiber fabric reinforcement body to graphitization, electrochemical treatment and surface sizing; dispersing inorganic nano thermally-conductive particles in an organic resin to obtain a matrix resin system; and placing the three-dimensional carbon fiber fabric reinforcement body in a mold, and injecting the matrix resin system by means of an RTM process to obtain the composite material. The composite material of the present invention has a thermal conductivity in the XY direction of 208-258 W / (m•K) and a thermal conductivity in the Z direction of 5-54 W / (m•K) at room temperature and also has excellent mechanical properties. Therefore, the composite material can be used for manufacturing structural / functional components of aerospace aircrafts, and can also meet the requirements of other industrial equipment fields for composite materials having light weight, high strength, high modulus and high thermal conductivity.

Description

A three-dimensional carbon fiber reinforced resin matrix composite material and its preparation method

[0001] This application claims priority to Chinese Patent Application No. 202411521846X, filed on October 29, 2024, entitled "A Three-Dimensional Carbon Fiber Reinforced Resin Matrix Composite Material and Its Preparation Method", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of resin-based composite materials technology, specifically relating to a method for preparing a three-dimensional high thermal conductivity carbon fiber reinforced resin-based composite material. Background Technology

[0003] Carbon fiber reinforced resin matrix composites possess a series of excellent properties such as high specific modulus, high specific strength, and easy molding, and are widely used in aerospace structures and load-bearing components of high-end industrial equipment. With the continuous expansion of applications, fields such as satellite space thermal management systems and electronic industrial heat sinks have created an urgent demand for lightweight, high-strength, and high-thermal-conductivity resin matrix composites. In carbon fiber reinforced resin matrix composites, carbon fibers are both the reinforcement and an important heat transfer carrier, directly affecting the final thermal conductivity of the composite material. Currently, resin composites prepared using high-strength polyacrylonitrile-based carbon fibers exhibit excellent mechanical properties, but their thermal conductivity is generally average. To improve the thermal conductivity of composite materials, highly thermally conductive mesophase pitch carbon fibers can be used in the preparation of the composite material.

[0004] Mesophase pitch-based carbon fiber is a crucial structural / functional fiber material produced from mesophase pitch through melt spinning, oxidative carbonization, and ultra-high temperature graphitization. Due to the highly oriented graphite crystal structure along the fiber axis, mesophase pitch-based carbon fiber possesses outstanding advantages such as high modulus, good stability, high thermal conductivity, low coefficient of thermal expansion, and the ability to produce zero-expansion products. In actual production of high thermal conductivity mesophase fibers, the heating process is categorized into precursor fibers (300-600℃), high-temperature carbonized fibers (1000-1600℃), and graphitized fibers (≥2800℃). Higher heating temperatures result in higher strength and modulus of the mesophase pitch fiber, but also increase the fiber's susceptibility to breakage and subsequent processing performance.

[0005] When resin-based composite materials are prepared directly using graphitized high thermal conductivity mesophase pitch carbon fibers, the high fiber modulus (≥800GPa) makes the fibers prone to damage and breakage during the preparation process. This severely affects the mechanical and thermal conductivity properties of the high thermal conductivity carbon fibers. As a result, although the prepared unidirectional or two-dimensional high thermal conductivity carbon fiber reinforced resin-based composite materials have high thermal conductivity in the unidirectional or XY plane, their thermal conductivity and mechanical properties in the thickness direction are low, making it difficult to meet the comprehensive performance requirements of high-end products for lightweight high thermal conductivity composite materials.

[0006] In summary, neither polyacrylonitrile-based carbon fiber nor mesophase pitch-based carbon fiber can simultaneously meet the comprehensive requirements of carbon fiber reinforced resin matrix composites for thermal conductivity, processability, and mechanical properties. Summary of the Invention

[0007] The purpose of this invention is to overcome the aforementioned defects and provide a three-dimensional carbon fiber reinforced resin matrix composite material and its preparation method, solving the technical problem that existing carbon fiber reinforced resin matrix composite materials cannot simultaneously possess high thermal conductivity, mechanical properties, and processing performance. The composite material obtained by this invention has a room temperature XY-direction thermal conductivity of 208–258 W / (m·K) and a Z-direction thermal conductivity of 5–54 W / (m·K), while also exhibiting excellent mechanical properties. It can be used to manufacture structural / functional components for aerospace vehicles and can also meet the needs of other industrial equipment fields for lightweight, high-strength, high-modulus, and high-thermal-conductivity composite materials.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0009] A method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material, comprising:

[0010] A three-dimensional carbon fiber fabric reinforcement was prepared by using carbon cloth woven from mesophase pitch carbon fiber as the XY axis reinforcement and polyacrylonitrile-based carbon fiber as the Z axis reinforcement fiber; the mesophase pitch carbon fiber was mesophase pitch carbon fiber that had undergone high-temperature carbonization treatment at 1000℃~1600℃.

[0011] The three-dimensional carbon fiber fabric reinforcement was graphitized.

[0012] The graphitized three-dimensional carbon fiber fabric reinforcement was placed in an alkaline electrolyte as a cathode for electrochemical treatment.

[0013] The electrochemically treated three-dimensional carbon fiber fabric reinforcement was impregnated with a sizing agent solution and then dried.

[0014] Inorganic thermally conductive nanoparticles are dispersed in an organic resin to obtain a matrix resin system.

[0015] The dried three-dimensional carbon fiber fabric reinforcement was placed in a mold and injected into the matrix resin system using the RTM process to obtain a three-dimensional carbon fiber reinforced resin matrix composite material.

[0016] Furthermore, the mesophase pitch carbon fiber treated with high-temperature carbonization at 1000℃~1600℃ has a carbon content of ≥98%, a tensile strength of ≥1200MPa, and a tensile modulus of ≥190GPa.

[0017] The polyacrylonitrile-based carbon fiber is one or more of the following: T300 grade high-strength carbon fiber, T700 grade high-strength carbon fiber, T800 grade high-strength carbon fiber, M40J grade high-strength high-modulus carbon fiber, or M55J grade high-strength high-modulus carbon fiber.

[0018] Furthermore, the carbon fiber fabric can be woven in one or more of the following forms: plain weave, satin weave, or twill weave.

[0019] Three-dimensional carbon fiber fabric reinforcements were prepared using a needle punching method;

[0020] The fiber volume content in the three-dimensional carbon fiber fabric reinforcement is 40% to 60%; the Z-axis needle-punching spacing is 2 mm to 6 mm.

[0021] Furthermore, the graphitization treatment is carried out at a temperature above 3000℃ for 1 to 2 hours, and the protective gas is nitrogen or argon.

[0022] Furthermore, the alkaline electrolyte is one or more of Ca(OH)2 or Ba(OH)2, and the concentration of the alkaline electrolyte is 0.1wt% to 2wt%; the anode is platinum, the DC voltage is 5V to 25V, the current is 0.1A to 1A, and the electrochemical treatment time is 5min to 10min.

[0023] Furthermore, the sizing agent includes one or more of epoxy sizing agents or phenolic sizing agents, the concentration of the sizing agent solution is 3wt% to 5wt%, and the soaking time is 1min to 30min.

[0024] Furthermore, the inorganic nano-thermal conductive particles are surface-treated in a silane coupling agent solution and then dispersed in an organic resin.

[0025] Inorganic nano-thermal conductive particles are carbon nanotubes or graphene;

[0026] The silane coupling agent is one or more of KH550 or KH560;

[0027] The organic resin is one or more of epoxy resin or phenolic resin; the epoxy resin includes one or more of 1,2-epoxycyclohexane-4,5-dicarboxylic acid diglycidyl ester or 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester; the phenolic resin includes one or more of high-carbon phenolic resin or barium phenolic resin.

[0028] The concentration of the silane coupling agent solution is 1 wt% to 3 wt%.

[0029] Furthermore, the matrix resin system comprises the following components in parts by weight:

[0030] Organic resin 100;

[0031] Inorganic nano-thermal conductive particles 0.5–3;

[0032] Solvent 30-60.

[0033] Furthermore, the matrix resin system was injected using the RTM process, and after solvent removal, heating and curing, and cooling and demolding, a three-dimensional carbon fiber reinforced resin matrix composite material was obtained.

[0034] When the organic resin is epoxy resin, the solvent in the matrix resin system is one or more of acetone or tetrahydrofuran, the curing agent is one or more of hexahydrophthalic anhydride or methylhexahydrophthalic anhydride, the mass fraction of the curing agent is 60 to 80 parts, the curing temperature is 100 to 200°C, and the curing time is 1 to 8 hours.

[0035] When the organic resin is phenolic resin, and the solvent in the matrix resin system is one or more of methanol or ethanol, the curing temperature is 120-200℃ and the curing time is 2-12 hours.

[0036] A three-dimensional carbon fiber reinforced resin matrix composite material is obtained by the above-mentioned preparation method of a three-dimensional carbon fiber reinforced resin matrix composite material.

[0037] Compared with the prior art, the present invention has at least one of the following advantages:

[0038] (1) The present invention uses two-dimensional carbon cloth woven from mesophase pitch carbon fiber and three-dimensional weaving of polyacrylonitrile-based carbon fiber, and graphitization treatment to ensure the high mechanical properties and thermal conductivity of the reinforcement.

[0039] (2) The present invention electroplats high thermal conductivity mesophase pitch carbon fiber with alkaline electrolyte to generate a large number of barbed inorganic salts on the carbon fiber surface, which significantly increases the surface area of ​​the carbon fiber and can combine with the resin matrix to form mechanical anchoring, significantly improving the mechanical and thermal conductivity properties of the composite material.

[0040] (3) The present invention uses silane coupling agent to treat inorganic nano thermally conductive particles, so that the inorganic nano thermally conductive particles are uniformly dispersed in the organic resin matrix, which can effectively improve the thermal conductivity of the matrix resin. Combined with three-dimensional carbon fiber fabric reinforcement, a multi-scale thermally conductive network is constructed, which is conducive to the full play of the thermal and mechanical properties of composite materials in the XY and Z directions.

[0041] (4) The present invention uses the RTM process to prepare three-dimensional carbon fiber reinforced resin matrix composite material with high thermal conductivity. The process is mature and simple, the resin is uniformly dispersed, and the thermal conductivity and mechanical properties are excellent. It is suitable for the structure / functional components of advanced equipment such as aerospace vehicles. Attached Figure Description

[0042] Figure 1 is a flowchart of the preparation process of the three-dimensional high thermal conductivity carbon fiber reinforced resin matrix composite material of the present invention.

[0043] Figure 2 is an electron microscope image of the surface microstructure of high thermal conductivity mesophase pitch carbon fiber after electrochemical treatment according to the present invention. Detailed Implementation

[0044] The features and advantages of the present invention will become clearer and more explicit from the following detailed description.

[0045] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0046] This invention provides a method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material with high thermal conductivity. The carbon fiber composite material prepared by this method not only has high thermal conductivity in both the XY and Z directions, but also excellent comprehensive mechanical properties. This invention first uses high-temperature carbonized mesophase pitch carbon fibers to weave a two-dimensional carbon cloth in the XY direction, and then uses polyacrylonitrile-based carbon fibers as Z-direction reinforcing fibers to needle-weave a three-dimensional carbon fiber fabric reinforcement. Graphitization treatment is then performed to give the three-dimensional carbon fiber fabric high thermal conductivity, solving the problem that it is difficult to weave a three-dimensional fabric reinforcement and that fiber damage is excessive when directly using high-modulus, high-thermal-conductivity carbon fibers. Next, the three-dimensional high-thermal-conductivity mesophase pitch carbon fiber fabric is used as a cathode in an alkaline electrolyte for electroplating treatment, generating a large number of barbed inorganic salts on the surface, as shown in Figure 2. This significantly increases the surface area of ​​the carbon fibers, which combine with the resin to form mechanical anchoring, improving... The mechanical and thermal conductivity properties of the composite material were improved. Sizing treatment further enhanced the interfacial bonding between the highly inert surface of the high thermal conductivity mesophase pitch carbon fiber and the resin matrix. Simultaneously, inorganic nano-thermal conductive particles were treated with a silane coupling agent and uniformly dispersed in the organic resin matrix to improve the thermal conductivity of the matrix resin. Finally, a three-dimensional high thermal conductivity carbon fiber reinforced resin matrix composite material with good surface quality was prepared using the RTM process. The composite material, which constructs a multi-scale thermal conductive network, exhibits high thermal conductivity and mechanical properties in both the XY and Z directions. It can be used to prepare structural / functional components for aerospace vehicles and can also meet the needs of other industrial equipment fields for lightweight, high-strength, high-modulus, and high thermal conductivity composite materials.

[0047] As shown in Figure 1, the present invention discloses a method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material with high thermal conductivity. 1) First, mesophase pitch carbon fibers treated with high-temperature carbonization at 1000℃~1600℃ are woven into carbon cloth as XY-axis reinforcement, and polyacrylonitrile-based carbon fibers are used as Z-axis reinforcement fibers (in this invention, XYZ axes are three mutually perpendicular directions). The three-dimensional carbon fiber fabric reinforcement is prepared by needle punching technology; 2) Then, the three-dimensional carbon fiber fabric reinforcement is placed in a graphitization furnace for ultra-high temperature graphitization treatment above 3000℃, and then placed in an alkaline environment. Electrochemical treatment was performed in an electrolyte, and finally the material was immersed in a sizing agent solution of a certain concentration. After drying, a three-dimensional high thermal conductivity carbon fiber fabric reinforcement was obtained. 3) At the same time, inorganic nano-thermal conductive particles were dispersed in a silane coupling agent solution for surface treatment. After drying, they were dispersed in an organic resin solution to obtain a matrix resin system. 4) Finally, the three-dimensional high thermal conductivity carbon fiber fabric reinforcement was placed in a mold, and the matrix resin system was injected using the RTM process. The solvent was removed, the material was heated and cured, and then cooled and demolded to prepare a three-dimensional high thermal conductivity carbon fiber reinforced resin matrix composite material.

[0048] In one specific embodiment, the carbon content of the mesophase pitch carbon fiber treated with high-temperature carbonization at 1000-1600℃ is ≥98%, the tensile strength is ≥1200MPa, and the tensile modulus is ≥190GPa.

[0049] In one specific embodiment, step 1) the carbon cloth weaving form includes at least one of plain weave, satin weave, and twill weave; the polyacrylonitrile-based carbon fiber is at least one of T300 grade, T700 grade, T800 grade high-strength carbon fiber or M40J grade, M55J grade high-strength high-modulus carbon fiber; the volume content of the reinforcing weight of the prepared three-dimensional carbon fiber fabric is 40% to 60%; the Z-direction needle punching spacing is 2 mm to 6 mm.

[0050] In one specific embodiment, step 2) involves a graphitization heat treatment time of 1 to 4 hours, with nitrogen or argon as the protective gas; an electrolyte of at least one of Ca(OH)2 or Ba(OH)2, with a solution concentration of 0.1% to 2%; and a sizing agent of at least one of epoxy or phenolic type, with a sizing agent solution concentration of 3% to 5% and a wetting time of 1 to 30 minutes.

[0051] In one specific embodiment, step 3) uses inorganic nano-thermal conductive particles, which are carbon nanotubes or graphene; the silane coupling agent is KH550 or KH560, the solution concentration is 1-3%, and the treatment time is 1-12 hours; the organic resin is epoxy resin or phenolic resin.

[0052] In one specific embodiment, the matrix resin system comprises the following components in parts by weight:

[0053] Organic resin matrix 100

[0054] Functionalized inorganic nano-thermal conductive particles 0.5–3

[0055] Solvent 30-60.

[0056] In one specific embodiment, the organic resin is an epoxy resin, specifically 1,2-epoxycyclohexane-4,5-dicarboxylic acid diglycidyl ester or 3,4-epoxycyclohexyl 3',4'-epoxycyclohexyl methyl ester; the curing agent is at least one of hexahydrophthalic anhydride or methylhexahydrophthalic anhydride, with a mass fraction of 60-80 parts; the curing temperature is 100-200°C, and the curing time is 1-8 hours.

[0057] In one specific embodiment, when the organic resin is a phenolic resin, and the phenolic resin is a high-carbon phenolic or barium phenolic resin, no curing agent is required, the curing temperature is 120-200°C, and the curing time is 2-12 hours.

[0058] This invention first uses high-temperature carbonized mesophase pitch carbon fibers to weave a two-dimensional carbon cloth as the XY-axis reinforcement, then uses high-strength or high-modulus polyacrylonitrile-based carbon fibers as the Z-axis reinforcement fibers to needle-weave a three-dimensional carbon fiber fabric reinforcement. Finally, it undergoes graphitization at 3000℃ to obtain a three-dimensional carbon fiber reinforcement with high thermal conductivity. This solves the problems of not being able to directly use ultra-high modulus, high thermal conductivity mesophase carbon fibers to weave a three-dimensional carbon fiber reinforcement and the large fiber loss, ensuring the full utilization of the thermal conductivity and mechanical properties of the high thermal conductivity mesophase pitch carbon fibers. This invention also uses an alkaline electrolyte to electroplate the high thermal conductivity mesophase pitch carbon fibers, generating a large number of barbed inorganic salts on the carbon fiber surface, significantly increasing the carbon fiber surface area and enabling it to bond with the resin matrix to form mechanical anchoring, significantly improving the mechanical and thermal conductivity properties of the composite material. Finally, this invention uses a silane coupling agent to treat inorganic nano-thermal conductive particles and uniformly disperse them in an organic resin matrix, improving the thermal conductivity of the matrix resin. Combined with the three-dimensional carbon fiber fabric reinforcement, a multi-scale thermal conductive network is constructed, which is beneficial for the full utilization of the XY and Z-axis thermal and mechanical properties of the composite material. This invention utilizes the RTM process to prepare high thermal conductivity three-dimensional carbon fiber reinforced resin matrix composites. This process is mature and simple, the resin is uniformly dispersed, and the thermal conductivity and mechanical properties are excellent. It is suitable for structural / functional components of advanced equipment such as aerospace vehicles.

[0059] Example:

[0060] In the following embodiments of the present invention, the density, tensile properties and compressive properties of the composite materials were tested according to the specifications in ASTM D-792, ASTM D-3039 and ASTM D-695, respectively, and the thermal conductivity was tested according to the specifications in ASTM E-1461.

[0061] Example 1

[0062] (1) Mesophase pitch carbon fibers that have undergone high-temperature carbonization treatment at 1000℃ are woven into plain weave carbon cloth and cut into 200mm×200mm as XY direction reinforcements. T300-3K high-strength carbon fibers are used as Z direction reinforcement fibers. The Z direction fiber bundle spacing is 2mm. A three-dimensional carbon fiber fabric reinforcement with a fiber volume content of 60% is prepared by needle punching technology. The size is 200mm×200mm×4mm.

[0063] (2) The three-dimensional carbon fiber fabric reinforcement prepared in step (1) is placed in a graphitization furnace and graphitized at 3000℃ for 4 hours under nitrogen protection; after cooling, it is placed in 2wt% Ba(OH)2 electrolyte for electrochemical treatment for 5 minutes, and then immersed in 3wt% epoxy sizing agent solution for 5 minutes. After immersion, it is placed in an oven to dry, and a three-dimensional high thermal conductivity carbon fiber fabric reinforcement is obtained.

[0064] (3) Disperse 1 part of carbon nanotubes in a 2wt% KH-550 silane coupling agent solution for surface treatment for 12h, take it out and dry it, and then disperse it in epoxy resin (100 parts of 1,2-epoxycyclohexane 4,5-dicarboxylic acid diglycidyl ester + 60 parts of hexahydrophthalic anhydride + 50 parts of acetone) to obtain the matrix resin system.

[0065] (4) The three-dimensional high thermal conductivity carbon fiber fabric reinforcement described in step (2) is placed in a mold, and the epoxy resin system prepared in step (3) is injected using the RTM process. The solvent is removed, and the mixture is heated and cured, then cooled and demolded. The curing process is (100℃ / 2h) + (180℃ / 4h). After curing in an oven, the mixture is cooled and demolded to obtain a three-dimensional high thermal conductivity carbon fiber reinforced epoxy resin matrix composite material. The properties of the composite material are shown in Table 1.

[0066] Example 2

[0067] (1) Mesophase pitch carbon fibers treated with high temperature of 1200℃ are woven into satin carbon cloth and cut into 200mm×200mm as XY direction reinforcement. T800-6K high strength medium modulus carbon fiber is used as Z direction reinforcement fiber. The Z direction fiber bundle spacing is 2mm. A three-dimensional carbon fiber fabric reinforcement with a fiber volume content of 60% is prepared by needle punching technology. The size is 200mm×200mm×4mm.

[0068] (2) The three-dimensional carbon fiber fabric reinforcement prepared in step (1) is placed in a graphitization furnace and graphitized at 3000℃ for 4 hours under nitrogen protection; after cooling, it is placed in 0.15wt% Ca(OH)2 electrolyte for electrochemical treatment for 10 minutes, and then taken out and immersed in 2wt% epoxy sizing agent solution for 10 minutes. After that, it is taken out and placed in an oven to dry, thus obtaining a three-dimensional high thermal conductivity carbon fiber fabric reinforcement.

[0069] (3) Two parts of carbon nanotubes were dispersed in a 3wt% KH-550 silane coupling agent solution for surface treatment for 10h. After drying, they were dispersed in epoxy resin (100 parts of 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester + 70 parts of methyl hexahydrophthalic anhydride + 40 parts of tetrahydrofuran) to obtain the matrix resin system.

[0070] (4) The three-dimensional high thermal conductivity carbon fiber fabric reinforcement described in step (2) is placed in a mold, and the epoxy resin system prepared in step (3) is injected using the RTM process. The mold is then placed in an oven for heating and curing. The curing process is (120℃ / 2h) + (200℃ / 4h). After curing in the oven, the mold is cooled and demolded to obtain a three-dimensional high thermal conductivity carbon fiber reinforced epoxy resin matrix composite material. The properties of the composite material are shown in Table 1.

[0071] Example 3

[0072] (1) Mesophase pitch carbon fibers treated with high temperature of 1400℃ are woven into plain weave carbon cloth and cut into 200mm×200mm as XY direction reinforcement. M40J-6K high strength and high modulus carbon fibers are used as Z direction reinforcement fibers. The Z direction fiber bundle spacing is 4mm. A three-dimensional carbon fiber fabric reinforcement with a fiber volume content of 55% is prepared by needle punching technology. The size is 200mm×200mm×3mm.

[0073] (2) The three-dimensional carbon fiber fabric reinforcement prepared in step (1) is placed in a graphitization furnace and graphitized at 3000℃ for 2 hours under nitrogen protection; after cooling, it is placed in 0.15wt% Ca(OH)2 electrolyte for electrochemical treatment for 10 minutes, and then immersed in 3wt% phenolic sizing agent solution for 20 minutes. After that, it is placed in an oven to dry, and a three-dimensional high thermal conductivity carbon fiber fabric reinforcement is obtained.

[0074] (3) 1 part of graphene was dispersed in a 2wt% KH-560 silane coupling agent solution for surface treatment for 8 hours. After drying, it was dispersed in high carbon phenolic resin (100 parts high carbon phenolic resin + 30 parts methanol) to obtain the matrix resin system.

[0075] (4) The three-dimensional high thermal conductivity carbon fiber fabric reinforcement described in step (2) is placed in a mold, and the high carbon phenolic matrix resin system prepared in step (3) is injected using the RTM process. The mold is then placed in an oven for heating and curing. The curing process is (120℃ / 2h) + (180℃ / 10h). After curing in the oven, the mold is cooled and demolded to obtain a three-dimensional high thermal conductivity carbon fiber reinforced epoxy resin matrix composite material. The properties of the composite material are shown in Table 1.

[0076] Example 4

[0077] (1) Mesophase pitch carbon fibers treated with high temperature of 1400℃ are woven into satin carbon cloth and cut into 200mm×200mm as XY direction reinforcement. M55J-6K high strength and high modulus carbon fibers are used as Z direction reinforcement fibers. The Z direction fiber bundle spacing is 4mm. A three-dimensional carbon fiber fabric reinforcement with a fiber volume content of 55% is prepared by needle punching technology. The size is 200mm×200mm×3mm.

[0078] (2) The three-dimensional carbon fiber fabric reinforcement prepared in step (1) is placed in a graphitization furnace and graphitized at 3000℃ for 2 hours under nitrogen protection; after cooling, it is placed in a 2wt% Ba(OH)2 electrolyte for electrochemical treatment for 10 minutes, and then taken out and immersed in a 3wt% phenolic sizing agent solution for 10 minutes. After that, it is taken out and placed in an oven to dry, thus obtaining a three-dimensional high thermal conductivity carbon fiber fabric reinforcement.

[0079] (3) Two parts of graphene were dispersed in a 2wt% KH-560 silane coupling agent solution for surface treatment for 8 hours. After drying, the graphene was dispersed in barium phenolic resin (100 parts barium phenolic resin + 40 parts ethanol) to obtain the matrix resin system.

[0080] (4) The three-dimensional high thermal conductivity carbon fiber fabric reinforcement described in step (2) is placed in a mold, and the barium phenolic resin matrix system prepared in step (3) is injected using the RTM process. The mold is then placed in an oven for heating and curing. The curing process is (120℃ / 2h) + (180℃ / 10h). After curing in the oven, the mold is cooled and demolded to obtain a three-dimensional high thermal conductivity carbon fiber reinforced epoxy resin matrix composite material. The properties of the composite material are shown in Table 1.

[0081] Comparative Example 1:

[0082] The other steps are the same as in Example 1, except that the electrochemical treatment step is omitted. The properties of the composite material are shown in Table 1.

[0083] Comparative Example 2:

[0084] The other steps are the same as in Example 3, except that the silane coupling agent treatment step is omitted. The properties of the composite material are shown in Table 1.

[0085] Table 1 Properties of three-dimensional high-conductivity carbon fiber reinforced resin composites

[0086] As can be seen from Examples 1-4, the three-dimensional high-conductivity carbon fiber reinforced resin composite material prepared by the present invention exhibits room temperature thermal conductivity of 208-248 W / (m·K) in the XY direction, tensile strength of 208-248 MPa, tensile modulus of 212-236 GPa, room temperature thermal conductivity of 5-54 W / (m·K) in the Z direction, and compressive strength of 222-252 MPa. Examples 1 and Comparative Example 1 show that the composite material obtained by electrochemical treatment has high thermal conductivity and mechanical properties, especially with a 20% increase in compressive strength. Examples 3 and Comparative Example 2 show that the composite material obtained by treatment with a silane coupling agent containing inorganic thermally conductive particles also has high thermal conductivity and mechanical properties. Therefore, the three-dimensional high-conductivity carbon fiber reinforced resin composite material prepared by the present invention possesses excellent thermal conductivity and mechanical properties in both the XY and Z directions, and can be applied in the structural / functional components of advanced equipment such as aerospace vehicles, fully demonstrating the effectiveness of the present invention.

[0087] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0088] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material, characterized in that, include: A three-dimensional carbon fiber fabric reinforcement was prepared by using carbon cloth woven from mesophase pitch carbon fiber as the XY axis reinforcement and polyacrylonitrile-based carbon fiber as the Z axis reinforcement fiber; the mesophase pitch carbon fiber was mesophase pitch carbon fiber that had undergone high-temperature carbonization treatment at 1000℃~1600℃. The three-dimensional carbon fiber fabric reinforcement was graphitized. The graphitized three-dimensional carbon fiber fabric reinforcement was placed in an alkaline electrolyte as a cathode for electrochemical treatment. The electrochemically treated three-dimensional carbon fiber fabric reinforcement was impregnated with a sizing agent solution and then dried. Inorganic thermally conductive nanoparticles are dispersed in an organic resin to obtain a matrix resin system. The dried three-dimensional carbon fiber fabric reinforcement was placed in a mold and injected into the matrix resin system using the RTM process to obtain a three-dimensional carbon fiber reinforced resin matrix composite material.

2. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 1, characterized in that, The carbon content of the mesophase pitch carbon fiber after high-temperature carbonization treatment at 1000℃~1600℃ is ≥98%, the tensile strength is ≥1200MPa, and the tensile modulus is ≥190GPa. The polyacrylonitrile-based carbon fiber is one or more of the following: T300 grade high-strength carbon fiber, T700 grade high-strength carbon fiber, T800 grade high-strength carbon fiber, M40J grade high-strength high-modulus carbon fiber, or M55J grade high-strength high-modulus carbon fiber.

3. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 1, characterized in that, The carbon fiber fabric weave includes one or more of the following: plain weave, satin weave, or twill weave. Three-dimensional carbon fiber fabric reinforcements were prepared using a needle punching method; The fiber volume content in the three-dimensional carbon fiber fabric reinforcement is 40% to 60%; the Z-axis needle-punching spacing is 2 mm to 6 mm.

4. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 1, characterized in that, The graphitization process is carried out at a temperature above 3000℃ for 1 to 2 hours, with nitrogen or argon as the protective gas.

5. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 1, characterized in that, The alkaline electrolyte is one or more of Ca(OH)2 or Ba(OH)2, and the concentration of the alkaline electrolyte is 0.1wt% to 2wt%; the anode is platinum, the DC voltage is 5V to 25V, the current is 0.1A to 1A, and the electrochemical treatment time is 5min to 10min.

6. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 1, characterized in that, The sizing agent includes one or more of epoxy sizing agents or phenolic sizing agents, with a sizing agent solution concentration of 3wt% to 5wt%; the soaking time is 1min to 30min.

7. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 1, characterized in that, Inorganic nano-thermal conductive particles are surface-treated in a silane coupling agent solution and then dispersed in an organic resin. Inorganic nano-thermal conductive particles are carbon nanotubes or graphene; The silane coupling agent is one or more of KH550 or KH560; The organic resin is one or more of epoxy resin or phenolic resin; the epoxy resin includes one or more of 1,2-epoxycyclohexane-4,5-dicarboxylic acid diglycidyl ester or 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester; the phenolic resin includes one or more of high-carbon phenolic resin or barium phenolic resin. The concentration of the silane coupling agent solution is 1 wt% to 3 wt%.

8. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 7, characterized in that, The matrix resin system contains the following components in parts by weight: 100 parts organic resin; 0.5-3 parts inorganic nano-thermal conductive particles; and 30-60 parts solvent.

9. The method for preparing a three-dimensional carbon fiber reinforced resin matrix composite material according to claim 7, characterized in that, A three-dimensional carbon fiber reinforced resin matrix composite material was obtained by injecting the matrix resin system using the RTM process, removing the solvent, heating and curing, and cooling and demolding. When the organic resin is epoxy resin, the solvent in the matrix resin system is one or more of acetone or tetrahydrofuran, the curing agent is one or more of hexahydrophthalic anhydride or methylhexahydrophthalic anhydride, the mass fraction of the curing agent is 60 to 80 parts, the curing temperature is 100 to 200°C, and the curing time is 1 to 8 hours. When the organic resin is phenolic resin, and the solvent in the matrix resin system is one or more of methanol or ethanol, the curing temperature is 120-200℃ and the curing time is 2-12 hours.

10. A three-dimensional carbon fiber reinforced resin matrix composite material, characterized in that, The three-dimensional carbon fiber reinforced resin matrix composite material was prepared using the method described in claims 1-10.

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