CN105818476B - A kind of surface modified 3 D network carbon fibre reinforced composite and preparation method - Google Patents

Abstract

The invention discloses a surface-modified three-dimensional network carbon fiber reinforced composite material and a preparation method thereof. Three-dimensional carbon fiber skeletons with different apertures are prepared according to requirements, and after surface pretreatment, diamonds, carbon nanotubes, and graphene are deposited by chemical vapor phase, and then combined with a substrate. Material composite, the matrix material is metal or polymer, and a carbon fiber reinforced metal matrix or polymer matrix composite material with a three-dimensional network skeleton structure is obtained. The surface-modified three-dimensional network carbon fiber forms a three-dimensional continuous heat conduction channel in the composite material, which greatly improves the thermal conductivity of the composite material. At the same time, the spatial distribution of the carbon fiber in the matrix material can also improve the performance of the composite material. Mechanical properties, the function of reducing its density and thermal expansion coefficient. At the same time, its thermal expansion coefficient and mechanical and thermal properties can also be adjusted by adding zero-dimensional particle reinforcement.

Description

A surface modified three-dimensional network carbon fiber reinforced composite material and its preparation method

technical field

The invention discloses a surface-modified three-dimensional network carbon fiber reinforced composite material and a preparation method thereof, belonging to the technical field of composite material preparation.

Background technique

The fierce evolution of international competition has continuously spawned the rapid development of science and technology. Microelectronics technology and guidance technology have naturally become the top priority of the competition between countries. All kinds of electronic equipment are more and more integrated, their energy density is getting higher and higher, and more and more heat is generated. To ensure the stable operation of the equipment, it is necessary to carry out effective thermal management on it. At the same time, higher requirements are put forward for the high strength and low density of the material. Pitch-based carbon fiber has attracted the attention of scientific researchers due to its low density, light weight, high tensile strength, high thermal conductivity, electrical conductivity and extremely low coefficient of thermal expansion.

CN105110809A provides a preparation method of graphene-modified high thermal conductivity three-dimensional carbon/carbon composite material, using graphene oxide and PAN carbon cloth as raw materials, forming a graphene oxide film on the surface of carbon fibers by impregnating methods; in high temperature, hydrogen atmosphere In the process, the graphene oxide film is reduced to graphene, followed by CVI densification and graphitization to obtain a three-dimensional carbon/carbon composite material with high thermal conductivity modified by graphene, which can improve the thermal conductivity and thermal conductivity of the three-dimensional carbon/carbon composite material. Bending strength, realizing large-scale and large-scale preparation of three-dimensional high thermal conductivity carbon/carbon composites. However, due to the characteristics of poor uniformity, easy peeling, and less coverage of the graphene film prepared by the impregnation method, the application range of this material is limited.

Metal matrix composites use metal or alloy as the matrix, and use the second phase with high thermal conductivity or low expansion coefficient as the reinforcement to give full play to the excellent properties of their respective components. Metal matrix composites have become electronic packaging due to their good comprehensive properties. Materials research hotspots. Carbon fiber reinforced metal matrix composites can increase the specific strength and specific modulus of metals, and reduce the thermal expansion coefficient of metals. The metals used for composite materials are often selected from lighter metals, alloys or intermetallic compounds, mainly aluminum, copper, titanium, magnesium, their alloys and intermetallic compounds. CN101713056A proposes a metal-based three-dimensional network carbon fiber composite material and its manufacturing method. The carbon fiber in the composite material is a three-dimensional network carbon fiber structure, and the three-dimensional network carbon fiber structure is composed of multilayer carbon nanotubes. The three-dimensional network Carbon fiber structure, binder and dispersant are mixed and stirred in proportion, dried, compression molded, hardened, high-temperature sintered to form a preform containing carbon fiber structure, and the molten sintered metal (silicon, magnesium, copper and nickel Aluminum alloys in such combinations) are impregnated in preforms containing carbon fiber structures, and solidified to form metal-based carbon fiber composites with excellent mechanical, thermal conductivity, and thermal expansion properties. However, since the electrochemical reaction between the carbon fiber and the metal matrix is easy to occur, and the electrode potential difference between the carbon fiber and the metal matrix is large, the primary battery is prone to corrosion in an environment with high humidity, so the material is prone to failure.

Contents of the invention

The object of the present invention is to overcome the deficiencies of the prior art and provide a composite material with high thermal conductivity, low thermal expansion coefficient and light weight and a preparation method.

The invention discloses a surface-modified three-dimensional network carbon fiber reinforced composite material. The composite material includes a matrix material and a three-dimensional network carbon fiber reinforcement, wherein the matrix material comprises a metal material or a polymer material.

The present invention is a surface-modified three-dimensional network carbon fiber reinforced composite material, wherein the metal matrix material is selected from one of metal copper and aluminum or one of copper-based alloy and aluminum-based alloy; the copper-based alloy, aluminum In the base alloy, the content of copper or aluminum is greater than or equal to 50%; the polymer matrix is a thermoplastic polymer or a thermosetting polymer; the thermoplastic polymer is selected from polyethylene, polypropylene, polystyrene, polyvinyl chloride, polytetrafluoroethylene One of vinyl, nylon, polycarbonate, polymethyl methacrylate, ethylene glycol ester, polyethylene terephthalic acid, polyoxymethylene, polyamide, polysulfone; the thermosetting polymer is selected from epoxy resin, One of phenolic resin, urea-formaldehyde resin, amino resin, melamine resin, unsaturated polyester resin, silicone resin, silicone rubber, expanded polystyrene, polyurethane.

The invention discloses a surface-modified three-dimensional network carbon fiber reinforced composite material. The three-dimensional network carbon fiber reinforced body has a pore diameter of 20 μm-5 mm, a porosity of 20-95 percent, and a carbon fiber diameter of 3-500 μm.

The invention discloses a surface-modified three-dimensional network carbon fiber reinforced composite material. A high thermal conductivity layer is directly deposited on the surface of a three-dimensional network carbon fiber reinforcement or a high thermal conductivity layer is deposited after surface modification.

The invention discloses a surface-modified three-dimensional network carbon fiber reinforced composite material. The surface modification of the three-dimensional network carbon fiber reinforcement is to deposit a metal layer on the surface of the carbon fiber, and the metal layer is selected from nickel, copper, tungsten, molybdenum, titanium, One or a combination of silver and chromium, and the metal layer is deposited by one of electroplating, chemical plating, vapor deposition, magnetron sputtering, chemical vapor deposition, and physical vapor deposition.

The present invention is a surface-modified three-dimensional network carbon fiber reinforced composite material, the deposited high thermal conductivity layer is selected from diamond, graphene, carbon nanotube, graphene/diamond, carbon nanotube/diamond, graphene/carbon nanotube, diamond /One of graphene/carbon nanotubes, the thickness of the high thermal conductivity layer is 5-200μm.

The invention is a surface-modified three-dimensional network carbon fiber reinforced composite material, which adopts CVD technology to deposit a high thermal conductivity layer, and is specifically selected from hot wire assisted method, microwave plasma enhanced method, DC plasma jet method and electron cyclotron resonance method in CVD technology , flame combustion method, direct current discharge method, low voltage radio frequency method, normal pressure radio frequency method at least one.

The invention discloses a surface-modified three-dimensional network carbon fiber reinforced composite material, and the matrix material of the composite material also contains high thermal conductivity particles.

The invention is a surface-modified three-dimensional network carbon fiber reinforced composite material, wherein the high thermal conductivity particles are selected from diamond, graphene, carbon nanotubes, graphene-coated diamond microspheres, carbon nanotube-coated diamond microspheres, carbonized At least one of silicon, boron carbide, aluminum nitride, and boron nitride, and the graphene-coated diamond microspheres and carbon nanotube-coated diamond microspheres are all obtained by chemical vapor deposition.

The present invention is a surface-modified three-dimensional reticular carbon fiber reinforced composite material. The composite material comprises the following components, which are composed by volume percentage: matrix material 20-80%, three-dimensional reticular carbon fiber reinforcement 10-70%, 0%-30% of high thermal conductivity particles, the volume percent sum of each component is 100%.

A method for preparing a surface-modified three-dimensional network carbon fiber reinforced composite material of the present invention comprises the following steps:

Step 1: Weave carbon fiber into a three-dimensional mesh, wash and dry;

Step 2: Deposit one of nickel, copper, tungsten, molybdenum, titanium, silver, and chromium on the surface of the carbon fiber by one of the methods of electroplating, chemical plating, evaporation, magnetron sputtering, chemical vapor deposition, and physical vapor deposition. Kind or composite metal layer;

The third step: Soak the three-dimensional network carbon fiber in nano-diamond powder or graphene powder or carbon nanotube suspension for ultrasonic vibration planting seed crystal pretreatment;

The fourth step: use chemical vapor deposition technology to deposit one or more composite high thermal conductivity layers of diamond, graphene, and carbon nanotubes on the surface of three-dimensional network carbon fiber to obtain a three-dimensional network carbon fiber reinforcement;

Step 5: Composite the three-dimensional network carbon fiber reinforcement, high thermal conductivity particles and metal matrix, using powder metallurgy sintering technology or one of the methods of pressureless infiltration, gas infiltration, and casting; the powder metallurgy sintering technology is selected One of self-cold press sintering, hot press sintering, SPS sintering, vacuum sintering and atmosphere sintering; or

The three-dimensional network carbon fiber reinforcement, high thermal conductivity particles and polymer matrix are compounded, and the composite adopts one of dip curing molding, injection molding, compression molding, injection molding, rotational molding, extrusion molding, lamination molding, and tape casting. way.

The invention discloses a method for preparing a surface-modified three-dimensional network carbon fiber reinforced composite material. When the matrix material is metal, a modified film is placed on the surface of the high thermal conductivity layer and then compounded with the matrix. The thickness of the modified film is 5nm-2μm; The film is selected from at least one of tungsten film, molybdenum film, titanium film, nickel film, and chromium film, or at least one of TiC, WC, Cr ₇ C ₃ , NiC, and Mo ₂ C.

A method for preparing a surface-modified three-dimensional network carbon fiber reinforced composite material of the present invention, in the fourth step, the parameters of graphene, carbon nanotubes, and diamond CVD deposition are:

Graphene CVD deposition parameters are: carbon-containing gas accounts for 0.5-80% of the total gas mass flow rate in the furnace; growth temperature is 400-1200°C, and growth pressure is 5-10 ⁵ Pa;

The carbon nanotube CVD deposition parameters are: carbon-containing gas accounts for 5-50% of the total gas mass flow rate in the furnace; the growth temperature is 400-1300°C, and the growth pressure is 10 ³ -10 ⁵ Pa;

The diamond CVD deposition parameters are: carbon-containing gas accounts for 0.5-10% of the total gas mass flow rate in the furnace; the growth temperature is 600-1000°C, and the growth pressure is 10 ³ -10 ⁴ Pa;

Realize graphene/diamond, carbon nanotube/diamond, graphene/carbon nanotube, diamond/graphene/carbon CVD deposition of nanotubes, the deposition parameters are:

Graphene CVD deposition parameters are: carbon-containing gas accounts for 0.5-80% of the total gas mass flow rate in the furnace; growth temperature is 400-1200°C, growth pressure is 5-10 ⁵ Pa; plasma current density is 0-50mA/cm ² ; The magnetic field strength in the deposition area is 100 Gauss to 30 Tesla.

The carbon nanotube CVD deposition parameters are: carbon-containing gas accounts for 5-50% of the total gas mass flow rate in the furnace; growth temperature is 400-1300°C, growth pressure is 10 ³ -10 ⁵ Pa; plasma current density is 0-30mA/cm ² ; The magnetic field strength in the deposition area is 100 Gauss to 30 Tesla.

The diamond CVD deposition parameters are as follows: the carbon-containing gas accounts for 0.5-10% of the total gas mass flow rate in the furnace; the growth temperature is 600-1000°C, and the growth pressure is 10 ³ -10 ⁴ Pa.

The present invention is a surface-modified three-dimensional network carbon fiber reinforced metal-based or polymer-based composite material, which can also add rare earth elements, such as one or more of Sc, Y, Ce and other rare earth elements, to strengthen the metal and polymer matrix. The binding properties of three-dimensional network carbon fiber reinforcement and high thermal conductivity particles; it is also possible to add a coupling agent to the polymer to change the hydrophilicity or organophilicity of the polymer, so that the polymer and the reinforcement are connected by a coupling agent to Improve binding properties.

The present invention prepares three-dimensional carbon fiber skeletons with different pore diameters, deposits uniform and dense diamond, carbon nanotubes or graphene films by chemical vapor phase after surface pretreatment, and composites them with matrix materials after surface modification by CVD to obtain three-dimensional Carbon fiber reinforced metal matrix composites with skeleton structure. After surface modification, the potential difference between the metal and carbon fiber is reduced, the electrochemical corrosion of the material is effectively alleviated, and the adaptability of the material is improved. At the same time, the surface-modified three-dimensional carbon fiber forms a three-dimensional continuous heat conduction channel in the composite material, which greatly improves the performance of the material. The thermal conductivity of the composite material is improved. At the same time, the spatial distribution of carbon fibers in the matrix material can also improve the mechanical properties of the composite material and reduce its density and thermal expansion coefficient. At the same time, its thermal expansion coefficient and mechanical and thermal properties can also be adjusted by adding zero-dimensional particle reinforcement.

Detailed ways

The technical solution of the present invention is further described below through specific examples.

Embodiments of the present invention are carried out according to the following processes or steps:

The thermal conductivity of the prepared composites was measured using a laser thermal conductivity meter.

Example 1: Diamond Modified Braided Carbon Fiber Reinforced Aluminum Matrix Composite

Include the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 500 μm and a porosity of 90%) in an acetone solution for ultrasonic cleaning;

(2) Using magnetron sputtering method to sputter W film on the surface of three-dimensional woven carbon fiber, wherein the thickness of W film is 150nm; using hot wire CVD to deposit diamond film, deposition process parameters: hot wire distance 6mm, substrate temperature 800 ℃, heat The wire temperature is 2200°C, the deposition pressure is 3KPa, and the volume flow ratio of CH ₄ /H ₂ is 1:99 to obtain a diamond film thickness of 120 μm; the Mo/Cu composite film is sputtered on the surface of the cored diamond three-dimensional network skeleton by magnetron sputtering. The Mo film thickness is 50nm, and the Cu film thickness is 100nm;

(3) Put the surface-modified braided carbon fiber obtained in (2) into a mold, heat and melt pure aluminum in a crucible to 730°C at the same time, pour the pure aluminum melt into the mold, and use a hydraulic press to apply a pressure of 60Mpa Pressure, forcing the aluminum or aluminum alloy melt to infiltrate into the gap between the diamond wires in the skeleton, keep the pressure for 15 seconds, cool and demould, take out the composite material, the thermal conductivity of the composite material is 552W/mK, the tensile strength is 561MPa, The bending strength is 53MPa.

Embodiment two: diamond/graphene modified braided carbon fiber reinforced PMMA composite material

Include the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 300 μm and a porosity of 80%) in an acetone solution for ultrasonic cleaning;

(2) The diamond film is deposited by hot wire CVD. The deposition process parameters are: hot wire distance 6mm, substrate temperature 800°C, hot wire temperature 2200°C, deposition pressure 3KPa, CH ₄ /H ₂ volume flow ratio 1:99, to obtain a diamond film The thickness is 200 μm; the graphene film layer is grown in situ on the diamond surface by plasma-assisted chemical vapor deposition, the deposition parameters are: H ₂ /CH ₄ atmosphere, the mass flow rate of CH ₄ gas is 10%, the growth temperature is 900°C, and the growth pressure is 5 ×10 ⁵ Pa, the plasma current density is 20mA/cm ² , the magnetic field strength in the deposition area is 200 Gauss, and the time is 20min; then vacuum evaporation is used to deposit a W film on the surface, and the thickness of the W film is 100nm;

(3) Compositing by dipping and curing: a) Preparation of PMMA (polymethyl methacrylate) precursor solution: take 20g PMMA, mix it with organic solvent chloroform, stir vigorously for 2h until PMMA is completely dissolved, and form a PMMA mass percentage of 10 % chloroform solution; b) mixing: put the diamond/graphene modified braided carbon fiber into the mold, then drop into the chloroform solution of PMMA according to the volume ratio of 1:5, make it penetrate and fully infiltrate the diamond/graphene modified braid carbon fiber to obtain a mixture; c) heating and curing: place the above mixture in a vacuum oven at 60°C for 24 hours to evaporate the chloroform solvent, then heat it to 110°C, keep it warm for 1 hour, and then cool it down to room temperature to finally obtain a three-dimensional The diamond/graphene modified woven carbon fiber/PMMA composite material with a network skeleton structure has a thermal conductivity of 252W/mK, a tensile strength of 274MPa, and a bending strength of 35MPa.

Example 3: Diamond Modified Braided Carbon Fiber Reinforced Aluminum Alloy Matrix Composite

Include the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 150 μm and a porosity of 60%) in an acetone solution for ultrasonic cleaning;

(2) Sputtering a Mo film on the surface of the cored diamond three-dimensional network skeleton using evaporation plating technology, wherein the thickness of the Mo film is 50nm; using hot wire CVD to deposit the diamond film, deposition process parameters: hot wire distance 6mm, substrate temperature 750°C, The temperature of the hot wire is 2200°C, the deposition pressure is 3KPa, the volume flow ratio of CH ₄ /H ₂ is 1:99, and the thickness of the diamond film is 80 μm; the Mo/Ni/Cu composite is sputtered on the surface of the cored diamond three-dimensional network skeleton by magnetron sputtering Film layer, wherein the Mo film thickness is 50nm, the Ni film thickness is 50nm, and the Cu film thickness is 20nm;

(3) Put the surface-modified braided carbon fiber obtained in (2) into a mold, place an Al-Si alloy twice the volume of the braided carbon fiber skeleton above the skeleton, wherein the mass content of Si is 15%, and then put In the heating furnace, under the protection of high-purity nitrogen gas, heat at 900°C for 30 minutes to obtain a diamond-modified braided carbon fiber reinforced aluminum alloy matrix composite material. The thermal conductivity of the composite material is 572W/mK, the tensile strength is 587MPa, and the bending strength is 56MPa. .

Example 4: Diamond/Carbon Nanotube Modified Braided Carbon Fiber Reinforced Copper Matrix Composite

Include the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 250 μm and a porosity of 70%) in an acetone solution for ultrasonic cleaning;

(2) Sputtering a Mo film on the surface of the cored diamond three-dimensional network skeleton using evaporation plating technology, wherein the thickness of the Mo film is 50nm; using hot wire CVD to deposit the diamond film, deposition process parameters: hot wire distance 6mm, substrate temperature 750°C, The temperature of the hot wire is 2200°C, the deposition pressure is 3KPa, the volume flow ratio of CH ₄ /H ₂ is 1:99, and the thickness of the diamond film is 500 μm; a nickel film with a thickness of 5 nm is deposited on the surface of the diamond film by magnetron sputtering technology, and then hot wire CVD is used Deposited on the surface of the diamond film to catalyze the growth of carbon nanotube forests, the deposition process: the mass flow rate of CH ₄ /H ₂ carbon-containing gas is 10.0%, the growth temperature is 800°C, the growth pressure is 10 ⁴ Pa, the plasma current density is 10mA/cm ² , The magnetic field strength in the deposition area is 30 Tesla, and the deposition time is 40 minutes. Then adopt the electroplating method to electroplate Cu film in the carbon nanotube forest, wherein the Cu film thickness is 300nm;

(3) Put the surface-modified woven carbon fiber obtained in (2) into a mold, place a pure Cu block twice the volume of the woven carbon fiber skeleton on top of the skeleton, and then put it into a heating furnace under the protection of high-purity nitrogen Heat at 1250°C for 30 minutes to obtain a diamond/carbon nanotube modified braided carbon fiber reinforced copper matrix composite material. The thermal conductivity of the composite material is 1052W/mK, the tensile strength is 679MPa, and the flexural strength is 78MPa.

Embodiment five: diamond/graphene/carbon nanotube modified braided carbon fiber reinforced epoxy resin-based composite material comprises the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 350 μm and a porosity of 50%) in an acetone solution for ultrasonic cleaning;

(2) Deposit a layer of Mo film on the surface of the cored diamond three-dimensional network skeleton by using evaporation coating technology, wherein the thickness of the Mo film is 50nm; use hot wire CVD to deposit the diamond film, deposition process parameters: hot wire distance 6mm, substrate temperature 750°C, The temperature of the hot wire is 2200°C, the deposition pressure is 3KPa, the volume flow ratio of CH ₄ /H ₂ is 1:99, and the thickness of the diamond film is 80 μm; a 5nm thick cobalt film is deposited on the surface of the diamond film by magnetron sputtering technology, and then hot wire CVD is used Carbon nanotube forest deposited on the surface of the diamond film, deposition process: CH ₄ /H ₂ carbon-containing gas mass flow percentage of 10.0%; growth temperature of 800°C, growth pressure of 10 ⁴ Pa; plasma current density of 10mA/cm ² ; deposition area The medium magnetic field strength is 200 Gauss, and the deposition time is 1 h. Then adopt the electroplating method to electroplate Cu film in the carbon nanotube forest, wherein the Cu film thickness is 300nm;

(3) subdivided by mass: 40 parts of epoxy resin, 20 parts of diamond/graphene composite heat-conducting particles, 0.8 part of coupling agent, 0.6 part of antioxidant, and 3 parts of processing aids; (2) The surface-modified woven carbon fiber obtained in the method is put into a mold, the mixed epoxy resin and other mixtures are placed on the modified woven carbon fiber, and the mold cavity is closed with a sealed and positioned vacuum bag. It is then heated in an oven to melt the resin. The resin is cured after permeating the fiber layer under the action of vacuum. The curing process is 130°C/1h+150°C/1h+180°C/2h+200°C/2h+220°C/6h. Cool naturally to room temperature after curing. The composite sample was taken out from the mold, and the thermal conductivity of the composite material was 282W/mK. The tensile strength is 261MPa, and the bending strength is 30MPa.

Example 6: Diamond Modified Braided Carbon Fiber Reinforced Copper Matrix Composite

Include the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 300 μm and a porosity of 70%) in an acetone solution for ultrasonic cleaning;

(2) Magnetron sputtering method is used to sputter W film on the surface of three-dimensional woven carbon fiber, wherein the thickness of W film is 250nm; hot wire CVD is used to deposit diamond film, deposition process parameters: hot wire distance 6mm, substrate temperature 800°C, heat The wire temperature is 2200°C, the deposition pressure is 3KPa, and the volume flow ratio of CH ₄ /H ₂ is 1:99, and the thickness of the diamond film is 520 μm; the Mo/Cu composite film is sputtered on the surface of the diamond-modified woven carbon fiber skeleton by magnetron sputtering. The Mo film thickness is 50nm, and the Cu film thickness is 100nm;

(3) Put the surface-modified braided carbon fiber obtained in (2) into the mold, heat and melt the pure copper in the crucible to 1140°C at the same time, pour the pure copper melt into the mold, and apply a hydraulic pressure of 60Mpa Pressure, forcing the copper melt to infiltrate into the gap of the diamond modified braided carbon fiber skeleton, keep the pressure for 15 seconds, cool and demould, take out the composite material diamond modified braided carbon fiber reinforced copper matrix composite material, the thermal conductivity is 552W/mK, The tensile strength is 940MPa, and the bending strength is 49MPa.

Example 7: Graphene Modified Braided Carbon Fiber Reinforced Aluminum Matrix Composite

Include the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 400 μm and a porosity of 75%) in an acetone solution for ultrasonic cleaning;

(2) Using magnetron sputtering method to sputter W film on the surface of three-dimensional woven carbon fiber, wherein the thickness of W film is 150nm; using hot wall CVD to deposit graphene film, specifically: heating to 950°C in the atmosphere of H2 and Ar (H2 and Ar flow rate are respectively 200 and 500mL/min during the heating process, and the heating rate is 33°C/min), heat treatment for 10min after the furnace temperature rises to 950°C; after heat treatment is completed, feed CH4, H2 and Ar mixed gas ( The gas flow rate is methane 5mL/min, hydrogen 200mL/min and argon 500mL/min), graphene starts to grow, the cooling rate is 100°C/min, and the average thickness of the graphene film is 1.7nm, that is, the graphene-coated carbon fiber is obtained skeleton;

(3) Put the graphene-modified braided carbon fiber obtained in (2) into the mold, heat and melt the pure aluminum in the crucible to 730°C at the same time, pour the pure aluminum melt into the mold, and apply a hydraulic pressure of 60Mpa The pressure of the aluminum or aluminum alloy melt is forced to infiltrate into the gap between the diamond wires in the skeleton, and the pressure is maintained for 15 seconds, cooled and demolded, and the composite material is taken out. The thermal conductivity of the composite material is 637W/mK, and the tensile strength is 594MPa. The bending strength is 60MPa.

Example 8: Carbon nanotube-coated graphene modified braided carbon fiber reinforced silicone rubber composite material

Include the following steps:

(1) Put the three-dimensional braided carbon fiber (with a pore size of 400 μm and a porosity of 75%) in an acetone solution for ultrasonic cleaning;

(2) Using magnetron sputtering method to sputter W film on the surface of three-dimensional woven carbon fiber, wherein the thickness of W film is 150nm; using hot wall CVD to deposit graphene film, specifically: heating to 950 in the atmosphere of _H2 and Ar ℃ (the flow rates of H ₂ and Ar during the heating process are 200 and 500mL/min respectively, and the heating rate is ₃₃ ℃/min), heat treatment for 10 minutes after the furnace temperature rises to ₉₅₀ ℃; Mixed gas (gas flow rate is methane 5mL/min, hydrogen 200mL/min and argon 500mL/min), start to grow graphene, cooling rate 100 ℃/min, the average thickness of the graphene film obtained is 1.7nm, that is, graphite Graphene-coated carbon fiber skeleton; then magnetron sputtering to deposit a layer of nickel on the surface of graphene, and then use plasma-assisted chemical vapor deposition to catalyze the growth of carbon nanotubes on the surface of graphene, and control the growth orientation of carbon nanotubes under the action of an external electric field , making them perpendicular to the graphene surface to form a carbon nanotube forest, and obtaining a reinforced layer of carbon nanotube-coated graphene film, the deposition parameters are: the mass flow rate of methane and hydrogen is 10%; the growth temperature is 600 ° C, and the growth pressure is 3000 Pa; The plasma current density is 5 mA/cm ² ; the magnetic field strength in the deposition area is 500 Gauss, and the carbon nanotube-coated graphene carbon fiber skeleton is obtained;

(3) Drop in the silicone rubber precursor solution according to the volume ratio of 1:2, make it infiltrate and fully infiltrate the carbon nanotube-coated graphene carbon fiber skeleton to obtain a mixture; vacuumize the above mixture for 2 hours, and remove the solvent therein and air bubbles, so that the silicone rubber precursor liquid can be better filled into the pores of the carbon fiber skeleton, heated to 80 ° C, and heat-preserved for 4 hours to obtain a carbon nanotube-coated graphene-modified braided carbon fiber-reinforced silicone rubber composite material. The composite material is heated The conductivity is 193W/(m·K), the tensile strength is 278MPa, and the bending strength is 28MPa.

From the thermal conductivity and mechanical performance data obtained in the above examples, it can be seen that the thermal conductivity, tensile strength and flexural strength of the surface modified three-dimensional network carbon fiber reinforced metal matrix or polymer matrix composite material prepared by the present invention have all obtained Huge improvement, the thermal conductivity is as high as 1052W/mK, the tensile strength is as high as 679MPa, and the bending strength is as high as 78MPa. The composite material prepared by the present invention makes the surface-strengthened three-dimensional network carbon fiber form a three-dimensional continuous skeleton in the composite material, greatly improving The thermal conductivity of the composite material is improved. At the same time, the spatial distribution of carbon fibers in the matrix material can also improve the mechanical properties of the composite material and reduce its density and thermal expansion coefficient. At the same time, the thermal expansion coefficient and mechanical and thermal properties can be effectively adjusted by adding zero-dimensional particle reinforcements. Compared with traditional metal-based or polymer-based composite materials, the composite material has more excellent comprehensive properties in terms of mechanics, heat, electricity, heat, light weight and high strength.

Claims (11)

1. A surface-modified three-dimensional network carbon fiber reinforced composite material, characterized in that: the composite material comprises a matrix material and a three-dimensional network carbon fiber reinforcement, wherein the matrix material comprises a metal material or a polymer material; Depositing a high thermal conductivity layer directly on the surface of a three-dimensional network carbon fiber reinforcement or depositing a high thermal conductivity layer after surface modification; The deposited high thermal conductivity layer is selected from one of graphene/diamond, carbon nanotube/diamond, graphene/carbon nanotube, diamond/graphene/carbon nanotube; Realize graphene/diamond, carbon nanotube/diamond, graphene/carbon nanotube, diamond/graphene/carbon CVD deposition of nanotubes, the deposition parameters are: Graphene CVD deposition parameters are: carbon-containing gas accounts for 0.5-80% of the total gas mass flow rate in the furnace; growth temperature is 400-1200°C, growth pressure is 5-10 ⁵ Pa; plasma current density is 0-50mA/cm ² ; The magnetic field strength in the deposition area is 100 Gauss to 30 Tesla; Carbon nanotube CVD deposition parameters are: carbon-containing gas accounts for 5-50% of the total gas mass flow rate in the furnace; growth temperature is 400-1300°C, growth pressure is 10 ³ -10 ⁵ Pa; plasma current density is 0-30mA/cm ² ; The magnetic field strength in the deposition area is 100 Gauss to 30 Tesla; The diamond CVD deposition parameters are as follows: carbon-containing gas accounts for 0.5-10% of the total gas mass flow rate in the furnace; the growth temperature is 600-1000°C, and the growth pressure is 10 ³ -10 ⁴ Pa. 2. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 1, characterized in that: the metal matrix material is selected from one of metal copper and aluminum, or a copper-based alloy or an aluminum-based alloy A kind of; In the copper-based alloy and the aluminum-based alloy, the content of copper or aluminum is greater than or equal to 50%; the polymer matrix is a thermoplastic polymer or a thermosetting polymer; the thermoplastic polymer is selected from polyethylene, polypropylene, One of polystyrene, polyvinyl chloride, polytetrafluoroethylene, polycarbonate, polymethyl methacrylate, polyoxymethylene, polyamide, polysulfone; the thermosetting polymer is selected from epoxy resin, phenolic resin , amino resin, unsaturated polyester resin, silicone resin, silicone rubber, expanded polystyrene, polyurethane in one. 3. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 2, characterized in that: the pore diameter of the three-dimensional network carbon fiber reinforcement is 20 μm-5 mm, the porosity is 20-95%, and the carbon fiber diameter is 3 -500 μm. 4. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 1, characterized in that: the surface modification of the three-dimensional network carbon fiber reinforcement is to deposit a layer of metal layer on the carbon fiber surface, and the metal layer is selected from One or a composite metal layer in nickel, copper, tungsten, molybdenum, titanium, silver, chromium, said metal layer adopts electroplating, chemical plating, vapor deposition, magnetron sputtering, chemical vapor deposition, physical vapor deposition One way to deposit. 5. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 1, characterized in that: the thickness of the high thermal conductivity layer is 5-200 μm. 6. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 5, characterized in that: CVD technology is used to deposit a high thermal conductivity layer, which is specifically selected from the hot wire assisted method and microwave plasma enhanced method in CVD technology , DC plasma injection method, electron cyclotron resonance method, flame combustion method, DC discharge method, low-voltage radio frequency method, and atmospheric pressure radio frequency method. 7. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 6, characterized in that: the matrix material of the composite material also includes high thermal conductivity particles. 8. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 7, characterized in that: said high thermal conductivity particles are selected from diamond, graphene, carbon nanotubes, graphene-coated diamond microspheres , at least one of carbon nanotube-coated diamond microspheres, silicon carbide, boron carbide, aluminum nitride, and boron nitride, and the graphene-coated diamond microspheres and carbon nanotube-coated diamond microspheres are all made of obtained by chemical vapor deposition. 9. A surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 8, characterized in that: said composite material comprises the following components, composed by volume percentage: matrix material 20-80%, Three-dimensional network carbon fiber reinforcement 10-70%, high thermal conductivity particles 0-30%, the volume percentage of each component is 100%. 10. A method for preparing a surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 9, comprising the steps of: Step 1: Weave carbon fiber into a three-dimensional mesh, wash and dry; Step 2: Deposit one of nickel, copper, tungsten, molybdenum, titanium, silver, and chromium on the surface of the carbon fiber by one of the methods of electroplating, chemical plating, evaporation, magnetron sputtering, chemical vapor deposition, and physical vapor deposition. Kind or composite metal layer; The third step: Soak the three-dimensional network carbon fiber in nano-diamond powder or graphene powder or carbon nanotube suspension for ultrasonic vibration planting seed crystal pretreatment; The fourth step: use chemical vapor deposition technology to deposit diamond, graphene, and carbon nanotube composite high thermal conductivity layers on the surface of three-dimensional network carbon fiber to obtain a three-dimensional network carbon fiber reinforcement; Step 5: Composite the three-dimensional network carbon fiber reinforcement, high thermal conductivity particles and metal matrix, using powder metallurgy sintering technology or one of the methods of pressureless infiltration, gas infiltration, and casting; the powder metallurgy sintering technology is selected One of self-cold press sintering, hot press sintering, SPS sintering, vacuum sintering and atmosphere sintering; or The three-dimensional network carbon fiber reinforcement, high thermal conductivity particles and polymer matrix are compounded, and the composite adopts one of dip curing molding, injection molding, compression molding, injection molding, rotational molding, extrusion molding, lamination molding, and tape casting. way. 11. A method for preparing a surface-modified three-dimensional network carbon fiber reinforced composite material according to claim 10, characterized in that: when the matrix material is metal, a modified film is placed on the surface of the high thermal conductivity layer and then compounded with the matrix; The modified film is selected from at least one of tungsten film, molybdenum film, titanium film, nickel film, and chromium film, or at least one of TiC, WC, Cr ₇ C ₃ , NiC, and Mo ₂ C.