Preparation method of carbon / carbon composite material with high thermal conductivity

Abstract

The invention relates to the technical field of high-temperature structural parts, in particular to a preparation method of a high-thermal-conductivity carbon / carbon composite material, which comprises the following steps: dipping a fiber preform in a graphene oxide solution, and then drying and shaping; performing high-temperature foaming treatment on the treated fiber preform; carrying out liquid phase impregnation on the treated prefabricated body, and then carrying out carbonization and graphitization treatment; according to the high-thermal-conductivity carbon / carbon composite material and the preparation method thereof, graphene oxide is attached to fibers in the prefabricated body, then rapid high-temperature treatment is carried out, so that graphene oxide is foamed to generate a large number of micropores, the fibers and pore bubbles are mutually connected to form a three-dimensional network structure, and after liquid-phase impregnation and heat treatment, the high-thermal-conductivity carbon / carbon composite material is obtained. The heat-conducting property and the mechanical strength of the carbon / carbon composite material are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature structural parts, and in particular to a method for preparing a high-thermal-conductivity carbon / carbon composite material. Background Art

[0002] With the development of the aviation industry, the performance and production capacity requirements for new aircraft engines and supersonic vehicles are rapidly increasing, and the performance requirements for their components in extreme operating environments are also constantly increasing. New high-performance aircraft engines require materials such as tail nozzles, liners, and turbine blades that are resistant to ultra-high temperatures and ablation. Thermal protection, heat conduction structures, and thermal control system components of new spacecraft require corrosion-resistant, lightweight, and highly thermally conductive materials.

[0003] Conventional composite materials and molding technologies are no longer able to meet current development needs because they have reached bottlenecks in mechanical properties, wear resistance, corrosion resistance, high-temperature oxidation resistance, and high-temperature thermal stability. High-thermal-conductivity carbon / carbon composites, reinforced with carbon fibers mixed with other high-performance fibers, offer not only high strength, ablation resistance, and high-temperature resistance, but also strong designability and excellent mechanical, thermophysical, and thermal shock properties. They are among the few materials that can achieve both lightweight performance and high mechanical properties above 2500°C, making them the preferred high-temperature thermal protection material in the aerospace industry. They are widely used in critical hot-end components such as strategic missile warheads, engine nozzles, and nose cones / leading edges of space shuttles and hypersonic vehicles. Conventional carbon / carbon composites prepared by current methods generally suffer from low density and poor thermal conductivity. To address these challenges, we propose a method for preparing high-thermal-conductivity carbon / carbon composites. Summary of the Invention

[0004] The object of the present invention is to provide a method for preparing a high thermal conductivity carbon / carbon composite material to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a high thermal conductivity carbon / carbon composite material comprises the following steps:

[0007] S1, dipping the fiber preform into a graphene oxide solution, and then drying and shaping it;

[0008] S2, subjecting the fiber preform processed in step S1 to high-temperature foaming treatment;

[0009] S3, subjecting the preform processed in step S2 to liquid phase impregnation, and then to carbonization and graphitization treatment;

[0010] S4. Repeat step S3 multiple times to obtain a finished high thermal conductivity carbon / carbon composite material.

[0011] Preferably, in step S1, the fibers in the fiber preform include, but are not limited to, one or more of polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, and polyimide fibers.

[0012] The fiber preform is used to make the embryonic body of carbon / carbon composite materials and is the skeleton of carbon / carbon composite materials.

[0013] Preferably, in step S1, the fiber preform is in a form selected from any one of fiber mat, fiber cloth, fiber shaped fabric, and chopped fiber embryo.

[0014] Preferably, in step S1, the graphene oxide solution is obtained by diluting graphene oxide slurry with pure water, the solid content of the graphene oxide solution is 1% to 5%, and the immersion time is 30 to 60 minutes.

[0015] Preferably, in step S1, the drying and shaping is carried out in a drying oven, the drying temperature is 60-100° C., and the drying time is 1-3 hours.

[0016] Preferably, in step S2, the high-temperature foaming treatment is performed in a high-temperature furnace, the temperature of the high-temperature furnace is 300-400° C., and the treatment time is 10-60 minutes.

[0017] The high-temperature foaming treatment is to send the fiber preform with added graphene oxide into a high-temperature furnace. Since the graphene oxide quickly rises to a high temperature in a short period of time, under the action of thermal expansion, the residual air inside will quickly diffuse outward, causing the graphene oxide to form a large number of bubbles and holes.

[0018] Preferably, in step S3, liquid phase impregnation refers to immersing the fiber preform in a phenolic resin solution or molten asphalt, so that the phenolic resin solution or molten asphalt fills the pores of the fiber preform, and the liquid phase impregnation time is 1 to 3 hours.

[0019] Preferably, in step S3, the carbonization treatment temperature is 800-1500° C., the carbonization treatment heating rate is 3-30° C. / min, and the holding time is 1-5 h.

[0020] Preferably, in step S3, the graphitization treatment temperature is 2300-2800° C., the graphitization treatment heating rate is 20-100° C. / min, and the holding time is 0.5-1 h.

[0021] Preferably, in step S4, step S3 is repeated 5 to 10 times.

[0022] The obtained finished high thermal conductivity carbon / carbon composite material consists of two main components: fiber carbon and matrix carbon. The fiber carbon is obtained by carbonizing and graphitizing fibers, and the matrix carbon is obtained by carbonizing and graphitizing phenolic resin or asphalt.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The preparation method of this high thermal conductivity carbon / carbon composite material uses fibers and graphene oxide bubbles to form a three-dimensional network porous structure. This structure serves as the basic skeleton of the carbon / carbon composite material and improves the thermal conductivity of the carbon / carbon composite material. The three-dimensional network porous structure is conducive to the adhesion of the matrix carbon, increases the density of the carbon / carbon composite material, and thus improves the mechanical strength of the carbon / carbon composite material.

[0025] 2. The method for preparing the high thermal conductivity carbon / carbon composite material using a fiber preform and a graphene oxide solution as raw materials is simple and easy to implement, convenient for industrial production, and conducive to the mass preparation and application of high-performance, low-cost high thermal conductivity carbon / carbon composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flow chart of the preparation method of the high thermal conductivity carbon / carbon composite material of the present invention;

[0027] Figure 2 These are scanning electron microscope images of the finished high thermal conductivity carbon / carbon composite material obtained in Example 1 of the present invention at different angles and sizes. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] Example 1

[0030] A method for preparing a high thermal conductivity carbon / carbon composite material comprises the following steps:

[0031] S1. Select polyacrylonitrile-based carbon fiber felt as a fiber preform of a carbon / carbon composite material, prepare a 3% solid content graphene oxide solution for standby use, immerse the fiber preform in the graphene oxide solution for 30 minutes, then take it out and place it in a drying oven for drying and shaping, and dry it at 60°C for 1 hour to remove the solvent, so that the graphene oxide is attached to the fibers in the preform;

[0032] S2, raising the temperature of the high-temperature furnace to 350° C., then placing the fiber preform treated in step S1 into the high-temperature furnace for high-temperature foaming treatment, and taking out the fiber preform after foaming is completed for later use;

[0033] S3, preparing a phenolic resin solution with a concentration of 20%, placing the preform treated in step S2 into the phenolic resin solution and immersing it for 1 hour, and then performing carbonization and graphitization treatment, the carbonization treatment temperature is 1500°C, the carbonization treatment heating rate is 15°C / min, and the holding time is 1 hour, the graphitization treatment temperature is 2600°C, the graphitization treatment heating rate is 50°C / min, and the holding time is 0.5 hour;

[0034] S4. Repeat step S3 six times to obtain a finished high thermal conductivity carbon / carbon composite material.

[0035] Example 2

[0036] A method for preparing a high thermal conductivity carbon / carbon composite material comprises the following steps:

[0037] S1. Select polyacrylonitrile-based carbon fiber felt as a fiber preform of a carbon / carbon composite material, prepare a 3% solid content graphene oxide solution for standby use, immerse the fiber preform in the graphene oxide solution for 30 minutes, then take it out and place it in a drying oven for drying and shaping, and dry it at 60°C for 1 hour to remove the solvent, so that the graphene oxide is attached to the fibers in the preform;

[0038] S2, raising the temperature of the high-temperature furnace to 350° C., then placing the fiber preform treated in step S1 into the high-temperature furnace for high-temperature foaming treatment, and taking out the fiber preform after foaming is completed for later use;

[0039] S3, placing the preform treated in step S2 into an asphalt impregnation tank and impregnating it with molten asphalt for 2 hours, and then performing carbonization and graphitization treatments, wherein the carbonization treatment temperature is 1500°C, the carbonization treatment heating rate is 15°C / min, and the holding time is 1 hour; the graphitization treatment temperature is 2800°C, the graphitization treatment heating rate is 50°C / min, and the holding time is 0.5 hour;

[0040] S4. Repeat step S3 six times to obtain a finished high thermal conductivity carbon / carbon composite material.

[0041] Example 3

[0042] A method for preparing a high thermal conductivity carbon / carbon composite material comprises the following steps:

[0043] S1. Select polyacrylonitrile-based carbon fiber felt as a fiber preform of a carbon / carbon composite material, prepare a 3% solid content graphene oxide solution for standby use, immerse the fiber preform in the graphene oxide solution for 30 minutes, then take it out and place it in a drying oven for drying and shaping, and dry it at 60°C for 1 hour to remove the solvent, so that the graphene oxide is attached to the fibers in the preform;

[0044] S2, raising the temperature of the high-temperature furnace to 350° C., then placing the fiber preform treated in step S1 into the high-temperature furnace for high-temperature foaming treatment, and taking out the fiber preform after foaming is completed for later use;

[0045] S3, placing the preform treated in step S2 into an asphalt impregnation tank and impregnating it with molten asphalt for 2 hours, and then performing carbonization and graphitization treatments, wherein the carbonization treatment temperature is 1500°C, the carbonization treatment heating rate is 15°C / min, and the holding time is 1 hour; the graphitization treatment temperature is 2800°C, the graphitization treatment heating rate is 50°C / min, and the holding time is 0.5 hour;

[0046] S4. Repeat step S3 eight times to obtain a finished high thermal conductivity carbon / carbon composite material.

[0047] Comparative Example 1

[0048] The preparation process of Comparative Example 1 is the same as that of Example 1, except that the fiber preform is not immersed in the graphene oxide solution, but only undergoes high-temperature foaming, liquid phase impregnation, carbonization, and graphitization.

[0049] Table 1 shows some properties of the carbon / carbon composite materials prepared in Examples 1 to 3 and Comparative Example 1.

[0050] Table 1 Properties of carbon / carbon composites

[0051]

[0052] In summary, the present technical solution is to impregnate a fiber preform with a graphene oxide solution, and then perform drying and shaping, high-temperature foaming, liquid-phase impregnation, carbonization, and graphitization treatments; repeat the liquid-phase impregnation, carbonization, and graphitization treatments multiple times to obtain a finished high-thermal conductivity carbon / carbon composite material. The fibers and graphene oxide pores form a three-dimensional network porous structure, which serves as the basic skeleton of the carbon / carbon composite material and improves the thermal conductivity of the carbon / carbon composite material. The three-dimensional network porous structure is conducive to the adhesion of the matrix carbon, increases the density of the carbon / carbon composite material, and thereby improves the mechanical strength of the carbon / carbon composite material.

[0053] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high thermal conductivity carbon / carbon composite material, characterized in that: The following steps are involved: S1, dipping the fiber preform into a graphene oxide solution, and then drying and shaping it; S2, subjecting the fiber preform processed in step S1 to high-temperature foaming treatment; S3, subjecting the preform processed in step S2 to liquid phase impregnation, and then to carbonization and graphitization treatment; S4. Repeat step S3 multiple times to obtain a finished high thermal conductivity carbon / carbon composite material.

2. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, characterized in that: In step S1, the fibers in the fiber preform include, but are not limited to, one or more of polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, and polyimide fibers.

3. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, wherein: In the step S1, the fiber preform is selected from any one of a fiber mat, a fiber cloth, a fiber shaped fabric, and a chopped fiber embryo.

4. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, wherein: In step S1, the graphene oxide solution is obtained by diluting the graphene oxide slurry with pure water, the solid content of the graphene oxide solution is 1% to 5%, and the immersion time is 30 to 60 minutes.

5. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, wherein: In the step S1, the drying and shaping is carried out in a drying oven at a drying temperature of 60 to 100° C. and a drying time of 1 to 3 hours.

6. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, characterized in that: In step S2, the high-temperature foaming treatment is performed in a high-temperature furnace, the temperature of the high-temperature furnace is 300-400° C., and the treatment time is 10-60 minutes.

7. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, characterized in that: In step S3, liquid phase impregnation refers to immersing the fiber preform in a phenolic resin solution or molten asphalt, so that the phenolic resin solution or molten asphalt fills the pores of the fiber preform. The liquid phase impregnation time is 1 to 3 hours.

8. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, characterized in that: In step S3, the carbonization treatment temperature is 800-1500° C., the carbonization treatment heating rate is 3-30° C. / min, and the holding time is 1-5 hours.

9. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, characterized in that: In step S3, the graphitization treatment temperature is 2300-2800° C., the graphitization treatment heating rate is 20-100° C. / min, and the holding time is 0.5-1 h.

10. The method for preparing a high thermal conductivity carbon / carbon composite material according to claim 1, characterized in that: In step S4, step S3 is repeated 5 to 10 times.

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