High-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material and preparation method thereof

Abstract

The application relates to the technical field of heat-conducting composite materials, in particular to a high-strength high-heat-conducting polyacrylonitrile carbon fiber composite material, which is prepared by stacking single-layer polyacrylonitrile carbon fiber cloth and single-layer polyacrylonitrile carbon fiber felt in sequence through needling to form a three-dimensional carbon fiber felt with a Z-direction structure; then, a reinforcing phase is added to the three-dimensional carbon fiber felt; finally, the carbon fiber felt after the reinforcing phase is filled is treated by a graphitization process to become a high-heat-conducting polyacrylonitrile carbon fiber composite material with a dense structure. Through optimization of the weaving process of the three-dimensional preform, the structural strength and the fiber content in the vertical direction of the material can be effectively improved, and the heat-conducting performance of the carbon / carbon composite material in the vertical direction is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat-conducting composite materials, and particularly relates to a high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof. BACKGROUND

[0002] High-precision and high-integration electronic components are inevitable products of economic development, and their safe and efficient operation requires that the accumulated heat be quickly dissipated. For communication satellites, advanced spacecraft and probes, efficient heat dissipation is essential. During operation, these space devices not only need to be cooled in time, but also need to maintain an appropriate temperature range to ensure their performance and service life.

[0003] To ensure the long-term, safe and reliable operation of space devices, a new type of heat-conducting material with high thermal conductivity, low thermal expansion rate and low cost has become a primary task of research and development. For new heat-conducting materials, light weight, high thermal conductivity, chemical stability and the like are basic requirements. In summary, carbon fiber composite materials have a high matching degree. At present, the preparation of carbon fiber composite materials generally focuses on the modification of carbon fibers themselves, but the thermal conductivity, electrical conductivity and mechanical properties cannot reach a high value to meet the application requirements of the high-precision field. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the present application provides a high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, which can effectively solve the above-mentioned problems existing in the prior art.

[0005] TECHNICAL SCHEME

[0006] To achieve the above-mentioned purposes, the present application is implemented by the following technical scheme:

[0007] The present application provides a high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material, which is prepared by stacking single-layer polyacrylonitrile carbon fiber cloth and single-layer polyacrylonitrile carbon fiber felt in turn by means of needling to prepare a three-dimensional carbon fiber felt with a Z-direction structure; then adding a reinforcing phase to the three-dimensional carbon fiber felt; and finally treating the carbon fiber felt after filling the reinforcing phase by graphitization process to make it into a high-thermal-conductivity polyacrylonitrile carbon fiber composite material with a dense structure.

[0008] Further, the single-layer polyacrylonitrile carbon fiber cloth and the single-layer polyacrylonitrile carbon fiber felt are both prepared into a planar skeleton structure by weaving or carding, and the thickness of the single-layer polyacrylonitrile carbon fiber cloth and felt is 0.1-0.5mm, and the density is 100-500g / m 2 ;

[0009] The needling density of the needling method is 500-1000 needles / cm2 ; the density of the three-dimensional carbon fiber felt is 0.2 g / cm 3 The thickness is 5-10 mm.

[0010] The needling process is mainly to build the Z-direction structure, and ensure that the final carbon fiber composite material has 2 or more layers of planar fiber felt or cloth. The needling density is 500-1000 needles / cm 2 , multiple needling can be repeated, and the number of layers of planar fiber felt is controlled to ensure that the density of the fiber felt is 0.2 g / cm 3 , and the thickness is 5-10 mm.

[0011] The needling process is mainly to build the Z-direction structure, and ensure that the final carbon fiber composite material has 2 or more layers of planar fiber felt or cloth. The needling density is 500-1000 needles / cm

[0012] Further, the three-dimensional carbon fiber felt is subjected to laser cleaning, and then the reinforcing phase is added. The laser cleaning parameters are as follows: laser scanning speed is 0-30 mm / s, laser pulse width is 0-350 ns, laser power is 0-100%, and laser frequency is 0-2000 kHz.

[0013] In order to better deposit the subsequent reinforcing phase, laser cleaning is used for pretreatment to increase the surface roughness. Laser cleaning is a green and environmentally friendly treatment method, which has higher efficiency than sand blasting and sandpaper polishing. The laser scanning speed (0-30 mm / s), laser pulse width (0-350 ns), laser power (0-100%), and laser frequency (0-2000 kHz) of the laser cleaning machine can be adjusted to achieve the best cleaning effect.

[0014] Further, the reinforcing phase is added to the three-dimensional carbon fiber felt by pressure difference method or chemical vapor deposition method.

[0015] Further, the reinforcing phase is added to the three-dimensional carbon fiber felt by pressure difference method or chemical vapor deposition method.

[0016] The pressure difference preparation method is as follows: the three-dimensional carbon fiber felt and the resin are put into an autoclave, the resin rapidly penetrates the fiber structure under high pressure and heating conditions, eliminates bubbles, and enhances the bonding force between the fiber and the resin. The impregnation pressure is 4-7 MPa, the impregnation time is usually 2-4 h, and the impregnation temperature is 60-80°C.

[0017] The heat pressing and curing adopts ultrasonic heating and curing, and the specific operation is as follows:

[0018] The resin composite to be cured is placed in an ultrasonic heating device, and the high-frequency vibration of the ultrasonic waves not only helps the resin to be more evenly distributed between the fibers, but also effectively removes bubbles, improving the density of the composite material. The curing temperature is generally controlled at 80-120℃, and the curing time is 4-6h. This heating method can achieve rapid and uniform heating, and the curing reaction can be completed at a lower temperature, reducing energy consumption and processing time.

[0019] Further, the reinforcing phase is deposited by chemical vapor deposition of carbon into a three-dimensional carbon fiber felt, and then graphitized at high temperature.

[0020] The chemical vapor deposition preparation method is specifically as follows: methane (CH4), ethylene (C2H4), propane (C3H8) and the like are selected as carbon sources. The laser cleaning treated polyacrylonitrile carbon fiber composite material is placed in a CVD reaction furnace, the reaction chamber temperature is controlled at 500-1500℃, carbon source gas and hydrogen are introduced, and the flow rate is adjusted by a gas flow controller (gas flow rate is 10-100sccm). The vacuum degree in the cavity is maintained at 10 -3 Under the condition of high temperature, the carbon source gas decomposes, and carbon atoms are deposited on the surface of the polyacrylonitrile carbon fiber. The deposition time is usually 0-24h, which can be adjusted according to the film thickness requirement. By precisely controlling the temperature, gas flow rate and pressure, high-quality carbon source can be introduced.

[0021] Further, the graphitization process temperature is 2800℃ and above; the heating rate is 20-40℃ / min; and the cooling rate is 20-40℃ / min.

[0022] Preferably, the graphitization process adopts stepwise holding and prolongs the holding time, and the slower heating process and holding time can make the material have a longer crystallization and structure adjustment time at high temperature, which is beneficial to reduce lattice defects and improve the thermal conductivity of the material; slow cooling or segmented cooling is adopted to avoid excessive stress in the material, thereby maintaining the structural integrity and further improving the thermal conductivity. Specifically, the stepwise holding temperature and holding time is 1000-1500℃, 2-4h; 1800-2200℃, 4-8h; 2200-2800℃, 8-12h; 2800℃ and above, 8-12h. The segmented cooling temperature and holding time is 2200-2800℃, 4-8h; 1800-2200℃, 2-4h; 1000-1500℃, 2-4h; 500-800℃, 1-2h.

[0023] Further, the reinforcing phase is one or both of carbon material and phenolic resin, which can give the carbon-carbon composite material better impact resistance, thermal stability and the like.

[0024] Preferably, the reinforcing phase adopts carbon material and phenolic resin, with a weight ratio of 3:1-1:1.

[0025] Further, the carbon fiber composite material has a thermal conductivity of more than 200 W / mK and 500 W / mK in the vertical and parallel directions respectively, an electrical conductivity of more than 1000 S / cm, a bending strength of more than 200 MPa, and a friction coefficient of less than 0.2.

[0026] A preparation method of a high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material, comprising the following steps:

[0027] S1: preparing a three-dimensional carbon fiber felt with a Z-direction structure by stacking single-layer polyacrylonitrile carbon fiber cloth and single-layer polyacrylonitrile carbon fiber felt in sequence through needling;

[0028] S2: adding a reinforcing phase to the three-dimensional carbon fiber felt;

[0029] S3: treating the carbon fiber felt filled with the reinforcing phase by using a graphitization process to make it into a high-thermal-conductivity polyacrylonitrile carbon fiber composite material with a dense structure.

[0030] Preferably, steps S2-S3 are repeated 1-5 times. Most preferably, steps S2-S3 are repeated 3 times.

[0031] Beneficial effects

[0032] Compared with the known prior art, the technical solution provided by the present application has the following beneficial effects:

[0033] (1) The present application first uses a weaving process combined with an air flow carding process to prepare single-layer planar skeleton structure polyacrylonitrile carbon fiber felt and carbon fiber cloth; then the single-layer polyacrylonitrile carbon fiber felt and the single-layer polyacrylonitrile carbon fiber cloth are stacked and compounded by needling to prepare a three-dimensional carbon fiber structure with a Z-direction structure; then a reinforcing phase is added to the carbon fiber felt or the fibers by using a differential pressure method or chemical vapor deposition; finally, the carbon fiber felt filled with the reinforcing phase is treated by using a graphitization process to make it into a high-thermal-conductivity carbon fiber composite material with a dense structure. The prepared carbon fiber composite material has a thermal conductivity of more than 200 W / mK in the vertical direction, an electrical conductivity of more than 1000 S / cm, a bending strength of more than 100 MPa, and a friction coefficient of less than 0.2.

[0034] (2) The weaving process of the three-dimensional preform is optimized, which can more effectively improve the structural strength and vertical fiber content of the material, and further greatly improve the thermal conductivity of the carbon / carbon composite material in the vertical direction.

[0035] (3) The present application adopts laser cleaning for pretreatment to increase the roughness of the surface of the carbon fiber, facilitating the subsequent deposition and adhesion of carbon, and the laser cleaning is a green and environmentally friendly treatment method, having higher efficiency than sand blasting and sandpaper polishing.

[0036] (4) The present application can increase the tightness between layers by using the mixed needle punching forming method of carbon fiber cloth and carbon fiber felt. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings described below are only some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0038] Figure 1 The preparation process of the high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material in Embodiment 1 of the present application is shown. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0040] The present application will be further described below in combination with the embodiments.

[0041] The raw material types and manufacturers used in the examples and comparative examples are as follows:

[0042] The polyacrylonitrile carbon fiber cloth and the polyacrylonitrile carbon fiber felt both use polyacrylonitrile carbon fiber as raw material, and the polyacrylonitrile carbon fiber is produced by the Japanese Toyo Rayon Co., Ltd., and the type is M60J.

[0043] The phenolic resin is manufactured by Jinan Shengquan Co., Ltd., and the type is PF7303.

[0044] (I) Examples

[0045] Example 1:

[0046] A high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, the preparation process is as shown in Figure 1 The preparation process includes the following steps:

[0047] (1) First, polyacrylonitrile carbon fiber is used as raw material, and a plane skeleton structure of polyacrylonitrile carbon fiber cloth and a polyacrylonitrile carbon fiber felt are prepared by weaving (PAN-based carbon fiber plain weave is interwoven into a net structure by a weaving machine, and the fibers are interwoven in the longitudinal and transverse directions during the weaving process to form a stable grid structure) and carding (the kinetic energy of the airflow is used to distribute the PAN-based carbon fiber in a certain direction to form a uniform fiber layer). The thickness of the formed polyacrylonitrile carbon fiber cloth and polyacrylonitrile carbon fiber felt is 100 μm, and the density is 100 g / m 2 ;

[0048] Then the polyacrylonitrile carbon fiber cloth and the polyacrylonitrile carbon fiber felt are stacked to prepare a complete 3D fiber felt with Z direction by needle punching; wherein the needle punching density is finally 1000 pricks / cm 2 , the thickness of the prepared three-dimensional polyacrylonitrile carbon fiber structure is 10 mm, and the density is 0.30 g / cm 3 ;

[0049] (2) The 3D fiber felt prepared in step (1) is pretreated by laser scanning at a speed of 30 mm / s, a laser pulse width of 350 ns, a laser power of 100%, and a laser frequency of 2000 kHz to facilitate the introduction of the carbon source later;

[0050] (3) The 3D fiber felt treated by laser in step (2) is placed in a high-pressure kettle, and a phenolic resin solution is injected into the fiber felt by using a high pressure of 7 MPa, and the impregnation temperature and time are 80℃ and 4h; then the 3D fiber felt / phenolic composite material is placed in an ultrasonic heating device for ultrasonic curing, and the curing temperature is 120℃, and the curing time is 6h, which is convenient for the subsequent graphitization step;

[0051] (4) The 3D fiber felt / phenolic composite material in step (3) is placed in a graphitization furnace for graphitization treatment, the graphitization temperature is 3000℃, the heating rate is 20℃ / min, and the stepwise holding temperature and time are: 1200℃, 4h; 2200℃, 8h; 2800℃, 12h; 3000℃, 12h; the cooling rate is 20℃ / min, and the segmented cooling temperature and holding time are 2500℃, 8h; 1800℃, 4h; 1000℃, 4h; 500℃, 1h.

[0052] (5) Repeat steps (3) and (4) 3 times to obtain a carbon / carbon composite material with a density of 1.8 g / cm 3 .

[0053] Example 2:

[0054] A high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, different from example 1, are characterized in that steps (3) and (4) are repeated 5 times, and the density of the polyacrylonitrile carbon fiber composite material prepared is 2.0 g / cm 3 .

[0055] Example 3

[0056] A high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, different from example 1, are characterized in that only step (3) is different, and step (3) is specifically as follows:

[0057] A 3D fiber felt / carbon composite material is prepared by chemical vapor deposition, wherein propane (C3H8) is selected as the carbon source, the reaction chamber temperature is 1500℃, the gas flow is 100sccm, the cavity vacuum degree is kept at 10 -4 , and the deposition time is 24h.

[0058] The density of the polyacrylonitrile carbon fiber composite material prepared by using example 3 is 2.0 g / cm 3 .

[0059] Comparative example 1

[0060] A high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, different from example 1, are characterized in that only step (4) is different, and is specifically as follows:

[0061] The 3D fiber felt / phenolic composite material in step (3) is placed into a graphitization furnace for graphitization treatment, the graphitization temperature is 2300℃, the heating rate is 20℃ / min, the stepwise holding temperature and time are 1200℃, 4h; 2300℃, 8h; the segmented cooling temperature and holding time are 2000℃, 8h; 1500℃, 4h; 1000℃, 4h; 500℃, 1h.

[0062] Comparative example 2

[0063] A high-strength and high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, different from example 1, are characterized in that only step (4) is different, and is specifically as follows:

[0064] The 3D fiber felt / phenolic composite material in step (3) is placed into a graphitization furnace for graphitization treatment, the graphitization temperature is 2300℃, the holding time is 8h, and the heating rate is 20℃ / min. No stepwise heating, holding and segmented cooling treatment is performed, and direct furnace cooling is performed.

[0065] Comparative example 3

[0066] A high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, the difference from example 1 is only that the reinforcing phase adopts graphite and phenolic resin, and the weight ratio is 3:1.

[0067] Comparative example 4:

[0068] A high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, the difference from example 1 is only that the reinforcing phase adopts graphite and phenolic resin, and the weight ratio is 1:1.

[0069] Comparative example 5:

[0070] A high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material and a preparation method thereof, the difference from example 1 is only that step (1) is different, and all polyacrylonitrile carbon fiber cloth is used, specifically:

[0071] (1) First, polyacrylonitrile carbon fiber is used as raw material to prepare a planar skeleton structure of polyacrylonitrile carbon fiber cloth, the thickness of the formed polyacrylonitrile carbon fiber cloth is 100 μm, and the density is 100 g / m 2 ;

[0072] Then, the polyacrylonitrile carbon fiber cloth is stacked in a needling manner to prepare a complete 3D fiber felt with Z direction; wherein the needling density is finally 1000 needles / cm 2 , and the thickness of the prepared three-dimensional polyacrylonitrile carbon fiber structure is 10 mm.

[0073] Comparative example 6:

[0074] The difference from example 1 is only that step (1) is different, and all polyacrylonitrile carbon fiber felt is used, specifically:

[0075] (1) First, polyacrylonitrile carbon fiber is used as raw material to prepare a planar skeleton structure of polyacrylonitrile carbon fiber felt, the thickness of the formed polyacrylonitrile carbon fiber felt is 100 μm, and the density is 100 g / m 2 ;

[0076] Then, the polyacrylonitrile carbon fiber felt is stacked in a needling manner to prepare a complete 3D fiber felt with Z direction; wherein the needling density is finally 1000 needles / cm 2 , and the thickness of the prepared three-dimensional polyacrylonitrile carbon fiber structure is 10 mm.

[0077] Comparative example 7:

[0078] The difference from example 1 is only that step (1) is different, specifically:

[0079] (1) First, polyacrylonitrile carbon fibers are used as raw materials to prepare a polyacrylonitrile carbon fiber cloth and a polyacrylonitrile carbon fiber felt with a planar skeleton structure by weaving (PAN-based carbon fibers are interwoven into a net-like structure by a weaving machine, and the fibers are interwoven in the longitudinal and transverse directions during the weaving process to form a stable grid structure) and carding (the kinetic energy of the airflow is used to distribute the PAN-based carbon fibers in a certain direction to form a uniform fiber layer). The thickness of the shaped polyacrylonitrile carbon fiber cloth and the polyacrylonitrile carbon fiber felt is 100 μm, and the density is 100 g / m 2 ;

[0080] Then the polyacrylonitrile carbon fiber cloth and the polyacrylonitrile carbon fiber felt are stacked to prepare a 3D fiber felt. The thickness of the three-dimensional polyacrylonitrile carbon fiber structure prepared is 10 mm.

[0081] Comparative Example 8:

[0082] The difference from Example 1 is only that step (2) is missing.

[0083] Comparative Example 9:

[0084] The difference from Example 1 is only that viscose-based carbon fibers are used as raw materials instead of polyacrylonitrile carbon fibers.

[0085] Comparative Example 10:

[0086] The difference from Example 1 is only that the reinforcing phase uses only graphite.

[0087] Comparative Example 11:

[0088] The difference from Example 1 is only that a sandblasting method with a pressure of 0.2 MPa and a spraying distance of 300 mm is used instead of laser cleaning to pretreat the PAN-based carbon fiber felt.

[0089] (B) Performance Test

[0090] (1) Test method

[0091] Conductivity: The volume resistivity and conductivity of the carbon fiber composite material are tested using a four-probe tester. The four metal probes of the four-probe tester are arranged in a straight line, one probe as a current source, another probe as a voltage measurement electrode, and the other two probes for measuring current and voltage. During the measurement process, the probes are placed on the surface of the carbon fiber composite material and a current is applied.

[0092] Thermal conductivity: The thermal conductivity of the carbon fiber composite material is mainly obtained by the product of thermal diffusivity, specific heat, and density. The thermal diffusivity is obtained by a laser thermal conductivity instrument, the model and manufacturer of which are LFA 467 and NETZSCH, Germany. The specific heat is measured by a differential scanning calorimeter under nitrogen at a heating rate of 10°C per minute, the model and manufacturer of which are DSC 214 and NETZSCH, Germany. The density is measured by a densimeter, the model and manufacturer of which are SJ-300G and Shanghai Shujue Instrument Technology Co., Ltd.

[0093] Bending strength: A CMT6103 electronic universal testing machine produced by MTS Industrial System is used as a testing device.

[0094] Friction coefficient: The room temperature friction coefficient of the carbon fiber composite material is tested by using a reciprocating friction and wear instrument. The model of the reciprocating friction and wear instrument is GF-1, and the manufacturer is Lanzhou Zhongke Kaixing Technology Development Co., Ltd. The applied friction force is 20 N, and the friction rate is 500 rpm.

[0095] (2) Test results

[0096]

[0097]

[0098] It can be known from Examples 1-3 that the thermal conductivity of the carbon fiber composite material prepared by the technical scheme of the application in the vertical and parallel directions is more than 200 W / mK and 500 W / mK respectively, the electrical conductivity is greater than 1000 S / cm, the bending strength is greater than 200 MPa, and the friction coefficient is less than 0.2.

[0099] It can be known from Examples 1 and Comparative Examples 1-2 that by using stepwise heating and stepwise cooling, the thermal and electrical conductivity of the carbon fiber composite material can be effectively improved. It can be known from Examples 1 and Comparative Examples 5-7 that the carbon fiber composite material prepared by stacking and needling polyacrylonitrile carbon fiber cloth and polyacrylonitrile carbon fiber felt has greatly improved thermal and electrical conductivity. It can be known from Examples 1 and Comparative Example 8 that the thermal and electrical conductivity of the carbon fiber composite material prepared without laser treatment will be affected. It can be known from Examples 1 and Comparative Example 11 that laser pretreatment is better than sandblasting or manual polishing. It can be known from Examples 1 and Comparative Examples 3-4 and 10 that using carbon materials as synergistic reinforcing phases can improve the thermal and electrical conductivity of the carbon fiber composite material. It can be known from Examples 1 and Comparative Example 9 that the composite material prepared by using PAN-based carbon fiber is better than viscose-based carbon fiber composite material.

[0100] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present application.

Claims

1. A high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material, characterized by, It is prepared by needle punching method to stack single layer polyacrylonitrile carbon fiber cloth and single layer polyacrylonitrile carbon fiber felt into three-dimensional carbon fiber felt with Z-direction structure; then laser cleaning is carried out on the three-dimensional carbon fiber felt, and then the reinforcing phase is added to the three-dimensional carbon fiber felt, the reinforcing phase is added to the three-dimensional carbon fiber felt by pressure difference method or chemical vapor deposition method, and the reinforcing phase is carbon source gas or phenolic resin; finally, the carbon fiber felt filled with the reinforcing phase is treated by graphitization process to become high-thermal-conductivity polyacrylonitrile carbon fiber composite material with dense structure. The thermal conductivity of the carbon fiber composite material in the vertical and parallel directions is more than 200 W / mK, 500 W / mK respectively, the electrical conductivity is greater than 1000 S / cm, the bending strength is greater than 200 MPa, and the friction coefficient is less than 0.

2.

2. The high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material according to claim 1, characterized in that, The laser cleaning parameters are as follows: 0< laser scanning speed ≤30 mm / s, 0< laser pulse width ≤350 ns, 0< laser power ≤100%, 0< laser frequency ≤2000 kHz.

3. The high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material according to claim 1, characterized in that, The reinforcing phase is filled into the three-dimensional carbon fiber felt by pressure difference preparation method, and then heat pressing and curing are carried out, and then high temperature graphitization treatment is carried out. The pressure difference preparation method is as follows: the three-dimensional carbon fiber felt and phenolic resin are put into an autoclave, the phenolic resin rapidly penetrates the fiber structure under high pressure heating conditions, the bubbles are eliminated, and the bonding force between the fiber and the resin is enhanced, wherein the impregnation pressure is 4-7 MPa, the impregnation time is 2-4 h, and the impregnation temperature is 60-80℃. The heat pressing and curing adopts ultrasonic heating and curing, and the specific operation is as follows: the resin composite to be cured is placed in an ultrasonic heating device, the curing temperature is 80-120℃, and the curing time is 4-6 h.

4. The high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material according to claim 1, characterized by, The reinforcing phase is deposited into the three-dimensional carbon fiber felt by chemical vapor deposition, and then high temperature graphitization treatment is carried out. The specific operation method of the chemical vapor deposition is as follows: the three-dimensional carbon fiber felt after the laser cleaning treatment is placed in a CVD reaction furnace, carbon source gas and hydrogen are introduced by controlling the reaction chamber temperature in the range of 500-1500℃, and the gas flow is adjusted to 10-100sccm by a gas flow controller, and the cavity vacuum degree is kept at 10 -3 Under the high temperature condition, the carbon source gas is decomposed, and carbon atoms are deposited on the surface of the polyacrylonitrile carbon fiber, and 0< deposition time≤24h.

5. The high-strength high-thermal-conductivity polyacrylonitrile carbon fiber composite material according to claim 3 or 4, characterized by, The graphitization process treatment temperature is above 2800℃; the heating rate is 20-40℃ / min; the cooling rate is 20-40℃ / min; The stepwise holding temperature and holding time is 1000-1500℃, 2-4h; 1800-2200℃, 4-8h; 2200-2800℃, 8-12h; above 2800℃, 8-12h; The segmented cooling temperature and holding time is 2200-2800℃, 4-8h; 1800-2200℃, 2-4h; 1000-1500℃, 2-4h; 500-800℃, 1-2h.

6. A method of producing a high-strength, high-thermal-conductivity polyacrylonitrile carbon fiber composite material according to any one of claims 1 to 5, characterized by: It includes the following steps: S1: single layer polyacrylonitrile carbon fiber cloth and single layer polyacrylonitrile carbon fiber felt are stacked in sequence by needle punching method to prepare three-dimensional carbon fiber felt with Z-direction structure; S2: adding the reinforcing phase to the three-dimensional carbon fiber felt; S3: treating the carbon fiber felt filled with the reinforcing phase by graphitization process to become high-thermal-conductivity polyacrylonitrile carbon fiber composite material with dense structure.

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