Preparation method of graphite-carbon carbon composite hot-pressing die and structure of hot-pressing die

Abstract

The application discloses a preparation method of a graphite-carbon composite hot-pressing die and a hot-pressing die structure, and belongs to the technical field of hot-pressing die preparation. The preparation method comprises the following steps: S1, graphite powder and a binder are put into a mixer according to a mass ratio of 10:3 and are mixed, and then a graphite core rod is obtained through cold isostatic pressing, vacuum sintering and turning; S2, carbon fibers are woven on the outer side of the graphite core rod to obtain a composite graphite rod; S3, carbon deposition is carried out on the inner and outer sides of the woven carbon fibers; S4, the carbon fibers subjected to the carbon deposition are dried to obtain a carbon-carbon outer die; and S5, the graphite core rod is machined to obtain graphite inner dies with different hole types, and then the obtained graphite outer die is sleeved on the outer side of the graphite inner dies to obtain a graphite-carbon composite hot-pressing die. The graphite and the carbon-carbon composite material are combined, the advantages of both can be combined, the composite die with good lubricity, easy processing and pressure resistance is obtained, and the service life of the die is prolonged.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of hot-pressing die preparation, in particular to a graphite-carbon-carbon composite hot-pressing die preparation method and a hot-pressing die structure. BACKGROUND

[0002] For powder sintering forming which is relatively difficult to sinter, a hot-pressing sintering process is usually adopted, powder is loaded in a metal or graphite die, and pressure is applied during sintering, so that dense, uniform and fine-grained material can be obtained in a short time under the action of temperature and pressure. At present, the die for hot-pressing sintering on the market is mostly graphite material. Graphite has good electrical conductivity, thermal conductivity, low thermal expansion coefficient and high thermal stability. In addition, as a die, its good lubricity and wear resistance also play a great role. However, with the development of various composite materials and the improvement of process requirements, the graphite die can only withstand a pressure of about 30-70 MPa, which limits its use. Increasing the wall thickness of the graphite die to improve the pressure resistance of the die cannot solve the problem.

[0003] Carbon-carbon composite material refers to a kind of composite material taking carbon fiber as a reinforcing body and taking carbon as a matrix. It is one of the materials with the best temperature resistance among the known materials at present, and its good wear resistance and fracture toughness make it widely used. In recent years, carbon-carbon composite material has been gradually applied in the die industry, but the carbon-carbon die is difficult to form and process, and the processing cycle is long, which limits its application. Therefore, a composite die with good lubricity, easy processing and pressure resistance is needed. SUMMARY

[0004] To solve the above technical problems, the application provides a graphite-carbon-carbon composite hot-pressing die preparation method and a hot-pressing die structure.

[0005] The technical scheme of the application is as follows: a graphite-carbon-carbon composite hot-pressing die preparation method, comprising the following steps:

[0006] S1, graphite core rod preparation:

[0007] The graphite powder and the binder are put into a mixer at a mass ratio of 10:3 for mixing, the mixer rotates at a speed of 200-220 r / min, and the mixing time is 10-20 min. After mixing, the mixture is put into a rubber sleeve, and the rubber sleeve is then put into a cold isostatic pressing machine to press the graphite rod, wherein the working pressure of the cold isostatic pressing machine is 100-300 MPa. Then, the graphite rod is put into a vacuum sintering furnace for sintering, and after sintering, the graphite rod is naturally cooled, then turned, and finally the graphite core rod is obtained.

[0008] S2, carbon fiber weaving:

[0009] The outer side of the graphite mandrel is wound and woven with carbon fibers, the winding thickness is 20-100mm, after winding, the materials on the upper and lower ends of the graphite mandrel are removed by a lathe to obtain a carbon fiber composite graphite rod;

[0010] S3, carbon deposition:

[0011] The outer wall of the carbon fiber composite graphite rod is subjected to carbon deposition treatment by chemical vapor deposition, the carbon deposition times are 3-5 times, the carbon deposition time is 20-40h, the carbon deposition temperature is 900-1300℃, after the carbon deposition is completed, the graphite mandrel in the center part of the carbon fiber composite graphite rod is taken out to obtain a carbon fiber woven sleeve and a graphite mandrel, and the inner wall of the carbon fiber woven sleeve is subjected to carbon deposition treatment, and the carbon carbon composite sleeve and the graphite mandrel are obtained after the carbon deposition treatment; The carbon deposition treatment on the outer wall of the carbon fiber composite graphite rod and the carbon deposition treatment on the inner wall of the carbon fiber woven sleeve are both carbon deposition methods of the prior art;

[0012] S4, drying:

[0013] The carbon carbon composite sleeve obtained in step S3 is placed in a drying machine and subjected to drying treatment at 200-1000℃ for 2-5h to obtain a carbon carbon outer mold;

[0014] S5, preparation of a composite mold:

[0015] The graphite mandrel obtained in step S3 is subjected to machining to remove the materials at the center position of the graphite mandrel to obtain a graphite inner mold with a required hole type and hole diameter, and the graphite outer mold obtained in step S4 is sleeved outside the graphite inner mold to obtain a graphite-carbon carbon composite hot-pressing mold.

[0016] Further, the binder in step S1 is composed of the following components by weight: 5-8 parts of graphene powder, 20-25 parts of organic silicone resin.

[0017] Description: The graphite mandrel prepared by the above graphene binder has the advantages of high strength, good corrosion resistance, light weight and good thermal conductivity.

[0018] Further, in step S1, the particle size of the graphite powder is 20-100μm, and when the graphite rod is sintered in a vacuum sintering furnace, the vacuum degree of the vacuum sintering furnace is 3-6Pa, and the sintering temperature is 800-1000℃.

[0019] Description: The graphite mandrel prepared by the above particle size of the graphite powder has the advantages of high strength and low surface roughness, and vacuum sintering can promote the crystal growth and defect repair of the graphite material, improve its structure and performance, and can exclude impurities such as oxygen and moisture in the air, avoid oxidation and hydrolysis reaction, thereby improving the purity of the graphite material.

[0020] Further, the carbon fibers in step S2 are a mixture of long carbon fibers and short carbon fibers or long carbon fibers, the length of the long carbon fibers is 1-2m, and the length of the short carbon fibers is 4-8cm.

[0021] Explanation: The longer the length of the carbon fibers, the higher the strength of the carbon fiber mold prepared. This is because longer carbon fibers have better tensile strength and stiffness, which can improve the compression and bending strength of the mold, and shorter carbon fibers have better toughness, which can improve the crack resistance and fatigue resistance of the mold. Therefore, the carbon carbon outer mold woven with long carbon fibers or long carbon fibers and short carbon fibers meets the performance requirements of production.

[0022] Further, the winding and weaving method in step S2 is direct winding, spiral winding, or layer-by-layer winding of the woven fabric.

[0023] Explanation: The above methods can realize the weaving of carbon fibers, and the weaving effect meets the requirements of production process.

[0024] Further, after the carbon carbon composite sleeve is placed in the drying machine in step S4, the drying machine needs to be evacuated to a vacuum degree of 3-5Pa, and then argon is introduced as a protective gas. The argon gas is introduced into the drying machine at an internal gas pressure of 0.12-0.15MPa.

[0025] Explanation: The drying machine can effectively remove cutting fluid, moisture, moisture, and gum during processing.

[0026] Further, before the outer wall of the carbon fiber composite graphite rod is subjected to chemical vapor deposition in step S3, a surface modifier needs to be brushed on the surface of the carbon fiber, and the surface modifier is composed of the following components by weight: 5-10 parts of silica powder, 7-11 parts of triethanolamine phosphate powder, 10-18 parts of urethane, and 3-5 parts of citric acid powder.

[0027] Explanation: The surface modifier can effectively prevent the carbon fiber surface from having poor chemical stability, which is easily affected by environmental factors such as oxidation and hydrolysis, and deteriorates.

[0028] Further, the carbon precursor used during carbon deposition in step S3 is mixed by volume ratio of 5:5:1 of nitrogen, methane, and hydrogen.

[0029] Explanation: Methane pyrolyzes to produce carbon powder deposited on the surface of the carbon fiber during carbon deposition, nitrogen is used as a protective gas, and hydrogen is used as a reducing gas to prevent oxidation of carbon elements during carbon deposition.

[0030] Further, the thickness of the carbon deposition on the outer wall of the carbon fiber composite graphite rod in step S3 is 0.5-1mm, and the thickness of the carbon deposition on the inner wall of the carbon fiber braided sleeve is 0.2-0.5mm.

[0031] Description: Carbon deposition can form a dense carbon film on the surface of the carbon fiber mold, thereby reducing the roughness and porosity of the surface and improving the strength and rigidity.

[0032] Further, the graphite-carbon carbon composite hot-pressing mold prepared by the above method comprises a graphite inner mold and a carbon carbon outer mold, the inner side wall and the outer side wall of the carbon carbon outer mold are covered with a deposition film, and the middle part of the graphite inner mold is provided with a cavity.

[0033] Description: When used, the graphite mold is clamped with the carbon carbon outer mold to prevent the graphite inner film from cracking and enhance the strength of the overall mold.

[0034] The beneficial effects of the present application are:

[0035] (1) The single graphite mold has poor bending resistance and low tensile strength, cracks under extreme pressure, and is brittle, which has a large impact on the equipment during hot-pressing sintering.

[0036] (2) The single carbon carbon mold has high tensile strength, but the inner cavity of the carbon carbon mold is prone to delamination of long carbon fibers or carbon fiber sheets due to repeated friction during repeated pressing and demolding in the hot-pressing process, which causes the carbon carbon mold to be unusable.

[0037] (3) The present application combines graphite and carbon carbon composite materials, which can combine the advantages of both and obtain a composite mold with good lubricity, easy processing, and pressure resistance, thereby prolonging the service life of the mold. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the processing flow chart of the graphite-carbon carbon composite hot-pressing mold of the present application.

[0039] Figure 2 is a structure diagram of the graphite-carbon carbon composite hot-pressing mold of the present application.

[0040] Among them, 1 is a graphite inner mold, 2 is a carbon carbon outer mold, 21 is a deposition film, and 3 is a cavity. DETAILED DESCRIPTION

[0041] Example 1:

[0042] As shown in Figure 1 , a preparation method of a graphite-carbon carbon composite hot-pressing mold comprises the following steps:

[0043] S1, graphite core rod preparation:

[0044] The graphite powder and the binder are put into a mixer at a mass ratio of 10:3, the mixer rotates at 200 r / min, the mixing time is 10 min, after the mixing is completed, the mixture is put into a rubber sleeve, the rubber sleeve is then put into a cold isostatic pressing machine to press into a graphite rod, the working pressure of the cold isostatic pressing machine is 100 MPa, then the graphite rod is put into a vacuum sintering furnace for sintering, after the sintering is completed, natural cooling is carried out, after the cooling is completed, turning is carried out, and the graphite core rod is obtained after the turning is completed;

[0045] S2, carbon fiber weaving:

[0046] The outer side of the graphite core rod is wound and woven with carbon fibers, the winding thickness is 20 mm, after the winding is completed, the materials at the upper and lower ends of the graphite core rod are removed through a lathe, and the carbon fiber composite graphite rod is obtained;

[0047] S3, carbon deposition:

[0048] The outer wall of the carbon fiber composite graphite rod is treated by carbon deposition in a chemical vapor deposition manner, the carbon deposition times are 3 times, the carbon deposition time is 20 h, the carbon deposition temperature is 900 DEG C, after the carbon deposition is completed, the graphite core rod in the center part of the carbon fiber composite graphite rod is taken out, the carbon fiber woven sleeve and the graphite core rod are obtained, the inner wall of the carbon fiber woven sleeve is treated by carbon deposition, and the carbon-carbon composite sleeve and the graphite core rod are obtained after the carbon deposition is completed; the carbon deposition treatment on the outer wall of the carbon fiber composite graphite rod and the carbon deposition treatment on the inner wall of the carbon fiber woven sleeve both adopt the carbon deposition method of the prior art;

[0049] S4, drying:

[0050] The carbon-carbon composite sleeve obtained in step S3 is put into a drying machine, and drying treatment is carried out at 200 DEG C, the drying treatment time is 2 h, and the carbon-carbon outer mold 2 is obtained;

[0051] S5, preparation of composite mold:

[0052] The graphite core rod obtained in step S3 is removed by machining to remove the material at the center position of the graphite core rod, and the graphite inner mold 1 with the required hole type and hole diameter is obtained, the graphite outer mold obtained in step S4 is sleeved outside the graphite inner mold 1, and the graphite-carbon-carbon composite hot-pressing mold is obtained.

[0053] The binder in step S1 is composed of the following components by weight: 5 parts of graphene powder, 20 parts of organic silicon resin.

[0054] In step S1, the particle size of the graphite powder is 20-50 μm, and when the graphite rod is sintered in the vacuum sintering furnace, the vacuum degree of the vacuum sintering furnace is 3 Pa, and the sintering temperature is 800 DEG C.

[0055] The carbon fiber in step S2 adopts a mixture of long carbon fiber and short carbon fiber or long carbon fiber, and the length of the long carbon fiber is 1 m and the length of the short carbon fiber is 4 cm.

[0056] The winding and weaving manner in step S2 is direct winding, spiral winding or layer-by-layer winding of the woven fabric.

[0057] In step S4, after the carbon-carbon composite sleeve is placed in the drying machine, the drying machine needs to be vacuumized to a vacuum degree of 3 Pa, and then argon is introduced as a protective gas. The argon is introduced at an internal gas pressure of 0.12 MPa.

[0058] In step S3, before the chemical vapor deposition on the outer wall of the carbon fiber composite graphite rod, a surface modifier needs to be brushed on the surface of the carbon fiber. The surface modifier is composed of the following components by weight: 5 parts of silica powder, 7 parts of triethanolamine phosphate powder, 10 parts of urethane, and 3 parts of citric acid powder.

[0059] In step S3, the carbon precursor used for carbon deposition is mixed by nitrogen, methane and hydrogen in a volume ratio of 5:5:1.

[0060] In step S3, the carbon deposition thickness of the outer wall of the carbon fiber composite graphite rod is 0.5 mm, and the carbon deposition thickness of the inner wall of the carbon fiber woven sleeve is 0.2 mm.

[0061] Example 2:

[0062] As shown in Figure 1 A preparation method of a graphite-carbon carbon composite hot-pressing mold, comprising the following steps:

[0063] S1, graphite core rod preparation:

[0064] The graphite powder and the binder are mixed in a mixer at a mass ratio of 10:3. The mixer rotates at a speed of 210 r / min, and the mixing time is 15 min. After mixing, the mixture is placed in a rubber sleeve, and the rubber sleeve is then placed in a cold isostatic press to press the graphite rod. The working pressure of the cold isostatic press is 200 MPa. Then, the graphite rod is placed in a vacuum sintering furnace for sintering. After sintering, the graphite rod is naturally cooled. After cooling, the graphite rod is turned to remove the material on the upper and lower ends of the graphite rod. The carbon fiber composite graphite rod is obtained.

[0065] S2, carbon fiber weaving:

[0066] The outer surface of the graphite core rod is wound and woven with carbon fiber. The winding thickness is 50 mm. After winding, the upper and lower ends of the graphite core rod are removed by a lathe to obtain a carbon fiber composite graphite rod.

[0067] S3, carbon deposition:

[0068] The outer wall of the carbon fiber composite graphite rod is subjected to carbon deposition treatment by chemical vapor deposition, the carbon deposition number is 4 times, the carbon deposition time is 30 hours, and the carbon deposition temperature is 1100°C. After the carbon deposition is completed, the graphite core rod in the center of the carbon fiber composite graphite rod is removed to obtain a carbon fiber braided sleeve and a graphite core rod, and then the inner wall of the carbon fiber braided sleeve is subjected to carbon deposition treatment to obtain a carbon-carbon composite sleeve and a graphite core rod. The carbon deposition treatment on the outer wall of the carbon fiber composite graphite rod and the carbon deposition treatment on the inner wall of the carbon fiber braided sleeve both adopt the carbon deposition method of the prior art.

[0069] S4, drying:

[0070] The carbon-carbon composite sleeve obtained in step S3 is placed in a drying machine and dried at 900° C. for 4 hours to obtain a carbon-carbon outer mold 2;

[0071] S5. Preparation of composite mold:

[0072] The graphite core rod obtained in step S3 is machined to remove the material at the center of the graphite core rod to obtain a graphite inner mold 1 with the required hole shape and aperture, and the graphite outer mold obtained in step S4 is put on the outer side of the graphite inner mold 1 to obtain a graphite-carbon-carbon composite hot pressing mold.

[0073] In step S1 , the binder is composed of the following components in parts by weight: 6 parts of graphene powder and 23 parts of silicone resin.

[0074] In step S1, the particle size of the graphite powder is 50-80 μm. When the graphite rod is sintered in a vacuum sintering furnace, the vacuum degree of the vacuum sintering furnace is 5 Pa and the sintering temperature is 900°C.

[0075] In step S2, the carbon fibers are a mixture of long carbon fibers and short carbon fibers or long carbon fibers, the length of the long carbon fibers is 1.5 m, and the length of the short carbon fibers is 5 cm.

[0076] The winding and braiding method in step S2 is direct winding, spiral winding or layer-by-layer winding of the braid to braid the carbon fibers.

[0077] In step S4, after the carbon-carbon composite sleeve is placed in the dryer, the dryer needs to be evacuated to a vacuum degree of 4 Pa, and then argon gas is introduced as a protective gas. The pressure in the dryer is 0.13 MPa when argon gas is introduced.

[0078] Before chemical vapor deposition is performed on the outer wall of the carbon fiber composite graphite rod in step S3, a surface modifier needs to be brushed on the surface of the carbon fiber. The surface modifier is composed of the following components in parts by weight: 9 parts of silicon oxide powder, 10 parts of triethanolamine phosphate powder, 15 parts of carbamate, and 4 parts of citric acid powder.

[0079] The carbon precursor used in the carbon deposition in step S3 is prepared by mixing nitrogen, methane and hydrogen in a volume ratio of 5:5:1.

[0080] The carbon deposition thickness of the outer wall of the carbon fiber composite graphite rod in step S3 is 0.9 mm, and the carbon deposition thickness of the inner wall of the carbon fiber braided sleeve is 0.3 mm.

[0081] Example 3:

[0082] As shown in Figure 1 A preparation method of a graphite-carbon composite hot-pressing mold, comprising the following steps:

[0083] S1, graphite core rod preparation:

[0084] The graphite powder and the binder are mixed in a mixer at a mass ratio of 10:3, the mixer rotates at a speed of 220 r / min, and the mixing time is 20 min. After mixing, the mixture is placed in a rubber sleeve, and the rubber sleeve is then placed in a cold isostatic press to press the graphite rod. The working pressure of the cold isostatic press is 300 MPa. Then, the graphite rod is placed in a vacuum sintering furnace for sintering. After sintering, the graphite rod is naturally cooled. After cooling, the graphite rod is turned. After turning, the graphite core rod is obtained.

[0085] S2, carbon fiber braiding:

[0086] The outer surface of the graphite core rod is wound and braided with carbon fibers, and the winding thickness is 100 mm. After winding, the materials at the upper and lower ends of the graphite core rod are removed by a lathe to obtain a carbon fiber composite graphite rod.

[0087] S3, carbon deposition:

[0088] The outer wall of the carbon fiber composite graphite rod is treated by chemical vapor deposition for carbon deposition. The carbon deposition is performed 5 times, and the carbon deposition time is 40 h. The carbon deposition temperature is 1300℃. After carbon deposition, the graphite core rod in the center part of the carbon fiber composite graphite rod is taken out to obtain a carbon fiber braided sleeve and a graphite core rod. The inner wall of the carbon fiber braided sleeve is then treated by carbon deposition. After carbon deposition, a carbon-carbon composite sleeve and a graphite core rod are obtained. The carbon deposition treatment of the outer wall of the carbon fiber composite graphite rod and the carbon deposition treatment of the inner wall of the carbon fiber braided sleeve both use the existing carbon deposition method.

[0089] S4, drying:

[0090] The carbon-carbon composite sleeve obtained in step S3 is placed in a drying machine and dried at 1000℃ for 5 h to obtain a carbon-carbon outer mold 2.

[0091] S5, preparation of a composite mold:

[0092] The graphite inner mold 1 with the required hole type and hole diameter is obtained by removing the material at the center position of the graphite core rod obtained in step S3 in a machining manner, and the graphite outer mold obtained in step S4 is sleeved outside the graphite inner mold 1 to obtain the graphite-carbon carbon composite hot-pressing mold.

[0093] The binder in step S1 is composed of the following components in parts by weight: 8 parts of graphene powder, 25 parts of silicone resin.

[0094] In step S1, the particle size of the graphite powder is 80-100 μm, and when the graphite rod is sintered in the vacuum sintering furnace, the vacuum degree of the vacuum sintering furnace is 6 Pa, and the sintering temperature is 1000 DEG C.

[0095] In step S2, the carbon fiber adopts a mixture of long carbon fiber and short carbon fiber or long carbon fiber, and the length of the long carbon fiber is 2 m and the length of the short carbon fiber is 8 cm.

[0096] In step S2, the winding and weaving method is a direct winding, a spiral winding or a layer-by-layer winding method for weaving the carbon fiber.

[0097] In step S4, after the carbon-carbon composite sleeve is placed in the drying machine, the drying machine needs to be vacuumed to a vacuum degree of 5 Pa, and then argon is introduced as a protective gas, and the argon is introduced. The internal gas pressure of the drying machine is 0.15 MPa.

[0098] In step S3, before the outer wall of the carbon fiber composite graphite rod is subjected to chemical vapor deposition, a surface modifier needs to be brushed on the surface of the carbon fiber, and the surface modifier is composed of the following components in parts by weight: 10 parts of silica powder, 11 parts of triethanolamine phosphate powder, 18 parts of urethane, and 5 parts of citric acid powder.

[0099] In step S3, the carbon precursor used in carbon deposition is mixed by volume ratio of 5:5:1 of nitrogen, methane and hydrogen.

[0100] In step S3, the carbon deposition thickness of the outer wall of the carbon fiber composite graphite rod is 1 mm, and the carbon deposition thickness of the inner wall of the carbon fiber weaving sleeve is 0.5 mm.

[0101] Comparative examples 1-3, example 3 prepared graphite-carbon carbon composite hot-pressing mold strength is the highest, the best use effect, therefore, example 3 is the best embodiment.

[0102] Example 4:

[0103] As Figure 2As shown, on the basis of Example 3, Example 4 provides a graphite-carbon carbon composite hot-pressing mold prepared by the above-mentioned graphite-carbon carbon composite hot-pressing mold preparation method, the graphite-carbon carbon composite hot-pressing mold comprises a graphite inner mold 1 and a carbon-carbon outer mold 2, the inner side wall and the outer side wall of the carbon-carbon outer mold 2 are covered with a deposited film 21, and the middle part of the graphite inner mold 1 is provided with a cavity 3.

[0104] The graphite-carbon carbon composite hot-pressing mold structure in Example 4 is used to clamp the graphite mold with the carbon-carbon outer mold 2 to prevent the graphite inner film from cracking and enhance the strength of the whole mold.

Claims

1. A method for producing a graphite-carbon carbon composite hot press mold, characterized by, The method comprises the following steps: S1, graphite core rod preparation: Put the graphite powder and the binder into a mixer at a mass ratio of 10:3, mix at a speed of 200-220 r / min for 10-20 min, then put the mixture into a rubber sleeve, and press the rubber sleeve into a graphite rod in a cold isostatic press at a working pressure of 100-300 MPa, then sinter the graphite rod in a vacuum sintering furnace, naturally cool after sintering, turn after cooling, and obtain the graphite core rod after turning; S2, carbon fiber weaving: Wrap and weave the outer side of the graphite core rod with carbon fibers, with a wrapping thickness of 20-100 mm, remove the materials at the upper and lower ends of the graphite core rod after wrapping and weaving by a lathe, and obtain the carbon fiber composite graphite rod; S3, carbon deposition: Perform carbon deposition treatment on the outer wall of the carbon fiber composite graphite rod by chemical vapor deposition, with 3-5 times of carbon deposition, a carbon deposition time of 20-40 h, and a carbon deposition temperature of 900-1300°C, remove the graphite core rod at the center of the carbon fiber composite graphite rod after carbon deposition, obtain the carbon fiber woven sleeve and the graphite core rod, perform carbon deposition treatment on the inner wall of the carbon fiber woven sleeve, and obtain the carbon-carbon composite sleeve and the graphite core rod after carbon deposition; S4, drying: Put the carbon-carbon composite sleeve obtained in step S3 into a drying machine and perform drying treatment at 200-1000°C for 2-5 h to obtain a carbon-carbon outer mold (2); S5, preparation of a composite mold: Remove the material at the center of the graphite core rod by machining to obtain a graphite inner mold (1) with a desired hole type and hole diameter, and place the carbon-carbon outer mold (2) obtained in step S4 outside the graphite inner mold (1) to obtain a graphite-carbon-carbon composite hot-pressing mold; The binder in step S1 is composed of the following components by weight: 5-8 parts of graphene powder and 20-25 parts of organic silicone resin; In step S1, the particle size of the graphite powder is 20-100 μm, and the vacuum degree of the vacuum sintering furnace is 3-6 Pa when the graphite rod is sintered in the vacuum sintering furnace, and the sintering temperature is 800-1000°C; In step S2, the carbon fiber is a mixture of long carbon fibers and short carbon fibers or long carbon fibers, the length of the long carbon fibers is 1-2 m, and the length of the short carbon fibers is 4-8 cm; In step S2, the wrapping and weaving method is direct wrapping, spiral wrapping, or layer-by-layer weaving of the woven fabric to weave the carbon fibers; In step S4, the drying machine needs to be evacuated to a vacuum degree of 3-5 Pa after the carbon-carbon composite sleeve is put into the drying machine, and argon gas is introduced as a protective gas, and the gas pressure in the drying machine is 0.12-0.15 MPa. The surface of the carbon fiber is brushed with a surface modifier before the outer wall of the carbon fiber composite graphite rod is subjected to chemical vapor deposition in the step S3, and the surface modifier is composed of the following components in parts by weight: 5-10 parts of silica powder, 7-11 parts of triethanolamine phosphate powder, 10-18 parts of urethane, and 3-5 parts of citric acid powder.

2. The method of claim 1, wherein the graphite-carbon carbon composite hot press mold is prepared by the steps of: mixing graphite powder and carbon powder to form a mixture; and hot-pressing the mixture to form the graphite-carbon carbon composite hot press mold. The carbon precursor used in the carbon deposition in the step S3 is prepared by mixing nitrogen, methane and hydrogen in a volume ratio of 5:5:

1.

3. The graphite-carbon carbon composite hot-pressing die prepared by the preparation method of the graphite-carbon carbon composite hot-pressing die according to claim 1, characterized in that, The graphite-carbon carbon composite hot-pressing mold comprises a graphite inner mold (1) and a carbon-carbon outer mold (2), the inner side wall and the outer side wall of the carbon-carbon outer mold (2) are covered with a deposition film (21), and the middle part of the graphite inner mold (1) is provided with a cavity (3).

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