A high thermal conductivity integrated C / C heat sink fin and its processing technology

Abstract

This invention relates to the field of heat dissipation material preparation technology, and particularly to a high thermal conductivity integrated C / C heat dissipation fin and its processing technology, comprising the following steps: S1, cutting and laying out the material; S2, laying out metal Ti tubes; S3, molding; S4, curing the prepreg blank after molding using compression molding or autoclave molding; S5, carbonization; S6, densification treatment to obtain a dense integrated C / C heat dissipation fin; S7, processing the outline dimensions of the dense integrated C / C heat dissipation fin using laser processing to obtain the final product. This invention uses high thermal conductivity mesophase pitch-based carbon fiber as the reinforcing material, and through directional arrangement, enables rapid heat conduction along the fiber direction. Furthermore, by co-curing the heat flow conduit Ti tube with the fin substrate, the integrated C / C heat dissipation fin is fabricated, simplifying the traditional secondary brazing process required to connect the C / C fin to the heat flow conduit.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation material preparation technology, specifically to a high thermal conductivity integrated C / C heat dissipation fin and its processing technology. Background Technology

[0002] With the rapid development of spaceflight and deep space exploration, higher design requirements have been placed on the lightweighting and heat dissipation efficiency of spacecraft thermal control systems. In recent years, in nuclear-powered spacecraft, traditional heat pipe radiators have been unable to meet design requirements due to the influence of high-temperature and complex operating conditions.

[0003] Compared to traditional metal heat dissipation materials, C / C composite materials have been widely used in the nuclear energy field due to their low density, high thermal conductivity, high strength, low coefficient of expansion, and low neutron activation energy. Therefore, C / C composite materials can replace traditional metal heat dissipation materials as heat dissipation fins in heat pipe radiators. By connecting them with heat flow ducts, they can effectively solve the high heat dissipation problem of thermal control systems in nuclear-powered spacecraft.

[0004] According to domestic and international literature, most existing C / C heat sink fins are single-sided wedge-shaped fin structures, and the reinforcing material in C / C composites is mostly PAN-based carbon fiber, which to some extent limits the heat conduction efficiency of C / C heat sink fins. Furthermore, C / C fins and heat flux conduits are often connected by vacuum brazing. Although this method is technically mature, it requires the C / C fins to be fabricated before brazing to the heat flux conduits, increasing manufacturing costs and production cycle.

[0005] Therefore, designing a C / C fin with high thermal conductivity and simplifying the connection method between the C / C fin and the heat flow conduit has become a technical problem that urgently needs to be solved in the upgrading of this type of product. Summary of the Invention

[0006] To address the problems of poor heat conduction performance, small heat path on single-layer radiating surface, and the need for secondary brazing connection between C / C fins and heat flow conduits in existing technologies, this invention provides a high thermal conductivity integrated C / C heat dissipation fin and its processing technology.

[0007] This invention is achieved through the following technical solution: A high thermal conductivity integrated C / C heat sink fin processing technology includes the following steps: S1, cut the high thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg into pieces and lay them in the upper and lower molds of the metal mold respectively; S2, After grinding and cleaning the surface of the metal Ti tube, the Ti tube is laid with a high carbon residue resin film containing filler; then the Ti tube with the resin film is placed flat in the axial groove of the prepreg blank on the surface of the lower mold. S3. Close the upper mold and the lower mold with the symmetrically laid prepreg blank on the mold surface. During the mold closing process, ensure that the Ti tube with the resin film is fixed in the axial groove of the prepreg blank. S4. The prepreg blank after mold closing is cured and formed by compression molding or autoclave molding to obtain CFRP blank. S5, the solidified CFRP preform is transferred to a graphite fixture for carbonization; after carbonization, the graphite fixture is removed to obtain an integrated C / C fin preform. S6, through chemical vapor infiltration (CVI) process, densifies the carbonized C / C preform to obtain dense integrated C / C heat dissipation fins; The S7 uses laser processing to process the outline dimensions of the dense integrated C / C heat sink fins to obtain the final product.

[0008] Preferably, in S1, the fiber areal density of the high thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg is 130 g / m². 2 -150g / m 2 The cutting angle during cutting is 0° or 5°.

[0009] Preferably, in step S1, several layers of pre-cut unidirectional carbon fiber prepreg are laid layer by layer in the lower mold of the metal mold according to a set layup structure, wherein the set layup structure is [0° / ±5° / 0°]. s Or [±5°] s ; In the upper mold of the metal mold, several layers of unidirectional carbon fiber prepreg are laid layer by layer in a symmetrical structure.

[0010] Preferably, in S2, the high carbon residue resin film is made of phenolic resin or modified benzoxazine resin and Ti-Zr-Ni-Cu alloy powder in a mass ratio of (85-90):(10-15), and the areal density of the resin film is 50 g / m³. 2 -100g / m 2 .

[0011] Preferably, in S5, the graphite tooling and the integrated finned CFRP preform forming metal mold have the same structural dimensions.

[0012] Preferably, in S5, the specific carbonization process is as follows: After transferring the integrated finned CFRP blank to the graphite tooling, it is placed in the carbonization furnace. Argon gas is introduced into the carbonization furnace and the temperature is raised to 1000-1200℃ and held for 6-8 hours. The furnace is then cooled to room temperature. During the heating process, heat preservation treatment is carried out in stages, and after the heat preservation, the heating continues at the same rate.

[0013] Preferably, in S6, the specific steps of the densification process are as follows: The integrated C / C fins are placed in a CVI deposition furnace. C3H6 is used as the carbon source gas and N2 is used as the dilution gas. The volume ratio of C3H6 to N2 is 3:1. The deposition temperature is 950℃-1100℃, the furnace pressure is less than 1kPa, and the deposition time is 150-200h.

[0014] A high thermal conductivity integrated C / C heat sink fin obtained by a high thermal conductivity integrated C / C heat sink fin processing technology.

[0015] Preferably, it includes high thermal conductivity C / C fins and metal Ti tubes. The combination of high thermal conductivity C / C fins and metal Ti tubes is a non-fully enclosed structure. An adhesive transition layer is provided between the high thermal conductivity C / C fins and the metal Ti tubes, and the high thermal conductivity C / C fins have a double-sided symmetrical structure.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a high thermal conductivity integrated C / C heat sink fin processing technology. It utilizes high-modulus, high thermal conductivity mesophase pitch-based carbon fiber as reinforcement and high-carbon-residue resin (phenolic resin, modified benzoxazine resin, etc.) as the matrix. A unidirectional carbon fiber prepreg is prepared, and through layup, curing, and carbonization processes, a high thermal conductivity C / C composite material with fiber orientation is formed. The high thermal conductivity C / C composite material is then co-cured with the prepreg preform. After high-temperature carbonization, the resin film layer transforms into an adhesive transition layer between the C / C fin and the metal Ti tube, forming a high thermal conductivity integrated C / C fin with fiber orientation.

[0017] The high thermal conductivity integrated C / C heat sink fins manufactured in this invention use high thermal conductivity mesophase pitch-based carbon fiber as the reinforcing material. Through directional arrangement, the heat source can be rapidly conducted along the fiber direction. In addition, by co-curing the heat flow conduit Ti tube with the fin substrate, the integrated C / C heat sink fins are fabricated, simplifying the traditional secondary brazing process required to connect C / C fins and heat flow conduits.

[0018] The combination of high thermal conductivity C / C fins and metal Ti tubes is a non-fully enclosed structure. This ensures that the high modulus, high thermal conductivity mesophase pitch-based carbon fibers do not break due to bending in the corner areas, thus maintaining the thermal conductivity of the C / C fins. Compared to traditional C / C fins, the high thermal conductivity C / C fins have a highly oriented fiber design, ensuring that heat transferred from the metal Ti tube to the high thermal conductivity C / C fins can be quickly conducted to the external environment along the fiber direction. Furthermore, the double-sided symmetrical structure of the fins provides a large radiative heat dissipation surface. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a high thermal conductivity integrated C / C heat sink fin processing technology according to the present invention.

[0020] Figure 2 This is a schematic diagram of a high thermal conductivity integrated C / C heat sink fin structure.

[0021] Figure 3 This is a cross-sectional view of a high thermal conductivity integrated C / C heat sink fin.

[0022] In the figure, 1. High thermal conductivity C / C fins; 2. Metal Ti tube; 3. Adhesive transition layer. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0024] This invention discloses a high thermal conductivity integrated C / C heat sink fin processing technology, referring to... Figure 1 This includes the following steps: S1, with a fiber areal density of 130 g / m 2 -150g / m 2 The high thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg is cut into blanks (cutting angle is 0° or 5°) and laid in the upper and lower molds of the metal mold respectively.

[0025] In the lower mold of the metal mold, several layers of unidirectional carbon fiber prepreg, which have been cut and prepared, are laid up according to a set layer structure ([0° / ±5° / 0°)). s Or [±5°] s Lay the tiles layer by layer.

[0026] In the upper mold of the metal mold, several layers of unidirectional carbon fiber prepreg are laid layer by layer in a symmetrical structure.

[0027] S2. After grinding and cleaning the surface of the metal Ti tube, the Ti tube is laid with a high-carbon-residue resin film containing filler. Then, the Ti tube with the resin film is placed flat in the axial groove of the prepreg blank on the surface of the lower mold.

[0028] The high carbon residue resin film is made of phenolic resin or modified benzoxazine resin and Ti-Zr-Ni-Cu alloy powder in a mass ratio of (85-90):(10-15), and the areal density of the resin film is 50 g / m³. 2 -100g / m 2 .

[0029] S3. Close the upper mold and the lower mold with the symmetrically laid prepreg blank on the mold surface. During the mold closing process, ensure that the Ti tube with the resin film is fixed in the axial groove of the prepreg blank.

[0030] S4. The prepreg blank after mold closing is cured and formed by compression molding or autoclave molding to obtain CFRP blank.

[0031] When using compression molding, place the upper and lower molds after mold closing on a hot press, and apply a heating rate of 1-3℃ / min and a pressure of 0.1MPa to raise the temperature from room temperature to 120℃, and hold the temperature and pressure for 30 minutes; then raise the temperature to 180℃, apply a pressure of 1-1.5MPa, and hold the temperature and pressure for 2 hours; then raise the temperature to 200℃, and hold the temperature and pressure for 2 hours at a pressure of 1-1.5MPa; then cool to 60℃ at a pressure of 1-1.5MPa.

[0032] When using autoclave molding, the upper and lower molds, after being closed, are sequentially wrapped with a perforated release film and a breathable felt. Then, they are placed into a vacuum bag sealed with a vacuum bag film. After connecting the vacuum line to the vacuum nozzle, a leak test is performed on the vacuum bag. When the vacuum level is ≤-0.095MPa, the vacuum system is shut off. If the vacuum gauge reading drops by no more than 0.02MPa within 10 minutes, the vacuum bag is considered well-sealed. Then, under a vacuum level ≤-0.095MPa, the mold in the vacuum bag is pre-evacuated for 30-40 minutes. After pre-evacuation, the vacuum bag containing the mold is transferred... Place the sample in an autoclave, evacuate to ≤-0.095MPa, and heat from room temperature to 110℃ at a rate of 1-2℃ / min. Hold at this temperature for 30 min, then pressurize to 0.1MPa at a rate of 0.02MPa / min and hold for 10 min. Next, heat to 180℃ at a rate of 1-2℃ / min, then pressurize to 0.9MPa at a rate of 0.02MPa / min and hold for 2 h. Then, heat to 200℃ at a rate of 1-2℃ / min and hold at 0.9MPa for 2 h. Finally, cool to 60℃ at a rate of 3℃ / min.

[0033] S5, the solidified CFRP blank is transferred to a graphite fixture (the graphite fixture has the same structural dimensions as the metal mold for forming the integrated finned CFRP blank) for carbonization; after carbonization, the graphite fixture is removed to obtain the integrated C / C finned blank.

[0034] The specific carbonization process is as follows: After transferring the integrated finned CFRP blank to the graphite tooling, it is placed in the carbonization furnace. After the carbonization furnace is filled with argon gas, the temperature is raised at a rate of 3-5℃ / min. The temperature is raised to 1000-1200℃ and held for 6-8 hours. The furnace is then cooled to room temperature. During the heating process, the temperature is held at 400℃, 700℃ and 900℃ for 30 minutes respectively, and then the temperature is raised at the same rate.

[0035] S6, through chemical vapor infiltration (CVI) process, densifies the carbonized C / C preform to obtain dense, integrated C / C heat dissipation fins. The specific process is as follows: The integrated C / C fins are placed in a CVI deposition furnace. C3H6 is used as the carbon source gas and N2 is used as the dilution gas. The volume ratio of C3H6 to N2 is 3:1. The deposition temperature is 950℃-1100℃, the furnace pressure is less than 1kPa, and the deposition time is 150-200h.

[0036] S7 uses laser processing to process the outline dimensions of the dense integrated C / C heat sink fins to obtain a finished product with a final thermal conductivity ≥450W / (m·K).

[0037] Example 1 S1, with a fiber areal density of 150 g / m 2 High thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg is cut at 0° and 5°. The cut and prepared unidirectional carbon fiber prepreg is laid layer by layer in the lower mold of the metal mold according to a [0° / ±5° / 0°]3 layup structure. The unidirectional carbon fiber prepreg is then laid layer by layer in the upper mold of the metal mold according to a symmetrical [0° / ±5° / 0°]3 layup structure. S2, after grinding and cleaning the surface of the metal Ti tube, is made using phenolic resin and Ti-Zr-Ni-Cu alloy powder in a mass ratio of 90:10, with an areal density of 100 g / m³. 2 The high carbon residue resin film is used to lay the Ti tube; the Ti tube with the resin film is placed flat in the axial groove of the prepreg blank on the surface of the lower mold. S3. Close the upper mold and the lower mold with the symmetrically laid prepreg blank on the mold surface. During the mold closing process, ensure that the Ti tube with the resin film is fixed in the axial groove of the prepreg blank. S4 employs a compression molding process. After the upper and lower molds are closed, they are placed on a hot press. The temperature is increased from room temperature to 120°C at a heating rate of 1-3°C / min and a pressure of 0.1MPa is applied. The temperature is then maintained at this temperature and pressure for 30 minutes. The temperature is then increased to 180°C and a pressure of 1-1.5MPa is applied. The temperature is then maintained at this temperature and pressure for 2 hours. The temperature is then increased to 200°C and a pressure of 1-1.5MPa is applied. The temperature is then maintained at this temperature and pressure for 2 hours. Finally, the temperature is cooled to 60°C under a pressure of 1-1.5MPa.

[0038] S5. Transfer the solidified CFRP preform to a graphite fixture and place it in a carbonization furnace. After argon gas is introduced into the carbonization furnace, start heating at a rate of 3-5℃ / min. Hold the temperature at 1000℃ for 8 hours and then cool it to room temperature with the furnace. During the heating process, hold the temperature at 400℃, 700℃ and 900℃ for 30 minutes each, and then continue heating at the same rate.

[0039] S6. The integrated C / C fin is placed in the CVI deposition furnace. C3H6 is used as the carbon source gas and N2 is used as the dilution gas. The volume ratio of C3H6 to N2 is 3:1. The deposition temperature is 950℃, the furnace pressure is less than 1kPa, and the deposition time is 150h.

[0040] The S7 uses laser processing to process the outline dimensions of the dense integrated C / C heat sink fins to obtain the final product.

[0041] Example 2 S1, with a fiber areal density of 130 g / m 2 High thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg is cut at ±5°. The cut unidirectional carbon fiber prepreg is then laid layer by layer in the lower mold of the metal mold according to a [±5°]3 layup structure. The unidirectional carbon fiber prepreg is then laid layer by layer in the upper mold of the metal mold according to a [±5°]3 layup structure with a symmetrical structure. S2, after grinding and cleaning the surface of the metal Ti tube, is made of phenolic resin and Ti-Zr-Ni-Cu alloy powder with a mass ratio of 85:15, and has an areal density of 50 g / m³. 2 The high carbon residue resin film is used to lay the Ti tube; the Ti tube with the resin film is placed flat in the axial groove of the prepreg blank on the surface of the lower mold. S3. Close the upper mold and the lower mold with the symmetrically laid prepreg blank on the mold surface. During the mold closing process, ensure that the Ti tube with the resin film is fixed in the axial groove of the prepreg blank. S4 employs a compression molding process. After the upper and lower molds are closed, they are placed on a hot press. The temperature is increased from room temperature to 120°C at a heating rate of 1-3°C / min and a pressure of 0.1MPa is applied. The temperature is then maintained at this temperature and pressure for 30 minutes. The temperature is then increased to 180°C and a pressure of 1-1.5MPa is applied. The temperature is then maintained at this temperature and pressure for 2 hours. The temperature is then increased to 200°C and a pressure of 1-1.5MPa is applied. The temperature is then maintained at this temperature and pressure for 2 hours. Finally, the temperature is cooled to 60°C under a pressure of 1-1.5MPa.

[0042] S5. Transfer the solidified CFRP preform to a graphite fixture and place it in a carbonization furnace. After argon gas is introduced into the carbonization furnace, start heating at a rate of 3-5℃ / min. Hold the temperature at 1000℃ for 8 hours and then cool it to room temperature with the furnace. During the heating process, hold the temperature at 400℃, 700℃ and 900℃ for 30 minutes each, and then continue heating at the same rate.

[0043] S6. The integrated C / C fin is placed in the CVI deposition furnace. C3H6 is used as the carbon source gas and N2 is used as the dilution gas. The volume ratio of C3H6 to N2 is 3:1. The deposition temperature is 950℃, the furnace pressure is less than 1kPa, and the deposition time is 150h.

[0044] The S7 uses laser processing to process the contour dimensions of the integrated C / C heat sink fins to obtain the final product.

[0045] Example 3 S1, with a fiber areal density of 150 g / m 2 High thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg is cut at 0° and 5°. The cut unidirectional carbon fiber prepreg is then layered in the lower mold of a metal mold according to a [0° / ±5° / 0°]3 layup structure. The unidirectional carbon fiber prepreg is then layered in the upper mold of a metal mold according to a symmetrical [0° / ±5° / 0°]3 layup structure. S2, after grinding and cleaning the surface of the metal Ti tube, is made using a mixture of modified benzoxazine resin and Ti-Zr-Ni-Cu alloy powder in a mass ratio of 90:10, with an areal density of 100 g / m³. 2 The high carbon residue resin film is used to lay the Ti tube; the Ti tube with the resin film is placed flat in the axial groove of the prepreg blank on the surface of the lower mold. S3. Close the upper mold and the lower mold with the symmetrically laid prepreg blank on the mold surface. During the mold closing process, ensure that the Ti tube with the resin film is fixed in the axial groove of the prepreg blank. S4 employs an autoclave molding process, where the upper and lower molds, after being closed, are sequentially wrapped with a perforated release film and a breathable felt. They are then placed into a vacuum bag sealed with a vacuum bag film. After connecting the vacuum line to the vacuum nozzle, a leak test is performed on the vacuum bag. When the vacuum level is ≤-0.095MPa, the vacuum system is shut off. If the vacuum gauge reading drops by no more than 0.02MPa within 10 minutes, the vacuum bag is considered well-sealed. Then, under a vacuum level ≤-0.095MPa, the mold in the vacuum bag is pre-evacuated for 30-40 minutes. After pre-evacuation, the vacuum bag containing the mold is transferred... Transfer to an autoclave, evacuate to ≤-0.095MPa, and heat from room temperature to 110℃ at a heating rate of 1-2℃ / min, hold for 30 min, then pressurize to 0.1MPa at a pressure rate of 0.02MPa / min, hold for 10 min; then heat to 180℃ at a heating rate of 1-2℃ / min, then pressurize to 0.9MPa at a pressure rate of 0.02MPa / min, hold for 2 h; then heat to 200℃ at a heating rate of 1-2℃ / min, hold for 2 h at 0.9MPa; finally, cool to 60℃ at a cooling rate of 3℃ / min.

[0046] S5. Transfer the solidified CFRP preform to a graphite fixture and place it in a carbonization furnace. After argon gas is introduced into the carbonization furnace, start heating at a rate of 3-5℃ / min. Hold the temperature at 1200℃ for 6 hours and then cool it to room temperature with the furnace. During the heating process, hold the temperature at 400℃, 700℃ and 900℃ for 30 minutes each, and then continue heating at the same rate.

[0047] S6. The integrated C / C fin is placed in the CVI deposition furnace. C3H6 is used as the carbon source gas and N2 is used as the dilution gas. The volume ratio of C3H6 to N2 is 3:1. The deposition temperature is 1100℃, the furnace pressure is less than 1kPa, and the deposition time is 200h.

[0048] The S7 uses laser processing to process the contour dimensions of the integrated C / C heat sink fins to obtain the final product.

[0049] Example 4 S1, with a fiber areal density of 130 g / m 2 High thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg is cut at ±5°. The cut unidirectional carbon fiber prepreg is then laid layer by layer in the lower mold of the metal mold according to a [±5°]3 layup structure. The unidirectional carbon fiber prepreg is then laid layer by layer in the upper mold of the metal mold according to a [±5°]3 layup structure with a symmetrical structure. S2, after grinding and cleaning the surface of the metal Ti tube, is made using a mixture of modified benzoxazine resin and Ti-Zr-Ni-Cu alloy powder in a mass ratio of 85:15, with an areal density of 50 g / m³. 2 The high carbon residue resin film is used to lay the Ti tube; the Ti tube with the resin film is placed flat in the axial groove of the prepreg blank on the surface of the lower mold. S3. Close the upper mold and the lower mold with the symmetrically laid prepreg blank on the mold surface. During the mold closing process, ensure that the Ti tube with the resin film is fixed in the axial groove of the prepreg blank. S4 employs an autoclave molding process, where the upper and lower molds, after being closed, are sequentially wrapped with a perforated release film and a breathable felt. They are then placed into a vacuum bag sealed with a vacuum bag film. After connecting the vacuum line to the vacuum nozzle, a leak test is performed on the vacuum bag. When the vacuum level is ≤-0.095MPa, the vacuum system is shut off. If the vacuum gauge reading drops by no more than 0.02MPa within 10 minutes, the vacuum bag is considered well-sealed. Then, under a vacuum level ≤-0.095MPa, the mold in the vacuum bag is pre-evacuated for 30-40 minutes. After pre-evacuation, the vacuum bag containing the mold is transferred... Transfer to an autoclave, evacuate to ≤-0.095MPa, and heat from room temperature to 110℃ at a heating rate of 1-2℃ / min, hold for 30 min, then pressurize to 0.1MPa at a pressure rate of 0.02MPa / min, hold for 10 min; then heat to 180℃ at a heating rate of 1-2℃ / min, then pressurize to 0.9MPa at a pressure rate of 0.02MPa / min, hold for 2 h; then heat to 200℃ at a heating rate of 1-2℃ / min, hold for 2 h at 0.9MPa; finally, cool to 60℃ at a cooling rate of 3℃ / min.

[0050] S5. Transfer the solidified CFRP preform to a graphite fixture and place it in a carbonization furnace. After argon gas is introduced into the carbonization furnace, start heating at a rate of 3-5℃ / min. Hold the temperature at 1200℃ for 6 hours and then cool it to room temperature with the furnace. During the heating process, hold the temperature at 400℃, 700℃ and 900℃ for 30 minutes each, and then continue heating at the same rate.

[0051] S6. The integrated C / C fin is placed in the CVI deposition furnace. C3H6 is used as the carbon source gas and N2 is used as the dilution gas. The volume ratio of C3H6 to N2 is 3:1. The deposition temperature is 1100℃, the furnace pressure is less than 1kPa, and the deposition time is 200h.

[0052] The S7 uses laser processing to process the contour dimensions of the integrated C / C heat sink fins to obtain the final product.

[0053] The present invention also discloses a high thermal conductivity integrated C / C heat dissipation fin, including a high thermal conductivity C / C fin 1 and a metal Ti tube 2. The combination and connection of the high thermal conductivity C / C fin 1 and the metal Ti tube 2 is a non-fully enclosed structure. An adhesive transition layer 3 is provided between the high thermal conductivity C / C fin 1 and the metal Ti tube 2, and the high thermal conductivity C / C fin 1 has a double-sided symmetrical structure.

[0054] The high thermal conductivity C / C fin 1 uses high modulus and high thermal conductivity mesophase pitch-based carbon fiber as the reinforcing material and high carbon residue resin (phenolic resin, modified benzoxazine resin, etc.) as the matrix. It is prepared into a unidirectional carbon fiber prepreg and then processed into a high thermal conductivity C / C composite material with fiber orientation through processes such as lay-up, curing and molding, and carbonization.

[0055] The Ti tube 2 is a thin-walled, corrosion-resistant, and high-heat-exchange heat transfer conduit. The high thermal conductivity integrated C / C heat sink fin is a combination structure of a high thermal conductivity C / C fin 1 and a metal Ti tube 2. The surface-polished metal Ti tube 2 is bonded to a high-carbon-residue resin film containing filler (such as 45μm Ti-Zr-Ni-Cu alloy powder), and then co-cured with a prepreg blank. After high-temperature carbonization, the resin film layer transforms into an adhesive transition layer 3 between the C / C fin 1 and the metal Ti tube 2, tightly connecting the two together to form a high thermal conductivity integrated C / C fin (thermal conductivity ≥450W / (m·K)) with fiber orientation. This eliminates the need for the traditional brazing process between the thermally conductive C / C fin and the metal heat flow conduit, greatly simplifying the manufacturing process.

[0056] See Figure 2 The high thermal conductivity integrated C / C heat sink fin structure includes a high thermal conductivity C / C fin 1 and a metal Ti tube 2 for heat flow conduit. The metal Ti tube and the C / C fin blank are co-cured and formed by "pre-embedding" to form an integrated C / C heat sink fin that does not require secondary brazing.

[0057] See Figure 3 The C / C fins 1 and the metal Ti tube 2 are connected by an adhesive transition layer 3, which is composed of high-carbon resin carbon containing Ti-Zr-Ni-Cu alloy powder. The adhesive transition layer 3 not only provides adhesion but also reduces residual thermal stress caused by the difference in thermal expansion coefficients between the C / C fins 1 and the metal Ti tube 2, thus improving the cracking problem that occurs when traditional C / C composite materials are connected to metals.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A high thermal conductivity integrated C / C heat sink fin processing technology, characterized in that, Includes the following steps: S1, cut the high thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg into pieces and lay them in the upper and lower molds of the metal mold respectively; S2, After grinding and cleaning the surface of the metal Ti tube, the Ti tube is laid with a high carbon residue resin film containing filler; then the Ti tube with the resin film is placed flat in the axial groove of the prepreg blank on the surface of the lower mold. S3. Close the upper mold and the lower mold with the symmetrically laid prepreg blank on the mold surface. During the mold closing process, ensure that the Ti tube with the resin film is fixed in the axial groove of the prepreg blank. S4. The prepreg blank after mold closing is cured and formed by compression molding or autoclave molding to obtain CFRP blank. S5, the solidified CFRP preform is transferred to a graphite fixture for carbonization; after carbonization, the graphite fixture is removed to obtain an integrated C / C fin preform. S6, through chemical vapor infiltration process, densifies the carbonized C / C blank to obtain dense integrated C / C heat dissipation fins; The S7 uses laser processing to process the outline dimensions of the dense integrated C / C heat sink fins to obtain the final product.

2. The high thermal conductivity integrated C / C heat sink fin processing technology according to claim 1, characterized in that, In S1, the fiber areal density of the high thermal conductivity mesophase pitch-based unidirectional carbon fiber prepreg is 130 g / m². 2 -150g / m 2 The cutting angle during cutting is 0° or 5°.

3. The high thermal conductivity integrated C / C heat sink fin processing technology according to claim 1, characterized in that, In S1, several layers of unidirectional carbon fiber prepreg, cut and prepared, are laid layer by layer in the lower mold of the metal mold according to a set layup structure, which is [0° / ±5° / 0°]. s Or [±5°] s ; In the upper mold of the metal mold, several layers of unidirectional carbon fiber prepreg are laid layer by layer in a symmetrical structure.

4. The high thermal conductivity integrated C / C heat sink fin processing technology according to claim 1, characterized in that, In S2, the high carbon residue resin film is made of phenolic resin or modified benzoxazine resin and Ti-Zr-Ni-Cu alloy powder in a mass ratio of (85-90):(10-15), and the areal density of the resin film is 50 g / m³. 2 -100g / m 2 .

5. The high thermal conductivity integrated C / C heat sink fin processing technology according to claim 1, characterized in that, In S5, the graphite tooling and the integrated finned CFRP preform forming metal mold have the same structural dimensions.

6. The high thermal conductivity integrated C / C heat sink fin processing technology according to claim 1, characterized in that, In S5, the specific carbonization process is as follows: After transferring the integrated finned CFRP blank to the graphite tooling, it is placed in the carbonization furnace. Argon gas is introduced into the carbonization furnace and the temperature is raised to 1000-1200℃ and held for 6-8 hours. The furnace is then cooled to room temperature. During the heating process, heat preservation treatment is carried out in stages, and after the heat preservation, the heating continues at the same rate.

7. The high thermal conductivity integrated C / C heat sink fin processing technology according to claim 1, characterized in that, In S6, the specific steps of densification are as follows: The integrated C / C fins are placed in a CVI deposition furnace. C3H6 is used as the carbon source gas and N2 is used as the dilution gas. The volume ratio of C3H6 to N2 is 3:

1. The deposition temperature is 950℃-1100℃, the furnace pressure is less than 1kPa, and the deposition time is 150-200h.

8. A high thermal conductivity integrated C / C heat sink fin obtained by the high thermal conductivity integrated C / C heat sink fin processing technology according to any one of claims 1 to 7.

9. The high thermal conductivity integrated C / C heat sink fin according to claim 8, characterized in that, It includes a high thermal conductivity C / C fin (1) and a metal Ti tube (2). The combination of the high thermal conductivity C / C fin (1) and the metal Ti tube (2) is a non-fully enclosed structure. An adhesive transition layer (3) is provided between the high thermal conductivity C / C fin (1) and the metal Ti tube (2). The high thermal conductivity C / C fin (1) has a double-sided symmetrical structure.

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