High thermal conductivity diamond composite material and method of making same
By optimizing the diamond particle size distribution and synthesis process, a diamond composite material with high thermal conductivity was prepared, which solved the problem of insufficient thermal conductivity of traditional materials and achieved a highly efficient heat dissipation effect, making it suitable for electronic packaging and thermal management in high-tech fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHONGNAN DIAMOND CO LTD
- Filing Date
- 2026-03-11
- Publication Date
- 2026-06-05
Abstract
Description
Technical Field
[0001] This invention belongs to the field of superhard composite material preparation technology, specifically relating to a method for preparing high thermal conductivity diamond composite materials, and also relating to high thermal conductivity diamond composite materials prepared using the above preparation method. Background Technology
[0002] With the rapid development of 5G communication, artificial intelligence, new energy vehicles, and aerospace technology, electronic devices are rapidly evolving towards miniaturization and high power density. This has led to a sharp increase in the heat flux density of chips and modules, and heat dissipation efficiency has become a core bottleneck restricting device performance and reliability. Traditional electronic packaging materials, such as tungsten copper and molybdenum copper, are no longer sufficient to meet the heat dissipation requirements of future high-power devices.
[0003] Diamond, with the highest thermal conductivity in nature (theoretically reaching 2000 W / (m·K), also possesses excellent properties such as a low coefficient of thermal expansion and low density. Using diamond as a reinforcing phase in composites with metals can theoretically yield ideal materials with both ideal thermal conductivity and an adjustable coefficient of thermal expansion, making it a key research direction for next-generation electronic packaging and thermal management materials. Driven by both technological advancements and market demand, diamond composite materials, as crucial materials for solving the challenges of high heat flux density heat dissipation and meeting ultra-wear resistance requirements, are moving from the laboratory to large-scale applications in high-tech fields such as electronic communications, aerospace, and new energy vehicles, demonstrating enormous development potential and broad application prospects.
[0004] However, single-crystal diamond suffers from difficulties in preparation, small size, high unit price, and mismatch in thermal expansion coefficients. Overcoming these weaknesses and leveraging its high thermal conductivity has become a crucial issue that needs to be addressed in diamond composite materials. Summary of the Invention
[0005] The first objective of this invention is to provide a method for preparing a diamond composite material with high thermal conductivity. Under high temperature and high pressure and catalytic action, by optimizing the diamond particle size distribution and combining it with a reasonable synthesis process, a good thermal conductivity pathway is formed between the diamond particles, and finally a diamond composite material with high thermal conductivity is prepared.
[0006] The second objective of this invention is to provide a high thermal conductivity diamond composite material prepared using the above-described preparation method.
[0007] The first technical solution adopted in this invention is a method for preparing high thermal conductivity diamond composite material, the specific method of which is as follows:
[0008] S1. Place the transition diamond micro powder and catalyst into a three-dimensional mixer, add metal balls, and mix them in a ball mill to obtain the first powder raw material; S2. Separately, the etched diamond particles and high-viscosity liquid are mixed in a three-dimensional mixer to obtain a second powder raw material. S3. Mix the two powder raw materials in a three-dimensional mixer to obtain a third powder raw material; S4. The third powder raw material is loaded into the molybdenum material cup to form a component; S5. The components are placed in a vacuum sintering furnace for reduction treatment to obtain the reduced components; S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
[0009] The invention is further characterized by: The mass ratio of transition diamond micro powder to catalyst in S1 is 15~35:5~10; The mass ratio of etched diamond particles to high-viscosity liquid in S2 is 55~75:0.1~0.3; The mass ratio of transition diamond micro powder to etched diamond particles is 15~35:55~75.
[0010] The mass ratio of transition diamond micro powder and metal spheres in S1 is 1:3~7; The mixing time on the ball mill is 8-10 hours; The particle size of transition diamond powder is 10~50um; The catalyst can be any one of the following: metal binders such as cobalt, nickel, and tungsten, or thermally conductive media such as CaCO3, MgCO3, and Si2O3.
[0011] The diamond particles etched in S2 have a particle size of 100um~500um; The high-viscosity liquid is any one of liquid paraffin, glycerin, epoxy resin or silicone oil; The mixing time for etching diamond particles and high-viscosity liquid is 30~60 minutes.
[0012] The mixing time for the two powders in S3 is 30-40 minutes.
[0013] The specific method for S4 is as follows: The evenly mixed powder is spread evenly in a molybdenum material cup, pre-pressed on a four-column press with a pressure of 5~10Mpa, and then the top cover is put on to form a component.
[0014] The specific method for S5 is as follows: Place the components in a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2The material is heated to 800~1000℃ at MPa and kept at that temperature while H2 is introduced for reduction treatment for 3~5 hours. Then it is cooled to 400~600℃ and subjected to forced cooling to room temperature to obtain the reduced component.
[0015] The specific operating procedures for the S6 six-sided top press are as follows: First, pre-press the synthetic block with a pressure of 0.5~1Gpa. Then, increase the pressure to 4~4.5Gpa within 50~200 seconds and maintain it for 150~300 seconds. Then, gradually increase it to 5~5.5Gpa within 400~800 seconds and maintain it for 200~500 seconds. Finally, reduce the pressure to 0 at a constant rate within 200~800 seconds. Heating begins when the pressure reaches 2-3 GPa, increasing the temperature to 800-1200℃ within 50-150 seconds, then gradually increasing it to 1600℃ within the next 400-700 seconds, and finally increasing it to 1800℃ within 200-400 seconds, which is then maintained for 10-300 seconds. Subsequently, the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
[0016] The second technical solution adopted in this invention is: a high thermal conductivity diamond composite material prepared according to the above preparation method, wherein the thermal conductivity of the high thermal conductivity diamond composite material is greater than 650 W / (m·K).
[0017] The beneficial effects of this invention are: (1) The preparation method of the high thermal conductivity diamond composite material of the present invention firstly prepares diamond micro powder and binder separately, then mixes the diamond micro powder and binder through a three-dimensional mixer to obtain a uniformly mixed powder; the mixed powder is evenly spread in a mold, pressure is applied by a hydraulic press, pressure is maintained to form a mixed blank, and then purified; the shaped mixed blank is placed in a synthesis cavity for sintering, and after sintering according to the preset process, a high thermal conductivity diamond composite material can be obtained. The process is simple and can prepare a diamond composite material with high thermal conductivity. (2) The high thermal conductivity diamond composite material prepared by the preparation method of the present invention has a thermal conductivity greater than 650 W / (m·K), which is much higher than that of conventional ceramic materials and metal materials such as copper and aluminum. The material has the characteristics of high strength and strong support. Detailed Implementation
[0018] The present invention will now be described in detail with reference to specific embodiments.
[0019] The preparation method of the high thermal conductivity diamond composite material of the present invention mainly consists of the preparation of high thermal conductivity polycrystalline layer powder and the manufacturing process of high temperature and high pressure synthesis, as detailed below: S1. The transition diamond micro powder and the catalyst are put into a three-dimensional mixer, metal balls are added, and the mixture is mixed in a ball mill for a certain period of time to obtain the first powder raw material. The mass ratio of transition diamond micron powder to catalyst is 15~35:5~10; The mass ratio of transition diamond micro powder to metal spheres is 1:3~7; Furthermore, the mixing time on the ball mill is 8-10 hours; The particle size of transition diamond powder is 10~50μm; The catalyst can be any one of the following: metal binders such as cobalt, nickel, and tungsten, or thermally conductive media such as CaCO3, MgCO3, and Si2O3.
[0020] S2. Separately, the etched diamond particles and high-viscosity liquid are placed together in a three-dimensional mixer and mixed for 30-60 minutes to obtain the second powder raw material. Furthermore, the etching diamond particle size is 100μm~500μm; The high-viscosity liquid is any one of liquid paraffin, glycerin, epoxy resin or silicone oil; The mass ratio of the etching diamond particles to the high-viscosity liquid is 55~75:0.1~0.3; The mass ratio of transition diamond micro powder to etched diamond particles is 15~35:55~75.
[0021] S3. The first powder raw material and the second powder raw material are put into the three-dimensional mixer and mixed to obtain a uniformly mixed third powder raw material. The mixing time for the two powders is 30-40 minutes.
[0022] S4. The third powder raw material is loaded into a molybdenum material cup to form a component; the specific method is as follows: The evenly mixed powder is spread evenly in a molybdenum material cup, pre-pressed on a four-column press with a pressure of 5~10Mpa, and then the top cover is put on to form a component.
[0023] S5. Place the component in a vacuum sintering furnace for reduction treatment to obtain the reduced component; the specific method is as follows: Place the components in a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2 The material is heated to 800~1000℃ at MPa and kept at that temperature while H2 is introduced for reduction treatment for 3~5 hours. Then it is cooled to 400~600℃ and subjected to forced cooling to room temperature to obtain the reduced component.
[0024] S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
[0025] The specific operating procedures for the six-sided top press are as follows: First, pre-press the synthetic block with a pressure of 0.5~1Gpa. Then, increase the pressure to 4~4.5Gpa within 50~200 seconds and maintain it for 150~300 seconds. Then, gradually increase it to 5~5.5Gpa within 400~800 seconds and maintain it for 200~500 seconds. Finally, reduce the pressure to 0 at a constant rate within 200~800 seconds. Heating begins when the pressure reaches 2-3 GPa, increasing the temperature to 800-1200℃ within 50-150 seconds, then gradually increasing it to 1600℃ within the next 400-700 seconds, and finally increasing it to 1800℃ within 200-400 seconds, which is then maintained for 10-300 seconds. Subsequently, the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
[0026] The preparation method of this invention enables the formation of good contact chemical bonds between diamond particles, thereby building a thermally conductive network with diamond as the framework and obtaining a high thermal conductivity diamond composite material.
[0027] The high thermal conductivity diamond composite material prepared according to the method of the present invention has a thermal conductivity greater than 650 W / (m·K).
[0028] This invention utilizes high temperature and pressure, along with catalytic action, to optimize the diamond particle size distribution and employ a reasonable synthesis process to achieve good thermal conductivity pathways between diamond particles, ultimately producing a diamond composite material with a high thermal conductivity (greater than 650 W / (m·K)).
[0029] Example 1 The preparation method of the high thermal conductivity diamond composite material in this embodiment is as follows: S1. The transition diamond micro powder and the catalyst are put into a three-dimensional mixer, metal balls are added, and the mixture is mixed in a ball mill for 8 hours to obtain the first powder raw material. The mass ratio of transition diamond micro powder to catalyst is 23:7; the mass ratio of transition diamond micro powder to metal spheres is 1:4. The particle size of transition diamond powder is 10~20μm; The catalyst is a cobalt metal binder.
[0030] S2. Separately, the etched diamond particles and liquid paraffin are placed together in a three-dimensional mixer and mixed for 60 minutes to obtain the second powder raw material. Furthermore, the etching diamond particle size is 400μm~500μm; The mass ratio of the etched diamond particles to the liquid paraffin is 70:0.3. The mass ratio of transition diamond micropowder to etched diamond particles is 23:70.
[0031] S3. Place the first powder raw material and the second powder raw material together into a three-dimensional mixer and mix for 30 minutes to obtain a uniformly mixed third powder raw material. S4. Spread the evenly mixed powder evenly in the molybdenum material cup, pre-press it on a four-column press with a pressure of 6 MPa, and then put on the top cover to form the component.
[0032] S5. Place the components into a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2 The material is heated to 800~1000℃ at MPa and kept at that temperature while being reduced by H2 for 4 hours. Then it is cooled to 400℃ and subjected to forced cooling to room temperature to obtain the reduced component.
[0033] S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
[0034] The specific operating procedures for the six-sided top press are as follows: The pressure curve is as follows: first, the synthetic block is pre-pressed with a pressure of 0.8 GPa, then the pressure is increased to 4 GPa within 50 seconds and maintained for 150 seconds, then gradually increased to 5.5 GPa within 600 seconds and maintained for 300 seconds, and finally the pressure is uniformly reduced to 0 within 800 seconds. The heating curve is as follows: heating begins when the pressure is increased to 2 GPa, and the temperature is increased to 1000℃ within 100 seconds, then gradually increased to 1600℃ within the next 400 seconds, and further increased to 1800℃ within 200 seconds, and held for 300 seconds; then the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
[0035] The obtained high thermal conductivity diamond composite material was tested and found to have a thermal conductivity of 692 W / (m·K).
[0036] Example 2 The preparation method of the high thermal conductivity diamond composite material in this embodiment is as follows: S1. The transition diamond micro powder and the catalyst are put into a three-dimensional mixer, metal balls are added, and the mixture is mixed in a ball mill for 10 hours to obtain the first powder raw material. The mass ratio of transition diamond micro powder to catalyst is 35:5; the mass ratio of transition diamond micro powder to metal spheres is 1:7. The particle size of transition diamond powder is 40~50μm; The catalyst is CaCO3, a thermally conductive medium.
[0037] S2. Separately, the etched diamond particles and glycerin are placed together in a three-dimensional mixer and mixed for 30 minutes to obtain the second powder raw material. Furthermore, the etching diamond particles have a particle size of 100μm~200μm; The mass ratio of the etched diamond particles to glycerin is 55:0.1. The mass ratio of transition diamond micropowder to etched diamond particles is 35:55.
[0038] S3. Place the first powder raw material and the second powder raw material together into a three-dimensional mixer and mix for 40 minutes to obtain a uniformly mixed third powder raw material. S4. Spread the evenly mixed powder evenly in the molybdenum material cup, pre-press it on a four-column press with a pressure of 10 MPa, and then put on the top cover to form the component.
[0039] S5. Place the components into a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2 The pressure was increased to 800~1000℃, and H2 was introduced during the heat treatment for 3 hours. Then the temperature was reduced to 600℃ and subjected to strong cooling to room temperature to obtain the reduced component.
[0040] S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
[0041] The specific operating procedures for the six-sided top press are as follows: The pressure curve is as follows: first, the synthetic block is pre-pressed with a pressure of 1 GPa, then the pressure is increased to 4.5 GPa within 100 seconds and maintained for 300 seconds, then gradually increased to 5 GPa within 400 seconds and maintained for 200 seconds, and finally the pressure is uniformly reduced to 0 within 500 seconds. The heating curve is as follows: heating begins when the pressure is increased to 3 GPa, the temperature is increased to 800℃ within 150 seconds, gradually increased to 1600℃ within the next 700 seconds, and increased to 1800℃ within 400 seconds, and held for 300 seconds; then the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
[0042] The obtained high thermal conductivity diamond composite material was tested and found to have a thermal conductivity of 665 W / (m·K).
[0043] Example 3 The preparation method of the high thermal conductivity diamond composite material in this embodiment is as follows: S1. The transition diamond micro powder and the catalyst are put into a three-dimensional mixer, metal balls are added, and the mixture is mixed in a ball mill for 9 hours to obtain the first powder raw material. The mass ratio of transition diamond micro powder to catalyst is 35:10; the mass ratio of transition diamond micro powder to metal spheres is 1:3. The particle size of transition diamond powder is 30~40μm; The catalyst is a nickel metal binder.
[0044] S2. Separately, the etched diamond particles and epoxy resin are placed together in a three-dimensional mixer and mixed for 50 minutes to obtain the second powder raw material. Furthermore, the etching diamond particle size is 200μm~300μm; The mass ratio of etched diamond particles to epoxy resin is 75:0.3. The mass ratio of transition diamond micropowder to etched diamond particles is 35:75.
[0045] S3. Place the first powder raw material and the second powder raw material together into a three-dimensional mixer and mix for 35 minutes to obtain a uniformly mixed third powder raw material. S4. Spread the evenly mixed powder evenly in the molybdenum material cup, pre-press it on a four-column press with a pressure of 5 MPa, and then put on the top cover to form the component.
[0046] S5. Place the components into a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2 The material is heated to 800~1000℃ at MPa and kept at that temperature while being reduced by H2 for 5 hours. Then it is cooled to 500℃ and subjected to forced cooling to room temperature to obtain the reduced component.
[0047] S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
[0048] The specific operating procedures for the six-sided top press are as follows: The pressure curve is as follows: first, the synthetic block is pre-pressed with a pressure of 0.8 GPa, then the pressure is increased to 4 GPa within 200 seconds and maintained for 250 seconds, then gradually increased to 5.5 GPa within 800 seconds and maintained for 500 seconds, and finally the pressure is uniformly reduced to 0 within 200 seconds. The heating curve is as follows: heating begins when the pressure is increased to 2 GPa, and the temperature is increased to 1200℃ within 50 seconds, then gradually increased to 1600℃ within the next 500 seconds, and then increased to 1800℃ within 300 seconds, and held for 300 seconds; then the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
[0049] The obtained high thermal conductivity diamond composite material was tested and found to have a thermal conductivity of 680 W / (m·K).
[0050] Example 4 The preparation method of the high thermal conductivity diamond composite material in this embodiment is as follows: S1. The transition diamond micro powder and the catalyst are put into a three-dimensional mixer, metal balls are added, and the mixture is mixed in a ball mill for 8 hours to obtain the first powder raw material. The mass ratio of transition diamond micro powder to catalyst is 15:5; the mass ratio of transition diamond micro powder to metal spheres is 1:6. The particle size of transition diamond powder is 20~30μm; The catalyst is a tungsten metal binder.
[0051] S2. Separately, the etched diamond particles and silicone oil are placed together in a three-dimensional mixer and mixed for 40 minutes to obtain the second powder raw material. Furthermore, the etching diamond particle size is 300μm~400μm; The mass ratio of etching diamond particles to silicone oil is 75:0.1. The mass ratio of transition diamond micropowder to etched diamond particles is 15:75.
[0052] S3. Place the first powder raw material and the second powder raw material together into a three-dimensional mixer and mix for 38 minutes to obtain a uniformly mixed third powder raw material. S4. Spread the evenly mixed powder evenly in the molybdenum material cup, pre-press it on a four-column press with a pressure of 8 MPa, and then put on the top cover to form the component.
[0053] S5. Place the components into a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2The pressure was increased to 900-1000℃, and H2 was introduced during the heat treatment for 4 hours. Then the temperature was reduced to 500℃ and subjected to strong cooling to room temperature to obtain the reduced component.
[0054] S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
[0055] The specific operating procedures for the six-sided top press are as follows: The pressure curve is as follows: first, the synthetic block is pre-pressed with a pressure of 0.9 GPa, then the pressure is increased to 4 GPa within 150 seconds and maintained for 200 seconds, then gradually increased to 5.5 GPa within 500 seconds and maintained for 400 seconds, and finally the pressure is uniformly reduced to 0 within 600 seconds. The heating curve is as follows: heating begins when the pressure is increased to 3 GPa, the temperature is increased to 1200℃ within 100 seconds, gradually increased to 1600℃ within the next 600 seconds, and increased to 1800℃ within 200 seconds, and held for 300 seconds; then the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
[0056] The obtained high thermal conductivity diamond composite material was tested and found to have a thermal conductivity of 673 W / (m·K).
[0057] Example 5 The preparation method of the high thermal conductivity diamond composite material in this embodiment is as follows: S1. The transition diamond micro powder and the catalyst are put into a three-dimensional mixer, metal balls are added, and the mixture is mixed in a ball mill for 10 hours to obtain the first powder raw material. The mass ratio of transition diamond micro powder to catalyst is 15:10; the mass ratio of transition diamond micro powder to metal spheres is 1:5. The particle size of transition diamond powder is 20~30μm; The catalyst is Si2O3, a thermally conductive medium.
[0058] S2. Separately, the etched diamond particles and liquid paraffin are placed together in a three-dimensional mixer and mixed for 40 minutes to obtain the second powder raw material. Furthermore, the etching diamond particles have a particle size of 100μm~200μm; The mass ratio of the etching diamond particles to the high-viscosity liquid is 65:0.3. The mass ratio of transition diamond micropowder to etched diamond particles is 15:65.
[0059] S3. Place the first powder raw material and the second powder raw material together into a three-dimensional mixer and mix for 30 minutes to obtain a uniformly mixed third powder raw material. S4. Spread the evenly mixed powder evenly in the molybdenum material cup, pre-press it on a four-column press with a pressure of 5 MPa, and then put on the top cover to form the component.
[0060] S5. Place the components into a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2 The material is heated to 800~900℃ at MPa and kept at that temperature while H2 is introduced for reduction treatment. The temperature is then maintained for 3 hours. Subsequently, the temperature is lowered to 600℃ and subjected to forced cooling to room temperature to obtain the reduced component.
[0061] S6. The method and specific process parameters are the same as in Example 1.
[0062] The obtained high thermal conductivity diamond composite material was tested and found to have a thermal conductivity of 686 W / (m·K).
[0063] Example 6 The preparation method of the high thermal conductivity diamond composite material in this embodiment is as follows: The methods and specific process parameters for S1 to S5 are the same as in Example 1.
[0064] S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
[0065] The specific operating procedures for the six-sided top press are as follows: The pressure curve is as follows: first, the synthetic block is pre-pressed with a pressure of 1.0 GPa, then the pressure is increased to 4.5 GPa within 90 seconds and maintained for 250 seconds, then gradually increased to 5 GPa within 550 seconds and maintained for 500 seconds, and finally the pressure is uniformly reduced to 0 within 400 seconds. The heating curve is as follows: heating begins when the pressure is increased to 3 GPa, the temperature is increased to 1200℃ within 150 seconds, gradually increased to 1600℃ within the next 600 seconds, and increased to 1800℃ within 250 seconds, and held for 300 seconds; then the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
[0066] The obtained high thermal conductivity diamond composite material was tested and found to have a thermal conductivity of 691 W / (m·K).
Claims
1. A method for preparing a high thermal conductivity diamond composite material, characterized in that, The specific method is as follows: S1. Place the transition diamond micro powder and catalyst into a three-dimensional mixer, add metal balls, and mix them in a ball mill to obtain the first powder raw material; S2. Separately, the etched diamond particles and high-viscosity liquid are mixed in a three-dimensional mixer to obtain a second powder raw material. S3. Mix the two powder raw materials in a three-dimensional mixer to obtain a third powder raw material; S4. The third powder raw material is loaded into the molybdenum material cup to form a component; S5. The components are placed in a vacuum sintering furnace for reduction treatment to obtain the reduced components; S6. The reduced components are placed into the assembly parts to obtain a composite block, which is then placed into a six-sided press and synthesized according to the pressure-power curve to obtain a high thermal conductivity diamond composite material.
2. The method for preparing the high thermal conductivity diamond composite material according to claim 1, characterized in that, The mass ratio of transition diamond micro powder to catalyst in S1 is 15~35:5~10; The mass ratio of the etched diamond particles to the high-viscosity liquid in S2 is 55~75:0.1~0.3; The mass ratio of the transition diamond micro powder to the etched diamond particles is 15~35:55~75.
3. The method for preparing the high thermal conductivity diamond composite material according to claim 1, characterized in that, The mass ratio of transition diamond micro powder and metal spheres in S1 is 1:3~7; The mixing time on the ball mill is 8-10 hours; The transition diamond micro powder has a particle size of 10~50 μm; The catalyst is any one of metal binders such as cobalt, nickel, and tungsten, or thermally conductive media such as CaCO3, MgCO3, and Si2O3.
4. The method for preparing the high thermal conductivity diamond composite material according to claim 1, characterized in that, The diamond particles etched in S2 have a particle size of 100um to 500um; The high-viscosity liquid is any one of liquid paraffin, glycerin, epoxy resin or silicone oil; The mixing time of the etched diamond particles and the high-viscosity liquid is 30~60 min.
5. The method for preparing the high thermal conductivity diamond composite material according to claim 1, characterized in that, The mixing time for the two powders in S3 is 30-40 minutes.
6. The method for preparing the high thermal conductivity diamond composite material according to claim 1, characterized in that, The specific method of S4 is as follows: The evenly mixed powder is spread evenly in a molybdenum material cup, pre-pressed on a four-column press with a pressure of 5~10Mpa, and then the top cover is put on to form a component.
7. The method for preparing the high thermal conductivity diamond composite material according to claim 1, characterized in that, The specific method of S5 is as follows: Place the components in a vacuum sintering furnace and evacuate to a vacuum level ≤10. -2 The material is heated to 800~1000℃ at MPa and kept at that temperature while H2 is introduced for reduction treatment for 3~5 hours. Then it is cooled to 400~600℃ and subjected to forced cooling to room temperature to obtain the reduced component.
8. The method for preparing the high thermal conductivity diamond composite material according to claim 1, characterized in that, The specific operating procedure in the six-sided top press in S6 is as follows: First, pre-press the synthetic block with a pressure of 0.5~1Gpa. Then, increase the pressure to 4~4.5Gpa within 50~200 seconds and maintain it for 150~300 seconds. Then, gradually increase it to 5~5.5Gpa within 400~800 seconds and maintain it for 200~500 seconds. Finally, reduce the pressure to 0 at a constant rate within 200~800 seconds. Heating begins when the pressure reaches 2-3 GPa, increasing the temperature to 800-1200℃ within 50-150 seconds, then gradually increasing it to 1600℃ within the next 400-700 seconds, and finally increasing it to 1800℃ within 200-400 seconds, which is then maintained for 10-300 seconds. Subsequently, the temperature is reduced to 200℃ within 400 seconds using a uniform cooling method, and the synthesis process is completed after the pressure is released. After removing the synthetic block, break it open and remove the outer skin of the preform to obtain the high thermal conductivity diamond composite material.
9. The high thermal conductivity diamond composite material prepared by any one of the preparation methods according to claims 1 to 8, characterized in that, The thermal conductivity of the high thermal conductivity diamond composite material is greater than 650 W / (m·K).