Heat pipe structure based on coating diamond and preparation method

Abstract

The invention discloses a heat pipe structure based on coated diamonds and a preparation method, the heat pipe structure comprises an evaporation section, a heat insulation section and a condensation section which are arranged in sequence, capillary cores of the evaporation section and the condensation section are double-coated diamonds, the middle heat insulation section is a copper capillary core, and the double-coated diamonds are double-coated diamonds plated with tungsten first and then plated with copper; the capillary core material of the hot end and the cold end of the heat pipe is changed from copper to double-plating diamond plated with tungsten and then copper, and the heat conductivity of the capillary cores of the hot end and the cold end can be greatly improved through the high heat conductivity of the diamond, so that the heat exchange resistance of the two ends is reduced, the heat exchange capacity of the heat pipe and the outside is improved, and the service life of the heat pipe is prolonged. And the use scene of a common heat pipe is further widened.

Description

Technical Field

[0001] The present invention belongs to the field of physical, chemical coating and powder metallurgy manufacturing technology, and particularly relates to a heat pipe structure based on coated diamond and a preparation method thereof. Background Art

[0002] As a passive heat transfer device, heat pipes do not consume any additional energy. They have high heat transfer efficiency and compact structure. The circulating working fluid can be adjusted according to working conditions, such as water, acetone, and methanol. Due to their simple structure, they can be prepared into almost any shape, making heat pipes have a wide range of application scenarios, covering many fields such as electronic equipment cooling, aerospace, solar collectors, medical equipment, nuclear energy technology, and household appliances.

[0003] The structure of the heat pipe is as follows Figure 1 As shown, the common heat pipe is structurally divided into a copper shell, a capillary core layer, and an internal cavity filled with a heat exchange medium, usually deionized water, wherein the capillary core layer is sequentially distributed in three parts: an evaporation section (hot end), an intermediate section (medium transport or insulation section), and a condensation section (cold end). At the hot end, heat is transferred from the outside through the shell and the capillary core to the inside of the heat pipe, heating the liquid medium in the pipe so that it vaporizes and passes through the middle hollow part to reach the condensation section, releasing heat and liquefying. The heat still needs to pass through the capillary core and the shell. Finally, the liquefied liquid is transported to the evaporation section by the capillary force of the capillary core, completing the circulation of the medium and heat.

[0004] At the hot end and the cold end, the heat transfer needs to pass through the copper shell and the capillary core layer first, and then realize the heat exchange. The thermal resistance diagram of the heat transfer process is as follows: Figure 2 Due to their low price and good thermal conductivity, the shell and capillary core are usually made of metal materials such as copper and aluminum. However, with the increase of heat flux density, due to the contact thermal resistance between the gaps in the sintered capillary core and the copper powder particles, the overall thermal conductivity of the capillary core still has a lot of room for improvement.

[0005] Diamond has an ultra-high thermal conductivity (2200-2600 W / (m·K)). In recent years, the technology of artificial diamond synthesis has become more mature, and the cost of artificial diamond particles has gradually decreased. Current industrial applications are already competitive. Replacing the copper capillary wicks at the hot and cold ends with diamond capillary wicks can improve thermal conductivity, improve the heat exchange efficiency of the hot and cold ends, and greatly improve the working performance of the heat pipe. The sintering of the capillary wick requires the sintering powder to soften and connect to each other at high temperatures. However, the melting point of diamond exceeds 3500°C, so it is obviously not easy to soften it. Secondly, the external shell material is usually made of metallic copper. Due to the large difference in the physical properties of copper and diamond, integrated sintering will be relatively difficult.

[0006] The utility model with announcement number CN221811508U discloses a fixed-type coated heat pipe, the technical solution of which includes three parts: a heat pipe, a coating, and a solder / reactive nano multilayer film / solder sandwich coating. The reactive nano multilayer film can undergo a self-propagating reaction under the induction of external energy, and the reaction heat release can melt the solder instantly, thereby directly connecting the heat pipe to the bottom of the heat pipe groove. The reactive nano multilayer film is relatively thin, and its extremely fast cooling speed can ensure that the structure of the heat pipe is not damaged. By fixing the fixed-type coated heat pipe to the bottom of the heat pipe groove, the problem of the heat pipe floating during the subsequent heat pipe radiator welding process is solved. However, the heat transfer efficiency of the heat pipe has not been optimized and improved, and the integrated sintering of the diamond capillary core and the copper shell has not been studied, so there is still room for improvement. Summary of the invention

[0007] The purpose of the present invention is to provide a heat pipe structure based on coated diamond and a preparation method to improve the heat exchange efficiency of the hot end and the cold end of the heat pipe, thereby improving the overall working capacity of the heat pipe.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: A heat pipe structure based on coated diamond, comprising a copper shell, an internal capillary core layer and a vacuum cavity, and an evaporation section, an insulation section and a condensation section are arranged in sequence; The capillary core layers of the evaporation section and the condensation section are sintered with double-layered diamond, the capillary core of the middle insulation section is a copper capillary core, and the double-layered diamond is a double-layered layer that is first plated with tungsten and then plated with copper.

[0009] A method for preparing a heat pipe structure based on coated diamond comprises the following steps: (1) First, clean the diamond; (2) Magnetron tungsten plating is performed on diamond under vacuum conditions to obtain tungsten-coated diamond; (3) heat treating the tungsten-coated diamond obtained in step (2) to obtain heat-treated tungsten-coated diamond; (4) coating the tungsten-coated diamond obtained in step (3) with a uniform copper layer by chemical plating, and reducing it with a reducing gas to obtain a double-coated diamond; (5) A round stainless steel core rod with a diameter slightly smaller than the copper shell is placed in the center of the copper shell with a sealed bottom and an open top. The annular gap is the capillary wick sintering area. Double-coated diamond, copper powder, and double-coated diamond are filled in this area from bottom to top in sequence, compacted, and placed in a vacuum atmosphere furnace for integrated sintering to obtain a preliminary structure of a heat pipe with coated diamond capillary wicks at both ends and a copper capillary wick in the middle. (6) The preliminary structure of the heat pipe obtained in (5) is filled with an appropriate amount of deionized water and then evacuated. The copper end caps prepared in advance are cleaned and assembled with the open ends. Brazing solder is filled in the connection gap, heated to melt it, and then slowly cooled to room temperature to obtain the new heat pipe.

[0010] In step (4), the chemical plating process includes sensitization-activation-chemical copper plating. a. Sensitization The tungsten-coated diamond after heat treatment in step (3) is placed in a mixed solution of SnCl and HCl and stirred with a magnetic stirrer to make Sn 2+ Deposited onto the diamond surface; b. Activation The sensitized diamond was rinsed with deionized water and placed in a PdCl solution and stirred with a magnetic stirrer. 2+ Pd 2+ Reduced to Pd atoms and deposited on the diamond surface; c. Chemical copper plating The activated diamond is rinsed with deionized water and then placed in a copper plating solution to displace the copper, and the thickness of the chemical copper plating layer is calculated by a weighing method; It is then placed in an atmosphere furnace and a nitrogen-hydrogen mixed gas is passed through to reduce a small amount of oxygen on the surface.

[0011] In step c, the copper plating solution includes a copper source CuSO4 solution, a reducing agent HCHO solution and a complexing agent EDTA, and the pH value of the solution is 13±0.5.

[0012] In step (5), the copper powder particle size is 70 / 80 mesh, and the integrated sintering temperature in the vacuum atmosphere furnace is 750°C.

[0013] In step (2), the magnetron sputtering apparatus used in magnetron tungsten plating is equipped with a rotating drum.

[0014] In step (1), acetone and anhydrous ethanol are used for ultrasonic cleaning respectively, and then deionized water is used to rinse and dry.

[0015] The power of the magnetron sputtering apparatus is 80W, the temperature is 300°C, the speed of the rotating drum is 45rpm, the time is 360min, and the thickness of the plated tungsten coating is 200-300nm.

[0016] In step (2), the heat treatment process parameters of the tungsten-plated diamond are set as follows: a heating rate of 5°C / min, heating to 1050°C, keeping the temperature for 2h, and then cooling at a cooling rate of 5°C / min to 300°C and then cooling to room temperature in the furnace.

[0017] In step (1), the diamond used is Henan Yellow River Cyclone HWD30 diamond with a particle size of 70 / 80 mesh.

[0018] The beneficial effects of the present invention are: (1) The present invention discloses a heat pipe structure based on coated diamond and a preparation method thereof. The heat pipe structure comprises an evaporation section, an insulation section and a condensation section which are arranged in sequence, and the capillary wicks of the evaporation section and the condensation section are double-coated diamonds, the middle insulation section is a copper capillary wick, and the double-coated diamond is a double-coated diamond that is first plated with tungsten and then plated with copper; the capillary wick material of the hot end and the cold end of the heat pipe is replaced from copper to double-coated diamond that is first plated with tungsten and then plated with copper. The high thermal conductivity of diamond can greatly improve the thermal conductivity of the capillary wicks at the hot end and the cold end, thereby reducing the heat exchange thermal resistance at the two ends, improving the heat exchange capacity between the heat pipe and the outside world, and further broadening the application scenarios of ordinary heat pipes.

[0019] (2) The present invention utilizes a high thermal conductivity diamond capillary wick to replace the traditional copper capillary wick, thereby greatly improving the thermal conductivity of the heat pipe at the hot end and the cold end, thereby enhancing the heat exchange efficiency of the heat pipe. At the same time, the surface of the diamond capillary wick is modified to address the problem that it is difficult to sinter, and a double layer of coating is plated on its surface. Since the capillary wick ultimately needs to be sintered with the outermost metal copper shell of the heat pipe, the outermost layer of the diamond coating is a copper coating. In view of the problem that copper and diamond are difficult to wet, the diamond surface is first plated with tungsten and then plated with copper, which can greatly improve the wettability of diamond and copper and improve the interfacial bonding strength of the diamond and copper coatings, thereby achieving the sintering of the diamond capillary wick and the outer metal copper shell, and finally preparing a new type of heat pipe with higher heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of an existing heat pipe; Figure 2 It is the heat transfer resistance diagram of the hot end of the heat pipe; Figure 3 It is a schematic diagram of the structure of the heat pipe of the present invention; DETAILED DESCRIPTION

[0021] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0022] The present invention provides a heat pipe structure based on coated diamond and a preparation method thereof, such as Figures 1 to 3 shown.

[0023] A heat pipe structure based on coated diamond includes a copper layer shell 1, an internal capillary core layer 2 and a hollow inner cavity 3, and an evaporation section, an insulation section and a condensation section are arranged in sequence; the capillary core layers of the evaporation section and the condensation section are sintered by double-coated diamond 21, the capillary core of the middle insulation section is a copper capillary core 22, and the double-coated diamond is a double-coated layer that is first plated with tungsten and then plated with copper, and the hollow inner cavity 3 is set as a vacuum cavity. In this embodiment, the vacuum cavity is filled with deionized water.

[0024] A method for preparing a heat pipe structure based on coated diamond comprises the following steps: (1) First, clean the diamond; (2) Magnetron tungsten plating is performed on diamond under vacuum conditions to obtain tungsten-coated diamond; (3) heat treating the tungsten-coated diamond obtained in step (2) to obtain heat-treated tungsten-coated diamond; (4) coating the tungsten-coated diamond obtained in step (3) with a uniform copper layer by chemical plating, and reducing it with a reducing gas to obtain a double-coated diamond; (5) A round stainless steel core rod with a diameter slightly smaller than the copper shell is placed in the center of the copper shell with a sealed bottom and an open top. The annular gap is the capillary wick sintering area. Double-coated diamond, copper powder, and double-coated diamond are filled in this area from bottom to top in sequence, compacted, and placed in a vacuum atmosphere furnace for integrated sintering to obtain a preliminary structure of a heat pipe with coated diamond capillary wicks at both ends and a copper capillary wick in the middle; (6) The preliminary structure of the heat pipe obtained in (5) is filled with an appropriate amount of deionized water and then evacuated. The copper end caps prepared in advance are cleaned and assembled with the open ends of the heat pipes. Brazing solder is filled in the connection gap, heated to melt it, and then slowly cooled to room temperature to obtain the heat pipe.

[0025] In step (4), the chemical plating process includes sensitization-activation-chemical copper plating. a. Sensitization The tungsten-coated diamond after heat treatment in step (3) is placed in a mixed solution of SnCl and HCl and stirred with a magnetic stirrer to make Sn 2+ Deposited onto the diamond surface; b. Activation The sensitized diamond was rinsed with deionized water and placed in a PdCl solution and stirred with a magnetic stirrer. 2+ Pd 2+ Reduced to Pd atoms and deposited on the diamond surface; c. Chemical copper plating The activated diamond is rinsed with deionized water and then placed in a copper plating solution to displace the copper, and the thickness of the chemical copper plating layer is calculated by a weighing method; It is then placed in an atmosphere furnace and a nitrogen-hydrogen mixed gas is passed through to reduce a small amount of oxygen on the surface.

[0026] In step c, the copper plating solution includes a copper source CuSO4 solution, a reducing agent HCHO solution and a complexing agent EDTA, and the pH value of the solution is 13±0.5.

[0027] In step (5), the copper powder particle size is 70 / 80 mesh, and the integrated sintering temperature in the vacuum atmosphere furnace is 750°C.

[0028] In step (2), the magnetron sputtering apparatus used for magnetron tungsten plating is equipped with a rotating drum.

[0029] In step (1), acetone and anhydrous ethanol are used for ultrasonic cleaning respectively, and then deionized water is used to rinse and dry.

[0030] The power of the magnetron sputtering apparatus is 80W, the temperature is 300°C, the speed of the rotating drum is 45rpm, the time is 360min, and the thickness of the plated tungsten coating is 200-300nm.

[0031] In step (2), the heat treatment process parameters of the tungsten-plated diamond are set as follows: a heating rate of 5°C / min, heating to 1050°C, keeping the temperature for 2h, and then cooling at a cooling rate of 5°C / min to 300°C and then cooling to room temperature in the furnace.

[0032] In step (1), the diamond used is Henan Yellow River Cyclone HWD30 diamond with a particle size of 70 / 80 mesh.

[0033] The present invention is described in detail below: The present invention aims to enhance the heat exchange capacity of the hot end and the cold end of the heat pipe. Due to the presence of the capillary wick, heat needs to pass through the copper shell and the thicker capillary wick to heat the heat pipe working medium, which will produce a large heat transfer resistance and affect the actual working performance of the heat pipe.

[0034] The present invention proposes to use diamond to reduce the heat transfer resistance of the hot end and the cold end of the heat pipe, which benefits from the high thermal conductivity of diamond and its increasingly low price. However, the melting point of pure diamond is too high to sinter the capillary core, and its wettability with metal copper is poor, making it difficult to sinter with the copper shell. The surface of the diamond needs to be coated with a double layer, first tungsten, and then copper. The metal copper coating softens at high temperature and then sintered into a diamond capillary core. At the same time, the copper layer can significantly improve the sintering bonding strength of the diamond capillary core and the copper shell. Tungsten is a strong carbon compound. The use of strong carbon compound elements such as tungsten, chromium, titanium, etc. can react with carbon at high temperature to generate compounds to improve the wetting of diamond and copper, and enhance the bonding strength of diamond and copper coatings, which can greatly improve the disadvantage of non-wetting of diamond and copper. The quality of the strong carbon compound coating has a great influence on the performance of the subsequent sintered capillary core. Whether the coating is uniform is crucial. Common coating methods mainly include thermal diffusion method, salt bath method, magnetron sputtering method, etc. The first two are reactive plating. Due to the uneven distribution of reaction sites in reactive plating, the uniformity of the coating is difficult to control, so magnetron sputtering is selected for surface coating. Magnetron sputtering is a physical plating method that uses a rotating drum to control the uniformity of the diamond surface coating, but the plating elements do not react with diamonds and need to be heat treated at high temperatures. This scheme chooses to plate tungsten on diamonds and selects the optimal heat treatment temperature of 1050℃ for 2h for heat treatment. The thermal diffusion coefficients of diamond and tungsten are quite different. Too fast heating and cooling speed will cause the coating to fall off, so the heating speed is controlled to 5℃ / min. The core of chemical copper plating is to sensitize and activate the diamond surface. After activation, it is convenient for Cu to deposit on the diamond surface, otherwise the coating growth rate will be very slow and the bonding force will be low.

[0035] A new heat pipe structure based on coated diamond and its preparation method, the preparation materials include diamond 70 / 80 mesh, pure copper powder 70 / 80 mesh, tungsten target, pure copper target, metal copper tube (one side is closed), the specific steps are as follows: (1) Diamond particle cleaning The diamond particles were first placed in a beaker containing acetone and cleaned in an ultrasonic cleaner for 10 minutes. They were then placed in a beaker containing anhydrous ethanol and cleaned in an ultrasonic cleaner for 10 minutes. They were then rinsed with deionized water and finally placed in a vacuum oven and heated at 50°C for 25 minutes.

[0036] (2) Magnetron sputtering tungsten coating on diamond surface The magnetron sputtering instrument was evacuated to 8 × 10 -4Pa, using DC sputtering, sputtering power 80W, sputtering temperature 300℃, taking 200g of cleaned diamond and placing it in a rotating drum, the drum rotation speed is 45r / min, sputtering for 360min, and the tungsten coating thickness is about 200nm calculated by weighing. According to research, the optimal thickness of diamond tungsten plating is about 200nm, so 360min is selected as the final sputtering time.

[0037] (3) Heat treatment of tungsten-coated diamond Place the tungsten-coated diamond in a stainless steel mold, press it tightly, put it in a vacuum furnace, and evacuate it to 1×10 -2 Pa, control the heating rate to 5℃ / min, heat to 1050℃, keep warm for 2h, then cool down to 300℃ at 5℃ / min, cool to room temperature with the furnace, and then take out.

[0038] (4) Chemical copper plating Heat-treated diamonds were placed in a mixed solution of 35 g / L SnCl and 30% HCl, with the volume ratio of the two solutions being 1000:70. Since the density of diamonds is much greater than the density of the solution, diamonds will accumulate at the bottom of the solution, so some areas cannot fully contact the solution. Therefore, a magnetic stirrer was used to stir the diamonds at a speed of 70 r / min, so that SnCl 2+ It is evenly deposited on the diamond surface for 10 minutes. After deposition, it is convenient for the subsequent deposition of Pd on the diamond surface. This process is called sensitization.

[0039] The sensitized diamond was rinsed with deionized water and placed in a 0.35 g / L PdCl solution. A magnetic stirrer was used to stir the diamond at a speed of 70 r / min. 2+ It has strong reducing ability and can convert Pd 2+ Reducing Pd atoms and depositing them on the diamond surface can maximize the growth of Cu on the diamond surface. This process is called activation.

[0040] In the process of chemical copper plating, the copper plating solution uses CuSo4 as the source of deposited copper, and HCHO is used as a reducing agent to reduce Cu 2 + EDTA was used as a complexing agent, and NaOH solution was used to control the pH of the copper plating solution at 13±0.5, and the solution temperature was controlled at 42±1°C; the composition of the chemical copper plating solution is shown in Table 1.

[0041] Table 1 Chemical copper plating solution After chemical plating, rinse with deionized water, place in a vacuum oven, heat bake at 50℃ for 25min, weigh the mass difference before and after chemical plating, and calculate the thickness of the copper layer according to the spherical weight gain method, which is about 8μm. Oxidation-reduction reaction occurs during chemical copper plating, and there is a small amount of oxygen on the surface of diamond. Place it in a heat treatment furnace, and control the heating and cooling speed to 5℃ / min. Heat treat at 200℃ for 1.5h, and use nitrogen and hydrogen mixed gas as a protective atmosphere to remove most of the oxygen.

[0042] (5) A round stainless steel core rod with a diameter slightly smaller than that of the copper shell is placed in the center of the copper shell with a sealed bottom and an open top. The annular gap is the capillary core sintering area. In this area, 25% by volume of double-coated diamond (particle size 70 / 80 mesh), 50% by volume of copper powder (particle size 70 / 80 mesh), and 25% by volume of double-coated diamond (particle size 70 / 80 mesh) are injected from bottom to top. The volume percentage refers to the percentage of powder in the volume of the capillary core. The core rod is compacted and placed in a vacuum atmosphere furnace. It is sintered at 750°C for 20 min at a heating and cooling rate of 10°C / min to obtain a preliminary structure of an open heat pipe.

[0043] (6) The preliminary structure of the heat pipe obtained in (5) is filled with 35% volume of deionized water, and the structure is evacuated to 3×10-1Pa. The previously prepared top copper end cap is ultrasonically treated for 10 min and dried. The end cap is then assembled with the open end of the heat pipe, and the fitting gap is filled with BAg-45CuZnCd brazing solder. The temperature is raised to 630°C, kept at this temperature for 10 min, and then cooled to room temperature. The heating and cooling rates are both 8°C / min. The novel heat pipe is thus obtained.

[0044] The present invention changes the capillary wick material of the hot end and the cold end of the heat pipe from copper to double-coated diamond that is first plated with tungsten and then copper. The high thermal conductivity of diamond can greatly improve the thermal conductivity of the capillary wick at the hot end and the cold end, thereby reducing the heat exchange resistance at both ends, improving the heat exchange capacity between the heat pipe and the outside world, and further broadening the application scenarios of ordinary heat pipes.

[0045] If the words "first", "second" and the like are used in this patent to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of describing the present invention and simplifying the description, and the above words have no special meaning.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the invention claimed for protection. The scope of protection claimed for the present invention is defined by the attached claims and their equivalents.

[0047] In the description of the present invention, it is necessary to understand that the terms "front", "rear", "left", "right", "center", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the protection content of the present invention.

Claims

1. A heat pipe structure based on coated diamond, characterized in that: It includes a copper shell, an internal capillary core layer and a vacuum cavity, and an evaporation section, an insulation section and a condensation section are arranged in sequence; The capillary core layers of the evaporation section and the condensation section are sintered with double-layered diamond, the capillary core of the middle insulation section is a copper capillary core, and the double-layered diamond is a double-layered layer that is first plated with tungsten and then plated with copper.

2. A method for preparing a heat pipe structure based on coated diamond according to claim 1, characterized in that: The following steps are involved: (1) First, clean the diamond; (2) Magnetron tungsten plating is performed on diamond under vacuum conditions to obtain tungsten-coated diamond; (3) heat treating the tungsten-coated diamond obtained in step (2) to obtain heat-treated tungsten-coated diamond; (4) coating the tungsten-coated diamond obtained in step (3) with a uniform copper layer by chemical plating, and reducing it with a reducing gas to obtain a double-coated diamond; (5) A round stainless steel core rod with a diameter slightly smaller than that of the copper shell is placed in the center of the copper shell with a sealed bottom and an open top. The annular gap is the capillary wick sintering area. Double-coated diamond, copper powder, and double-coated diamond are filled in this area from bottom to top in sequence, compacted, and placed in a vacuum atmosphere furnace for integrated sintering to obtain a preliminary structure of a heat pipe with coated diamond capillary wicks at both ends and a copper capillary wick in the middle. (6) The preliminary structure of the heat pipe obtained in (5) is filled with an appropriate amount of deionized water and then evacuated. The copper end caps prepared in advance are cleaned and assembled with the open ends. Brazing solder is filled in the connection gap, heated to melt it, and then slowly cooled to room temperature to obtain the new heat pipe.

3. The method for preparing a heat pipe structure based on coated diamond according to claim 2, characterized in that: In step (4), the chemical plating process includes sensitization-activation-chemical copper plating. a. Sensitization The tungsten-coated diamond after heat treatment in step (3) is placed in a mixed solution of SnCl and HCl and stirred with a magnetic stirrer to make Sn 2+ Deposited onto the diamond surface; b. Activation The sensitized diamond was rinsed with deionized water and placed in a PdCl solution and stirred with a magnetic stirrer. 2+ Pd 2+ Reduced to Pd atoms and deposited on the diamond surface; c. Chemical copper plating The activated diamond is rinsed with deionized water and then placed in a copper plating solution to displace the copper, and the thickness of the chemical copper plating layer is calculated by a weighing method; It is then placed in an atmosphere furnace and a nitrogen-hydrogen mixed gas is passed through to reduce a small amount of oxygen on the surface.

4. The method for preparing a heat pipe structure based on coated diamond according to claim 3, characterized in that: In step c, the copper plating solution includes a copper source CuSO4 solution, a reducing agent HCHO solution and a complexing agent EDTA, and the pH value of the solution is 13±0.

5.

5. The method for preparing a heat pipe structure based on coated diamond according to claim 2, characterized in that: In step (5), the copper powder particle size is 70 / 80 mesh, and the integrated sintering temperature in the vacuum atmosphere furnace is 750°C.

6. The method for preparing a heat pipe structure based on coated diamond according to claim 2, characterized in that: In step (2), the magnetron sputtering apparatus used in magnetron tungsten plating is equipped with a rotating drum.

7. The method for preparing a heat pipe structure based on coated diamond according to claim 2, characterized in that: In step (1), acetone and anhydrous ethanol are used for ultrasonic cleaning respectively, and then deionized water is used to rinse and dry.

8. The method for preparing a heat pipe structure based on coated diamond according to claim 6, characterized in that: The power of the magnetron sputtering apparatus is 80W, the temperature is 300°C, the speed of the rotating drum is 45rpm, the time is 360min, and the thickness of the plated tungsten coating is 200-300nm.

9. The method for preparing a heat pipe structure based on coated diamond according to claim 2, characterized in that: In step (2), the heat treatment process parameters of the tungsten-plated diamond are set as follows: a heating rate of 5°C / min, heating to 1050°C, keeping the temperature for 2h, and then cooling at a cooling rate of 5°C / min to 300°C and then cooling to room temperature in the furnace.

10. The method for preparing a heat pipe structure based on coated diamond according to claim 2, characterized in that: In step (1), the diamond used is Henan Yellow River Cyclone HWD30 diamond with a particle size of 70 / 80 mesh.

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