Aluminum vapor cavity liquid absorption core and preparation method thereof

Abstract

The application provides an aluminum vapor cavity liquid wick and a preparation method thereof, and relates to the technical field of electronic chip heat dissipation. The preparation method of the aluminum vapor cavity liquid wick comprises the following steps: preparing a porous MAO ceramic film layer on the surface of an aluminum base, significantly increasing the bubble nucleation site density and the corrosion resistance of the aluminum surface; loading FeCo nanoparticles on the surface of the porous MAO ceramic film layer through a self-assembly method, and enhancing the catalytic performance of the surface; and preparing a CNTs coating with a vertical FeCo CNTs array on the surface of the porous MAO ceramic film layer through a chemical vapor deposition method, so that the CNTs coating has the advantages of a high aspect ratio and small pores, the capillary wicking effect is increased, and liquid rewetting is promoted. The aluminum vapor cavity liquid wick with the FeCo CNTs / MAO composite coating on the surface of the aluminum base is prepared, and the composite coating can exert the advantages of the MAO layer and the CNTs coating, and synergistically enhance the heat transfer efficiency and the boiling heat transfer stability of the surface of the aluminum vapor cavity liquid wick.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for electronic chips, and more specifically, to an aluminum vapor chamber liquid-absorbing core and its preparation method. Background Technology

[0002] Chip technology is at the heart of modern electronic engineering and forms the foundation for the development of high-performance electronic devices. However, the development of high-performance chips increases the chip's payload, causing a rapid increase in heat within a limited space. If this heat cannot be dissipated in time, the chip temperature will rise rapidly, affecting its performance and lifespan. Therefore, developing efficient heat dissipation technologies is crucial to ensuring chip performance and reliability.

[0003] A steam chamber is a highly efficient heat dissipation device that transfers heat through a liquid-gas phase change. In the steam chamber, the liquid absorbs heat at the bottom capillary wick and undergoes a phase change, transforming into a gas. The gas then liquefies at the top condenser, releasing heat, and ultimately, efficient heat dissipation is achieved through continuous gas-liquid circulation. The capillary wick, as the key component of the steam chamber, is primarily responsible for heat transfer and liquid transport.

[0004] Aluminum is widely used in capillary wicks for steam chambers due to its low cost, lightweight, and good thermal conductivity. However, common aluminum capillary wicks lack bubble nucleation sites on their surface, resulting in low heat transfer efficiency. Furthermore, aluminum surfaces are prone to oxidation, leading to poor boiling heat transfer stability. Summary of the Invention

[0005] The problem addressed by this invention is how to solve the problems of low heat transfer efficiency caused by the lack of bubble nucleation sites on the surface of aluminum capillary wicks and poor boiling heat transfer stability caused by the easy oxidation of the aluminum capillary wick surface.

[0006] To address the above problems, this invention provides an aluminum vapor chamber liquid suction core and its preparation method.

[0007] In a first aspect, the present invention provides a method for preparing an aluminum vapor chamber liquid-absorbing core, comprising the following steps:

[0008] S1: A porous MAO ceramic film was prepared on the surface of an aluminum substrate using a micro-arc oxidation method;

[0009] S2: FeCo nanoparticles are loaded onto the surface of a porous MAO ceramic film using a self-assembly method;

[0010] S3: A CNT coating with a vertically oriented FeCoCNTs array was prepared on the surface of a porous MAO ceramic film by chemical vapor deposition, resulting in an aluminum vapor chamber wick with a FeCoCNTs / MAO composite coating on the aluminum substrate surface.

[0011] Optionally, step S1 includes: placing an aluminum substrate in an electrolyte system and performing arc discharge on the surface of the aluminum substrate, wherein the electrical parameters include: unidirectional pulse, constant voltage mode, pulse voltage of 300 to 500V, frequency of 100 to 2000Hz, and current density of 5 to 40A / dm³. 2 The discharge time is 5 to 100 seconds.

[0012] Optionally, the electrolyte system includes an alkaline sodium salt solution, silicate, phosphate, fluoride, and tungstate.

[0013] Optionally, step S2 includes: placing an aluminum substrate with a porous MAO ceramic film layer in an ethanol solution containing dissolved iron and cobalt salts to self-assemble FeCo nanoparticles.

[0014] Optionally, the iron salt is ferrous acetate, with a density of 4 to 5 g / L in ethanol solution, and the cobalt salt is cobalt acetate, with a density of 6 to 8 g / L in ethanol solution.

[0015] Optionally, step S3 includes: adding a carbon source to the self-assembled aluminum substrate, performing low-temperature chemical vapor deposition in an atmosphere with a N2 to H2 flow ratio of 95:5, and calcining at below 600°C for more than 3 hours.

[0016] Alternatively, the carbon source may be melamine, methane, or acetylene.

[0017] Optionally, before performing the low-temperature chemical vapor deposition step, the self-assembled aluminum substrate is dried in a nitrogen atmosphere with a nitrogen flow rate of 100 sccm or higher.

[0018] Secondly, the present invention provides an aluminum vapor chamber liquid suction core, which is manufactured using the preparation method of the aluminum vapor chamber liquid suction core as described in any of the preceding claims.

[0019] The beneficial effects of the aluminum vapor chamber wick and its preparation method of the present invention are as follows: Micro-arc oxidation is a surface treatment technology that forms a wear-resistant and corrosion-resistant porous MAO ceramic film on the surface of an aluminum substrate by applying a high voltage in an electrolyte and utilizing the arc discharge effect. This can significantly increase the density of bubble nucleation sites and improve the corrosion resistance of the aluminum surface. Self-assembly is a method that uses intermolecular forces to uniformly distribute nanoparticles on the substrate surface. The self-assembly method loads FeCo nanoparticles, which further enhances the catalytic performance of the surface. Chemical vapor deposition is a technology that deposits a thin film on the substrate surface through a gaseous chemical reaction at high temperature. The vertically oriented FeCoCNTs array prepared by chemical vapor deposition has the advantages of high aspect ratio and small pore size, which can increase capillary wicking and promote liquid rewetting. Through its excellent capillary action and thermal conductivity, it significantly improves the heat transfer performance. The composite coating can give full play to the advantages of the MAO layer and the CNTs coating, and synergistically enhance the heat transfer efficiency and boiling heat transfer stability of the aluminum vapor chamber wick surface. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the preparation method of the aluminum vapor chamber liquid suction core according to an embodiment of the present invention;

[0021] Figure 2 A flowchart illustrating the preparation of a FeCoCNTs / MAO composite coating on the aluminum substrate surface of the aluminum vapor chamber suction core according to an embodiment of the present invention;

[0022] Figure 3 This is a SEM image of the FeCoCNTs / MAO composite coating according to an embodiment of the present invention. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this invention's description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] The term "comprising" and its variations as used herein are open-ended inclusion, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the description below.

[0026] To address the problems existing in the aforementioned related technologies, this embodiment provides an aluminum vapor chamber liquid suction core and its preparation method.

[0027] like Figure 1 As shown in the figure, the method for preparing an aluminum vapor chamber liquid suction core provided by an embodiment of the present invention includes the following steps:

[0028] S1: A porous MAO ceramic film was prepared on the surface of an aluminum substrate using a micro-arc oxidation method;

[0029] S2: FeCo nanoparticles are loaded onto the surface of a porous MAO ceramic film using a self-assembly method;

[0030] S3: A CNT coating with a vertically oriented FeCoCNTs array was prepared on the surface of a porous MAO ceramic film by chemical vapor deposition, resulting in an aluminum vapor chamber wick with a FeCoCNTs / MAO composite coating on the aluminum substrate surface.

[0031] In this embodiment, micro-arc oxidation is a surface treatment technology that uses high voltage applied to an electrolyte to form a wear-resistant and corrosion-resistant porous MAO ceramic film on the aluminum substrate surface through arc discharge. This not only prevents corrosion of the aluminum substrate surface but also significantly increases the density of bubble nucleation sites. Self-assembly is a method that uses intermolecular forces to uniformly distribute nanoparticles on the substrate surface. The self-assembly method, loading FeCo nanoparticles, further enhances the surface's catalytic performance. Chemical vapor deposition (CVD) is a technique that deposits thin films on the substrate surface through gaseous chemical reactions at high temperatures. The vertically oriented FeCoCNTs array prepared by CVD significantly improves liquid rewetting ability and boiling heat transfer efficiency through its excellent capillary action and thermal conductivity. Therefore, the FeCoCNTs / MAO composite coating integrates the advantages of porous MAO ceramic layers and CNTs coatings, resulting in significant advantages for the aluminum vapor chamber wick in terms of heat transfer efficiency and boiling heat transfer stability.

[0032] Specifically, Figure 2 A flowchart illustrating the preparation of a FeCoCNTs / MAO composite coating on the surface of an aluminum substrate for an aluminum vapor chamber suction core. Figure 2 d is Figure 2 c. Enlarged view of the circled area. Figure 2The red spheres in d represent FeCo nanoparticles, which serve as catalysts for the growth of FeCoCNT arrays. The self-assembly method for loading FeCo nanoparticles further enhances the catalytic performance of the surface.

[0033] The FeCoCNTs / MAO composite coating was imaged using a scanning electron microscope (SEM), such as... Figure 3 As shown, Figure 3 As can be seen, the FeCoCNTs array is a tubular structure with a diameter of 45 nm and a distance of approximately 20 nm between adjacent nanotubes. The FeCoCNTs array grows vertically on the surface of the porous MAO ceramic film, with a length ranging from 1.6 to 2.2 μm. Furthermore, the high-density FeCoCNTs array morphology resembles a nanoforest, and the capillary force formula is:

[0034]

[0035] Where R eff σ represents the effective capillary radius, σ represents the surface tension, and θ represents the contact angle.

[0036] According to the capillary force formula, reducing the effective capillary radius is beneficial to enhancing capillary force; therefore, the FeCoCNTs array with a nanoforest morphology has a large aspect ratio and small porosity, which can effectively reduce R eff This enhances capillary force, an advantage that facilitates the flow and rewetting of the liquid working fluid on the coating surface during boiling, thereby delaying film expansion and increasing the critical heat flux (CHF). Furthermore, Figure 3 The FeCoCNTs / MAO composite coating exhibits a surface roughness greater than 2 μm. This higher surface roughness provides more microscopic protrusions or depressions, which can serve as potential bubble nucleation sites, thus promoting bubble formation. Furthermore, the roughened CNTs coating enhances heat transfer efficiency by increasing the contact area between the liquid and solid surfaces. This micro-nano multi-scale integration not only increases the density of bubble nucleation sites but also improves the thermal conductivity between the coating and the fluid. The improved heat transfer coefficient is particularly crucial in cooling systems or heat exchangers, significantly enhancing their overall heat transfer performance.

[0037] Optionally, step S1 includes: placing an aluminum substrate in an electrolyte system and performing arc discharge on the surface of the aluminum substrate, wherein the electrical parameters include: unidirectional pulse, constant voltage mode, pulse voltage of 300 to 500V, frequency of 100 to 2000Hz, and current density of 5 to 40A / dm³. 2 The discharge time is 5 to 100 seconds.

[0038] In this optional embodiment, arc discharge is performed on the surface of an aluminum substrate. Using a unidirectional pulse and constant voltage mode, and with appropriate electrical parameters set, a porous MAO ceramic film layer is successfully prepared. Compared with existing technologies, the technical solution of this application has significant advantages in the following aspects: First, by precisely controlling the electrolyte system and electrical parameters, a uniform and structurally stable porous MAO ceramic film layer can be formed on the surface of the aluminum substrate, significantly improving the quality and performance of the film layer. Second, the formation of the porous structure increases the density of bubble nucleation sites, effectively improving heat transfer performance. Finally, the method of this application is simple to operate, suitable for large-scale production, and has high industrial application value. Therefore, this application provides an efficient and feasible technical solution for solving the technical problem of preparing porous MAO ceramic films on aluminum substrate surfaces.

[0039] Optionally, the electrolyte system includes an alkaline sodium salt solution, silicate, phosphate, fluoride, and tungstate.

[0040] In this optional embodiment, different components of the electrolyte system play different roles in the preparation of the aluminum vapor chamber wick. The alkaline sodium salt solution provides the necessary alkaline environment, which helps form a stable oxide film on the aluminum substrate surface. Silicates and phosphates enhance the corrosion resistance and mechanical strength of the oxide film. Fluorides help improve the wear resistance of the oxide film and prevent further oxidation of the aluminum substrate surface. Tungstates improve the hardness and wear resistance of the oxide film. Through the synergistic effect of these components, the stability and performance issues of the aluminum vapor chamber wick in the electrolyte system can be effectively solved, improving its overall performance and durability.

[0041] Specifically, alkaline sodium salt solutions can be prepared by dissolving sodium hydroxide and sodium carbonate in deionized water, with the concentration range adjustable according to specific needs. Silicates and phosphates can be obtained by adding sodium silicate and sodium dihydrogen phosphate, respectively. Fluorides can be sourced from sodium fluoride, while tungstates can be obtained by adding sodium tungstate. All these components need to be mixed in appropriate proportions to ensure the overall performance of the electrolyte system.

[0042] Optionally, step S2 includes: placing an aluminum substrate with a porous MAO ceramic film layer in an ethanol solution containing dissolved iron and cobalt salts to self-assemble FeCo nanoparticles.

[0043] In this optional embodiment, iron salt and cobalt salt serve as catalysts for the self-assembly reaction, achieving uniform distribution and stable loading of FeCo nanoparticles on the surface of the porous MAO ceramic film. This solves the problem of insufficient bubble nucleation sites in the prior art, thereby improving heat transfer efficiency and stability.

[0044] Optionally, the iron salt is ferrous acetate, with a density of 4 to 5 g / L in ethanol solution, and the cobalt salt is cobalt acetate, with a density of 6 to 8 g / L in ethanol solution.

[0045] In this optional embodiment, the density of ferrous acetate in the ethanol solution is 4 to 5 g / L, which ensures the stable formation of Fe nanoparticles, while the density of cobalt acetate in the ethanol solution is 6 to 8 g / L, which facilitates the formation of Co nanoparticles. The uniform distribution and stability of these nanoparticles in the solution ensures the uniform loading of FeCo nanoparticles on the porous MAO ceramic film layer on the aluminum substrate surface.

[0046] Specifically, the loading effect of FeCo nanoparticles can be further optimized by adjusting the concentrations of ferrous acetate and cobalt acetate. For example, the loading density of FeCo nanoparticles can be increased by increasing the concentrations of ferrous acetate and cobalt acetate in the ethanol solution. Furthermore, the formation and loading effect of FeCo nanoparticles can be further optimized by changing the self-assembly time and temperature.

[0047] Optionally, step S3 includes: adding a carbon source to the self-assembled aluminum substrate, performing low-temperature chemical vapor deposition in an atmosphere with a N2 to H2 flow ratio of 95:5, and calcining at below 600°C for more than 3 hours.

[0048] In this optional embodiment, a carbon source is added, low-temperature chemical vapor deposition is performed under a specific atmosphere, and calcination is carried out at below 600°C for more than 3 hours. These technical features work together to successfully prepare a vertically oriented carbon nanotube array coating on an aluminum substrate. Specifically, the low-temperature chemical vapor deposition method is performed in an atmosphere with a N2 to H2 flow ratio of 95:5, which ensures that the carbon source is uniformly deposited on the aluminum substrate surface and forms a vertically oriented carbon nanotube array. The calcination step helps to enhance the stability and adhesion of the coating, thereby improving heat transfer efficiency and capillary action.

[0049] Alternatively, the carbon source may be melamine, methane, or acetylene.

[0050] In this optional embodiment, by selecting melamine, methane, or acetylene as the carbon source and employing a low-temperature chemical vapor deposition method, a vertically oriented carbon nanotube coating was successfully formed on the surface of an aluminum substrate. Compared with the prior art, this technical solution not only improves the heat transfer performance and heat dissipation efficiency of the aluminum vapor chamber wick, but also solves the problem of insufficient bubble nucleation sites in the prior art. In this way, the application effect of the aluminum vapor chamber wick in efficient heat dissipation can be significantly improved.

[0051] Optionally, before performing the low-temperature chemical vapor deposition step, the self-assembled aluminum substrate is dried in a nitrogen atmosphere with a nitrogen flow rate of 100 sccm or higher.

[0052] In this optional embodiment, the self-assembled aluminum substrate is dried before the low-temperature chemical vapor deposition step to ensure that the surface of the aluminum substrate is free of moisture and other impurities, thus avoiding interference with the subsequent chemical vapor deposition process. Drying under a nitrogen atmosphere can effectively prevent oxidation of the aluminum substrate surface, improving the quality and performance of the coating. A nitrogen flow rate of 100 sccm or higher ensures the efficiency and effectiveness of the drying process.

[0053] The aluminum vapor chamber liquid suction core provided in this embodiment of the invention is manufactured using the preparation method of the aluminum vapor chamber liquid suction core as described in any of the preceding embodiments.

[0054] In this embodiment, the aluminum vapor chamber wick provides nucleation sites matching the bubble nucleation size by preparing a porous MAO ceramic film layer on the aluminum substrate surface, increasing the density of bubble nucleation sites. Furthermore, the capillary action and heat transfer performance are further enhanced by a CNT coating loaded with FeCo nanoparticles and a vertically oriented FeCo CNT array. Therefore, the aluminum vapor chamber wick of this application has significant advantages in terms of efficient heat dissipation and heat transfer performance. The above technical means solve the problems of insufficient bubble nucleation sites on the surface of aluminum capillary wicks, low heat transfer efficiency, and easy oxidation and poor boiling heat transfer stability of aluminum substrate surfaces in the prior art.

[0055] Specifically, the application of aluminum vapor chamber wicks in the field of electronic chips can significantly improve the heat dissipation efficiency of electronic chips, ensuring chip performance and reliability. Compared with existing technologies, this application solves the problems of low bubble nucleation site density and weak capillary action in existing technologies by preparing a porous MAO ceramic film layer on the surface of an aluminum substrate and loading FeCo nanoparticles and a CNTs coating of vertically oriented FeCoCNTs arrays onto it, thus significantly improving heat transfer performance and heat dissipation efficiency.

[0056] The present invention will be further described below with reference to specific embodiments.

[0057] Example 1

[0058] Preparation of aluminum vapor chamber suction core with FeCoCNTs / MAO composite coating:

[0059] 1. A porous MAO ceramic film was prepared on the surface of an aluminum sheet using a micro-arc oxidation method. The electrical parameters of the arc discharge included: unidirectional pulse, constant voltage mode, pulse voltage of 450V, frequency of 550Hz, and current density of 20A / dm³. 2 The discharge time is 30 seconds and the duty cycle is 30%.

[0060] 2. Dissolve 217 mg cobalt acetate and 311 mg ferrous acetate in 50 mL of ethanol solution. Then, vertically immerse the micro-arc oxidized aluminum sheet into the above solution and soak at room temperature for 48 h. FeCo nanoparticles are loaded on the surface of the porous MAO ceramic film by self-assembly.

[0061] 3. The aluminum sheet after soaking was quickly placed in a quartz tube for drying, with a nitrogen flow rate of 100 sccm to avoid the formation of oxides; then, in an atmosphere with a N2 to H2 flow rate ratio of 95:5 and in the presence of 1 g of melamine, the sample was calcined at 550°C for 3 h. A CNTs coating with a vertically oriented FeCoCNTs array was prepared on the surface of the porous MAO ceramic film using a low-temperature chemical vapor deposition method, resulting in an aluminum vapor chamber liquid wick with a FeCoCNTs / MAO composite coating.

[0062] Comparative Example 1

[0063] Take pure aluminum sheets.

[0064] Comparative Example 2

[0065] Preparation of aluminum vapor chamber suction core with MAO coating:

[0066] 1. A porous MAO ceramic film was prepared on the surface of an aluminum sheet using a micro-arc oxidation method. The electrical parameters of the arc discharge included: unidirectional pulse, constant voltage mode, pulse voltage of 450V, frequency of 550Hz, and current density of 20A / dm³. 2 With a discharge time of 30s and a duty cycle of 30%, an aluminum vapor chamber suction core with a MAO coating was obtained.

[0067] Comparative Example 3

[0068] Preparation of aluminum vapor chamber wick with CNT coating:

[0069] 1. Dissolve 217 mg cobalt acetate and 311 mg ferrous acetate in 50 mL of ethanol solution. Then, vertically immerse an aluminum sheet in the above solution and soak at room temperature for 48 h to load FeCo nanoparticles on the surface of the aluminum sheet by self-assembly.

[0070] 2. The aluminum sheet after soaking was quickly placed in a quartz tube for drying, with a nitrogen flow rate of 100 sccm to avoid the formation of oxides; then, in an atmosphere with a N2 to H2 flow rate ratio of 95:5 and in the presence of 1 g of melamine, the sample was calcined at 550°C for 3 h. A CNTs coating with a vertically oriented FeCoCNTs array was prepared on the surface of the aluminum sheet by low-temperature chemical vapor deposition, resulting in an aluminum vapor chamber wick with a CNTs coating.

[0071] Effect Example

[0072] The boiling heat transfer performance of the products prepared in Example 1, Comparative Examples 1, 2, and 3 was tested. The test results are shown in Table 1.

[0073] Table 1. Results of boiling heat transfer performance tests on the products prepared in Example 1 and Comparative Examples 1, 2, and 3.

[0074]

[0075] As shown in Table 1, pure aluminum has the highest superheat (21.7 K), CHF (118.4 W / cm²). -2 ) and HTC (53.9kW m - 2 K -1 The lowest concentration of FeCoCNTs indicates the worst boiling heat transfer performance. However, FeCoCNTs modification or MAO treatment results in enhanced CHF and HTC on the heating surface. Specifically, the CHF of Comparative Example 3 and Comparative Example 2 is 163.7 W / cm². -2 and 155.8W cm -2 The two are similar. However, the HTC in Comparative Example 3 has a power output of 114.9 kW / m². -2 K -1 It is superior to Comparative Example 2 (90.1kW m -2 K -1 The reason for this difference is that the FeCoCNTs array grows vertically on the aluminum surface, and the heat transfer direction during boiling heat transfer is consistent with the carbon surface direction of the FeCoCNTs, which enhances the phonon transfer efficiency. Conversely, oxygen defects in the porous MAO ceramic film act as phonon scattering centers, increasing phonon scattering and energy dissipation.

[0076] Compared with other control groups, Example 1 had the best CHF and HTC, with CHF and HTC of 195.7 W / cm². -2 and 117.6kW m -2 K -1Compared to the original aluminum surface, the boiling heat transfer performance was improved by 65.2% and 118.2%, respectively; compared to Comparative Example 2, it was improved by 25.6% and 30.4%; and compared to Comparative Example 3, it was improved by 19.6% and 2.4%, respectively. This indicates that the boiling heat transfer performance of the FeCoCNTs / MAO composite coating is superior to that of a single MAO ceramic film or FeCoCNTs array, demonstrating a synergistic enhancement effect. This is mainly because the FeCoCNTs / MAO composite coating provides different paths for bubble detachment and liquid flow. Bubbles rapidly detach at small sizes within the MAO pores, reducing the onset of nucleate boiling (ONB) and enhancing the high-temperature boiling (HTC). Simultaneously, the rapid flow of liquid within the FeCoCNTs enables timely rewetting of local hot / dry areas, thereby enhancing the heat transfer flux (CHF). During boiling, the MAO pores and FeCoCNTs array on the FeCoCNTs / MAO composite coating surface work synergistically to efficiently enhance the boiling heat transfer performance of the heated surface.

[0077] The HTC changes before and after 10 boiling tests were statistically analyzed for the products prepared in Example 1 and Comparative Examples 1, 2, and 3, and the results are shown in Table 2.

[0078] Table 2. Changes in HTC levels before and after 10 boiling tests in the products prepared in Example 1 and Comparative Examples 1, 2, and 3.

[0079]

[0080] Table 2 shows that the HTC of the original aluminum was 53.9 kW m³ after the first boiling heat transfer test. -2 K -1 After the 10th boiling heat transfer test, HTC's efficiency dropped to 37.3 kW m³. -2 K -1 The HTC retention rate was 69.3%. After cyclic boiling heat transfer testing, the HTC in Comparative Example 3 decreased from 114.9 kW / m³. -2 K -1 Reduced to 87.9kW m -2 K -1 The HTC retention rate was 76.6%. Under the same boiling heat transfer test conditions, the HTC changes in Comparative Example 2 and Example 1 were minimal, with an HTC retention rate greater than 95%, indicating that the MAO coating and the FeCoCNTs / MAO composite coating exhibit superior boiling heat transfer stability. This is mainly because the MAO ceramic film contains high-temperature ceramic phases such as mullite and α-Al2O3, which possess high hardness, high strength, corrosion resistance, and good thermal and chemical stability, effectively enhancing the corrosion resistance of the aluminum surface. Therefore, the aluminum vapor chamber wick with the FeCoCNTs / MAO composite coating prepared in this invention exhibits optimal boiling heat transfer performance and boiling heat transfer stability.

[0081] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method of making an aluminum vapor cavity wick, comprising: The method comprises the following steps: S1: preparing a porous MAO ceramic film layer on the surface of an aluminum substrate by a micro-arc oxidation method; S2: loading FeCo nanoparticles on the surface of the porous MAO ceramic film layer by a self-assembly method; S3: preparing a CNTs coating with vertically oriented FeCo CNTs array on the surface of the porous MAO ceramic film layer by a chemical vapor deposition method, by adding a carbon source to the self-assembled aluminum substrate, performing low-temperature chemical vapor deposition under an atmosphere with a flow ratio of N2 to H2 being 95:5, and calcining at 600°C or below for 3 hours or more, to obtain an aluminum vapor cavity wick with a FeCo CNTs / MAO composite coating on the surface of the aluminum substrate.

2. The method of claim 1, wherein the aluminum vapor cavity wick is prepared by the steps of: Said step S1 comprises: placing an aluminum substrate in an electrolytic bath, performing arc discharge on the surface of said aluminum substrate, wherein the electrical parameters include: unidirectional pulse, constant voltage mode, pulse voltage of 300 to 500 V, frequency of 100 to 2000 Hz, current density of 5 to 40 A / dm 2 , discharge time of 5 to 100 s.

3. The method of claim 2, wherein the aluminum vapor cavity wick is prepared by the steps of: The electrolyte system comprises an alkaline sodium salt solution, a silicate, a phosphate, a fluoride, and a tungstate.

4. The method of claim 1, wherein the aluminum vapor cavity wick is prepared by the steps of: The step S2 comprises: placing the aluminum substrate with the porous MAO ceramic film layer in an ethanol solution in which iron salt and cobalt salt are dissolved to self-assemble the FeCo nanoparticles.

5. The method of claim 4, wherein the aluminum vapor cavity wick is formed by the steps of: The iron salt is ferrous acetate, the density of the ferrous acetate in the ethanol solution is 4-5 g / L, the cobalt salt is cobalt acetate, and the density of the cobalt acetate in the ethanol solution is 6-8 g / L.

6. The method of claim 1, wherein the aluminum vapor cavity wick is prepared by the steps of: The carbon source is melamine, methane, or acetylene.

7. The method of claim 1, wherein the aluminum vapor cavity wick is prepared by the steps of: Before the low-temperature chemical vapor deposition step, the self-assembled aluminum substrate is dried under a nitrogen atmosphere, and the flow rate of the nitrogen is 100 sccm or more.

8. An aluminum vapor cavity wick, characterized by, The aluminum vapor cavity wick is prepared by the method according to any one of claims 1-7.

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