Method for preparing powder-sintered aluminum-based composite porous wick

Abstract

Disclosed in the present invention is a method for preparing a powder-sintered aluminum-based composite porous wick. The preparation method comprises the steps of preparing a raw material A for a supported metal catalyst, preparing an aluminum-CNT composite material B, preparing a raw material C for an aluminum-based composite porous wick, sintering same to obtain an aluminum-based composite porous wick, etc. By means of a chemical vapor deposition method, a metal catalyst supported by an aluminum-based raw material is used for in-situ growth of high-thermal-conductivity carbon nanotubes, and an oxidation film on the surface of aluminum powder is broken by means of auxiliary sintering of an auxiliary, thereby achieving the preparation of the aluminum-CNT composite wick by means of aluminum powder sintering. In the present invention, the requirements of equipment and tooling are low, the preparation process is simple, the strength and the thermal conductivity coefficient of the prepared wick are obviously improved, and high-performance and light-weight two-phase soaking devices such as a heat pipe, a vapor chamber and a liquid cooling plate can be manufactured at low cost.

Description

Preparation method of powder sintered aluminum-based composite porous liquid-absorbing core Technical Field

[0001] The invention relates to the technical field of liquid absorbent core processing, in particular to a preparation method of a powder sintered aluminum-based composite porous liquid absorbent core. Background Art

[0002] With the emergence and rapid development of fifth-generation mobile communication technology (5G technology), consumer electronics, especially smartphones and tablets, as well as automotive electronics and communication base stations, are increasingly moving towards high performance, high integration, and miniaturization. Traditional thermal conductive materials such as graphite heat dissipation films are increasingly unable to meet the heat dissipation requirements within confined internal structures. Vapor chambers (VCs), as two-dimensional heat pipes, offer advantages such as light weight, large heat transfer area, good temperature uniformity, and high reliability. Therefore, the development of high-performance, high-stability vapor chambers is the primary approach to solving the heat dissipation problem of increasingly thin electronic devices.

[0003] Generally speaking, most heat pipes and vapor chambers use copper for their shells and wicks, primarily due to its high thermal conductivity and machinability. Compared to commonly used copper heat pipes, aluminum heat pipe radiators offer advantages such as light weight and improved corrosion resistance. However, the preparation of powder-sintered porous aluminum wicks has always been a challenge in the industry. The technical specifications and stability of the capillary wicks in aluminum vapor chambers are crucial and represent a bottleneck in their production.

[0004] Currently, there is research on the preparation of aluminum foam and improving the properties of aluminum alloys. Meanwhile, industry research on aluminum-based temperature-stabilizing devices primarily focuses on heat sinks, aluminum fins, and other cooling devices. Research on aluminum heat pipes and vapor chambers, which offer higher temperature-stabilizing efficiencies, is relatively limited. This is primarily due to the difficulty in removing the surface oxide layer, making it difficult to effectively sinter aluminum powder using powder metallurgy techniques. Carbon nanotubes (CNTs) possess extremely high axial thermal conductivity and are currently one of the world's best thermally conductive materials. However, directly compounding these highly conductive and high-modulus CNTs with aluminum-based raw materials significantly increases the difficulty of sintering the porous wick and controlling its thermal conductivity. Consequently, the preparation of composite aluminum-based porous wicks using powder sintering presents challenges such as low technical maturity, low yield, significant manufacturing difficulty, and high cost.

[0005] Summary of the Invention

[0006] The present invention provides a method for preparing a powder-sintered aluminum-based composite porous liquid-absorbing core. The method comprises the following steps: using aluminum-based raw material powder loaded with a metal catalyst to in-situ grow high-thermal-conductivity carbon nanotubes, and sintering to prepare an aluminum-CNTs composite liquid-absorbing core. The aluminum powder surface oxide film is removed by auxiliary sintering through an additive, and the aluminum powder is sintered to prepare the aluminum-CNTs composite liquid-absorbing core. The liquid-absorbing core can be used in two-phase temperature-equalizing devices in the field of heat dissipation, including but not limited to various types of heat pipes, conventional / ultra-thin heat spreaders, and direct / liquid cooling plates.

[0007] The technical solutions provided by the present invention are as follows:

[0008] A method for preparing a powder sintered aluminum-based composite porous liquid-absorbing core comprises the following steps:

[0009] Step S1, uniformly loading the catalyst metal on the surface of the aluminum-based raw material powder, baking and calcining, to obtain a supported metal catalyst raw material A;

[0010] Step S2, catalytically cracking pyrolysis gases of different carbon sources to in-situ grow carbon nanotubes on the surface of the supported metal catalyst aluminum-based raw material A to obtain an aluminum-CNTs composite material B;

[0011] Step S3, uniformly mixing the aluminum-CNTs composite material B with an auxiliary agent, a pore-forming agent, and a binder to obtain an aluminum-based composite porous liquid-absorbing wick raw material C;

[0012] Step S4: Pressing or rolling the aluminum-based composite porous absorbent core raw material C into an aluminum-based composite porous absorbent core green body D according to specific requirements, and sintering at a high temperature to obtain the aluminum-based composite porous absorbent core.

[0013] The aluminum-based raw material powder includes but is not limited to pure aluminum powder, aluminum-silicon alloy powder, aluminum-magnesium alloy powder, aluminum-copper alloy powder and aluminum-zinc alloy powder. The particle size of the aluminum-based raw material powder ranges from 50 to 200 μm.

[0014] Furthermore, in step S2, the catalytic cracking of the pyrolysis gas of different carbon sources is specifically:

[0015] In an atmosphere sintering furnace, different carbon sources are cracked at high temperature to produce cracked gas, which is then vapor-deposited on the surface of the aluminum-based raw material A under the action of a catalyst to form carbon nanotubes.

[0016] Among them, the atmosphere sintering furnace is a two-stage sintering furnace, and each section of the two-stage sintering furnace is heated by a heating wire controlled by a different thermocouple. Different carbon sources are thermally cracked in the first section sintering furnace, and the generated pyrolysis gas is catalyzed by the second section sintering furnace to grow carbon nanotubes by vapor deposition on the surface of the raw material A to obtain an aluminum-CNTs composite material B.

[0017] Among them, the in-situ grown CNTs have controllable growth mode, number of tube wall layers and arrangement mode. By regulating the growth of CNTs, in-situ composite of CNTs with high axial thermal conductivity and aluminum-based raw materials can be achieved, while also overcoming the high interfacial thermal resistance problem caused by direct mixing.

[0018] Furthermore, in step S2, the carbon source includes hydrocarbon gaseous substances and polymer solid materials such as plastics.

[0019] Furthermore, the catalyst is a transition metal catalyst such as nickel, iron, or cobalt. It has catalytic activity on the CH bonds and C=C bonds of pyrolysis gases from different carbon sources, and can promote carbon deposition on the surface of aluminum-based raw materials and the growth of CNTs.

[0020] Furthermore, the auxiliary agents include but are not limited to silicon powder, magnesium powder, copper powder, tin powder, aluminum silicon powder and aluminum magnesium powder. The auxiliary agents such as copper, silicon and magnesium powder react with the surface oxide layer of the aluminum-based raw material to form an alloy, and the formation of a eutectic liquid phase promotes the sintering of aluminum powder; auxiliary agents such as tin powder can promote sintering by increasing the amount of liquid phase in the system; the particle size range of the auxiliary agents is 25 to 100 μm.

[0021] Furthermore, the pore-forming agent includes NaCl, ZnCl, urea and PMMA, and its particle size ranges from 25 to 100 μm.

[0022] Furthermore, when water-soluble pore-forming agents such as NaCl and urea are selected, they are added by dry mixing methods such as mechanical stirring and ball milling; pore-forming agents such as PMMA are added by wet mixing, and the solvent can be selected from anhydrous ethanol, deionized water, etc.

[0023] Furthermore, in step S1, the catalyst metal is uniformly loaded on the surface of the aluminum-based raw material powder by an impregnation method;

[0024] The calcination temperature is less than 650° C., the heating rate is less than 5° C., the calcination atmosphere is air, and the furnace is cooled after calcination.

[0025] Furthermore, in step S4, the aluminum-based composite porous liquid-absorbing wick raw material C is formed by pressing or rolling according to specific requirements and sintered at a high temperature;

[0026] The compression molding comprises the following steps:

[0027] A high-purity graphite block is used as a sintering tool. The sintering tool is provided with a groove. The aluminum-based composite porous wick raw material C is evenly spread in the groove and pressed by a hydraulic press at a pressing pressure of 5 to 30 tons to obtain a composite porous wick green body D.

[0028] The rolling forming comprises the following steps:

[0029] Using a powder rolling mill, setting the feed speed to 0.1-2 m / min and the rolling pressure to 0.5-5 t, the aluminum-based composite porous liquid absorbent core raw material C is rolled to obtain a composite porous liquid absorbent core green body D;

[0030] Furthermore, the composite porous liquid-absorbing core green body D is placed in a sintering furnace for sintering;

[0031] Wherein, the sintering furnace includes a vacuum sintering furnace or an atmosphere sintering furnace, and the atmosphere is high-purity N2 or H2;

[0032] Among them, the vacuum degree of vacuum sintering furnace is less than 1×10 -2 Pa, the atmosphere sintering furnace gas flow rate is 1~5L / min, and the sintering temperature is <650℃.

[0033] Furthermore, in step S4, the prepared aluminum-based composite porous liquid-absorbing core has a porosity of 25-65%, a thickness of 0.3-1 mm, and a pore size of 30-200 μm.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a method for preparing a powder sintered aluminum-based composite porous absorbent core. Compared with an uncomposite CNTs porous absorbent core, the high modulus and high thermal conductivity of CNTs increase the compressive strength and thermal conductivity of the composite absorbent core.

[0036] The present invention provides a method for preparing a powder-sintered aluminum-based composite porous liquid-absorbing core. Compared with porous liquid-absorbing cores prepared by ex-situ CNT composite, the composite material prepared by in-situ growth of CNTs on the surface of aluminum-based raw material powder can effectively reduce the interfacial thermal resistance, thereby greatly improving the heat distribution efficiency of the device.

[0037] The present invention provides a method for preparing a powder sintered aluminum-based composite porous liquid-absorbing core. The present invention has low requirements for equipment and tooling, a simple preparation process, and significantly improves the strength and thermal conductivity of the prepared liquid-absorbing core. It can achieve lightweight and low-cost manufacturing of two-phase heat-absorbing devices such as heat pipes, heat sinks and liquid cooling plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG1 is a flow chart of a method for preparing a powder sintered aluminum-based composite porous liquid-absorbing core provided by the present invention;

[0039] FIG2 is a schematic diagram of a reactor for producing aluminum-CNTs composite materials according to an embodiment of the present invention;

[0040] FIG3 is a schematic diagram of a sintering process of an aluminum-based porous wick according to an embodiment of the present invention;

[0041] FIG4 is a SEM test image of the aluminum-based composite porous wick prepared in an embodiment of the present invention;

[0042] FIG5 is a TEM test image of the aluminum-based composite porous liquid-absorbing core prepared in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the embodiments described below are part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0044] Referring to FIG1 , the present invention provides a method for preparing a powder sintered aluminum-based composite porous liquid-absorbing core, comprising the following steps:

[0045] Step S1: uniformly load the catalyst metal on the surface of the aluminum-based raw material powder, and perform baking, calcination and other processes to obtain a supported metal catalyst raw material A.

[0046] Step S2: In situ growth of carbon nanotubes on the surface of the supported metal catalyst raw material A by catalytically cracking cracked gases of different carbon sources to obtain an aluminum-CNTs composite material B.

[0047] Step S3: Evenly mix the aluminum-CNTs composite material B with the auxiliary agent, the pore-forming agent, and the binder to obtain the aluminum-based composite porous liquid-absorbing wick raw material C.

[0048] In step S3, the aluminum-CNTs composite material B is mixed evenly with the auxiliary agent, the pore-forming agent, and the binder. The mixing can be performed by a wet method or a dry method.

[0049] Step S4: Pressing or rolling the aluminum-based composite porous absorbent core raw material C according to specific requirements to obtain an aluminum-based composite porous absorbent core green body D, and sintering at a high temperature to obtain the aluminum-based composite porous absorbent core.

[0050] Optionally, the aluminum-based raw material powder includes but is not limited to pure aluminum powder, aluminum-silicon alloy powder, aluminum-magnesium alloy powder, aluminum-copper alloy powder and aluminum-zinc alloy powder, and the particle size range of the aluminum-based raw material powder is 50 to 200 μm.

[0051] Optionally, in step S2, pyrolysis gas of different carbon sources is catalytically cracked, specifically:

[0052] In an atmosphere sintering furnace, pyrolysis gases from different carbon sources are catalytically cracked by vapor deposition;

[0053] The atmosphere sintering furnace is a two-stage sintering furnace, and each section of the two-stage sintering furnace is heated by a heating wire controlled by a different thermocouple.

[0054] Optionally, in step S2, the carbon source includes hydrocarbon substances and plastic polymer materials. The hydrocarbon substances can be ethylene, acetylene, etc., and the plastic polymer materials can be polyethylene, polypropylene, high-density polyethylene, low-density polyethylene, polyvinyl chloride, etc.

[0055] Optionally, the catalyst is a transition metal catalyst such as nickel, iron, cobalt, etc., with a particle size range of 25 to 100 μm.

[0056] Optionally, the additives include but are not limited to silicon powder, magnesium powder, copper powder, tin powder, aluminum silicon powder and aluminum magnesium powder.

[0057] In the present application, additives such as copper, silicon, and magnesium powder react with the surface oxide layer of the aluminum-based raw material to form an alloy, and the formation of a eutectic liquid phase promotes the sintering of aluminum powder; additives such as tin powder can promote sintering by increasing the amount of liquid phase in the system; the particle size range of the additives is 25 to 100 μm.

[0058] Optionally, the pore-forming agent includes NaCl, ZnCl, urea, PMMA, etc., and the particle size thereof ranges from 25 to 100 μm.

[0059] Optionally, when water-soluble pore-forming agents such as NaCl and urea are selected, they are added by dry mixing methods such as mechanical stirring and ball milling; pore-forming agents such as PMMA are added by wet mixing, and the solvent can be anhydrous ethanol, deionized water, etc.

[0060] Optionally, in step S1, uniformly loading the catalyst metal on the surface of the aluminum-based raw material powder is achieved by an impregnation method;

[0061] The calcination temperature is less than 650°C, the heating rate is less than 5°C, the calcination atmosphere is air, and the calcination is followed by furnace cooling.

[0062] Optionally, in step S4, the aluminum-based composite porous liquid-absorbing wick raw material C is formed by pressing or rolling according to specific requirements and sintered at a high temperature;

[0063] The compression molding comprises the following steps:

[0064] A high-purity graphite block is used as a sintering tool. The sintering tool is provided with a groove. The aluminum-based composite porous wick raw material C is evenly spread in the groove and pressed by a hydraulic press at a pressing pressure of 5 to 30 tons to obtain a composite porous wick green body D.

[0065] The rolling forming comprises the following steps:

[0066] Using a powder rolling mill, setting the feed speed to 0.1-2 m / min and the rolling pressure to 0.5-5 t, the aluminum-based composite porous liquid absorbent core raw material C is rolled to obtain a composite porous liquid absorbent core green body D;

[0067] Furthermore, the composite porous liquid-absorbing core green body D is placed in a sintering furnace for sintering;

[0068] Wherein, the sintering furnace includes a vacuum sintering furnace or an atmosphere sintering furnace, and the atmosphere is high-purity N2 or H2;

[0069] Among them, the vacuum degree of vacuum sintering furnace is less than 1×10 -2 Pa, the atmosphere sintering furnace gas flow rate is 1~5L / min, and the sintering temperature is <650℃.

[0070] Example 1

[0071] This embodiment provides a method for preparing a powder sintered aluminum-based composite porous liquid-absorbing wick, comprising the following steps:

[0072] Step 1: Add 10g of nickel nitrate or ferric nitrate to 20mL of anhydrous ethanol and dissolve it completely. After thorough stirring, add the corresponding mass of aluminum-based raw material powder (particle size range is 50-150μm), the Al / Ni mass ratio is 20:1-5:1, and stir thoroughly in a water bath and evaporate to dryness to obtain a supported metal catalyst raw material A.

[0073] Step 2: Place PP and supported metal catalyst raw material A in a two-stage atmosphere sintering furnace at a mass ratio of 5:1 to 20:1. As shown in Figure 2, PP is placed in the upper section and supported metal catalyst raw material A in the lower section. Each section is heated and monitored by independent heating wires and thermocouples. If a hydrocarbon gas, such as acetylene or ethylene, is used as the carbon source, only quartz wool is placed in the upper section to filter out gas impurities and ensure uniformity of the permeating gas. Then, proceed as follows:

[0074] First, high-purity nitrogen was introduced from the upper end to the lower end of the two-stage sintering furnace at a flow rate of 1 L / min for 30 minutes to exhaust the air in the sintering furnace.

[0075] Subsequently, the lower reactor was heated to 200°C at 5°C / min, kept at this temperature for 20 min, and then heated to 650°C for 60 min.

[0076] When the lower sintering furnace reaches the set temperature and starts to keep warm, the upper sintering furnace is heated at 10℃ min -1 The temperature is raised from room temperature to 600°C. As the temperature rises, the PP placed in the upper section or the hydrocarbon gas introduced begins to crack into hydrocarbons of different chain lengths. These hydrocarbons, along with the high-purity nitrogen, reach the supported metal catalyst raw material A in the lower section, where they are catalytically broken down on the nickel surface within the supported metal catalyst raw material A and deposited thereon, obtaining an aluminum-based liquid-absorbing wick raw material B that is in situ composited with carbon nanotubes (CNTs), namely, aluminum-CNTs composite material B.

[0077] Step 3. Dry-mix the obtained aluminum-CNTs composite material B and the auxiliary agent Al88Si (particle size 50 μm) at a ratio of 1:1-10:1, and then add the pore-forming agent 45-75 μm PMMA to anhydrous ethanol at a mass ratio of 10:1-10:3, and stir and mix thoroughly. Evaporate the anhydrous ethanol in a water bath, and further mix thoroughly by mechanical methods to obtain an aluminum-based composite porous liquid-absorbing core raw material C.

[0078] Step 4: Use a high-purity graphite block as a sintering tool. A 100×50mm groove with a thickness of 1.5mm is processed on the sintering tool. 10g of aluminum-based composite porous wick raw material C is evenly spread in the groove. Then, it is placed under a hydraulic press for pressing and forming. The pressing pressure is 5 / 15 / 30t and the holding time is 300s to obtain a composite porous wick green body D.

[0079] Step 5: Place the composite porous liquid absorbent core green body D in a high-purity nitrogen atmosphere sintering furnace. The sintering process curve is shown in Figure 3. The temperature is raised from room temperature to 150°C at 5°C / min, maintained for 30 minutes, raised to 250 minutes, maintained for 30 minutes, raised to 460°C, maintained for 30 minutes, and then raised to 590°C. After maintaining for 120 minutes, the temperature is cooled in the furnace to obtain an aluminum-based composite porous liquid absorbent core.

[0080] When the aluminum-based raw material particle size is 150μm, Al / Ni = 10:1, PP / raw material A = 20:1, raw material B / additive = 1:1, 75μm PMMA is selected as the pore-forming agent, the ratio is 30%, and the green body D is prepared by pressing at a pressure of 30t. The finished product is sintered and the following tests are performed on the sintered product:

[0081] Wicking capacity testing: Acetone was used as the test fluid, and the test environment temperature was controlled at 27°C to minimize acetone volatilization. An infrared thermal imager was used to dynamically record the fluid's rise within the wick. The sintered wick had a thickness of 0.33 mm, and the fluid climbed to a height of 35.3 mm, exceeding one-third of the sample's length. This indicates that the aluminum-based porous wick, after incorporating CNTs, possesses high capillary suction, facilitating the reflow of condensed liquid and preventing device burnout.

[0082] Electron Microscope Observation: The pore size and porosity of the composite material, as well as the CNT doping, were observed using scanning electron microscope (SEM) and TEM (TEM). As shown in Figures 4 and 5, the SEM and TEM measurements show that the sintered pores are mostly through-holes, with a porosity of approximately 65% ​​and a pore diameter of approximately 50-200 μm. The CNTs are multi-walled carbon nanotubes, with micrometer-scale lengths and diameters of approximately 30-50 nm.

[0083] Thermal Conductivity and Compressive Strength Testing: Thermal conductivity and compressive strength tests were conducted on aluminum-based porous wicks composited with CNTs, along with uncompounded and directly composited aluminum wicks prepared using the same formula and process. Thermal conductivity was also measured in both dry and saturated states, as shown in Table 1. The results demonstrate that in-situ CNT composites significantly improve the thermal conductivity of the porous wicks, while the addition of high-modulus CNTs significantly enhances their compressive strength.

[0084] Table 1.

[0085] Binding strength test: The aluminum-CNTs composite sintered porous liquid absorbent core was subjected to vibration test and temperature shock test. No particles were found to fall off, indicating strong particle bonding.

[0086] In summary, the present invention provides a method for preparing a powder-sintered aluminum-based composite porous wick. Using chemical vapor deposition, a metal catalyst is loaded onto an aluminum-based raw material to in situ grow highly thermally conductive carbon nanotubes. The oxide film on the aluminum powder surface is then removed through additive-assisted sintering, allowing the aluminum powder to be sintered to prepare an aluminum-CNT composite wick. Compared to porous wicks without CNTs, the high modulus and high thermal conductivity of CNTs increase the compressive strength and thermal conductivity of the composite wick. Compared to porous wicks without CNTs, composite materials prepared by in situ growth of CNTs on the surface of aluminum-based raw material powder can effectively reduce interfacial thermal resistance, thereby significantly improving the device's heat dissipation efficiency. This method has low equipment and tooling requirements, a simple preparation process, and significantly improved strength and thermal conductivity of the prepared wick, enabling high-performance, lightweight, and low-cost manufacturing of two-phase heat dissipation devices such as heat pipes, vapor chambers, and liquid cooling plates.

[0087] The preparation method of the powder sintered aluminum-based composite porous liquid-absorbing core provided by the present invention is applied to two-phase temperature-equalizing devices in the field of heat dissipation, including but not limited to various types of heat pipes, conventional / ultra-thin heat spreaders, and straight / liquid cooling plates.

[0088] The above is merely the preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application shall be included in the scope of protection of this application. Therefore, the scope of protection of this application shall be based on the scope of protection of the claims.

Claims

1. A method for preparing a powder sintered aluminum-based composite porous liquid-absorbing core, characterized in that: The following steps are involved: Step S1, uniformly loading the catalyst metal on the surface of the aluminum-based raw material powder, baking and calcining, to obtain a loaded metal catalyst aluminum-based raw material A; Step S2, by catalytically cracking cracked gas from different carbon sources, in-situ growing carbon nanotubes on the surface of the supported metal catalyst aluminum-based raw material A, to obtain an aluminum-CNTs composite material B; Step S3, mixing the aluminum-CNTs composite material B with an auxiliary agent, a pore-forming agent, and a binder to obtain an aluminum-based composite porous liquid-absorbing core raw material C; Step S4, pressing or rolling the aluminum-based composite porous absorbent core raw material C according to specific requirements to obtain an aluminum-based composite porous absorbent core green body D, and sintering at high temperature to obtain an aluminum-based composite porous absorbent core.

2. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 1, characterized in that: The aluminum-based raw material powder includes but is not limited to pure aluminum powder, aluminum-silicon alloy powder, aluminum-magnesium alloy powder, aluminum-copper alloy powder and aluminum-zinc alloy powder. The particle size range of the aluminum-based raw material powder is 50 to 200 μm.

3. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 1, characterized in that: In step S2, the pyrolysis gas of different carbon sources is catalytically cracked, specifically: In an atmosphere sintering furnace, different carbon sources are pyrolyzed at high temperature to form pyrolysis gas, and carbon nanotubes are vapor-deposited on the surface of aluminum-based raw material A under the action of a catalyst; Among them, the atmosphere sintering furnace is a two-stage sintering furnace, each section of the two-stage sintering furnace is heated by a heating wire controlled by a different thermocouple, different carbon sources are thermally cracked in the first section sintering furnace, and the generated pyrolysis gas is catalyzed by the second section sintering furnace, and carbon nanotubes are grown by vapor deposition on the surface of the raw material A to obtain the aluminum-CNTs composite material B.

4. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to any one of claims 1 to 3, characterized in that: In step S2, the carbon source includes hydrocarbon gaseous substances and polymer solid materials such as plastics.

5. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 4, characterized in that: The catalyst is a transition metal catalyst such as nickel, iron, cobalt, etc., and its loading mass ratio ranges from 1 to 20%.

6. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 5, characterized in that: The auxiliary agent includes but is not limited to silicon powder, magnesium powder, copper powder, tin powder, aluminum silicon powder and aluminum magnesium powder, and the particle size range of the auxiliary agent is 25-100 μm.

7. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 5 or 6, characterized in that: The pore-forming agent includes NaCl, ZnCl, urea and PMMA, etc., and the particle size range is 25-100 μm.

8. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 5 or 6, characterized in that: In step S1, the catalyst metal is uniformly loaded on the surface of the aluminum-based raw material powder by an impregnation method; The calcination temperature is less than 650° C., the heating rate is less than 5° C., the calcination atmosphere is air, and the calcination is followed by furnace cooling.

9. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 5 or 6, characterized in that: In step S4, the aluminum-based composite porous liquid-absorbing core raw material C is formed by pressing or rolling according to specific requirements, and sintered at high temperature; The compression molding comprises the following steps: A high-purity graphite block is used as a sintering tool, and a groove is provided on the sintering tool. The aluminum-based composite porous liquid absorbent core raw material C is evenly spread in the groove, and is pressed by a hydraulic press at a pressing pressure of 5 to 30 tons to obtain a composite porous liquid absorbent core green body D; The rolling forming process includes the following steps: Using a powder rolling mill, setting the feed speed to 0.1-2 m / min and the rolling pressure to 0.5-5 t, the aluminum-based composite porous liquid absorbent core raw material C is rolled to obtain a composite porous liquid absorbent core green body D; Placing the composite porous liquid-absorbing core green body D in a sintering furnace for sintering; Wherein, the sintering furnace includes a vacuum sintering furnace or an atmosphere sintering furnace, such as a high-purity N2 or H2 atmosphere sintering furnace; Among them, the vacuum degree of vacuum sintering furnace is less than 1×10 -2 Pa, the gas flow rate of the atmosphere sintering furnace is 1-5L / min. The sintering temperature is <650℃.

10. The method for preparing the powder sintered aluminum-based composite porous liquid absorbent core according to claim 9, characterized in that: In step S4, the prepared aluminum-based composite porous liquid-absorbing core has a porosity of 25-65%, a thickness of 0.3-1 mm, and a pore size of 30-200 μm.

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