Metal porous micro-nano composite wick and preparation method thereof

Abstract

The invention discloses a metal porous micro-nano composite wick which comprises a metal porous matrix, a micro-boss structure arranged on the surface of the metal porous matrix and a nano-porous structure arranged on the micro-boss structure. The preparation method of the composite wick comprises the following steps: 1, compression molding of the metal porous matrix; 2, sintering the metal porous matrix; 3, machining a micro-boss structure; 4, performing surface nanocrystallization treatment on the micro-boss structure; and step 5, post-processing. The metal porous micro-nano composite wick provided by the invention has a micro-nano-scale aperture structure, has good capillary suction force and permeability for a liquid working medium, and improves the heat transfer capability of a heat pipe; the metal porous micro-nano composite wick is prepared by adopting powder metallurgy, micro-milling and anodic oxidation processes, the process is simple, the pore characteristics are controllable, and the method is suitable for the fields of thermal management, batteries and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-nano processing of porous metal materials, and particularly relates to a porous metal micro-nano composite liquid-absorbing core and a preparation method thereof. Background Art

[0002] In recent years, with the rapid advancement of science and technology, optoelectronics and other technologies have made rapid progress. Electronic components are becoming increasingly miniaturized, high-powered, and highly integrated. Solving the problem of dissipating high heat flux densities in confined spaces is a daunting challenge. Heat pipes, as efficient heat transfer components, offer high thermal conductivity, excellent temperature uniformity, and high reliability, and have been widely used in smart devices, aerospace, and other fields.

[0003] When a heat pipe is operating, it absorbs heat by vaporizing the working fluid, which then liquefies at the cold source, releasing the heat. Simultaneously, the capillary force provided by the porous wick drives the working fluid back to the evaporation section of the heat pipe, ensuring that the working fluid absorbs heat again and vaporizes, achieving cyclical heat dissipation. As a key component of the heat pipe, the porous metal wick not only provides a channel for the working fluid to flow but also generates capillary force to drive the working fluid back to the evaporation section. Therefore, the structure of the porous metal wick directly affects the heat transfer performance of the heat pipe.

[0004] The working principle of heat pipes shows that when the pore size of the porous wick decreases, the capillary force of the porous wick heat pipe increases and the permeability decreases; when the pore size of the porous wick increases, the capillary force of the porous wick heat pipe decreases and the permeability increases. In other words, the porous wick of a conventional single-pore structure porous wick heat pipe has an antagonistic relationship between capillary force and permeability, which limits the heat transfer capacity of conventional single-pore structure porous wick heat pipes. Therefore, it is necessary to consider the characteristics of each part of the heat pipe and construct a metal porous micro-nano composite wick to balance the contradiction between the capillary force and permeability of the porous wick, thereby improving the heat transfer capacity of the heat pipe. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the shortcomings of the above-mentioned prior art and provide a porous metal micro-nano composite liquid absorbent wick. This porous metal micro-nano composite liquid absorbent wick utilizes a micro-platform structure on the surface of a porous metal substrate and a nanoporous structure on the micro-platform structure. This increases the surface area by utilizing the micro-nanoscale pore structure, achieving both good capillary suction force and permeability for liquid working media, thus resolving the trade-off between capillary force and permeability in porous liquid absorbent wicks.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a metal porous micro-nano composite liquid-absorbing core, characterized in that it includes a metal porous matrix, a micro-convex structure arranged on the surface of the metal porous matrix, and a nanoporous structure on the micro-convex structure, wherein the porosity of the metal porous matrix is 15% to 45%, the maximum pore diameter is 5μm to 25μm, and the thickness is 1mm to 10mm; the height of the micro-convex structure is 0.1mm to 0.5mm, the length is 0.3mm to 0.7mm, and the width is 0.3mm to 0.7mm; the nanoporous structure is prepared by an anodizing process, and has a thickness of 5μm to 30μm and a pore diameter of 30nm to 95nm.

[0007] At the same time, the present invention also discloses a method for preparing the above-mentioned porous metal micro-nano composite liquid-absorbing core, which comprises the following steps:

[0008] Step 1: Pressing the porous metal matrix: placing the metal powder into a mold and then placing it in a cold isostatic pressing device for cold isostatic pressing to obtain a porous metal matrix green body; the cold isostatic pressing pressure is 160 MPa to 200 MPa, and the holding time is 20 seconds to 30 seconds;

[0009] Step 2: Sintering the porous metal matrix: sintering the porous metal matrix green body obtained in step 1 to obtain a porous metal matrix; the sintering temperature is 950° C. to 1250° C., and the holding time is 1.5 h to 3.5 h;

[0010] Step 3: Processing the micro-convex structure: CAXA software is used to design a processing model for the micro-convex structure. The porous metal substrate obtained in step 2 is then micro-milled using the designed processing model to form a micro-convex structure, thereby obtaining a porous metal substrate having a micro-convex structure on the surface. The micro-milling process uses a feed rate of 0.01 mm to 0.02 mm and a rotation speed of 8000 rpm to 12000 rpm.

[0011] Step 4, surface nano-processing of the micro-convex structure: the metal porous substrate with a micro-convex structure on the surface obtained in step 3 is placed as an anode in an electrolytic cell containing an ethylene glycol electrolyte, and a platinum sheet is used as a cathode for an anodic oxidation treatment to form a nanoporous structure on the micro-convex structure to obtain a metal porous micro-nano composite liquid-absorbing core blank; the ethylene glycol electrolyte contains 0.25% to 1.25% by mass of ammonium fluoride and 1% to 2% by volume of H2O; the anodic oxidation treatment is carried out at a temperature of 10°C to 70°C, a voltage of 20V to 50V, and a time of 1h to 5h;

[0012] Step 5, post-processing: the metal porous micro-nano composite liquid absorbent core blank obtained in step 4 is cleaned with deionized water and anhydrous ethanol in sequence, and then heat-treated at 80° C. to 500° C. to obtain the metal porous micro-nano composite liquid absorbent core.

[0013] In step five of the present invention, organic matter and moisture introduced during the preparation process are removed by heat treatment.

[0014] The above method is characterized in that the metal powder in step 1 is selected from nickel powder, Inconel625 powder, Inconel718 powder, and 316L powder.

[0015] The above method is characterized in that the particle size distribution range of the metal powder in step 1 is selected from: 80μm to 180μm, 80μm to 280μm, 300μm to 400μm, -22μm, and -16μm.

[0016] The above method is characterized in that the metal powder in step 1 is selected from nickel powder, Inconel625 powder, and Inconel718 powder, and the sintering atmosphere in step 2 is a hydrogen atmosphere, and the hydrogen flow rate is 0.25m 3 / h~0.4m 3 In the present invention, the nickel or nickel alloy powder is sintered in a hydrogen atmosphere, which ensures the sintering effect and realizes the reduction of part of the nickel or nickel alloy powder during the sintering process, thereby improving its sintering activity.

[0017] The above method is characterized in that the metal powder in step 1 is selected from 316L powder, and the sintering in step 2 is carried out under vacuum conditions, and the vacuum degree is not greater than 9.0×10 -2 In the present invention, the 316L powder is vacuum sintered. The vacuum environment is not only conducive to removing the gas adsorbed on the surface of the 316L powder, but also avoids the adverse effects of impurities such as hydrogen on the properties of the porous metal matrix obtained after sintering.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention obtains a metal porous micro-nano composite wick by arranging a micro-convex structure on the surface of a metal porous substrate and arranging a nanoporous structure on the micro-convex structure. The surface area of the composite wick is effectively increased by utilizing the micro-nano structure, so that it has higher heat transfer efficiency and stability in terms of heat transfer than a single pore size unit wick.

[0020] 2. The composite wick with a micro-nanoscale pore structure of the present invention has good capillary suction force for liquid working fluids, small flow resistance and high permeability, thereby effectively balancing the contradiction between the capillary force and permeability of the porous wick, thereby improving the heat transfer capacity of the heat pipe.

[0021] 3. The present invention combines powder metallurgy, micro-milling and anodizing processes to develop a method for preparing a metal porous liquid-absorbing core with a simple process and controllable pore properties. It has important application prospects in the fields of high heat flux density, high power heat dissipation and thermal management of aerospace equipment.

[0022] 4. The metal porous micro-nano composite liquid absorbent core prepared by the present invention has the advantages of low cost and easy operation, and can be used as a metal functional material in the fields of heat exchange, direct alcohol fuel cells, etc.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a physical picture of the metal porous micro-nano composite liquid-absorbing core prepared in Example 1 of the present invention and an SEM picture of the micro-convex platform structure. DETAILED DESCRIPTION

[0025] Example 1

[0026] The preparation method of this embodiment comprises the following steps:

[0027] Step 1: Pressing the porous metal matrix: 500 g of nickel powder with a particle size distribution range of -22 μm was placed in a mold, and then placed in a cold isostatic pressing device for cold isostatic pressing at a pressure of 160 MPa and a holding time of 20 s to obtain a nickel porous matrix green body;

[0028] Step 2: Sintering of the porous metal matrix: The nickel porous matrix green body obtained in step 1 is sintered in a hydrogen atmosphere with a hydrogen flow rate of 0.3 m 3 / h, the sintering temperature is 950℃, and the holding time is 2h to obtain a nickel porous matrix;

[0029] Step 3: Processing the micro-convex structure: CAXA software is used to design a processing model for the micro-convex structure, and then the nickel porous substrate obtained in step 2 is micro-milled using the designed processing model to form a micro-convex structure, thereby obtaining a nickel porous substrate having a micro-convex structure on the surface; the micro-milling process uses a feed rate of 0.015 mm and a rotation speed of 10,000 rpm;

[0030] Step 4, surface nano-treatment of the micro-convex structure: The nickel porous substrate with a micro-convex structure on the surface obtained in step 3 is placed as an anode in an electrolytic cell containing ethylene glycol electrolyte, and a platinum sheet is used as a cathode. Anodization treatment is performed at a temperature of 30°C, a voltage of 30V, and a time of 2h to form a nanoporous structure on the micro-convex structure to obtain a nickel porous micro-nano composite liquid-absorbing core blank; the ethylene glycol electrolyte contains 0.75% by mass of ammonium fluoride and 2% by volume of H2O;

[0031] Step 5, post-processing: the nickel porous micro-nano composite liquid absorbent core blank obtained in step 4 is cleaned with deionized water and anhydrous ethanol in sequence, and then heat-treated at 200° C. to obtain a nickel porous micro-nano composite liquid absorbent core.

[0032] like Figure 1 As shown, the nickel porous micro-nano composite liquid-absorbing core prepared in this embodiment includes a nickel porous matrix, a micro-convex structure arranged on the surface of the nickel porous matrix, and a nanoporous structure on the micro-convex structure; after testing, the porosity of the nickel porous matrix in the nickel porous micro-nano composite liquid-absorbing core is 15%, the maximum pore diameter is 5μm, and the thickness is 5mm. The height of the micro-convex structure on the surface of the nickel porous matrix is 0.5mm, the length is 0.5mm, and the width is 0.5mm. The thickness of the nanoporous structure on the micro-convex structure is 5μm, and the pore diameter is 30nm~75nm.

[0033] Example 2

[0034] The difference between this embodiment and embodiment 1 is that the particle size distribution range of the nickel powder in step 1 is -16 μm.

[0035] Example 3

[0036] The preparation method of this embodiment comprises the following steps:

[0037] Step 1, pressing and molding of the metal porous matrix: After 500g of Inconel718 powder with a particle size distribution range of 300μm to 400μm is loaded into the mold, the mold is placed in a cold isostatic pressing device for cold isostatic pressing at a pressure of 180MPa and a holding time of 25s to obtain an Inconel718 porous matrix green body;

[0038] Step 2: Sintering of the porous metal matrix: The Inconel 718 porous matrix green body obtained in step 1 was sintered in a hydrogen atmosphere with a hydrogen flow rate of 0.4 m 3 / h, the sintering temperature is 1100℃, and the holding time is 2.5h to obtain the Inconel718 porous matrix;

[0039] Step 3, processing of the micro-convex structure: CAXA software is used to design a processing model of the micro-convex structure, and then the Inconel718 porous matrix obtained in step 2 is micro-milled using the designed processing model to form a micro-convex structure, thereby obtaining an Inconel718 porous matrix with a micro-convex structure on the surface; the feed rate used in the micro-milling process is 0.015 mm and the rotation speed is 10000 rpm;

[0040] Step 4, surface nano-treatment of the micro-convex structure: the Inconel718 porous substrate with a micro-convex structure on the surface obtained in step 3 is placed as an anode in an electrolytic cell containing ethylene glycol electrolyte, and a platinum sheet is used as a cathode, and an anodizing treatment is performed at a temperature of 30°C, a voltage of 30V, and a time of 3h to form a nanoporous structure on the micro-convex structure to obtain an Inconel718 porous micro-nano composite liquid-absorbing core blank; the ethylene glycol electrolyte contains 0.75% by mass of ammonium fluoride and 1.5% by volume of H2O;

[0041] Step 5, post-processing: the Inconel 718 porous micro-nano composite liquid absorbent core blank obtained in step 4 is cleaned with deionized water and anhydrous ethanol in sequence, and then heat-treated at 200° C. to obtain the Inconel 718 porous micro-nano composite liquid absorbent core.

[0042] The Inconel718 porous micro-nano composite liquid-absorbing core prepared in this embodiment includes an Inconel718 porous matrix, a micro-boss structure arranged on the surface of the Inconel718 porous matrix, and a nanoporous structure on the micro-boss structure; after testing, the porosity of the Inconel718 porous matrix in the Inconel718 porous micro-nano composite liquid-absorbing core is 35%, the maximum pore diameter is 10μm, and the thickness is 3mm. The height of the micro-boss structure on the surface of the Inconel718 porous matrix is 0.5mm, the length is 0.5mm, and the width is 0.5mm. The thickness of the nanoporous structure on the micro-boss structure is 15μm, and the pore diameter is 30nm~95nm.

[0043] Example 4

[0044] The preparation method of this embodiment comprises the following steps:

[0045] Step 1: Pressing the porous metal matrix: 500 g of 316L powder with a particle size distribution range of 80 μm to 180 μm was placed in a mold, and then placed in a cold isostatic pressing device for cold isostatic pressing at a pressure of 160 MPa and a holding time of 20 s to obtain a 316L porous matrix green body;

[0046] Step 2: Sintering of the porous metal matrix: The 316L porous matrix green body obtained in step 1 is sintered under vacuum conditions, and the vacuum degree is not greater than 9.0×10 -2 Pa, the sintering temperature was 1250 °C, the holding time was 3.5 h, and the 316L porous matrix was obtained;

[0047] Step 3: Processing the micro-convex structure: CAXA software is used to design a processing model for the micro-convex structure. The designed processing model is then used to micro-mill the 316L porous substrate obtained in step 2 to form a micro-convex structure, thereby obtaining a 316L porous substrate having a micro-convex structure on the surface. The micro-milling process uses a feed rate of 0.01 mm and a rotation speed of 8000 rpm.

[0048] Step 4: Surface nano-processing of the micro-convex structure: The 316L porous substrate with a micro-convex structure on the surface obtained in step 3 is placed as an anode in an electrolytic cell containing an ethylene glycol electrolyte, and a platinum sheet is used as a cathode. Anodization treatment is performed at a temperature of 10°C, a voltage of 20V, and a time of 1 hour to form a nanoporous structure on the micro-convex structure to obtain a 316L porous micro-nano composite liquid-absorbing core blank; the ethylene glycol electrolyte contains 0.25% by mass of ammonium fluoride and 1% by volume of H2O;

[0049] Step 5, post-processing: the 316L porous micro-nano composite liquid absorbent core blank obtained in step 4 is cleaned with deionized water and anhydrous ethanol in sequence, and then heat-treated at 80° C. to obtain a 316L porous micro-nano composite liquid absorbent core.

[0050] The 316L porous micro-nano composite liquid absorbent core prepared in this embodiment includes a 316L porous matrix, a micro-convex structure arranged on the surface of the 316L porous matrix, and a nanoporous structure on the micro-convex structure; after testing, the porosity of the 316L porous matrix in the 316L porous micro-nano composite liquid absorbent core is 33%, the maximum pore diameter is 25μm, and the thickness is 5mm; the height of the micro-convex structure on the surface of the 316L porous matrix is 0.3mm, the length is 0.3mm, and the width is 0.3mm; the thickness of the nanoporous structure on the micro-convex structure is 5μm, and the pore diameter is 30nm~95nm.

[0051] Example 5

[0052] The preparation method of this embodiment comprises the following steps:

[0053] Step 1, pressing and molding of the metal porous matrix: 500g of Inconel625 powder with a particle size distribution range of 80μm to 180μm is loaded into a mold, and then placed in a cold isostatic pressing device for cold isostatic pressing with a pressure of 200MPa and a holding time of 20s to obtain an Inconel625 porous matrix green body;

[0054] Step 2: Sintering of the porous metal matrix: The Inconel 625 porous matrix green body obtained in step 1 was sintered in a hydrogen atmosphere with a hydrogen flow rate of 0.25 m 3 / h, the sintering temperature is 1200℃, and the holding time is 3.5h to obtain the Inconel625 porous matrix;

[0055] Step 3, processing of the micro-convex structure: CAXA software is used to design a processing model of the micro-convex structure, and then the Inconel625 porous matrix obtained in step 2 is micro-milled using the designed processing model to form a micro-convex structure, thereby obtaining an Inconel625 porous matrix with a micro-convex structure on the surface; the feed rate used in the micro-milling process is 0.02 mm and the rotation speed is 12000 rpm;

[0056] Step 4, surface nano-treatment of the micro-convex structure: the Inconel625 porous substrate with a micro-convex structure on the surface obtained in step 3 is placed as an anode in an electrolytic cell containing ethylene glycol electrolyte, and a platinum sheet is used as a cathode, and an anodizing treatment is performed at a temperature of 70 ° C, a voltage of 50 V, and a time of 1 h to form a nanoporous structure on the micro-convex structure to obtain an Inconel625 porous micro-nano composite liquid-absorbing core blank; the ethylene glycol electrolyte contains 1.25% by mass of ammonium fluoride and 2% by volume of H2O;

[0057] Step 5, post-processing: the Inconel 625 porous micro-nano composite liquid absorbent core blank obtained in step 4 is cleaned with deionized water and anhydrous ethanol in turn, and then heat-treated at 500° C. for 1 h to obtain the Inconel 625 porous micro-nano composite liquid absorbent core.

[0058] The Inconel625 porous micro-nano composite liquid-absorbing core prepared in this embodiment includes an Inconel625 porous matrix, a micro-boss structure arranged on the surface of the Inconel625 porous matrix, and a nanoporous structure on the micro-boss structure; after testing, the porosity of the Inconel625 porous matrix in the Inconel625 porous micro-nano composite liquid-absorbing core is 45%, the maximum pore diameter is 15μm, and the thickness is 10mm. The height of the micro-boss structure on the surface of the Inconel625 porous matrix is 0.1mm, the length is 0.7mm, and the width is 0.7mm. The thickness of the nanoporous structure on the micro-boss structure is 30μm, and the pore diameter is 30nm~95nm.

[0059] Example 6

[0060] The preparation method of this embodiment comprises the following steps:

[0061] Step 1: Pressing the porous metal matrix: 500 g of nickel powder with a particle size distribution range of 80 μm to 280 μm is placed in a mold, and then placed in a cold isostatic pressing device for cold isostatic pressing at a pressure of 160 MPa and a holding time of 30 s to obtain a nickel porous matrix green body;

[0062] Step 2: Sintering of the porous metal matrix: The nickel porous matrix green body obtained in step 1 is sintered in a hydrogen atmosphere with a hydrogen flow rate of 0.3 m 3 / h, the sintering temperature is 1150℃, and the holding time is 1.5h to obtain a nickel porous matrix;

[0063] Step 3: Processing the micro-convex structure: CAXA software is used to design a processing model for the micro-convex structure, and then the nickel porous substrate obtained in step 2 is micro-milled using the designed processing model to form a micro-convex structure, thereby obtaining a nickel porous substrate having a micro-convex structure on the surface; the micro-milling process uses a feed rate of 0.015 mm and a rotation speed of 10,000 rpm;

[0064] Step 4, surface nano-treatment of the micro-convex structure: the nickel porous substrate with a micro-convex structure on the surface obtained in step 3 is placed as an anode in an electrolytic cell containing ethylene glycol electrolyte, and a platinum sheet is used as a cathode, and an anodization treatment is performed at a temperature of 30°C, a voltage of 50V, and a time of 1 hour to form a nanoporous structure on the micro-convex structure to obtain a nickel porous micro-nano composite liquid-absorbing core blank; the ethylene glycol electrolyte contains 0.75% by mass of ammonium fluoride and 2% by volume of H2O;

[0065] Step 5, post-processing: the nickel porous micro-nano composite liquid absorbent core blank obtained in step 4 is cleaned with deionized water and anhydrous ethanol in sequence, and then heat-treated at 200° C. to obtain a nickel porous micro-nano composite liquid absorbent core.

[0066] The nickel porous micro-nano composite liquid-absorbing core prepared in this embodiment includes a nickel porous matrix, a micro-convex structure arranged on the surface of the nickel porous matrix, and a nanoporous structure on the micro-convex structure; after testing, the porosity of the nickel porous matrix in the nickel porous micro-nano composite liquid-absorbing core is 35%, the maximum pore diameter is 15μm, and the thickness is 5mm; the micro-convex structure on the surface of the nickel porous matrix has a height of 0.5mm, a length of 0.5mm, and a width of 0.5mm; the nanoporous structure on the micro-convex structure has a thickness of 5μm and a pore diameter of 50nm to 95nm.

[0067] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation made to the above embodiment based on the essence of the invention technology shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A metal porous micro-nano composite liquid absorbent core, characterized in that: It includes a metal porous matrix, a micro-bump structure arranged on the surface of the metal porous matrix, and a nanoporous structure on the micro-bump structure, wherein the porosity of the metal porous matrix is 15% to 45%, the maximum pore diameter is 5μm to 25μm, and the thickness is 1mm to 10mm. The height of the micro-bump structure is 0.1mm to 0.5mm, the length is 0.3mm to 0.7mm, and the width is 0.3mm to 0.7mm. The nanoporous structure is prepared by an anodizing process, and has a thickness of 5μm to 30μm and a pore diameter of 30nm to 95nm.

2. A method for preparing the metal porous micro-nano composite liquid absorbent core according to claim 1, characterized in that: The method comprises the following steps: Step 1: Pressing the porous metal matrix: placing the metal powder into a mold and then placing it in a cold isostatic pressing device for cold isostatic pressing to obtain a porous metal matrix green body; the cold isostatic pressing pressure is 160 MPa to 200 MPa, and the holding time is 20 seconds to 30 seconds; Step 2: Sintering the porous metal matrix: sintering the porous metal matrix green body obtained in step 1 to obtain a porous metal matrix; the sintering temperature is 950° C. to 1250° C., and the holding time is 1.5 h to 3.5 h; Step 3: Processing the micro-convex structure: CAXA software is used to design a processing model for the micro-convex structure. The porous metal substrate obtained in step 2 is then micro-milled using the designed processing model to form a micro-convex structure, thereby obtaining a porous metal substrate having a micro-convex structure on the surface. The micro-milling process uses a feed rate of 0.01 mm to 0.02 mm and a rotation speed of 8000 rpm to 12000 rpm. Step 4, surface nano-processing of the micro-convex structure: the metal porous substrate with a micro-convex structure on the surface obtained in step 3 is placed as an anode in an electrolytic cell containing an ethylene glycol electrolyte, and a platinum sheet is used as a cathode for an anodic oxidation treatment to form a nanoporous structure on the micro-convex structure to obtain a metal porous micro-nano composite liquid-absorbing core blank; the ethylene glycol electrolyte contains 0.25% to 1.25% by mass of ammonium fluoride and 1% to 2% by volume of H2O; the anodic oxidation treatment is carried out at a temperature of 10°C to 70°C, a voltage of 20V to 50V, and a time of 1h to 5h; Step 5, post-processing: the metal porous micro-nano composite liquid absorbent core blank obtained in step 4 is cleaned with deionized water and anhydrous ethanol in sequence, and then heat-treated at 80° C. to 500° C. to obtain the metal porous micro-nano composite liquid absorbent core.

3. The method according to claim 2, characterized in that The metal powder in step 1 is selected from nickel powder, Inconel 625 powder, Inconel 718 powder, and 316L powder.

4. The method according to claim 2, characterized in that The particle size distribution range of the metal powder in step 1 is selected from: 80 μm to 180 μm, 80 μm to 280 μm, 300 μm to 400 μm, -22 μm, and -16 μm.

5. The method according to claim 3, characterized in that The metal powder in step 1 is selected from nickel powder, Inconel 625 powder, and Inconel 718 powder. The sintering atmosphere in step 2 is a hydrogen atmosphere, and the hydrogen flow rate is 0.25m 3 / h~0.4m 3 / h.

6. The method according to claim 3, characterized in that The metal powder in step 1 is selected from 316L powder, and the sintering in step 2 is carried out under vacuum conditions, and the vacuum degree is not greater than 9.0×10 -2 Pa.

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