Additive manufacturing method of microscale flow channels and applications thereof

Abstract

The present application relates to the technical field of additive manufacturing, in particular to a kind of micrometer flow channel's additive manufacturing method and its application.Micrometer flow channel's additive manufacturing method, comprising the following steps: (a) based on the distribution of preset micrometer flow channel in target configuration, configuration main body is split into several mutually parallel solid cylinders, obtain stl model and carry out slicing, obtain slice file;(b) based on the slice file, metal powder is formed by selective laser melting process and is additively manufactured, obtain the target configuration with micrometer flow channel;In step (a), adjacent solid cylinders are tangent or intersect, and the pore surrounded by every 4 solid cylinders corresponds to micrometer flow channel.The additive manufacturing method of the present application, by appropriate micrometer flow channel configuration design, without changing SLM equipment and technology, can realize the controllable preparation of micrometer flow channel, significantly improve the forming precision of extremely fine structure.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to an additive manufacturing method for micron-level flow channels and its application. Background Technology

[0002] To meet the stringent temperature resistance requirements of materials for hot-end components of next-generation hypersonic vehicles under extreme service environments, active thermal protection technology has become a key research focus in the field of thermal protection. Among these technologies, evaporative cooling is widely used in critical hot-end components such as combustion chambers and leading edges due to its excellent cooling efficiency and temperature uniformity. However, the effective implementation of this technology places higher demands on the storage and transport systems of the cooling fluid, necessitating the development of functional component fabrication technologies with micron-level fine flow channel structures.

[0003] In the existing metal additive manufacturing technology system, selective laser melting (SLM) is considered the most promising solution due to its excellent forming accuracy (up to ±50μm) and ability to form complex structures. Current industrial-grade SLM equipment generally uses fiber lasers with a wavelength of 1070nm as the energy source, and their spot diameter is typically limited to the diffraction limit, remaining within the range of 80–120μm. Based on the forming mechanism of powder bed melting, to ensure good powder spreading quality and molten pool stability, process specifications require the metal powder particle size to be controlled within the range of 15–53μm. This combination of parameters leads to significant heat accumulation and spheroidization during the forming process, resulting in the minimum feature size of the controllable flow channel structure generally exceeding 100μm.

[0004] This technological limitation severely restricts the application of additive manufacturing in microscale fluid devices, especially for sweating cooling structures requiring 10μm-level flow channel precision. Research shows that when the flow channel diameter is less than 50μm, the cooling medium exhibits significant microscale flow characteristics, which can improve sweating cooling efficiency by more than 30%. Therefore, overcoming the resolution limitations of existing SLM technology and developing precision forming processes for 10μm-level flow channels has become a core technological challenge for the development of thermal protection systems for hypersonic vehicles.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an additive manufacturing method for micron-level flow channels and its application. The method of this invention, through micron-level flow channel configuration design, can achieve controllable fabrication of 10μm-level microchannels without changing SLM equipment and technology.

[0007] To achieve the above-mentioned objectives of the present invention, a first aspect of the present invention provides an additive manufacturing method for micron-level flow channels, comprising the following steps:

[0008] (a) Based on the distribution of micron-level flow channels in the target configuration, the main body of the configuration is divided into several parallel solid cylinders to obtain the STL model and slice it to obtain the slice file;

[0009] (b) Based on the slice file, the metal powder is additively manufactured using a selective laser melting process to obtain a target configuration with micron-level flow channels;

[0010] In step (a), adjacent solid cylinders are tangent or intersecting, and the pores formed by every 4 solid cylinders correspond to micron-level flow channels.

[0011] In a specific embodiment of the present invention, the radius r of the solid cylinder is 0.25 to 1.5 mm. Further, the radius r of each of the solid cylinders is the same.

[0012] In a specific embodiment of the present invention, in step (a), the distance d0 between the axes of the nearest solid cylinder satisfies

[0013] In a specific embodiment of the present invention, in the target configuration with micron-level flow channels obtained in step (b), the theoretical diameter of the micron-level flow channels is...

[0014] In a specific embodiment of the present invention, in the target configuration with micron-level flow channels obtained in step (b), the diameter of the micron-level flow channels is 30 to 1240 μm.

[0015] In a specific embodiment of the present invention, the distribution of the preset micron-level flow channels includes the diameter of the micron-level flow channels and the number of micron-level flow channels.

[0016] In a specific embodiment of the present invention, the plurality of parallel solid cylinders are arranged in a matrix. Further, the distance between the axes of adjacent solid cylinders arranged laterally is the same as the distance between the axes of adjacent solid cylinders arranged longitudinally, and both are d0.

[0017] In a specific embodiment of the present invention, the particle size of the metal powder is 10–40 μm.

[0018] In a specific embodiment of the present invention, the selective laser melting process employs a selective laser melting device with a forming accuracy of <100μm.

[0019] In a specific embodiment of the present invention, in the selective laser melting, the powder layer thickness is ≤30μm and the spot diameter is ≤100μm.

[0020] In a specific embodiment of the present invention, the metal powder includes nickel-based high-temperature alloy powder.

[0021] In a specific embodiment of the present invention, in the selective laser melting, the laser power is 180-250W, the scanning speed is 700-1000mm / s, and the scanning interval is 100-110μm.

[0022] The second aspect of the present invention provides the application of the additive manufacturing method of the micron-level flow channel of the first aspect of the present invention in the preparation of a sweating cooling unit.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The additive manufacturing method of this invention, through appropriate micron-level flow channel configuration design, can achieve controllable fabrication of micron-level flow channels without changing SLM equipment and technology, significantly improving the forming accuracy of ultra-fine structures. Furthermore, the additive manufacturing method of this invention is simple to operate and easy to implement. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 A schematic diagram of micron-level flow channel configuration design with different diameters and numbers per unit volume provided for embodiments of the present invention;

[0027] Figure 2 Metallographic image of the side cross-section of the micron-scale flow channel configuration obtained in Example 1 of the present invention;

[0028] Figure 3 This is a metallographic image of the side cross-section of the micron-scale flow channel configuration obtained in Comparative Example 1 of the present invention. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0030] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] Research on the design of active thermal protection structures shows that the sweating cooling effect is significantly related to the diameter and number of the working fluid transport channels. When the channel diameter is less than 50 μm, the cooling working fluid will exhibit significant microscale flow characteristics, which can improve the sweating cooling efficiency by more than 30%. However, due to limitations in laser control precision and powder particle size in selective laser melting technology, it is difficult to achieve controllable forming of fine structures below 100 μm. Chinese patent application CN117733180A uses selective laser melting (SLM) to form a blank, followed by femtosecond laser processing to create 30-50 μm micropores on the surface sweating structure layer, but does not achieve integrated forming. Chinese patent application CN112935277A increases the laser beam energy input to create small holes at the bottom of the laser cladding pool. Utilizing the gas entrainment effect at the bottom of the molten pool caused by the periodic collapse of these unstable holes, gas-like micropores are naturally formed at the bottom of each laser cladding line; this is an unstable fabrication method. Chinese patent application CN108941563A adds chromium nitride during the SLM process to form a porous structure smaller than 100 μm, but the size and distribution of the pores are uncontrollable, failing to provide technical support for the design of micron-level flow channels for sweating cooling. Therefore, achieving controllable forming of 10 μm-level microchannels in selective laser melting technology is of great significance for the development and application of active thermal protection components.

[0032] Based on this, the first aspect of the present invention provides an additive manufacturing method for micron-level flow channels, comprising the following steps:

[0033] (a) Based on the distribution of micron-level flow channels in the target configuration, the main body of the configuration is divided into several parallel solid cylinders to obtain the STL model and slice it to obtain the slice file;

[0034] (b) Based on the slice file, the metal powder is additively manufactured by selective laser melting process to obtain the target configuration with micron-level flow channels;

[0035] In step (a), adjacent solid cylinders are tangent or intersecting, and the pores formed by every 4 solid cylinders correspond to micron-level flow channels.

[0036] The target configuration refers to a structure containing a predetermined distribution of micron-level flow channels within a main body with a certain structure. The structure of the main body is not limited; it can be a regular structure or an irregular, irregular shape, such as a cube, sphere, cylinder, cone, prism, regular polyhedron, torus, etc., but is not limited thereto. The specific structure of the main body can be adjusted and selected according to the three-dimensional shape required by the target configuration. The additive manufacturing method of this invention, through appropriate micron-level flow channel configuration design, can achieve controllable fabrication of micron-level flow channels without changing SLM equipment and technology, significantly improving the forming accuracy of extremely fine structures. Furthermore, the additive manufacturing method of this invention is simple to operate and easy to implement.

[0037] In a specific embodiment of the present invention, the radius r of the solid cylinder is 0.25–1.5 mm. In different embodiments, the radius r of the solid cylinder can be 0.25 mm, 0.5 mm, 0.75 mm, 1 mm, 1.2 mm, 1.5 mm, or any rational value within the range of 0.25–1.5 mm that can be recognized by 3D modeling software. The larger the value of the radius r of the solid cylinder, the fewer micrometer-level flow channels are required within the same volume. Figure 1 In (a) to (c), within the same volume, as the radius of the solid cylinder gradually decreases, the number of micrometer-level flow channels within the same volume gradually increases. By adjusting the radius r within the above range, it is possible to ensure the forming accuracy of the cylindrical solid during selective laser melting and forming, while guaranteeing a sufficient number of micrometer-level flow channels within the same volume to meet the practical application requirements of the sweating cooling unit.

[0038] In practice, the main structure of the configuration can be modeled using software such as UG. Then, based on the distribution of the micron-level flow channels in the target configuration, the main body of the configuration is divided into several parallel solid cylinders and exported as an STL file. The STL file is then imported into software such as Materialise Magics for slicing to obtain a slice file.

[0039] In a specific embodiment of the present invention, the radius r of each solid cylinder is the same.

[0040] In a specific embodiment of the present invention, in step (a), the distance d0 between the axes of the nearest solid cylinder satisfies The distance d0 between the axes of the nearest solid cylinders can be selected as any rational value with a precision recognizable by 3D modeling software that satisfies the above conditions. Specifically, the smaller the value of d0 within the specified range, the smaller the diameter of the micrometer-level flow channel; when... When d0 > 2r, adjacent cylindrical solids are tangent or intersecting at a 45° angle, resulting in a dense solid with no micron-level flow channels. When d0 > 2r, all solid cylinders are separated, and all micron-level flow channels are connected, rendering the concept of "flow channels" meaningless. For the case where d0 = 2r, the nearest solid cylinders are all tangent, as shown below. Figure 1 As shown in (d), the diameter of the micron-level flow channel reaches its maximum value, and each micron-level flow channel remains independent and unconnected.

[0041] In a specific embodiment of the present invention, in the target configuration with micron-level flow channels obtained in step (b), the theoretical diameter of the micron-level flow channels is: Theoretically, the diameter of micron-sized flow channels can encompass all scales within the range of 0–1240 μm. However, due to limitations imposed by powder particle size and the precision of equipment forming control, the actual controllable diameter of micron-sized flow channels is any scale within the range of 30–1240 μm. That is, in the target configuration with micron-sized flow channels obtained in step (b), the diameter of the micron-sized flow channels is 30–1240 μm.

[0042] In various embodiments, the target configuration with micron-level flow channels obtained by the method of the present invention can have a diameter of 30 μm, 40 μm, 50 μm, 60 μm, 80 μm, 100 μm, or any combination thereof. Furthermore, in the target configuration with micron-level flow channels obtained by the method of the present invention, the length of the micron-level flow channels is ≥10 mm, and there is no powder residue or blockage in the length of the micron-level flow channels exceeding 10 mm in the flow channel length direction, indicating good flow channel connectivity.

[0043] It is understood that, since the micron-level flow channels generated by the solid cylindrical spacer model are not regular geometric shapes, the diameter of the micron-level flow channels in this invention is the geometrically equivalent diameter of the micron-level flow channel cross-section.

[0044] In a specific embodiment of the present invention, the additive manufacturing method for micron-level flow channels includes the following steps:

[0045] (a) Based on the pre-defined distribution of micron-level flow channels in the target configuration, the main body of the configuration is divided into several parallel solid cylinders with radii r of 0.25–1.5 mm. Adjacent solid cylinders are tangent or intersecting, and the distance d0 between the axes of the nearest solid cylinder satisfies the following condition. Obtain the STL model and slice it to get the slice file;

[0046] (b) Based on the sliced ​​file, the metal powder is additively manufactured using a selective laser melting process to obtain a metal powder with a theoretical diameter of [missing information]. The target configuration of the micron-scale flow channel.

[0047] In a specific embodiment of the present invention, the preset distribution of micron-level flow channels includes the diameter of the micron-level flow channels and the number of micron-level flow channels.

[0048] Depending on the varying requirements for cooling fluid transport within micron-level channels to ensure effective thermal protection, the diameter and / or number of micron-level channels in the target configuration must meet certain criteria. Based on these requirements, the main body of the configuration is divided into several parallel solid cylinders, so that each solid cylinder encloses micron-level channels within the main body, forming channels with the desired diameter and number.

[0049] In a specific embodiment of the present invention, a plurality of parallel solid cylinders are arranged in a matrix. Furthermore, the distance between the axes of adjacent solid cylinders arranged laterally is the same as the distance between the axes of adjacent solid cylinders arranged longitudinally.

[0050] In a specific embodiment of the present invention, the particle size of the metal powder is 10–40 μm, for example, it can be a range of 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, or any combination thereof. In actual operation, the metal powder is subjected to conventional drying treatment before additive manufacturing.

[0051] In a specific embodiment of the present invention, the particle size of the metal powder does not exceed the diameter of the preset micron-level flow channel, thereby ensuring the powder cleaning operation of the formed component.

[0052] In specific embodiments of the present invention, the type of metal powder is not limited, and any metal material powder that can be used for additive manufacturing is acceptable, such as, but not limited to, any one of stainless steel powder, aluminum alloy, titanium alloy, nickel-based high-temperature alloy, and refractory alloy.

[0053] In a specific embodiment of the present invention, a selective laser melting device with a forming accuracy of <100μm is used in the selective laser melting process. This method does not have specific requirements regarding the model of the selective laser melting device, as long as its forming accuracy meets the above-mentioned conditions.

[0054] In a specific embodiment of the present invention, in selective laser melting, the powder layer thickness is ≤30μm, for example, it can be 30μm, 25μm, 25μm, 20μm, 15μm, 10μm, etc. There is no specific limit to the lower limit of the powder layer thickness, which can reach the limit allowed by the equipment; the spot diameter is ≤100μm, for example, it can be 100μm, 90μm, 80μm, 70μm, 60μm, 50μm, etc. There is no specific limit to the lower limit of the spot diameter, which can reach the limit allowed by the equipment.

[0055] The method of this invention provides a micron-level flow channel configuration design approach, without imposing specific limitations on the metal materials used to form the micron-level flow channel configuration or the specific SLM process. Under the micron-level flow channel configuration design approach of this invention, the type of metal material is selected according to application requirements. Given a determined type of metal material, the conventional control schemes for laser power, scanning speed, scanning spacing, etc., in the SLM process are still within the scope of protection of this invention.

[0056] In specific embodiments of the present invention, the metal powder includes nickel-based high-temperature alloy powder, such as, but not limited to, Inconel 718 powder.

[0057] In a specific embodiment of the present invention, in selective laser melting, the powder layer thickness is 20–30 μm; the spot diameter is 80–100 μm. Further, in selective laser melting, the laser power is 180–250 W, the scanning speed is 700–1000 mm / s, and the scanning interval is 100–110 μm.

[0058] The laser power includes, but is not limited to, a range of 180W, 200W, 210W, 230W, 250W, or any combination thereof; the scanning speed includes, but is not limited to, a range of 700mm / s, 800mm / s, 900mm / s, 1000mm / s, or any combination thereof; and the scanning spacing includes, but is not limited to, a range of 100μm, 102μm, 105μm, 108μm, 110μm, or any combination thereof.

[0059] The second aspect of the present invention provides the application of the additive manufacturing method of the micron-level flow channel of the first aspect of the present invention in the preparation of a sweating cooling unit.

[0060] Specifically, the main configuration can be disassembled according to the specific requirements of the application area of ​​the sweating cooling unit for the diameter and number of micron-level flow channels, so as to obtain a sweating cooling unit with micron-level flow channels that meet the requirements.

[0061] It is understood that the sweating cooling unit is only one target configuration that can be achieved by the additive manufacturing method of the micron-level flow channel of the present invention. Other structures that require the setting of micron-level flow channels in the main body of the configuration can also be obtained according to the additive manufacturing method of the present invention, and will not be described in detail here.

[0062] The following embodiments use a cube as the main body of the configuration for illustration. However, it is understood that the cube as the main body of the configuration is only for illustration. The structure of the main body of the configuration is not limited to this and can be adjusted and selected according to the three-dimensional graphic required by the target configuration.

[0063] Example 1

[0064] This embodiment provides an additive manufacturing method for micron-level flow channels, including the following steps:

[0065] (1) The main structure of the configuration is modeled using UG software. The main structure is divided into several parallel solid cylinders arranged in a matrix. The radius r of the solid cylinder is 1.5mm. The distance d0 between the axes of adjacent solid cylinders in the horizontal direction and adjacent solid cylinders in the vertical direction is 2.18mm (refer to the method of division). Figure 1 In (a) to (c)), after modeling, export the STL format file; import the STL format file into Materialise Magics software for slicing, and export it as an SLM format file.

[0066] (2) The Inconel 718 alloy powder obtained by vacuum induction gas atomization was screened into a particle size range of 10-40μm, dried at 75℃ for 6h and then added to the selective laser melting equipment SLM Solutions SLM125. The selective laser melting forming process parameters were set as follows: powder layer thickness 30μm, spot diameter 80μm, laser power 210W, scanning speed 800mm / s, and scanning spacing 110μm. The SLM format file was imported into the above-mentioned selective laser melting equipment for additive manufacturing to obtain the target configuration with micron-level flow channels.

[0067] Example 2

[0068] This embodiment refers to the additive manufacturing method of the micron-level flow channel in Embodiment 1, the only difference being that in step (1), the radius r of the solid cylinder and the spacing d0 between the axes of each adjacent solid cylinder are different.

[0069] In step (1) of this embodiment, the radius r of the solid cylinder is 1 mm, and the distance d0 between the axes of each adjacent solid cylinder is set to 1.45 mm.

[0070] Example 3

[0071] This embodiment refers to the additive manufacturing method of the micron-level flow channel in Embodiment 1, the only difference being that in step (1), the radius r of the solid cylinder and the spacing d0 between the axes of each adjacent solid cylinder are different.

[0072] In step (1) of this embodiment, the radius r of the solid cylinder is 0.5 mm, and the distance d0 between the axes of each adjacent solid cylinder is set to 0.73 mm.

[0073] Example 4

[0074] This embodiment refers to the additive manufacturing method of the micron-level flow channel in Embodiment 1, the only difference being that in step (1), the radius r of the solid cylinder and the spacing d0 between the axes of each adjacent solid cylinder are different.

[0075] In step (1) of this embodiment, the radius r of the solid cylinder is 0.25 mm, and the distance d0 between the axes of each adjacent solid cylinder is 0.39 mm.

[0076] Comparative Example 1

[0077] Comparative Example 1 refers to the additive manufacturing method of the micron-level flow channel in Example 1, the difference being that step (1) is different.

[0078] The steps (1) of Comparative Example 1 include: modeling the main structure of the configuration using UG software, then drilling holes directly, setting the hole diameter to 80μm, arranging the holes in a matrix, and the rows and columns formed by the holes intersecting at right angles, with the center distance between adjacent holes being 3mm, exporting the STL format file after modeling, and importing the STL format file into Materialise Magics software for slicing.

[0079] Comparative Example 2

[0080] Comparative Example 2 refers to the additive manufacturing method of the micron-level flow channel in Example 1, the difference being that step (1) is different.

[0081] The steps (1) of Comparative Example 2 include: modeling the main structure of the configuration using UG software, then drilling holes directly, setting the hole diameter to 50μm, arranging the holes in a matrix, and having the rows and columns formed by the holes intersect at right angles, with the center distance between adjacent holes being 2mm, exporting the STL format file after modeling, and importing the STL format file into Materialise Magics software for slicing.

[0082] Comparative Example 3

[0083] The additive manufacturing method of the micron-scale flow channel in Comparative Example 3 is different from that in Example 1, step (1) is different.

[0084] The steps (1) of Comparative Example 3 include: modeling the main structure of the configuration using UG software, then drilling holes directly, setting the hole diameter to 30μm, arranging the holes in a matrix, and the rows and columns formed by the holes intersecting at right angles, with the center distance between adjacent holes being 1mm. After modeling, exporting the STL format file and importing the STL format file into Materialise Magics software for slicing.

[0085] Comparative Example 4

[0086] The additive manufacturing method of the micron-scale flow channel in Comparative Example 4 is different from that in Example 1, except that step (1) is different.

[0087] The steps (1) of Comparative Example 4 include: modeling the main structure of the configuration using UG software, then drilling holes directly, setting the hole diameter to 50μm, arranging the holes in a matrix, and ensuring that the rows and columns formed by the holes intersect at right angles, with the center distance between adjacent holes being 0.5mm. After modeling, exporting the STL format file and importing the STL format file into Materialise Magics software for slicing.

[0088] Experimental Example

[0089] For the target configuration samples with micron-level flow channels obtained in different embodiments and comparative examples, wire electrical discharge machining was performed to obtain the side profile of the micron-level flow channels. The samples were sanded until the widest part of the micron-level flow channels was exposed, polished, and observed using an optical microscope. The average diameter of the micron-level flow channels formed in each embodiment and comparative example (referred to as the test diameter) was calculated using ImageJ software. The test results are shown in Table 1. Figure 2 and Figure 3 The images shown are metallographic images of the micron-scale flow channel configurations of Embodiment 1 and Comparative Example 1 of the present invention, respectively.

[0090] Table 1. State of the formed micron-scale flow channels in different embodiments and comparative examples.

[0091]

[0092] Water flow experiments were conducted on the micron-level flow channel configuration of this invention, showing that the pressure was average and the flow rate was stable in each micron-level flow channel. The test results indicate that the additive manufacturing method for the micron-level flow channels of this invention, compared to the comparative method, can significantly improve the forming stability of ten-micron-level flow channels, ensuring the practicality of the ten-micron-level flow channels in sweating and cooling functions. This invention's method successfully achieves controllable fabrication of ten-micron-level flow channels without changing the selective laser melting equipment conditions and forming parameters, demonstrating broad application prospects and research value.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An additive manufacturing method for micron-scale flow channels, characterized in that, Includes the following steps: (a) Based on the distribution of micron-level flow channels in the target configuration, the main body of the configuration is divided into several parallel solid cylinders to obtain the STL model and slice it to obtain the slice file; (b) Based on the sliced ​​file, the metal powder is additively manufactured using a selective laser melting process to obtain a target configuration with micron-level flow channels; In step (a), adjacent solid cylinders are tangent or intersecting, and the pores formed by every 4 solid cylinders correspond to micron-level flow channels. The radius r of the solid cylinder is 0.25 to 1.5 mm; the radius r of each solid cylinder is the same. In step (a), the distance d0 between the axes of the nearest solid cylinders satisfies r < d0 ≤ 2r; In the target configuration with micrometer-scale flow channels obtained in step (b), the theoretical diameter of the micrometer-scale flow channels is: d0-2r; In the target configuration with micron-level flow channels obtained in step (b), the diameter of the micron-level flow channels is 30 to 1240 μm.

2. The additive manufacturing method for micron-scale flow channels according to claim 1, characterized in that, The preset distribution of micron-level flow channels includes the diameter of the micron-level flow channels and the number of micron-level flow channels.

3. The additive manufacturing method for micron-scale flow channels according to claim 1, characterized in that, The plurality of parallel solid cylinders are arranged in a matrix.

4. The additive manufacturing method for micron-scale flow channels according to claim 3, characterized in that, The distance between the axes of adjacent solid cylinders arranged horizontally is the same as the distance between the axes of adjacent solid cylinders arranged vertically.

5. The additive manufacturing method for micron-scale flow channels according to claim 1, characterized in that, The particle size of the metal powder is 10–40 μm.

6. The additive manufacturing method for micron-scale flow channels according to claim 1, characterized in that, The selected area laser melting process has at least one of the following characteristics: (1) Selective laser melting equipment with forming accuracy <100μm is used; (2) The thickness of the powder layer is ≤30μm; (3) The diameter of the light spot is ≤100μm.

7. The additive manufacturing method for micron-scale flow channels according to claim 1, characterized in that, The metal powder includes nickel-based high-temperature alloy powder.

8. The additive manufacturing method for micron-scale flow channels according to claim 7, characterized in that, In the selected area laser melting, the laser power is 180-250W, the scanning speed is 700-1000mm / s, and the scanning interval is 100-110μm.

9. The application of the additive manufacturing method of the micron-scale flow channel according to any one of claims 1 to 8 in the preparation of a sweating cooling unit.

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