A gamma-prime phase strengthened cobalt-based superalloy for lpbf processes and methods of making the same

Abstract

The present application relates to the technical field of metal additive manufacturing, and provides a gamma prime phase strengthened cobalt-based high-temperature alloy for an LPBF process and a preparation method thereof.The gamma prime phase strengthened cobalt-based high-temperature alloy for the LPBF process comprises the following elements: Ni: 27-32%; Ta: 11%-13%; Al: 4-6%; V: 4-5%; Ti: 1-2%; and the balance is Co.The preparation method melts and prepares alloy element materials into cobalt-based alloy spherical powder, places the obtained cobalt-based alloy spherical powder in a laser powder bed fusion printing device, and prepares the cobalt-based alloy spherical powder into a workpiece with a set shape, forms a unique net-shaped gamma prime precipitated phase, breaks the traditional square block L12 morphology structure, and the structure has excellent room temperature and high-temperature mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of metal additive manufacturing technology, and particularly relates to a γ' phase strengthened cobalt-based superalloy for laser powder bed fusion (LPBF) process and its preparation method. Background Technology

[0002] High-temperature alloys are widely used in critical hot-end components in aerospace and gas turbines due to their excellent high-temperature strength, oxidation resistance, and creep resistance. Currently, high-temperature alloys with practical applications can be classified into nickel-based and cobalt-based high-temperature alloys according to their matrix elements, and into solid solution-strengthened and precipitation-strengthened alloys according to their strengthening type. Typical γ' phase (L12 phase) precipitation-strengthened high-temperature alloys typically use traditional processes such as directional solidification to obtain columnar and single-crystal structures, and then obtain a high volume fraction of γ' precipitates through aging heat treatment to ensure the high-temperature alloy meets operating requirements. The γ' phase morphology of these traditionally cast materials is usually close-packed cubic. Breaking this morphological pattern could potentially improve mechanical properties. However, high volume fraction γ' phase precipitation-strengthened high-temperature alloys often exhibit strong non-weldability, frequently resulting in numerous cracks and defects in additive manufacturing processes, making them difficult to form and posing a significant challenge to process optimization. The emergence of metal additive manufacturing technology has brought about a technological revolution in response to the high cost of traditional processes. Among numerous metal additive manufacturing technologies, laser powder bed fusion (LPBF) is the most widely used and extensively researched. It utilizes a focused laser beam to selectively fuse metal powder particles layer by layer. This technology boasts extremely high forming temperatures, enabling the metal powder to fully melt during the manufacturing process, thereby producing high-density parts. LPBF offers significant advantages such as high material utilization, stable manufacturing process, high machining accuracy, and fewer post-processing steps. In the LPBF process, the temperature gradient of the molten pool is opposite to the material's building direction, similar to a directional solidification process, ultimately resulting in a strongly textured columnar crystal structure.

[0003] High-temperature alloy heat treatment typically involves two steps: solution heat treatment and aging heat treatment. The former eliminates elemental segregation within the material, while the latter promotes the precipitation of the γ' phase, resulting in superior high-temperature mechanical properties. During LPBF (Limited-Breakage Burning), the complex thermal history leads to the formation of high-density dislocations, particularly in high-temperature alloys where high-density dislocation cell structures are commonly observed. This high-density dislocation structure causes recrystallization during solution heat treatment, resulting in the loss of the natural strong texture and columnar crystal structure, leading to relatively poor mechanical properties.

[0004] It is evident that in existing technologies, the traditional close-packed blocky L12 precipitate morphology restricts performance optimization. Many L12-strengthened superalloys typically exhibit numerous cracks and porosity defects during LPBF (Limited Part Forming) processes, lacking effective process control strategies. Superalloys prepared by LPBF technology possess a high-density dislocation structure, which easily induces recrystallization during solution-aging heat treatment, causing the printed samples to lose their columnar crystal and strong texture advantages. Summary of the Invention

[0005] The purpose of this invention is to overcome at least one of the shortcomings of the prior art and to provide a γ' phase-strengthened cobalt-based superalloy for laser powder bed melting (LPBF) process and its preparation method, which has excellent mechanical properties.

[0006] The technical solution of the present invention is: a γ' phase strengthened cobalt-based superalloy for LPBF process, comprising the following elements (each element is composed of the following by mass percentage): Ni: 27-32%; Ta: 11%-13%; Al: 4-6%; V: 4-5%; Ti: 1-2%; balance Co.

[0007] Specifically, it includes the following elements: Ni: 28.4%–30.6%; Ta: 11.2%–12.4%; Al: 4.2%–5.8%; V: 4.1%–4.6%; Ti: 1.2%–1.8%; with the balance being Co.

[0008] Specifically, the alloy composition by mass percentage is: Ni: 29.4%; Ta: 11.82%; Al: 4.51%; V: 4.21%; Ti: 1.63%; with the balance being Co.

[0009] This invention also provides a method for preparing a γ' phase strengthened cobalt-based superalloy, which includes the following steps:

[0010] Raw material preparation steps: Weigh the alloying elements according to the following mass percentages: Ni: 27-32%; Ta: 11%-13%; Al: 4-6%; V: 4-5%; Ti: 1-2%; balance Co;

[0011] Powder preparation step: The alloying element materials obtained in the raw material preparation step are smelted and prepared into cobalt-based alloy spherical powder.

[0012] Specifically, the powder preparation step includes the following steps:

[0013] The alloying element materials obtained in the raw material preparation step are smelted into an intermediate alloy, the intermediate alloy is then formulated into an alloy mixture, and the alloy mixture is prepared into cobalt-based alloy spherical powder by vacuum atomization.

[0014] Specifically, after obtaining the cobalt-based alloy spherical powder, cobalt-based alloy spherical powder with a particle size of 15-53 μm is screened to obtain the screened cobalt-based alloy spherical powder.

[0015] Specifically, the screened cobalt-based alloy spherical powder has the following particle size distribution: D10 = 26.682 μm; D50 = 41.983 μm; D90 = 65.844 μm.

[0016] Specifically, after obtaining the cobalt-based alloy spherical powder, the preparation method further includes a laser powder bed melting and forming step:

[0017] The obtained cobalt-based alloy spherical powder is placed in a laser powder bed fusion printing device to form a part of a set shape.

[0018] Specifically, in the laser powder bed fusion molding step, the parameters of the laser powder bed fusion printing device are: laser power 85-100W, scanning speed 700-900mm / s, scanning spacing 25-40μm, layer thickness 25-35μm, and scanning strategy is interlayer counterclockwise rotation 67°.

[0019] Specifically, after obtaining the part through a laser powder bed melting process, the part is subjected to aging heat treatment at 1000 degrees Celsius for 48 hours.

[0020] This invention provides a γ' phase-strengthened cobalt-based superalloy for LPBF process and its preparation method. Ta and Ti elements play a crucial role in controlling the morphology of the γ' phase based on a high-density dislocation structure. Ti, as one of the γ' phase forming elements, enhances the high-temperature mechanical properties of the alloy. Ta, which segregates in the γ' phase, is one of the strong stabilizing elements of the γ' phase, significantly increasing the melting temperature and stability of the γ' phase and enhancing its high-temperature mechanical properties. Both Ta and Ti have large atomic radii and low diffusion rates; therefore, during the LPBF process, they easily segregate in the high-energy dislocation cell wall structure, playing a key role in controlling the γ' phase precipitation morphology through subsequent aging heat treatment, which is beneficial for improving the material's mechanical properties. This invention provides a laser powder bed melting process for preparing γ' phase precipitation-strengthened cobalt-based superalloys and a subsequent heat treatment process. Furthermore, it utilizes the unique density dislocation cell structure advantage of the printed part to control the γ' phase precipitation mode, forming a unique network-like γ' precipitate phase, breaking the traditional blocky L12 morphology structure. This structure possesses excellent room-temperature and high-temperature mechanical properties. The process conditions designed in this invention can avoid solution heat treatment. While obtaining a uniform, high-density network γ' phase precipitate, it can maintain columnar crystal and strong texture morphology for a long time at temperatures up to 1000℃, indicating that the structure has excellent thermal stability and good application performance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1(a) is a metallographic image of the first material provided in the embodiment of the present invention;

[0023] Figure 1(b) is a metallographic image of the second material provided in an embodiment of the present invention;

[0024] Figure 1(c) is a metallographic image of the third material provided in the embodiment of the present invention;

[0025] Figure 1(d) is a metallographic image of the fourth material provided in the embodiment of the present invention;

[0026] Figure 2(a) is a grain orientation diagram of the printed deposited material in the printing xy plane in an embodiment of the present invention;

[0027] Figure 2(b) is a projection of the polar diagram of the (100) crystal plane onto the xy plane of the material in the printed deposition state in an embodiment of the present invention;

[0028] Figure 2(c) is a grain orientation diagram of the printed deposited material on the printed yz plane in an embodiment of the present invention;

[0029] Figure 2(d) is a grain orientation diagram of the heat-treated material in the printed xy plane in an embodiment of the present invention;

[0030] Figure 2(e) is a projection of the heat-treated material in the (100) crystal plane pole figure onto the xy plane in an embodiment of the present invention;

[0031] Figure 2(f) is a grain orientation diagram of the heat-treated material on the printed yz plane in an embodiment of the present invention.

[0032] Figure 3(a) is a scanning electron microscope image of the printed deposition state under a typical scattered electron mode in an embodiment of the present invention;

[0033] Figure 3(b) is a scanning electron microscope image of the printed deposition state under a typical scattered electron mode in an embodiment of the present invention;

[0034] Figure 3(c) is a scanning electron microscope image of a typical scattered electron mode in the heat-treated state in an embodiment of the present invention;

[0035] Figure 3(d) is a scanning electron microscope image of a typical scattered electron mode in the heat-treated state in an embodiment of the present invention;

[0036] Figure 4This is a schematic diagram of the formation mechanism of the γ / γ' dual-phase structure in an embodiment of the present invention;

[0037] Figure 5(a) is an engineering stress-strain curve of the heat-treated cobalt-based superalloy in the room temperature tensile test in the embodiment of the present invention.

[0038] Figure 5(b) is an engineering stress-strain curve of the γ' phase strengthened cobalt-based superalloy under high temperature compression at 800 degrees Celsius in the embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] The various specific technical features and embodiments described in the detailed embodiments can be combined in any suitable manner without contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the various specific technical features / embodiments in this invention will not be described separately.

[0041] This invention provides a γ' phase-strengthened cobalt-based superalloy for LPBF process, comprising the following elements (by mass percentage): Ni: 27-32%; Ta: 11%-13%; Al: 4-6%; V: 4-5%; Ti: 1-2%; with the balance being Co and unavoidable impurities. Ta and Ti play a crucial role in regulating the morphology of the γ' phase based on a high-density dislocation structure. Ti, as one of the γ' phase forming elements, enhances the high-temperature mechanical properties of the alloy. Ta segregates within the γ' phase and is one of the strong stabilizing elements of the γ' phase, significantly increasing the melting temperature and stability of the γ' phase and enhancing its high-temperature mechanical properties. Both Ta and Ti have large atomic radii and low diffusion rates; therefore, during the LPBF process, they easily segregate within the high-energy dislocation cell wall structure, playing a key role in controlling the γ' phase precipitation morphology through subsequent aging heat treatment, which is beneficial for improving the material's mechanical properties.

[0042] Specifically, the γ' phase strengthened cobalt-based superalloy comprises the following elements by mass percentage: Ni: 28–31%; Ta: 11%–12.8%; Al: 4.1–5.9%; V: 4.05–4.85%; Ti: 1.1–1.9%; with the balance being Co. In this embodiment, the γ' phase strengthened cobalt-based superalloy includes the following elements (by mass percentage): Ni: 28.4–30.6%; Ta: 11.2%–12.4%; Al: 4.2–5.8%; V: 4.1–4.6%; Ti: 1.2–1.8%; with the balance being Co.

[0043] Specifically, the alloy composition of the prepared part, by mass percentage, is as follows: Ni: 29.4%; Ta: 11.82%; Al: 4.51%; V: 4.21%; Ti: 1.63%; with the balance being Co.

[0044] This invention also provides a method for preparing a γ' phase strengthened cobalt-based superalloy, used to prepare the above-mentioned γ' phase strengthened cobalt-based superalloy for laser powder bed melting process, comprising the following steps:

[0045] Raw material preparation steps: Weigh each alloying element according to the following mass percentages: Ni: 27-32%; Ta: 11%-13%; Al: 4-6%; V: 4-5%; Ti: 1-2%; balance Co.

[0046] Powder preparation steps: The alloy element materials obtained in the raw material preparation step are smelted and made into cobalt-based alloy spherical powder. After the materials are mixed and smelted, an alloy mixture melt is obtained. It can be made into cobalt-based alloy spherical powder by means of vacuum atomization, etc. Under vacuum conditions, the alloy mixture melt is atomized into fine droplets by high-pressure gas flow. The droplets solidify into spherical particles during flight, thus obtaining cobalt-based alloy spherical powder. The produced cobalt-based alloy spherical powder particles have regular shapes, mostly spherical or near-spherical, and smooth surfaces.

[0047] Specifically, the powder preparation step includes the following steps:

[0048] The alloying elements obtained in the raw material preparation step are smelted into an intermediate alloy, which is then formulated into an alloy mixture. The alloy mixture is then atomized into cobalt-based alloy spherical powder using a vacuum atomization method (under a protective gas atmosphere). Under the protection of the protective gas, the molten metal formed by smelting the alloy mixture flows out through an insulated crucible and a guide nozzle. The molten metal is then atomized and broken into a large number of fine droplets by a high-pressure gas flow through a nozzle. The droplets solidify into spherical cobalt-based alloy powder particles during flight. In specific applications, the protective gas is an inert gas, such as argon, with a purity of not less than 99.999%.

[0049] Specifically, after obtaining the cobalt-based alloy spherical powder, cobalt-based alloy spherical powder with a particle size of 15-53 μm is screened to obtain the screened cobalt-based alloy spherical powder.

[0050] Specifically, the screened cobalt-based alloy spherical powder has the following particle size distribution: D10 = 26.682 μm; D50 = 41.983 μm; D90 = 65.844 μm.

[0051] Specifically, after obtaining the cobalt-based alloy spherical powder, the preparation method further includes a laser powder bed melting and forming step:

[0052] The obtained cobalt-based alloy spherical powder is placed in a laser powder bed fusion printing device to form a part of a set shape.

[0053] Specifically, in the laser powder bed fusion molding step, the parameters of the laser powder bed fusion printing device are: laser power 85-100W, scanning speed 700-900mm / s, scanning spacing 25-40μm, layer thickness 25-35μm, and scanning strategy of 67° counterclockwise rotation between layers. In specific applications, the laser power can be 90-100W, the scanning speed 780-850mm / s, the scanning spacing 28-32μm, and the layer thickness 28-32μm. In this embodiment, the laser power is 95W, the scanning speed is 800mm / s, the scanning spacing is 30μm, and the layer thickness is 30μm.

[0054] Specifically, after obtaining the part through the laser powder bed melting molding step, the part is directly subjected to aging heat treatment at a set temperature (950 to 100 degrees Celsius) in the furnace for a set duration (36 to 60 hours).

[0055] In this embodiment, after obtaining the part through the laser powder bed melting molding step, the part is directly placed in a muffle furnace and subjected to aging heat treatment at 1000 degrees Celsius for 48 hours.

[0056] In this embodiment, after obtaining the cobalt-based alloy spherical powder, the product with a particle size of 15-53 μm was screened using a standard sieve to obtain a cobalt-based high-temperature alloy material for laser powder bed melting process. In this embodiment, ICP composition analysis results show that the alloy composition, by mass percentage, is: Ni: 29.40%; Ta: 11.82%; Al: 4.51%; V: 4.21%; Ti: 1.63%; with the balance being Co. Laser particle size analysis shows that the alloy's particle size distribution is D10 = 26.682 μm; D50 = 41.983 μm; D90 = 65.844 μm.

[0057] Material preparation was performed using an EasyAdd 3D EP-M150 laser powder bed fusion printer. After experimental optimization, the process window was determined to be: laser power 95W, scanning speed 800mm / s, scanning spacing 30μm, layer thickness 30μm, and scanning strategy of 67° counterclockwise rotation between layers. To optimize the airflow environment within the printing chamber, laser scanning angles between 70° and 290° were eliminated. The printing environment was argon gas, with the oxygen content controlled below 200ppm. This invention employs a special low-power, low-scanning-spacing, high-scanning-speed printing process, successfully achieving defect-free printing.

[0058] Figures 1(a) to 1(d) The following are metallographic images of materials under similar bulk energy density conditions and different processes: Figure 1(a) corresponds to a power of 200W, a scanning speed of 800mm / s, and a scanning spacing of 60μm; Figure 1(b) corresponds to a power of 95W, a scanning speed of 800mm / s, and a scanning spacing of 30μm; Figure 1(c) corresponds to a power of 85W, a scanning speed of 400mm / s, and a scanning spacing of 50μm; Figure 1(d) corresponds to a power of 125W, a scanning speed of 400mm / s, and a scanning spacing of 80μm. It can be seen that, while maintaining a similar bulk energy density (around 135J / mm3), with a fixed layer thickness of 30μm, only low power, low scanning spacing, and high scanning speed can achieve relatively defect-free printing success. Other process parameters all show a large number of crack defects and porosity defects.

[0059] In this embodiment, the composition of the cobalt-based superalloy material, by mass percentage, is: Ni: 29.40%; Ta: 11.82%; Al: 4.51%; V: 4.21%; Ti: 1.63%; with the balance being Co. Laser particle size analysis shows that the alloy's particle size distribution is D10 = 26.682 μm; D50 = 41.983 μm; D90 = 65.844 μm. The parameters for laser powder bed fusion printing are: laser power 95W, scanning speed 800 mm / s, scanning spacing 30 μm, layer thickness 30 μm, and scanning strategy of 67° counterclockwise rotation between layers. After obtaining the part from the cobalt-based superalloy material through the laser powder bed fusion molding step, the part is directly placed in a muffle furnace and subjected to aging heat treatment at 1000 degrees Celsius for 48 hours.

[0060] Based on DSC testing, the dissolution temperature of the γ' phase was determined to be 1244.96 degrees Celsius, the solidus to be 1314.12 degrees Celsius, and the liquidus to be 1377.92 degrees Celsius. To avoid the recrystallization problem mentioned in the technical issues and defects, and to maintain the strong texture and columnar crystal morphology of the alloy, this invention does not employ the traditional two-step solution-aging heat treatment. Instead, it uses a muffle furnace for direct aging heat treatment at 1000 degrees Celsius for 48 hours, obtaining both the original printed deposition state and the directly aged heat-treated material.

[0061] EBSD tests were performed on the printed deposited state and the heat-treated state (direct aging heat treatment) of the materials, respectively. The results are shown in [Figure number missing]. Figures 2(a) to 2(f) It can be observed that the cobalt-based superalloy of the present invention has excellent thermal stability, maintaining a strong <001> texture and columnar crystal morphology in both the printed deposition state and the heat-treated state.

[0062] Figure 2(a)-2(c) shows the grain orientation diagram of the material in the printed deposition state in the printed xy plane, the projection of the (100) crystal plane pole figure on the xy plane and the grain orientation diagram of the yz plane; Figure 2(d)-2(f) shows the corresponding grain orientation diagram of the heat-treated state.

[0063] Figures 3(a) to 3(d) These are typical SEM images of the printed and heat-treated states under scattered electron mode. Figure 3 shows typical SEM images: printed state: (a) surface and (c) side view; heat-treated state: (b) surface and (d) side view. It can be observed that the printed state exhibits a high-density dislocation cell structure characteristic of the printing process, with high contrast in the dislocation cell walls, indicating that heavy metal elements (especially Ta) are enriched at the dislocation cells, and this elemental segregation regulates the γ' precipitation behavior. The heat-treated state shows a typical uniform γ / γ' dual-phase structure, with the γ phase having lower contrast and the γ' phase having higher contrast. Unlike the microstructure of high-temperature alloys prepared by traditional processes, the γ' phase in this invention exhibits precipitation and growth from the dislocation cell walls, with the morphology of the precipitated phase highly correlated with the morphology of the dislocation cells, ultimately leaving residual γ phase at the dislocation cell centers, forming a unique microstructure.

[0064] Figure 4 The diagram illustrates the special microstructure formation mechanism obtained in the embodiments of the present invention, namely, the special γ / γ' dual-phase structure formation mechanism in the present invention.

[0065] Figures 5(a) and 5(b) show the engineering stress-strain curves of the heat-treated cobalt-based superalloy under room temperature tensile and 800°C compressive conditions in the heat-treated state according to the embodiments of the present invention. The loading direction of the load is the y-direction of the printed preparation. The results show that the room temperature tensile yield strength of the heat-treated state is 623.00 MPa and the tensile strength is 1329.83 MPa; the compressive yield strength at 800°C is 819.12 MPa and the compressive strength is 1359.66 MPa. Under both test conditions, the heat-treated sample exhibits good plastic deformation ability, indicating that the cobalt-based superalloy with network γ' phase precipitation reinforcement based on additive manufacturing process of the present invention has good room temperature and high temperature mechanical properties.

[0066] As can be seen, in this embodiment of the invention, a method for preparing a γ' phase-strengthened cobalt-based superalloy for Laser Powder Bed Fusion (LPBF) and its preparation is provided. This invention offers a method for preparing and subsequently heat-treating a γ' phase precipitation-strengthened cobalt-based superalloy using the LPBF process. A defect-free printing process window was successfully designed, and the γ' phase precipitation mode was controlled by utilizing the unique density dislocation cell structure of the printed part, forming a unique network-like γ' precipitate phase. This breaks the traditional blocky L12 morphology structure, and the structure possesses excellent room-temperature and high-temperature mechanical properties. The process conditions designed in this invention avoid solution heat treatment, achieving a uniform, high-density network-like γ' phase precipitate phase while maintaining columnar crystal and strong texture morphology for extended periods at temperatures up to 1000℃. This indicates that the structure has excellent thermal stability and good application performance.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A γ' phase-strengthened cobalt-based superalloy for LPBF process, characterized in that, The composition, by mass percentage, includes the following elements: Ni: 27-32%; Ta: 11%-13%; Al: 4-6%; V: 4-5%; Ti: 1-2%; with the balance being Co. Among them, Ti is one of the γ' phase forming elements, Ta is segregated in the γ' phase, and Ta and Ti are segregated in the high-energy dislocation cell wall structure.

2. The γ' phase strengthened cobalt-based superalloy as described in claim 1, characterized in that, Includes the following elements: Ni: 28.4–30.6%; Ta: 11.2%~12.4%; Al: 4.2~5.8%; V: 4.1–4.6%; Ti: 1.2–1.8%; balance Co.

3. The γ' phase-strengthened cobalt-based superalloy as described in claim 1, characterized in that, The alloy composition by mass percentage is: Ni: 29.4%; Ta: 11.82%; Al: 4.51%; V: 4.21%; Ti: 1.63%; with the balance being Co.

4. A method for preparing a γ' phase-strengthened cobalt-based superalloy, characterized in that, The preparation of γ' phase-strengthened cobalt-based superalloys as described in any one of claims 1 to 3 includes the following steps: Raw material preparation steps: Weigh the materials of each element according to the following mass percentages: Ni: 27-32%; Ta: 11%-13%; Al: 4-6%; V: 4-5%; Ti: 1-2%; balance Co; Powder preparation step: Melt the alloying element material obtained in the raw material preparation step and prepare it into cobalt-based alloy spherical powder; The powder preparation step includes the following steps: The alloying elements obtained in the raw material preparation step are smelted into an intermediate alloy, which is then formulated into an alloy mixture. Under a protective gas atmosphere, the alloy mixture is atomized into cobalt-based alloy spherical powder using a vacuum atomization method. The molten metal is atomized and broken into a large number of fine droplets by a high-pressure gas flow through a nozzle. The droplets solidify into spherical cobalt-based alloy powder particles during flight. After obtaining the cobalt-based alloy spherical powder, the product with a particle size of 15-53 μm is screened using a standard sieve to obtain a cobalt-based high-temperature alloy material for laser powder bed melting process. After obtaining cobalt-based alloy spherical powder, the preparation method further includes a laser powder bed melting and forming step: The obtained cobalt-based alloy spherical powder is placed in a laser powder bed fusion printing device to form a part of a set shape; the part is then subjected to direct aging heat treatment at 1000 degrees Celsius for 48 hours in a muffle furnace.

5. The preparation method according to claim 4, characterized in that, The screened cobalt-based alloy spherical powder has the following particle size distribution: D10 = 26.682 μm; D50 = 41.983 μm; D90 = 65.844 μm.

6. The preparation method according to claim 4, characterized in that, In the laser powder bed fusion molding step, the parameters of the laser powder bed fusion printing device are: laser power 85-100 W, scanning speed 700-900 mm / s, scanning spacing 25-40 μm, layer thickness 25-35 μm, and scanning strategy is interlayer counterclockwise rotation 67°.

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