A nickel-based superalloy powder, a nickel-based superalloy part and its preparation method

Abstract

This invention relates to a nickel-based superalloy powder, nickel-based superalloy parts, and their preparation method, belonging to the field of nickel-based superalloy technology. The main technical solution adopted is as follows: a method for preparing nickel-based superalloy powder, comprising the following steps: preparing alloy powder from a nickel-based superalloy master alloy ingot; ball milling the alloy powder to obtain ball-milled alloy powder, wherein the particle size of the ball-milled alloy powder is 5-60 μm; sieving the ball-milled alloy powder to screen out alloy powders of various particle sizes; then, mixing the alloy powders of various particle sizes to reduce the gaps between the alloy powders, thereby obtaining nickel-based superalloy powder; the nickel-based superalloy powder prepared by this invention can be used to form uniform, dense parts with excellent mechanical properties after additive manufacturing.

Description

Technical Field

[0001] This invention relates to the field of nickel-based superalloy technology, and in particular to a nickel-based superalloy powder, a nickel-based superalloy part, and a method for preparing the same. Background Technology

[0002] Nickel-based superalloys possess excellent creep properties, fatigue strength, good corrosion resistance, and environmental stability, making them widely used in hot-end components of aerospace engines, particularly turbines. The mechanical properties of nickel-based superalloys are primarily improved through solid solution strengthening and γ′ precipitation strengthening. Because nickel-based superalloys can produce a large number of high-cubic-density γ′ precipitates after solid solution treatment and aging, they retain high fatigue strength and tensile strength even without forging, making them an irreplaceable key material in aero-engines.

[0003] With the increasing maturity of additive manufacturing technology and a significant decrease in cost, its application scope, depth, and scale are constantly expanding, and it has gradually been applied to the aerospace field. Among these applications, the use of additive manufacturing technology to prepare nickel-based superalloy parts is the most widespread. Compared with traditional cast and forged superalloys, superalloy parts prepared from nickel-based superalloy powder using additive manufacturing technology have advantages such as uniform microstructure, no macroscopic segregation, high yield strength, and good fatigue performance. It overcomes the segregation caused by conventional processes. Each particle of the pre-alloyed powder used is a "micro-ingot," and alloy segregation can only occur within a small range of powder particles. This improves the overall performance of the alloy, reduces machining operations, and increases alloy utilization. In particular, as the composition of superalloys becomes increasingly complex and the size of parts continues to increase, powder metallurgy superalloys show even greater advantages.

[0004] The size and uniformity of nickel-based superalloy powder directly determine the density and mechanical properties of the parts after additive manufacturing. Therefore, adjusting the size and uniformity of nickel-based superalloy powder is the key to superalloy additive manufacturing. Summary of the Invention

[0005] In view of this, the present invention provides a nickel-based superalloy powder, a nickel-based superalloy part and a method for preparing the same. The main purpose is to prepare a nickel-based superalloy powder with a small powder gap ratio so as to obtain a highly dense nickel-based superalloy part through additive manufacturing, thereby significantly improving its mechanical properties.

[0006] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0007] On one hand, embodiments of the present invention provide a method for preparing nickel-based superalloy powder, which includes the following steps:

[0008] Powder preparation steps: The nickel-based high-temperature alloy master alloy ingot is made into alloy powder;

[0009] Ball milling step: The alloy powder is ball milled to obtain ball-milled alloy powder; wherein the particle size of the ball-milled alloy powder is 5-60μm;

[0010] Screening and mixing steps: The alloy powder after ball milling is screened to select alloy powders of various particle sizes; then, the alloy powders of various particle sizes are mixed to reduce the gap between the alloy powders to obtain nickel-based high-temperature alloy powder.

[0011] Preferably, the alloy powders of various particle sizes include a first particle size alloy powder, a second particle size alloy powder, and a third particle size alloy powder; wherein, the particle size D1 of the first particle size alloy powder is: 10 < D1 ≤ 20 μm; the particle size D2 of the second particle size alloy powder is: 20 < D2 ≤ 40 μm; and the particle size D3 of the third particle size alloy powder is: 40 < D3 ≤ 50 μm; preferably, the first particle size alloy powder accounts for 30-35% of the mass of the nickel-based superalloy powder; the second particle size alloy powder accounts for 45-50% of the mass of the nickel-based superalloy powder; and the third particle size alloy powder accounts for 20-25% of the mass of the nickel-based superalloy powder.

[0012] Preferably, the particle size D1 of the first particle size alloy powder and the particle size D2 of the second particle size alloy powder are calculated by the following formula.

[0013]

[0014] The powder particle size calculated using the above formula can achieve the densest packing state, thereby improving the density and strength of the formed parts. The selection of a relatively large particle size for D3 grade is mainly to improve powder flowability and prevent powder agglomeration during the forming process, which would result in uneven powder distribution.

[0015] It should be noted that the formulas for calculating particle sizes D1 and D2 meet the requirements of the closest packing, while the D3 particle size provides flowability. Therefore, the theoretical packing model ratio obtained from the above formula is D1:D2:D3≈3:4:2 (that is, the particle size ratios of each level are approximately 30-35%, 45-50%, and 20-25%, respectively).

[0016] Preferably, the chemical composition of the nickel-based superalloy powder, by weight percentage, is as follows: C: 0.12-0.16 wt%, Cr: 8.00-9.50 wt%, Co: 9.00-10.50 wt%, Mo: 1.20-2.40 wt%, Al: 5.10-5.70 wt%, Ti: 2.00-2.90 wt%, W: 9.50-11.00 wt%, Nb: 0.80-1.20 wt%, rare earth elements: 0.015-0.03 wt%, grain boundary strengthening elements: 0.015-0.035 wt%, with the balance being Ni;

[0017] Preferably, the rare earth elements include Y and Ce; wherein, in the nickel-based superalloy powder, the mass fraction of Y is 0.005-0.01 wt%, and the mass fraction of Ce is 0.01-0.02 wt%.

[0018] Preferably, the grain boundary strengthening element includes element B; wherein, in the nickel-based superalloy powder, the mass fraction of element B is 0.015-0.035 wt%.

[0019] Preferably, the preparation steps of the nickel-based superalloy master alloy ingot are as follows:

[0020] According to the chemical composition, the first raw material is loaded into the furnace, and a vacuum is drawn. When the vacuum degree is less than 50 Pa, power is supplied to start melting until the first raw material is completely melted. Then, a first refining process is performed. After the first refining process, the power is cut off and the temperature is lowered to the molten metal film state. The second raw material is added to the alloy liquid through the side feeding bin, and a second refining process is performed. After the second refining process is completed, the temperature is raised to the casting temperature for casting to obtain a nickel-based high-temperature alloy master alloy ingot. Preferably, the order of loading the first raw material into the furnace is: cobalt, carbon, tungsten, molybdenum, niobium, chromium, and nickel. Preferably, the order of adding the second raw material is: aluminum, yttrium aluminum, nickel cerium, titanium, and nickel boron.

[0021] Preferably, the high-temperature refining treatment is performed at a temperature of 1500±30℃ for a time of 50±10 min; preferably, the low-temperature refining treatment is performed at a temperature of 1400±30℃ for a time of 50±10 min; preferably, the casting temperature is 1450±30℃. Preferably, in the powder preparation step: the nickel-based high-temperature alloy master alloy ingot is prepared into alloy powder using vacuum atomization; preferably, the particle size of the alloy powder is 7-68 μm; preferably, the morphology of the alloy powder is an irregular spherical shape with edges; preferably, the atomization pressure is 3.5±0.5 MPa, and the atomizing gas temperature is 100±10℃.

[0022] Preferably, in the ball milling step: the diameter of the grinding balls is 3-5 mm, the ball-to-material ratio is (15-17):1, the ball milling time is 2±0.2 h, and the rotation speed is 280±20 r / min; and / or a planetary vacuum ball mill is used to ball mill the alloy powder to prevent the alloy powder from oxidizing and introducing impurity gases during the exothermic process of ball milling; and / or the morphology of the alloy powder after ball milling is approximately spherical without sharp edges.

[0023] Preferably, in the screening and mixing steps: alloy powders of various particle sizes are screened and added to a mixing container, and the alloy powders of various particle sizes are mixed using a vacuum airflow mixing method. Simultaneously, the feeding sequence and amount of different particle size powders are controlled during mixing to achieve thorough mixing between powders of different grades. First, the third particle size alloy powder is added; second, the second particle size alloy powder is slowly added; finally, the first particle size alloy powder is slowly added, so that the powder is added and mixed simultaneously, ensuring thorough and uniform mixing. Here, the present invention strictly controls the particle size and the proportion of different particle sizes, while also controlling the feeding sequence and amount during mixing. Furthermore, existing technologies add a certain amount of binder to the powder to improve the bonding force and uniformity between powders. However, the addition of binder affects the density and mechanical properties of the molded parts. In contrast, the present invention does not require the addition of binder; through reasonable process parameter design, low-cost and high-performance parts can be obtained.

[0024] In another aspect, embodiments of the present invention provide a nickel-based superalloy powder, wherein the nickel-based superalloy powder is a mixture of alloy powders of various particle size grades: preferably, the nickel-based superalloy powder is a mixture of a first particle size grade alloy powder, a second particle size grade alloy powder, and a third particle size grade alloy powder; wherein the particle size D1 of the first particle size grade alloy powder is: 10μm < D1 ≤ 20μm; the particle size D2 of the second particle size grade alloy powder is: 20μm < D2 ≤ 40μm; and the particle size D3 of the third particle size grade alloy powder is: 40μm < D3≤50μm; wherein, the first particle size alloy powder accounts for 30-35% of the mass of the nickel-based superalloy powder; the second particle size alloy powder accounts for 45-50% of the mass of the nickel-based superalloy powder; the third particle size alloy powder accounts for 20-25% of the mass of the nickel-based superalloy powder; preferably, the morphology of the nickel-based superalloy powder is approximately spherical without sharp edges; preferably, the nickel-based superalloy powder is prepared by the preparation method of nickel-based superalloy powder described in any one of the above claims.

[0025] In another aspect, embodiments of the present invention provide a method for preparing a nickel-based high-temperature alloy part, wherein the preparation method includes the following steps:

[0026] Step 1): The above-mentioned nickel-based superalloy powder is shaped using additive manufacturing technology to obtain a nickel-based superalloy molded part;

[0027] Step 2): Heat treat the nickel-based high-temperature alloy molded part to obtain a nickel-based high-temperature alloy part.

[0028] Preferably, the additive manufacturing technology is selective laser melting technology; preferably, the process parameters of the selective laser melting technology are set as follows: laser power is 150-300W, laser scanning rate is 100-350mm / s, laser scanning spacing is 20-100μm, and powder layer thickness is 30-50μm.

[0029] Preferably, step 2) includes:

[0030] Solution treatment: The nickel-based superalloy molded parts are subjected to solution treatment, and after cooling, the nickel-based superalloy molded parts after solution treatment are obtained;

[0031] First aging treatment: The nickel-based superalloy molded part after solution treatment is subjected to a first aging treatment, and after cooling, the nickel-based superalloy molded part after the first aging treatment is obtained.

[0032] Second aging treatment: The nickel-based superalloy molded part after the second aging treatment is subjected to a second aging treatment, and after cooling, a nickel-based superalloy part is obtained.

[0033] Preferably, the solution treatment temperature is 1220±10℃, and the holding time at the solution treatment temperature is 2±0.5h;

[0034] Preferably, the temperature for the first aging treatment is 1050±10℃, and the holding time at the temperature for the first aging treatment is 4±0.5h;

[0035] Preferably, the temperature for the second aging treatment is 840±10℃, and the holding time at the temperature for the second aging treatment is 16±0.5h.

[0036] Preferably, in the steps of solution treatment, first aging treatment, and second aging treatment, the cooling method is: cooling to room temperature by purging with argon gas.

[0037] In another aspect, embodiments of the present invention provide a nickel-based superalloy part, characterized in that the nickel-based superalloy part is prepared by the preparation method of nickel-based superalloy parts described in any one of the above claims; preferably, the density of the nickel-based superalloy part is above 99.5%, and the average grain size is 30-35 μm. Preferably, the γ′ precipitate in the nickel-based superalloy part has a size of 0.6-0.7 μm, exhibits a near-cubic structure, and is uniformly dispersed in the matrix.

[0038] Compared with the prior art, the nickel-based superalloy powder, nickel-based superalloy parts and their preparation method of the present invention have at least the following beneficial effects:

[0039] The conventional process for preparing nickel-based superalloy powder is as follows: after casting the raw material into an alloy ingot, nickel-based superalloy powder is obtained by vacuum atomization, and then the obtained powder is directly 3D printed. The nickel-based superalloy powder obtained by this process is large in size, has poor sphericity, and uneven morphology, which directly affects the density and mechanical properties of the parts after molding.

[0040] Unlike existing technologies, this invention provides a method for preparing a nickel-based superalloy, comprising the following steps: preparing a nickel-based superalloy master alloy ingot into alloy powder; ball milling the alloy powder to obtain ball-milled alloy powder; sieving the ball-milled alloy powder to select alloy powders of multiple particle sizes; then, mixing the alloy powders of multiple particle sizes according to a specific ratio and feeding sequence to reduce the gaps between the alloy powders, thereby obtaining nickel-based superalloy powder. Here, this invention ball-mills and then sieves the alloy powder to select alloy powders of different particle sizes, resulting in alloy powders with good morphology. Multi-stage mixing of different particle sizes makes the particle size distribution more reasonable, reduces the gap ratio between powders, and refines the microstructure. Based on this powder, through the synergistic effect of various optimized process parameters, uniform, dense parts with excellent mechanical properties can be obtained after additive manufacturing.

[0041] Furthermore, the alloy powders of various particle sizes include a first particle size alloy powder, a second particle size alloy powder, and a third particle size alloy powder; wherein, the particle size D1 of the first particle size alloy powder is 10μm < D1 ≤ 20μm, the particle size D2 of the second particle size alloy powder is 20μm < D2 ≤ 40μm, and the particle size D3 of the third particle size alloy powder is 40μm < D3 ≤ 50μm; wherein, the first particle size alloy powder accounts for 30-35% of the mass of the nickel-based superalloy powder; the second particle size alloy powder accounts for 45-50% of the mass of the nickel-based superalloy powder; and the third particle size alloy powder accounts for 20-25% of the mass of the nickel-based superalloy powder. It should be noted that excessive amounts of fine or coarse powder will not achieve a good gradation. The mixing scheme provided by this invention involves a continuous distribution of powders from fine to large particle size, with each grade occupying an appropriate proportion. This continuous gradation fills the gaps in the coarse powder with medium powder, and vice versa. This step-by-step filling ensures the powder forms the densest possible packing, minimizing porosity and maximizing packing density, thus improving the density after molding. Here, the nickel-based alloy powder obtained by mixing the first, second, and third particle size alloy powders in the above proportions can be molded into nickel-based high-temperature alloy parts with a density of over 99.5%, an average grain size of 30 μm, and superior mechanical properties.

[0042] On another aspect, embodiments of the present invention provide a method for preparing nickel-based superalloy parts. Based on the characteristics of the nickel-based superalloy powder, the present invention adjusts the process parameters of selective melting to change the solidification rate of powder forming, reduce the tendency of the alloy to generate cracks during 3D printing, improve the bonding strength and density of the formed parts, solve the drawback of the alloy being prone to cracking during additive manufacturing, and thus greatly improve the mechanical properties of the formed parts.

[0043] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0044] Figure 1 These are images showing the particle size and morphology of alloy powder after it has undergone high-energy ball milling for different durations. Figure 1 Figure (a) shows the particle size and morphology of the alloy powder after high-energy ball milling for 1 hour. Figure 1 Figure (b) shows the particle size and morphology of the alloy powder after high-energy ball milling for 2 hours.

[0045] Figure 2Images show the microstructures of the nickel-based superalloy parts prepared in Example 1 and Comparative Example 1, respectively. Figure 2 Figure (a) in the figure is a microstructure image of the nickel-based superalloy part (corresponding to ratio 1) of Example 1; Figure 2 Figure (b) in the figure shows the microstructure of the nickel-based superalloy part of Comparative Example 1 (corresponding to ball milling for 2 hours).

[0046] Figure 3 The fracture morphology and crack distribution of nickel-based superalloy specimens prepared in Example 1 and Comparative Example 1, respectively, after tensile testing. Figure 3 Figure (a) shows the fracture morphology and crack distribution of the nickel-based superalloy sample (corresponding to ratio 1) prepared in Example 1 after tensile testing; Figure 3 Figure (b) shows the fracture morphology and crack distribution of the nickel-based superalloy sample prepared in Comparative Example 1 (corresponding to ball milling for 2 hours) after stretching.

[0047] Figure 4 Images showing the size and morphology of precipitated phases in nickel-based superalloy samples prepared in Example 1 and Comparative Example 1 after heat treatment; wherein... Figure 4 Figure (a) shows the size and morphology of the precipitated phases in the nickel-based superalloy sample (corresponding to ratio 1) prepared in Example 1 after heat treatment; Figure 4 Figure (b) shows the size and morphology of the precipitated phases after heat treatment of the nickel-based superalloy sample prepared in Comparative Example 1 (corresponding to ball milling for 2 hours). Detailed Implementation

[0048] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0049] This invention provides a nickel-based superalloy powder, nickel-based superalloy parts, and a method for their preparation. The inventive concept is as follows: by sieving the ball-milled alloy powder, powders of different particle sizes are obtained. The powders of different particle sizes are then rationally proportioned and mixed to make the particle size distribution more reasonable, reduce the gap ratio between powders, and improve the bonding force and density of the parts after molding. This solves the problem that the alloy is prone to cracking during additive manufacturing, thereby greatly improving the mechanical properties of the molded parts.

[0050] Furthermore, the raw materials are smelted into alloy ingots, and then nickel-based high-temperature alloy powder is obtained by reasonably setting the atomization parameters of the vacuum atomization method. The obtained alloy powder is then subjected to high-energy ball milling, with appropriate grinding ball diameter and ball-to-material ratio selected, and the ball milling time adjusted to make the nickel-based high-temperature alloy powder finer and more uniform. After that, the powder is sieved to obtain powders of different particle sizes, which are then mixed and the mixing ratio is adjusted to eliminate cracks generated during molding, thereby greatly improving the density and mechanical properties of the molded parts.

[0051] The technical solution of the present invention is as follows:

[0052] On one hand, embodiments of the present invention provide a method for preparing nickel-based high-temperature alloy powder, which mainly includes the following steps:

[0053] Preparation steps of nickel-based superalloy master alloy ingot: In this step, the master alloy ingot is smelted according to the chemical composition of the alloy.

[0054] The chemical composition of the nickel-based superalloy master alloy ingot, by weight percentage, is as follows:

[0055] C: 0.12-0.16wt%, Cr: 8.00-9.50wt%, Co: 9.00-10.50wt%, Mo: 1.20-2.40wt%, Al: 5.10-5.70wt%, Ti: 2.00-2.90wt%, W: 9.50-11.00wt%, Nb: 0.80-1.20wt%, rare earth elements: 0.015-0.03wt%, grain boundary strengthening elements: 0.015-0.035wt%, balance Ni.

[0056] Preferably, the rare earth elements include Y and Ce; wherein, in the nickel-based superalloy powder, the mass fraction of Y is 0.005-0.01 wt%, and the mass fraction of Ce is 0.01-0.02 wt%.

[0057] Preferably, the grain boundary strengthening element includes element B; wherein, in the nickel-based superalloy powder, the mass fraction of element B is 0.015-0.035 wt%.

[0058] The alloy incorporates small amounts of Y, Ce, and B. Y and Ce are rare earth elements, which are added to remove impurities such as oxygen and improve the purity of the alloy. B is a grain boundary strengthening element that can improve the stability of grain boundaries and enhance mechanical properties.

[0059] The raw materials must be free of gas adsorption and inclusions. The prepared main materials are loaded into the furnace in the following order: cobalt, carbon, tungsten, molybdenum, niobium, chromium, and nickel. The alloy minors are added to the molten steel through the side feeding hopper. After the first refining is completed, the power is turned off and the temperature is lowered until the molten metal reaches a solidified film state before adding the alloy minors. Then, a second refining is carried out, with the following order of addition: aluminum, yttrium aluminum, nickel cerium, titanium, and nickel boron.

[0060] After the furnace charge is loaded, the furnace door is closed and a vacuum is drawn. When the vacuum level is less than 50 Pa, power is supplied to begin melting until all the furnace charge is melted. Then, the first refining process is carried out at a refining temperature of 1500±30℃. After the first refining is completed, the temperature is lowered for a second low-temperature refining process at a refining temperature of 1400±30℃. After the refining is completed, the power is increased to raise the temperature. After the temperature reaches 1450±30℃, the casting is carried out.

[0061] Powder preparation step: The nickel-based high-temperature alloy master alloy ingot is made into alloy powder.

[0062] Nickel-based superalloy master alloys were prepared into alloy powders using a vacuum atomization method.

[0063] The atomization pressure and atomizing gas temperature both affect the particle size and morphology of the powder. Preferably, the atomization pressure is 3.5 MPa and the atomizing gas temperature is 100℃.

[0064] Ball milling step: The alloy powder is ball milled to obtain ball-milled alloy powder.

[0065] Fine and uniform alloy powder was obtained by adjusting the ball milling parameters. The alloy powder obtained by vacuum atomization was subjected to high-energy ball milling to further adjust the particle size and morphology of the alloy powder. The preferred grinding ball diameter was 3-5 mm, the ball-to-material ratio was 15-17:1, and the ball milling time was 1 h ± 0.2 h and 2 h ± 0.2 h, respectively.

[0066] Screening and mixing steps: The alloy powder after ball milling is screened to obtain alloy powder of different particle size grades. Then, the alloy powder of different particle size grades is mixed to make the resulting parts have higher bonding strength.

[0067] In this step, alloy powders of various particle sizes are selected and added to a mixing container all at once. A vacuum airflow mixing method is used to blend the powders of different particle sizes. The order and amount of powder added during mixing are controlled to ensure thorough mixing between the different particle sizes. First, the third particle size grade of alloy powder is added; then, the second particle size grade is slowly added; finally, the first particle size grade is slowly added, ensuring that the powders are mixed continuously and thoroughly. Using a vacuum airflow mixing method effectively prevents oxidation of the powders during mixing, improving purity and thus enhancing the mechanical properties of the parts.

[0068] Here, the alloy powder after atomization treatment becomes more uniform and without sharp edges after ball milling, which avoids stress concentration in the parts and reduces the tendency for crack initiation. The ball-milled powder is then sieved and mixed, which allows the powder to bond better, resulting in lower porosity, higher density and performance.

[0069] Specifically, the alloy powder after ball milling is sieved to separate alloy powder of first particle size, second particle size, and third particle size; then, the first particle size alloy powder, second particle size alloy powder, and third particle size alloy powder are mixed to obtain nickel-based high-temperature alloy powder.

[0070] The first particle size grade alloy powder has a particle size D1 of 10 μm < D1 ≤ 20 μm, and preferably, the first particle size grade alloy powder accounts for 30-35% of the mass of the nickel-based superalloy powder; the second particle size grade alloy powder has a particle size D2 of 20 μm < D2 ≤ 40 μm, and preferably, the second particle size grade alloy powder accounts for 45-50% of the mass of the nickel-based superalloy powder; the third particle size grade alloy powder has a particle size D3 of 40 μm < D3 ≤ 50 μm, and preferably, the third particle size grade alloy powder accounts for 20-25% of the mass of the nickel-based superalloy powder. It should be noted that if there is too much fine powder or coarse powder, a good gradation state cannot be achieved. The above-mentioned mixing scheme provided by the present invention has powders continuously distributed from small to large, with each grade occupying an appropriate proportion. It belongs to continuous gradation. The gaps of coarse powder are filled by medium powder, and the gaps of medium powder are filled by fine powder. This step-by-step filling makes the powder form the densest packing state, with the porosity reaching the minimum value and the packing density reaching the maximum value, thereby improving the density after molding.

[0071] In another aspect, embodiments of the present invention provide a nickel-based high-temperature alloy part, which mainly includes the following steps:

[0072] Step 1): The above-mentioned nickel-based superalloy powder is shaped using additive manufacturing technology to obtain nickel-based superalloy molded parts.

[0073] Here, selective laser melting (SLM) is selected as the additive manufacturing technology. Preferably, the process parameters of SLM are set as follows: laser power of 150-300W, laser scanning rate of 100-350mm / s, laser scanning spacing of 20-100μm, and powder layer thickness of 30-50μm. The laser power used here is more compatible with the powder particle size. At this power, most particle sizes of powder can be melted quickly, while the powder layer thickness is similar to the average particle size of the powder, reducing the heat-affected zone during scanning and improving density and adhesion.

[0074] Step 2): Heat treat the nickel-based high-temperature alloy molded part to obtain a nickel-based high-temperature alloy part.

[0075] The nickel-based superalloy molded parts were subjected to solution treatment, first aging treatment and second aging treatment in sequence. The solution treatment temperature was 1220±10℃, held for 2 hours and cooled to room temperature by argon gas. The first aging treatment temperature was 1050±10℃, held for 4 hours and cooled to room temperature by argon gas. The second aging treatment temperature was 840±10℃, held for 16 hours and cooled to room temperature by argon gas.

[0076] The present invention will be further illustrated below with specific embodiments and comparative examples:

[0077] Example 1

[0078] This embodiment prepares a nickel-based high-temperature alloy powder and a nickel-based high-temperature alloy part. The main preparation steps are as follows:

[0079] Preparation steps of nickel-based superalloy master alloy ingot: First, the crucible is tamped into shape using high-Al dry vibratory feed, followed by pure nickel sintering and furnace cleaning. Materials are weighed according to the batching list, using qualified platform scales, balances, and other equipment. The error between the actual and calculated amounts should not exceed ±2%. Since higher C content increases the tendency for crack initiation, the C content here is taken as the lower limit of the required composition. By weight percentage: C: 0.12wt%, Cr: 9.00wt%, Co: 10.00wt%, Mo: 2.00wt%, Al: 5.70wt%, Ti: 2.70wt%, W: 10.00wt%, Nb: 1.00wt%, Y: 0.005wt%, Ce: 0.01wt%, B: 0.02wt%, balance Ni. The raw materials must be free of gas adsorption and inclusions. The prepared main materials are loaded into the furnace in the following order: cobalt, carbon, tungsten, molybdenum, niobium, chromium, nickel. The alloy components are added to the molten steel through a side feeding hopper, and the order of addition is aluminum, yttrium aluminum, nickel cerium, titanium, nickel boron, etc.

[0080] After the main material is loaded into the furnace, the furnace door is closed and a vacuum is drawn. When the vacuum degree is less than 50Pa, power is supplied to start melting until all the furnace material is melted. Then, the first refining process is carried out at a refining temperature of 1500℃. After the first refining is completed, the power is cut off and the temperature is lowered to the solidified state of the molten metal. The alloy small material is added to the alloy liquid through the side feeding bin and then the second low-temperature refining is carried out at a refining temperature of 1400℃. After the refining is completed, the power is increased to raise the temperature. After the temperature reaches 1450℃, the casting is carried out.

[0081] Powder preparation steps: The smelted alloy ingot is subjected to vacuum atomization treatment. The atomization pressure and atomization gas temperature will affect the particle size and morphology of the powder. Within a certain range, the higher the atomization pressure, the smaller the powder will be. However, if the atomization pressure is too high, the sphericity of the powder will be poor. Therefore, in this embodiment, the atomization pressure is selected as 3.5 MPa and the atomization gas temperature is selected as 100℃.

[0082] In this embodiment, the particle size of the atomized alloy powder is 7-68 μm, and the alloy morphology is an irregular sphere with sharp edges.

[0083] Ball milling step: To further improve the particle size and spheroidization degree of the nickel-based superalloy powder, the powder obtained by vacuum atomization was subjected to high-energy ball milling. A planetary vacuum ball mill was used to ball mill the alloy powder to prevent oxidation and introduction of impurity gases during the exothermic ball milling process. Furthermore, a short ball milling time has little effect on the particle size of the alloy powder, while a long ball milling time can cause cold welding of the powder during the process, leading to larger powder size and reduced spheroidization. Therefore, the ball milling parameters in this embodiment are set as follows: planetary ball mill speed of 280 r / min, ball-to-powder ratio of 15:1, grinding ball diameter of 5 mm, and ball milling time of 2 h. The particle size and morphology of the alloy powder after 2 h of high-energy ball milling are described in [reference needed]. Figure 1 As shown in Figure (b), the particle size of the alloy powder after ball milling is 5-60 μm, and the morphology of the alloy powder is roughly a spherical shape without sharp edges.

[0084] Sieving and mixing steps: The ball-milled alloy powder is sieved to separate the first particle size class (greater than 10 μm and less than or equal to 20 μm), the second particle size class (greater than 20 μm and less than or equal to 40 μm), and the third particle size class (greater than 40 μm and less than or equal to 50 μm). The sieved powders are then mixed (using a vacuum airflow mixing method). During mixing, the order and amount of adding different particle size classes are controlled to ensure thorough mixing between the powders. First, the third particle size class alloy powder is added; second, the second particle size class alloy powder is added slowly; finally, the first particle size class alloy powder is added slowly, allowing the powder to mix continuously while being added, ensuring thorough and uniform mixing. The mixing ratios are shown in Table 1.

[0085] Table 1 Different proportions of alloy powder

[0086] Particle size / μm 1 ratio 2 ratio 3 ratio 4 ratio Greater than 10 and less than or equal to 20 30％ 80％ 10％ 10％ Greater than 20, less than or equal to 40 50％ 10％ 80％ 10％ Greater than 40 and less than or equal to 50 20％ 10％ 10％ 80％

[0087] According to Table 1, four types of nickel-based high-temperature alloy powders were prepared in this embodiment: the first type of nickel-based high-temperature alloy powder (corresponding to ratio 1), the second type of nickel-based high-temperature alloy powder (corresponding to ratio 2), the third type of nickel-based high-temperature alloy powder (corresponding to ratio 3), and the fourth type of nickel-based high-temperature alloy powder (corresponding to ratio 4).

[0088] Selective laser melting was performed on the four types of nickel-based superalloy powders to obtain four types of nickel-based superalloy parts. The laser power was 300W, the laser scanning rate was 200mm / s, the laser scanning spacing was 30μm, and the powder layer thickness was 50μm.

[0089] Four types of nickel-based superalloy parts were subjected to heat treatment. Specifically, the heat treatment was carried out in a vacuum heat treatment furnace. The solution treatment temperature was 1220℃±10℃, held for 2 hours, and then cooled to room temperature by argon gas. The first aging temperature was 1050℃±10℃, held for 4 hours, and then cooled to room temperature by argon gas. The second aging temperature was 840℃±10℃, held for 16 hours, and then cooled to room temperature by argon gas.

[0090] Density and mechanical properties of four nickel-based superalloy samples were tested. The sample with a ratio of 1 showed the best density, exceeding 99.5%, and an average grain size of 30 μm (see [reference]). Figure 2 The microstructure shown in Figure (a) is as follows; simultaneously, the size of the γ′ precipitate in the alloy after heat treatment is 0.6-0.7 μm, exhibiting an approximately cubic structure, and is uniformly dispersed throughout the matrix. Due to the small size of the precipitate, the precipitation strengthening effect is better (e.g., Figure 4 As shown in Figure (a), this makes its mechanical properties the highest, with a yield strength of 1200MPa and a tensile strength of 1346MPa at 800℃.

[0091] In addition, the yield strength of the nickel-based superalloy samples corresponding to proportions 2, 3, and 4 is between 1090-1124 MPa, and the tensile strength is between 1200-1230 MPa. These are all inferior to the performance of the nickel-based superalloy sample corresponding to proportion 1. This is because the proportions of proportions 2-4 are unreasonable, and their performance is actually inferior to the comparative proportion.

[0092] Example 2

[0093] This embodiment prepares a nickel-based high-temperature alloy powder and nickel-based high-temperature alloy parts. The difference from Example 1 is that the alloy powder composition in the sieving and mixing steps is as shown in Table 2. Other steps and parameters are the same as in Example 1.

[0094] After testing, the yield strength of the nickel-based superalloy prepared in this embodiment is 1185 MPa and the tensile strength is 1322 MPa.

[0095] Table 2 Different proportions of alloy powder

[0096] Particle size / μm Proportion Greater than 10 and less than or equal to 20 30％ Greater than 20, less than or equal to 40 45％ Greater than 40 and less than or equal to 50 25％

[0097] Example 3

[0098] This embodiment prepares a nickel-based high-temperature alloy powder and nickel-based high-temperature alloy parts. The difference from Example 1 is that the alloy powder composition in the sieving and mixing steps is as shown in Table 3. Other steps and parameters are the same as in Example 1.

[0099] After testing, the yield strength of the nickel-based superalloy prepared in this embodiment is 1179 MPa and the tensile strength is 1321 MPa.

[0100] Table 3 Different proportions of alloy powder

[0101] Particle size / μm Proportion Greater than 10 and less than or equal to 20 35％ Greater than 20, less than or equal to 40 45％ Greater than 40 and less than or equal to 50 20％

[0102] Comparative Example 1

[0103] Comparative Example 1 describes the preparation of a nickel-based superalloy powder and nickel-based superalloy parts, mainly including the following steps:

[0104] Preparation steps of nickel-based superalloy master alloy ingot: First, the crucible is tamped into shape using high-Al dry vibratory feed, followed by pure nickel sintering and furnace cleaning. Materials are weighed according to the batching list, using qualified platform scales, balances, and other equipment. The error between the actual and calculated amounts should not exceed ±2%. The weight percentages are: C: 0.12wt%, Cr: 9.00wt%, Co: 10.00wt%, Mo: 2.00wt%, Al: 5.70wt%, Ti: 2.70wt%, W: 10.00wt%, Nb: 1.00wt%, Y: 0.005wt%, Ce: 0.01wt%, B: 0.02wt%, with the balance being Ni. The raw materials must be free of gas adsorption and inclusions. The prepared main materials are loaded into the furnace in the following order: cobalt, carbon, tungsten, molybdenum, niobium, chromium, nickel. The alloy components are added to the molten steel through a side feeding hopper, and the order of addition is aluminum, yttrium aluminum, nickel cerium, titanium, nickel boron, etc.

[0105] After the furnace charge is loaded, the furnace door is closed and a vacuum is drawn. When the vacuum level is less than 50 Pa, power is supplied to begin melting until all the furnace charge is completely melted. Then, the first refining process is carried out at a refining temperature of 1500℃±30℃. After the first refining is completed, the power is cut off and the temperature is lowered to the solidified state of the molten metal. After adding small alloy materials to the molten metal through the side feeding bin, the second low-temperature refining is carried out at a refining temperature of 1400℃±30℃. After the refining is completed, the power is increased to raise the temperature. After the temperature reaches 1450℃±30℃, the casting is carried out.

[0106] Powder preparation steps: The smelted alloy ingot is subjected to vacuum atomization. Both atomization pressure and atomizing gas temperature affect the particle size and morphology of the powder. Within a certain range, higher atomization pressure results in smaller powder particles; however, excessive atomization pressure leads to poor powder sphericity. Therefore, in this embodiment, an atomization pressure of 3.5 MPa and an atomizing gas temperature of 100°C are selected. In this embodiment, the particle size of the atomized alloy powder is 7-68 μm, and the alloy morphology is an irregular spherical shape with sharp edges.

[0107] Ball milling step: To further improve the particle size and spheroidization degree of the nickel-based superalloy powder, the powder obtained by vacuum atomization was subjected to high-energy ball milling. A short ball milling time has little effect on the particle size of the alloy powder; however, if the ball milling time is too long, cold welding occurs during the milling process, leading to an increase in powder size and a decrease in spheroidization. Therefore, the ball milling parameters in this embodiment are set as follows: the planetary ball mill speed is 280 r / min, the ball-to-powder ratio is 15:1, the grinding ball diameter is 5 mm, and the ball milling times are 1 h and 2 h, respectively, yielding two types of nickel-based superalloy powder: nickel-based superalloy powder after 1 h of ball milling and nickel-based superalloy powder after 2 h of ball milling. The particle size and morphology of the alloy powder after 1 h of high-energy ball milling are described in [reference needed]. Figure 1 As shown in Figure (a); the particle size and morphology of the alloy powder after high-energy ball milling for 2 hours are shown in [reference]. Figure 1 As shown in Figure (b) of the document. According to... Figure 1 Figures (a) and (b) show that the ball milling time has a significant impact on the morphology and fineness of the powder.

[0108] Selective laser melting was performed on the two nickel-based superalloy powders to obtain two nickel-based superalloy molded parts; wherein the laser power was 300W, the laser scanning rate was 200mm / s, the laser scanning spacing was 30μm, and the powder layer thickness was 50μm.

[0109] Two types of nickel-based superalloy formed parts were heat-treated to obtain two types of nickel-based superalloy parts. The heat treatment was carried out in a vacuum heat treatment furnace. The solution treatment temperature was 1220℃±10℃, held for 2 hours, and then cooled to room temperature by argon gas. The first aging temperature was 1050℃±10℃, held for 4 hours, and then cooled to room temperature by argon gas. The second aging temperature was 840℃±10℃, held for 16 hours, and then cooled to room temperature by argon gas.

[0110] The performance of the two nickel-based superalloy samples obtained after heat treatment was tested. The results showed that at 800℃, the yield strengths of the first nickel-based superalloy sample (corresponding to ball milling for 1 hour) and the second nickel-based superalloy sample (corresponding to ball milling for 2 hours) were 1106 MPa and 1135 MPa, respectively, and the tensile strengths were 1227 MPa and 1260 MPa, respectively. It can be seen that the strength of the second nickel-based superalloy sample (corresponding to ball milling for 2 hours) is slightly higher than that of the first nickel-based superalloy sample (corresponding to ball milling for 1 hour), but neither is as good as the mechanical properties of the mixed sample obtained in the embodiment of the present invention.

[0111] Figure 2 Images show the microstructures of the nickel-based superalloy parts prepared in Example 1 and Comparative Example 1, respectively. Figure 2 Figure (a) in the figure is a microstructure image of the nickel-based superalloy part of Example 1 (corresponding to ratio 1) (average grain size is 30 μm); Figure 2 Figure (b) shows the microstructure of the nickel-based superalloy part of Comparative Example 1 (corresponding to ball milling for 2 hours) (average grain size is 50 μm). It can be seen that the nickel-based superalloy part prepared in Example 1 has a smaller average grain size and is more dense.

[0112] Figure 3 The fracture morphology and crack distribution of nickel-based superalloy specimens prepared in Example 1 and Comparative Example 1, respectively, after tensile testing. Figure 3 Figure (a) shows the fracture morphology and crack distribution of the nickel-based superalloy sample (corresponding to ratio 1) prepared in Example 1 after tensile testing; Figure 3 Figure (b) shows the fracture morphology and crack distribution of the nickel-based superalloy sample prepared in Comparative Example 1 (corresponding to ball milling for 2 hours) after tensile testing. It can be seen that compared with the nickel-based superalloy sample in Example 1 (corresponding to ratio 1), the cracks on the nickel-based superalloy sample prepared in Comparative Example 1 (corresponding to ball milling for 2 hours) are significantly wider and longer.

[0113] See Figure 4 As shown in (b), the precipitated phases of the nickel-based superalloy sample prepared in Comparative Example 1 (corresponding to ball milling for 2 hours) have a size between 1 and 1.5 μm, poor cubicity, and are distributed throughout the matrix.

[0114] Comparative Example 2

[0115] Comparative Example 2 prepared a nickel-based high-temperature alloy powder and nickel-based high-temperature alloy parts. The alloy after vacuum atomization was directly mixed without ball milling. The main steps included:

[0116] Preparation steps of nickel-based superalloy master alloy ingot: First, the crucible is tamped into shape using high-Al dry vibratory feed, followed by pure nickel sintering and furnace cleaning. Materials are weighed according to the batching list, using qualified platform scales, balances, and other equipment. The error between the actual and calculated amounts should not exceed ±2%. The weight percentages are: C: 0.12wt%, Cr: 9.00wt%, Co: 10.00wt%, Mo: 2.00wt%, Al: 5.70wt%, Ti: 2.70wt%, W: 10.00wt%, Nb: 1.00wt%, Y: 0.005wt%, Ce: 0.01wt%, B: 0.02wt%, with the balance being Ni. The raw materials must be free of gas adsorption and inclusions. The prepared main materials are loaded into the furnace in the following order: cobalt, carbon, tungsten, molybdenum, niobium, chromium, nickel. The alloy components are added to the molten steel through a side feeding hopper, and the order of addition is aluminum, yttrium aluminum, nickel cerium, titanium, nickel boron, etc.

[0117] After the main material is loaded into the furnace, the furnace door is closed and a vacuum is drawn. When the vacuum degree is less than 50Pa, power is supplied to start melting until all the furnace material is melted. Then, the first refining process is carried out at a refining temperature of 1500℃±30℃. After the first refining is completed, the power is cut off and the temperature is lowered to the solidified state of the molten metal. The alloy small material is added to the alloy liquid through the side feeding bin and then the second low-temperature refining is carried out at a refining temperature of 1400℃±30℃. After the refining is completed, the power is increased to raise the temperature. After the temperature reaches 1450℃±30℃, the casting is carried out.

[0118] Powder preparation steps: The smelted alloy ingot is subjected to vacuum atomization treatment. The atomization pressure and atomization gas temperature will affect the particle size and morphology of the powder. Within a certain range, the higher the atomization pressure, the smaller the powder will be. However, if the atomization pressure is too high, the sphericity of the powder will be poor. Therefore, in this embodiment, the atomization pressure is selected as 3.5 MPa and the atomization gas temperature is selected as 100℃.

[0119] In this embodiment, the particle size of the atomized alloy powder is 7-68 μm, and the alloy morphology is an irregular sphere with sharp edges.

[0120] Sieving and mixing steps: The powder obtained by vacuum atomization is sieved to select alloy powder of the first particle size (greater than 10 μm and less than or equal to 20 μm), alloy powder of the second particle size (greater than 20 μm and less than or equal to 40 μm), and alloy powder of the third particle size (greater than 40 μm and less than or equal to 50 μm). The sieved powders are then mixed (using a vacuum airflow mixing method) according to the mixing ratio 1 in Table 1.

[0121] Selective laser melting was performed on the two nickel-based superalloy powders to obtain two nickel-based superalloy molded parts; wherein the laser power was 300W, the laser scanning rate was 2mm / s, the laser scanning spacing was 30μm, and the powder layer thickness was 50μm.

[0122] The above-mentioned nickel-based superalloy formed parts were subjected to heat treatment to obtain nickel-based superalloy parts. The heat treatment was carried out in a vacuum heat treatment furnace. The solution treatment temperature was 1220℃±10℃, held for 2 hours, and then cooled to room temperature by argon gas. The first aging temperature was 1050℃±10℃, held for 4 hours, and then cooled to room temperature by argon gas. The second aging temperature was 840℃±10℃, held for 16 hours, and then cooled to room temperature by argon gas.

[0123] Performance tests were conducted on the heat-treated nickel-based superalloy samples. The results showed that the yield strength was 1161 MPa and the tensile strength was 1301 MPa at 800℃.

[0124] By comparing the above examples and comparative examples, it can be seen that "ball milling" and "sieving and mixing" of vacuum-atomized alloy powder have a synergistic effect on additive manufacturing technology, and the two work together to improve the mechanical properties of nickel-based superalloy parts. Furthermore, how to mix the powder (i.e., what particle size of alloy powder to select and in what proportion to mix) is also crucial for improving alloy performance; if the mixing is not reasonable, the improvement in the mechanical properties of the alloy will be minimal.

[0125] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for producing a nickel-based superalloy powder, characterized by, It comprises the following steps: The powder preparation step: the nickel-based superalloy master alloy ingot is made into alloy powder; The ball milling step: the alloy powder is subjected to ball milling treatment to obtain the ball-milled alloy powder; wherein the particle size of the ball-milled alloy powder is 5-60 μm; The screening and mixing step: the ball-milled alloy powder is subjected to screening treatment to screen out alloy powders of multiple particle size grades; then, the alloy powders of multiple particle size grades are mixed to reduce the gap between the alloy powders, thereby obtaining the nickel-based superalloy powder; The alloy powder comprises first, second and third particle size grade alloy powders; wherein, The particle size D1 of the first particle size grade alloy powder is 10 μm < D1 ≤ 20 μm; The particle size D2 of the second particle size grade alloy powder is 20 μm < D2 ≤ 40 μm; The particle size D3 of the third particle size grade alloy powder is 40 μm < D3 ≤ 50 μm; The mass percentage of the first particle size grade alloy powder in the nickel-based superalloy powder is 30-35%; the mass percentage of the second particle size grade alloy powder in the nickel-based superalloy powder is 45-50%; and the mass percentage of the third particle size grade alloy powder in the nickel-based superalloy powder is 20-25%.

2. The method of producing a nickel-based superalloy powder according to claim 1, characterized by, The particle size D1 of the first particle size grade alloy powder and the particle size D2 of the second particle size grade alloy powder satisfy the following relationship: 。 3. The method of producing a nickel-based superalloy powder according to claim 1, characterized by, The chemical composition of the nickel-based superalloy powder is as follows in terms of weight percentage: C: 0.12-0.16 wt%, Cr: 8.00-9.50 wt%, Co: 9.00-10.50 wt%, Mo: 1.20-2.40 wt%, Al: 5.10-5.70 wt%, Ti: 2.00-2.90 wt%, W: 9.50-11.00 wt%, Nb: 0.80-1.20 wt%, rare earth elements: 0.015-0.03 wt%, grain boundary strengthening elements: 0.015-0.035 wt%, and the balance being Ni.

4. The method of producing a nickel-based superalloy powder according to claim 3, characterized by, The rare earth elements include Y and Ce; wherein, the mass fraction of Y element in the nickel-based superalloy powder is 0.005-0.01 wt%, and the mass fraction of Ce element is 0.01-0.02 wt%.

5. The method of producing a nickel-based superalloy powder according to claim 3, characterized by, The grain boundary strengthening elements include B element; wherein, the mass fraction of B element in the nickel-based superalloy powder is 0.015-0.035 wt%.

6. The method of producing a nickel-based superalloy powder according to any one of claims 1 to 5, characterized in that, The preparation steps of the nickel-based superalloy master alloy ingot are as follows: According to the chemical composition, the first raw material is charged into the furnace, vacuum is drawn, and when the vacuum degree is less than 50 Pa, power is supplied to start melting until the first raw material is completely melted; then, the first refining treatment is performed; after the first refining treatment, the power is turned off to cool down to the metal liquid film state, the second raw material is added to the alloy liquid through the side charging bin, and then the second refining treatment is performed; after the second refining treatment, the temperature is raised to the pouring temperature for pouring, thereby obtaining the nickel-based superalloy master alloy ingot.

7. The method of producing a nickel-based superalloy powder according to claim 6, characterized in that, The charging sequence of the first raw material is: cobalt, carbon, tungsten, molybdenum, niobium, chromium and nickel.

8. The method of producing a nickel-based superalloy powder according to claim 6, characterized by, The adding sequence of the second raw material is: aluminum, aluminum yttrium, nickel cerium, titanium, nickel boron.

9. The method of producing a nickel-based superalloy powder according to claim 6, characterized by, The temperature of the first refining treatment is 1500±30℃, and the time of the first refining treatment is 50±10min. 10.The method of claim 6, wherein the nickel-based superalloy powder is prepared by the following steps: The temperature of the second refining treatment is 1400±30℃, and the time of the second refining treatment is 50±10min. 11.The method of claim 6, wherein the nickel-based superalloy powder is prepared by the following steps: The pouring temperature is 1450±30℃.

12. The method of producing a nickel-based superalloy powder according to any one of claims 1 to 5, characterized in that, In the powdering step: The vacuum gas atomization method is used to prepare the alloy powder from the nickel-based superalloy master alloy ingot.

13. The method of producing a nickel-based superalloy powder according to claim 12, characterized in that, In the powdering step:

14. The method of claim 12, wherein the nickel-base superalloy powder is produced by a process comprising: The particle size of the alloy powder is 7-68μm. ​ 15. The method for preparing nickel-based superalloy powder according to claim 12, characterized in that, In the powdering step:

16. The method of producing a nickel-based superalloy powder according to any one of claims 1 to 5, characterized in that, The atomization pressure is 3.5±0.5MPa, and the atomization gas temperature is 100±10℃. In the ball milling step: The diameter of the grinding ball is 3-5mm, the ball-to-powder ratio is (15-17):1, the ball milling time is 2±0.2h, and the rotation speed is 280±20r / min; and / or The planetary vacuum ball mill is used to perform the ball milling treatment on the alloy powder to prevent the alloy powder from being oxidized and introducing impurity gas during the ball milling heat release process; and / or 17. The method of producing a nickel-based superalloy powder according to any one of claims 1 to 5, characterized in that, The morphology of the alloy powder after the ball milling treatment is approximately spherical without edges and corners. In the screening and mixing step: The alloy powder of multiple particle size grades is added into a mixing container, and the vacuum airflow mixing method is used to mix the alloy powder of multiple particle size grades; 18. A nickel-based superalloy powder characterized in that, During the mixing, the third particle size grade alloy powder is added first, the second particle size grade alloy powder is then added gradually, and finally the first particle size grade alloy powder is added gradually while mixing the powder to fully mix the powder. The nickel-based superalloy powder is prepared by mixing multiple particle size grades of alloy powder: The nickel-based superalloy powder is prepared by mixing the first particle size grade alloy powder, the second particle size grade alloy powder, and the third particle size grade alloy powder; the particle size D1 of the first particle size grade alloy powder is 10μm<D1≤20μm; the particle size D2 of the second particle size grade alloy powder is 20μm<D2≤40μm, and the particle size D3 of the third particle size grade alloy powder is 40μm<D3≤50μm; 19. The nickel-based superalloy powder of claim 18, wherein, The mass percentage of the first particle size grade alloy powder in the nickel-based superalloy powder is 30-35%; the mass percentage of the second particle size grade alloy powder in the nickel-based superalloy powder is 45-50%; and the mass percentage of the third particle size grade alloy powder in the nickel-based superalloy powder is 20-25%.

20. The nickel-base superalloy powder of claim 18, wherein, The morphology of the nickel-based superalloy powder is approximately spherical without edges and corners.

21. A method of making a nickel-based superalloy article, characterized in that, The nickel-based superalloy powder is prepared by the method of any one of claims 1-17. The method comprises the following steps: Step 1): molding the nickel-based superalloy powder according to any one of claims 18-20 by using an additive manufacturing technology to obtain a nickel-based superalloy molding; Step 2): heat treating the nickel-based superalloy molding to obtain a nickel-based superalloy piece.

22. The method of producing a nickel-based superalloy piece according to claim 21, characterized in that, The additive manufacturing technology is selected from a selective laser melting technology.

23. The method for preparing a nickel-based superalloy piece according to claim 22, wherein the process parameters of the selective laser melting technology are set as follows: a laser power of 150-300 W, a laser scanning rate of 100-350 mm / s, a laser scanning interval of 20-100 μm, and a powder layer thickness of 30-50 μm. The step 2) comprises:

24. The method of producing a nickel-based superalloy piece according to any one of claims 21 to 23, characterized in that, solution treatment: solution treating the nickel-based superalloy molding, and cooling to obtain a solution-treated nickel-based superalloy molding; first aging treatment: first aging treating the solution-treated nickel-based superalloy molding, and cooling to obtain a first-aged nickel-based superalloy molding; second aging treatment: second aging treating the second-aged nickel-based superalloy molding, and cooling to obtain the nickel-based superalloy piece. The solution treatment temperature is 1220±10℃, and the holding time at the solution treatment temperature is 2±0.5 h.

25. The method of producing a nickel-based superalloy piece according to claim 24, characterized in that, The first aging treatment temperature is 1050±10℃, and the holding time at the first aging treatment temperature is 4±0.5 h.

26. The method of producing a nickel-based superalloy piece according to claim 24, characterized in that, The second aging treatment temperature is 840±10℃, and the holding time at the second aging treatment temperature is 16±0.5 h.

27. The method of producing a nickel-base superalloy piece of claim 24, wherein, In the steps of solution treatment, first aging treatment and second aging treatment, the cooling mode is argon cooling to room temperature.

28. The method of producing a nickel-base superalloy piece of claim 24, wherein, The nickel-based superalloy piece is prepared by the method for preparing a nickel-based superalloy piece according to any one of claims 21-28.

29. A nickel-base superalloy article, characterized by, The nickel-based superalloy piece has a density of 99.5% or more and an average grain size of 30-35 μm.

30. The nickel-base superalloy piece of claim 29, wherein, The γ' precipitated phase in the nickel-based superalloy piece has a size of 0.6-0.7 μm, a near-cubic structure, and is uniformly dispersed in the matrix.

31. The nickel-base superalloy piece of claim 29, wherein, ​

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