Additive manufacturing high-temperature-bearing nickel-based high-temperature alloy and preparation method thereof

Abstract

The invention relates to an additive manufacturing high-temperature-bearing nickel-based superalloy and a preparation method thereof, and relates to the technical field of superalloy materials and additive manufacturing. According to the main technical scheme, the preparation method of the high-temperature-bearing nickel-based superalloy for additive manufacturing comprises the following steps: preparing alloy powder: preparing the alloy powder; wherein the alloy powder comprises the following chemical components in percentage by weight: 17.0 to 21.0 weight percent of Cr, 50 to 55 weight percent of Ni, 5.0 to 5.5 weight percent of Nb, 2.8 to 3.3 weight percent of Mo, 0.75 to 1.15 weight percent of Ti, 0.3 to 0.7 weight percent of Al, 0.2 to 0.5 weight percent of C, 0.1 to 0.3 weight percent of Mn, 0.1 to 0.3 weight percent of Si, less than or equal to 0.015 weight percent of S, less than or equal to 0.02 weight percent of O, 0.01 to 1.0 weight percent of Y and the balance of Fe; and the additive manufacturing step is conducted, specifically, the alloy powder with the set particle size range is screened out from the alloy powder to be subjected to additive manufacturing treatment, and the additive manufacturing high-temperature-bearing nickel-based high-temperature alloy is obtained. The method is mainly used for preparing the in-situ oxide dispersion strengthened additive manufacturing high-temperature-bearing nickel-based high-temperature alloy with excellent high-temperature performance.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloy material and additive manufacturing, and in particular to an additively manufactured high-temperature-bearing nickel-based high-temperature alloy and a preparation method thereof. Background Art

[0002] In pursuit of higher performance turbine engines, it is necessary to develop high-temperature alloys that can withstand mechanical stresses up to 650°C and above. Nickel-based high-temperature alloys are ideal for this purpose, such as In 718 and Hastelloy X, because they have high strength, creep resistance, corrosion resistance and microstructural stability at higher operating temperatures. With the continuous upgrading of turbine engines, the requirements for metal parts are getting higher and higher, including: high performance, lightweight, high precision, resource conservation, and environmental friendliness, and higher requirements are also put forward for additive manufacturing (AM) technology. However, due to the non-equilibrium solidification behavior, complex internal stress and metallurgical defects in the AM process, the alloy has the problems of deformation cracking and poor strength-toughness matching. These problems seriously restrict the development and engineering application of AM technology in the preparation of aero-engine parts. Therefore, in the face of the urgent demand for metal parts in the new generation of aero-engines, how to design new materials and new processes to realize the additive manufacturing of nickel-based high-temperature alloys with coordinated shape control is one of the important scientific research tasks at present.

[0003] The oxidizability of metal materials is a problem that is difficult to fundamentally avoid in the additive manufacturing process, and is also the direct cause of metallurgical defects such as pores, cracks, and inclusions. Additive manufacturing involves extremely complex thermal conditions and physical processes point by point, layer by layer, and domain by domain. Oxygen and its reaction products are complexly distributed in different parts and scales such as grain boundaries, grains, and deposited layers, which directly affects the mechanical and service performance of components.

[0004] The starting point of traditional metal additive manufacturing is to reduce the oxygen content as much as possible and reduce its adverse effects, but it is impossible to fundamentally eliminate the impact of oxygen content. Based on the urgent demand for high temperature-bearing alloys for aerospace parts, combined with the beneficial contribution of oxide enhancement and high thermal stability, it has a significant contribution to the high temperature-bearing capacity of the alloy. By using reverse thinking method innovation, the original "oxygen control" is transformed into "oxygen use". By rationally utilizing and regulating oxygen and modifying elements in the additive manufacturing system, optimizing the formation, layout and size of the oxide dispersed phase, the effects of oxide dispersion strengthening (ODS) and high temperature bearing capacity can be achieved.

[0005] Existing research shows that by using nano-inert particles with high thermal and chemical stability (such as Y2O3, ZrO2, Ce2O3, etc.) to disperse them in the alloy matrix, the movement of dislocations and grain boundaries can be hindered by the combination of oxide dispersion composite strengthening and various strengthening methods of high-temperature alloys, which is expected to achieve the purpose of improving the high-temperature mechanical properties of the alloy. At the same time, nano-oxide particles have the ability to compensate for shrinkage in the late solidification period and inhibit grain boundary cracking. At the same time, they can act as nucleation particles to play a role in fine grain strengthening, which has a beneficial effect on the strength and plasticity of the alloy. Combined with the composition design of high-performance additive manufacturing high-temperature alloys, it can also take into account the good printability of the alloy. Therefore, oxide dispersion-strengthened high-temperature alloys have opened up a new idea for additive manufacturing of high-performance and high-temperature-bearing high-temperature alloys.

[0006] At present, the preparation of ODS high-temperature alloy powder usually adopts external composite technology, such as mechanical ball milling, dry method or wet method and other mixing methods, to add oxide particle reinforcement phase to high-temperature alloy powder to prepare composite material powder. Subsequently, it is deposited and formed together with the matrix material during the additive manufacturing process. This method often leads to a decrease in the sphericity of the powder, which will reduce the formability and mechanical properties of the additively manufactured high-temperature alloy. In addition, this method of adding oxide particles is not conducive to the dispersion distribution of oxides in the alloy matrix after the forming is completed, and has strict requirements on the uniformity of the mixed alloy powder and the AM forming process. These limit the further application and development of additive manufacturing of high-performance oxide dispersion-strengthened nickel-based high-temperature alloys.

[0007] The room temperature tensile properties of additively manufactured high-temperature alloys can be improved by utilizing the strengthening effect of rare earth oxide particles. However, few reports in the prior art focus on the tensile properties and durability of ODS nickel-based high-temperature alloys at 650°C, which are the key to the application of additively manufactured ODS high-temperature alloys in the aerospace field. In addition, considering the morphology, size and distribution of the reinforcement phase, there are few reports on the in-situ ODS nickel-based high-temperature alloys based on the oxygen content control of "powder-forming-sample" in the additive manufacturing process.

[0008] In summary, there is an urgent need to provide an in-situ oxide dispersion strengthened additively manufactured high temperature bearing nickel-based high temperature alloy with excellent high temperature performance and a preparation method thereof, which has important research significance and application value. Summary of the invention

[0009] In view of this, the present invention provides an additively manufactured high-temperature-bearing nickel-based high-temperature alloy and a preparation method thereof, the main purpose of which is to prepare an additively manufactured high-temperature-bearing nickel-based high-temperature alloy with in-situ oxide dispersion strengthening and excellent high-temperature performance.

[0010] In order to achieve the above object, the present invention mainly provides the following technical solutions:

[0011] On the one hand, an embodiment of the present invention provides a method for preparing a high-temperature-bearing nickel-based high-temperature alloy by additive manufacturing, which comprises the following steps:

[0012] The step of preparing alloy powder is as follows: preparing alloy powder; wherein, in terms of weight percentage, the chemical composition of the alloy powder includes: Cr 17.0-21.0wt%, Ni 50-55wt%, Nb 5.0-5.5wt%, Mo 2.8-3.3wt%, Ti0.75-1.15wt%, Al 0.3-0.7wt%, C 0.2-0.5wt%, Mn0.1-0.3wt%, Si 0.1-0.3wt%, S≤0.015wt%, O≤0.02wt%, Y 0.01-1.0wt%, and the balance is Fe;

[0013] Additive manufacturing step: sieve out alloy powder within a set particle size range from the alloy powder for additive manufacturing processing to obtain an additive manufacturing high-temperature-bearing nickel-based high-temperature alloy.

[0014] Preferably, in the alloy powder, the weight percentage of Y is 0.05 to 0.1 wt %;

[0015] Preferably, the chemical composition of the alloy powder includes, by weight percentage:

[0016] Cr 18.0~19.5wt%, Ni 51.5~52.5wt%, Nb 5.0~5.5wt%, Mo 3.0~3.3wt%, Ti 0.8~1.1wt%, Al 0.50~0.65wt%, C 0.3~0.5wt%, Mn 0.1~0.2wt%, Si 0.1~0.2wt%, Y 0.05~0.7wt%, S≤0.015wt%, O≤0.02wt%, and the balance is Fe;

[0017] Preferably, the chemical composition of the alloy powder includes, by weight percentage:

[0018] Cr 18.64~18.70wt%, Ni 51.9~52.2wt%, Nb 5.27~5.29wt%, Mo 3.16~3.17wt%, Ti 0.95~0.99wt%, Al 0.51~0.54wt%, C 0.43~0.44wt%, Mn 0.16~0.18wt%, Si 0.17~0.19wt%, S≤0.015wt%, O 0.01~0.02wt%, Y 0.05~0.70wt%, Fe balance.

[0019] Preferably, the step of preparing the alloy powder comprises:

[0020] An alloy ingot is prepared, and then the alloy ingot is subjected to vacuum gas atomization smelting and powder making treatment to obtain alloy powder.

[0021] Preferably, during the vacuum atomization smelting and powder making process: the atomization working temperature is 1520-1670°C, the vacuum degree is 4.0×10 -1 ~6.5×10 -1 Pa; and / or after the alloy ingot is completely melted to form a liquid, an inert gas is used as an atomizing gas flow, so that the liquid metal is atomized and crushed under the action of the atomizing gas flow to obtain an alloy powder.

[0022] Preferably, the alloy powder has a sphericity of 80-85%, a particle size distribution of 1-180 μm, and a bulk density of 4.68-4.90 g / cm 3 , fluidity is 17.9~18.3s / 50g, and the powder oxygen content is below 200ppm.

[0023] Preferably, in the additive manufacturing step: the additive manufacturing process uses a powder-spreading laser powder bed melting process or a powder-feeding laser energy deposition process; wherein, if the additive manufacturing process uses a powder-spreading laser powder bed melting process, the set particle size range is 15 to 53 μm; if the additive manufacturing process uses a powder-feeding laser energy deposition process, the set particle size range is 54 to 180 μm.

[0024] Preferably, in the additive manufacturing step, the additive manufacturing process uses a powder-laying laser powder bed melting process; wherein the process parameters of the additive manufacturing process are set as follows:

[0025] The laser power is 130-260W, the scanning speed is 700-1000mm / s, the scanning spacing is 0.06-0.1mm, the layer thickness is 0.03-0.08mm, the interlayer rotation angle is 0-90°, and the substrate preheating temperature is 25-70°C;

[0026] Preferably, the laser power is 165-230 W, the scanning speed is 800-900 mm / s, the scanning spacing is 0.08-0.1 mm, the layer thickness is 0.03-0.05 mm, the interlayer rotation angle is 45-90°, and the substrate preheating temperature is 50-70°C;

[0027] Preferably, when the Y content in the alloy powder is 0.05-0.1wt%, the process parameters of the additive manufacturing process are set as follows: laser power is 185-195W, scanning rate is 800-850mm / s, layer thickness is 0.03-0.04mm, scanning spacing is 0.09-0.1mm, interlayer rotation angle is 65-67°, and substrate preheating temperature is 65-70°C;

[0028] Preferably, when the Y content in the alloy powder is ≥0.01wt% and <0.05wt%, the process parameters of the additive manufacturing process are set as follows: laser power 145-165W, scanning rate 700-850mm / s, layer thickness 0.03-0.04mm, scanning spacing 0.09-0.1mm, rotation angle 65-67°, substrate preheating temperature 50-55°C;

[0029] Preferably, when the Y content in the alloy powder is greater than 0.1wt% and ≤1wt%, the process parameters of the additive manufacturing process are set as follows: laser power 245-260W, 950-1000mm / s, layer thickness 0.03-0.04mm, scanning spacing 0.09-0.1mm, rotation angle 85-90°, substrate preheating temperature 65-70°C.

[0030] Preferably, in the additive manufacturing step: during the forming process, the oxygen content in the forming cavity is controlled to be 3000-8000 ppm, preferably 5000-7000 ppm; after the forming is completed, the oxygen content in the forming cavity is reduced to 150-400 ppm.

[0031] On the other hand, an embodiment of the present invention provides an additively manufactured high temperature bearing nickel-based high temperature alloy, wherein the chemical composition of the additively manufactured high temperature bearing nickel-based high temperature alloy comprises, by weight percentage:

[0032] Cr 17.0~21.0wt%, Ni 50~55wt%, Nb 5.0~5.5wt%, Mo 2.8~3.3wt%, Ti0.75~1.15wt%, Al 0.3~0.7wt%, C 0.2~0.5wt%, Mn 0.1~0.3wt%, Si0.1~0.3wt%, S≤0.015wt%, O 0.02~0.1wt%, Y 0.01~1.0wt%, the balance is Fe;

[0033] Preferably, the additively manufactured high temperature bearing nickel-based high temperature alloy contains: micron-sized spherical Y2O3 particles and nano-sized Y2O3 particles; wherein the micron-sized spherical Y2O3 particles have a size of 10-30 μm and are dispersedly distributed at the bottom of the molten pool of the additively manufactured high temperature bearing nickel-based high temperature alloy; the nano-sized spherical Y2O3 particles have a size of 400-500 nm and are distributed inside the additively manufactured high temperature bearing nickel-based high temperature alloy;

[0034] Further preferably, the additively manufactured high temperature-resistant nickel-based high-temperature alloy also contains micron-sized Y-Al-O particles; wherein the micron-sized Y-Al-O particles have a size of 10-15 μm and are dispersedly distributed at the bottom and edge of the molten pool of the additively manufactured high temperature-resistant nickel-based high-temperature alloy; preferably, the Y-Al-O particles are irregular in shape.

[0035] Preferably, the additively manufactured high temperature-resistant nickel-based high-temperature alloy is prepared by the additively manufactured high temperature-resistant nickel-based high-temperature alloy preparation method described in any one of the above.

[0036] The additively manufactured high-temperature-bearing nickel-based high-temperature alloy and the preparation method thereof of the present invention have at least the following beneficial effects:

[0037] On the one hand, an embodiment of the present invention provides a method for preparing an additively manufactured high-temperature-bearing nickel-based high-temperature alloy. By designing the composition of the alloy powder, the designed composition ensures the solidification temperature range of the alloy on the one hand, and realizes polymorphic oxide particles from a thermodynamic point of view on the other hand, thereby being able to prepare an additively manufactured nickel-based high-temperature alloy with in-situ oxide dispersion strengthening and excellent high-temperature performance.

[0038] Furthermore, the embodiment of the present invention provides a method for preparing a high-temperature-bearing nickel-based high-temperature alloy for additive manufacturing, wherein the steps for preparing alloy powder are designed as follows: preparing an alloy ingot, and then subjecting the alloy ingot to a vacuum gas atomization melting and powdering treatment to obtain alloy powder. In the process of the vacuum atomization melting and powdering treatment: the atomization working temperature is 1520-1670°C, the vacuum degree is 4.0×10 -1 ~6.5×10 -1 The above steps make the alloy powder have a sphericity of 80-85%, a particle size distribution of 1-180 μm, and a bulk density of 4.68-4.90 g / cm 3 , fluidity is 17.9-18.3s / 50g, and the oxygen content of the powder is below 200ppm. Here, the present invention obtains nickel-based high-temperature alloy powder with high sphericity, low oxygen content and good fluidity through vacuum gas atomization smelting powder making technology.

[0039] Furthermore, an embodiment of the present invention provides a method for preparing an additively manufactured high-temperature-bearing nickel-based high-temperature alloy. By designing corresponding process parameters of the additive manufacturing process, especially adapting the process parameters of the additive manufacturing process to the Y content, multi-scale and multi-morphological oxides are formed in situ in the nickel-based high-temperature alloy, which can effectively improve the high-temperature mechanical properties of the additively manufactured high-temperature-bearing nickel-based high-temperature alloy.

[0040] Furthermore, an embodiment of the present invention provides an additively manufactured high-temperature-bearing nickel-based high-temperature alloy, wherein the additively manufactured high-temperature-bearing nickel-based high-temperature alloy is prepared by the additively manufactured nickel-based high-temperature alloy preparation method described above. Preferably, the additively manufactured nickel-based high-temperature alloy contains: micron-sized spherical Y2O3 particles, micron-sized Y-Al-O particles, and nano-sized Y2O3 particles. Among them, the size of the micron-sized spherical Y2O3 particles is 10-30 μm, and they are dispersedly distributed at the bottom of the molten pool of the additively manufactured nickel-based high-temperature alloy. On the one hand, this oxide can purify the molten pool to avoid the formation of impurity elements or inclusions. On the other hand, for the vicinity of large-angle crystals, it can alleviate the initiation and expansion of cracks at large-angle grain boundaries; the size of the nano-sized spherical Y2O3 particles is 400-500 nm, and they are dispersedly distributed inside the additively manufactured nickel-based high-temperature alloy. As nucleation particles, they play a role in fine grain strengthening and make a favorable contribution to the strength and plasticity of the alloy; the size of the micron-sized Y-Al-O particles is 10-15 μm, and they are dispersedly distributed at the bottom and edge of the molten pool of the additively manufactured nickel-based high-temperature alloy, which can ensure the structural stability of the alloy under high temperature conditions and contribute to the high temperature bearing capacity of the alloy; preferably, the Y-Al-O particles are irregular in shape.

[0041] In summary, the invention proposes a high-temperature-bearing nickel-based high-temperature alloy for additive manufacturing and a preparation method thereof, which realizes the reasonable regulation of oxygen content during powder preparation and forming, and reduces the burning loss of elements such as Al, Ti, and Y. On the other hand, the addition of Y element in the invention realizes the control of S element in atomized powder, and also realizes the effective regulation of oxygen element in "powder-forming-sample". Compared with the existing alloys and prior art: the invention expands the scope of use of rare metal components in the additive manufacturing nickel-based high-temperature alloy. In the tensile test at 650°C, the tensile strength of the deposited additive manufacturing high-temperature nickel-based high-temperature alloy can reach 1030-1040MPa, the elongation can reach 25-26%, and the endurance life can reach 210-215h at the same temperature (650°C) and 690MPa stress. In addition, unlike the prior art, the additive manufacturing high-temperature nickel-based high-temperature alloy obtained by the invention has multi-scale and multi-morph oxides, such as micron-sized spherical Y2O3 particles, large-sized micron-sized Y-Al-O and nano-sized Y2O3. This multi-scale, multi-morphological oxide particle is mainly present at the bottom of the molten pool, and the micron-sized particles pin the molten pool interface or high-angle grain boundaries. Compared with spherical yttrium oxide, this ternary oxide (micron-sized Y-Al-O) exhibits better high-temperature stability, maintains excellent performance, and can improve the tensile properties and durability of the alloy at high temperatures.

[0042] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a powder morphology diagram of the additively manufactured nickel-based high-temperature alloy of the present invention.

[0044] Figure 2 This is the forming quality diagram of the additively manufactured nickel-based high-temperature alloy prepared in Example 1.

[0045] Figure 3 This is a scanning morphology image of the additively manufactured nickel-based high-temperature alloy prepared in Example 1.

[0046] Figure 4 This is a transmission morphology image of the additively manufactured nickel-based high-temperature alloy prepared in Example 1.

[0047] Figure 5 This is the oxide EDS image of the additively manufactured nickel-based high-temperature alloy prepared in Example 1.

[0048] Figure 6 This is the forming quality diagram of the additively manufactured nickel-based high-temperature alloy prepared in Example 2.

[0049] Figure 7 This is the forming quality diagram of the additively manufactured nickel-based high-temperature alloy prepared in Example 3.

[0050] Figure 8 This is a scanning morphology image of the additively manufactured nickel-based high-temperature alloy prepared in Comparative Example 1.

[0051] Fig. 9 This is a diagram of the mechanical properties of the additively manufactured nickel-based high-temperature alloy prepared in Comparative Example 1. DETAILED DESCRIPTION

[0052] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0053] The present invention utilizes the concept of in-situ oxide dispersion strengthening alloys to design the content and relative proportion of oxygen and modifying elements (such as element Y). On this basis, the oxygen content in the gas atomization powder making and additive manufacturing forming process is further strictly controlled (such as the vacuum degree in the atomization process, ensuring that the oxygen content in the powder after the preparation is below 200ppm) to achieve multi-scale oxide dispersion distribution, so as to improve the comprehensive high temperature performance of additively manufactured high temperature alloys and expand their application in the aerospace field. The specific scheme of the present invention is as follows:

[0054] On the one hand, an embodiment of the present invention provides a method for preparing a high-temperature-bearing nickel-based high-temperature alloy by additive manufacturing, which comprises the following steps:

[0055] Preparation of alloy powder step: In this step, in order to achieve the purpose of the present invention, the present invention first designs the chemical composition of the alloy raw material (alloy powder); the details are as follows:

[0056] Among them, the chemical composition of the alloy powder includes, in weight percentage: Cr17.0~21.0wt%, Ni 50~55wt%, Nb 5.0~5.5wt%, Mo 2.8~3.3wt%, Ti0.75~1.15wt%, Al 0.3~0.7wt%, C0.2~0.5wt%, Mn 0.1~0.3wt%, Si0.1~0.3wt%, S≤0.015wt%, O≤0.02wt%, Y 0.01~1.0wt%, and the balance is Fe.

[0057] Preferably, the chemical composition of the alloy powder includes, in weight percentage, Cr18.0-19.5wt%, Ni51.5-52.5wt%, Nb 5.0-5.5wt%, Mo 3.0-3.3wt%, Ti0.8-1.1wt%, Al 0.50-0.65wt%, C 0.3-0.5wt%, Mn 0.1-0.2wt%, Si0.1-0.2wt%, Y 0.05-0.7wt%, S≤0.015wt%, O≤0.02wt%, and the balance is Fe.

[0058] Preferably, the alloy powder is spherical, the sphericity of the alloy powder is 80-85%, the particle size distribution is 1-180 μm, and the bulk density is 4.68-4.90 g / cm 3 , fluidity is 17.9~18.3s / 50g.

[0059] Preferably, the preparation method of the alloy powder is as follows: the alloy raw material is put into a smelting furnace, and after the composition is controlled and the atmosphere is protected, an alloy ingot is obtained. The alloy ingot is surface treated and the center is hollowed out for vacuum gas atomization smelting and powdering. In the vacuum gas atomization smelting and powdering process: the atomization working temperature is 1520-1670°C, and the vacuum degree is 4.0×10 -1 ~6.5×10 -1 Pa. After the alloy ingot is completely melted and formed into liquid, an inert gas is used as the atomizing gas flow. Under the action of high-speed and low-temperature inert gas, the liquid metal is atomized and broken to obtain a nickel-based high-temperature alloy powder with high sphericity, low oxygen content and good fluidity.

[0060] Additive manufacturing step: sieve out alloy powder within a set particle size range from the alloy powder for additive manufacturing processing to obtain an additive manufacturing high temperature bearing nickel-based high-temperature alloy.

[0061] The additive manufacturing process uses a powder-spreading laser powder bed fusion process or a powder-feeding laser energy deposition process; if the additive manufacturing process uses a powder-spreading laser powder bed fusion process, the particle size range is set to 15 to 53 μm. If the additive manufacturing process uses a powder-feeding laser energy deposition process, the particle size range is set to 54 to 180 μm.

[0062] Preferably, in the additive manufacturing step, the additive manufacturing process uses a powder-laying laser powder bed fusion process (Laser Powder Bed Fusion, LPBF); wherein the process parameters of the additive manufacturing process are set as follows:

[0063] The laser power is 130-260 W (preferably 165-230 W), the scanning speed is 700-1000 mm / s (scanning speed is 800-900 mm / s), the scanning spacing is 0.06-0.1 mm (preferably 0.08-0.1 mm), the layer thickness is 0.03-0.08 mm (preferably 0.03-0.05 mm), the interlayer rotation angle is 0-90° (preferably 45-90°C), and the substrate preheating temperature is 25-70°C (preferably 50-70°C).

[0064] During the forming process, the oxygen content in the forming cavity is controlled to be 3000-8000 ppm, preferably 5000-7000 ppm; after the forming is completed, the oxygen content in the forming cavity is reduced to 150-400 ppm.

[0065] On the other hand, an embodiment of the present invention provides an additively manufactured high temperature-resistant nickel-based high-temperature alloy, wherein the additively manufactured nickel-based high-temperature alloy is prepared by the above-mentioned additively manufactured high temperature-resistant nickel-based high-temperature alloy preparation method.

[0066] It should be noted that the oxygen content in the alloy powder is controlled to be below 0.02wt%, and the sulfur content is below 0.015%. The prepared additive manufacturing nickel-based high-temperature alloy has an O content of 0.02-0.1wt%, and an S content of below 0.0015wt%.

[0067] Among them, the additively manufactured high-temperature nickel-based high-temperature alloy contains: micron-sized spherical Y2O3 particles, micron-sized Y-Al-O particles, and nano-sized Y2O3 particles; wherein the size of the micron-sized spherical Y2O3 particles is 10-30 μm, and is dispersedly distributed at the bottom of the molten pool of the additively manufactured high-temperature nickel-based high-temperature alloy; the size of the micron-sized spherical Y2O3 particles is 400-500 nm, and is distributed inside the additively manufactured high-temperature nickel-based high-temperature alloy; the size of the micron-sized Y-Al-O particles is 10-15 μm, and is dispersedly distributed at the bottom and edge of the molten pool of the additively manufactured high-temperature nickel-based high-temperature alloy; preferably, the Y-Al-O particles are irregular in shape. It should be noted here that compared with spherical yttrium oxide particles, this ternary oxide Y-Al-O particle exhibits better high-temperature stability and maintains excellent performance.

[0068] On the other hand, regarding the above-mentioned additively manufactured high temperature bearing nickel-based high temperature alloy and its preparation method, one of the preferred solutions is as follows:

[0069] The chemical composition of the alloy powder is as follows, in weight percentage: Cr 18.64-18.70%, Ni 51.9-52.2%, Nb 5.27-5.29%, Mo 3.16-3.17%, Ti 0.95-0.99%, Al 0.51-0.54%, C 0.43-0.44%, Mn 0.16-0.18%, Si 0.17-0.19%, S≤0.015%, O 0.01-0.02%, Y 0.05-0.70%, Fe balance.

[0070] When LPBF technology is used for additive manufacturing, the additive manufacturing process parameters are: laser power of 195W, scanning speed of 850mm / s, scanning spacing of 0.1mm, layer thickness of 0.03mm, interlayer rotation angle of 67°, and substrate preheating temperature of 70°C. Among them, during the printing process, the initial value of the oxygen content in the molding cavity is 5000ppm, and the oxygen content in the cavity is 150-200ppm after the printing is completed. The oxygen content in the obtained additively manufactured high-temperature nickel-based high-temperature alloy is 0.02-0.04wt%, S≤0.0015%. Compared with the elemental composition of the alloy powder, the O element increases due to the control of the oxygen content in the molding cavity, and the S element content is significantly controlled. The Y content in the additively manufactured high-temperature nickel-based high-temperature alloy deviates from the Y content in the powder by less than 5%, which indicates that the Y element is almost not burned during the molding process, and does not affect the in-situ oxide dispersion strengthening designed in the present invention.

[0071] The deposited alloy (additive manufacturing high-temperature nickel-based high-temperature alloy) obtained by the above scheme has a density of 99.9%, a porosity of less than 0.1%, and good formability; the alloy has a tensile strength of 1030-1040MPa at 650°C, an elongation of 25-26%, and a long-lasting life of 210-215h at 650°C / 690MPa.

[0072] The present invention is further described below by specific embodiments:

[0073] Example 1

[0074] This embodiment prepares a high-temperature-bearing nickel-based high-temperature alloy by additive manufacturing, which mainly includes the following steps:

[0075] 1) Preparation of alloy powder step: wherein, in terms of weight percentage, the alloy powder comprises the following chemical components: Cr 18.64wt%, Ni 51.9wt%, Nb 5.27wt%, Mo 3.16wt%, Ti0.99wt%, Al 0.51wt%, C0.44wt%, Mn 0.16wt%, Si 0.19wt%, S≤0.015wt%, O 0.018wt%, Y 0.06wt%, and Fe balance.

[0076] Specifically, an alloy ingot is prepared according to the above chemical composition, and the alloy ingot is prepared into alloy powder using a vacuum gas atomization smelting and powder making equipment. In the vacuum gas atomization smelting and powder making process: the atomization working temperature is 1665°C, the vacuum degree is 6.0×10 -1 Pa. After the alloy ingot is completely melted and formed into liquid, an inert gas is used as the atomizing gas flow. Under the action of high-speed and low-temperature inert gas, the liquid metal is atomized and broken to obtain a nickel-based high-temperature alloy powder with high sphericity, low oxygen content and good fluidity.

[0077] Among them, the morphology of the alloy powder is as follows Figure 1 As shown in the figure, the sphericity is good, the particle size distribution of the alloy is 15-53 μm, and the loose density of the powder is 4.81 g / cm 3 The fluidity is 17.92s / 50g and the oxygen content is below 200ppm.

[0078] 2) Additive manufacturing step: From the above alloy powder, powder with a particle size distribution of 15 to 53 μm is sieved, and a laser powder bed melting technology is used to prepare an additively manufactured nickel-based high-temperature alloy.

[0079] Among them, during the LPBF forming process, the laser power is 195W, the scanning rate is 850mm / s, the layer thickness is 0.03mm, the scanning spacing is 0.1mm, the interlayer rotation angle is 67°, the substrate preheating is 70°C, and the oxygen content in the forming cavity is 5000ppm. During the forming process, the oxygen content in the forming cavity forms dispersed yttrium oxide due to the presence of Y element in the alloy powder. After the printing is completed, the oxygen content in the forming cavity is reduced to 180ppm. The O content in the prepared additively manufactured nickel-based high-temperature alloy is 0.04wt%, and the S content is ≤0.0015wt%.

[0080] When the size of the sample (additive manufacturing nickel-based high-temperature alloy) reaches the set deposition height, remove the substrate and cut and process the sample. Use wire cutting equipment to process the block sample into the required small metallographic specimens and tensile specimens. Perform surface treatment and observation on the metallographic specimens, such as Figure 2 As shown, from Figure 2 It can be seen that there are no obvious cracks or pores on the surface of the sample, and the formability is good. According to statistics, the porosity of the sample is less than 0.1%, and the density is 99.9%.

[0081] Further observation of the scanning morphology in Example 1 shows that there are three types of oxides in the additively manufactured nickel-based high-temperature alloy, which are different from the results in the prior art. One is spherical yttrium oxide, which is micrometer-scale (10-30 μm) under scanning, such as Figure 3 As shown; the other is nano-scale yttrium oxide (400-500nm), as Figure 4 Another oxide is Y-Al-O, such as Figure 5 As shown, it has an irregular shape and is relatively large in size (micrometer level, 10 to 15 μm).

[0082] The room temperature and high temperature mechanical properties of the additively manufactured high temperature bearing nickel-based high temperature alloy prepared in Example 1 of the present invention were tested. The test conditions were: strain rate 0.001s -1At 650°C, the alloy has a tensile strength of 1037MPa, a yield strength of 894MPa, and an elongation of 25%; under 650°C / 690MPa conditions, the additively manufactured nickel-based high-temperature alloy has a long life of 211h and an elongation of 3.5%.

[0083] Here, compared with Embodiment 2 and Embodiment 3, Embodiment 1 is the best embodiment.

[0084] Example 2

[0085] This embodiment prepares an additive manufacturing high temperature bearing nickel-based high temperature alloy. Compared with embodiment 1, embodiment 2 mainly adjusts the process parameters of the additive manufacturing process. Specifically, this embodiment mainly includes the following steps:

[0086] 1) Preparation of alloy powder step: wherein, in terms of weight percentage, the alloy powder comprises the following chemical components: Cr 18.64wt%, Ni 51.9wt%, Nb 5.27wt%, Mo 3.16wt%, Ti0.99wt%, Al 0.51wt%, C0.44wt%, Mn 0.16wt%, Si 0.19wt%, S≤0.015wt%, O 0.018wt%, Y 0.06wt%, and Fe balance.

[0087] Specifically, an alloy ingot is prepared according to the above chemical composition, and the alloy ingot is prepared into alloy powder using a vacuum gas atomization smelting and powder making equipment. In the vacuum gas atomization smelting and powder making process: the atomization working temperature is 1665°C, the vacuum degree is 6.0×10 -1 Pa. After the alloy ingot is completely melted and formed into liquid, an inert gas is used as the atomizing gas flow. Under the action of high-speed and low-temperature inert gas, the liquid metal is atomized and broken to obtain a nickel-based high-temperature alloy powder with high sphericity, low oxygen content and good fluidity.

[0088] Among them, the morphology of the alloy powder is as follows Figure 1 As shown in the figure, the sphericity is good, the particle size distribution of the alloy is 15-53 μm, and the loose density of the powder is 4.81 g / cm 3 The fluidity is 17.92s / 50g and the oxygen content is below 200ppm.

[0089] 2) Additive manufacturing step: From the above alloy powder, powder with a particle size distribution of 15 to 53 μm is sieved, and a laser powder bed melting technology is used to prepare an additively manufactured nickel-based high-temperature alloy.

[0090] During the LPBF forming process, the laser power was 215W, the scanning rate was 900mm / s, the layer thickness was 0.03mm, the scanning spacing was 0.1mm, the interlayer rotation angle was 67°, the substrate was preheated to 70°C, and the oxygen content in the forming cavity was 5000ppm. During the forming process, the oxygen content in the forming cavity formed dispersed yttrium oxide due to the presence of Y element in the alloy powder. After the printing was completed, the oxygen content in the forming cavity was reduced to 180ppm. The O content in the prepared additively manufactured nickel-based high-temperature alloy was 0.04wt%, and the S content was ≤0.0015%.

[0091] After the size of the sample (additively manufactured nickel-based high-temperature alloy) reaches the set deposition height, the substrate is removed and the sample is cut and processed. The block sample is processed into the required small metallographic specimens and tensile specimens using wire cutting equipment. The surface of the small specimen is observed to have many pore defects, with a density of 99.80% and a porosity of 0.16%. Figure 6 Here, the change of additive manufacturing process parameters will affect the formability of the high-temperature alloy and its mechanical properties; but its microstructure, that is, the morphology and distribution of the oxides are consistent with those in Example 1.

[0092] Under the same test conditions as those in Example 1, the mechanical properties of Example 2 were tested. The alloy had a tensile strength of 1011 MPa, a yield strength of 856 MPa, and an elongation of 18.5% at 650°C.

[0093] Example 3

[0094] This embodiment prepares an additively manufactured original nickel-based high-temperature alloy. Compared with Example 1, this embodiment mainly adjusts the content of Y. Specifically, this embodiment mainly includes the following steps:

[0095] 1) Preparation of alloy powder step: wherein, in terms of weight percentage, the alloy powder comprises the following chemical components: Cr 18.64wt%, Ni 52.2wt%, Nb 5.29wt%, Mo 3.17wt%, Ti0.98wt%, Al 0.52wt%, C0.43wt%, Mn 0.16wt%, Si 0.19wt%, S≤0.015%, O 0.016wt%, Y 0.34wt%, and Fe balance.

[0096] Specifically, an alloy ingot is prepared according to the above chemical composition, and the alloy ingot is prepared into alloy powder using a vacuum gas atomization smelting and powder making equipment. In the vacuum gas atomization smelting and powder making process: the atomization working temperature is 1660°C, the vacuum degree is 6.0×10 -1Pa. After the alloy ingot is completely melted and formed into liquid, an inert gas is used as the atomizing gas flow. Under the action of high-speed and low-temperature inert gas, the liquid metal is atomized and broken to obtain a nickel-based high-temperature alloy powder with high sphericity, low oxygen content and good fluidity.

[0097] Among them, the alloy powder has good sphericity and a bulk density of 4.82g / cm 3 , fluidity is 18.0s / 50g, and oxygen content is below 200ppm.

[0098] 2) Additive manufacturing step: From the above alloy powder, sieve out powder with a particle size distribution of 15 to 53 μm, and use laser powder bed melting technology to prepare additive manufacturing high temperature-bearing nickel-based high-temperature alloy.

[0099] Here, the present embodiment selects the same printing parameters as those of the embodiment 1 during the LPBF forming process, except that: since the Y content in the present embodiment is higher than that in the embodiment 1, the oxygen content in the forming cavity is set to 7000ppm to ensure that the Y element can fully play its role in the forming process and form dispersed oxide particles. After the printing is completed, the oxygen content in the forming cavity is reduced to 200ppm, and the O content in the prepared additively manufactured nickel-based high-temperature alloy is 0.10wt%, and the S content is ≤0.0015%.

[0100] After the sample size reaches the set deposition height, remove the substrate and cut and process the sample. Use wire cutting equipment to process the block sample into the required small metallographic specimens and tensile specimens. Perform surface treatment and observation on the metallographic specimens, such as Figure 7 As shown, there are a large number of voids on the surface, and the forming quality is worse than that of Example 1 and Example 2, which is also the main reason why its mechanical properties are not as good as those of Example 1 and Example 2. For microstructural characterization, as in Example 1, yttrium oxide particles are present; however, due to the increase in Y content and the extremely strong affinity of Y for oxygen, there are no Y-Al-O particles in the alloy prepared in this Example 3, which is attributed to the change in elemental composition affecting the thermodynamic conditions of the alloy and the inability to form the ternary oxide. Subsequently, the same mechanical property test conditions as in Example 1 were selected, and the additively manufactured nickel-based high-temperature alloy prepared in Example 3 had a tensile strength of 897 MPa, a yield strength of 811 MPa, and an elongation of 14.0% at 650°C.

[0101] Comparative Example 1

[0102] Comparative Example 1: Preparation of an additively manufactured nickel-based high-temperature alloy, mainly comprising the following steps:

[0103] 1) Preparation of alloy powder step: wherein, in terms of weight percentage, the alloy powder comprises the following chemical components: Cr 18.65wt%, Ni 52.0wt%, Nb 5.28wt%, Mo 3.16wt%, Ti0.97wt%, Al 0.52wt%, C0.43wt%, Mn 0.17wt%, Si 0.18wt%, S≤0.015wt%, O 0.013wt%, and Fe balance.

[0104] Specifically, an alloy ingot is prepared according to the above chemical composition, and the alloy ingot is prepared into alloy powder using a vacuum gas atomization smelting and powder making equipment. In the vacuum gas atomization smelting and powder making process: the atomization working temperature is 1660°C, the vacuum degree is 6.0×10 -1 Pa. After the alloy ingot is completely melted and formed into liquid, an inert gas is used as the atomizing gas flow. Under the action of high-speed and low-temperature inert gas, the liquid metal is atomized and broken to obtain a nickel-based high-temperature alloy powder with high sphericity, low oxygen content and good fluidity.

[0105] Among them, the alloy powder has good sphericity and a bulk density of 4.68g / cm 3 , fluidity is 16.2s / 50g.

[0106] 2) Additive manufacturing step: From the above alloy powder, powder with a particle size distribution of 15 to 53 μm is sieved, and a laser powder bed melting technology is used to prepare an additively manufactured nickel-based high-temperature alloy.

[0107] During the LPBF forming process, the laser power of the nickel-based high-temperature alloy is 195W, the scanning rate is 850mm / s, the layer thickness is 0.03mm, the scanning spacing is 0.1mm, the interlayer rotation angle is 67°, the substrate is preheated to 70°C, the process parameters are the same as those in Example 1, and the oxygen content in the forming cavity is controlled to be 3000ppm. After forming, the O content in the prepared additively manufactured nickel-based high-temperature alloy is 0.012wt%, and the S content is ≤0.015%.

[0108] When the sample size reaches the set deposition height, the substrate is removed and the sample is cut and processed. The block sample is processed into the required small metallographic specimens and tensile specimens using wire cutting equipment. Figure 8 The scanning morphology of the additively manufactured nickel-based high-temperature alloy of Example 1 shows that the alloy mainly contains Laves phase and carbides, and the spherical or irregularly shaped oxides described in Examples 1, 2 and 3 are absent.

[0109] The room temperature and high temperature mechanical properties of the nickel-based high temperature alloy prepared in Comparative Example 1 of the present invention were tested under the following test conditions: strain rate 0.001s -1 , at 650℃, the tensile strength is 996MPa. Fig. 9 As shown in the figure, the yield strength is 847MPa, the elongation is 7.5%, and the endurance life is 20h under the condition of 650℃ / 690MPa. It can be seen that: the alloy powder does not contain Y element, and the mechanical properties of the alloy sample are poor under the same alloy composition and printing process, which is attributed to the lack of multi-scale in-situ oxide dispersion strengthening.

[0110] Comparative Example 2

[0111] Comparative Example 2 prepares an additively manufactured nickel-based high-temperature alloy, and its chemical composition is the same as that of Comparative Example 1, except that the process parameters of the additively manufactured nickel-based high-temperature alloy are: the laser power of Comparative Example 2 is 215 W, the scanning rate is 900 mm / s, the layer thickness is 0.03 mm, the scanning spacing is 0.1 mm, the interlayer rotation angle is 67°, and the substrate preheating is 70°C.

[0112] The performance of the sample obtained in comparative example 2 was tested, and the high temperature tensile strength (650° C.) was 780 MPa, the yield strength was 727 MPa, and the elongation was 3.5%.

[0113] Table 1 is the performance test results of the nickel-based high-temperature alloys prepared in the embodiments of the present invention and the comparative examples

[0114] 650℃ Tensile strength(MPa) Yield strength (MPa) Elongation(%) Example 1 1037 894 25 Example 2 1011 856 18.5 Example 3 897 811 14 Comparative Example 1 996 847 7.5 Comparative Example 2 780 727 3.5

[0115] Here, according to the data of Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2 and Table 1:

[0116] 1) Compared with Example 1, due to the difference in process or Y content, there are more pore defects in Example 2 and Example 3, and the performance level of Example 1 is significantly better than that of Example 2 and Example 3, indicating that the adaptation of Y content and additive process parameters needs to be strictly considered. On the other hand, due to the presence of polymorphic oxides, the performance of Example 1 and Example 2 is significantly better than that of Comparative Examples 1 and 2. The alloy performance of Example 3 is slightly lower than that of Comparative Example 1 due to inappropriate additive manufacturing process parameters.

[0117] 2) Comparing Example 1 and Example 2, it can be seen that under the same alloy composition, different printing parameters have a great influence on the mechanical properties of the additively manufactured nickel-based high-temperature alloy, which is mainly attributed to the difference in forming quality. Therefore, it is determined that for the alloy composition of "Cr 18.64-18.70wt%, Ni 51.9-52.2wt%, Nb 5.27-5.29wt%, Mo 3.16-3.17wt%, Ti 0.95-0.99wt%, Al 0.51-0.54wt%, C 0.43-0.44wt%, Mn 0.16-0.18wt%, Si0.17-0.19wt%, S≤0.015wt%, O0.01-0.02wt%, Y 0.05-0.1wt%, Fe balance", the optimal process parameters are: laser power of 180-195W, scanning rate of 820-870mm / s.

[0118] 3) Although the forming quality of Example 3 is not as good as that of Example 2, the Y content in Example 3 is higher than that in Example 2, and there is dispersion strengthening of in-situ oxides, so that the mechanical properties of Example 3 are not significantly reduced compared with Example 2. This confirms the superiority of the additively manufactured nickel-based high-temperature alloy in the present invention, and the process window of additively manufactured nickel-based high-temperature alloys can be expanded by means of in-situ oxide dispersion strengthening, which greatly promotes the application and development of additively manufactured nickel-based high-temperature alloys in the aerospace field.

[0119] 4) Compared with Example 1, the alloy powder of Comparative Example 1 does not contain the Y element. Under the same alloy composition and printing process, the mechanical properties of the alloy sample are poor, which is attributed to the lack of multi-scale in-situ oxide dispersion strengthening.

[0120] 5) Compared with all the embodiments, the poor performance results presented in Comparative Example 2 are attributed to two aspects: first, there is no Y element in the alloy, so there are no multi-scale and multi-morphological oxide particles to in-situ disperse and strengthen the nickel-based high-temperature alloy; on the other hand, the process parameters of Comparative Example 2 are compared with those of Comparative Example 1, which shows that there is a close relationship between the formability of the nickel-based high-temperature alloy and the process parameters, which determines the final mechanical properties of the alloy.

[0121] Based on the content and results of the above specific cases, the in-situ addition of the Y element and the control of the O content help to achieve high temperature bearing capacity and good high-temperature mechanical properties of the alloy by obtaining multi-scale and multi-morphological oxide particles. There are three types of multi-scale and multi-morphological oxide particles: micron-sized spherical yttrium oxide, nano-sized spherical yttrium oxide, and micron-sized irregular Y-Al-O particles. Among them, micron-sized spherical yttrium oxide is mainly distributed at the bottom of the molten pool, which is used to purify the alloy molten pool and remove impurities; nano-sized spherical yttrium oxide can be used as a nucleation particle to play a role in fine grain strengthening, and its contribution is reflected in the simultaneous improvement of alloy strength and plasticity; micron-sized Y-Al-O particles ensure the structural stability of the alloy at high temperatures and contribute to the mechanical properties of high temperature bearing alloys at high temperatures. Moreover, compared with spherical yttrium oxide particles, Y-Al-O particles show more beneficial structural stability at high temperatures, and contribute more to the mechanical properties of the alloy than yttrium oxide. At the same time, due to the affinity of Y for the O element, as the Y content increases, when it exceeds 0.1wt%, it is difficult to obtain the Y-Al-O ternary oxide in the alloy. In addition, when the oxygen content is insufficient during the additive manufacturing process, it will also affect the formation of yttrium oxide in the alloy. Therefore, in order to obtain a high-temperature nickel-based high-temperature alloy with excellent high-temperature mechanical properties, it is necessary to obtain multi-scale yttrium oxide and Y-Al-O ternary oxide particles under the in-situ addition of the Y element, so as to achieve multi-scale and multi-morphological in-situ oxide dispersion enhancement to ensure the structural stability of the alloy at high temperatures, indicating excellent high-temperature mechanical properties.

[0122] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a high-temperature-bearing nickel-based high-temperature alloy by additive manufacturing, characterized in that: It includes the following steps: The step of preparing alloy powder is as follows: preparing alloy powder; wherein, in terms of weight percentage, the chemical composition of the alloy powder includes: Cr 17.0-21.0wt%, Ni 50-55wt%, Nb 5.0-5.5wt%, Mo 2.8-3.3wt%, Ti 0.75-1.15wt%, Al 0.3-0.7wt%, C 0.2-0.5wt%, Mn 0.1-0.3wt%, Si 0.1-0.3wt%, S≤0.015wt%, O≤0.02wt%, Y 0.01-1.0wt%, and the balance is Fe; Additive manufacturing step: sieve out alloy powder within a set particle size range from the alloy powder for additive manufacturing processing to obtain an additive manufacturing high-temperature-bearing nickel-based high-temperature alloy.

2. The method for preparing a high temperature-bearing nickel-based high-temperature alloy by additive manufacturing according to claim 1, characterized in that: In the alloy powder, the weight percentage of Y is 0.05-0.1wt%; Preferably, the chemical composition of the alloy powder includes, by weight percentage: Cr 18.0~19.5wt%, Ni 51.5~52.5wt%, Nb 5.0~5.5wt%, Mo 3.0~3.3wt%, Ti0.8~1.1wt%, Al 0.50~0.65wt%, C 0.3~0.5wt%, Mn 0.1~0.2wt%, Si 0.1~0.2wt%, Y 0.05~0.7wt%, S≤0.015wt%, O≤0.02wt%, and the balance is Fe; Preferably, the chemical composition of the alloy powder includes, by weight percentage: Cr 18.64~18.70wt%, Ni 51.9~52.2wt%, Nb 5.27~5.29wt%, Mo 3.16~3.17wt%, Ti 0.95~0.99wt%, Al 0.51~0.54wt%, C 0.43~0.44wt%, Mn 0.16~0.18wt%, Si 0.17~0.19wt%, S≤0.015wt%, O 0.01~0.02wt%, Y 0.05~0.70wt%, Fe balance.

3. The method for preparing a high temperature-bearing nickel-based high-temperature alloy by additive manufacturing according to claim 1 or 2, characterized in that: The step of preparing the alloy powder comprises: An alloy ingot is prepared, and then the alloy ingot is subjected to vacuum gas atomization smelting and powder making treatment to obtain alloy powder.

4. The method for preparing a high temperature-bearing nickel-based high-temperature alloy by additive manufacturing according to claim 3, characterized in that: During the vacuum atomization smelting and powder making process: The atomization working temperature is 1520~1670℃, and the vacuum degree is 4.0×10 -1 ~6.5×10 -1 Pa; and / or After the alloy ingot is completely melted to form a liquid state, an inert gas is used as an atomizing gas flow, so that the liquid metal is atomized and crushed under the action of the atomizing gas flow to obtain alloy powder.

5. The method for preparing a high temperature-bearing nickel-based high-temperature alloy by additive manufacturing according to any one of claims 1 to 4, characterized in that: The alloy powder has a sphericity of 80-85%, a particle size distribution of 1-180 μm, and a bulk density of 4.68-4.90 g / cm 3 , fluidity is 17.9~18.3s / 50g, and the powder oxygen content is below 200ppm.

6. The method for preparing a high temperature-bearing nickel-based high-temperature alloy by additive manufacturing according to any one of claims 1 to 5, characterized in that: In the additive manufacturing step: The additive manufacturing process uses a powder-laying laser powder bed fusion process or a powder-feeding laser energy deposition process; Wherein, if the additive manufacturing process adopts a powder-laying laser powder bed melting process, the set particle size range is 15 to 53 μm; If the additive manufacturing process adopts a powder feeding laser energy deposition process, the set particle size range is 54 to 180 μm.

7. The method for preparing a high temperature bearing nickel-based high temperature alloy by additive manufacturing according to any one of claims 1 to 6, characterized in that: In the additive manufacturing step, the additive manufacturing process uses a powder-laying laser powder bed melting process; wherein the process parameters of the additive manufacturing process are set as follows: The laser power is 130-260W, the scanning speed is 700-1000mm / s, the scanning spacing is 0.06-0.1mm, the layer thickness is 0.03-0.08mm, the interlayer rotation angle is 0-90°, and the substrate preheating temperature is 25-70°C; Preferably, the laser power is 165-230 W, the scanning speed is 800-900 mm / s, the scanning spacing is 0.08-0.1 mm, the layer thickness is 0.03-0.05 mm, the interlayer rotation angle is 45-90°, and the substrate preheating temperature is 50-70°C; Preferably, when the Y content in the alloy powder is 0.05-0.1wt%, the process parameters of the additive manufacturing process are set as follows: laser power is 185-195W, scanning rate is 800-850mm / s, layer thickness is 0.03-0.04mm, scanning spacing is 0.09-0.1mm, interlayer rotation angle is 65-67°, and substrate preheating temperature is 65-70°C; Preferably, when the Y content in the alloy powder is ≥0.01wt% and <0.05wt%, the process parameters of the additive manufacturing process are set as follows: laser power 145-165W, scanning rate 700-850mm / s, layer thickness 0.03-0.04mm, scanning spacing 0.09-0.1mm, rotation angle 65-67°, substrate preheating temperature 50-55°C; Preferably, when the Y content in the alloy powder is greater than 0.1wt% and ≤1wt%, the process parameters of the additive manufacturing process are set as follows: laser power 245-260W, 950-1000mm / s, layer thickness 0.03-0.04mm, scanning spacing 0.09-0.1mm, rotation angle 85-90°, substrate preheating temperature 65-70°C.

8. The method for preparing a high temperature bearing nickel-based high temperature alloy by additive manufacturing according to any one of claims 1 to 7, characterized in that: In the additive manufacturing step: During the forming process, the oxygen content in the forming cavity is controlled to be 3000-8000 ppm, preferably 5000-7000 ppm; after the forming is completed, the oxygen content in the forming cavity is reduced to 150-400 ppm.

9. An additively manufactured high temperature bearing nickel-based high temperature alloy, characterized in that: The chemical composition of the additively manufactured high temperature bearing nickel-based high temperature alloy includes, by weight percentage: Cr 17.0~21.0wt%, Ni 50~55wt%, Nb 5.0~5.5wt%, Mo 2.8~3.3wt%, Ti0.75~1.15wt%, Al 0.3~0.7wt%, C 0.2~0.5wt%, Mn 0.1~0.3wt%, Si0.1~0.3wt%, S≤0.015wt%, O 0.02~0.1wt%, Y 0.01~1.0wt%, the balance is Fe; Preferably, the additively manufactured high temperature bearing nickel-based high temperature alloy contains: micron-sized spherical Y2O3 particles and nano-sized Y2O3 particles; wherein the micron-sized spherical Y2O3 particles have a size of 10-30 μm and are dispersedly distributed at the bottom of the molten pool of the additively manufactured high temperature bearing nickel-based high temperature alloy; the nano-sized spherical Y2O3 particles have a size of 400-500 nm and are distributed inside the additively manufactured high temperature bearing nickel-based high temperature alloy; Further preferably, the additively manufactured high temperature-resistant nickel-based high-temperature alloy also contains micron-sized Y-Al-O particles; wherein the micron-sized Y-Al-O particles have a size of 10-15 μm and are dispersedly distributed at the bottom and edge of the molten pool of the additively manufactured high temperature-resistant nickel-based high-temperature alloy; preferably, the Y-Al-O particles are irregular in shape.

10. The additively manufactured high temperature bearing nickel-based high temperature alloy according to claim 9, characterized in that: The additively manufactured high-temperature-bearing nickel-based high-temperature alloy is prepared by the additively manufactured high-temperature-bearing nickel-based high-temperature alloy preparation method described in any one of claims 1-8.

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