Additive manufacturing nickel-based superalloy and laser forming method and heat treatment method thereof

Abstract

The invention relates to the technical field of additive manufacturing, in particular to an additive manufacturing nickel-based superalloy and a laser forming method and a heat treatment method thereof. The additive manufacturing nickel-based superalloy comprises the following components in percentage by mass: 8.0%-8.5% of Cr, 9.0%-9.5% of Co, 9.0%-10.0% of W, 0%-0.6% of Mo, 2.5%-3.5% of Ta, 5.0%-6.0% of Al, 0.5%-1.0% of Ti, 2.0%-2.5% of Hf, 0.01%-0.07% of C, less than or equal to 0.3% of B + Zr + Si and the balance of Ni. By regulating and controlling the element composition in the nickel-based superalloy and matching with proper laser forming parameters, the nickel-based superalloy has good formability, and by matching with a certain heat treatment system, not only can a small number of microcracks possibly existing in laser forming be effectively bridged, but also the mechanical property can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to an additive manufacturing method for nickel-based superalloys and its laser forming and heat treatment methods. Background Technology

[0002] Traditional age-hardening nickel-based superalloys (such as GH4169) typically have a service temperature not exceeding 900℃. Above this temperature, the content of the γ' phase or γ'' phase decreases significantly, and phase transformations may even occur, generating harmful phases and leading to performance degradation. High-alumina-titanium nickel-based superalloys are widely used due to their excellent mechanical properties, good corrosion resistance, and fatigue resistance. However, high-alumina-titanium nickel-based superalloys (such as IN738 and CM247LC) are prone to cracking during laser forming. Furthermore, the mechanical properties of laser-formed components from high-alumina-titanium nickel-based superalloys currently available for laser forming are somewhat lower than those produced using traditional manufacturing methods. Therefore, ensuring good laser formability while maintaining excellent mechanical properties has become a core challenge for the application of high-alumina-titanium nickel-based superalloys in advanced manufacturing.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The purpose of this invention is to provide additive manufacturing of nickel-based superalloys and their laser forming and heat treatment methods. The nickel-based superalloys of this invention have fewer cracks during laser forming, and after heat treatment, not only can the cracks be effectively closed, but the mechanical properties can also be significantly improved.

[0005] To achieve the above-mentioned objectives of the present invention, a first aspect of the present invention provides an additively manufactured nickel-based superalloy comprising, by mass percentage, the following components: Cr 8.0%~8.5%, Co 9.0%~9.5%, W 9.0%~10.0%, Mo 0%~0.6%, Ta 2.5%~3.5%, Al 5.0%~6.0%, Ti 0.5%~1.0%, Hf 2.0%~2.5%, C 0.01%~0.07%, B+Zr+Si≤0.3%, balance Ni.

[0006] Furthermore, the mass percentages of Ti, Hf, and C satisfy the condition: (Ti+Hf) / C≤70, preferably 45~70.

[0007] A second aspect of the present invention provides a laser forming method, comprising the following steps: An alloy powder is provided according to the composition of the additive manufacturing nickel-based superalloy provided in the first aspect of the present invention; the alloy powder is then laser-formed. In the laser forming process, the laser power is 180-225W and the scanning speed is 900-1200mm / s.

[0008] Furthermore, in the laser forming process, the scanning interval is 0.06–0.11 mm, and the powder layer thickness is 0.02–0.04 mm.

[0009] The third aspect of the present invention provides an additive manufacturing alloy component, which is obtained by the laser forming method provided in the second aspect of the present invention.

[0010] A fourth aspect of the present invention provides a heat treatment method for an additively manufactured alloy component provided in the third aspect of the present invention, comprising the following steps: The additively manufactured alloy component is subjected to hot isostatic pressing, followed by solution treatment and aging treatment. In the hot isostatic pressing process, the temperature is 1230–1250℃, the pressure is 140–190MPa, and the holding time is 2–6 hours.

[0011] Furthermore, in the solution treatment, the solution temperature is 1230–1270°C, and the holding time is 2–6 hours.

[0012] Furthermore, the aging treatment includes: holding at 1070-1100℃ for 4-8 hours, then cooling to 850-880℃ for 20-24 hours, and finally cooling to room temperature.

[0013] Furthermore, in the aging process, the cooling rate to 850–880°C is 20–30°C / min.

[0014] Furthermore, in the aging process, the cooling rate to room temperature is 150–200 °C / min.

[0015] Furthermore, after the heat treatment, the room temperature tensile strength of the additively manufactured alloy component is not less than 1350 MPa, and the room temperature elongation is not less than 20%.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves good formability by controlling the elemental composition of nickel-based superalloys and using appropriate laser forming parameters. Furthermore, by combining this with a certain heat treatment process, it can not only effectively close the small number of microcracks that may exist in laser forming, but also significantly improve mechanical properties. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 The lateral and longitudinal organization of the printed component provided in Embodiment 1 of the present invention are shown; wherein, (a) is the lateral organization and (b) is the longitudinal organization; Figure 2 The printing state provides horizontal and vertical organization in Embodiment 2 of the present invention; wherein, (a) is horizontal organization and (b) is vertical organization; Figure 3 The transverse and longitudinal structures of the heat-treated component provided in Embodiment 1 of the present invention are shown; wherein, (a) is the transverse structure and (b) is the longitudinal structure. Figure 4 The transverse and longitudinal structures of the heat-treated component provided in Embodiment 2 of the present invention are shown; wherein, (a) is the transverse structure and (b) is the longitudinal structure. Figure 5 The images shown are SEM images of the heat-treated component provided in Embodiment 3 of the present invention. (a) and (b) correspond to different magnifications, respectively. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0020] Currently, to improve the high-temperature performance of nickel-based superalloys with high aluminum and titanium content, some alloys are strengthened by adding appropriate amounts (e.g., ≤1.7wt%) of hafnium (Hf) (e.g., IN738, CM247LC), thereby enhancing their high-temperature mechanical properties. However, these alloys are prone to cracking during laser forming, and these cracks are difficult to repair through subsequent heat treatment. Studies have shown that removing Hf from the CM247LC alloy can reduce laser forming cracks, but this results in a significant decrease in mechanical properties. A Chinese patent application with publication number CN116949320A used Hf content exceeding 3.5%, and the sample printed by SLM showed no cracks; however, its alloy plasticity was significantly reduced. Therefore, how to ensure good laser formability while maintaining excellent mechanical properties has always been a challenge for nickel-based superalloys with high aluminum and titanium content.

[0021] Based on this, the first aspect of the present invention provides an additive manufacturing nickel-based superalloy comprising the following components by mass percentage: Cr 8.0%~8.5%, Co 9.0%~9.5%, W 9.0%~10.0%, Mo 0%~0.6%, Ta 2.5%~3.5%, Al 5.0%~6.0%, Ti 0.5%~1.0%, Hf 2.0%~2.5%, C 0.01%~0.07%, B+Zr+Si≤0.3%, balance Ni.

[0022] This invention adapts nickel-based superalloys for additive manufacturing by controlling their elemental composition. Specifically, it employs an appropriate amount of Hf and a low C content, while simultaneously controlling the contents of W, Mo, Ta, Al, and Ti to improve their formability. Further optimization with specific laser forming parameters and heat treatment processes not only effectively eliminates any microcracks that may exist during laser forming but also significantly improves their mechanical properties.

[0023] The Cr content in this invention is 8.0% to 8.5%, for example, it can be 8.0%, 8.1%, 8.2%, 8.3%, 8.4%, 8.5%, or any combination thereof; the Co content is 9.0% to 9.5%, for example, it can be 9.0%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, or any combination thereof; the W content is 9.0% to 10.0%, for example, it can be 9.0%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, or any combination thereof. The content of elements is 0.5%, 9.6%, 9.7%, 9.8%, 9.9%, 10.0%, or any combination thereof; the content of molybdenum (Mo) is 0% to 0.6%, for example, it can be 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, or any combination thereof; the content of ta (Ta) is 2.5% to 3.5%, for example, it can be 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%. The content of Al is 5.0% to 6.0%, for example, it can be 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.0%, or any two of these; the content of Ti is 0.5% to 1.0%, for example, it can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or any two of these; the content of Hf is 2.0% to 2%. 0.5%, for example, it can be a range of 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, or any two of them; the content of element C is 0.01% to 0.07%, for example, it can be a range of 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, or any two of them; the sum of the contents of B, Zr, and Si does not exceed 0.3%, for example, it can be a range of 0.3%, 0.2%, 0.1%, 0%, or any two of them.

[0024] In a specific embodiment of the present invention, the alloy contains 0.01% to 0.1% B, 0.001% to 0.05% Zr, and 0.01% to 0.15% Si by mass percentage.

[0025] In a specific embodiment of the present invention, the mass percentages of Ti, Hf, and C satisfy the following condition: (Ti+Hf) / C≤70.

[0026] In this invention, the ratio of the sum of the mass percentages of Ti and Hf to the mass percentage of C (Ti+Hf) / C is controlled to not exceed 70. For example, it can be a range of 70, 68, 65, 62, 60, 55, 50, 45, 40, 35, 30, or any combination thereof, preferably 45-70. By controlling the contents of Ti, Hf, and C to meet the above conditions, the alloy forms a favorable microstructure (multi-scale γ' phase, dispersed granular MC carbides, etc.) during rapid solidification and subsequent heat treatment, while reducing its solidification cracking index and liquefaction cracking index, thereby improving both the formability and the strength and plasticity of the alloy.

[0027] A second aspect of the present invention provides a laser forming method, comprising the following steps: The alloy powder is provided according to the composition of the additive manufacturing nickel-based superalloy provided in the first aspect of the present invention; the alloy powder is laser-formed. In laser forming, the laser power is 180–225W and the scanning speed is 900–1200 mm / s.

[0028] Using the additive manufacturing of nickel-based superalloys according to the present invention, and with the corresponding laser forming parameters, only a small number of microcracks exist in the corresponding printed components, and the corresponding microcracks can be repaired in the subsequent heat treatment process.

[0029] In the laser forming of the present invention, the laser power is 180 to 225 W, for example, it can be 180 W, 185 W, 190 W, 195 W, 200 W, 205 W, 210 W, 215 W, 220 W, 225 W or any combination thereof; the scanning speed is 900 to 1200 mm / s, for example, it can be 900 mm / s, 950 mm / s, 1000 mm / s, 1050 mm / s, 1100 mm / s, 1150 mm / s, 1200 mm / s or any combination thereof.

[0030] In a specific embodiment of the present invention, in laser forming, the scanning spacing is 0.06 to 0.11 mm, for example, it can be a range of 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.10 mm, 0.11 mm or any two of these ranges; the powder layer thickness is 0.02 to 0.04 mm, for example, it can be a range of 0.02 mm, 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm or any two of these ranges.

[0031] The preparation method of the alloy powder of the present invention is not limited. For example, gas atomization or plasma rotating electrode method can be used to obtain powder with sphericity, oxygen content, etc., that meet the requirements of conventional additive manufacturing. The particle size of the powder used for laser forming in the present invention is 15-53 μm.

[0032] The third aspect of the present invention provides an additive manufacturing alloy component, which is obtained by the laser forming method provided in the second aspect of the present invention.

[0033] In a specific embodiment of the present invention, the density of the additively manufactured alloy component is not less than 99%.

[0034] The fourth aspect of the present invention provides a heat treatment method for the additive manufacturing alloy component provided in the third aspect of the present invention, comprising the following steps: hot isostatic pressing of the additive manufacturing alloy component, followed by solution treatment and aging treatment.

[0035] In a specific embodiment of the present invention, in the hot isostatic pressing process, the temperature is 1230–1250°C, for example, it can be a range of 1230°C, 1235°C, 1240°C, 1245°C, 1250°C or any combination thereof; the pressure is 140–190 MPa, for example, it can be a range of 140 MPa, 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa or any combination thereof; and the heat and pressure holding time is 2–6 hours, for example, it can be 2 hours, 3 hours, 4 hours, 5 hours, 6 hours or any combination thereof.

[0036] The hot isostatic pressing process of this invention can close microcracks in printed alloy components and homogenize the microstructure.

[0037] In a specific embodiment of the present invention, the solution treatment temperature is 1230–1270°C, for example, it can be a range of 1230°C, 1240°C, 1250°C, 1260°C, 1270°C, or any combination thereof; the holding time is 2–6 hours, for example, it can be a range of 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, or any combination thereof. For the additive manufacturing alloy components of the present invention, controlling the temperature and time of the solution treatment within the above range after hot isostatic pressing is beneficial for homogenizing the microstructure and promoting recrystallization.

[0038] In a specific embodiment of the present invention, during the solution treatment, after the heat preservation is completed, the solution is cooled to room temperature in the furnace.

[0039] In a specific embodiment of the present invention, the aging treatment includes: holding at 1070-1100°C for 4-8 hours, then cooling down to 850-880°C for 20-24 hours, and finally cooling to room temperature.

[0040] In the aging process of this invention, the temperature is first maintained at 1070–1100°C, such as 1070°C, 1075°C, 1080°C, 1085°C, 1090°C, 1095°C, 1100°C, or any combination thereof, for 4–8 hours, such as 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, or any combination thereof; then the temperature is lowered to 850–880°C, such as 850°C, 855°C, 860°C, 865°C, 870°C, 875°C, 880°C, or any combination thereof, for 20–24 hours, such as 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, or any combination thereof; and then cooled to room temperature.

[0041] The aging treatment method of the present invention can control the precipitation of multi-scale γ' phase and MC-type carbides (HfC / TiC), thereby improving the strength and plasticity of additively manufactured alloy components.

[0042] In a specific embodiment of the present invention, during the aging process, the cooling rate to 850-880°C is 20-30°C / min, for example, it can be a range of 20°C / min, 22°C / min, 25°C / min, 28°C / min, 30°C / min, or any combination thereof.

[0043] In a specific embodiment of the present invention, during the aging process, the cooling rate to room temperature is 150 to 200°C / min, for example, it can be a range of 150°C / min, 160°C / min, 170°C / min, 180°C / min, 190°C / min, 200°C / min or any combination thereof.

[0044] In a specific embodiment of the present invention, after heat treatment, the γ' phase content in the microstructure of the additively manufactured alloy component exceeds 60%, and the size distribution ranges from 0.1 to 2 μm; the MC carbide content is greater than 1%, and the average size does not exceed 0.2 μm.

[0045] In a specific embodiment of the present invention, after heat treatment, the room temperature tensile strength of the additively manufactured alloy component is not less than 1350 MPa, for example, it can be a range of 1350 MPa, 1360 MPa, 1370 MPa, 1380 MPa, 1390 MPa, 1400 MPa, 1410 MPa, 1421 MPa or any two of these; the room temperature elongation is not less than 20%, for example, it can be a range of 20%, 21%, 22%, 23%, 24% or any two of these.

[0046] Example 1 This embodiment provides a method for preparing additively manufactured alloy components, including the following steps: (1) The powder was prepared by conventional gas atomization according to the composition of additive manufacturing of nickel-based high-temperature alloys, and the powder was sieved to obtain alloy powder with a particle size of 15-53 μm. The additively manufactured nickel-based superalloy comprises the following components by mass percentage: Cr 8.19%, Co 9.10%, W 9.17%, Mo 0.47%, Ta 3.25%, Al 5.57%, Ti 0.71%, Hf 2.01%, C 0.04%, B 0.01%, Zr 0.02%, Si 0.1%, with the balance being Ni.

[0047] (2) The alloy powder obtained in step (1) is added to the printing chamber, argon gas is introduced to reduce the oxygen content to below 200ppm, and the substrate is heated to 100°C. Then, a laser forming process is performed to obtain the printed alloy component. The laser forming parameters are: laser power 180W, scanning speed 900mm / s, scanning spacing 0.11mm, powder layer thickness 0.03mm, and spot diameter 80μm.

[0048] (3) The printed alloy component obtained in step (2) is subjected to hot isostatic pressing, solution treatment and aging treatment in sequence; In the hot isostatic pressing process, the temperature is 1230℃, the pressure is 160MPa, the holding time is 3h, and the furnace is cooled to room temperature after the holding time is completed. Solution treatment includes: solution treatment at 1230℃ for 6 hours, followed by furnace cooling to room temperature; The aging process includes: holding at 1070℃ for 6 hours, cooling down to 880℃ at a cooling rate of 30℃ / min and holding at that temperature for 20 hours, and then air cooling to room temperature at a cooling rate of 150℃ / min.

[0049] Example 2 This embodiment provides a method for preparing additively manufactured alloy components, including the following steps: (1) Referring to step (1) in Example 1, the only difference is the different composition ratio of the additively manufactured nickel-based superalloy; the additively manufactured nickel-based superalloy of this example includes the following components by mass percentage: Cr 8.34%, Co 9.13%, W 9.42%, Mo 0.50%, Ta 3.05%, Al 5.54%, Ti 0.76%, Hf 2.45%, C 0.06%, B 0.03%, Zr 0.01%, Si 0.12%, with the balance being Ni.

[0050] (2) The alloy powder obtained in step (1) is added to the printing chamber, argon gas is introduced to reduce the oxygen content to below 200ppm, and the substrate is heated to 100°C. Then, a laser forming process is performed to obtain the printed alloy component. The laser forming parameters are: laser power 225W, scanning speed 1200mm / s, scanning spacing 0.06mm, powder layer thickness 0.03mm, and spot diameter 80μm.

[0051] (3) The printed alloy component obtained in step (2) is subjected to hot isostatic pressing, solution treatment and aging treatment in sequence; In the hot isostatic pressing process, the temperature is 1250℃, the pressure is 160MPa, the holding time is 3h, and the furnace is cooled to room temperature after the holding time is completed. Solution treatment includes: solution treatment at 1270℃ for 2 hours, followed by furnace cooling to room temperature; The aging process includes: holding at 1080℃ for 8 hours, cooling down to 850℃ at a cooling rate of 20℃ / min and holding at that temperature for 24 hours, and then air cooling to room temperature at a cooling rate of 200℃ / min.

[0052] Example 3 This embodiment provides a method for preparing additively manufactured alloy components, including the following steps: (1) Referring to step (1) in Example 1, the only difference is the different composition ratio of the additively manufactured nickel-based superalloy; the additively manufactured nickel-based superalloy of this example includes the following components by mass percentage: Cr 8.30%, Co 9.36%, W 9.29%, Mo 0.58%, Ta 3.10%, Al 5.63%, Ti 0.74%, Hf 2.15%, C 0.06%, B 0.03%, Zr 0.02%, Si 0.15%, with the balance being Ni.

[0053] (2) Add the alloy powder obtained in step (1) into the printing chamber, introduce argon gas to reduce the oxygen content to below 200ppm, heat the substrate to 100℃, and then perform a laser forming process to obtain a printed alloy component; the laser forming parameters are: laser power 200W, scanning speed 1100mm / s, scanning spacing 0.06mm, powder layer thickness 0.03mm, and spot diameter 80μm.

[0054] (3) The printed alloy component obtained in step (2) is subjected to hot isostatic pressing, solution treatment and aging treatment in sequence; In the hot isostatic pressing process, the temperature is 1240℃, the pressure is 160MPa, the holding time is 3h, and the furnace is cooled to room temperature after the holding time is completed. Solution treatment includes: solution treatment at 1245℃ for 4 hours, followed by furnace cooling to room temperature; The aging process includes: holding at 1070℃ for 4 hours, cooling down to 850℃ at a cooling rate of 20℃ / min and holding at that temperature for 24 hours, and then air cooling to room temperature at a cooling rate of 200℃ / min.

[0055] Example 4 This embodiment refers to the preparation method of Embodiment 3, the only difference being that the hot isostatic pressing treatment in step (3) is different.

[0056] The hot isostatic pressing process in this embodiment includes: a temperature of 1200℃, a pressure of 140MPa, a holding time of 3h, and furnace cooling to room temperature after the holding time is completed.

[0057] Example 5 This embodiment refers to the preparation method of Example 3, the only difference being the solution treatment in step (3).

[0058] The solution treatment in this embodiment includes: solution treatment at 1200℃ for 4 hours, followed by furnace cooling to room temperature.

[0059] Example 6 This embodiment refers to the preparation method of embodiment 3, the only difference being the aging treatment in step (3).

[0060] The aging process in this embodiment includes: holding at 900°C for 24 hours, and then air-cooling to room temperature at a cooling rate of 200°C / min.

[0061] Comparative Example 1 Comparative Example 1 provides a method for preparing additively manufactured alloy components, comprising the following steps: (1) Refer to step (1) in Example 1, the only difference being the different composition ratio of the additively manufactured nickel-based superalloy; the additively manufactured nickel-based superalloy of Comparative Example 1 includes the following components by mass percentage: Cr 8.01%, Co 9.32%, W 2.81%, Mo 0.50%, Ta 3.20%, Al 4.25%, Ti 1.74%, Hf 4.15%, C 0.07%, B 0.01%, Zr 0.1%, Si 0.14%, with the balance being Ni.

[0062] (2) The alloy powder obtained in step (1) is added to the printing chamber, argon gas is introduced to reduce the oxygen content to below 200ppm, and the substrate is heated to 100℃. Then, a laser forming process is performed to obtain the printed alloy component. The laser forming parameters are: laser power 200W, scanning speed 900mm / s, scanning spacing 0.10mm, powder layer thickness 0.03mm, and spot diameter 80μm.

[0063] (3) The printed alloy components obtained in step (2) are subjected to solution treatment and aging treatment in sequence; The solution treatment includes: solution treatment at 1220℃ for 2 hours, followed by air cooling to room temperature; The aging process includes: holding at 850℃ for 10 hours, and then air-cooling to room temperature at a cooling rate of 200℃ / min.

[0064] Comparative Example 2 Comparative Example 2 provides a method for preparing additively manufactured alloy components, including the following steps: (1) Refer to step (1) in Example 1, the only difference being the different composition ratio of the additively manufactured nickel-based superalloy; the additively manufactured nickel-based superalloy of Comparative Example 2 includes the following components by mass percentage: Cr 8.25%, Co 9.15%, W 9.20%, Mo 0.50%, Ta 3.25%, Al 5.13%, Ti 0.94%, Hf 0.02%, C 0.12%, B 0.01%, Zr 0.05%, Si 0.10%, with the balance being Ni.

[0065] (2) The alloy powder obtained in step (1) is added to the printing chamber, argon gas is introduced to reduce the oxygen content to below 200ppm, and the substrate is heated to 100℃. Then, a laser forming process is performed to obtain the printed alloy component. The laser forming parameters are: laser power 200W, scanning speed 900mm / s, scanning spacing 0.10mm, powder layer thickness 0.03mm, and spot diameter 80μm.

[0066] (3) The printed alloy components obtained in step (2) are subjected to solution treatment and aging treatment in sequence; The solution treatment includes: solution treatment at 1220℃ for 2 hours, followed by air cooling to room temperature; The aging process includes: holding at 850℃ for 10 hours, and then air-cooling to room temperature at a cooling rate of 200℃ / min.

[0067] Comparative Example 3 Comparative Example 3 uses the same preparation method as Example 3, except that the composition ratio of the additive manufacturing nickel-based superalloy in step (1) is different.

[0068] Comparative Example 3: The additive manufacturing nickel-based superalloy was replaced with CM247LC alloy; specifically, the CM247LC alloy, by mass percentage, includes the following components: Cr 8.15%, Co 9.15%, W 9.40%, Mo 0.50%, Ta 3.10%, Al 5.50%, Ti 0.80%, Hf 1.50%, C 0.09%, B 0.01%, Zr 0.02%, Si 0.10%, with the balance being Ni.

[0069] Experimental Example The transverse and longitudinal structures in the printed state of Examples 1 and 2 are as follows: Figure 1 and Figure 2 As shown in the figure, the printed component of this embodiment has a small number of microcracks in both the horizontal and vertical directions, and exhibits a distinct molten pool morphology.

[0070] The transverse and longitudinal microstructures of the heat-treated states in Examples 1 and 2 are as follows: Figure 3 and Figure 4 As shown in the figure, there are no cracks in the heat-treated microstructure of Embodiments 1 and 2 of the present invention, and the molten pool morphology has disappeared. The SEM image of the heat-treated component of Embodiment 3 is shown below. Figure 5 As shown in the figure, the heat-treated component of Embodiment 3 of the present invention has a multi-scale γ' phase distributed within the grains and MC-type carbides dispersed at the grain boundaries.

[0071] The room temperature tensile properties of the heat-treated state of different embodiments and comparative examples were further tested. The sample sampling direction was transverse. The test results are shown in Table 1.

[0072] Table 1. Microstructure and room temperature tensile properties of heat-treated microstructures of different embodiments and comparative examples.

[0073] The test results above show that by adjusting the elemental composition of the nickel-based superalloy and combining it with appropriate laser forming parameters, the present invention has good formability. Furthermore, by combining it with a certain heat treatment process, it can not only effectively bridge the small number of microcracks that may exist in laser forming, but also significantly improve mechanical properties.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An additive manufacturing method for nickel-based superalloys, characterized in that, It includes the following components by mass percentage: Cr 8.0%~8.5%, Co 9.0%~9.5%, W 9.0%~10.0%, Mo 0%~0.6%, Ta 2.5%~3.5%, Al 5.0%~6.0%, Ti 0.5%~1.0%, Hf 2.0%~2.5%, C 0.01%~0.07%, B+Zr+Si≤0.3%, balance Ni.

2. The additive manufacturing nickel-based superalloy according to claim 1, characterized in that, The mass percentages of Ti, Hf, and C satisfy the following condition: (Ti+Hf) / C≤70, preferably 45~70.

3. A laser forming method, characterized in that, Includes the following steps: The alloy powder is provided according to the composition of the additive manufacturing nickel-based superalloy as described in claim 1 or 2; the alloy powder is then laser-formed. In the laser forming process, the laser power is 180-225W and the scanning speed is 900-1200mm / s.

4. The laser forming method according to claim 3, characterized in that, In the laser forming process, the scanning interval is 0.06–0.11 mm, and the powder layer thickness is 0.02–0.04 mm.

5. An additively manufactured alloy component, characterized in that, It is mainly produced by the laser forming method described in claim 3 or 4.

6. The heat treatment method for additively manufactured alloy components according to claim 5, characterized in that, Includes the following steps: The additively manufactured alloy component is subjected to hot isostatic pressing, followed by solution treatment and aging treatment. In the hot isostatic pressing process, the temperature is 1230–1250℃, the pressure is 140–190MPa, and the holding time is 2–6 hours.

7. The heat treatment method according to claim 6, characterized in that, In the solution treatment, the solution temperature is 1230–1270℃, and the holding time is 2–6 hours.

8. The heat treatment method according to claim 6, characterized in that, The aging treatment includes: holding at 1070-1100℃ for 4-8 hours, then cooling to 850-880℃ for 20-24 hours, and finally cooling to room temperature.

9. The heat treatment method according to claim 8, characterized in that, The timeliness processing has at least one of the following characteristics: (1) The cooling rate to 850-880℃ is 20-30℃ / min; (2) The cooling rate to room temperature is 150-200℃ / min.

10. The heat treatment method according to claim 6, characterized in that, After the heat treatment, the room temperature tensile strength of the additively manufactured alloy component is not less than 1350 MPa, and the room temperature elongation is not less than 20%.

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