3D printing method for nickel-based superalloys, 3D printed parts obtained and heat treatment method

Abstract

This invention relates to the field of additive manufacturing technology, and in particular to a method for 3D printing nickel-based superalloys, the resulting 3D printed parts, and a heat treatment method. The method for 3D printing nickel-based superalloys includes the following steps: 3D printing nickel-based superalloy powder under vacuum or a protective atmosphere; in the 3D printing, the power is 220–260 W, and the scanning speed is 1100–1350 mm / s; the nickel-based superalloy powder is prepared by plasma rotating electrode atomization. Based on the composition of nickel-based superalloys, this invention employs specific alloy powder preparation and 3D printing processes to produce 3D printed parts with high density and strength similar to alloys prepared by traditional processes, meeting practical application requirements.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a method for 3D printing nickel-based high-temperature alloys, the resulting 3D printed parts, and a heat treatment method. Background Technology

[0002] Rocket engines contain many structurally complex components, making welding extremely difficult and resulting in welded joints that often fail to meet performance requirements. Additive manufacturing technology has garnered widespread attention due to its significant advantages, including its ability to process complex components, short processing cycles, and elimination of the need for tooling and molds.

[0003] However, the high temperature gradient and rapid cooling rate during additive manufacturing solidification result in significantly different performance characteristics between additively manufactured structural components and those produced by traditional casting and forging. Therefore, developing a structural component that can be produced through additive manufacturing and meets the requirements of rocket engines for hot-end components is of great significance for the development of rocket engines.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] One objective of this invention is to provide a method for 3D printing nickel-based high-temperature alloys, wherein the strength of the 3D printed parts is close to that of alloy parts prepared by traditional processes, thus meeting the needs of practical applications.

[0006] Another object of the present invention is to provide a 3D printed part having high density and excellent room temperature strength and elongation.

[0007] Another object of the present invention is to provide a heat treatment method for 3D printed parts.

[0008] To achieve the above-mentioned objectives of the present invention, one aspect of the present invention provides a method for 3D printing nickel-based high-temperature alloys, comprising the following steps:

[0009] 3D printing of nickel-based superalloy powders under vacuum or protective atmosphere;

[0010] In the 3D printing process, the power is 220-260W and the scanning speed is 1100-1350mm / s;

[0011] The nickel-based high-temperature alloy powder is prepared by plasma rotating electrode atomization powder preparation.

[0012] In a specific embodiment of the present invention, the 3D printing process has at least one of the following features:

[0013] (1) The diameter of the light spot is 30-40 μm;

[0014] (2) The scanning interval is 0.07–0.09 mm;

[0015] (3) The thickness of a single layer of powder is 25-35 μm.

[0016] In a specific embodiment of the present invention, the particle size of the nickel-based high-temperature alloy powder is 15–53 μm.

[0017] In a specific embodiment of the present invention, the plasma rotating electrode atomization has at least one of the following characteristics:

[0018] (1) The spindle speed is 22000~26000r / min;

[0019] (2) The feed rate is 0.8 to 1 mm / s;

[0020] (3) The main arc current is 1100-1200A;

[0021] (4) The plasma working gas flow rate is 10-15 L / min.

[0022] In a specific embodiment of the present invention, the plasma rotating electrode atomization includes:

[0023] (a) Alloy bars were obtained by vacuum induction melting and vacuum consumable arc melting.

[0024] (b) Using the alloy rod as a consumable electrode, setting the parameters for plasma rotating electrode atomization powder preparation, and starting the equipment to prepare the powder;

[0025] (c) The powder obtained in step (b) is sieved to collect alloy powder with a particle size of 15 to 53 μm.

[0026] In a specific embodiment of the present invention, the nickel-based superalloy comprises the following components by mass percentage: C 0.01%–0.035%, Cr 17.1%–18.5%, Nb 4.81%–5.5%, Mo 3.55%–5%, Al 0.5%–1.15%, Ti 0.6%–1%, Fe 13.1%–16%, V 0.41%–0.6%, B 0.001%–0.01%, Cu 0.1%–0.55%, Zr 0.001%–0.1%, Ce 0.001%–0.01%, Mn 0.001%–0.7%, Si 0.01%–0.5%, P ≤ 0.015%, S ≤ 0.01%, and the balance Ni.

[0027] Another aspect of the present invention provides a 3D printed part, which is prepared by any of the nickel-based superalloy 3D printing methods described above.

[0028] In a specific embodiment of the present invention, the density of the 3D printed part is ≥99.92%.

[0029] In a specific embodiment of the present invention, the room temperature tensile strength of the 3D printed part in the printed state is ≥1000MPa.

[0030] Another aspect of the present invention provides a heat treatment method for 3D printed parts, comprising the following steps: performing solution treatment and double aging treatment on any of the above-described 3D printed parts;

[0031] The solution treatment includes: holding at 1030–1060°C for 2–4 hours, followed by air cooling.

[0032] In a specific embodiment of the present invention, the dual aging treatment includes: holding at 720-740℃ for 14-16 hours followed by air cooling; and holding at 640-660℃ for 9-11 hours followed by air cooling.

[0033] In a specific embodiment of the present invention, after the heat treatment, the room temperature tensile strength of the longitudinally printed 3D part is ≥1370MPa, and the room temperature elongation is ≥23.0%.

[0034] In a specific embodiment of the present invention, after the heat treatment, the precipitated phase includes a γ′-γ″ symbiotic phase.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] (1) Based on the composition of nickel-based high-temperature alloys, this invention uses a certain alloy powder making and 3D printing process to produce 3D printed parts with high density and strength similar to that of alloys prepared by traditional processes, which meets the needs of practical applications.

[0037] (2) Based on the composition of nickel-based high-temperature alloys and the powder preparation and 3D printing processes, the present invention regulates the heat treatment process to generate γ′-γ″ symbiotic phases in the precipitated phases, which significantly improves the strength of the 3D printed parts and meets the requirements of rocket engines. Attached Figure Description

[0038] 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.

[0039] Figure 1 This is a microscopic morphology diagram of the plasma rotating electrode atomization (PREP) powder provided in Embodiment 1 of the present invention;

[0040] Figure 2This is a microscopic morphology diagram of the gas atomized powder provided in Comparative Example 1 of the present invention.

[0041] Figure 3 This is a diagram of the printed structure of the 3D printed part provided in Embodiment 1 of the present invention;

[0042] Figure 4 This is a diagram of the printed structure of the 3D printed part provided in Embodiment 2 of the present invention;

[0043] Figure 5 This is a diagram of the printed structure of the 3D printed part provided in Comparative Example 2 of the present invention;

[0044] Figure 6 This is a diagram of the printed structure of the 3D printed part provided in Comparative Example 3 of the present invention;

[0045] Figure 7 This is a microstructure diagram of the 3D printed part in its heat-treated state provided in Embodiment 1 of the present invention;

[0046] Figure 8 This is a microstructure diagram of the 3D printed part in its heat-treated state provided in Embodiment 2 of the present invention;

[0047] Figure 9 This is a microstructure diagram of the 3D printed part in its heat-treated state provided in Embodiment 7 of the present invention;

[0048] Figure 10 This is a microstructure diagram of the 3D printed part in its heat-treated state provided in Embodiment 8 of the present invention;

[0049] Figure 11 This is a microstructure diagram of the 3D printed part in the heat-treated state provided in Embodiment 1 of the present invention;

[0050] Figure 12 This is a microstructure diagram of the 3D printed part in the heat-treated state provided in Comparative Example 1 of the present invention. Detailed Implementation

[0051] 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.

[0052] Research has found that alloy powders produced by gas atomization form varying degrees of "satellite spheres" on their surface, affecting powder usability. Plasma rotating electrode atomization (PREP) powder production yields powders with high sphericity, fewer "satellite spheres," and a more concentrated particle size distribution. Existing technologies document that using powders with suitable particle size distribution helps achieve better powder spreading effects. Based on this, this invention, according to the composition of nickel-based superalloys, employs a specific PREP powder production process and further coordinates it with 3D printing process control to produce 3D printed parts with high density and high strength, meeting practical application requirements.

[0053] This invention provides a method for 3D printing nickel-based superalloys, comprising the following steps:

[0054] 3D printing of nickel-based superalloy powders under vacuum or protective atmosphere;

[0055] In 3D printing, the power is 220-260W and the scanning speed is 1100-1350mm / s;

[0056] Nickel-based high-temperature alloy powder is prepared by plasma rotating electrode atomization powder preparation.

[0057] Based on the composition of nickel-based high-temperature alloys, this invention employs plasma rotating electrode atomization powder preparation and adjusts the 3D printing process according to the powder morphology, resulting in 3D printed parts with high density and strength similar to alloys prepared by traditional processes.

[0058] In different implementations, the power in 3D printing can be a range of 220W, 225W, 230W, 235W, 240W, 245W, 250W, 255W, 260W, or any combination thereof; the scanning speed can be a range of 1100mm / s, 1120mm / s, 1150mm / s, 1180mm / s, 1200mm / s, 1220mm / s, 1250mm / s, 1280mm / s, 1300mm / s, 1320mm / s, 1350mm / s, or any combination thereof.

[0059] This invention employs appropriate power and scanning speed, combined with the characteristics of the powder, to achieve a uniform molding surface, increased density, and improved alloy strength.

[0060] In a specific embodiment of the present invention, 3D printing has at least one of the following features:

[0061] (1) The diameter of the light spot is 30-40 μm;

[0062] (2) The scanning interval is 0.07–0.09 mm;

[0063] (3) The thickness of a single layer of powder is 25-35 μm.

[0064] In different implementations, during 3D printing, the spot diameter can be 30μm, 32μm, 34μm, 35μm, 36μm, 38μm, 40μm, or any combination thereof; the scanning spacing can be 0.07mm, 0.072mm, 0.075mm, 0.078mm, 0.08mm, 0.082mm, 0.085mm, 0.088mm, 0.09mm, or any combination thereof; and the single-layer powder thickness can be 25μm, 28μm, 30μm, 32μm, 35μm, or any combination thereof.

[0065] In a specific embodiment of the present invention, the particle size of the nickel-based high-temperature alloy powder is 15–53 μm.

[0066] In a specific embodiment of the present invention, plasma rotating electrode atomization has at least one of the following characteristics:

[0067] (1) The spindle speed is 22000~26000r / min;

[0068] (2) The feed rate is 0.8 to 1 mm / s;

[0069] (3) The main arc current is 1100-1200A;

[0070] (4) The plasma working gas flow rate is 10-15 L / min.

[0071] In different embodiments, during plasma rotating electrode atomization, the spindle speed can be within the range of 22000 r / min, 23000 r / min, 24000 r / min, 25000 r / min, 26000 r / min, or any combination thereof; the feed speed can be within the range of 0.8 mm / s, 0.85 mm / s, 0.9 mm / s, 0.95 mm / s, 1 mm / s, or any combination thereof; the main arc current can be within the range of 1100 A, 1120 A, 1150 A, 1180 A, 1200 A, or any combination thereof; and the plasma working gas flow rate can be within the range of 10 L / min, 11 L / min, 12 L / min, 13 L / min, 14 L / min, 15 L / min, or any combination thereof.

[0072] In a specific embodiment of the present invention, plasma rotating electrode atomization includes:

[0073] (a) Alloy bars were obtained by vacuum induction melting and vacuum consumable arc melting.

[0074] (b) Using the alloy rod as a consumable electrode, setting the parameters for plasma rotating electrode atomization powder preparation, and starting the equipment to prepare the powder;

[0075] (c) The powder obtained in step (b) is sieved to collect alloy powder with a particle size of 15 to 53 μm.

[0076] In practice, vacuum induction melting and vacuum arc melting can be adjusted according to the conventional melting process of alloys, which will not be elaborated here.

[0077] Specifically, plasma rotating electrode atomization may include: loading alloy rods into a rotating feed device, evacuating the atomization chamber to a preset vacuum level, filling it with protective gas to achieve a preset pressure, monitoring the oxygen content in the atomization chamber to ensure it does not exceed 100 ppm; then starting the rotating feed device and the plasma gun power supply to perform atomization powder production, generating a high-temperature plasma arc between the alloy rods and the plasma gun, melting the rods under the combined action of centrifugal force and surface tension to form tiny droplets, which then solidify into metal powder for sieving and collection.

[0078] In a specific embodiment of the present invention, the nickel-based superalloy comprises the following components by mass percentage: C 0.01%–0.035%, Cr 17.1%–18.5%, Nb 4.81%–5.5%, Mo 3.55%–5%, Al 0.5%–1.15%, Ti 0.6%–1%, Fe 13.1%–16%, V 0.41%–0.6%, B 0.001%–0.01%, Cu 0.1%–0.55%, Zr 0.001%–0.1%, Ce 0.001%–0.01%, Mn 0.001%–0.7%, Si 0.01%–0.5%, P ≤ 0.015%, S ≤ 0.01%, and the balance Ni.

[0079] The nickel-based superalloy used in this invention is an age-hardening nickel-based superalloy with a high content of Nb, Ti, and Al elements. Combined with PREP powder preparation process and corresponding 3D printing process, the 3D printed parts formed with γ′-γ″ symbiotic phase can significantly improve the strength of the 3D printed parts.

[0080] In another aspect, the present invention provides a 3D printed part, which is prepared by any of the above-mentioned nickel-based high-temperature alloy 3D printing methods.

[0081] In a specific embodiment of the present invention, the density of the 3D printed part is ≥99.92%.

[0082] The 3D printed parts of the present invention, while maintaining high density, can control the precipitated phase to improve the strength properties of the 3D printed parts. For example, in different embodiments, the density of the 3D printed parts can be 99.92%, 99.93%, 99.94%, 99.95%, 99.96%, or any combination thereof.

[0083] In a specific embodiment of the present invention, the room temperature tensile strength of the 3D printed part in the printed state is ≥1000MPa.

[0084] In this invention, the room temperature tensile strength of the 3D printed parts printed vertically can meet ≥1000MPa, and the room temperature tensile strength of the 3D printed parts printed horizontally can not only meet ≥1000MPa, but also ≥1100MPa.

[0085] In different implementations, the room temperature tensile strength of the 3D printed part in the printed state can be a range of 1000MPa, 1010MPa, 1020MPa, 1030MPa, 1040MPa, 1046MPa, 1060MPa, 1070MPa, 1080MPa, 1090MPa, 1100MPa, or any combination thereof.

[0086] Another aspect of the present invention provides a heat treatment method for 3D printed parts, comprising the following steps: performing solution treatment and double aging treatment on any of the above-mentioned 3D printed parts;

[0087] Solution treatment includes: holding at 1030–1060℃ for 2–4 hours, followed by air cooling.

[0088] This invention, by controlling the conditions of solution treatment, combined with appropriate alloys and 3D printing processes, enables the formation of a γ′-γ″ symbiotic phase in the precipitated phase of the heat-treated 3D printed part, which can significantly improve the strength of the 3D printed part.

[0089] In different embodiments, the solution treatment temperature can be a range of 1030°C, 1035°C, 1040°C, 1045°C, 1050°C, 1055°C, 1060°C or any combination thereof; the solution treatment holding time can be a range of 2h, 2.5h, 3h, 3.5h, 4h or any combination thereof.

[0090] In a specific embodiment of the present invention, the dual aging treatment includes: holding at 720-740°C for 14-16 hours followed by air cooling; and holding at 640-660°C for 9-11 hours followed by air cooling.

[0091] In a specific embodiment of the present invention, after heat treatment, the room temperature tensile strength of the longitudinally printed 3D part is ≥1370MPa and the room temperature elongation is ≥23.0%.

[0092] In this invention, the 3D printed parts printed vertically can achieve a room temperature tensile strength of ≥1370MPa after heat treatment, while the 3D printed parts printed horizontally can achieve a room temperature tensile strength of ≥1370MPa and ≥1450MPa after heat treatment.

[0093] In different embodiments, after heat treatment, the room temperature tensile strength of the 3D printed part can be in the range of 1370MPa, 1380MPa, 1390MPa, 1400MPa, 1410MPa, 1420MPa, 1430MPa, 1440MPa, 1450MPa, 1460MPa, 1470MPa, 1472MPa or any combination thereof; and the room temperature elongation can be in the range of 23%, 23.2%, 23.5%, 23.8%, 24%, 24.2%, 24.5% or any combination thereof.

[0094] The 3D printed parts of this invention exhibit significantly improved tensile strength after heat treatment, and their longitudinal tensile properties are also significantly superior to those of alloys produced by traditional processes.

[0095] In a specific embodiment of the present invention, after heat treatment, the precipitated phase includes a γ′-γ″ symbiotic phase.

[0096] In the following specific embodiments, unless otherwise specified, the 3D printing direction is described as vertical printing.

[0097] Example 1

[0098] This embodiment provides a 3D printing method and heat treatment method for nickel-based superalloys, including the following steps:

[0099] (1) Prepare raw materials according to the composition and content of nickel-based high-temperature alloys, and obtain alloy blocks by vacuum induction melting + vacuum consumable arc melting, and process them into alloy bars; set the powder making process parameters: main arc current 1150A, arc current 90A, feed speed 0.9mm / s, spindle speed 22000~26000r / min, spindle stepping speed set to 1000r / min, and working gas inlet flow rate for plasma gun is 15L / min;

[0100] The arc is initiated at 22,000 rpm. The bar stock is fed 20 mm, and the rpm is increased to 23,000 rpm. The bar stock is fed another 20 mm, and the rpm is increased to 24,000 rpm. The bar stock is fed 60 mm, and the rpm is increased to 25,000 rpm. The bar stock is fed 50 mm, and the rpm is increased to 26,000 rpm, until the refining is complete. After cooling, the powder is collected and sieved to obtain 15–53 μm powder as the finished product.

[0101] The nickel-based superalloy composition includes, by mass percentage: C 0.011%, Cr 17.24%, Nb 5.08%, Mo 3.95%, Al 0.95%, Ti 0.70%, Fe 14.03%, V 0.45%, B 0.0062%, Cu 0.35%, Zr 0.052%, Ce 0.0016%, Mn 0.0034%, Si 0.029%, P < 0.0040%, S 0.0006%, and the balance Ni.

[0102] (2) Using the finished powder obtained in step (1), a 3D printing sample was prepared by SLM process. The 3D printing process parameters were: 3D printing power of 240W, 3D printing scanning speed of 1200mm / s, 3D printing spot diameter of 35μm, 3D printing scanning spacing of 0.08mm, and 3D printing single-layer powder thickness of 0.03mm.

[0103] (3) The 3D printed part obtained in step (2) is kept at 1050℃ for 3 hours and then air-cooled; then kept at 730℃ for 15 hours and then air-cooled; and then kept at 650℃ for 10 hours and then air-cooled.

[0104] Example 2

[0105] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Embodiment 1, the only difference being that the 3D printing power and scanning speed are different in step (2).

[0106] The 3D printing power in this embodiment is 220W, and the scanning speed is 1200mm / s.

[0107] Example 3

[0108] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Embodiment 1, the only difference being that the 3D printing power and scanning speed are different in step (2).

[0109] The 3D printing power in this embodiment is 260W, and the scanning speed is 1200mm / s.

[0110] Example 4

[0111] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Embodiment 1, the only difference being that the 3D printing power and scanning speed are different in step (2).

[0112] The 3D printing power in this embodiment is 240W, and the scanning speed is 1100mm / s.

[0113] Example 5

[0114] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Embodiment 1, the only difference being that the 3D printing power and scanning speed are different in step (2).

[0115] The 3D printing power in this embodiment is 240W, and the scanning speed is 1350mm / s.

[0116] Example 6

[0117] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Embodiment 1, the only difference being: in step (3), the heat treatment regime is different.

[0118] Step (3) of this embodiment includes: heat-treating the 3D printed part obtained in step (2) at 980°C for 3 hours and then air-cooling it; then heat-treating it at 730°C for 15 hours and then air-cooling it; and then heat-treating it at 650°C for 10 hours and then air-cooling it.

[0119] Example 7

[0120] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Embodiment 2, the only difference being: in step (3), the heat treatment regime is different.

[0121] Step (3) of this embodiment includes: heat-treating the 3D printed part obtained in step (2) at 980°C for 3 hours and then air-cooling it; then heat-treating it at 730°C for 15 hours and then air-cooling it; and then heat-treating it at 650°C for 10 hours and then air-cooling it.

[0122] Example 8

[0123] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Embodiment 1, the only difference being: in step (3), the heat treatment regime is different.

[0124] Step (3) of this embodiment includes: heat-treating the 3D printed part obtained in step (2) at 1100℃ for 3 hours and then air-cooling it; then heat-treating it at 730℃ for 15 hours and then air-cooling it; and then heat-treating it at 650℃ for 10 hours and then air-cooling it.

[0125] Comparative Example 1

[0126] Comparative Example 1 provides a method for 3D printing nickel-based superalloys, including the following steps:

[0127] (1) Prepare the same nickel-based high-temperature alloy block according to the method of Example 1; load the alloy block into the melting furnace and evacuate the melting furnace until the vacuum degree reaches 7-9 Pa; adjust the medium frequency voltage and perform vacuum melting until the melt temperature reaches 1745℃ and the melting time is about 70 min; then refine and degas to obtain alloy liquid; turn on the intermediate ladle heating system (1690-1720℃), introduce high-purity argon gas at a pressure of 4.05 MPa, pour the alloy liquid into the intermediate ladle, perform atomization powder spraying, and after cooling, sieve and collect powder with a particle size of 25-53 μm as finished powder.

[0128] (2) Using the finished powder obtained in step (1), 3D printing samples were prepared by SLM process. The 3D printing process parameters were: 3D printing power of 287W, 3D printing scanning speed of 945mm / s, 3D printing spot diameter of 65μm, 3D printing scanning spacing of 110μm, and 3D printing single-layer powder thickness of 40μm.

[0129] The heat treatment method of Comparative Example 1 includes: holding at 980℃ for 1 hour and then air cooling; then holding at 730℃ for 15 hours and then air cooling; and finally holding at 650℃ for 10 hours and then air cooling.

[0130] Comparative Example 2

[0131] Comparative Example 2 refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Example 1, the difference being that in step (2), the 3D printing power and scanning speed are different.

[0132] The 3D printing power of Comparative Example 2 is 240W, and the scanning speed of 3D printing is 800mm / s.

[0133] Comparative Example 3

[0134] Comparative Example 3 refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Example 1, the difference being that in step (2), the 3D printing power and scanning speed are different.

[0135] The 3D printing power of Comparative Example 3 is 140W, and the scanning speed of 3D printing is 1200mm / s.

[0136] Comparative Example 4

[0137] Comparative Example 4 refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Example 1, the difference being that in step (2), the 3D printing power and scanning speed are different.

[0138] The 3D printing power of Comparative Example 4 is 200W, and the scanning speed of 3D printing is 1200mm / s.

[0139] Comparative Example 5

[0140] Comparative Example 5 refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Example 1, the difference being that in step (2), the 3D printing power and scanning speed are different.

[0141] The 3D printing power of Comparative Example 5 is 280W, and the scanning speed of 3D printing is 1200mm / s.

[0142] Comparative Example 6

[0143] Comparative Example 6 refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Example 1, the difference being that in step (2), the 3D printing power and scanning speed are different.

[0144] The 3D printing power of Comparative Example 6 is 240W, and the scanning speed of 3D printing is 1000mm / s.

[0145] Comparative Example 7

[0146] Comparative Example 7 refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Example 1, the difference being that in step (2), the 3D printing power and scanning speed are different.

[0147] The 3D printing power of Comparative Example 7 is 240W, and the scanning speed of 3D printing is 1400mm / s.

[0148] Experimental Example 1

[0149] The microstructure of the plasma rotating electrode atomized powder provided in Example 1 and the gas atomized powder provided in Comparative Example 1 were observed using SEM, as shown below. Figure 1 and Figure 2 As shown in the figure, the powder provided in Example 1 of the present invention has a relatively concentrated particle size distribution and a high degree of sphericity; while the powder provided in Comparative Example 1 has more "satellite spheres" and a relatively poor degree of sphericity.

[0150] Experimental Example 2

[0151] Defects in the 3D printed specimens obtained in Examples 1-2 and Comparative Examples 2-3 were observed using an optical microscope, as detailed below. Figures 3-6 As can be seen from the figure, the printed specimens obtained using the methods of Examples 1 and 2 have low porosity and few defects. In contrast, the printed specimens obtained using the methods of Comparative Examples 2 and 3 have high porosity and defects such as cracks. Figures 7-10The figures show the microstructure of the 3D printed parts in the heat-treated state provided in Embodiments 1, 2, 7 and 8 of this invention. As can be seen from the figures, the grain size of the heat-treated specimens obtained by the methods of Embodiments 1 and 2 of this invention is relatively uniform, and the molten pool morphology has disappeared; the precipitated phase of the heat-treated specimens obtained by Embodiment 7 of this invention is not completely dissolved, and the molten pool morphology is still retained; the grain size of the heat-treated specimens obtained by Embodiment 8 of this invention is relatively uniform, but the grains are large, and the molten pool morphology has disappeared.

[0152] The density data of the printed specimens of each embodiment and comparative example are shown in Table 1 below (characterized by metallographic binarization).

[0153] Table 1 Density data

[0154] serial number Power (W) Scanning speed (mm / s) Density (%) Example 1 240 1200 99.951 Example 2 220 1200 99.949 Example 3 260 1200 99.958 Example 4 240 1100 99.949 Example 5 240 1350 99.947 Comparative Example 1 287 945 99.901 Comparative Example 2 240 800 99.904 Comparative Example 3 140 1200 99.913 Comparative Example 4 200 1200 99.916 Comparative Example 5 280 1200 99.921 Comparative Example 6 240 1000 99.929 Comparative Example 7 240 1400 99.923

[0155] Printed tensile test bars were prepared according to the methods of different embodiments and comparative examples. The tensile test bars were then heat-treated according to the heat treatment methods of their respective embodiments and comparative examples to obtain printed tensile test bars and heat-treated tensile test bars. Tensile properties were tested separately, and the test results are shown in Table 2.

[0156] Table 2. Tensile properties at room temperature

[0157]

[0158]

[0159] The microstructure of the 3D printed parts obtained in the heat-treated state of Embodiment 1 and Comparative Example 1 of the present invention was further observed, as follows: Figure 11 and Figure 12 As shown in the figure, in the printed sample obtained by the gas atomization powder preparation method, the main precipitated phase is the γ′ phase; in the printed sample obtained by the powder preparation and 3D printing process of Example 1 of the present invention, the precipitated phase forms a γ′-γ″ symbiotic phase, which can significantly improve the strength of the 3D printed part.

[0160] Based on the process parameters of Example 1, transversely printed tensile test bars were prepared and heat-treated according to the heat treatment regime of Example 1. Then, tensile properties were tested, and the test results are shown in Table 3.

[0161] Table 3. Lateral Printing Room Temperature Tensile Properties Data

[0162]

[0163] The test results above show that the present invention, based on the composition of nickel-based high-temperature alloys, uses a certain alloy powder preparation and 3D printing process to produce 3D printed parts with high density and strength similar to that of alloys prepared by traditional processes, thus meeting the needs of practical applications.

[0164] 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. A method for 3D printing nickel-based superalloys, characterized in that, Includes the following steps: Nickel-based superalloy powder is 3D printed under vacuum or protective atmosphere to obtain 3D printed parts; the 3D printed parts are then subjected to solution treatment and double aging treatment. In the 3D printing process, the power is 220-260W and the scanning speed is 1100-1350mm / s; The nickel-based high-temperature alloy powder is prepared by plasma rotating electrode atomization powder preparation method; The solution treatment includes: holding at 1030–1060°C for 2–4 hours, followed by air cooling; The nickel-based superalloy comprises the following components by mass percentage: C 0.01%–0.035%, Cr 17.1%–18.5%, Nb 4.81%–5.5%, Mo 3.55%–5%, Al 0.5%–1.15%, Ti 0.6%–1%, Fe 13.1%–16%, V 0.41%–0.6%, B 0.001%–0.01%, Cu 0.1%–0.55%, Zr 0.001%–0.1%, Ce 0.001%–0.01%, Mn 0.001%–0.7%, Si 0.01%–0.5%, P≤0.015%, S≤0.01%, and the balance Ni.

2. The method for 3D printing nickel-based superalloys according to claim 1, characterized in that, The 3D printing process has at least one of the following characteristics: (1) The diameter of the light spot is 30-40 μm; (2) The scanning interval is 0.07–0.09 mm; (3) The thickness of a single layer of powder is 25-35 μm.

3. The method for 3D printing nickel-based superalloys according to claim 1, characterized in that, The particle size of the nickel-based superalloy powder is 15–53 μm.

4. The method for 3D printing nickel-based superalloys according to claim 1, characterized in that, The plasma rotating electrode atomization process has at least one of the following characteristics: (1) The spindle speed is 22000~26000r / min; (2) The feed rate is 0.8 to 1 mm / s; (3) The main arc current is 1100-1200A; (4) The plasma working gas flow rate is 10-15 L / min.

5. The method for 3D printing nickel-based superalloys according to claim 1, characterized in that, The plasma rotating electrode atomization includes: (a) Alloy bars are obtained by vacuum induction melting and vacuum consumable arc melting; (b) Using the alloy rod as a consumable electrode, setting the parameters for plasma rotating electrode atomization powder preparation, and starting the equipment to prepare the powder; (c) The powder obtained in step (b) is sieved to collect alloy powder with a particle size of 15 to 53 μm.

6. A 3D printed part, characterized in that, It was prepared using the nickel-based high-temperature alloy 3D printing method according to any one of claims 1 to 5.

7. The 3D printed part according to claim 6, characterized in that, The density of the 3D printed part is ≥99.92%; The 3D printed part has a room temperature tensile strength ≥1000MPa in the printed state.

8. The 3D printed part according to claim 6, characterized in that, After heat treatment, the longitudinally printed 3D printed part has a room temperature tensile strength ≥1370MPa and a room temperature elongation ≥23.0%.

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