Nickel-based superalloy 3D printing method, 3D printed piece prepared through nickel-based superalloy 3D printing method and heat treatment method

Abstract

The invention relates to the technical field of additive manufacturing, in particular to a nickel-based high-temperature alloy 3D printing method, a prepared 3D printed piece and a heat treatment method. The nickel-based superalloy 3D printing method comprises the following steps that 3D printing is conducted on nickel-based superalloy powder under the vacuum or protective atmosphere; in the 3D printing process, the power ranges from 220 W to 260 W, and the scanning speed ranges from 1100 mm / s to 1350 mm / s; the nickel-based high-temperature alloy powder is prepared in a plasma rotating electrode atomization powder preparation mode. According to the composition of the nickel-based superalloy, a certain alloy powder preparation and 3D printing process is adopted, the prepared 3D printing piece is high in density, the strength of the 3D printing piece is similar to that of an alloy prepared through a traditional process, and the actual application requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a nickel-based high-temperature alloy 3D printing method, a prepared 3D printed part, and a heat treatment method. Background Art

[0002] There are many complex structural components in rocket engines, which are very difficult to weld and the performance of welded joints is difficult to meet the requirements. Additive manufacturing technology has attracted widespread attention due to its significant advantages such as strong ability to process complex components, short processing cycle, and no need for tooling and molds.

[0003] However, the high temperature gradient and fast cooling rate during the solidification process of additive manufacturing result in significant differences in the performance of additively manufactured structural parts from those of traditional casting and forging processing. Therefore, developing a structural part that can be obtained through additive manufacturing and meets the requirements of rocket engines for hot end components is of great significance to the development of rocket engines.

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

[0005] One object of the present invention is to provide a nickel-based high-temperature alloy 3D printing method, wherein the strength of the obtained 3D printed parts is close to that of the alloy parts prepared by traditional processes, meeting the actual application requirements.

[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] In order to achieve the above-mentioned object of the present invention, the present invention provides a nickel-based high-temperature alloy 3D printing method on the one hand, comprising the following steps:

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

[0010] In the 3D printing, 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 making.

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

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

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

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

[0016] In a specific embodiment of the present invention, the particle size of the nickel-based high-temperature alloy powder is 15 to 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) Feed speed is 0.8-1 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 comprises:

[0023] (a) The alloy bars are obtained by vacuum induction melting and vacuum consumable arc melting;

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

[0025] (c) Sieving the powder obtained in step (b) 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 high-temperature alloy includes the following components in mass percentage: C 0.01% to 0.035%, Cr 17.1% to 18.5%, Nb 4.81% to 5.5%, Mo3.55% to 5%, Al0.5% to 1.15%, Ti 0.6% to 1%, Fe 13.1% to 16%, V 0.41% to 0.6%, B 0.001% to 0.01%, Cu 0.1% to 0.55%, Zr 0.001% to 0.1%, Ce 0.001% to 0.01%, Mn 0.001% to 0.7%, Si 0.01% to 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 one of the above-mentioned nickel-based high-temperature alloy 3D printing methods.

[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 ≥1000 MPa.

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

[0031] The solution treatment comprises: heat preservation treatment at 1030-1060° C. for 2-4 hours, followed by air cooling.

[0032] In a specific embodiment of the present invention, the double aging treatment comprises: keeping at 720-740°C for 14-16 hours, followed by air cooling; keeping at 640-660°C 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 printed part is ≥1370 MPa, 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″ intergrowth phase.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The present invention adopts a certain alloy powder making and 3D printing process based on the composition of the nickel-based high-temperature alloy, and the obtained 3D printed parts have high density and strength similar to that of the alloy prepared by the traditional process, meeting the actual application requirements;

[0037] (2) The present invention regulates the heat treatment process according to the composition of the nickel-based high-temperature alloy as well as the powder making and 3D printing processes, so that a γ′-γ″ symbiotic phase is generated in the precipitated phase, which significantly improves the strength of the 3D printed parts and meets the requirements of the rocket engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A microscopic morphology of the plasma rotating electrode atomization (PREP) powder provided in Example 1 of the present invention;

[0040] Figure 2This is a microscopic morphology of the aerosolized powder provided in Comparative Example 1 of the present invention;

[0041] Figure 3 A printed tissue diagram of a 3D printed part provided in Example 1 of the present invention;

[0042] Figure 4 A printed tissue diagram of a 3D printed part provided in Example 2 of the present invention;

[0043] Figure 5 The printed tissue diagram of the 3D printed part provided in Comparative Example 2 of the present invention;

[0044] Figure 6 The printed tissue diagram of the 3D printed part provided in Comparative Example 3 of the present invention;

[0045] Figure 7 A heat-treated microstructure diagram of a 3D printed part provided in Example 1 of the present invention;

[0046] Figure 8 A heat-treated microstructure diagram of a 3D printed part provided in Example 2 of the present invention;

[0047] Fig. 9 A heat-treated microstructure diagram of a 3D printed part provided in Example 7 of the present invention;

[0048] Fig.10 A heat-treated microstructure diagram of a 3D printed part provided in Example 8 of the present invention;

[0049] Fig.11 A microstructure diagram of a 3D printed part in a heat-treated state provided in Example 1 of the present invention;

[0050] Fig.12 This is a microstructure diagram of the heat-treated 3D printed part provided in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0051] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0052] Studies have found that the surface of alloy powders produced by gas atomization will form "satellite balls" to varying degrees, affecting the use of the powder. The plasma rotating electrode atomization (PREP) powder making method produces powders with high sphericity, a small proportion of "satellite balls", and a more concentrated powder size distribution. It is recorded in the prior art that the use of powders with a suitable particle size distribution can help achieve better powder laying effects. Based on this, the present invention adopts a certain PREP powder making process based on the composition of the nickel-based high-temperature alloy, and further cooperates with the regulation of the 3D printing process, so that the 3D printed parts obtained have high density and high strength to meet the needs of actual applications.

[0053] In one aspect, the present invention provides a nickel-based high-temperature alloy 3D printing method, comprising the following steps:

[0054] 3D printing of nickel-based high-temperature alloy 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 produced by plasma rotating electrode atomization.

[0057] The present invention adopts plasma rotating electrode atomization to prepare powder according to the composition of nickel-based high-temperature alloy, and regulates the 3D printing process according to the powder morphology, so that the obtained 3D printed parts have high density and the strength is similar to that of alloys prepared by traditional processes.

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

[0059] The present invention adopts appropriate power and scanning speed, and cooperates with the characteristics of powder to make the molding surface uniform, improve the density, and improve the strength of the alloy.

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

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

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

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

[0064] For example, in different embodiments, in 3D printing, the spot diameter can be 30μm, 32μm, 34μm, 35μm, 36μm, 38μm, 40μm or a range consisting of any two thereof; the scanning interval can be 0.07mm, 0.072mm, 0.075mm, 0.078mm, 0.08mm, 0.082mm, 0.085mm, 0.088mm, 0.09mm or a range consisting of any two thereof; the thickness of a single layer of powder can be 25μm, 28μm, 30μm, 32μm, 35μm or a range consisting of any two thereof.

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

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

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

[0068] (2) Feed speed is 0.8-1 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] For example, in different embodiments, in plasma rotating electrode atomization, the spindle speed can be 22000r / min, 23000r / min, 24000r / min, 25000r / min, 26000r / min or a range composed of any two thereof; the feed speed can be 0.8mm / s, 0.85mm / s, 0.9mm / s, 0.95mm / s, 1mm / s or a range composed of any two thereof; the main arc current can be 1100A, 1120A, 1150A, 1180A, 1200A or a range composed of any two thereof; the plasma working gas flow rate can be 10L / min, 11L / min, 12L / min, 13L / min, 14L / min, 15L / min or a range composed of any two thereof.

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

[0073] (a) The alloy bars are obtained by vacuum induction melting and vacuum consumable arc melting;

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

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

[0076] In actual operation, vacuum induction melting and vacuum consumable arc melting can be adjusted according to the conventional melting process of the alloy, which will not be described in detail here.

[0077] Specifically, plasma rotary electrode atomization may include: loading the alloy rod into a rotary feeding device, evacuating the atomization chamber to a preset vacuum degree, filling the protective gas to make the air pressure in the atomization chamber reach the preset air pressure, monitoring the oxygen content in the atomization chamber to ensure that the oxygen content in the atomization chamber is not greater than 100 ppm; then starting the rotary feeding device and the plasma gun power supply to perform atomization and powder making, generating a high-temperature plasma arc between the alloy rod and the plasma gun, and under the combined action of centrifugal force and surface tension, the rod melts and forms tiny droplets, which are solidified into metal powder for screening and collection.

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

[0079] The nickel-based high-temperature alloy used in the present invention is an aging-strengthened nickel-based high-temperature alloy. The alloy has a relatively high content of Nb, Ti, and Al elements. In combination with the PREP powder making process and the corresponding 3D printing process, a γ′-γ″ symbiotic phase is formed in the obtained 3D printed parts, which can significantly improve the strength of the 3D printed parts.

[0080] Another aspect of the present invention provides a 3D printed part, which is prepared by any one 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 part of the present invention can control the precipitation phase and improve the strength performance of the 3D printed part while taking into account high density. For example, in different embodiments, the density of the 3D printed part can be 99.92%, 99.93%, 99.94%, 99.95%, 99.96% or a range composed of any two 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 ≥1000 MPa.

[0084] Among them, the room temperature tensile strength of the 3D printed parts by longitudinal printing of the present invention can meet ≥1000MPa, and the room temperature tensile strength of the 3D printed parts by transverse printing can not only meet ≥1000MPa, but also ≥1100MPa.

[0085] For example, in different embodiments, the room temperature tensile strength of the 3D printed part in the printed state can be 1000 MPa, 1010 MPa, 1020 MPa, 1030 MPa, 1040 MPa, 1046 MPa, 1060 MPa, 1070 MPa, 1080 MPa, 1090 MPa, 1100 MPa, or a range consisting of any two of them.

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

[0087] The solution treatment includes: heat preservation at 1030-1060°C for 2-4 hours and then air cooling.

[0088] The present invention regulates the conditions of the solid solution treatment, cooperates with the corresponding alloy and 3D printing process, so that a γ′-γ″ intergrowth phase is generated in the precipitation phase of the 3D printed part after heat treatment, which can significantly improve the strength of the 3D printed part.

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

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

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

[0092] Among them, the room temperature tensile strength of the 3D printed parts through longitudinal printing of the present invention can meet ≥1370MPa after heat treatment, and the room temperature tensile strength of the 3D printed parts through transverse printing can not only meet ≥1370MPa but also ≥1450MPa after heat treatment.

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

[0094] The tensile strength of the 3D printed part of the present invention is significantly improved after heat treatment, and the longitudinal tensile performance is also significantly better than that of the alloy produced by the traditional process.

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

[0096] In the following specific embodiments, if no additional description is given on the 3D printing direction, it is described as vertical printing.

[0097] Example 1

[0098] This embodiment provides a nickel-based high-temperature alloy 3D printing method and a heat treatment method, comprising the following steps:

[0099] (1) Raw materials were prepared according to the composition and content of nickel-based high-temperature alloy, and vacuum induction melting + vacuum consumable arc melting were used to obtain alloy blocks, which were then processed into alloy rods; the powder making process parameters were set as follows: main arc current 1150A, maintenance arc current 90A, feed speed 0.9mm / s, spindle speed 22000-26000r / min, spindle step speed was set at 1000r / min, and the working gas intake flow rate for the plasma gun was 15L / min;

[0100] Arcing at 22000rpm, bar feed 20mm, speed increased to 23000rpm, bar feed 20mm, speed increased to 24000rpm, bar feed 60mm, speed increased to 25000rpm, bar feed 50mm, speed increased to 26000rpm, until the refining is completed. After cooling, collect the powder, sieve the powder, and obtain 15-53μm powder as the finished powder.

[0101] The nickel-based high-temperature alloy comprises, by mass percentage, the following: 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) The finished powder obtained in step (1) was used to prepare a 3D printed sample using the SLM process. The 3D printing process parameters were: the 3D printing power was 240 W, the 3D printing scanning speed was 1200 mm / s, the 3D printing spot diameter was 35 μm, the 3D printing scanning interval was 0.08 mm, and the 3D printed single layer powder thickness was 0.03 mm.

[0103] (3) The 3D printed part obtained in step (2) was heat-treated at 1050° C. for 3 h and then air-cooled; then, the 3D printed part was heat-treated at 730° C. for 15 h and then air-cooled; and then, the 3D printed part was heat-treated at 650° C. for 10 h 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, with the only difference being that in step (2), the 3D printing power and scanning speed are different.

[0106] The power of 3D printing in this embodiment is 220W, and the scanning speed of 3D printing 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, with the only difference being that in step (2), the 3D printing power and scanning speed are different.

[0109] The power of 3D printing in this embodiment is 260W, and the scanning speed of 3D printing 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, with the only difference being that in step (2), the 3D printing power and scanning speed are different.

[0112] The power of 3D printing in this embodiment is 240W, and the scanning speed of 3D printing 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, with the only difference being that in step (2), the 3D printing power and scanning speed are different.

[0115] The power of 3D printing in this embodiment is 240W, and the scanning speed of 3D printing 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 Example 1, with the only difference being that in step (3), the heat treatment system 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; then heat-treating at 730° C. for 15 hours and then air-cooling; and heat-treating at 650° C. for 10 hours and then air-cooling.

[0119] Example 7

[0120] This embodiment refers to the nickel-based high-temperature alloy 3D printing method and heat treatment method of Example 2, with the only difference being that in step (3), the heat treatment system 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; then heat-treating at 730° C. for 15 hours and then air-cooling; and heat-treating at 650° C. for 10 hours and then air-cooling.

[0122] Example 8

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

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

[0125] Comparative Example 1

[0126] Comparative Example 1 provides a nickel-based high-temperature alloy 3D printing method, comprising the following steps:

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

[0128] (2) The finished powder obtained in step (1) was used to prepare a 3D printed sample using the SLM process. The 3D printing process parameters were: the 3D printing power was 287 W, the 3D printing scanning speed was 945 mm / s, the 3D printing spot diameter was 65 μm, the 3D printing scanning interval was 110 μm, and the 3D printed single layer powder thickness was 40 μm.

[0129] The heat treatment method of comparative example 1 includes: heat preservation treatment at 980°C for 1 hour, followed by air cooling; then heat preservation treatment at 730°C for 15 hours, followed by air cooling, and heat preservation treatment at 650°C for 10 hours, followed by 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, except that: in step (2), the power and scanning speed of 3D printing are different.

[0132] The power of 3D printing of Comparative Example 2 is 240 W, and the scanning speed of 3D printing is 800 mm / 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, except that: in step (2), the power and scanning speed of 3D printing are different.

[0135] The 3D printing power of Comparative Example 3 is 140 W, and the scanning speed of 3D printing is 1200 mm / 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, except that: in step (2), the power and scanning speed of 3D printing are different.

[0138] The 3D printing power of Comparative Example 4 is 200 W, and the scanning speed of 3D printing is 1200 mm / 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, except that: in step (2), the power and scanning speed of 3D printing are different.

[0141] The 3D printing power of Comparative Example 5 is 280 W, and the scanning speed of 3D printing is 1200 mm / 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, except that: in step (2), the power and scanning speed of 3D printing are different.

[0144] The 3D printing power of Comparative Example 6 is 240 W, and the scanning speed of 3D printing is 1000 mm / 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, except that: in step (2), the power and scanning speed of 3D printing are different.

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

[0148] Experimental Example 1

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

[0150] Experimental Example 2

[0151] The defects of the 3D printed test pieces prepared in Examples 1 to 2 and Comparative Examples 2 to 3 were observed using an optical microscope. Figure 3 to Figure 6 As can be seen from the figure, the printed test pieces obtained by the methods of Examples 1 to 2 have low porosity and few defects. However, the printed test pieces obtained by the methods of Comparative Examples 2 to 3 have high porosity and defects such as cracks. Figure 7 to Figure 10The heat-treated microstructure diagrams of the 3D printed parts provided in Examples 1, 2, 7 and 8 of the present invention show that the grain size of the heat-treated test pieces obtained by the methods of Examples 1 to 2 of the present invention is relatively uniform, and the molten pool morphology disappears; the precipitated phase of the heat-treated test piece obtained by Example 7 of the present invention is not completely dissolved, and the molten pool morphology is still retained; the grain size of the heat-treated test piece obtained by Example 8 of the present invention is relatively uniform, but the grains are larger, and the molten pool morphology disappears.

[0152] The density data of the printed test pieces of the specific embodiments and comparative examples are shown in Table 1 below (characterized by metallographic binarization method).

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

[0156] Table 2 Room temperature tensile properties data

[0157]

[0158]

[0159] The heat-treated microstructures of the 3D printed parts obtained in Example 1 of the present invention and Comparative Example 1 were further observed. Fig.11 and Fig.12 As shown in the figure, in the printed sample obtained by the aerosol powder making method, the main precipitated phase is the γ′ phase; in the printed sample obtained by the powder making and 3D printing process of Example 1 of the present invention, a γ′-γ″ symbiotic phase is formed in the precipitated phase, thereby significantly improving the strength of the 3D printed part.

[0160] Based on the process parameters of Example 1, a horizontally printed tensile test bar was prepared, and heat treated according to the heat treatment system of Example 1, and then a tensile performance test was performed. The test results are shown in Table 3.

[0161] Table 3 Transverse printing room temperature tensile performance data

[0162]

[0163] From the above test results, it can be seen that the present invention adopts certain alloy powder making and 3D printing processes based on the composition of the nickel-based high-temperature alloy, and the 3D printed parts produced have high density and strength similar to that of the alloy prepared by the traditional process, which meets the actual application needs.

[0164] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 nickel-based high-temperature alloy 3D printing method, characterized in that: The steps include: 3D printing of nickel-based high-temperature alloy powders under vacuum or protective atmosphere; In the 3D printing, 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 making.

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

3. The nickel-based high-temperature alloy 3D printing method according to claim 1, characterized in that: The particle size of the nickel-based high-temperature alloy powder is 15 to 53 μm.

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

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

6. The nickel-based high-temperature alloy 3D printing method according to claim 1, characterized in that: The nickel-based high-temperature alloy includes the following components in percentage by mass: C 0.01%-0.035%, Cr17.1%-18.5%, Nb 4.81%-5.5%, Mo 3.55%-5%, Al 0.5%-1.15%, Ti0.6%-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%, Si0.01%-0.5%, P≤0.015%, S≤0.01%, and the balance Ni.

7. A 3D printed part, characterized in that: The nickel-based high-temperature alloy is prepared by the 3D printing method according to any one of claims 1 to 6.

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

9. A method for heat treatment of a 3D printed part, characterized in that: The method comprises the following steps: performing a solution treatment and a double aging treatment on the 3D printed part according to claim 7; The solution treatment comprises: heat preservation treatment at 1030-1060° C. for 2-4 hours, followed by air cooling.

10. The heat treatment method for 3D printed parts according to claim 9, characterized in that: After the heat treatment, the room temperature tensile strength of the longitudinally printed 3D printed part is ≥1370 MPa, and the room temperature elongation is ≥23.0%.

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