A method for preparing a high-strength and plasticity additive manufacturing nickel-based superalloy

Abstract

The application discloses a preparation method of high-strength and high-plasticity additive manufacturing nickel-based high-temperature alloy. The application effectively solves the problem of high strength and low plasticity of the nickel-based high-temperature alloy caused by heat treatment of precipitation strengthening, and obtains high-performance nickel-based high-temperature alloy with a tensile strength of 1609 MPa and an elongation rate of 16.6%. The application first uses 1160 DEG C. to 1200 DEG C. solid solution treatment, and then carries out 843 DEG C. / 4 h+760 DEG C. / 8 h two-stage aging heat treatment process, to prepare a multi-scale heterogeneous structure composed of bimodal size distribution grains, nano second phases and nano defects, and the heat-treated product has excellent strength and plasticity. The preparation process is simple, controllable and adjustable, the product has excellent performance, and is convenient for large-scale industrial application.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high-temperature alloy and additive manufacturing, and relates to a high-strength and plasticity nickel-based high-temperature alloy heat treatment process for additive manufacturing. BACKGROUND

[0002] Nickel-based high-temperature alloy has excellent strength, damage tolerance and durability, and is the preferred structural material for aerospace hot-end components. Laser powder bed fusion (PBF-LB) as one of the advanced additive manufacturing technologies can realize the integrated forming of parts with complex geometry, and has become a key development technology and a front direction of aerospace manufacturing. However, the extremely fast solidification rate (10 6 -10 8 K / s) in the PBF-LB process will inhibit the precipitation of strengthening phase, and the main strengthening phase in the precipitation strengthened nickel-based high-temperature alloy cannot fully play the strengthening effect. Therefore, subsequent heat treatment is needed for the PBF-LB formed precipitation strengthened nickel-based high-temperature alloy to release residual stress, make the strengthening phase precipitate, and improve the microstructure and mechanical properties.

[0003] Currently, the common heat treatment process for additive manufacturing of nickel-based superalloys is usually solid solution + aging treatment. Yong Hu, Huibin Jia, Xu Zhang, et al. [Yong Hu, Huibin Jia, Xu Zhang, et al., Delayed recrystallization behavior and deformation mechanism of IN738LC alloy prepared by laser powder bed fusion [J]. Materials Science & Engineering A, 2024, 903: 146697] prepared IN738LC alloy by additive manufacturing, and the yield strength, tensile strength and elongation of the alloy were 975 MPa, 1260 MPa and 16.8%, respectively. After 1250℃ / 2 h solid solution treatment and 850℃ / 2 h aging treatment, the yield strength, tensile strength and elongation of the alloy were 1305 MPa, 14620 MPa and 5.4%, respectively. Xinxin Liu, Rui Hu, Chenyu Yang, et al. [Xinxin Liu, Rui Hu, Chenyu Yang, et al., Microstructure evolution and strengthening mechanism of γ′-strengthening superalloy prepared by laser powder bed fusion [J]. Materials Science & Engineering A, 2023, 871: 144915] prepared Haynes 230 alloy by additive manufacturing, and after 1200℃ / 2 h solid solution treatment and 750℃ / 24 h aging treatment, the yield strength, tensile strength and elongation of the alloy were 1245 MPa, 1468 MPa and 6.3%, respectively.Liang [Jiangkai Liang, Zhubin He, Wei Du et al., Tailoring the microstructure and mechanical properties of laser metal-deposited Hastelloy X superalloy sheets via post heat-treatment [J]. Materials Science & Engineering A, 2023, 884: 145546] et al. through the 1175℃ / 1 h solid solution treatment and 720℃ / 8 h+620℃ / 8 h double-stage aging treatment of the Haynes X alloy prepared by additive manufacturing, the yield strength, tensile strength and elongation of the alloy are 355 MPa, 688 MPa and 47.4%, respectively. The previous research of the research group developed a technology to improve the performance of 3D printed nickel-based superalloy by in-situ heat treatment, and the yield strength of the obtained René104 alloy can reach 1017 MPa, the tensile strength can reach 1242 MPa, and the elongation can reach 11.1%. The yield strength of the René104 nickel-based superalloy added with trace rare earth Sc can reach 1145 MPa, the tensile strength can reach 1252 MPa [Liu Zuming, Wei Bing, Nong Bizhong et al., A method for improving the mechanical properties of 3D printed nickel-based superalloy by in-situ heat treatment [P]. Hunan Province: CN112008079B, 2020-08-30]. Moreover, the research group further found that the René104 alloy adopts solid solution treatment (1160℃ / 1h) + aging treatment (820℃ / 8h+760℃ / 8h), and the alloy cracks, and the yield strength, tensile strength and elongation are 1230 MPa, 1298 MPa and 2.62% [Wei Bing, Selective laser melting forming and cracking inhibition of René104 superalloy [D], Changsha: Central South University, 2022].

[0004] As can be seen from the above search results, the existing technology is difficult to realize the coordination of alloy strength and plasticity after heat treatment of the nickel-based superalloy prepared by additive manufacturing, especially after heat treatment of the precipitation strengthened nickel-based superalloy. At the same time, more importantly, many nickel-based superalloys prepared by additive manufacturing are prone to plasticity loss and even cracking after heat treatment. The present application proposes to obtain a multi-scale heterogeneous structure composed of bimodal size distribution grains, nanometer second phase and nanometer defects by solid solution and double-stage aging heat treatment, which effectively solves the problem of high strength and low plasticity caused by heat treatment of the existing precipitation strengthened nickel-based superalloy. SUMMARY

[0005] In view of the deficiencies of the prior art, based on the previous research of the inventors (CN112008079B), a solid solution + two-stage aging treatment process is first designed to simultaneously improve the tensile strength and yield strength of the product while maintaining good elongation. Through process optimization, the additive manufacturing nickel-based superalloy with excellent strength and ductility synergistic effect is first obtained.

[0006] The application provides a preparation method of high-strength and ductility additive manufacturing nickel-based superalloy. The additive manufacturing nickel-based superalloy is used as raw material, and a multi-scale heterogeneous structure composed of bimodal size distribution grains, nano second phase and nano crystal defects is formed in the heat-treated alloy, realizing excellent strength and ductility synergistic effect.

[0007] The application provides a preparation method of high-strength and ductility additive manufacturing nickel-based superalloy. The nickel-based superalloy is a Sc and Y containing René 104 alloy, and the Sc and Y containing René 104 alloy is prepared by additive manufacturing using René 104ScY alloy powder as raw material; the mass percentage of Sc and Y in the Sc and Y containing René 104 alloy is 0.005wt.% to 0.01wt.%.

[0008] The laser additive manufacturing is:

[0009] Step one: using the René 104ScY alloy powder with designed composition as raw material, a printing state product is prepared by laser beam powder bed fusion (PBF-LB) process; the PBF-LB optimal process parameters are used for forming: the laser input power is controlled to be 200-400 W, preferably 320-400 W, and further preferably 345-355 W; the scanning speed is controlled to be 200-1200 mm / s, preferably 750-1200 mm / s, and further preferably 780-820 mm / s; the layer thickness is 35-60 μm; and the rotation angle between adjacent layers is 67°.

[0010] Step two: using the obtained printing state product as a processing object, solid solution treatment is carried out at 1160-1220℃, preferably 1160-1200℃ for 50-240 min to obtain a solid solution state product.

[0011] Step three: using the obtained solid solution state product as a processing object, the solid solution state product is subjected to aging treatment, and the aging conditions are as follows: aging treatment is first carried out at 830-850℃ for 200-280 min, then the furnace is cooled to 755-765℃, and after holding for 450-500 min, an aging state product is obtained.

[0012] The application discloses a preparation method of a high-strength and high-plasticity additive manufacturing nickel-based high-temperature alloy.

[0013] According to the designed components, the raw materials are prepared, all the raw materials are mixed, the alloy powder is prepared through a tight-coupling argon atomization system, a graphite crucible is used as the crucible, the smelting temperature is 1600-1650 DEG C, the continuous holding time is 10-20 min, and the gas pressure is 3-5 MPa; the René104ScY alloy powder with a particle size less than 100 mu m and preferably 15-74 mu m is screened out through a vibrating screening device, and is used as the powder for laser additive manufacturing.

[0014] Preferably, the Sc is introduced by using an Al-Sc intermediate alloy, and the other raw materials can be simple metals or intermediate alloys.

[0015] The application discloses a preparation method of a high-strength and high-plasticity additive manufacturing nickel-based high-temperature alloy.

[0016] Co: 21.4-21.6 wt.%, Cr: 12.9-13.1 wt.%, Mo: 3.7-3.9 wt.%, Ti: 3.8-4.0 wt.%, Al: 3.3-3.4 wt.%, Ta: 2.2-2.3 wt.%, W: 3.3-3.5 wt.%, Nb: 0.8-1.0 wt.%, C: 0.03-0.06 wt.%, Zr: 0.04-0.06 wt.%, B: 0.02-0.04 wt.%, Sc+Y: 0.006-0.08 wt.%, and the balance is Ni, and the molar ratio of Sc:Y is 1:1.

[0017] In the second step of the application, the obtained printing state product is taken as a processing object, and is subjected to solid solution treatment at 1175-1185 DEG C for 60-120 min to obtain a solid solution state product.

[0018] Preferably, the solid solution state product is subjected to aging treatment, and the aging condition is that the solid solution state product is subjected to aging treatment at 843 DEG C for 4 h, is cooled to 760 DEG C in the furnace, and is subjected to aging treatment at 760 DEG C for 8 h to obtain an aging state product.

[0019] The printing state product has a yield strength of 960-1059 MPa, a tensile strength of 1315-1405 MPa, and an elongation of 21.3-28.8%.

[0020] As preferred, in the present application, the relative density of the printed product is higher than 99.8%, and the yield strength, tensile strength and elongation are 1059 MPa, 1405 MPa and 28.8% respectively.

[0021] The preparation method of the René104ScY alloy raw material powder used in the present application is as follows:

[0022] According to the designed components, the raw materials are prepared, all the raw materials are mixed, the alloy powder is prepared through a tightly coupled argon atomization system, the crucible is a graphite crucible, the smelting temperature is 1600-1650 DEG C, the continuous holding time is 10-20 min, and the gas pressure is 3-5 MPa; the René104ScY alloy powder with a particle size range of less than 100 mu m, preferably 15-74 mu m, is screened out by using a vibrating sieve device, and is used as a powder for laser additive manufacturing;

[0023] As preferred, Sc is introduced by using an Al-Sc intermediate alloy, and the other raw materials can adopt elemental metals or intermediate alloys.

[0024] As preferred: the René104ScY alloy powder with the designed components is used as the raw material powder, and the printed product is prepared by using the PBF-LB process; the printed product is formed by using the optimal process parameters of the PBF-LB process: the laser power is 350 W, the scanning speed is 800 mm / s, the layer thickness is 40 mu m, the serpentine scanning strategy is adopted, and the rotation angle between adjacent layers is 67 DEG; the sample is characterized in that: the microstructure of the obtained product is mainly composed of equiaxed crystals and columnar crystals.

[0025] The present application discloses a preparation method of a high-strength and high-plasticity additive manufacturing nickel-based superalloy.

[0026] The present application discloses a preparation method of a high-strength and high-plasticity additive manufacturing nickel-based superalloy,

[0027] When the alloy is treated by solid solution treatment at a temperature of 1160 DEG C for 1 h and then treated by double-stage aging heat treatment of 843 DEG C / 4 h+760 DEG C / 8 h, the yield strength of the alloy is 1152 MPa, the tensile strength is 1464 MPa, and the elongation is 3.2%;

[0028] When the alloy is treated by solid solution treatment at a temperature of 1180 DEG C for 1 h and then treated by double-stage aging heat treatment of 843 DEG C / 4 h+760 DEG C / 8 h, the yield strength of the alloy is 1281 MPa, the tensile strength is 1609 MPa, and the elongation is 16.6%;

[0029] When the alloy is treated by solid solution at 1200 DEG C for 1 h and two-stage aging heat treatment of 843 DEG C / 4 h+760 DEG C / 8 h, the yield strength of the alloy is 1152 MPa, the tensile strength is 1402 MPa, and the elongation is 6.4%.

[0030] It is also found in the technical development process that the microstructure of the alloy changes with the increase of the solid solution temperature; the higher the solid solution temperature, the less obvious the melt pool boundary and the cellular structure of the alloy are. With the further increase of the solid solution temperature, the recrystallization and grain growth in the alloy are obvious.

[0031] The preparation method of the high-strength and high-plasticity additive manufacturing nickel-based superalloy provided by the application is characterized in that the heat-treated nickel-based superalloy has nano defects; the nano defects include at least one of nano twins, high-density dislocations and Lomer-Cottrell locks.

[0032] In the application, the solid solution and two-stage aging treatment with appropriate parameters can greatly increase the yield strength and tensile strength of the product.

[0033] The application first develops a René104ScY alloy with high excellent strength and plasticity synergistic effect, the René104ScY alloy designed and prepared in the application has an elongation greater than 16%, and a yield strength greater than or equal to 1281 MPa and a tensile strength greater than or equal to 1609 MPa.

[0034] The preparation method of the high-strength and high-plasticity additive manufacturing nickel-based superalloy provided by the application is characterized in that the heat-treated nickel-based superalloy has nano defects; the nano defects include at least one of nano twins, high-density dislocations and Lomer-Cottrell locks.

[0035] The material process of the application is reasonable in design, reduces the requirement on the production process, and the prepared alloy parts have high strength and high elongation, which provides necessary conditions for industrialization.

[0036] Compared with the Chinese patent CN112008079B, the heat-treated additive manufacturing nickel-based superalloy provided by the application has higher strength and elongation.

[0037] Principles and advantages

[0038] 1. The application first designs a preparation method of a high-strength and high-plasticity additive manufacturing nickel-based superalloy, and first proposes a solid solution and two-stage aging process for heat treatment of a printed sample. After the heat treatment process is used, a multi-scale heterogeneous structure including at least one of double-peak size distribution grains, nano phases, nano twins, high-density dislocations and Lomer-Cottrell locks is generated in the sample, and the microstructure of the alloy is effectively controlled.

[0039] 2. The present application adopts a heat treatment process combining proper parameter solid solution treatment and aging treatment, successfully solves the problem of high strength, low plasticity and even cracking of the additive manufacturing high Al, Ti nickel-based superalloy after heat treatment, the yield strength reaches 1281 MPa, the tensile strength is 1609 MPa, the elongation is 16.6%, and excellent strength and plasticity synergy is realized.

[0040] 3. The present application has reasonable component design, simple and controllable preparation process, excellent product performance, excellent mechanical properties of the sample after heat treatment, and is convenient for large-scale industrial application, and provides a new method for developing high-performance nickel-based superalloy for additive manufacturing and microstructure regulation. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0042] Figure 1 EBSD analysis images and SEM images of the microstructure of the nickel-based superalloy after heat treatment in the present application examples 1 to 3 and γ' phase morphology;

[0043] Figure 2 SEM and TEM images of aging twin in the present application example 2;

[0044] Figure 3 Room temperature engineering stress-strain curves of different heat treatment samples in the present application examples 1 to 3;

[0045] Figure 4 EBSD analysis images and SEM images of the microstructure of the nickel-based superalloy after heat treatment in the present application comparative examples 1, 2 and 3 and γ' phase morphology;

[0046] Figure 5 Room temperature engineering stress-strain curves of different heat treatment samples in the present application comparative examples 1, 2 and 3. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below.

[0048] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be appreciated that the present application can be practiced in a variety of ways beyond the specifics set forth herein, which can be practiced in any number of manners, and that the present application should not be limited to the particular embodiments described. The present application should not be construed as limited to the particular forms set forth herein, but should be understood to cover all modifications, equivalents, and alternatives falling within the scope of the present application.

[0049] Second, the "one embodiment" or "an embodiment" as used herein means a specific implementation, or a specific feature, structure, or characteristic within at least one implementation of the present application. The various embodiments presented in the specification are not necessarily mutually exclusive, and can be selectively mixed and matched as desired. Thus, the various features, structures, or characteristics of the present application can be combined in any suitable manner in one or more embodiments.

[0050] Embodiment One:

[0051] (1) All raw materials are mixed to prepare René104ScY alloy powder through a tight-coupling argon atomization system, a graphite crucible is used as the crucible, the melting temperature is 1600-1650 °C, the holding time is 10-20 min, and the gas pressure is 3-5 MPa; the René104ScY alloy powder with a particle size of 15-74 μm is screened out using a vibrating screening device for laser additive manufacturing, the layer thickness is controlled to be 40 μm, the laser power is 350 W, the scanning speed is 800 mm / s, the interlayer rotation angle is 67°, and a serpentine scanning strategy is used;

[0052] The prepared René104ScY alloy powder comprises the following components in mass percentage:

[0053] Co: 21.5 ± 0.1 wt.%, Cr: 13.0 ± 0.1 wt.%, Mo: 3.8 ± 0.1 wt.%, Ti: 3.9 ± 0.1 wt.%, Al: 3.35 ± 0.05 wt.%, Ta: 2.25 ± 0.05 wt.%, W: 3.4 ± 0.1 wt.%, Nb: 0.9 ± 0.1 wt.%, C: 0.045 ± 0.015 wt.%, Zr: 0.05 ± 0.01 wt.%, B: 0.03 ± 0.01 wt.%, Sc+Y: 0.007 ± 0.001 wt.% (molar ratio of Sc:Y is 1:1), and the balance is Ni;

[0054] (2) The prepared as-printed sample is vacuum-sealed in a tube and subjected to solid solution treatment at 1160 °C, the temperature is raised at a rate of 5 °C / min, and the holding time is 1 h, and then the sample is taken out and cooled to room temperature;

[0055] (3) Then the sample after the solid solution treatment is subjected to two-stage aging heat treatment according to the program of 843 °C / 4 h + 760 °C / 8 h, and the sample is taken out and cooled to room temperature after the program is completed;

[0056] (4) After heat treatment, the sample still retains columnar crystals parallel to the building direction;

[0057] (5) After heat treatment, two different sizes of γ' phase are formed in the sample;

[0058] The mechanical properties of the heat-treated nickel-based superalloy are detected, and the results are as follows: the yield strength is 1152 MPa, the tensile strength is 1464 MPa, the strength is obviously improved, and the elongation is 3.2%, the comprehensive mechanical properties are obviously better than the same type alloy.

[0059] Example Two:

[0060] (1) All raw materials are mixed, and René104ScY alloy powder is prepared through a tight coupling argon atomization system, the crucible is a graphite crucible, the smelting temperature is 1600-1650℃, the holding time is 10-20 min, and the gas pressure is 3-5 MPa; the René104ScY alloy powder with a particle size of 15-74 μm is screened by a vibrating screening device for laser additive manufacturing, the layer thickness is controlled to be 40 μm, the laser power is 350 W, the scanning speed is 800 mm / s, the interlayer rotation angle is 67°, and a serpentine scanning strategy is adopted;

[0061] The prepared René104ScY alloy powder comprises the following components in mass percentage:

[0062] Co: 21.5±0.1wt.%, Cr: 13.0±0.1wt.%, Mo: 3.8±0.1wt.%, Ti: 3.9±0.1wt.%, Al: 3.35±0.05wt.%, Ta: 2.25±0.05wt.%, W: 3.4±0.1wt.%, Nb: 0.9±0.1wt.%, C: 0.045±0.015wt.%, Zr: 0.05±0.01wt.%, B: 0.03±0.01wt.%, Sc+Y: 0.007±0.001wt.% (molar ratio of Sc:Y is 1:1), and the balance is Ni;

[0063] (2) The prepared as-printed sample is vacuum sealed and subjected to solid solution treatment at 1180℃, the temperature is raised at a rate of 5℃ / min, and the sample is cooled to room temperature after being taken out and kept for 1 h.

[0064] (3) Then the sample after solid solution treatment is subjected to two-stage aging heat treatment according to the program of 843℃ / 4 h+760℃ / 8 h, and the sample is cooled to room temperature after being taken out after the end of the program.

[0065] (4) After heat treatment, a large number of equiaxed crystals are formed in the sample;

[0066] (5) After heat treatment, two different sizes of γ' phase were formed in the sample, but the size was obviously refined;

[0067] (6) After heat treatment, aging twins with a size of about 380 nm were formed in the sample;

[0068] The mechanical properties of the heat-treated nickel-based superalloy were detected, and the results were as follows: the yield strength was 1281 MPa, the tensile strength was 1609 MPa, the strength was obviously improved, and the elongation was 16.6%, the comprehensive mechanical properties were obviously better than those of the same type alloy.

[0069] Example Three:

[0070] (1) All raw materials were mixed, and René104ScY alloy powder was prepared through a tight coupling argon atomization system, the crucible was a graphite crucible, the melting temperature was 1600-1650℃, the holding time was 10-20 min, and the gas pressure was 3-5 MPa; the René104ScY alloy powder with a particle size of 15-74 μm was screened out by using a vibrating screening device for laser additive manufacturing, the layer thickness was controlled to be 40 μm, the laser power was 350 W, the scanning speed was 800 mm / s, the interlayer rotation angle was 67°, and a serpentine scanning strategy was adopted;

[0071] The prepared René104ScY alloy powder comprises the following components in mass percentage:

[0072] Co: 21.5±0.1wt.%, Cr: 13.0±0.1wt.%, Mo: 3.8±0.1wt.%, Ti: 3.9±0.1wt.%, Al: 3.35±0.05wt.%, Ta: 2.25±0.05wt.%, W: 3.4±0.1wt.%, Nb: 0.9±0.1wt.%, C: 0.045±0.015wt.%, Zr: 0.05±0.01wt.%, B: 0.03±0.01wt.%, Sc+Y: 0.007±0.001wt.% (molar ratio of Sc:Y is 1:1), and the balance is Ni;

[0073] (2) The prepared printing state sample was vacuum sealed and subjected to solid solution treatment at 1200℃, the temperature was raised at a rate of 5℃ / min, and the sample was kept for 1 h, and then taken out and cooled to room temperature.

[0074] (3) Then the sample after solid solution treatment was subjected to two-stage aging heat treatment according to the program of 843℃ / 4 h+760℃ / 8 h, and after the end of the program, the sample was taken out and cooled to room temperature.

[0075] (4) After heat treatment, larger size equiaxed crystals were formed in the sample;

[0076] (5) After heat treatment, a uniform single size γ' phase is formed in the sample, but the size is further refined;

[0077] The mechanical properties of the heat-treated nickel-based superalloy are detected, and the results are as follows: the yield strength is 1152 MPa, the tensile strength is 1409 MPa, the strength is obviously improved, and the elongation is 6.4%, and the comprehensive mechanical properties are obviously better than those of the same type alloy.

[0078] Comparative Example 1:

[0079] (1) All raw materials are mixed to prepare René104ScY alloy powder through a tight coupling argon atomization system, the crucible is a graphite crucible, the melting temperature is 1600-1650℃, the holding time is 10-20 min, and the gas pressure is 3-5 MPa; the René104ScY alloy powder with a particle size of 15-74 μm is screened by a vibrating screening device for laser additive manufacturing, the layer thickness is controlled to be 40 μm, the laser power is 350 W, the scanning speed is 800 mm / s, the interlayer rotation angle is 67°, and a serpentine scanning strategy is adopted;

[0080] The prepared René104ScY alloy powder comprises the following components in mass percentage:

[0081] Co: 21.4-21.6wt.%, Cr: 12.9-13.1wt.%, Mo: 3.7-3.9wt.%, Ti: 3.8-4.0wt.%, Al: 3.3-3.4wt.%, Ta: 2.2-2.3wt.%, W: 3.3-3.5wt.%, Nb: 0.8-1.0wt.%, C: 0.03-0.06wt.%, Zr: 0.04-0.06wt.%, B: 0.02-0.04wt.%, Sc, Y: 0.006-0.08wt.% (Sc:Y is 1:1), and the balance is Ni.

[0082] (2) The prepared printing state sample is vacuum sealed in a tube, and is subjected to solid solution treatment at 1140℃, the temperature is raised at a rate of 5℃ / min, and is kept for 1 h, and then is taken out and cooled to room temperature.

[0083] (3) Then the solid solution treated sample is subjected to two-stage aging heat treatment according to the program of 843℃ / 4 h+760℃ / 8 h, and is taken out and cooled to room temperature after the end of the program.

[0084] (4) After heat treatment, the sample still retains columnar crystals parallel to the building direction;

[0085] (5) After heat treatment, two different sizes of γ' phase are formed in the sample, but the size of the γ' phase is significantly increased compared with the present application;

[0086] The mechanical properties of the obtained heat-treated nickel-based superalloy were detected, and the results showed that the yield strength was 1195 MPa, the tensile strength was 1400 MPa, the strength was obviously improved, and the elongation was 1.1%.

[0087] Comparative Example Two:

[0088] (1) All raw materials were mixed to prepare René104ScY alloy powder through a tight coupling argon atomization system, a graphite crucible was used as a crucible, the smelting temperature was 1600-1650 °C, the holding time was 10-20 min, and the gas pressure was 3-5 MPa; the René104ScY alloy powder with a particle size of 15-74 μm was screened out by using a vibrating screening device for laser additive manufacturing, the layer thickness was controlled to be 40 μm, the laser power was 350 W, the scanning speed was 800 mm / s, the interlayer rotation angle was 67°, and a serpentine scanning strategy was adopted;

[0089] The prepared René104ScY alloy powder included the following components in mass percentage:

[0090] Co: 21.4-21.6 wt.%, Cr: 12.9-13.1 wt.%, Mo: 3.7-3.9 wt.%, Ti: 3.8-4.0 wt.%, Al: 3.3-3.4 wt.%, Ta: 2.2-2.3 wt.%, W: 3.3-3.5 wt.%, Nb: 0.8-1.0 wt.%, C: 0.03-0.06 wt.%, Zr: 0.04-0.06 wt.%, B: 0.02-0.04 wt.%, Sc and Y: 0.006-0.08 wt.% (Sc:Y is 1:1), and the balance is Ni.

[0091] (2) The prepared printing state sample was vacuum sealed in a tube, and was subjected to solid solution treatment at 1180 °C, the temperature was raised at a rate of 5 °C / min, and was kept for 1 h, and then was taken out and cooled to room temperature.

[0092] (3) Then, the sample after the solid solution treatment was subjected to aging heat treatment according to the procedure of 843 °C / 12 h, and was taken out and cooled to room temperature after the end of the procedure.

[0093] (4) After the heat treatment, the columnar crystals parallel to the building direction were still retained in the sample;

[0094] (5) After the heat treatment, two kinds of γ' phases with different sizes were formed in the sample, but the size of the γ' phase was significantly increased compared with the present application;

[0095] The mechanical properties of the obtained heat-treated nickel-based superalloy were detected, and the results showed that the yield strength was 1195 MPa, the tensile strength was 1400 MPa, the strength was obviously improved, and the elongation was 1.1%.

[0096] Comparative Example Three

[0097] Other conditions are consistent with Example Two, except that:

[0098] (3) Then the solution treated sample is subjected to two-stage aging heat treatment according to the procedure of 815°C / 8 h + 760°C / 8 h, and after the procedure is finished, it is taken out and cooled to room temperature.

[0099] After heat treatment, the sample still retains columnar crystals parallel to the building direction;

[0100] After heat treatment, the sample forms two kinds of γ' phases with different sizes, but compared with the present application, the size of the γ' phase is significantly increased;

[0101] The mechanical properties of the obtained heat treated nickel-based superalloy are detected, and the results are as follows: the yield strength is 1184 MPa, the tensile strength is 1398 MPa, the strength is significantly improved, and the elongation is 6.5%. As can be seen from Comparative Example Three and Example Two, during two-stage aging, a slight temperature difference can seriously affect the strength and elongation of the product after aging.

Claims

1. A method of making a high-strength, ductile, additively manufactured nickel-based superalloy, the method comprising: The nickel-based superalloy is Sc and Y containing Rene104 alloy, and the Sc and Y containing Rene104 alloy is prepared by a laser additive manufacturing technology with Rene104ScY alloy powder as raw material; ​ The Rene104ScY alloy raw powder comprises the following components in mass percentage: Co: 21.4-21.6wt.%, Cr: 12.9-13.1wt.%, Mo: 3.7-3.9wt.%, Ti: 3.8-4.0wt.%, Al: 3.3-3.4wt.%, Ta: 2.2-2.3wt.%, W: 3.3-3.5wt.%, Nb: 0.8-1.0wt.%, C: 0.03-0.06wt.%, Zr: 0.04-0.06wt.%, B: 0.02-0.04wt.%, Sc+Y: 0.006-0.08wt.%, and the balance is Ni, and the molar ratio of Sc:Y is 1:1; The laser additive manufacturing is: Step one: taking the Rene104ScY alloy powder with the designed components as raw material, a printing state product is prepared by a laser powder bed melting process; the laser powder bed melting optimal process parameters are used for forming: the laser input power is controlled to be 200-400 W, the scanning speed is controlled to be 200-1200 mm / s, the layer thickness is 35-60 μm, and the rotation angle between adjacent layers is 67°; Step two: taking the obtained printing state product as a processing object, solid solution treatment is performed on the printing state product at 1160-1220℃ for 50-240 min to obtain a solid solution state product; Step three: taking the obtained solid solution state product as a processing object, the solid solution state product is subjected to aging treatment, and the aging condition is that: first aging treatment is performed at 830-850℃ for 200-280 min, the furnace is cooled to 755-765℃, and then the temperature is kept for 450-500 min to obtain an aging state product.

2. The method of claim 1, wherein the method further comprises: The preparation method of the selected Rene104ScY alloy raw powder is as follows: ​ According to the designed components, the raw materials are prepared, all the raw materials are mixed, the alloy powder is prepared through a tight coupling argon atomization system, a graphite crucible is used as a crucible, the smelting temperature is 1600-1650℃, the temperature is kept for 10-20 min, and the gas pressure is 3-5 MPa; the vibration screening equipment is used to screen the Rene104ScY alloy powder with a particle size range of less than 100 μm, which is used as the powder for laser additive manufacturing; The Al-Sc intermediate alloy is selected to introduce Sc, and the other raw materials are single metals or intermediate alloys.

3. The method of claim 1, wherein the method further comprises: The laser powder bed melting optimal process parameters are used for forming: the laser input power is controlled to be 320-400 W, the scanning speed is controlled to be 750-1200 mm / s, the layer thickness is 35-60 μm, and the rotation angle between adjacent layers is 67°. ​ 4. The method of claim 1, wherein the method further comprises: The Rene 104 ScY alloy powder designed as a component is used as a raw powder, and a printing state product is prepared by using a laser powder bed melting process; the printing state product is used as a processing object, and solid solution treatment is performed at 1175-1185 ℃ for 60-120 min to obtain a solid solution state product.

5. The method of claim 1, wherein the method further comprises: In step two, the obtained printing state product is used as a processing object, and solid solution treatment is performed at 1175-1185 ℃ for 60-120 min to obtain a solid solution state product.

6. The method of claim 5, wherein the method further comprises: The solid solution state product is subjected to aging treatment, and the aging conditions are as follows: aging treatment is first performed at 843 ℃ for 4 h, the furnace is cooled to 760 ℃, and then aging treatment is performed at 760 ℃ for 8 h to obtain an aging state product.

7. The method of claim 1, wherein the method further comprises: After the two-stage aging treatment, the obtained product contains a multi-scale heterogeneous structure composed of grains with a bimodal size distribution, a nano second phase and nano crystal defects.

8. The preparation method of the high-strength and high-plasticity additive manufacturing nickel-based superalloy according to claim 1, characterized in that: when the alloy is subjected to solid solution treatment at a temperature of 1160 ℃ and then subjected to 843 ℃ / 4 h+760 ℃ / 8 h two-stage aging heat treatment, the yield strength of the alloy is 1152 MPa, the tensile strength is 1464 MPa, and the elongation is 3.2%; when the alloy is subjected to solid solution treatment at a temperature of 1180 ℃ and then subjected to 843 ℃ / 4 h+760 ℃ / 8 h two-stage aging heat treatment, the yield strength of the alloy is 1281 MPa, the tensile strength is 1609 MPa, and the elongation is 16.6%; when the alloy is subjected to solid solution treatment at a temperature of 1200 ℃ and then subjected to 843 ℃ / 4 h+760 ℃ / 8 h two-stage aging heat treatment, the yield strength of the alloy is 1152 MPa, the tensile strength is 1409 MPa, and the elongation is 6.4%.

Images