A nickel-based superalloy and method of additive manufacturing thereof

Abstract

The application provides a nickel-based superalloy and an additive manufacturing method thereof. The additive manufacturing method comprises component optimization on a nickel-based alloy powder, and then double laser hysteresis heat treatment on the component-optimized nickel-based alloy powder, wherein the double laser hysteresis heat treatment comprises scanning by using a main laser and a secondary laser, the secondary laser lags behind the main laser, the power of the secondary laser is [0.3-0.05x(M Al +M Ti -7.5)]xP 主 , the lag distance of the secondary laser is 150 mu m+15x(ΔT-50) mu m, and the pulse frequency is 1.5-3 kHz. The alloy solidification interval is narrowed and the gamma prime phase content is balanced through multi-parameter component coupling control, and the prepared nickel-based superalloy has less cracks, and the strength and plasticity are synergistically improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of additive manufacturing of nickel-based superalloys, and particularly relates to a nickel-based superalloy and an additive manufacturing method thereof. BACKGROUND

[0002] Metal additive manufacturing (AM) technology has important application value in the field of aerospace, which is mainly due to its ability to efficiently prepare near-net-shape components with complex geometries.

[0003] However, when using the laser powder bed fusion (LPBF) process to prepare nickel-based superalloys, the composition and process of the nickel-based superalloys used in the prior art can cause microstructure defects, such as cracking problems. Such microscale crack defects seriously restrict the use of LPBF technology to prepare low-defect, high-performance nickel-based superalloy hot end components that meet extreme service requirements (such as high-temperature strength, creep resistance, and fatigue life). Because of the presence of cracks, not only does it directly reduce the effective load-bearing area of the component, but it also easily becomes a stress concentration point and a fatigue crack source, significantly shortening the service life of the component and even causing catastrophic failure. SUMMARY

[0004] To solve all or part of the above technical problems, the present application provides the following technical solutions:

[0005] The first aspect of the present application provides an additive manufacturing method of a nickel-based superalloy, comprising:

[0006] A nickel-based alloy powder is provided, and its composition satisfies: 8.2wt%≤Al+Ti+Nb+Ta≤8.8 wt%, 0.10wt%≤C+B+Zr≤0.15wt%, Hf=0.5×(0.06wt%-Zr) +0.1 wt%, the ratio of the contents of Al and Ti is 0.95~1.05, the ratio of the contents of Ta and Al is 0.45~0.55, Cr is 15.5wt%~16.5wt%, Mo is 1.7wt%~1.8wt%, Co is 8.2wt%~8.5wt%, W is 2.5wt%~2.8wt%, and the balance includes Ni;

[0007] The nickel-based alloy powder is subjected to double laser hysteresis heat treatment, the double laser hysteresis heat treatment uses a main laser and a secondary laser to scan the nickel-based alloy powder, and the secondary laser lags behind the main laser;

[0008] The power of the secondary laser is [0.3- 0.5×(M Al +M Ti -7.5)]×P 主 , M Al , M Tirespectively, mass percentage of Al, Ti in the nickel-based alloy powder, P 主 The main laser power is represented; the auxiliary laser lag distance is 150 mu m+15x(DT-50) mu m, DT is the solidification temperature interval of the nickel-based alloy powder; the pulse frequency of the auxiliary laser scanning is 1.5 kHz~3 kHz.

[0009] The present application carries out fine component design on the nickel-based superalloy, and cooperates with the double laser lag heat treatment technology, so that it has high gamma prime phase content, so as to maintain excellent high temperature strength; at the same time, the thermal cracks caused by element segregation and stress in the additive manufacturing process can be effectively inhibited. The nickel-based superalloy with optimized composition can accurately control the crack formation in the non-equilibrium solidification process, the total content and relative content of key elements of gamma prime phase content, so as to obtain a narrow solidification temperature interval, and combine with the liquid phase feeding double laser lag heat treatment process optimization, so that the crack sensitivity and residual stress of the alloy composition nickel-based superalloy are reduced, and at the same time, the high gamma prime phase content is maintained, so that the strength and plasticity are simultaneously improved.

[0010] In some preferred embodiments, 8.3wt%≤Al+Ti+Nb+Ta≤8.6 wt%, more preferably, 8.4wt%≤Al+Ti+Nb+Ta≤8.5 wt%. Specifically, the sum of the mass percentages of Al, Ti, Nb and Ta can be, for example, any one of 8.3wt%, 8.4wt%, 8.5wt%, 8.6wt% or a range between any two of them.

[0011] In some preferred embodiments, 0.10wt%≤C+B+Zr≤0.13 wt%, more preferably, 0.11wt%≤C+B+Zr≤0.12 wt%. Specifically, the sum of the mass percentages of C, B and Zr can be, for example, any one of 0.10wt%, 0.11wt%, 0.12wt%, 0.13wt% or a range between any two of them.

[0012] In some embodiments, the particle size of the nickel-based alloy powder is 18-50 mu m, for example, any one of 18 mu m, 24 mu m, 30 mu m, 36 mu m, 42 mu m, 48 mu m, 50 mu m or a range between any two of them.

[0013] In some embodiments, the nickel-based alloy powder has no hollow powder, and the sphericity is more than 90%.

[0014] In some embodiments, the particle size distribution of the nickel-based alloy powder used is: D10 is 15-20%, D50 is 30-40%, and D90 is 40-50%.

[0015] In some embodiments, the spot diameter of the main laser is 150-250 pm, the scanning power is 250-300 W, the scanning interval is 0.07-0.12 mm, the scanning speed is 900-1100 mm / s, and the interlayer deflection angle is 55-75°. Specifically, the spot diameter of the main laser can be, for example, any one of 150 pm, 170 pm, 190 pm, 210 pm, 230 pm, 250 pm, or a range between any two of them; the scanning power can be, for example, any one of 250 W, 260 W, 270 W, 280 W, 290 W, 300 W, or a range between any two of them; the scanning interval can be, for example, any one of 0.07 mm, 0.08 mm, 0.09 mm, 0.10 mm, 0.11 mm, 0.12 mm, or a range between any two of them; and the scanning speed can be, for example, any one of 900 mm / s, 950 mm / s, 1000 mm / s, 1050 mm / s, 1100 mm / s, or a range between any two of them.

[0016] In some preferred embodiments, the spot diameter of the main laser is 180-210 pm, the scanning power is 280-290 W, the scanning interval is 0.08-0.09 mm, and the scanning speed is 950-1050 mm / s. Specifically, the spot diameter of the main laser can be, for example, any one of 180 pm, 190 pm, 200 pm, 210 pm, or a range between any two of them; the scanning power can be, for example, any one of 280 W, 285 W, 290 W, or a range between any two of them; the scanning interval can be, for example, any one of 0.08 mm, 0.085 mm, 0.09 mm, or a range between any two of them; and the scanning speed can be, for example, any one of 950 mm / s, 950 mm / s, 1050 mm / s, or a range between any two of them.

[0017] In some embodiments, the double laser hysteresis heat treatment is performed after the nickel-based alloy powder is laid into a powder layer with a thickness of 0.025-0.045 mm. The powder layer thickness can be, for example, any one of 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, or a range between any two of them.

[0018] In some preferred embodiments, the double laser hysteresis heat treatment is performed after the nickel-based alloy powder is laid into a powder layer with a thickness of 0.03-0.04 mm. The powder layer thickness can be, for example, any one of 0.03 mm, 0.035 mm, 0.04 mm, or a range between any two of them.

[0019] The second aspect of the present application provides a nickel-based superalloy prepared by the additive manufacturing method of the nickel-based superalloy according to any one of the technical solutions above.

[0020] In some embodiments, the nickel-based superalloy prepared by the method has a yield strength of 976 MPa or more, a tensile strength of 1350 MPa or more, and an elongation after fracture of 15% or more.

[0021] In some preferred embodiments, the nickel-based superalloy has a yield strength of 1000 MPa or more, a tensile strength of 1400 MPa or more, and an elongation after fracture of 18% or more.

[0022] In some embodiments, the nickel-based superalloy has a crack density of 0.8 / mm 2 In some preferred embodiments, the nickel-based superalloy has a crack density of 0.6 / mm 2 In some preferred embodiments, the nickel-based superalloy has a crack density of 0.6 / mm

[0023] In some embodiments, the nickel-based superalloy has a γ' phase content of 40% or more.

[0024] Compared with the prior art, the present application has at least the following beneficial effects: the method provided by the present application cooperatively regulates the composition of the nickel-based alloy and the additive manufacturing process conditions, realizes the narrowing of the solidification interval of the high-temperature nickel-based alloy and the balance of the γ' phase, can make the solidification interval narrow by 35% or more in some embodiments, the interdendritic liquid phase post-shrinking efficiency is 85% or more, realizes the shape and property control of the additive nickel-based superalloy, and the high-temperature nickel-based alloy prepared has few cracks, and in preferred embodiments, almost no cracks can be achieved, and the strength and plasticity are cooperatively improved, solving the high crack sensitivity problem of the nickel-based superalloy in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Figure 1 Metallographic photograph of the additive manufacturing nickel-based superalloy of Example 1 of the present application;

[0027] Figure 2 Metallographic photograph of the nickel-based superalloy of Comparative Example 1 of the present application;

[0028] Figure 3 Metallographic photograph of the nickel-based superalloy of Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described in detail below in conjunction with specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present application. The specific functional details disclosed herein should not be interpreted as limiting, but only as a basis for the claims and for teaching those skilled in the art to employ the representative basis of the present application in different ways in any appropriate detailed embodiment in fact.

[0030] In addition, unless otherwise specified, the various raw materials used in the following examples can be obtained from the market or the like, and the various production and testing equipment used is equipment known in the art, and the testing methods used are methods known in the art.

[0031] Example 1

[0032] The present embodiment provides an additive manufacturing anti-cracking high-strength nickel-based superalloy and a preparation method thereof, specifically comprising the following steps:

[0033] S1, take a nickel-based superalloy powder, the composition of which includes, in terms of weight percentage: C 0.095wt%, B 0.01wt%, Hf 0.11wt%, Cr 15.83wt%, Zr 0.04wt%, Mo 1.8wt%, Co 8.47wt%, Nb 0.7wt%, W 2.6wt%, Ti 3.15wt%, Al 3.25wt%, Ta 1.5wt%, and the balance is Ni and unavoidable impurities.

[0034] The particle size of the powder is in the range of 18-50 μm, the average diameter is 22.8 μm, there is no hollow powder, the sphericity is more than 90%, no inclusions are detected, and the oxygen content is 150 ppm.

[0035] S2, double laser hysteresis heat treatment is performed on the powder of step S1 to print a nickel-based superalloy printed product:

[0036] The diameter of the spot of the main laser of the printing process is 190 μm, the scanning power is 285 W, the scanning interval is 0.80 mm, the scanning speed is 1000 mm / s, the powder laying thickness is 0.04 mm, and the deflection angle is 67°. The power of the secondary laser is 101 W, the hysteresis distance is 225 μm, the pulse frequency is 2.5 kHz, and the protective atmosphere is argon.

[0037] The hysteresis distance of the secondary laser is obtained according to "150 μm+15×(ΔT-50) μm", where ΔT is the solidification temperature interval of the nickel-based superalloy powder, which is the difference between the liquidus temperature and the solidus temperature of the material, and is usually in the range of 50℃-100℃. In the present embodiment, ΔT is 55℃.

[0038] The crack density of the nickel-based superalloy printing product prepared in this embodiment is 0.4 / mm 2 , and the content of γ' phase is 45%.

[0039] Embodiment 2

[0040] The embodiment provides an additive manufacturing anti-cracking high-strength nickel-based superalloy and a preparation method thereof, and specifically comprises the following steps:

[0041] (1) Take the nickel-based superalloy powder, and the composition components meet the following requirements in terms of weight percentage: C 0.095wt%, B 0.01wt%, Hf 0.11wt%, Cr 15.83wt%, Zr 0.04wt%, Mo 1.8wt%, Co 8.47wt%, Nb 0.7wt%, W 2.6wt%, Ti 3.15wt%, Al 3.25wt%, Ta 1.5wt%, and the balance is Ni and inevitable impurities. The particle size of the powder is in the range of 18-50 μm, the average diameter is 22.8 μm, there is no hollow powder, the sphericity is more than 90%, no inclusions are detected, and the oxygen content is 150 ppm.

[0042] (2) The powder in step S1 is subjected to double laser lag heat treatment to form a nickel-based superalloy printing product:

[0043] The diameter of the main light spot of the printing process is 180 μm, the scanning power is 280 W, the scanning interval is 0.80 mm, the scanning speed is 950 mm / s, the powder laying thickness is 0.03 mm, and the deflection angle is 67°. The power of the secondary laser is 99.4 W, the lag distance is 225 μm, the pulse frequency is 2.5 kHz, and the protective atmosphere is argon.

[0044] The crack density of the nickel-based superalloy printing product prepared in this embodiment is 0.6 / mm 2 , and the content of γ' phase is 44%.

[0045] Embodiment 3

[0046] The embodiment provides an additive manufacturing anti-cracking high-strength nickel-based superalloy and a preparation method thereof, and specifically comprises the following steps:

[0047] (1) Take the nickel-based superalloy powder, the composition meets: C 0.1wt%, B 0.005wt%, Hf 0.13wt%, Cr 15.83wt%, Zr 0.045wt%, Mo 1.8wt%, Co 8.47wt%, Nb 0.7wt%, W 2.6wt%, Ti 3.15wt%, Al 3.25wt%, Ta 1.5wt%, and the balance is Ni and inevitable impurities. The particle size of the powder is in the range of 18-50μm, the average diameter is 22.8μm, there is no hollow powder, the sphericity is more than 90%, no inclusions are detected, and the oxygen content is 150ppm.

[0048] (2) The powder of step S1 is subjected to double laser lag heat treatment, and a nickel-based superalloy printed product is printed:

[0049] The diameter of the spot of the main laser of the printing process is 250μm, the scanning power is 300W, the scanning interval is 0.12mm, the scanning speed is 1100mm / s, the powder laying thickness is 0.03mm, and the deflection angle is 67°. The power of the auxiliary laser is 106.5W, the lag distance is 230μm, ΔT in this embodiment is 60℃, the pulse frequency is 2.5kHz, and the protective atmosphere is argon.

[0050] The crack density of the nickel-based superalloy printed product prepared in this embodiment is 0.8 / mm 2 , and the γ' phase content is 44%.

[0051] Comparative Example 1

[0052] Comparative Example 1 differs from Example 1 in that Comparative Example 1 does not undergo double laser lag heat treatment, and specifically includes the following steps:

[0053] S1, take the nickel-based superalloy powder, the composition meets: C 0.1wt%, B 0.005wt%, Hf 0.13wt%, Cr 15.83wt%, Zr 0.045wt%, Mo 1.8wt%, Co 8.47wt%, Nb 0.7wt%, W 2.6wt%, Ti 3.15wt%, Al 3.25wt%, Ta 1.5wt%, and the balance is Ni and inevitable impurities. The particle size of the powder is in the range of 18-50μm, the average diameter is 22.8μm, there is no hollow powder, the sphericity is more than 90%, no inclusions are detected, and the oxygen content is 150ppm.

[0054] S2, the powder of step S1 is subjected to a single laser printing process, and a nickel-based superalloy printed product is printed:

[0055] The printing process has a spot diameter of 190 μm, a scanning power of 285 W, a scanning interval of 0.80 mm, a scanning speed of 1000 mm / s, a powder laying thickness of 0.04 mm, and a deflection angle of 67°.

[0056] The nickel-based superalloy prepared in the embodiment has a crack density of 1.2 / mm 2 , and a γ' phase content of 44%.

[0057] Comparative Example 2

[0058] Comparative Example 2 is different from Example 1 only in that the alloy powder used in Comparative Example 2 is a nickel-based superalloy in the prior art, which has a composition of C 0.1wt%, B 0.009wt%, Hf 0wt%, Cr 15.83wt%, Zr 0.06wt%, Mo 1.71wt%, Co 8.47wt%, Nb 0.74wt%, W 2.67wt%, Ti 3.41wt%, Al 3.36wt%, Ta 1.63wt%, and the balance of Ni and inevitable impurities.

[0059] The rest is the same as in Example 1 and will not be repeated here.

[0060] The nickel-based superalloy printing product prepared in Comparative Example 2 has a crack density of 6.5 / mm 2 , and a γ' phase content of 46%.

[0061] The nickel-based superalloy prepared in each of the examples and comparative examples was tested, and the performance test results are shown in Table 1.

[0062] Table 1 Performance test results of nickel-based superalloy in the examples and comparative examples of the present application

[0063]

[0064] Figure 1 is a metallograph of the additive manufacturing nickel-based superalloy in Example 1 of the present application; Figure 2 is a metallograph of the nickel-based superalloy in Comparative Example 1 of the present application, Figure 3 is a metallograph of the nickel-based superalloy in Comparative Example 2 of the present application. Figure 1 、 Figure 2 、 Figure 3 It can be seen that the nickel-based superalloy prepared in Example 1 has almost no cracks, the nickel-based superalloy prepared in Comparative Example 1 has a small amount of cracks, and the nickel-based superalloy prepared in Comparative Example 2 has a large number of cracks.

[0065] In summary, the present application proposes a kind of additive manufacturing anti-cracking high-strength nickel-based superalloy component-process synergistic regulation method, based on the concept of alloying, in the original standard component interval range, in combination with the optimization of process parameters, prepare near defect-free nickel-based superalloy, can further improve the service performance of nickel-based superalloy, also help to prepare defect-free high-temperature alloy, to promote and application in various high-performance structural components. Specifically, the present application realizes the narrowing of solidification interval and the balance of gamma prime phase content by multi-parameter component coupling control, establishes the solidification interval accurate regulation model of additive manufacturing nickel-based superalloy and the matching rule of double laser process parameters, so that the solidification interval is narrowed by more than 35%, and the interdendritic liquid phase supplementing efficiency is more than 85%. Compared with the standard nickel-based superalloy in the prior art, the problem of cracking of the same component in additive manufacturing nickel-based superalloy is broken, the strength and plasticity are synergistically improved, and in some excellent embodiment modes, the yield strength of the prepared nickel-based superalloy is more than 976 MPa, the tensile strength is more than 1350 MPa, and the elongation after fracture is more than 15%.

[0066] In addition, the present application has also been tested with other raw materials, process operations and process conditions described in the specification by referring to the foregoing examples, and ideal results have been obtained.

[0067] The aspects, embodiments, features and examples of the present application should be considered illustrative, for the purpose of explanation, illustration and description, but not for the purpose of limitation, the scope of the present application is only defined by the claims.

[0068] Although the present application has been described with reference to the illustrative embodiments, it should be understood that various changes, omissions and / or additions can be made without departing from the spirit and scope of the present application, and elements in the embodiments can be substituted with substantially equivalent elements. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present application without departing from the scope thereof. Therefore, the present application is not intended to be limited to the particular embodiments disclosed, but is to include all embodiments falling within the scope of the appended claims. Furthermore, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but is used for the purpose of nomenclature.

Claims

1. A nickel-based superalloy, characterized in that: The nickel-based superalloy has a yield strength of ≥976 MPa, a tensile strength of ≥1350 MPa, and an elongation after fracture of ≥15%; and a crack density of 0.6 / mm². 2 The γ′ phase content is above 40% in the following cases; The preparation method of the nickel-based superalloy includes: The nickel-based alloy powder is provided, and its composition, by mass percentage, satisfies the following: 8.2wt%≤Al+Ti+Nb+Ta≤8.8wt%, 0.10wt%≤C+B+Zr≤0.15wt%, Hf=0.5×(0.06wt%-Zr) + 0.1wt%, the ratio of Al to Ti is 0.95~1.05, the ratio of Ta to Al is 0.45~0.55; Cr is 15.5wt%~16.5wt%, Mo is 1.7wt%~1.8wt%, Co is 8.2wt%~8.5wt%, W is 2.5wt%~2.8wt%, and the balance includes Ni. The nickel-based alloy powder is subjected to dual-laser hysteresis heat treatment, wherein the nickel-based alloy powder is scanned by a main laser and a secondary laser, and the secondary laser hysteresis is the main laser. The power of the secondary laser is [0.3-0.05×(M Al +M Ti -7.5)]×P 主 M Al M Ti The percentages of Al and Ti in the nickel-based alloy powder are respectively, and P is... 主 The value represents the main laser power; the secondary laser hysteresis distance is 150μm + 15×(ΔT-50)μm, where ΔT is the solidification temperature range of the nickel-based alloy powder; the pulse frequency of the secondary laser scanning is 1.5kHz~3kHz.

2. The nickel-based superalloy according to claim 1, characterized in that: 8.3wt%≤Al+Ti+Nb+Ta≤8.6wt%.

3. The nickel-based superalloy according to claim 2, characterized in that: 8.4wt%≤Al+Ti+Nb+Ta≤8.5wt%.

4. The nickel-based superalloy according to claim 1, characterized in that: 0.10wt%≤C+B+Zr≤0.13 wt%.

5. The nickel-based superalloy according to claim 4, characterized in that: 0.11wt%≤C+B+Zr≤0.12wt%.

6. The nickel-based superalloy according to claim 1, characterized in that: The particle size of the nickel-based alloy powder is 18μm~50μm.

7. The nickel-based superalloy according to claim 1, characterized in that: In the dual-laser hysteresis thermal processing, the spot diameter of the main laser is 150μm~250μm, the scanning power is 250W~300W, the scanning spacing is 0.07mm~0.12mm, the scanning speed is 900mm / s~1100mm / s, and the interlayer deflection angle is 55°~75°.

8. The nickel-based superalloy according to claim 7, characterized in that: The main laser has a spot diameter of 180μm~210μm, a scanning power of 280W~290W, a scanning spacing of 0.08mm~0.09mm, and a scanning speed of 950mm / s~1050mm / s.

9. The nickel-based superalloy according to claim 1, characterized in that: The nickel-based alloy powder is laid into a powder layer with a thickness of 0.025 mm to 0.045 mm and then subjected to the dual laser hysteresis heat treatment.

10. The nickel-based superalloy according to claim 9, characterized in that: The nickel-based alloy powder is laid into a powder layer with a thickness of 0.03 mm to 0.04 mm and then subjected to the dual laser hysteresis heat treatment.

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