Nickel-based single-crystal high-temperature alloy and preparation method thereof

Abstract

The invention provides a nickel-based single-crystal high-temperature alloy and a preparation method thereof. The nickel-based single-crystal high-temperature alloy is prepared from the following components in percentage by weight: 0.05 to 0.15 weight percent of C, 3.5 to 5.5 weight percent of Cr, 6 to 8 weight percent of Al, 6 to 14 weight percent of Co, 1 to 2 weight percent of Mo, 8 to 10 weight percent of W, 1.5 to 2.5 weight percent of Nb, 4 to 6 weight percent of Ta, 4 to 5 weight percent of Re, 0.05 to 0.15 weight percent of Hf, 0.5 to 1.5 weight percent of Ru and the balance of Ni. According to the nickel-based single-crystal high-temperature alloy and the preparation method thereof provided by the invention, through unique alloy component design, the nickel-based single-crystal high-temperature alloy has excellent endurance strength and creep resistance at high temperature. The alloy can better meet the use requirements of aero-engine blades and other high-temperature parts under extreme working conditions, the performance and reliability of an engine are remarkably improved, a proper amount of Cr and other elements in the alloy enhance the capacity of forming a compact oxidation film on the surface of the alloy, and the oxidation resistance of the alloy is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of superalloys, and particularly to a nickel-based single crystal superalloy and a preparation method thereof. Background Art

[0002] Single crystal superalloys have become the core materials for manufacturing turbine blades of advanced power equipment such as aeroengines and gas turbines due to their excellent comprehensive properties. With the increase in the inlet temperature of gas turbines, advanced power equipment has higher and higher requirements for the comprehensive mechanical properties of single crystal alloys.

[0003] To meet the requirements of aeroengines for turbine blade materials, superalloys have experienced a development process from equiaxed crystals to directionally solidified columnar crystals to single crystals, and their temperature-bearing capacity has been significantly improved. Since the birth of nickel-based single crystal superalloys, relying on their excellent temperature-bearing capacity, high-temperature mechanical properties, and oxidation and corrosion resistance, they have become the preferred materials for hot-end components such as high-pressure turbine blades of advanced aeroengines.

[0004] However, there is still room for improvement in the high-temperature strength, creep resistance, and cost and efficiency of the preparation process of existing nickel-based single crystal superalloys. For example, the conventional alloys have insufficient creep rupture strength at high temperatures and are difficult to meet the increasing high-performance requirements of aeroengines; during the preparation process, the complex process leads to high costs and the quality stability needs to be improved.

[0005] Therefore, it is necessary to provide a nickel-based single crystal superalloy and a preparation method thereof to solve the above technical problems. Summary of the Invention

[0006] The present invention provides a nickel-based single crystal superalloy and a preparation method thereof, which solve the problems in the background art.

[0007] To solve the above technical problems, the nickel-based single crystal superalloy provided by the present invention includes the following weight groups:

[0008] C: 0.05 - 0.15 wt%, Cr: 3.5 - 5.5 wt%, Al: 6 - 8 wt%, Co: 6 - 14 wt%, Mo: 1 - 2 wt%, W: 8 - 10 wt%, Nb: 1.5 - 2.5 wt%, Ta: 4 - 6 wt%, Re: 4 - 5 wt%, Hf: 0.05 - 0.15 wt%, Ru: 0.5 - 1.5 wt%, Ni: balance.

[0009] Preferably, it includes the following weight groups: C: 0.07-0.13 wt%, Cr: 4-5 wt%, Al: 6-7.5 wt%, Co: 8-12 wt%, Mo: 1.2-1.8 wt%, W: 8.2-9.8 wt%, Nb: 1.7-2.2 wt%, Ta: 4.5-5.5 wt%, Re: 4-5 wt%, Hf: 0.1-0.15 wt%, Ru: 0.1-1.5 wt%, Ni: the balance.

[0010] Preferably, it includes the following weight groups: C: 0.07-0.1 wt%, Cr: 4-4.5 wt%, Al: 7-7.5 wt%, Co: 10-12 wt%, Mo: 1.4-1.8 wt%, W: 9-9.8 wt%, Nb: 1.9-2.2 wt%, Ta: 4.5-5 wt%, Re: 4-5 wt%, Hf: 0.12-0.15 wt%, Ru: 0.13-1.5 wt%, Ni: the balance.

[0011] Preferably, it further includes the following weight groups: Sc: 0.1-0.5 wt%, Si 0.1-0.2 wt%, B 0.05-0.1 wt%.

[0012] A preparation method of a nickel-based single-crystal superalloy for preparing the nickel-based single-crystal superalloy includes the following steps:

[0013] S1. Master alloy melting: Weigh each component raw material according to the weight ratio, add it to a vacuum induction furnace, and carry out melting in a high-vacuum environment. During the melting process, by precisely controlling the heating power and time, the alloy liquid is fully mixed and reaches a uniform temperature;

[0014] S2. Single-crystal preparation: Pour the melted master alloy into a specific mold, place it in a single-crystal growth furnace, and establish a stable and high-intensity temperature gradient in the single-crystal growth furnace;

[0015] S3. Solution treatment: Carry out solution treatment on the single-crystal billet, and the solution treatment is carried out in multiple stages;

[0016] S4. Aging treatment: Carry out aging treatment after solution treatment, and then obtain the finished nickel-based single-crystal superalloy.

[0017] Preferably, the vacuum degree of the high-vacuum environment in S1 reaches 10 -3 -10 -4 Pa, and the melting temperature is controlled at 1500-1600 °C.

[0018] Preferably, the temperature gradient range in S2 is 70-120 K / cm.

[0019] Preferably, in S2, the single crystal growth rate is controlled at 3-8 mm / min.

[0020] Preferably, in S3, the solution treatment is first carried out at 1250-1300 °C for 2-4 h, and then gradually heated to 1320-1350 °C and held for 3-5 h.

[0021] Preferably, in S4, the aging treatment is first carried out with high-temperature aging, held at 1100-1150 °C for 8-12 h, and then followed by low-temperature aging, held at 850-950 °C for 10-15 h.

[0022] Compared with the related technologies, the nickel-based single crystal superalloy and its preparation method provided by the present invention have the following beneficial effects:

[0023] The present invention provides a nickel-based single crystal superalloy and its preparation method. Through unique alloy composition design, the nickel-based single crystal superalloy of the present invention has excellent creep rupture strength and creep resistance at high temperatures. It can better meet the use requirements of high-temperature components such as aeroengine blades under extreme working conditions, significantly improve the performance and reliability of the engine. Appropriate amounts of elements such as Cr in the alloy enhance the ability of the alloy surface to form a dense oxide film, effectively improving the oxidation resistance of the alloy. At the same time, in a complex hot corrosion environment, the alloy of the present invention exhibits good hot corrosion resistance, can extend the service life of high-temperature components, and reduce maintenance costs. The innovative preparation method, including a precisely controlled master alloy melting process, directional solidification parameters, and multi-stage heat treatment method, not only improves the quality stability of the alloy but also improves the production efficiency to a certain extent. Compared with the traditional preparation method, the method of the present invention can reduce the scrap rate and production cost, and has significant economic benefits and industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a preferred embodiment of the nickel-based single crystal superalloy and its preparation method provided by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will be further described below in conjunction with the drawings and embodiments.

[0026] Please refer to Figure 1 , wherein, Figure 1 It is a schematic structural diagram of a preferred embodiment of the nickel-based single crystal superalloy and its preparation method provided by the present invention.

[0027] Example 1

[0028] The nickel-based single crystal superalloy comprises the following weight groups:

[0029] C: 0.07 - 0.13 wt%, Cr: 4 - 5 wt%, Al: 6 - 7.5 wt%, Co: 8 - 12 wt%, Mo: 1.2 - 1.8 wt%, W: 8.2 - 9.8 wt%, Nb: 1.7 - 2.2 wt%, Ta: 4.5 - 5.5 wt%, Re: 4 - 5 wt%, Hf: 0.1 - 0.15 wt%, Ru: 0.1 - 1.5 wt%, Ni: the balance.

[0030] It also includes the following weight groups: Sc: 0.1 - 0.5 wt%, Si 0.1 - 0.2 wt%, B 0.05 - 0.1 wt%.

[0031] A method for preparing a nickel-based single crystal superalloy for preparing the nickel-based single crystal superalloy includes the following steps:

[0032] S1. Master alloy melting: Weigh each component raw material according to the weight ratio, add it to a vacuum induction furnace, and carry out melting in a high-vacuum environment. The vacuum degree reaches 10 -3 -10 -4 Pa. During the melting process, by precisely controlling the heating power and time, the alloy liquid is fully mixed and reaches a uniform temperature. The melting temperature is controlled at 1500 - 1600 °C;

[0033] S2. Single crystal preparation: Pour the melted master alloy into a specific mold, place it in a single crystal growth furnace. In the single crystal growth furnace, establish a stable and high-strength temperature gradient. The temperature gradient range is 70 - 120 K / cm. At the same time, control the single crystal growth rate at 3 - 8 mm / min;

[0034] S3. Solution treatment: Carry out solution treatment on the single crystal blank. The solution treatment is carried out in multiple stages. First, keep it at 1250 - 1300 °C for 2 h, and then gradually heat it up to 1320 - 1350 °C and keep it for 3 h;

[0035] S4. Aging treatment: After solution treatment, carry out aging treatment, and then obtain the finished product of the nickel-based single crystal superalloy. First, carry out high-temperature aging, keep it at 1100 - 1150 °C for 8 h, and then carry out low-temperature aging, keep it at 850 - 950 °C for 10 h.

[0036] Example 2

[0037] The nickel-based single crystal superalloy includes the following weight groups:

[0038] C: 0.07 - 0.13 wt%, Cr: 4 - 5 wt%, Al: 6 - 7.5 wt%, Co: 8 - 12 wt%, Mo: 1.2 - 1.8 wt%, W: 8.2 - 9.8 wt%, Nb: 1.7 - 2.2 wt%, Ta: 4.5 - 5.5 wt%, Re: 4 - 5 wt%, Hf: 0.1 - 0.15 wt%, Ru: 0.1 - 1.5 wt%, Ni: the balance.

[0039] It also includes the following weight groups: Sc: 0.1 - 0.5 wt%, Si 0.1 - 0.2 wt%, B 0.05 - 0.1 wt%.

[0040] A method for preparing a nickel-based single-crystal superalloy for preparing the nickel-based single-crystal superalloy includes the following steps:

[0041] S1. Master alloy melting: Weigh each component raw material according to the weight ratio, add it to a vacuum induction furnace, and carry out melting in a high-vacuum environment. The vacuum degree reaches 10 -3 -10 -4 Pa. During the melting process, by precisely controlling the heating power and time, the alloy liquid is fully mixed and reaches a uniform temperature. The melting temperature is controlled at 1500 - 1600 °C;

[0042] S2. Single-crystal preparation: Pour the melted master alloy into a specific mold, place it in a single-crystal growth furnace. In the single-crystal growth furnace, establish a stable and high-intensity temperature gradient. The temperature gradient range is 70 - 120 K / cm. At the same time, control the single-crystal growth rate at 3 - 8 mm / min;

[0043] S3. Solution treatment: Carry out solution treatment on the single-crystal blank. The solution treatment is carried out in multiple stages. First, keep it at 1250 - 1300 °C for 3 h, then gradually heat it up to 1320 - 1350 °C and keep it for 4 h;

[0044] S4. Aging treatment: Carry out aging treatment after solution treatment, and then obtain the finished nickel-based single-crystal superalloy. First, carry out high-temperature aging, keep it at 1100 - 1150 °C for 9 h, and then carry out low-temperature aging, keep it at 850 - 950 °C for 11 h.

[0045] Example 3

[0046] The nickel-based single-crystal superalloy includes the following weight groups:

[0047] C: 0.07 - 0.1 wt%, Cr: 4.1 - 5 wt%, Al: 6.5 - 7 wt%, Co: 7 - 10 wt%, Mo:

[0048] C: 0.05 - 0.08 wt%, Cr: 3.5 - 4.5 wt%, Al: 6 - 7 wt%, Co: 7.3 - 8.8 wt%, Mo: 1 - 1.3 wt%, W: 8.2 - 9.8 wt%, Nb: 1.7 - 2 wt%, Ta: 4.5 - 5.2 wt%, Re: 4 - 5 wt%, Hf: 0.1 - 0.14 wt%, Ru: 0.1 - 1.2 wt%, Ni: the balance.

[0049] It also includes the following weight groups: Sc: 0.1 - 0.5 wt%, Si 0.1 - 0.2 wt%, B 0.05 - 0.1 wt%.

[0050] A preparation method of a nickel-based single-crystal superalloy for preparing the said nickel-based single-crystal superalloy, comprising the following steps:

[0051] S1. Master alloy melting: Weigh each component raw material according to the weight ratio, add it into a vacuum induction furnace, and carry out melting in a high-vacuum environment. The vacuum degree reaches 10 -3 -10 -4 Pa. During the melting process, by precisely controlling the heating power and time, the alloy liquid is fully mixed and reaches a uniform temperature. The melting temperature is controlled at 1500 - 1600 °C;

[0052] S2. Single-crystal preparation: Pour the melted master alloy into a specific mold, put it into a single-crystal growth furnace. In the single-crystal growth furnace, establish a stable and high-intensity temperature gradient, and the temperature gradient range is 70 - 120 K / cm. At the same time, control the single-crystal growth rate at 3 - 8 mm / min;

[0053] S3. Solution treatment: Carry out solution treatment on the single-crystal blank. The solution treatment is carried out in multiple stages. First, keep it at 1250 - 1300 °C for 4 h, and then gradually heat it up to 1320 - 1350 °C and keep it for 4.5 h;

[0054] S4. Aging treatment: Carry out aging treatment after solution treatment, and then obtain the finished product of the nickel-based single-crystal superalloy. First, carry out high-temperature aging, keep it at 1100 - 1150 °C for 11 h, and then carry out low-temperature aging, keep it at 850 - 950 °C for 13 h.

[0055] Example 4

[0056] The nickel-based single-crystal superalloy includes the following weight groups:

[0057] C: 0.05 - 0.08 wt%, Cr: 3.5 - 4.5 wt%, Al: 6 - 7 wt%, Co: 7.3 - 8.8 wt%, Mo: 1 - 1.3 wt%, W: 8.2 - 9.8 wt%, Nb: 1.7 - 2 wt%, Ta: 4.5 - 5.2 wt%, Re: 4 - 5 wt%, Hf: 0.1 - 0.14 wt%, Ru: 0.1 - 1.2 wt%, Ni: the balance.

[0058] It also includes the following weight groups: Sc: 0.1 - 0.5 wt%, Si 0.1 - 0.2 wt%, B 0.05 - 0.1 wt%.

[0059] A method for preparing a nickel - based single - crystal superalloy, which is used to prepare the nickel - based single - crystal superalloy, includes the following steps:

[0060] S1. Melting of master alloy: Weigh each component raw material according to the weight ratio, add it into a vacuum induction furnace, and carry out melting in a high - vacuum environment. The vacuum degree reaches 10 -3 -10 -4 Pa. During the melting process, by precisely controlling the heating power and time, the alloy liquid is fully mixed and reaches a uniform temperature. The melting temperature is controlled at 1500 - 1600 °C;

[0061] S2. Single - crystal preparation: Pour the melted master alloy into a specific mold, put it into a single - crystal growth furnace. In the single - crystal growth furnace, establish a stable and high - strength temperature gradient, and the temperature gradient range is 70 - 120 K / cm. At the same time, control the single - crystal growth rate at 3 - 8 mm / min;

[0062] S3. Solution treatment: Carry out solution treatment on the single - crystal blank. The solution treatment is carried out in multiple stages. First, keep it at 1250 - 1300 °C for 4 h, and then gradually raise the temperature to 1320 - 1350 °C and keep it for 5 h;

[0063] S4. Aging treatment: Carry out aging treatment after solution treatment, and then obtain the finished product of the nickel - based single - crystal superalloy. First, carry out high - temperature aging, keep it at 1100 - 1150 °C for 12 h, and then carry out low - temperature aging, keep it at 850 - 950 °C for 15 h.

[0064] The working principle of the nickel - based single - crystal superalloy and its preparation method provided by the present invention is as follows:

[0065] Weigh each component raw material according to the weight ratio, add it into a vacuum induction furnace, and carry out melting in a high - vacuum environment. During the melting process, by precisely controlling the heating power and time, the alloy liquid is fully mixed and reaches a uniform temperature; Pour the melted master alloy into a specific mold, put it into a single - crystal growth furnace. In the single - crystal growth furnace, establish a stable and high - strength temperature gradient; Carry out solution treatment on the single - crystal blank. The solution treatment is carried out in multiple stages; Carry out aging treatment after solution treatment, and then obtain the finished product of the nickel - based single - crystal superalloy.

[0066] Compared with the related technology, the nickel - based single - crystal superalloy and its preparation method provided by the present invention have the following beneficial effects:

[0067] Through unique alloy composition design, the nickel-based single crystal superalloy of the present invention has excellent creep rupture strength and anti-creep performance at high temperatures. It can better meet the usage requirements of high-temperature components such as aeroengine blades under extreme working conditions, significantly improving the performance and reliability of the engine. Appropriate elements such as Cr in the alloy enhance the ability of the alloy surface to form a dense oxide film, effectively improving the oxidation resistance of the alloy. At the same time, in a complex hot corrosion environment, the alloy of the present invention exhibits good hot corrosion resistance, which can extend the service life of high-temperature components and reduce maintenance costs. The innovative preparation method, including the precisely controlled master alloy melting process, directional solidification parameters, and multi-stage heat treatment method, not only improves the quality stability of the alloy but also increases the production efficiency to a certain extent. Compared with the traditional preparation method, the method of the present invention can reduce the scrap rate and production cost, having significant economic benefits and industrial application value.

[0068] The above are only embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A nickel-based single crystal superalloy, characterized in that, Comprising the following weight groups: C: 0.05 - 0.15 wt%, Cr: 3.5 - 5.5 wt%, Al: 6 - 8 wt%, Co: 6 - 14 wt%, Mo: 1 - 2 wt%, W: 8 - 10 wt%, Nb: 1.5 - 2.5 wt%, Ta: 4 - 6 wt%, Re: 4 - 5 wt%, Hf: 0.05 - 0.15 wt%, Ru: 0.5 - 1.5 wt%, Ni: balance.

2. The nickel-based single crystal superalloy according to claim 1, characterized in that, Comprising the following weight groups: C: 0.07 - 0.13 wt%, Cr: 4 - 5 wt%, Al: 6 - 7.5 wt%, Co: 8 - 12 wt%, Mo: 1.2 - 1.8 wt%, W: 8.2 - 9.8 wt%, Nb: 1.7 - 2.2 wt%, Ta: 4.5 - 5.5 wt%, Re: 4 - 5 wt%, Hf: 0.1 - 0.15 wt%, Ru: 0.1 - 1.5 wt%, Ni: balance.

3. The nickel-based single crystal superalloy according to claim 1, characterized in that, Comprising the following weight groups: C: 0.07 - 0.1 wt%, Cr: 4 - 4.5 wt%, Al: 7 - 7.5 wt%, Co: 10 - 12 wt%, Mo: 1.4 - 1.8 wt%, W: 9 - 9.8 wt%, Nb: 1.9 - 2.2 wt%, Ta: 4.5 - 5 wt%, Re: 4 - 5 wt%, Hf: 0.12 - 0.15 wt%, Ru: 0.13 - 1.5 wt%, Ni: balance.

4. The nickel-based single-crystal superalloy according to claim 1, characterized in that, Also comprising the following weight groups: Sc: 0.1 - 0.5 wt%, Si 0.1 - 0.2 wt%, B 0.05 - 0.1 wt%.

5. A preparation method of a nickel-based single crystal superalloy for preparing the nickel-based single crystal superalloy according to any one of claims 1-4, characterized in that, Comprising the following steps: S1. Master alloy melting: Weigh each component raw material according to the weight ratio, add it to a vacuum induction furnace, and carry out melting in a high vacuum environment. During the melting process, by precisely controlling the heating power and time, the alloy liquid is fully mixed and reaches a uniform temperature; S2. Single crystal preparation: Pour the melted master alloy into a specific mold, place it in a single crystal growth furnace, and establish a stable and high-intensity temperature gradient in the single crystal growth furnace; S3. Solution treatment: Carry out solution treatment on the single crystal blank, and the solution treatment is carried out in multiple stages; S4. Aging treatment: Carry out aging treatment after solution treatment, and then obtain the finished nickel-based single crystal superalloy.

6. The preparation method of the nickel-based single crystal superalloy according to claim 5, characterized in that, The vacuum degree of the high-vacuum environment in S1 reaches 10 -3 -10 -4 Pa, and the melting temperature is controlled at 1500-1600 °C.

7. The preparation method of the nickel-based single crystal superalloy according to claim 5, characterized in that, The temperature gradient range in S2 is 70 - 120 K / cm.

8. The preparation method of the nickel-based single crystal superalloy according to claim 5, characterized in that Control the single crystal growth rate in S2 at 3 - 8 mm / min.

9. The preparation method of the nickel-based single crystal superalloy according to claim 5, wherein In S3, for the solution treatment, first keep it at 1250 - 1300 °C for 2 - 4 h, and then gradually raise the temperature to 1320 - 1350 °C and keep it for 3 - 5 h.

10. The preparation method of the nickel-based single crystal superalloy according to claim 1, characterized in that, In S4, for the aging treatment, first carry out high-temperature aging, keep it at 1100 - 1150 °C for 8 - 12 h, and then carry out low-temperature aging, keep it at 850 - 950 °C for 10 - 15 h.

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