Application of nickel-based single-crystal high-temperature alloy in high-temperature working scene

Abstract

The invention relates to the technical field of high-temperature alloys, in particular to application of a nickel-based single-crystal high-temperature alloy in a high-temperature working scene. Different from the strategy that the high-temperature creep property of a [001]-oriented nickel-based single-crystal high-temperature alloy is improved by adding refractory elements, [111] orientation is used as the alloy loading direction, the crystal anisotropy of the single-crystal high-temperature alloy is utilized, and a / 2lt is adjusted; 110gt, 110gt; the Schmidt factor of the slip system enables a / 2lt of starting; 110gt, 110gt; base dislocation cannot generate alt through dislocation reaction; 100 gt; the overdislocation is realized, and the alt is inhibited; 100 gt; and in the super-dislocation forming process, the high-temperature creep property of the nickel-based single-crystal high-temperature alloy is greatly improved while refractory elements are not added and extra cost is not increased.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloys, and in particular to the application of a nickel-based single crystal high-temperature alloy in high-temperature working scenarios. Background Art

[0002]

[001] Oriented nickel-based single crystal high temperature alloys have become the most widely used turbine blade materials for aircraft engines due to their excellent fatigue resistance, creep resistance and corrosion resistance. High temperature creep failure caused by centrifugal force is one of the main failure modes of turbine blades. With the increase of thrust-to-weight ratio of aircraft engines, the turbine front design temperature of new generation aircraft engines has reached 2400K, which makes the structure of turbine blades become a double-layer thin-walled hollow structure through refined design, so as to achieve extremely high turbine front inlet temperature by greatly improving cooling efficiency.

[0003] Studies have shown that the high-temperature creep properties of nickel-based single crystal high-temperature alloys mainly depend on the hindering effect of the dislocation network at the γ / γ′ phase interface. The current way to improve the high-temperature creep properties is mainly to increase the mismatch between the γ / γ′ phases in the nickel-based single crystal high-temperature alloy by adding refractory elements such as Cr, Re, Mo, W, and Ru. The increase in the mismatch makes the interface dislocation network denser and the interface dislocation network structure more stable, which can more effectively hinder the matrix dislocation movement from cutting the γ′ phase.

[0004] According to the strategy of adding refractory elements and reasonably matching refractory elements to improve high-temperature creep performance, the sixth generation of single crystal high-temperature alloys has been developed. However, excessive addition of refractory elements will reduce the stability of the alloy structure, precipitate harmful TCP hard and brittle phases, and reduce the safe service life of the engine. In addition, the addition of refractory elements causes the density of single crystal alloys to increase sharply, thereby reducing the thrust-to-weight ratio of aircraft engines. For example, the density of the sixth generation alloys such as TMS-238 and TMS-238+ has exceeded 9g / cm 3 . Moreover, the price of refractory elements is extremely expensive, making high-generation nickel-based single crystal high-temperature alloys an "unaffordable" material.

[0005] In summary, a new design strategy for the creep resistance of nickel-based single crystal high-temperature alloys is urgently needed to achieve low density, low cost and excellent high-temperature creep strength. Summary of the invention

[0006] The purpose of the present invention is to provide a nickel-based single crystal high-temperature alloy for use in high-temperature working scenarios. The present invention adopts a

[111] oriented nickel-based single crystal high-temperature alloy, which has excellent high-temperature creep strength, does not require the addition of refractory elements, and has both low density and low cost.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides an application of a nickel-based single crystal high-temperature alloy in a high-temperature working scene, wherein the nickel-based single crystal high-temperature alloy is

[111] oriented; the density of the nickel-based single crystal high-temperature alloy is ≤8.4g / cm 3 .

[0009] Preferably, the element composition of the nickel-based single crystal high-temperature alloy is, in terms of mass percentage, 7-9% Al, 8-12% Mo, 1-1.5% Re, 2.5-4% Ta, 1.0-1.5% Cr, 0.005-0.01% C and the remainder Ni.

[0010] Preferably, the density of the nickel-based single crystal high temperature alloy is 7.8-8.4 g / cm 3 .

[0011] Preferably, the thickness of the nickel-based single crystal high-temperature alloy is ≤0.6 mm.

[0012] Preferably, the temperature of the high temperature working scene is 900-1200°C.

[0013] Preferably, the high-temperature working scenario includes: using the nickel-based single crystal high-temperature alloy for aircraft engine turbine blades.

[0014] Preferably, the aircraft engine turbine working blade is a double-layer thin-walled hollow structure.

[0015] The present invention provides an application of a nickel-based single crystal high-temperature alloy in a high-temperature working scene, wherein the nickel-based single crystal high-temperature alloy is

[111] oriented; the density of the nickel-based single crystal high-temperature alloy is ≤8.4g / cm 3 Different from the strategy of improving the high temperature creep performance of

[001] oriented nickel-based single crystal high temperature alloy by adding refractory elements, the present invention takes

[111] orientation as the alloy loading direction, utilizes the crystal anisotropy of single crystal high temperature alloy, and adjusts the a / 2 <110> The Schmidt factor of the slip system makes the starting a / 2 <110> Matrix dislocations cannot generate a through dislocation reactions <100> Super dislocation, suppressing a <100> The super dislocation formation process greatly improves the high-temperature creep properties of nickel-based single crystal high-temperature alloys without adding refractory elements or increasing additional costs.

[0016] The new generation of aircraft engines requires single crystal turbine blades with extremely high temperature bearing capacity. The present invention uses

[111] oriented nickel-based single crystal high-temperature alloy for aircraft engine turbine working blades, which has improved temperature bearing capacity and can be used for the new generation of aircraft engine high-efficiency air-cooled blade materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the slip system generated by loading along the traditional

[001] orientation;

[0018] Figure 2 It is the slip system generated by loading along the

[111] orientation. DETAILED DESCRIPTION

[0019] The present invention provides an application of a nickel-based single crystal high-temperature alloy in a high-temperature working scene, wherein the nickel-based single crystal high-temperature alloy is

[111] oriented; the density of the nickel-based single crystal high-temperature alloy is ≤8.4g / cm 3 .

[0020] In the present invention, the density of the nickel-based single crystal high temperature alloy is preferably 7.8 to 8.4 g / cm 3 .

[0021] In the present invention, the element composition of the nickel-based single crystal high-temperature alloy is, in terms of mass percentage, 7-9% Al, 8-12% Mo, 1-1.5% Re, 2.5-4% Ta, 1.0-1.5% Cr, 0.005-0.01% C and the balance Ni.

[0022] In the present invention, the thickness of the nickel-based single crystal high-temperature alloy is preferably ≤0.6 mm, more preferably ≤0.5 mm.

[0023] The present invention has no special requirements on the preparation method of the nickel-based single crystal high-temperature alloy, and any preparation method known in the art can be used. In a specific embodiment of the present invention, the nickel-based single crystal high-temperature alloy is obtained by directional solidification using a seed crystal method.

[0024] In the present invention, the temperature of the high temperature working scene is preferably 900-1200°C. In a specific embodiment, the temperature of the high temperature working scene can be 900°C, 1000°C, 1100°C or 1200°C.

[0025] In the present invention, the high-temperature working scenario preferably includes: using the nickel-based single crystal high-temperature alloy for aircraft engine turbine blades.

[0026] In the present invention, the aircraft engine turbine working blade is preferably a double-layer thin-walled hollow structure.

[0027] The present invention uses the

[111] orientation as the alloy loading direction and utilizes the crystal anisotropy of the single crystal high temperature alloy by adjusting the a / 2 <110> The Schmidt factor of the slip system makes the starting a / 2 <110> Matrix dislocations cannot generate a through dislocation reactions <100> Super dislocation, suppressing a <100> The formation process of super dislocations can improve the high temperature creep performance.

[0028] The specific principle is as follows Figure 1 and Figure 2 As shown:

[0029] like Figure 1As shown, when loading along the traditional

[001] orientation, each a / 2 <110> The Schmidt factors of the slip system are shown in Table 1. During the high temperature creep process, the specimen approaches a uniaxial stress state, where σ1≈σ3, then τ1=τ2, and the resulting a / 2 <110> Slip systems can be formed by dislocation reactions in two ways: <010> Super dislocation. ① Two groups of a / 2 in the matrix channel or interface dislocation network <110> Dislocations react: ② a / 2 in two sets of adjacent {111} faces in the matrix channel <112> Dislocations react: Form a <010> Super dislocations lead to an increase in the amount of cut γ′ phase.

[0030] Table 1. a / 2 when loading along

[001] orientation <110> Shear stress of slip system

[0031]

[0032] like Figure 2 As shown, when loading along the

[111] orientation, each a / 2 <110> The Schmidt factors of the slip system are shown in Table 2. During the high temperature creep process, the specimen is close to the uniaxial stress state, at which time σ1≈σ3, then τ1=τ2, Figure 2 The six green slip systems in the system are activated, and the resulting groups of a / 2 <110> The slip system cannot form a through dislocation reaction <010> Super dislocations effectively reduce the amount of super dislocations cutting the γ′ phase, thereby improving the high-temperature creep performance.

[0033] Table 2. a / 2 when loading along

[111] orientation <110> Shear stress of slip system

[0034]

[0035]

[0036] In Tables 1 and 2, σ2 is defined as the principal stress direction, σ1 and σ3 are defined as two directions perpendicular to σ2, and τ1 and τ2 are the shear stresses of different slip system groups under loading.

[0037] The application of the nickel-based single crystal high-temperature alloy provided by the present invention in high-temperature working scenarios is described in detail below in conjunction with the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0038] Examples 1 to 6

[0039] 2101 g of high-purity 99.99% aluminum source, 2701 g of high-purity 99.99% molybdenum source, 301 g of high-purity 99.99% rhenium source, 756 g of high-purity 99.99% tantalum source, 301 g of high-purity 99.99% chromium source, 0.156 g of high-purity 99.99% carbon source, and 23850 g of high-purity 99.99% nickel source were mixed and smelted at 1600° C. for 3 hours to obtain a melt;

[0040] The melt was placed in an alumina mold and solidified by Bridgman directional solidification method at a pulling rate of 3 mm / min and a temperature gradient of 25 K / cm. <111> The seed crystal is subjected to a seed crystal method for directional solidification to obtain a green body;

[0041] The blank is subjected to a first solution treatment at 1280°C for 10 hours and then to a second solution treatment at 1300°C for 12 hours; after the solution treatment, the product is subjected to a first aging treatment at 1070°C for 8 hours and then to a second aging treatment at 880°C for 50 hours to obtain a

[111] oriented nickel-based single crystal high-temperature alloy; in terms of mass percentage, the chemical composition of the nickel-based single crystal high-temperature alloy is 7-9% Al, 8-12% Mo, 1-1.5% Re, 2.5-4% Ta, 1.0-1.5% Cr, 0.005-0.01% C and the remainder Ni, and the density is: 7.8-8.4 g / cm 3 , wall thickness 0.5mm.

[0042] Comparative Examples 1 to 6

[0043] 2101 g of high-purity 99.99% aluminum source, 2701 g of high-purity 99.99% molybdenum source, 301 g of high-purity 99.99% rhenium source, 756 g of high-purity 99.99% tantalum source, 301 g of high-purity 99.99% chromium source, 0.156 g of high-purity 99.99% carbon source, and 23850 g of high-purity 99.99% nickel source were mixed and smelted at 1600° C. for 3 hours to obtain a melt;

[0044] The melt is placed in an alumina mold shell and directional solidified by a spiral crystal selector at a pulling rate of 3 mm / min and a temperature gradient of 25 K / cm according to the Bridgman directional solidification method to obtain a green body;

[0045] The blank is subjected to a first solution treatment at 1280°C for 10 hours and then to a second solution treatment at 1300°C for 12 hours; after the solution treatment, the product is subjected to a first aging treatment at 1070°C for 8 hours and then to a second aging treatment at 880°C for 50 hours to obtain a

[001] oriented nickel-based single crystal high-temperature alloy; the chemical composition of the nickel-based single crystal high-temperature alloy is 7-9% Al, 8-12% Mo, 1-1.5% Re, 2.5-4% Ta, 1.0-1.5% Cr, 0.005-0.01% C and the balance Ni, and the density is 7.8-8.4 g / cm3 , wall thickness 0.5mm.

[0046] Comparative Examples 7 to 9

[0047] The preparation method of the embodiment is different only in that a nickel-based single crystal high-temperature alloy with a

[011] orientation is prepared.

[0048] The high temperature creep performance test was carried out on the single crystal nickel-based high temperature alloys of the embodiment and the comparative example with reference to GB / T 2039-2012. The test results are shown in Table 3.

[0049] Table 3 High temperature creep properties of the embodiments and comparative examples

[0050] Loading direction Experimental conditions High temperature endurance life (h) Example 1

[111] 980℃ / 300MPa 289 Example 2

[111] 1100℃ / 137MPa 1412 Example 3

[111] 1100℃ / 160MPa 510 Example 4

[111] 1120℃ / 137MPa 976 Example 5

[111] 1150℃ / 137MPa 215 Example 6

[111] 1150℃ / 160MPa 47 Comparative Example 1

[001] 980℃ / 230MPa 120 Comparative Example 2

[001] 1070℃ / 137MPa 141 Comparative Example 3

[001] 1100℃ / 110MPa 207 Comparative Example 4

[001] 1100℃ / 120MPa 129 Comparative Example 5

[001] 1100℃ / 137MPa 52 Comparative Example 6

[001] 1150℃ / 100MPa 265 Comparative Example 7

[011] 980℃ / 250MPa 429 Comparative Example 8

[011] 1100℃ / 137MPa 242 Comparative Example 9

[011] 1100℃ / 120MPa 548

[0051] It can be seen from Table 3 that the

[111] oriented nickel-based single crystal superalloy has better high-temperature creep resistance than the

[001] oriented and

[011] oriented nickel-based single crystal superalloys.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of a nickel-based single crystal high-temperature alloy in a high-temperature working scenario, characterized in that: The nickel-based single crystal high temperature alloy is [111] oriented; the density of the nickel-based single crystal high temperature alloy is ≤8.4 g / cm 3 .

2. The use according to claim 1, characterized in that: Calculated by mass percentage, the element composition of the nickel-based single crystal high-temperature alloy is: 7-9% Al, 8-12% Mo, 1-1.5% Re, 2.5-4% Ta, 1.0-1.5% Cr, 0.005-0.01% C and the balance Ni.

3. The use according to claim 1 or 2, characterized in that: The density of the nickel-based single crystal high temperature alloy is 7.8-8.4 g / cm 3 .

4. The use according to claim 1, characterized in that: The thickness of the nickel-based single crystal high-temperature alloy is ≤0.6 mm.

5. The use according to claim 1, characterized in that: The temperature of the high temperature working scene is 900-1200°C.

6. The use according to claim 1 or 5, characterized in that: The high-temperature working scenario includes: using the nickel-based single crystal high-temperature alloy for aircraft engine turbine blades.

7. The use according to claim 6, characterized in that: The aero-engine turbine working blade is a double-layer thin-wall hollow structure.

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