CN115029586A - Nickel-based single crystal superalloy and preparation method thereof - Google Patents
Nickel-based single crystal superalloy and preparation method thereof Download PDFInfo
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- 229910000601 superalloy Inorganic materials 0.000 title claims abstract description 114
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- 229910052742 iron Inorganic materials 0.000 claims abstract description 4
- 229910052753 mercury Inorganic materials 0.000 claims abstract description 4
- 229910052706 scandium Inorganic materials 0.000 claims abstract description 4
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 4
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- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
- C22C19/051—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
- C22C19/057—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being less 10%
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D11/00—Process control or regulation for heat treatments
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- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/10—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon
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- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
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- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
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Abstract
The invention relates to a nickel-based single crystal superalloy and a preparation method thereof, and relates to the field of high-generation single crystal superalloy materials. The nickel-based single crystal superalloy comprises the following components in percentage by weight: 3.5 to 5.5 weight percent of Cr, 6 to 14 weight percent of Co, 5 to 7 weight percent of W, 0.5 to 2.5 weight percent of Mo, 4 to 7.5 weight percent of Re, 1.5 to 4 weight percent of Ru, 5 to 6.8 weight percent of Al, 7 to 10 weight percent of Ta, less than or equal to 0.8 weight percent of Ti, less than or equal to 0.5 weight percent of Sc, less than or equal to 0.2 weight percent of Si, less than or equal to 0.3 weight percent of Hf, less than or equal to 0.05 weight percent of Y, less than or equal to 0.03 weight percent of Zr, less than or equal to 0.02 weight percent of Fe, less than or equal to 0.0075 weight percent of Na, less than or equal to 0.0045 weight percent of Be, less than or equal to 0.0065 weight percent of Sr, less than or equal to 0.0055 weight percent of Hg, and the balance of Ni. The above component design can reduce the integral dislocation energy of the alloy, limit dislocation movement by utilizing compression bar dislocation, L-C dislocation lock and the like formed by dislocation expansion and reaction to strengthen the alloy, and simultaneously ensure the structural stability and the high-temperature precipitation strengthening effect of the alloy. Furthermore, in the preparation of the nickel-based single crystal superalloy, the invention quantificationally establishes a reasonable high-temperature solid solution heat treatment system, and realizes the targeted design and the full play of high-temperature strength of the low-layer fault energy nickel-based single crystal superalloy by synergistically regulating and controlling the components of the alloy and the heat treatment process.
Description
Technical Field
The invention relates to the technical field of high-generation single crystal superalloy materials, in particular to a nickel-based single crystal superalloy and a preparation method thereof.
Background
The single crystal high temperature alloy has excellent comprehensive performance, so that the single crystal high temperature alloy becomes a core material for manufacturing advanced power equipment turbine blades of aeroengines, gas turbines and the like. With the increase of the inlet temperature of the gas turbine, the requirements of advanced power equipment on the comprehensive mechanical properties of the single crystal alloy are higher and higher.
The idea of the design of the single crystal superalloy is to increase the content of alloy elements to improve the comprehensive performance of the alloy. However, the design methods or principles of existing single crystal alloys are relatively broad. For example, it is required to keep the volume fraction of γ 'precipitated phase in the single crystal alloy at about 65%, minimize the mismatching at the γ/γ' phase interface in the alloy, minimize the content of refractory elements without TCP phase precipitation, and consider oxidation resistance and corrosion resistance. With the increasing requirements of aero-engines on single crystal alloys, it is difficult to develop new alloys according to the current single crystal superalloy design method or principle. Therefore, on the premise of ensuring the design method or principle of the alloy, it becomes a very challenging task to design the components of the alloy more specifically from the perspective of the micro-strengthening mechanism.
In addition, when the alloy components are determined, how to make a reasonable heat treatment system is the key point for fully playing the roles of the alloy elements. The general method is to adopt a metallographic microscope and a scanning electron microscope to observe the structure condition between dendrite trunks and dendrites after high-temperature solution heat treatment, and artificially judge whether the heat treatment system is reasonable. It is difficult to scientifically and reasonably determine the optimum solution heat treatment regime.
Disclosure of Invention
In view of this, the invention provides a nickel-based single crystal superalloy and a preparation method thereof, and mainly aims to solve the problems that an existing single crystal superalloy design method or principle is wide and not strong in pertinence, and a low-layer fault-energy nickel-based single crystal superalloy is designed.
In order to achieve the purpose, the invention mainly provides the following technical scheme:
in one aspect, embodiments of the present invention provide a nickel-based single crystal superalloy, wherein the nickel-based single crystal superalloy comprises the following components in weight percent:
3.5 to 5.5 weight percent of Cr, 6 to 14 weight percent of Co, 5 to 7 weight percent of W, 0.5 to 2.5 weight percent of Mo, 4 to 7.5 weight percent of Re, 1.5 to 4 weight percent of Ru, 5 to 6.8 weight percent of Al, 7 to 10 weight percent of Ta, less than or equal to 0.8 weight percent of Ti, less than or equal to 0.5 weight percent of Sc, less than or equal to 0.2 weight percent of Si, less than or equal to 0.3 weight percent of Hf, less than or equal to 0.05 weight percent of Y, less than or equal to 0.03 weight percent of Zr, less than or equal to 0.02 weight percent of Fe, less than or equal to 0.0075 weight percent of Na, less than or equal to 0.0045 weight percent of Be, less than or equal to 0.0065 weight percent of Sr, less than or equal to 0.0055 weight percent of Hg, and the balance of Ni.
Preferably, in the composition of the nickel-based single crystal superalloy: the sum of the contents of the Co element and the Re element is more than or equal to 15.0 wt%; and/or the sum of the contents of the Co element and the Ru element is more than or equal to 12.0 wt; and/or the sum of the contents of the Co element, the Re element and the Ru element is more than or equal to 16.0 wt%.
Preferably, in the composition of the nickel-based single crystal superalloy: the content ratio of the Ru element to the Co element is more than or equal to 0.12 and less than or equal to 0.50; and/or the sum of the contents of the Mo, W and Ta elements is more than or equal to 12.0 wt% and less than or equal to 18.0 wt%; and/or the content ratio of the Ta element to the Al element is more than or equal to 1.25 and less than or equal to 1.40.
Preferably, the volume fraction of the gamma prime strengthening phase in the nickel-based single crystal superalloy is greater than 65%; and/or the durable service life of the nickel-based single crystal superalloy exceeds 100 hours under the condition of 1140 ℃/137 MPa; and/or the low cycle fatigue life of the nickel-based single crystal superalloy alloy exceeds 1000 cycles at 900 ℃ under the condition that the total strain amplitude is 1.6 percent.
In another aspect, an embodiment of the present invention provides a method for preparing the nickel-based single crystal superalloy, which includes the following steps:
preparing a master alloy ingot: smelting a master alloy ingot by adopting a vacuum smelting mode;
preparing a single crystal piece: preparing the master alloy ingot into a single crystal piece in a directional solidification furnace;
high-temperature solution heat treatment: carrying out high-temperature solution heat treatment on the single crystal piece;
aging heat treatment: and carrying out aging heat treatment on the single crystal piece subjected to the high-temperature solution heat treatment to obtain the nickel-based single crystal superalloy.
Preferably, in the step of preparing a single crystal piece: the single crystal piece is any one of a bar, a plate, and a blade.
Preferably, in the step of preparing a single crystal piece: in the directional solidification furnace, a spiral crystal selection method is adopted to prepare the master alloy ingot into a single crystal piece.
Preferably, in the high-temperature solution heat treatment step: the high-temperature solid solution heat treatment system comprises the following steps: the single crystal piece is heated to 1315 +/-5 ℃, kept warm for 7.5-8.5h (preferably 8-8.5h, and further preferably 8h), then heated to 1325 +/-5 ℃, kept warm for 7.5-8.5h (preferably 8-8.5h, and further preferably 8h), and then cooled to room temperature in air.
Preferably, the aging heat treatment step includes:
the first step of aging treatment: heating the single crystal piece subjected to high-temperature solution heat treatment to 1120-1150 ℃, preserving the heat for 2-6 hours, and cooling to room temperature;
the second step of aging treatment: heating the single crystal piece subjected to the aging treatment in the first step to 860-880 ℃, preserving the temperature for 20-26 hours, and cooling to room temperature to obtain the nickel-based single crystal superalloy;
preferably, in the first aging treatment and the second aging treatment, the cooling system is an air cooling system.
Preferably, before the step of subjecting the single crystal piece to high-temperature solution heat treatment, the method further comprises:
evaluating and selecting a high-temperature solution heat treatment system: and evaluating a plurality of preset high-temperature solid solution heat treatment schedules, and selecting a required high-temperature solid solution heat treatment schedule so as to adopt the required high-temperature solid solution heat treatment schedule to carry out high-temperature solid solution heat treatment on the single crystal piece in the step of high-temperature solid solution heat treatment.
Preferably, in the step of evaluating and selecting the high-temperature solution heat treatment system:
taking a plurality of single crystal samples, respectively carrying out different preset high-temperature solid solution heat treatment schedules, then carrying out aging treatment on the single crystal samples which are not subjected to the high-temperature solid solution heat treatment schedule and the single crystal samples which are subjected to the preset high-temperature solid solution heat treatment schedule, and finally carrying out tissue analysis on alloy samples obtained after the aging treatment; during analysis, a parameter omega representing the structural uniformity of the alloy gamma/gamma' is introduced, an optimal high-temperature solution heat treatment system is determined from the variation trend of an omega curve and is used as a required high-temperature solution heat treatment system, and the rationality of the optimal high-temperature solution heat treatment system is evaluated by utilizing a creep performance test; wherein,
ω＝((L i γ′ -L d γ′ )/(L i γ′ +L d γ′ ))×100％；
wherein L is i γ′ The size of the precipitated phase (i.e., the side length of the cubic strengthening phase), L, for the interdendritic region γ d γ′ The size of the precipitated phase for the dendrite trunk region γ' (i.e., the side length of the cubic strengthening phase);
preferably, the ω -curve is: based on data statistical analysis, obtaining the relationship between different high-temperature solid solution heat treatment times and the size difference of gamma' precipitated phases in two areas between dendrite trunks and dendrites in the alloy sample;
preferably, the ω -curve comprises three phases in sequence: an omega value change region (a region in which the omega value can be obviously changed along with the small increase of the solid solution time), a transition region (a region in which the omega value change is obviously reduced along with the extension of the solid solution time), and a steady state region (a region in which the omega value is basically stable along with the extension of the solid solution time); wherein the value of ω in the steady-state region is in a steady state; the transition region is used for transitioning the omega value change region to the steady state region.
Preferably, the high-temperature solution heat treatment time corresponding to the transition region of the ω -curve is set as the optimum high-temperature solution heat treatment time.
Preferably, in the step of evaluating and selecting the high-temperature solution heat treatment system:
the plurality of preset high-temperature solid solution heat treatment schedules comprise a first preset high-temperature solid solution heat treatment schedule, a second preset high-temperature solid solution heat treatment schedule, a third preset high-temperature solid solution heat treatment schedule and a fourth preset high-temperature solid solution heat treatment schedule;
the first preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃, kept warm for 3.5-4.5h (preferably 4-4.5h, further preferably 4h), then heated to 1325 +/-5 ℃, kept warm for 3.5-4.5h (preferably 4-4.5h, further preferably 4h), and then cooled to room temperature by air;
the second preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃, kept warm for 7.5-8.5h (preferably 8-8.5h, further preferably 8h), then heated to 1325 +/-5 ℃, kept warm for 7.5-8.5h (preferably 8-8.5h, further preferably 8h), and then cooled to room temperature by air;
the third preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃, kept warm for 15.5-16.5h (preferably 16-16.5h, further preferably 16h), then heated to 1325 +/-5 ℃, kept warm for 15.5-16.5h (preferably 16-16.5h, further preferably 16h), and then cooled to room temperature by air;
the fourth preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃, kept warm for 23.5-24.5h (preferably 24-24.5h, further preferably 24h), then heated to 1325 +/-5 ℃, kept warm for 23.5-24.5h (preferably 24-24.5h, further preferably 24h), and then cooled to room temperature by air;
preferably, after the analysis and evaluation, the second predetermined high-temperature solution heat treatment schedule is set as a required high-temperature solution heat treatment schedule to perform the high-temperature solution heat treatment on the single-crystal piece.
Compared with the prior art, the nickel-based single crystal superalloy and the preparation method thereof have at least the following beneficial effects:
in one aspect, embodiments of the present invention provide a nickel-based single crystal superalloy, which belongs to a high-generation single crystal superalloy. The chemical composition design of the nickel-based single crystal superalloy provided by the embodiment of the invention is based on the basic material science principle that dislocations caused by low-layer dislocation energy are easy to expand and react to form immobile dislocations such as pressure bar dislocation, L-C dislocation lock and the like. For example, the overall stacking fault energy of the alloy is reduced by regulating the content of low stacking fault energy forming elements such as Co, Re, Ru and the like; dislocation movement is limited by pressure rod dislocation, L-C dislocation lock and the like formed by dislocation expansion and reaction so as to strengthen the alloy; the total amount of refractory elements W, Mo and Ta and the content ratio of Ta/Al are synergistically regulated and controlled, and the structural stability and the high-temperature precipitation strengthening effect of the alloy are ensured. The nickel-based single crystal superalloy provided by the embodiment of the invention can provide reference for design and research and development of a novel single crystal superalloy.
In addition, the nickel-based single crystal superalloy provided by the embodiment of the invention has the advantages of strong design pertinence and strong operability, obviously shortens the research and development period of a novel single crystal superalloy, reduces the research and development cost, and is utilized, popularized and applied.
On the other hand, the embodiment of the invention provides a preparation method of the nickel-based single crystal superalloy, and in the preparation process, through data analysis, a parameter omega representing the structural uniformity of the alloy is introduced, the rationality and scientificity of a high-temperature solid solution heat treatment system of the alloy are evaluated, and a reasonable high-temperature solid solution heat treatment system is established. In addition, the thought can quantify and characterize the quality of the solid solution heat treatment system, and provides method support for optimizing the heat treatment system of the existing single crystal high-temperature alloy and exploring the comprehensive performance potential of the existing single crystal alloy.
Here, it should be noted that: the morphology and chemical composition uniformity of the dendritic stem and interdendritic gamma' precipitated phase are evaluated by introducing the concept of the structure uniformity omega, and the method can effectively determine the optimal solution heat treatment time of the single crystal superalloy. Compared with the method for judging the effect of the heat treatment system by carrying out a large amount of metallographic observation and data calculation of dendrite spacing and holes, the method can more directly judge the structural uniformity of the alloy after heat treatment and can be correlated with the performance of the alloy. Therefore, the method can greatly reduce the establishment period of the alloy heat treatment system, reduce unnecessary analysis and detection, and can be popularized to the determination of the solution heat treatment time of other various single crystal high temperature alloys.
In summary, the nickel-based single crystal superalloy and the preparation method thereof provided by the embodiment of the invention realize the targeted design and the full play of high temperature strength of the low-layer fault energy nickel-based single crystal superalloy by synergistically regulating and controlling the components of the alloy and the heat treatment system process.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.
Drawings
FIGS. 1A-1E are graphs of dendrite trunk and interdendritic microstructure of samples of nickel-based single crystal superalloys prepared in examples 1-5; FIG. 1A is a dendritic stem and interdendritic microstructure of the Ni-based single crystal superalloy fabricated in example 1; FIG. 1B is a graphical representation of the dendrite trunk and interdendritic microstructure of the nickel-based single crystal superalloy samples prepared in example 2; FIG. 1C is a graph of the dendrite trunk and interdendritic microstructure of the Ni-based single crystal superalloy prepared in example 3; FIG. 1D is a graphical representation of the dendrite trunk and interdendritic microstructure of the nickel-based single crystal superalloy samples prepared in example 4; FIG. 1E is a graph of the dendrite trunk and interdendritic microstructure of the Ni-based single crystal superalloy prepared in example 5.
FIG. 2 is a plot of omega curves for samples of nickel-based single crystal superalloys prepared in examples 1-10.
FIG. 3 is an isothermal creep curve at 1140 deg.C/150 MPa for samples of nickel-based single crystal superalloys prepared in examples 1-5.
FIG. 4 is a transmission electron microscope structure of a sample of the nickel-based single crystal superalloy prepared in example 3.
FIG. 5 is a tensile stress-strain curve of samples of the nickel-based single crystal superalloy prepared in example 8 at various temperatures.
FIG. 6 is a low cycle fatigue cycle response curve at 900 deg.C for various strain magnitudes for the nickel-based single crystal superalloy prepared in example 8.
FIGS. 7A-7C are TEM tissues of Ni-based single crystal superalloy prepared in example 3 after being stretched at different temperatures. FIG. 7A shows TEM (transmission electron microscopy) tissues of a Ni-based single crystal superalloy prepared in example 3 after being stretched at room temperature; FIG. 7B is a TEM microstructure of a Ni-based single crystal superalloy prepared as described in example 3 after stretching at a temperature of 600 deg.C; FIG. 7C is a TEM microstructure of a Ni-based single crystal superalloy prepared as described in example 3 after stretching at a temperature of 760 ℃.
FIG. 8 is a transmission electron microscope structure of a sample of the nickel-based single crystal superalloy prepared in example 3 after low cycle fatigue fracture.
FIG. 9 is a schematic diagram illustrating the strengthening principle of the low-stacking fault energy single crystal superalloy designed according to the embodiment of the present invention.
Detailed Description
To further explain the technical means and effects of the present invention adopted to achieve the predetermined object, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
As can be seen from the background art, the design methods or principles of the existing single crystal alloys are wider, and with the increasing requirements of aero-engines on the single crystal alloys, it is difficult to develop novel alloys according to the design methods or principles of the existing single crystal high temperature alloys.
In fact, the strength of the alloy depends on the form of the dislocation motion on a microscopic scale, which is closely related to the composition of the alloy. Therefore, the dislocation motion can be limited or delayed by regulating and controlling the components of the alloy, so that the aim of improving the temperature bearing capacity of the single crystal alloy is fulfilled.
On the one hand, the embodiment of the invention provides a nickel-based single crystal superalloy, which mainly aims to solve the problems that the existing single crystal superalloy design method or principle is wider and not strong in pertinence, and designs a low-layer fault energy nickel-based single crystal superalloy.
Specifically, the nickel-based single crystal superalloy comprises the following components in percentage by weight: 3.5 to 5.5 weight percent of Cr, 6 to 14 weight percent of Co, 5 to 7 weight percent of W, 0.5 to 2.5 weight percent of Mo, 4 to 7.5 weight percent of Re, 1.5 to 4 weight percent of Ru, 5 to 6.8 weight percent of Al, 7 to 10 weight percent of Ta, less than or equal to 0.8 weight percent of Ti, less than or equal to 0.5 weight percent of Sc, less than or equal to 0.2 weight percent of Si, less than or equal to 0.3 weight percent of Hf, less than or equal to 0.05 weight percent of Y, less than or equal to 0.03 weight percent of Zr, less than or equal to 0.02 weight percent of Fe, less than or equal to 0.0075 weight percent of Na, less than or equal to 0.0045 weight percent of Be, less than or equal to 0.0065 weight percent of Sr, less than or equal to 0.0055 weight percent of Hg, and the balance of Ni and other impurity elements which are difficult to remove.
Preferably, in the composition of the nickel-based single crystal superalloy: the sum of the contents of the Co element and the Re element is more than or equal to 15.0 wt%; the sum of the contents of the Co element and the Ru element is more than or equal to 12.0 wt; the sum of the contents of the Co element, the Re element and the Ru element is more than or equal to 16.0 wt%. Preferably, the content ratio of the Ru element to the Co element is 0.12 or more and 0.50 or less. The sum of the contents of the Mo, W and Ta elements is more than or equal to 12.0wt percent and less than or equal to 18.0wt percent. Preferably, the content ratio of the Ta element to the Al element is greater than or equal to 1.25 and less than or equal to 1.40.
It should be noted that, regarding the nickel-base superalloy with the above chemical composition, the design concept of the present invention is as follows:
the invention can reduce the integral fault energy of the single crystal high temperature alloy according to the basic principle that partial alloy elements (such as Co, Re, Ru and the like) can reduce the integral fault energy of the single crystal high temperature alloy, so that the dislocation is expanded and reacts to form the immovable dislocation such as the compression bar dislocation, the L-C dislocation lock and the like, thereby pertinently realizing the design of high-generation secondary high strength alloy.
Wherein, Co element is a key element for improving the high-temperature creep property of the single crystal superalloy. The addition of Co element can improve the structural stability of the alloy on one hand, and can reduce the stacking fault energy of the alloy on the other hand, so that dislocation is easy to decompose to form extended dislocation, and the difficulty of alloy cross sliding and climbing is increased, thereby improving the strength of the alloy.
Re and Ru are important strengthening elements of single-crystal high-temperature alloys (especially high-generation single-crystal alloys), and the strengthening effect of the Re and Ru in the alloys is extremely remarkable. The strengthening effect of the Re element and the Ru element is mainly shown in the aspects of solid solution strengthening when entering a matrix, solute atom diffusion resistance, alloy stacking fault energy reduction and the like. Therefore, in order to ensure that the high-generation single crystal superalloy has lower stacking fault energy and good solid solution strengthening effect, the addition amounts of three elements of Co, Re and Ru are required to be ensured, namely the content of Co + Re + Ru is more than or equal to 16.0 wt%. In addition, in order to make the single crystal superalloy have lower stacking fault energy and lower cost and density, the content ratio of Ru/Co elements needs to be controlled in the design process of alloy components, namely the content ratio of Ru to Co (Ru/Co) is less than or equal to 0.12 and less than or equal to 0.50.
W is one of the main solid solution strengthening elements of the nickel-based single crystal superalloy, and the strengthening effect of W is good at high temperature. Mo can also improve the strength of the nickel-based single crystal superalloy, and the Mo element has larger atomic radius, can cause obvious lattice expansion after being added into the alloy, plays a role in solid solution strengthening, and forms stable Ni-Mo bonds in the alloy, thereby improving the high-temperature strength of the alloy. However, considering the problem of solid solution limit of high-generation single crystal superalloy, when the total amount of refractory elements in the alloy exceeds the solid solution limit of the alloy, needle-shaped and rod-shaped TCP phases are separated out from the alloy in the actual service process, and the structure stability of gamma-gamma' two phases in the alloy is seriously damaged. Therefore, after certain amounts of Re and Ru are added, the strengthening effect of the other refractory elements W, Mo and Ta in the alloy is ensured, and the total amount of the elements is controlled within a certain range, namely the content of the elements Mo + W + Ta is more than or equal to 12.0 wt% and less than or equal to 18.0 wt%.
In addition, Ta and Al are both important γ' phase-forming elements in single crystal superalloys, and in order to ensure that the alloy has excellent precipitation strengthening effect at high temperature, appropriate amounts of the two elements need to be added. In the design process of the alloy, the addition amount of the Ta/Al element is comprehensively determined by mainly considering the content ratio of the Ta/Al element, and the proper content ratio of the Ta/Al element is favorable for improving the negative mismatching degree and the volume fraction of the gamma 'phase of the alloy and optimizing the cubic degree of the gamma' phase. However, when the content ratio of Ta/Al in the alloy is too high, the total amount of refractory elements in the alloy is difficult to control coordinately, and the alloy density is increased; when the content ratio of Ta/Al is too low, the high-temperature steady-state creep rate of the alloy is improved along with the low content ratio, and the overall creep life of the alloy is not prolonged, so that the alloy disclosed by the invention has the following advantages: the content ratio of Ta and Al (Ta/Al) is more than or equal to 1.25 and less than or equal to 1.40.
In addition, the Hf element can improve the adhesion force of an oxide film and a substrate, so that the oxidation resistance of the alloy is improved, the fluidity and the mold filling capacity of alloy liquid can be improved, and the improvement of the single crystal casting process performance of the alloy is facilitated; however, too much Hf will lower the initial melting temperature of the alloy and thus reduce the heat treatment window of the alloy, and Hf is a chemically higher element and is liable to form HfO which is difficult to remove in the alloy 2 And the like. Therefore, the content of the element Hf in the alloy of the present invention is controlled to be 0 to 0.3 wt%.
On the other hand, the embodiment of the invention also provides a preparation method of the nickel-based superalloy, which mainly comprises the following steps:
preparing a master alloy ingot: preparing raw materials according to the designed alloy components, and smelting the raw materials into master alloy ingots in a vacuum induction furnace.
Preparing a single crystal part: a single crystal piece (such as a single crystal test bar) is prepared in a directional solidification furnace by adopting a spiral crystal selection method.
High-temperature solution heat treatment: and carrying out high-temperature solution heat treatment on the single crystal piece.
Aging heat treatment: and (2) carrying out aging heat treatment on the single crystal piece after the high-temperature solution heat treatment to obtain the nickel-based single crystal superalloy (the specific steps comprise heat preservation for 2-6 hours at 1120-1150 ℃, air cooling to room temperature, heat preservation for 20-26 hours at 860-880 ℃, and air cooling to room temperature).
Here, regarding the above-mentioned production steps, wherein, in the production method, the present invention also solves the problem of establishing an optimum solution heat treatment regime for single crystal superalloys, specifically, establishing and quantitatively evaluating an optimum heat treatment process by introducing a texture characterization parameter. The method comprises the following steps:
first, a single crystal piece sample (e.g., a single crystal test bar) is subjected to high-temperature solution heat treatment under the following five different solution conditions:
(1)1315 +/-5 ℃/0h +1325 +/-5 ℃/0h (as-cast); the sample corresponds to a single crystal sample which is not subjected to high-temperature solution heat treatment.
(2)1315 +/-5 ℃/4-4.5h +1325 +/-5 ℃/4-4.5h + air cooling; the method is equivalent to that the single crystal piece is subjected to high-temperature solution heat treatment under a first preset high-temperature solution heat treatment schedule.
(3)1315 +/-5 ℃/8-8.5h +1325 +/-5 ℃/8-8.5h + air cooling; the method is equivalent to that the single crystal piece is subjected to high-temperature solution heat treatment under a second preset high-temperature solution heat treatment schedule.
(4)1315 +/-5 ℃/16-16.5h +1325 +/-5 ℃/16-16.5h + air cooling; the high-temperature solution heat treatment is performed on the single crystal piece under a third preset high-temperature solution heat treatment schedule.
(5)1315 +/-5 ℃/24-24.5h +1325 +/-5 ℃/24-24.5h + air cooling; the high-temperature solution heat treatment is performed on the single crystal piece under a fourth preset high-temperature solution heat treatment schedule.
Then, the single crystal samples subjected to the high temperature solution heat treatment under the five different solution conditions were subjected to aging treatment (note that the single crystal sample subjected to the first solution condition corresponds to a single crystal sample which was not subjected to the high temperature solution heat treatment, and the single crystal sample was subjected to aging treatment as it is), to thereby obtain a nickel-base superalloy sample. And the aging treatment step is as above (heat preservation at 1120-1150 ℃ for 2-6 hours, then air cooling to room temperature, then heat preservation at 860-880 ℃ for 20-26 hours, and then air cooling to room temperature).
And finally, when the high-temperature solution heat treatment system is evaluated, introducing a parameter omega for representing the structural uniformity of the alloy gamma/gamma' by analyzing the structure of an alloy sample subjected to aging treatment, determining the optimal solution heat treatment system from the variation trend of an omega curve, and evaluating the rationality of the optimal solution heat treatment system by utilizing a creep performance test.
Wherein,
ω＝((L i γ′ -L d γ′ )/(L i γ′ +L d γ′ ))×100％；
wherein L is i γ′ The size of the gamma prime precipitates of the interdendritic region, L d γ′ The size of a precipitated phase gamma' in a dendritic crystal dry region;
wherein, the high-temperature solution heat treatment time corresponding to the transition section of the omega curve is taken as the optimal high-temperature solution heat treatment time.
After analysis and evaluation, the second preset high-temperature solution heat treatment regime is considered to be the optimal high-temperature solution heat treatment regime. Therefore, the second predetermined high-temperature solution heat treatment schedule is set as a required high-temperature solution heat treatment schedule. After evaluation, in the preparation of the nickel-based single crystal superalloy, a second preset high-temperature solution heat treatment system is directly adopted to carry out high-temperature solution heat treatment on a single crystal piece, and then aging treatment is carried out, so that the nickel-based single crystal superalloy can be prepared.
It should be noted here that: the invention breaks through the formulation method of the traditional single crystal high temperature alloy heat treatment system, and quantificationally analyzes the change trend of the gamma 'phase size between dendrites and dendrites by introducing the parameter omega representing the structural uniformity of the alloy gamma/gamma'. Based on data statistical analysis, the relationship between different high-temperature solid solution heat treatment time and the size difference of gamma' precipitated phases in two areas between dendrite trunks and dendrites in the alloy sample is obtained, and the relationship is an omega curve. The curve can be divided into three phases: a significant change zone of the omega value, a transition zone and a steady-state zone. Based on the variation trend of the ω -curve, an optimal range, i.e., a transition region, can be obtained. The corresponding solution heat treatment time in the optimal range is the optimal solution heat treatment time range, and the optimal solution heat treatment system of the alloy is further provided.
The invention quantitatively evaluates the solid solution heat treatment system of the alloy by introducing the parameter omega representing the structure uniformity of gamma/gamma' in the single crystal alloy, provides theoretical support for making an optimal heat treatment system, guides the design of novel single crystal high temperature alloy, simultaneously explores the potential of the existing single crystal high temperature alloy and promotes the wide application of the single crystal high temperature alloy in China.
In addition, after the nickel-based single crystal superalloy is subjected to optimal heat treatment, the gamma 'strengthening phase in the alloy is small in size and uniform in distribution, and the volume fraction of the gamma' strengthening phase is larger than 65%. The durable life of the nickel-based single crystal superalloy exceeds 100 hours under the condition of 1140 ℃/137MPa, and the alloy is overloaded within 60 minutes at the temperature of 1200 ℃/137MPa in the isothermal creep process of 1140 ℃/137MPa, so that the overall creep life of the alloy cannot be reduced. The ultimate tensile strength of the nickel-based single crystal superalloy can reach 1200MPa, 1150MPa and 450MPa at room temperature, 760 ℃ and 1100 ℃; the low cycle fatigue life of the nickel-based single crystal superalloy exceeds 1000 cycles at 900 ℃ under the condition that the total strain amplitude is 1.6 percent. In addition, the nickel-based single crystal superalloy has good compatibility with coatings such as MCrAlY coatings, Pt-Al coatings and the like.
In summary, the most significant features of the embodiments of the present invention are: on one hand, the high-generation high-strength single crystal high-temperature alloy is designed according to the basic principle of material science; on the other hand, a scientific and reasonable solution heat treatment system is quantitatively formulated. Therefore, the technical scheme of the invention provides candidate materials for advanced aeroengines in China.
The invention is further illustrated below by means of specific examples:
examples 1 to 10
Examples 1-10 a nickel-based single crystal superalloy was designed and prepared and subjected to corresponding performance characterization, as follows:
1. design of nickel-based single crystal superalloy
In order to reduce the stacking fault energy of the alloy as much as possible during component design, the alloy element capable of effectively reducing the stacking fault energy in the alloy has the Co content of more than or equal to 10.0 wt%, the Re content of more than or equal to 4.6 wt% and the Ru content of more than or equal to 2.6 wt%; in addition, the content of Co + Re is more than or equal to 15.0 wt%, the content of Co + Ru is more than or equal to 12.0 wt%, the content of Co + Re + Ru is more than or equal to 16.0 wt%, the content ratio of Ru/Co (the content ratio of Ru to Co) is more than or equal to 0.12 and less than or equal to 0.50, and the content ratio of Ta/Al (the content ratio of Ta to Al) is more than or equal to 1.25 and less than or equal to 1.40.
The chemical compositions of the nickel-based single crystal superalloys designed for examples 1-5 are shown in table 1.
TABLE 1 chemical composition (wt%) of nickel-based single crystal superalloys designed for examples 1-5
The chemical compositions of the nickel-based single crystal superalloys designed for examples 6-10 are shown in table 2.
TABLE 2 chemical composition (wt%) of nickel-based single crystal superalloys designed for examples 6-10
2. Preparation of nickel-based single crystal superalloy
(1) Preparing a master alloy ingot: the alloy components shown in the table 1 are mixed, vacuum induction melting and casting are adopted to obtain a master alloy, and then the master alloy is polished to remove oxide skin for preparing a single crystal test rod.
(2) Preparing a single crystal piece: the preparation of the single crystal test bar is carried out on a directional solidification furnace by adopting a spiral crystal selection method. The temperature gradient of the single crystal growth furnace is 65 +/-5K/cm, the pouring temperature is 1500 +/-10 ℃, and the temperature of the mould shell is consistent with the pouring temperature; pulling the single crystal at a growth rate of 7mm/min to prepare a single crystal test bar.
(3) High-temperature solution heat treatment: and (3) carrying out high-temperature solution heat treatment on the single crystal piece (single crystal test bar). The prepared as-cast single crystal test bar is subjected to high-temperature solution heat treatment under the following five different solution conditions:
example 1, example 6: 1315 +/-5 ℃/0h +1325 +/-5 ℃/0h (as-cast); the high-temperature solution heat treatment is not performed.
Example 2, example 7: 1315 +/-5 ℃/4h +1325 +/-5 ℃/4h + air cooling; the method is equivalent to that the single crystal piece is subjected to high-temperature solution heat treatment under a first preset high-temperature solution heat treatment schedule.
Example 3, example 8: 1315 +/-5 ℃/8h +1325 +/-5 ℃/8h + air cooling; the method is equivalent to that the single crystal piece is subjected to high-temperature solution heat treatment under a second preset high-temperature solution heat treatment schedule.
Example 4, example 9: 1315 +/-5 ℃/16h +1325 +/-5 ℃/16h + air cooling; equivalently, the single crystal piece is subjected to high-temperature solution heat treatment under a third preset high-temperature solution heat treatment schedule.
Example 5, example 10: 1315 +/-5 ℃/24h +1325 +/-5 ℃/24h + air cooling; the high-temperature solution heat treatment is performed on the single crystal piece under a fourth preset high-temperature solution heat treatment schedule.
(4) Aging heat treatment: preserving the temperature of the single crystal test rod subjected to the high-temperature solution treatment at the temperature of 1120-1150 ℃ for 2-6 hours, and then cooling the single crystal test rod to room temperature in air; then the temperature is preserved for 20-26 hours at 860-880 ℃, and then the nickel-based single crystal superalloy samples are prepared by air cooling to room temperature (wherein, the embodiment 1 and the embodiment 6 are equivalent to that the high-temperature solution treatment is not carried out, and the aging treatment is directly carried out).
3. The high temperature solution heat treatment schedules selected in examples 1 to 10 and the prepared nickel-based single crystal superalloy samples were evaluated and tested.
(1) The nickel-based single crystal superalloy of examples 1-10 is prepared into a metallographic sample, and the morphology of a gamma' precipitated phase in a dendritic trunk and an intercrystalline region of the alloy is observed by a scanning electron microscope. The size of a gamma 'precipitated phase is statistically analyzed by IPP software, and a parameter omega for representing the structural uniformity of the alloy gamma/gamma' is introduced, wherein the expression is as follows:
ω＝((L i γ′ -L d γ′ )/(L i γ′ +L d γ′ ))×100％
wherein L is i γ′ The size of the gamma prime precipitates of the interdendritic region, L d γ′ The size of the precipitated phase is the dendrite dry region gamma'.
Wherein, the larger the value of omega is, the larger the difference of components between the dendrite trunk and the dendrite of the alloy is, and the worse the structural uniformity of the alloy is; on the contrary, the smaller the composition difference between dendrite trunk and dendrite of the alloy is, the better the structural uniformity of the alloy is, but the longer the solid solution time is, the content of defects (such as holes) can be increased obviously. Therefore, an optimal region must exist on the ω -curve, and the high-temperature solution heat treatment time corresponding to the optimal region is the optimal solution heat treatment time. Finally, the rationality of the selection of the high-temperature solution heat treatment regime is verified by using a high-temperature creep experiment (at 1140 ℃/150 MPa).
(2) The samples of the nickel-based single crystal superalloy prepared in examples 1 to 5 were subjected to texture analysis, as shown in FIGS. 1A to 1E. After statistical analysis, the structure uniformity parameter ω and the high temperature durability life of the alloy samples of examples 1-5 vary with the time of the high temperature solution heat treatment, as shown in the upper part of FIG. 2. As can be seen from the upper part of fig. 2, the ω -curve can be basically divided into three phases: a rapid change phase (a significant change zone), a transition phase (a transition zone), and a steady state phase (a steady state zone).
FIG. 3 is a graph showing creep curves and creep lives of samples of the nickel-based single crystal superalloys prepared in examples 1-5 at 1140 deg.C/150 MPa. The lower part of fig. 2 is the relationship between the high temperature solution heat treatment time and the endurance life of the nickel-based single crystal superalloy sample. By comprehensively comparing the relationship between the homogeneity ω of the alloy structure, the high-temperature durability and the high-temperature solution heat treatment time in FIG. 2, it can be found that: the sample (structure) in the transition stage has the highest mechanical property (see example 3), mainly because the alloy components are not uniform and the structure uniformity is poor when the high-temperature solution heat treatment time is too short, and the effect of the alloy elements cannot be fully exerted; the high-temperature solution heat treatment time is too long, the alloy has good component uniformity and uniform structure, but the long-time solution treatment at the high temperature close to the initial melting point can cause the defect content such as holes in the alloy to be obviously increased, thereby reducing the mechanical property of the alloy. Therefore, the solution heat treatment time corresponding to the transition of the ω -curve is the optimum solution heat treatment time (total time is about 16h, i.e., the solution heat treatment schedule of example 3).
(3) The transmission electron microscope structure of the nickel-based single crystal superalloy sample prepared in example 3 is shown in fig. 4. As can be seen from fig. 4: after the alloy is subjected to the optimal heat treatment process, the stacking fault occurs in the matrix, which shows that the single crystal high temperature alloy with low stacking fault energy is successfully designed.
(4) The tensile stress-strain curves of the nickel-based single crystal superalloy samples prepared in example 8 at different temperatures are shown in fig. 5. As can be seen from fig. 5: the alloy has the highest strength at the temperature of 760 ℃, and the ultimate tensile strength exceeds 1150 MPa; under the high temperature of 1100 ℃, the yield strength of the alloy can still reach more than 500MPa, and the elongation rate is close to 30 percent. This shows that the alloy has excellent tensile properties after the alloy is subjected to an optimal high-temperature solution heat treatment schedule and aging treatment.
(5) The isothermal low cycle fatigue cycle response curve at 900 c for the nickel base single crystal superalloy samples prepared in example 8 is shown in fig. 6. As can be seen from fig. 6: when the total strain amplitude is 2.0% and 1.6%, the fatigue life of the alloy exceeds 100 weeks and 1000 weeks respectively; while at a total strain amplitude of 1.3%, the fatigue life of the alloy reaches about 8000 weeks. This indicates that the alloy has the desired low cycle fatigue life after the alloy has undergone the optimum heat treatment process.
(6) The structure of the nickel-based single crystal superalloy sample prepared in example 3 after stretching is shown in fig. 7A-7C. As can be seen from fig. 7A-7C: the alloy shows a large number of stacking faults in the matrix after being stretched, and the interaction between the stacking faults shows that the low stacking fault energy design method of the single crystal high temperature alloy of the embodiment of the invention is reasonably feasible.
(7) The structure of the nickel-based single crystal superalloy prepared in example 3 after low cycle fatigue is shown in fig. 8. As can be seen from fig. 8: a large number of faults occur in the alloy in the low cycle fatigue process, the faults react with each other to form a large number of compression bar dislocations, L-C dislocation locks and other immobile dislocations, and the matrix of the alloy is obviously strengthened.
(8) The nickel-based single crystal station alloy prepared in the example 3 is a schematic diagram of the formation of pressure rod dislocation and L-C dislocation lock in the processes of stretching and low cycle fatigue, and is shown in figure 9. As can be seen from fig. 9: after the compression bar dislocation and the L-C dislocation lock are formed, the partial dislocation is difficult to form a full dislocation again, so that the alloy matrix dislocation and the dislocation formed subsequently are difficult to move, and the alloy can be remarkably strengthened.
In summary, the embodiment of the invention provides a nickel-based superalloy and a preparation method thereof, and belongs to the field of high-generation single crystal superalloy materials. The content of elements formed by low-level fault energy such as Co, Re, Ru and the like is regulated and controlled, so that the overall fault energy of the alloy is reduced; and dislocation movement is limited by pressure rod dislocation, L-C dislocation lock and the like formed by dislocation expansion and reaction so as to strengthen the alloy. The total amount of refractory elements W, Mo and Ta and the content ratio of Ta/Al are synergistically regulated and controlled, and the structural stability and the high-temperature precipitation strengthening effect of the alloy are ensured. In addition, through data analysis, a parameter omega representing the homogeneity of an alloy structure is introduced, the rationality and scientificity of a high-temperature solution heat treatment system of the alloy are evaluated, and a reasonable heat treatment system is formulated. In conclusion, the invention realizes the targeted design and the full play of the high-temperature strength of the low-stacking fault energy nickel-based single crystal superalloy by synergistically regulating and controlling the components of the alloy and the heat treatment process.
While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. The nickel-based single crystal superalloy is characterized by comprising the following components in percentage by weight:
3.5 to 5.5 weight percent of Cr, 6 to 14 weight percent of Co, 5 to 7 weight percent of W, 0.5 to 2.5 weight percent of Mo, 4 to 7.5 weight percent of Re, 1.5 to 4 weight percent of Ru, 5 to 6.8 weight percent of Al, 7 to 10 weight percent of Ta, less than or equal to 0.8 weight percent of Ti, less than or equal to 0.5 weight percent of Sc, less than or equal to 0.2 weight percent of Si, less than or equal to 0.3 weight percent of Hf, less than or equal to 0.05 weight percent of Y, less than or equal to 0.03 weight percent of Zr, less than or equal to 0.02 weight percent of Fe, less than or equal to 0.0075 weight percent of Na, less than or equal to 0.0045 weight percent of Be, less than or equal to 0.0065 weight percent of Sr, less than or equal to 0.0055 weight percent of Hg, and the balance of Ni.
2. The nickel-base single crystal superalloy according to claim 1, wherein in the composition of the nickel-base single crystal superalloy:
the sum of the contents of the Co element and the Re element is more than or equal to 15.0 wt%; and/or
The sum of the contents of the Co element and the Ru element is more than or equal to 12.0 wt; and/or
The sum of the contents of the Co element, the Re element and the Ru element is more than or equal to 16.0 wt%.
3. Nickel-base single crystal superalloy according to claim 1 or 2, wherein in the composition of the nickel-base single crystal superalloy:
the content ratio of the Ru element to the Co element is more than or equal to 0.12 and less than or equal to 0.50; and/or
The sum of the contents of the Mo, W and Ta elements is more than or equal to 12.0 wt% and less than or equal to 18.0 wt%; and/or
The content ratio of the Ta element to the Al element is more than or equal to 1.25 and less than or equal to 1.40.
4. The nickel-base single crystal superalloy of any of claims 1-3, wherein the volume fraction of the gamma prime strengthening phase in the nickel-base single crystal superalloy is greater than 65%; and/or
The durable service life of the nickel-based single crystal superalloy exceeds 100 hours under the conditions of 1140 ℃/137 MPa; and/or
The low cycle fatigue life of the nickel-based single crystal superalloy exceeds 1000 cycles at 900 ℃ under the condition that the total strain amplitude is 1.6 percent.
5. The method for preparing the nickel-based single crystal superalloy as in any of claims 1 to 4, comprising the steps of:
preparing a master alloy ingot: smelting a master alloy ingot by adopting a vacuum smelting mode;
preparing a single crystal piece: preparing the master alloy ingot into a single crystal piece in a directional solidification furnace;
high-temperature solution heat treatment: carrying out high-temperature solution heat treatment on the single crystal piece;
aging heat treatment: carrying out aging heat treatment on the single crystal piece subjected to the high-temperature solution heat treatment to obtain a nickel-based single crystal high-temperature alloy;
preferably, in the step of preparing a single crystal piece: the single crystal piece is any one of a bar, a plate and a blade;
preferably, in the step of preparing a single crystal piece: and preparing the master alloy ingot into a single crystal piece in a directional solidification furnace by adopting a spiral crystal selection method.
6. The method for producing the nickel-based single crystal superalloy according to claim 5, wherein in the high temperature solution heat treatment step:
the high-temperature solid solution heat treatment system comprises the following steps: heating the single crystal piece to 1315 +/-5 ℃, preserving heat for 7.5-8.5h, then heating to 1325 +/-5 ℃, preserving heat for 7.5-8.5h, and then cooling to room temperature in air.
7. The method for preparing the nickel-based single crystal superalloy according to claim 5, wherein the aging heat treatment step comprises:
the first step of aging treatment: heating the single crystal piece subjected to high-temperature solution heat treatment to 1120-1150 ℃, preserving the heat for 2-6 hours, and cooling to room temperature;
the second step of aging treatment: heating the single crystal piece subjected to the aging treatment in the first step to 860-880 ℃, preserving the temperature for 20-26 hours, and cooling to room temperature to obtain the nickel-based single crystal superalloy;
preferably, in the first aging treatment and the second aging treatment, the cooling system is an air cooling system.
8. The method for producing the nickel-based single crystal superalloy according to any of claims 5 to 7, wherein the step of subjecting the single crystal piece to the high temperature solution heat treatment further comprises:
evaluating and selecting a high-temperature solution heat treatment system: and evaluating a plurality of preset high-temperature solid solution heat treatment schedules, and selecting a required high-temperature solid solution heat treatment schedule so as to adopt the required high-temperature solid solution heat treatment schedule to carry out high-temperature solid solution heat treatment on the single crystal piece in the step of high-temperature solid solution heat treatment.
9. The method for producing a nickel-based single crystal superalloy according to claim 8, wherein the step of evaluating and selecting a high temperature solution heat treatment schedule is:
taking a plurality of single crystal samples to carry out different preset high-temperature solid solution heat treatment schedules, then carrying out aging treatment on the single crystal samples which are not subjected to the high-temperature solid solution heat treatment schedule and the single crystal samples which are subjected to the preset high-temperature solid solution heat treatment schedule, and finally carrying out tissue analysis on alloy samples obtained after the aging treatment; during analysis, a parameter omega representing the structural uniformity of the alloy gamma/gamma' is introduced, an optimal high-temperature solution heat treatment system is determined from the variation trend of an omega curve and is used as a required high-temperature solution heat treatment system, and the rationality of the optimal high-temperature solution heat treatment system is evaluated by utilizing a creep performance test; wherein,
ω＝((L i γ′ -L d γ′ )/(L i γ′ +L d γ′ ))×100％；
wherein L is i γ′ The size of the gamma prime precipitates of the interdendritic region, L d γ′ The size of the precipitated phase of the dendrite dry region gamma';
preferably, the ω -curve is: the relationship between different high-temperature solution heat treatment time and the size difference of gamma' precipitated phases in two regions between dendrite trunks and dendrites in the alloy sample;
preferably, the ω -curve comprises three phases in sequence: a omega value change region, a transition region and a steady state region; wherein the value of ω in the steady-state region is in a steady state;
preferably, the high-temperature solution heat treatment time corresponding to the transition region of the ω -curve is set as the optimum high-temperature solution heat treatment time.
10. The method for producing a nickel-base single crystal superalloy according to claim 8 or 9, wherein in the step of evaluating and selecting the high temperature solution heat treatment schedule:
the preset high-temperature solid solution heat treatment system comprises a first preset high-temperature solid solution heat treatment system, a second preset high-temperature solid solution heat treatment system, a third preset high-temperature solid solution heat treatment system and a fourth preset high-temperature solid solution heat treatment system;
the first preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃ firstly, is kept warm for 3.5-4.5h, is heated to 1325 +/-5 ℃ again, is kept warm for 3.5-4.5h, and is cooled to room temperature in air;
the second preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃ firstly, is kept warm for 7.5-8.5h, is heated to 1325 +/-5 ℃ and is kept warm for 7.5-8.5h, and is then cooled to room temperature in air;
the third preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃ firstly, is kept warm for 15.5-16.5h, is heated to 1325 +/-5 ℃ and is kept warm for 15.5-16.5h, and is cooled to room temperature in air;
the fourth preset high-temperature solid solution heat treatment system is that the single crystal piece is heated to 1315 +/-5 ℃ firstly, is kept warm for 23.5-24.5 hours, is heated to 1325 +/-5 ℃ and is kept warm for 23.5-24.5 hours, and is cooled to room temperature in air;
preferably, after the analysis and evaluation, a second predetermined high-temperature solution heat treatment schedule is set as a desired high-temperature solution heat treatment schedule to perform high-temperature solution heat treatment on the single-crystal piece.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115094360A (en) * | 2022-07-13 | 2022-09-23 | 北航（四川）西部国际创新港科技有限公司 | Heat treatment process of single crystal high temperature alloy with deformation and recrystallization resistant effects |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4743514A (en) * | 1983-06-29 | 1988-05-10 | Allied-Signal Inc. | Oxidation resistant protective coating system for gas turbine components, and process for preparation of coated components |
| CN103382536A (en) * | 2012-05-03 | 2013-11-06 | 中国科学院金属研究所 | Fourth-generation single-crystal high temperature alloy with high strength and stable structure and preparation method thereof |
| CN105200521A (en) * | 2014-05-28 | 2015-12-30 | 中国科学院金属研究所 | Rhenium-free low-density high-performance nickel-based monocrystalline high-temperature alloy and heat treatment technology thereof |
| CN106756249A (en) * | 2016-12-09 | 2017-05-31 | 中国科学院金属研究所 | A kind of nickel-base high-temperature single crystal alloy of high intensity and tissue stabilization and preparation method thereof |
| US20180251868A1 (en) * | 2016-04-08 | 2018-09-06 | Northwestern University | Optimized gamma-prime strengthened austenitic trip steel and designing methods of same |
| CN111379028A (en) * | 2020-04-08 | 2020-07-07 | 中国科学院金属研究所 | Ni-Al binary single crystal alloy, Ni-Al binary model single crystal alloy and preparation method thereof |
-
2022
- 2022-04-22 CN CN202210428186.5A patent/CN115029586B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4743514A (en) * | 1983-06-29 | 1988-05-10 | Allied-Signal Inc. | Oxidation resistant protective coating system for gas turbine components, and process for preparation of coated components |
| CN103382536A (en) * | 2012-05-03 | 2013-11-06 | 中国科学院金属研究所 | Fourth-generation single-crystal high temperature alloy with high strength and stable structure and preparation method thereof |
| CN105200521A (en) * | 2014-05-28 | 2015-12-30 | 中国科学院金属研究所 | Rhenium-free low-density high-performance nickel-based monocrystalline high-temperature alloy and heat treatment technology thereof |
| US20180251868A1 (en) * | 2016-04-08 | 2018-09-06 | Northwestern University | Optimized gamma-prime strengthened austenitic trip steel and designing methods of same |
| CN106756249A (en) * | 2016-12-09 | 2017-05-31 | 中国科学院金属研究所 | A kind of nickel-base high-temperature single crystal alloy of high intensity and tissue stabilization and preparation method thereof |
| CN111379028A (en) * | 2020-04-08 | 2020-07-07 | 中国科学院金属研究所 | Ni-Al binary single crystal alloy, Ni-Al binary model single crystal alloy and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| （苏）Н.Ф.科什科著: "《钢和合金的物理-化学相分析》", 北京：国防工业出版社 * |
| 郭建亭: "一种性能优异的低成本定向凝固镍基高温合金DZ417G", 金属学报, no. 11, pages 191 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115094360A (en) * | 2022-07-13 | 2022-09-23 | 北航（四川）西部国际创新港科技有限公司 | Heat treatment process of single crystal high temperature alloy with deformation and recrystallization resistant effects |
| CN115094360B (en) * | 2022-07-13 | 2022-11-29 | 北航（四川）西部国际创新港科技有限公司 | Heat treatment process of single crystal high temperature alloy with deformation resistance and recrystallization resistance effects |
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