Pt-based high-temperature alloy thermal expansion coefficient prediction method based on multi-scale integrated calculation

Abstract

The invention relates to the technical field of high-temperature alloy materials, and discloses a Pt-based high-temperature alloy thermal expansion coefficient prediction method based on multi-scale integrated calculation, and the method comprises the following steps: S1, building a Pt-based high-temperature alloy crystal structure model through a high-throughput modeling technology; s2, calculating a first thermal expansion coefficient and a second thermal expansion coefficient through a high-flux first principle, and respectively calculating a first thermal expansion change rate and a second thermal expansion change rate through the first thermal expansion coefficient and the second thermal expansion coefficient; s3, a thermodynamic database is obtained through AutoCalphi software; s4, calculating to obtain a third thermal expansion coefficient according to the first thermal expansion change rate and the thermodynamic data; calculating a fourth thermal expansion coefficient according to the second thermal expansion change rate and thermodynamic data; and according to the third thermal expansion coefficient and the fourth thermal expansion coefficient, a multi-phase mixed model is established, and the thermal expansion coefficient of the Pt-based high-temperature alloy is obtained. The experimental characterization number of thermal expansion can be reduced, and the research and development period of the Pt-based high-temperature alloy is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloy materials, and in particular to a method for predicting the thermal expansion coefficient of a Pt-based high-temperature alloy based on multi-scale integrated calculation. Background Art

[0002] The precious metal platinum (Pt) has excellent high-temperature oxidation resistance and corrosion resistance. It can serve stably under complex and extreme conditions and has become an indispensable material in many special application environments, such as rocket propulsion engine nozzles, satellite attitude control engine nozzles, and high-temperature thermal barrier coating bonding layers. Pt-based high-temperature alloys with γ-phase and γ'-phase structures have good oxidation resistance, but when used as a high-temperature thermal barrier coating bonding layer, the thermal expansion of alumina in the adjacent thermally grown oxide layer is relatively smaller than that of the bonding layer. The resulting thermal expansion mismatch leads to reduced adhesion between alumina and the bonding layer during thermal cycles, ultimately shortening the life of the thermal barrier coating system. The smaller the thermal expansion mismatch, the longer the life of the thermal barrier coating system. Therefore, studying the thermal expansion coefficient of Pt-based high-temperature alloys and developing new Pt-based high-temperature alloys with matching thermal expansion is crucial for long-life thermal barrier coatings.

[0003] However, the thermal expansion coefficient of Pt-based superalloys is currently mainly characterized by experiments. In the experiment, a large number of precious metal samples need to be prepared, and the cost of a single high-temperature thermal expansion test is also more than several thousand yuan, and the raw material cost and experimental cost are huge. Therefore, there is an urgent need for a method to predict the thermal expansion coefficient of Pt-based superalloys that can reduce the number of experimental characterizations of thermal expansion, shorten the R&D cycle of Pt-based superalloys, and reduce R&D costs, thereby accelerating the application of new Pt-based superalloys. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a method for predicting the thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation, which can reduce the number of experimental characterizations of thermal expansion, shorten the research and development cycle of Pt-based high-temperature alloys and reduce research and development costs, thereby accelerating the application of new Pt-based high-temperature alloys.

[0005] The technical solution adopted by the present invention is as follows: A method for predicting the thermal expansion coefficient of a Pt-based high-temperature alloy based on multi-scale integrated calculation, comprising the following steps:

[0006] S1: Establish the crystal structure model of γ-phase solid solution Pt-based binary superalloy and the crystal structure model of γ'-phase solid solution Pt-based ternary superalloy by high-throughput modeling technology;

[0007] S2: Calculate the first thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy by high-throughput first-principles calculation, and calculate the first thermal expansion change rate of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements by the first thermal expansion coefficient, and calculate the second thermal expansion coefficient of the γ'-phase solid solution Pt-based ternary high-temperature alloy, and calculate the second thermal expansion change rate of the γ'-phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements by the second thermal expansion coefficient;

[0008] S3: The thermodynamic database is obtained by AutoCalphad software, and the corresponding phase fraction, element mole fraction and occupancy fraction thermodynamic data of γ-phase solid solution Pt-based binary superalloy and γ'-phase Pt-based ternary superalloy are obtained respectively;

[0009] S4: Calculate the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy according to the first thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ-phase solid solution Pt-based binary high-temperature alloy;

[0010] The fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy is calculated based on the second thermal expansion change rate and the phase fraction, the mole fraction of the element and the occupancy fraction thermodynamic data corresponding to the γ' phase solid solution Pt-based ternary high-temperature alloy;

[0011] A multiphase mixed model of thermal expansion is established according to the third thermal expansion coefficient and the fourth thermal expansion coefficient, and the thermal expansion coefficient of the Pt-based high-temperature alloy having a γ phase and a γ' phase is obtained.

[0012] As a preferred embodiment of the present invention, S1 comprises the following steps:

[0013] S11: Obtain the crystal structure of γ-phase Pt and γ'-phase Pt based on the Materials Project database 3 Crystal structure of Al;

[0014] S12: Using Phonopy software, the crystal structure of γ-phase Pt was expanded from a single-cell Pt containing 4 atoms to a 2×2×2 supercell Pt containing 32 Pt atoms. 32 , the γ' phase Pt 3 The crystal structure of Al consists of a unit cell Pt containing four atoms. 3 Al, expanded to a 2×2×2 supercell Pt containing 24 Pt atoms and 8 Al atoms 24 Al 18 ;

[0015] S13: Supercell Pt 32 One Pt atom in the alloy is replaced by the alloying element X to form a γ-phase solid solution Pt 31X high temperature alloy crystal structure model;

[0016] Pt 24 Al 18 One Pt atom in the alloy is replaced by the alloying element X to establish a γ' phase solid solution Pt 23 Al 18 X high temperature alloy crystal structure model;

[0017] Pt 24 Al 18 One Al atom is replaced by alloying element X to establish a γ' phase solid solution Pt 24 Al 17 X high temperature alloy crystal structure model.

[0018] As a preferred embodiment of the present invention, S2 comprises the following steps:

[0019] S211: Calculation of γ-phase solid solution Pt corresponding to different alloying elements X by high-throughput first-principles calculation 31 X first thermal expansion coefficient of high temperature alloy;

[0020] S212: Calculate the γ-phase solid solution Pt corresponding to different alloy elements X by the first expansion coefficient 31 The first thermal expansion rate of the X high temperature alloy is shown in formula (1):

[0021]

[0022] In formula (1), K X Indicates the γ phase solid solution Pt corresponding to different alloy elements X 31 The first thermal expansion rate of X high temperature alloy, α X Indicates the γ phase solid solution Pt corresponding to different alloy elements X 31 The first thermal expansion coefficient of X high temperature alloy, α Pt represents the thermal expansion coefficient of γ-phase Pt, x X Represents γ-phase solid solution Pt 31 X is the mole fraction of X atoms in the high temperature alloy.

[0023] As a preferred embodiment of the present invention, S2 comprises the following steps:

[0024] S221: High-throughput first-principles calculations of γ'-phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 The crystal structure of X high-temperature alloy is relaxed with high precision to obtain the γ' phase solid solution Pt corresponding to different alloy elements X. 23 Al 18 X, Pt24 Al 17 X static total energy of high temperature alloy;

[0025] S222: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is used to screen out the effective alloying element X;

[0026] S223: Calculation of the γ' phase solid solution Pt corresponding to the effective alloying element X by high-throughput first-principles calculation 23 Al 18 X, Pt 24 Al 17 The second expansion coefficient of X high temperature alloy;

[0027] S224: Calculate the γ' phase solid solution Pt corresponding to the effective alloy element X through the second expansion coefficient 23 Al 18 X, Pt 24 Al 17 The second thermal expansion rate of X high temperature alloy is shown in formulas (2) and (3).

[0028]

[0029] In formula (2), Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion rate of X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion coefficient of X high temperature alloy, Indicates γ' phase Pt 3 Thermal expansion coefficient of Al, Indicates γ' phase solid solution Pt 23 Al 18 The occupancy fraction of X atoms in X high temperature alloy;

[0030] In formula (3), Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion rate of X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion coefficient of X high temperature alloy, Indicates γ' phase Pt 3Thermal expansion coefficient of Al, Indicates γ' phase solid solution Pt 24 Al 17 The occupancy fraction of X atoms in X high-temperature alloy.

[0031] As a preferred embodiment of the present invention, high-throughput first-principles calculations are performed to determine the γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 When performing high-precision structural relaxation on the crystal structure of X high-temperature alloy, the energy convergence standard is 10 - 6 eV / atom, the force convergence criterion is

[0032] As a preferred embodiment of the present invention, S222 includes the following steps:

[0033] S222-11: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is used to calculate the transfer energy, as shown in formula (4):

[0034]

[0035] In formula (4), Pt 23 Al 18 X, Pt 25 Al 17 , Pt 24 Al 17 X, Pt 3 The static total energy of Al, Indicates that the alloying element X is in Pt 3 In Al, the transfer energy required to shift from the Al site to occupy the Pt site;

[0036] S222-12: Determine the different alloy elements X in Pt based on the transfer energy 24 Al 18 The occupancy tendency in the γ' phase solid solution Pt corresponding to different alloying elements X is determined. 23 Al 18 X, Pt 24 Al 17 X Crystal structure of high temperature alloy;

[0037] S222-13: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt24 Al 17 The crystal structure of X high temperature alloy, using Phonopy software, calculates the phonon spectrum to evaluate the γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 The dynamic stability of X high-temperature alloy is determined to determine the effective alloying element X.

[0038] As a preferred embodiment of the present invention, S222 includes the following steps:

[0039] S222-21: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is calculated by calculating the different alloying elements X in the corresponding γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 Mixing enthalpy in X high temperature alloy, evaluate the different alloying elements X in the corresponding γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 Solid solubility of X in high temperature alloy, so as to screen out effective alloying element X;

[0040] As a preferred embodiment of the present invention, S4 includes the following steps:

[0041] S41: According to the first thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ-phase solid solution Pt-based binary high-temperature alloy, the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy is calculated, as shown in formula (5),

[0042]

[0043] In formula (5), α γ The third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, α Pt represents the thermal expansion coefficient of γ-phase Pt, K X represents the first thermal expansion rate of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, x X Represents γ-phase solid solution Pt 31 The mole fraction of X atoms in X superalloy;

[0044] S42: According to the second thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ' phase solid solution Pt-based ternary high temperature alloy, the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high temperature alloy is calculated, as shown in formula (6),

[0045]

[0046] In formula (6), α γ' represents the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements X, Indicates γ' phase Pt 3 Thermal expansion coefficient of Al, Indicates γ' phase solid solution Pt 23 Al 18 The occupancy fraction of X atoms in X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion rate of X high temperature alloy, Indicates γ' phase solid solution Pt 24 Al 17 The occupancy fraction of X atoms in X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion rate of the X high temperature alloy;

[0047] S43: A multiphase mixed model of thermal expansion is established according to the third thermal expansion coefficient and the fourth thermal expansion coefficient to obtain the thermal expansion coefficient of the Pt-based high-temperature alloy having the γ phase and the γ' phase, as shown in formula (7).

[0048] α alloy =f γ α γ +f γ' α γ' (7)

[0049] In formula (7), α alloy represents the thermal expansion coefficient of the Pt-based superalloy with γ phase and γ' phase, α γ represents the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, f γ represents the phase fraction of γ-phase solid solution Pt-based binary high-temperature alloy, α γ' represents the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements X, f γ' Represents the phase fraction of γ' phase solid solution Pt-based ternary high-temperature alloy.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present invention adopts high-throughput first-principles calculations coupled with phase diagram thermodynamics and other multi-scale integrated calculation methods to evaluate the thermal expansion coefficient of Pt-based high-temperature alloys. It can quickly predict the thermal expansion coefficient of a Pt-based alloy with a specific composition, and can predict the influence of 33 alloy elements on the thermal expansion coefficient of Pt-based high-temperature alloys. The prediction capability covers all possible Pt-based alloy composition ranges, and can reduce the number of times of experimental detection of high-temperature thermal expansion coefficients in the research and development of precious metal alloys, and can reduce the raw material cost and experimental characterization cost of researching and developing Pt-based high-temperature alloys by more than 10 times, shorten the research and development cycle and research and development cost of Pt-based high-temperature alloys, thereby accelerating the application of new Pt-based high-temperature alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a flow chart of the method for predicting the thermal expansion coefficient of Pt-based high-temperature alloy based on multi-scale integrated calculation of the present invention;

[0053] Figure 2 It is a thermal expansion coefficient-temperature curve diagram of a γ-phase solid solution of a Pt-based high-temperature alloy thermal expansion coefficient prediction method based on multi-scale integrated calculation of the present invention;

[0054] Figure 3 It is a thermal expansion change rate-temperature curve diagram of the γ-phase solid solution of the Pt-based high-temperature alloy thermal expansion coefficient prediction method based on multi-scale integrated calculation of the present invention;

[0055] Figure 4 The γ' phase Pt of the Pt-based high temperature alloy thermal expansion coefficient prediction method based on multi-scale integrated calculation of the present invention 24 Al 18 and the anti-γ' phase Pt 24 Al 18 Thermal expansion coefficient-temperature curve and thermal expansion rate-temperature curve;

[0056] Figure 5 The present invention is a method for predicting the thermal expansion coefficient of a Pt-based high-temperature alloy based on multi-scale integrated calculation, and the γ' phase Pt containing alloy elements is 24 Al 18 Thermal expansion coefficient-temperature curve;

[0057] Figure 6 The present invention is a method for predicting the thermal expansion coefficient of a Pt-based high-temperature alloy based on multi-scale integrated calculation, and the γ' phase Pt containing alloy elements is 24 Al 18 Thermal expansion rate-temperature curve;

[0058] Figure 7It is a curve diagram of the thermal expansion coefficient of a Pt-Al binary alloy varying with temperature according to the thermal expansion coefficient prediction method of a Pt-based high-temperature alloy based on multi-scale integrated calculation of the present invention;

[0059] Figure 8 It is a curve diagram showing the variation of thermal expansion coefficient of Pt-Al-Cr alloy with Al content according to the thermal expansion coefficient prediction method of Pt-based high-temperature alloy based on multi-scale integrated calculation of the present invention;

[0060] Fig. 9 It is a curve diagram of the change of thermal expansion coefficient of Pt-Al-Cr alloy with Cr content in the thermal expansion coefficient prediction method of Pt-based high-temperature alloy based on multi-scale integrated calculation of the present invention. DETAILED DESCRIPTION

[0061] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0062] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0063] Explanation: Pt-based high-temperature alloys include Pt-based binary high-temperature alloys with γ phase and Pt-based ternary high-temperature alloys with γ' phase. Pt-based binary high-temperature alloys are represented by Pt 31 X high temperature alloy, Pt-based ternary high temperature alloy is represented by Pt 23 Al 18 X high temperature alloy or Pt 24 Al 17 X high temperature alloy, Indicates the magnitude and units of thermal expansion.

[0064] Example 1

[0065] The prediction method of thermal expansion coefficient of Pt-based superalloy based on multi-scale integrated calculation, such as Figure 1 As shown, the following steps are included:

[0066] S1: Establish the crystal structure model of γ-phase solid solution Pt-based binary superalloy and the crystal structure model of γ'-phase solid solution Pt-based ternary superalloy by high-throughput modeling technology;

[0067] In this embodiment, S1 includes the following steps:

[0068] S11: Obtain the crystal structure of γ-phase Pt and γ'-phase Pt based on the Materials Project database 3 Crystal structure of Al;

[0069] S12: Using Phonopy software, the crystal structure of γ-phase Pt was expanded from a single-cell Pt containing 4 atoms to a 2×2×2 supercell Pt containing 32 Pt atoms. 32 , the γ' phase Pt 3 The crystal structure of Al consists of a unit cell Pt containing four atoms. 3 Al, expanded to a 2×2×2 supercell Pt containing 24 Pt atoms and 8 Al atoms 24 Al 18 ;

[0070] S13: Supercell Pt 32 One Pt atom in the alloy is replaced by the alloying element X to form a γ-phase solid solution Pt 31 X high temperature alloy crystal structure model;

[0071] Pt 24 Al 18 One Pt atom in the alloy is replaced by the alloying element X to establish a γ' phase solid solution Pt 23 Al 18 X high temperature alloy crystal structure model;

[0072] Pt 24 Al 18 One Al atom is replaced by alloying element X to establish a γ' phase solid solution Pt 24 Al 17 X high temperature alloy crystal structure model.

[0073] In this embodiment, the alloy elements X are Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Hf, Ta, W, Re, Os, Ir, Au, and Th, a total of 33 elements.

[0074] In this embodiment, the γ-phase solid solution Pt 31 There are 33 crystal structure models of X high-temperature alloys and 66 crystal structure models of γ' phase solid solution Pt-based ternary high-temperature alloys. Specifically, Pt 24 Al 18 One Pt atom in the alloy is replaced by the alloying element X to establish a γ' phase solid solution Pt 23 Al 18 X high temperature alloy crystal structure model, a total of 33 types, Pt 24 Al 18 One Al atom is replaced by alloying element X to establish a γ' phase solid solution Pt 24 Al 17 X high temperature alloy crystal structure model, a total of 33 types, of which Pt 24Al 18 One Pt atom in the Pt is replaced by Al, and Al occupies the Pt position. 23 Al 19 The anti-site crystal structure model, Pt 24 Al 18 One Al atom is replaced by Pt element, and Pt occupies Al in the Pt 25 Al 17 Model of the antisite crystal structure.

[0075] S2: Calculate the first thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy by high-throughput first-principles calculation, and calculate the first thermal expansion change rate of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements by the first thermal expansion coefficient, and calculate the second thermal expansion coefficient of the γ'-phase solid solution Pt-based ternary high-temperature alloy, and calculate the second thermal expansion change rate of the γ'-phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements by the second thermal expansion coefficient;

[0076] In this embodiment, S2 includes the following steps:

[0077] S211: Calculation of γ-phase solid solution Pt corresponding to different alloying elements X by high-throughput first-principles calculation 31 The first thermal expansion coefficient of X high temperature alloy, such as Figure 2 As shown;

[0078] S212: Calculate the γ-phase solid solution Pt corresponding to different alloy elements X by the first expansion coefficient 31 The first thermal expansion rate of X high temperature alloy is as follows Figure 3 As shown in formula (1),

[0079]

[0080] In formula (1), K X Indicates the γ phase solid solution Pt corresponding to different alloy elements X 31 The first thermal expansion rate of X high temperature alloy, α X Indicates the γ phase solid solution Pt corresponding to different alloy elements X 31 The first thermal expansion coefficient of X high temperature alloy, α Pt represents the thermal expansion coefficient of γ-phase Pt, x X Represents γ-phase solid solution Pt 31 The mole fraction of X atoms in X superalloy;

[0081] S221: High-throughput first-principles calculations of γ'-phase solid solution Pt 23 Al 18 X, Pt 24 Al 17The crystal structure of X high-temperature alloy is relaxed with high precision to obtain the γ' phase solid solution Pt corresponding to different alloy elements X. 23 Al 18 X, Pt 24 Al 17 X static total energy of high temperature alloy;

[0082] S222: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is used to screen out the effective alloying element X;

[0083] In this embodiment, S222 includes the following steps:

[0084] S222-11: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is used to calculate the transfer energy, as shown in formula (4):

[0085]

[0086] In formula (4), Pt 23 Al 18 X, Pt 25 Al 17 , Pt 24 Al 17 X, Pt 3 The static total energy of Al, Indicates that the alloying element X is in Pt 3 In Al, the transfer energy required to shift from the Al site to occupy the Pt site;

[0087] S222-12: According to the transfer energy Determine the content of different alloy elements X in Pt 24 Al 18 The occupancy tendency in the γ' phase solid solution Pt corresponding to different alloying elements X is determined. 23 Al 18 X, Pt 24 Al 17 X Crystal structure of high temperature alloy;

[0088] In this embodiment, when When it is negative, the alloying element Y tends to occupy the Pt position; When it is positive, the alloying element Y tends to occupy the Al site.

[0089] S222-13: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The crystal structure of X high temperature alloy, using Phonopy software, calculates the phonon spectrum to evaluate the γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 The dynamic stability of X high-temperature alloy is determined to determine the effective alloying element X.

[0090] In this embodiment, when the calculated phonon spectrum has no imaginary frequency, it means that the γ' phase solid solution Pt corresponding to the alloy element X 23 Al 18 X, Pt 24 Al 17 The X high-temperature alloy is kinetically stable, and the alloying element X can exist in the γ' phase solid solution Pt-based ternary high-temperature alloy, thereby determining the effective alloying element X.

[0091] S223: Calculation of the γ' phase solid solution Pt corresponding to the effective alloying element X by high-throughput first-principles calculation 23 Al 18 X, Pt 24 Al 17 The second expansion coefficient of X high temperature alloy, such as Figure 4-7 As shown;

[0092] S224: Calculate the γ' phase solid solution Pt corresponding to the effective alloy element X through the second expansion coefficient 23 Al 18 X, Pt 24 Al 17 The second thermal expansion rate of X high temperature alloy, such as Figure 4-7 As shown in formulas (2) and (3),

[0093]

[0094] In formula (2), Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion rate of X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion coefficient of X high temperature alloy, Indicates γ' phase Pt 3 Thermal expansion coefficient of Al, Indicates γ' phase solid solution Pt23 Al 18 The mole fraction of X atoms in X superalloy;

[0095] In formula (3), Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion rate of X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion coefficient of X high temperature alloy, Indicates γ' phase Pt 3 Thermal expansion coefficient of Al, Indicates γ' phase solid solution Pt 24 Al 17 X is the mole fraction of X atoms in the high temperature alloy.

[0096] In this example, high-throughput first-principles calculations were performed to investigate the γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 When performing high-precision structural relaxation on the crystal structure of X high-temperature alloy, the energy convergence standard is 10 -6 eV / atom, the force convergence criterion is Set the parameters “IBRION=8,NSW=1” in the first principles calculation software vasp.

[0097] S3: The thermodynamic database is obtained by AutoCalphad software, and the corresponding phase fraction, element mole fraction and occupancy fraction thermodynamic data of γ-phase solid solution Pt-based binary superalloy and γ'-phase Pt-based ternary superalloy are obtained respectively;

[0098] S4: Calculate the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy according to the first thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ-phase solid solution Pt-based binary high-temperature alloy;

[0099] The fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy is calculated based on the second thermal expansion change rate and the phase fraction, the mole fraction of the element and the occupancy fraction thermodynamic data corresponding to the γ' phase solid solution Pt-based ternary high-temperature alloy;

[0100] A multiphase mixed model of thermal expansion is established according to the third thermal expansion coefficient and the fourth thermal expansion coefficient to obtain the thermal expansion coefficient of the Pt-based high-temperature alloy having a γ phase and a γ' phase;

[0101] In this embodiment, S4 includes the following steps:

[0102] S41: According to the first thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ-phase solid solution Pt-based binary high-temperature alloy, the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy is calculated, such as Figure 7 As shown in formula (5),

[0103]

[0104] In formula (5), α γ The third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, α Pt represents the thermal expansion coefficient of γ-phase Pt, K X represents the first thermal expansion rate of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, x X Represents γ-phase solid solution Pt 31 The mole fraction of X atoms in X superalloy;

[0105] S42: According to the second thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ' phase solid solution Pt-based ternary high temperature alloy, the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high temperature alloy is calculated, such as Figure 8 , 9 As shown in formula (6),

[0106]

[0107] In formula (6), α γ' represents the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements X, Indicates γ' phase Pt 3 Thermal expansion coefficient of Al, Indicates γ' phase solid solution Pt 23 Al 18 The occupancy fraction of X atoms in X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion rate of X high temperature alloy, Indicates γ' phase solid solution Pt 24 Al 17 The occupancy fraction of X atoms in X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion rate of the X high temperature alloy;

[0108] S43: A multiphase mixed model of thermal expansion is established according to the third thermal expansion coefficient and the fourth thermal expansion coefficient to obtain the thermal expansion coefficient of the Pt-based high-temperature alloy having the γ phase and the γ' phase, as shown in formula (7).

[0109] α alloy =f γ α γ +f γ' α γ' (7)

[0110] In formula (7), α alloy represents the thermal expansion coefficient of the Pt-based superalloy with γ phase and γ' phase, α γ represents the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, f γ represents the phase fraction of γ-phase solid solution Pt-based binary high-temperature alloy, α γ' represents the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements X, f γ' Represents the phase fraction of γ' phase solid solution Pt-based ternary high-temperature alloy.

[0111] Example 2

[0112] This embodiment is basically the same as Embodiment 1, except that S222 includes the following steps:

[0113] S222-21: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is calculated by calculating the different alloying elements X in the corresponding γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 Mixing enthalpy in X high temperature alloy, evaluate the different alloying elements X in the corresponding γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 The solid solubility of X in high-temperature alloys is used to screen out the effective alloying element X.

[0114] In this embodiment, when the mixing enthalpy is ≤0.01 eV, it means that the alloy element X can be dissolved into the γ' phase solid solution Pt-based ternary high temperature alloy. When calculating the mixing enthalpy, the energy convergence standard is 10 -6 eV / atom.

[0115] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A method for predicting the thermal expansion coefficient of a Pt-based high-temperature alloy based on multi-scale integrated calculation, characterized in that: The following steps are involved: S1: Establish the crystal structure model of γ-phase solid solution Pt-based binary superalloy and the crystal structure model of γ'-phase solid solution Pt-based ternary superalloy by high-throughput modeling technology; S2: Calculate the first thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy by high-throughput first-principles calculation, and calculate the first thermal expansion change rate of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements by the first thermal expansion coefficient, and calculate the second thermal expansion coefficient of the γ'-phase solid solution Pt-based ternary high-temperature alloy, and calculate the second thermal expansion change rate of the γ'-phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements by the second thermal expansion coefficient; S3: The thermodynamic database is obtained by AutoCalphad software, and the corresponding phase fraction, element mole fraction and occupancy fraction thermodynamic data of γ-phase solid solution Pt-based binary superalloy and γ'-phase Pt-based ternary superalloy are obtained respectively; S4: Calculate the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy according to the first thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ-phase solid solution Pt-based binary high-temperature alloy; The fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy is calculated based on the second thermal expansion change rate and the phase fraction, the mole fraction of the element and the occupancy fraction thermodynamic data corresponding to the γ' phase solid solution Pt-based ternary high-temperature alloy; A multiphase mixed model of thermal expansion is established according to the third thermal expansion coefficient and the fourth thermal expansion coefficient, and the thermal expansion coefficient of the Pt-based high-temperature alloy having a γ phase and a γ' phase is obtained.

2. The method for predicting thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation according to claim 1, characterized in that: S1 includes the following steps: S11: Obtain the crystal structure of γ-phase Pt and γ'-phase Pt3Al based on the Materials Project database; S12: Using Phonopy software, the crystal structure of γ-phase Pt was expanded from a single-cell Pt containing 4 atoms to a 2×2×2 supercell Pt containing 32 Pt atoms. 32 The crystal structure of the γ' phase Pt3Al is expanded from a single cell Pt3Al containing 4 atoms to a 2×2×2 supercell Pt3Al containing 24 Pt atoms and 8 Al atoms. 24 Al 18 ; S13: Supercell Pt 32 One Pt atom in the alloy is replaced by the alloying element X to form a γ-phase solid solution Pt 31 X high temperature alloy crystal structure model; Pt 24 Al 18 One Pt atom in the alloy is replaced by the alloying element X to establish a γ' phase solid solution Pt 23 Al 18 X high temperature alloy crystal structure model; Pt 24 Al 18 One Al atom is replaced by alloying element X to establish a γ' phase solid solution Pt 24 Al 17 X high temperature alloy crystal structure model.

3. The method for predicting thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation according to claim 1, characterized in that: S2 includes the following steps: S211: Calculation of γ-phase solid solution Pt corresponding to different alloying elements X by high-throughput first-principles calculation 31 X first thermal expansion coefficient of high temperature alloy; S212: Calculate the γ-phase solid solution Pt corresponding to different alloy elements X by the first expansion coefficient 31 The first thermal expansion rate of the X high temperature alloy is shown in formula (1): In formula (1), K X Indicates the γ phase solid solution Pt corresponding to different alloy elements X 31 The first thermal expansion rate of X high temperature alloy, α X Indicates the γ phase solid solution Pt corresponding to different alloy elements X 31 The first thermal expansion coefficient of X high temperature alloy, α Pt represents the thermal expansion coefficient of γ-phase Pt, x X Represents γ-phase solid solution Pt 31 X is the mole fraction of X atoms in the high temperature alloy.

4. The method for predicting thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation according to claim 1, characterized in that: S2 includes the following steps: S221: High-throughput first-principles calculations of γ'-phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 The crystal structure of X high-temperature alloy is relaxed with high precision to obtain the γ' phase solid solution Pt corresponding to different alloy elements X. 23 Al 18 X, Pt 24 Al 17 X static total energy of high temperature alloy; S222: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is used to screen out the effective alloying element X; S223: Calculation of the γ' phase solid solution Pt corresponding to the effective alloying element X by high-throughput first-principles calculation 23 Al 18 X, Pt 24 Al 17 The second expansion coefficient of X high temperature alloy; S224: Calculate the γ' phase solid solution Pt corresponding to the effective alloy element X through the second expansion coefficient 23 Al 18 X, Pt 24 Al 17 The second thermal expansion rate of X high temperature alloy is shown in formulas (2) and (3). In formula (2), Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion rate of X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion coefficient of X high temperature alloy, represents the thermal expansion coefficient of γ' phase Pt3Al, Indicates γ' phase solid solution Pt 23 Al 18 The occupancy fraction of X atoms in X high temperature alloy; In formula (3), Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion rate of X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion coefficient of X high temperature alloy, represents the thermal expansion coefficient of γ' phase Pt3Al, Indicates γ' phase solid solution Pt 24 Al 17 The occupancy fraction of X atoms in X high-temperature alloy.

5. The method for predicting thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation according to claim 4, characterized in that: Through high-throughput first-principles calculations, the γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 When performing high-precision structural relaxation on the crystal structure of X high-temperature alloy, the energy convergence standard is 10 -6 eV / atom, the force convergence criterion is 6. The method for predicting thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation according to claim 4, characterized in that: S222 includes the following steps: S222-11: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is used to calculate the transfer energy, as shown in formula (4): In formula (4), Pt 23 Al 18 X, Pt 25 Al 17 , Pt 24 Al 17 The static total energy of X and Pt3Al, It represents the transfer energy required for the alloy element X to shift from the Al site to the Pt site in Pt3Al; S222-12: Determine the different alloy elements X in Pt based on the transfer energy 24 Al 18 The occupancy tendency in the γ' phase solid solution Pt corresponding to different alloying elements X is determined. 23 Al 18 X, Pt 24 Al 17 X Crystal structure of high temperature alloy; S222-13: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The crystal structure of X high temperature alloy, using Phonopy software, calculates the phonon spectrum to evaluate the γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 The dynamic stability of X high-temperature alloy is determined to determine the effective alloying element X.

7. The method for predicting thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation according to claim 4, characterized in that: S222 includes the following steps: S222-21: γ' phase solid solution Pt based on different alloying elements X 23 Al 18 X, Pt 24 Al 17 The static total energy of X high temperature alloy is calculated by calculating the different alloying elements X in the corresponding γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 Mixing enthalpy in X high temperature alloy, evaluate the different alloying elements X in the corresponding γ' phase solid solution Pt 23 Al 18 X, Pt 24 Al 17 The solid solubility of X in high-temperature alloys is used to screen out the effective alloying element X.

8. The method for predicting thermal expansion coefficient of Pt-based high-temperature alloys based on multi-scale integrated calculation according to claim 1, characterized in that: S4 includes the following steps: S41: According to the first thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ-phase solid solution Pt-based binary high-temperature alloy, the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy is calculated, as shown in formula (5), In formula (5), α γ The third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, α Pt represents the thermal expansion coefficient of γ-phase Pt, K X represents the first thermal expansion rate of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, x X Represents γ-phase solid solution Pt 31 The mole fraction of X atoms in the X superalloy; S42: According to the second thermal expansion change rate and the phase fraction, element mole fraction and occupancy fraction thermodynamic data corresponding to the γ' phase solid solution Pt-based ternary high temperature alloy, the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high temperature alloy is calculated, as shown in formula (6), In formula (6), α γ' represents the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements X, represents the thermal expansion coefficient of γ' phase Pt3Al, Indicates γ' phase solid solution Pt 23 Al 18 The occupancy fraction of X atoms in X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 23 Al 18 The second thermal expansion rate of X high temperature alloy, Indicates γ' phase solid solution Pt 24 Al 17 The occupancy fraction of X atoms in X high temperature alloy, Indicates the γ' phase solid solution Pt corresponding to different alloy elements X 24 Al 17 The second thermal expansion rate of the X high temperature alloy; S43: A multiphase mixed model of thermal expansion is established according to the third thermal expansion coefficient and the fourth thermal expansion coefficient to obtain the thermal expansion coefficient of the Pt-based high-temperature alloy having the γ phase and the γ' phase, as shown in formula (7). a alloy =f γ a γ +f γ' a γ' (7), In formula (7), α alloy represents the thermal expansion coefficient of the Pt-based superalloy with γ phase and γ' phase, α γ represents the third thermal expansion coefficient of the γ-phase solid solution Pt-based binary high-temperature alloy corresponding to different alloy elements X, f γ represents the phase fraction of γ-phase solid solution Pt-based binary high-temperature alloy, α γ' represents the fourth thermal expansion coefficient of the γ' phase solid solution Pt-based ternary high-temperature alloy corresponding to different alloy elements X, f γ' Represents the phase fraction of γ' phase solid solution Pt-based ternary high-temperature alloy.

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