High-strength platinum-based multi-component solid solution alloy and design method thereof

Abstract

The invention belongs to the technical field of material design, and particularly relates to a design method of a high-strength platinum-based multi-element solid solution alloy, which comprises the following steps: obtaining crystal structures of various platinum-based alloys, calculating according to a first principle to obtain the mixing enthalpy of various binary alloy systems, and selecting elements with stable thermodynamics as the platinum-based alloy systems; adopting a Calphad phase diagram calculation method to predict platinum-based alloy phase diagrams with different proportions and combinations, and calculating according to the phase diagrams to obtain the component proportion and temperature range of each single-phase solid solution; according to a simulation result, proportioning according to an element proportion, and preparing a sample through a vacuum arc melting method; the method does not depend on historical data and empirical data, the novel platinum-based multi-element solid solution alloy can be designed from the source, the raw material cost and the test cost of experimental research and development are reduced, and the discovery and optimization process of materials is accelerated; the invention further relates to a high-strength platinum-based multi-component solid solution alloy, the raw material cost is reduced by more than 30% compared with the original alloy, and the mechanical property is improved by more than 10% compared with the original alloy.

Description

Technical Field

[0001] The invention relates to the technical field of material design, and in particular to a high-strength platinum-based multinary solid solution alloy and a design method thereof. Background Art

[0002] High-temperature alloys refer to metal materials that can withstand complex stresses for a long time and maintain stable performance in a high-temperature environment. In order to meet this requirement, high-temperature alloys not only need to have superior strength under high-temperature conditions, but also should have excellent oxidation resistance, thermal corrosion resistance and fatigue resistance. Commonly used high-temperature alloys include nickel-based, cobalt-based and titanium-based alloys. Among them, titanium-based alloys can work stably for a long time at 400℃ to 600℃, and nickel-based alloys and cobalt-based alloys can work stably for a long time at 650℃ to 1000℃. However, for more extreme high-temperature environments, commonly used high-temperature alloys are difficult to meet the use requirements.

[0003] Platinum group metals have a higher melting point (Pt: 1772°C, Ni: 1455°C), extremely strong oxidation resistance and corrosion resistance, and generally do not require coating protection when used at high temperatures. Therefore, as the next generation of high-temperature resistant materials, platinum has a very broad application prospect.

[0004] In the current design of platinum-based alloys, components (basic chemical elements or compounds that constitute alloys or material systems) can only be added based on past experience to prepare platinum-based alloys. The mechanical properties of platinum-based alloys in various proportions cannot be accurately predicted, which makes it difficult to obtain platinum-based alloys that meet performance requirements and easily leads to waste of resources. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a high-strength platinum-based multinary solid solution alloy and a design method thereof, which can accurately predict the mechanical properties of platinum-based alloys at various proportions before preparing samples, make it easier to obtain platinum-based alloys that meet performance requirements, reduce the number of preparation and verification, and save resources.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A design method for a high-strength platinum-based multinary solid solution alloy comprises the following steps:

[0008] S1: Obtain the crystal structures of various platinum-based alloys, calculate the mixing enthalpy of various binary alloy systems based on first-principles calculations, and select thermodynamically stable elements as the platinum-based alloy system;

[0009] S2: According to the corresponding platinum-based alloy system, the Calphad phase diagram calculation method is used, combined with thermodynamic models and experimental data, to predict the phase diagrams of platinum-based alloys with different proportions and combinations, and the proportions and temperature ranges of each single-phase solid solution are calculated based on the phase diagram;

[0010] S3: According to the simulation results of step S2, one of the raw materials is selected according to the performance requirements, and the raw materials are mixed and pressed into tablets according to the element ratio;

[0011] S4: The raw material pressed into sheets is subjected to vacuum arc melting to obtain a sample;

[0012] S5: Slice the sample and characterize it using instruments.

[0013] As a preferred embodiment of the present invention, step S1 specifically includes:

[0014] S101: Obtain the crystal structures of various platinum-based alloys;

[0015] S102: Using the first-principles calculation method of density functional theory, the crystal structures of various platinum-based alloys were substituted into the VASP software for calculation, with the cutoff energy set to 400 eV and the energy convergence criterion of electronic self-consistency set to 10 -6 eV / atom, the convergence accuracy of the force is less than A full relaxation calculation was performed on the input unit cell using an 8×8×8 Monkhorst-Pack K-point grid and ISIF=3, and the unit cell parameters were obtained from the calculation results;

[0016] S103: Calculate the thermodynamic properties based on the unit cell parameters and fit the interaction parameters using the Redlich-Kister polynomial.

[0017] As a preferred embodiment of the present invention, in the step S101, cells are built based on the Materials Project (open source materials database), OQMD (open source quantum materials database), Springer Materials (analyzed, screened and sorted material properties database), ICSD (inorganic crystal structure database) and NIST database (covering data sets in multiple fields such as physics, chemistry, biology, information technology, etc.) and the mcsqs code of the alloy theory automation toolkit.

[0018] As a preferred embodiment of the present invention, the step S102 specifically includes: in the step S102, the cutoff energy is set to 400 eV, and the energy convergence criterion of the electron self-consistency is 10 -6 eV / atom, the convergence accuracy of the force is less than An 8×8×8 Monkhorst-Pack K-point grid and ISIF=3 were used.

[0019] As a preferred implementation of the present invention, step S103 specifically includes:

[0020] S1031: Convert the Gibbs free energy and Helmholtz energy of the element and platinum-based alloy in the unit cell parameters from electron volts to joules. The specific calculation method is as follows:

[0021] 1eV=96485J / mol (1)

[0022] In formula (1), eV is the unit of electron volt, and J / mol is the unit of joule;

[0023] S1032: Differentiate the Gibbs free energy of the element and the platinum-based alloy with the temperature to obtain the entropy of the element and the platinum-based alloy. The specific calculation method is as follows:

[0024]

[0025] In formula (2), S represents the entropy of the element or platinum-based alloy, G represents the Gibbs free energy of the element or platinum-based alloy, T represents the temperature of the element or platinum-based alloy, is the symbol for partial differential;

[0026] S1033: Calculate the Gibbs free energy, temperature and entropy of the element and platinum-based alloy respectively to obtain the enthalpy of the element and platinum-based alloy. The specific calculation method is as follows:

[0027] G=HT*S (3)

[0028] In formula (3), G represents the Gibbs free energy of the element or the platinum-based alloy, H represents the enthalpy of the element or the platinum-based alloy, T represents the temperature of the element or the platinum-based alloy, and S represents the entropy of the element or the platinum-based alloy;

[0029] S1034: Calculate the enthalpy of the single substance and the platinum-based alloy respectively to obtain the mixing enthalpy of the alloy. The specific calculation method is as follows:

[0030]

[0031] In formula (4), A x B y represents platinum-based alloy, A represents elemental A, B represents elemental B, and x represents elemental A in platinum-based alloy A. x B y The percentage of y is expressed as the percentage of element B in platinum-based alloy A. x B y The percentage of E(A) is the enthalpy (H) of element A, E(B) is the enthalpy (H) of element B, △E(A x B y ) represents platinum-based alloy A x B y Enthalpy of mixing (△H);

[0032] S1035: The specific expression of Redlich-Kister polynomial is as follows:

[0033]

[0034] In formula (5), G ex It is expressed as the excess free energy of platinum-based alloy, A represents element A, B represents element B, and X A Expressed as element A in platinum-based alloy A x B y The percentage of X B Expressed as element B in platinum-based alloy A x B y The percentage of Φ is expressed as the phase of the platinum-based alloy. i L represents the i-th order interaction parameter; when i = 0,

[0035] It is a regular solution model.

[0036] In this embodiment, the mixing behavior of the actual alloy deviates from the ideal mixing model; the interaction parameter is introduced through the RK polynomial to describe the deviation from the ideal state between different components, and is also used to construct a thermodynamic model of the multi-component alloy; when the temperature is 0K, the Gibbs free energy of the alloy is equal to the enthalpy value, and the mixing enthalpy of the single substance is 0, and the interaction parameter can be obtained using the mixing enthalpy value of the alloy.

[0037] As a preferred embodiment of the present invention, step S2 specifically includes:

[0038] S201: Collect thermodynamic experimental data of platinum-based alloy systems in the literature, including entropy, enthalpy, heat capacity, Gibbs free energy, and experimental phase diagrams, and compare the thermodynamic experimental data with the thermodynamic calculated data of the platinum-based alloy system to ensure the accuracy of the calculated data;

[0039] S202: Determine a lattice model of a platinum-based multi-element alloy system based on the calculated and collected crystal structure and thermodynamic data of the platinum-based alloy, wherein the lattice model can simulate the distribution of atoms in a solid solution on a regular crystal structure;

[0040] S203: using AutoCalphad software to read the thermodynamic data and the calculated interaction parameters, and generating a corresponding initial thermodynamic model according to the lattice model, wherein the initial thermodynamic model describes the thermodynamic properties of the platinum-based alloy system by defining the types and proportions of components occupying lattice positions and the corresponding Gibbs free energy;

[0041] S204: the initial thermodynamic model cannot accurately describe the corresponding phase diagram, and the Monte Carlo Markov chain method is used to perform multiple Bayesian parameter optimizations on the model parameters of the initial thermodynamic model until the optimized phase diagram matches the experimental phase diagram, and then the optimization is terminated to obtain a set of self-consistent thermodynamic parameters, thereby completing the construction of the final thermodynamic model;

[0042] S205: Calculating according to the phase diagram corresponding to the final thermodynamic model to obtain each single-phase solid solution composition and temperature range.

[0043] In this embodiment, binary alloys are calculated to obtain their thermodynamic properties (enthalpy, entropy), and a tdb file of the binary alloy is obtained through the thermodynamic properties (the tdb file can be used to depict the phase diagram), and then a ternary phase diagram is obtained based on the binary phase diagram (for example, in the Pt-Ir-Ni phase diagram, there is an FCC phase in Pt-Ir. When Ni is added, Ni is added to the FCC phase. Originally, there are only interaction parameters of Pt and Ir in the FCC phase. After the addition, there are more interaction parameters of Pt and Ni, as well as Ir and Ni). The same is true for quaternary phases. The generation process of the Tdb file is as follows. First, there must be a lattice model, that is, a yaml file (in this file It describes how many specific phases the alloy system has and what atoms the phases are composed of. For example, the Pt-Ir phase diagram has Liquid phase and FCC phase in its yaml file. There is only one atomic position in Liquid, that is, there is only one lattice. This atomic position can be Pt or Ir. There is also only one in the FCC phase, which can be written into the yaml file accordingly). The thermodynamic data and interaction parameters obtained by first-principles calculations are written in the input-data folder. Then, the AutoCalphad software will automatically generate the initial thermodynamic model, that is, the tdb file, based on the lattice model and the input-data folder.

[0044] As a preferred embodiment of the present invention, step S4 specifically includes:

[0045] S401: Vacuum arc melting furnace is used for melting. The vacuum degree in the furnace is required to be greater than 2.0×10 -3 Pa, then fill with argon gas, and then smelt at a temperature of 1500-1700°C, the number of smelting times is greater than or equal to 10 times, and the molten state is maintained for more than 2 minutes each time;

[0046] S402: After cooling, take out the sample, seal the tube in vacuum and put it into a tube furnace, fill it with argon, increase the temperature at a rate of 5 min / °C, set the temperature at 1200°C, keep it warm for 72 hours, then cool it to room temperature with the furnace and take out the sample.

[0047] As a preferred embodiment of the present invention, step S5 specifically includes:

[0048] S501: After the sample is sliced, it is characterized by X-ray diffraction to observe the phase composition;

[0049] S502: morphology analysis using a field emission gun scanning electron microscope;

[0050] S503: Test hardness on a digital microhardness tester;

[0051] S504: Test the tensile strength, compressive strength and other properties on the electronic universal mechanical properties testing machine.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. The combination of the three material research methods of Calphad phase diagram calculation method, first principle calculation method and vacuum arc melting experimental method in the method of the present invention greatly reduces the research cycle and research cost, and can verify the accuracy of the information obtained. The new platinum-based alloy developed by this method has high strength and good thermal stability. It can be used in multiple industries such as aerospace, energy and power in the future to achieve reduction in the amount of precious metals and increase in efficiency.

[0054] 2. Based on the currently open Materials Project, OQMD, Springer Materials, ICSD and NIST databases and the mcsqs code of the Alloy Theory Automation Toolkit (ATAT), the crystal structures of various platinum-based alloys are obtained, and the first-principles calculation method based on density functional theory is adopted to calculate the thermodynamic properties based on the crystal structure after relaxation, and the interaction parameters are fitted by RK polynomials to provide reliable data for thermodynamic modeling of platinum-based alloys; the elements selected by the above method in the present invention have reliable theoretical support, so that the structure of the selected alloy has thermodynamic stability, which can effectively enhance the thermal stability of the platinum-based alloy.

[0055] 3. Determine the lattice model and thermodynamic model of different phases in the platinum-based alloy system, use AutoCalphad software to optimize the thermodynamic parameters of the platinum-based alloy and construct a thermodynamic database; further use AutoCalphad software to automatically read the thermodynamic data and the calculated interaction parameters to generate an initial model of the thermodynamic phase diagram, and use Bayesian statistics and Markov chain Monte Carlo method to optimize the model parameters to obtain the final thermodynamic phase diagram; finally, calculate the single-phase solid solution composition and temperature range based on the thermodynamic phase diagram; The Calphad phase diagram calculation method is a widely recognized thermodynamic system optimization method. This method can be used to obtain an accurate phase diagram of the alloy, and can also analyze the relationship between alloy composition, synthesis temperature and phase structure.

[0056] An embodiment of the present invention also provides a high-strength platinum-based multinary solid solution alloy, which is prepared by the design method of the high-strength platinum-based multinary solid solution alloy described above, and the elements in the high-strength platinum-based multinary solid solution alloy are calculated by atomic percentage: 1-10at% Ir, 0.1-1at% Ni, 1-10at% Co or W or Re, and the remainder is Pt.

[0057] Beneficial effects: In the present invention, the added Ir element itself has a structure similar to that of the Pt element, and there is nearly infinite solid solution between Pt and Ir. The Ir element is corrosion-resistant and oxidation-resistant. The addition of the element Ir at about 10% can significantly improve the corrosion resistance and oxidation resistance of the alloy. The Ni element also has a structure similar to that of the Pt element, and has a solid solution strengthening effect with the Pt element, which can improve the strength of the alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a preparation flow chart of an embodiment of a design method for a high-strength platinum-based multinary solid solution alloy of the present invention;

[0059] Figure 2 is the mixing enthalpy of the platinum-based binary alloy;

[0060] Figure 3 is a SEM morphology characterization diagram of the sample in Example 1 of the present invention;

[0061] Figure 4 is a SEM morphology characterization diagram of the sample in Example 2 of the present invention;

[0062] Figure 5 This is a SEM morphology characterization diagram of the sample in Example 3 of the present invention. DETAILED DESCRIPTION

[0063] 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.

[0064] In the description of the present application, the terms "first", "second", etc. are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the structure referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0065] Embodiment 1:

[0066] like Figures 1 to 3 As shown, the design method of the high-strength platinum-based multinary solid solution alloy of this embodiment comprises the following steps:

[0067] S1: Based on the currently open Materials Project, OQMD, Springer Materials, ICSD and NIST databases and the mcsqs code cell building of the Alloy Theory Automation Toolkit (ATAT), the alloy structures of various platinum-based alloys are obtained, and the first-principles calculation method based on density functional theory is used to optimize and calculate their mixing enthalpy.

[0068] S101: Obtain the structure of binary alloys in platinum-based alloys from Materials projects. If there is no stable structure, use the mcsqs code of the alloy theory automation toolkit to build an SQS model. In this example, 33 elements are selected to construct Pt 31 X alloy crystal structure, X is Au, 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, Th.

[0069] S102: Structural optimization, using the first-principles calculation method of density functional theory, using VASP software for calculation, with a cutoff energy of 400 eV and an energy convergence criterion of 10 -6 eV / atom, the convergence accuracy of the force is less than A full relaxation calculation was performed on the input cell using a 8 × 8 × 8 Monkhorst-Pack K-point grid with ISIF = 3.

[0070] S103: Calculate the mixing enthalpy of each binary alloy system after optimization, select a binary system with negative mixing enthalpy, that is, a thermodynamically stable element, and fit the interaction parameters through the RK polynomial. In this experimental example, Pt, Ir, Ni, and Re are selected for the next step of analysis.

[0071] S103 includes the following steps:

[0072] S1031: The Gibbs free energy and Helmholtz energy of the element and alloy are converted from electron volts to joules. The specific calculation method is as follows:

[0073] 1eV=96485J / mol (1)

[0074] In formula (1), eV is the unit of electron volt, and J / mol is the unit of joule;

[0075] S1032: Differentiate the Gibbs free energy and temperature of the element and the platinum-based alloy respectively to obtain the entropy of the element and the platinum-based alloy. The specific calculation method is as follows:

[0076]

[0077] In formula (2), S represents the entropy of the element or platinum-based alloy, G represents the Gibbs free energy of the element or platinum-based alloy, T represents the temperature of the element or platinum-based alloy, is the partial differential symbol; specifically, the platinum-based alloy Pt 31 The difference between the Gibbs free energy of X and the element at a temperature of 300 and the temperature gives the platinum-based alloy Pt 31 X and the entropy of the element;

[0078] S1033: Calculate the Gibbs free energy, temperature and entropy of the element and platinum-based alloy respectively to obtain the enthalpy of the element and platinum-based alloy. The specific calculation method is as follows:

[0079] G=HT*S (3)

[0080] In formula (3), G represents the Gibbs free energy of the single substance or platinum-based alloy, H represents the enthalpy of the single substance or platinum-based alloy, T represents the temperature of the single substance or platinum-based alloy, and S represents the entropy of the single substance or platinum-based alloy. Specifically, the platinum-based alloy Pt 31 The Gibbs free energy, temperature and entropy of X and the element at a temperature of 300° are treated according to formula (3) to obtain the platinum-based alloy Pt 31 X and the enthalpy of the element;

[0081] S1034: Calculate the enthalpy of the single substance and the platinum-based alloy respectively to obtain the mixing enthalpy of the alloy. The specific calculation method is as follows:

[0082]

[0083] In formula (4), A x B y represents platinum-based alloy, A represents elemental A, B represents elemental B, and x represents elemental A in platinum-based alloy A. x B y The percentage of y is expressed as the percentage of element B in platinum-based alloy A. x B y The percentage of E(A) is the enthalpy (H) of element A, E(B) is the enthalpy (H) of element B, △E(A x B y ) represents platinum-based alloy A x B y The mixing enthalpy (△H) of the platinum-based alloy Pt 31 The enthalpy of X and the element at a temperature of 300 is processed according to formula (4) to obtain the platinum-based alloy Pt 31 Enthalpy of mixing of X;

[0084] S1035: The specific expression of Redlich-Kister (abbreviated as RK) polynomial is as follows:

[0085]

[0086] In formula (5), G ex It is expressed as the excess free energy of platinum-based alloy, A represents element A, B represents element B, and X A Expressed as element A in platinum-based alloy A x B y The percentage of X B Expressed as element B in platinum-based alloy A x B y The percentage of Φ is expressed as the phase of the platinum-based alloy. i L represents the i-th order interaction parameter; when i = 0, Specifically, the platinum-based alloy Pt 31 The mixing enthalpy of X and the three points (0,0) and (1,0) were used to obtain the 0th order interaction parameters using the RK polynomial through the nonlinear curve fitting module of the origin software;

[0087] S1036: The mixing behavior of actual alloys deviates from the ideal mixing model; the interaction parameters are introduced through the RK polynomial to describe the deviations from the ideal state between different components, and are also used to construct thermodynamic models of multi-component alloys; when the temperature is 0K, the Gibbs free energy of the alloy is equal to the enthalpy value, and the mixing enthalpy of the single substance is 0. The interaction parameters can be obtained using the mixing enthalpy value of the alloy.

[0088] S2: Determine the lattice model and thermodynamic model of different phases in the Pt-Ir-Ni-Re system, use AutoCalphad software to optimize the thermodynamic parameters of platinum-based alloys and construct a thermodynamic database.

[0089] S201: Collect and evaluate the thermodynamic experimental data of Pt-Ir-Ni-Re system in the literature;

[0090] S202: Determine the lattice model of the binary alloy in the Pt-Ir-Ni-Re system;

[0091] S203: using AutoCalphad software to automatically read the thermodynamic database obtained by first-principles calculation to generate an initial thermodynamic model and automatically generate a .tdb file;

[0092] S204: Use the Monte Carlo Markov chain method to perform multiple Bayesian parameter optimizations on the model parameters. When the phase diagram to be optimized matches the experimental phase diagram, the optimization is terminated to obtain a set of self-consistent thermodynamic parameters and complete the construction of the system thermodynamic database.

[0093] S205: Based on the results of the thermodynamic model, Pt is selected 0.92 Ir 0.03 Re 0.04 Ni 0.01 As a research object.

[0094] S3: According to the simulation results of S2, the following metal element powders are used in atomic percentage: 3at% Ir, 1at% Ni, 4at% Re, and the balance is Pt. The ingredients are mixed according to the proportion of the metal element powders, and the raw materials are initially evenly mixed and pressed into tablets.

[0095] S4: melting and heat treatment in a vacuum arc melting furnace;

[0096] S401: Vacuum arc melting furnace is used for melting. The vacuum degree in the furnace is required to be greater than 2.0×10 -3 Pa, then fill with argon as a protective gas, and then smelt at a temperature of 1500-1700°C, the number of smelting times is greater than or equal to 10 times, and each smelting time of maintaining the molten state is greater than 2 minutes;

[0097] S402: After cooling, take out the sample, seal the tube in vacuum and put it into a tube furnace, fill it with argon, increase the temperature at a rate of 5 min / °C, set the temperature at 1200°C, keep it warm for 72 hours, then cool it to room temperature with the furnace and take out the sample.

[0098] S5: The cast samples were sliced ​​and then subjected to a series of characterizations, including X-ray diffractometer, Zeiss ultra-field emission gun scanning electron microscope, Vickers hardness test and room temperature tensile test.

[0099] S501: XRD-7000S diffractometer was used to test and analyze the phase composition of the sample prepared by melting. The sample was ground into a cross section with sandpaper, and polished and cleaned with 3μm diamond polishing agent to make the cross section smooth. The XRD test conditions were: scanning diffraction angle range of 10-70°, scanning speed of 10min, step length of 0.02deg, and MDIjade6.0 data analysis software was used to calibrate the XRD phase analysis results.

[0100] S502: A field emission gun scanning electron microscope (SEM) is used for morphology analysis. The sample for point scanning analysis is polished with a 3 μm diamond polishing agent. During the analysis, an acceleration voltage of 30 kV is used, and EDS point scanning is performed on a single particle.

[0101] S503: Use a digital microhardness tester to test the Vickers hardness of the sample. Analyze the sample results. Prepare 5 samples for each alloy, remove the maximum and minimum values, and Pt 0.92 Ir 0.03 Re0.04 Ni 0.01 The average hardness is 386.82HV, which is 111% higher than that of Pt-10%Ir alloy and 9.7% higher than that of Pt-10%Ru-2%Ir alloy.

[0102] S504: Use electronic universal mechanical properties testing machine to test the tensile strength and tensile strength of the samples. Analyze the sample results, Pt 0.92 Ir 0.03 Re 0.04 Ni 0.01 The maximum compressive strength is 1846MPa, corresponding to a deformation of 41%, which is 1199% higher than that of Pt-25%Ir alloy; the tensile strength is 752.49MPa, and the total elongation is 37%, which is 98.5% higher than that of Pt-10%Ir alloy and 1.28% higher than that of Pt-10%Ru-2%Ir alloy.

[0103] This embodiment also provides a high-strength platinum-based multinary solid solution alloy, comprising the following metal element powders in atomic percentage: 3at% Ir, 1at% Ni, 4at% Re, and the remainder is Pt.

[0104] Embodiment 2:

[0105] like Figure 1 and Figure 4 As shown, the design method of the high-strength platinum-based multinary solid solution alloy of this embodiment comprises the following steps:

[0106] S1: Based on the currently open Materials Project, OQMD, Springer Materials, ICSD and NIST databases and the mcsqs code cell building of the Alloy Theory Automation Toolkit (ATAT), the crystal structures of various platinum-based alloys are obtained, and the first-principles calculation method based on density functional theory is used to optimize and calculate their mixing enthalpy.

[0107] S101: Obtain the structure of binary alloys in platinum-based alloys from Materials projects. If there is no stable structure, use the mcsqs code of the alloy theory automation toolkit to build an SQS model. In this example, 33 elements are selected to construct Pt 31 X alloy crystal structure, X is Au, 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, Th.

[0108] S102: Structural optimization, using the first-principles calculation method of density functional theory, using VASP software for calculation, with a cutoff energy of 400 eV and an energy convergence criterion of 10 -6 eV / atom, the convergence accuracy of the force is less than A full relaxation calculation was performed on the input cell using a 8 × 8 × 8 Monkhorst-Pack K-point grid with ISIF = 3.

[0109] S103: Calculate the mixing enthalpy of each binary alloy system after optimization, select a binary system with negative mixing enthalpy, that is, a thermodynamically stable element, and fit the interaction parameters through the RK polynomial. In this experimental example, Pt, Ir, Ni, and W are selected for the next step of analysis.

[0110] S103 includes the following steps:

[0111] S1031: The Gibbs free energy and Helmholtz energy of the element and alloy are converted from electron volts to joules. The specific calculation method is as follows:

[0112] 1eV=96485J / mol (1)

[0113] In formula (1), eV is the unit of electron volt, and J / mol is the unit of joule;

[0114] S1032: Differentiate the Gibbs free energy and temperature of the element and the platinum-based alloy respectively to obtain the entropy of the element and the platinum-based alloy. The specific calculation method is as follows:

[0115]

[0116] In formula (2), S represents the entropy of the element or platinum-based alloy, G represents the Gibbs free energy of the element or platinum-based alloy, T represents the temperature of the element or platinum-based alloy, is the partial differential symbol; specifically, the platinum-based alloy Pt 31 The difference between the Gibbs free energy of X and the element at a temperature of 300 and the temperature gives the platinum-based alloy Pt 31 X and the entropy of the element;

[0117] S1033: Calculate the Gibbs free energy, temperature and entropy of the element and platinum-based alloy respectively to obtain the enthalpy of the element and platinum-based alloy. The specific calculation method is as follows:

[0118] G=HT*S (3)

[0119] In formula (3), G represents the Gibbs free energy of the single substance or platinum-based alloy, H represents the enthalpy of the single substance or platinum-based alloy, T represents the temperature of the single substance or platinum-based alloy, and S represents the entropy of the single substance or platinum-based alloy. Specifically, the platinum-based alloy Pt31 The Gibbs free energy, temperature and entropy of X and the element at a temperature of 300° are treated according to formula (3) to obtain the platinum-based alloy Pt 31 X and the enthalpy of the element;

[0120] S1034: Calculate the enthalpy of the single substance and the platinum-based alloy respectively to obtain the mixing enthalpy of the alloy. The specific calculation method is as follows:

[0121]

[0122] In formula (4), A x B y represents platinum-based alloy, A represents elemental A, B represents elemental B, and x represents elemental A in platinum-based alloy A. x B y The percentage of y is expressed as the percentage of element B in platinum-based alloy A. x B y The percentage of E(A) is the enthalpy (H) of element A, E(B) is the enthalpy (H) of element B, △E(A x B y ) represents platinum-based alloy A x B y The mixing enthalpy (△H) of the platinum-based alloy Pt 31 The enthalpy of X and the element at a temperature of 300 is processed according to formula (4) to obtain the platinum-based alloy Pt 31 Enthalpy of mixing of X;

[0123] S1035: The specific expression of Redlich-Kister (abbreviated as RK) polynomial is as follows:

[0124]

[0125] In formula (5), G ex It is expressed as the excess free energy of platinum-based alloy, A represents element A, B represents element B, and X A Expressed as element A in platinum-based alloy A x B y The percentage of X B Expressed as element B in platinum-based alloy A x B y The percentage of Φ is expressed as the phase of the platinum-based alloy. i L represents the i-th order interaction parameter; when i = 0, Specifically, the platinum-based alloy Pt 31The mixing enthalpy of X and the three points (0,0) and (1,0) are used to obtain the 0th order interaction parameter using the RK polynomial through the nonlinear curve fitting module of the origin software; at the same time, thermodynamically stable elements are selected. In this embodiment, Pt, Ir, Ni, and W are selected for the next step of analysis;

[0126] S1036: The mixing behavior of actual alloys deviates from the ideal mixing model; the interaction parameters are introduced through the RK polynomial to describe the deviations from the ideal state between different components, and are also used to construct thermodynamic models of multi-component alloys; when the temperature is 0K, the Gibbs free energy of the alloy is equal to the enthalpy value, and the mixing enthalpy of the single substance is 0. The interaction parameters can be obtained using the mixing enthalpy value of the alloy.

[0127] S2: Determine the lattice model and thermodynamic model of different phases in the Pt-Ir-Ni-W system, use AutoCalphad software to optimize the thermodynamic parameters of platinum-based solid solution alloys and construct a thermodynamic database.

[0128] S201: Collect and evaluate the thermodynamic experimental data of Pt-Ir-Ni-W system in the literature;

[0129] S202: Determine the lattice model of the binary alloy in the Pt-Ir-Ni-W system;

[0130] S203: using AutoCalphad software to automatically read the thermodynamic database obtained by first-principles calculation to generate an initial thermodynamic model and automatically generate a .tdb file;

[0131] S204: using the Monte Carlo Markov chain method to perform Bayesian parameter optimization on the model parameters. When the phase diagram to be optimized matches the experimental phase diagram, the optimization is terminated to obtain a set of self-consistent thermodynamic parameters and complete the construction of the system thermodynamic database.

[0132] S205: Based on the results of the thermodynamic model, Pt is selected 0.80 Ir 0.10 W 0.09 Ni 0.01 As a research object.

[0133] S3: According to the simulation results of S2, the following metal element powders are used in atomic percentage: 10at% Ir, 1at% Ni, 9% atW, and the balance is Pt.

[0134] S4: melting and heat treatment in a vacuum arc melting furnace;

[0135] S401: Mix the raw materials according to the proportion of metal element powder, and preliminarily mix and evenly press them into tablets;

[0136] S402: Vacuum arc melting furnace is used for melting. The vacuum degree in the furnace is required to be greater than 2.0×10 -3 Pa, then fill with argon gas, and then smelt at a temperature of 1500-1700°C, the number of smelting times is greater than or equal to 10 times, and the molten state is maintained for more than 2 minutes each time;

[0137] S403: After cooling, take out the sample, seal the tube in vacuum and put it into a tube furnace, fill it with argon, increase the temperature at a rate of 5 min / °C, set the temperature at 1200°C, keep it warm for 72 hours, then cool it to room temperature with the furnace and take out the sample.

[0138] S5: The cast samples were sliced ​​and then subjected to a series of characterizations, including X-ray diffractometer, Zeiss ultra-field emission gun scanning electron microscope, Vickers hardness test and room temperature tensile test.

[0139] S501: XRD-7000S diffractometer was used to test and analyze the phase composition of the sample prepared by melting. The sample was ground into a cross section with sandpaper, and polished and cleaned with 3μm diamond polishing agent to make the cross section smooth. The XRD test conditions were: scanning diffraction angle range of 10-70°, scanning speed of 10min, step length of 0.02deg, and MDIjade6.0 data analysis software was used to calibrate the XRD phase analysis results.

[0140] S502: A field emission gun scanning electron microscope (SEM) is used for morphology analysis. The sample for point scanning analysis is polished with a 3 μm diamond polishing agent. During the analysis, an acceleration voltage of 30 kV is used, and EDS point scanning is performed on a single particle.

[0141] S503: Use a digital microhardness tester to test the Vickers hardness of the sample. Analyze the sample results. Prepare 5 samples for each alloy, remove the maximum and minimum values, and Pt 0.80 Ir 0.10 W 0.09 Ni 0.01 The average hardness is 379.79 HV, which is 107% higher than that of Pt-10% Ir alloy and 7.7% higher than that of Pt-10% Ru-2% Ir alloy.

[0142] S504: Use electronic universal mechanical properties testing machine to test the tensile strength and tensile strength of the samples. Analyze the sample results, Pt 0.80 Ir 0.10 W 0.09 Ni 0.01The maximum compressive strength is 1683MPa, corresponding to a deformation of 36%, which is 1044% higher than that of Pt-25%Ir alloy; the fracture strength is 948.28MPa, and the total elongation is 28.5%, which is 150.2% higher than that of Pt-10%Ir alloy, and 27.6% higher than that of Pt-10%Ru-2%Ir alloy.

[0143] This embodiment also provides a high-strength platinum-based multi-component solid solution alloy, which, in atomic percentage, includes: 10 at% Ir, 1 at% Ni, 9 at% W, and the remainder is Pt.

[0144] Embodiment 3

[0145] like Figure 1 and Figure 5 As shown, the design method of the high-strength platinum-based multinary solid solution alloy of this embodiment comprises the following steps:

[0146] S1: Based on the currently open Materials Project, OQMD, Springer Materials, ICSD and NIST databases and the mcsqs code cell building of the Alloy Theory Automation Toolkit (ATAT), the crystal structures of various platinum-based alloys are obtained, and the first-principles calculation method based on density functional theory is used to optimize and calculate their mixing enthalpy.

[0147] S101: Obtain the structure of binary alloys in platinum-based alloys from Materials projects. If there is no stable structure, use the mcsqs code of the alloy theory automation toolkit to build an SQS model. In this example, 33 elements are selected to construct Pt 31 X alloy crystal structure, X is Au, 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, Th.

[0148] S102: Structural optimization, using the first-principles calculation method of density functional theory, using VASP software for calculation, with a cutoff energy of 400 eV and an energy convergence criterion of 10 -6 eV / atom, the convergence accuracy of the force is less than A full relaxation calculation was performed on the input cell using a 8 × 8 × 8 Monkhorst-Pack K-point grid with ISIF = 3.

[0149] S103: Calculate the mixing enthalpy of each binary alloy system after optimization, select a binary system with negative mixing enthalpy, that is, a thermodynamically stable element, and fit the interaction parameters through the RK polynomial. In this experimental example, Pt, Ir, Ni, and Co are selected for the next step of analysis.

[0150] S103 includes the following steps:

[0151] S1031: The Gibbs free energy and Helmholtz energy of the element and alloy are converted from electron volts to joules. The specific calculation method is as follows:

[0152] 1eV=96485J / mol (1)

[0153] In formula (1), eV is the unit of electron volt, and J / mol is the unit of joule;

[0154] S1032: Differentiate the Gibbs free energy and temperature of the element and the platinum-based alloy respectively to obtain the entropy of the element and the platinum-based alloy. The specific calculation method is as follows:

[0155]

[0156] In formula (2), S represents the entropy of the element or platinum-based alloy, G represents the Gibbs free energy of the element or platinum-based alloy, T represents the temperature of the element or platinum-based alloy, is the partial differential symbol; specifically, the platinum-based alloy Pt 31 The difference between the Gibbs free energy of X and the element at a temperature of 300 and the temperature gives the platinum-based alloy Pt 31 X and the entropy of the element;

[0157] S1033: Calculate the Gibbs free energy, temperature and entropy of the element and platinum-based alloy respectively to obtain the enthalpy of the element and platinum-based alloy. The specific calculation method is as follows:

[0158] G=HT*S (3)

[0159] In formula (3), G represents the Gibbs free energy of the single substance or platinum-based alloy, H represents the enthalpy of the single substance or platinum-based alloy, T represents the temperature of the single substance or platinum-based alloy, and S represents the entropy of the single substance or platinum-based alloy. Specifically, the platinum-based alloy Pt 31 The Gibbs free energy, temperature and entropy of X and the element at a temperature of 300° are treated according to formula (3) to obtain the platinum-based alloy Pt 31 X and the enthalpy of the element;

[0160] S1034: Calculate the enthalpy of the single substance and the platinum-based alloy respectively to obtain the mixing enthalpy of the alloy. The specific calculation method is as follows:

[0161]

[0162] In formula (4), A x B y represents platinum-based alloy, A represents elemental A, B represents elemental B, and x represents elemental A in platinum-based alloy A. x B y The percentage of y is expressed as the percentage of element B in platinum-based alloy A. x B y The percentage of E(A) is the enthalpy (H) of element A, E(B) is the enthalpy (H) of element B, △E(A x B y ) represents platinum-based alloy A x B y The mixing enthalpy (△H) of the platinum-based alloy Pt 31 The enthalpy of X and the element at a temperature of 300 is processed according to formula (4) to obtain the platinum-based alloy Pt 31 Enthalpy of mixing of X;

[0163] S1035: The specific expression of Redlich-Kister (abbreviated as RK) polynomial is as follows:

[0164]

[0165] In formula (5), G ex It is expressed as the excess free energy of platinum-based alloy, A represents element A, B represents element B, and X A Expressed as element A in platinum-based alloy A x B y The percentage of X B Expressed as element B in platinum-based alloy A x B y The percentage of Φ is expressed as the phase of the platinum-based alloy. i L represents the i-th order interaction parameter; when i = 0, Specifically, the platinum-based alloy Pt 31 The mixing enthalpy of X and the three points (0,0) and (1,0) are used to obtain the 0th order interaction parameter using the RK polynomial through the nonlinear curve fitting module of the origin software; at the same time, thermodynamically stable elements are selected. In this embodiment, Pt, Ir, Ni, and Re are selected for the next step of analysis;

[0166] S1036: The mixing behavior of actual alloys deviates from the ideal mixing model; the interaction parameters are introduced through the RK polynomial to describe the deviations from the ideal state between different components, and are also used to construct thermodynamic models of multi-component alloys; when the temperature is 0K, the Gibbs free energy of the alloy is equal to the enthalpy value, and the mixing enthalpy of the single substance is 0. The interaction parameters can be obtained using the mixing enthalpy value of the alloy.

[0167] S2: Determine the lattice model and thermodynamic model of different phases in the Pt-Ir-Ni-Co system, use AutoCalphad software to optimize the thermodynamic parameters of platinum-based solid solution alloys and construct a thermodynamic database.

[0168] S201: Collect and evaluate the thermodynamic experimental data of Pt-Ir-Ni-Co system in the literature;

[0169] S202: Determine the lattice model of the binary alloy in the Pt-Ir-Ni-Co system;

[0170] S203: using AutoCalphad software to automatically read the thermodynamic database obtained by first-principles calculation to generate an initial thermodynamic model and automatically generate a .tdb file;

[0171] S204: using the Monte Carlo Markov chain method to perform Bayesian parameter optimization on the model parameters. When the phase diagram to be optimized matches the experimental phase diagram, the optimization is terminated to obtain a set of self-consistent thermodynamic parameters and complete the construction of the system thermodynamic database.

[0172] S205: Based on the results of the thermodynamic model, Pt is selected 0.80 Ir 0.10 Co 0.09 Ni 0.01 As a research object.

[0173] S3: According to the simulation results of S2, the following metal element powders are used in atomic percentage: 10at% Ir, 1at% Ni, 9at% Co, and the balance is Pt.

[0174] S4: melting and heat treatment in a vacuum arc melting furnace;

[0175] S401: Vacuum arc melting furnace is used for melting. The vacuum degree in the furnace is required to be greater than 2.0×10 -3 Pa, then fill with argon gas, and then smelt at a temperature of 1500-1700°C, the number of smelting times is greater than or equal to 10 times, and the molten state is maintained for more than 2 minutes each time;

[0176] S402: After cooling, take out the sample, seal the tube in vacuum and put it into a tube furnace, fill it with argon, increase the temperature at a rate of 5 min / °C, set the temperature at 1200°C, keep it warm for 72 hours, then cool it to room temperature with the furnace and take out the sample.

[0177] S5: The cast samples were sliced ​​and then subjected to a series of characterizations, including X-ray diffractometer, Zeiss ultra-field emission gun scanning electron microscope, Vickers hardness test and room temperature tensile test.

[0178] S501: XRD-7000S diffractometer was used to test and analyze the phase composition of the sample prepared by melting. The sample was ground into a cross section with sandpaper, and polished and cleaned with 3μm diamond polishing agent to make the cross section smooth. The XRD test conditions were: scanning diffraction angle range of 10-70°, scanning speed of 10min, step length of 0.02deg, and MDIjade6.0 data analysis software was used to calibrate the XRD phase analysis results.

[0179] S502: A field emission gun scanning electron microscope (SEM) is used for morphology analysis. The sample for point scanning analysis is polished with a 3 μm diamond polishing agent, and an acceleration voltage of 30 kV is used during the analysis.

[0180] S503: Use a digital microhardness tester to test the Vickers hardness of the sample. Analyze the sample results. Prepare 5 samples for each alloy, remove the maximum and minimum values, and Pt 0.80 Ir 0.10 Co 0.09 Ni 0.01 The average hardness is 369.10HV, which is 101.5% higher than that of Pt-10%Ir alloy and 4.7% higher than that of Pt-10%Ru-2%Ir alloy.

[0181] S504: Use electronic universal mechanical properties testing machine to test the tensile strength and tensile strength of the samples. Analyze the sample results, Pt 0.80 Ir 0.10 Co 0.09 Ni 0.01 The maximum compressive strength is 1414MPa, corresponding to a deformation of 40%, which is 861% higher than that of Pt-25%Ir alloy; the fracture strength is 812.78MPa, and the total elongation is 21%, which is 114.4% higher than that of Pt-10%Ir alloy, and 9.4% higher than that of Pt-10%Ru-2%Ir alloy.

[0182] This embodiment also provides a high-strength platinum-based multi-component solid solution alloy, which, in atomic percentage, includes: 10 at% Ir, 1 at% Ni, 9 at% Co, and the remainder is Pt.

[0183] Comparative Examples 1 to 3:

[0184] S1: Three alloys, Pt-10% Ir, Pt-25% Ir and Pt-10% Ru-2% Ir, were selected as comparative examples.

[0185] S2: Use vacuum arc melting furnace for melting and heat treatment.

[0186] S201: The raw materials are mixed uniformly according to the proportion of metal element powder and pressed into tablets.

[0187] S202: Vacuum arc melting furnace is used for melting. The vacuum degree in the furnace is required to be greater than 2.0×10 -3 Pa, then filled with argon, followed by smelting, the smelting temperature is 1500-1700°C, the number of smelting times is greater than or equal to 10 times, and the molten state is maintained for more than 2 minutes each time.

[0188] S203: After cooling, take out the sample, seal the tube in vacuum and put it into a tube furnace, fill it with argon, increase the temperature at a rate of 5 min / °C, set the temperature at 1200°C, keep it warm for 72 hours, then cool it to room temperature with the furnace and take out the sample.

[0189] S3: The cast samples were sliced ​​and then subjected to a series of characterizations, including X-ray diffractometer, Zeiss ultra-field emission gun scanning electron microscope, Vickers hardness test and room temperature tensile test.

[0190] S301: XRD-7000S diffractometer was used to test and analyze the phase composition of the sample prepared by melting. The sample was ground into a cross section with sandpaper, and polished and cleaned with 3μm diamond polishing agent to make the cross section smooth. The XRD test conditions were: scanning diffraction angle range of 10-70°, scanning speed of 10min, step length of 0.02deg, and MDIjade6.0 data analysis software was used to calibrate the XRD phase analysis results.

[0191] S302: A field emission gun scanning electron microscope (SEM) is used for morphology analysis. The sample for point scanning analysis is polished with a 3 μm diamond polishing agent, and an acceleration voltage of 30 kV is used during the analysis.

[0192] S303: Use a digital microhardness tester to test the Vickers hardness of the samples. Analyze the sample results. Five samples were made for each alloy. Excluding the maximum and minimum values, the average hardness of Pt-10% Ir is 183.15HV, the average hardness of Pt-25% Ir is 307.93HV, and the average hardness of Pt-10% Ru-2% Ir is 352.60HV.

[0193] S304: The tensile strength and anti-tensile strength of the samples were tested using an electronic universal mechanical properties testing machine. The results of the sample analysis showed that the maximum compressive strength of Pt-10% Ir was 118.6MPa, corresponding to a deformation of 31%; the tensile strength was 379MPa, and the total elongation was 25%. The maximum compressive strength of Pt-25% Ir was 147.1MPa, corresponding to a deformation of 29%; the tensile strength was 453MPa, and the total elongation was 29%. The maximum compressive strength of Pt-10% Ru-2% Ir was 1275MPa, corresponding to a deformation of 33%; the tensile strength was 743MPa, and the total elongation was 16%.

[0194] The element ratios and test results of Examples 1 to 3 are as follows:

[0195] Table 1. Types and amounts of elements in the alloys of Examples 1 to 3

[0196]

[0197]

[0198] Table 2. Hardness test results in Examples 1 to 3

[0199]

[0200] Table 3. Compressive strength test results in Examples 1 to 3

[0201]

[0202] Table 4. Tensile strength test results in Examples 1 to 3

[0203]

[0204] The composition ratios and test results of Comparative Examples 1 to 3 are as follows:

[0205] Table 5. Types and amounts of elements in alloys from Comparative Examples 1 to 3

[0206]

[0207] Table 6. Hardness test results in Comparative Examples 1 to 3

[0208]

[0209]

[0210] Table 7. Compressive strength test results in Comparative Examples 1 to 3

[0211]

[0212] Table 8. Tensile strength test results in Comparative Examples 1 to 3

[0213]

[0214] 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 design method for a high-strength platinum-based multinary solid solution alloy, characterized in that: The steps include: S1: Obtain the crystal structures of various platinum-based alloys, calculate the mixing enthalpy of various binary alloy systems based on first-principles calculations, and select thermodynamically stable elements as the platinum-based alloy system; S2: According to the corresponding platinum-based alloy system, the Calphad phase diagram calculation method is used, combined with thermodynamic models and experimental data, to predict the phase diagrams of platinum-based alloys with different proportions and combinations, and the proportions and temperature ranges of each single-phase solid solution are calculated based on the phase diagram; S3: According to the simulation results of step S2, one of the raw materials is selected according to the performance requirements, and the raw materials are mixed and pressed into tablets according to the element ratio; S4: The raw material pressed into sheets is subjected to vacuum arc melting to obtain a sample; S5: Slice the sample and characterize it using instruments.

2. The design method of high-strength platinum-based multinary solid solution alloy according to claim 1, characterized in that: The step S1 specifically includes: S101: Obtain the crystal structures of various platinum-based alloys; S102: Using the first-principles calculation method of density functional theory, the crystal structures of various platinum-based alloys were substituted into the VASP software for calculation, and the input unit cell was fully relaxed to obtain the unit cell parameters from the calculation results; S103: Calculate the thermodynamic properties based on the unit cell parameters and fit the interaction parameters using the Redlich-Kister polynomial.

3. The design method of high-strength platinum-based multinary solid solution alloy according to claim 2, characterized in that: In step S102, the crystal structures of various platinum-based alloys are obtained based on the Materials Project, OQMD, Springer Materials, ICSD and NIST databases and the mcsqs code of the alloy theory automation toolkit.

4. The design method of high-strength platinum-based multinary solid solution alloy according to claim 2, characterized in that: In step S102, the cutoff energy is set to 400 eV, and the energy convergence criterion of the electron self-consistency is 10 -6 eV / atom, the convergence accuracy of the force is less than An 8×8×8 Monkhorst-Pack K-point grid and ISIF=3 were used.

5. The design method of high-strength platinum-based multinary solid solution alloy according to claim 2, characterized in that: The step S103 specifically includes: S1031: Convert the Gibbs free energy and Helmholtz energy of the element and platinum-based alloy in the unit cell parameters from electron volts to joules. The specific calculation method is as follows: 1eV = 96485 J / mol (1) In formula (1), eV is the unit of electron volt, and J / mol is the unit of joule; S1032: Differentiate the Gibbs free energy of the element and the platinum-based alloy with the temperature to obtain the entropy of the element and the platinum-based alloy. The specific calculation method is as follows: In formula (2), S represents the entropy of the element or platinum-based alloy, G represents the Gibbs free energy of the element or platinum-based alloy, T represents the temperature of the element or platinum-based alloy, is the symbol for partial differential; S1033: Calculate the Gibbs free energy, temperature and entropy of the element and platinum-based alloy respectively to obtain the enthalpy of the element and platinum-based alloy. The specific calculation method is as follows: G=HT*S (3) In formula (3), G represents the Gibbs free energy of the element or the platinum-based alloy, H represents the enthalpy of the element or the platinum-based alloy, T represents the temperature of the element or the platinum-based alloy, and S represents the entropy of the element or the platinum-based alloy; S1034: Calculate the enthalpy of the single substance and the platinum-based alloy respectively to obtain the mixing enthalpy of the alloy. The specific calculation method is as follows: In formula (4), A x B y represents platinum-based alloy, A represents elemental A, B represents elemental B, and x represents elemental A in platinum-based alloy A. x B y The percentage of y is expressed as the percentage of element B in platinum-based alloy A. x B y The percentage of E(A) is the enthalpy (H) of element A, E(B) is the enthalpy (H) of element B, △E(A x B y ) represents platinum-based alloy A x B y Enthalpy of mixing (△H); S1035: The specific expression of Redlich-Kister polynomial is as follows: In formula (5), G ex It is expressed as the excess Gibbs free energy of platinum-based alloy, A represents element A, B represents element B, and X A Expressed as element A in platinum-based alloy A x B y The percentage of X B Expressed as element B in platinum-based alloy A x B y The percentage of Φ is expressed as the phase of the platinum-based alloy. i L represents the i-th order interaction parameter; when i = 0, It is a regular solution model.

6. The design method of high-strength platinum-based multinary solid solution alloy according to claim 1, characterized in that , the step S2 specifically includes: S201: Collect thermodynamic experimental data of platinum-based alloy systems in the literature, including entropy, enthalpy, heat capacity, Gibbs free energy, and experimental phase diagrams, and compare the thermodynamic experimental data with the thermodynamic calculated data of the platinum-based alloy system to ensure the accuracy of the calculated data; S202: Determine a lattice model of a platinum-based multi-element alloy system based on the calculated and collected crystal structure and thermodynamic data of the platinum-based alloy, wherein the lattice model can simulate the distribution of atoms in a solid solution on a regular crystal structure; S203: using AutoCalphad software to read the thermodynamic data and the calculated interaction parameters, and generating a corresponding initial thermodynamic model according to the lattice model, wherein the initial thermodynamic model describes the thermodynamic properties of the platinum-based alloy system by defining the types and proportions of components occupying lattice positions and the corresponding Gibbs free energy; S204: the initial thermodynamic model cannot accurately describe the corresponding phase diagram, and the Monte Carlo Markov chain method is used to perform multiple Bayesian parameter optimizations on the model parameters of the initial thermodynamic model until the optimized phase diagram matches the experimental phase diagram, and then the optimization is terminated to obtain a set of self-consistent thermodynamic parameters, thereby completing the construction of the final thermodynamic model; S205: Calculating according to the phase diagram corresponding to the final thermodynamic model to obtain each single-phase solid solution composition and temperature range.

7. The design method of high-strength platinum-based multinary solid solution alloy according to claim 6, characterized in that , The thermodynamic model of the platinum-based alloy system is specifically as follows: a mathematical fitting model is used for pure elements; a substitution solution model is used for the solid solution phase, in which the excess Gibbs free energy is represented by RK polynomial fitting; and a sublattice model is used for the compound phase, in which the excess Gibbs free energy is represented by RK polynomial fitting.

8. The design method of high-strength platinum-based multinary solid solution alloy according to claim 1, characterized in that: Step S4 specifically includes: S401: Vacuum arc melting furnace is used for melting. The vacuum degree in the furnace is required to be greater than 2.0×10 -3 Pa, then fill with argon gas, and then smelt at a temperature of 1500-1700°C, the number of smelting times is greater than or equal to 10 times, and the molten state is maintained for more than 2 minutes each time; S402: After cooling, take out the sample, seal the tube in vacuum and put it into a tube furnace, fill it with argon, increase the temperature at a rate of 5 min / °C, set the temperature at 1200°C, keep it warm for 72 hours, then cool it to room temperature with the furnace and take out the sample.

9. The design method of high-strength platinum-based multinary solid solution alloy according to claim 1, characterized in that ,Step S5 specifically includes: S501: After the sample is sliced, it is characterized by X-ray diffraction to observe the phase composition; S502: morphology analysis using a field emission gun scanning electron microscope; S503: Test hardness on a digital microhardness tester; S504: Test the tensile strength, compressive strength and other properties on the electronic universal mechanical properties testing machine.

10. A high-strength platinum-based multinary solid solution alloy, characterized in that: The high-strength platinum-based multinary solid solution alloy is prepared by the design method of any one of claims 1 to 8, wherein the elements in the high-strength platinum-based multinary solid solution alloy are calculated by atomic percentage: 1-10at% Ir, 0.1-1at% Ni, 1-10at% Co or W or Re, and the balance is Pt.

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