A high-temperature platinum-based high-entropy resistive strain material, preparation method and use thereof

Abstract

The present invention discloses a high-temperature platinum-based high-entropy resistive strain material, a preparation method and a use thereof, comprising: 5-20% rhodium, 5-10% tungsten, 2-10% molybdenum, 1-7% iridium, 0-5% rhenium, and platinum as the balance. The present invention optimizes the composition of each component to obtain a high-entropy alloy, and adds trace elements to achieve the purpose of improving the resistivity of the material; a gradient material is obtained by surface refinement treatment, and the mechanical properties of the material are improved without significantly reducing its plastic deformation ability, thereby achieving the effect of improving the processing yield rate. The finished ultrafine wire and strip are obtained by hot forging blanking, surface refinement, high-frequency induction coil heating hot drawing, "heat treatment-cold drawing" cycle, rolling, heat treatment and the like. The performance is: the maximum use temperature is 1200°C, the room temperature tensile strength is ≥1750MPa, the room temperature resistivity is ≥72μΩ·cm, and the room temperature sensitivity coefficient K is ≥2.5. The material of the present invention can be used to prepare a high-temperature dynamic strain gauge for testing the hot end components of an aero-engine.

Description

Technical Field

[0001] The present invention belongs to the field of high-temperature resistive strain materials, and relates to a sensitive grid of a high-temperature strain gauge for high-temperature dynamic stress / strain testing of a novel aircraft engine hot end component, and in particular to a high-temperature gradient platinum-based high-entropy resistive strain material, a preparation method and use thereof. Background Art

[0002] With the continuous progress of aircraft engine development, higher requirements are put forward for high-temperature strain gauges used for stress / strain testing of hot end components of aircraft engines. The performance (operating temperature) of the strain gauge sensitive grid determines its application capability. Existing strain gauge sensitive grid materials mainly include systems such as constantan, nickel-chromium, iron-chromium-aluminum and precious metal alloys. Among them, NiCr is mainly used in the form of thin film. At a temperature of 500℃, the resistivity increases by an order of magnitude compared with 400℃, and the performance changes from metal state to semiconductor state, indicating that at 500℃, the alloy can no longer meet the use requirements of thin film resistance strain gauges. The sensitive grid materials of high-temperature strain gauges mainly use precious metal systems. Bertodo's research found that Pt-W alloy is the high-temperature resistive strain material with the best comprehensive performance. After special treatment, the maximum operating temperature can reach 800℃; He Huachun prepared PtWReNi alloy with Re and Ni elements in Pt-W alloy, and the maximum operating temperature can reach 860℃ strain test; based on Pt-W alloy, through element addition, some scholars have developed Pt-W-Re-Ni-Cr (Y) series strain materials, and the maximum operating temperature can reach 900℃; Yin Junmei and others' research showed that the resistance-temperature linear range of PtRhMoReCr alloy wire is 0-1000℃. When the temperature is above 1000℃, Mo, Re and Cr oxidize and volatilize, and the resistance of the alloy drops sharply. The maximum operating temperature of the alloy can reach 1000℃.

[0003] At present, the maximum operating temperature of the existing self-developed dynamic strain gauge materials in China is 1100℃. On this basis, every 10℃ increase in the operating temperature is a major technological breakthrough. In order to improve its key properties such as operating temperature and resistivity, it is necessary to add other high melting point elements and a small amount of easily oxidized elements to the Pt-W series alloys. However, the addition of these elements will lead to complex preparation processes, difficult processing, and poor performance stability. Summary of the invention

[0004] The technical problem solved by the present invention is to prepare a Pt-based strain material through high entropy alloy, improve the tensile strength, resistivity, stable resistance temperature coefficient, temperature drift and other key properties, and at the same time obtain a gradient material with good tensile strength through surface refinement treatment to improve the material yield.

[0005] Based on key properties such as tensile strength, resistivity, temperature coefficient of resistance, and temperature drift, the present invention adds Rh and Ir elements to the Pt-W alloy. Rh and Pt form a solid solution strengthening effect to improve its high-temperature mechanical properties; Ir can also further improve its high-temperature strength; Mo and Re elements will be oxidized during the heat treatment process, which can increase their resistivity; through the addition of these elements and the optimization of the composition, finally, a platinum-based high-entropy resistive strain material with a use temperature of 1200°C can be obtained.

[0006] The high entropy alloy material prepared by the preparation method of the present invention has higher tensile strength while maintaining the plastic deformation ability basically unchanged, reduces the risk of wire breakage during drawing, and successfully prepares a high-temperature resistive strain material with a maximum operating temperature of 1200°C.

[0007] The technical solution of the present invention is:

[0008] Aiming at the key properties of high-temperature resistive strain materials such as tensile strength, resistivity, temperature coefficient of resistance, and temperature drift, the present invention is based on the Pt-W alloy of high-temperature resistive strain materials with the best comprehensive performance, and prepares Pt-based high-entropy alloy strain materials by adding Rh and Ir elements with the best high-temperature solid solution strengthening performance, as well as Mo and Re elements that are easily oxidized during heat treatment, so as to improve its mechanical properties at high temperatures and resistivity at room temperature. After high-temperature forging, surface refinement, hot drawing, intermediate annealing, room temperature drawing, rolling and other processes, it is processed into ultra-fine wires or strips of finished product size.

[0009] Specifically, the alloy composition (wt.%) of the high-temperature platinum-based high-entropy resistive strain material of the present invention includes: 5% to 20% rhodium, 5% to 10% tungsten, 2% to 10% molybdenum, 1% to 7% iridium, 0% to 2% rhenium, and the balance of platinum. The resistive strain material is prepared by raw material batching, smelting, annealing, hot forging and blanking to prepare rods, using the skin effect of high-frequency induction coil heating to obtain rods with surface fine grain areas, and processing into ultrafine wires or strips.

[0010] A method for preparing a high-temperature platinum-based high-entropy resistive strain material is prepared by the following process steps:

[0011] (1) Ingredients: Calculated by weight percentage (wt.%), the content of each element is: rhodium 5% to 20%, tungsten 5% to 10%, molybdenum 2% to 10%, iridium 1% to 7%, rhenium 0% to 5%, and platinum as the balance. Since Mo and Re are volatile, the ingredients can be increased by 0.2 to 0.3%;

[0012] (2) Master alloy: Use a vacuum high-frequency induction furnace and a magnesium oxide crucible to melt the high-melting-point W element and Pt into a master alloy;

[0013] (3) Melting: Other elements are added according to the composition design, and the alloy is refined for 10 minutes using a vacuum high-frequency induction furnace and a magnesium oxide crucible filled with inert gas. To ensure the uniformity of the composition, at least one turnaround melting is performed, and a water-cooled copper mold crucible is used for casting to obtain a cylindrical ingot with a diameter of φ8 to 15 mm;

[0014] (4) Annealing: Ingot at 800-1000℃, vacuum degree ≤3×10 -2 Stress relief annealing is carried out in a vacuum environment of 1.5 Pa;

[0015] (5) Hot forging: The ingot is forged at a high temperature of 1100-1400°C to obtain a rod with a diameter of φ6 mm;

[0016] (6) Surface refinement: The hot forged bar is rapidly heated by the skin effect of high-frequency induction coil heating. When the surface temperature reaches 1300-1500°C, it is rapidly cooled with an ice-water mixture to obtain a bar with a surface fine grain area.

[0017] (7) Processing and forming: Through hot drawing, intermediate annealing, room temperature drawing, rolling and other processes, it is processed into ultra-fine wire or strip of finished size.

[0018] Furthermore, the step (7) specifically includes:

[0019] (1) The surface refined bar is subjected to a hot drawing rough drawing process at a temperature of 700 to 900° C.; the deformation amount of a single hot forging pass is controlled to be ≤5%, the ingot is processed into a bar with a diameter of φ6 mm, and the deformation amount of a single hot drawing pass is controlled to be ≤5%, so as to obtain a wire with a diameter of φ1 mm;

[0020] (2) subjecting the wire to an intermediate heat treatment at 750-950° C., wherein the intermediate heat treatment is protected by reducing hydrogen;

[0021] (3) Adopting the "intermediate heat treatment-cold drawing" cycle and rolling process to obtain ultra-fine wire or strip of finished product size; controlling the deformation of the cold drawing single pass to ≤3% until the ultra-fine wire or strip of finished product size is obtained;

[0022] (4) The finished ultrafine wire or strip is subjected to a performance control heat treatment in a hydrogen-argon protective atmosphere, wherein the performance control heat treatment process of the finished product is a continuous annealing at 780-850°C.

[0023] Furthermore, in step (3), the high frequency induction furnace is first used to evacuate the smelting chamber to a vacuum degree of ≤5×10 - 2 Pa, and then filled with argon gas with a vol% purity of 99.999% to 0.05MPa.

[0024] Furthermore, in step (7):

[0025] The intermediate annealing process is 700-900°C, protected by reducing hydrogen; the hot drawing is heated by a high-frequency induction coil, the induction coil length is 20cm, the power is 20-40KW, to ensure uniform heating;

[0026] During the hot drawing process, the hot drawing die needs to be heated to 700-800° C., graphite is used for lubrication, and the processed rod and the die are continuously heated by a hydrogen-oxygen reducing flame.

[0027] Furthermore, in the step (1), the purity of each raw material is wt.%≥99.95; the diameter of the ultrafine wire is φ0.03-0.05 mm, and the size of the strip is 0.05×0.3 mm.

[0028] Furthermore, in the step (1), the raw material batching accuracy is ±0.02g. Since Mo and Re are volatile, the raw material batching can be increased by 0.2-0.3%. Before alloying and smelting, acetone or alcohol must be used for ultrasonic cleaning to remove surface oil and impurities. The cleaning time should be ≥10min, and then the raw material is washed with deionized water and dried for use.

[0029] The high-temperature platinum-based high-entropy resistance strain material of the present invention can be used to prepare a high-temperature dynamic strain gauge for testing aircraft engines.

[0030] Beneficial effects of the present invention:

[0031] The present invention obtains a high-entropy alloy with high tensile strength and high resistivity by optimizing the alloy composition, obtains a gradient material by surface refinement treatment, and the surface fine-grained hardened layer promotes stable plastic rheology, thereby delaying local damage. Therefore, while substantially not reducing the plastic deformation capacity, the tensile strength of the material is improved and the risk of wire breakage during drawing processing is reduced, further improving the yield rate of the material. The maximum use temperature of the platinum-based high-entropy resistive strain material prepared by the present invention is 1200°C, the room temperature tensile strength is ≥1750MPa, the room temperature resistivity is ≥72μΩ·cm, and the room temperature sensitivity coefficient is: K≥2.5. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the resistance drift characteristic curve of Pt-10Rh-8W-6Mo-6Ir-0.5Re alloy at 1200℃.

[0033] Figure 2 This is the resistance-temperature characteristic curve of Pt-10Rh-8W-6Mo-6Ir-0.5Re alloy from room temperature to 1200℃.

[0034] Figure 3This is the fracture morphology and microstructure of the Pt-10Rh-8W-6Mo-6Ir-0.5Re alloy after surface refinement treatment. DETAILED DESCRIPTION

[0035] The purity of the raw materials used is ≥99.95 (wt.%), and the batching accuracy is ±0.02g. Since Mo and Re are volatile, the batching can be increased by 0.2-0.3%. Before the alloy is smelted, it must be ultrasonically cleaned with acetone or alcohol to remove surface oil and impurities, and the cleaning time should be ≥10min; then, through hot forging, surface refinement, hot drawing, intermediate annealing, room temperature drawing, rolling and other processes, it is processed into ultrafine wire or strip of finished size.

[0036] Example 1

[0037] (1) Ingredients: Calculated by weight percentage (wt.%), the content of each element is: rhodium 10%, tungsten 5%, molybdenum 4%, iridium 4%, rhenium 0.5%, and platinum as the balance;

[0038] (2) Master alloy: Use vacuum high-frequency induction furnace and magnesium oxide crucible to melt W element and Pt into master alloy;

[0039] (3) Melting: vacuum high frequency induction furnace vacuum degree 3.1×10 -2 Pa, fill with high-purity argon gas to 0.05MPa, refine in a magnesium oxide crucible for 10min, perform one turnaround smelting, and cast in a water-cooled copper mold crucible to obtain an ingot with a diameter of φ15mm;

[0040] (4) Annealing: 800℃ / 3h, vacuum degree 2.3×10 -2 Stress relief annealing is carried out in an environment of Pa;

[0041] (5) Hot forging: The ingot is forged at a high temperature of 1100°C. During the forging process, it is continuously heated by a hydrogen-oxygen flame to obtain a rod with a diameter of φ6 mm.

[0042] (6) Surface grain refinement: The hot forged bar is rapidly heated by a high-frequency induction coil. When the surface temperature is about 1300°C, it is rapidly cooled by a mixed solution of ice and water to obtain a bar with a surface grain refinement zone.

[0043] (7) Processing: Through hot drawing, intermediate annealing, room temperature drawing and other processes, it is processed into ultra-fine wires of φ0.03 mm;

[0044] (8) Performance control: The heat treatment process is 780°C and hydrogen-argon protection continuous annealing.

[0045] The properties of the PtRhWMoIrRe ultrafine wire prepared by the above process are: room temperature tensile strength of 1750-1790 MPa, room temperature resistivity of 72.3-74.5 μΩ·cm, and room temperature sensitivity coefficient of 2.6.

[0046] Example 2

[0047] (1) Ingredients: Calculated by weight percentage (wt.%), the content of each element is: rhodium 10%, tungsten 5%, molybdenum 4%, iridium 4%, rhenium 0.5%, and platinum as the balance;

[0048] (2) Master alloy: Use vacuum high-frequency induction furnace and magnesium oxide crucible to melt W element and Pt into master alloy;

[0049] (3) Melting: vacuum high frequency induction furnace vacuum degree 3.3×10 -2 Pa, fill with high-purity argon to 0.05MPa, refine in a magnesium oxide crucible for 10min, perform one turnaround smelting, and cast in a water-cooled copper mold crucible to obtain an ingot with a diameter of φ15mm;

[0050] (4) Annealing: 800℃ / 3h, vacuum degree 2.5×10 -2 Stress relief annealing is carried out in an environment of Pa;

[0051] (5) Hot forging: The ingot is forged at a high temperature of 1100°C. During the forging process, it is continuously heated by a hydrogen-oxygen flame to obtain a rod with a diameter of φ6 mm.

[0052] (6) Processing and forming: The wire is seriously broken during drawing, and it is difficult to process and form. Only a small amount of it can be processed into ultra-fine wires of φ0.03mm;

[0053] (7) Performance control: The heat treatment process is 780°C and hydrogen-argon protection continuous annealing.

[0054] The properties of the PtRhWMoIrRe ultrafine wire prepared by the above process are: room temperature tensile strength of 1680-1730 MPa, room temperature resistivity of 71.8-73.2 μΩ·cm, and room temperature sensitivity coefficient of 2.6.

[0055] Example 3

[0056] (1) Ingredients: Calculated by weight percentage (wt.%), the content of each element is: rhodium 10%, tungsten 8%, molybdenum 6%, iridium 6%, rhenium 0.5%, and platinum as the balance;

[0057] (2) Master alloy: Use vacuum high-frequency induction furnace and magnesium oxide crucible to melt W element and Pt into master alloy;

[0058] (3) Melting: vacuum high frequency induction furnace vacuum degree 2.9×10-2 Pa, fill with high-purity argon gas to 0.05MPa, refine in a magnesium oxide crucible for 10min, perform one turnaround smelting, and cast in a water-cooled copper mold crucible to obtain an ingot with a diameter of φ15mm;

[0059] (4) Annealing: 880℃ / 3h, vacuum degree 2.6×10 -2 Stress relief annealing is carried out in an environment of Pa;

[0060] (5) Hot forging: The ingot is forged at a high temperature of 1200°C. During the forging process, hydrogen-oxygen flame is used for continuous heating to obtain a rod with a diameter of φ6 mm.

[0061] (6) Surface grain refinement: The hot forged bar is rapidly heated by a high-frequency induction coil. When the surface temperature is about 1370°C, it is rapidly cooled by a mixture of ice and water to obtain a bar with a surface grain refinement zone.

[0062] (7) Processing: Through hot drawing, intermediate annealing, room temperature drawing and other processes, it is processed into ultra-fine wires of φ0.03 mm;

[0063] (8) Performance control: The heat treatment process is 810°C and hydrogen-argon protected continuous annealing.

[0064] The properties of the PtRhWMoIrRe ultrafine wire prepared by the above process are: room temperature tensile strength of 1780-1830 MPa, room temperature resistivity of 74.1-75.9 μΩ·cm, and room temperature sensitivity coefficient of 2.7.

[0065] Example 4

[0066] (1) Ingredients: Calculated by weight percentage (wt.%), the content of each element is: rhodium 15%, tungsten 10%, molybdenum 8%, iridium 6%, rhenium 0.5%, and platinum as the balance;

[0067] (2) Master alloy: Use vacuum high-frequency induction furnace and magnesium oxide crucible to melt W element and Pt into master alloy;

[0068] (3) Melting: vacuum high frequency induction furnace vacuum degree 3.5×10 -2 Pa, fill with high-purity argon gas to 0.05MPa, refine in a magnesium oxide crucible for 10min, perform one turnaround smelting, and cast in a water-cooled copper mold crucible to obtain an ingot with a diameter of φ15mm;

[0069] (4) Annealing: 950℃ / 3h, vacuum degree 2.3×10 -2 Stress relief annealing is carried out in an environment of Pa;

[0070] (5) Hot forging: The ingot is forged at a high temperature of 1300°C. During the forging process, hydrogen-oxygen flame is used for continuous heating to obtain a rod with a diameter of φ6 mm.

[0071] (6) Surface grain refinement: The hot forged bar is rapidly heated by a high-frequency induction coil. When the surface temperature is about 1430°C, it is rapidly cooled by a mixture of ice and water to obtain a bar with a surface grain refinement zone.

[0072] (7) Processing: Through hot drawing, intermediate annealing, room temperature drawing and other processes, it is processed into ultra-fine wires of φ0.03 mm;

[0073] (8) Performance control: The heat treatment process is 830°C and hydrogen-argon protection continuous annealing.

[0074] The properties of the PtRhWMoIrRe ultrafine wire prepared by the above process are: room temperature tensile strength of 1850-1900 MPa, room temperature resistivity of 76.6-79.0 μΩ·cm, and room temperature sensitivity coefficient of 2.5.

[0075] Example 5

[0076] (1) Ingredients: Calculated by weight percentage (wt.%), the content of each element is: rhodium 20%, tungsten 10%, molybdenum 8%, iridium 7%, rhenium 2%, and platinum as the balance;

[0077] (2) Master alloy: Use vacuum high-frequency induction furnace and magnesium oxide crucible to melt W element and Pt into master alloy;

[0078] (3) Melting: vacuum high frequency induction furnace vacuum degree 4.2×10 -2 Pa, fill with high-purity argon to 0.05MPa, refine in a magnesium oxide crucible for 10min, perform two U-turn smelting, and cast in a water-cooled copper mold crucible to obtain an ingot with a diameter of φ15mm;

[0079] (4) Annealing: 1000℃ / 3h, vacuum degree 2.6×10 -2 Stress relief annealing is carried out in an environment of Pa;

[0080] (5) Hot forging: The ingot is forged at a high temperature of 1400°C. During the forging process, hydrogen-oxygen flame is used for continuous heating to obtain a rod with a diameter of φ6 mm.

[0081] (6) Surface grain refinement: The hot forged bar is rapidly heated by a high-frequency induction coil. When the surface temperature is about 1500°C, it is rapidly cooled by a mixture of ice and water to obtain a bar with a surface grain refinement zone.

[0082] (7) Processing: Through hot drawing, intermediate annealing, room temperature drawing and other processes, it is processed into ultra-fine wires of φ0.03 mm;

[0083] (8) Performance control: The heat treatment process is 850°C and hydrogen-argon protection continuous annealing.

[0084] The properties of the PtRhWMoIrRe ultrafine wire prepared by the above process are: room temperature tensile strength is 1870-1910 MPa, room temperature resistivity is 77.4-79.3 μΩ·cm, and room temperature sensitivity coefficient is 2.5.

[0085] The results of surface refinement treatment and main performance comparison of several grades of Pt-Rh-W-Mo-Ir-Re alloys prepared in Examples 1-5 are shown in Table 1.

[0086] Table 1 Comparison of main properties of several grades of Pt-Rh-W-Mo-Ir-Re alloys

[0087]

[0088] As can be seen from Table 1, for the same Pt-10Rh-5W-4Mo-4Ir-0.5Re alloy, the key indicators of ultrafine wires obtained by hot forging and surface refinement treatment are improved, such as room temperature tensile strength and room temperature resistivity. The properties of ultrafine wires prepared by hot forging and surface refinement treatment of the other three alloys Pt-10Rh-8W-6Mo-6Ir-0.5Re, Pt-15Rh-10W-8Mo-6Ir-0.5Re, and Pt-20Rh-10W-8Mo-7Ir-2Re all meet the room temperature tensile strength ≥ 1750MPa, room temperature resistivity ≥ 72μΩ·cm, and room temperature sensitivity coefficient: K ≥ 2.5.

Claims

1. A method for preparing a high-temperature platinum-based high-entropy resistive strain material, characterized in that: The following steps are involved: Step 1, raw material ingredients: by mass percentage, the content of each element is: rhodium 5%~20%, tungsten 5%~10%, molybdenum 2%~10%, iridium 1%~7%, rhenium 0%~5%, and platinum as the balance; Step 2, master alloy: using a vacuum high-frequency induction furnace and a magnesium oxide crucible to melt the high-melting-point W element and Pt into a master alloy; Step 3, smelting: other elements are added according to the composition design, and the alloy is refined for 10 minutes by using a vacuum high-frequency induction furnace and a magnesium oxide crucible filled with inert gas. To ensure the uniformity of the composition, at least one turn-around smelting is performed, and a water-cooled copper mold crucible is used for casting to obtain a cylindrical ingot with a diameter of φ8~15mm; Step 4, annealing: ingot at 800~1000℃, vacuum degree ≤3×10 -2 Stress relief annealing is carried out in a vacuum environment of 1.5 Pa; Step 5, hot forging: the ingot is forged at a high temperature of 1100-1400°C to obtain a rod with a diameter of φ6 mm; Step 6, surface grain refinement: using the skin effect of high-frequency induction coil heating, the hot forged rod is quickly heated, and after the surface temperature reaches 1300-1500°C, it is rapidly cooled with an ice-water mixed solution to obtain a rod with a surface grain refinement area; Step 7: Processing into ultra-fine wire or strip.

2. The preparation method according to claim 1, characterized in that: The step 7 specifically includes: Step 7.1, the surface refined bar is subjected to hot drawing rough drawing at a temperature of 700-900° C. under the protection of reducing hydrogen; the deformation amount of a single hot forging pass is controlled to be ≤5%, the ingot is processed into a bar with a diameter of φ6 mm, and the deformation amount of a single hot drawing pass is controlled to be ≤5%, and a wire with a diameter of φ1 mm is obtained; Step 7.2, subjecting the wire to an intermediate heat treatment at 750-950° C.; Step 7.3, adopting the "intermediate heat treatment-cold drawing" cycle and rolling process to obtain the ultra-fine wire or strip of finished size; Step 7.4, performing a heat treatment for property regulation on the finished ultrafine wire or strip in a hydrogen-argon protective atmosphere.

3. The preparation method according to claim 1, characterized in that: In step 3, the high frequency induction furnace is first evacuated to a vacuum degree of ≤5×10 -2 Pa, and then filled with argon gas with a vol% purity of 99.999% to 0.05MPa.

4. The preparation method according to claim 2, characterized in that: In step 7.1: The hot drawing adopts high-frequency induction coil heating, the induction coil length is 20cm, the power is 20~40KW, to ensure uniform heating; During the hot drawing process, the hot drawing die needs to be heated to 700-800° C., graphite lubrication is used, and the processed rod and the die are continuously heated by a hydrogen-oxygen reducing flame.

5. The preparation method according to claim 2, characterized in that: In step 7.2: The intermediate heat treatment is protected by reducing hydrogen.

6. The preparation method according to claim 2, characterized in that: In step 7.3, the deformation of a single cold drawing pass is controlled to be ≤3% until the ultra-fine wire or strip is obtained in the finished product size.

7. The preparation method according to claim 2, characterized in that: In step 7.4, the finished product performance control heat treatment process is 780-850°C continuous annealing.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The purity of each raw material in step 1 is wt.%≥99.

95.

9. The preparation method according to any one of claims 1 to 7, characterized in that: The diameter of the ultrafine wire is φ0.03-0.05 mm, and the size of the strip is 0.05×0.3 mm.

10. Use of a high-temperature platinum-based high-entropy resistive strain material prepared by the preparation method according to any one of claims 1 to 9 in preparing a high-temperature dynamic strain gauge for an aircraft engine.

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