A high-entropy alloy with good processing performance and mechanical performance and a preparation method thereof

Abstract

The application relates to a high-entropy alloy with good processing performance and mechanical performance and a preparation method thereof, and comprises the following steps: ingredient preparation: preparing high-entropy alloy atom percentage molten materials; master alloy smelting: smelting is carried out by using an ultrasonic vibration auxiliary vacuum non-consumable arc furnace or an ultrasonic vibration auxiliary electromagnetic cold crucible suspension furnace; pre-rolling heat treatment: annealing heat treatment is carried out in a heat treatment furnace, the alloy is cooled to room temperature in the furnace and taken out; hot rolling: hot rolling is carried out through double roller shaft rolling; post-rolling heat treatment: annealing heat treatment is carried out in a heat treatment furnace; preparation completion: after the alloy is cooled in the furnace, the ultrasonic vibration auxiliary vacuum non-consumable arc furnace smelting or the ultrasonic vibration auxiliary electromagnetic cold crucible suspension smelting device is closed, and the preparation is completed; the preparation method of the patent can not only ensure low alloy cost, but also develop the high-entropy alloy with good processing performance and mechanical performance, and lays a foundation for engineering application.

Description

Technical Field

[0001] This invention relates to the field of high-entropy alloys and their preparation technology, and in particular to a high-entropy alloy with both good processing performance and mechanical properties, and its preparation method. Background Technology

[0002] High-entropy alloys are metallic materials that combine good processing performance and mechanical properties. Currently, high-entropy alloys have had a significant impact on the field of metallic materials, replacing traditional alloys and attracting great attention. This is of great importance for improving the engineering application of high-entropy alloys.

[0003] High strength and high plasticity are significant characteristics of high-entropy alloys. Achieving both high plasticity and ease of machining, along with high strength, is a challenge in the engineering applications of high-entropy alloys. Hot-rolled high-entropy alloys can achieve machinability and can also induce dynamic recrystallization to refine the microstructure, significantly impacting the alloy's structure. For example, in the hot-rolled CoCrNi medium-entropy alloy, the plasticity increases from 40% to 70%, while the strength decreases from 778 MPa to 549 MPa, exhibiting poor plasticity but high strength. In contrast, the AlCrFeNiCu high-entropy alloy, annealed after hot rolling, shows a deformation of only about 20%, with a maximum fracture toughness of only 171.39 MPa·m. 1 / 2 The low Al content results in poor plasticity and difficulty in processing; for hot-rolled CoCrFeMn high-entropy alloys, the strength decreases significantly from 559 MPa to 467 MPa; for Al... 0.5 Cu 1.25 CoFeNi 1.25 High-entropy alloys, when rolled, can only achieve a maximum alloy composition of 40%, with a hardness value reaching a maximum of only 280 MPa; Al 0.25 The CrFeNiCu high-entropy alloy not only does not show significant strengthening after annealing and rolling, but its ductility is also significantly reduced.

[0004] Current technologies for melting high-entropy alloys using vacuum non-consumable arc furnaces typically produce small ingots weighing a few hundred grams, making them unsuitable for large-scale industrial production. These ingots often exhibit surface oxidation and contain large particles of impurities. While vacuum induction magnetic levitation melting can achieve the melting of kilogram-sized ingots, casting defects such as bubbles, shrinkage cavities, and porosity still exist, significantly reducing the utilization rate of high-entropy alloy ingots and increasing production costs. How to effectively avoid casting defects such as bubbles and shrinkage cavities while ensuring low production costs and uniform melting, and obtain large-sized high-entropy alloy ingots with uniform composition and no casting defects, has become one of the core bottlenecks restricting the widespread application of high-entropy alloys. In summary, existing technologies have gaps in addressing this problem, severely limiting the practical production and application of this alloy. There is an urgent need to develop a high-entropy alloy that combines good machinability and mechanical properties. Summary of the Invention

[0005] Purpose of the invention This invention provides a high-entropy alloy with both good processing and mechanical properties and its preparation method, using low-cost pure metals; at the same time, it can avoid defects generated during melting, providing assurance for subsequent processing and analysis.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high-entropy alloy possessing both good machinability and mechanical properties, the atomic formula of its alloying elements is: Al x CrFeNiCu 1.5， Where 0 ≤ x ≤ 5.

[0007] As a further description of the above scheme, the Al x CrFeNiCu 1.5 The high-entropy alloy has a dendritic structure, in which Cu is enriched between the dendrites of the alloy to bind the dendrites together.

[0008] A method for preparing the above-mentioned high-entropy alloy with both good processing performance and mechanical properties includes the following steps: Step 1, Ingredient Preparation: High-entropy alloy Al, which possesses both good machinability and mechanical properties. x CrFeNiCu 1.5 The alloy composition consists of Al, Cr, Fe, Ni, and Cu elements, among which Al x CrFeNiCu 1.5 The alloy has a VEC value greater than 8, with Al accounting for 0.01 at.%-32.5 at.%, Cr accounting for 15 at.%-22.22 at.%, Fe accounting for 15 at.%-22.22 at.%, Ni accounting for 15 at.%-22.22 at.%, and Cu accounting for 22.5 at.%-33.33 at.%, and the total percentage of the above elements is 100 at.%. The metal raw materials of Al, Cr, Fe, Ni and Cu are weighed according to the composition ratio, and an additional 1wt.%-5wt.% of Al is added to the above metal raw materials as burn-off. Step 2, Master alloy melting: The materials prepared in Step 1 are melted using a vacuum non-consumable arc furnace or an electromagnetic cold crucible suspension furnace; When the dimensions of the long strip billets cut by wire cutting are less than 15mm in length, less than 3mm in width, and less than 3mm in height, a vacuum non-consumable arc furnace is used to melt the material prepared in step 1. The material prepared in step 1 is placed in one of the circular melting tanks of the vacuum non-consumable arc furnace. At the same time, Zr or Ti pure metal is placed in another circular melting tank to absorb residual oxygen. An ultrasonic vibration probe is inserted into the vacuum non-consumable arc furnace and connected to the bottom of the crucible. Then, vacuuming and argon filling are performed. Turn on the power switch of the vacuum non-consumable arc furnace, adjust the tungsten electrode height, turn on the start / stop power handle, and start the arc with the melting current. First, melt the Zr ingot or pure Ti ingot in the circular melting tank, then melt the material prepared in step one until it is completely melted, and use ultrasonic vibration assistance. Add stirring current to melt it into button ingots; put the button ingots into the long strip melting tank to melt them into long strip billets; turn off the stirring current, ultrasonic vibration assistance, and the power switch of the vacuum non-consumable arc furnace; use wire cutting to cut the long strip billets to obtain the required samples; When the length of the long strip billet cut by wire cutting is 15-200mm, the width is 3-80mm, and the height is 3-80mm, an electromagnetic cold crucible levitation furnace is used for melting. First, the ultrasonic vibration probe is inserted into the electromagnetic cold crucible levitation furnace. Then, the material prepared in step one is melted under argon conditions until it is completely melted. Ultrasonic vibration is assisted by a lifting drive mechanism to insert the ultrasonic transducer into the molten metal. The vibration of the ultrasonic transducer is transmitted to the vibrating plate. The drive coil is wound with iron-gallium alloy to form a vibrator. Current is applied to generate strain and vibration. The double vibration assists in melting into a uniform master alloy ingot. Before the melting is completed, the vibrating rod and ultrasonic vibration probe are raised by the lifting drive mechanism, the power is turned off, and the ingot is cooled and removed. Step 3, pre-rolling heat treatment: The surface of the long strip billet finally prepared in step 2 is uniformly coated with high-temperature coating, and then placed in a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace, and the prepared product is taken out after cooling. Step 4, Hot Rolling: The long strip billet after the annealing heat treatment in Step 3 is placed in a heat treatment furnace for annealing heat treatment, and then hot rolled by twin-roll milling. After hot rolling, the alloy is completely air-cooled and the rolling preparation device is turned off. Step 5: Heat treatment after rolling: Place the hot-rolled alloy from Step 4 into a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace and then removed after cooling.

[0009] As a further description of the above scheme, in step 1, Al, Cr, Fe, Ni and Cu are added in the form of pure metals with a purity of ≥99.9wt.%, wherein the pure metal particles of Al, Cr, Fe, Ni and Cu are all <50mm in diameter.

[0010] As a further description of the above scheme, in step 2, when using a vacuum non-consumable arc furnace for melting, pure Zr or Ti metal with a purity ≥99.9wt.% is placed in another circular melting tank, and then argon gas is introduced. Once the pressure reaches ≥5Pa, the argon cylinder valve is closed. The furnace is then repeatedly cleaned 1-5 times, followed by evacuation and argon gas refilling until the vacuum gauge resistance drops to 0.5*10. 1 ~1.0*10 1 After that, open the pre-valve and wait for the vacuum resistance unit to drop to 3.0*10. 0 ~5.0*10 0 After that, turn on the molecular pump power and wait for the vacuum gauge ionization unit to drop to 7*10. -4 ~9*10 -4 After that, keep it closed for 5 minutes. When filling with gas, keep the argon pressure at 200Pa-500Pa. Adjust the height of the tungsten electrode to 1-5mm from the top surface of the material to be melted. Start the arc with a melting current of 70A-100A. Melt with a melting current of 300A-700A until the prepared material is completely melted. Add a stirring current of 10A-20A. Each button ingot needs to be melted 4-8 times. Then perform wire cutting.

[0011] As a further description of the above scheme, when using an electromagnetic cold crucible levitation furnace for melting in step 2, the melting is carried out at an argon pressure of 200Pa-500Pa, the melting temperature is 1200℃-1800℃, and the temperature is maintained for 5min-15min to melt into a master alloy ingot, which is then wire-cut; the ultrasonic vibration assists the vibration at a frequency of 60kHz-80kHz, and the displacement amplitude of the ultrasonic vibration is 30μm.

[0012] As a further description of the above scheme, the high-temperature coating in step 3 is ZS-1 high-temperature coating. After applying the high-temperature coating, it is left to stand for 30-60 minutes. The annealing heat treatment is carried out at a rate of 5-10℃ / min to raise the temperature to 700℃-1200℃ and hold it for 1-5 hours. In step 4, after being placed in the heat treatment furnace, the temperature is raised to 700℃-1200℃ at a rate of 5-10℃ / min and held for 5-25 minutes. The twin-roll rolling device controls the reduction per pass to 5%-20%, the rolling speed to 20mm / s-50mm / s, and 3-6 passes. After each pass, the alloy temperature must reach 700℃-1200℃ and be held for 5-25 minutes before the next rolling. In step 5, the annealing heat treatment is carried out at a rate of 5-10℃ / min to raise the temperature to 700℃-1200℃ and hold it for 5-25 minutes.

[0013] As a further description of the above solution, the electromagnetic cold crucible levitation furnace in step 3 includes a furnace body, a vibration transmission mechanism, an ultrasonic vibration mechanism, and a lifting drive mechanism. The ultrasonic transducer extends into the furnace from the furnace cover; the lifting drive mechanism is connected to the ultrasonic vibration mechanism and the vibration transmission mechanism via a connecting component; the vibration transmission mechanism is abutted against the bottom of the ultrasonic vibration mechanism.

[0014] As a further description of the above solution, the top of the furnace body is provided with an ultrasonic transducer inlet channel and a conduction mechanism inlet channel, and flexible rubber sealing rings are provided in both the ultrasonic transducer inlet channel and the conduction mechanism inlet channel. The ultrasonic vibration mechanism includes an ultrasonic transducer and an ultrasonic generator. The ultrasonic transducer is electrically connected to the ultrasonic generator, and the ultrasonic transducer extends into the furnace through the ultrasonic transducer inlet channel. An ultrasonic transducer connection part is provided on the upper part of the ultrasonic transducer. The lifting drive mechanism includes a lifting cylinder, a slider, and a slide rail. The slide rail is fixedly installed in the vertical direction, and a slide groove matching the slider is opened on the slide rail. The slider is slidably installed on the slide groove. The lifting cylinder is installed below the slider, and the lifting end of the lifting cylinder is fixedly connected to the lower end of the slider. The connecting assembly includes a locking bolt and a bracket. One end of the bracket is disposed on the slider, and the bracket is provided with a first mounting slot and a second mounting slot. The first mounting slot is fixedly connected to the connecting part of the ultrasonic transducer by the locking bolt. The vibration transmission mechanism includes a ceramic sleeve, a vibrating plate, a vertical connecting rod, and a vibrating part. Multiple vibrating parts are provided, and multiple vibrating parts are fixedly installed at the bottom of the vibrating plate. One end of the vertical connecting rod is threadedly fixedly connected to the top of the vibrating plate, and the other end of the vertical connecting rod passes through the transmission mechanism and enters the channel to extend to the outside of the furnace body. A snap-fit ​​part is fixedly provided on one side of the vertical connecting rod outside the furnace body, and the snap-fit ​​part is fixedly connected to the second mounting slot by a locking bolt. The vibrating plate is positioned below the ultrasonic transducer, and the top surface of the vibrating plate is in contact with the ultrasonic transducer. The vibrating part includes a magnetic yoke, a drive coil, cyclic toughness SUMITEN 950-TMCP steel, and an iron-gallium alloy. The magnetic yoke is threaded to the bottom of the vibrating plate, the iron-gallium alloy is fixedly disposed at the lower end of the magnetic yoke, the drive coil is wound around the iron-gallium alloy, and one end of the drive coil extends into the interior of the vertical connecting rod and extends outward to be electrically connected to an external power source; the cyclic toughness SUMITEN 950-TMCP steel is spaced between the ceramic sleeve and the drive coil. The ceramic sleeve is wrapped around the vibrating plate, the vertical connecting rod, the vibrating part, and the ultrasonic transducer. The length of the ceramic sleeve wrapped around the vertical connecting rod is 1 / 3 to 1 / 4 of the total length of the vertical connecting rod. The length of the ceramic sleeve wrapped around the ultrasonic transducer is 1 / 3 to 1 / 4 of the total length of the ultrasonic transducer. The ceramic sleeve is fixed to the vertical connecting rod by a chemical adhesive.

[0015] Advantages and effects This invention employs an ultrasonic vibration-assisted vacuum non-consumable arc furnace or an ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace to melt a master alloy and prepare Al. x CrFeNiCu 1.5 It is a high-entropy alloy, which does not contain precious metals or rare elements, significantly reducing costs and meeting the demand for large-sized high-entropy alloy ingots with uniform composition and no casting defects.

[0016] In this invention, pure metal particles of Al, Cr, Fe, Ni, and Cu with diameters of <50mm are selected during the batching process to improve weighing accuracy, thereby ensuring the accuracy of the high-entropy alloy composition and ensuring that the composition of the prepared high-entropy alloy ingot meets the design requirements.

[0017] This invention is composed of multiple elements. In order to ensure uniform alloy melting, an ultrasonic vibration-assisted electromagnetic cold crucible suspension furnace is selected to melt the master alloy to prepare a high-entropy alloy.

[0018] This invention employs twin-roll hot rolling, which significantly reduces energy consumption and costs, improves the machinability of metals and alloys, promotes crack healing, reduces or eliminates casting defects, transforms as-cast structures into deformed structures, and enhances the machinability of alloys. Hot rolling typically utilizes large ingots and large reductions, which not only improves production efficiency but also increases rolling speed. High-temperature rolling avoids the fatal damage to the mechanical properties of alloy workpieces caused by unfavorable coarse grains, thereby improving the stability of the alloy's mechanical properties.

[0019] In this invention, the AlxCrFeNiCu1.5 alloy has a valence electron concentration greater than 8, indicating it is an fcc phase, making it easy to process. The single face-centered cubic (FCC) high-entropy alloy exhibits good plasticity and ductility, but poor strength and hardness. Many researchers have only used non-consumable arc furnaces for melting high-entropy alloys, but the results are generally limited, and it cannot achieve low-cost alloy processing applications. Therefore, the ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace has emerged. Its research significance lies in minimizing defects and improving the alloy's strength, hardness, and other mechanical properties while ensuring machinability. This allows the high-entropy alloy to form a simple and stable solid solution structure, possessing both machinability and mechanical properties. The defect-free uniform ingot obtained by this invention has a measured hardness of 380-450 HV and a yield strength of 800-1000 MPa.

[0020] The high-entropy alloy ingots prepared by the method of this invention have uniform composition, effectively avoiding casting defects such as lack of bubbles, shrinkage cavities, and porosity in large-size high-entropy alloy ingots, and realizing low-cost industrial-grade alloy preparation.

[0021] Existing technology involves vibrating an ultrasonic transducer by inserting it into a solution. However, the equipment used in the ultrasonic vibration-assisted electromagnetic cold crucible suspension melting technology of this invention uses a lifting cylinder to pass the lower end of the ultrasonic transducer 1 through the furnace cover 2 and press it against the vibrating plate 5. This allows the vibration of the ultrasonic transducer 1 to be transmitted to the vibrating plate 5, and the lower end of the ultrasonic transducer 1 penetrates into the molten material. At this time, the circular vibrating plate 5 and the ultrasonic transducer 1 vibrate together. The vibrating plate is connected to the vibrating rod connector 4, which is fixed and buffered by a flexible rubber ring. The vibrating rod connector 4 passes through the vibrating plate 5 and connects... The magnetic yoke 7 is connected to an iron-gallium alloy 8 at its lower end. A drive coil 9 is wound around the iron-gallium alloy 8. The magnetic yoke, iron-gallium alloy, and drive coil together form a vibrator, which vibrates by generating mechanical energy through strain. The lower end of the vibrator extends into the molten material that will be poured into the water-cooled crucible. The drive coil is connected by a wire that passes through the inside of the vibrating rod connector to connect to the power supply. A water-cooled crucible is located inside the housing, and a water-cooled coil is located around the perimeter of the water-cooled crucible. A ceramic sleeve encloses the ultrasonic transducer, vibrating rod connector, vibrating plate, and vibrator. The drive coil is supported by cyclic toughness SUMITEN 950-TMCP steel (main component: CrNiMnMo). SUMITEN 950-TMCP steel (main component: CrNiMnMo) has good vibration resistance, low toughness, and is not easily deformed. The ceramic sleeve effectively avoids material loss, resulting in a more uniform composition of the molten ingot under dual vibration. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace structure of the present invention; Figure 2 This is a top view of the housing and internal structure of the ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace of the present invention. Figure 3 This is a structural diagram of the vibrator of the ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace of the present invention; Figure 4 This is a top view of the connecting components of the ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace of the present invention. Figure 5 Al is an embodiment of the present invention x CrFeNiCu 1.5 Fracture toughness diagram of high-entropy alloy.

[0023] Explanation of reference numerals in the attached figures: 1. Ultrasonic transducer; 2. Furnace cover; 3. Furnace wall; 4. Vertical connecting rod; 5. Vibrating plate; 6. Slider; 7. Magnetic yoke; 8. Iron-gallium alloy; 9. Drive coil; 10. Water-cooled coil; 11. Flexible rubber sealing ring; 12. Wire; 13. Alloy melt; 14. Power supply; 15. Water-cooled crucible; 16. Ceramic sleeve; 17. Nut; 18. Cyclic toughness SUMITEN 950-TMCP steel; 19. Slide rail; 20. Locking wing nut; 21. Bolt; 22. Lifting cylinder. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0027] like Figure 1-4 As shown, the present invention provides the following technical solution: A high-entropy alloy possessing both good machinability and mechanical properties, the atomic formula of its alloying elements is: Al x CrFeNiCu 1.5， Where 0 ≤ x ≤ 5.

[0028] The Al of the present invention x CrFeNiCu 1.5 High-entropy alloys have a dendritic structure, a high melting point, and high hardness. The hardness increases with the increase of the atomic radius of the added elements. Al can change the structural composition of the alloy, and Cu enriched between the dendrites of the alloy acts as a binder, reducing the brittleness of the alloy and preventing the alloy from cooling and breaking. It is essential.

[0029] A method for preparing the above-mentioned high-entropy alloy with both good processing performance and mechanical properties includes the following steps: Step 1, Ingredient Preparation: High-entropy alloy Al with good machinability x CrFeNiCu 1.5The alloy composition consists of Al, Cr, Fe, Ni, and Cu elements, among which Al x CrFeNiCu 1.5 The alloy has a VEC value greater than 8, with Al accounting for 0.01 at.%-32.5 at.%, Cr accounting for 15 at.%-22.22 at.%, Fe accounting for 15 at.%-22.22 at.%, Ni accounting for 15 at.%-22.22 at.%, and Cu accounting for 22.5 at.%-33.33 at.%, and the total percentage of the above elements is 100 at.%. The metal raw materials of Al, Cr, Fe, Ni and Cu are weighed according to the composition ratio, and an additional 1wt.%-5wt.% of Al is added to the above metal raw materials as burn-off. Step 2, Master alloy melting: The materials prepared in Step 1 are melted using a vacuum non-consumable arc furnace or an electromagnetic cold crucible suspension furnace; When the dimensions of the long strip billets cut by wire cutting are less than 15mm in length, less than 3mm in width, and less than 3mm in height, a vacuum non-consumable arc furnace is used to melt the material prepared in step 1. The material prepared in step 1 is placed in one of the circular melting tanks of the vacuum non-consumable arc furnace. At the same time, Zr or Ti pure metal is placed in another circular melting tank to absorb residual oxygen. An ultrasonic vibration probe is inserted into the vacuum non-consumable arc furnace and connected to the bottom of the crucible. Then, vacuuming and argon filling are performed. Turn on the power switch of the vacuum non-consumable arc furnace, adjust the tungsten electrode height, turn on the start / stop power handle, and start the arc with the melting current. First, melt the Zr ingot or pure Ti ingot in the circular melting tank, then melt the material prepared in step one until it is completely melted, and use ultrasonic vibration assistance. Add stirring current to melt it into button ingots; put the button ingots into the long strip melting tank to melt them into long strip billets; turn off the stirring current, ultrasonic vibration assistance, and the power switch of the vacuum non-consumable arc furnace; use wire cutting to cut the long strip billets to obtain the required samples; When the length of the long strip billet cut by wire cutting is 15-200mm, the width is 3-80mm, and the height is 3-80mm, an electromagnetic cold crucible levitation furnace is used for melting. First, the ultrasonic vibration probe is inserted into the electromagnetic cold crucible levitation furnace. Then, the material prepared in step one is melted under argon conditions until it is completely melted. Ultrasonic vibration is assisted by a lifting drive mechanism to insert the ultrasonic transducer into the molten metal. The vibration of the ultrasonic transducer is transmitted to the vibrating plate. The drive coil is wound with iron-gallium alloy to form a vibrator. Current is applied to generate strain and vibration. The double vibration assists in melting into a uniform master alloy ingot. Before the melting is completed, the vibrating rod and ultrasonic vibration probe are raised by the lifting drive mechanism, the power is turned off, and the ingot is cooled and removed. Step 3, pre-rolling heat treatment: The surface of the long strip billet finally prepared in step 2 is uniformly coated with high-temperature coating, and then placed in a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace, and the prepared product is taken out after cooling. Step 4, Hot Rolling: The long strip billet after the annealing heat treatment in Step 3 is placed in a heat treatment furnace for annealing heat treatment, and then hot rolled by twin-roll milling. After hot rolling, the alloy is completely air-cooled and the rolling preparation device is turned off. The long strip billet hot rolled in Step 4 is composed of multiple elements. In order to ensure uniform alloy melting, an ultrasonic vibration-assisted electromagnetic cold crucible suspension furnace is selected to melt the master alloy to prepare a high-entropy alloy. Step 5: Post-rolling heat treatment: The hot-rolled alloy from Step 4 is placed in a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature in the furnace and then removed after cooling. This invention uses an ultrasonic vibration-assisted vacuum non-consumable arc furnace or an ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace to melt the master alloy to prepare Al. x CrFeNiCu 1.5 This invention relates to a high-entropy alloy, which contains no precious metals or rare elements, significantly reducing costs and meeting the demand for large-sized, high-entropy alloy ingots with uniform composition and free from casting defects. Secondly, the invention employs twin-roll hot rolling, which significantly reduces energy consumption and costs, improves the machinability of metals and alloys, promotes crack healing, reduces or eliminates casting defects, transforms the as-cast structure into a deformed structure, and enhances the alloy's machinability. Hot rolling typically utilizes large ingots and large reductions, which not only improves production efficiency but also increases rolling speed. High-temperature rolling avoids the fatal damage to the mechanical properties of alloy workpieces caused by unfavorable coarse grains, thereby improving the stability of the alloy's mechanical properties. Secondly, the high-entropy alloy ingots prepared by the method of this invention have uniform composition, effectively avoiding casting defects such as bubbles, shrinkage cavities, and porosity in large-size high-entropy alloy ingots, and realizing the preparation of low-cost industrial-grade alloys. In addition, the AlxCrFeNiCu1.5 alloy of this invention has a VEC value greater than 8, which is an fcc phase that is easy to machine. The single face-centered cubic (FCC) phase high-entropy alloy has good plasticity and ductility, but poor strength and hardness. Many scholars have only used non-consumable arc furnaces to melt high-entropy alloys. However, the effect is generally poor, and it cannot realize the application of low-cost alloys in processing. Therefore, ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace has emerged. Its research significance lies in minimizing defects and improving the strength, hardness, and other mechanical properties of the alloy while ensuring that the alloy is machinable. This invention enables the high-entropy alloy to form a simple and stable solid solution structure while possessing both machinability and mechanical properties. The defect-free uniform ingot obtained by this invention has a measured hardness of 380-450 HV and a yield strength of 800-1000 MPa.

[0030] In step 1 of this invention, Al, Cr, Fe, Ni, and Cu are added in the form of pure metals with a purity ≥ 99.9 wt.%, wherein the pure metal particles of Al, Cr, Fe, Ni, and Cu are all < 50 mm in diameter. Compared with the prior art, the use of smaller pure metal particles maximizes purity. At the same time, it can improve weighing accuracy, thereby ensuring the accuracy of the high-entropy alloy composition and making the composition of the prepared high-entropy alloy ingot meet the design requirements.

[0031] In step 2 of this invention, when using a vacuum non-consumable arc furnace for melting, pure Zr or Ti metal with a purity ≥99.9wt.% is placed in another circular melting tank, and then argon gas is introduced. Once the pressure reaches ≥5Pa, the argon cylinder valve is closed. The furnace is then repeatedly cleaned 1-5 times, followed by evacuation and argon gas refilling. The vacuum gauge resistance unit drops to 0.5*10⁻⁶. 1 -1.0*10 1 After that, open the pre-valve and wait for the vacuum resistance unit to drop to 3.0*10. 0 -5.0*10 0 After that, turn on the molecular pump power and wait for the vacuum gauge ionization unit to drop to 7*10. -4 -9*10 -4 After the following steps, keep the gas supply closed for 5 minutes. During argon filling, maintain the argon pressure at 200Pa-500Pa. Adjust the tungsten electrode height to 1-5mm above the top surface of the material to be melted. Initiate the arc with a melting current of 70A-100A, and then melt with a melting current of 300A-700A until the prepared material is completely melted. Add a stirring current of 10A-20A. Each button ingot needs to be melted 4-8 times, and then wire cut. Compared with existing technologies, adding pure metal absorbs residual oxygen, preventing the alloy ingot from oxidizing. The increased number of melting cycles results in an alloy with a uniform composition and structure, and prevents cracks due to defects during rolling.

[0032] In step 2 of this invention, when melting is carried out using an electromagnetic cold crucible levitation furnace, the melting is performed at an argon pressure of 200Pa-500Pa and a melting temperature of 1200℃-1800℃, which is maintained for 5min-15min to produce a master alloy ingot, which is then wire-cut. The ultrasonic vibration assists the melting with a frequency of 60kHz-80kHz and a displacement amplitude of 30μm. Compared with the prior art, there is a gap in the ultrasonic vibration-assisted electromagnetic cold crucible levitation furnace for melting high-entropy alloys. This allows for the production of larger alloy ingots for large-scale industrial production or wire cutting to multiple desired sizes for processing, thereby improving the engineering efficiency of high-entropy alloys.

[0033] In step 3 of this invention, after the surface is coated with a high-temperature coating, it is left to stand for 30-60 minutes. The annealing heat treatment is carried out at a rate of 5-10℃ / min to 700℃-1200℃ and held for 1-5 hours. Compared with the prior art, the surface is more resistant to oxidation after the high-temperature coating is applied, and the annealing makes the structure more uniform.

[0034] In step 4 of this invention, after being placed in a heat treatment furnace, the temperature is raised to 700℃-1200℃ at a rate of 5-10℃ / min and held for 5min-25min. The twin-roll rolling process involves hot rolling with a reduction of 5%-20% per pass, a rolling speed of 20mm / s-50mm / s, and 3-6 passes. After each pass, the alloy temperature must reach 700℃-1200℃ and be held for 5min-25min before the next rolling pass. Compared with existing technologies, high-temperature rolling is more effective in healing cracks, reducing or eliminating casting defects, transforming the as-cast structure into a deformed structure, and improving the alloy's machinability.

[0035] In step 5 of this invention, the annealing heat treatment is heated to 700℃-1200℃ at a rate of 5-10℃ / min and held for 5min-25min. Compared with the prior art, rolling annealing is performed to make the microstructure more uniform.

[0036] The electromagnetic cold crucible levitation furnace of the present invention includes a furnace body, a vibration transmission mechanism, an ultrasonic vibration mechanism, and a lifting drive mechanism, wherein the ultrasonic transducer extends into the furnace through the furnace cover; wherein the lifting drive mechanism is driven to connect with the ultrasonic vibration mechanism and the vibration transmission mechanism through a connecting component; wherein the vibration transmission mechanism is in contact with the bottom of the ultrasonic vibration mechanism. An ultrasonic transducer inlet channel and a transmission mechanism inlet channel are provided at the top of the furnace body, and flexible rubber sealing rings 11 are provided in both the ultrasonic transducer inlet channel and the transmission mechanism inlet channel. The ultrasonic vibration mechanism includes an ultrasonic transducer 1 and an ultrasonic generator. The ultrasonic transducer 1 is electrically connected to the ultrasonic generator, and the ultrasonic transducer 1 extends into the furnace through the ultrasonic transducer inlet channel. An ultrasonic transducer connection part is provided on the upper part of the ultrasonic transducer 1. The lifting drive mechanism is fixed on the operating platform, and the electromagnetic cold crucible levitation furnace is placed on the operating platform. The lifting drive mechanism includes a lifting cylinder 22, a slider 6, and a slide rail 19. The slide rail 19 is fixedly arranged in the vertical direction, and a slide groove matching the slider 6 is opened on the slide rail 19. The slider 6 is slidably arranged on the slide groove. The lifting cylinder 22 is located below the slider 6, and the lifting end of the lifting cylinder 22 is fixedly connected to the lower end of the slider 6. like Figure 1 and Figure 4As shown, the connecting assembly includes a locking bolt 20 and a bracket. One end of the bracket is mounted on the slider 6, and the bracket has a first mounting slot and a second mounting slot. The first mounting slot is fixedly connected to the ultrasonic transducer 1 via the locking bolt 20. Specifically, the locking bolt 20 is a wing bolt. The bracket includes a first bracket and a second bracket, which are rotatably mounted on the slider 6. Multiple arc-shaped slots are correspondingly provided on both the first and second brackets, forming the first mounting slot and the second mounting slot. When the ultrasonic transducer 1 needs to be fixed, the first mounting slot is locked to the ultrasonic transducer 1 via the locking bolt 20. Similarly, the vertical connecting rod 4 can also be fixed. Specifically, the ultrasonic transducer connection is fixed to the ultrasonic transducer 1 with a chemical adhesive. Then, the ultrasonic transducer 1 is connected to the second mounting slot through the ultrasonic transducer connection. The ultrasonic transducer connection has an upper limit plate and a lower limit plate. The upper limit plate is in contact with the top surface of the first mounting slot, and the lower limit plate is in contact with the bottom surface of the first mounting slot.

[0037] The vibration transmission mechanism includes a ceramic sleeve 16, a vibrating plate 5, a vertical connecting rod 4, and multiple vibrating parts, which are fixedly installed at the bottom of the vibrating plate 5. One end of the vertical connecting rod 4 is threadedly connected to the top of the vibrating plate 5, and the other end of the vertical connecting rod 4 passes through the transmission mechanism and extends to the outside of the furnace body. A snap-fit ​​part is fixedly installed on one side of the vertical connecting rod 4 outside the furnace body. The snap-fit ​​part is fixedly connected to the second mounting slot by locking bolts 20. Specifically, the snap-fit ​​part is fixed to the vertical connecting rod 4 with chemical adhesive, and then the vertical connecting rod 4 is connected to the second mounting slot through the snap-fit ​​part. The snap-fit ​​part has an upper limit plate and a lower limit plate, wherein the upper limit plate abuts against the top surface of the second mounting slot, and the lower limit plate abuts against the bottom surface of the second mounting slot.

[0038] The vibrating plate 5 is located below the ultrasonic transducer 1, and the top surface of the vibrating plate 5 is in contact with the ultrasonic transducer 1. The vibrating part includes a magnetic yoke 7, a drive coil 9, a cyclic toughness SUMITEN 950-TMCP steel 18, and an iron-gallium alloy 8. The magnetic yoke 7 is threaded to the bottom of the vibrating plate 5. The iron-gallium alloy 8 is fixedly disposed at the lower end of the magnetic yoke 7. The drive coil 9 is wound around the iron-gallium alloy 8, and one end of the drive coil 9 extends into the vertical connecting rod 4 and extends outward to be electrically connected to an external power source. The cyclic toughness SUMITEN 950-TMCP steel 18 is spaced between the ceramic sleeve 16 and the drive coil 9. The ceramic sleeve 16 is wrapped around the vibrating plate 5, the vertical connecting rod 4, the vibrating part and the ultrasonic transducer 1. The length of the ceramic sleeve 16 wrapped around the vertical connecting rod 4 is 1 / 3 to 1 / 4 of the total length of the vertical connecting rod 4. The length of the ceramic sleeve 16 wrapped around the ultrasonic transducer 1 is 1 / 3 to 1 / 4 of the total length of the ultrasonic transducer 1. The ceramic sleeve 16 is fixed to the vertical connecting rod 4 by a chemical adhesive, specifically acrylic resin. Existing technology involves vibrating an ultrasonic transducer by inserting it into a solution. However, the equipment used in the ultrasonic vibration-assisted electromagnetic cold crucible suspension melting technology described in this invention uses a lifting drive mechanism to pass the lower end of the ultrasonic transducer 1 through the furnace cover 2 and press it against the vibrating plate 5. This allows the vibration of the ultrasonic transducer 1 to be transmitted to the vibrating plate 5, and the lower end of the ultrasonic transducer 1 penetrates into the molten material. At this time, the circular vibrating plate 5 and the ultrasonic transducer 1 vibrate together. The vibrating plate is connected to the vibrating rod connector 4, which is fixed and buffered by a flexible rubber ring. The vibrating rod connector 4 passes through the vibrating plate 5 and connects to the magnetic yoke. The lower end of the magnetic yoke 7 is... The iron-gallium alloy 8 is surrounded by a drive coil 9. The magnetic yoke 7, iron-gallium alloy 8, and drive coil 9 form a vibrator, which vibrates by generating mechanical energy through strain. The lower end of the vibrator extends into the molten material that is subsequently poured into the water-cooled crucible 15. The drive coil 9 is connected by a wire 12, which passes through the interior of the vertical connecting rod 4 to connect to an external power source. A water-cooled crucible 15 is located inside the furnace, and a water-cooled coil 10 is arranged around the perimeter of the water-cooled crucible 15. A ceramic sleeve encloses the ultrasonic transducer 1, the vertical connecting rod 4, the vibrating plate 5, and the vibrating part. The drive coil is supported by cyclic toughness SUMITEN 950-TMCP steel 18 (main component: CrNiMnMo). The cyclic toughness SUMITEN 950-TMCP steel 18 (main component: CrNiMnMo) material has good vibration properties, low toughness, and is not easily deformed. The ceramic sleeve effectively avoids material loss, and the composition of the molten ingot is more uniform under dual vibration.

[0039] Specifically, a water-cooled high-frequency induction coil is installed outside the furnace body. The lower end of the ultrasonic transducer 1 passes through the furnace cover and rests on the vibrating plate 5. The vibrating plate 5 is connected to the vibrating rod connector 4. The vibrating rod connector 4 passes through the vibrating plate 5 and connects to the magnetic yoke 7. The lower end of the magnetic yoke 7 is made of iron-gallium alloy 8. The driving coil 9 is wound around the iron-gallium alloy 8. The lower end of the vibrating part is to penetrate into the smelting material 13 that is subsequently poured into the water-cooled crucible 15. The driving coil 9 is connected by a wire 12. The wire 12 passes through the inside of the vibrating rod connector 4 and is connected to an external power supply 14. A water-cooled crucible 15 is installed inside the housing 3. A water-cooled coil 10 is arranged around the perimeter of the water-cooled crucible 15. A ceramic sleeve 16 wraps the vibrating rod connector 4, the vibrating plate 5, and the vibrating part. The driving coil 9 is supported by cyclic toughness SUMITEN 950-TMCP steel 18 (main components: CrNiMnMo).

[0040] Two examples are provided below. Example 1 uses conventional methods to prepare AlCrFeNiCu high-entropy alloys, while Example 2 uses the method of the present invention to prepare Al x CrFeNiCu 1.5 High-entropy alloy. Example 1 is used for comparison to demonstrate the advantages of the method of this patent in Example 2. Example

[0041] This embodiment uses conventional methods to prepare AlCrFeNiCu high-entropy alloys, including the following steps: Step 1, Ingredients: The high-entropy alloy metal raw materials with good processing performance and mechanical properties include Al, Cr, Fe, Ni and Cu. The Al, Cr, Fe, Ni and Cu are added in the form of pure metal with a purity of ≥99.9wt.%, wherein the pure metal particles of Cr, Fe, Ni and Cu are all <50mm in diameter.

[0042] In addition, 1 wt.%-5 wt.% of Al is added to the above-mentioned metal raw materials as burn-off; Step 2, Master Alloy Melting: When melting the material prepared in Step 1 using a vacuum non-consumable arc furnace, place the material prepared in Step 1 into one of the circular melting tanks in the vacuum non-consumable arc furnace, then evacuate and purge with argon; turn on the melting power switch of the vacuum non-consumable arc furnace, adjust the tungsten electrode height, turn on the handle to start and stop the power, and start the arc with the melting current to melt the material prepared in Step 1 until it is completely melted, melting it into a button ingot; place the button ingot into a long strip melting tank to melt it into a long strip billet; use wire cutting to cut the long strip billet to obtain the required sample.

[0043] Step 3, pre-rolling heat treatment: The long strip billet finally prepared in step 2 is placed in a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace. The prepared product is taken out after cooling. Step 4, Hot rolling: The long strip billet after the annealing heat treatment in step 3 is placed in a heat treatment furnace for annealing heat treatment, and then hot rolled by a twin-roll mill. After hot rolling, the alloy is completely air-cooled and the twin-roll mill is shut down. Step 5, post-rolling heat treatment: Place the hot-rolled alloy from step four into a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace and then removed after cooling.

[0044] The AlCrFeNiCu high-entropy alloy exhibits obvious cracks, which significantly affect its subsequent fracture toughness value. Example

[0045] Combination Figures 1-5 This embodiment describes the preparation of Al using the method of the present invention. x CrFeNiCu1.5 High-entropy alloys, comprising the following steps: Step 1, Batching: The raw materials for a high-entropy alloy, possessing both good processing and mechanical properties, include Al, Cr, Fe, Ni, and Cu. These Al, Cr, Fe, Ni, and Cu are added in pure metal form with a purity ≥ 99.9 wt.%, wherein the pure metal particles of Cr, Fe, Ni, and Cu are all < 50 mm in diameter. Step 2, Master Alloy Melting: The materials prepared in Step 1 are melted using a vacuum non-consumable arc furnace or an electromagnetic cold crucible levitation furnace. When using a vacuum non-consumable arc furnace to melt the material prepared in step 1, the material is placed in one of the circular melting tanks of the vacuum non-consumable arc furnace. Simultaneously, pure Zr or Ti metal is placed in another circular melting tank to absorb residual oxygen. An ultrasonic vibration probe is inserted into the vacuum non-consumable arc furnace and connected to the bottom of the crucible. Then, a vacuum is drawn and argon gas is added. The melting power switch of the vacuum non-consumable arc furnace is turned on, the tungsten electrode height is adjusted, and the power is turned on / off. The melting current initiates the arc. First, the Zr ingot or pure Ti ingot in the circular melting tank is melted, then the material prepared in step 1 is melted completely. Ultrasonic vibration is used as an aid, and a stirring current is added to melt it into a button ingot. The button ingot is then placed in a long strip melting tank to melt into a long strip-shaped billet. The stirring current, ultrasonic vibration aid, and vacuum non-consumable arc furnace melting power switch are turned off. The long strip-shaped billet is cut using wire cutting to obtain the desired sample.

[0046] When using an electromagnetic cold crucible levitation furnace for melting, the ultrasonic vibration probe is first inserted into the furnace. Then, the material prepared in step one is melted under argon conditions until completely melted, and ultrasonic vibration is assisted. The ultrasonic transducer is inserted into the molten metal through a lifting drive mechanism. The vibration of the ultrasonic transducer is transmitted to the vibrating plate, and the driving coil is wound with iron-gallium alloy to form a vibrator. Current is applied to generate strain and vibration. The dual vibration assists in melting into a uniform master alloy ingot. Before the melting is completed, the vibrating rod and ultrasonic vibration probe are raised through the lifting drive mechanism, the power is turned off, and the ingot is cooled and removed. The desired sample is obtained by wire cutting into long strips.

[0047] Step 3, pre-rolling heat treatment: The surface of the long strip billet finally prepared in step 2 is uniformly coated with high-temperature coating, and then placed in a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace, and the prepared product is taken out after cooling. Step 4, Hot rolling: The long strip billet after the annealing heat treatment in step 3 is placed in a heat treatment furnace for annealing heat treatment, and then hot rolled by a twin-roll mill. After hot rolling, the alloy is completely air-cooled and the twin-roll mill is shut down. Step 5, post-rolling heat treatment: Place the hot-rolled alloy from step four into a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace and then removed after cooling.

[0048] like Figure 5 As shown, the fracture toughness of the AlCrFeNiCu high-entropy alloy is demonstrated, with the compressive stress direction perpendicular to the rolling direction during the fracture toughness test. With the same holding time interval, the average fracture toughness is improved after the alloy microstructure is oriented, especially the stability of mechanical properties is significantly improved, with fracture toughness values ​​all reaching 150 MPa·mm. 1 / 2 about.

[0049] The ultrasonic generator used in the specific embodiments of the patent is the HDR-2000 model manufactured by Hangzhou Haoda Ultrasonic Equipment Co., Ltd.

[0050] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing a high-entropy alloy with both good machinability and mechanical properties, characterized in that, The alloy composition consists of Al, Cr, Fe, Ni and Cu elements, with Al accounting for 0.01 at.%-32.5 at.%, Cr accounting for 15 at.%-22.22 at.%, Fe accounting for 15 at.%-22.22 at.%, Ni accounting for 15 at.%-22.22 at.%, and Cu accounting for 22.5 at.%-33.33 at.%, and the total percentage of the above elements is 100 at.%. The high-entropy alloy has a valence electron concentration value greater than 8 and has good processing performance. The high-entropy alloy, which has both good processing performance and mechanical properties, has a dendritic structure, in which Cu is enriched between the dendrites of the alloy to bind the dendrites together. The preparation method includes the following steps: Step 1, Batching: Weigh the metal raw materials according to the alloy composition ratio, and add an additional 1wt.%-5wt.% Al to the above metal raw materials as burn-off; Step 2, Master alloy melting: The materials prepared in Step 1 are melted using a vacuum non-consumable arc furnace or an electromagnetic cold crucible suspension furnace; When the dimensions of the long strip billets cut by wire cutting are less than 15mm in length, less than 3mm in width, and less than 3mm in height, a vacuum non-consumable arc furnace is used to melt the material prepared in step 1. The material prepared in step 1 is placed in one of the circular melting tanks of the vacuum non-consumable arc furnace. At the same time, Zr or Ti pure metal is placed in another circular melting tank to absorb residual oxygen. An ultrasonic vibration probe is inserted into the vacuum non-consumable arc furnace and connected to the bottom of the crucible. Then, vacuuming and argon filling are performed. Turn on the power switch of the vacuum non-consumable arc furnace, adjust the tungsten electrode height, turn on the start / stop power handle, and start the arc with the melting current. First, melt the Zr ingot or pure Ti ingot in the circular melting tank, then melt the material prepared in step one until it is completely melted, and use ultrasonic vibration assistance. Add stirring current to melt it into button ingots; put the button ingots into the long strip melting tank to melt them into long strip billets; turn off the stirring current, ultrasonic vibration assistance, and the power switch of the vacuum non-consumable arc furnace; use wire cutting to cut the long strip billets to obtain the required samples; When the length of the long strip billet cut by wire cutting is 15-200mm, the width is 3-80mm, and the height is 3-80mm, an electromagnetic cold crucible levitation furnace is used for melting. First, the ultrasonic vibration probe is inserted into the electromagnetic cold crucible levitation furnace. Then, the material prepared in step one is melted under argon conditions until it is completely melted. Ultrasonic vibration is assisted by a lifting drive mechanism to insert the ultrasonic transducer into the molten metal. The vibration of the ultrasonic transducer is transmitted to the vibrating plate. The drive coil is wound with iron-gallium alloy to form a vibrator. Current is applied to generate strain and vibration. The double vibration assists in melting into a uniform master alloy ingot. Before the melting is completed, the vibrating rod and ultrasonic vibration probe are raised by the lifting drive mechanism, the power is turned off, and the ingot is cooled and removed. Step 3, Pre-rolling heat treatment: The surface of the long strip billet finally prepared in Step 2 is uniformly coated with a high-temperature coating, and then placed in a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature in the furnace, and the finished product is taken out after cooling. Step 4, Hot rolling: The long strip billet after the annealing heat treatment in step 3 is placed in a heat treatment furnace for annealing heat treatment, and then hot rolled by a twin-roll mill. After hot rolling, the alloy is completely air-cooled and the twin-roll mill is shut down. Step 5, post-rolling heat treatment: Place the hot-rolled alloy from step four into a heat treatment furnace for annealing heat treatment. The alloy is cooled to room temperature with the furnace and then removed after cooling.

2. The method for preparing a high-entropy alloy with both good processing performance and mechanical properties according to claim 1, characterized in that, The high-entropy alloy raw material with good processing performance and mechanical properties in step 1 includes Al, which is added in the form of pure metal with a purity of ≥99.9wt.%, wherein the pure metal Al particles are all <50mm in diameter.

3. The method for preparing a high-entropy alloy with both good processing performance and mechanical properties according to claim 2, characterized in that, The high-entropy alloy raw materials with good processing performance and mechanical properties in step 1 include Cr, Fe, Ni and Cu. The Cr, Fe, Ni and Cu are added in the form of pure metal with a purity of ≥99.9wt.%, wherein the pure metal particles of Cr, Fe, Ni and Cu are all <50mm in diameter.

4. The method for preparing a high-entropy alloy with both good processing performance and mechanical properties according to claim 3, characterized in that, In step 2, when using a vacuum non-consumable arc furnace for melting, pure Zr or Ti metal with a purity ≥99.9wt.% is placed in another circular melting tank, and then argon gas is introduced. Once the pressure reaches ≥5Pa, the argon cylinder valve is closed. The furnace is then repeatedly cleaned 1-5 times, followed by evacuation and argon filling. The vacuum gauge resistance unit drops to 0.5*10. 1 ~1.0*10 1 After that, open the pre-valve and wait for the vacuum resistance unit to drop to 3.0*10. 0 ~5.0*10 0 After that, turn on the molecular pump power and wait for the vacuum gauge ionization unit to drop to 7*10. -4 ~9*10 -4 After that, keep it closed for 5 minutes. When filling with gas, keep the argon pressure at 200Pa-500Pa. Adjust the height of the tungsten electrode to 1-5mm from the top surface of the material to be melted. Start the arc with a melting current of 70A-100A. Melt with a melting current of 300A-700A until the prepared material is completely melted. Add a stirring current of 10A-20A. Each button ingot needs to be melted 4-8 times. Then perform wire cutting.

5. The method for preparing a high-entropy alloy with both good processing performance and mechanical properties according to claim 3, characterized in that, In step 2, when using an electromagnetic cold crucible levitation furnace for melting, the melting is carried out at an argon pressure of 200Pa-500Pa and a melting temperature of 1200℃-1800℃, which is maintained for 5min-15min to produce a master alloy ingot, which is then wire-cut. The ultrasonic vibration assists the melting at a frequency of 60kHz-80kHz, with a displacement amplitude of 30μm.

6. The method for preparing a high-entropy alloy with both good processing performance and mechanical properties according to claim 3, characterized in that, The high-temperature coating used in step 3 is ZS-1 high-temperature coating. After applying the high-temperature coating, the coating is left to stand for 30-60 minutes. The annealing heat treatment is carried out at a rate of 5-10℃ / min to raise the temperature to 700℃-1200℃ and then held for 1-5 hours. In step 4, after the coating is placed in the heat treatment furnace, the temperature is raised to 700℃-1200℃ at a rate of 5-10℃ / min and then held for 5-25 minutes. The twin-roll mill controls the reduction per pass in hot rolling at 5%-20%, with a rolling speed of 20mm / s-50mm / s, and 3-6 passes. After each pass, the alloy temperature must reach 700℃-1200℃ and be held for 5min-25min before the next rolling pass. In step 5, the annealing heat treatment is carried out at a rate of 5-10℃ / min to 700℃-1200℃ and held for 5min-25min.

7. The method for preparing a high-entropy alloy with both good processing performance and mechanical properties according to claim 1, characterized in that: The electromagnetic cold crucible levitation furnace in step 2 includes a furnace body, a vibration transmission mechanism, an ultrasonic vibration mechanism, and a lifting drive mechanism. The ultrasonic transducer (1) is inserted into the furnace through the furnace cover (2) of the furnace body; the lifting drive mechanism is connected to the ultrasonic vibration mechanism and the vibration transmission mechanism through the connecting component; the vibration transmission mechanism is abutted against the bottom of the ultrasonic vibration mechanism.

8. The method for preparing a high-entropy alloy with both good processing performance and mechanical properties according to claim 7, characterized in that: The top of the furnace body is provided with an ultrasonic transducer inlet channel and a conduction mechanism inlet channel, and a flexible rubber sealing ring (11) is provided in both the ultrasonic transducer inlet channel and the conduction mechanism inlet channel. The ultrasonic vibration mechanism includes an ultrasonic transducer (1) and an ultrasonic generator. The ultrasonic transducer (1) is electrically connected to the ultrasonic generator, and the ultrasonic transducer (1) extends into the furnace through the ultrasonic transducer inlet channel. An ultrasonic transducer connection part is provided on the upper part of the ultrasonic transducer (1). The lifting drive mechanism includes a lifting cylinder (22), a slider (6) and a slide rail (19). The slide rail (19) is fixedly arranged in the vertical direction. A slide groove matching the slider (6) is opened on the slide rail (19). The slider (6) is slidably arranged on the slide groove. The lifting cylinder (22) is arranged below the slider (6), and the lifting end of the lifting cylinder (22) is fixedly connected to the lower end of the slider (6). The connecting assembly includes a locking bolt (20) and a bracket. One end of the bracket is disposed on the slider (6), and the bracket is provided with a first mounting slot and a second mounting slot. The first mounting slot is fixedly connected to the connection part of the ultrasonic transducer (1) by the locking bolt (20). The vibration transmission mechanism includes a ceramic sleeve (16), a vibrating plate (5), a vertical connecting rod (4), and a vibration part. Multiple vibration parts are provided, and multiple vibration parts are fixedly installed at the bottom of the vibrating plate (5). One end of the vertical connecting rod (4) is threadedly fixedly connected to the top of the vibrating plate (5), and the other end of the vertical connecting rod (4) passes through the transmission mechanism and extends to the outside of the furnace body. A snap-fit ​​part is fixedly provided on one side of the vertical connecting rod (4) outside the furnace body. The snap-fit ​​part is fixedly connected to the second mounting slot by a locking bolt (20). The vibrating plate (5) is located below the ultrasonic transducer (1), and the top surface of the vibrating plate (5) is in contact with the ultrasonic transducer (1). The vibrating part includes a magnetic yoke (7), a drive coil (9), a cycle toughness SUMITEN 950-TMCP steel (18), and an iron-gallium alloy (8). The magnetic yoke (7) is threaded to the bottom of the vibrating plate (5). The iron-gallium alloy (8) is fixedly disposed at the lower end of the magnetic yoke (7). The drive coil (9) is wound around the iron-gallium alloy (8), and one end of the drive coil (9) extends into the interior of the vertical connecting rod (4) and extends outward to be electrically connected to an external power source. The cycle toughness SUMITEN 950-TMCP steel (18) is spaced between the ceramic sleeve (16) and the drive coil (9). The ceramic sleeve (16) is wrapped around the vibrating plate (5), the vertical connecting rod (4), the vibrating part and the ultrasonic transducer (1). The length of the ceramic sleeve (16) wrapped around the vertical connecting rod (4) is 1 / 3 to 1 / 4 of the total length of the vertical connecting rod (4). The length of the ceramic sleeve (16) wrapped around the ultrasonic transducer (1) is 1 / 3 to 1 / 4 of the total length of the ultrasonic transducer (1). The ceramic sleeve (16) is fixed to the vertical connecting rod (4) by chemical adhesive.

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