A high-entropy alloy preparation method based on staged mixing

Abstract

The application provides a high-entropy alloy preparation method based on staged mixing, which comprises the following steps: first ball milling of at least two refractory metals to obtain a high-surface-activity metal mixture; second ball milling of at least three low-melting-point metals mixed with the high-surface-activity metal mixture to obtain a precursor; and melting of the precursor into a preform to obtain a high-entropy alloy. The high-entropy alloy preparation method based on staged mixing provided by the application can reduce the burn loss rate of volatile low-melting-point metals by more than 60% through the premixing of the first ball milling, and can induce mechanical alloying of the low-melting-point metals and the refractory metals at an atomic scale through the second ball milling, and then can greatly shorten the alloying time through the preform melting, and can shorten the melting cycle by more than 30%, and the deviation of the obtained alloy composition from the target alloy composition can be controlled within ±0.5 at.%.

Description

Technical Field

[0001] This invention relates to the field of high-entropy alloy technology, and specifically to a method for preparing high-entropy alloys based on staged mixing. Background Technology

[0002] High entropy alloys (HEAs) consist of five or more principal elements. Due to the high mixing entropy effect, they can form simple solid solution structures and possess excellent properties such as high hardness, high temperature resistance, and corrosion resistance, making them promising for applications in aerospace, nuclear industry, and other fields. However, the significant differences in the physicochemical properties (melting point, density, vapor pressure) between the elements present two major challenges during vacuum arc melting: 1. Compositional segregation: The density difference between refractory high-density elements such as W, Mo, and Ta and low-melting-point low-density elements such as Al and Mn can reach 15 g / cm³. 3 In short-term molten pool convection, it is difficult to achieve uniform mixing, which easily leads to gravity segregation or unmelted particles.

[0003] 2. Severe ablation: Volatile elements such as Al and Mn have extremely high vapor pressures at high temperatures (5000K) in an electric arc and vaporize instantly in their elemental state. Existing technologies require the addition of 3%-10% in excess to compensate for ablation loss, but it is still difficult to control the actual composition, and excessive addition can easily introduce impurity phases.

[0004] Currently, existing technologies such as patents CN119455964A and CN107841672A propose a scheme of mixing and ball milling metal powders before melting. However, most of these methods employ a "one-step" ball milling process, placing all powders into the milling jar simultaneously. This approach has several drawbacks: 1. Powders with large density differences (such as W and Al) are prone to centrifugal separation within the milling jar, making it difficult to achieve microscopic uniformity; 2. Soft metals (such as Al) are easily encapsulated by hard metals (such as W), preventing further refinement and diffusion; 3. It fails to fundamentally shorten the alloying time during arc melting, and volatile elements still face severe ablation in their elemental state during the initial melting stage. Summary of the Invention

[0005] The purpose of this invention is to achieve deep plastic deformation and mechanical alloying between components by differentiating and controlling parameters based on the mechanical alloying behavior of the components, thereby obtaining a premixed powder with uniform composition. Furthermore, the alloying time can be significantly shortened by pressing and melting the billet, reducing the burn-off rate of volatile components by more than 60%, and controlling the composition deviation within ±0.5 at.%.

[0006] To achieve the above-mentioned technical objectives, this invention provides a method for preparing high-entropy alloys based on staged mixing, comprising: At least two refractory metals are first ball-milled to obtain a metal mixture with high surface activity; The precursor is obtained by mixing at least three low-melting-point metals with a mixture of highly surface-active metals and then ball-milling the mixture. The precursor is made into a preform and then melted to obtain a high-entropy alloy.

[0007] Furthermore, before the first ball milling, a process control agent comprising 0.5%-2% of the mass of the refractory metal is added; The process control agent includes at least one of stearic acid, anhydrous ethanol, and ethylene glycol.

[0008] Furthermore, the refractory metal includes W, Mo, Ta, Nb, Re, Hf, and Zr; The low-melting-point metals include Al, Mn, Mg, Cu, Ni, Co, Cr, and Fe.

[0009] Furthermore, the D50 of the highly surface-active metal mixture is 0.5-2 μm.

[0010] Furthermore, the ball-to-material ratio of the first ball mill is 12-18:1, and the rotation speed is 350-500 rpm; The ball-to-material ratio of the second ball mill is 18-28:1, and the rotation speed is 200-300 rpm.

[0011] Furthermore, the process of forming the precursor into a preform includes, The precursor is loaded into a mold and subjected to cold isostatic pressing and / or unidirectional hydraulic pressure, and held at 200-400MPa for 1-5 minutes to obtain a preform with a relative density ≥70%.

[0012] Furthermore, the smelting is carried out using a vacuum electric furnace; The preform is repeatedly melted on both sides 2-3 times.

[0013] Furthermore, the refractory metal and the low-melting-point metal are dehydrated and degassed in a vacuum environment at 80-120°C for 2-4 hours before use.

[0014] Furthermore, the purity of both the refractory metal and the low-melting-point metal is ≥99.9%, and the particle size is 10-50μm.

[0015] The present invention also provides a high-entropy alloy, which is obtained by the above-described high-entropy alloy preparation method based on staged mixing.

[0016] Compared with the prior art, the beneficial effects of the present invention include: 1. Significantly reduced ablation rate: The invention uses ball milling to encapsulate volatile low-melting-point metals with refractory metals or form mechanical alloying phases, which greatly reduces their activity. During smelting, the powder compact is rapidly heated as a whole, and volatile elements dissolve into the melt before they vaporize, reducing the ablation rate of volatile elements by more than 60%.

[0017] 2. Extremely high compositional accuracy: The premixing of the first ball mill in this invention eliminates macroscopic segregation. Combined with the low burn-off rate of volatile elements, the deviation between the final alloy composition and the target alloy composition can be controlled within ±0.5 at.%, without the need for excessive addition of volatile elements.

[0018] 3. Shorten the melting cycle: This invention induces mechanical alloying of low-melting-point metals and refractory metals at the atomic scale through a second ball mill, and then significantly shortens the alloying time through billet melting, reducing the melting cycle by more than 30%.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0021] Figure 1 A flowchart of the high-entropy alloy preparation method based on staged mixing of the present invention is shown. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] High-entropy alloys are typically composed of a combination of various high-melting-point metals (W 3620℃, Ta 3017℃, Mo 2896℃) and low-melting-point metals (Ti 1933K, V 1890℃). The melting point difference can exceed 1500℃. In traditional vacuum arc melting processes, this significant melting point difference causes a wide liquid-solid two-phase temperature range when refractory metals are mixed, resulting in a substantial solidification time difference. The difference between refractory high-density elements such as W, Mo, and Ta and low-melting-point, low-density elements such as Al and Mn easily leads to gravitational segregation during melting due to their density differences. High-melting-point, high-density components sink to the bottom of the crucible, while low-melting-point, low-density components float on top of the melt, making uniform mixing impossible within a limited time. Specifically, high-melting-point elements such as Mo, Ta, and Hf mainly segregate in dendritic regions, while low-melting-point elements such as Ti and V mainly segregate in interdendritic regions. For example, in the molten TaNbHfZrTi alloy, even after annealing at 1200℃ for 24 hours, a uniform distribution of components cannot be achieved. This segregation not only causes instability in alloy properties but also reduces the configurational entropy of the high-entropy alloy, adversely affecting its structural stability. Even if macroscopic fusion is completed, differences in solute partition coefficients of different elements during solidification can lead to interdendritic segregation. Studies have shown that in the as-cast structure of AlFeCuCoNiCr high-entropy alloys, copper elements accumulate in large quantities in the intergranular spaces, forming severe compositional segregation; similarly, severe density segregation exists in CuAgAlFeNi high-entropy alloys, with the as-cast structure divided into a hypoeutectic layer and a solid solution layer. This segregation not only causes instability in alloy properties but also makes the preparation of large-sized high-entropy alloys extremely difficult.

[0026] Furthermore, during vacuum arc melting, the arc temperature can exceed 5000K. While high-boiling-point components such as W (boiling point 5555℃) and Mo (boiling point 4639℃) are still in the solid state or have just melted, low-boiling-point components such as Al (boiling point 2467℃) and Mn (boiling point 2061℃) have already vaporized violently. Studies indicate that during the melting and preparation of refractory high-entropy alloys, the volatilization of low-melting-point substances is very likely to occur, leading to a deviation of the final alloy composition from the initial design. To compensate for burn-off, existing technologies often require the excessive addition of 3%-10% of volatile elements. However, this "extensive compensation" has a fundamental flaw: The compensation amount is difficult to control precisely: the burn-off rate is affected by many factors such as melting current, melting time, crucible position, and number of times it is turned over, resulting in large fluctuations between batches; It can easily introduce impurity phases: excessive addition changes the nominal composition and may exceed the single-phase solid solution region, precipitating a harmful second phase.

[0027] In view of this, the present invention provides a method for preparing high-entropy alloys based on staged mixing, comprising, At least two refractory metals are first ball-milled to obtain a metal mixture with high surface activity; The precursor is obtained by mixing at least three low-melting-point metals with a mixture of highly surface-active metals and then ball-milling the mixture. The precursor is made into a preform and then melted to obtain a high-entropy alloy.

[0028] In some preferred embodiments, a process control agent comprising 0.5%-2% of the mass of the refractory metal is added before the first ball milling. The process control agent includes at least one of stearic acid, anhydrous ethanol, and ethylene glycol.

[0029] In some preferred embodiments, the refractory metal includes W, Mo, Ta, Nb, Re, Hf, and Zr; The low-melting-point metals include Al, Mn, Mg, Cu, Ni, Co, Cr, and Fe.

[0030] It should be noted that the present invention does not strictly limit the amount of specific refractory metals and low-melting-point metals added. The general formula for high-entropy alloys is defined as AB, where A is a refractory metal and B is a low-melting-point metal. Specific refractory metals are designated as A1, A2, A3…An, and specific low-melting-point metals are designated as B1, B2, B3…Bn. A1, A2, A3…An and B1, B2, B3…Bn can be added in equimolar amounts according to the strict definition of high-entropy alloys in this field (excess amounts added due to ablation are not counted). Alternatively, the molar amount of a metal such as A1, A3, B3 or A2, A3, B1 can be calculated as 1, while the molar amounts of other metals are 0.45-1.05, which can be freely selected and adjusted.

[0031] In some preferred embodiments, the D50 of the highly surface-active metal mixture is 0.5-2 μm.

[0032] In some preferred embodiments, the ball-to-material ratio of the first ball mill is 12-18:1, and the rotation speed is 350-500 rpm; The ball-to-material ratio of the second ball mill is 18-28:1, and the rotation speed is 200-300 rpm.

[0033] In some preferred embodiments, the D50 of the highly surface-active metal mixture is 0.5-2 μm.

[0034] In this invention, the first stage employs ball milling at a relatively high speed of 350-500 rpm. The purpose is not simply to refine the metal, but rather to: 1. form "grind media-like" particles with sharp edges and high surface activity on the surface of the refractory metal; 2. form an amorphous / nanocrystalline activation layer on the surface of the refractory metal; and 3. control the median particle size D50 of the refractory metal to be between 0.5-2 μm. In the second stage, a mixture of low-melting-point metal and highly surface-active metal is mixed and then ball-milled at a lower speed of 200-300 rpm, with an increased ball-to-material ratio. The low speed prevents the low-melting-point metal from excessively cold-welding into lumps, while prolonged ball milling induces mechanical alloying of the low-melting-point metal and the refractory metal at the atomic scale.

[0035] In some preferred embodiments, the process of forming the precursor into a preform includes, The precursor is loaded into a mold and subjected to cold isostatic pressing and / or unidirectional hydraulic pressure, and held at 200-400MPa for 1-5 minutes to obtain a preform with a relative density ≥70%.

[0036] In some preferred embodiments, the melting is carried out in a vacuum electric furnace; the vacuum electric furnace melting specifically includes: 1. Pretreatment: placing the pre-made billet in a water-cooled copper crucible and evacuating it to a vacuum level of ≤5×10. -3 1. Fill with high-purity Ar gas to 0.03-0.06 MPa; 2. Arc ignition melting: Since the powder has been pre-alloyed and has good thermal conductivity, a relatively stable current curve can be used. Set the arc ignition current to 150-200A and maintain it for 10-20s to allow the surface layer to be initially sintered; then increase it to the working current of 250-350A and maintain it in the liquid phase for 20-40 seconds; 3. Remelting by flipping: Repeat the melting of the front and back sides of the preform 2-3 times.

[0037] In some preferred embodiments, the refractory metal and the low-melting-point metal are dehydrated and degassed under vacuum at 80-120°C for 2-4 hours before use. This is done to avoid introducing oxygen impurities during ball milling.

[0038] In some preferred embodiments, the purity of both the refractory metal and the low-melting-point metal is ≥99.9%, and the particle size is 10-50 μm.

[0039] The present invention will be further described in detail below through specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0040] Example 1 like Figure 1 As shown, a method for preparing high-entropy alloys based on staged mixing includes the following steps: S1. Weigh the raw materials With Al 0.5 CoCrFeNiW 0.5 Mo 0.5 Weigh out the following refractory metals: W powder (99.9%, 10μm), Mo powder (99.9%, 10μm), and low-melting-point metals: Al powder (99.9%, 20μm), Co powder (99.9%, 20μm), Cr powder (99.9%, 20μm), Fe powder (99.9%, 20μm), and Ni powder (99.9%, 20μm).

[0041] S2, Staged Ball Milling First stage: Under argon protection, W powder, Mo powder and stearic acid (1% of the total mass of W powder and Mo powder) were put into a ball mill and ball milled for 20 hours at a ball-to-material ratio of 15:1 and a speed of 400 rpm to obtain a metal mixture with high surface activity. The D50 was measured to be 1.2 μm by a laser particle size analyzer.

[0042] Second stage: Add Al powder, Co powder, Cr powder, Fe powder and Ni powder into the ball mill, adjust the ball-to-material ratio to 22:1 and the rotation speed to 250 rpm, and ball mill for 45 hours to obtain the precursor.

[0043] S3, precast blank The precursor was passed through a 150-mesh sieve to remove large agglomerated particles, and then loaded into a rubber mold. Cold isostatic pressing was used, and the pressure was held at 300 MPa for 3 minutes to obtain a preform with a relative density of 75±3%.

[0044] S4, Vacuum Melting The preform was placed in a water-cooled copper crucible and evacuated to a vacuum level of 4 × 10⁻⁶. -3 The pressure was increased to 0.05 MPa by introducing argon gas, and the arc current was maintained at 180 A for 15 s. The working current was maintained at 300 A for 30 s. The melting was repeated twice on both sides, for a total of 4 meltings, to obtain a high-entropy alloy ingot.

[0045] Example 2 A method for preparing high-entropy alloys based on staged mixing includes the following steps: S1. Weigh the raw materials With Al 0.5 CoCrNiW 0.5 Mo 0.5 Weigh out the following refractory metals: W powder (99.9%, 10μm), Mo powder (99.9%, 10μm), and low-melting-point metals: Al powder (99.9%, 20μm), Co powder (99.9%, 20μm), Cr powder (99.9%, 20μm), and Ni powder (99.9%, 20μm).

[0046] S2, Staged Ball Milling First stage: Under argon protection, W powder, Mo powder and stearic acid (1% of the total mass of W powder and Mo powder) were put into a ball mill and ball milled for 20 hours at a ball-to-material ratio of 15:1 and a speed of 400 rpm to obtain a metal mixture with high surface activity. The D50 was measured to be 1.2 μm by a laser particle size analyzer.

[0047] Second stage: Add Al powder, Co powder, Cr powder and Ni powder to the ball mill, adjust the ball-to-material ratio to 22:1 and the rotation speed to 250 rpm, and ball mill for 45 hours to obtain the precursor.

[0048] S3, precast blank The precursor was passed through a 150-mesh sieve to remove large agglomerated particles, and then loaded into a rubber mold. Cold isostatic pressing was used, and the pressure was held at 300 MPa for 3 minutes to obtain a preform with a relative density of 75±3%.

[0049] S4, Vacuum Melting The preform was placed in a water-cooled copper crucible and evacuated to a vacuum level of 4 × 10⁻⁶. -3 The pressure was increased to 0.05 MPa by introducing argon gas, and the arc current was maintained at 180 A for 15 s. The working current was maintained at 300 A for 30 s. The melting was repeated twice on both sides, for a total of 4 meltings, to obtain a high-entropy alloy ingot.

[0050] Comparative Example 1 A method for preparing a high-entropy alloy includes the following steps: S1. Weigh the raw materials With Al 0.5 CoCrFeNiW 0.5 Mo 0.5 Weigh out the following refractory metals: W powder (99.9%, 10μm), Mo powder (99.9%, 10μm), and low-melting-point metals: Al powder (99.9%, 20μm), Co powder (99.9%, 20μm), Cr powder (99.9%, 20μm), Fe powder (99.9%, 20μm), and Ni powder (99.9%, 20μm).

[0051] S2, ball mill Under argon protection, W powder, Mo powder, stearic acid (1% of the total mass of W and Mo powder), Al powder, Co powder, Cr powder, Fe powder, and Ni powder were fed into a ball mill and ball-milled for 65 hours at a ball-to-material ratio of 22:1 and a speed of 300 rpm to obtain the precursor.

[0052] S3, precast blank The precursor was passed through a 150-mesh sieve to remove large agglomerated particles, and then loaded into a rubber mold. Cold isostatic pressing was used, and the pressure was held at 300 MPa for 3 minutes to obtain a preform with a relative density of 75±3%.

[0053] S4, Vacuum Melting The preform was placed in a water-cooled copper crucible and evacuated to a vacuum level of 4 × 10⁻⁶. -3 The pressure was increased to 0.05 MPa by introducing argon gas, and the arc current was maintained at 180 A for 15 s. The working current was maintained at 300 A for 30 s. The melting was repeated on both sides 3 times, for a total of 6 meltings, to obtain a high-entropy alloy ingot.

[0054] Comparative Example 2 A method for preparing a high-entropy alloy includes the following steps: S1. Weigh the raw materials With Al 0.5 CoCrNiW 0.5 Mo 0.5 Weigh out the following refractory metals: W powder (99.9%, 10μm), Mo powder (99.9%, 10μm), and low-melting-point metals: Al powder (99.9%, 20μm), Co powder (99.9%, 20μm), Cr powder (99.9%, 20μm), and Ni powder (99.9%, 20μm).

[0055] S2, ball mill Under argon protection, W powder, Mo powder, stearic acid (1% of the total mass of W and Mo powder), Al powder, Co powder, Cr powder and Ni powder were fed into a ball mill and ball-milled for 65 hours at a ball-to-material ratio of 22:1 and a speed of 300 rpm to obtain the precursor.

[0056] S3, precast blank The precursor was passed through a 150-mesh sieve to remove large agglomerated particles, and then loaded into a rubber mold. Cold isostatic pressing was used, and the pressure was held at 300 MPa for 3 minutes to obtain a preform with a relative density of 75±3%.

[0057] S4, Vacuum Melting The preform was placed in a water-cooled copper crucible and evacuated to a vacuum level of 4 × 10⁻⁶. -3The pressure was increased to 0.05 MPa by introducing argon gas, and the arc current was maintained at 180 A for 15 s. The working current was maintained at 300 A for 30 s. The melting was repeated on both sides 3 times, for a total of 6 meltings, to obtain a high-entropy alloy ingot.

[0058] Comparative Example 3 A method for preparing a high-entropy alloy includes the following steps: S1. Weigh the raw materials With Al 0.5 CoCrFeNiW 0.5 Mo 0.5 Weigh out the following refractory metals: W powder (99.9%, 10μm), Mo powder (99.9%, 10μm), and low-melting-point metals: Al powder (99.9%, 20μm), Co powder (99.9%, 20μm), Cr powder (99.9%, 20μm), Fe powder (99.9%, 20μm), and Ni powder (99.9%, 20μm).

[0059] S2, precast blank After mixing the raw materials, they are passed through a 150-mesh sieve to remove large agglomerates. Then, they are placed into a rubber mold and cold isostatically pressed at 300 MPa for 3 minutes to obtain a preform with a relative density of 75±3%.

[0060] S3, Vacuum Melting The preform was placed in a water-cooled copper crucible and evacuated to a vacuum level of 4 × 10⁻⁶. -3 The pressure was increased to 0.05 MPa by introducing argon gas, and the arc current was maintained at 180 A for 15 s. The working current was maintained at 300 A for 30 s. The melting was repeated 4 times on both sides, for a total of 8 meltings, to obtain a high-entropy alloy ingot.

[0061] Table 1 summarizes the number of melting cycles, Al burn-off rate, and alloy composition deviations for the examples and comparative examples.

[0062] Table 1

[0063] As can be seen from the results in Table 1, compared with Comparative Examples 1-3, Examples 1 and 2 of the present invention show a significant reduction in the number of melting cycles, Al burn-off rate, and compositional deviation. This is due to the staged ball milling process provided by the present invention. In the first stage, a relatively high ball milling speed of 350-500 rpm is used to form "grind media-like" particles with sharp edges and high surface activity on the surface of the refractory metal; a nano-sized amorphous / nanocrystalline activation layer is formed on the surface of the refractory metal; and the median particle size D50 of the refractory metal is controlled at 0.5-2 μm. In the second stage, after mixing the low-melting-point metal with a high-surface-activity metal mixture, a relatively low ball milling speed of 200-300 rpm is used, and the ball-to-material ratio is increased. The low speed avoids excessive cold welding of the low-melting-point metal into lumps, while the long-term ball milling induces mechanical alloying of the low-melting-point metal and the refractory metal at the atomic scale. This process yields a premixed powder with uniform composition, which in turn significantly shortens the alloying time through compact melting, reducing the melting cycle by more than 30%, reducing the burn-off rate of volatile components by more than 60%, and controlling the composition deviation within ±0.5 at.%.

[0064] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing high-entropy alloys based on staged mixing, characterized in that, include, At least two refractory metals are first ball-milled to obtain a metal mixture with high surface activity; The precursor is obtained by mixing at least three low-melting-point metals with a mixture of highly surface-active metals and then ball-milling the mixture. The precursor is made into a preform and then melted to obtain a high-entropy alloy.

2. The method for preparing high-entropy alloys based on staged mixing according to claim 1, characterized in that, Before the first ball milling, a process control agent of 0.5%-2% of the mass of the refractory metal is added; The process control agent includes at least one of stearic acid, anhydrous ethanol, and ethylene glycol.

3. The method for preparing high-entropy alloys based on staged mixing according to claim 1, characterized in that, The refractory metals include W, Mo, Ta, Nb, Re, Hf, and Zr; The low-melting-point metals include Al, Mn, Mg, Cu, Ni, Co, Cr, and Fe.

4. The method for preparing high-entropy alloys based on staged mixing according to claim 1, characterized in that, The D50 of the highly surface-active metal mixture is 0.5-2 μm.

5. The method for preparing high-entropy alloys based on staged mixing according to claim 1, characterized in that, The ball-to-material ratio of the first ball mill is 12-18:1, and the rotation speed is 350-500 rpm; The ball-to-material ratio of the second ball mill is 18-28:1, and the rotation speed is 200-300 rpm.

6. The method for preparing high-entropy alloys based on staged mixing according to claim 1, characterized in that, The process of forming the precursor into a preform includes, The precursor is loaded into a mold and subjected to cold isostatic pressing and / or unidirectional hydraulic pressure, and held at 200-400MPa for 1-5 minutes to obtain a preform with a relative density ≥70%.

7. The method for preparing high-entropy alloys based on staged mixing according to claim 1, characterized in that, The smelting is carried out using a vacuum electric furnace. The preform is repeatedly melted on both sides 2-3 times.

8. The method for preparing high-entropy alloys based on staged mixing according to claim 1, characterized in that, The refractory metal and the low-melting-point metal are dehydrated and degassed in a vacuum environment at 80-120℃ for 2-4 hours before use.

9. The method for preparing high-entropy alloys based on staged mixing according to any one of claims 1-8, characterized in that, The purity of both the refractory metal and the low-melting-point metal is ≥99.9%, and the particle size is 10-50 μm.

10. A high-entropy alloy, characterized in that, The high-entropy alloy is prepared by the staged mixing method according to any one of claims 1-9.

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