High-entropy alloys and their preparation methods and applications

Abstract

This application belongs to the field of high-entropy alloy preparation, and specifically relates to a high-entropy alloy, a preparation method thereof, and an application. The preparation method includes the following steps: melting a metal cylinder of high-entropy alloy raw materials to obtain a high-entropy alloy; arranging N metal layers radially outward from the central axis of the metal cylinder, and the melting point of the nth metal layer is lower than that of the (n + 1)th metal layer; where n takes 1, 2, 3, ……, N - 1, and N is a positive integer. The preparation method of the high-entropy alloy provided by this application melts the high-entropy alloy raw materials in the form of a metal cylinder, so that each metal in the high-entropy alloy raw materials is melted in a large-volume block (metal layer), reducing the oxidation of easily oxidized metals in the high-entropy alloy raw materials; the melting points of the metals decrease sequentially from the central axis of the metal cylinder radially outward, reducing the loss of low-melting-point elements during the melting process.

Description

Technical Field

[0001] This application belongs to the field of high-entropy alloy preparation, and specifically relates to a preparation method and application of a high-entropy alloy. Background Art

[0002] High-entropy alloy is a new type of material composed of five or more main elements, and the single atom ratio of each element is not less than 5%, so it is also called a multi-component alloy. Due to the multi-component characteristics of the alloy, the alloy has a very high mixing entropy, can form a relatively stable single-phase super solid solution, and has a simple microstructure.

[0003] The unique effects of high-entropy alloys (such as high-entropy effect, sluggish diffusion effect, lattice distortion effect, and cocktail effect, etc.) can exhibit many excellent properties (such as excellent high-temperature strength and hardness, good wear and corrosion resistance, and excellent anti-irradiation performance, etc.). Among them, the anti-irradiation performance of high-entropy alloys is reflected in their relatively high lattice distortion, and the formation energy of atomic vacancy defects is relatively high during neutron irradiation, which is not conducive to the formation of defects; even if irradiation causes the formation of vacancy defects and interstitial atoms, the high lattice distortion makes it difficult for them to diffuse and aggregate to form large-size defects. During plasma irradiation, deuterium and tritium plasmas trapped in the material are not easy to agglomerate, avoiding the formation of large-size hydrogen bubbles or helium bubbles, and even the Fuss structure.

[0004] For refractory high-entropy alloys, currently, they are mainly refractory high-entropy alloys based on tungsten elements. The manufacturing methods of refractory high-entropy alloys mainly include vacuum arc melting and spark plasma sintering. When the high-entropy alloy contains easily oxidizable metals, if powders are used as raw materials for preparation, the content of metal oxides in the prepared high-entropy alloy is too high and difficult to remove, which affects the mechanical properties and irradiation performance of the high-entropy alloy. Summary of the Invention

[0005] This application proposes a preparation method and application of a high-entropy alloy to solve at least one aspect of the above technical problems.

[0006] This application is realized through the following technical solutions:

[0007] In the first aspect of this application, a preparation method of a high-entropy alloy is provided, including the following steps:

[0008] Melting a metal cylinder of high-entropy alloy raw materials to obtain a high-entropy alloy;

[0009] Arrange N metal layers radially outward from the central axis of the metal cylinder, and the melting point of the nth metal layer is lower than that of the (n + 1)th metal layer;

[0010] Wherein, n takes 1, 2, 3,..., N - 1, and N is a positive integer.

[0011] In some possible implementation manners, the difference between the melting point of the (n + 1)-th metal layer and the melting point of the n-th metal layer is 55°C to 1563°C.

[0012] In some possible implementation manners, the value of N is less than or equal to the sum of the types of metals in the high-entropy alloy raw material.

[0013] In some possible implementation manners, in the high-entropy alloy raw material, the purity of each metal raw material is above 99.9%.

[0014] In some possible implementation manners, preparing the metal cylinder includes the following steps:

[0015] According to the set volume ratio of the high-entropy alloy raw material, the size of the metal cylinder, and the total molar amount of the high-entropy alloy, each metal material in the high-entropy alloy raw material is turned into a corresponding metal layer;

[0016] The metal layers are sleeved to obtain the metal cylinder.

[0017] In some possible implementation manners, the step of turning the metal material into a corresponding metal layer includes: first adding the innermost cylinder, and then successively processing the corresponding outer circular tubes;

[0018] Processing of the innermost cylinder: Using a lathe to turn off the outer surface layer of the cylinder and processing the diameter of the cylinder to the target size;

[0019] Processing of the n-th metal layer (n≠1): Using a lathe to perform turning on the inner wall and outer wall of the n-th metal tube;

[0020] In some possible implementation manners, in the metal cylinder, the n-th metal layer and the (n + 1)-th metal layer are in interference fit.

[0021] In some possible implementation manners, the difference between the bottom surface diameter of the outer wall of the n-th metal layer and the bottom surface diameter of the inner wall of the (n + 1)-th metal layer is 0.01 mm to 0.06 mm. It should be noted that when n is 1, for the innermost metal, the innermost metal is a solid cylinder, and there is only the bottom surface diameter of the cylinder outer wall.

[0022] In some possible implementation manners, the bottom surface diameter of the metal cylinder is 30 mm to 200 mm. In this case, according to the cylinder volume calculation: Volume = base area × height, when the heights of the metal layers in the metal cylinder are equal, the cross-sectional area ratio is equal to the volume ratio. It should be noted that the height of the metal cylinder can be adaptively adjusted and set during actual preparation, and there is no special limitation in this application. However, as an example, the height of the metal cylinder can be 150 mm.

[0023] In some possible implementation manners, the smelting method is levitation melting, and the conditions for the levitation melting include: performing under an inert gas atmosphere, with the smelting temperature being 2800°C to 3300°C, the number of smelting times being more than 5 times, and the smelting time for each time being 3 min to 5 min. In this case, after each smelting is completed, the ingot is flipped to prepare for the next smelting, so as to improve the compositional uniformity of the ingot.

[0024] In some possible implementation manners, the inert gas atmosphere is argon, helium or neon.

[0025] In some possible implementation manners, in the levitation melting, the heating rate is 50°C / s to 150°C / s.

[0026] In some possible implementation manners, the steps of the levitation melting include:

[0027] Placing the metal cylinder in a levitation melting furnace;

[0028] After evacuating the levitation melting furnace to below 1×10 -3 Pa, filling it with an argon atmosphere until the gas pressure is 0.01 MPa to 0.1 MPa;

[0029] Smelting steps: heating at a heating rate of 50°C / s to 150°C / s to 2800°C to 3300°C, then holding for 3 min to 5 min, and cooling in the furnace to 25°C to 200°C, and then flipping the ingot;

[0030] Repeating the smelting steps more than 5 times to obtain the high-entropy alloy.

[0031] In some possible implementation manners, the purity of the argon atmosphere is more than 99.99%.

[0032] In some possible implementation manners, the high-entropy alloy raw materials include four or more of W, Nb, Co, Ta, Mo, Ti, V, Cr, and Zr.

[0033] In some possible implementation manners, the raw materials of the high-entropy alloy are composed of components with the following molar fractions:

[0034] W: 20% to 35%, Nb: 20% to 30%, Ti: 10% to 15%, Zr: 15% to 35%, Cr: 6% to 20%.

[0035] In some possible implementation manners, the raw materials of the high-entropy alloy are composed of components with the following molar fractions:

[0036] W: 20% to 35%, Ta: 20% to 30%, Nb: 10% to 20%, Ti: 10% to 15%, V: 15% to 35%.

[0037] In some possible implementation manners, the raw materials of the high-entropy alloy are composed of components with the following molar fractions:

[0038] W: 20% - 35%, Mo: 20% - 30%, Ti: 10% - 15%, Ta: 6% - 20%, Zr: 10% - 15%.

[0039] The second aspect of the present application provides a high-entropy alloy prepared by the preparation method of the high-entropy alloy of the present application. The third aspect of the present application provides an application of the high-entropy alloy provided by the present application in the technical field of refractory high-entropy alloy preparation.

[0040] The high-entropy alloy and its preparation method provided by the present application, compared with the prior art, have at least the following beneficial technical effects:

[0041] (1) In the preparation method of the high-entropy alloy provided by the present application, the cylindrical metal raw materials of the high-entropy alloy are melted, so that each metal in the high-entropy alloy raw materials is melted in a large-volume block (metal layer), reducing the oxidation of easily oxidized metals in the high-entropy alloy raw materials.

[0042] (2) In the preparation method of the high-entropy alloy provided by the present application, the melting points of the metals in each metal layer of the metal cylinder increase sequentially from the central axis of the metal cylinder radially outwards. During melting, the inner layer and outer layer metals are heated simultaneously, and the heating principle is that the eddy current generated by the alternating magnetic field in the metal heats the metal. The outermost layer metal has the highest temperature due to the largest circumference. The temperature of the innermost layer metal is the lowest. However, due to the low melting point of the innermost layer metal, the element loss after melting of the inner layer metal is also less, and the single-element loss rate is below 10%.

[0043] (3) In the preparation method of the high-entropy alloy provided by the present application, there is an interference fit between the nth metal layer and the (n + 1)th metal layer in the metal cylinder, and the metal layers do not easily fall off each other during the melting process, affecting the melting effect.

[0044] (4) In the preparation method of the high-entropy alloy provided by the present application, the metal cylinder is melted by levitation melting, so that the molten metal liquid does not contact the crucible, thereby avoiding the pollution of the crucible material to the molten pool and improving the purity and uniformity of the material.

[0045] (5) The high-entropy alloy provided by the present application has a single-phase BCC structure, a relative density of more than 99%, and an oxygen content of 85 ppm - 105 ppm. Description of the Drawings

[0046] To more clearly illustrate the technical solutions in the embodiments of this drawing or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of this drawing. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0047] Figure 1 Schematic diagram of the three-dimensional structure of the metal cylinder in a preparation method of a high-entropy alloy in an embodiment of the present application;

[0048] Figure 2 Schematic diagram of the cross-sectional structure of the metal cylinder in a preparation method of a high-entropy alloy in Embodiment 1 of the present application;

[0049] Figure 3 XRD pattern of the high-entropy alloy prepared by the preparation method of a high-entropy alloy in Embodiment 1 of the present application;

[0050] Figure 4 SEM image of the high-entropy alloy prepared by the preparation method of a high-entropy alloy in Embodiment 2 of the present application;

[0051] Figure 5 EDS map of tungsten metal element in the high-entropy alloy prepared by the preparation method of a high-entropy alloy in Embodiment 2 of the present application;

[0052] Figure 6 EDS map of tantalum metal element in the high-entropy alloy prepared by the preparation method of a high-entropy alloy in Embodiment 2 of the present application;

[0053] Figure 7 EDS map of vanadium metal element in the high-entropy alloy prepared by the preparation method of a high-entropy alloy in Embodiment 2 of the present application;

[0054] Figure 8 EDS map of titanium metal element in the high-entropy alloy prepared by the preparation method of a high-entropy alloy in Embodiment 2 of the present application;

[0055] Figure 9 EDS map of niobium metal element in the high-entropy alloy prepared by the preparation method of a high-entropy alloy in Embodiment 2 of the present application.

[0056] Explanation of reference numerals: 1 - the nth metal layer, 2 - the (n + 1)th metal layer.

[0057] The realization, functional features and advantages of the purpose of this drawing will be further described in conjunction with the embodiments and with reference to the drawings. Detailed implementation manners

[0058] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be described and explained below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0059] Obviously, the following description is only some examples or embodiments of the present application. For those of ordinary skill in the art, the present application can also be applied to other similar scenarios without creative efforts. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some design, manufacturing or production changes based on the technical content disclosed in the present application are only conventional technical means and should not be understood as the content disclosed in the present application being insufficient.

[0060] However, there will be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters are omitted and repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present application and is not intended to limit the subject matter recited in the claims.

[0061] If there is no special description, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0062] In the following specific embodiments, the melting points of the various metals involved are as follows:

[0063] Titanium (Ti): 1668 °C; Zirconium (Zr): 1852 °C; Chromium (Cr): 1907 °C; Vanadium (V): 1917 °C; Molybdenum (Mo): 2622 °C; Tantalum (Ta): 2980 °C; Tungsten (W): 3380 °C.

[0064] Example 1

[0065] Example 1 provides a method for preparing a high-entropy alloy, and the steps are as follows:

[0066] (1) Prepare a metal cylinder with a diameter of 60 mm and a height of 150 mm:

[0067] ① The selected high-entropy alloy raw materials are composed of the following components in mole fractions: W 35%, Nb 29%, Zr 15%, Cr 6% and Ti 15%.

[0068] ② Calculate the volume of each metal required based on the metal density of W, Nb, Zr, Cr, and Ti and the total mass of the high-entropy alloy.

[0069] ③ Arrange according to the volume of each metal, the dimensions of the metal cylinder, and the melting points of each metal (melting point: Ti < Zr < Cr < Nb < W), and use the cross-sectional area ratio of each metal layer as the volume ratio of the high-entropy alloy raw material to turn each metal bar into a metal layer with a corresponding thickness (the same height);

[0070] Among them, from the central axis of the metal cylinder radially outward, there are arranged in sequence: a Ti bar, a Zr metal layer, a Cr metal layer, an Nb metal layer, and a W metal layer (that is, titanium is the innermost layer and tungsten is the outermost layer);

[0071] The nth metal layer and the (n + 1)th metal layer are in interference fit, and the difference between the bottom diameter of the outer wall of the nth metal layer and the bottom diameter of the inner wall of the (n + 1)th metal layer is 0.01 mm to 0.06 mm.

[0072] ④ Sleeve each metal layer to obtain a metal cylinder, as shown in the attached drawings of the specification Figure 1 and attached Figure 2 shown, the attached drawing of the specification Figure 1 is a schematic three-dimensional structure diagram of the metal cylinder, and the attached drawing of the specification Figure 2 is a schematic cross-sectional structure diagram of the metal cylinder. Among them, 1 is the nth metal layer, 2 is the (n + 1)th metal layer. It should be noted that n is not limited to the metal layer referred to in the attached Figure 1 drawings, and when n = 1, the nth metal layer (that is, the first metal layer) is the innermost layer and is in the shape of a metal cylinder.

[0073] (2) Suspension melting:

[0074] ① Place the metal cylinder in a suspension melting furnace.

[0075] ② After evacuating the suspension melting furnace to above 1x10 -3 Pa, fill it with an argon atmosphere until the gas pressure is 0.05 MPa.

[0076] ③ Heat at a heating rate of 60 °C / s to 2900 °C, hold for 3 min, and then cool the ingot in the furnace to 100 °C, and then turn over the ingot.

[0077] ④ Repeat step ③ for melting 5 times to obtain the high-entropy alloy.

[0078] Example 2

[0079] Example 2 provides a method for preparing a high-entropy alloy. The steps are basically the same as those in Example 1, except that:

[0080] In step (1), ① the selected high-entropy alloy raw materials are composed of the following components in mole fractions: 25% W, 25% Ta, 20% Nb, 15% V, and 15% Ti.

[0081] In step (2), ③ the heating rate is 120 °C / s, the holding temperature is 3300 °C, the holding time is 5 min, and it is cooled to 200 °C with the furnace.

[0082] In step (2), ③ the heating rate is 120 °C / s, the holding temperature is 3300 °C, the holding time is 5 min, and it is cooled to 200 °C with the furnace.

[0083] Example 3

[0084] Example 3 provides a method for preparing a high-entropy alloy. The steps are basically the same as those in Example 1, except that:

[0085] In step (1), ① the selected high-entropy alloy raw materials are composed of the following components in mole fractions: 30% W, 20% Mo, 20% Ta, 15% Ti, and 15% Zr.

[0086] In step (2), ③ the heating rate is 90 °C / s, the holding temperature is 2800 °C, the holding time is 3 min, and it is cooled to 25 °C with the furnace.

[0087] Comparative Example 1

[0088] Comparative Example 1 provides a method for preparing a high-entropy alloy. The steps are as follows:

[0089] (1) The selected high-entropy alloy raw materials are composed of the following components in mole fractions: 35% W, 29% Nb, 15% Zr, 6% Cr, and 15% Ti.

[0090] (2) After mixing the metal powders of the high-entropy alloy raw materials into a metal powder mixture, suspension melting is carried out:

[0091] ① Place the metal powder mixture in a suspension melting furnace.

[0092] ② Pump the suspension melting furnace to a vacuum of 1x10 -3 Pa, and then fill it with an argon atmosphere until the gas pressure is 0.05 MPa.

[0093] ③ Heat it to 2800 °C at a heating rate of 100 °C / s, and then hold for 3 min.

[0094] ④ Cool it to 100 °C in a furnace-cooling manner, and then turn over the ingot.

[0095] ⑤ Repeat steps ③ and ④ for melting 5 times to obtain the high-entropy alloy.

[0096] Comparative Example 2

[0097] Comparative Example 2 provides a method for preparing a high-entropy alloy, and the steps are as follows:

[0098] (1) Prepare a metal melting block

[0099] ① The selected high-entropy alloy raw materials are composed of the following components in mole fractions: W 35%, Nb 29%, Zr 15%, Cr 6% and Ti 15%.

[0100] ② Calculate the required volume of each metal based on the metal density of W, Ta, Cr, V and Ti and the total mass of the high-entropy alloy.

[0101] ③ Arrange according to the volume of each metal, the size of the metal cylinder and the melting point of each metal (melting point: Ti < Zr < Cr < Nb < W), and use the cross-sectional area ratio of each metal layer as the volume ratio of the high-entropy alloy raw materials. Turn the metal rods of Ti, V, and W into metal layers with corresponding thicknesses (the same height), and fill Zr and Nb in the form of metal powders between the Ti and Cr metal layers and between the Cr and W metal layers respectively to obtain a metal melting block.

[0102] (2) Levitation melting: The steps are basically the same as those in Example 1, except that in this comparative example, some metals are melted by powder (i.e., the melting block prepared in step (1)).

[0103] Comparative Example 3

[0104] Comparative Example 3 provides a method for preparing a high-entropy alloy, and the steps are basically the same as those in Example 1, except that:

[0105] In ③ of step (1), there are arranged successively radially outward from the central axis of the metal cylinder: a Zr rod, a Ti metal layer, a Cr metal layer, an Nb metal layer and a W metal layer (i.e., zircon is the innermost layer and tungsten is the outermost layer), that is, arranged in ascending order of volume ratio.

[0106] Comparative Example 4

[0107] Comparative Example 4 provides a method for preparing a high-entropy alloy, and the steps are basically the same as those in Example 1, except that:

[0108] In step (2):

[0109] ③ Heat to 3400 °C at a heating rate of 10 °C / s and hold for 8 min.

[0110] ④ Cool to 500 °C in a furnace-cooling manner, and then turn over the ingot.

[0111] ⑤ Repeat steps ③ and ④ for cyclic melting 5 times to obtain a high-entropy alloy.

[0112] Comparative Example 5

[0113] Comparative Example 5 provides a preparation method of a high-entropy alloy. The steps are basically the same as those in Example 1, except that:

[0114] In step (2):

[0115] ③ Heat to 2700°C at a heating rate of 300°C / s and hold for 1 min.

[0116] ④ Cool down to 400°C in a furnace cooling manner.

[0117] ⑤ Repeat steps ③ and ④ for cyclic melting 5 times to obtain the high-entropy alloy.

[0118] To verify the progressiveness of the preparation method of the high-entropy alloy provided in the embodiments of the present application, taking the total mole of the high-entropy alloy as 100 mol, the molar ratios, masses, moles, densities, melting points, masses, volumes, and volume ratios of the high-entropy alloy raw materials in Examples 1 to 3 are shown in Table 1 below (other embodiments and comparative examples selected the high-entropy alloy of Example 1, so they are omitted). Taking Example 1, Example 2, Comparative Example 1, and Comparative Example 2 as examples, high-entropy alloys with a total mole of 100 mol were prepared, and the relative density, oxygen content, and phase structure of the prepared high-entropy alloys were detected. The detection results are shown in Table 2 below. Taking Example 1 as an example, the XRD pattern of the high-entropy alloy prepared by using the preparation method of Example 1 (the standard PDF card is 89-9000, and the crystal form is tungsten cubic) is as shown in the Figure 3 specification appendix. Taking Example 2 as an example, the elemental distribution of the alloy was detected by using the X-ray energy spectrometer of the scanning electron microscope for the high-entropy alloy prepared by the preparation method of Example 1, as shown in the Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 shown. Among them, Figure 4 is the SEM image of the high-entropy alloy prepared in Example 2, Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 are the EDS images of tungsten, tantalum, vanadium, titanium, and niobium metal elements in the high-entropy alloy, respectively.

[0119] Among them,

[0120] 1. The relative density of the high-entropy alloys prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 was detected by the Archimedes drainage method, and the steps are as follows:

[0121] (1) Weigh a clean sample to be measured with a mass of m0 in air.

[0122] (2) Wax the sample to be measured to prevent water from seeping into the interior of the sample. After waxing, measure the mass of the sample in air as m1.

[0123] (3) Place the waxed sample in water and measure its mass in water as m2.

[0124] (4) According to Archimedes' principle, the density (ρ m ) of the sample can be calculated by the following formula:

[0125] where ρ0 is the density of water.

[0126] (5) Compare the calculated density with the theoretical density of the sample to obtain the relative density. The theoretical density can be calculated from the density and atomic percentage of each constituent element.

[0127] 2. In the high-entropy alloys prepared in the examples and comparative examples, XRD was used to detect the oxygen content of the high-entropy alloys and observe the phase structure of the alloys.

[0128] Table 1

[0129] .

[0130] Table 2

[0131] .

[0132] From Table 1, Table 2, the attached Figure 3 , attached Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 at least the following conclusions can be drawn:

[0133] (1) As can be seen from Table 2, for the preparation method of the high-entropy alloy provided in the examples of the present application, although a bulk (metal layer) metal is used instead of metal powder for melting to obtain the high-entropy alloy, its relative density can reach more than 99%.

[0134] (2) From Table 2, the attached Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9It can be seen that for the preparation method of the high-entropy alloy provided by the embodiments of the present application, a metal structure in the form of a cylindrical block (metal layer) is used instead of metal powder for smelting to obtain the high-entropy alloy, which can reduce the oxidation of easily oxidized metals in the raw materials of the high-entropy alloy; and the melting points of the metals are set to decrease sequentially from the central axis of the metal cylinder radially outwards, reducing the burnout of low-melting-point elements during the smelting process.

[0135] (3) From Table 2 and the appended Figure 4 It can be seen that the high-entropy alloy prepared by the preparation method of the high-entropy alloy provided by the embodiments of the present application has a BCC single-phase structure (body-centered cubic (Body-Centered Cubic) crystal structure).

[0136] It should be noted that the present application is not limited to the above embodiments. The above embodiments are only examples, and embodiments with the same composition and the same function and effect as the technical idea within the technical solution scope of the present application are all included in the technical scope of the present application. In addition, within the scope not departing from the gist of the present application, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways constructed by combining some constituent elements of the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing a high entropy alloy, characterized in that: The steps include: The metal cylinder of the high entropy alloy raw material is melted to obtain the high entropy alloy; The high entropy alloy raw materials include four or more of W, Nb, Co, Ta, Mo, Ti, V, Cr, and Zr; N metal layers are arranged radially outward from the central axis of the metal cylinder, and the melting point of the nth metal layer is lower than the melting point of the n+1th metal layer; Wherein, n is 1, 2, 3, ..., N-1, and N is a positive integer; The preparation of the metal cylinder comprises the following steps: According to the set volume ratio of the high entropy alloy raw material, the size of the metal cylinder and the total molar amount of the high entropy alloy, each metal material in the high entropy alloy raw material is machined into a corresponding metal layer; The metal layers are sleeved to obtain the metal cylinder; The smelting method is suspension smelting; the conditions of the suspension smelting include: being carried out in an inert gas atmosphere, the smelting temperature is 2800°C to 3300°C, the smelting times are more than 5 times, and the smelting time for each time is 3min to 5min.

2. The method for preparing a high entropy alloy according to claim 1, characterized in that: The difference between the melting point of the n+1th metal layer and the melting point of the nth metal layer is 55° C. to 1563° C.

3. The method for preparing a high entropy alloy according to claim 1, characterized in that: In the metal cylinder, the nth metal layer and the (n+1)th metal layer are interference fit.

4. The method for preparing a high entropy alloy according to claim 1, characterized in that: The difference between the diameter of the bottom surface of the outer wall of the nth metal layer and the diameter of the bottom surface of the inner wall of the (n+1)th metal layer is 0.01 mm to 0.06 mm.

5. The method for preparing a high entropy alloy according to claim 1, characterized in that: The bottom diameter of the metal cylinder is 30 mm to 200 mm.

6. The method for preparing a high entropy alloy according to claim 1, characterized in that: The suspension smelting step comprises: placing the metal cylinder in a suspension smelting furnace; The suspension melting furnace was evacuated to a vacuum of 1 × 10 -3 After the pressure is below Pa, fill with argon atmosphere until the gas pressure is 0.01MPa~0.1MPa; Melting steps: heating to 2800℃~3300℃ at a heating rate of 50℃ / s~150℃ / s, keeping warm for 3min~5min, cooling to 25℃~200℃ with the furnace, and turning the ingot; The smelting step is repeated for more than 5 times to obtain the high entropy alloy.

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