High-entropy alloy with nano-scale heterostructure and preparation method thereof

Abstract

The application discloses a high-entropy alloy with nano-scale heterogeneous structure and a preparation method thereof, and comprises the following steps: mixing Al, Co, Cr, Ni and V particles to obtain solid mixed particles; performing vacuumizing treatment on a vacuum melting furnace and introducing protective gas, and then melting the solid mixed particles to obtain an AlCoCrNiV high-entropy alloy sample; performing wire cutting and rough machining on the AlCoCrNiV sample; and performing mechanical property testing and high-temperature cyclic oxidation testing on the high-entropy alloy sample, and then obtaining the microhardness, compressive strength and high-temperature oxidation resistance of the high-entropy alloy AlCoCrNiV. The method can obtain a high-entropy alloy block with uniform structure through vacuum arc melting, and the microstructure of the high-entropy alloy is changed by adding Al, so that the nano-scale precipitated phase heterogeneous structure is uniformly distributed in the matrix, and the mechanical properties such as the microhardness and yield strength of the material are effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alloy materials, and particularly relates to a high-entropy alloy with a nano-scale heterogeneous structure and a preparation method thereof. BACKGROUND

[0002] With the development of aerospace and military industry, traditional metals and alloys cannot meet the demand for material performance and special functions. Since the 21st century, a new type of alloy, high-entropy alloy, has emerged. The high-entropy alloy is composed of five or more elements, and the atomic proportion of each element is between 5% and 35%. Due to the complexity of the middle part of the quinary phase diagram, adjusting the content of each element or different elements may obtain high-entropy alloys with different properties.

[0003] Due to the unique composition of the high-entropy alloy, it has four special effects: high-entropy effect, lattice distortion effect, delayed diffusion effect and component synergy effect. Based on these four special effects, the composition combination of high-entropy alloy tends to be diversified. Since high-entropy alloys mostly use 3d transition metals and refractory metals, there are higher requirements for sample preparation temperature. Although the traditional face-centered cubic system high-entropy alloy has the characteristics of good plasticity, it is a disadvantage that its strength and hardness are insufficient. In view of this disadvantage, the application adds the body-centered cubic refractory metal element vanadium to replace the face-centered cubic metal element iron, and adjusts the content of aluminum metal element, obtains a nano-scale heterogeneous structure, obtains uniform nano precipitates, and thus improves the strength and hardness of the high-entropy alloy. And the service conditions required by cutting-edge technology are mostly harsh, and most of them require certain strength and oxidation resistance at high temperature. The addition of Al element can also improve the oxidation resistance of the high-entropy alloy.

[0004] Therefore, the AlCoCrNiV high-entropy alloy is prepared by a vacuum arc melting method; traditional metallurgical casting cannot meet the temperature and vacuum environment requirements. By adjusting the element content in the high-entropy alloy, the microstructure of the high-entropy alloy is controlled and the mechanical properties and high-temperature oxidation resistance of the high-entropy alloy are improved. SUMMARY

[0005] The technical problem to be solved by the application is to provide a high-entropy alloy with a nano-scale heterogeneous structure and a preparation method thereof to solve the technical problem of low strength and hardness of the face-centered cubic system high-entropy alloy.

[0006] The application adopts the following technical scheme:

[0007] A preparation method of a high-entropy alloy with a nano-scale heterogeneous structure, wherein Al, Co, Cr, Ni and V elemental particles are mixed to obtain solid particles; the solid particles are subjected to vacuum arc melting to obtain an AlCoCrNiV high-strength high-entropy alloy.

[0008] Specifically, in the solid particles, the Al single-element particles are 0% to 4% by mass percentage, the Co single-element particles are 26.5% to 32.5%, the Cr single-element particles are 16.5% to 23.5%, the Ni single-element particles are 26.5% to 32.5%, and the V single-element particles are 16.5% to 23.5%.

[0009] Specifically, the number of vacuum arc melting is greater than or equal to 5 times.

[0010] Specifically, during the vacuum arc melting, the distance between the arc striking needle and the solid particles is 3.5 to 3.7 mm.

[0011] Specifically, Ar gas is introduced during the vacuum arc melting.

[0012] Further, the number of Ar gas introduction is greater than or equal to 3 times.

[0013] Specifically, during the vacuum arc melting, the actual temperature of the circulating water is set to be 22 to 24℃, and the melting current is adjusted to be 150 to 160 A.

[0014] Specifically, during the vacuum arc melting, the gas pressure is controlled to be less than 0.05 MPa, the arc striking current is 20 A, the melting current is 150 to 160 A, the melting temperature is greater than 2000℃, and the melting time is 2 to 3 minutes.

[0015] Another technical solution of the present application is a high-entropy alloy with a nano-scale heterogeneous structure.

[0016] Specifically, the microhardness of the high-strength high-entropy alloy is 239.2 to 619.3 HV, the compressive yield strength is 232 to 1239 MPa, the compressive strength is 1800 to 1850 MPa, and the oxidation weight gain after 100h 700℃ high-temperature cyclic oxidation experiment is 0.95 to 2.14 mg·cm -2 .

[0017] Compared with the prior art, the present application has at least the following beneficial effects:

[0018] A preparation method of a high-entropy alloy with a nano-scale heterogeneous structure, by using a vacuum arc melting method, an AlCoCrNiV high-entropy alloy material is prepared, the addition of V element changes the structure of the high-entropy alloy, and a nano-scale uniform precipitated phase is produced, by adjusting the content of Al element, the yield strength, compressive strength and microhardness and other mechanical properties and high-temperature oxidation resistance of the high-entropy alloy are effectively improved, which has very important significance.

[0019] Further, the Al single-element particles are 0% to 4%, the Co single-element particles are 26.5% to 32.5%, the Cr single-element particles are 16.5% to 23.5%, the Ni single-element particles are 26.5% to 32.5%, and the V single-element particles are 16.5% to 23.5% in percentage of mass, compared with the traditional face-centered cubic system high-entropy alloy, the high-entropy alloy has higher strength and hardness.

[0020] Further, by adjusting the content of the alloying element Al in AlCoCrNiV, on one hand, the addition of the alloying element increases the content of the phase with high hardness, changes the phase composition, and on the other hand, the alloying element can play the role of solid solution strengthening and cause high-entropy alloy lattice distortion, so that the strength of the structural material can be effectively improved.

[0021] Further, the distance between the arc drawing needle and the solid particles is adjusted to be 3.5 to 3.7 mm, on one hand, the distance between the arc drawing needle and the solid particles is prevented from being too close, and the needle is prevented from being stuck during initial smelting, and on the other hand, the distance between the arc drawing needle and the solid particles is prevented from being too far, so that the arc drawing is difficult, and the smelting process is affected.

[0022] Further, during smelting, three vacuumizing treatments are performed, and three times of argon is filled, so that the smelting atmosphere is finally ensured to be argon, the oxidation of the smelted sample caused by air at a high temperature is prevented, and the cooling circulating water at 22 DEG C is introduced, so as to accelerate the cooling rate of the smelting process, reduce the segregation of the sample, and ensure the homogenization of the structure to the greatest extent. The sample is repeatedly smelted for 5 times, so that the solid particles can be fully smelted, the sample is uniformly distributed, the voltage is adjusted to be a fixed voltage during the smelting process, and the current is adjusted to be 150 to 160 A, on one hand, the current is prevented from being too low, so that the solid particles are not fully melted, and the smelting efficiency is reduced, and on the other hand, the current is prevented from being too high, so that the alloying element is burned, and the mechanical properties of the material are affected.

[0023] Further, after the content of the Al element is adjusted, the phase and the structure of the high-entropy alloy are changed. The phases in the high-entropy alloy are divided into three kinds, the first kind is a hard intermetallic compound phase, the second kind is a BCC phase with moderate hardness, and the third kind is an FCC phase with the lowest hardness. With the increase of the Al element, the alloy shows the trend that the strength and the hardness are higher and higher (the hard and brittle intermetallic compound phase is more and more), and the plasticity is worse and worse. In addition, due to the difference of the binary mixing enthalpy and the element diffusion rate, some different scale heterogeneous structures such as short-range ordered structure and nano precipitates are precipitated in the high-entropy alloy. The existence of these heterogeneous structures hinders the dislocation movement, so that the strength and the hardness of the high-entropy alloy are improved.

[0024] In summary, the microstructure of the material is changed by the non-consumable vacuum arc smelting, and the mechanical properties such as the microhardness and the compressive strength and the high-temperature oxidation resistance of the material are effectively improved.

[0025] The technical solutions of the present application will be further described in detail below with the help of the accompanying drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The microstructure of the equal atomic ratio high-entropy alloy without adding Al element;

[0027] Figure 2 The microstructure of the non-equal atomic ratio high-entropy alloy without adding Al element;

[0028] Figure 3 The microstructure of the non-equal atomic ratio high-entropy alloy with 4% Al element;

[0029] Figure 4 The TEM bright field image of the non-equal atomic ratio high-entropy alloy with 4% Al element;

[0030] Figure 5 The compression stress-strain curves of different high-entropy alloys;

[0031] Figure 6 The hardness of different high-entropy alloys;

[0032] Figure 7 The oxidation weight gain curves of different high-entropy alloys. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be further described in detail below with the help of the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0034] In the present application, all the embodiments and preferred embodiments mentioned in the present application can be combined to form new technical solutions, if not specifically stated.

[0035] In the present application, all the technical features and preferred features mentioned in the present application can be combined to form new technical solutions, if not specifically stated.

[0036] In the present application, the percentage (%) or part refers to the percentage by weight or weight part of the composition, if not specifically stated.

[0037] In the present application, all the components or preferred components involved can be combined to form new technical solutions, if not specifically stated.

[0038] In the present application, unless otherwise specified, the numerical range "a~b" represents a shorthand notation for any real combination of numbers between a and b, wherein a and b are both real numbers. For example, the numerical range "6~22" represents that all real numbers between "6~22" have been listed herein, and "6~22" is only a shorthand notation for these numerical combinations.

[0039] The lower limit and the upper limit of the range disclosed in the present application can be one or more lower limits and one or more upper limits, respectively.

[0040] In the present application, the term "and / or" used herein means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0041] In the present application, unless otherwise specified, each reaction or operation step can be carried out sequentially or in accordance with the sequence. Preferably, the reaction method herein is carried out sequentially.

[0042] Unless otherwise specified, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to that described can also be applied in the present application.

[0043] The present application provides a high-entropy alloy with a nano-scale heterogeneous structure and a preparation method thereof, wherein Al, Co, Cr, Ni, and V particles are mixed to obtain solid particles; a vacuum melting furnace is subjected to vacuumizing treatment and protective gas is introduced, and then the solid particles are subjected to melting to obtain an AlCoCrNiV high-entropy alloy sample; the AlCoCrNiV sample is subjected to wire cutting and rough machining; the AlCoCrNiV sample is subjected to performance testing, and then the microhardness and compressive strength of the high-strength high-toughness high-entropy alloy AlCoCrNiV are obtained. The method of the present application obtains a high-entropy alloy bulk body with uniform organization through vacuum arc melting, and changes the microstructure of the high-entropy alloy by adding Al, thereby effectively improving the mechanical properties such as microhardness and compressive strength of the material.

[0044] The present application provides a preparation method of a high-entropy alloy with a nano-scale heterogeneous structure, comprising the following steps:

[0045] S1, mixing Al, Co, Cr, Ni, and V elemental particles to obtain solid particles;

[0046] According to the mass fraction, 0%~4% of Al elemental particles, 26.5%~32.5% of Co elemental particles, 16.5%~23.5% of Cr elemental particles, 26.5%~32.5% of Ni elemental particles, and 16.5%~23.5% of V elemental particles are weighed.

[0047] The mass is accurate to the hundredth place (<0.05g) when weighing.

[0048] S2, arc melting

[0049] The mixed solid particles weighed in step S1 are placed into a clean furnace bin, the distance between the arc striking needle and the solid particles is adjusted to 3.5-3.7 mm, and the bin door is closed; vacuum treatment is performed by pumping, after the vacuum treatment is completed, Ar gas is flushed in; the pumping and gas releasing operation is repeated at least 3 times, to ensure that the protective atmosphere in the bin during melting is Ar gas; the cooling circulating water is turned on, and the actual temperature and the preset temperature of the circulating water are set to 22-24 DEG C; the melting current is adjusted to 150-160 A, and the voltage is a fixed voltage, the solid particles are melted, and the melting is repeated at least 5 times, to obtain an AlCoCrNiV high-entropy alloy sample.

[0050] S3, the AlCoCrNiV high-entropy alloy sample obtained in step S2 is subjected to wire cutting, and then rough machining is performed;

[0051] Rhizosphere with a predetermined size of 10*5*1mm-10*5*1.2mm and The AlCoCrNiV high-entropy alloy sample prepared in step S2 is subjected to wire cutting treatment, and then polished with 200# sandpaper until the sample surface exposes a metallic luster.

[0052] S4, the AlCoCrNiV sample obtained in step S3 is subjected to mechanical property testing and high-temperature cyclic oxidation testing.

[0053] First, the original weight of the sample is recorded, the initial temperature of the high-temperature cyclic oxidation test is room temperature, the heating time is 70 min, the terminal heating temperature is 700 DEG C, the holding temperature is 700 DEG C, the holding time is 600 min, and then the furnace is cooled to room temperature, the weight after oxidation is recorded, and the process is repeated ten times, for a total of 100 h of holding, to obtain an oxidation weight gain curve.

[0054] The AlCoCrNiV high-entropy alloy with a nano-scale heterogeneous structure has a microhardness of 239.2-619.3 HV, a compressive yield strength of 232-1239 MPa, a compressive strength of 1800-1850 MPa, and an oxidation weight gain of 0.95-2.14 mg·cm -2 .

[0055] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments 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.

[0056] Embodiment 1

[0057] The CoCrNiV high-entropy alloy material is prepared by mixing 0% Al elemental particles, 26.5% Co elemental particles, 23.5% Cr elemental particles, 26.5% Ni elemental particles and 23.5% V elemental particles according to the mass fraction by non-consumable vacuum arc melting.

[0058] Before arc melting, the furnace bin is first wiped clean with alcohol-soaked dust-free cloth, and after the mixed solid particles are placed in the bin, the distance between the arc needle and the solid particles is adjusted to 3.7 mm, then the bin door is closed, and the process of three times of vacuum pumping and three times of Ar gas filling is carried out. During each vacuum pumping process, the pressure gauge is kept at near vacuum state for 3 min, and during each Ar gas filling process, the pressure gauge is kept at micro-positive pressure for 1 min. During the third Ar gas filling process, the furnace is kept at a negative pressure of 0.05 MPa to ensure that the atmosphere during melting is Ar gas protective gas. Then the cooling circulating water is opened, the circulating water temperature is set to 22℃, and then the melting current is adjusted to 20 A. After the arc is successfully struck, the current is slowly adjusted to 150 A, and the mixed solid particles are melted. The melting process needs to be repeated for 5 times to ensure that the components of the sample are uniform to the greatest extent, and the high-entropy alloy material CoCrNiV is prepared. The prepared high-entropy alloy button sample is designed to have a size of 10x5x1mm and φ4x6mm, and the wire-cutting sample is polished to a metal luster with 200# sandpaper. The microstructure, mechanical properties and high-temperature oxidation resistance are observed and tested.

[0059] The embodiment can effectively improve the strength of the material, and the prepared sample has relatively uniform phase distribution and relatively few cracks and pore defects. The microhardness of the high-entropy alloy material AlCoCrNiV is 619.3 HV. According to the requirements of the ASTM C633 standard, the yield strength of the high-entropy alloy CoCrNiV is 1239 MPa, the compressive strength is 1828 MPa, and the compressive strain is 20.1% measured on a universal testing machine. After 100 h of high-temperature cyclic oxidation test, the oxidation weight gain of the alloy is 2.05 mg·cm -2 .

[0060] The application discloses a preparation method of a high-entropy alloy with high strength and toughness, oxidation resistance and a nano-scale heterogeneous structure. As can be seen from Embodiment 1, although the high-entropy alloy has high strength and hardness, the plasticity is poor, and no nano precipitated phase exists. In order to improve the brittleness of the high-entropy alloy and optimize the high-temperature oxidation resistance, the scheme in the application is improved. The content of the body-centered cubic elements V and Cr is reduced, the four elements CoCrNiV are changed from equal atomic ratio to non-equal atomic ratio, and the new embodiment is prepared according to the process in the original procedure.

[0061] Embodiment 2

[0062] AlCoCrNiV high-entropy alloy material is prepared by non-consumable vacuum arc melting, and 0% of Al single-element particles, 32.5% of Co single-element particles, 17.5% of Cr single-element particles, 32.5% of Ni single-element particles and 17.5% of V single-element particles are mixed according to mass fraction. The distance between the arc needle and the solid particles is 3.6 mm, the melting current is 155 A, the cooling circulating water temperature is 23 DEG C, and the non-equal atomic ratio high-entropy alloy CoCrNiV is prepared. The wire cutting with a designed size of 10*5*1.1 mm and φ4*6 mm is carried out, and the wire-cut sample is polished to a metal luster by using 200# sandpaper. The organizational structure is observed, the mechanical properties and the high-temperature oxidation resistance are tested.

[0063] The sample prepared in the embodiment has relatively uniform phase distribution and almost no cracks and pore defects. Only one single phase, namely the FCC phase, exists in the high-entropy alloy material CoCrNiV, the hardness is 239.2 HV, according to the requirements of the ASTM C633 standard, the compressive yield strength of the high-entropy alloy CoCrNiV is 232 MPa measured on a universal testing machine, the sample cannot be broken, and no compressive strength data is obtained. The high-temperature cyclic oxidation experiment is carried out on the coarsely processed sample, and after 10 cycles of 100 h at 700 DEG C, the oxidation weight gain of the alloy is 2.14 mg·cm -2 .

[0064] Embodiment 3

[0065] The AlCoCrNiV high-entropy alloy material is prepared by mixing 4% Al single-element particles, 31.5% Co single-element particles, 16.5% Cr single-element particles, 31.5% Ni single-element particles and 16.5% V single-element particles in terms of mass fraction, the distance between the arc needle and the solid particles is 3.5 mm before smelting, the smelting current is adjusted to 160 A, and the cooling circulating water temperature is opened to 24℃. The wire-cutting sample is polished to a metallic luster with 200# sandpaper. The microstructure is observed, the mechanical properties are tested, and the high-temperature oxidation resistance is tested.

[0066] The strength and hardness of the material are effectively improved based on the embodiment 2, the phase distribution of the high-entropy alloy AlCoCrNiV prepared by the embodiment is relatively uniform, the uniform Cr-rich nano precipitates are found in the FCC matrix through TEM microstructure observation, the strength and hardness are improved, the microhardness of the high-entropy alloy material AlCoCrNiV prepared by the method is 351.7HV, the yield strength of the high-entropy alloy material AlCoCrNiV is 568MPa measured on the universal testing machine according to the ASTM C633 standard requirement, the sample cannot be broken, and the compressive strength data is not available. The high-temperature cyclic oxidation experiment is carried out on the coarsely processed sample, after 10 cycles of 100h test at 700℃, the oxidation weight gain of the alloy is 0.95mg·cm -2 After the Al element content is increased, the yield strength and hardness of the high-entropy alloy are improved, and the high-temperature oxidation resistance is also improved.

[0067] The AlCoCrFeNi high-entropy alloy prepared by the spark plasma sintering (sps) method has high compressive yield strength, but the plasticity is poor, and the plasticity of the high-entropy alloy is not more than 15%. In the embodiment, the high-entropy alloy has 20% plasticity before improvement under the condition of similar yield strength, and the plasticity is improved after improvement and cannot be broken in the compression experiment.

[0068] Please refer to Figure 1 The microstructure diagram of the equal-atomic-ratio high-entropy alloy CoCrNiV without adding Al element is shown in the figure. It can be found from the observation of the SEM diagram that the grain boundary of the high-entropy alloy is not obvious, and the distribution of the two intermetallic compounds tends to be non-uniform, which is due to the fact that the body-centered cubic structure of the refractory metal element deepens the lattice distortion effect of the high-entropy alloy, so that the fluidity of the alloy is poor, thereby leading to poor uniformity of the microstructure.

[0069] Please refer to Figure 2Figure 4 is a structure diagram of the non-equatomic high-entropy alloy CoCrNiV without adding Al element. It can be found from the structure in the SEM image that the high-entropy alloy is single-phase FCC structure, and the structure arrangement is relatively neat, and no second phase or precipitated phase is generated.

[0070] Referring to Figure 3 Figure 5 is a structure diagram of the non-equatomic high-entropy alloy AlCoCrNiV when the mass fraction of Al element is 4%. It can be found from the structure in the SEM image that, in addition to the FCC phase of the matrix, small nanometer precipitated phases are uniformly distributed in the matrix, and the nanometer-scale heterogeneous structure improves the strength and hardness of the high-entropy alloy.

[0071] Referring to Figure 4 Figure 6 is a bright-field TEM image of the non-equatomic high-entropy alloy AlCoCrNiV when the mass fraction of Al element is 4%. It can be found from the image that, in the matrix structure, nanometer-scale precipitated phases with a particle size of 20 nm to 40 nm are precipitated, and the precipitated phase is a Cr-rich region through energy spectrum comparison. The uniformly distributed nanometer-scale precipitated phase has a gain effect on the strength and hardness of the material, and the precipitation of Cr element can effectively improve the oxidation resistance of the high-entropy alloy.

[0072] Referring to Figure 5 Figure 7 is a compression stress-strain diagram of the high-entropy alloy AlCoCrNiV. It can be found through comparative analysis that the optimized high-entropy alloy has good plasticity, and the high-entropy alloy with 4% Al element has higher yield strength than the non-equatomic high-entropy alloy without adding Al element, which is increased from 232 MPa to 568 MPa, which is caused by the uniform distribution of nanometer precipitated phases; the plasticity of the high-entropy alloy is from 20.1% compression strain of the equatomic high-entropy alloy to non-compression strain of the non-equatomic high-entropy alloy, which is caused by the change of the phase structure of the high-entropy alloy due to the regulation of the composition of the high-entropy alloy, and the brittle intermetallic compound phase is changed to the plastic FCC phase.

[0073] Referring to Figure 6 Figure 8 is a hardness comparison diagram of the high-entropy alloy AlCoCrNiV. It can be found through comparative analysis that the hardness of the equatomic high-entropy alloy is the highest, which is 619.3 HV, because the main phase is an intermetallic compound phase; the hardness of the non-equatomic high-entropy alloy is lower, which is composed of FCC phase, and the addition of Al element causes the precipitation of Cr-rich nanometer precipitated phases in the matrix, which improves the hardness of the high-entropy alloy, which is increased from 239.2 HV to 351.7 HV.

[0074] Referring to Figure 7As shown in Fig. 2, the weight gain curves of the high-entropy alloy AlCoCrNiV are shown. It is found by comparative analysis that the weight gain of the equal-atom-ratio high-entropy alloy is almost equal to that of the non-equal-atom-ratio high-entropy alloy, but the weight gain of the high-entropy alloy is reduced from 2.14 mg·cm-2 to 0.95 mg·cm-2 by adding Al element in the non-equal-atom-ratio high-entropy alloy, which improves the oxidation resistance of the high-entropy alloy. -2 -2

[0075] In summary, the high-entropy alloy with nano-scale heterogeneous structure and the preparation method thereof change the organizational structure of the material, effectively improve the microhardness and strength of the material, and improve the high-temperature oxidation resistance of the high-entropy alloy.

[0076] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.​​

Claims

1. A method for preparing a high entropy alloy with a nanoscale heterostructure, characterized in that: Al, Co, Cr, Ni, and V single-substance particles are mixed to obtain solid particles, wherein, by mass percentage, Al single-substance particles account for 4%, Co single-substance particles account for 26.5%-32.5%, Cr single-substance particles account for 16.5%-23.5%, Ni single-substance particles account for 26.5%-32.5%, and V single-substance particles account for 16.5%-23.5%; the solid particles are vacuum arc melted to obtain an AlCoCrNiV high-strength high-entropy alloy.

2. The method for preparing a high entropy alloy having a nanoscale heterostructure according to claim 1, characterized in that The number of vacuum arc melting is greater than or equal to 5 times.

3. The method for preparing a high entropy alloy having a nanoscale heterostructure according to claim 1, wherein: During the vacuum arc melting process, the distance between the arc needle and the solid particles is 3.5~3.7mm.

4. The method for preparing a high entropy alloy having a nanoscale heterostructure according to claim 1, wherein: Ar gas is introduced during the vacuum arc melting process.

5. The method for preparing a high entropy alloy having a nanoscale heterostructure according to claim 4, characterized in that: The number of times Ar gas is introduced is greater than or equal to 3 times.

6. The method for preparing a high entropy alloy having a nanoscale heterostructure according to claim 1, wherein: During vacuum arc melting, set the actual temperature of the circulating water and the preset temperature to 22~24℃; adjust the melting current to 150~160A.

7. The method for preparing a high entropy alloy having a nanoscale heterostructure according to claim 1, wherein: During the vacuum arc melting process, the gas pressure is controlled to be less than 0.05MPa, the arc striking current is 20A, the melting current is 150~160A, the melting temperature is greater than 2000℃, and the melting time is 2~3 minutes.

8. A high entropy alloy with a nanoscale heterostructure, characterized in that: Prepared according to the preparation method according to claim 1.

9. The high entropy alloy having a nanoscale heterostructure according to claim 8, characterized in that: The microhardness of the high-strength high-entropy alloy is 239.2~619.3HV, the compressive yield strength is 232~1239MPa, the compressive strength is 1800~1850MPa, and the oxidation weight gain after 100h 700℃ high temperature cyclic oxidation test is 0.95~2.14mg·cm -2 .

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