AlCoCrFeNi2 dual-phase high-entropy alloy with high toughness, acid corrosion resistance and hydrogen embrittlement resistance and a preparation method thereof

Abstract

The application provides an AlCoCrFeNi2 dual-phase high-entropy alloy with high toughness, corrosion resistance and hydrogen embrittlement resistance, which contains, in percentage by mass, Al 8-9%, Co 18-19%, Cr 16-17%, Fe 17-18%, and Ni 37-38%, and is a stable dual-phase high-entropy alloy. The application also provides a preparation method of the high-entropy alloy, which regulates the microstructure of the alloy through simple and industrialized heat treatment. The AlCoCrFeNi2 high-entropy alloy has the phase composition characteristics of stable FCC and B2 phases, retains part of the heterogeneous lamellar region, and the refined microstructure improves the toughness, sulfuric acid corrosion resistance and hydrogen embrittlement resistance of the high-entropy alloy.

Description

Technical Field

[0001] This invention relates to a high-strength, high-toughness, corrosion-resistant, and hydrogen-embrittle-resistant AlCoCrFeNi2 dual-phase high-entropy alloy and its preparation method, belonging to the field of novel alloy materials and their preparation technology. Background Technology

[0002] High-entropy alloys are novel alloys containing multiple main elements, typically five or more, with each element accounting for 5–35 at.%. High-entropy alloys exhibit four core effects: entropy effect, lattice distortion effect, hysteresis diffusion effect, and cocktail effect. The entropy effect, in particular, makes high-entropy alloys more prone to forming simple solid solutions. These novel alloys can possess a variety of excellent properties, such as high strength, high toughness, good corrosion resistance, radiation resistance, and high-temperature oxidation resistance. They show promising application prospects in chemical production, aerospace, and petroleum equipment.

[0003] Currently, the design of this novel alloy mainly focuses on forming a proportional single-phase high-entropy alloy, which narrows the scope for exploring the alloy's composition. Furthermore, the strength of single face-centered cubic alloys is typically low (less than 700 MPa), and the toughness of single body-centered cubic alloys is poor (less than 15%), limiting the mechanical properties of high-entropy alloys. In addition, current research largely neglects the influence of microstructure control on the properties of high-entropy alloys. Summary of the Invention

[0004] This invention provides a high-strength, high-toughness, corrosion-resistant, and hydrogen-embrittle-resistant AlCoCrFeNi2 dual-phase high-entropy alloy. Its microstructure can be controlled through simple, industrially applicable heat treatment, thereby improving its mechanical properties, acid corrosion resistance, and hydrogen embrittlement resistance. This provides a high-performance new material for harsh industrial environments requiring high acid resistance and expands the design and preparation space of high-entropy alloys, which is of great significance for developing a variety of new materials with excellent properties. This invention also provides a method for preparing this alloy.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] The high-strength, high-toughness, corrosion-resistant, and hydrogen-embrittle-resistant AlCoCrFeNi2 dual-phase high-entropy alloy described in this invention contains, by mass percentage, 8-9% Al, 18-19% Co, 16-17% Cr, 17-18% Fe, and 37-38% Ni, and is a stable dual-phase high-entropy alloy.

[0007] Preferably, the high-strength, high-toughness, corrosion-resistant, and hydrogen-embrittlement-resistant AlCoCrFeNi2 is a non-equiatomic ratio dual-phase high-entropy alloy, which breaks through the limitation of equiatomic ratio. Its alloy phase is composed of a stable FCC phase and a B2 phase, wherein the FCC phase accounts for 62% to 64% with an average grain size of 780 to 850 nm; the B2 phase accounts for 36% to 38% with an average grain size of 930 to 990 nm.

[0008] The high-strength, high-toughness, corrosion-resistant, and hydrogen-embrittle-resistant AlCoCrFeNi2 dual-phase high-entropy alloy of this invention is initially prepared in a WKⅡ type vacuum arc furnace, and subsequently requires simple and industrially feasible cold rolling and heat treatment. The preparation method includes the following steps:

[0009] Step 1, Cleaning and Weighing of Materials: Place Al, Co, Cr, Fe, and Ni metals into containers respectively, clean and dry them, and then convert them into mass according to the atomic percentage of AlCoCrFeNi2 high-entropy alloy and weigh them. The mass percentage of each element is: Al 8-9%, Co 18-19%, Cr 16-17%, Fe 17-18%, Ni 37-38%.

[0010] Step 2, smelting and casting: The weighed metal from step 1 is placed in a copper dry pot of a vacuum electric arc furnace. After evacuation, nitrogen gas is introduced, and then the arc is ignited for smelting and casting to obtain an alloy block.

[0011] Step 3, cold rolling and heat treatment: After removing the skin of the alloy block obtained in step 2 by wire cutting, it is subjected to multiple passes of cold rolling and heat treatment to obtain the high-entropy alloy.

[0012] Preferably, in step two, a vacuum is evacuated to below 1.0 × 10⁻⁶ using a combination of a mechanical pump and a molecular pump. -4 Pa, then argon gas is introduced to -0.05 MPa, and then arc ignition melting is carried out.

[0013] Preferably, in step two, the melting current is 180-300A, the single melting time is 60-100s, and the melting is performed 3-5 times.

[0014] Preferably, in step three, the thickness of the alloy block skin removed by wire cutting is 0.3 to 0.5 mm.

[0015] Preferably, in step three, multiple passes of cold rolling are performed to reduce the thickness of the original block to 20%, with each reduction not exceeding 0.5 mm.

[0016] Preferably, in step three, after multiple passes of cold rolling, the alloy is placed in a heat treatment furnace and heated from room temperature to 950°C at a rate of 10°C / min, held at that temperature for 1 hour, and then water-cooled.

[0017] In one specific embodiment of the present invention, the method for preparing the high-entropy alloy includes the following steps:

[0018] (1) Cleaning, Weighing and Discharging: Some of the required metal materials are prone to forming an oxide film in the air, which affects the accuracy of weighing and the performance of the alloy. Therefore, the initial material needs to be polished before weighing to restore the metallic luster of the raw material surface. Then, it should be cleaned with acetone and anhydrous ethanol in sequence, and dried with a hair dryer before use. After that, the material is weighed using a balance with an accuracy of 0.1 mg.

[0019] Before loading the materials, clean the inside of the electric arc furnace with anhydrous ethanol to ensure that there is no dust or metal deposits inside. Then, in order of increasing melting point, add Al, Ni, Co, Fe, and Cr into the copper dry pot, and place the smooth titanium ball into the dry pot in the middle of the vacuum electric arc furnace. Then close the furnace door.

[0020] (2) Vacuuming: First, use a mechanical pump to evacuate the electric arc furnace. When the pressure is less than 5 Pa, turn off the mechanical pump and turn on the molecular pump to evacuate to below 1.0 × 10⁻⁶ Pa. -4 Pa, then nitrogen gas is slowly introduced into the chamber through a pinhole valve to raise the vacuum level to about 0 Pa. A vacuum pump and a molecular pump are then used to evacuate the chamber to 1.0 × 10 Pa. -4 Pa, repeat the above process three times. Finally, slowly introduce argon gas into the chamber through the pinhole valve until the pressure reaches approximately -0.05 MPa.

[0021] (3) Melting: First, melt the titanium ball in the intermediate crucible three times to remove residual oxygen in the cavity. The melting current is 150-200A, and the time is 60-100s. After melting three times, the titanium ball should be white after solidification. Then melt the target alloy with a current of 180-300A, each time lasting 60-100s. During melting, use an external arc flame and slightly rotate the arc rod to maximize and uniformly heat the material. Repeat the melting 3-5 times, turning the alloy over each time to ensure the uniformity of the high-entropy alloy. After melting, let it cool for 20 minutes, and then use the operating spoon of the electric arc furnace to move the high-entropy alloy ingot from the copper dry pot to the copper mold.

[0022] (4) Suction casting: Operate the arc rod at a current of 160A, sweeping around the high-entropy alloy ingot, and then suddenly increase the current to 300A to completely melt the ingot into liquid and quickly drop it into the copper mold. After standing and cooling for 20 minutes, remove the high-entropy alloy from the copper mold. The inner cavity of the copper mold has dimensions of 15×15×60mm. 3 .

[0023] (5) Cold rolling and heat treatment: The rectangular alloy block after melting and casting is de-skinned by wire cutting to remove the outer skin, with a thickness of 0.3-0.5 mm. Then, it is cold rolled in multiple passes to 20% of the original block thickness, with each reduction not exceeding 0.5 mm. The alloy is then placed in a heat treatment furnace and heated from room temperature to 650-1200℃ at a rate of 10℃ / min. After holding at 650-1200℃ for 1 hour, it is water-cooled.

[0024] This invention provides a non-equiatomic-ratio dual-phase AlCoCrFeNi2 high-entropy alloy, whose microstructure can be controlled through simple and industrially applicable heat treatment. The phase composition of this AlCoCrFeNi2 high-entropy alloy is characterized by stable FCC and B2 phases, retaining some heterogeneous lamellar regions. The refined microstructure simultaneously improves the high-entropy alloy's strength, toughness, resistance to sulfuric acid corrosion, and resistance to hydrogen embrittlement.

[0025] The advantages and beneficial effects of this invention are as follows:

[0026] The refined microstructure of the AlCoCrFeNi2 high-entropy alloy of this invention expands the design space for non-equiatomic-ratio two-phase high-entropy alloys and optimizes various properties of the alloy by combining microstructure control. The alloy exhibits optimal microstructure and properties at a heat treatment temperature of 950℃, with specific performance parameters as follows:

[0027] 1. The refined microstructure of the AlCoCrFeNi2 high-entropy alloy of the present invention is composed of a stable FCC phase and a B2 phase, wherein the FCC phase accounts for 62% to 64% and the average grain size is 780 to 850 nm; the B2 phase accounts for 36% to 38% and the average grain size is 930 to 990 nm.

[0028] 2. The AlCoCrFeNi2 high-entropy alloy with refined microstructure of the present invention has excellent strength and toughness matching, with a tensile strength of about 1.2 GPa and an elongation after fracture of about 20%.

[0029] 3. The AlCoCrFeNi2 high-entropy alloy with refined microstructure of the present invention exhibits excellent corrosion resistance in 0.1M H₂SO₄ solution, with a passivation current density of approximately 3.5 μA / cm². 2 The passivation region width is approximately 0.93V, and the passivation breaking potential is approximately 1.11V vs. SCE. It shows promising application prospects in chemical production, aerospace, and petroleum equipment.

[0030] 4. The AlCoCrFeNi2 high-entropy alloy with refined microstructure of the present invention still has good resistance to hydrogen embrittlement under high tensile strength, with a hydrogen embrittlement sensitivity of only 8.9%. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 XRD diffraction patterns of AlCoCrFeNi2 high-entropy alloys under different processing techniques;

[0033] Figure 2 The microstructure of AlCoCrFeNi2 high-entropy alloy under different processing techniques;

[0034] Figure 3 These are the engineering stress-strain curves of AlCoCrFeNi2 high-entropy alloy under different processing techniques;

[0035] Figure 4 The graph shows the potentiodynamic polarization curves of AlCoCrFeNi2 high-entropy alloys in the as-cast state and after cold rolling and heat treatment at 950℃ and 1200℃ in 0.1MH2SO4 solution.

[0036] Figure 5 This is an engineering stress-strain curve diagram of AlCoCrFeNi2 high-entropy alloy with and without hydrogen influence, which is the AlCoCrFeNi2 high-entropy alloy with and without hydrogen influence after cold rolling and heat treatment at 950℃. Detailed Implementation

[0037] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be described in detail below with reference to specific embodiments. It should be understood that the embodiments described in this specification are merely illustrative and not intended to limit the scope of the invention.

[0038] Example

[0039] A high-strength, high-toughness, corrosion-resistant, and hydrogen-embrittlement-resistant AlCoCrFeNi2 dual-phase high-entropy alloy was prepared, with the following mass percentages of each element: Al 8.51%, Co 18.59%, Cr 16.40%, Fe 17.62%, and Ni 38.88%. The preparation method includes the following steps:

[0040] (1) Grinding and cleaning: Some of the required materials are prone to forming an oxide film in the air, which affects the accuracy of weighing and the performance of the alloy. Therefore, the initial materials need to be ground before weighing to restore the metallic luster of the raw material surface, and then cleaned with acetone and anhydrous ethanol in sequence, and dried with a hair dryer before use.

[0041] (2) Weighing: Weigh the material using a balance with an accuracy of 0.1 mg.

[0042] (3) Cleaning of electric arc furnace: Before feeding, clean the inside of the electric arc furnace with anhydrous ethanol to ensure that there is no dust or metal deposits inside the electric arc furnace.

[0043] (4) Feeding: Al, Ni, Co, Fe and Cr are added to the copper dry pot in order of increasing melting point, and titanium balls are placed in the middle crucible.

[0044] (5) Vacuuming: First, use a mechanical pump to evacuate the electric arc furnace. When the pressure is less than 5 Pa, turn off the mechanical pump and turn on the molecular pump to evacuate to below 1.0 × 10⁻⁶ Pa. -4 Pa, then nitrogen gas is slowly introduced into the chamber through a pinhole valve to raise the vacuum level to about 0 Pa. A vacuum pump and a molecular pump are then used to evacuate the chamber to 1.0 × 10 Pa. -4 Pa, repeat the above process three times, and finally, slowly introduce argon gas into the chamber through the pinhole valve to about -0.05 MPa.

[0045] (6) Melting: First, melt the titanium ball in the intermediate crucible three times to remove residual oxygen in the cavity. The melting current is 150-200A, and the time is 60-100s. After melting three times, the titanium ball should be white after solidification. Then melt the target alloy with a current of 180-300A, each time lasting 60-100s. During the arc melting process, the current value and duration are within the above range, so an accurate current value cannot be obtained. During melting, use an external flame with a small arc and slightly rotate the arc rod to maximize and uniformly heat the material. Repeat the melting process five times, flipping the alloy each time to ensure the uniformity of the high-entropy alloy.

[0046] (7) Cooling: After melting, let it stand and cool for 20 minutes, and then use the operating spoon of the electric arc furnace to move the high entropy alloy ingot from the copper dry pot to the copper mold.

[0047] (8) Suction casting: Operate the arc rod at a current of 160A, sweeping around the high-entropy alloy ingot, and then suddenly increase the current to 300A to completely melt the ingot into liquid and quickly drop it into a copper mold. After standing and cooling for 20 minutes, remove the high-entropy alloy from the copper mold. The inner cavity of the copper mold has dimensions of 15×15×60mm. 3 .

[0048] (9) Cold rolling and heat treatment: The rectangular block after melting and casting is first subjected to wire cutting to remove the outer skin of the prepared alloy block, removing about 0.3-0.5 mm of thickness. Then, it is cold rolled in multiple passes to 20% of the original block thickness, with each reduction not exceeding 0.5 mm. Then, the alloy is placed in a heat treatment furnace and heated from room temperature to the target temperature at a rate of 10℃ / min. After holding at the target temperature for 1 hour, it is water cooled.

[0049] The applicant changed the heat treatment temperature in step (9), that is, after the multi-pass cold rolling was completed, the temperature was increased from room temperature to the target temperature in the furnace at a heating rate of 10℃ / min. The target temperatures were 650℃, 750℃, 850℃, 950℃ and 1200℃, respectively. Then, the temperature was kept at the target temperature for 1 hour and then water-cooled to obtain Examples 1 to 5.

[0050] In another example, step (9) was not performed after step (8) was completed, that is, only the as-cast high-entropy alloy was obtained, and it was not cold rolled and heat treated, resulting in Comparative Example 1.

[0051] Figure 1 The XRD diffraction patterns of AlCoCrFeNi2 high-entropy alloys under different heat treatment processes show that all AlCoCrFeNi2 high-entropy alloys under different heat treatment processes are composed of FCC and B2 phases. At heat treatment temperatures of 650–1200℃, the peak positions of the AlCoCrFeNi2 high-entropy alloy increase, indicating that the heat treatment process of this invention increases the crystal orientation of the AlCoCrFeNi2 alloy and simultaneously changes the phase ratio of the AlCoCrFeNi2 alloy.

[0052] Figure 2 This invention relates to the microstructure of AlCoCrFeNi2 high-entropy alloy under different processing techniques, where black represents the FCC phase and white represents the B2 phase. Under different cold rolling and heat treatment processes, the phase composition of the AlCoCrFeNi2 high-entropy alloy is the same as that of the as-cast AlCoCrFeNi2 high-entropy alloy, consisting of both FCC and B2 phases. Table 1 shows the average phase proportions of the AlCoCrFeNi2 high-entropy alloy under different heat treatment processes. At a heat treatment temperature of 650℃, the FCC phase proportion of the AlCoCrFeNi2 high-entropy alloy is approximately 59%, which is lower than the FCC phase proportion (78%) of the as-cast AlCoCrFeNi2 high-entropy alloy. As the heat treatment temperature increases, the FCC phase proportion in the AlCoCrFeNi2 high-entropy alloy increases slightly. When the heat treatment temperature is 1200℃, the FCC phase proportion in the AlCoCrFeNi2 high-entropy alloy is approximately 68%, still lower than the FCC phase proportion in the as-cast state. This indicates that the cold rolling and heat treatment processes involved in this invention do not change the phase composition of the AlCoCrFeNi2 high-entropy alloy, but reduce the proportion of the FCC phase and increase the proportion of the B2 phase.

[0053] Furthermore, different heat treatment processes alter the two-phase distribution and grain orientation of the AlCoCrFeNi2 high-entropy alloy. The microstructure of the as-cast AlCoCrFeNi2 high-entropy alloy consists of two-phase lamellar regions and island-like areas, with long, straight lamellars running longitudinally throughout the observation range. The FCC phase has a consistent orientation, and the B2 phase has a substantially similar orientation. In the heat treatment process of this invention, at temperatures between 650 and 950°C, the AlCoCrFeNi2 high-entropy alloy retains a heterogeneous lamellar structure, but the lamellars are shorter and no longer straight, consisting of grains with different orientations. This heterogeneous lamellar structure and uniform orientation are beneficial for improving the alloy's strength and toughness. At a heat treatment temperature of 1200°C, the AlCoCrFeNi2 high-entropy alloy completely loses its lamellar structure, consisting of two-phase recrystallized grains with a uniform orientation distribution. The applicant needs to clarify that grain orientation is not visible in black-and-white images and is only apparent in color images.

[0054] Table 2 shows the average grain size of the two phases of the AlCoCrFeNi2 high-entropy alloy under different processing techniques. As can be seen from Table 2, the heat treatment of this invention significantly refines the microstructure of the alloy. At a heat treatment temperature of 650℃, the grain sizes of the FCC and B2 phases of the AlCoCrFeNi2 high-entropy alloy are approximately 0.43 μm and 0.46 μm, respectively; at a heat treatment temperature of 950℃, the grain sizes of the FCC and B2 phases are approximately 0.83 μm and 0.98 μm, respectively. At heat treatment temperatures between 650 and 950℃, the two phases of the AlCoCrFeNi2 high-entropy alloy consist of recrystallized grains, with an average grain size of less than 1 μm. At a heat treatment temperature of 1200℃, the grain sizes of the two phases of the AlCoCrFeNi2 alloy are approximately 1.38 μm and 1.52 μm, respectively.

[0055] Table 1. Two-phase ratio of AlCoCrFeNi2 high-entropy alloy under different heat treatment processes

[0056]

[0057] Table 2. Average grain size of the two phases of AlCoCrFeNi2 high-entropy alloy under different heat treatment processes.

[0058]

[0059] Figure 3These are the engineering stress-strain curves of AlCoCrFeNi2 high-entropy alloy under different processing techniques. The yield strength and tensile strength of the as-cast AlCoCrFeNi2 high-entropy alloy are 490 MPa and 1000 MPa, respectively, with an elongation after fracture of 12%. After the processing of this invention, the strength of the AlCoCrFeNi2 high-entropy alloy is significantly higher than that of the untreated as-cast AlCoCrFeNi2 high-entropy alloy. Specifically, when the heat treatment temperature after cold rolling is 650℃, the tensile strength of the AlCoCrFeNi2 high-entropy alloy is the highest, not less than 1.7 GPa, while the elongation after fracture is only about 4%. Figure 3 It can be seen that when the heat treatment temperature after cold rolling is 950℃ and 1200℃, the elongation after fracture of the AlCoCrFeNi2 high-entropy alloy is not less than 20%, and the tensile strength is not less than 1.2GPa and 1GPa, respectively. Considering the strength and toughness matching of the AlCoCrFeNi2 high-entropy alloy, the optimal processing technology for the AlCoCrFeNi2 high-entropy alloy is determined to be a heat treatment temperature of 950℃ after cold rolling.

[0060] Figure 4 This is a potentiodynamic polarization curve of AlCoCrFeNi2 high-entropy alloy in the as-cast state and after cold rolling heat treatment at 950℃ and 1200℃ in 0.1MH2SO4 solution. The curve shows that the passivation current density of the as-cast AlCoCrFeNi2 high-entropy alloy in 0.1MH2SO4 solution is approximately 4.6 μA / cm². 2 The passivation range is approximately 810 mV; the passivation current density of the AlCoCrFeNi2 high-entropy alloy after cold rolling and heat treatment at temperatures of 950°C and 1200°C in step three of this invention is approximately 3.5 μA / cm². 2 The passivation range is approximately 930 mV, and the passivation failure potential is approximately 1.11 V vs. SCE. This indicates that the processing technology involved in this invention improves the acid corrosion resistance of the AlCoCrFeNi2 high-entropy alloy. Furthermore, combined with... Figure 3 Regarding the mechanical properties, the heat treatment temperature of 950℃ after cold rolling in step three of this invention is the optimal treatment process for improving the mechanical properties and corrosion resistance of AlCoCrFeNi2 high-entropy alloy.

[0061] Figure 5This figure shows the engineering stress-strain curves of the AlCoCrFeNi2 high-entropy alloy prepared at a heat treatment temperature of 950℃ after cold rolling in step three of this invention, and the as-cast AlCoCrFeNi2 high-entropy alloy, under the influence of hydrogen. The electrochemical pre-hydrogen charging operation is the same. As can be seen from the figure, after the same pre-hydrogen charging treatment, the hydrogen embrittlement susceptibility of the AlCoCrFeNi2 high-entropy alloy prepared at the heat treatment temperature of 950℃ in this invention is 8.9%, while the hydrogen embrittlement susceptibility of the as-cast AlCoCrFeNi2 high-entropy alloy without cold rolling and heat treatment in step three is approximately 25%. This indicates that the hydrogen embrittlement susceptibility of the AlCoCrFeNi2 high-entropy alloy is significantly reduced after the processing technology proposed in this invention.

[0062] comprehensive Figures 2-5 The mechanical, corrosion resistance and hydrogen embrittlement sensitivity tests show that the heat treatment process with a temperature of 950°C after cold rolling in step three of this invention is the optimal heat treatment process.

[0063] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this invention, and these modifications or substitutions should all be covered within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope defined in the claims.

Claims

1. A high-strength, high-toughness, corrosion-resistant, and hydrogen-embrittlement-resistant AlCoCrFeNi2 dual-phase high-entropy alloy, characterized in that, Calculated by mass percentage, it contains Al 8~9%, Co 18~19%, Cr 16~17%, Fe 17~18%, and Ni 37~38%, and is a non-equiatomic dual-phase high-entropy alloy; The high-entropy alloy has a heterogeneous lamellar structure, and the alloy phase is composed of a stable FCC phase and a B2 phase. The FCC phase accounts for 62%~64% with an average grain size of 780~850 nm, and the B2 phase accounts for 36~38% with an average grain size of 930~990 nm. Compared with the microstructure of the as-cast AlCoCrFeNi2 high-entropy alloy, the heterogeneous lamellar structure of the high-entropy alloy has shorter and no longer straight lamellars, and is composed of grains with different orientations. At this time, the heterogeneous lamellar structure and uniform orientation are beneficial to improving the strength and toughness of the alloy. The method for preparing the high-entropy alloy includes the following steps: Step 1, Cleaning and Weighing of Materials: Place Al, Co, Cr, Fe, and Ni metals into separate containers, clean and dry them, then convert their mass to the atomic percentages of the AlCoCrFeNi2 high-entropy alloy and weigh them. The mass percentages of each element are: Al 8~9%, Co 18~19%, Cr 16~17%, Fe 17~18%, Ni 37~38%. Step 2, smelting and casting: The weighed metal from step 1 is placed in a copper dry pot of a vacuum electric arc furnace. After evacuation, nitrogen gas is introduced, and then the arc is ignited for smelting and casting to obtain an alloy block. Step 3, cold rolling and heat treatment: After removing the skin of the alloy block obtained in step 2 by wire cutting, it is subjected to multiple passes of cold rolling and heat treatment to obtain the high entropy alloy. In step two, the melting current is 180~300 A, the single melting time is 60~100 s, and the melting is repeated 3~5 times; In step three, the thickness of the prepared alloy block skin is removed by wire cutting, which is 0.3~0.5 mm. The block is then subjected to multiple passes of cold rolling to reduce the thickness to 20% of the original block thickness, with each reduction not exceeding 0.5 mm. In step three, after multiple passes of cold rolling, the alloy is placed in a heat treatment furnace and heated from room temperature to 650~950 ℃ at a heating rate of 10 ℃ / min. After holding at this temperature for 1 h, it is water cooled.

2. The high-entropy alloy according to claim 1, characterized in that, The high-entropy alloy exhibits excellent strength-toughness matching, with a tensile strength of 1.2 GPa and an elongation after fracture of 20%.

3. The high-entropy alloy according to claim 1, characterized in that, The high-entropy alloy exhibits a passivation current density of 3.5 μA / cm² in a 0.1 M H₂SO₄ solution. 2 The passivation region width is 0.93 V, and the passivation breaking potential is 1.11 V vs. SCE.

4. The high-entropy alloy according to claim 1, characterized in that, The high-entropy alloy is at 1×10 -4 It still exhibits good resistance to hydrogen embrittlement at a tensile strain rate of / s, with a hydrogen embrittlement sensitivity of 8.9%.

5. The high-entropy alloy according to claim 1, characterized in that, In step two, a vacuum is evacuated to below 1.0 × 10⁻⁶ using a combination of mechanical and molecular pumps. -4 Pa, then argon gas is introduced to -0.05 MPa, and then arc ignition melting is carried out.

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