Flaky high-entropy alloy material containing refractory metal and preparation method of flaky high-entropy alloy material

Abstract

The invention discloses a flaky high-entropy alloy material containing refractory metal and a preparation method of the flaky high-entropy alloy material, the flaky high-entropy alloy material is FeCoNiMnNb alloy, and the molar ratio of Fe to Co to Ni to Mn to Nb in the alloy material is (1-4): (1-3): (1-3): (1-3.5): (0.5-2). The flaky high-entropy alloy material containing the refractory metal is high in flaky degree and saturation magnetization intensity and excellent in high-temperature magnetic stability, and has good application prospects in the fields of electromagnetic shielding and high-temperature magnetic devices.

Description

Technical Field

[0001] This invention belongs to the field of metal powder manufacturing technology, specifically relating to a sheet-like high-entropy alloy material containing refractory metal and its preparation method. Background Technology

[0002] High-entropy alloys (HEA) are a new type of alloy composed of five or more main metals in equal or near-equal atomic ratios. Due to their unique high-entropy effect, hysteresis diffusion effect, and lattice distortion effect, they exhibit excellent mechanical properties, corrosion resistance, and high-temperature stability, and have broad application prospects in aerospace, energy, electronics and other fields.

[0003] High-entropy alloys possess excellent resistance to high-temperature oxidation and mechanical stability. Plate-like high-entropy alloys containing refractory metals further enhance their performance in various aspects. For example, the high melting point of the refractory metal and the interfacial strengthening of the plate-like structure form a dual-effect barrier, greatly enhancing ultra-high temperature strength and creep resistance. Some high-entropy alloys can even maintain yield strengths of 1.17 GPa and 0.92 GPa at 1473 K and 1673 K, respectively. The refractory metal forms a dense passivation film, while the plate-like interface delays the diffusion of corrosion ions through a labyrinthine physical barrier, significantly improving the alloy's corrosion and wear resistance. The lattice distortion strengthening of the refractory metal improves magnetocrystalline anisotropy, and the layered structure achieves high saturation magnetization and low coercivity, which also plays a crucial role in improving the material's magnetic properties. Therefore, plate-like high-entropy alloys containing refractory metals can meet the stringent requirements of many fields for materials with high strength, high temperature resistance, and corrosion resistance.

[0004] However, the preparation of lamellar high-entropy alloys containing refractory metals still faces many technical challenges. On the one hand, traditional preparation processes, such as smelting and casting, struggle to precisely control grain morphology, resulting in low lamellarity and poor structural uniformity. This leads to large fluctuations in material properties, failing to meet practical application requirements. On the other hand, while introducing refractory metal elements such as molybdenum (Mo), tantalum (Ta), and tungsten (W) into high-entropy alloys can further enhance their high-temperature strength and oxidation resistance, the high melting points and low diffusion coefficients of these metals make them prone to segregation during smelting and processing. This makes it difficult to mix them uniformly with other components, limiting the formation of lamellar structures and causing stress concentration within the alloy, thus reducing the overall performance of the material.

[0005] CN119194137A proposes a vacuum suspension melting method and apparatus for high-entropy alloys of refractory metals. The method uses distributed vacuum suspension melting to prepare high-entropy alloys containing multi-component refractory metals. However, the melting point of refractory metals is much higher than that of metals such as Fe and Co. The melting method causes segregation of refractory metal components, resulting in a low degree of sheet formation in the material prepared by this method.

[0006] CN119317089A proposes a dielectric and magnetic loss coupled multi-frequency high-absorption composite microwave absorbing material and its preparation method. The multi-frequency high-absorption sheet-like high-entropy composite microwave absorbing material was prepared by suspension melting and vacuum atomization. However, since the materials used are all conventional melting point metals, its high-temperature strength and oxidation resistance are not outstanding.

[0007] CN116079066A proposes a method for preparing spherical powder of refractory high-entropy alloy TaNbTiZr, which involves multiple melting and hydrogenation processes to obtain uniformly composed TaNbTiZr high-entropy alloy. However, the preparation process is energy-intensive and complex. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a sheet-like high-entropy alloy material containing refractory metal and its preparation method. The sheet-like high-entropy alloy material has a high degree of sheet formation, excellent high-temperature strength and oxidation resistance, and the preparation process is safe, reliable and energy-efficient.

[0009] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: A sheet-like high-entropy alloy material containing refractory metal is provided. The sheet-like high-entropy alloy material is a FeCoNiMnNb alloy, and the molar ratio of Fe:Co:Ni:Mn:Nb elements in the alloy material is 1-4:1-3:1-3:1-3.5:0.5-2.

[0010] According to the above scheme, the dominant phase of the plate-like high-entropy alloy material is a face-centered cubic structure phase with good uniformity. Its average axial length of grains is 30~50μm, average radial length is 0.5~2μm, and aspect ratio is 50~80:1.

[0011] According to the above scheme, the magnetic transition temperature of the plate-like high-entropy alloy material is 920~990K.

[0012] This invention also provides a method for preparing the above-mentioned sheet-like high-entropy alloy material containing refractory metal, the specific steps of which are as follows: 1) Weigh out iron powder, cobalt powder, nickel powder, manganese powder, and niobium powder according to the elemental molar ratio of Fe:Co:Ni:Mn:Nb 1-4:1-3:1-3:1-3.5:0.5-2; 2) Place the raw material weighed in step 1) into an atmosphere ball mill jar for dry ball milling to obtain FeCoNiMnNb initial metal powder; 3) The FeCoNiMnNb initial metal powder obtained in step 2) is placed in a ball mill jar for a first wet ball milling to obtain FeCoNiMnNb secondary metal powder; 4) Dry the FeCoNiMnNb secondary metal powder obtained in step 3), then put it into an atmosphere furnace for annealing treatment, then put the annealed product into a ball mill jar for secondary wet ball milling, and finally dry it to obtain a sheet-like high-entropy alloy material containing refractory metal.

[0013] According to the above scheme, in step 1), the purity of the iron powder is ≥99.97wt%, and the particle size is 3~15μm; the purity of the cobalt powder is ≥99.95wt%, and the particle size is 10~25μm; the purity of the nickel powder is ≥99.9wt%, and the particle size is 30~75μm; the purity of the manganese powder is ≥99.9wt%, and the particle size is 20~60μm; and the purity of the niobium powder is ≥99.9wt%, and the particle size is 15~53μm.

[0014] According to the above scheme, the dry ball milling process conditions in step 2) are as follows: tungsten carbide grinding balls are selected, and the size and mass ratio of the grinding balls is 3~6mm:8~13mm:15~20mm = 2:2:1, the ball-to-material ratio is 30~60:1, inert gas (nitrogen or argon) is introduced into the atmosphere ball milling jar for gas washing, and then a vacuum is drawn to a vacuum degree of -0.1~-0.07MPa. The ball milling is carried out at a speed of 240~360r / min for 24~48h.

[0015] According to the above scheme, the process conditions for step 3) of the single wet ball milling are as follows: tungsten carbide grinding balls are selected, and the size and mass ratio of the grinding balls are 3~6mm:8~13mm=2:3, the ball-to-material ratio is 20~30:1, anhydrous ethanol is used as the ball milling medium, the mass-to-volume ratio of the initial FeCoNiMnNb metal powder to anhydrous ethanol is 0.5~1g / mL, and the ball milling is carried out at a speed of 240~360r / min for 12~24h.

[0016] According to the above scheme, the drying process conditions for step 4) are: drying at 40~80℃ for 6~8 hours.

[0017] According to the above scheme, the annealing process conditions for step 4) are: heating at 600~800℃ for 1~5h in an inert atmosphere (nitrogen or argon).

[0018] According to the above scheme, the secondary wet ball milling process conditions in step 4) are as follows: tungsten carbide grinding balls are selected, and the grinding ball size and mass ratio is 3~6mm:8~13mm=2:3, the ball-to-material ratio is 20~30:1, anhydrous ethanol is used as the ball milling medium, the mass-to-volume ratio of the annealed product to anhydrous ethanol is 0.3~1g / mL, and the ball milling is carried out at a speed of 240~360r / min for 12~24h.

[0019] According to the above scheme, the drying process conditions for step 4) are: drying at 40~80℃ for 4~6 hours.

[0020] This invention also includes the application of the aforementioned sheet-like high-entropy alloy material containing refractory metals in the fields of electromagnetic shielding or high-temperature magnetic devices. The sheet-like high-entropy alloy material containing refractory metals provided by this invention combines the magnetic properties of Fe, Co, and Ni with the corrosion resistance of Nb, enabling the alloy to simultaneously meet the requirements of structural-functional integration. Mn can improve the plasticity of the alloy. By controlling the microstructure of the alloy through the preparation process, the optimization of soft magnetic properties and high strength is achieved, making it particularly suitable for the fields of electromagnetic shielding or high-temperature magnetic devices.

[0021] The atomic radii, electronegativity, and valence electron numbers of the four elements Fe, Co, Ni, and Mn are similar. After forming a high-entropy solid solution FCC structure with equal atomic ratios, the mixing entropy is approximately 1.6R, exceeding the critical value for high-entropy alloys (1.5R). This ensures that a single solid solution matrix is ​​formed during solidification, providing a stable framework for the uniform distribution of subsequent strengthening phases. Fe, Co, and Ni provide high strength, high toughness, and good oxidation resistance, while the high-entropy solid solution of Fe, Co, and Ni provides matrix stability. Mn can improve the plasticity of the alloy and promote the formation of the FCC phase. The refractory properties of Nb and the difference in atomic size induce lamellar strengthening phases, achieving a dual-scale structure of "high-entropy matrix + refractory strengthening phase".

[0022] This invention achieves a superior flake-like structure compared to the smelting method by first dry ball milling (mechanical alloying), followed by wet milling, annealing, and a second wet milling process. Firstly, in the dry ball milling mechanical alloying stage, the high-energy milling subjectes the powder to impact and shear forces, causing particle deformation and initially forming a flake-like structure. The subsequent wet milling, aided by a liquid medium, prevents high-temperature welding of particles while promoting particle breakage and refinement. The annealing step eliminates internal hardening and stress, improves plasticity, and induces directional recrystallization. Finally, the annealed particles are more easily shaped during the second wet milling, making them easier to roll into thinner flakes under the shear stress of ball milling.

[0023] The beneficial effects of this invention are as follows: 1. The high-entropy alloy material containing refractory metals provided by this invention has a high degree of lamellarization and saturation magnetization, and excellent high-temperature magnetic stability, showing good application prospects in the fields of electromagnetic shielding and high-temperature magnetic devices. 2. The preparation method of this invention can precisely control the alloy element ratio, reduce unnecessary raw material loss, and through the impact and crushing action of the ball milling media, the refractory metal particles are refined to the nanoscale and uniformly distributed in the matrix, avoiding component segregation, enabling rapid diffusion of alloy elements, promoting the formation of lamellar material, and resulting in high uniformity of material composition, low energy consumption (energy consumption is only 20-30% of that of the smelting method), simple process flow, and no harmful substances are generated during the preparation process, making it green and environmentally friendly. Attached Figure Description

[0024] Figure 1 The image shows the SEM image and aspect ratio statistics of the initial FeCoNiMnNb metal powder obtained in step 2) of Example 1 of this invention. Figure 2 The image shows the SEM image and aspect ratio statistics of the FeCoNiMnNb secondary metal powder obtained in step 3) of Example 1. Figure 3 The SEM image and aspect ratio statistics of the sample obtained after annealing treatment in step 4) of Example 1 are shown. Figure 4 SEM image and aspect ratio statistics of the sheet-like FeCoNiMnNb high-entropy alloy material obtained in Example 1; Figure 5 The XRD diffraction pattern of the FeCoNiMnNb high-entropy alloy obtained in Example 1; Figure 6 The images show the magnetometer test results of the vibrating samples of the sheet-like FeCoNiMnNb high-entropy alloy material obtained in Example 1 and the FeCoNiMnNb high-entropy alloy material obtained in Comparative Example 1. Figure 7 The magnetic transition temperature test results are shown for the sheet-like FeCoNiMnNb high-entropy alloy material obtained in Example 1 and the FeCoNiMnNb high-entropy alloy material obtained in Comparative Example 1. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] Example 1 A sheet-like high-entropy alloy material containing a refractory metal is prepared by the following method: 1) Using a high-precision electronic balance with an accuracy of 0.001g, iron powder (purity ≥99.97wt%, 3~15μm), cobalt powder (≥99.95wt%, 10~25μm), nickel powder (≥99.9wt%, 30~75μm), manganese powder (≥99.97wt%, 20~60μm) and niobium powder (≥99.95wt%, 15~53μm) were weighed and batched according to the elemental molar ratio of Fe:Co:Ni:Mn:Nb 3:3:2:1:1; 2) After the raw materials are prepared, put 30g of raw materials into an atmosphere ball mill jar with a vent valve, add tungsten carbide grinding balls, and the grinding ball size and mass ratio is 3~6mm:8~13mm:15~20mm=2:2:1, the ball-to-material ratio is 40:1. Nitrogen gas is introduced into the atmosphere ball mill jar for gas washing, and then the vacuum is evacuated to a vacuum degree of -0.07MPa. The jar is ball-milled at 340r / min for 24h to obtain FeCoNiMnNb initial metal powder. 3) Take 20g of the initial FeCoNiMnNb metal powder obtained in step 2) and put it into a ball mill jar for a first wet ball milling. Add tungsten carbide grinding balls. The size and mass ratio of the grinding balls is 3~6mm:8~13mm = 2:3, and the ball-to-material ratio is 30:1. Add 20mL of anhydrous ethanol as the ball milling medium and ball mill at 320r / min for 12h to obtain FeCoNiMnNb secondary metal powder. 4) The FeCoNiMnNb secondary metal powder obtained in step 3) was dried in a 70℃ oven for 8 hours, then annealed in an atmosphere furnace at 600℃ for 1 hour under a nitrogen atmosphere. 15g of the annealed product was then placed in a ball mill jar for secondary wet ball milling. Tungsten carbide grinding balls were added, with a ball size and mass ratio of 3~6mm:8~13mm = 2:3 and a ball-to-material ratio of 20:1. 20mL of anhydrous ethanol was added as the ball milling medium, and the mixture was ball milled at 340r / min for 24 hours. Finally, it was dried in a 50℃ oven for 6 hours to obtain a sheet-like FeCoNiMnNb high-entropy alloy material.

[0027] Figure 1 The image on the left is a SEM image of the initial FeCoNiMnNb metal powder obtained in step 2) of this embodiment. It can be seen that under the continuous impact and shearing of the grinding balls, the metal powder particles are broken. Simultaneously, the mechanical force of the ball mill induces a cold welding phenomenon, causing the broken grains to deform continuously and gradually flatten. At this point, the average aspect ratio of the initial FeCoNiMnNb metal powder is 17:1 (see...). Figure 1 right).

[0028] Figure 2The image on the left is a SEM image of the FeCoNiMnNb secondary metal powder obtained in step 3) of this embodiment. At this point, the powder is continuously subjected to external force and is refined and broken. However, due to the presence of the liquid medium, the resistance to grain deformation is reduced, making it easier for plastic deformation to occur along a specific direction, and the degree of grain flattening continuously increases. At this time, the average aspect ratio of the FeCoNiMnNb secondary metal powder is 23:1 (see...). Figure 2 right).

[0029] Figure 3 The image on the left is an SEM image of the sample obtained after annealing in step 4) of this embodiment. Annealing eliminates the high-density dislocations and lattice distortions present after mechanical alloying in step 2), reduces internal resistance, and improves the plasticity and toughness of the particles. Simultaneously, it was observed that some larger particles fractured and broke during stress release, resulting in a certain degree of reduction in the aspect ratio. At this point, the average aspect ratio of the particles in the sample is 21:1 (see...). Figure 3 right).

[0030] Figure 4 The left image shows a SEM image of the plate-like FeCoNiMnNb high-entropy alloy material obtained in this embodiment. Secondary wet ball milling further mixes the powder grains, accelerates element diffusion, and makes the alloy composition more uniform. Simultaneously, the particle plasticity improves after annealing, and the secondary wet milling further promotes the plate-like formation of the grains. Furthermore, the presence of the liquid medium makes the particle shape more regular and the surface smoother. Statistical analysis of the SEM image shows that the average axial length of the grains in the final product of this embodiment is 44.02 μm, the average radial length is 0.63 μm, and the aspect ratio reaches 67:1. See the particle aspect ratio statistical chart below. Figure 4 right.

[0031] Figure 5 The image shows the XRD diffraction pattern of the FeCoNiMnNb high-entropy alloy obtained in this embodiment. As can be seen from the image, the alloy mainly contains a face-centered cubic (FCC) phase.

[0032] Comparative Example 1 A sheet-like high-entropy alloy material containing refractory metal is prepared using a traditional vacuum induction melting method, as follows: 1) Using a high-precision electronic balance with an accuracy of 0.001g, iron powder (purity ≥99.97wt%, 3~15μm), cobalt powder (≥99.95wt%, 10~25μm), nickel powder (≥99.9wt%, 30~75μm), manganese powder (≥99.97wt%, 20~60μm) and niobium powder (≥99.95wt%, 15~53μm) were weighed and batched according to the elemental molar ratio of Fe:Co:Ni:Mn:Nb 3:3:2:1:1; 2) After the materials are prepared, put 30g of raw materials into an Al2O3 crucible and place it in a vacuum induction melting furnace. Perform vacuum induction melting for 20 minutes at a vacuum degree of 0.05MPa. Crush the metal block obtained after melting into FeCoNiMnNb initial metal particles of less than 40 mesh. 3) Take 20g of the initial FeCoNiMnNb metal particles obtained in step 2) and put them into a ball mill jar for a first wet ball milling. Add tungsten carbide grinding balls. The size and mass ratio of the grinding balls is 3~6mm:8~13mm = 2:3, and the ball-to-material ratio is 30:1. Add 20mL of anhydrous ethanol as the ball milling medium and ball mill at 320r / min for 12h to obtain FeCoNiMnNb secondary metal powder. 4) The FeCoNiMnNb secondary metal powder obtained in step 3) was dried in a 70℃ oven for 8 hours, then annealed in an atmosphere furnace at 600℃ for 1 hour under a nitrogen atmosphere. 15g of the annealed product was then placed in a ball mill jar for secondary wet ball milling. Tungsten carbide grinding balls were added, with a ball size and mass ratio of 3~6mm:8~13mm = 2:3 and a ball-to-material ratio of 20:1. 20mL of anhydrous ethanol was added as the ball milling medium, and the mixture was ball milled at 340r / min for 24 hours. Finally, it was dried in a 50℃ oven for 6 hours to obtain the FeCoNiMnNb high-entropy alloy material.

[0033] SEM analysis showed that the aspect ratio of the FeCoNiMnNb high-entropy alloy material prepared in this comparative example was approximately 30~40:1.

[0034] Figure 6 The results of the vibration sample magnetometer test (VSM test) for the sheet-like FeCoNiMnNb high-entropy alloy material obtained in Example 1 and the FeCoNiMnNb high-entropy alloy material obtained in Comparative Example 1 are shown. The small graph shows that the coercivity H of Example 1 and Comparative Example 1 is low, both less than 10 Oe, indicating low resistance to domain wall movement, fewer impurities, and weaker pinning effect, demonstrating a high degree of microstructure uniformity. The large graph shows that the Ms value of the saturation segment of the curve in Example 1 (152.4 emu / g) is higher than that in Comparative Example 1 (118.7 emu / g), meaning that the saturation magnetization per unit mass of Example 1 is higher than that of Comparative Example 1. The saturation magnetization increased by approximately 30% while the coercivity remained essentially unchanged. The low coercivity combined with the higher saturation magnetization indicates that the high-entropy alloy material prepared in Example 1 possesses superior magnetic properties.

[0035] Figure 7The graphs show the magnetic transition temperatures of the sheet-like FeCoNiMnNb high-entropy alloy material obtained in Example 1 and the FeCoNiMnNb high-entropy alloy material obtained in Comparative Example 1. As can be seen from the graphs, the descending segment of the curve in Example 1 (corresponding to the transition of the magnetic moment from order to disorder, which is directly related to the magnetic transition temperature of the material) is in the range of 800~1100K, which is shifted to the right compared to the descending segment (700~1000K) in Comparative Example 1. This indicates that the magnetic transition temperature of Example 1 is higher, increasing from 860K to 975K, an increase of approximately 14%. This demonstrates that the high-entropy alloy material of Example 1 exhibits superior high-temperature magnetic stability.

[0036] Example 2 A sheet-like high-entropy alloy material containing a refractory metal is prepared by the following method: 1) Using a high-precision electronic balance with an accuracy of 0.001g, iron powder (purity ≥99.97wt%, 3~15μm), cobalt powder (≥99.95wt%, 10~25μm), nickel powder (≥99.9wt%, 30~75μm), manganese powder (≥99.97wt%, 20~60μm) and niobium powder (≥99.95wt%, 15~53μm) were weighed and batched according to the elemental molar ratio of Fe:Co:Ni:Mn:Nb 2:2:2:2:0.5; 2) After the raw materials are prepared, put 30g of raw materials into an atmosphere ball mill jar with a vent valve, add tungsten carbide grinding balls, and the grinding ball size and mass ratio is 3~6mm:8~13mm:15~20mm=2:2:1, the ball-to-material ratio is 40:1. Nitrogen gas is introduced into the atmosphere ball mill jar for gas washing, and then the vacuum is evacuated to a vacuum degree of -0.07MPa. The jar is ball-milled at 340r / min for 24h to obtain FeCoNiMnNb initial metal powder. 3) Take 20g of the initial FeCoNiMnNb metal powder obtained in step 2) and put it into a ball mill jar for a first wet ball milling. Add tungsten carbide grinding balls. The size and mass ratio of the grinding balls is 3~6mm:8~13mm = 2:3, and the ball-to-material ratio is 30:1. Add 20mL of anhydrous ethanol as the ball milling medium and ball mill at 320r / min for 12h to obtain FeCoNiMnNb secondary metal powder. 4) The FeCoNiMnNb secondary metal powder obtained in step 3) was dried in a 70℃ oven for 8 hours, then annealed in an atmosphere furnace at 800℃ for 1 hour under a nitrogen atmosphere. 15g of the annealed product was then placed in a ball mill jar for secondary wet ball milling. Tungsten carbide grinding balls were added, with a ball size and mass ratio of 3~6mm:8~13mm = 2:3 and a ball-to-material ratio of 20:1. 20mL of anhydrous ethanol was added as the ball milling medium, and the mixture was ball milled at 320r / min for 24 hours. Finally, it was dried in a 50℃ oven for 6 hours to obtain a sheet-like FeCoNiMnNb high-entropy alloy material.

[0037] Example 3 A sheet-like high-entropy alloy material containing a refractory metal is prepared by the following method: 1) Using a high-precision electronic balance with an accuracy of 0.001g, iron powder (purity ≥99.97wt%, 3~15μm), cobalt powder (≥99.95wt%, 10~25μm), nickel powder (≥99.9wt%, 30~75μm), manganese powder (≥99.97wt%, 20~60μm) and niobium powder (≥99.95wt%, 15~53μm) were weighed and batched according to the elemental molar ratio of Fe:Co:Ni:Mn:Nb 3:2:2:2:1; 2) After the raw materials are prepared, put 30g of raw materials into an atmosphere ball mill jar with a vent valve, add tungsten carbide grinding balls, and the grinding ball size and mass ratio is 3~6mm:8~13mm:15~20mm=2:2:1, the ball-to-material ratio is 40:1. Argon gas is introduced into the atmosphere ball mill jar for cleaning, and then the vacuum is evacuated to a vacuum degree of -0.09MPa. The jar is ball-milled at 360r / min for 24h to obtain FeCoNiMnNb initial metal powder. 3) Take 20g of the initial FeCoNiMnNb metal powder obtained in step 2) and put it into a ball mill jar for a first wet ball milling. Add tungsten carbide grinding balls. The size and mass ratio of the grinding balls is 3~6mm:8~13mm = 2:3, and the ball-to-material ratio is 30:1. Add 20mL of anhydrous ethanol as the ball milling medium and ball mill at 300r / min for 12h to obtain FeCoNiMnNb secondary metal powder. 4) The FeCoNiMnNb secondary metal powder obtained in step 3) was dried in a 70℃ oven for 8 hours, then annealed in an atmosphere furnace at 750℃ for 1 hour under an argon atmosphere. 15g of the annealed product was then placed in a ball mill jar for secondary wet ball milling. Tungsten carbide grinding balls were added, with a grinding ball size and mass ratio of 3~6mm:8~13mm = 2:3 and a ball-to-material ratio of 20:1. 20mL of anhydrous ethanol was added as the ball milling medium, and the mixture was ball milled at 300r / min for 24 hours. Finally, it was dried in a 50℃ oven for 6 hours to obtain a sheet-like FeCoNiMnNb high-entropy alloy material.

[0038] The lamellar structure of the FeCoNiMnNb high-entropy alloy material of this invention is achieved through a combination of the following strengthening mechanisms: mechanical alloying breaks down and redistributes grains; primary wet milling effectively reduces particle agglomeration and significantly refines grains; annealing eliminates internal stress and improves plasticity and toughness; secondary wet milling further reduces crystal surface energy and enhances the lamellar shaping effect. The final product has a high degree of lamellarity. Under the conditions of reducing energy consumption and simplifying the process, the degree of lamellarity of the product is twice that of the same type of high-entropy alloy material prepared by the smelting process.

[0039] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A sheet-like high-entropy alloy material containing a refractory metal, characterized in that, The plate-like high-entropy alloy material is a FeCoNiMnNb alloy, in which the molar ratio of Fe:Co:Ni:Mn:Nb elements is 1-4:1-3:1-3:1-3.5:0.5-2.

2. The sheet-like high-entropy alloy material containing refractory metal according to claim 1, characterized in that, The dominant phase of the plate-like high-entropy alloy material is a face-centered cubic structure phase with good uniformity. Its average axial length of grains is 30~50μm, average radial length is 0.5~2μm, and aspect ratio is 50~80:

1.

3. The sheet-like high-entropy alloy material containing refractory metal according to claim 1, characterized in that, The magnetic transition temperature of the plate-like high-entropy alloy material is 920~990K.

4. A method for preparing a sheet-like high-entropy alloy material containing a refractory metal as described in any one of claims 1-3, characterized in that, The specific steps are as follows: 1) Weigh out iron powder, cobalt powder, nickel powder, manganese powder, and niobium powder according to the elemental molar ratio of Fe:Co:Ni:Mn:Nb 1-4:1-3:1-3:1-3.5:0.5-2; 2) Place the raw material weighed in step 1) into an atmosphere ball mill jar for dry ball milling to obtain FeCoNiMnNb initial metal powder; 3) The FeCoNiMnNb initial metal powder obtained in step 2) is placed in a ball mill jar for a first wet ball milling to obtain FeCoNiMnNb secondary metal powder; 4) Dry the FeCoNiMnNb secondary metal powder obtained in step 3), then put it into an atmosphere furnace for annealing treatment, then put the annealed product into a ball mill jar for secondary wet ball milling, and finally dry it to obtain a sheet-like high-entropy alloy material containing refractory metal.

5. The method for preparing the sheet-like high-entropy alloy material containing refractory metal according to claim 4, characterized in that, Step 1) The iron powder has a purity ≥ 99.97 wt% and a particle size of 3~15 μm; the cobalt powder has a purity ≥ 99.95 wt% and a particle size of 10~25 μm; the nickel powder has a purity ≥ 99.9 wt% and a particle size of 30~75 μm; the manganese powder has a purity ≥ 99.9 wt% and a particle size of 20~60 μm; the niobium powder has a purity ≥ 99.9 wt% and a particle size of 15~53 μm.

6. The method for preparing the sheet-like high-entropy alloy material containing refractory metal according to claim 4, characterized in that, Step 2) Dry ball milling process conditions: Tungsten carbide grinding balls are selected, and the grinding ball size and mass ratio is 3~6mm:8~13mm:15~20mm=2:2:1, the ball-to-material ratio is 30~60:1, inert gas is introduced into the atmosphere ball milling jar for cleaning, and then vacuum is drawn to a vacuum degree of -0.1~-0.07MPa, and ball milling is carried out at a speed of 240~360r / min for 24~48h.

7. The method for preparing the sheet-like high-entropy alloy material containing refractory metal according to claim 4, characterized in that, Step 3) The conditions for the one-time wet ball milling process are as follows: tungsten carbide grinding balls are selected, and the size and mass ratio of the grinding balls is 3~6mm:8~13mm=2:3, the ball-to-material ratio is 20~30:1, anhydrous ethanol is used as the ball milling medium, the mass-to-volume ratio of the initial FeCoNiMnNb metal powder to anhydrous ethanol is 0.5~1g / mL, and the ball milling is carried out at a speed of 240~360r / min for 12~24h.

8. The method for preparing the sheet-like high-entropy alloy material containing refractory metal according to claim 4, characterized in that, Step 4) Drying process conditions: Dry at 40~80℃ for 6~8h; Step 4) Annealing process conditions: Heat at 600~800℃ for 1~5h in an inert atmosphere (nitrogen or argon).

9. The method for preparing the sheet-like high-entropy alloy material containing refractory metal according to claim 4, characterized in that, Step 4) The secondary wet ball milling process conditions are as follows: tungsten carbide grinding balls are selected, and the grinding ball size and mass ratio is 3~6mm:8~13mm=2:3, the ball-to-material ratio is 20~30:1, anhydrous ethanol is used as the ball milling medium, the mass-to-volume ratio of the annealed product to anhydrous ethanol is 0.3~1g / mL, and the ball milling is carried out at a speed of 240~360r / min for 12~24h.

10. The application of a sheet-like high-entropy alloy material containing refractory metal as described in any one of claims 1-3 in the field of electromagnetic shielding or high-temperature magnetic devices.

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