A high-strength, high-entropy alloy induced by nano-SiC precipitation of σ / VC / M7C3 multiphase and its preparation method

Abstract

The application relates to a high-strength high-entropy alloy and a preparation method of the high-strength high-entropy alloy by nano-SiC induced sigma / VC / M7C3 multi-phase precipitation, and relates to the field of high-entropy alloy materials. The application aims to solve the problem of relatively low strength of the existing FCC structure high-entropy alloy. The application discloses a high-strength high-entropy alloy composite material by nano-SiC induced sigma / VC / M7C3 multi-phase precipitation, which comprises an FCC matrix phase, a sigma phase, a VC phase and an M7C3 phase; and the high-strength high-entropy alloy composite material comprises the following components in percentage by weight: Al: 2.61% to 2.68%, Co: 22.84% to 23.38%, Cr: 20.15% to 20.63%, Fe: 21.64% to 22.16%, Ni: 22.74% to 23.29%, V: 6.91% to 7.07% and SiC: 0.79% to 3.11%. The application improves the mechanical properties of the high-entropy alloy and realizes a breakthrough in the strength of the high-entropy alloy.

Description

Technical Field

[0001] This invention relates to the field of high-entropy alloy materials, specifically to a high-strength high-entropy alloy and its preparation method that induces the precipitation of σ / VC / M7C3 multiphases by nano-SiC. Background Technology

[0002] High-entropy alloys are a new type of alloy composed of five or more elements, each with approximately equal atomic concentrations, typically between 5% and 35%. Unlike traditional alloys, high-entropy alloys, through multi-principal element design and high mixing entropy effects, suppress the formation of intermetallic compounds, resulting in a structure dominated by solid solutions. This unique structure endows high-entropy alloys with excellent properties, including high-temperature strength, corrosion resistance, wear resistance, and good mechanical properties. The superior comprehensive properties of high-entropy alloys make them suitable for a wide range of applications. In the aerospace field, they are used to manufacture rocket engine blades and high-temperature structural components; in energy equipment, they serve as structural materials for nuclear reactors and fuel cell connectors; and in high-end manufacturing, they are used for superhard cutting tools and mold materials.

[0003] Compared to high-entropy alloys with BCC structure as the main component, FCC structure has higher plasticity but generally suffers from insufficient strength. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of relatively low strength in existing FCC structure high-entropy alloys, and to provide a high-strength high-entropy alloy and its preparation method by inducing the precipitation of σ / VC / M7C3 multiphases through nano-SiC.

[0005] A high-strength, high-entropy alloy composite material with σ / VC / M7C3 multiphase precipitation induced by nano-SiC includes an FCC matrix phase, a σ phase, a VC phase, and an M7C3 phase; VC and M7C3 are formed in situ through the in-situ reaction of nano-SiC precursors during the melting process, and residual nano-SiC is dispersed in the matrix.

[0006] The high-entropy alloy comprises the following components by weight percentage: Al: 2.61%~2.68%, Co: 22.84%~23.38%, Cr: 20.15%~20.63%, Fe: 21.64%~22.16%, Ni: 22.74%~23.29%, V: 6.91%~7.07%, SiC: 0.79%~3.11%.

[0007] A method for preparing a high-strength, high-entropy alloy composite material through the induction of σ / VC / M7C3 multiphase precipitation by nano-SiC is specifically carried out according to the following steps:

[0008] I. Weigh the following weight percentages: Al: 2.61%~2.68%, Co: 22.84%~23.38%, Cr: 20.15%~20.63%, Fe: 21.64%~22.16%, Ni: 22.74%~23.29%, V: 6.91%~7.07%, SiC: 0.79%~3.11%. Weigh the Al, Co, Cr, Fe, Ni, V, and SiC powders to obtain the raw materials.

[0009] 2. The raw materials are pickled and then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for scrubbing and as a protective gas during the melting and casting process.

[0010] III. Smelting:

[0011] ① Under the protection of argon atmosphere, first adjust the power of the vacuum suspension melting furnace to 100kW, and melt at 100kW for 5min~10min, then adjust to 150kW, and melt at 150kW for 5min~10min, then adjust to 200kW, and melt at 200kW for 5min~10min, and finally adjust to 150kW, and melt at 150kW for 10min~15min, and cool with the furnace to 100℃~150℃;

[0012] ② Repeat step 3.① 3 to 5 times. The material needs to be turned over between the two meltings. After melting, cast the material to obtain a high-strength, high-entropy alloy composite material with σ / VC / M7C3 multiphase precipitation induced by nano SiC.

[0013] The principle of this invention:

[0014] This invention, starting from the mechanisms of composition regulation and phase evolution, adopts an Al–Co–Cr–Fe–Ni–V system. By precisely controlling the Al content, it introduces and stabilizes the FCC solid solution in the alloy, providing a continuous plastic load-bearing channel. Simultaneously, it utilizes the incompatibility effect caused by the positive mixing enthalpy between V and Cr / Fe to induce local compositional fluctuations and reduce the nucleation barrier of the σ phase, enabling the alloy to effectively contribute to strength enhancement. Furthermore, nanoscale SiC particles are added. During melting and holding, SiC reacts in situ with V and Cr to generate VC and M7C3, while some residual SiC is distributed as dispersed particles in the matrix, synergistically achieving Orowan bypass strengthening and grain boundary pinning. The resulting multiphase microstructure includes multi-scale structural units such as the FCC matrix phase, σ phase, VC phase, and M7C3 phase. This not only avoids the defects of insufficient strength of a single FCC phase or excessive brittleness of a single σ phase, but also further influences the volume fraction and size distribution of each phase through the controllable SiC content, thereby improving the mechanical properties of the high-entropy alloy and achieving a breakthrough in strength.

[0015] Effects of the invention:

[0016] The high-strength SiC0.15 high-entropy alloy composite material prepared by the present invention, which induces the precipitation of σ / VC / M7C3 multiphase by nano-SiC, maintains a tensile strength of over 800MPa, a tensile strain of 9.5%, and a hardness of over 280HV, thus enabling the high-entropy alloy material to have both high strength and certain plasticity. Attached Figure Description

[0017] Figure 1 The XRD patterns of the high-entropy alloys prepared in Examples 1-4 and Comparative Example 1 are shown.

[0018] Figure 2 SEM scan of the SiC0.15 high-entropy alloy prepared in Example 1;

[0019] Figure 3 Tensile curve of the SiC0.15 high-entropy alloy prepared in Example 1;

[0020] Figure 4 The IPF diagram of the SiC0.15 high-entropy alloy prepared in Example 1;

[0021] Figure 5 Tensile curve of the SiC0.05 high-entropy alloy prepared in Example 2;

[0022] Figure 6 The IPF diagram of the SiC0.05 high-entropy alloy prepared in Example 2;

[0023] Figure 7 The tensile curve of the SiC0.1 high-entropy alloy prepared in Example 3;

[0024] Figure 8 The IPF diagram of the SiC0.1 high-entropy alloy prepared in Example 3;

[0025] Figure 9 The tensile curve of the SiC0.2 high-entropy alloy prepared in Example 4;

[0026] Figure 10 The IPF diagram of the SiC0.2 high-entropy alloy prepared in Example 4;

[0027] Figure 11 Tensile curves of the SiCO high-entropy alloy prepared in Comparative Example 1;

[0028] Figure 12 IPF diagram of the SiC0 high-entropy alloy prepared in Comparative Example 1;

[0029] Figure 13 Tensile curves of the V0.4 high-entropy alloy prepared in Comparative Example 2;

[0030] Figure 14 The tensile strength comparison diagrams show the high-entropy alloys prepared in Examples 1-4 and Comparative Examples 1-2. Detailed Implementation

[0031] Specific implementation method one: This implementation method is a high-strength high-entropy alloy composite material induced by nano-SiC to precipitate σ / VC / M7C3 multiphase, which includes FCC matrix phase, σ phase, VC phase and M7C3 phase; VC and M7C3 are formed by in-situ reaction of nano-SiC precursor during the melting process, and residual nano-SiC is dispersed in the matrix;

[0032] The high-entropy alloy comprises the following components by weight percentage: Al: 2.61%~2.68%, Co: 22.84%~23.38%, Cr: 20.15%~20.63%, Fe: 21.64%~22.16%, Ni: 22.74%~23.29%, V: 6.91%~7.07%, SiC: 0.79%~3.11%.

[0033] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the high-entropy alloy comprises the following components by weight percentage: Al: 2.63%, Co: 23.02%, Cr: 20.31%, Fe: 21.81%, Ni: 22.92%, V: 6.96%, SiC: 2.35%. Other steps are the same as in Specific Implementation Method One.

[0034] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the high-entropy alloy comprises the following components by weight percentage: Al: 2.68%, Co: 23.38%, Cr: 20.63%, Fe: 22.16%, Ni: 23.29%, V: 7.07%, SiC: 0.79%. Other steps are the same as in Specific Implementation Method One or Two.

[0035] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the high-entropy alloy comprises the following components by weight percentage: Al: 2.65%, Co: 23.20%, Cr: 20.47%, Fe: 21.98%, Ni: 23.10%, V: 7.02%, SiC: 1.58%. Other steps are the same as in Specific Implementation Methods One to Three.

[0036] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the high-entropy alloy comprises the following components by weight percentage: Al: 2.61%, Co: 22.84%, Cr: 20.15%, Fe: 21.64%, Ni: 22.74%, V: 6.91%, SiC: 3.11%. Other steps are the same as in Specific Implementation Methods One to Four.

[0037] Specific Implementation Method Six: This implementation method is a method for preparing a high-strength, high-entropy alloy composite material through the induction of σ / VC / M7C3 multiphase precipitation by nano-SiC, specifically completed according to the following steps:

[0038] I. Weigh the following weight percentages: Al: 2.61%~2.68%, Co: 22.84%~23.38%, Cr: 20.15%~20.63%, Fe: 21.64%~22.16%, Ni: 22.74%~23.29%, V: 6.91%~7.07%, SiC: 0.79%~3.11%. Weigh the Al, Co, Cr, Fe, Ni, V, and SiC powders to obtain the raw materials.

[0039] 2. The raw materials are pickled and then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for scrubbing and as a protective gas during the melting and casting process.

[0040] III. Smelting:

[0041] ① Under the protection of argon atmosphere, first adjust the power of the vacuum suspension melting furnace to 100kW, and melt at 100kW for 5min~10min, then adjust to 150kW, and melt at 150kW for 5min~10min, then adjust to 200kW, and melt at 200kW for 5min~10min, and finally adjust to 150kW, and melt at 150kW for 10min~15min, and cool with the furnace to 100℃~150℃;

[0042] ② Repeat step 3.① 3 to 5 times. The material needs to be turned over between the two meltings. After melting, cast the material to obtain a high-strength, high-entropy alloy composite material with σ / VC / M7C3 multiphase precipitation induced by nano SiC.

[0043] Specific Implementation Method Seven: The difference between this implementation method and Specific Implementation Methods One to Six is ​​that the content of a single impurity in the raw material described in step one is less than 0.03 wt.%, and the total amount of impurities is <0.10 wt.%. The other steps are the same as those in Specific Implementation Methods One to Six.

[0044] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: in step two, hydrochloric acid with a mass fraction of 5% to 20% is used to acid wash the raw materials. The other steps are the same as in Specific Implementation Methods One to Seven.

[0045] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: In step three①, under argon atmosphere protection, the power of the vacuum suspension melting furnace is first adjusted to 100kW, and melting is performed at 100kW for 5 minutes. Then, it is adjusted to 150kW, and melting is performed at 150kW for 5 minutes. Next, it is adjusted to 200kW, and melting is performed at 200kW for 5 minutes. Finally, it is adjusted to 150kW, and melting is performed at 150kW for 15 minutes, followed by furnace cooling to 100℃~150℃. The other steps are the same as in Specific Implementation Methods One to Eight.

[0046] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that: Step Three ① is repeated five times in step Three ②, and the material needs to be turned over between the two melting processes. After melting, the material is cast to obtain a high-strength, high-entropy alloy composite material induced by nano-SiC to precipitate σ / VC / M7C3 multiphase. Other steps are the same as in Specific Implementation Methods One to Nine.

[0047] The beneficial effects of the present invention are verified using the following embodiments:

[0048] Example 1: A method for preparing a high-strength, high-entropy alloy composite material through the induction of σ / VC / M7C3 multiphase precipitation by nano-SiC, specifically completed according to the following steps:

[0049] I. Weigh out Al, Co, Cr, Fe, Ni, V, and SiC powders according to the following weight percentages: Al: 2.63%, Co: 23.02%, Cr: 20.31%, Fe: 21.81%, Ni: 22.92%, V: 6.96%, SiC: 2.35% to obtain the raw material;

[0050] The raw material described in step one contains less than 0.03 wt.% of a single impurity and less than 0.10 wt.% of a total impurity.

[0051] 2. The raw materials are pickled with 5% hydrochloric acid, then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for cleaning and as a protective gas during the melting and casting process.

[0052] III. Smelting:

[0053] Under the protection of argon atmosphere, the power of the vacuum suspension melting furnace is first adjusted to 100kW and melted for 5 minutes at 100kW. Then it is adjusted to 150kW and melted for 5 minutes at 150kW. Next, it is adjusted to 200kW and melted for 5 minutes at 200kW. Finally, it is adjusted to 150kW and melted for 15 minutes at 150kW. The furnace is then cooled to 100℃.

[0054] ② Repeat step 3.1 five times, turning the material over between each melting operation. After melting, cast the material into a sheet to obtain Al. 0.25 CoCrFeNiV 0.35 (SiC) 0.15 High-entropy alloy, denoted as SiC0.15.

[0055] Figure 1 The XRD patterns of the high-entropy alloys prepared in Examples 1-4 and Comparative Example 1 are shown.

[0056] from Figure 1 It can be seen that the alloy matrix is ​​composed of FCC and σ phase. After the addition of SiC, M7C3 and VC phases appear. The strongest diffraction peak of FCC in the matrix alloy becomes an asymmetric diffraction peak after the addition of SiC powder. This is because the newly generated VC phase overlaps with its diffraction peak. In addition, XRD diffraction results show that the alloy is composed of FCC, σ phase, VC, and M7C3 phase. This is because V in the matrix is ​​a strong carbide-forming element, while Cr and Fe are weak carbide-forming elements. After the introduction of C, V, Cr, and Fe elements are consumed to generate VC and M7C3 phases. With the increase of SiC content, the volume fraction of σ phase decreases significantly, while the corresponding volume fraction of VC and M7C3 phases increases.

[0057] Figure 2 SEM scan of the SiC0.15 high-entropy alloy prepared in Example 1;

[0058] from Figure 2 It can be seen that the alloy exhibits a dendritic structure. Notably, the dendrites are relatively dispersed throughout the alloy system, indicating that the addition of SiC plays a crucial role in the evolution of the alloy's microstructure. In the alloy, the σ phase exhibits the lightest-colored plate-like structure, the VC phase exhibits a darker-colored fine dendritic structure, and the M7C3 phase exhibits a gray, larger dendritic structure.

[0059] Example 2: A method for preparing a high-strength, high-entropy alloy composite material through the induction of σ / VC / M7C3 multiphase precipitation by nano-SiC, specifically completed according to the following steps:

[0060] I. Weigh out Al, Co, Cr, Fe, Ni, V, and SiC powders according to the following weight percentages: Al: 2.68%, Co: 23.38%, Cr: 20.63%, Fe: 22.16%, Ni: 23.29%, V: 7.07%, SiC: 0.79% to obtain the raw material;

[0061] The raw material described in step one contains less than 0.03 wt.% of a single impurity and less than 0.10 wt.% of a total impurity.

[0062] 2. The raw materials are pickled with 5% hydrochloric acid, then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for cleaning and as a protective gas during the melting and casting process.

[0063] III. Smelting:

[0064] Under the protection of argon atmosphere, the power of the vacuum suspension melting furnace is first adjusted to 100kW and melted for 5 minutes at 100kW. Then it is adjusted to 150kW and melted for 5 minutes at 150kW. Next, it is adjusted to 200kW and melted for 5 minutes at 200kW. Finally, it is adjusted to 150kW and melted for 15 minutes at 150kW. The furnace is then cooled to 100℃.

[0065] ② Repeat step 3.1 five times, turning the material over between each melting operation. After melting, cast the material into a sheet to obtain Al. 0.25 CoCrFeNiV 0.35 (SiC) 0.05 High-entropy alloy, denoted as SiC0.05.

[0066] Example 3: A method for preparing a high-strength, high-entropy alloy composite material through the induction of σ / VC / M7C3 multiphase precipitation by nano-SiC, specifically completed according to the following steps:

[0067] I. Take Al, Co, Cr, Fe, Ni, V and SiC powders according to the following weight percentages: Al: 2.65%, Co: 23.20%, Cr: 20.47%, Fe: 21.98%, Ni: 23.10%, V: 7.02%, SiC: 1.58% to obtain the raw material;

[0068] The raw material described in step one contains less than 0.03 wt.% of a single impurity and less than 0.10 wt.% of a total impurity.

[0069] 2. The raw materials are pickled with 5% hydrochloric acid, then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for cleaning and as a protective gas during the melting and casting process.

[0070] III. Smelting:

[0071] Under the protection of argon atmosphere, the power of the vacuum suspension melting furnace is first adjusted to 100kW and melted for 5 minutes at 100kW. Then it is adjusted to 150kW and melted for 5 minutes at 150kW. Next, it is adjusted to 200kW and melted for 5 minutes at 200kW. Finally, it is adjusted to 150kW and melted for 15 minutes at 150kW. The furnace is then cooled to 100℃.

[0072] ② Repeat step 3.1 five times, turning the material over between each melting operation. After melting, cast the material into a sheet to obtain Al. 0.25 CoCrFeNiV 0.35 (SiC) 0.1 High-entropy alloy, denoted as SiC0.1.

[0073] Example 4: A method for preparing a high-strength, high-entropy alloy composite material through the induction of σ / VC / M7C3 multiphase precipitation by nano-SiC, specifically completed according to the following steps:

[0074] I. Take Al, Co, Cr, Fe, Ni, V and SiC powders according to the following weight percentages: Al: 2.61%, Co: 22.84%, Cr: 20.15%, Fe: 21.64%, Ni: 22.74%, V: 6.91%, SiC: 3.11% to obtain the raw material;

[0075] The raw material described in step one contains less than 0.03 wt.% of a single impurity and less than 0.10 wt.% of a total impurity.

[0076] 2. The raw materials are pickled with 5% hydrochloric acid, then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for cleaning and as a protective gas during the melting and casting process.

[0077] III. Smelting:

[0078] Under the protection of argon atmosphere, the power of the vacuum suspension melting furnace is first adjusted to 100kW and melted for 5 minutes at 100kW. Then it is adjusted to 150kW and melted for 5 minutes at 150kW. Next, it is adjusted to 200kW and melted for 5 minutes at 200kW. Finally, it is adjusted to 150kW and melted for 15 minutes at 150kW. The furnace is then cooled to 100℃.

[0079] ② Repeat step 3.1 five times, turning the material over between each melting operation. After melting, cast the material into a sheet to obtain Al. 0.25 CoCrFeNiV 0.35 (SiC) 0.2 High-entropy alloy, denoted as SiC0.2.

[0080] Comparative Example 1: Al0.25 CoCrFeNiV 0.35 The preparation method of high-entropy alloy (SiCO) is specifically carried out according to the following steps:

[0081] I. Weigh out Al, Co, Cr, Fe, Ni, and V powders according to the following weight percentages: Al: 2.71%, Co: 23.57%, Cr: 20.79%, Fe: 22.33%, Ni: 23.47%, V: 7.13% to obtain the raw material;

[0082] The raw material described in step one contains less than 0.03 wt.% of a single impurity and less than 0.10 wt.% of a total impurity.

[0083] 2. The raw materials are pickled with 5% hydrochloric acid, then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for cleaning and as a protective gas during the melting and casting process.

[0084] III. Smelting:

[0085] Under the protection of argon atmosphere, the power of the vacuum suspension melting furnace is first adjusted to 100kW and melted for 5 minutes at 100kW. Then it is adjusted to 150kW and melted for 5 minutes at 150kW. Next, it is adjusted to 200kW and melted for 5 minutes at 200kW. Finally, it is adjusted to 150kW and melted for 15 minutes at 150kW. The furnace is then cooled to 100℃.

[0086] ② Repeat step 3.1 five times, turning the material over between each melting operation. After melting, cast the material into a sheet to obtain Al. 0.25 CoCrFeNiV 0.35 High-entropy alloys are denoted as SiC0.

[0087] Comparative Example 2: A comparison with the microstructure evolution and enhanced strength-toughness balance in Gd-doped CoCrFeNiV published in the journal *J. Alloys Compd.* 0.4 As-cast CoCrFeNiV alloys after cold rolling and annealing (DOI: 10.1016 / j.jallcom.2025.182959) 0.4 The preparation method of high-entropy alloys is specifically carried out according to the following steps:

[0088] I. Take Co, Cr, Fe, Ni, and V powders according to the following weight percentages: Co: 23.97%, Cr: 21.15%, Fe: 22.72%, Ni: 23.87%, V: 8.29% to obtain the raw material;

[0089] The raw material described in step one contains less than 0.03 wt.% of a single impurity and less than 0.10 wt.% of a total impurity.

[0090] 2. The raw materials are pickled with 5% hydrochloric acid, then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for cleaning and as a protective gas during the melting and casting process.

[0091] III. Smelting:

[0092] Under the protection of argon atmosphere, the power of the vacuum suspension melting furnace is first adjusted to 100kW and melted for 5 minutes at 100kW. Then it is adjusted to 150kW and melted for 5 minutes at 150kW. Next, it is adjusted to 200kW and melted for 5 minutes at 200kW. Finally, it is adjusted to 150kW and melted for 15 minutes at 150kW. The furnace is then cooled to 100℃.

[0093] ② Repeat step 3.1 five times, turning the material over between each melting operation. After melting, cast the material into a plate to obtain CoCrFeNiV. 0.4 High-entropy alloy, denoted as V0.4.

[0094] Table 1 shows the tensile strain, tensile strength, hardness, and average grain size of the high-entropy alloys prepared in Examples 1-4 and Comparative Example 1.

[0095] Table 1

[0096]

[0097] Table 1 shows that the amount of SiC added has a significant impact on the mechanical properties of high-entropy alloys. With the increase of SiC content, the tensile strength of the alloy shows a trend of first decreasing and then increasing, while the hardness shows a trend of slightly decreasing and then gradually increasing. Among them, the matrix SiC0 alloy (Comparative Example 1) is mainly composed of FCC+σ phase, with a tensile strength of 634.2 MPa and an average grain size of 3.1 μm. With the introduction of a small amount of SiC (Example 2), the VC phase begins to form, and the σ phase content decreases, so the strength decreases and the elongation increases. Therefore, SiC0.05 (Example 2) has obvious plasticity compared with other alloys. When the SiC content is 0.1%, the VC phase content further increases while the M7C3 phase is formed, resulting in coarser grains. Therefore, the alloy strength increases while its plasticity decreases. When the SiC content is 0.15%, the formed σ / VC / M7C3 multiphase synergistic structure increases the tensile strength to 843.9 MPa, a 33% increase compared to the SiC0 alloy. Its hardness is 285.8 HV, while maintaining a 9.5% elongation. Further increasing the SiC content to 0.20%, the alloy strength increases further to 929.9 MPa. Therefore, it can be concluded that adding an appropriate amount of SiC can significantly improve the hardness and strength of the alloy. Nano-SiC at an addition of 0.15% exhibits both strength and a certain degree of plasticity, and its induced multiphase evolution is most beneficial for a balance between strength and toughness.

[0098] Figure 14 The tensile strength comparison diagrams show the high-entropy alloys prepared in Examples 1-4 and Comparative Examples 1-2.

[0099] from Figure 14 It can be seen that compared with the low strength of traditional high-entropy alloys, the strength of this series of alloys is significantly improved, with SiC0.15 showing the best overall performance in several examples; Al 0.25 CoCrFeNiV 0.35 Alloy, CoCrFeNiV 0.4 The alloys have strengths of 634.2 MPa and 454.6 MPa, respectively; Al 0.25 CoCrFeNiV 0.35 (SiC) 0.15 The alloy exhibits a tensile strength of 843.9 MPa, a hardness of 285.8 HV, and a tensile strain of 9.5%. Compared to other alloys, the addition of SiC increased the tensile strength by 33.1% and 85.6%, respectively. Comparative analysis shows that the addition of nano-SiC generates fine VC and M7C3 particles through the in-situ reaction of V and Cr, achieving Orowan strengthening and grain boundary pinning, forming a fine-grained multiphase synergistic structure. It can be concluded that by controlling the addition of SiC nanoparticles, the grain size is refined, improving the mechanical properties of the high-entropy alloy, resulting in a significant improvement in strength, achieving the expected effects of this invention.

Claims

1. A high-strength, high-entropy alloy induced by nano-SiC to precipitate σ / VC / M7C3 multiphase, characterized in that... The high-entropy alloy comprises an FCC matrix phase, a σ phase, a VC phase, and an M7C3 phase; VC and M7C3 are formed in situ through the in-situ reaction of nano-SiC precursors during the melting process, and residual nano-SiC is dispersed in the matrix; The high-entropy alloy comprises the following components by weight percentage: Al: 2.61%~2.68%, Co: 22.84%~23.38%, Cr: 20.15%~20.63%, Fe: 21.64%~22.16%, Ni: 22.74%~23.29%, V: 6.91%~7.07%, SiC: 0.79%~3.11%.

2. The high-strength, high-entropy alloy according to claim 1, characterized in that it induces the precipitation of σ / VC / M7C3 multiphases via nano-SiC, is characterized in that... The high-entropy alloy comprises the following components by weight percentage: Al: 2.63%, Co: 23.02%, Cr: 20.31%, Fe: 21.81%, Ni: 22.92%, V: 6.96%, SiC: 2.35%.

3. The high-strength, high-entropy alloy according to claim 1, characterized in that it induces the precipitation of σ / VC / M7C3 multiphases via nano-SiC, is characterized in that... The high-entropy alloy comprises the following components by weight percentage: Al: 2.68%, Co: 23.38%, Cr: 20.63%, Fe: 22.16%, Ni: 23.29%, V: 7.07%, SiC: 0.79%.

4. A high-strength, high-entropy alloy according to claim 1, characterized in that it induces the precipitation of σ / VC / M7C3 multiphases via nano-SiC. The high-entropy alloy comprises the following components by weight percentage: Al: 2.65%, Co: 23.20%, Cr: 20.47%, Fe: 21.98%, Ni: 23.10%, V: 7.02%, SiC: 1.58%.

5. A high-strength, high-entropy alloy according to claim 1, characterized in that it induces the precipitation of σ / VC / M7C3 multiphases via nano-SiC. The high-entropy alloy comprises the following components by weight percentage: Al: 2.61%, Co: 22.84%, Cr: 20.15%, Fe: 21.64%, Ni: 22.74%, V: 6.91%, SiC: 3.11%.

6. The method for preparing a high-strength, high-entropy alloy by inducing σ / VC / M7C3 multiphase precipitation via nano-SiC as described in claim 1, characterized in that... The preparation method is specifically carried out according to the following steps: I. Weigh out Al, Co, Cr, Fe, Ni, V, and SiC powders according to the following weight percentages: Al: 2.61%~2.68%, Co: 22.84%~23.38%, Cr: 20.15%~20.63%, Fe: 21.64%~22.16%, Ni: 22.74%~23.29%, V: 6.91%~7.07%, SiC: 0.79%~3.11% to obtain the raw materials; 2. The raw materials are pickled and then loaded into a vacuum suspension melting furnace and evacuated. Argon gas is then used for scrubbing and as a protective gas during the melting and casting process. III. Smelting: ① Under the protection of argon atmosphere, first adjust the power of the vacuum suspension melting furnace to 100kW, and melt at 100kW for 5min~10min, then adjust to 150kW, and melt at 150kW for 5min~10min, then adjust to 200kW, and melt at 200kW for 5min~10min, and finally adjust to 150kW, and melt at 150kW for 10min~15min, and cool with the furnace to 100℃~150℃; ② Repeat step 3.① 3 to 5 times. The material needs to be turned over between the two meltings. After melting, cast the alloy to obtain a high-strength, high-entropy alloy with σ / VC / M7C3 multiphase precipitation induced by nano SiC.

7. The method for preparing a high-strength, high-entropy alloy by inducing σ / VC / M7C3 multiphase precipitation via nano-SiC according to claim 6, characterized in that... The content of a single impurity in the raw material mentioned in step one is less than 0.03 wt.%, and the total amount of impurities is less than 0.10 wt.%.

8. The method for preparing a high-strength, high-entropy alloy by inducing σ / VC / M7C3 multiphase precipitation via nano-SiC according to claim 6, characterized in that... In step two, the raw materials are pickled using hydrochloric acid with a mass fraction of 5% to 20%.

9. The method for preparing a high-strength, high-entropy alloy by inducing σ / VC / M7C3 multiphase precipitation via nano-SiC according to claim 6, characterized in that... In step 3①, under the protection of an argon atmosphere, first adjust the power of the vacuum suspension melting furnace to 100kW and melt for 5 minutes at 100kW, then adjust it to 150kW and melt for 5 minutes at 150kW, then adjust it to 200kW and melt for 5 minutes at 200kW, and finally adjust it to 150kW and melt for 15 minutes at 150kW, and then cool it with the furnace to 100℃~150℃.

10. The method for preparing a high-strength, high-entropy alloy by inducing σ / VC / M7C3 multiphase precipitation via nano-SiC according to claim 6, characterized in that... Step 3② is repeated 5 times. The material needs to be turned over between the two melting processes. After melting, the material is cast to obtain a high-strength, high-entropy alloy with σ / VC / M7C3 multiphase precipitation induced by nano SiC.

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