UVTaTi series high-thermal-stability uranium-containing high-entropy alloy

Abstract

The application discloses a high-entropy alloy containing uranium element and based on U-V-Ta-Ti series high thermal stability, belongs to the field of high-entropy alloy materials, and the U-V-Ta-Ti series alloy components are as follows in terms of atomic percentage: uranium: 15-60%; vanadium: 10-35%; tantalum: 10-35%; titanium: 15-50%; niobium: 0.01-10%; aluminum: 0.01-10%, and the balance is inevitable impurities; the current high-entropy alloy NiCoFeCr cannot maintain sufficient strength at high temperature, and alloys such as NbTiVZr and AlTiVNb are prone to phase change at high temperature; meanwhile, other researches do not pay enough attention to the research on U-containing high-entropy alloy; the application proposes a high-entropy alloy based on U-V-Ta-Ti series and having high thermal stability, and the special role of the U element is fully considered, so that the structural function integration of the high-entropy alloy is realized.

Description

Technical Field

[0001] This invention belongs to the field of high-entropy alloy materials, and in particular relates to a high-entropy alloy containing uranium and its preparation method. Background Technology

[0002] Structural materials used in nuclear reactors are subjected to harsh irradiation environments. Irradiation-induced defects and the resulting changes in mechanical properties seriously threaten the safety and reliability of the reactor. Therefore, suppressing defect evolution and maintaining the integrity of mechanical properties are key tasks for materials used in next-generation reactors with even harsher irradiation conditions. Single-phase solid solution alloys, including high-entropy and medium-entropy alloys, have attracted widespread attention due to their excellent mechanical properties, corrosion resistance, and especially radiation resistance.

[0003] Extensive research has been reported on the ion irradiation response of unidirectional solid solution alloys over the past decade. However, these alloys typically contain elements with high neutron activity, and most of them fail to maintain sufficient strength and phase stability at high temperatures. For example, NiCoFeCr alloys with a face-centered cubic (FCC) structure have exhibited improved irradiation resistance, including reduced void / bubble expansion and weaker element segregation. However, this alloy contains elements with high neutron activity and cannot maintain sufficient strength at high temperatures. DJM King et al. found a large number of precipitates in NbTiVZrx alloys after annealing at 700°C, O. El-Atwani et al. observed Cr- and V-rich second-phase particles in W-Ta-Cr-V alloys after annealing at 1073 K, and B. Schu et al. found the formation of intermetallic phases in AlTiVNb after severe plastic deformation and subsequent annealing at 700 and 900°C. This instability can threaten the reliability of performance during service. Therefore, high-entropy alloys have outstanding radiation resistance and broad application prospects in the nuclear field. However, their strength and phase stability at high temperatures need to be addressed.

[0004] VTaTi is a high-entropy alloy with a single-phase body-centered cubic (BCC) structure. This alloy exhibits excellent strength-ductility balance at both room and high temperatures, making it potentially suitable for applications in nuclear engineering. However, its irradiation response remains largely unknown. N. Jia et al. investigated the microstructural response of equiatomic TiVTa alloys to MeV He ion irradiation, focusing primarily on the formation and growth of helium bubbles and the resistance to He bubble formation. They found that under the same irradiation dose, TiVTa exhibits the largest average He bubble size and the lowest bubble density.

[0005] However, research on UV-Ta-Ti high-entropy alloys is still scarce, and the mechanisms by which elements such as U and V play their roles in the UV-Ta-Ti system remain unclear. Developing high-entropy alloys based on the UV-Ta-Ti system, while fully considering the role of U, to achieve structural-functional integration of uranium-containing high-entropy alloys, is of great significance for developing uranium-containing high-entropy alloys with high thermal stability and promoting the safe development of nuclear materials. Summary of the Invention

[0006] Addressing the bottleneck issues of poor thermal stability in alloys such as NbTiVZr and AlTiVNb, which are prone to phase transformation at high temperatures and radiation damage after prolonged exposure in reactors, and considering the insufficient attention given to U-containing high-entropy alloy fuels in other studies, this invention proposes a high-entropy alloy based on the UV-Ta-Ti system with high thermal stability, and fully considers the special role of U element, thereby achieving the integration of structure and function of the high-entropy alloy.

[0007] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows.

[0008] A high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium has the following composition by atomic percentage: uranium: 15-60%; vanadium: 10-35%; tantalum: 10-35%; titanium: 15-50%; niobium: 0.1-10%; aluminum: 0.01-10%, with the balance being unavoidable impurities.

[0009] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 15%; vanadium: 20%; tantalum: 35%; titanium: 15%; niobium: 10%; aluminum: 5%, with the balance being unavoidable impurities.

[0010] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 15-60%; vanadium: 10-35%; tantalum: 10-20%; titanium: 15-50%; niobium: 0.1-10%; aluminum: 0.01-10%, with the balance being unavoidable impurities.

[0011] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 60%; vanadium: 10%; tantalum: 10%; titanium: 19.89%; niobium: 0.1%; aluminum: 0.01%, with the balance being unavoidable impurities.

[0012] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 15-30%; vanadium: 10-35%; tantalum: 10-20%; titanium: 15-50%; niobium: 3-10%; aluminum: 2-10%, with the balance being unavoidable impurities.

[0013] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 30%; vanadium: 20%; tantalum: 20%; titanium: 15%; niobium: 10%; aluminum: 5%, with the balance being unavoidable impurities.

[0014] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 15-30%; vanadium: 10-35%; tantalum: 10-15%; titanium: 15-50%; niobium: 3-5%; aluminum: 2-10%, with the balance being unavoidable impurities.

[0015] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 15%; vanadium: 10%; tantalum: 10%; titanium: 50%; niobium: 5%; aluminum: 10%, with the balance being unavoidable impurities.

[0016] Further improvements and optimizations to the above technical solution, with the following atomic percentage composition: uranium: 30%; vanadium: 35%; tantalum: 15%; titanium: 15%; niobium: 3%; aluminum: 2%, with the balance being unavoidable impurities.

[0017] The aforementioned uranium-containing high-entropy alloy based on the UV-Ta-Ti system with high thermal stability has a compressive yield strength of 720~1200MPa and an elongation of 5%-20%.

[0018] The present invention discloses a method for preparing a high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium, which specifically includes the following steps:

[0019] (1) Prepare raw materials: Weigh the required alloy raw materials according to the proportion of uranium-containing refractory high-entropy UV-Ta-Ti alloy;

[0020] (2) Arc melting: Under the protection of a protective gas, U, V, Ta, Ti, Nb, and Al powders were rapidly heated and melted. To obtain a uniform alloy ingot, all samples were repeatedly melted five times, and the samples were turned over after each melting. To avoid the potential impact of melting time and melting current differences on the microstructure and properties of the samples, the current was turned off directly after each melting of each sample, once all alloying elements had completely melted into a liquid state. This ensured that the surface of all melted samples remained bright, indicating that no significant oxidation of the alloy occurred during the melting process.

[0021] Beneficial effects:

[0022] This invention proposes a high-entropy alloy with integrated structure and function based on the UV-Ta-Ti system, exhibiting high thermal stability. Due to the addition of U, the alloy's strength at high temperatures is significantly improved compared to the traditional BCC structure multi-principal element alloy VTaTi. Furthermore, the addition of V and Ti effectively enhances the alloy's strength at high temperatures. The addition of Nb and Al improves the alloy's high-temperature oxidation resistance while maintaining high yield strength, making this high-entropy alloy widely applicable in the nuclear industry. Therefore, this invention, based on the UV-Ta-Ti system, achieves integrated structure and function by fully considering the special role of U, which is of great significance for the development and application of high-entropy alloys with high thermal stability. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in further detail. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0024] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions. The invention will be further described below in conjunction with specific embodiments.

[0025] Example 1

[0026] A UV-Ta-Ti uranium-containing high-entropy alloy, specifically composed of: 15 at.%U, 20% V, 35% Ta, 15% Ti, 10% Nb, 5% Al, with the remainder being unavoidable impurity elements.

[0027] The preparation method of the uranium-containing high-entropy alloy in this embodiment is as follows:

[0028] (1) Prepare raw materials: Weigh the required alloy raw materials according to the ratio of uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy. The specific alloy composition is: 15 at.%U, 20% V, 35%Ta, 15% Ti, 10% Nb, 5%Al;

[0029] (2) Arc melting: Under the protection of a protective gas, U, V, Ta, Ti, Nb, and Al powders were rapidly heated and melted. To obtain alloy ingots with uniform composition, all samples were repeatedly melted five times, and the samples were turned over after each melting. To avoid the possible influence of melting time and melting current differences on the microstructure and properties of the samples, the current was turned off directly after all alloying elements were completely melted into a liquid state for 1 minute during each melting of each sample.

[0030] The mechanical property tests of the uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy ingot prepared in this embodiment show that the compressive yield strength is 720 MPa and the elongation is 20%, exhibiting strong ductility.

[0031] Example 2

[0032] A UV-Ta-Ti uranium-containing high-entropy alloy, specifically composed of: 60 at.% U, 10% V, 10% Ta, 19.89% Ti, 0.1% Nb, 0.01% Al, with the remainder being unavoidable impurity elements.

[0033] The preparation method of the uranium-containing high-entropy alloy in this embodiment is as follows:

[0034] (1) Prepare raw materials: Weigh the required alloy raw materials according to the ratio of uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy. The specific alloy composition is: 60 at.%U, 10% V, 10%Ta, 19.89% Ti, 0.1% Nb, 0.01% Al;

[0035] (2) Arc melting: Under the protection of a protective gas, U, V, Ta, Ti, Nb, and Al powders were rapidly heated and melted. To obtain alloy ingots with uniform composition, all samples were repeatedly melted five times, and the samples were turned over after each melting. To avoid the possible influence of melting time and melting current differences on the microstructure and properties of the samples, the current was turned off directly after all alloying elements were completely melted into a liquid state for 1 minute during each melting of each sample.

[0036] The mechanical property tests of the uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy ingot prepared in this embodiment show that the compressive yield strength is 1200 MPa and the elongation is 5%, exhibiting extremely high strength characteristics.

[0037] Example 3

[0038] A UV-Ta-Ti uranium-containing high-entropy alloy, specifically composed of: 30 at.% U, 20% V, 20% Ta, 15% Ti, 10% Nb, 5% Al, with the remainder being unavoidable impurity elements.

[0039] The preparation method of the uranium-containing high-entropy alloy in this embodiment is as follows:

[0040] (1) Prepare raw materials: Weigh the required alloy raw materials according to the ratio of uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy. The specific alloy composition is: 30 at.%U, 20% V, 20%Ta, 15% Ti, 10% Nb, 5% Al;

[0041] (2) Arc melting: Under the protection of a protective gas, U, V, Ta, Ti, Nb, and Al powders were rapidly heated and melted. To obtain alloy ingots with uniform composition, all samples were repeatedly melted five times, and the samples were turned over after each melting. To avoid the possible influence of melting time and melting current differences on the microstructure and properties of the samples, the current was turned off directly after all alloying elements were completely melted into a liquid state for 1 minute during each melting of each sample.

[0042] The mechanical property tests of the uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy ingot prepared in this embodiment show that the compressive yield strength is 1150 MPa and the elongation is 12%, exhibiting good characteristics of both strength and plasticity.

[0043] Example 4

[0044] A UV-Ta-Ti uranium-containing high-entropy alloy, specifically composed of: 15 at.%U, 10% V, 10% Ta, 50% Ti, 5% Nb, 10% Al, with the remainder being unavoidable impurity elements.

[0045] The preparation method of the uranium-containing high-entropy alloy in this embodiment is as follows:

[0046] (1) Prepare raw materials: Weigh the required alloy raw materials according to the ratio of uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy. The specific alloy composition is: 15 at.%U, 10% V, 10%Ta, 50% Ti, 5% Nb, 10% Al;

[0047] (2) Arc melting: Under the protection of a protective gas, U, V, Ta, Ti, Nb, and Al powders were rapidly heated and melted. To obtain alloy ingots with uniform composition, all samples were repeatedly melted five times, and the samples were turned over after each melting. To avoid the possible influence of melting time and melting current differences on the microstructure and properties of the samples, the current was turned off directly after all alloying elements were completely melted into a liquid state for 1 minute during each melting of each sample.

[0048] The mechanical property tests of the uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy ingot prepared in this embodiment show that the compressive yield strength is 860 MPa and the elongation is 17%, exhibiting good characteristics of both strength and plasticity.

[0049] Example 5

[0050] A UV-Ta-Ti uranium-containing high-entropy alloy, specifically composed of: 30 at.%U, 35%V, 15%Ta, 15%Ti, 3%Nb, 2%Al, with the remainder being unavoidable impurity elements.

[0051] The preparation method of the uranium-containing high-entropy alloy in this embodiment is as follows:

[0052] (1) Prepare raw materials: Weigh the required alloy raw materials according to the ratio of uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy. The specific alloy composition is: 30 at.%U, 35% V, 15%Ta, 15% Ti, 3% Nb, 2% Al;

[0053] (2) Arc melting: Under the protection of a protective gas, U, V, Ta, Ti, Nb, and Al powders were rapidly heated and melted. To obtain alloy ingots with uniform composition, all samples were repeatedly melted five times, and the samples were turned over after each melting. To avoid the possible influence of melting time and melting current differences on the microstructure and properties of the samples, the current was turned off directly after all alloying elements were completely melted into a liquid state for 1 minute during each melting of each sample.

[0054] The mechanical property tests of the uranium-containing high-entropy UV-Ta-Ti-Nb-Al alloy ingot prepared in this embodiment show that the compressive yield strength is 1080 MPa and the elongation is 15%, exhibiting good characteristics of both strength and plasticity.

[0055] This invention provides a uranium-containing high-entropy UV-Ta-Ti alloy and its preparation method, which has the following advantages over existing materials:

[0056] 1. Due to the addition of U, this high-entropy alloy exhibits a significantly improved yield strength at room temperature compared to other multi-principal-element BCC structure alloys. For example, the compressive yield strength of the U15-V20-Ta35-Ti15-Nb10-Al5 alloy with a U content of 15 at.% is ~720 MPa, while the tensile yield strength of the U30-V20-Ta20-Ti15-Nb10-Al5 alloy increases to ~1150 MPa after increasing the U content to 30 at.%.

[0057] 2. The addition of Ta and V elements largely ensures plasticity while improving the high-temperature strength of the alloy, making UV-Ta-Ti high-entropy alloys promising for application under high-temperature irradiated nuclear reactor conditions.

[0058] 3. The addition of Nb and Ti elements improves the mechanical properties of UV-Ta-Ti high-entropy alloys, exhibiting higher strength and performance, making them applicable to many nuclear fields.

[0059] 4. Due to the addition of high U content, UV-Ta-Ti high-entropy alloys provide the best candidate material for high-entropy alloys with both high strength and toughness and good radiation resistance, achieving integrated structural and functional characteristics.

Claims

1. A high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium, characterized in that, Its composition by atomic percentage is as follows: uranium: 15-60%; vanadium: 10-35%; tantalum: 10-35%; titanium: 15-50%; niobium: 0.1-10%; aluminum: 0.01-10%, with the balance being unavoidable impurities.

2. The high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 1, characterized in that, Its components, by atomic percentage, are: uranium: 15%; vanadium: 20%; tantalum: 35%; titanium: 15%; niobium: 10%; aluminum: 5%.

3. A high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 1, characterized in that, Its composition by atomic percentage is as follows: uranium: 15-60%; vanadium: 10-35%; tantalum: 10-20%; titanium: 15-50%; niobium: 0.1-10%; aluminum: 0.01-10%, with the balance being unavoidable impurities.

4. A high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 3, characterized in that, Its composition by atomic percentage is: uranium: 60%; Vanadium: 10%; Tantalum: 10%; Titanium: 19.89%; Niobium: 0.1%; Aluminum: 0.01%.

5. A high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 1, characterized in that, Uranium: 15-30%; Vanadium: 10-35%; Tantalum: 10-20%; Titanium: 15-50%; Niobium: 3-10%; Aluminum: 2-10%, with the balance being unavoidable impurities.

6. The high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 5, characterized in that, Its components, by atomic percentage, are: uranium: 30%; vanadium: 20%; tantalum: 20%; titanium: 15%; niobium: 10%; aluminum: 5%.

7. The high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 1, characterized in that, Its composition by atomic percentage is as follows: uranium: 15-30%; vanadium: 10-35%; tantalum: 10-15%; titanium: 15-50%; niobium: 3-5%; aluminum: 2-10%, with the balance being unavoidable impurities.

8. A high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 7, characterized in that, Its components, by atomic percentage, are: uranium: 15%; vanadium: 10%; tantalum: 10%; titanium: 50%; niobium: 5%; aluminum: 10%.

9. A high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements according to claim 7, characterized in that, Its components, by atomic percentage, are: uranium: 30%; vanadium: 35%; tantalum: 15%; titanium: 15%; niobium: 3%; aluminum: 2%.

10. The method for preparing the high-entropy alloy with high thermal stability based on the UV-Ta-Ti system containing uranium elements as described in any one of claims 1-9, specifically comprising the following steps: (1) Prepare raw materials: Weigh the required alloy raw materials according to the UV-Ta-Ti-Nb-Al high entropy alloy ratio; (2) Arc melting: Under the protection of protective gas, U, V, Ta, Ti, Nb and Al powders are rapidly heated and melted; in order to obtain alloy ingots with uniform composition, all samples are repeatedly melted five times, and the samples are turned over after each melting; in order to avoid the influence of melting time and melting current difference on the microstructure and properties of the samples, each sample is kept in the melting state for 1 minute after all alloy elements are completely melted into liquid state before the current is turned off; to ensure that the surface of all samples remains bright after melting, that is, the alloy does not undergo obvious oxidation during the melting preparation process.