High-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium series high-entropy alloy material and preparation method thereof

Abstract

The present invention discloses a high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium-based high-entropy alloy material and its preparation method, relating to the technical field of high-temperature alloy materials. The present invention uses a titanium, tantalum, zirconium, and niobium high-entropy alloy as a matrix, introduces the regulatory elements oxygen and vanadium, and achieves directional optimization of oxidation resistance and mechanical properties. By doping with oxygen, the alloy achieves an oxidation rate of 8.1178×10-10 after static oxidation at 900°C for 24 hours. ‑10 mg 2 cm ‑4 ·s ‑1 , forming a dense and stable oxide film on the surface, significantly improving high-temperature oxidation resistance; the addition of vanadium enhances its room-temperature tensile properties. The high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium-based high-entropy alloy material provided by the present invention achieves targeted performance optimization and diversified expansion of the material system, suitable for applications in fields such as aerospace engine hot-end components and high-temperature structural parts. It effectively addresses the limited oxidation resistance, insufficient mechanical properties, and complex preparation processes of existing alloys.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloy materials, and in particular to a high-temperature oxidation-resistant titanium-tantalum-zirconium-niobium series high-entropy alloy material and a preparation method thereof. Background Art

[0002] As an emerging alloy system, high-entropy alloys (HEAs) exhibit excellent comprehensive properties due to their multi-principal element design concept and unique high-entropy, lattice distortion, and slow diffusion effects. They hold broad application prospects, particularly in the field of high-temperature structural materials. TiTaZrNb-based HEAs, a class of aluminum- and chromium-free, medium-density refractory metal HEAs, have attracted widespread attention for their excellent thermal stability, high melting point, and corrosion resistance.

[0003] However, TiTaZrNb-based high-entropy alloys currently face two significant challenges in engineering applications: First, limited oxidation resistance. Due to the lack of elements that form a stable, dense oxide film, this system readily forms a loose, non-protective oxide layer in high-temperature oxidizing environments, resulting in a high oxidation rate and poor durability. Second, mechanical properties need to be improved. Despite the alloy's excellent high-temperature stability, its strength and ductility at room or moderate temperatures still struggle to meet the load-bearing requirements of certain structural components, limiting its practical application.

[0004] Prior art studies have attempted to improve oxidation resistance by optimizing alloying elements (such as aluminum, chromium, and silicon) or by employing surface coating techniques. However, these approaches often present challenges such as complex preparation, unstable interfaces, and high costs. In recent years, studies have proposed introducing trace amounts of carbon and oxygen into high-entropy alloys to form stable dispersed oxide phases, thereby enhancing the alloy's overall thermal stability while also strengthening its oxidation resistance. However, this approach remains exploratory, with the underlying oxygen doping mechanism remaining unclear and lacking systematic experimental validation and engineering support. In particular, there remains a lack of clear design strategies and implementation paths for controlling the oxygen doping level to achieve optimal oxidation resistance. Furthermore, to enhance the mechanical properties of these systems, researchers have attempted to introduce transition metal elements for solid solution strengthening or precipitation strengthening. However, while these elements improve strength, they can also further weaken oxidation resistance or exacerbate element segregation, leading to uneven performance. Summary of the Invention

[0005] In response to the above-mentioned deficiencies in the prior art, the present invention provides a high-temperature oxidation-resistant titanium-tantalum-zirconium-niobium high-entropy alloy material and a preparation method thereof. By introducing different regulating elements, the oxidation resistance and mechanical properties of the titanium-tantalum-zirconium-niobium based alloy are improved, effectively solving the problems of limited oxidation resistance, insufficient mechanical properties and complex preparation process of existing alloys.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve its technical problem is: to provide a titanium, tantalum, zirconium, and niobium series high entropy alloy material that is resistant to high-temperature oxidation, wherein the above-mentioned titanium, tantalum, zirconium, and niobium series high entropy alloy material that is resistant to high-temperature oxidation is a TiTaZrNbO high entropy alloy material or a TiTaZrNbV high entropy alloy material.

[0007] Furthermore, the above-mentioned TiTaZrNbO high entropy alloy material includes the following raw materials in atomic percentage: Ti 40-41%, Ta 26-27%, Zr 15-16%, Nb 15-15.5% and O 2-2.5%.

[0008] Furthermore, the above-mentioned TiTaZrNbO high entropy alloy material includes the following raw materials in atomic percentage: Ti 41%, Ta 27%, Zr 15%, Nb 15% and O 2%.

[0009] Furthermore, the above-mentioned TiTaZrNbV high entropy alloy material includes the following raw materials in atomic percentage: Ti 19.5-20.5%, Ta 19.5-20.5%, Zr 19.5-20.5%, Nb 19.5-20.5% and V 19.5-20.5%.

[0010] Furthermore, the above-mentioned TiTaZrNbV high entropy alloy material includes the following raw materials in atomic percentage: Ti 20%, Ta 20%, Zr 20%, Nb 20% and V 20%.

[0011] The method for preparing the above-mentioned high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium-based high-entropy alloy material comprises the following steps:

[0012] S1. Take Ti, Ta, Zr, Nb and TiO2 / V particles, polish the surface with sandpaper, wash them in anhydrous ethanol and dry them;

[0013] S2. Ti, Zr, Nb, Ta and TiO2 blocks are stacked in the order of bottom to top or Ti, Zr, V, Nb and Ta are stacked in the order of bottom to top for smelting. After smelting, cooling is performed to obtain a titanium, tantalum, zirconium and niobium series high entropy alloy material resistant to high temperature oxidation.

[0014] The beneficial effect of adopting the above further scheme is that TiTaZrNbO with excellent oxidation resistance is prepared by adjusting the element ratio. The above high entropy alloy is a single-phase solid solution structure of "body-centered cubic structure" and has the characteristics of β-type titanium alloy. Titanium has the characteristics of high strength and high plasticity, low density, and good high-temperature stability. The refractory high-entropy alloy containing titanium can combine the high ductility and high melting point of the high entropy alloy with the properties of titanium itself by means of the cocktail effect, one of the four major effects of high entropy alloys. A large amount of β-stabilizing elements, including tantalum and niobium, are introduced into the above alloy, which significantly improves the stability of the β phase; at the same time, zirconium is a neutral element, which helps to maintain structural uniformity and the stability of the composition distribution. Titanium, as the main base element, works together with other transition metal elements to help the alloy form a stable β-phase structure, which has a better ability to inhibit oxygen diffusion at high temperatures.

[0015] The trace oxygen-doped high-temperature, oxidation-resistant high-entropy alloy material provided by the present invention has the introduced trace oxygen primarily dispersed at grain boundaries or dendrite regions, facilitating the formation of a continuous, dense passivation film that is less susceptible to flaking during oxidation, thereby effectively inhibiting further oxidation. This is because the pre-introduced oxygen tends to accumulate at grain boundaries, acting as heterogeneous nucleation sites during high-temperature oxidation, accelerating the formation of a protective oxide film and forming a localized oxide "barrier" that blocks rapid diffusion pathways. Furthermore, the trace oxygen introduced in this manner can dissolve in the body-centered cubic lattice, causing lattice distortion and slowing grain boundary diffusion at high temperatures, thereby inhibiting the oxidation rate.

[0016] Furthermore, in step S1, the particle purity of Ta, Ta, Zr, Nb, V and TiO2 is greater than 99.5%.

[0017] Furthermore, in step S1, the particle size of Ta, Ta, Zr, Nb and V is 1-3 mm.

[0018] The beneficial effect of adopting this further solution is that the melting effect is optimized by controlling the particle size of the raw material particles within the above range. Particles that are too large will lead to uneven melting, leaving unmelted cores of the high-melting-point tantalum metal, increasing the temperature gradient in the molten pool, causing component segregation and porosity defects. Particles that are too small are easily blown away by the arc or oxidized prematurely, resulting in uneven element distribution and the introduction of impurities.

[0019] Furthermore, in step S1, the particle size of TiO2 is 2.5-3 mm.

[0020] The benefits of adopting this further approach include: The particle size of titanium dioxide particles needs to be controlled. If the oxygen content in the alloy is too high or unevenly distributed, it can become a source of cracks and inhomogeneous regions, reducing the material's mechanical properties and corrosion resistance. Incompletely melted oxide inclusions can act as stress concentration points, reducing the alloy's high-temperature serviceability. If the oxygen content in the alloy is too low, the solid solution strengthening effect of the pre-introduction of oxygen is insignificant.

[0021] Furthermore, in step S1, it is ensured that the TiO2 particles are completely decomposed and evenly dispersed.

[0022] Furthermore, in step S1, ultrasonic cleaning is performed for 290-310 seconds.

[0023] Furthermore, in step S1, ultrasonic cleaning is performed for 300 seconds.

[0024] Furthermore, in step S1, the product is placed in a vacuum drying oven and dried at 85-95°C.

[0025] Furthermore, in step S1, the product is placed in a vacuum drying oven and dried at 90°C.

[0026] Furthermore, in step S2, the TiO2 block is prepared by the following method: TiO2 particles are filled into a mold and pressed into a TiO2 block using a hydraulic press.

[0027] Furthermore, in step S2, during pressing, the maximum axial pressure is 25-35 MPa, and is maintained for 9-11 minutes.

[0028] Furthermore, in step S2, during pressing, the maximum axial pressure is 30 MPa and maintained for 10 minutes.

[0029] Furthermore, in step S2, the diameter of the TiO2 block is 5-10 mm and the thickness is 2-4 mm.

[0030] The beneficial effects of adopting the above further solution are: controlling the oxygen release rate and reaction stability.

[0031] Furthermore, in step S2, after pressing and molding, the product is dried at 110-130°C for 1.5-2.5 hours.

[0032] Furthermore, in step S2, after pressing and forming, the product is dried at 120° C. for 2 hours.

[0033] The beneficial effect of adopting the above further solution is: removing the adsorbed moisture.

[0034] Furthermore, in step S2, the molten metal is placed in a vacuum suspension melting furnace and smelted using a vacuum suspension melting method.

[0035] The beneficial effects of adopting the above further scheme are: electromagnetic stirring makes the melt composition more uniform, which is more energy-efficient than arc melting, and can reduce the impurity problem caused by electrodes; it can accurately control the oxygen release rhythm of titanium dioxide raw materials, avoid local instantaneous oxygen concentration peaks, and prevent oxidation inclusions and tissue coarsening.

[0036] Furthermore, in step S2, the metal particles are stacked from bottom to top in order of melting point from low to high.

[0037] Furthermore, in step S2, before smelting, the vacuum is first pumped to 4-6 Pa using a mechanical pump, and then the molecular pump is turned on to continue vacuuming to 4.5×10 -3 -5×10 -3 Pa, and filled with high-purity argon gas to make the pressure in the furnace 0.5-0.7atm.

[0038] Furthermore, in step S2, before smelting, the vacuum was first pumped to 5 Pa using a mechanical pump, and then the molecular pump was turned on to continue vacuuming to 5×10 -3 Pa, and filled with high-purity argon gas to make the pressure in the furnace 0.6atm.

[0039] Furthermore, in step S2, high-frequency electromagnetic induction heating is used during smelting.

[0040] The beneficial effect of adopting the above further solution is that the sample is suspended by electromagnetic force without the support of a crucible, thereby achieving pollution-free operation during the smelting process.

[0041] Furthermore, in step S2, double-sided melting is completed by adopting a step-by-step heating method.

[0042] Furthermore, in step S2, three-stage power control is adopted during smelting.

[0043] Furthermore, in step S2, during smelting, the power is first adjusted to 90-110 kW and maintained for 4-6 minutes, then adjusted to 110-130 kW and maintained for 4-6 minutes, then adjusted to 130-150 kW and maintained for 4-6 minutes, and finally adjusted to 180-200 kW and smelted at 1600-1700°C for 8-10 minutes.

[0044] Furthermore, in step S2, during smelting, the power is first adjusted to 100 kW and maintained for 5 minutes, then adjusted to 120 kW and maintained for 5 minutes, then adjusted to 140 kW and maintained for 5 minutes, and finally adjusted to 190 kW and smelted at 1650°C for 9 minutes.

[0045] Furthermore, in step S2, during melting, the steel is completely turned over and remelted 3-5 times.

[0046] The beneficial effect of adopting the above further solution is to improve the distribution uniformity of the alloy components.

[0047] Furthermore, in step S2, smelting is repeated 5-7 times.

[0048] The beneficial effects of taking the above further operations are: ensuring that the composition is fully homogenized and eliminating macroscopic composition segregation.

[0049] Furthermore, in step S2, after smelting, the smelting is completed and the furnace is cooled for 25-35 minutes.

[0050] Furthermore, in step S2, after smelting, the smelting is completed and the furnace is cooled for 30 minutes.

[0051] Furthermore, in step S2, during the cooling process, a directional solidification mold or a cold zone seeding control method is used to regulate the solidification structure.

[0052] The beneficial effect of adopting the above further solution is: obtaining a dense and refined alloy ingot.

[0053] The method for evaluating the oxidation resistance of the above-mentioned high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium high-entropy alloy material comprises the following steps: subjecting the high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium high-entropy alloy material to a static constant-temperature oxidation treatment, and continuously recording the oxidation weight gain per unit area, fitting the oxidation weight gain data as a function of time, and judging whether it conforms to a parabolic law or a linear law. At the same time, combining the shedding of surface oxides and the continuity of the oxide layer, a comprehensive evaluation is made of the protectiveness of the oxide film and the oxidation resistance of the high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium high-entropy alloy material.

[0054] Furthermore, a static constant temperature oxidation treatment is performed at 850-950°C.

[0055] Furthermore, a static constant temperature oxidation treatment is performed at 900°C.

[0056] Furthermore, the evaluation criteria are: if the oxidation weight gain data conforms to the parabolic law and there is no obvious shedding of surface oxides, it is judged to have excellent antioxidant properties.

[0057] In summary, the present invention has the following beneficial effects:

[0058] 1. The present invention proposes a new high-entropy alloy performance control design strategy, which realizes the directional optimization of alloy performance by introducing trace oxygen elements or equiatomic vanadium elements into the titanium, tantalum, zirconium and niobium-based high-entropy alloy system. Targeting high-temperature service environments, by introducing trace oxygen elements, it is dispersed in the alloy body phase, which promotes the in-situ formation of a dense continuous oxide film during the high-temperature oxidation process, thereby effectively blocking the oxygen diffusion path and significantly improving the alloy's oxidation resistance and service stability. Compared with traditional antioxidant methods, such as surface coatings, pre-oxidation treatments or multi-pass heat treatment processes, this strategy has the advantages of strong material body protection, simple process flow, and high performance stability, avoiding performance degradation caused by problems such as local shedding and interface failure.

[0059] 2. To address the practical application needs of high-entropy alloys in terms of structural strength, this invention introduces vanadium in an equiatomic ratio into the titanium, tantalum, zirconium, and niobium system to form a titanium, tantalum, zirconium, niobium, and vanadium high-entropy alloy, achieving a mechanical property enhancement strategy primarily based on solid solution strengthening. Vanadium, as a transition metal with a medium atomic radius, enhances lattice distortion and increases resistance to dislocation motion, thereby significantly improving the alloy's tensile strength and plasticity.

[0060] 3. The two types of alloys provided by the present invention: TiTaZrNbO2 high-entropy alloy materials and TiTaZrNbV high-entropy alloy materials are respectively aimed at the engineering application requirements of high-temperature oxidation resistance and structural mechanical properties. By forming a systematic and functionally complementary material combination, they meet the material selection with different performance focuses in complex service environments, providing a more flexible and efficient technical path for the promotion of high-entropy alloys in the field of high-end equipment manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 X-ray diffraction spectra of different alloy materials;

[0062] Figure 2 Scanning electron microscope images of different alloy materials; (a) is the backscattered electron image of TiTaZrNb, and (b) is the backscattered electron image of TiTaZrNbO2;

[0063] Figure 3 This is the X-ray energy spectrum analysis surface scan of the backscattered electron image of TiTaZrNb;

[0064] Figure 4 This is the X-ray energy spectrum analysis surface scan of the backscattered electron image of TiTaZrNbO2;

[0065] Figure 5 The continuous weight gain curves of different alloy materials after oxidation at 900℃ for 24 hours;

[0066] Figure 6X-ray diffraction spectra of samples of different alloy materials after oxidation at 900℃ for 24 h;

[0067] Figure 7 Surface morphology of the oxide layer of different alloy materials; (a) is the surface morphology of the TiTaZrNb oxide layer, (b) is the surface morphology of the TiTaZrNbO2 oxide layer, and (c) is the surface morphology of the TiTaZrNbO 3.2 Surface morphology of the oxide layer;

[0068] Figure 8 This is an X-ray energy spectrum analysis surface scan of the backscattered electron image of TiTaZrNb after oxidation;

[0069] Figure 9 This is an X-ray energy spectrum analysis surface scan of the backscattered electron image of TiTaZrNbO2 after oxidation;

[0070] Figure 10 TiTaZrNbO 3.2 X-ray energy spectrum analysis surface scan of the backscattered electron image after oxidation;

[0071] Figure 11 The tensile stress-strain diagrams of different alloy materials;

[0072] Figure 12 Compressive stress-strain diagrams of different alloy materials. DETAILED DESCRIPTION

[0073] The principles and features of the present invention are described below. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. In the examples, where specific conditions are not specified, conventional conditions or manufacturer-recommended conditions were used. Reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially.

[0074] Example 1

[0075] The TiTaZrNbO high entropy alloy material includes the following raw materials in atomic percentage: Ti 41%, Ta 27%, Zr 15%, Nb 15% and O 2%.

[0076] The preparation method of the above-mentioned TiTaZrNbO high entropy alloy material comprises the following steps:

[0077] S1. Take particles of Ti, Ta, Zr, Nb and TiO2, polish their surfaces with sandpaper, place them in anhydrous ethanol, clean them with ultrasonic waves for 300 seconds, and then place them in a vacuum drying oven to dry at 90°C. The purity of the Ti, Ta, Zr, Nb and TiO2 particles is greater than 99.5%, the particle size of the Ti, Ta, Zr and Nb particles is 1-3 mm, and the particle size of the TiO2 particles is 2.5-3 mm.

[0078] S2. Fill TiO2 particles into a mold and use a hydraulic press to press into a TiO2 block. The diameter of the TiO2 block is 5-10 mm and the thickness is 2-4 mm. During pressing, the maximum axial pressure is 30 MPa and maintained for 10 min. After pressing and molding, it is dried at 120 ° C for 2 h. Then, according to the melting point, Ti, Zr, Nb, Ta and TiO2 blocks are stacked from bottom to top in order for smelting. Before smelting, vacuum is first pumped to 5 Pa with a mechanical pump, and then the molecular pump is turned on to continue vacuuming to 5×10 -3 Pa, and filled with high-purity argon gas to make the pressure in the furnace 0.6atm, high-frequency electromagnetic induction heating, and double-sided melting were completed by a step-by-step temperature increase method. During melting, three-stage power control was adopted, first adjusting the power to 100kW and holding it for 5min, then adjusting the power to 120kW and holding it for 5min, then adjusting the power to 140kW and holding it for 5min, and finally adjusting the power to 190kW and melting at 1650℃ for 9min, completely turning over and remelting 3 times, repeating the melting 5 times, and cooling with the furnace for 30min after the melting was completed to obtain TiTaZrNbO high entropy alloy material (TiTaZrNbO2).

[0079] Example 2

[0080] The TiTaZrNbO high entropy alloy material includes the following raw materials in atomic percentage: Ti 40%, Ta 26%, Zr 16%, Nb 15.5% and O 2.5%.

[0081] The preparation method of the above-mentioned TiTaZrNbO high entropy alloy material comprises the following steps:

[0082] S1. Take particles of Ti, Ta, Zr, Nb and TiO2, polish their surfaces with sandpaper, place them in anhydrous ethanol, clean them with ultrasonic waves for 290 seconds, and then place them in a vacuum drying oven to dry at 85°C. The purity of the particles of Ti, Ta, Zr, Nb and TiO2 is greater than 99.5%, the particle size of the particles of Ti, Ta, Zr and Nb is 1-3 mm, and the particle size of the particles of TiO2 is 2.5-3 mm.

[0083] S2. Fill TiO2 particles into a mold and use a hydraulic press to press into a TiO2 block. The diameter of the TiO2 block is 5-10 mm and the thickness is 2-4 mm. During pressing, the maximum axial pressure is 25 MPa and maintained for 9 minutes. After pressing and molding, it is dried at 110 ° C for 1.5 hours. Then, according to the melting point, Ti, Zr, Nb, Ta and TiO2 blocks are stacked from bottom to top in order according to the melting point size for smelting. Before smelting, first use a mechanical pump to evacuate to 4 Pa, then turn on the molecular pump and continue to evacuate to 4.5×10 -3 Pa, and filled with high-purity argon gas to make the pressure in the furnace 0.5atm, high-frequency electromagnetic induction heating, and double-sided melting were completed by a step-by-step temperature increase method. During melting, three-stage power control was adopted, first adjusting the power to 90kW and holding it for 4 minutes, then adjusting the power to 110kW and holding it for 2 minutes, then adjusting the power to 130kW and holding it for 4 minutes, and finally adjusting the power to 180kW and melting at 1600℃ for 8 minutes, completely turning over and remelting 4 times, repeating the melting 6 times, and cooling with the furnace for 25 minutes after the melting was completed to obtain TiTaZrNbO high-entropy alloy material.

[0084] Example 3

[0085] The TiTaZrNbV high entropy alloy material includes the following raw materials in atomic percentage: Ti 20%, Ta 20%, Zr 20%, Nb 20% and V 20%.

[0086] The preparation method of the above-mentioned TiTaZrNbV high entropy alloy material comprises the following steps:

[0087] S1. Take particles of Ti, Ta, Zr, Nb and V, polish their surfaces with sandpaper, place them in anhydrous ethanol, clean them with ultrasonic waves for 310 seconds, and then place them in a vacuum drying oven to dry at 95°C. The purity of the particles of Ti, Ta, Zr, Nb and V is greater than 99.5%, and the particle size of the particles of Ti, Ta, Zr, Nb and V is 1-3 mm.

[0088] S2. Ti, Zr, V, Nb and Ta are stacked in order from bottom to top according to their melting points for smelting. Before smelting, vacuum is first pumped to 6 Pa with a mechanical pump, and then the molecular pump is turned on to continue vacuuming to 5×10 -3Pa, and filled with high-purity argon gas to make the pressure in the furnace 0.7atm, used high-frequency electromagnetic induction heating, and adopted a step-by-step temperature increase method to complete double-sided melting. During melting, three-stage power control was adopted. The power was first adjusted to 110kW and maintained for 6min, then adjusted to 130kW and maintained for 6min, then adjusted to 150kW and maintained for 6min, and finally adjusted to 200kW and melted at 1700℃ for 10min. The material was completely turned over and remelted 5 times, and the melting was repeated 7 times. After the melting was completed, it was cooled with the furnace for 35min to obtain TiTaZrNbV high entropy alloy material (TiTaZrNbV).

[0089] Comparative Example 1

[0090] A titanium, tantalum, zirconium, and niobium refractory high-entropy alloy material comprises the following raw materials in atomic percentage: 41% Ti, 27% Ta, 16% Zr, and 16% Nb.

[0091] The preparation method of the above titanium, tantalum, zirconium and niobium refractory high entropy alloy material is similar to that in Example 1 (TiTaZrNb).

[0092] Comparative Example 2

[0093] A titanium, tantalum, zirconium, and niobium refractory high-entropy alloy material comprises the following raw materials in atomic percentage: 40.7% Ti, 26.7% Ta, 14.7% Zr, 14.7% Nb, and 3.2% O.

[0094] The preparation method of the above titanium, tantalum, zirconium and niobium refractory high entropy alloy material is similar to that in Example 1 (TiTaZrNb 3.2 ).

[0095] Comparative Example 3

[0096] A titanium, tantalum, zirconium, and niobium refractory high-entropy alloy material comprises the following raw materials in atomic percentage: 41.3% Ti, 27.3% Ta, 15.3% Zr, 15.3% Nb, and 0.8% O.

[0097] The preparation method of the above titanium, tantalum, zirconium and niobium refractory high entropy alloy material is similar to that of Example 1.

[0098] In the titanium, tantalum, zirconium, and niobium refractory high-entropy alloy material prepared above, no diffusely distributed oxygen element is observed in most areas of the matrix.

[0099] Test Example 1

[0100] The TiTaZrNbO high entropy alloy material TiTaZrNbO2 prepared in Example 1, the titanium tantalum zirconium niobium refractory high entropy alloy material TiTaZrNb prepared in Comparative Example 1, and the titanium tantalum zirconium niobium refractory high entropy alloy material TiTaZrNb prepared in Comparative Example 2 were mixed. 3.2Cut the metal block into 5*5*10 mm size, and use sandpaper to polish its upper surface step by step. Use 400 mesh, 800 mesh, 1200 mesh, and 2000 mesh silicon carbide sandpaper to polish the sample step by step. After the sample is polished, it can be tested by X-ray diffraction. During the test, the 2θ angle is set to 10-90° and the scanning speed is 5° / min. The X-ray diffraction (XRD) spectrum obtained after the test is completed is as follows Figure 1 As shown, Figure 1 In the figure, BCC is a body-centered cubic structure.

[0101] Depend on Figure 1 It can be seen that all three alloys present a single-phase body-centered cubic structure, and the addition of oxygen does not change the phase composition of the original titanium, tantalum, zirconium, and niobium system, which indicates that the oxygen element is distributed in the alloy matrix in the form of solid solution.

[0102] Test Example 2

[0103] Use a wire cutting machine to cut out a sample from the TiTaZrNbO2 obtained in Example 1 and the TiTaZrNb obtained in Comparative Example 1, respectively. Place them in anhydrous ethanol and clean them with ultrasound for 300 seconds, and then blow dry with a hair dryer. Then, mount the sample with the flat surface facing up. Use the hot mounting method to raise the mounting table, place the dry and neat sample on the mounting cylinder of the hot mounting machine, and then lower the mounting table. Add an appropriate amount of resin powder and cover the sealing cover tightly. Maintain a temperature of 180°C and a pressure of 250 bar. After 8 minutes of heating-insulation-cooling process, open the sealing cover, raise the test table, and take out the mounted sample.

[0104] The samples were polished step by step using 400-mesh, 800-mesh, 1200-mesh, and 2000-mesh silicon carbide sandpapers, and then polished using a diamond polishing paste with a particle size of 1.5 mm. After cleaning the samples and drying them with a hair dryer, the samples were placed under a metallographic microscope to observe surface scratches. If no obvious scratches were observed at 100 times magnification, the samples could be used for scanning electron microscopy (SEM) characterization. The results are shown in Figure 2. Figure 2 As shown, Figure 2 In the figure, (a) is the backscattered electron image of TiTaZrNb, and (b) is the backscattered electron image of TiTaZrNbO2.

[0105] Depend on Figure 2 It can be seen that the composition of the TiTaZrNb matrix without oxygen doping is uniform and single, while TiTaZrNbO2 presents a dendritic morphology.

[0106] The X-ray energy dispersive spectrometry (EDS) surface scan of the backscattered electron (BSE) image of TiTaZrNb is shown below: Figure 3As shown, the X-ray energy dispersive spectrometry (EDS) surface scan of the backscattered electron (BSE) image of TiTaZrNbO2 is shown in Figure 4 shown.

[0107] Depend on Figure 3 and Figure 4 It can be seen that the elements of the two matrix alloys are evenly distributed. The surface scan image of the titanium, tantalum, zirconium, and niobium refractory high-entropy alloy does not contain oxygen, while the surface scan image of the TiTaZrNbO2 high-entropy alloy with trace oxygen doping shows that the oxygen element is diffusely distributed in the matrix, titanium, zirconium, niobium and oxygen are enriched in the dendrites, and tantalum is enriched between the dendrites.

[0108] Test Example 3

[0109] The TiTaZrNbO2 prepared in Example 1, the TiTaZrNb prepared in Comparative Example 1, and the TiTaZrNbO prepared in Comparative Example 2 were 3.2 Wire cutting was performed to obtain a 5 mm x 5 mm x 10 mm metal block. The sample was then polished using silicon carbide sandpaper in a stepwise fashion, with the grits ranging from 240, 600, 800, 1200, and 2000, until the surface appeared mirror-like. The sample was then polished using a 1.5 mm diamond polishing paste until no visible scratches were visible under an optical microscope. The sample was ultrasonically cleaned in ethanol for 5 minutes and then dried with a hair dryer. The dried sample was weighed using an electronic balance with an accuracy of 0.0001 g. The sample was then placed in an alumina crucible, and the total weight of the sample and crucible was weighed. The crucible was then placed in a 900°C tube furnace for a 24-hour oxidation test. The sample was removed every two hours, cooled to room temperature, and then weighed.

[0110] TiTaZrNbO2 prepared in Example 1, TiTaZrNb prepared in Comparative Example 1, and TiTaZrNbO prepared in Comparative Example 2 3.2 After oxidation at 900℃ for 24h, the samples remained intact. TiTaZrNbO2 and TiTaZrNbO 3.2 There is no obvious oxide shedding on the surface, and the oxide layer of TiTaZrNbO2 is smooth and very thin, indicating that the TiTaZrNbO2 high-entropy alloy has good oxidation resistance. A small amount of oxide scale shedding can be seen on TiTaZrNb, and the oxide layer is relatively thick.

[0111] TiTaZrNbO2 prepared in Example 1, TiTaZrNb prepared in Comparative Example 1, and TiTaZrNbO prepared in Comparative Example 2 3.2 The continuous weight gain curve after oxidation at 900℃ for 24 h is as follows Figure 5 shown.

[0112] Depend on Figure 5It can be seen from the data fitting that the unit area oxidation weight gain of the TiTaZrNb high entropy alloy prepared in Comparative Example 1 without the introduction of oxygen element conforms to the linear law at the initial stage of oxidation, and its oxidation rate is 1.4512×10 -3 mg cm -2 ·s -1 (That is 2.106×10 -6 mg 2 cm -4 ·s -1 ), indicating that the oxidation rate is controlled by surface chemical reactions, the oxide film has no protective properties, and the base alloy material is consumed quickly. The unit area oxidation weight gain of Example 1 and Comparative Example 1 both conform to the parabolic law. The oxidation rate of TiTaZrNbO2 prepared by the method of doping trace oxygen elements in Example 1 is only 8.1178×10 -10 mg 2 cm -4 ·s -1 , showing the best antioxidant performance. In contrast, the TiTaZrNbO prepared by further increasing the amount of oxygen added in Comparative Example 2 3.2 alloy, the oxidation rate is 1.0254×10 -9 mg 2 cm -4 ·s -1 , which is one order of magnitude higher than that of Example 1, indicating poor antioxidant capacity. This shows that by precisely controlling the amount of oxygen added, it is possible to optimize the antioxidant properties of TiTaZrNb-based high-entropy alloys.

[0113] Test Example 4

[0114] TiTaZrNbO2 prepared in Example 1, TiTaZrNb prepared in Comparative Example 1, and TiTaZrNbO prepared in Comparative Example 2 3.2 The XRD spectrum of the sample after oxidation at 900℃ for 24h is as follows Figure 6 shown.

[0115] Depend on Figure 6 It can be seen that all three alloys produce five oxides: titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), tantalum dioxide (TaO2), niobium pentoxide (Nb2O5) and titanium niobium oxide (TiNb2O7).

[0116] TiTaZrNbO2 prepared in Example 1, TiTaZrNb prepared in Comparative Example 1, and TiTaZrNbO prepared in Comparative Example 2 3.2 After oxidation at 900℃ for 24h, the samples were characterized by scanning electron microscopy (SEM). The surface morphology of the oxide layer is shown in Figure 2. Figure 7 As shown, Figure 7In the figure, (a) is the surface morphology of the TiTaZrNb oxide layer, (b) is the surface morphology of the TiTaZrNbO2 oxide layer, and (c) is the surface morphology of the TiTaZrNbO 3.2 Surface morphology of the oxide layer.

[0117] Depend on Figure 7 It can be seen that by observing the surface state of the oxide layer, it can be seen that after the TiTaZrNb undoped with oxygen was oxidized at 900℃ for 24 hours, a thicker oxide layer was generated on the surface of the sample, and there were many obvious cracks. The oxide layer is discontinuous, indicating that part of the oxide scale has peeled off, exposing the fresh metal surface, which can easily lead to direct contact of oxygen, corrosive media, etc. with the substrate in practical applications, causing secondary oxidation or local corrosion. The surface morphology of the oxide layer of TiTaZrNbO2 prepared in Example 1 shows that only a very thin oxide film is generated after the oxidation of the TiTaZrNbO2 high entropy alloy, and the oxide film is smooth and continuous. The TiTaZrNbO prepared in Comparative Example 2 3.2 The surface morphology of the oxide layer is continuous but not smooth, showing a convex morphology but not peeling off.

[0118] The X-ray energy dispersive spectrometry (EDS) surface scan of the backscattered electron (BSE) image of the above TiTaZrNb after oxidation is shown in the figure below. Figure 8 As shown, the X-ray energy dispersive spectrometry (EDS) surface scan of the backscattered electron (BSE) image of TiTaZrNbO2 after oxidation is shown in Figure 9 As shown, TiTaZrNbO 3.2 The X-ray energy dispersive spectroscopy (EDS) surface scan of the backscattered electron (BSE) image after oxidation is shown in the figure below. Figure 10 shown.

[0119] Depend on Figures 8-10 It can be seen that the oxygen element in the TiTaZrNbO2 prepared in Example 1 is mainly concentrated in the oxide thin layer, and only a small amount of diffusely distributed oxygen element introduced during smelting is present in the matrix, indicating that the oxide thin layer plays a good role in blocking the diffusion of oxygen elements. 3.2 The oxygen elements in the water penetrate deep into the base.

[0120] Test Example 5

[0121] A sample was cut from the TiTaZrNbV high-entropy alloy material prepared in Example 3 using a wire cutter, ultrasonically cleaned in anhydrous ethanol for 300 seconds, and dried with a hair dryer. The sample was then hot-mounted with the flat surface facing upward. After mounting, grinding, and polishing, a hardness test was performed. The hardness test was performed using a 1000g indenter for 15 seconds at five different points. The hardness test results are shown in the table below.

[0122] Table 1 Hardness test results

[0123]

[0124] A tensile specimen and a cylindrical compression specimen with a height of 8 mm and a diameter of 4 mm were cut out of TiTaZrNbV using a wire cutting machine. The surfaces of the specimens were then polished step by step, with the polishing mesh numbers being 240 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh, respectively, and then polished to a mirror finish using a diamond polishing paste with a particle size of 1.5 μm. After all the samples were polished, they were ultrasonically cleaned with anhydrous ethanol, the surface was blown dry, and the axial tensile and compressive properties were tested at room temperature using a WD-100D universal mechanical testing machine. The tensile stress-strain diagram of TiTaZrNbV is shown in Figure 2. Figure 11 As shown, the compressive stress-strain diagram of TiTaZrNbV is as follows Figure 12 shown.

[0125] Depend on Figure 11 and Figure 12 It can be seen that the TiTaZrNbV alloy exhibits good mechanical properties, with a tensile yield strength of about 1.1GPa and a maximum compressive strength of 2.5GPa, with high yield strength and compressive plasticity. The optimization of its mechanical properties can be attributed to the synergistic effect of the following aspects: First, the atomic radius of the vanadium element is small, and after doping, it can cause a strong lattice distortion effect in the lattice, thereby enhancing the solid solution strengthening effect of the alloy; second, the vanadium element has a high binding energy, which can promote the stability of the multi-principal element high entropy solid solution structure and delay phase decomposition or the formation of brittle phases; third, in terms of microstructure, the introduction of vanadium inhibits grain coarsening and refines the grain size, thereby significantly improving the strength of the material. This provides a solution for strengthening the mechanical properties of TiTaZrNb-based high entropy alloy structural parts under high-temperature service environments.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium-based high-entropy alloy material, characterized in that: The high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium series high-entropy alloy material is a TiTaZrNbO high-entropy alloy material or a TiTaZrNbV high-entropy alloy material; The TiTaZrNbO high entropy alloy material is composed of the following raw materials in atomic percentage: Ti 40-41%, Ta 26-27%, Zr15-16%, Nb 15-15.5% and O 2.5%; The TiTaZrNbV high entropy alloy material is composed of the following raw materials in atomic percentage: Ti 19.5-20.5%, Ta 19.5-20.5%, Zr 19.5-20.5%, Nb 19.5-20.5% and V 19.5-20.5%; The following steps are involved: S1. Take particles of Ti, Ta, Zr, Nb and TiO2 / V, polish their surfaces with sandpaper, wash them in anhydrous ethanol and then dry them. The particle size of the Ti, Ta, Zr, Nb and V particles is 1-3 mm, and the particle size of the TiO2 particles is 2.5-3 mm. S2. Stack Ti, Zr, Nb, Ta and TiO2 blocks in the order of Ti, Zr, V, Nb and Ta from bottom to top and place them in a vacuum suspension melting furnace for melting using a vacuum suspension melting method. During melting, first adjust the power to 90-110kW and keep it for 4-6 minutes, then adjust the power to 110-130kW and keep it for 4-6 minutes, then adjust the power to 130-150kW and keep it for 4-6 minutes, and finally adjust the power to 180-200kW and keep it warm at 1600-1700℃ for 8-10 minutes. After melting, cool it to obtain a titanium, tantalum, zirconium and niobium high entropy alloy material resistant to high temperature oxidation.

2. The method for preparing a high-temperature oxidation-resistant titanium, tantalum, zirconium, and niobium-based high-entropy alloy material according to claim 1, wherein: The TiTaZrNbV high entropy alloy material is composed of the following raw materials in atomic percentage: Ti 20%, Ta 20%, Zr 20%, Nb 20% and V 20%.

3. The method for preparing a high-temperature oxidation-resistant titanium-tantalum-zirconium-niobium series high-entropy alloy material according to claim 1, characterized in that: In step S2, the diameter of the TiO2 block is 5-10 mm and the thickness is 2-4 mm.

4. The method for preparing a high-temperature oxidation-resistant titanium-tantalum-zirconium-niobium series high-entropy alloy material according to claim 1, characterized in that: In step S2, before smelting, the vacuum is first pumped to 4-6 Pa using a mechanical pump, and then the molecular pump is turned on to continue vacuuming to 4.5×10 -3 -5.5×10 -3 Pa, and filled with high-purity argon gas to make the pressure in the furnace 0.5-0.7atm.

5. The method for preparing a high-temperature oxidation-resistant titanium-tantalum-zirconium-niobium series high-entropy alloy material according to claim 1, characterized in that: In step S2, high-frequency electromagnetic induction heating is used during smelting.

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