Single-phase TiZrMo series spherical refractory high-entropy alloy powder and preparation method thereof

Abstract

This invention belongs to the field of metallic materials technology, specifically a single-phase TiZrMo spherical refractory high-entropy alloy powder and its preparation method. The refractory high-entropy alloy powder is composed of any two of Al, Cr, and Nb, and Ti, Zr, and Mo. The atomic radius difference of the refractory high-entropy alloy powder is ≤6.5%, the alloy entropy enthalpy ratio Ω is ≥1.4, and the mixing enthalpy ΔH is... mix The energy density is -20.27 to -3.27 kJ / mol, and the vacancy electron concentration (VEC) is <4.96. Furthermore, the preparation method of this invention has the advantages of simple steps, easy composition control, high production efficiency, and near-net-shape forming. The prepared spherical single-phase BCC refractory high-entropy alloy powder has a high sphericity, smooth surface, and low cost. The high-entropy alloy bulk prepared from this powder has stable microstructure and properties, and its density (2.70–10.22 g / cm³) can be adjusted within a wide range. 3 It possesses both good plasticity (compressive fracture strain ≥10.0%) and strength (compressive strength ≥965MPa), making it suitable for large-scale industrial applications.

Description

Technical Field

[0001] This invention relates to the field of metallic materials technology, specifically to a single-phase TiZrMo spherical refractory high-entropy alloy powder and its preparation method. Background Technology

[0002] The rapid development of high-temperature fields such as modern aerospace, nuclear reactors, weaponry, and gas turbines has led to increasingly stringent requirements for the performance of high-temperature structural materials. However, the performance of traditional alloys, represented by nickel-based alloys, has reached its limit, necessitating disruptive new alloy design concepts. Refractory high-entropy alloys break away from the traditional concept of alloys being dominated by one or two alloying elements, combining multiple high-melting-point elements to achieve better high-temperature strength, resistance to high-temperature softening, corrosion resistance, and radiation resistance. This represents a new direction and approach for developing new high-temperature, high-strength structural materials. However, current research is still in its early stages. Alloy composition design needs further refinement, and most alloys exhibit limited properties, including room-temperature brittleness, high alloy density, and low high-temperature oxidation resistance. Furthermore, composition design is currently challenging: refractory high-entropy alloys are composed of multiple elements, requiring consideration of the proportions of these elements, their atomic radii, and interactions. The design and optimization of novel refractory high-entropy alloys require extensive experimental and theoretical calculations.

[0003] Currently, most (>90%) methods for preparing refractory high-entropy alloys in China employ melting. However, the complexity of the composition and the significant melting point differences between different components lead to substantial volatilization and loss of low-melting-point elements in refractory high-entropy alloys prepared by melting, easily resulting in significant elemental segregation and introducing defects such as porosity and looseness into the alloy. Furthermore, the batching and machining processes for alloys prepared by melting are cumbersome, resulting in irregular shapes and limited dimensions. Powder metallurgy, as an advanced and mature forming method, features near-net-shape forming, almost no component segregation, fine and uniform grains without anisotropy, and the ability to produce large quantities with minimal subsequent machining. It has significant advantages in preparing homogenized elements and forming large-size, irregularly shaped components. The challenges of preparing refractory high-entropy alloys by powder metallurgy include the difficulty in controlling powder preparation and the crucial importance of a uniform, fine powder composition. When using processes such as ball milling, prolonged mechanical activation treatment is necessary to ensure system mixing. However, mechanical stirring and milling processes can lead to powder surface oxidation or contamination, affecting the oxidation resistance and mechanical properties of high-entropy alloys. Furthermore, the powder raw materials require high-quality raw materials and are expensive. Controlling the alloying process is challenging, and high-entropy alloys are typically prepared using high-temperature sintering under oxygen-free conditions or spark plasma sintering. However, in these methods, the sintering conditions significantly influence the composition, microstructure, and properties of the high-entropy alloy. Excessively high or low temperatures, inappropriate holding times, and inadequate atmosphere control can all lead to weight loss, thus reducing its performance. Summary of the Invention

[0004] To address the problems existing in the prior art, the main objective of this invention is to propose a single-phase TiZrMo spherical refractory high-entropy alloy powder and its preparation method.

[0005] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0006] A single-phase TiZrMo spherical refractory high-entropy alloy powder, by atomic percentage, is composed of any two of the following: 5-35% Al, 5-35% Cr, and 5-35% Nb, and 5-35% Ti, 5-35% Zr, and 5-35% Mo. The single-phase TiZrMo spherical refractory high-entropy alloy powder has a single-phase body-centered cubic structure, with an atomic radius difference δ≤6.5%, an alloy entropy enthalpy ratio Ω≥1.4, and a mixing enthalpy ΔH. mix The energy ranges from -20.27 to -3.27 kJ / mol, and the vacancy electron concentration VEC < 4.96.

[0007] As a preferred embodiment of the single-phase TiZrMo spherical refractory high-entropy alloy powder described in this invention, the density of the single-phase TiZrMo spherical refractory high-entropy alloy powder is 2.70–10.22 g / cm³. 3 Compressive fracture strain ≥10.0%, compressive strength ≥965MPa.

[0008] To solve the above-mentioned technical problems, according to another aspect of the present invention, the present invention provides the following technical solution:

[0009] A method for preparing the above-mentioned single-phase TiZrMo spherical refractory high-entropy alloy powder includes the following steps:

[0010] S1. Take the elemental blocks of each element, pre-treat them, crush, grind and sieve them to obtain elemental powders of each element.

[0011] S2. Take the elemental powders according to the alloy composition ratio and mix them in a mixer to obtain a preliminary mixture;

[0012] S3. Add the preliminary mixture, wet grinding solvent and grinding balls into the ball milling jar, and after vacuuming, perform high-energy ball milling to obtain refractory high-entropy alloy powder.

[0013] S4. After drying the refractory high-entropy alloy powder in a drying oven, grind it and pass the powder through a 5000-mesh sieve to obtain pre-spheroidized powder.

[0014] S5. The pre-spheroidized powder is spheroidized to obtain single-phase TiZrMo spherical refractory high-entropy alloy powder.

[0015] As a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S1, the purity of the elemental bulk is ≥99.5%, and the particle size of the elemental powder is <38μm.

[0016] As a preferred embodiment of the preparation method of the single-phase TiZrMo spherical refractory high-entropy alloy powder of the present invention, in step S1, the pretreatment includes: grinding the oxide scale on the surface of the elemental block with a grinding wheel, then placing it in a beaker containing anhydrous ethanol and treating it with ultrasound; after the surface impurities and dirt of the elemental block are removed, it is placed in a drying oven to dry.

[0017] In a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, the ultrasonic treatment time in step S1 is 30-60 min.

[0018] In a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S1, the drying process is carried out under vacuum in a drying oven with a vacuum degree ≤1×10⁻⁶. -3 Pa, drying time is 5-10 hours.

[0019] In a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S2, the mixer is a three-dimensional mixer, and mixing is carried out under vacuum with a vacuum degree ≤1×10⁻⁶. -3 Pa, mixing time is 1 to 5 hours.

[0020] As a preferred embodiment of the preparation method of the single-phase TiZrMo spherical refractory high-entropy alloy powder of the present invention, in step S3, the wet grinding solvent is anhydrous ethanol and / or n-heptane and / or acetone, and the solid-liquid ratio of the preliminary mixture and the wet grinding solvent is 100g:(20~100)mL.

[0021] In a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S3, the grinding balls are stainless steel balls of different sizes, with diameters of 20 mm, 10 mm, and 6 mm, and a mass ratio of (0.5-10):(0.5-10):1.

[0022] As a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S3, the high-energy ball milling adopts an omnidirectional planetary ball mill, the ball-to-material ratio is 5-20:1, and the vacuum degree after vacuuming is ≤1×10⁻⁶. -3 Pa, the rotation speed of the large disc is 200-400 r / min, the rotation speed of the ball mill jar is 200-400 r / min, the rotation speed of the large disc is 0.5-2 r / min, and the ball milling time is 30-100 h.

[0023] As a preferred embodiment of the preparation method of the single-phase TiZrMo spherical refractory high-entropy alloy powder of the present invention, in step S3, the ball milling jar is taken out every 5 hours during high-energy ball milling, and the powder in the jar body, including the inner wall and the jar cover, is scraped into the bottom of the jar under the protection of inert gas, so that the powder is fully alloyed.

[0024] In a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S4, the drying process is carried out under vacuum in a drying oven with a vacuum degree ≤1×10⁻⁶. -3 Pa, drying time is 5-10 hours.

[0025] As a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S5, spheroidization is carried out in a radio frequency plasma spheroidization device. After the radio frequency plasma spheroidization device is purged, the pre-spheroidized powder is loaded into the radio frequency plasma spheroidization device for spheroidization.

[0026] As a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S5, the gas washing operation is as follows: first, vacuum is drawn, then argon gas is introduced for gas washing, then vacuum is drawn again, and so on for at least 5 times, and finally argon gas is continuously introduced for 10-15 minutes.

[0027] As a preferred embodiment of the method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to the present invention, in step S5, the spheroidizing process parameters of the radio frequency plasma spheroidizing device are as follows: powder feeding rate of 3-60 g / min, internal pressure of the spheroidizing device of 40-200 kPa, carrier gas flow rate of 1-20 L / min, central gas flow rate of 5-80 L / min, protective argon gas flow rate of 20-150 L / min, voltage of 5-20 kV, power of 5-35 kW, and vibration frequency of 50-150 Hz.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention proposes a single-phase TiZrMo spherical refractory high-entropy alloy powder and its preparation method. The refractory high-entropy alloy powder is composed of any two of Al, Cr, and Nb, and Ti, Zr, and Mo. The atomic radius difference of the refractory high-entropy alloy powder is ≤6.5%, the alloy entropy enthalpy ratio Ω is ≥1.4, and the mixing enthalpy ΔH is... mix The energy density is -20.27 to -3.27 kJ / mol, and the vacancy electron concentration (VEC) is <4.96. Furthermore, the preparation method of this invention has the advantages of simple steps, easy composition control, high production efficiency, and near-net-shape forming. The prepared spherical single-phase BCC refractory high-entropy alloy powder has a high sphericity, smooth surface, and low cost. The high-entropy alloy bulk prepared from this powder has stable microstructure and properties, and its density (2.70–10.22 g / cm³) can be adjusted within a wide range. 3 It possesses both good plasticity (compressive fracture strain ≥10.0%) and strength (compressive strength ≥965MPa), making it suitable for large-scale industrial applications. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0031] Figure 1 The image shows the XRD pattern of the spherical refractory high-entropy alloy powder prepared in Example 1 of this invention.

[0032] Figure 2 This is a SEM image of the spherical refractory high-entropy alloy powder prepared in Example 1 of the present invention;

[0033] Figure 3 The image shows the XRD pattern of the spherical refractory high-entropy alloy powder prepared in Example 2 of this invention.

[0034] Figure 4 This is a SEM image of the spherical refractory high-entropy alloy powder prepared in Example 2 of the present invention;

[0035] Figure 5 The image shows the XRD pattern of the spherical refractory high-entropy alloy powder prepared in Example 3 of this invention.

[0036] Figure 6 This is a SEM image of the spherical refractory high-entropy alloy powder prepared in Example 3 of the present invention.

[0037] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] To address the problems of existing technologies, this invention proposes a single-phase TiZrMo spherical refractory high-entropy alloy powder and its preparation method.

[0040] According to one aspect of the present invention, the present invention provides the following technical solution:

[0041] A single-phase TiZrMo spherical refractory high-entropy alloy powder, by atomic percentage, is composed of any two of the following: 5-35% Al, 5-35% Cr, and 5-35% Nb, and 5-35% Ti, 5-35% Zr, and 5-35% Mo. The single-phase TiZrMo spherical refractory high-entropy alloy powder has a single-phase body-centered cubic structure, with an atomic radius difference δ≤6.5%, an alloy entropy enthalpy ratio Ω≥1.4, and a mixing enthalpy ΔH. mix The energy ranges from -20.27 to -3.27 kJ / mol, and the vacancy electron concentration VEC < 4.96.

[0042] in,

[0043]

[0044]

[0045]

[0046]

[0047] VEC=∑C i (VEC i )

[0048] In the above formula, T m ΔS represents the melting point of a refractory high-entropy alloy. mix For the mixed entropy change of the refractory high-entropy alloy system, ΔH mix For the mixing enthalpy change of refractory high-entropy alloy systems, (T m ) i Let r be the melting point of the i-th element. i Let be the atomic radius of the i-th element. Let C be the enthalpy of mixing between the i-th and j-th elements. i and C j The atomic percentage content of the i-th and j-th elements, respectively, VEC i Let be the vacancy electron concentration of the i-th element.

[0049] Preferably, the density of the single-phase TiZrMo spherical refractory high-entropy alloy powder is 2.70–10.22 g / cm³. 3 Compressive fracture strain ≥10.0%, compressive strength ≥965MPa.

[0050] According to another aspect of the present invention, the present invention provides the following technical solution:

[0051] A method for preparing the above-mentioned single-phase TiZrMo spherical refractory high-entropy alloy powder includes the following steps:

[0052] S1. Take the elemental blocks of each element, pre-treat them, crush, grind and sieve them to obtain elemental powders of each element.

[0053] S2. Take the elemental powders according to the alloy composition ratio and mix them in a mixer to obtain a preliminary mixture;

[0054] S3. Add the preliminary mixture, wet grinding solvent and grinding balls into the ball milling jar, and after vacuuming, perform high-energy ball milling to obtain refractory high-entropy alloy powder.

[0055] S4. After drying the refractory high-entropy alloy powder in a drying oven, grind it and pass the powder through a 5000-mesh sieve to obtain pre-spheroidized powder.

[0056] S5. The pre-spheroidized powder is spheroidized to obtain single-phase TiZrMo spherical refractory high-entropy alloy powder.

[0057] Preferably, in step S1, the purity of the elemental block is ≥99.5%, and the particle size of the elemental powder is <38μm; the pretreatment includes: grinding the oxide scale off the surface of the elemental block with a grinding wheel, then placing it in a beaker containing anhydrous ethanol and treating it with ultrasound; after the surface impurities and dirt of the elemental block are removed, it is placed in a drying oven to dry; the ultrasonic treatment time is 30-60 minutes; the drying process is carried out under vacuum in the drying oven, with a vacuum degree ≤1×10 -3 Pa, the drying time is 5 to 10 hours. Specifically, the ultrasonic treatment time can be, for example, but not limited to, any one or any two of 30 min, 40 min, 50 min, 60 min; the drying time can be, for example, but not limited to, any one or any two of 5 h, 6 h, 7 h, 8 h, 9 h, 10 h.

[0058] Preferably, in step S2, the mixer is a three-dimensional mixer, and mixing is performed under vacuum with a vacuum degree ≤1×10⁻⁶. -3 Pa, the mixing time is 1 to 5 hours. The mixing time can be, for example, but not limited to, any one of 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, or a range between any two.

[0059] Preferably, in step S3, the wet grinding solvent is anhydrous ethanol and / or n-heptane and / or acetone, and the solid-liquid ratio of the initial mixture to the wet grinding solvent is 100g:(20-100)mL; the grinding balls are stainless steel balls of different sizes, with diameters of 20mm, 10mm, and 6mm, and a mass ratio of (0.5-10):(0.5-10):1; the high-energy ball mill uses an omnidirectional planetary ball mill, with a ball-to-material ratio of 5-20:1, and the vacuum degree after vacuuming is ≤1×10⁻⁶. -3Pa, the rotation speed of the large disc is 200-400 r / min, the rotation speed of the ball mill jar is 200-400 r / min, the rotation speed of the large disc is 0.5-2 r / min, and the ball milling time is 30-100 h; during high-energy ball milling, the ball mill jar is removed every 5 h, and under the protection of inert gas, the powder in the jar body, including the inner wall and the jar cover, is scraped into the bottom of the jar to allow the powder to be fully alloyed. Specifically, the solid-liquid ratio of the initial mixture and the wet milling solvent can be, for example, but not limited to, any one or a range between any two of 100g:20mL, 100g:40mL, 100g:60mL, 100g:80mL, and 100g:100mL; the ball-to-material ratio can be, for example, but not limited to, any one or a range between any two of 5:1, 10:1, 15:1, and 20:1; and the rotational speed of the large disc (i.e., the revolution speed) can be, for example, but not limited to, any one or a range between any two of 200r / min, 250r / min, 300r / min, 350r / min, and 400r / min. The range between these values; the rotational speed of the ball mill jar (i.e., its rotational speed) can be, for example, but not limited to, any one or any two of 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min; the tumbling speed of the large disc can be, for example, but not limited to, any one or any two of 0.5 r / min, 1.0 r / min, 1.5 r / min, 2 r / min; the ball milling time can be, for example, but not limited to, any one or any two of 30 h, 40 h, 50 h, 60 h, 70 h, 80 h, 90 h, 100 h;

[0060] Preferably, in step S4, the drying process is carried out under vacuum in a drying oven, with a vacuum degree ≤1×10⁻⁶. -3 Pa, the drying time is 5 to 10 hours. Specifically, the drying time can be any one or a range between any two of, for example, but not limited to, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, and 10 hours.

[0061] Preferably, in step S5, spheroidization is carried out in a radio frequency plasma spheroidization device. After purging the radio frequency plasma spheroidization device, the pre-spheroidized powder is loaded into the device for spheroidization. The purging operation is as follows: first, a vacuum is drawn, then argon gas is introduced for purging, then a vacuum is drawn again, and this process is repeated at least 5 times. Finally, argon gas is continuously introduced for 10-15 minutes. The spheroidization process parameters of the radio frequency plasma spheroidization device are: powder feeding rate of 3-60 g / min, internal pressure of the spheroidization device of 40-200 kPa, carrier gas flow rate of 1-20 L / min, central gas flow rate of 5-80 L / min, argon gas flow rate of the protective layer of 20-150 L / min, voltage of 5-20 kV, power of 5-35 kW, and vibration frequency of 50-150 Hz. Specifically, the powder feeding rate can be, for example, but not limited to, any one or any two of 3 g / min, 5 g / min, 10 g / min, 20 g / min, 30 g / min, 40 g / min, 50 g / min, 60 g / min; the internal pressure of the spheroidizing device can be, for example, but not limited to, any one or any two of 40 kPa, 80 kPa, 120 kPa, 160 kPa, 200 kPa; the carrier gas flow rate can be, for example, but not limited to, any one or any two of 1 L / min, 2 L / min, 5 L / min, 10 L / min, 15 L / min, 20 L / min; and the central gas flow rate can be, for example, but not limited to, 5 L / min, 10 ... The flow rate of the protective layer can be any one or a range between any two of the following: L / min, 30L / min, 50L / min, 70L / min, 80L / min; the argon flow rate of the protective layer can be any one or a range between any two of the following: 20L / min, 50L / min, 100L / min, 150L / min; the voltage value can be, for example, but not limited to, any one or a range between any two of the following: 5kV, 10kV, 15kV, 20kV; the power can be, for example, but not limited to, any one or a range between any two of the following: 5kW, 15kW, 25kW, 35kW; and the vibration frequency can be, for example, but not limited to, any one or a range between any two of the following: 50Hz, 75Hz, 100Hz, 125Hz, 150Hz.

[0062] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0063] Example 1

[0064] A single-phase TiZrMo spherical refractory high-entropy alloy powder, with an atomic percentage ratio of Ti:Zr:Mo:Al:Nb = 1:1:1:1:0.8, an alloy entropy enthalpy ratio of 1.563, an atomic radius difference of 4.79%, and a mixing enthalpy ΔH. mixThe concentration of vacancy electrons (VEC) is -17.95 kJ / mol, and the vacancy electron concentration is 4.375.

[0065] The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder in this embodiment includes the following steps:

[0066] S1. Take the elemental blocks of each element, pre-treat them, crush, grind and sieve them to obtain elemental powders of each element.

[0067] The purity of the elemental block is ≥99.5%; pretreatment includes: grinding the oxide scale off the surface of the elemental block with a grinding wheel, then placing it in a beaker containing anhydrous ethanol and treating it with ultrasound; after removing surface impurities and dirt, the elemental block is placed in a drying oven for drying; the ultrasonic treatment time is 60 minutes; the drying process is carried out under vacuum in the drying oven, with a vacuum degree ≤1×10⁻⁶. -3 Pa, drying time is 5h; after drying, it is placed in a crusher for crushing and grinding; the particle sizes of Ti, Zr, Mo, Al and Nb elemental powders obtained by passing through a 400-mesh sieve are as follows: D50 of Ti powder is 31.4μm, D50 of Zr powder is 26.3μm, D50 of Mo powder is 35.4μm, D50 of Al powder is 22.2μm and D50 of Nb powder is 31.4μm;

[0068] S2. Take the elemental powders according to the alloy composition ratio (Ti:Zr:Mo:Al:Nb=1:1:1:1:0.8) and mix them in a mixer to obtain a preliminary mixture.

[0069] The mixer is a three-dimensional mixer that performs mixing under vacuum, with a vacuum degree ≤1×10⁻⁶. -3 Pa, mixing time is 2h, and the D50 of the initial mixture is 29.7μm.

[0070] S3. Add the preliminary mixture, wet grinding solvent and grinding balls into the ball milling jar, and after vacuuming, perform high-energy ball milling to obtain refractory high-entropy alloy powder.

[0071] The wet grinding solvent is acetone, and the solid-liquid ratio of the initial mixture to the wet grinding solvent is 100g:50mL. The grinding balls are stainless steel balls of different sizes, with diameters of 20mm, 10mm, and 6mm, and a mass ratio of 5:5:1. The high-energy ball mill uses an omnidirectional planetary ball mill with a ball-to-material ratio of 10:1, and the vacuum degree after vacuuming is ≤1×10⁻⁶. -3 Pa, the rotation speed of the large disc is 350 r / min, the rotation speed of the ball mill jar is 350 r / min, the rotation speed of the large disc is 0.5 r / min, and the ball milling time is 90 h; during high-energy ball milling, the ball mill jar is removed every 5 h, and under the protection of inert gas, the powder in the jar body, including the inner wall and the jar cover, is scraped into the bottom of the jar to allow the powder to be fully alloyed.

[0072] S4. After drying the refractory high-entropy alloy powder in a drying oven, grind it and pass the powder through a 5000-mesh sieve to obtain pre-spheroidized powder.

[0073] The drying process is carried out under vacuum in a drying oven, with a vacuum degree ≤1×10⁻⁶. -3 Pa, drying time is 10h.

[0074] S5. The pre-spheroidized powder is spheroidized to obtain single-phase TiZrMo spherical refractory high-entropy alloy powder.

[0075] Spheroidization is carried out in a radio frequency plasma spheroidization device. After purging the radio frequency plasma spheroidization device, the pre-spheroidized powder is loaded into the device for spheroidization. The purging operation is as follows: first, a vacuum is drawn, then argon gas is introduced for purging, then a vacuum is drawn again, and this process is repeated 5 times. Finally, argon gas is continuously introduced for 15 minutes. The spheroidization process parameters of the radio frequency plasma spheroidization device are as follows: powder feeding rate is 30 g / min, internal pressure of the spheroidization device is 100 kPa, carrier gas flow rate is 10 L / min, central gas flow rate is 50 L / min, argon gas flow rate for the protective layer is 100 L / min, voltage is 10 kV, power is 25 kW, and vibration frequency is 100 Hz.

[0076] The XRD results of the single-phase TiZrMo spherical refractory high-entropy alloy powder prepared in this embodiment are as follows: Figure 1 As shown in the figure, the SEM image is as follows: Figure 2 As shown, the XRD diffraction pattern reveals that the single-phase TiZrMo spherical refractory high-entropy alloy powder exhibits a single BCC crystal structure solid solution diffraction peak, demonstrating significant alloying effect and a near-spherical morphology. After vacuum solid-state sintering, the prepared spherical single-phase BCC refractory high-entropy alloy powder yields a stable microstructure and properties, with a density of 6.40 g / cm³. 3 It possesses both good plasticity (compressive fracture strain of 10.1%) and strength (compressive strength of 967.9 MPa).

[0077] Example 2

[0078] A single-phase TiZrMo spherical refractory high-entropy alloy powder, with an atomic percentage ratio of Ti:Zr:Mo:Al:Nb = 0.4:1:1:1:1, an alloy entropy enthalpy ratio of 1.544, an atomic radius difference of 4.96%, and a mixing enthalpy ΔH. mix The concentration of vacancy electrons (VEC) is -18.14 kJ / mol, and the vacancy electron concentration (VEC) is 4.45.

[0079] The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder in this embodiment includes the following steps:

[0080] S1. Take the elemental blocks of each element, pre-treat them, crush, grind and sieve them to obtain elemental powders of each element.

[0081] The purity of the elemental block is ≥99.5%; pretreatment includes: grinding the oxide scale off the surface of the elemental block with a grinding wheel, then placing it in a beaker containing anhydrous ethanol and treating it with ultrasound; after removing surface impurities and dirt, the elemental block is placed in a drying oven for drying; the ultrasonic treatment time is 30 minutes; the drying process is carried out under vacuum in the drying oven, with a vacuum degree ≤1×10⁻⁶. -3 Pa, drying time is 10h; after drying, it is placed in a crusher for crushing and grinding; the particle sizes of Ti, Zr, Mo, Al and Nb elemental powders obtained by passing through a 400-mesh sieve are as follows: D50 of Ti powder is 31.6μm, D50 of Zr powder is 25.0μm, D50 of Mo powder is 35.4μm, D50 of Al powder is 21.3μm and D50 of Nb powder is 31.1μm;

[0082] S2. Take the elemental powders according to the alloy composition ratio (Ti:Zr:Mo:Al:Nb=0.4:1:1:1:1) and mix them in a mixer to obtain a preliminary mixture.

[0083] The mixer is a three-dimensional mixer that performs mixing under vacuum, with a vacuum degree ≤1×10⁻⁶. -3 Pa, mixing time is 2h, and the D50 of the initial mixture is 30.0μm.

[0084] S3. Add the preliminary mixture, wet grinding solvent and grinding balls into the ball milling jar, and after vacuuming, perform high-energy ball milling to obtain refractory high-entropy alloy powder.

[0085] The wet grinding solvent is acetone, and the solid-liquid ratio of the initial mixture to the wet grinding solvent is 100g:50mL. The grinding balls are stainless steel balls of different sizes, with diameters of 20mm, 10mm, and 6mm, and a mass ratio of 5:5:1. The high-energy ball mill uses an omnidirectional planetary ball mill with a ball-to-material ratio of 20:1, and the vacuum degree after vacuuming is ≤1×10⁻⁶. -3 Pa, the rotation speed of the large disc is 400 r / min, the rotation speed of the ball mill jar is 400 r / min, the rotation speed of the large disc is 2 r / min, and the ball milling time is 75 h; during high-energy ball milling, the ball mill jar is removed every 5 h, and under the protection of inert gas, the powder in the jar body, including the inner wall and the jar cover, is scraped into the bottom of the jar to allow the powder to be fully alloyed.

[0086] S4. After drying the refractory high-entropy alloy powder in a drying oven, grind it and pass the powder through a 5000-mesh sieve to obtain pre-spheroidized powder.

[0087] The drying process is carried out under vacuum in a drying oven, with a vacuum degree ≤1×10⁻⁶. -3Pa, drying time is 10h.

[0088] S5. The pre-spheroidized powder is spheroidized to obtain single-phase TiZrMo spherical refractory high-entropy alloy powder.

[0089] Spheroidization is carried out in a radio frequency plasma spheroidization device. After purging the radio frequency plasma spheroidization device, the pre-spheroidized powder is loaded into the device for spheroidization. The purging operation is as follows: first, a vacuum is drawn, then argon gas is introduced for purging, then a vacuum is drawn again, and this process is repeated 5 times. Finally, argon gas is continuously introduced for 10 minutes. The spheroidization process parameters of the radio frequency plasma spheroidization device are as follows: powder feeding rate is 25 g / min, internal pressure of the spheroidization device is 100 kPa, carrier gas flow rate is 10 L / min, central gas flow rate is 60 L / min, argon gas flow rate for the protective layer is 110 L / min, voltage is 10 kV, power is 25 kW, and vibration frequency is 100 Hz.

[0090] The XRD results of the single-phase TiZrMo spherical refractory high-entropy alloy powder prepared in this embodiment are as follows: Figure 3 As shown in the figure, the SEM image is as follows: Figure 4 As shown, the XRD diffraction pattern reveals that the single-phase TiZrMo spherical refractory high-entropy alloy powder exhibits a single BCC crystal structure solid solution diffraction peak, demonstrating significant alloying effect and a near-spherical morphology. After vacuum solid-state sintering, the prepared spherical single-phase BCC refractory high-entropy alloy powder yields a stable microstructure and properties, with a density of 6.72 g / cm³. 3 It possesses both good plasticity (compressive fracture strain of 12.1%) and strength (compressive strength of 987.2 MPa).

[0091] Example 3

[0092] A single-phase TiZrMo spherical refractory high-entropy alloy powder, with an atomic percentage ratio of Ti:Zr:Mo:Cr:Nb = 1:1:1:0.4:1, an alloy entropy enthalpy ratio of 7.419, an atomic radius difference of 6.23%, and a mixing enthalpy ΔH. mix The concentration of vacancy electrons (VEC) is -4.21 kJ / mol, and the vacancy electron concentration (VEC) is 4.86.

[0093] The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder in this embodiment includes the following steps:

[0094] S1. Take the elemental blocks of each element, pre-treat them, crush, grind and sieve them to obtain elemental powders of each element.

[0095] The purity of the elemental block is ≥99.5%; pretreatment includes: grinding the oxide scale off the surface of the elemental block with a grinding wheel, then placing it in a beaker containing anhydrous ethanol and treating it with ultrasound; after removing surface impurities and dirt, the elemental block is placed in a drying oven for drying; the ultrasonic treatment time is 30 minutes; the drying process is carried out under vacuum in the drying oven, with a vacuum degree ≤1×10⁻⁶. -3 The drying process was carried out at 10 h. After drying, the powder was crushed and ground in a crusher. The particle sizes of Ti, Zr, Mo, Cr, and Nb elemental powders obtained by passing through a 400-mesh sieve were as follows: D50 of Ti powder was 33.1 μm, D50 of Zr powder was 24.9 μm, D50 of Mo powder was 33.2 μm, D50 of Cr powder was 23.1 μm, and D50 of Nb powder was 31.9 μm.

[0096] S2. Take the elemental powders according to the alloy composition ratio (Ti:Zr:Mo:Cr:Nb=1:1:1:0.4:1) and mix them in a mixer to obtain a preliminary mixture.

[0097] The mixer is a three-dimensional mixer that performs mixing under vacuum, with a vacuum degree ≤1×10⁻⁶. -3 Pa, mixing time is 2h, and the D50 of the initial mixture is 30.6μm.

[0098] S3. Add the preliminary mixture, wet grinding solvent and grinding balls into the ball milling jar, and after vacuuming, perform high-energy ball milling to obtain refractory high-entropy alloy powder.

[0099] The wet grinding solvent is acetone, and the solid-liquid ratio of the initial mixture to the wet grinding solvent is 100g:50mL. The grinding balls are stainless steel balls of different sizes, with diameters of 20mm, 10mm, and 6mm, and a mass ratio of 5:5:1. The high-energy ball mill uses an omnidirectional planetary ball mill with a ball-to-material ratio of 20:1, and the vacuum degree after vacuuming is ≤1×10⁻⁶. -3 Pa, the rotation speed of the large disc is 400 r / min, the rotation speed of the ball mill jar is 400 r / min, the rotation speed of the large disc is 1.5 r / min, and the ball milling time is 100 h; during high-energy ball milling, the ball mill jar is removed every 5 h, and under the protection of inert gas, the powder in the jar body, including the inner wall and the jar cover, is scraped into the bottom of the jar to allow the powder to be fully alloyed.

[0100] S4. After drying the refractory high-entropy alloy powder in a drying oven, grind it and pass the powder through a 5000-mesh sieve to obtain pre-spheroidized powder.

[0101] The drying process is carried out under vacuum in a drying oven, with a vacuum degree ≤1×10⁻⁶. -3 Pa, drying time is 10h.

[0102] S5. The pre-spheroidized powder is spheroidized to obtain single-phase TiZrMo spherical refractory high-entropy alloy powder.

[0103] Spheroidization is carried out in a radio frequency plasma spheroidization device. After purging the radio frequency plasma spheroidization device, the pre-spheroidized powder is loaded into the device for spheroidization. The purging operation is as follows: first, a vacuum is drawn, then argon gas is introduced for purging, then a vacuum is drawn again, and this process is repeated 5 times. Finally, argon gas is continuously introduced for 10 minutes. The spheroidization process parameters of the radio frequency plasma spheroidization device are as follows: powder feeding rate is 30 g / min, internal pressure of the spheroidization device is 100 kPa, carrier gas flow rate is 10 L / min, central gas flow rate is 50 L / min, argon gas flow rate for the protective layer is 100 L / min, voltage is 10 kV, power is 25 kW, and vibration frequency is 100 Hz.

[0104] The XRD results of the single-phase TiZrMo spherical refractory high-entropy alloy powder prepared in this embodiment are as follows: Figure 5 As shown in the figure, the SEM image is as follows: Figure 6 As shown, the XRD diffraction pattern reveals that the single-phase TiZrMo spherical refractory high-entropy alloy powder exhibits a single BCC crystal structure solid solution diffraction peak, demonstrating significant alloying effect and a near-spherical morphology. After vacuum solid-state sintering, the prepared spherical single-phase BCC refractory high-entropy alloy powder yields a stable microstructure and properties, with a density of 7.40 g / cm³. 3 It possesses both good plasticity (compressive fracture strain of 11.6%) and strength (compressive strength of 1920.9 MPa).

[0105] The refractory high-entropy alloy powder of this invention is composed of any two of Al, Cr, and Nb, and Ti, Zr, and Mo. The atomic radius difference of the refractory high-entropy alloy powder is ≤6.5%, the alloy entropy enthalpy ratio is ≥1.4, and the mixing enthalpy ΔH is... mix The energy density is -20.27 to -3.27 kJ / mol, and the vacancy electron concentration (VEC) is <4.96. Furthermore, the preparation method of this invention has the advantages of simple steps, easy composition control, high production efficiency, and near-net-shape forming. The prepared spherical single-phase BCC refractory high-entropy alloy powder has a high sphericity, smooth surface, and low cost. The high-entropy alloy bulk prepared from this powder has stable microstructure and properties, and its density (2.70–10.22 g / cm³) can be adjusted within a wide range. 3 It possesses both good plasticity (compressive fracture strain ≥10.0%) and strength (compressive strength ≥965MPa), making it suitable for large-scale industrial applications.

[0106] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A single-phase TiZrMo spherical refractory high-entropy alloy powder, characterized in that, consisting of any two of 5-35% of Al, 5-35% of Cr, 5-35% of Nb and 5-35% of Ti, 5-35% of Zr, 5-35% of Mo in atomic percentage; the single-phase TiZrMo series spherical refractory high-entropy alloy powder is a single-phase body-centered cubic structure, the atomic radius difference δ is ≤6.5%, the alloy entropy enthalpy ratio Ω is ≥1.4, and the mixing enthalpy ΔH mix is-20.27--3.27 kJ / mol, and the vacancy electron concentration VEC is <4.96; The density of single-phase TiZrMo spherical refractory high-entropy alloy powder is 2.70~10.22 g / cm³. 3 Compressive fracture strain ≥10.0%, compressive strength ≥965MPa.

2. A method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder as described in claim 1, characterized in that, Includes the following steps: S1. Take the elemental blocks of each element, pre-treat them, crush, grind and sieve them to obtain elemental powders of each element. S2. Take the elemental powders according to the alloy composition ratio and mix them in a mixer to obtain a preliminary mixture; S3. Add the preliminary mixture, wet grinding solvent and grinding balls into the ball milling jar, and after vacuuming, perform high-energy ball milling to obtain refractory high-entropy alloy powder. S4. After drying the refractory high-entropy alloy powder in a drying oven, grind it and pass the powder through a 5000-mesh sieve to obtain pre-spheroidized powder. S5. The pre-spheroidized powder is spheroidized to obtain single-phase TiZrMo spherical refractory high-entropy alloy powder.

3. The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to claim 2, characterized in that, In step S1, the purity of the elemental block is ≥99.5%, and the particle size of the elemental powder is <38μm.

4. The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to claim 2, characterized in that, In step S2, the mixer is a three-dimensional mixer that performs mixing under vacuum, with a vacuum degree ≤1×10⁻⁶. -3 Pa, mixing time is 1~5h.

5. The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to claim 2, characterized in that, In step S3, the wet grinding solvent is anhydrous ethanol and / or n-heptane and / or acetone, and the solid-liquid ratio of the initial mixture to the wet grinding solvent is 100g:(20~100)mL; the grinding balls are stainless steel balls of different sizes, with diameters of 20mm, 10mm, and 6mm, and a mass ratio of (0.5~10):(0.5~10):1; the high-energy ball mill uses an omnidirectional planetary ball mill, with a ball-to-material ratio of 5~20:1, and the vacuum degree after vacuuming is ≤1×10 -3 Pa, the rotation speed of the large disc is 200~400 r / min, the rotation speed of the ball mill jar is 200~400 r / min, the rotation speed of the large disc is 0.5~2 r / min, and the ball milling time is 30~100 h.

6. The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to claim 2, characterized in that, In step S4, the drying process is carried out under vacuum in a drying oven, with a vacuum degree ≤1×10⁻⁶. -3 Pa, drying time is 5~10h.

7. The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to claim 2, characterized in that, In step S5, spheroidization is carried out in a radio frequency plasma spheroidization device. After the radio frequency plasma spheroidization device is purged, the pre-spheroidized powder is loaded into the radio frequency plasma spheroidization device for spheroidization.

8. The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to claim 7, characterized in that, In step S5, the gas washing operation is as follows: first, a vacuum is drawn, then argon gas is introduced for gas washing, then a vacuum is drawn again, and this process is repeated at least 5 times. Finally, argon gas is continuously introduced for 10-15 minutes.

9. The method for preparing single-phase TiZrMo spherical refractory high-entropy alloy powder according to claim 7, characterized in that, In step S5, the spheroidizing process parameters of the radio frequency plasma spheroidizing device are as follows: powder feeding rate is 3~60g / min, internal pressure of the spheroidizing device is 40~200kPa, carrier gas flow rate is 1~20L / min, central gas flow rate is 5~80L / min, protective layer argon flow rate is 20~150L / min, voltage is 5~20kV, power is 5~35kW, and vibration frequency is 50~150Hz.

Images