Preparation method of high-toughness tungsten-nickel-copper alloy material with heterogeneous structure

Abstract

The application discloses a preparation method of high-strength and high-toughness tungsten-nickel-copper alloy material with a heterogeneous structure and belongs to the field of powder metallurgy technology.The alloy comprises, in percentage by mass, 80-90% of tungsten, Ni / Cu=8:2-3:2, 0.5% of Fe and 1% of Co.The preparation method comprises the following steps: high-energy ball milling of micron tungsten powder to obtain nano tungsten powder;uniform mixing of the nano tungsten powder, micron tungsten powder, nickel powder, copper powder, iron powder and cobalt powder in an inert atmosphere through an acoustic resonance mixing instrument; cold isostatic pressing to form a green body; sintering in a hydrogen atmosphere tube furnace; and finally, heat treatment in a vacuum atmosphere.The application forms a bimodal grain heterogeneous structure by introducing nano and micron tungsten powder, combines the addition of micro-alloying elements Fe and Co and vacuum heat treatment, so that the tensile strength of the alloy is greater than or equal to 900 MPa, and the elongation after fracture is greater than or equal to 25%, and the problem that the strength and elongation of a traditional tungsten-nickel-copper alloy are difficult to be considered simultaneously is solved.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology, and specifically relates to a method for preparing a high-strength and high-toughness tungsten-nickel-copper alloy material with a heterogeneous structure. Background Technology

[0002] Tungsten-nickel-copper alloy is an alloy material formed by adding small amounts of nickel and copper to tungsten as the base material. It also includes modified alloys with further additions of other alloying elements. Due to its excellent properties such as non-magnetism, high specific gravity, high strength, low coefficient of thermal expansion, good electrical and thermal conductivity, and non-toxicity, this alloy has been widely used in many fields such as aerospace and mechanical equipment. Examples of its applications include key components such as the core of armor-piercing projectiles, nozzles of rocket engines, rotors of gyroscopes, and electrical contacts of high-voltage electrical switches.

[0003] Traditionally, tungsten-nickel-copper alloys are mainly prepared using liquid-phase sintering. However, alloys prepared by this method often suffer from the following technical problems: First, it's difficult to simultaneously achieve both strength and elongation in the alloy. Traditional processes produce tungsten-nickel-copper alloys with a uniform tungsten grain size distribution. While fine grains improve strength, they lack ductility; coarse grains improve ductility but reduce strength. This makes it difficult to simultaneously improve ductility and elongation, resulting in generally low tensile strength and elongation after fracture typically less than 10%, severely limiting its application in high-end equipment. Second, the powder mixing is uneven and prone to oxidation. Traditional mixing methods struggle to achieve uniform dispersion of powders with significant density differences, such as tungsten, nickel, and copper powders, at both the macroscopic and microscopic scales, easily leading to component segregation. Simultaneously, the powder is easily oxidized during mixing, and surface oxides are difficult to completely reduce during subsequent sintering, reducing interparticle wettability and metallurgical bonding quality, thus degrading the alloy's mechanical properties. Third, the green blank has low density and is prone to forming defects. Traditional pressing processes struggle to obtain high-density and uniform green blanks. The bridging effect within the powder easily leads to defects such as cracks and delamination in the green blank, and the uneven density distribution severely affects the subsequent sintering densification process and the final alloy's microstructure uniformity. Fourth, oxide residues and grain coarsening during sintering. Traditional sintering processes struggle to effectively reduce oxides on the powder surface. Oxide inclusions lead to poor wettability between tungsten particles and the nickel-based liquid phase, hindering densification. Simultaneously, excessively high sintering temperatures or prolonged holding times can cause abnormal grain coarsening, further deteriorating the alloy's mechanical properties. Fifth, brittle phase precipitation reduces alloy toughness. In traditional tungsten-nickel-copper alloy systems, brittle phases, such as WNi4-β phase, easily precipitate during sintering and cooling. These brittle phases accumulate at grain boundaries, severely reducing the alloy's toughness and elongation, becoming a key bottleneck restricting the development of high-toughness alloys.

[0004] To address the aforementioned issues, although subsequent attempts by technicians have incorporated novel preparation methods such as microwave sintering, spark plasma sintering, and hot isostatic pressing, while these methods can improve the alloy's strength to some extent, the elongation remains low, failing to fundamentally solve the problem of the difficulty in simultaneously improving strength and plasticity. Therefore, how to successfully prepare tungsten-nickel-copper alloys that possess both high strength and good toughness has become a key technical problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned problems, one objective of this invention is to provide a high-strength and high-toughness tungsten-nickel-copper alloy material with a tensile strength ≥900MPa and an elongation after fracture ≥25%, which can meet the requirements for use in special applications such as armor-piercing projectile cores, rocket nozzles, and gyroscope rotors.

[0006] The second objective of this invention is to provide a tungsten-nickel-copper alloy material with a heterogeneous structure. The tungsten grains exhibit a bimodal distribution. By introducing a heterogeneous microstructure, the plastic deformation capacity of the alloy is significantly improved, and the strength and elongation of the tungsten-nickel-copper alloy are synergistically enhanced. Moreover, the process is simple, the production cost is low, and it is suitable for mass production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A high-strength and high-toughness tungsten-nickel-copper alloy material with a heterogeneous structure, comprising by mass percentage: tungsten 80-90%, Ni / Cu=8:2-3:2, Fe 0.5%, and cobalt 1%.

[0008] This invention also provides a method for preparing a high-strength and high-toughness tungsten-nickel-copper alloy material with a heterostructure, comprising the following steps: S1: Micron-sized tungsten powder is ball-milled using a high-energy ball mill to obtain nano-sized tungsten powder; S2: The nano-tungsten powder, micron-tungsten powder, nickel powder, copper powder, iron powder and cobalt powder are placed in an acoustic resonance mixer and thoroughly mixed. The mixing process is carried out under an inert atmosphere. S3: The uniformly mixed powder is pressed into a blank by cold isostatic pressing; S4: The pressed green blank is sintered in a tube furnace through which H2 is introduced; S5: The sintered alloy material is heat-treated under a vacuum atmosphere.

[0009] Preferably, in step S1, the micron-sized tungsten powder is ball-milled using a high-energy ball mill. During the ball milling process, argon gas is introduced into the mill, the rotation speed is 800-1000 rpm, and the intermittent operation mode is adopted (every 30 minutes of operation followed by a 30-minute pause). The effective ball milling time is 10-24 hours.

[0010] Preferably, in step S2, the nano-tungsten powder, micron-tungsten powder, nickel powder, copper powder, iron powder and cobalt powder are mixed using an acoustic resonance mixer. During the mixing process, argon gas is introduced into the mixing tank at an acceleration of 70-100 g, a mixing frequency of 60 Hz, and an effective mixing time of 30-40 min.

[0011] Preferably, in step S3, the forming pressure of the cold isostatic pressing is 200-600 MPa, and the pressure increase process adopts a step-by-step pressure increase and holding pressure method, with a holding pressure time of 30-60 min.

[0012] Preferably, in step S4, the sintering temperature under H2 atmosphere is 1400-1500℃, the holding time is 1-3 h, and the heating rate is 2-10℃ / min.

[0013] Preferably, in step S5, the sintered alloy is subjected to an oxygen partial pressure of 10... -3 Heat treatment is carried out under a vacuum atmosphere of Pa at a temperature of 1200-1400℃ and a holding time of 1-5 h.

[0014] Preferably, the mass ratio of micron-sized tungsten powder to nano-sized tungsten powder in step S2 is 4:1.

[0015] The present invention has the following beneficial effects: 1. Formation of a bimodal grain heterostructure, overcoming the bottleneck of strength-elongation mutual exclusion. This invention involves high-energy ball milling of micron-sized tungsten powder to obtain nano-sized tungsten powder, which is then mixed with unmilled micron-sized tungsten powder to form a heterogeneous microstructure with a bimodal grain size distribution during sintering. The fine-grained tungsten particles provide high strength, while the coarse-grained particles provide good plastic deformation capacity. Their synergistic effect results in an alloy with a tensile strength exceeding 900 MPa and an elongation after fracture exceeding 25%, successfully overcoming the technical bottleneck of traditional tungsten-nickel-copper alloys where strength and elongation are difficult to achieve simultaneously. The alloy without the introduction of nano-tungsten powder has a tensile strength of only 730-770 MPa and an elongation of only about 5%, confirming the crucial role of the bimodal heterostructure.

[0016] 2. Optimize ball milling and mixing processes to ensure powder quality and component uniformity. This invention controls the ball milling speed at 800-1000 rpm and the effective ball milling time at 10-24 hours, employing an intermittent operation mode. This ensures that the tungsten powder is sufficiently refined to the nanoscale, significantly improving sintering activity, reducing sintering activation energy, and promoting material migration and densification during liquid-phase sintering. Simultaneously, it avoids powder undercooling, agglomeration, or the introduction of impurities caused by prolonged continuous ball milling. Simultaneously, an acoustic resonance mixer is used at an acceleration of 70-100 g and a frequency of 60 Hz to achieve uniform dispersion of powders of different particle sizes and densities at both macroscopic and microscopic scales within 30-40 minutes. Argon gas is continuously introduced during the mixing process to effectively prevent powder oxidation, ensuring the activity of alloying elements and the quality of metallurgical bonding during subsequent sintering.

[0017] 3. Cold isostatic pressing combined with liquid phase sintering achieves high-density, defect-free molding. This invention employs cold isostatic pressing at a pressure of 200-600 MPa, using a stepped pressure increase and holding method, holding for 30-60 minutes to ensure uniform pressure on the powder in all directions. The resulting green blank density reaches 60-65%, effectively eliminating the bridging effect within the powder and reducing defects such as cracks and delamination. Subsequently, liquid-phase sintering is performed in a hydrogen atmosphere at a temperature of 1400-1500℃ for 1-3 hours. The hydrogen atmosphere effectively reduces oxides on the powder particle surface, improving wettability and metallurgical bonding quality. The formation of the nickel-copper phase as a liquid phase wets and rearranges the tungsten particles, achieving rapid densification of the alloy and laying the microstructural foundation for obtaining a high-strength and high-toughness alloy.

[0018] 4. Vacuum heat treatment induces phase transformation, synergistically suppressing brittle phases and enhancing strength and plasticity. This invention is performed when the oxygen partial pressure is 10. -3 Under a vacuum atmosphere of 1200-1400℃, the sintered alloy is heat-treated for 1-5 hours. This process promotes the formation and modulated decomposition of the γ phase in the nickel-based solid solution, resulting in a nanoscale composition-modulated structure that significantly improves the alloy's strength and plasticity. Furthermore, the addition of iron and cobalt effectively suppresses the precipitation of the brittle WNi4-β phase, improving the bonding quality between tungsten particles and the nickel-based solid solution interface and preventing grain boundary embrittlement. By adjusting the heat treatment temperature and holding time, a wide range of tensile strengths (905-961 MPa) and elongation (25.5%-29.5%) can be achieved to meet the performance requirements of different applications.

[0019] 5. Microalloying and synergistic process control enable wide process window and industrial adaptability. This invention adds 0.5% iron and 1% cobalt to a traditional tungsten-nickel-copper alloy. The addition of iron and cobalt reduces the contact angle between the nickel-based liquid phase and tungsten particles, enhancing the wettability of the liquid phase on the tungsten particles, promoting the rearrangement and dissolution-precipitation process of the tungsten particles, and increasing the density of the alloy. Simultaneously, iron and cobalt dissolve in the nickel-based phase, inhibiting the formation of harmful brittle phases, and in conjunction with vacuum heat treatment, promoting the amplitude-modulated decomposition of the γ-phase. Excellent mechanical properties are obtained under different combinations of process parameters, indicating that this invention can effectively control the bimodal grain ratio, grain size, and degree of γ-phase precipitation by adjusting ball milling time, mixing parameters, pressing pressure, sintering temperature, and heat treatment parameters. It has a wide process window and good industrial operability and stability. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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.

[0022] Example 1 A method for preparing a high-strength and high-toughness tungsten-nickel-copper alloy material with a heterostructure includes the following steps: S1: Take 800 g of tungsten powder with a particle size of 5 μm and pack it into a container equipped with tungsten carbide balls ( 6mm tungsten carbide spheres account for 40%. In a tungsten carbide ball milling jar containing 60% 2mm tungsten carbide balls, argon gas was introduced into the jar during the ball milling process. The rotation speed of the ball milling jar was set to 800 rpm, and an intermittent operation mode was adopted (running for 30 minutes and pausing for 30 minutes). The ball-to-material ratio was 10:1, and the effective ball milling time was 24 hours to obtain nano-tungsten powder. S2: The total mass of the formula is 5000g, and the composition ratio is: tungsten mass fraction 80%, Fe 0.5%, Co 1%, and the balance Ni and Cu, with a Ni / Cu mass ratio of 8:2; Take 800g of nano tungsten powder, 3200g of micron tungsten powder with a particle size of 5 μm, 740g of nickel powder with a particle size of 2 μm, 185g of electrolytic copper powder with a particle size of 8 μm, 25g of iron powder with a particle size of 2 μm, and 50g of cobalt powder with a particle size of 3 μm obtained in step S1, and put them into an acoustic resonance mixer. During the mixing process, argon gas is introduced into the mixing tank, the acceleration is set to 70g, the mixing frequency is 60 Hz, and the effective mixing time is 40 minutes; S3: Place the powder that has been mixed evenly in step S2 into a mold and press it into a blank by cold isostatic pressing. The molding pressure is 200 MPa, and a stepped pressure increase method is adopted. The holding time is 60 minutes. S4: The green blank pressed in step S3 is placed into a tube furnace with H2 flowing in for sintering. The sintering temperature is 1500℃, the holding time is 1 hour, and the heating rate is 5℃ / min. S5: The sintered alloy material obtained in step S4 is heat-treated under a vacuum atmosphere with an oxygen partial pressure of 10. -3 Pa, heat treatment temperature is 1400 ℃, holding time is 1 hour.

[0023] The tungsten-nickel-copper alloy prepared in this embodiment has a tensile strength of 905 MPa and an elongation after fracture of 29.5%, as tested.

[0024] Example 2 A method for preparing a high-strength and high-toughness tungsten-nickel-copper alloy material with a heterostructure includes the following steps: S1: Take 800 g of 10 μm micron-sized tungsten powder and pack it into a container fitted with tungsten carbide balls ( 6mm tungsten carbide spheres account for 40%. In a tungsten carbide ball milling jar containing 60% 2mm tungsten carbide balls, argon gas was introduced into the jar during the ball milling process. The rotation speed of the ball milling jar was set to 900 rpm, and an intermittent operation mode was adopted (running for 30 minutes and pausing for 30 minutes). The ball-to-material ratio was 10:1, and the effective ball milling time was 20 hours to obtain nano-tungsten powder. S2: The total mass of the formula is 5000g, and the composition ratio is: tungsten mass fraction 80%, Fe 0.5%, Co 1%, and the balance Ni and Cu, with a Ni / Cu mass ratio of 8:2; Take 800g of nano tungsten powder, 3200g of micron tungsten powder with a particle size of 5 μm, 740g of nickel powder with a particle size of 2 μm, 185g of electrolytic copper powder with a particle size of 8 μm, 25g of iron powder with a particle size of 2 μm, and 50g of cobalt powder with a particle size of 3 μm obtained in step S1, and put them into an acoustic resonance mixer. During the mixing process, argon gas is introduced into the mixing tank, the acceleration is set to 80g, the mixing frequency is 60 Hz, and the effective mixing time is 40 minutes; S3: Place the powder that has been mixed evenly in step S2 into a mold and press it into a blank by cold isostatic pressing. The molding pressure is 400 MPa, and a stepped pressure increase method is adopted. The holding time is 40 minutes. S4: The green blank pressed in step S3 is placed into a tube furnace with H2 flowing in for sintering. The sintering temperature is 1450℃, the holding time is 2 hours, and the heating rate is 5℃ / min. S5: The sintered alloy material obtained in step S4 is heat-treated under a vacuum atmosphere with an oxygen partial pressure of 10. -3 Pa, heat treatment temperature is 1300 ℃, holding time is 3 hours.

[0025] The tungsten-nickel-copper alloy prepared in this embodiment has a tensile strength of 923 MPa and an elongation after fracture of 28.0% as tested.

[0026] Example 3 A method for preparing a high-strength and high-toughness tungsten-nickel-copper alloy material with a heterostructure includes the following steps: S1: Take 800 g of tungsten powder with a particle size of 20 μm and pack it into a container equipped with tungsten carbide balls ( 6mm tungsten carbide spheres account for 40%. In a tungsten carbide ball milling jar containing 60% 2mm tungsten carbide balls, argon gas was introduced into the jar during the ball milling process. The rotation speed of the ball milling jar was set to 1000 rpm, and an intermittent operation mode was adopted (every 30 minutes of operation followed by a 30-minute pause). The ball-to-material ratio was 10:1, and the effective ball milling time was 10 hours, resulting in nano-tungsten powder. S2: The total mass of the formula is 5000g, and the composition ratio is: tungsten mass fraction 80%, Fe 0.5%, Co 1%, and the balance Ni and Cu, with a Ni / Cu mass ratio of 8:2; Take 800g of nano tungsten powder, 3200g of micron tungsten powder with a particle size of 5 μm, 740g of nickel powder with a particle size of 2 μm, 185g of electrolytic copper powder with a particle size of 8 μm, 25g of iron powder with a particle size of 2 μm, and 50g of cobalt powder with a particle size of 3 μm obtained in step S1, and put them into an acoustic resonance mixer. During the mixing process, argon gas is introduced into the mixing tank, the acceleration is set to 100g, the mixing frequency is 60 Hz, and the effective mixing time is 30 minutes; S3: Place the powder that has been mixed evenly in step S2 into a mold and press it into a blank by cold isostatic pressing. The molding pressure is 600 MPa, and a stepped pressure increase method is adopted. The holding time is 30 minutes. S4: The green blank pressed in step S3 is placed into a tube furnace with H2 flowing in for sintering. The sintering temperature is 1400℃, the holding time is 3 hours, and the heating rate is 5℃ / min. S5: The sintered alloy material obtained in step S4 is heat-treated under a vacuum atmosphere with an oxygen partial pressure of 10. -3 Pa, heat treatment temperature is 1200 ℃, holding time is 5 hours.

[0027] The tungsten-nickel-copper alloy prepared in this embodiment has a tensile strength of 961 MPa and an elongation after fracture of 26.4%, as tested.

[0028] Example 4 A method for preparing a high-strength and high-toughness tungsten-nickel-copper alloy material with a heterostructure includes the following steps: S1: Take 900 g of tungsten powder with a particle size of 20 μm, and pack it into a container equipped with tungsten carbide balls ( 6mm tungsten carbide spheres account for 40%. Argon gas was introduced into the tungsten carbide ball milling jar (60% of which are 2mm tungsten carbide balls) during the ball milling process. The rotation speed of the ball milling jar was set to 1000 rpm. The intermittent operation mode was adopted (every 30 minutes of operation followed by a 30-minute pause). The ball-to-material ratio was 10:1, and the effective ball milling time was 10 hours to obtain nano-tungsten powder. S2: The total mass of the formula is 5000g, and the composition ratio is: tungsten mass fraction 90%, Fe 0.5%, Co 1%, and the balance Ni and Cu, with a Ni / Cu mass ratio of 3:2; Take 900g of nano tungsten powder, 3600g of micron tungsten powder with a particle size of 5 μm, 255g of nickel powder, 170g of electrolytic copper powder, 25g of iron powder, and 50g of cobalt powder obtained in step S1, and put them into an acoustic resonance mixer. During the mixing process, argon gas is introduced into the mixing tank, the acceleration is set to 100g, the mixing frequency is 60 Hz, and the effective mixing time is 30 minutes; S3: Place the powder mixed evenly in step S2 into a mold and press it into a blank by cold isostatic pressing. The molding pressure is 600 MPa, and a stepped pressure increase method is adopted. The holding time is 30 minutes. S4: The green blank pressed in step S3 is placed in a tube furnace through which H2 is introduced for sintering. The sintering temperature is 1400 ℃, the holding time is 3 hours, and the heating rate is 5 ℃ / min. S5: The sintered alloy material obtained in step S4 is heat-treated under a vacuum atmosphere with an oxygen partial pressure of 10. - 3 Pa, heat treatment temperature is 1200 ℃, holding time is 5 hours.

[0029] The tungsten-nickel-copper alloy prepared in this embodiment has a tensile strength of 986 MPa and an elongation after fracture of 25.5%, as tested.

[0030] Comparative Example 1 A method for preparing a tungsten-nickel-copper alloy material includes the following steps: S1: This step is omitted; high-energy ball milling is not performed. S2: The total mass of the formula is 5000g, and the composition ratio is as follows: tungsten mass fraction 80%, Fe 0.5%, Co 1%, and the balance Ni and Cu, with a Ni / Cu mass ratio of 8:2. Take 4000g of tungsten powder with a particle size of 5 μm, 740g of nickel powder with a particle size of 2 μm, 185g of electrolytic copper powder with a particle size of 8 μm, 25g of iron powder with a particle size of 2 μm, and 50g of cobalt powder with a particle size of 3 μm, and put them into an acoustic resonance mixer. During the mixing process, argon gas is introduced into the mixing tank, the acceleration is set to 70g, the mixing frequency is 60 Hz, and the effective mixing time is 40 minutes. S3: Place the powder that has been mixed evenly in step S2 into a mold and press it into a blank by cold isostatic pressing. The molding pressure is 200 MPa, and a stepped pressure increase method is adopted. The holding time is 60 minutes. S4: The green blank pressed in step S3 is placed into a tube furnace with H2 flowing in for sintering. The sintering temperature is 1500℃, the holding time is 1 hour, and the heating rate is 5℃ / min. S5: The sintered alloy material obtained in step S4 is heat-treated under a vacuum atmosphere with an oxygen partial pressure of 10. -3 Pa, heat treatment temperature is 1400 ℃, holding time is 1 hour.

[0031] The tungsten-nickel-copper alloy prepared in this comparative example has a tensile strength of 750±20 MPa and an elongation after fracture of approximately 5%.

[0032] Experiments and Analysis Table 1 shows the mechanical test results of the tungsten-nickel-copper alloys prepared in the examples and comparative examples. ; As shown in the test results of Examples 1-4 and Comparative Example 1, the present invention introduces nano-tungsten powder obtained by high-energy ball milling in step S1, which forms a bimodal grain distribution with micron-sized tungsten powder. Combined with the addition of microalloying elements Fe and Co, and a reasonable liquid-phase sintering and vacuum heat treatment process, the mechanical properties of the tungsten-nickel-copper alloy are significantly improved. The tensile strength of the prepared alloys all exceeds 900 MPa, and the elongation after fracture all exceed 25%, achieving a synergistic improvement in both high strength and good plasticity.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, or improvements made by those skilled in the art without departing from the principles of the present invention should be considered to fall within the scope of protection of the present invention.

Claims

1. A high-strength, high-toughness tungsten-nickel-copper alloy material with a heterogeneous structure, characterized in that: By mass percentage, it includes: W 80-90%, Ni / Cu = 8:2-3:2, Fe 0.5%, Co 1%.

2. A method for preparing a high-strength, high-toughness tungsten-nickel-copper alloy material with a heterogeneous structure, characterized in that: The preparation method includes the following steps: S1: Micron-sized tungsten powder is placed in a high-energy ball mill for high-energy ball milling to obtain nano-sized tungsten powder; S2: The nano-tungsten powder is mixed with micron-sized tungsten powder, nickel powder, copper powder, iron powder and cobalt powder in an acoustic resonance mixer. The mixing process is carried out under an inert atmosphere. S3: The uniformly mixed powder is pressed into a blank by cold isostatic pressing; S4: The pressed green blank is sintered in a tube furnace through which H2 is introduced; S5: The sintered alloy material is subjected to vacuum heat treatment.

3. The preparation method according to claim 2, characterized in that: In step S1, argon gas is introduced into the milling jar during the ball milling process. The rotation speed of the milling jar is 800-1000 rpm, and the intermittent operation mode is adopted. The effective milling time is 10-24 hours.

4. The preparation method according to claim 2, characterized in that: In step S2, the acceleration during mixing is 70-100g, the mixing frequency is 60Hz, and argon gas is introduced into the mixing vessel at the same time. The effective mixing time is 30-40min.

5. The preparation method according to claim 2, characterized in that: In step S3, the cold isostatic pressing molding pressure is 200-600 MPa, and a stepped pressure increase and holding pressure method is adopted, with a holding pressure time of 30-60 min.

6. The preparation method according to claim 2, characterized in that: In step S4, the sintering temperature under H2 atmosphere is 1400-1500℃, the holding time is 1-3h, and the heating rate is 2-10℃ / min.

7. The preparation method according to claim 2, characterized in that: In step S5, the sintered alloy is subjected to an oxygen partial pressure of 10. -3 Heat treatment is carried out under a vacuum atmosphere of Pa, with a heat treatment temperature of 1200-1400℃ and a holding time of 1-5h.

8. The preparation method according to claim 2, characterized in that: The alloy material has a tensile strength ≥900MPa and an elongation after fracture ≥25%.

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