A method for preparing a tungsten-copper alloy with ultrafine grains and the tungsten-copper alloy

Abstract

The application relates to the technical field of metal material preparation, in particular to a method for preparing ultra-fine-grain tungsten-copper alloy and the tungsten-copper alloy, the method comprises the following steps: S1, first, tungsten powder, copper powder and added nickel, silicon, manganese, chromium and silver are weighed according to a predetermined proportion; S2, all the weighed raw materials in S1 are mixed and homogenized; S3, dry treatment is carried out in a vacuum environment; S4, pulse current treatment is carried out on the dry alloy precursor powder; S5, cold isostatic pressing treatment is carried out on the powder subjected to the pulse current treatment; S6, high-temperature hot isostatic pressing sintering treatment is carried out on the blank; S7, rapid cooling is carried out immediately after sintering is completed; and S8, mechanical processing and surface treatment are carried out. According to the application, the microstructure uniformity and the performance of the alloy are remarkably improved through pulse current treatment and precise temperature and pressure control, the production efficiency and the material utilization rate are optimized, and the strict requirements of modern industry on high-performance materials are met.

Description

Technical Field

[0001] This invention relates to the field of metal material preparation technology, and in particular to a method for preparing ultrafine-grained tungsten-copper alloys and the tungsten-copper alloy thereof. Background Technology

[0002] Tungsten-copper alloys are widely used in electronic packaging, high-voltage switches and heat sinks due to their excellent thermal conductivity, electrical conductivity and mechanical properties. Although traditional tungsten-copper alloys have many advantages, the large size of tungsten particles during sintering often results in insufficient thermal and electrical conductivity to meet the requirements of high-performance applications. In addition, powder metallurgy technology in traditional methods often cannot obtain an ultra-fine grain structure without sacrificing the material density, which further limits the improvement of alloy performance.

[0003] To address these issues, this invention aims to develop a novel preparation method to achieve an ultrafine grain structure in tungsten-copper alloys and optimize their overall performance. The limitations of existing technologies mainly lie in the insufficient control over powder processing and subsequent sintering processes, which prevents the performance of tungsten-copper alloys from reaching the ideal state.

[0004] Therefore, it is necessary to develop a preparation method that can precisely control the particle size of raw material powder, improve the homogeneity of powder mixing, and optimize the sintering and rapid cooling processes to ensure the reliability and efficiency of tungsten-copper alloys in high-performance applications. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides a method for preparing ultrafine-grained tungsten-copper alloys and the tungsten-copper alloy thereof.

[0006] A tungsten-copper alloy comprises tungsten powder, copper powder, nickel, silicon, manganese, chromium, and silver; wherein the components are expressed in the following mass percentages:

[0007] The tungsten powder content is 73.4%-85.1%;

[0008] Copper powder content: 14%-24%;

[0009] The nickel content is 0.5%-1%;

[0010] The silicon content is 0.1%-0.5%;

[0011] The manganese content is 0.1%-0.5%;

[0012] The chromium content is 0.1%-0.3%;

[0013] The silver content is 0.1%-0.3%.

[0014] Furthermore, the tungsten powder has an average particle size of 1-5 micrometers; the copper powder has an average particle size of 0.5-3 micrometers.

[0015] A method for preparing ultrafine-grained tungsten-copper alloys includes the following steps:

[0016] S1: First, weigh out tungsten powder, copper powder, and added nickel, silicon, manganese, chromium, and silver according to the predetermined ratio;

[0017] S2: Use a high-energy ball mill to mix and homogenize all the raw materials weighed in S1 to form alloy precursor powder;

[0018] S3: The alloy precursor powder is dried in a vacuum environment to remove any residual moisture and organic impurities.

[0019] S4: The dried alloy precursor powder is subjected to pulsed current treatment to promote micro-welding between powder particles through short-duration high-current pulses.

[0020] S5: The powder that has been treated with pulsed current is subjected to cold isostatic pressing to form a green body;

[0021] S6: Under a protective atmosphere, the billet is subjected to high-temperature hot isostatic pressing sintering treatment to completely fuse the billet and form a dense material structure.

[0022] S7: Rapid cooling is performed immediately after sintering to lock in the ultra-fine grain structure, resulting in a tungsten-copper alloy blank;

[0023] S8: The tungsten-copper alloy blank obtained in S7 is machined and surface treated to achieve the required dimensions and surface roughness, thus completing the manufacturing of the final product.

[0024] Furthermore, S2 specifically includes:

[0025] S21: Select a high-energy ball mill and adjust the speed to 200 to 800 rpm;

[0026] S22: The powders of each component weighed in S1 are loaded into the ball mill jar according to a predetermined ratio, and the filling rate of the ball mill jar is controlled at 40%-50%;

[0027] S23: Add hard steel balls or ceramic balls to the ball mill jar as the ball milling medium, and control the mass ratio of balls to powder to be between 10:1 and 15:1; and mill the balls for 1 to 4 hours to form alloy precursor powder.

[0028] Furthermore, S3 specifically includes:

[0029] S31: Transfer the alloy precursor powder to a vacuum drying furnace and set the vacuum level to 0.1 mbar;

[0030] S32: Control the temperature of the vacuum drying oven at 120°C to 180°C and maintain this temperature and vacuum level to continuously dry the alloy precursor powder for 2 to 6 hours to fully remove moisture and organic impurities.

[0031] S33: After the drying process is completed, the furnace temperature is slowly reduced to room temperature and cooled under vacuum. Then the dried powder is removed.

[0032] Furthermore, S4 specifically includes:

[0033] S41: The dried alloy precursor powder from S3 is evenly spread in a processing container with good electrical conductivity to ensure that the thickness of the powder layer is uniform.

[0034] S42: Set the parameters of the pulse current generator, including pulse frequency from 100Hz to 500Hz, pulse width from 10µs to 100µs, and current density of 200A / cm². 2 Up to 500A / cm 2 ;

[0035] S43: Apply the pulsed current set in S42 to the loaded powder in a controlled environment for a duration of 1 to 5 minutes to promote micro-welding and interparticle bonding between powder particles through short-duration high-current pulses.

[0036] Furthermore, S5 specifically includes:

[0037] S51: Load the alloy precursor powder that has been treated with pulsed current in S4 into a preset cold isostatic pressing mold, and ensure that the powder is evenly distributed in the mold.

[0038] S52: Set the pressure of the cold isostatic press to 200MPa to 500MPa and maintain the ambient temperature at 20°C to 25°C;

[0039] S53: Under the environmental conditions controlled by S52, gradually apply pressure to the set pressure value, and control the pressure rise rate at 10MPa / min;

[0040] S54: After reaching the predetermined pressure, maintain this pressure for 5 to 10 minutes to ensure that the powder is fully compacted and the particles are bonded together. Then, slowly reduce the pressure to zero, with the pressure release rate controlled at 5 MPa / min.

[0041] Furthermore, S6 specifically includes:

[0042] S61: A furnace prepared for hot isostatic pressing sintering, and the required protective atmosphere is maintained inside the furnace, specifically using argon as the inert gas;

[0043] S62: Set the sintering temperature to 900°C to 1200°C and the pressure to 300MPa to 700MPa;

[0044] S63: Slowly heat the sintering furnace to the set sintering temperature, with the heating rate controlled at 5℃ / min. After reaching the target temperature, maintain this temperature for 1 to 3 hours to ensure that the materials inside the billet are completely fused.

[0045] S64: While reaching the sintering temperature, gradually apply the set pressure and maintain this pressure throughout the holding period;

[0046] S65: After heat preservation, the furnace temperature is reduced to room temperature at a controlled rate of 5℃ / min. After cooling to room temperature, the pressure is slowly reduced and the sintered billet is removed in a protective atmosphere.

[0047] Furthermore, S7 specifically includes:

[0048] S71: Connect the sintering furnace to the prepared cooling system, which can quickly reduce the furnace temperature through an external cooling medium;

[0049] S72: Immediately after the sintering process is completed, the cooling system is activated to rapidly reduce the furnace temperature from the sintering temperature to room temperature. The cooling rate is controlled at 50°C to 100°C / minute to quickly stabilize the microstructure of the material.

[0050] S73: After cooling to room temperature, slowly release the pressure inside the furnace and remove the tungsten-copper alloy blank while maintaining a protective atmosphere.

[0051] Furthermore, S8 specifically includes:

[0052] S81: Perform preliminary machining on the tungsten-copper alloy blank obtained in step S7. Use a CNC machine tool to cut and shape the blank to approximate the size of the final product. The dimensional tolerance of the rough machining is controlled within ±0.5mm.

[0053] S82: Precision machining is performed on the rough-machined blank to achieve strict dimensional accuracy and shape requirements. The dimensional tolerance of precision machining is controlled within ±0.05mm.

[0054] S83: Surface treatment of the precision-machined tungsten-copper alloy blank, including grinding and polishing, to achieve the required surface roughness, with a required surface roughness index of Ra 0.2 μm to 0.8 μm.

[0055] The beneficial effects of this invention are:

[0056] This invention effectively solves the problems of coarse grains and insufficient material density in traditional tungsten-copper alloys by employing advanced pulsed current treatment and precisely controlled hot and cold isostatic pressing sintering processes. This novel preparation method can significantly reduce grain size, thereby improving the mechanical strength and thermal conductivity of the alloy and enhancing its stability in high-temperature environments. In addition, the optimized sintering and rapid cooling steps further ensure the uniformity of the alloy's microstructure, improving electrical conductivity and wear resistance.

[0057] This invention provides higher production efficiency and material utilization, reduces energy consumption and raw material waste in the production process, and improves the performance of tungsten-copper alloys through refined powder processing and precise machining steps. It also ensures high precision in product dimensions and surface quality, meeting the stringent requirements of modern electronic and electrical applications for high-performance materials. Therefore, the tungsten-copper alloy preparation method of this invention provides an economical and effective solution for the commercial production and application of high-performance tungsten-copper alloys. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in this 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 for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 This is a schematic diagram of the method for preparing ultrafine-grained tungsten-copper alloy according to an embodiment of the present invention;

[0060] Figure 2 This is a schematic diagram of the pulse current processing flow according to an embodiment of the present invention. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0062] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0063] Example 1

[0064] like Figures 1-2As shown, a tungsten-copper alloy comprises tungsten powder, copper powder, nickel, silicon, manganese, chromium, and silver; wherein each component is expressed in the following mass percentages:

[0065] The tungsten powder content is 80.4%.

[0066] The copper powder content is 18%.

[0067] The nickel content is 0.7%;

[0068] The silicon content is 0.3%;

[0069] The manganese content is 0.2%;

[0070] The chromium content is 0.2%;

[0071] The silver content is 0.2%.

[0072] The average particle size of tungsten powder is 3 micrometers; the average particle size of copper powder is 1.5 micrometers.

[0073] A method for preparing ultrafine-grained tungsten-copper alloys includes the following steps:

[0074] S1: First, weigh out tungsten powder, copper powder, and added nickel, silicon, manganese, chromium, and silver according to the predetermined ratio;

[0075] S2: Use a high-energy ball mill to mix and homogenize all the raw materials weighed in S1 to form high-quality alloy precursor powder;

[0076] S3: The alloy precursor powder is dried in a vacuum environment to remove any residual moisture and organic impurities, so as to avoid the generation of pores and defects in the subsequent sintering process.

[0077] S4: The dried alloy precursor powder is subjected to pulsed current treatment. The short-duration high-current pulse promotes micro-welding between powder particles and enhances the compaction and sintering activity of the powder.

[0078] S5: The powder treated with pulsed current is subjected to cold isostatic pressing to form a green body, laying the foundation for the sintering step;

[0079] S6: Under a protective atmosphere, the billet is subjected to high-temperature hot isostatic pressing sintering treatment to completely fuse the billet and form a dense material structure.

[0080] S7: Rapid cooling is performed immediately after sintering to lock in the ultra-fine grain structure, resulting in a tungsten-copper alloy blank;

[0081] S8: The tungsten-copper alloy blank obtained in S7 is machined and surface treated to achieve the required dimensions and surface roughness, thus completing the manufacturing of the final product.

[0082] S2 specifically includes:

[0083] S21: Select a high-energy ball mill and adjust the speed to 600 rpm;

[0084] S22: The powders of each component weighed in S1 are loaded into the ball mill jar according to a predetermined ratio. The filling rate of the ball mill jar is controlled at 45% to ensure sufficient space for efficient ball milling.

[0085] S23: Add hard steel balls to the ball mill jar as the ball milling medium. The mass ratio of balls to powder is controlled at 12:1 to ensure sufficient impact and shear force for effective powder crushing and mixing. The ball milling time is 3 hours to form alloy precursor powder.

[0086] S3 specifically includes:

[0087] S31: Transfer the alloy precursor powder to a vacuum drying furnace and set the vacuum level to 0.1 mbar to ensure a low-pressure drying environment.

[0088] S32: Control the temperature of the vacuum drying oven at 150°C and maintain this temperature and vacuum level to continuously dry the alloy precursor powder for 4 hours to fully remove moisture and organic impurities.

[0089] S33: After the drying process is completed, the furnace temperature is slowly reduced to room temperature and cooled under vacuum. Then the dried powder is removed.

[0090] S4 specifically includes:

[0091] S41: The dried alloy precursor powder from S3 is evenly spread in a processing container with good electrical conductivity to ensure that the thickness of the powder layer is uniform.

[0092] S42: Set the parameters of the pulse current generator, including pulse frequency of 300Hz, pulse width of 50 microseconds, and current density of 350A / cm². 2 To adapt to the characteristics of different types of powder materials;

[0093] S43: Apply the pulsed current set in S42 to the loaded powder in a controlled environment for a duration of 3 minutes to promote micro-welding and interparticle bonding between powder particles through short-duration high-current pulses.

[0094] S5 specifically includes:

[0095] S51: Load the alloy precursor powder that has been treated with pulsed current in S4 into a preset cold isostatic pressing mold, and ensure that the powder is evenly distributed in the mold.

[0096] S52: Set the pressure of the cold isostatic press to 350 MPa and maintain the ambient temperature at 23°C to suit the physical properties of the powder and the compression requirements.

[0097] S53: Under the environmental conditions controlled by S52, gradually apply pressure to the set pressure value, and control the pressure rise rate at 10MPa / min to prevent rapid deformation or crack formation of the powder material.

[0098] S54: After reaching the predetermined pressure, maintain this pressure for 7 minutes to ensure that the powder is fully compacted and the interparticles are bonded. Then, slowly reduce the pressure to zero, with the pressure release rate controlled at 5 MPa / min to avoid material damage caused by rapid pressure release.

[0099] S6 specifically includes:

[0100] S61: A furnace for hot isostatic pressing sintering is prepared, and the required protective atmosphere is maintained inside the furnace. Specifically, argon is used as the inert gas to prevent material oxidation.

[0101] S62: Set the sintering temperature to 1050°C and the pressure to 500MPa;

[0102] S63: Slowly heat the sintering furnace to the set sintering temperature, with the heating rate controlled at 5℃ / min, to avoid stress concentration and damage to the material. After reaching the target temperature, maintain the temperature for 2 hours to ensure that the material inside the billet is completely fused.

[0103] S64: While reaching the sintering temperature, gradually apply the set pressure and maintain this pressure throughout the holding period to promote the densification of the material and the optimization of its microstructure.

[0104] S65: After heat preservation, the furnace temperature is reduced to room temperature at a controlled rate of 5℃ / min to avoid internal stress in the material caused by rapid cooling. After cooling to room temperature, the pressure is slowly reduced and the sintered billet is removed in a protective atmosphere.

[0105] S7 specifically includes:

[0106] S71: Connect the sintering furnace to the prepared cooling system, which can rapidly reduce the furnace temperature through an external cooling medium (such as cooling water or liquid nitrogen);

[0107] S72: The cooling system is activated immediately after the sintering process is completed to rapidly reduce the furnace temperature from the sintering temperature to room temperature. The cooling rate is controlled at 75°C / minute to quickly stabilize the microstructure of the material.

[0108] S73: After cooling to room temperature, slowly release the pressure inside the furnace and remove the tungsten-copper alloy blank while maintaining a protective atmosphere.

[0109] S8 specifically includes:

[0110] S81: Perform preliminary machining on the tungsten-copper alloy blank obtained in step S7. Use a CNC machine tool to cut and shape the blank to approximate the size of the final product. The dimensional tolerance of the rough machining is controlled within ±0.5mm.

[0111] S82: Precision machining is performed on the rough-machined blank to achieve strict dimensional accuracy and shape requirements. The dimensional tolerance of precision machining is controlled within ±0.05mm to ensure the precise assembly of each component.

[0112] S83: Surface treatment of the precision-machined tungsten-copper alloy blank, including grinding and polishing, to achieve the required surface roughness, with a required surface roughness index of Ra0.2μm, to meet the surface smoothness requirements of specific applications.

[0113] Example 2

[0114] S1: First, accurately weigh each component raw material, including: tungsten powder (85.1% by mass, average particle size 1 micrometer), copper powder (14% by mass, average particle size 0.5 micrometer), nickel (0.5%), silicon (0.1%), manganese (0.1%), chromium (0.1%), and silver (0.1%). This precise ratio is the foundation for ensuring the alloy's performance.

[0115] S2: Place the prepared raw materials into a high-energy ball mill. The grinding media is ceramic balls. The filling rate of the ball mill jar is controlled at 50%. The rotation speed is set to 200 rpm. The ball milling process is carried out for 1 hour. During this process, the mass ratio of balls to powder is maintained at 10:1 to ensure that the powder can be mixed evenly to form alloy precursor powder.

[0116] S3: Transfer the ball-milled alloy precursor powder to a vacuum drying oven, set the vacuum level to 0.1 mbar, control the temperature at 120°C, and set the drying time to 2 hours. This step aims to remove moisture and organic impurities from the powder to create conditions for subsequent processing.

[0117] S4: Evenly spread the dried powder in a container with good electrical conductivity, and perform pulsed current treatment, setting the current density to 200A / cm². 2 The pulse width is 10 microseconds, the pulse frequency is 100Hz, and the processing time is 1 minute. This step promotes micro-welding between powder particles through short-duration high-current pulses.

[0118] S5: The processed powder is loaded into a preset cold isostatic pressing mold. The pressure of the cold isostatic press is set to 200 MPa, the ambient temperature is controlled at 20°C, the pressure rise rate is 10 MPa / min, and the pressure is maintained for 5 minutes. This step aims to fully compact the powder and form a green body.

[0119] S6: Place the compacted billet in a hot isostatic pressing furnace under a protective atmosphere of argon. Set the sintering temperature to 900°C, the pressure to 300MPa, and the holding time to 1 hour. This step is crucial for alloy forming, ensuring that the internal materials of the billet are completely fused together to form a dense structure.

[0120] S7: After sintering, immediately start the cooling system connected to the furnace to rapidly reduce the furnace temperature at a rate of 50°C / minute until room temperature. Rapid cooling is an important step in locking in the ultrafine grain structure to ensure that the desired physical properties are obtained.

[0121] S8: The sintered tungsten copper alloy blank is initially machined, cut and shaped using a CNC machine tool. The dimensional tolerance of the rough machining is controlled within ±0.3mm. Precision machining is then carried out, with the dimensional tolerance controlled within ±0.05mm. Finally, grinding and polishing are performed to achieve the required surface roughness Ra0.5μm. These post-processing steps ensure that the product meets the final specifications and quality standards.

[0122] Example 3

[0123] S1: First, accurately weigh each component raw material, including: tungsten powder (73.4% by mass, average particle size 5 micrometers), copper powder (24% by mass, average particle size 3 micrometers), nickel (1%), silicon (0.5%), manganese (0.5%), chromium (0.3%), and silver (0.3%). This precise ratio is the foundation for ensuring the alloy's performance.

[0124] S2: Place the prepared raw materials into a high-energy ball mill. The grinding media are hard steel balls. The filling rate of the ball mill jar is controlled at 40%. The rotation speed is set to 800 rpm. The ball milling process is carried out for 4 hours. During this process, the mass ratio of balls to powder is maintained at 15:1 to ensure that the powder can be mixed evenly to form alloy precursor powder.

[0125] S3: Transfer the ball-milled alloy precursor powder to a vacuum drying oven, set the vacuum level to 0.1 mbar, control the temperature at 180°C, and set the drying time to 6 hours. This step aims to remove moisture and organic impurities from the powder to create conditions for subsequent processing.

[0126] S4: Evenly spread the dried powder in a container with good electrical conductivity, and perform pulsed current treatment, setting the current density to 500 A / cm². 2The pulse width is 100 microseconds, the pulse frequency is 500Hz, and the processing time is 5 minutes. This step promotes micro-welding between powder particles through short-duration high-current pulses.

[0127] S5: The processed powder is loaded into a preset cold isostatic pressing mold. The pressure of the cold isostatic press is set to 500 MPa, the ambient temperature is controlled at 25°C, the pressure rise rate is 10 MPa / min, and the pressure is maintained for 10 minutes. This step aims to fully compact the powder and form a green body.

[0128] S6: Place the compacted billet in a hot isostatic pressing furnace under a protective atmosphere of argon. Set the sintering temperature to 1200°C, the pressure to 700MPa, and the holding time to 3 hours. This step is crucial for alloy forming, ensuring that the internal materials of the billet are completely fused together to form a dense structure.

[0129] S7: After sintering, immediately start the cooling system connected to the furnace to rapidly reduce the furnace temperature at a rate of 100°C / minute until room temperature. Rapid cooling is an important step in locking in the ultrafine grain structure to ensure that the desired physical properties are obtained.

[0130] S8: The sintered tungsten copper alloy blank is initially machined, cut and shaped using CNC machine tools, with the dimensional tolerance of rough machining controlled within ±0.3mm. Precision machining continues, with the dimensional tolerance controlled within ±0.05mm. Finally, grinding and polishing are performed to achieve the required surface roughness Ra0.8μm. These post-processing steps ensure that the product meets the final specifications and quality standards.

[0131] Table 1 Comparison of performance parameters of finished tungsten-copper alloys

[0132]

[0133] As can be seen from Table 1 above, Example 1 shows superior results in multiple performance indicators, especially in terms of hardness, conductivity, and compressive strength. Example 1 provides higher performance values, indicating that it has better mechanical and electrical properties in practical applications. In addition, Example 1's corrosion resistance and thermal stability are also slightly better than the other two examples, providing a wider range of application environments. Through a comprehensive evaluation of these key performance parameters, Example 1 has been proven to be the best implementation method, not only meeting the high standards of industrial application requirements in terms of performance, but also demonstrating superior durability and reliability.

[0134] Table 2 Comparison of other performance parameters

[0135]

[0136] As can be seen from Table 2 above, Example 1 exhibits superior performance in several key performance indicators, especially in terms of thermal shock resistance and thermal conductivity. Example 1 demonstrates better performance, which is crucial for materials used in environments with extreme temperature changes and high thermal loads. Furthermore, Example 1 also has a higher elastic modulus, indicating that it can better recover its original shape after being subjected to stress, which is an important advantage for applications subjected to cyclic stress. Example 1 has the lowest coefficient of thermal expansion, which means that it has better stability in volume and shape when temperature changes. The performance in flexural strength and abrasion resistance also demonstrates the advantages of Example 1 in terms of mechanical strength and durability.

[0137] In summary, Example 1 is the preferred implementation method for tungsten-copper alloy materials due to its superior overall performance and adaptability, especially in technical fields and applications with extremely high performance requirements. Its advanced physical, mechanical, and thermoelectric properties ensure excellent performance in a variety of extreme and demanding environments.

[0138] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing ultrafine-grained tungsten-copper alloys, characterized in that, It includes tungsten powder, copper powder, nickel, silicon, manganese, chromium, and silver; wherein each component is expressed as a percentage by mass. The tungsten powder content is 73.4%-85.1%; Copper powder content: 14%-24%; The nickel content is 0.5%-1%; The silicon content is 0.1%-0.5%; The manganese content is 0.1%-0.5%; The chromium content is 0.1%-0.3%; The silver content is 0.1%-0.3%; The tungsten powder has an average particle size of 1-5 micrometers; the copper powder has an average particle size of 0.5-3 micrometers. The method for preparing ultrafine-grained tungsten-copper alloy includes the following steps: S1: First, weigh out tungsten powder, copper powder, and added nickel, silicon, manganese, chromium, and silver according to the predetermined ratio; S2: Use a high-energy ball mill to mix and homogenize all the raw materials weighed in S1 to form alloy precursor powder; S3: The alloy precursor powder is dried in a vacuum environment to remove any residual moisture and organic impurities. S4: The dried alloy precursor powder is subjected to pulsed current treatment to promote micro-welding between powder particles through short-duration high-current pulses. S4 specifically includes: S41: The dried alloy precursor powder from S3 is evenly spread in a processing container with good electrical conductivity to ensure that the thickness of the powder layer is uniform. S42: Set the parameters of the pulse current generator, including pulse frequency from 100Hz to 500Hz, pulse width from 10µs to 100µs, and current density of 200A / cm². 2 Up to 500A / cm 2 ; S43: Apply the pulsed current set in S42 to the loaded powder in a controlled environment for a duration of 1 to 5 minutes to promote micro-welding and interparticle bonding between powder particles through short-duration high-current pulses. S5: The powder treated with pulsed current is subjected to cold isostatic pressing to form a green body; S6: Under a protective atmosphere, the billet is subjected to high-temperature hot isostatic pressing sintering treatment to completely fuse the billet and form a dense material structure. S6 specifically includes: S61: A furnace prepared for hot isostatic pressing sintering, and the required protective atmosphere is maintained inside the furnace, specifically using argon as the inert gas; S62: Set the sintering temperature to 900°C to 1200°C and the pressure to 300MPa to 700MPa; S63: Slowly heat the sintering furnace to the set sintering temperature, with the heating rate controlled at 5℃ / min. After reaching the target temperature, maintain this temperature for 1 to 3 hours to ensure that the materials inside the billet are completely fused. S64: While reaching the sintering temperature, gradually apply the set pressure and maintain this pressure throughout the holding period; S65: After heat preservation, the furnace temperature is reduced to room temperature at a controlled rate of 5℃ / min. After cooling to room temperature, the pressure is slowly reduced and the sintered billet is removed in a protective atmosphere. S7: Rapid cooling is performed immediately after sintering to lock in the ultra-fine grain structure, resulting in a tungsten-copper alloy blank; Specifically, S7 includes: S71: Connect the sintering furnace to the prepared cooling system, which can quickly reduce the furnace temperature through an external cooling medium; S72: Immediately after the sintering process is completed, the cooling system is activated to rapidly reduce the furnace temperature from the sintering temperature to room temperature. The cooling rate is controlled at 50°C to 100°C / minute to quickly stabilize the microstructure of the material. S73: After cooling to room temperature, slowly release the pressure inside the furnace and remove the tungsten-copper alloy blank while maintaining a protective atmosphere; S8: The tungsten-copper alloy blank obtained in S7 is machined and surface treated to achieve the required dimensions and surface roughness, thus completing the manufacturing of the final product.

2. The method for preparing ultrafine-grained tungsten-copper alloy according to claim 1, characterized in that, S2 specifically includes: S21: Select a high-energy ball mill and adjust the speed to 200 to 800 rpm; S22: The powders of each component weighed in S1 are loaded into the ball mill jar according to a predetermined ratio, and the filling rate of the ball mill jar is controlled at 40%-50%; S23: Add hard steel balls or ceramic balls to the ball mill jar as the ball milling medium, and control the mass ratio of balls to powder to be between 10:1 and 15:1; and mill the balls for 1 to 4 hours to form alloy precursor powder.

3. The method for preparing ultrafine-grained tungsten-copper alloy according to claim 1, characterized in that, S3 specifically includes: S31: Transfer the alloy precursor powder to a vacuum drying furnace and set the vacuum level to 0.1 mbar; S32: Control the temperature of the vacuum drying oven at 120°C to 180°C and maintain this temperature and vacuum level to continuously dry the alloy precursor powder for 2 to 6 hours to fully remove moisture and organic impurities. S33: After the drying process is completed, the furnace temperature is slowly reduced to room temperature and cooled under vacuum. Then the dried powder is removed.

4. The method for preparing ultrafine-grained tungsten-copper alloy according to claim 1, characterized in that, S5 specifically includes: S51: Load the alloy precursor powder that has been treated with pulsed current in S4 into a preset cold isostatic pressing mold, and ensure that the powder is evenly distributed in the mold. S52: Set the pressure of the cold isostatic press to 200MPa to 500MPa and maintain the ambient temperature at 20°C to 25°C; S53: Under the environmental conditions controlled by S52, gradually apply pressure to the set pressure value, and control the pressure rise rate at 10MPa / min; S54: After reaching the predetermined pressure, maintain this pressure for 5 to 10 minutes to ensure that the powder is fully compacted and the particles are bonded together. Then, slowly reduce the pressure to zero, with the pressure release rate controlled at 5 MPa / min.

5. The method for preparing ultrafine-grained tungsten-copper alloy according to claim 1, characterized in that, S8 specifically includes: S81: Perform preliminary machining on the tungsten-copper alloy blank obtained in step S7. Use a CNC machine tool to cut and shape the blank to approximate the size of the final product. The dimensional tolerance of the rough machining is controlled within ±0.5mm. S82: Precision machining is performed on the rough-machined blank to achieve strict dimensional accuracy and shape requirements. The dimensional tolerance of precision machining is controlled within ±0.05mm. S83: Surface treatment of the precision-machined tungsten-copper alloy blank, including grinding and polishing, to achieve the required surface roughness, with a required surface roughness index of Ra 0.2 μm to 0.8 μm.

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