A method for producing a high-strength tungsten alloy

Abstract

The application discloses a preparation method of high-strength tungsten alloy and belongs to the technical field of powder metallurgy. In the method, upper layer solid solution elements, lower layer solid solution elements, solid lubricating powder and activated powder with tungsten powder are uniformly mixed by ball milling according to a target mass fraction ratio with a predetermined particle size ratio, and then the target tungsten alloy is prepared through vacuum pressing, vacuum low-temperature sintering, vacuum heat preservation treatment, discharge plasma sintering, low-temperature annealing treatment and cross rolling, so that the properties of the target tungsten alloy are improved. In the preparation process of the target tungsten alloy, the vacuum environment, the short sintering time and the tungsten carbide can avoid the penetration of impurity elements such as oxygen into the inside of the target tungsten alloy, so that the target tungsten alloy is free of defects such as bubbles, holes and unevenness, and the strength of the target tungsten alloy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of powder metallurgy, and in particular to a method for preparing a high-strength tungsten alloy. Background Art

[0002] High-density tungsten alloys are widely used due to their high strength, high hardness, and good ductility. Domestic and international researchers have conducted research on powder modification, enhanced sintering, deformation strengthening, and heat treatment processes to improve the performance of high-density tungsten alloys.

[0003] Chinese patent application publication number CN109338160A discloses a castable, forgeable solid solution tungsten alloy and its preparation method. The method involves adding elements that dissolve in tungsten and grain boundary strengthening elements, and then producing the tungsten alloy through vacuum melting, forging, and aging. The mass fraction ratios of the various components in the tungsten alloy prepared in this patent are arbitrarily set, and no reasonable method for controlling these ratios is provided.

[0004] Chinese patent application publication number CN118006997A discloses a method for preparing a low-oxygen heterostructured tungsten-based composite material. The method involves ball milling W powder, Ti powder, TiB2 powder, and WC carbide balls in a milling jar. The resulting material is then sintered using a two-step process to produce a W-Ti-TiB2 tungsten-based composite material with high hardness and low oxygen content. The two-step sintering process employed in this patent takes a long time to prepare, resulting in a high oxygen content and numerous internal gaps in the composite material.

[0005] Chinese patent application publication number CN103602868A discloses a method for preparing a high-density, fine-grained W-TiC alloy. The method involves first mixing TiC powder and W powder using wet high-energy ball milling, vacuum drying the resulting mixed powder, then subjecting the mixed powder to spark plasma sintering to produce a sintered billet. Finally, the sintered billet is subjected to multi-fire die forging to produce the high-density, fine-grained W-TiC alloy. However, the multi-fire die forging process in the aforementioned patent takes a long time, causing surface oxidation of the W-TiC alloy and reducing its strength.

[0006] Chinese patent application publication number CN116024448A discloses a method for preparing a high-density, fine-grained tungsten alloy with a non-equiatomic high-entropy alloy binder phase. The method first involves mixing tungsten powder with a high-entropy alloy binder phase powder, then subjecting the mixture to low-energy ball milling to obtain a mixed powder. The mixed powder is then pre-pressed, subjected to spark plasma sintering, and cooled to obtain a high-density, fine-grained tungsten alloy with a non-equiatomic high-entropy alloy binder phase. The aforementioned patent utilizes low-energy ball milling to obtain the mixed powder, which results in agglomeration between the mixed powders. During spark plasma sintering, the tungsten powder and the high-entropy alloy binder phase powder diffuse, increasing friction and hindering the preparation of the tungsten alloy. Therefore, further improvements are needed in the existing technology. Summary of the Invention

[0007] To address the deficiencies of the aforementioned prior art, the present invention proposes a method for preparing a high-strength tungsten alloy. The method selects an upper layer solid solution element, a lower layer solid solution element, a solid lubricant powder, and an activated powder with predetermined particle size ratios, uniformly mixes them with tungsten powder at a target mass fraction ratio, and then proceeds through vacuum pressing, vacuum low-temperature sintering, vacuum insulation treatment, spark plasma sintering, low-temperature annealing, and cross-rolling to prepare the target tungsten alloy and improve its properties.

[0008] The technical solution of the present invention is achieved as follows:

[0009] A method for preparing a high-strength tungsten alloy comprises the following steps:

[0010] Step 1: Select at least one upper-layer solid-solution element and one lower-layer solid-solution element from the solid-solution element set, select a tungsten powder particle size within the particle size range, and determine the particle sizes of the upper-layer solid-solution element and the lower-layer solid-solution element based on the particle size of the tungsten powder and a predetermined particle size ratio;

[0011] Step 2: Establish a three-dimensional atomic model based on the particle size of the tungsten powder, the particle size of the upper and lower solid-solution elements, and the pressing mold. Determine the target mass fraction ratio of the tungsten powder, the upper and lower solid-solution elements based on the three-dimensional atomic model.

[0012] Step 3: Set the ball milling parameters, place the tungsten powder with a predetermined particle size ratio, the upper layer solid solution element, and the lower layer solid solution element in a ball mill according to the target mass fraction ratio, and perform ball milling to prepare tungsten alloy powder;

[0013] Step 4: Select at least one activation element from the activation set, add tungsten alloy powder, solid lubricant powder and activation powder into the pressing die and mix them, and select the target pressure within the first pressure range for vacuum pressing;

[0014] Step 5: performing vacuum low-temperature sintering and vacuum heat preservation treatment on the tungsten alloy powder within the first temperature range to prepare a tungsten alloy embryo;

[0015] Step 6: Spark plasma sintering the tungsten alloy embryo within the second temperature range, adding carbon powder for low temperature annealing to prepare the tungsten alloy;

[0016] Step 7: Microscopically scan the tungsten alloy to obtain the average length and average width of the tungsten alloy voids and establish a constitutive model of the tungsten alloy;

[0017] Step 8: Determine the target transverse stress and target longitudinal stress based on the constitutive model and the average length and average width of the tungsten alloy voids, and perform cross-rolling on the tungsten alloy based on the target transverse stress and target longitudinal stress to prepare the target tungsten alloy;

[0018] Step 9: Measure the properties of the target tungsten alloy. If the properties of the target tungsten alloy are qualified, the process ends; otherwise, return to step 1.

[0019] In the present invention, in step 1, the solid solution element set includes all elements that can be solid-soluble with tungsten, namely solid solution elements, and the solid solution element set = {molybdenum, tantalum, niobium, rhenium, chromium, vanadium, vanadium, titanium, iron, nickel, cobalt}, and the solid solution elements whose mass ratio to tungsten atoms is greater than 0.9 are lower-layer solid solution elements, otherwise they are upper-layer solid solution elements.

[0020] In the present invention, in step 1, the particle size range is 1 nm to 10 nm, and the predetermined particle size ratio of the tungsten powder, the upper layer solid solution element and the lower layer solid solution element is .

[0021] In the present invention, in step 2, the mass fraction ratio of the upper solid solution element and the lower solid solution element is 1:1, and when min{V3} in the three-dimensional atomic model is min{V3}, the mass fraction ratio of tungsten powder, upper solid solution element and lower solid solution element is the target mass fraction ratio, wherein V3=V0-V1-V2, V0 is the volume of the pressing mold, V1 is the volume of the tungsten powder in the pressing mold, V2 is the sum of the volumes of the upper solid solution element and the lower solid solution element, and V3 is the volume of the voids in the pressing mold.

[0022] In the present invention, in step 4, the activation set = {lanthanum, cerium, nickel, copper, silver, cobalt, aluminum oxide, titanium dioxide, titanium carbide, tantalum carbide, hafnium carbide, titanium boride}, the solid lubricating powder is a powder that can reduce friction, the activation powder is a powder of an activation element, the particle size of the solid lubricating powder is ≤ the particle size of the activation powder < the particle size of the tungsten alloy powder, the mass fraction of the tungsten alloy powder accounts for [90%, 95%], the mass fraction of the solid lubricating powder accounts for [1%, 2%], and the mass fraction of the activation powder accounts for [1%, 8%].

[0023] In the present invention, in step 5, the first temperature range is [800°C, 1000°C], the vacuum low-temperature sintering time is [100min, 160min], the vacuum insulation treatment time is [60min, 100min], and the vacuum insulation treatment temperature is [400°C, 800°C].

[0024] In the present invention, in step 6, the second temperature range is [1000°C, 1200°C], the spark plasma sintering time is [2 min, 5 min], the sintering pressure is [30 MPa, 80 MPa], the heating rate is [40°C / min, 100°C / min], the particle size of the activated powder is < the particle size of the carbon powder ≤ the particle size of the tungsten alloy powder, the mass fraction of the carbon powder is [1%, 2%], the temperature of the low-temperature annealing treatment is [100°C, 500°C], and the time of the low-temperature annealing treatment is [60 min, 240 min].

[0025] In the present invention, in step 7, the constitutive model is , σ is the stress applied to the tungsten alloy, E is the elastic modulus of the tungsten alloy, ε1 is the plastic strain of the tungsten alloy, σ1 is the yield stress of the tungsten alloy, and n is the hardening index of the tungsten alloy.

[0026] In the present invention, in step 9, the properties of the target tungsten alloy include strength, hardness, and density.

[0027] The method and system for preparing a high-density tungsten alloy according to the present invention have the following beneficial effects: By setting a predetermined particle size ratio between tungsten powder, upper-layer solid-solution elements, and lower-layer solid-solution elements, the present invention ensures that the upper-layer solid-solution elements and lower-layer solid-solution elements fully fill the gaps between tungsten powder particles, thereby enhancing the density of the target tungsten alloy. The target mass fraction ratio of tungsten powder, upper-layer solid-solution elements, and lower-layer solid-solution elements is determined based on a three-dimensional atomic model, thereby improving the strength of the target tungsten alloy and facilitating the subsequent pressing of the tungsten alloy powder and the preparation of the target tungsten alloy. The particle size of the tungsten powder is reduced through ball milling, and the upper-layer solid-solution elements and lower-layer solid-solution elements are fully mixed with the tungsten powder by adding solid lubricant powder, thereby improving the powder's fluidity, reducing friction during pressing, and promoting the diffusion of activated elements, upper-layer solid-solution elements, and lower-layer solid-solution elements during sintering, thereby reducing the difficulty of preparing the target tungsten alloy. By combining activated sintering, two-step sintering, and spark plasma sintering to prepare the target tungsten alloy, the grain growth and porosity of the target tungsten alloy are better controlled, thereby optimizing the material's mechanical and physical properties. Vacuum low-temperature sintering helps remove volatile components, reducing the risk of bubbles or other defects during spark plasma sintering. It also makes the material more uniform, creating better conditions for spark plasma sintering, thereby improving the overall quality of the target tungsten alloy. Activation sintering reduces energy consumption during both vacuum low-temperature sintering and spark plasma sintering. Spark plasma sintering shortens sintering time, reduces unnecessary oxidation reactions, and improves the density of the target tungsten alloy. Low-temperature annealing of the tungsten alloy preform by adding carbon powder forms dense tungsten carbide on the surface of the preform, improving hardness, wear resistance, and corrosion resistance. Cross-rolling the tungsten alloy reduces voids and increases the strength of the target tungsten alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of the method for preparing the high-strength tungsten alloy of the present invention;

[0029] Figure 2 A schematic diagram of the predetermined particle size ratio of the present invention;

[0030] Figure 3 is a schematic diagram of the three-dimensional atomic model of the present invention;

[0031] Figure 4 Schematic diagram of the microstructure of the tungsten alloy of the present invention. DETAILED DESCRIPTION

[0032] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0033] Due to the different weights of the upper and lower dissolved elements, they occupy the gaps within the tungsten powder during ball milling, facilitating subsequent sintering. During low-temperature vacuum sintering, the upper and lower dissolved elements separately form solid solutions with tungsten, inhibiting the dissolution-precipitation process of tungsten, thereby refining the tungsten grains and improving the strength, toughness, and wear resistance of the preformed tungsten alloy. At sintering temperatures between 1000°C and 1200°C, the densification mechanism during spark plasma sintering is primarily particle sliding driven by sintering pressure. Above 1200°C, based on creep theory, increasing the sintering pressure and temperature increases the stress factor and reduces the apparent activation energy. Consequently, the densification mechanism may shift from being dominated by dislocation climb to being dominated by grain boundary diffusion, leading to larger grain boundaries and reduced strength and hardness of the target tungsten alloy. Tungsten carbide exhibits excellent resistance to oxidation at both room and elevated temperatures. However, its oxidation rate increases in temperatures above 500°C, so low-temperature annealing is performed below 500°C. Throughout the target tungsten alloy preparation process, the vacuum environment, short sintering times, and tungsten carbide prevent the infiltration of impurities such as oxygen into the target tungsten alloy, which could lead to bubbles, holes, and uneven surfaces. This improves the density of the target tungsten alloy. The density and strength of tungsten alloys generally have a positive correlation, with higher density contributing to increased strength. Example 1

[0034] like Figures 1 to 4 As shown, the preparation method of the high-strength tungsten alloy of the present invention includes the following steps.

[0035] Step 1: Select at least one upper-layer solid-solution element and one lower-layer solid-solution element from the solid-solution element set, select a particle size of tungsten powder within the particle size range, and determine the particle size of the upper-layer solid-solution element and the lower-layer solid-solution element according to the particle size of tungsten powder and the predetermined particle size ratio. The solid-solution element set contains all elements that can be solid-solved with tungsten element, namely solid-solution elements, and the solid-solution element set = {molybdenum, tantalum, niobium, rhenium, chromium, vanadium, vanadium, titanium, iron, nickel, cobalt}. The solid-solution element with a mass ratio to tungsten atoms greater than 0.9 is the lower-layer solid-solution element, and vice versa. The lower-layer solid-solution element can be rhenium or tantalum, and the upper-layer solid-solution element can be molybdenum, niobium, chromium, vanadium, vanadium, titanium, iron, nickel, and cobalt. The particle size range is 1 nanometer to 10 nanometers. In order to fully fill the gaps between the particles of tungsten powder with the upper-layer solid-solution element and the lower-layer solid-solution element, such as Figure 2 As shown in the figure, the big circle represents tungsten powder, the small circle represents the upper solid solution element and the lower solid solution element, and the predetermined particle size ratio R1:R2:R3 of tungsten powder, upper solid solution element and lower solid solution element is set to .

[0036] Step 2: According to the particle size of tungsten powder, the particle size of upper and lower solid solution elements, and the pressing mold, a three-dimensional atomic model is established. According to the three-dimensional atomic model, the target mass fraction ratio of tungsten powder, upper and lower solid solution elements is determined. The mass fraction ratio of upper and lower solid solution elements is 1:1. Figure 3 As shown in the figure, the rectangular parallelepiped in the three-dimensional atomic model represents the pressing die, the large circle represents the tungsten powder, and the small circle represents the upper and lower solid solution elements. When min{V3} in the three-dimensional atomic model is reached, the mass fraction ratio of the tungsten powder, the upper and lower solid solution elements is the target mass fraction ratio, where V3 = V0-V1-V2, where V0 is the volume of the pressing die, V1 is the volume of the tungsten powder in the pressing die, V2 is the sum of the volumes of the upper and lower solid solution elements, and V3 is the volume of the voids in the pressing die. The smaller the void volume in the pressing die, the higher the density of the tungsten alloy, which is more conducive to the subsequent pressing of tungsten alloy powder and the preparation of tungsten alloy.

[0037] Step 3: Set the ball milling parameters and place tungsten powder, upper and lower solid solution elements with a predetermined particle size ratio into a ball mill according to the target mass fraction ratio to prepare tungsten alloy powder. The particle size of the tungsten powder initially added during ball milling is not within the particle size range; it simply forms a predetermined particle size ratio with the upper and lower solid solution elements. By adjusting the ball milling parameters and ball milling for a long period of time, the particle size of the tungsten powder is reduced until it is within the particle size range. The ball milling operation reduces the particle size of the tungsten powder and allows the upper and lower solid solution elements to be fully mixed with the tungsten powder, reducing the difficulty of tungsten alloy preparation. The ball milling time is generally 12 to 48 hours. The larger the particle size of the tungsten powder, the longer the ball milling time.

[0038] Step 4: Select at least one activating element from the activation set. Add tungsten alloy powder, solid lubricant powder, and activation powder to the pressing mold and mix. Vacuum pressing is performed at a target pressure within the first pressure range. The activation set consists of {lanthanum, cerium, nickel, copper, silver, cobalt, aluminum oxide, titanium dioxide, titanium carbide, tantalum carbide, hafnium carbide, and titanium boride}. The activation powder is composed of the activating elements. Activating elements significantly lower sintering temperature, promote densification, and improve material properties by modifying surface energy and interfacial structure and providing additional diffusion pathways. Solid lubricant powder is a friction-reducing powder that improves powder flowability, reduces friction during pressing, and facilitates diffusion of the activating element, upper-solution elements, and lower-solution elements during sintering. The particle size of the solid lubricant powder must be ≤ that of the activation powder and < that of the tungsten alloy powder. The mass fractions of the tungsten alloy powder, solid lubricant powder, and activation powder are [90%, 95%], [1%, 2%], and [1%, 8%].

[0039] Step 5: Vacuum low-temperature sintering and vacuum holding treatment are performed on the tungsten alloy powder within the first temperature range to produce a tungsten alloy preform. The first temperature range is [800°C, 1000°C], and the vacuum low-temperature sintering time is [100 min, 160 min]. The vacuum holding treatment time is [60 min, 100 min], and the vacuum holding temperature is [400°C, 800°C]. During vacuum low-temperature sintering, the upper and lower dissolved elements respectively form solid solutions with tungsten, inhibiting the dissolution-precipitation process of tungsten, thereby refining the tungsten grains and improving the strength, toughness, and wear resistance of the tungsten alloy preform. After vacuum low-temperature sintering, the vacuum holding treatment eliminates temperature gradients caused by uneven heating rates, prevents deformation or cracking of the tungsten alloy preform due to local overheating, and provides sufficient time for atomic diffusion, allowing for full microstructural changes within the tungsten alloy preform.

[0040] Step 6: Spark plasma sintering (SPS) the tungsten alloy preform within the second temperature range, followed by low-temperature annealing with the addition of carbon powder to produce the tungsten alloy. The second temperature range is [1000°C, 1200°C], the SPS duration is [2 min, 5 min], the sintering pressure is [30 MPa, 80 MPa], and the heating rate is [40°C / min, 100°C / min]. Replacing the second step of the two-step sintering process with SPS shortens the sintering time and reduces unnecessary oxidation reactions. The hot pressing and discharge effects provide uniform pressure distribution, enhancing contact and bonding between particles. An advanced control system allows for real-time monitoring and adjustment of SPS parameters such as temperature, pressure, and current, facilitating the preparation of the tungsten alloy. The activated powder particle size is < the carbon powder particle size ≤ the tungsten alloy powder particle size, and the carbon powder mass fraction is [1%, 2%]. The low-temperature annealing treatment is performed at temperatures between 100°C and 500°C for a duration between 60 minutes and 240 minutes. Carbon powder is added during the annealing process to form dense tungsten carbide on the surface of the tungsten alloy preform. Oxygen is isolated at 500°C to prevent oxidation of the tungsten alloy preform, which could lead to a decrease in density and other properties. By defining the particle sizes of the solid lubricant powder, activation powder, carbon powder, and tungsten alloy powder, the problem of powder agglomeration is resolved. This overcomes the difficulty of evenly mixing the activation powder into the tungsten alloy powder, ensuring lubrication and activation. Furthermore, the carbon powder is encouraged to form tungsten carbide on the surface of the tungsten alloy preform, preventing it from penetrating the interior, thereby improving hardness, wear resistance, and corrosion resistance.

[0041] Step 7: Scan the tungsten alloy microscopically to obtain the average length and average width of the tungsten alloy voids and establish the constitutive model of the tungsten alloy. Scan the tungsten alloy microscopically using a scanning electron microscope to obtain the following: Figure 4 The microstructure of tungsten alloy shown is composed of Figure 4It can be seen that there are a lot of voids inside the tungsten alloy. The gray mass is the tungsten alloy and the black area is the void. By measuring the length and width of all the voids in the figure, the average length and average width are obtained. The constitutive model of tungsten alloy is , σ is the stress applied to the tungsten alloy, E is the elastic modulus of the tungsten alloy, ε1 is the plastic strain in the tungsten alloy, σ1 is the yield stress of the tungsten alloy, and n is the hardening exponent of the tungsten alloy. The elastic modulus of the tungsten alloy is measured through static tensile testing, and the hardening exponent and yield stress of the tungsten alloy are measured through uniaxial tensile testing and compression testing, thereby deriving the specific functions of the constitutive model.

[0042] Step 8: Determine the target transverse and longitudinal stresses based on the constitutive model and the average length and width of the tungsten alloy voids. Cross-roll the tungsten alloy according to the target transverse and longitudinal stresses to produce the target tungsten alloy. Cross-rolling the tungsten alloy reduces voids and increases the density of the tungsten alloy. Substitute the average length and average width into the constitutive model to determine the target transverse and longitudinal stresses. Cross-roll the tungsten alloy according to the target transverse and longitudinal stresses.

[0043] Step 9: Measure the properties of the target tungsten alloy. If the properties of the target tungsten alloy are qualified, the process ends; otherwise, the process returns to step 1. The properties of the target tungsten alloy include strength, hardness, and density. In addition, depending on specific production requirements, the properties may also include melting point, thermal expansion coefficient, etc.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a high-strength tungsten alloy, characterized in that: The following steps are involved: Step 1: Select at least one upper-layer solid-solution element and one lower-layer solid-solution element from the solid-solution element set, select a tungsten powder particle size within the particle size range, and determine the particle sizes of the upper-layer solid-solution element and the lower-layer solid-solution element based on the particle size of the tungsten powder and a predetermined particle size ratio; Step 2: Establish a three-dimensional atomic model based on the particle size of the tungsten powder, the particle size of the upper and lower solid-solution elements, and the pressing mold. Determine the target mass fraction ratio of the tungsten powder, the upper and lower solid-solution elements based on the three-dimensional atomic model. Step 3: Set the ball milling parameters, place the tungsten powder with a predetermined particle size ratio, the upper layer solid solution element, and the lower layer solid solution element in a ball mill according to the target mass fraction ratio, and perform ball milling to prepare tungsten alloy powder; Step 4: Select at least one activation element from the activation set, add tungsten alloy powder, solid lubricant powder and activation powder into the pressing die and mix them, and select the target pressure within the first pressure range for vacuum pressing; Step 5: performing vacuum low-temperature sintering and vacuum heat preservation treatment on the tungsten alloy powder within the first temperature range to prepare a tungsten alloy embryo; Step 6: Spark plasma sintering the tungsten alloy embryo within the second temperature range, adding carbon powder for low temperature annealing to prepare the tungsten alloy; Step 7: Microscopically scan the tungsten alloy to obtain the average length and average width of the tungsten alloy voids and establish a constitutive model of the tungsten alloy; Step 8: Determine the target transverse stress and target longitudinal stress based on the constitutive model and the average length and average width of the tungsten alloy voids, and perform cross-rolling on the tungsten alloy based on the target transverse stress and target longitudinal stress to prepare the target tungsten alloy; Step 9: Measure the properties of the target tungsten alloy. If the properties of the target tungsten alloy are qualified, the process ends; otherwise, return to step 1.

2. The method for preparing a high-strength tungsten alloy according to claim 1, wherein In step 1, the solid solution element set includes all elements that can be dissolved in tungsten, namely solid solution elements, and the solid solution element set = {molybdenum, tantalum, niobium, rhenium, chromium, vanadium, vanadium, titanium, iron, nickel, cobalt}. The solid solution elements whose mass ratio to tungsten atoms is greater than 0.9 are lower-layer solid solution elements, otherwise they are upper-layer solid solution elements.

3. The method for preparing high-strength tungsten alloy according to claim 1, wherein In step 1, the particle size range is 1 nm to 10 nm, and the predetermined particle size ratio of the tungsten powder, the upper layer solid solution element and the lower layer solid solution element is .

4. The method for preparing high-strength tungsten alloy according to claim 1, wherein In step 2, the mass fraction ratio of the upper solid solution element and the lower solid solution element is 1:

1. When min{V3} in the three-dimensional atomic model is reached, the mass fraction ratio of the tungsten powder, the upper solid solution element, and the lower solid solution element is the target mass fraction ratio, where V3=V0-V1-V2, V0 is the volume of the pressing mold, V1 is the volume of the tungsten powder in the pressing mold, V2 is the sum of the volumes of the upper solid solution element and the lower solid solution element, and V3 is the volume of the voids in the pressing mold.

5. The method for preparing high-strength tungsten alloy according to claim 1, wherein In step 4, the activation set = {lanthanum, cerium, nickel, copper, silver, cobalt, aluminum oxide, titanium dioxide, titanium carbide, tantalum carbide, hafnium carbide, titanium boride}, the solid lubricating powder is a powder that can reduce friction, the activation powder is a powder of an activation element, the particle size of the solid lubricating powder is ≤ the particle size of the activation powder < the particle size of the tungsten alloy powder, the mass fraction of the tungsten alloy powder is [90%, 95%], the mass fraction of the solid lubricating powder is [1%, 2%], and the mass fraction of the activation powder is [1%, 8%].

6. The method for preparing high-strength tungsten alloy according to claim 1, wherein In step 5, the first temperature range is [800°C, 1000°C], the vacuum low-temperature sintering time is [100min, 160min], the vacuum insulation treatment time is [60min, 100min], and the vacuum insulation treatment temperature is [400°C, 800°C].

7. The method for preparing high-strength tungsten alloy according to claim 1, wherein In step 6, the second temperature range is [1000°C, 1200°C], the spark plasma sintering time is [2 min, 5 min], the sintering pressure is [30 MPa, 80 MPa], the heating rate is [40°C / min, 100°C / min], the particle size of the activated powder is < the particle size of the carbon powder ≤ the particle size of the tungsten alloy powder, the mass fraction of the carbon powder is [1%, 2%], the temperature of the low-temperature annealing treatment is [100°C, 500°C], and the time of the low-temperature annealing treatment is [60 min, 240 min].

8. The method for preparing high-strength tungsten alloy according to claim 1, wherein In step 7, the constitutive model is , σ is the stress applied to the tungsten alloy, E is the elastic modulus of the tungsten alloy, ε1 is the plastic strain of the tungsten alloy, σ1 is the yield stress of the tungsten alloy, and n is the hardening index of the tungsten alloy.

9. The method for preparing high-strength tungsten alloy according to claim 1, wherein In step 9, the properties of the target tungsten alloy include strength, hardness, and density.

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