Tungsten-rhenium alloy powder mixing method for controlling shrinkage rate during composite sintering of double-layer metal

Abstract

The invention discloses a tungsten-rhenium alloy powder mixing method for controlling the shrinkage rate during double-layer metal composite sintering, and relates to the technical field of medical CT machine bulb tube target material preparation. According to the method, W-Re powder prepared through a wet chemical method and solid-liquid mixing is mixed in different proportions, the influence of different powder mixing proportions on the shrinkage rate is explored through pre-sintering and sintering processes, then the requirements of composite sintering for different shrinkage rates are met, and the sintering density is measured. The result shows that the sintering density of different powder mixing proportions is changed along with the continuous change of the powder mixing components, and the linear shrinkage of the tungsten-rhenium alloy powder is gradually reduced along with the continuous reduction of the proportion of the tungsten-rhenium alloy powder prepared by the wet chemical method, so that the requirement on the shrinkage of the tungsten-rhenium alloy in the preparation industry is met.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of medical CT machine tube target materials, and in particular to a tungsten-rhenium alloy powder mixing method for controlling the shrinkage rate during double-layer metal composite sintering. Background Art

[0002] CT (Computerized Tomography)-Computerized tomography has become an important means of modern medical diagnosis. The performance of CT machines depends largely on the quality of the X-ray tube. The anode target is a crucial component of the X-ray tube, which directly affects the X-ray emission intensity and the service life of the tube. When the X-ray tube is working, the anode target is bombarded by the high-energy electron beam and emits X-rays. However, the energy conversion rate is very low, only about 1%, and more than 99% of the energy is converted into heat energy, and the heat is mainly concentrated on the anode. The temperature of the anode target can rise very high in a vacuum environment. It is reported that the ambient temperature of the X-ray tube is above 1300℃ when it is working, and its local temperature can be as high as 2600℃. Therefore, the rotating anode target material of the CT machine is required to have the characteristics of high melting point, high heat capacity, low high-temperature vapor pressure, and good thermal shock resistance.

[0003] Tungsten has an extremely high elastic modulus (407Gpa at room temperature), a high melting point (3410℃), and high high-temperature strength. However, since the X-ray tube works intermittently and is sometimes hot and sometimes cold, the target surface material is prone to cracking. Tungsten has a notch sensitivity effect, which easily leads to the expansion and deepening of cracks and peeling from the substrate. After the cracks expand and deepen, the substrate material will be exposed to electron beam bombardment and produce X-rays of unnecessary wavelengths, which will damage the X-ray tube. In order to improve the comprehensive performance of pure tungsten, a small amount of rhenium is added to tungsten. Rhenium and tungsten have similar atomic numbers and similar physical and chemical properties. They are more likely to form an infinite solid solution. The addition of rhenium reduces the Peirce stress of tungsten plastic deformation and thus improves the plastic toughness of tungsten. Due to the solid solution strengthening and toughening mechanism caused by the addition of rhenium, tungsten as a target surface material greatly improves the target surface's ability to withstand electron bombardment, effectively reduces the dose attenuation rate, and at the same time reduces the pure notch sensitivity, greatly improving the service life of the target disk.

[0004] At present, the tube target of medical CT machine is generally prepared by combining bimetallic materials, one part is prepared by molybdenum zirconium titanium alloy (TZM), and the other part is prepared by W-10 (wt%) Re powder. When the target disk is sintered, the density of W-10 (wt%) Re and TZM cannot be satisfied at the same time. Usually, it is selected to ensure that TZM reaches a high density and W-10 (wt%) Re reaches a certain density, and then the density is increased by plastic deformation. In addition, the sintering activity of the powder and the characteristics of the blank comprehensively affect the bonding performance of the W-10 (wt%) Re and TZM layers during the sintering process. However, the W-10 (wt%) Re powder prepared by a single method has the problem of cracking in the preparation of the target during use. This reason is mainly caused by the different shrinkage rates when dissimilar metals are sintered. The shrinkage rate of the TZM layer during sintering is usually 0.16-0.2. The difference in shrinkage rates between the W-10 (wt%) Re powder and the TZM layer leads to cracking during the preparation of the target. In this paper, the W-10 (wt%) Re powder prepared by wet chemical method and W-10 (wt%) Re powder prepared by solid-liquid mixing are mixed in different proportions to control the linear shrinkage of the green body, and at the same time obtain a green body with a higher sintering density to solve the cracking problem occurring during composite sintering. Summary of the invention

[0005] The present invention mixes W-10 (wt%) Re powder prepared by a wet chemical method and W-10 (wt%) Re powder prepared by solid-liquid mixing in different proportions, and explores the influence of different powder mixing ratios on the shrinkage rate through pre-sintering and sintering processes, thereby meeting the requirements of composite sintering for different shrinkage rates, and measures the sintering density. Regulating the shrinkage rate of W-10 (wt%) Re powder by a powder mixing method is a method for regulating the shrinkage of the green body with high efficiency and simple process. The present invention achieves the purpose of controlling the shrinkage rate of the green body by mixing W-10 (wt%) Re powder prepared by a wet chemical method and W-10 (wt%) Re powder prepared by solid-liquid mixing in different proportions.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is:

[0007] A tungsten-rhenium alloy powder mixing method for controlling the shrinkage rate during double-layer metal composite sintering, the steps are as follows:

[0008] Step 1: Preparation of tungsten-rhenium precursor by wet chemical method

[0009] First, add ammonium metatungstate powder into deionized water until fully dissolved, and place the solution in a magnetic stirrer for heating, adjust the rotor to a suitable speed, and heat to 100-120°C; after the temperature stabilizes, add ammonium rhenate to the solution, and after the ammonium rhenate is fully stirred and dissolved, add oxalic acid, and after the oxalic acid is completely dissolved, stabilize the temperature at 100-120°C and allow the solution to react for 3-5 hours. After the solute reaction is complete, a tungsten-rhenium precursor solution is obtained, and the solid content of the precursor solution is 25%-32%;

[0010] Step 2: Spray drying the tungsten-rhenium precursor solution prepared in step 1

[0011] The working parameters of the spray drying equipment are set. The spray drying starts heating and the air inlet temperature is raised to 200-230°C. After the air outlet temperature is stable, the feed port and the tungsten-rhenium precursor solution are connected and the peristaltic pump is turned on. After the precursor solution is spray dried, the powder in the collection tank is collected to obtain the tungsten-rhenium precursor powder.

[0012] Step 3: Preparation of tungsten-rhenium precursor by solid-liquid mixing

[0013] A certain proportion of ammonium rhenate is dissolved in deionized water by heating, and then a certain proportion of pure tungsten powder is evenly added into the ammonium rhenate solution, requiring that the tungsten powder is completely immersed in the solution, and then the slurry tungsten powder is stirred and dried until all the water in the ammonium rhenate solution evaporates; after evaporation, the ammonium rhenate is attached to the surface of the tungsten powder particles in the form of fine particles to form a preliminary pre-alloyed W-10 (wt%) Re precursor powder;

[0014] Step 4: Restore

[0015] The tungsten-rhenium precursor is spread flat in a firing boat, and then the firing boat is placed in a hydrogen reduction furnace, hydrogen is introduced, and then the temperature is raised to 1000-1100°C at 8-12°C / min, and the temperature is kept for 2-4 hours, and then the temperature is reduced to 480-520°C at 8-12°C / min, and then the furnace is cooled to room temperature to obtain tungsten-rhenium alloy powder; the objects of reduction in step 4 are the tungsten-rhenium precursors prepared in steps 2 and 3, and they are reduced separately;

[0016] Step 5: Mix the powder

[0017] The tungsten-rhenium alloy prepared by the reduced solid-liquid method and the tungsten-rhenium alloy powder prepared by the reduced wet chemical method were mixed in different proportions, respectively:

[0018] 100% wet chemical tungsten-rhenium powder;

[0019] 75% wet chemical tungsten-rhenium powder, 25% solid-liquid mixed tungsten-rhenium powder;

[0020] 50% wet chemical tungsten-rhenium powder, 50% solid-liquid mixed tungsten-rhenium powder;

[0021] 25% wet chemical tungsten-rhenium powder, 75% solid-liquid mixed tungsten-rhenium powder;

[0022] 100% solid-liquid mixed tungsten-rhenium powder;

[0023] The tungsten-rhenium alloy powder prepared by solid-liquid mixing and wet chemical method was placed in a powder mixer, and the parameters were set to a speed of 700 rpm / min and a powder mixing time of 2 h;

[0024] Step 6: Sintering

[0025] The mold filled with tungsten-rhenium alloy powder is placed in a tablet press, and a single-side axial pressure of 650-700 MPa is applied to the mold and maintained for 1-2 minutes. The pressure is then released and the pressed block is taken out; the pressed block is pre-sintered in hydrogen and sintered in high-temperature argon to prepare tungsten-rhenium alloys with different mixed powder ratios.

[0026] As a preferred technical solution of the present invention, in the tungsten-rhenium alloy powder mixing method:

[0027] In the step 1, the added amounts of ammonium rhenate and oxalic acid are 11.94% and 0-38% of the mass of ammonium metatungstate, respectively.

[0028] The working parameters of the spray drying equipment in step 2 are: inlet air temperature 200-230°C, outlet air temperature 100-120°C, atomizer speed 300-350r / min, and feed rate 1-2L / h.

[0029] The sintering step in step six is ​​as follows: first, the pressed block is pre-sintered with hydrogen, the block is laid flat in a sintering boat, and then the sintering boat is placed in an argon tube furnace, the argon tube furnace is evacuated and then argon is introduced; the temperature is increased from room temperature to 1100°C at 5-10°C / min and kept for 2h, then decreased to 480-520°C at 5-10°C / min, and then cooled to room temperature with the furnace to obtain a tungsten-rhenium alloy with a certain bonding strength; finally, the pre-sintered block is subjected to high-temperature argon sintering, the sintering boat with the block is placed in a graphite furnace, and then argon is introduced; then the temperature is increased to 2150°C at 10-15°C / min, kept for 2h, decreased to 580-620°C at 10-15°C / min, and then cooled to room temperature with the furnace to obtain a tungsten-rhenium alloy.

[0030] Compared with the prior art, the beneficial effects of the present invention are mainly manifested in:

[0031] The present invention uses a tungsten-rhenium alloy powder prepared by a wet chemical method to mix with a tungsten-rhenium alloy powder prepared by solid-liquid mixing, and by changing the ratio of the tungsten-rhenium alloy powders prepared by different methods, the change in shrinkage before and after sintering is explored to meet the application requirements of double-layer metal composite sintering. The results show that with the continuous change of the mixed powder composition, the sintering density of different mixed powder ratios also changes. With the continuous reduction of the ratio of the tungsten-rhenium alloy powder prepared by the wet chemical method, its linear shrinkage rate also gradually decreases, thereby meeting the requirements of the shrinkage rate of tungsten-rhenium alloy in the preparation industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 These are pre-sintered images of Examples 1, 2, 3, 4, and 5.

[0033] Figure 2 These are the sintering images of Examples 1, 2, 3, 4, and 5.

[0034] Figure 3 Metallographic microscope images of tungsten-rhenium alloys prepared in Examples 1, 2, 3, 4, and 5.

[0035] Figure 4 Statistical diagram of grain size of tungsten-rhenium alloy prepared in Examples 1, 2, 3, 4, and 5. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with embodiments and drawings.

[0037] Example 1

[0038] Step 1: Preparation of tungsten-rhenium precursor by wet chemical method

[0039] Dissolve a certain proportion of ammonium metatungstate (AMT, Aladdin, purity ≥99.95%), ammonium rhenate (NH4ReO4, purity ≥99.9%), and oxalic acid (C2H2O4·2H2O, analytical grade) in deionized water, and stir thoroughly until the solution is clear without precipitation. First, add ammonium metatungstate powder to deionized water until it is fully dissolved, and place the solution in a magnetic stirrer for heating, adjust the rotor to a suitable speed, and heat it to 120°C. After the temperature stabilizes, add ammonium rhenate to the solution. After the ammonium rhenate is fully stirred and dissolved, add oxalic acid. After the oxalic acid is completely dissolved, stabilize the temperature at 120°C and let the solution react for 4 hours. After the solute reaction is complete, a tungsten-rhenium precursor solution is obtained, and the solid content of the precursor solution is 25%-32%.

[0040] In step 1, the added amounts of ammonium rhenate and oxalic acid are 11.94% and 20% of the mass of ammonium metatungstate, respectively.

[0041] Step 2: Spray drying the tungsten-rhenium precursor solution prepared in step 1

[0042] The working parameters of the spray drying equipment were set to 220°C inlet temperature, 110°C outlet temperature, 300r / min atomizer speed, and 1.5L / h feed rate. The spray drying started heating and the inlet temperature was raised to 220°C. After the outlet temperature was stable, the feed port and the tungsten-rhenium precursor solution were connected and the peristaltic pump was turned on. After the precursor solution was spray dried, the powder in the collection tank was collected to obtain the tungsten-rhenium precursor powder.

[0043] Step 3: Restore

[0044] The tungsten-rhenium precursor was spread flat in the firing boat, and then the firing boat was placed in the hydrogen reduction furnace, and then hydrogen (hydrogen purity ≥ 99.999%, hydrogen flow rate 2m 3 / h) to ensure that there is no gas other than hydrogen in the furnace chamber of the tubular furnace, then heat it to 1100°C at 10°C / min, keep it for 3h, then cool it to 520°C at 10°C / min, and then cool it to room temperature with the furnace to obtain tungsten-rhenium alloy powder.

[0045] Step 4: Sintering

[0046] The mold containing the tungsten-rhenium alloy powder is placed in a tablet press, and a single-side axial pressure of 700 MPa is applied to the mold, and the pressure is maintained for 1 minute, and then the pressure is released to take out the pressed block. The pressed block is pre-sintered in hydrogen, and the block is spread flat in a calcining boat, and then the calcining boat is placed in an argon tube furnace, and the argon tube furnace is evacuated and then argon gas is introduced (argon purity ≥ 99.999%, argon gas flow rate 2m 3 / h). The temperature was raised from room temperature to 1100℃ at 10℃ / min and kept for 2h, then dropped to 520℃ at 10℃ / min, and then cooled to room temperature with the furnace to obtain a tungsten-rhenium alloy with a certain bonding strength. Finally, the pre-sintered block was sintered in high-temperature argon gas, and the sintering boat with the block was placed in a graphite furnace, and then argon gas (argon purity ≥ 99.999%, argon gas flow rate 8m 3 / h). Then the temperature was raised to 2150°C at 10°C / min, kept at that temperature for 2h, then dropped to 600°C at 10°C / min, and then cooled to room temperature along with the furnace to obtain tungsten-rhenium alloy (mixed powder ratio: 100% tungsten-rhenium powder prepared by wet chemical method).

[0047] Embodiment 2:

[0048] Step 1: Preparation of tungsten-rhenium precursor by wet chemical method

[0049] Dissolve a certain proportion of ammonium metatungstate (AMT, Aladdin, purity ≥99.95%), ammonium rhenate (NH4ReO4, purity ≥99.9%), and oxalic acid (C2H2O4·2H2O, analytical grade) in deionized water, and stir thoroughly until the solution is clear without precipitation. First, add ammonium metatungstate powder to deionized water until it is fully dissolved, and place the solution in a magnetic stirrer for heating, adjust the rotor to a suitable speed, and heat it to 120°C. After the temperature stabilizes, add ammonium rhenate to the solution. After the ammonium rhenate is fully stirred and dissolved, add oxalic acid. After the oxalic acid is completely dissolved, stabilize the temperature at 120°C and let the solution react for 4 hours. After the solute reaction is complete, a tungsten-rhenium precursor solution is obtained, and the solid content of the precursor solution is 25%-32%.

[0050] In step 1, the added amounts of ammonium rhenate and oxalic acid are 11.94% and 20% of the mass of ammonium metatungstate, respectively.

[0051] Step 2: Preparation of tungsten-rhenium precursor by solid-liquid mixing

[0052] A certain proportion of ammonium rhenate (NH4ReO4, purity ≥99.9%) is dissolved in deionized water at 80°C, and then a certain proportion of pure tungsten powder is evenly added to the ammonium rhenate solution, requiring that the tungsten powder is completely immersed in the solution, and then the slurry tungsten powder is stirred and dried until all the water in the ammonium rhenate solution evaporates. After evaporation, the ammonium rhenate is attached to the surface of the tungsten powder particles in the form of fine particles to form a preliminary pre-alloyed W-10 (wt%) Re precursor powder.

[0053] Step 3: Spray drying the tungsten-rhenium precursor solution prepared in step 1

[0054] The working parameters of the spray drying equipment were set to 220°C inlet temperature, 110°C outlet temperature, 300r / min atomizer speed, and 1.5L / h feed rate. The spray drying started heating and the inlet temperature was raised to 220°C. After the outlet temperature was stable, the feed port and the tungsten-rhenium precursor solution were connected and the peristaltic pump was turned on. After the precursor solution was spray dried, the powder in the collection tank was collected to obtain the tungsten-rhenium precursor powder.

[0055] Step 4: Restore

[0056] The tungsten-rhenium precursor was spread flat in a firing boat, and then the firing boat was placed in a hydrogen reduction furnace, and then hydrogen (hydrogen purity ≥ 99.999%, hydrogen flow rate 2m 3 / h) to ensure that there is no gas other than hydrogen in the furnace chamber of the tubular furnace, then heat it to 1100°C at 10°C / min, keep it for 3h, then cool it to 520°C at 10°C / min, and then cool it to room temperature with the furnace to obtain tungsten-rhenium alloy powder.

[0057] Step 5: Mix the powder

[0058] Weigh 15g of tungsten-rhenium alloy powder prepared by wet chemical method, and then weigh 5g of tungsten-rhenium alloy powder prepared by solid-liquid mixing, and put them into a powder mixer, and set the parameters of the powder mixer to a speed of 700rpm / min and a powder mixing time of 12h.

[0059] Step 6: Sintering

[0060] The mold containing the tungsten-rhenium alloy powder is placed in a tablet press, and a single-side axial pressure of 700 MPa is applied to the mold, and the pressure is maintained for 1 minute, and then the pressure is released to take out the pressed block. The pressed block is pre-sintered in hydrogen, and the block is spread flat in a calcining boat, and then the calcining boat is placed in an argon tube furnace, and the argon tube furnace is evacuated and then argon gas is introduced (argon purity ≥ 99.999%, argon gas flow rate 2m 3 / h). The temperature was raised from room temperature to 1100℃ at 10℃ / min and kept for 2h, then dropped to 520℃ at 10℃ / min, and then cooled to room temperature with the furnace to obtain a tungsten-rhenium alloy with a certain bonding strength. Finally, the pre-sintered block was sintered in high-temperature argon gas, and the sintering boat with the block was placed in a graphite furnace, and then argon gas (argon purity ≥ 99.999%, argon gas flow rate 8m 3 / h). Then the temperature was raised to 2150℃ at 10℃ / min, kept at that temperature for 2h, then dropped to 600℃ at 10℃ / min, and then cooled to room temperature along with the furnace to obtain tungsten-rhenium alloy (mixed powder ratio: 75% tungsten-rhenium powder prepared by wet chemical method + 25% tungsten-rhenium powder prepared by solid-liquid mixing).

[0061] Example 3

[0062] The preparation steps are basically the same as those in Example 2, except that in step 5, 10 g of tungsten-rhenium alloy powder prepared by wet chemical method is weighed, and then 10 g of tungsten-rhenium alloy powder prepared by solid-liquid mixing is weighed. The final mixed powder ratio for preparing the tungsten-rhenium alloy is: 50% tungsten-rhenium powder prepared by wet chemical method + 50% tungsten-rhenium powder prepared by solid-liquid mixing.

[0063] Embodiment 4:

[0064] The preparation steps are basically the same as those in Example 2, except that in step 5, 5 g of tungsten-rhenium alloy powder prepared by wet chemical method is weighed, and then 15 g of tungsten-rhenium alloy powder prepared by solid-liquid mixing is weighed. The final mixed powder ratio for preparing the tungsten-rhenium alloy is: 25% tungsten-rhenium powder prepared by wet chemical method + 75% tungsten-rhenium powder prepared by solid-liquid mixing.

[0065] Embodiment 5:

[0066] Step 1: Preparation of tungsten-rhenium precursor by solid-liquid mixing

[0067] A certain proportion of ammonium rhenate (NH4ReO4, purity ≥99.9%) is dissolved in deionized water at 80°C, and then a certain proportion of pure tungsten powder is evenly added to the ammonium rhenate solution, requiring that the tungsten powder is completely immersed in the solution, and then the slurry tungsten powder is stirred and dried until all the water in the ammonium rhenate solution evaporates. After evaporation, the ammonium rhenate is attached to the surface of the tungsten powder particles in the form of fine particles to form a preliminary pre-alloyed W-10 (wt%) Re precursor powder.

[0068] Step 2: Restore

[0069] The tungsten-rhenium precursor was spread flat in a firing boat, and then the firing boat was placed in a hydrogen reduction furnace, and then hydrogen (hydrogen purity ≥ 99.999%, hydrogen flow rate 2m 3 / h) to ensure that there is no gas other than hydrogen in the furnace chamber of the tubular furnace, then heat it to 1100°C at 10°C / min, keep it for 3h, then cool it to 520°C at 10°C / min, and then cool it to room temperature with the furnace to obtain tungsten-rhenium alloy powder.

[0070] Step 3: Sintering

[0071] The mold containing the tungsten-rhenium alloy powder is placed in a tablet press, and a single-side axial pressure of 700 MPa is applied to the mold, and the pressure is maintained for 1 minute, and then the pressure is released to take out the pressed block. The pressed block is pre-sintered in hydrogen, and the block is spread flat in a calcining boat, and then the calcining boat is placed in an argon tube furnace, and the argon tube furnace is evacuated and then argon gas is introduced (argon purity ≥ 99.999%, argon gas flow rate 2m 3 / h). The temperature was raised from room temperature to 1100℃ at 10℃ / min and kept for 2h, then dropped to 520℃ at 10℃ / min, and then cooled to room temperature with the furnace to obtain a tungsten-rhenium alloy with a certain bonding strength. Finally, the pre-sintered block was sintered in high-temperature argon gas, and the sintering boat with the block was placed in a graphite furnace, and then argon gas (argon purity ≥ 99.999%, argon gas flow rate 8m 3 / h). Then the temperature was raised to 2150°C at 10°C / min, kept at that temperature for 2h, then dropped to 600°C at 10°C / min, and then cooled to room temperature along with the furnace to obtain tungsten-rhenium alloy (mixed powder ratio: 100% solid-liquid mixing to prepare tungsten-rhenium powder).

[0072] Table 1 Comparison of density and shrinkage before and after sintering of Examples 1, 2, 3, 4, and 5

[0073]

[0074] See also Figure 1-4As shown in Table 1, the present invention obtains W-10 (wt%) Re mixed powder by mixing W-10 (wt%) Re powder prepared by wet chemical method and W-10 (wt%) Re powder prepared by solid-liquid mixing method in different proportions. The mixed powder is pressed and sintered to obtain tungsten-rhenium alloy prepared in Examples 1-5, and metallographic and linear shrinkage analysis is performed on the alloy.

[0075] The results show that as the proportion of tungsten-rhenium powder prepared by the wet chemical method increases, the density after sintering shows a trend of first increasing and then decreasing. When the mixed powder ratio reaches 75%, the density reaches the maximum value. The linear shrinkage rate of Example 2 after sintering is 0.2015. Compared with other embodiments, its linear shrinkage rate slightly exceeds the linear shrinkage rate range of the TZM layer after sintering (0.16-0.2), but its density after sintering is higher. Similarly, as the proportion of tungsten-rhenium alloy powder prepared by the solid-liquid mixing method increases, the grain size also increases first and then decreases. When the proportion of tungsten-rhenium alloy prepared by the wet chemical method is 25%, the maximum average grain size appears. Therefore, the present invention obtains a higher sintering density while ensuring the shrinkage rate by adjusting the mixed powder ratio, and solves the cracking problem caused by the difference in shrinkage rate between the TZM layer and the tungsten-rhenium alloy during the composite sintering process.

[0076] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A tungsten-rhenium alloy powder mixing method for controlling the shrinkage rate during double-layer metal composite sintering, characterized in that: Here are the steps: Step 1: Preparation of tungsten-rhenium precursor by wet chemical method First, add ammonium metatungstate powder into deionized water until fully dissolved, and place the solution in a magnetic stirrer for heating, adjust the rotor to a suitable speed, and heat to 100-120°C; after the temperature stabilizes, add ammonium rhenate to the solution, and after the ammonium rhenate is fully stirred and dissolved, add oxalic acid, and after the oxalic acid is completely dissolved, stabilize the temperature at 100-120°C and allow the solution to react for 3-5 hours. After the solute reaction is complete, a tungsten-rhenium precursor solution is obtained, and the solid content of the precursor solution is 25%-32%; Step 2: Spray drying the tungsten-rhenium precursor solution prepared in step 1 The working parameters of the spray drying equipment are set. The spray drying starts heating and the air inlet temperature is raised to 200-230°C. After the air outlet temperature is stable, the feed port and the tungsten-rhenium precursor solution are connected and the peristaltic pump is turned on. After the precursor solution is spray dried, the powder in the collection tank is collected to obtain the tungsten-rhenium precursor powder. Step 3: Preparation of tungsten-rhenium precursor by solid-liquid mixing A certain proportion of ammonium rhenate is dissolved in deionized water by heating, and then a certain proportion of pure tungsten powder is evenly added into the ammonium rhenate solution, requiring that the tungsten powder is completely immersed in the solution, and then the slurry tungsten powder is stirred and dried until all the water in the ammonium rhenate solution evaporates; after evaporation, the ammonium rhenate is attached to the surface of the tungsten powder particles in the form of fine particles to form a preliminary pre-alloyed W-10 (wt%) Re precursor powder; Step 4: Restore The tungsten-rhenium precursor is spread flat in a firing boat, and then the firing boat is placed in a hydrogen reduction furnace, hydrogen is introduced, and then the temperature is raised to 1000-1100°C at 8-12°C / min, and the temperature is kept for 2-4 hours, and then the temperature is reduced to 480-520°C at 8-12°C / min, and then the furnace is cooled to room temperature to obtain tungsten-rhenium alloy powder; the objects of reduction in step 4 are the tungsten-rhenium precursors prepared in steps 2 and 3, and they are reduced separately; Step 5: Mix the powder The tungsten-rhenium alloy prepared by the reduced solid-liquid method and the tungsten-rhenium alloy powder prepared by the reduced wet chemical method were mixed in different proportions, respectively: 100% wet chemical tungsten-rhenium powder; 75% wet chemical tungsten-rhenium powder, 25% solid-liquid mixed tungsten-rhenium powder; 50% wet chemical tungsten-rhenium powder, 50% solid-liquid mixed tungsten-rhenium powder; 25% wet chemical tungsten-rhenium powder, 75% solid-liquid mixed tungsten-rhenium powder; 100% solid-liquid mixed tungsten-rhenium powder; The tungsten-rhenium alloy powder prepared by solid-liquid mixing and wet chemical method was placed in a powder mixer, and the parameters were set to a speed of 700 rpm / min and a powder mixing time of 2 h; Step 6: Sintering The mold filled with tungsten-rhenium alloy powder is placed in a tablet press, and a single-side axial pressure of 650-700 MPa is applied to the mold and maintained for 1-2 minutes. The pressure is then released and the pressed block is taken out; the pressed block is pre-sintered in hydrogen and sintered in high-temperature argon to prepare tungsten-rhenium alloys with different mixed powder ratios.

2. The tungsten-rhenium alloy powder mixing method according to claim 1, characterized in that: In the step 1, the added amounts of ammonium rhenate and oxalic acid are 11.94% and 0-38% of the mass of ammonium metatungstate, respectively.

3. The tungsten-rhenium alloy powder mixing method according to claim 1, characterized in that: The working parameters of the spray drying equipment in step 2 are: inlet air temperature 200-230°C, outlet air temperature 100-120°C, atomizer speed 300-350r / min, and feed rate 1-2L / h.

4. The tungsten-rhenium alloy powder mixing method according to claim 1, characterized in that: The sintering step in step six is: First, the pressed block is pre-sintered in hydrogen, the block is laid flat in a firing boat, and then the firing boat is placed in an argon tube furnace, the argon tube furnace is evacuated and then argon is introduced; the temperature is raised from room temperature to 1100°C at 5-10°C / min and kept for 2 hours, then reduced to 480-520°C at 5-10°C / min, and then cooled to room temperature with the furnace to obtain a tungsten-rhenium alloy with a certain bonding strength; finally, the pre-sintered block is sintered in high-temperature argon, the firing boat with the block is placed in a graphite furnace, and then argon is introduced; Then increase the temperature to 2150℃ at 10-15℃ / min, keep it for 2h, decrease the temperature to 580-620℃ at 10-15℃ / min, and then cool to room temperature with the furnace to obtain tungsten-rhenium alloy.

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