Tungsten-rhenium-tantalum alloy and preparation method thereof

Abstract

The invention relates to a tungsten-rhenium-tantalum alloy and a preparation method thereof, and belongs to the technical field of refractory metal alloy preparation. The preparation method of the tungsten-rhenium-tantalum alloy comprises the following steps: (1) performing stepped heating reduction on tungsten-rhenium-tantalum powder in a reducing atmosphere to obtain powder A; (2) adding carbon powder into the powder A, and carrying out ball milling and mixing under an anti-oxidation condition to obtain powder B; and (3) pressing the powder B into a green body, and sintering in a reducing atmosphere to obtain the tungsten-rhenium-tantalum alloy. The preparation method of the tungsten-rhenium-tantalum alloy is simple and convenient in process and high in practicability, the oxygen impurity content of the prepared tungsten-rhenium-tantalum alloy is remarkably reduced, the technical problem that the oxygen content is too high in a traditional preparation process is solved, and meanwhile a new thought is provided for preparation of other refractory metal alloys.

Description

Technical Field

[0001] This invention relates to the field of refractory metal alloy preparation technology, and in particular to a tungsten-rhenium-tantalum alloy and its preparation method. Background Technology

[0002] Tungsten, due to its high density, high strength, high hardness, and good electrical and thermal conductivity, is widely used in modern industry, defense, and high-tech fields. Furthermore, due to its low sputtering yield and low neutron activation in fusion environments, it is also considered a candidate material for plasma materials. However, it suffers from drawbacks such as low-temperature brittleness, recrystallization brittleness, radiation brittleness, and a high ductile-brittle transition temperature. Appropriate addition of rhenium can improve the strength and plasticity of the alloy, enhance its processing performance, and lower the ductile-brittle transition temperature; appropriate addition of tantalum can improve the strength, hardness, and toughness of the alloy. Based on the synergistic effect of tantalum and rhenium, multi-component tungsten-rhenium-tantalum alloys are a feasible approach to optimize the microstructure and mechanical properties of tungsten-based materials.

[0003] However, tantalum is a reactive refractory metal, and surface oxidation and oxygen adsorption are highly likely to occur during powder metallurgy preparation. This oxygen contamination problem is further aggravated during subsequent sintering, adversely affecting the performance of tungsten alloys. Excessive oxygen content leads to increased brittleness of the material, significantly deteriorating its processing performance and service effectiveness. Especially at high temperatures, the impact of oxygen is more pronounced—oxygen atoms diffuse more easily to grain boundaries and defect regions of the alloy, weakening the material's high-temperature strength and thermal stability, thereby reducing its service life and reliability.

[0004] Therefore, it is crucial to develop a preparation method that can effectively control the oxygen content in tungsten-rhenium-tantalum alloys, which can provide important supplements and expansions to this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a tungsten-rhenium-tantalum alloy and its preparation method. The tungsten-rhenium-tantalum alloy preparation method provided by this invention is highly practical and can significantly reduce the oxygen impurity content of the prepared tungsten-rhenium-tantalum alloy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a method for preparing a tungsten-rhenium-tantalum alloy, comprising the following steps: (1) Tungsten-rhenium-tantalum powder was reduced by stepwise heating in a reducing atmosphere to obtain powder A; (2) Add carbon powder to powder A and ball mill and mix under anti-oxidation conditions to obtain powder B; (3) The powder B is pressed into a green blank and sintered in a reducing atmosphere to obtain the tungsten-rhenium-tantalum alloy.

[0007] The raw material tungsten-rhenium-tantalum powder used in this invention can be a mixed powder or a partially alloyed mixed powder. First, the powder is subjected to preliminary hydrogen reduction to obtain powder A with a preliminary reduced oxygen content. Then, the reduced tungsten-rhenium-tantalum powder and carbon powder are ball-milled under anti-oxidation conditions to reduce the generation of oxygen impurities and obtain powder B. After pressing powder B to obtain a green blank, it is sintered to finally obtain a tungsten-rhenium-tantalum alloy with low oxygen content.

[0008] This invention primarily reduces the oxygen content during the preparation of tungsten-rhenium-tantalum alloys by adding carbon powder. Compared to tungsten-rhenium-tantalum alloys prepared without carbon powder, the preparation method provided by this invention can reduce the oxygen content by an order of magnitude. This application adds carbon powder and ball-mills it before sintering the alloy, ensuring uniform carbon powder distribution and improving oxygen removal efficiency. Simultaneously, carbothermic reduction is performed: under high temperature and oxygen-deficient conditions, the uniformly distributed carbon powder first reduces metal oxide impurities (such as Ta₂O₅) and then generates metal. The gas generated under the reducing atmosphere overflows from the system and is carried away, thereby significantly reducing the oxygen content of the tungsten-rhenium-tantalum alloy while preparing the alloy.

[0009] The method for preparing tungsten-rhenium-tantalum alloy provided by this invention solves the technical problem of high oxygen content in traditional preparation processes, and also provides a new approach for the preparation of other refractory metal alloys. This method is simple, highly practical, and has a significant oxygen-reducing effect. The oxygen content of the tungsten-rhenium-tantalum alloy can be effectively controlled by adjusting the amount of carbon powder added, resulting in a significant improvement in alloy performance.

[0010] Preferably, in step (1), the preparation method of tungsten-rhenium-tantalum powder is as follows: tungsten salt, rhenium salt and tantalum salt are dissolved in water, and a precursor is formed by quick freezing with liquid nitrogen. Then, the precursor is subjected to vacuum freeze-drying, followed by crushing and hydrogen reduction to obtain the tungsten-rhenium-tantalum powder.

[0011] The present invention provides uniform nano-sized tungsten-rhenium-tantalum powder prepared by the above-mentioned freeze-drying method; however, tungsten-rhenium-tantalum powder prepared by sol-gel or uniform precipitation methods has the problem of excessive tantalum oxide content.

[0012] Preferably, in step (1), the tantalum content in the tungsten-rhenium-tantalum powder is ≤20% by mass.

[0013] Preferably, in step (1), the tungsten-rhenium-tantalum powder comprises tungsten, rhenium and tantalum in a mass ratio of (6-8):(1-2):(1-2).

[0014] Preferably, the mass ratio of tungsten, rhenium, and tantalum in the tungsten-rhenium-tantalum powder is 8:1:1.

[0015] Preferably, in step (1), the temperature of the stepwise heating reduction is 400-1000℃.

[0016] More preferably, in step (1), the stepwise heating reduction is specifically as follows: first, the temperature is raised to 450-550 ℃ and held for 0.5-1.5 h, then the temperature is raised to 650-750 ℃ ​​and held for 1.5-2.5 h, and finally the temperature is raised to 850-950 ℃ and held for 2.5-3.5 h.

[0017] Preferably, in step (2), the mass of the carbon powder is 0.05-1% of the tungsten-rhenium-tantalum powder.

[0018] Preferably, in step (2), the anti-oxidation condition is an inert atmosphere.

[0019] Preferably, in step (2), the ball milling can be performed using a planetary ball mill.

[0020] Preferably, in step (3), the pressing equipment is a molding press or a cold isostatic press, and the pressing mold is a stainless steel mold or a rubber sleeve.

[0021] Preferably, in step (3), the sintering temperature is 1800-2600 ℃ and the sintering time is 6-10 h.

[0022] Preferably, the reducing atmosphere is a hydrogen atmosphere.

[0023] Secondly, the present invention provides a tungsten-rhenium-tantalum alloy prepared by the above-mentioned method.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: The tungsten-rhenium-tantalum alloy preparation method provided by this invention mainly reduces the oxygen content during the preparation process by adding carbon powder, and further significantly reduces the oxygen content in the tungsten-rhenium-tantalum alloy by comprehensively controlling the amount of tantalum and carbon. The tungsten-rhenium-tantalum alloy preparation method of this invention is simple, practical, and has a significant oxygen reduction effect, which can significantly improve the alloy's performance. Attached Figure Description

[0025] Figure 1 This is a flowchart of the preparation method of the tungsten-rhenium-tantalum alloy of the present invention; Figure 2 This is a scanning electron microscope image of the tungsten-rhenium-tantalum nanopowder prepared by freeze-drying in Example 1; Figure 3 The image shows an EDS surface scan of the tungsten-rhenium-tantalum nanopowder prepared by freeze-drying in Example 1. Detailed Implementation

[0026] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available reagents and materials.

[0027] The following examples and comparative examples demonstrate the specific method for preparing nano-sized tungsten-rhenium-tantalum powder using freeze-drying: S1. Dissolve ammonium metatungstate, ammonium rhenium, and tantalum oxalate in deionized water, and control the tungsten, rhenium, and tantalum elements to meet a specific mass ratio to obtain a solution. Then, add the solution dropwise into liquid nitrogen at a rate of 5~10 ml / min, and the liquid nitrogen will quickly freeze to form a precursor. S2. Place the quick-frozen precursor solid in a vacuum freeze dryer for sublimation drying; set the cold trap temperature ≤ -45℃ and the drying time ≥ 24h, then grind and crush to obtain powder; S3. The powder is subjected to hydrogen reduction, with the hydrogen flow rate controlled at 1~5L / min, the reduction temperature raised to 800~1000℃, and the reduction time at 2~5h, to prepare the nano-sized tungsten-rhenium-tantalum powder.

[0028] Example 1 This invention provides an embodiment of a method for preparing a tungsten-rhenium-tantalum alloy. The preparation process of the tungsten-rhenium-tantalum alloy described in this embodiment is as follows: Figure 1 The details are as follows: (1) 1 kg of nano-sized tungsten-rhenium-tantalum powder was prepared by freeze-drying, wherein the mass ratio of tungsten, rhenium, and tantalum was 8:1:1. The scanning electron microscopy analysis results of the powder are as follows: Figure 2 As shown, the EDS area scan data is as follows: Figure 3 As shown, the elements are evenly distributed. Tungsten-rhenium-tantalum powder was placed in a tungsten crucible and then placed in a hydrogen reduction furnace. First, a vacuum was drawn, and then high-purity hydrogen was introduced to carry out stepwise heating hydrogen reduction: first, the temperature was raised to 500℃ and held for 1 hour, then raised to 700℃ and held for 2 hours, and finally raised to 900℃ and held for 3 hours. After cooling, powder A was obtained. (2) Add the powder A and 10g of carbon powder together into a ball mill jar, seal the ball mill jar and purge it with inert nitrogen gas to prevent oxidation, and then put it into a planetary ball mill. Ball mill at a ball-to-material ratio of 1:4 and a speed of 200rpm for 8 hours to obtain powder B. (3) Powder B is loaded into a rubber sleeve with a diameter of 30 mm and pressed on a cold isostatic pressing device to obtain a green billet of tungsten rhenium tantalum alloy; the green billet is placed in a tungsten tooling mold in a high-temperature sintering furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2250℃ and a sintering time of 9h to obtain the tungsten rhenium tantalum alloy.

[0029] Example 2 This invention provides an embodiment of a method for preparing a tungsten-rhenium-tantalum alloy. The preparation process of the tungsten-rhenium-tantalum alloy described in this embodiment is as follows: Figure 1 The details are as follows: (1) 1 kg of nano-sized tungsten-rhenium-tantalum powder was prepared by freeze-drying, wherein the mass ratio of tungsten, rhenium, and tantalum was 8:1:1. The scanning electron microscopy analysis results of the powder are as follows: Figure 2 As shown, the EDS area scan data is as follows: Figure 3 As shown, the elements are evenly distributed. Tungsten-rhenium-tantalum powder was placed in a tungsten crucible and then placed in a hydrogen reduction furnace. First, a vacuum was drawn, and then high-purity hydrogen was introduced to carry out stepwise heating hydrogen reduction: first, the temperature was raised to 500℃ and held for 1 hour, then raised to 700℃ and held for 2 hours, and finally raised to 900℃ and held for 3 hours. After cooling, powder A was obtained. (2) Add the powder A and 0.5g of carbon powder together into a ball mill jar, seal the ball mill jar and purge it with inert nitrogen gas to prevent oxidation, and then put it into a planetary ball mill. Ball mill at a ball-to-material ratio of 1:4 and a speed of 200rpm for 8 hours to obtain powder B. (3) Powder B is loaded into a rubber sleeve with a diameter of 30 mm and pressed on a cold isostatic pressing device to obtain a green billet of tungsten rhenium tantalum alloy; the green billet is placed in a tungsten tooling mold in a high-temperature sintering furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2250 ℃ and a sintering time of 9 h to obtain the tungsten rhenium tantalum alloy.

[0030] Example 3 This invention provides an embodiment of a method for preparing a tungsten-rhenium-tantalum alloy. The preparation process of the tungsten-rhenium-tantalum alloy described in this embodiment is as follows: Figure 1 The details are as follows: (1) 1 kg of nano-sized tungsten-rhenium-tantalum powder was prepared by freeze-drying, wherein the mass ratio of tungsten, rhenium, and tantalum was 8:1:1. The scanning electron microscopy analysis results of the powder are as follows: Figure 2 As shown, the EDS area scan data is as follows: Figure 3 As shown, the elements are evenly distributed. Tungsten-rhenium-tantalum powder was placed in a tungsten crucible and then placed in a hydrogen reduction furnace. First, a vacuum was drawn, and then high-purity hydrogen was introduced to carry out stepwise heating hydrogen reduction: first, the temperature was raised to 500℃ and held for 1 hour, then raised to 700℃ and held for 2 hours, and finally raised to 900℃ and held for 3 hours. After cooling, powder A was obtained. (2) Add the powder A and 30g of carbon powder together into a ball mill jar, seal the ball mill jar and purge it with inert nitrogen gas to prevent oxidation, and then put it into a planetary ball mill. Ball mill at a ball-to-material ratio of 1:4 and a speed of 200rpm for 8 hours to obtain powder B. (3) Powder B is loaded into a rubber sleeve with a diameter of 30 mm and pressed on a cold isostatic pressing device to obtain a green billet of tungsten rhenium tantalum alloy; the green billet is placed in a tungsten tooling mold in a high-temperature sintering furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2250 ℃ and a sintering time of 9 h to obtain the tungsten rhenium tantalum alloy.

[0031] Example 4 This invention provides an embodiment of a method for preparing a tungsten-rhenium-tantalum alloy. The preparation process of the tungsten-rhenium-tantalum alloy described in this embodiment is as follows: Figure 1 The details are as follows: (1) 1 kg of nano-sized tungsten-rhenium-tantalum powder was prepared by freeze drying, wherein the mass ratio of tungsten, rhenium and tantalum was 6:2:2; Tungsten-rhenium-tantalum powder was placed in a tungsten crucible and then placed in a hydrogen reduction furnace. First, a vacuum was drawn, and then high-purity hydrogen was introduced to carry out stepwise heating hydrogen reduction: first, the temperature was raised to 500℃ and held for 1 hour, then raised to 700℃ and held for 2 hours, and finally raised to 900℃ and held for 3 hours. After cooling, powder A was obtained. (2) Add the powder A and 10g of carbon powder together into a ball mill jar, seal the ball mill jar and purge it with inert nitrogen gas to prevent oxidation, and then put it into a planetary ball mill. Ball mill at a ball-to-material ratio of 1:4 and a speed of 200rpm for 8 hours to obtain powder B. (3) Powder B is loaded into a rubber sleeve with a diameter of 30 mm and pressed on a cold isostatic pressing device to obtain a green billet of tungsten rhenium tantalum alloy; the green billet is placed in a tungsten tooling mold in a high-temperature sintering furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2250 ℃ and a sintering time of 9 h to obtain the tungsten rhenium tantalum alloy.

[0032] Example 5 This invention provides an embodiment of a method for preparing a tungsten-rhenium-tantalum alloy. The preparation process of the tungsten-rhenium-tantalum alloy described in this embodiment is as follows: Figure 1 The details are as follows: (1) 1 kg of nano-sized tungsten-rhenium-tantalum powder was prepared by freeze drying, wherein the mass ratio of tungsten, rhenium and tantalum was 5:2.5:2.5; Tungsten-rhenium-tantalum powder was placed in a tungsten crucible and then placed in a hydrogen reduction furnace. First, a vacuum was drawn, and then high-purity hydrogen was introduced to carry out stepwise heating hydrogen reduction: first, the temperature was raised to 500℃ and held for 1 hour, then raised to 700℃ and held for 2 hours, and finally raised to 900℃ and held for 3 hours. After cooling, powder A was obtained. (2) Add the powder A and 10g of carbon powder together into a ball mill jar, seal the ball mill jar and purge it with inert nitrogen gas to prevent oxidation, and then put it into a planetary ball mill. Ball mill at a ball-to-material ratio of 1:4 and a speed of 200rpm for 8 hours to obtain powder B. (3) Powder B is loaded into a rubber sleeve with a diameter of 30 mm and pressed on a cold isostatic pressing device to obtain a green billet of tungsten rhenium tantalum alloy; the green billet is placed in a tungsten tooling mold in a high-temperature sintering furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2250 ℃ and a sintering time of 9 h to obtain the tungsten rhenium tantalum alloy.

[0033] Comparative Example 1 The preparation method of the tungsten-rhenium-tantalum alloy in Comparative Example 1 includes the following steps: (1) 1 kg of nano-sized tungsten-rhenium-tantalum powder was prepared by freeze-drying, wherein the mass ratio of tungsten, rhenium, and tantalum was 8:1:1. The scanning electron microscopy analysis results of the powder are as follows: Figure 2 As shown, the EDS area scan data is as follows: Figure 3 As shown, the elements are evenly distributed. Tungsten-rhenium-tantalum powder was placed in a tungsten crucible and then placed in a hydrogen reduction furnace. First, a vacuum was drawn, and then high-purity hydrogen was introduced to carry out stepwise heating hydrogen reduction: first, the temperature was raised to 500℃ and held for 1 hour, then raised to 700℃ and held for 2 hours, and finally raised to 900℃ and held for 3 hours. After cooling, powder A was obtained. (2) Powder A is loaded into a rubber sleeve with a diameter of 30 mm and pressed on a cold isostatic pressing device to obtain a green billet of tungsten rhenium tantalum alloy; the green billet is placed in a tungsten tooling mold in a high-temperature sintering furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2250 ℃ and a sintering time of 9 h to obtain the tungsten rhenium tantalum alloy.

[0034] Comparative Example 2 The preparation method of the tungsten-rhenium-tantalum alloy in Comparative Example 2 includes the following steps: (1) 1 kg of nano-sized tungsten-rhenium-tantalum powder was prepared by freeze-drying, wherein the mass ratio of tungsten, rhenium, and tantalum was 8:1:1. The scanning electron microscopy analysis results of the powder are as follows: Figure 2 As shown, the EDS area scan data is as follows: Figure 3 As shown, the elements are evenly distributed. Tungsten-rhenium-tantalum powder was placed in a tungsten crucible and then placed in a hydrogen reduction furnace. First, a vacuum was drawn, and then high-purity hydrogen was introduced to carry out stepwise heating hydrogen reduction: first, the temperature was raised to 500℃ and held for 1 hour, then raised to 700℃ and held for 2 hours, and finally raised to 900℃ and held for 3 hours. After cooling, powder A was obtained. (2) Powder A is manually mixed with 10 g of carbon powder to obtain powder B; (3) Powder B is loaded into a rubber sleeve with a diameter of 30 mm and pressed on a cold isostatic pressing device to obtain a green billet of tungsten rhenium tantalum alloy; the green billet is placed in a tungsten tooling mold in a high-temperature sintering furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2250 ℃ and a sintering time of 9 h to obtain the tungsten rhenium tantalum alloy.

[0035] Example of effect To investigate the oxygen content of the tungsten-rhenium-tantalum alloy prepared by the method provided in this invention, the oxygen content of the raw material powder and the prepared tungsten-rhenium-tantalum alloy were tested in the examples and comparative examples, respectively. The methods were performed according to YS / T1563.6 Chemical Analysis Methods for Molybdenum-Rhenium Alloys, Part 6: Determination of Oxygen and Nitrogen Content using the inert gas melting-infrared absorption method and the thermal conductivity method. The results are shown in Table 1 below.

[0036] Table 1 Comparison of oxygen content tests in the examples and comparative examples. As shown in Table 1: The tungsten-rhenium-tantalum alloy preparation method provided in this invention can significantly reduce the oxygen content in the raw material powder: by gradually reducing the oxygen content and reducing the generation of impurity oxygen in the preparation steps, the oxygen content of the tungsten-rhenium-tantalum alloy is reduced by an order of magnitude, thereby significantly improving the performance of the tungsten-rhenium-tantalum alloy.

[0037] Compared to Example 1, the lack of carbon powder treatment in Comparative Example 1 resulted in a significant increase in oxygen content in the alloy, leading to increased brittleness and a significant deterioration in its processing performance and usability. In Comparative Example 2, the absence of anti-oxidation operations and ball milling mixing in the preparation steps resulted in a significant decrease in oxygen removal rate in the tungsten-rhenium-tantalum alloy, which is related to the introduction of oxide impurities and uneven carbon distribution in the process.

[0038] Comparing Examples 1-5, it can be seen that in the tungsten-rhenium-tantalum alloy preparation method used in this application, the oxygen content of the prepared tungsten-rhenium-tantalum alloy can be further controlled by adjusting the content of added carbon powder and the tantalum element content in the raw material powder, thereby further improving the application performance, processing performance and use effect of the alloy.

[0039] In summary, this invention provides a method for preparing a tungsten-rhenium-tantalum alloy. By adding carbon powder, the oxygen content during the alloy preparation process is reduced. Furthermore, by comprehensively controlling the amounts of tantalum and carbon, the oxygen content in the tungsten-rhenium-tantalum alloy can be significantly reduced further. The tungsten-rhenium-tantalum alloy preparation method of this invention is simple, highly practical, and has a significant oxygen-reducing effect, preventing deterioration of the alloy's processing performance and improving its overall performance.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a tungsten-rhenium-tantalum alloy, characterized in that, Includes the following steps: (1) Tungsten-rhenium-tantalum powder was reduced by stepwise heating in a reducing atmosphere to obtain powder A; (2) Add carbon powder to powder A and ball mill and mix under anti-oxidation conditions to obtain powder B; (3) The powder B is pressed into a green blank and sintered in a reducing atmosphere to obtain the tungsten-rhenium-tantalum alloy.

2. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 1, characterized in that, In step (1), the preparation method of tungsten-rhenium-tantalum powder is as follows: tungsten salt, rhenium salt and tantalum salt are dissolved in water, and a precursor is formed by quick freezing with liquid nitrogen. Then the precursor is subjected to vacuum freeze-drying, followed by crushing and hydrogen reduction to obtain the tungsten-rhenium-tantalum powder.

3. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 1, characterized in that, In step (1), the tantalum content in the tungsten-rhenium-tantalum powder is ≤20% by mass.

4. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 1, characterized in that, In step (1), the tungsten-rhenium-tantalum powder comprises tungsten, rhenium and tantalum elements in a mass ratio of (6-8):(1-2):(1-2).

5. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 1, characterized in that, In step (1), the temperature for the stepwise heating reduction is 400-1000℃.

6. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 5, characterized in that, In step (1), the stepwise heating reduction is as follows: first, heat to 450-550 ℃ and hold for 0.5-1.5 h, then heat to 650-750 ℃ ​​and hold for 1.5-2.5 h, and finally heat to 850-950 ℃ and hold for 2.5-3.5 h.

7. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 1, characterized in that, In step (2), the mass of the carbon powder is 0.05-1% of the tungsten-rhenium-tantalum powder.

8. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 1, characterized in that, In step (3), the sintering temperature is 1800-2600 ℃ and the sintering time is 6-10 h.

9. The method for preparing the tungsten-rhenium-tantalum alloy as described in claim 1, characterized in that, The reducing atmosphere is a hydrogen atmosphere.

10. The tungsten-rhenium-tantalum alloy prepared by the method according to any one of claims 1-9.

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