阅读说明：本技术 一种高密度W-Ta-Nb系难熔固溶体合金及其制备方法 (High-density W-Ta-Nb series refractory solid solution alloy and preparation method thereof ) 是由 刘金旭 刘天宇 王欣 刘兴伟 贺川 蔡奇 冯新娅 于 2021-06-28 设计创作，主要内容包括：本发明提供了一种高密度W-Ta-Nb系难熔固溶体合金及其制备方法,涉及粉末冶金技术领域。本发明设计了一种高密度、高强度、高塑性W-Ta-Nb系难熔固溶体合金来改善W的适用性。W、Ta和Nb元素能够形成无限固溶体,并通过固溶强化实现材料强度的显著提升,同时Ta和Nb作为高塑性元素,加入到W基体中可以改善W的高温塑性,本发明的W-Ta-Nb系难熔固溶体合金还具有高密度、高致密度、高强度和高塑性等优点。(The invention provides a high-density W-Ta-Nb series refractory solid solution alloy and a preparation method thereof, relating to the technical field of powder metallurgy. The invention designs a W-Ta-Nb series refractory solid solution alloy with high density, high strength and high plasticity to improve the applicability of W. W, Ta and Nb elements can form an infinite solid solution, the material strength is obviously improved through solid solution strengthening, meanwhile, Ta and Nb are used as high-plasticity elements and added into a W matrix to improve the high-temperature plasticity of W, and the W-Ta-Nb series refractory solid solution alloy also has the advantages of high density, high strength, high plasticity and the like.)

1. A high-density W-Ta-Nb series refractory solid solution alloy comprises the following chemical components in percentage by mass: 50-95% of W, 2.5-40% of Ta and 2.5-40% of Nb; the high-density W-Ta-Nb series refractory solid solution alloy is a body-centered cubic solid solution phase.

2. The method of producing a high density W-Ta-Nb based refractory solid solution alloy according to claim 1, comprising the steps of:

mixing W powder, Ta powder and Nb powder according to the chemical composition of the high-density W-Ta-Nb series refractory solid solution alloy to obtain mixed powder;

carrying out cold isostatic pressing on the mixed powder to obtain a green body;

carrying out solid-phase sintering on the green body to obtain a sintered body;

and carrying out hot isostatic pressing on the sintered blank to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

3. The method according to claim 2, wherein the particle size of the W powder is 3 to 25 μm; the particle size of the Ta powder is 5-45 mu m, and the particle size of the Nb powder is 5-45 mu m.

4. The production method according to claim 2, wherein the cold isostatic pressing is performed at a forming pressure of 200 to 400MPa and a dwell time of 10 to 60 min.

5. The method of claim 2, wherein the solid phase sintering comprises: heating to 500 ℃ and preserving heat for 0.5-2 h, heating from 500 ℃ to 800 ℃ and preserving heat for 1-5 h, and heating from 800 ℃ to 1800-2500 ℃ and preserving heat for 2-5 h.

6. The method according to claim 5, wherein the rate of temperature rise from 500 ℃ to 800 ℃ is 1 to 5 ℃/min; the heating rate of the temperature from 800 ℃ to 1800-2500 ℃ is 1-3 ℃/min.

7. The method according to claim 2, 5 or 6, wherein the solid phase sintering is performed under vacuum conditions or under protection of a protective gas.

8. The preparation method according to claim 2, wherein the hot isostatic pressing pressure is 5-15 MPa, the heat treatment temperature is 1800-2300 ℃, and the holding pressure time is 0.5-2 h.

9. The method of manufacturing according to claim 2, wherein the hot isostatic pressing is performed under Ar gas protection.

10. The method of claim 2, wherein the mixing is by ball milling, V-type mixing, double cone mixing, three-dimensional mixing, or dual motion mixing; when ball milling mixing is adopted, the rotating speed of the ball milling mixing is 100-300 r/min, the time is 5-20 h, and the ball material ratio is (1-4): 1;

when V-shaped mixing, double-cone mixing, three-dimensional mixing or double-motion mixing is adopted, the rotating speed is 20-50 r/min, and the time is 12-48 h.

Technical Field

The invention relates to the technical field of powder metallurgy, in particular to a high-density W-Ta-Nb series refractory solid solution alloy and a preparation method thereof.

Background

Tungsten (W) is considered a powerful candidate for plasma-oriented applications due to its high sputtering threshold, melting point, tensile strength and good corrosion resistance, and has found widespread use in nuclear fusion devices. However, tungsten exhibits a high ductile-brittle transition temperature and is brittle at medium-low temperatures, which leads to premature failure and fracture of the tungsten during application due to thermal stress generated inside the part, which severely limits its application in actual industrial production.

Disclosure of Invention

The invention aims to provide a high-density W-Ta-Nb series refractory solid solution alloy and a preparation method thereof, which can improve the high-temperature plasticity of W and improve the applicability of W, and meanwhile, the W-Ta-Nb series refractory solid solution alloy also has the advantages of high density, high strength, high plasticity and the like.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a high-density W-Ta-Nb series refractory solid solution alloy which comprises the following chemical components in percentage by mass: 50-95% of W, 2.5-40% of Ta2.5-40% of Nb and 2.5-40% of Nb; the high-density W-Ta-Nb series refractory solid solution alloy is a body-centered cubic solid solution phase.

The invention provides a preparation method of the high-density W-Ta-Nb series refractory solid solution alloy, which comprises the following steps:

mixing W powder, Ta powder and Nb powder according to the chemical composition of the high-density W-Ta-Nb series refractory solid solution alloy to obtain mixed powder;

carrying out cold isostatic pressing on the mixed powder to obtain a green body;

carrying out solid-phase sintering on the green body to obtain a sintered body;

and carrying out hot isostatic pressing on the sintered blank to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

Preferably, the particle size of the W powder is 3-25 μm; the particle size of the Ta powder is 5-45 mu m, and the particle size of the Nb powder is 5-45 mu m.

Preferably, the forming pressure of the cold isostatic pressing is 200-400 MPa, and the pressure maintaining time is 10-60 min.

Preferably, the solid phase sintering comprises: heating to 500 ℃ and preserving heat for 0.5-2 h, heating from 500 ℃ to 800 ℃ and preserving heat for 1-5 h, and heating from 800 ℃ to 1800-2500 ℃ and preserving heat for 2-5 h.

Preferably, the heating rate of heating from 500 ℃ to 800 ℃ is 1-5 ℃/min; the heating rate of the temperature from 800 ℃ to 1800-2500 ℃ is 1-3 ℃/min.

Preferably, the solid-phase sintering is performed under vacuum conditions or under protection of protective gas.

Preferably, the hot isostatic pressing pressure is 5-15 MPa, the heat treatment temperature is 1800-2300 ℃, and the heat preservation and pressure maintaining time is 0.5-2 h.

Preferably, the hot isostatic pressing is performed under the protection of Ar gas.

Preferably, the mixing mode is ball milling mixing, V-shaped mixing, double cone mixing, three-dimensional mixing or double motion mixing; when ball milling mixing is adopted, the rotating speed of the ball milling mixing is 100-300 r/min, the time is 5-20 h, and the ball material ratio is (1-4): 1; when V-shaped mixing, double-cone mixing, three-dimensional mixing or double-motion mixing is adopted, the rotating speed is 20-50 r/min, and the time is 12-48 h.

The invention provides a high-density W-Ta-Nb series refractory solid solution alloy which comprises the following chemical components in percentage by mass: 50-95% of W, 2.5-40% of Ta and 2.5-40% of Nb; the high-density W-Ta-Nb series refractory solid solution alloy is a body-centered cubic solid solution phase. Because tantalum (Ta) and niobium (Nb) have higher high-temperature plasticity and neutron activation is easier to perform compared with W, the invention designs the W-Ta-Nb series refractory solid solution alloy with high density, high strength and high plasticity to improve the applicability of W. W, Ta and Nb can form an infinite solid solution, the material strength is obviously improved through solid solution strengthening, and meanwhile Ta and Nb are used as high-plasticity elements and added into the W matrix to improve the high-temperature plasticity of W.

The invention provides a preparation method of the high-density W-Ta-Nb series refractory solid solution alloy. In order to obtain an alloy with higher density in the prior art, the main preparation method is smelting-casting, and subsequent production modes such as thermal deformation and thermal treatment are combined, so that the process is excessive, the preparation process is complex, and the cost is high.

The W-Ta-Nb series refractory solid solution alloy material is prepared by taking W powder, Ta powder and Nb powder as raw materials, and the particle size and the proportion of the original metal powder are changed, so that the flexible regulation and control on the element content, the density and the mechanical property of the prepared W-Ta-Nb series alloy can be realized, and the requirements of different application environments are met.

Drawings

FIG. 1 is a microstructure photograph of a W-Ta-Nb system refractory solid solution alloy prepared in example 1 of the present invention;

FIG. 2 is a compressive stress strain curve of W-Ta-Nb based refractory solid solution alloys prepared in examples 1 to 5.

Detailed Description

The invention provides a high-density W-Ta-Nb series refractory solid solution alloy which comprises the following chemical components in percentage by mass: 50-95% of W, 2.5-40% of Ta and 2.5-40% of Nb; the high-density W-Ta-Nb series refractory solid solution alloy is a body-centered cubic solid solution phase.

In the present invention, the mass fraction of W is 50 to 95%, preferably 55 to 93%, more preferably 60 to 90%, and further preferably 65 to 85%.

In the present invention, the mass fraction of Ta is 2.5 to 40%, preferably 5 to 35%, more preferably 8 to 30%, and still more preferably 10 to 25%.

In the present invention, the mass fraction of Nb is 2.5 to 40%, preferably 5 to 35%, more preferably 8 to 30%, and still more preferably 10 to 25%.

W, Ta and Nb can form an infinite solid solution, the material strength is obviously improved through solid solution strengthening, and meanwhile Ta and Nb are used as high-plasticity elements and added into the W matrix to improve the high-temperature plasticity of W. The high-density W-Ta-Nb series refractory solid solution alloy is a body-centered cubic solid solution phase, and is favorable for obtaining higher plasticity.

The invention provides a preparation method of the high-density W-Ta-Nb series refractory solid solution alloy, which comprises the following steps:

mixing W powder, Ta powder and Nb powder according to the chemical composition of the high-density W-Ta-Nb series refractory solid solution alloy to obtain mixed powder;

carrying out cold isostatic pressing on the mixed powder to obtain a green body;

carrying out solid-phase sintering on the green body to obtain a sintered body;

and carrying out hot isostatic pressing on the sintered blank to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

According to the chemical composition of the high-density W-Ta-Nb series refractory solid solution alloy, W powder, Ta powder and Nb powder are mixed to obtain mixed powder.

In the invention, the particle size of the W powder is preferably 3-25 μm, more preferably 5-20 μm, and further preferably 10-15 μm; the particle size of the Ta powder is preferably 5-45 μm, more preferably 10-40 μm, and further preferably 15-35 μm; the particle size of the Nb powder is preferably 5-45 μm, more preferably 10-40 μm, and further preferably 15-35 μm.

In the invention, the mixing mode is preferably ball milling mixing, V-shaped mixing, double cone mixing, three-dimensional mixing or double motion mixing; when ball milling mixing is adopted, the rotation speed of the ball milling mixing is preferably 100-300 r/min, and more preferably 150-250 r/min; the time is preferably 5-20 h, and more preferably 8-16 h; the ball-to-feed ratio is preferably (1-4) to 1, more preferably (2-3): 1; when V-shaped mixing, double-cone mixing, three-dimensional mixing or double-motion mixing is adopted, the rotating speed is preferably 20-50 r/min, and more preferably 30-40 r/min; the time is preferably 12 to 48 hours, more preferably 15 to 40 hours, and further preferably 20 to 35 hours.

According to the invention, different metal powders are fully and uniformly mixed by controlling the mixing conditions, and the uniformly mixed powder can realize uniform distribution of different elements in the sintering process, so that the method is the basis of good performance.

After the mixed powder is obtained, the mixed powder is subjected to cold isostatic pressing to obtain a green body.

According to the invention, the rubber mould filled with powder is preferably placed in the cold isostatic pressing working cavity and pressed under the set process parameters.

In the invention, the forming pressure of the cold isostatic pressing is preferably 200-400 MPa, more preferably 230-360 MPa, and further preferably 250-320 MPa; the pressure maintaining time is preferably 10 to 60min, more preferably 20 to 50min, and still more preferably 30 to 40 min. The invention obtains a compact blank through cold isostatic pressing. Compared with die pressing, the cold isostatic pressing method has the advantages that the powder is subjected to three-way compressive stress in the pressing process, the obtained pressed compact is more uniform in component, and stress concentration can be greatly reduced.

After a green body is obtained, the green body is subjected to solid-phase sintering to obtain a sintered body.

In the present invention, the solid-phase sintering preferably includes: heating to 500 ℃ and preserving heat for 0.5-2 h, heating from 500 ℃ to 800 ℃ and preserving heat for 1-5 h, and heating from 800 ℃ to 1800-2500 ℃ and preserving heat for 2-5 h; more preferably, it comprises: heating to 500 ℃ and preserving heat for 0.5-1 h, heating from 500 ℃ to 800 ℃ and preserving heat for 1-2 h, and heating from 800 ℃ to 2000-2400 ℃ and preserving heat for 3-4 h.

The invention adopts segmented solid-phase sintering, the purpose of the low-temperature sintering segment (500 ℃) is to volatilize the adsorbed gas and water of the pressed compact, meanwhile, the temperature is slowly increased, the heat preservation time of the low-temperature and medium-temperature stages is set to be beneficial to the sintering densification of the green body, the high-temperature heat preservation stage (1800-2500 ℃) is the main sintering process, the diffusion and the flow among elements are fully carried out, closed pores are formed and continue to shrink, and the alloying and the densification are completed.

The temperature of the invention is preferably raised from room temperature to 500 ℃, and the heating rate is preferably 5-10 ℃. In the invention, the heating rate of heating from 500 ℃ to 800 ℃ is preferably 1-5 ℃/min, and more preferably 1-3 ℃/min; the heating rate of the temperature rise from 800 ℃ to 1800 ℃ to 2500 ℃ is preferably 1 to 3 ℃/min, and more preferably 1 ℃/min.

The invention controls the temperature rise rate in the range, and is beneficial to improving the strong plasticity of the alloy. Too fast heating rate may cause under-burning, the material is not compact, the heating rate is too slow, too long heat preservation time may cause over-burning of the material, resulting in growth of crystal grains, which is not beneficial to strong plasticity of the alloy.

In the present invention, the solid-phase sintering is preferably performed under vacuum conditions or under protection of a protective gas. The invention has no special requirement on the vacuum degree of the vacuum condition; in the present invention, the shielding gas is preferably argon; the pressure of the argon gas is preferably 0.1 MPa.

After the solid-phase sintering is completed, the solid-phase sintering method is preferably cooled to room temperature along with the furnace to obtain a sintered blank.

After the sintered blank is obtained, the sintered blank is subjected to hot isostatic pressing to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

In the present invention, the hot isostatic pressing is preferably performed in a hot isostatic pressing furnace.

In the invention, the pressure of the hot isostatic pressing is preferably 5-15 MPa, more preferably 7-13 MPa, and further preferably 8-11 MPa; the heat treatment temperature is preferably 1800-2300 ℃, more preferably 1900-2200 ℃, and further preferably 2000-2100 ℃; the heat preservation and pressure maintaining time is preferably 0.5-2 h, and more preferably 1-1.5 h.

The tungsten, tantalum and niobium in the invention are high-melting point refractory metals, the elements diffuse slowly in the sintering process, the sintering densification difficulty is high, and the hot isostatic pressing can make the material subjected to balanced pressure in all directions in the heating process and promote the densification of the material under the combined action of high temperature and high pressure. The invention obtains the alloy with high density and tissue uniformity by combining pressureless sintering with hot isostatic pressing, thereby improving the strength and plasticity of the alloy.

The high-density W-Ta-Nb based refractory solid solution alloy and the method for producing the same according to the present invention will be described in detail with reference to the following examples, which should not be construed as limiting the scope of the present invention.

Example 1

A high-density W-Ta-Nb series refractory solid solution alloy comprises the following components in percentage by mass: the preparation process comprises the following steps of (1) 90% of W, 5% of Ta and 5% of Nb:

(1) and (4) mixing the powder. The powder is mixed by adopting a high-energy ball milling method. The particle size of W powder is 3 μm, the mass fraction is 90%, the particle size of Ta powder is 25 μm, the mass fraction is 5%, the particle size of Nb powder is 10 μm, and the mass fraction is 5%. Weighing raw materials according to the component ratio, putting the raw materials into a ball milling tank, and mounting the ball milling tank on a planetary ball mill for ball milling, wherein the ball-material ratio is 1:1, the ball milling rotation speed is 200r/min, and the ball milling time is 16 h.

(2) And (5) pressing and forming. And (2) placing the mixed powder obtained in the step (1) into a rubber mold, and performing compression molding by adopting a cold isostatic pressing process, wherein the pressure is 350MPa, and the pressure maintaining time is 40 min.

(3) And (5) solid-phase sintering. And (3) placing the green body obtained by pressing in the step (2) into a sintering furnace for step-by-step pressureless sintering, wherein the step-by-step sintering process comprises the following steps: (a) heating the mixture from room temperature to 500 ℃; (b) keeping the temperature at 500 ℃ for 0.5 h; (c) heating from 500 ℃ to 800 ℃, wherein the heating rate is 1 ℃/min; (d) keeping the temperature at 800 ℃ for 1 h. (e) Heating to 2300 ℃ at 800 ℃ and preserving heat for 3 h; (f) and (5) cooling along with the furnace. Ar gas with about 0.1MPa is introduced as protective gas in the whole sintering process.

(4) And (4) hot isostatic pressing. And (4) putting the sintered blank obtained in the step (3) into a hot isostatic pressing furnace for hot isostatic pressing, introducing Ar gas, keeping the sintering temperature at 1900 ℃, the pressure at 10MPa, and keeping the temperature for 1h to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

Microstructure observation of the W-Ta-Nb-based refractory solid solution alloy prepared in example 1 was carried out, and the results are shown in FIG. 1. As can be seen from fig. 1, the alloy microstructure was uniformly dense with almost no voids.

Example 2

A high-density W-Ta-Nb series refractory solid solution alloy comprises the following components in percentage by mass: the preparation process comprises the following steps of (1) 60% of W, 30% of Ta and 10% of Nb:

(1) and (4) mixing the powder. The powder is mixed by adopting a high-energy ball milling method. The particle size of W powder is 5 μm, the mass fraction is 60%, the particle size of Ta powder is 10 μm, the mass fraction is 30%, the particle size of Nb powder is 8 μm, and the mass fraction is 10%. Weighing raw materials according to the component ratio, putting the raw materials into a ball milling tank, vacuumizing the ball milling tank by a vacuum pump for 2min, and installing the ball milling tank on a planetary ball mill for ball milling, wherein the ball-material ratio is 3:1, the ball milling rotation speed is 250r/min, and the ball milling time is 10 h.

(2) And (5) pressing and forming. And (2) placing the mixed powder obtained in the step (1) into a rubber mold, and performing compression molding by adopting a cold isostatic pressing process, wherein the pressure is 200MPa, and the pressure maintaining time is 30 min.

(3) And (5) solid-phase sintering. And (3) placing the green body obtained by pressing in the step (2) into a sintering furnace for step-by-step pressureless sintering, wherein the sintering temperature is 2200 ℃, and the heat preservation time is 3 hours. The step-by-step sintering process comprises the following steps: (a) heating the mixture from room temperature to 500 ℃; (b) keeping the temperature at 500 ℃ for 0.5 h; (c) heating from 500 ℃ to 800 ℃, wherein the heating rate is 1 ℃/min; (d) keeping the temperature at 800 ℃ for 1 h. (e) Heating to 2200 ℃ at 800 ℃ and preserving heat for 3 h; (f) and (5) cooling along with the furnace. Ar gas with about 0.1MPa is introduced as protective gas in the whole sintering process.

(4) And (4) hot isostatic pressing. And (4) putting the sintered blank obtained in the step (3) into a hot isostatic pressing furnace for hot isostatic pressing, introducing Ar gas, keeping the sintering temperature at 2100 ℃ under the pressure of 5MPa, and keeping the temperature for 1h to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

Example 3

A high-density W-Ta-Nb series refractory solid solution alloy comprises the following components in percentage by mass: the preparation process of 80% of W, 10% of Ta and 10% of Nb comprises the following steps:

(1) and (4) mixing the powder. The powder is mixed by adopting a high-energy ball milling method. The particle size of the W powder is 20 μm, the mass fraction is 80%, the particle size of the Ta powder is 30 μm, the mass fraction is 10%, and the particle size of the Nb powder is 8 μm, the mass fraction is 10%. Weighing raw materials according to the component ratio, putting the raw materials into a ball milling tank, and mounting the ball milling tank on a planetary ball mill for ball milling, wherein the ball-material ratio is 1:1, the ball milling rotation speed is 250r/min, and the ball milling time is 16 h.

(2) And (5) pressing and forming. And (2) placing the mixed powder obtained in the step (1) into a rubber mold, and performing compression molding by adopting a cold isostatic pressing process, wherein the pressure is 350MPa, and the pressure maintaining time is 40 min.

(3) And (5) solid-phase sintering. And (3) placing the green body obtained by pressing in the step (2) into a sintering furnace for step-by-step pressureless sintering, wherein the sintering temperature is 2300 ℃, and the heat preservation time is 3 hours. The step-by-step sintering process comprises the following steps: (a) heating the mixture from room temperature to 500 ℃; (b) keeping the temperature at 500 ℃ for 0.5 h; (c) heating from 500 ℃ to 800 ℃, wherein the heating rate is 1 ℃/min; (d) keeping the temperature at 800 ℃ for 1 h. (e) Heating to 2400 ℃ at 800 ℃ and preserving heat for 3 h; (f) and (5) cooling along with the furnace. Ar gas with about 0.1MPa is introduced as protective gas in the whole sintering process.

(4) And (4) hot isostatic pressing. And (4) putting the sintered blank obtained in the step (3) into a hot isostatic pressing furnace for hot isostatic pressing, introducing Ar gas, keeping the sintering temperature at 1800 ℃, keeping the pressure at 15MPa, and keeping the temperature for 2 hours to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

Example 4

A high-density W-Ta-Nb series refractory solid solution alloy comprises the following components in percentage by mass: 70% of W, 20% of Ta and 10% of Nb, and the preparation process comprises the following steps:

(1) and (4) mixing the powder. The powder is mixed by adopting a high-energy ball milling method. The particle size of W powder is 3 μm, the mass fraction is 70%, the particle size of Ta powder is 25 μm, the mass fraction is 20%, the particle size of Nb powder is 10 μm, and the mass fraction is 10%. Weighing raw materials according to the component ratio, putting the raw materials into a ball milling tank, and mounting the ball milling tank on a planetary ball mill for ball milling, wherein the ball-material ratio is 1:1, the ball milling rotation speed is 200r/min, and the ball milling time is 12 h.

(2) And (5) pressing and forming. And (2) placing the mixed powder obtained in the step (1) into a rubber mold, and performing compression molding by adopting a cold isostatic pressing process, wherein the pressure is 250MPa, and the pressure maintaining time is 20 min.

(3) And (5) solid-phase sintering. And (3) placing the green body obtained by pressing in the step (2) into a sintering furnace for step-by-step pressureless sintering, wherein the sintering temperature is 1800 ℃, and the heat preservation time is 3 hours. The step-by-step sintering process comprises the following steps: (a) heating the mixture from room temperature to 500 ℃; (b) keeping the temperature at 500 ℃ for 0.5 h; (c) heating from 500 ℃ to 800 ℃, wherein the heating rate is 1 ℃/min; (d) keeping the temperature at 800 ℃ for 1 h. (e) Heating to 1800 ℃ at 800 ℃ and preserving heat for 3 h; (f) and (5) cooling along with the furnace. Ar gas with about 0.1MPa is introduced as protective gas in the whole sintering process.

(4) And (4) hot isostatic pressing. And (4) putting the sintered blank obtained in the step (3) into a hot isostatic pressing furnace for hot isostatic pressing, introducing Ar gas, keeping the sintering temperature at 2000 ℃, keeping the pressure at 12MPa, and keeping the temperature for 1h to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

Example 5

A high-density W-Ta-Nb series refractory solid solution alloy comprises the following components in percentage by mass: 93 percent of W, 3.5 percent of Ta and 3.5 percent of Nb, and the preparation process comprises the following steps:

(1) and (4) mixing the powder. The powder is mixed by adopting a high-energy ball milling method. The particle size of W powder was 3 μm, the mass fraction was 93%, the particle size of Ta powder was 10 μm, the mass fraction was 3.5%, and the particle size of Nb powder was 8 μm, the mass fraction was 3.5%. Weighing raw materials according to the component ratio, putting the raw materials into a ball milling tank, and mounting the ball milling tank on a planetary ball mill for ball milling, wherein the ball-material ratio is 1:1, the ball milling rotation speed is 250r/min, and the ball milling time is 10 h.

(2) And (5) pressing and forming. And (2) placing the mixed powder obtained in the step (1) into a rubber mold, and performing compression molding by adopting a cold isostatic pressing process, wherein the pressure is 350MPa, and the pressure maintaining time is 40 min.

(3) And (5) solid-phase sintering. And (3) putting the green body obtained by pressing in the step (2) into a sintering furnace for step-by-step pressureless sintering, wherein the sintering temperature is 2350 ℃, and the heat preservation time is 3 hours. The step-by-step sintering process comprises the following steps: (a) heating the mixture from room temperature to 500 ℃; (b) keeping the temperature at 500 ℃ for 0.5 h; (c) heating from 500 ℃ to 800 ℃, wherein the heating rate is 1 ℃/min; (d) keeping the temperature at 800 ℃ for 1 h. (e) Heating to 2350 deg.c at 800 deg.c and maintaining for 3 hr; (f) and (5) cooling along with the furnace. Ar gas with about 0.1MPa is introduced as protective gas in the whole sintering process.

(4) And (4) hot isostatic pressing. And (4) putting the sintered blank obtained in the step (3) into a hot isostatic pressing furnace for hot isostatic pressing, introducing Ar gas, keeping the sintering temperature at 2200 ℃ and the pressure at 8MPa, and keeping the temperature for 1.5h to obtain the high-density W-Ta-Nb series refractory solid solution alloy.

Comparative example

The only difference from example 1 is that no hot isostatic pressing treatment was performed.

The alloys prepared in each of the examples and comparative examples were subjected to performance tests in which the strength and critical failure strain were measured by quasi-static compression, the test results are shown in fig. 2, and the corresponding results in fig. 2 are shown in table 1; the density and compactness were determined by archimedes drainage method, the specific test results are shown in table 1.

TABLE 1 Performance data for the alloys obtained in the examples and comparative examples

	Strength (MPa)	Critical strain to failure (%)	Density (g/cm)3)	Density (%)
					Example 1	1560	36	17.41	96.5
Example 2	1750	36	16.0	97.2
					Example 3	1700	38	18.2	95.8
Example 4	2320	＞50	16.4	98.5
					Example 5	2600	＞50	18.0	97.8
Comparative example	1015	17.9	16.5	91.3

Note: the compression process was generally not tested until 50% was reached and did not substantially fracture even after continued compression, so the critical failure strains of examples 4 and 5 of Table 1 were > 50%.

The results in Table 1 show that the W-Ta-Nb series refractory solid solution alloy prepared by the invention has the advantages of high density, high compactness, high strength, high plasticity and the like. Comparative example the resulting alloy was less dense, less strong and less plastic due to no hot isostatic pressing.

From the above embodiments, the invention provides a high-density W-Ta-Nb series refractory solid solution alloy and a preparation method thereof, which can improve the high-temperature plasticity of W and improve the applicability of W, and meanwhile, the W-Ta-Nb series refractory solid solution alloy of the invention also has the advantages of high density, high strength, high plasticity and the like.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.