Refractory metal alloy spherical powder, preparation method and application thereof

Abstract

The present application belongs to the technical field of refractory metal alloy powder preparation, and particularly relates to a kind of refractory metal alloy spherical powder and its preparation method and application. Metal oxide, activator and reducing agent are mixed to obtain a molten metal by smelting;The metal oxide includes refractory metal oxide and low melting point metal oxide;In a protective gas atmosphere, the molten metal is dispersed and atomized to form a mist-shaped molten droplet particle, which is cooled to obtain the refractory metal alloy spherical powder. The preparation method provided by the present application realizes the uniform surface alloying and spheroidization of the refractory metal alloy powder, and provides a fundamental quality guarantee for subsequent surfacing, spraying (or spray welding) or laser cladding and other applications.

Description

Technical Field

[0001] This invention belongs to the field of refractory metal alloy powder preparation technology, specifically relating to a spherical powder of refractory metal alloy, its preparation method and application. Background Technology

[0002] Refractory metal alloys are the best way to solve the thermal / oxidation protection problem of refractory metals (metals with melting points above 2000℃ are generally considered refractory metals, such as tungsten, molybdenum, niobium, tantalum, vanadium, zirconium, etc.). Currently, researchers both domestically and internationally mainly develop refractory metal alloys with excellent mechanical properties and high-temperature oxidation resistance through rational alloy composition design, or by preparing high-temperature oxidation-resistant coatings with excellent thermal / oxidation protection properties on the surface of refractory metals. Among these methods, surface coating technology can significantly improve the oxidation resistance of refractory metal alloys without significantly altering the mechanical properties of the base material, and is currently a common process for improving the high-temperature oxidation resistance of refractory metal alloys. Preparation methods mainly include embedding infiltration, slurry method, molten salt method, thermal spraying method, electro-sintering method, vapor deposition method, multi-arc ion plating method, and sputtering method.

[0003] Refractory metal alloy powders, as a type of alloy powder, show great application potential in additive manufacturing and surface hardening technologies. High-melting-point metals such as tungsten, chromium, and rhenium not only possess extremely strong heat and corrosion resistance but also maintain their structural integrity even at high temperatures. Applying refractory metal alloy powders to workpieces through methods such as surfacing, spraying (or welding), or laser cladding not only improves the workpiece's wear resistance, corrosion resistance, and oxidation resistance but also extends its service life. Therefore, refractory metal alloy powders are an excellent choice for a range of highly challenging aerospace, industrial, and scientific applications.

[0004] However, how to uniformly coat the surface of refractory metal powder with low melting point and low density metal to form a uniformly alloyed refractory metal powder, and provide more efficient and broader application prospects for downstream refractory metal alloy applications, remains a research challenge in the industry. Summary of the Invention

[0005] The purpose of this invention is to provide a spherical powder of refractory metal alloy, its preparation method and application. The spherical powder of refractory metal alloy provided by this invention realizes the uniform surface alloying and spheroidization of refractory metal alloy powder, which provides a fundamental quality guarantee for its subsequent applications such as cladding, spraying (or spray welding) or laser cladding.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing spherical powder of refractory metal alloy, comprising the following steps:

[0008] Metal oxides, activators, and reducing agents are mixed and smelted to obtain a molten metal liquid; the metal oxides include refractory metal oxides and low-melting-point metal oxides, wherein the low-melting-point metal oxides are oxides formed from metals with melting points less than 2000℃; the refractory metal oxides and low-melting-point metal oxides are formulated according to the chemical composition of the refractory metal alloy spherical powder.

[0009] In a protective gas atmosphere, the molten metal is dispersed and atomized, and the resulting atomized droplet particles are cooled to obtain the spherical powder of the refractory metal alloy.

[0010] Preferably, the dispersion atomization is centrifugal atomization, and the rotation speed of the centrifugal atomization is 8000-19000 r / min.

[0011] Preferably, the smelting involves a self-propagating combustion reaction of metal oxides, activators, and reducing agents.

[0012] Preferably, the activator includes one or more of calcium fluoride, potassium permanganate, sodium nitrate, and potassium nitrate; the activator accounts for 1 to 10% of the mass percentage of the metal oxide.

[0013] Preferably, the reducing agent includes one or more of silicon powder, magnesium powder, and aluminum powder; the reducing agent accounts for 5-30% of the mass percentage of the metal oxide.

[0014] Preferably, the melting time is ≥0.5 min.

[0015] Preferably, the refractory metal oxide includes one or more of tungsten oxide, molybdenum oxide, niobium oxide, tantalum oxide, vanadium oxide, and zirconium oxide;

[0016] The low-melting-point metal oxides include one or more of copper oxide, nickel oxide, iron oxide, chromium oxide, titanium oxide, and cobalt oxide.

[0017] The present invention provides a refractory metal alloy spherical powder prepared by the preparation method described above, comprising a refractory metal core, a transition layer of refractory metal and low melting point metal alloyed and wrapped around the surface of the refractory metal core, and a low melting point metal surface layer wrapped around the surface of the transition layer.

[0018] Preferably, the particle size of the refractory metal alloy spherical powder is 15–200 μm.

[0019] This invention provides the application of the refractory metal alloy spherical powder described above in additive manufacturing or surface hardening treatment.

[0020] This invention provides a method for preparing spherical powder of refractory metal alloy, comprising the following steps: mixing a metal oxide, an activator, and a reducing agent, and then melting the mixture to obtain a molten metal liquid; wherein the metal oxide includes refractory metal oxides and low-melting-point metal oxides, and the low-melting-point metal oxides are oxides formed from metals with melting points less than 2000℃; the refractory metal oxides and low-melting-point metal oxides are formulated according to the chemical composition of the spherical powder of refractory metal alloy; and in a protective gas atmosphere, the molten metal liquid is dispersed and atomized, and the resulting atomized droplet particles are cooled to obtain the spherical powder of refractory metal alloy. After obtaining the molten metal, this invention disperses and atomizes it. During the dispersion and atomization process, the atomized droplets formed by the molten metal, protected by a protective gas, shrink into spherical shapes due to their own surface tension and the influence of ambient temperature. Since the melting point of the refractory metal is ≥2000℃, during cooling, the refractory metal preferentially solidifies and crystallizes before the low-melting-point metal, shrinking into a spherical core under the action of surface tension. The low-melting-point metal, still in a molten state, uniformly coats the surface of the refractory metal core, ultimately forming a uniform low-melting-point metal layer on the surface of the refractory metal core. Therefore, the spherical refractory metal alloy powder prepared by the method provided by this invention achieves uniform surface alloying and sphericalization of the refractory metal alloy powder, providing fundamental quality assurance for its subsequent applications such as cladding, spraying (or spray welding), or laser cladding. The preparation method provided by this invention has low energy consumption, simple equipment and methods, and is environmentally friendly. There is no carbon dioxide emission, and only water vapor is generated in the entire reaction process, which can be recycled through cooling. At the same time, the equipment investment is small, and it can be mass-produced, which is convenient for industrial production applications. Moreover, the element balance in the entire reaction process can obtain ideal refractory metal alloy powder, which can provide a more efficient and broader application prospect for the application of high-quality refractory metal alloys.

[0021] Furthermore, in this invention, the smelting involves a self-propagating combustion reaction between a metal oxide, an activator, and a reducing agent to form the molten metal. Preferably, this invention utilizes a self-propagating combustion reaction, allowing the refractory metal to form a high-temperature molten pool through an exothermic reaction, eliminating the need for an external heat source. This short-term high-temperature melting state promotes homogenization of the alloy liquid, resulting in low production costs.

[0022] Furthermore, in this invention, the activator includes one or more of calcium fluoride, potassium permanganate, sodium nitrate, and potassium nitrate; the activator accounts for 5-30% of the mass percentage of the metal oxide. By controlling the type and mass content of the activator, this invention ensures the smooth progress of the self-propagating combustion reaction.

[0023] Furthermore, in this invention, the reducing agent includes one or more of silicon powder, magnesium powder, and aluminum powder; the reducing agent accounts for 1-10% of the mass percentage of the metal oxide. By controlling the type and mass content of the reducing agent, this invention can coordinate with the activator to ensure the smooth progress of the self-propagating combustion reaction. Attached Figure Description

[0024] Figure 1 These are micrographs of refractory metal alloy powders prepared according to embodiments of the present invention;

[0025] Figure 2 This is a flowchart illustrating the preparation of refractory metal alloy powder according to an embodiment of the present invention. Detailed Implementation

[0026] This invention provides a method for preparing spherical powder of refractory metal alloy, comprising the following steps:

[0027] Metal oxides, activators, and reducing agents are mixed and smelted to obtain a molten metal liquid; the metal oxides include refractory metal oxides and low-melting-point metal oxides, wherein the low-melting-point metal oxides are oxides formed from metals with melting points less than 2000℃; the refractory metal oxides and low-melting-point metal oxides are formulated according to the chemical composition of the refractory metal alloy spherical powder.

[0028] In a protective gas atmosphere, the molten metal is dispersed and atomized, and the resulting atomized droplet particles are cooled to obtain the spherical powder of the refractory metal alloy.

[0029] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0030] This invention involves mixing metal oxides, activators, and reducing agents, and then smelting them to obtain a molten metal liquid. The metal oxides include refractory metal oxides and low-melting-point metal oxides, wherein the low-melting-point metal oxides are oxides formed from metals with melting points less than 2000°C. The refractory metal oxides and low-melting-point metal oxides are formulated according to the chemical composition of the refractory metal alloy spherical powder.

[0031] In this invention, the metal oxide includes refractory metal oxides and low-melting-point metal oxides.

[0032] In this invention, the refractory metal oxide is an oxide formed from a metal with a melting point ≥2000℃.

[0033] In a specific embodiment of the present invention, the refractory metal oxide is preferably one or more selected from tungsten oxide, molybdenum oxide, niobium oxide, tantalum oxide, vanadium oxide, and zirconium oxide.

[0034] In this invention, the low-melting-point metal oxide preferably includes one or more of copper oxide, nickel oxide, iron oxide, chromium oxide, titanium oxide, and cobalt oxide, and more preferably includes any two of copper oxide, nickel oxide, iron oxide, chromium oxide, titanium oxide, and cobalt oxide.

[0035] In a specific embodiment of the present invention, the low-melting-point metal oxide is preferably a mixture of nickel oxide and iron oxide or a mixture of iron oxide and cobalt oxide.

[0036] In specific embodiments of the present invention, the refractory metal alloy spherical powder is preferably tungsten-nickel-iron alloy spherical powder, tungsten-iron-cobalt alloy spherical powder, or tungsten-cobalt carbide alloy spherical powder. In the present invention, when the refractory metal alloy spherical powder is preferably tungsten-cobalt carbide alloy spherical powder, the raw materials for preparing the tungsten-cobalt carbide alloy spherical powder preferably also include a carbon source, and the carbon source is preferably a carbon-containing compound.

[0037] In this invention, the activator preferably includes one or more of calcium fluoride, potassium permanganate, sodium nitrate, and potassium nitrate.

[0038] In this invention, the activator accounts for 1 to 10% of the mass percentage of the metal oxide, more preferably 2 to 7%, and even more preferably 3 to 5%.

[0039] In this invention, the reducing agent preferably includes one or more of silicon powder, magnesium powder, and aluminum powder.

[0040] In this invention, the reducing agent accounts for 5-30% of the mass percentage of the metal oxide, more preferably 8-25%, and even more preferably 10-20%.

[0041] In this invention, the smelting is preferably carried out by a self-propagating combustion reaction of metal oxides, activators and reducing agents to form the molten metal.

[0042] In this invention, the smelting is preferably carried out in a smelting system, and more preferably, the smelting is initiated by a reaction device to carry out the self-propagating combustion reaction. In this invention, the reaction temperature of the self-propagating combustion reaction is above 3400°C, which can instantly reach the melting point of sparingly soluble metals (e.g., tungsten).

[0043] In order to ensure the quality of refractory metal alloy powder, the present invention preferably sets a minimum liquid level parameter in the smelting system. When the molten liquid level drops to the set value, the program closes the flow channel gate valve, allowing the reaction slag to remain in the smelting system for cooling. The cooled slag then enters the slag treatment system for processing.

[0044] The present invention preferably utilizes the waste heat and water vapor generated in the smelting system through a cooling recovery system and reuses them in the centrifugal atomization system, thereby improving the environmental friendliness and recycling mechanism of the refractory metal alloy spherical powder preparation process of the present invention.

[0045] In this invention, the melting time is preferably ≥0.5 min. In this invention, the melting time is preferably determined based on the mass of the metal oxide raw material.

[0046] After obtaining the molten metal, the present invention disperses and atomizes the molten metal in a protective gas atmosphere, and the resulting atomized droplet particles are cooled to obtain the spherical powder of the refractory metal alloy.

[0047] In this invention, the dispersion atomization is preferably centrifugal atomization, and the rotation speed of the centrifugal atomization is preferably 8000-19000 r / min, more preferably 8500-18000 r / min.

[0048] In this invention, the preferred speed of centrifugal atomization is 9000 r / min, which yields spherical alloy powder with an average particle size of 180 μm, exhibiting high fluidity and making it suitable for the welding material industry to produce surfacing materials.

[0049] In this invention, the preferred rotation speed of the centrifugal atomization is 10,000 to 13,000 r / min, which yields spherical alloy powder with an average particle size of 45 to 150 μm, which can be applied to the spray welding industry, plasma spraying and laser spraying fields.

[0050] In this invention, the preferred rotation speed of the centrifugal atomization is 14,000 to 19,000 r / min, which yields spherical alloy powder with an average particle size of 15 to 45 μm. This powder can be applied to the 3D printing industry, additive manufacturing field, and surface hardening treatment technology.

[0051] In this invention, the protective gas is preferably an inert gas, and more preferably argon.

[0052] In this invention, the cooling is preferably rapid cooling, and there are no special requirements for the specific implementation process of the cooling.

[0053] In this invention, the dispersion atomization is preferably carried out in a centrifugal atomization system, which is equipped with an inert gas protection and an atomizing medium. The molten metal falls freely in the centrifugal atomization system, passing through a high-speed centrifugal diffuser before falling into the atomizing medium, forming mist-like molten droplets. While protected by the inert gas, these droplets are rapidly cooled and contracted into spherical shapes due to their own surface tension and the influence of ambient temperature. In this invention, the atomizing medium is a protective medium, whose main function is to prevent the atomized powder from sticking together and to slowly cool and reduce internal stress within the particles. This invention does not have any special requirements regarding the type of atomizing medium.

[0054] In this invention, since the melting point of refractory metal melt is ≥2000℃, during rapid cooling, refractory metal preferentially solidifies and crystallizes compared to other low-melting-point metals, and shrinks into a spherical shape under the action of surface tension. Other low-melting-point, low-density metals, still in a molten state, are uniformly coated on the surface of the refractory metal. Therefore, the refractory metal alloy powder prepared by this invention has a spherical or near-spherical shape. In the centrifugal atomization system, the average particle size of the alloy powder is affected by the atomizing disk rotation speed, atomizing disk diameter, and surface tension of the molten metal. Given a specific atomizing material and fixed process parameters, the particle size of the refractory metal alloy powder is controlled by controlling the rotation speed of the centrifugal diffuser in the centrifugal atomization system.

[0055] In this invention, the refractory metal alloy spherical powder obtained after cooling is preferably subjected to sequential sieving and collection. Preferably, the sieving is performed in a grading sieving system, and the collection is preferably performed in a material collection system.

[0056] The present invention provides a refractory metal alloy spherical powder prepared by the preparation method described above, comprising a refractory metal core, a transition layer of refractory metal and low melting point metal alloyed and wrapped around the surface of the refractory metal core, and a low melting point metal surface layer wrapped around the surface of the transition layer.

[0057] In this invention, the particle size of the refractory metal alloy spherical powder is 15-200 μm.

[0058] In this invention, the refractory metal alloy spherical powder has a particle size of 180 μm, has high fluidity, and is suitable for the welding material industry to produce surfacing materials.

[0059] In this invention, the particle size of the refractory metal alloy spherical powder is 45-150 μm, and it can be applied to the spray welding industry, plasma spraying and laser spraying fields.

[0060] In this invention, the particle size of the refractory metal alloy spherical powder is 15-45 μm, and it can be applied to the 3D printing industry, additive manufacturing field and surface hardening treatment technology.

[0061] This invention provides the application of the refractory metal alloy spherical powder described above in additive manufacturing or surface hardening treatment.

[0062] This invention combines self-propagating combustion technology with centrifugal atomization to produce spherical powders of refractory metal alloys, providing a method for preparing spherical powders of refractory metal alloys and their applications. The preparation method provided by this invention achieves uniform surface alloying and sphericalization of the refractory metal alloy powder, providing fundamental quality assurance for subsequent processes such as cladding, spraying (or spray welding), or laser cladding. Simultaneously, this method significantly reduces the high energy consumption and stringent material requirements of refractory metal melting, making it possible to produce low-cost, high-quality refractory metal alloy powders, enabling mass production and efficient expansion into industry application markets.

[0063] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0064] Example 1

[0065] according to Figure 2 The flowchart shown below:

[0066] Taking tungsten-iron-cobalt alloy as an example, the theoretical proportions of its components, calculated according to the mass percentage of each component, are detailed in Table 1.

[0067] A total of 1.5 kg of metal oxide raw materials (tungsten oxide, iron oxide, cobalt oxide, chromium oxide, titanium oxide, molybdenum oxide, copper oxide, and niobium oxide), activator (calcium fluoride), and reducing agent (silicon powder) were prepared. First, the various metal oxides were added to the mixing system according to the theoretical metal mass ratio (Table 1) and mixed evenly. When preparing the materials according to Table 1, the metal oxide raw materials and chemical components in Table 1 in this embodiment need to be matched with the use of metal oxides based on the overall heat absorption and release balance, and the loss of substances during the reaction process should also be considered for comprehensive evaluation. Then, the reducing agent (aluminum powder) and activator (calcium fluoride) required for self-propagation were added to the mixing system to ensure spontaneous self-propagation. The amount of reducing agent and activator added was calculated as 5% and 1% of the total weight of metal oxides, respectively, and mixed evenly.

[0068] The uniformly mixed ingredients are fed into the smelting system, where a self-propagating combustion reaction is initiated by a reaction initiation device. 1.5 kg of material undergoes a reaction process in the smelting system within 3 minutes, reaching a temperature exceeding 3400°C, instantly reaching the melting point of tungsten.

[0069] The flow channel gate valve in the smelting system is opened to release the high-temperature molten metal generated by the self-propagating reaction. This molten metal then enters the centrifugal atomization system through the flow channel opening. The system is equipped with inert gas protection and an atomizing medium. The molten metal falls freely within the centrifugal atomization system and is dispersed and atomized by a high-speed centrifugal diffuser and the atomizing medium, forming mist-like molten droplets. While protected by the inert gas, these droplets are rapidly cooled and contracted into spherical shapes due to their own surface tension and the influence of ambient temperature. During this rapid cooling process, refractory metals solidify and crystallize preferentially over other low-melting-point metals, and under the influence of surface tension, they contract into spherical shapes. Other low-melting-point, low-density metals, still in a molten state, are uniformly coated on the surface of the refractory metal. Therefore, the refractory metal alloy powder prepared in this embodiment has a spherical or near-spherical shape. The rotation speed of the centrifugal diffuser in the centrifugal atomization system is adjusted and controlled within the range of 8000–19000 r / min to obtain refractory metal alloy powder with a particle size between 15–200 μm.

[0070] The refractory metal alloy powder formed by centrifugal atomization enters the classification and sieving system for particle size classification. Then, the refractory metal alloy powder of different particle sizes is collected in the material collection system. Finally, 1 kg of spherical refractory metal alloy powder is collected; its morphology is detailed in the image below. Figure 1 By comparing the surface composition analysis of refractory metal alloy powder with the composition analysis after grinding (as shown in Tables 2 and 3), it can be clearly shown that low-melting-point metals and low-density metals are organically coated on the surface of refractory tungsten metal powder, achieving the expected pre-alloying purpose;

[0071] In order to ensure the quality of refractory metal alloy powder, this embodiment sets a minimum liquid level parameter in the smelting system. When the molten liquid level drops to the set value, the program closes the flow channel gate valve, allowing the reaction slag to remain in the smelting system for cooling. The cooled slag then enters the slag treatment system for processing. The waste heat and water vapor generated in the smelting system are recycled to the centrifugal atomization system through the cooling recovery system, improving the environmental friendliness and recycling mechanism of the process.

[0072] In this embodiment:

[0073] The centrifugal disperser rotates at 9000 r / min, producing spherical alloy powder with an average particle size of 180 μm. This powder has high fluidity and is suitable for the welding material industry, for making welding surfacing materials.

[0074] The centrifugal disperser rotates at 10,000 to 13,000 r / min, producing spherical alloy powder with an average particle size of 45 to 150 μm, which can be applied to the spray welding industry, plasma spraying and laser spraying fields.

[0075] The centrifugal disperser rotates at 14,000–19,000 r / min, producing spherical alloy powder with an average particle size of 15–45 μm, which can be applied to the 3D printing industry, additive manufacturing field, and surface hardening treatment technology.

[0076] Table 1 Comparison of Composition Analysis of Refractory Metal Alloy Powders

[0077] Theoretical ratio 60.00 28.00 10.00 0.25 0.50 0.50 0.30 0.23 0.22 Component content after grinding of ball powder 59.13 28.30 10.04 0.44 0.80 0.42 0.27 0.222 0.211 Surface component content of ball powder 32.75 52.60 10.09 2.15 0.59 0.54 0.00 0.24 0.219

[0078] Table 2 Surface composition analysis of refractory metal alloy spherical powder

[0079] Fe 52.60 0.17 W 32.75 0.18 Co 10.09 0.08 Ti 2.15 0.08 Cr 0.59 0.03 Mn 0.56 0.02 Cu 0.54 0.03 Mo 0.240 0.005 Nb 0.219 0.005

[0080] Table 3. Composition analysis of refractory metal alloy spherical powder after grinding.

[0081]

[0082]

[0083] The beneficial effects of this invention are as follows:

[0084] (1) Through the self-propagating combustion process, refractory metals form a high-temperature molten pool through self-exothermic reaction without the need for external heat source. The short-term high-temperature melting state promotes the homogenization of the alloy liquid. During the centrifugal atomization process, the different surface tensions of the molten liquid form spherical powder particles of low-melting-point metal organically coated with high-melting-point metal, forming spherical powder of refractory metal alloy, which improves the fluidity of refractory metal alloy powder. This provides a fundamental guarantee for subsequent processes such as overlay welding, spraying (or spray welding) or laser cladding, making the workpiece less prone to ablation and oxidation, and achieving the optimal combination of welding performance and service performance of the workpiece.

[0085] (2) The entire process has low energy consumption, simple equipment and environmental protection, no carbon dioxide emissions, and only water vapor is generated during the entire reaction process, which is recycled through cooling.

[0086] (3) The investment in process equipment is small, it can be mass-produced, and it is convenient for industrial production applications;

[0087] (4) The entire reaction process is elementally balanced, which can obtain ideal refractory metal alloy powder, and can provide a more efficient and broader application prospect for the application of high-quality refractory metal alloys.

[0088] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing spherical powder of a refractory metal alloy, characterized in that, Includes the following steps: A metal oxide, activator, and reducing agent are mixed and smelted. The smelting process involves a self-propagating combustion reaction between the metal oxide, activator, and reducing agent to obtain a molten metal. The metal oxide includes refractory metal oxides and low-melting-point metal oxides. The refractory metal oxides include one or more of tungsten oxide, molybdenum oxide, niobium oxide, tantalum oxide, vanadium oxide, and zirconium oxide. The low-melting-point metal oxides include one or more of copper oxide, nickel oxide, iron oxide, chromium oxide, titanium oxide, and cobalt oxide. The refractory and low-melting-point metal oxides are formulated according to the chemical composition of the refractory metal alloy spherical powder. The activator includes one or more of calcium fluoride, potassium permanganate, sodium nitrate, and potassium nitrate. The activator constitutes a significant portion of the metal... The oxide has a mass percentage content of 1-10%; the reducing agent includes one or more of silicon powder, magnesium powder, and aluminum powder; the reducing agent accounts for 5-30% of the mass percentage of the metal oxide; the molten metal is dispersed and atomized in a protective gas atmosphere, the dispersion and atomization is centrifugal atomization, and the resulting atomized droplet particles are cooled to obtain the refractory metal alloy spherical powder; the refractory metal alloy spherical powder includes a refractory metal core, a transition layer of refractory metal and low melting point metal alloyed and wrapped around the surface of the refractory metal core, and a low melting point metal surface layer wrapped around the surface of the transition layer; when the centrifugal atomization speed is 9000 r / min, the average particle size of the obtained refractory metal alloy spherical powder is 180 μm; When the centrifugal atomization speed is 10000~13000 r / min, the average particle size of the refractory metal alloy spherical powder is 45~150 μm; when the centrifugal atomization speed is 14000~19000 r / min, the average particle size of the refractory metal alloy spherical powder is 15~45 μm.

2. The preparation method according to claim 1, characterized in that, The melting time is ≥0.5 min.

3. The refractory metal alloy spherical powder prepared by the preparation method according to claim 1 or 2, characterized in that, It includes a refractory metal core, a transition layer of alloyed refractory metal and low-melting-point metal encapsulated on the surface of the refractory metal core, and a low-melting-point metal surface layer encapsulated on the surface of the transition layer; the particle size of the refractory metal alloy spherical powder is 15~200µm.

4. The application of the refractory metal alloy spherical powder according to claim 3 in additive manufacturing or surface hardening treatment.

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