Method for removing oxygen from refractory metal

Abstract

The invention provides a method for removing oxygen from refractory metal, and relates to the technical field of metal smelting. The method for removing oxygen from the refractory metal comprises the steps that the refractory metal is placed in a vacuum cavity to be heated; wherein the heating temperature is lower than the melting point of the refractory metal; bubble cores are formed on the surface of the refractory metal through a focused ultrasound system, and plasma discharge is induced on the surface of the refractory metal through a pulse microwave source; volatile substances in the vacuum cavity are extracted; and under the condition that the oxygen concentration in the vacuum cavity is reduced to be below the oxygen concentration threshold value, heating is stopped, the focused ultrasound system and the pulse microwave source are closed, and the oxygen-removed refractory metal is obtained after cooling. According to the invention, the deoxidation effect of refractory metal can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of metal smelting, and in particular to a method for removing oxygen from refractory metals. Background Art

[0002] Refractory metals, due to their high melting points, excellent high-temperature strength, and corrosion resistance, are widely used in aerospace, nuclear power, electronic devices, and high-temperature equipment. However, during smelting and processing, these metals readily react with oxygen, forming oxide inclusions or dissolved oxygen. This increases the material's brittleness, decreases its ductility, and compromises its high-temperature performance and long-term stability. Therefore, deoxidation technology is a key step in improving the performance of refractory metals.

[0003] Currently, the methods for removing oxygen from refractory metals include vacuum melting, electron beam melting, and hydrogen reduction. However, these methods generally have the problem of poor deoxidation effect.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0005] The purpose of the present disclosure is to provide a method for deoxidizing refractory metals, thereby overcoming the problem of poor deoxidation effect in refractory metals at least to a certain extent.

[0006] The present disclosure provides a method for deoxygenating refractory metals, comprising: placing the refractory metal in a vacuum chamber and heating it; wherein the heating temperature is lower than the melting point of the refractory metal; forming bubble nuclei on the surface of the refractory metal using a focused ultrasonic system, and inducing plasma discharge on the surface of the refractory metal using a pulsed microwave source; extracting volatile substances from the vacuum chamber; and when the oxygen concentration in the vacuum chamber drops below an oxygen concentration threshold, stopping the heating and turning off the focused ultrasonic system and the pulsed microwave source, and obtaining the deoxygenated refractory metal after cooling.

[0007] Optionally, placing the refractory metal in the vacuum chamber for heating includes: cutting the original refractory metal to be deoxidized into blocks, and polishing the blocks of the original refractory metal to be deoxidized to obtain the refractory metal; wherein the polishing method includes sandpaper polishing and / or chemical polishing; placing the refractory metal in a quartz crucible, and placing the quartz crucible in the vacuum chamber; and heating while reducing the gas pressure in the vacuum chamber to below a gas pressure threshold.

[0008] Optionally, the method further includes: adjusting the ultrasonic power of the focused ultrasound system and / or the microwave pulse width of the pulse microwave source in real time based on the oxygen concentration in the vacuum cavity through an energy coupling control system.

[0009] Optionally, the operating frequency of the focused ultrasound system is 20 kHz to 40 kHz.

[0010] Optionally, the operating power of the pulse microwave source is 500W to 1000W.

[0011] Optionally, extracting the volatile substances in the vacuum chamber includes: extracting the volatile oxides in the vacuum chamber by a vacuum pump assembly, so that the pressure of the vacuum chamber is 5×10 -4 Pa to 1×10 -3 Pa; among them, volatile oxides are produced by the combination of surface oxides of refractory metals and active oxygen atoms.

[0012] Optionally, the method further comprises: transporting the volatile oxides to a condensation system for recovery.

[0013] Optionally, heating is stopped and the focused ultrasonic system and the pulsed microwave source are turned off, and the deoxygenated refractory metal is obtained after cooling, including: stopping heating and turning off the focused ultrasonic system and the pulsed microwave source, injecting protective gas into the vacuum cavity, and cooling by water cooling or liquid nitrogen quenching to obtain the deoxygenated refractory metal.

[0014] Optionally, the cooling rate is 10° C. / s to 50° C. / s.

[0015] Optionally, the method further includes: acquiring property information of the refractory metal and obtaining process parameter information of the deoxidized refractory metal, and obtaining a deoxidation parameter library for the refractory metal after data binding.

[0016] In the exemplary embodiment of the present disclosure, on the one hand, through the synergistic effect of ultrasound and plasma, the oxides on the metal surface can be efficiently decomposed in a vacuum environment, deep deoxidation can be achieved, the deoxidation efficiency is increased, and the deoxidation effect is improved. On the other hand, given that the heating temperature of the disclosed solution is lower than the melting point of the refractory metal, this low-temperature energy coupling process can effectively reduce energy consumption while avoiding the problems of metal overburning and grain coarsening, thereby ensuring the original mechanical properties of the material. On the other hand, the disclosed solution can accurately control the deoxidation process, reduce thermal damage to the metal matrix, and enable the refractory metal after deoxidation to still maintain excellent physical and chemical properties, providing a reliable material basis for subsequent processing and application.

[0017] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0019] Figure 1 A flow chart schematically illustrates a method for removing oxygen from a refractory metal according to an exemplary embodiment of the present disclosure.

[0020] Figure 2 The flowchart of the deoxidation process of tungsten in the present disclosure is schematically shown. DETAILED DESCRIPTION

[0021] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present disclosure will be more comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or that other methods, processes, steps, etc. may be employed. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0022] In addition, the accompanying drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Identical reference numerals in the drawings represent identical or similar parts, and thus their repeated descriptions will be omitted. The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all steps. For example, some steps may be decomposed, while others may be combined or partially combined. Therefore, the actual order of execution may vary depending on the actual situation.

[0023] Refractory metals generally refer to metals with melting points above 1650°C, including tungsten (W), molybdenum (Mo), tantalum (Ta), niobium (Nb), rhenium (Re), and chromium (Cr). These metals possess numerous exceptional properties, such as their high melting points, which enable them to maintain stable physical and chemical properties even at high temperatures; their high hardness and excellent wear resistance, which make them suitable for manufacturing wear-resistant components; and their excellent electrical and thermal conductivity, which lends them to important applications in electronics and heat exchange. Consequently, refractory metals are widely used in numerous high-tech fields and critical industrial applications, including aerospace, electronics, energy, metallurgy, and machinery manufacturing.

[0024] Solutions for removing oxygen from some refractory metals include vacuum melting, electron beam melting, and hydrogen reduction. Vacuum melting volatilizes metal oxides (such as WO3, MoO3, etc.) under high temperature and low pressure, but is limited by the oxide volatilization rate and the surface tension of the melt, and the ability to control the oxygen content is limited, usually requiring a multi-stage melting process. Electron beam melting uses a high-energy electron beam to bombard the metal surface, achieving localized high temperatures to decompose the oxides. This has a high deoxidation efficiency, but it has stringent equipment requirements and high energy consumption, making it difficult to apply on a large scale. Hydrogen reduction generates water vapor through the reaction of hydrogen with oxides (such as MoO3 + 3H2 → Mo + 3H2O). It is suitable for pre-deoxidation of powder metallurgy precursors, but residual hydrogen may introduce new impurities.

[0025] For high-melting-point metals (such as tungsten and molybdenum), carbothermal reduction uses a carbonaceous reducing agent (such as graphite) to generate CO gas at high temperatures for deoxidation. However, residual carbon may form carbides, affecting material purity. Furthermore, molten salt electrolysis utilizes a chloride or fluoride molten salt system to electrochemically reduce metal oxides, but this suffers from low electrolysis efficiency and molten salt contamination.

[0026] In view of this, the embodiments of the present disclosure provide a new method for deoxidizing refractory metals to solve or at least alleviate the problem of poor overall effect of deoxidation in refractory metals at present.

[0027] Figure 1 The flow chart of the method for removing oxygen from refractory metal according to an exemplary embodiment of the present disclosure is schematically shown. Figure 1 The method for removing oxygen from a refractory metal according to an exemplary embodiment of the present disclosure may include the following steps: S12. Placing a refractory metal in a vacuum chamber and heating the metal; wherein the heating temperature is lower than the melting point of the refractory metal.

[0028] According to some embodiments of the present disclosure, the refractory metal may be directly placed in a quartz crucible, and the quartz crucible may be moved into a vacuum chamber for heating.

[0029] According to other embodiments of the present disclosure, first, the original refractory metal to be deoxidized can be cut into blocks to ensure uniformity of subsequent processing. Next, the blocks of the original refractory metal to be deoxidized are polished to obtain the refractory metal of the present disclosure. Then, the refractory metal is placed in a quartz crucible, and the quartz crucible is placed in a vacuum chamber. Subsequently, the gas in the vacuum chamber is extracted, and heating is performed while the pressure in the vacuum chamber is reduced to below a pressure threshold. The pressure threshold is, for example, 1×10 -3 Pa, this disclosure does not limit its value.

[0030] Specifically, sandpaper or chemical polishing can be used to remove the oxide film on the metal surface to ensure that the deoxidation reaction can proceed evenly. In addition, the air pressure is reduced to prevent oxygen from re-penetrating into the metal during the deoxidation process.

[0031] For heating, the refractory metal can be heated to 800°C to 1200°C using a resistance furnace or induction heating. It's important to note that the heating temperature varies depending on the type of refractory metal being treated, as the melting point of each refractory metal may vary. However, the proposed method requires the heating temperature to be below the melting point of the refractory metal, thereby preventing splashing of the liquid metal and affecting the deoxidation effect.

[0032] S14. Bubble nuclei are formed on the surface of refractory metals using a focused ultrasound system and plasma discharge is induced on the surface of refractory metals using a pulsed microwave source.

[0033] When the heating temperature reaches an appropriate range (e.g., 800°C to 1200°C), the focused ultrasound system is activated. The operating frequency of the focused ultrasound system is set to 20kHz to 40kHz, depending on the acoustic characteristics of the refractory metal. This system forms dense micron-sized bubble nuclei on the surface of the refractory metal, a phenomenon known as cavitation. These bubbles, when ruptured, generate localized high pressure and high temperature, breaking down the oxide layer on the metal surface and promoting oxygen diffusion.

[0034] Meanwhile, a pulsed microwave source is activated, with a frequency set to, for example, 2.45 GHz and an operating power controlled between 500 W and 1000 W. This pulsed microwave source can induce plasma discharge on the metal surface, causing high-energy electrons (with energies of approximately 10 eV) in the plasma to collide with oxygen molecules, breaking them down into reactive oxygen atoms.

[0035] The focused ultrasound system may be a high-intensity focused ultrasound (HIFU) device, and the pulsed microwave source may be a 2.45 GHz magnetron (with a pulse modulation frequency of 1 kHz and a power of 500 W to 1000 W).

[0036] According to some embodiments of the present disclosure, during the reaction process, the energy coupling control system can also adjust the ultrasonic power of the focused ultrasound system and / or the microwave pulse width of the pulsed microwave source in real time based on the oxygen concentration in the vacuum cavity to ensure efficient superposition of cavitation and plasma energy.

[0037] Specifically, the energy coupling control system can integrate a spectrometer, an infrared thermal imager, an oxygen sensor (such as a mass spectrometer or a residual gas analyzer), etc. For example, when it is detected that the oxygen concentration in the vacuum chamber drops below 10ppm, the ultrasonic power is adjusted to 200W. For another example, when the bubble density is lower than the threshold, the ultrasonic power can be increased in a gradient, such as increasing by 50W every 5s until the cavitation sound pressure reaches saturation. For another example, at O + When the spectral line intensity decreases, the pulse width can be extended, for example, from 50μs to 80μs. Strategies such as improving the plasma ionization efficiency can also be employed.

[0038] By adjusting the ultrasonic power and microwave pulse width in real time through the energy coupling control system, the deoxidation process can be precisely controlled. This not only improves the deoxidation effect, but also makes the entire process more stable and reliable.

[0039] S16. Evacuate volatile substances from the vacuum chamber.

[0040] According to some embodiments of the present disclosure, the volatile oxides in the vacuum chamber can be extracted by a vacuum pump group to make the pressure of the vacuum chamber be between 5×10 -4 Pa to 1×10 -3 Pa, to avoid secondary oxidation. The volatile oxides are generated by the combination of the surface oxides of the refractory metal and active oxygen atoms. That is, through the synergistic effect of the ultrasound and plasma scheme in step S14, the oxides on the metal surface can combine with the active oxygen atoms to generate low-boiling-point volatile oxides.

[0041] It should be noted that the vacuum pump group can be started at the same time as the focused ultrasound system and the pulsed microwave source are started.

[0042] In addition, the extracted volatile oxygenates can be sent to a condensation system for recovery.

[0043] During the extraction of volatile oxide products, the vacuum pump unit continuously extracts the volatile oxides and maintains negative pressure within the vacuum chamber, effectively preventing secondary oxidation. The extracted volatile oxides can also be recovered through the condensation system, achieving resource reuse and helping to reduce production costs.

[0044] S18. When the oxygen concentration in the vacuum chamber drops below a threshold oxygen concentration, heating is stopped and the focused ultrasonic system and pulsed microwave source are turned off, and the deoxygenated refractory metal is obtained after cooling.

[0045] In the exemplary embodiment of the present disclosure, different refractory metals correspond to different oxygen concentration thresholds, and the present disclosure does not limit the specific values thereof.

[0046] According to some embodiments of the present disclosure, heating is stopped, the focused ultrasound system and pulsed microwave source are turned off, a protective gas (such as argon) is injected into the vacuum chamber, and cooling is performed by water cooling or liquid nitrogen quenching to obtain a deoxygenated refractory metal. The cooling rate is 10°C / s to 50°C / s.

[0047] After the deoxidized microstructure is fixed by cooling, appropriate tests can be performed. For example, the oxygen content of the deoxidized metal can be measured using Laser-Induced Breakdown Spectroscopy (LIBS) or X-ray Fluorescence (XRF), while the oxide removal effect and the presence of grain boundary defects can be verified using Scanning Electron Microscope (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS).

[0048] Furthermore, ultrasonic power, microwave frequency, and reaction time can be adjusted based on test results, creating a standardized parameter library for different refractory metals to optimize the deoxidation process and improve metal quality. Specifically, the refractory metal's property information and process parameter information for deoxidizing the refractory metal are obtained and bound together to create a deoxidation parameter library for the refractory metal. This property information includes, for example, the refractory metal's type and production batch.

[0049] Advanced technologies such as laser-induced breakdown spectroscopy and X-ray fluorescence are used to measure the oxygen content of the deoxidized metal. Scanning electron microscopy and energy dispersive spectroscopy are used to verify oxide removal and grain boundary defects, further ensuring deoxidation quality and product reliability. This intelligent control method and resource recovery mechanism give this disclosure broader application prospects and higher economic value in the field of refractory metal deoxidation.

[0050] Reference below Figure 2 The exemplary embodiments of the present disclosure will be described using tungsten as an example.

[0051] In step S202 , the tungsten rod is cut into tungsten blocks, and the tungsten blocks are polished.

[0052] First, the tungsten rod can be cut into 5mm to 10mm tungsten blocks to ensure uniformity and consistency in subsequent processing.

[0053] Next, each tungsten block can be polished using, for example, 600-grit sandpaper to remove the oxide layer attached to the surface, as well as burrs and microcracks caused by cutting. The oxide layer not only affects the material's appearance but can also reduce its mechanical properties and corrosion resistance. Sanding effectively improves surface roughness, laying a good foundation for subsequent processing.

[0054] Since mechanical grinding may not be able to completely remove the oxide layer at the microscopic level, chemical cleaning methods can also be used.

[0055] Specifically, tungsten blocks can be immersed in a mixture of hydrofluoric acid and nitric acid in a specific ratio (for example, a 1:5 mass ratio) for 1 to 3 minutes. This acid mixture effectively penetrates and dissolves the microscopic oxide layer on the tungsten surface. Furthermore, due to the acid's selectivity and controlled reaction rate, excessive corrosion of the substrate material is avoided. After treatment, the block is rinsed with clean water to remove any residual acid and then dried to ensure no water stains remain on the surface to prevent re-oxidation.

[0056] In step S204 , the tungsten block is placed in a quartz crucible and transferred to a vacuum chamber.

[0057] In the disclosed embodiments, the quartz crucible is lined with a boron nitride (BN) coating. The BN coating, due to its excellent high-temperature and corrosion resistance, effectively protects the quartz crucible from chemical attack at high temperatures. After the crucible is sealed, it is transferred to a vacuum chamber.

[0058] In step S206, a mechanical pump is used to pump the pressure of the vacuum chamber to 1×10 -4 Pa and stabilize for 30 minutes.

[0059] This process can ensure the high purity of the processing environment and avoid the interference of impurities such as oxygen and water vapor on the processing process.

[0060] In step S208, the temperature is raised using a resistance furnace until it reaches 1000°C.

[0061] For tungsten, although 1000°C is well below its melting point (3422°C), it is sufficient to allow residual gases and volatile impurities to escape, further purifying the material. Furthermore, a 20-minute holding period at 1000°C is recommended to ensure that all removable gases are fully released.

[0062] It should be noted that 1000° C. is only an exemplary description. The present disclosure selects the temperature only to ensure that it is lower than the melting point of the material, and does not limit the specific value.

[0063] In step S210 , a surface modification process under the combined action of ultrasound and microwaves is performed, and the vacuum cavity is evacuated.

[0064] The focused ultrasound system's frequency can be modulated to 30kHz, with the power initially set to 500W. The distance between the ultrasound source and the tungsten surface is kept within 5cm to ensure efficient and uniform energy transfer. Ultrasonic waves form dense, micron-sized bubble nuclei on the metal surface. These bubbles rapidly expand and burst under the influence of ultrasound, generating transient high pressure (over 1000 bar) and high temperature (over 5000K). These extreme conditions effectively destroy and remove the oxide layer on the tungsten surface.

[0065] On the other hand, the frequency of the pulsed microwave source can be fixed at 2.45 GHz, the power can be set to 800 W, and the pulse modulation frequency can be set to 1 kHz (duty cycle is 50%). The role of microwaves is to induce plasma discharge on the metal surface, generating high-energy electrons. These electrons can collide with oxygen molecules and decompose them into active oxygen atoms (O + ), and then participate in the chemical reaction and remove the oxide layer. The oxygen molecules mentioned here come from oxygen atoms dissolved in the metal lattice gaps and oxygen atoms distributed in tiny forms inside or on the surface of the metal. The specific chemical reaction formula is as follows:

[0066] Among them, there may be a situation of conversion to CO2, although the specific generation path of CO2 in this reaction system may involve a more complex chemical reaction process.

[0067] In addition, in order to further achieve reaction control, an energy coupling control system can be configured in some embodiments. The energy coupling control system can detect the oxygen content of volatile gases in the vacuum chamber in real time, and its detection limit is 1ppm. For example, once it is detected that the oxygen concentration in the vacuum chamber drops below 10ppm, the energy coupling control system can switch the system to a low-power maintenance mode. At this time, the ultrasonic frequency can be adjusted to 200W and the microwave power is adjusted to 400W to maintain the stability of the reaction environment while avoiding excessive processing. Specifically, the energy coupling control system can send control instructions to the focused ultrasound system and the pulsed microwave source respectively to adjust the working parameters.

[0068] The gaseous byproducts generated during the reaction, such as CO2 and possible MgO vapor (trace Mg elements are introduced as catalysts and impurities during the treatment process), are continuously pumped out by a Rhodes pump and transported to the condensation system to maintain the negative pressure in the chamber at 1×10 -3 Pa or less, thereby effectively preventing the tungsten block from being secondary oxidized.

[0069] In step S212 , when the oxygen concentration in the vacuum chamber drops below an oxygen concentration threshold and remains unchanged for a predetermined time, the device is turned off.

[0070] The present disclosure does not limit the specific value of the predetermined time, for example, 20 minutes to 30 minutes. In addition, the equipment shut down here includes the equipment of the above process, that is, the focused ultrasound system, the pulsed microwave source, the energy coupling control system, etc.

[0071] In step S214, argon gas is introduced into the vacuum chamber, and a deoxidized tungsten block is obtained after cooling.

[0072] First, high-purity argon gas is injected into the vacuum chamber at a flow rate of, for example, 10 L / min to displace residual reaction gases and impurities. Subsequently, a combination of water cooling and liquid nitrogen quenching is used for rapid cooling. During the water cooling stage, room temperature circulating water (e.g., 25°C) is used to rapidly reduce the temperature to 200°C at a cooling rate of 10°C per second. This process helps to quickly solidify the material's microstructure and reduce deformation caused by thermal stress. The sample is then immersed in liquid nitrogen (e.g., -196°C) for 10 seconds to achieve even faster cooling, further solidifying the grain structure and improving the material's stability and performance.

[0073] After cooling, the oxygen content of the tungsten surface can be monitored to ensure it meets predetermined quality standards. Furthermore, the microstructure and mechanical properties of the tungsten block can be examined using analytical techniques such as scanning electron microscopy and X-ray diffraction to assess the effectiveness of the treatment.

[0074] In addition, in the present disclosure, a database containing a variety of refractory metals can be established, covering the source information, physical and chemical information, parameter information in the above-mentioned processes, processing conditions and effects, etc. of different metals. This database can provide valuable reference basis for cross-material applications and promote the promotion and application of new technologies in different fields.

[0075] In addition, noble gases (such as argon) can be introduced as plasma carriers to further optimize the reaction environment. Because of their stable chemical properties and resistance to reaction with other substances, noble gases can be used as protective gases to reduce impurity interference during the reaction. At the same time, the high-energy electrons they carry can more effectively promote the decomposition and removal of the oxide layer, further improving oxidation efficiency.

[0076] Table 1 shows the comparison of the effects of different deoxidation schemes using tungsten as an example.

[0077] Table 1

[0078] Table 2 shows the parameter optimization experimental data taking tungsten as an example.

[0079] Table 2

[0080] Based on the data results shown in Table 1 and Table 2, compared with other processes, the final oxygen content in the deoxidation of tungsten metal in the disclosed solution is reduced to 8 ppm, and the deoxidation rate reaches 99.2%, which is much better than vacuum melting and electron beam melting, and the processing time is shortened to 45 minutes. The key advantage of this effect comes from the ultrasonic-microwave energy coupling mechanism of the embodiment of the present disclosure. Referring to Table 2, under the synergistic effect of 30kHz ultrasonic frequency and 800W microwave power, the oxygen content and grain size are optimized to 8 ppm and 0.8μm respectively, which is significantly improved compared with a single parameter (such as 35 ppm at 20kHz / 500W). Further optimize the vacuum degree to 5×10⁻ 4 Pa, the oxygen content can be reduced to 6 ppm, but there is a trade-off between energy consumption and efficiency.

[0081] In addition, compared with other processes, the present invention achieves deep deoxidation at a low temperature (1000°C), avoiding grain coarsening caused by metal overburning. While other vacuum melting processes coarsen grains from 1.2μm to 2.5μm, the present invention refines them to 0.8μm. Simultaneously, the Vickers hardness is increased to 450HV, meeting the stringent requirements of nuclear-grade tungsten for oxygen content (<10ppm) and high-temperature performance. Furthermore, energy consumption is only 12.5 kW·h / kg, a 76% reduction compared to electron beam melting (52.6 kW·h / kg), achieving both high efficiency and economic efficiency. The data in Table 2 demonstrate that the present method, through dynamic parameter control, can be adapted to different refractory metals, providing a green solution for the industrialization of high-purity metal production.

[0082] It should be noted that although the steps of the method of the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all steps must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0083] Furthermore, the figures above are merely illustrative of the processes included in the methods according to exemplary embodiments of the present disclosure and are not intended to be limiting. It is readily understood that the processes illustrated in the figures above do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0084] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing what is disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the claims.

[0085] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for removing oxygen from refractory metals, characterized in that: include: placing a refractory metal in a vacuum chamber and heating it; wherein the heating temperature is lower than the melting point of the refractory metal; forming bubble nuclei on the surface of the refractory metal by a focused ultrasonic system, and inducing plasma discharge on the surface of the refractory metal by a pulsed microwave source; Extracting volatile substances from the vacuum chamber; When the oxygen concentration in the vacuum chamber drops below an oxygen concentration threshold, heating is stopped, the focused ultrasound system and the pulse microwave source are turned off, and the deoxygenated refractory metal is obtained after cooling.

2. The method for removing oxygen from refractory metals according to claim 1, wherein: Heating refractory metals in a vacuum chamber includes: Cutting the original refractory metal to be deoxidized into blocks, and polishing the blocks of the original refractory metal to be deoxidized to obtain refractory metal; wherein the polishing method includes sandpaper polishing and / or chemical polishing; placing the refractory metal in a quartz crucible, and placing the quartz crucible in a vacuum chamber; Heating is performed when the air pressure in the vacuum chamber is reduced to below an air pressure threshold.

3. The method for removing oxygen from refractory metals according to claim 1, wherein: The method further comprises: The ultrasonic power of the focused ultrasonic system and / or the microwave pulse width of the pulse microwave source are adjusted in real time based on the oxygen concentration in the vacuum cavity through an energy coupling control system.

4. The method for removing oxygen from refractory metals according to claim 1 or 3, characterized in that: The operating frequency of the focused ultrasound system is 20 kHz to 40 kHz.

5. The method for removing oxygen from refractory metals according to claim 1 or 3, characterized in that: The operating power of the pulse microwave source is 500W to 1000W.

6. The method for removing oxygen from refractory metals according to claim 1, wherein: Extracting volatile substances from the vacuum chamber includes: The volatile oxides in the vacuum chamber are extracted by a vacuum pump group, so that the pressure of the vacuum chamber is 5×10 - 4 Pa to 1×10 -3 Pa; The volatile oxides are generated by combining the surface oxides of the refractory metal with active oxygen atoms.

7. The method for removing oxygen from refractory metals according to claim 6, wherein: The method further comprises: The volatile oxygenates are sent to a condensation system for recovery.

8. The method for removing oxygen from refractory metals according to claim 1, wherein: The method comprises: stopping heating and shutting down the focused ultrasonic system and the pulsed microwave source, and obtaining a deoxidized refractory metal after cooling. The heating is stopped and the focused ultrasonic system and the pulse microwave source are turned off. A protective gas is injected into the vacuum cavity, and the cavity is cooled by water cooling or liquid nitrogen quenching to obtain a deoxygenated refractory metal.

9. The method for removing oxygen from refractory metals according to claim 8, characterized in that: The cooling rate is 10°C / s to 50°C / s.

10. The method for removing oxygen from refractory metals according to claim 1, wherein: The method further comprises: The property information of the refractory metal and the process parameter information of the deoxidized refractory metal are obtained, and a deoxidation parameter library for the refractory metal is obtained after data binding.

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