290 results about "Refractory metals" patented technology

The invention discloses a multi-component composite oxide dispersion strengthening molybdenum alloy and a preparation method thereof, and relates to the technical field of refractory metal powder metallurgy preparation. The molybdenum alloy comprises a molybdenum matrix and a Y-X-O composite oxide nano precipitated phase dispersed and distributed in the molybdenum matrix. The molybdenum alloy comprises the following components in percentage by mass: 1%-2% of Y2O3, 0.3%-1.2% of an active element X, 96.5%-98.7% of molybdenum and inevitable impurities, wherein X is selected from one of Ti, Zr and Hf; the Y-X-O composite oxide nano precipitated phase and the molybdenum matrix form a coherent or semi-coherent interface, and the interface mismatch degree is less than or equal to 5%. The molybdenum alloy has excellent high-temperature strength and creep resistance, and can be applied to the high-temperature fields of nuclear industry, aerospace and the like.

The invention discloses a preparation method of niobium-tungsten alloy spherical powder and a 3D printing method of the niobium-tungsten alloy spherical powder, and belongs to the technical field of refractory metal material preparation.The preparation method comprises the steps that niobium, tungsten, molybdenum and zirconium refractory metal raw materials are smelted to obtain cast ingots with uniform components, and hydride powder is formed after hydrotreating and mechanical crushing; spherical powder is prepared by adopting a plasma spheroidizing technology, then dehydrogenation is performed for 1-3 hours at the temperature of 450-750 DEG C, magnesium powder is added, treatment is performed for 2-5 hours in an inert atmosphere at the temperature of 800-1100 DEG C, and finally the low-oxygen niobium-tungsten alloy spherical powder with the oxygen content lower than 120 ppm is obtained. Compared with a traditional process, the spheroidizing treatment is innovatively carried out before the dehydrogenation and oxygen reduction process, the deoxidation efficiency is improved through the relatively small specific surface area of spherical powder, and oxygen content control is achieved in combination with magnesium powder heat treatment. The problems of high oxygen content and low powder yield in a traditional process are solved, and material support is provided for high-performance niobium-tungsten alloy components in the fields of aerospace, nuclear power and the like.

The invention relates to the technical field of tungsten metal surface refinement, in particular to a method for refining grains on the surface of a tungsten material based on friction induction and application, and the method achieves grain refinement on the surface of refractory metal through the shear friction force and the thermal-mechanical coupling effect. Firstly, a tungsten material sample is in contact with a friction pair of a friction instrument, then a certain pressure is applied to the surface of the tungsten material through the friction pair, the material is heated to a preset temperature through a temperature control module, then rotary friction is conducted at a certain rotating speed, and after a period of time, a nanoscale gradient structure layer can be formed on the surface of the sample. By means of the method, the grain size can be refined to the nanometer level from the initial micrometer level, and the surface hardness of the material is greatly improved. The method is simple in process, low in cost and obvious in grain refinement effect, and has important engineering application value.

Disclosed are exemplary methods for rheologically controlling a metal amalgam by including non-refractory filler particles (e.g., non-refractory metal filler particles, etc.) for processing and reliability enhancement as a thermal interface material. An exemplary method may comprise rheologically controlling a metal amalgam including filler particles (e.g., non-refractory metal filler particles, etc.) for use as a thermal interface material without sacrificing thermal conductivity and while maintaining rheology and spread control (e.g., limiting or preventing material migration, etc.) when pressed between two substrates. An exemplary method may comprise using non-refractory (not corrosive resistant) filler particles (e.g., non-refractory metal filler particles, etc.) to achieve a stable homogenous metal amalgam suspension with viscosity control based on total filler particle loading without sacrificing thermal performance for thermal interface material applications. The rheology controlled metal amalgam may be used as a thermal interface material between a heat source and another component of an electronic device.

The invention discloses a preparation method of a refractory metal reinforced copper-based composite material EBSD sample. The method comprises the following steps: 1, carrying out linear cutting to obtain a to-be-treated original sample; 2, performing thermal inlaying on the sample; 3, mechanical grinding; 4, vibration polishing; 5, chemically and mechanically polishing; and sixthly, cleaning and blow-drying are conducted, and the refractory metal reinforced copper-based composite EBSD sample is obtained. Scratches and defects of the sample are removed through vibration polishing, and synergistic regulation and control of the corrosion rate are achieved and tiny corrosion pit defects on the surface of the sample are eliminated by means of the oxidation effect, the complexing effect and the corrosion inhibition effect of the chemical mechanical polishing solution on the two phases of the heterogeneous refractory metal reinforced copper-based composite material. The sample surface is kept in a flat, smooth and low-stress state, the sample surface quality is remarkably improved, the analysis rate of the obtained EBSD sample is high, and the method has the advantages of being practical, efficient and low in cost.

The invention discloses a high-speed aircraft folding rudder aerodynamic configuration design method based on aerodynamic thermal constraint, which comprises the following steps of: determining a rudder leading edge radius and a rudder leading edge sweepback angle by taking a current state nominal trajectory as a basis and taking a rudder leading edge thermal response temperature as a judgment standard; secondly, the cone angle of one conical surface of the folded rudder is determined through iterative calculation, so that the chordwise size of the high-temperature-resistant refractory metal material and the thickness of a skin and a heat-proof coating at the cone position are designed; and thirdly, through the design of the interference position of the arched shock wave of the heat-proof cup, the gap between the fixed rudder and the movable rudder avoids the interference area of the arched shock wave, so that the chordwise distance between the folding gap and the rudder shaft is determined. By means of the aerodynamic configuration design method, the radius of the front edge of the rudder can be as low as 3 mm, the taper angle is as low as 4 degrees, it can be guaranteed that ablation deformation does not occur when the maximum heat flow of the front edge of the rudder does not exceed 10 MW / m < 2 >, the resistance characteristic of a high-speed aircraft can be effectively reduced, the characteristic of near-zero ablation is achieved, and the good aerodynamic configuration is maintained.

The invention relates to the technical field of rare earth permanent magnet materials, in particular to permanent magnet alloy powder, a preparation method thereof, a prepared permanent magnet and a method. Wherein the permanent magnet alloy powder and the permanent magnet alloy comprise the following components: REa (La1-mCems) b-Feba-Mc-Tn-Bd, and RE is at least one of Pr, Nd, Sm, Y, Gd, Tb, Dy, Ho and Yb; m is at least one of Zr, Nb, Mo, Hf, Mn, Ta and W; t is at least one of Cr, V, Si and Ti; wherein 0 < a < = 2.0, 11 < = b < = 13.5, 0 < = c < = 1.5, 6 < = d < = 8.1, 0 < = m < = 1, and 0 < n < = 3.0. According to the permanent magnet alloy powder, lanthanum and cerium are adopted to replace part of precious rare earth elements to prepare the permanent magnet alloy powder, the cost can be greatly reduced, the oxidation resistance is improved and the flammability is reduced through a small amount of refractory metal M and antioxidant reinforced metal T matched elements, and the problem that a pure praseodymium neodymium-lanthanum cerium / cerium-based iron boron material is poor in temperature resistance and oxidation resistance is solved.

The invention relates to the technical field of nuclear fusion surface plasma W materials, in particular to nano rare earth oxide ceramic-Ti microalloy composite reinforced W powder, a composite material and a preparation method of the nano rare earth oxide ceramic-Ti microalloy composite reinforced W powder. The composite powder is of a nearly spherical core-shell hierarchical structure, and the particle size is 30-50 nm; according to the composite powder, refractory metal W serves as a matrix, nano rare earth oxide ceramic particles are evenly dispersed in matrix W crystal grains, Ti mainly forms an enrichment area on the surface of the matrix or a matrix / rare earth oxide interface in a simple substance or oxide mode, the phase interface structure is effectively improved, W crystal boundary migration and dislocation motion are hindered, W crystal grains are remarkably refined, and the composite powder is prepared. Part and W form semi-coherence, fine grain and interface strengthening and toughening are achieved, and a brand new thought and a technical method are provided for synergistically improving the strength and toughness of the W composite material. The composite powder is subjected to organic reduction synthesis and low-temperature reinforced sintering to prepare the composite material, the tensile strength at the room temperature reaches 500-610 MPa, and the ductility is 5%-8%.

The invention relates to the technical field of metal surface coating preparation, in particular to a high-temperature thermal cycle impact resistant yttrium oxide composite coating on the surface of refractory metal and a preparation method of the yttrium oxide composite coating. The refractory metal composite coating material is composed of a refractory metal matrix and a coating. The coating comprises a bonding layer, a middle layer and a surface layer which are arranged in a contact manner; the bonding layer is composed of the refractory metal and yttrium oxide, and the porosity of the bonding layer is 1%-5%; the middle layer is a pure yttrium oxide layer with the porosity of 5%-10%; the porosity of the surface layer is 1t; 2% of a pure yttrium oxide layer; the melting point of the refractory metal is 2470 DEG C or higher. According to the refractory metal composite coating material and the preparation method and application thereof, the refractory metal coating structure is optimized, the porosity of the coating is further adjusted, the high-temperature molten metal corrosion resistance and the high-temperature thermal shock resistance of the coating are improved, meanwhile, the bonding strength between the coatings is guaranteed, and the service life of the coating is prolonged. The method is expected to be applied to high-melting-point metal smelting equipment.

The invention discloses a reversible metal 4D printing method based on hydrogel reversible deformation and a metal part, and belongs to the field of metal additive manufacturing. The method comprises the following steps: firstly, constructing a three-dimensional model comprising a hydrogel driving layer and a metal blank layer; respectively preparing hydrogel light-cured ink and metal or precursor slurry thereof; printing the two layers of materials sequentially or alternately by adopting a photocuring printer to obtain a composite green body; the hydrogel layer is dehydrated and shrunk through drying, the component is driven to generate preset shape deformation, the hydrogel layer absorbs water and expands through soaking, and reversible recovery of the shape of the component is achieved; and degreasing, selective reduction and sintering heat treatment are conducted on the component, and the compact final metal component is obtained. According to the invention, the independent hydrogel layer is used as a deformation driver, the dependence on the intrinsic phase change characteristic of a metal material is avoided, the material universality is extremely high, the method can be widely applied to 4D printing of various materials including refractory metal and high-reflection metal, and reversible control of shape change is realized.

The invention relates to an automatic filling rubber sheath preforming method and device for rare refractory metal powder. The device comprises a vacuum feeding mechanism, a weighing and metering mechanism, a vibration filling mechanism, an automatic plugging mechanism, a sheath transposition mechanism, a manipulator loading and unloading mechanism and a control system. According to the system, efficient, uniform and sealed filling of tantalum powder is achieved through vacuum material suction, weighing control, filling and compaction at the same time, automatic plugging and sealing and bag sleeve replacement through linkage of a mechanical arm. The control system coordinates sequential operation of all links on the basis of signals of multiple sensors, the powder amount range of a single bag is 6-17 kg, and the control system is matched with rubber bags of multiple specifications such as phi 60 * 1000 mm and the like. According to the method, the powder loading density consistency, the sealing reliability and the production line rhythm are improved, the labor intensity and the dust pollution are remarkably reduced, and the method is suitable for the field of metallurgy preforming of tantalum, alloy powder of tantalum and other metals.

The invention provides an automatic profiling tungsten-copper alloy and a preparation method thereof, and belongs to the technical field of refractory metal powder metallurgy. After a spherical tungsten powder compact is degummed and sintered, vacuum pretreatment is adopted, copper infiltration is conducted for 5-15 min in the argon environment with the temperature of 1100-1200 DEG C and the pressure of 0.5-2 MPa, the driving force and the inert protection effect of high-pressure argon on molten copper liquid are fully utilized, rapid, uniform and thorough infiltration of the copper liquid in pores of a tungsten framework is achieved, and the compactness and the structure uniformity of the tungsten-copper alloy are improved. Meanwhile, oxidation of tungsten and copper at high temperature and volatilization loss of copper liquid can be avoided through the synergistic effect of vacuum and argon, and the adverse effect of impurities on performance is reduced. And the rapid copper infiltration in the high-pressure environment can shorten the production period and improve the process efficiency, and is suitable for industrial batch production. And the problems of insufficient infiltration, oxidation pollution, component segregation and the like easily occurring in the traditional copper infiltration process are effectively solved.

A method of preparing a metal matrix composite powder for additive manufacturing, by mixing a metal powder with a ceramic powder, binding the mixed powders together to form an electrode; and using the electrode in an electrode induction gas atomisation (EIGA) process to prepare the metal matrix composite powder. The ceramic can be TiB2, SiC, AlN or a MAX-phase ceramic, the latter having the formula Mn+1AXn where M is a metal, A is an A-group element and X is C, N and / or B, e.g. Ti3SiC2, Al4SiC4 or Al8SiC7. The metal powder can be steel (e.g. stainless steel), titanium, aluminium, cobalt, magnesium, copper, refractory metals, PGMs vanadium and alloys thereof (e.g. 6061 aluminium). Binding to form the electrode can be by cold isostatic pressing, sintering and / or the application of pressure. The powder can be processed by laser powder bed fusion AM or direct energy deposition printing.

The present invention belongs to the technical field of material surface treatment, and discloses a method for enhancing the ablation resistance performance of an armature by selective laser melting and injecting refractory metals, which includes the following steps: grinding and cleaning the surface of the armature to be enhanced; designing the selective laser melting and injecting structure on the surface of the armature into different shapes according to the electromagnetic emission working conditions and the ablation characteristics of the armature; setting laser parameters, feeding refractory metal powder onto the surface of the armature to be enhanced based on the shape of the selective laser melting and injecting structure, and using the laser to perform laser melting and injection on the surface of the armature to be enhanced to form a melted and injected layer. After multiple meltings and injections, an enhanced armature composite structure with an alternating distribution of strengthened area melted and injected layers and non-strengthened areas is obtained on the surface of the armature. The present invention can solve the transition ablation problem caused by severe ablation of the armature in existing electromagnetic railguns.

The invention relates to the technical field of large steel casting manufacturing, and discloses a crusher rack set for mining machinery and a casting method of the crusher rack set. The rack set comprises a cast steel body and a functional gradient reaction framework which is arranged in the cast steel body in advance and forms metallurgical bonding. The framework is made of refractory metal alloy, and an A area and a B area are divided on the framework. The area A is arranged at the heat accumulation core of the casting and is provided with a strong reaction coating on the surface; the area B extends outwards from the area A, and the surface of the area B is provided with a high-thermal-conductivity ceramic coating. The method comprises the steps of preparing the framework, installing the framework in a casting mold cavity, and then carrying out molten steel pouring and heat treatment. In-situ forced nucleation is initiated at the core of the casting through the strong reaction coating of the area A, a heat conduction path from inside to outside is established by means of the high heat conduction coating of the area B, and sequential solidification of the casting is achieved, so that defects such as shrinkage porosity and shrinkage cavities are effectively transferred, the density and uniformity of the internal structure of the casting are improved, and the casting quality is improved. And the overall mechanical property of the rack set is improved.

The invention discloses an efficient preparation method of a small-grain-size rhenium-containing alloy, and relates to the technical field of refractory metal powder metallurgy. The preparation method mainly comprises the following steps: preparing oxide composite powder by adopting a combustion synthesis method and taking soluble transition metal salt, ammonium perrhenate, hydrogen peroxide or ammonium nitrate and fuel as raw materials, reducing the oxide composite powder through hydrogen to obtain nano alloy powder, and performing compression molding and high-temperature sintering through a hydraulic press to prepare the rhenium-containing alloy material. The material has the advantages of being high in purity, uniform in doping, excellent in mechanical performance, resistant to corrosion, long in service life and the like, and a new breakthrough is brought to the field of powder metallurgy of refractory metal.

The invention discloses a high-efficiency catalyst and a preparation and application method thereof, and relates to the technical field of nano carbon material preparation, the high-efficiency catalyst comprises the following components: an organic metal compound containing iron, cobalt and nickel, a refractory metal organic compound, a cocatalyst and a functional auxiliary agent, the catalyst is used for preparing the carbon nanotube by a floating chemical vapor deposition method, a high-temperature plasma CVD method or a plasma arc method, all components of the catalyst are uniformly mixed through melting granulation, the defect that the proportion is difficult to accurately control due to independent feeding is avoided, meanwhile, powder feeding can be cracked and evaporated in the subsequent carbon nanotube preparation process, and the carbon nanotube preparation efficiency is improved. The catalyst with higher concentration is obtained, and the preparation efficiency of the single-walled carbon nanotube is remarkably improved.

The invention discloses a method for improving the yield of refractory metal powder prepared through PREP, and the method comprises the following steps: 1, carrying out lathe machining on a refractory metal blank to obtain a bar with an external thread at one end; secondly, the bar is placed in PREP equipment to be connected with a mechanical shaft, protective gas is inflated after vacuumizing is conducted, and then preheating is conducted through an induction coil arranged at the end of a bar molten pool; and thirdly, the preheated bar is rotated, plasma arc powder manufacturing is adopted, the rotating speed of the bar is gradually increased in the powder manufacturing process, and the refractory metal powder is obtained after cooling. According to the method, the induction coil is additionally arranged at the molten pool end of the metal bar to preheat the bar, so that a heat buffer area is established between the molten pool of the bar and the rear end of the bar, the molten pool end of the bar is uniformly heated, the power supply current of the bar can be greatly reduced, the abrasion degree of a carbon brush for carrying current and supplying power to a mechanical shaft is reduced, and the service life of the mechanical shaft is prolonged. The rotating speed of the bar is effectively increased, the yield of the fine powder is increased, and the method is suitable for the technical field of metal powder preparation.

According to the Ta-based refractory alloy reinforced by the silicide phase eutectic structure and the preparation method of the Ta-based refractory alloy reinforced by the silicide phase eutectic structure, nanoscale HfSi2 powder is introduced, and the alloy reinforced by the silicide phase eutectic structure is formed in the Ta-based alloy. According to the alloy, particles or powder of refractory metal elements such as Ta serves as a matrix raw material, nanoscale HfSi2 powder is introduced into the matrix raw material, an alloy ingot is prepared through a smelting process, and the alloy material is subjected to sufficient deformation recovery and homogenization through multiple times of pressure processing and high-temperature vacuum annealing treatment. A multi-level spherical eutectic structure exists in the alloy prepared through the method, the silicide phase serves as a strengthening phase, dislocation movement can be effectively inhibited, and the room-temperature mechanical property of the alloy is remarkably enhanced. The room temperature tensile elongation is about 30%, the yield strength is about 600 MPa, the tensile strength is about 700 MPa, and compared with a traditional Ta-based alloy, the tensile strength is obviously improved. The alloy of the system can be widely applied to structural parts by means of plastic deformation processing, heat treatment and the like.

The invention relates to a high-temperature-resistant nuclear fuel cladding tube based on a porous interface, which comprises a refractory metal inner layer and a SiC-based composite material outer layer which are used as the inner wall and the outer wall of the nuclear fuel cladding tube, and at least one nano beta-SiC porous interface middle layer with the porosity of not less than 20% arranged between the refractory metal inner layer and the SiC-based composite material outer layer. The invention further provides an intelligent manufacturing method of the high-temperature-resistant nuclear fuel cladding tube based on the porous interface. According to the nanometer beta-SiC porous interface interlayer structure provided by the invention, the interface thermal stress caused by thermal mismatch and temperature gradient of the nuclear fuel cladding in a high-temperature environment is greatly reduced, the thermal stability and the high-temperature resistance of the nuclear fuel cladding are improved, the design and optimization of the nuclear fuel cladding interface structure are realized, and the nuclear fuel cladding interface structure is optimized. And based on a mechanical, digital and informationized preparation process, process parameters during preparation of the nuclear fuel cladding can be accurately controlled, high-quality production is ensured, and intelligent manufacturing of the nuclear fuel cladding is realized.

A coating system includes a diffusion coating on a refractory metal or refractory metal alloy. The coating can be applied to a component such as a rocket engine component that includes a substrate including the refractory metal and is useful to protect the substrate from high temperature oxidation. The diffusion coating process employs an activator that includes a compound of the metal to be diffused into the surface of the substrate and is a vapor phase process in which the vapor includes metal from the activator and additional from the metal source being activated. Aluminum trifluoride can be used to activate an aluminum metal source to form an aluminide coating on a refractory metal-based alloy, such as a niobium alloy.

The invention discloses a copper metal complex and a preparation method thereof. The copper metal complex is prepared by mixing copper powder and refractory metal powder, adding a dispersing agent and graphite and carrying out compression and vacuum sintering. The outer layer of the complex structure is copper foil, the inner layer is uniform alloy powder, the complex structure can be used as intermediate alloy for subsequent smelting, the smelting temperature is remarkably reduced, element oxidation is inhibited, and the component uniformity is improved; the method is suitable for preparing the copper-based complexes of various high-melting-point and easily-oxidized elements.

The invention relates to a preparation method of Mo toughened boride-based ultra-high-temperature ceramic, which comprises the following steps: mixing a carbonyl complex of metal Mo with boride powder, heating in a solution, heating and decomposing the metal complex, generating metal Mo particles under the action of a surfactant, and growing on the surfaces of boride particles, thereby obtaining the Mo toughened boride-based ultra-high-temperature ceramic. Centrifuging and drying the heated mixture to obtain boride powder wrapped by refractory metal Mo; and then a proper sintering process is adopted to prepare the boride-based ultra-high-temperature ceramic material with improved performance. According to the technical scheme, the refractory metal Mo additive is introduced through a chemical method, and a brand-new thought and scheme are provided for introduction of a refractory metal toughening phase in ultra-high-temperature ceramic research.

The invention relates to the technical field of alloy preparation, particularly provides a 650 DEG C high temperature resistant titanium-based composite material plate, and further provides a preparation method of the plate. The titanium-based composite material plate resistant to the high temperature of 650 DEG C, provided by the invention, is prepared from the following chemical components in percentage by mass: 6.0 percent to 7.0 percent of Al, 1.0 percent to 3.0 percent of Zr, 0.5 percent to 2.0 percent of Mo, 0.4 percent to 1.0 percent of Nb, 0.4 percent to 1.0 percent of W, 0.1 percent to 0.4 percent of Si, 0.4 percent to 0.7 percent of B, 0.01 percent to 0.10 percent of C and the balance of Ti and inevitable impurities. According to the titanium-based composite material component system provided by the invention, a vanadium element which is easy to generate interface reaction at high temperature is abandoned, and refractory metal elements such as niobium and tungsten are adopted to cooperate with a ceramic reinforced phase formed by boron, carbon and the like, so that the high-temperature performance and the thermal stability of the material are improved; meanwhile, by controlling the content of molybdenum, aluminum and other elements within a specific interval, the hot working performance of the material is remarkably improved while high strength is maintained, and the contradiction between insufficient high-temperature performance and poor hot working performance of a traditional titanium-based composite material is effectively solved.

The application discloses a method for preparing high-purity superfine tungsten powder by series impurity removal and microwave calcination, and relates to the technical field of refractory metal powder metallurgy. The method uses 99% and below industrial-grade ammonium paratungstate as raw material, and sequentially performs pyrolysis, two-stage physical purification, ultrasonic synergic acidolysis deep purification, microwave uniform calcination and sectional reduction. Firstly, the ammonia solution-evaporation crystallization method and the chemical precipitation method are connected in series to realize deep impurity removal, and the chemical precipitation method is used to directly obtain a nano tungsten oxide precursor, so that the morphology of the tungsten powder is guaranteed for subsequent reduction; secondly, the microwave calcination process is introduced to realize fast and green and environment-friendly uniform heating, and the hard agglomeration of the precursor is significantly reduced; finally, the sectional reduction method is adopted to effectively block the CVT effect in the reduction process, and abnormal grain growth is avoided. The method solves the problems of incomplete purification, sintering agglomeration of the precursor during reduction and out-of-control reduction particle size in the prior art, and the prepared tungsten powder has high purity and small average particle size.

The present invention relates to a method for manufacturing an R-Fe-B-based permanent magnet by grain boundary diffusion of refractory metal alloys and rare earth alloys and an R-Fe-B-based permanent magnet manufactured thereby, wherein the grain boundary diffusion of a light rare earth alloy containing light rare earth elements that are less expensive than costly heavy rare earth elements can lead to a low manufacturing cost, effective suppression of crystal grain growth (coarsening) inside the permanent magnet, a reduction in the Pr-shell thickness, and an increase in the Pr concentration around the crystal grains, and thus can produce a permanent magnet having enhanced magnetic properties, such as coercivity.

The present invention proposes a powder standard sample comprising at least one of titanium carbonitride, titanium carbide, and titanium nitride; wherein the nitrogen content is 3% to 22%, the oxygen content is less than 1.0%, the hydrogen content is less than 0.05%, and the total impurity elements are less than 0.2%. When the powder standard sample is used for testing, the data is fitted into a working curve using a linear regression method with a linear coefficient of 0.9998, indicating good linearity. The resulting working curve meets the high nitrogen analysis range of refractory metals such as tungsten, titanium, tantalum, and niobium, as well as ceramic alloy samples, and provides stable, accurate, and reliable test results.

A cold tundish which has a surface made from a thermally conductive metal, and which is cooled by a cooling fluid, is disposed so as to receive a molten material from a cold crucible; high-speed jets of an inert gas are produced from a nozzle at a narrow portion of an orifice that is open at the exit side of the cold tundish, producing a low-pressure region on the exit side of the orifice that draws the molten material and a plasma through the orifice; the high-speed jets of inert gas impinge on the molten material to achieve atomization thereof, using an apparatus that is compatible with atomization of even reactive and refractory metals.

The application relates to the technical field of refractory metal material processing, in particular to a vacuum smelting system and method for high-purity molybdenum and a fiber-structure molybdenum material, the vacuum smelting system for high-purity molybdenum comprises a three-layer composite crucible, the vacuum smelting method for high-purity molybdenum comprises the following steps: step S1): under the condition of a vacuum degree of less than or equal to 5*10 ‑3 Pa, a three-layer composite crucible is used to perform consumable smelting on molybdenum raw materials; step S2): a directional solidification rate is controlled to be 8-12 mm / min, and a longitudinal temperature gradient is formed to be greater than or equal to 100 DEG C / cm; step S3): multi-stage plastic deformation is implemented on a solidified ingot, and a total deformation amount is greater than or equal to 90%; the fiber-structure molybdenum material is formed with a longitudinal continuous fiber structure in the material, a grain length-diameter ratio is greater than or equal to 10:1, a fiber diameter is less than or equal to 5 microns, hydrogen content is less than or equal to 5 ppm, oxygen content is less than or equal to 50 ppm, and a room-temperature tensile strength is greater than or equal to 780 MPa; the application can prepare high-purity fiber-structure molybdenum material, and improves the problem of insufficient axial performance caused by the isotropy of a traditional equiaxed crystal structure.