380 results about "Refractory metals" patented technology

The present invention relates to a process for producing coated substrates. In the process, first at least one region of a surface of a porous substrate is provided with at least one surface sealing layer. At least one aqueous suspension is then applied onto the at least one surface sealing layer, the at least one aqueous suspension containing at least one refractory metal carbide and water. The substrate is then subjected to a sintering process. The present invention also relates to a coated substrate, which can be produced or is produced by the method according to the invention, and to the use of such a coated substrate.

A method for processing a substrate that includes: forming a passivation layer over sidewalls of a recess in a carbon-containing layer over a substrate by a cyclic passivation process including a plurality of cycles, each of the plurality of cycles including, exposing the substrate to a first gas including a refractory metal in the absence of a plasma, and after exposing to the first gas, exposing the substrate to a second gas including oxygen or nitrogen.

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 low-cost tantalum-tungsten alloy powder preparation method which comprises the following steps: degassing treatment: uniformly mixing superfine tantalum powder and tungsten powder according to a required ratio to obtain mixed powder, putting the obtained mixed powder into degassing equipment, vacuumizing and heating to volatilize gas impurities in the mixed powder and discharging the gas impurities; and isostatic pressing forming is conducted, specifically, the powder obtained after degassing treatment is loaded into a rubber mold sheath, isostatic pressing forming is conducted in a high-pressure environment, the powder is densified, and an obtained formed blank is put into a vacuum sintering furnace to be sintered. According to the method, an effective way for manufacturing low-cost, low-oxygen and low-carbon alloy powder is provided for the refractory metal spherical powder for additive manufacturing, low-grade, high-oxygen and unqualified tantalum-tungsten alloy fine powder waste can be recycled and formed, and the tantalum-tungsten alloy spherical powder reaching or exceeding the industrial standard is produced; the powder preparation production cost is greatly reduced, time and labor are saved, and the working efficiency is improved.

A nickel based active brazing material for high temperature furnace and laser brazing of stainless steels, nickel and cobalt based alloys and superalloys, refractory metals and alloys in vacuum and inert gases for manufacturing and repair of turbine engine components and other articles comprising in weight percentage (wt. %) of (4.5-8.5)% Cr, (4.2-6.5)% Ti, (5.0-9.5)% Zr, (3.0-4.5)% Hf, (0.5-1.6)% Ta, (1.0-3.5)% Al, (0.5-1.7)% Si, (0-12.0)% Fe, (0-0.2)% Mo, (0-0.05)% W, and nickel to balance.

The invention discloses a method for improving the strength and long-term service performance of a brazed joint in a skutterudite thermoelectric device by using a cobalt-based barrier layer, and belongs to the technical field of thermoelectric material connection. The problems that the long-term service performance of existing skutterudite and electrode brazing is poor, and the strength of a brazed joint is low are solved. The cobalt-based barrier layer added between the skutterudite and the electrode is cobalt and the refractory metal, and the refractory metal is high in melting point, bond energy and diffusion activation energy, so that diffusion of the Sb element through the barrier layer to the electrode is inhibited, and the components of the cobalt-based barrier layer can be flexibly adjusted, so that the thermal expansion coefficient of the barrier layer is easily matched with that of the skutterudite. The barrier layer powder and the skutterudite powder are subjected to integrated hot pressed sintering, and staggered interfaces are formed between the powder and the powder; and the interface stress can be well relieved. Due to the fact that the barrier layer contains fewer grain boundaries, diffusion of the Sb element can be better restrained. The shearing strength of the obtained brazed joint of skutterudite and the electrode reaches 33.6 MPa.

The invention discloses a low-cost tantalum-tungsten alloy powder preparation method which comprises the following steps: degassing treatment: uniformly mixing superfine tantalum powder and tungsten powder according to a required ratio to obtain mixed powder, putting the obtained mixed powder into degassing equipment, vacuumizing and heating to volatilize gas impurities in the mixed powder and discharging the gas impurities; and isostatic pressing forming is conducted, specifically, the powder obtained after degassing treatment is loaded into a rubber mold sheath, isostatic pressing forming is conducted in a high-pressure environment, the powder is densified, and an obtained formed blank is put into a vacuum sintering furnace to be sintered. According to the method, an effective way for manufacturing low-cost, low-oxygen and low-carbon alloy powder is provided for the refractory metal spherical powder for additive manufacturing, low-grade, high-oxygen and unqualified tantalum-tungsten alloy fine powder waste can be recycled and formed, and the tantalum-tungsten alloy spherical powder reaching or exceeding the industrial standard is produced; the powder preparation production cost is greatly reduced, time and labor are saved, and the working efficiency is improved.

The invention relates to an electron beam melting-ultrasonic atomization pulverizing system and method, belongs to the technical field of preparation of metal powder materials, and solves the problems that in an existing metal powder preparation technology, high-melting-point metal powder is difficult to prepare, and due to medium introduction, the powder purity is low, the cost is high, the sphericity degree of the powder is low, and the particle size is uncontrollable. The electron beam melting-ultrasonic atomization pulverizing system comprises an electron beam system, a vacuum system, a cooling system, an ultrasonic pulverizing system and a powder collecting system. By means of the system, powder preparation under the high-vacuum condition can be achieved, medium introduction is avoided, impurity removal is promoted, and low-oxygen ultra-pure powder can be obtained easily; the energy density of electron beams is high, and preparation of high-melting-point metal powder can be successfully achieved; by means of ultrasonic atomization, the metal powder is high in sphericity degree, controllable in particle size and few in defect, and the method is particularly suitable for preparing ultrapure powder of refractory metal (such as W, Mo and Ta) and active metal (such as Ti, Nb, Co and V).

The invention discloses a wide-temperature-range high-strength light eutectic high-entropy alloy and a preparation method thereof, belongs to the technical field of metal materials, and provides a corresponding preparation method, and the atomic percent expression of the eutectic high-entropy alloy is NiaFebAlcTidCre. The eutectic high-entropy alloy prepared by the invention not only has excellent mechanical properties at room temperature and high temperature, but also does not contain noble metal elements and refractory metal elements; the method can realize triple beneficial effects of improving the mechanical property of the eutectic high-entropy alloy, reducing the weight and reducing the cost, widens the engineering application range of the eutectic high-entropy alloy, and has a wide industrial application scene.

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 belongs to the technical field of thermal protection coating materials, and discloses a composite gradient structure coating on a Ta-based refractory metal surface and a preparation method of the composite gradient structure coating. The composite gradient structure coating comprises a base layer, a diffusion barrier layer, a transition layer and a thermal protection layer which are sequentially arranged on a Ta base body from inside to outside. The component of the base layer is metal or metal carbide; the component of the diffusion barrier layer is metal carbide; the components of the transition layer are metal carbide and Re; the content of metal carbides in the transition layer is reduced in a gradient manner from inside to outside, and the content of Re is increased in a gradient manner; and the thermal protection layer sequentially comprises an Re layer, an Ir layer and an HfO2-Y2O3 layer from inside to outside. The high-vacuum magnetron sputtering technology is adopted, and the coating of the composite gradient structure is formed on the Ta-based refractory metal; and the layers of the coating prepared by the method are tightly combined with the matrix, so that the formation of volatile oxides of iridium elements is effectively reduced, and the overall high-temperature protection performance of the coating is improved.

Disclosed in the present invention is a fatigue life determination device for a refractory metal elastic element. A movable rod is slidably and sealingly inserted on a pressure bearing cavity; a driving mechanism for driving the movable rod to move reciprocatingly is connected to the movable rod; one end of a fixed rod extends into the pressure bearing cavity, a refractory metal elastic element is abutted between said end and the movable rod, and the other end of the fixed rod extends out of the pressure bearing cavity and a heating furnace and is connected to a vibration frequency detection sensor; a pressurizing channel for high pressure gas to flow is formed in the fixed rod; a pressurizing opening communicated with the pressurizing channel is formed in the end wall of the fixed rod corresponding to the interior of the refractory metal elastic element; an internal pressure connector communicated with the pressurizing channel is formed in the position of the fixed rod located outside the heating furnace; an external pressure connector communicated with the interior of the pressure bearing cavity is formed in a side wall of the pressure bearing cavity; the external pressure connector is communicated with an external pressure pipeline extending out of the heating furnace; and the external pressure pipeline and the internal pressure connector are both communicated with a high-pressure charging mechanism. Thus, the loss rate of temperature and pressure is reduced, and the use requirements of special working conditions are met.

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 discloses Ag-free high-temperature active alloy brazing filler metal and a preparation method and application thereof. The brazing filler metal alloy comprises 9.5-12.5 wt% of Ge, 9-11 wt% of Ti, 0.1-1.5 wt% of Ni and the balance Cu, the melting point of the brazing filler metal alloy ranges from 960 DEG C to 975 DEG C, and the recommended brazing temperature ranges from 1000 DEG C to 1100 DEG C. The product forms comprise foil strips, wires and powder paste. The preparation method comprises the steps of vacuum alloying, spherical gas atomization powder preparation, centrifugal ball milling powder mixing, spark plasma sintering, homogenizing heat treatment, isothermal rolling, isothermal rotary swaging and precise drawing. The alloy brazing filler metal is suitable for ceramic high-temperature direct packaging, diamond material device high-temperature brazing, refractory metal vacuum brazing and the like, high-strength weld joints can be obtained, the service temperature is high, the cost is low, and the problem that Ag element steam pollutes devices can be effectively solved.

Catalytic articles comprising a first washcoat comprising a first refractory metal oxide support, platinum, palladium, and, optionally, a zeolite, and a second washcoat comprising a second refractory metal oxide support, platinum, and manganese. Also disclosed are exhaust gas treatment systems and methods for treating an exhaust gas stream comprising the same.

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 discloses a positive electrode material, a preparation method thereof, a positive electrode plate containing the positive electrode material, a secondary battery and an electric device. The positive electrode material comprises positive electrode material particles, the positive electrode material particles comprise a matrix and modified elements, the matrix comprises LiNixCoyMnzO2, x is larger than or equal to 0.8, y is smaller than or equal to 0.2, x + y + z = 1, and the modified elements comprise rare earth elements and / or refractory metal elements. The high-nickel ternary particles are modified by rare earth elements and / or refractory metal elements, so that the cycling stability of the positive electrode material can be improved.

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.