103 results about "Tungsten cathode" patented technology

The invention provides a preparing method for ultra-fine high-purity Ti2AlNb alloy powder. The preparing method comprises the following steps that 1, components of a Ti2AlNb base alloy are used as ingredients and smelted into a Ti2AlNb alloy bar; 2, finish turning is carried out on the smelted Ti2AlNb alloy bar, the diameter of a processed electrode bar ranges from 10 mm to 100 mm, and the length ranges from 100 mm to 1000 mm; 3, the electrode bar is loaded into a reaction chamber, the reaction chamber is vacuumized, and helium or argon or helium and argon mixed gas is introduced into the reaction chamber; 4, plasma gun powder of PREP powder manufacturing equipment ranges from 100 kW to 300 kW, a plasma torch comprises a tungsten cathode and a copper anode, the electrode bar is not used as an electrode, the end of the electrode bar is heated to be melted uniformly, atomized drops are tossed out from the end of the electrode bar, the drops are cooled fast in an inert gas environment to form spherical particles, and the spherical particles drop into a bottom collector of the reaction chamber; 5, prepared Ti2AlNb alloy powder is screened and packaged in the inert gas protection environment; 6, the Ti2AlNb alloy powder prepared through the method has the advantages of being ultra-fine, high in purity, high in spherical degree and low in oxygen content.

The invention relates to a preparation method of superfine high-grade spherical EP741NP alloy powder. The method comprises the following steps: 1) proportionally preparing materials according to the EP741NP alloy composition, and smelting to obtain an EP741NP alloy bar; 2) processing the smelted EP741NP alloy bar into an electrode bar; 3) installing the electrode bar into a reaction chamber, vacuumizing the reaction chamber, and proportionally charging inert gas into the reaction chamber; 4) heating the end of an electrode bar to uniformly melt the end, throwing atomized liquid drops from the end of the electrode bar so that the liquid drops are quickly cooled into spherical particles in an inert gas atmosphere and fall into a collector, wherein a plasma torch comprises a tungsten cathode and a copper anode, and the electrode bar is not used as an electrode; and 5) carrying out electrostatic separation on the prepared EP741NP alloy powder in an inert gas protective atmosphere, screening, sampling and packaging. The EP741NP alloy powder prepared by the method is superfine, and has the characteristics of high purity, high-grade sphericity and no hollow powder or satellite powder.

The invention discloses a direct-current argon arc plasma powder spray gun and a manufacturing method and belongs to the field of flame spraying equipment and technology of metal powder and metal ceramic powder.Two novel technologies including a hollow tungsten cathode outer surface annular arcing direct-current plasma heating method and an axial powder feeding mechanism penetrating the core of an argon arc are adopted, and position matching of a negative voltage pressure of the electric arc and the powder feeding mechanism is utilized, so that stability of the spray gun during long-time working is improved, and uniformity in heating temperature of metal powder particles, uniformity in spray speed and stability of spray layer quality are guaranteed.In addition, due to structural changing of a gun body, technology application field of the gun is expanded obviously, and the gun is expected to make a beneficial contribution to development of high technology in the future.

The invention relates to a rhenium tungsten based cathode material and a preparation method thereof and belongs to the technical field of a refractory metal thermal cathode material. BaO, CaO and Al2O3 are loaded in pores of a porous rhenium tungsten base; the rhenium tungsten base is formed by coating tungsten grains by rhenium. The preparation method comprises the following steps: dissolving ammonium perrhenate in water, thereby preparing into a solution; adding tungsten powder into the ammonium perrhenate solution and stirring; drying; resolving and reducing in two steps under the hydrogen atmosphere, thereby obtaining rhenium tungsten powder; and pressing and sintering the rhenium tungsten powder under the hydrogen atmosphere, thereby obtaining a rhenium tungsten base and steeping into a molten barium aluminate calcium salt. The preparation method provided by the invention has the advantages that the preparation process is simple, the introduction of impurity element during the preparation process is avoided, the repeatability is strong, the prepared cathode material is excellent in emitting property, and the ion bombardment resistance of a traditional barium tungsten cathode is enhanced.

The invention discloses a dip-coated barium-tungsten cathode for traveling-wave tubes and a preparation method thereof. The dip-coated barium-tungsten cathode comprises a cathode drum, a cathode spongy body positioned inside the cathode drum. The invention is characterized in that the cathode spongy body is laminated by a tungsten spongy body and a tungsten-rhenium spongy body, wherein the tungsten-rhenium spongy body is coated with a noble metal film on the surface. With the above structure and preparation method, compared with the prior art, the cathode spongy body is a two-layered cathode spongy body laminated by the tungsten spongy body and the tungsten-rhenium spongy body, to replace the single-layer alloy substrate with uniform porosity in the prior art; the consumption of the noble metal Re is reduced; the porosity of the tungsten spongy body is increased; the storage level of cathode salts is increased; and the preferable proportion of the cathode salts allows both the emission behavior and the stability of salts better. With the noble metal Re coating, the cost of target materials is reduced. The consumption of noble metal is greatly reduced while ensuring the maximal emission and long service life of alloy substrate film-coated cathodes. The storage quantity of cathode salts is increased and the service life of cathode is prolonged.

Cathode is composed of 10-30% wt iridium powder and 70-90% wt tungsten powder, and dipping aluminate is in small opening. Preparation method is as following: annealing is carried out for iridium powder and tungsten powder in hydrogen furnace under 1000-1500deg.C; mixing iridium powder and tungsten powder and grinding the mixture evenly; pressing the mixture by stamper with molybdenum tube being inside so as to prepare flat-headed cathode; putting cathode in hydrogen furnace for heat preservation 1-10 hours under 1500-2000 deg.C; putting cathode in aluminate powder, at hydrogen atmosphere, 1500-2000 deg.C for 1-10 minutes and cleaning out float salt; installing heater obtains cathode needed.

The invention discloses a small-size and miniwatt hollow barium-tungsten cathode for an electric thruster. Barium-tungsten emissive material conducts thermionic emission through external heating. The small-size and miniwatt hollow barium-tungsten cathode is small and compactly structured, is mainly applied to low-power Hall thrusters and ion thrusters, and can provide high energy electrons for ionization of propellant and neutralize plume flows of the thrusters. A sidewise hole of a ceramic separation blade is used for introducing a heating wire, and a cathode pipe ceramic sleeve prevents contact of the wire and a cathode pipe to prevent short circuit due to contact of the wire and the cathode pipe. When the heating wire heats an emitter to 1100 DEG C, high voltage is applied on a contact holding stage for igniting. After successful ignition, the heating wire can be turned off and a self-holding heating mode is on. Electrons generated in the hollow cathode are sprayed to a high potential area on the downstream of the cathode, thereby completing thermionic emission.

The invention relates to a manufacture method of an annular barium-tungsten cathode emitter. The manufacture method comprises the following steps of: putting a molding mould in a latex sleeve, loading tungsten powder and then packaging; carrying out isostatic pressing; washing and removing the latex sleeve and putting the molding mould in a tungsten-mesh hydrogen furnace for heating and sintering at low temperature; roughly lathing, unloading mould, and cutting off to obtain a rough lathed tungsten blank; putting the tungsten blank in the tungsten-mesh hydrogen furnace and heating and sintering at high temperature; coating an active substance aluminate, putting the tungsten blank into a molybdenum-shell hydrogen furnace and heating and dipping; clamping and boring; and fine lathing the excircle and both end faces. The invention adopts a copper dipping free process and uses a molybdenum rod to process the tungsten molding mould. The method is simple and practical, saves resources and has low production cost, and because processes of dipping and removing the copper are saved, a horizontal hydrogen furnace used for dipping the copper and a vacuum degassing furnace used for removing the copper in practical production are saved, thus funds of about 500 thousands RMB can be saved. The method has quite obvious application prospect in the production of electric vacuum devices.

Provided is a cathode material which becomes an alternative material of a cathode material formed of a W—ThO₂ alloy and is formed of a tungsten alloy that does not include thorium which is a radioactive element. When particles of a rare earth oxide and tungsten carbide are finely dispersed in a tungsten cathode material used as a discharge cathode material used in TIG, plasma spraying, plasma cutting, electrical discharge machining, discharge lamps and the like, reduction and diffusion of the rare earth oxide are accelerated, and supply of rare earth elements to a cathode surface is ensured, thereby improving discharge characteristics.

The invention provides a Wu fiber-based impregnated Ba-Wu cathode, its components in weight percent: Wu fiber 10-30% and Wu powder 79-90% and its hole is impregnated with aluminate. Its preparing method: place Wu fibe and Wu powder 1000-1500 deg.C in hydrogen furnaces for annealing, respectively; in weight percent, take Wu fiber 10-30% and Wu powder the rest to grind and mix uniformly and make all the fiber ports show certain directionality. Use press mould with Mo tube inside to press the mixture into flat-roofed cathode body; place the cathode body in hydrogen furnace: when the temperature reaches 1500-2000 deg.C, preserve heat for 1-10 hours; place in aluminate powder and in a hydrogen atmosphere, to dip for 1-10 minutes at 15000-2000 deg.C, and then eliminate the floating salt by Wu sleave group; install ohmic heating carrier getter to make it.

The invention provides a preparation method of a rhenium doped tungsten-based alloy cathode. The preparation method comprises the steps of: mixing metal tungsten powder with rhenium powder to obtain evenly mixed tungsten-rhenium alloy powder; mixing the tungsten-rhenium alloy powder with 1.5wt% nitro-cotton solution evenly, applying the mixed solution to the surface of a tungsten cathode substrate, and baking; and placing a tungsten wire with the tungsten-rhenium alloy powder applied on surface into a high-temperature hydrogen furnace, and keeping the tungsten wire at the temperature of 1600+/-50 DEG C for 10-15 minutes, thereby preparing the rhenium doped tungsten-based alloy cathode. The invention further provides the rhenium doped tungsten-based alloy cathode prepared by adopting the method. The rhenium doped tungsten-based alloy cathode provided by the invention can increase emission current density of a pure tungsten cathode used for a high-power continuous wave magnetron, reduce working temperature of the pure tungsten cathode, reducing surface evaporation rate of the cathode, and further prolonging service life of the cathode.

The invention discloses alloy solder for dipping a barium tungsten cathode and a welding method thereof. The alloy solder consists of cobalt powder and tungsten powder which respectively have the average grain size of between 1 micrometer and 10 micrometers and the purity of between 99.0-99.99 percent and are fully mixed after hydrogen purification. The welding method mainly comprises the two steps of: preparing the alloy solder and welding a tungsten cake and a cathode cylinder. The invention has the beneficial effects that the melting point temperature of the alloy solder has good moderate flowing property and less evapotranspiration, is between the working temperature and the melting point temperature of a cathode activity material and can not cause the precipitation of the cathode activity material in the welding process; with the adoption of the alloy solder and the welding method, the tungsten cake dipped into the cathode activity material forms an effective welding with a molybdenum tube on a whole contact surface; and the alloy solder has high repeatability, stability and reliability.

The invention discloses a thin film scandium-tungsten cathode and a preparation method thereof, and the thin film scandium-tungsten cathode and the preparation method thereof belong to the field of microwave vacuum electronic apparatuses. The thin film scandium-tungsten cathode comprises a cathode matrix; a molybdenum shielding barrel is arranged at the lower part of the matrix; a heater assembly is arranged in the shielding barrel; and a synthetic scandium-tungsten covering film is arranged on the surface of the top of the cathode matrix. The preparation method of the thin film scandium-tungsten cathode comprises the following steps: preparing the cathode matrix, assembling the cathode matrix with the molybdenum shielding barrel, dipping an active emitting substance, processing the surface of the cathode, and sputtering a scandium-tungsten film in a direct current way. By using the cathode prepared by the method, the electron emission capacity is increased beneficially, and the emission uniformity is improved.

The invention discloses cathode salt, a preparation method of the cathode salt, a barium tungsten cathode comprising the cathode salt and a preparation method of the barium tungsten cathode. The cathode salt includes components, by weight, 3-4 parts of barium carbonate, 0.3-0.8 part of calcium carbonate and 1.5-2.5 parts of aluminum powder. The preparation method of the cathode salt includes weighing, ball milling, drying and synthesizing. The barium tungsten cathode prepared by the cathode salt has high emitting power which can be up to hundreds of amperes and meets the requirements of high-power and high-frequency development of microwave devices.

The invention provides a high-thermal-conductivity insulating medium fast-heating cathode hot wire assembly and a preparation method thereof. The high-thermal-conductivity insulating medium fast-heating cathode hot wire assembly comprises a tungsten cathode (1), a cathode tube (2), hot wires (3) and an insulating medium (4). The cathode tube (2) and the hot wires (3) are closely packaged into an integrated structure through the insulating medium (4). High-solid-content ceramic slurry is prepared by mixing organic solvents of alcohol and the like and aluminum nitride powders; the slurry is poured into the cathode tube and the hot wires are added to the cathode tube; and the high-thermal-conductivity insulating medium fast-heating cathode hot wire assembly is obtained through high-temperature sintering after centrifugal treatment and forming densifying. The high-thermal-conductivity insulating medium fast-heating cathode hot wire assembly is far higher in thermal conductivity than a conventional aluminum oxide ceramic assembly, and has higher heat transfer efficiency; the cathode hot wire assembly is shorter in preheating time, and can reach an operating temperature of 1050 DEG C within 5 s; the cathode hot wire assembly is higher in high-temperature strength and good in antiknock performance, meets the quick starting requirement under high shock vibration, is excellent in performance, high in reliability and long in service life, and can be widely applied to a quick start traveling-wave tube.

The invention discloses a storage film-coating dipped barium-tungsten cathode and relates to an electron device technology. The cathode adopts the following chamber tungsten sponge matrix structure: the cathode is divided into both inner and outer tungsten sponge matrixes; the inner end face of the inner tungsten sponge matrix is fixedly connected with a partition; the rest faces of the inner tungsten sponge matrix are coated with the outer tungsten sponge matrix; the lateral surface of the outer tungsten sponge matrix is fixedly connected with the inner wall of another accommodating cavity; the inner tungsten sponge matrix has porosity of 40 percent to 45 percent; the outer tungsten sponge matrix has porosity of 20 percent to 22 percent; and the outer end face of the outer tungsten sponge matrix is coated with a 0s-Ir-Al film. The cathode disclosed by the invention has the characteristics of large emission current density, long service life and the like; and a DC (Direct Current) emission volt-ampere characteristic curve result shows that when the working temperature of the cathode is 950 DEG C, a current of a deviated point can reach 5A/cm<2>. According to the invention, the emission current density of the barium-tungsten cathode is improved; storage of active materials is improved; the service life of the cathode is prolonged to 12 to 15 years; and the development requirement of a space travelling wave tube on the long service life of the hot cathode is met.

The invention relates to the field of metal material manufacturing technology, and specifically relates to a negative electrode material for a high intensity discharge lamp and a manufacturing method thereof. The negative electrode material comprises the following components: 1.5%-2.0% of thorium oxide, 0.0020%-0.0080% of potassium and 97%-98% of tungsten. Compared with a conventional negative electrode material, the negative electrode material provided by the invention has the following advantages that (1) thorium oxide particles of a thorium tungsten negative electrode even if 0.0020%-0.0080% of potassium is doped are fine and uniformly distributed; and (2) the thorium tungsten negative electrode contains a trace amount of potassium element, and by adopting the potassium-doped tungsten thorium negative electrode, the growth speed of crystal particles is slow, the tip shape of the electrode can be stably maintained, and the service life of the discharge lamp is prolonged.

The invention discloses aluminate for assembling barium-tungsten cathode of diode and a preparation method thereof. The aluminate is formed by 5.6 to 5.8 moles of barium carbonate, 1.2 to 1.4 moles of calcium carbonate and 4.0 moles of aluminium hydroxide. Experiment study indicates that the mixing ratio of the components is reasonable, that the prepared aluminate has high emission performance and high anti-poisoning performance, and that the service life of the assembled cathode is long. The preparation method of the aluminate has high operability and reasonable process design; and particularly, under optimal pressing mode, sintering temperature, sintering heat-preservation time, sintering atmosphere and the like, the preparation method can prepare the aluminate which has high emission performance and long service life and can meet requirements for high-standard traveling-wave diode cathode assembly.

The invention discloses a preparation method of a tungsten cathode for molten salt electrolysis, which comprises the following steps: sequentially carrying out laser cladding on the surface to be subjected to laser cladding of a tungsten substrate in copper, stainless steel and an anti-corrosion metal composite material to obtain the tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer; wherein the surface to be subjected to laser cladding is the surface of the tungsten substrate in the area between the 1/10 position of the length of the tungsten substrate and the 1/4 position of the length of the tungsten substrate from the same end part of the tungsten substrate; the anti-corrosion metal composite material is prepared from the following components: 0.02 wt%-0.06 wt% of C, 1.5 wt%-2.5 wt% of Si, 2.5 wt%-3.5 wt% of W, less than or equal to 7 wt% of Fe, 10 wt%-20 wt% of Mo, 20 wt%-30 wt% of Cr, 8 wt%-20 wt% of ZrO, 0.4 wt%-0.8 wt% of B and the balance Ni. According to the method, the service life of a traditional tungsten cathode can be prolonged from about 200 days to 310-320 days.

The present invention relates to a high ampere density electron emitter material and a manufacture method thereof, in particular to a high ampere density electron emitter material having zirconium-tungsten matrix and the manufacture method thereof; the basal body of the material of the invention is zirconium dioxide and tungsten; tungsten powder is weighed, annealed in a hydrogen furnace, then grinded, and filtered with a screen of 80 meshes; the filtered tungsten powder and ZrO2are grinded to be even, then molded, and disposed in aluminate powder and immersed in hydrogen circumstance; after the floating salt is removed, the electron emitter material is made. The average pore diameter of the zirconium-tungsten basal body made by the invention becomes smaller, and the pore diameter distribution becomes narrower; when the working temperature is 1050 DEG C, the current density emitted by the cathode of the invention is 1.73 to 1.86 times larger than that of the traditional barium-tungsten cathode.