67results about How to "Composition control with high precision" patented technology

The invention relates to a preparation method of a rare earth microalloyed high-density high-strength tungsten-nickel-copper alloy. The preparation method comprises the following steps: firstly, preparing tungsten nitrate, nickel nitrate, copper nitrate, yttrium nitrate and water into a mixed solution according to a preset metering ratio, then preparing an alkali solution together with certain concentration of ammonia water solution, stirring the alkali solution, crystallizing, filtering, washing and drying to obtain precursor powder; placing the precursor powder into a reducing atmosphere furnace for dissociating and reducing, to obtain yttrium-containing tungsten-nickel-copper alloy powder; and grinding the alloy powder and mixing together with a forming agent and press-forming, dewaxing the formed blank and performing high-temperature sintering to finally obtain the rare earth microalloyed high-density high-strength tungsten-nickel-copper alloy. The tungsten-nickel-copper alloy prepared by taking the rare earth microalloyed tungsten-nickel-copper alloy powder prepared by adopting a liquid/liquid doping method as a raw material through a proper powder metallurgy technology has the advantages that the density is more than or equal to 18.1g/cm<3>, the tensile strength is more than or equal to 850MPa, and the yielding strength is more than or equal to 690MPa.

The invention discloses a preparation method of a cell structure gradient tungsten alloy material. The preparation method comprises the following steps that high-tungsten base prealloy powder and low-tungsten base prealloy powder are obtained through prealloying treatment in advance, after the high-tungsten base prealloy powder is atomized and pelletized and is uniformly mixed with the low-tungsten base prealloy powder, compression forming is carried out in a cold isostatic pressing machine, two-step sintering is carried out in a high-temperature vacuum tube type furnace, and finally the cellstructure gradient tungsten alloy material is obtained.

The invention discloses a preparation method of W-Ni-Cu prealloyed powder. The preparation method comprises the steps that NiCl2 6H2O, CuCl2 and deionized water are prepared into a solution, and then WO3 powder is added into the solution; a (NH4)2C2O4 solution is added into turbid liquid according to the volume ratio; the solution is filtered and dried in air, and precursor powder is obtained; dried powder is placed in a tube furnace to be reduced under the hydrogen atmosphere condition; and high energy ball milling is carried out on the reduced powder, and the W-Ni-Cu prealloyed powder is finally obtained. The average particle size of the W-Ni-Cu prealloyed powder prepared through the method is smaller than or equal to 0.2 micron, and the distance between dissimilar metal atoms is smaller than or equal to 580 pm.

The invention discloses a method for preparing water-permeable bricks from vanadium-titanium magnetite tailings. The method includes: performing roughening treatment to obtain activated vanadium-titanium magnetite tailings, subjecting to mixed ball milling along with strengthening materials, a foaming agent and an activating agent, adopting a low-pressure mould for compression molding, and finallysubjecting to foaming, sintering and subsequent treatment in a tunnel kiln to obtain a water-permeable brick material. By adoption of the vanadium-titanium magnetite tailings as a main material, high-water-permeability bricks are prepared according to a surface strengthening process through adding of the strengthening materials, the foaming agent and the activating agent, and water resistance ofpavement bricks is remarkably improved. The prepared water-permeable bricks have comprehensive strength larger than or equal to 12400MPa, porosity larger than or equal to 23.6% and through hole rate larger than or equal to 22.9%.

The invention discloses a method of preparing ferrotitanium alloy powder by adopting ferrovanadium slag and vanadium-titanium magnetite tailings. The method comprises the following steps: first, carrying out ball-milling treatment on mixed powder of ferrovanadium slag, graphite powder and calcium carbonate powder and then pre-sintering mixed powder of the vanadium-titanium magnetite tailings, sodium oxide and calcium chloride at a low temperature in a sintering furnace; granulating and degreasing the prepared two types of mixed powder; and finally, reductively sintering, crushing and screeningthe degreased powder to obtain the ferrotitanium alloy powder material finally. The method has the advantages of being high in component control precision, good in process stability and relatively high in repeatability, and high purity ferrotitanium alloy powder can be prepared.

The invention discloses a preparation method of a multilevel strip-shaped crystalline tungsten alloy material. The preparation method comprises the following steps of firstly, carrying out turning-over frequency vibration impact treatment on mixed powder of tungsten powder, titanium powder and yttrium powder in a certain proportion, adding a seaming agent into the obtained micron-sized layered tungsten-based composite powder to carry out biaxial micro-rolling continuation, degreasing, pressing, forming, and finally, placing the material in a normal-pressure inert atmosphere heat collection device for firing and molding to finally obtain the multilevel strip-shaped crystalline tungsten alloy material. The method has high component control precision, strong process stability and strong repeatability, and can realize strengthening and toughening and long service life of the tungsten alloy material.

The invention discloses a method for preparing microcrystal foam glass from vanadium titano-magnetite tailings. Pickling is firstly carried out, so that activated vanadium titano-magnetite tailings are obtained, the activated vanadium titano-magnetite tailings, correcting material, a cosolvent and a foaming agent are mixed and ball-milled, the mixture is pressed to be shaped in a cold press, and is finally melted, crystallized and treated by heat in a sintering furnace, and ultimately, the microcrystal foam glass material is obtained. With vanadium titano-magnetite tailings as a main material,by adding the correcting material, the foaming agent and the cosolvent and adopting the crystallization process, the method can prepare the foam glass containing a small amount of microcrystals, thematerial cost is greatly reduced, and the toughness of the glass is increasedimproved. The method has the advantages of high component control precision and high process stability and repeatability, and can achieve higher industrial added value from vanadium titano-magnetite tailings.

The invention discloses a preparation method of a complex-phase co-strengthening hard alloy material. According to the method, firstly, pre-alloying treatment is carried out to obtain tungsten carbidebase pre-alloying powder and titanium carbonitride base pre-allying powder, the two kinds of powder are mixed with cobalt powder uniformly, the powder is subjected to secondary atomizing, drying andpelletizing, then pressed and formed in a cold pressing machine, and finally sintered in a high-temperature vacuum pipe type furnace, and finally, the complex-phase co-strengthening hard alloy material is obtained.

The invention discloses a method for preparing an unglazed stair brick from vanadium-titanium magnet tailings. The method comprises the following steps: firstly, performing refining treatment to obtain micron-sized active vanadium-titanium magnet tailings, mixing the micron-sized active vanadium-titanium magnet tailings with a correcting raw material, an oxidant and a cosolvent, mounding, finallysintering in a pushed slab kiln, and performing surface wear resisting treatment to finally obtain an unglazed stair brick material. By the method, with the vanadium-titanium magnet tailings as a mainraw material, through addition of the correcting raw material, the oxidant and the cosolvent and by a surface wear resisting technology, preparation of the unglazed stair brick is achieved, the costof the raw materials is greatly reduced and the wear resistance of the surface of the brick is improved. The unglazed stair brick prepared by the method provided by the invention has the compressive strength being higher than or equal to 14100 MPa, the surface hardness being higher than or equal to 6800 MPa and the porosity being lower than or equal to 2.6%.

The invention provides a stripped tungsten alloy material with a self-sharpening structure, as well as a preparation method and application thereof, and belongs to the technical field of tungsten alloy preparation. The preparation method comprises the steps of carrying out pulse reduction plasma jet treatment and cooling treatment on mixed powder obtained after mixing tungsten oxide powder, nickeloxide powder and ferric oxide powder, and obtaining tungsten-nickel-iron prealloyed powder; carrying out four-stage roll forming treatment on the tungsten-nickel-iron prealloyed powder, and obtaininga plate type tungsten-nickel-iron alloy; carrying out roll-bending deformation treatment on the plate type tungsten-nickel-iron alloy, and obtaining a deformed tungsten-nickel-iron alloy; and carrying out warm-pressing densification treatment on the deformed tungsten-nickel-iron alloy, and obtaining the stripped tungsten alloy material with the self-sharpening structure. According to the strippedtungsten alloy material with the self-sharpening structure, as well as the preparation method and the application thereof provided by the invention, through adopting a pulse reduction plasma jet technology, four-stage roll forming treatment, roll-bending deformation treatment and warm-pressing densification treatment, the technical advantages of chemical reduction and plastic deformation are fully played, so that the compatibility of the strength and the plasticity of the tungsten alloy material can be optimized, and the obtained stripped tungsten alloy material with the self-sharpening structure has a better adiabatic shear performance.

The invention discloses a preparation method of a silicon nitride high-temperature ceramic material in a multistage twin structure. The method comprises processing monatomic silicon powder at high impulse, subjecting the processed monatomic silicon powder to reaction with nitrogen to obtain silicon nitride nanopowder, adding in gel for nodulizing and degreasing shaping to obtain a cold pressing blank, and sintering the shaped cold pressing blank at ultrahigh pressure and high temperature to obtain the silicon nitride high-temperature ceramic material in the multistage twin structure. The preparation method of the silicon nitride high-temperature ceramic material in the multistage twin structure is high in composition control precision, technical stability and repeatability and capable of achieving high-temperature toughening of silicon nitride ceramic materials.

The invention discloses a low-density anti-corrosion hard alloy material and a preparation method thereof. Tungsten carbide powder, cobalt powder and calcium carbonate powder are weighed according tomass percent and are put in a cold pressing machine to be made into cylindrical green bodies after being evenly mixed in a three-dimensional vortex material mixing machine; and the premade green bodies and nickel-based high-temperature brazing filler metal are put into a high-temperature electric conduction mould according to the mass ratio and are fired into the low-density anti-corrosion hard alloy material in a double-shaft high-pressure infiltration device.

The invention discloses a preparation method of a multi-scale spherical-grain hard alloy material. The preparation method comprises the steps that tungsten carbide powder is reduced through positive-pressure shearing and micro-grinding treatment, then selective nano-cobalt plating is conducted, a gelling material is added into obtained polygonal tungsten carbide composite powder locally wrapped with a cobalt film for grinding and pelletizing, high-temperature steady-state re-crystallization is conducted after degreasing; and finally, the powder is placed in an over-pressure heat-collection vacuum device to be sintered and molded, so that a multi-scale multi-layer interface hard alloy material is obtained. The preparation method of the multi-scale spherical-grain hard alloy material has theadvantages that the component control precision is high, the process stability and repeatability are high, high strength and toughness of the hard alloy materials are achieved, and the long service life of the hard alloy material is also achieved.

The invention discloses a method for preparing a porous ceramic material from vanadium-titanium magnetite tailings. The method comprises the following steps: firstly, treating the vanadium-titanium magnetite tailings by a polyacid leaching method, placing the treated vanadium-titanium magnetite tailings, aluminum oxide powder, calcium carbonate powder and glass powder into a backflow-type wheel-milling blowing device according to a certain ratio for refining, then putting the refined mixture into a slow-speed eccentric stirring device, adding water for pulping, carrying out water displacementtreatment, and finally carrying out foaming formation in a high-temperature blast heat-collection device to finally obtain the porous ceramic material. The method has the advantages that the componentcontrol precision is high, process stability and repeatability are relatively high, and high industrial additional values of the vanadium-titanium magnetite tailings can be realized.

The invention provides a low-tungsten-carbide-adjacency hard alloy and a preparing method thereof, and belongs to the technical field of tungsten alloy preparation. The preparing method includes the following steps of sequentially performing balling treatment and screening treatment on tungsten carbide powder to obtain screened powder, spray-coating the surface of the screened powder with a cobaltfilm to obtain cobalt film and tungsten carbide composite powder, mixing the cobalt film and tungsten carbide composite powder with tantalum carbide powder, performing interface diffusion heat treatment under the stirring condition to obtain precursor powder, and performing selected laser sintering on the precursor powder to obtain the low-tungsten-carbide-adjacency hard alloy. The hard alloy prepared through the method has the low tungsten carbide adjacency, the excellent mechanical properties, the tungsten carbide adjacency of lower than or equal to 4.3%, the microhardness of higher than orequal to 14.5 GPa, the bending strength of higher than or equal to 2550 MPa and the breaking tenacity of higher than or equal to 11.3 MPa.m[1/2].

The invention provides a remelting method for producing titanium iron, and belongs to the technical field of iron alloy smelting. The invention solves the technical problem of remelting method for producing titanium iron. The method uses ordinary iron as an iron source; molten iron smelting is carried out to control the impurities in the molten iron within 0.5%; the molten iron is heated to higher than 1700 DEG C, and hanged in vacuum or inert gas protection; and a titanium source is added in molten iron; constant bottom blowing of inert gas is carried out; and then casting cooling is carried out. The method of the invention can not only produce titanium iron series products with different titanium content requirements, and the production method is simple, has the advantages of high component control precision, low content of impurity and harmful elements; and the titanium iron product has high quality. The invention effectively solves the problems of difficult control and high content of impurities in a traditional titanium iron production process.

The invention discloses a method for preparing ceramic fritted glaze from vanadium titano-magnetite tailings. The method comprises the following steps: weighing the vanadium titano-magnetite tailings,a correction raw material and a decolorizing agent according to a certain ratio, performing ball-milling, putting the materials into a natural gas furnace, performing high-temperature melting, putting the obtained glaze high-temperature liquid into frit cutting and quick-cooling equipment, quickly cooling the liquid to prepare blocks, and finally grinding the blocks in a vertical mill to obtain the ceramic fritted glaze. The method has the advantages of being high in component control precision and high in process stability and repeatability, and fine application and a high utilization rate of the vanadium titano-magnetite tailings can be achieved.

The invention discloses a multi-scale multi-layered interface cemented carbide material preparation method. Firstly, impact treatment is conducted on tungsten carbide powder, the tungsten carbide powder is mixed with zirconium dioxide whiskers, then a spherical agent is added for stirring granulation, the obtained product is mixed with the cobalt powder after degreasing, finally, the mixed powderis placed in a hydraulic fast-heating device for burning molding to obtain a multi-scale multi-layered interface cemented carbide material finally. The method has high component control precision andhigh process stability and repeatability, and can realize the high toughness and long service life of the cemented carbide material.