Abstract: Solid solutions of molybdenum and tungsten having molybdenum to tungsten atom ratios between about 1:1 and about 10:1 are produced by heating a mechanically milled mixture of a molybdenum oxide and tungsten oxide to a temperature between about 1000.degree. C. and about 1300.degree. C. at a rate of at least about 20.degree. C. per minute in a hydrogen-containing atmosphere and holding at temperature to reduce the oxides of molybdenum and tungsten and to provide a homogeneous solid solution of molybdenum and tungsten. The homogeneous solid solution is mixed with a stoichiometric excess of carbon and heated to a temperature between about 1200.degree. C. and about 1800.degree. C. under a protective atmosphere to react the carbon with the alloy powder to form a solid solution of hexagonal monocarbides.

Abstract: A uniform, large size tungsten powder having properties which make it suitable for producing large size tungsten carbide powder is produced by doping a tungsten oxide starting powder with a lithium compound prior to reduction

Abstract: The present invention relates to a process for the production of a solid solution constructed of at least one hard phase having a crystal structure of simple hexagonal type and selected from mixed carbides or carbonitrides of molybdenum and tungsten, which process comprises preparing an alloy powder consisting of a solid solution of molybdenum and tungsten, adding to the alloy powder carbon in an amount necessary for forming (Mo, W).sub.2 C and/or (Mo, W).sub.2 (CN), heating the mixture at a temperature at which (Mo, W).sub.2 C and/or (Mo, W).sub.2 (CN) is stable, adding to the (Mo, W).sub.2 C and/or (Mo, W).sub.2 (CN) carbon in an amount necessary for forming (Mo, W)C and/or (Mo, W)(CN) optionally with an iron group metal and then heating the mixture at a temperature at which (Mo, W)C and/or (Mo, W)(CN) is stable.

Abstract: A method for imparting ductility and very high electrical conductivity to very brittle refractory single crystals by subjecting said crystals to a hydrostatic deformation technique at room temperature and at pressures of from about 5 to 25 kilobars.

Abstract: Selected portions of metal carbide are recovered from scrap material containing pieces of cemented metal carbide having various compositions of metal carbide distributed in a matrix material. The scrap material is treated with a suitable liquid for a sufficient period of time to dissolve the matrix material and form a piece of matrix depleted metal carbide which is introduced as a feed into a ferrofluid material. A magnetic field is passed through the ferrofluid for positioning pieces of metal carbide of the type having a heavier density spaced from pieces of metal carbide of a lighter density. The separated portions of matrix depleted metal carbide are collected to produce metal carbide powder which may be further reprocessed to produce a desired cemented metal carbide.

Abstract: A process for the preparation of an extrahard material based on tungsten and molybdenum carbides and having a hexagonal crystal structure identical with that of tungsten carbide. According to this process, one heats between 1000.degree. C. and a temperature T.sub.x, which is lower than the maximum stability limit of the Mo.sub.x W.sub.l-x C phase wherein 0.01.times.1, a mixture, intimate to the molecular or atomic scale, of tungsten and molybdenum the total content of which in Fe, Ni and Co does not exceed 0.1% with carbon and/or a carbon compound.T.sub.x is defined as follows:For 0.01<.times.<0.8, T.sub.x =2700-1375x.degree.C;For 0.8<.times.<1, T.sub.x =3400-2250x.degree.C.

Abstract: Metal carbide powders containing free carbon which have heretofore been difficult to refine can be refined excellently by charging the metal carbide powders in a fluidizing bed consisting of fluidized heat-resistant particles and having a temperature of a determined range to burn and remove the free carbon contained therein, and by subsequently discharging refined metal carbide powders and combustion gas from an upper part of the fluidizing bed for recovery of the refined metal carbide powders.

Abstract: The present invention relates to a method for producing gaseous or liquid fuels or hydrocarbons from solid mineral sources and, more particularly, to a process for producing solid compounds, hereinafter designated fuel precursors, capable of releasing or generating flammable gases or liquids by chemical and/or physical conversion phenomena and to the process and methods to accomplish said fuel generation. The fuel precursors consist primarily of carbides formed from two or more metallic elements combined with carbon. The precursors additionally may contain minor amounts of free metal, unreacted carbon or other impurities.

Abstract: Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt nickel, iron, and copper. The scrap is calcined with sodium carbonate in air to convert the refractory metal values to MoO.sub.4.sup..dbd., VO.sub.4.sup..tbd., WO.sub.4.sup..dbd., CrO.sub.4.sup..dbd., and the base metals to water insoluble oxides. A leach of the calcined materials produces a pregnant liquor rich in refractory metals which, after separation of the vanadium, molybdenum and tungsten values, is treated with CO, CHOO.sup.-, CH.sub.3 OH, or HCHO to reduce Cr.sup.+6 to Cr.sup.+3. The carbonate and bicarbonate salts produced as a byproduct of the reduction are recycled to the calcination stage.As a result of the V, W, and Mo partition, a mixed solid comprising CaO.multidot.nV.sub.2 O.sub.5, CaMoO.sub.4, and CaWO.sub.4 is produced.

Abstract: In order to prevent a protective carbide layer on a graphitic molded article from splitting off under thermal stress, an external carbide layer is provided on a graphitic molded article having a graded content of silicon or zirconium (in the carbide state) that increases from near zero at the interior boundary of the layer to about 50 atomic percent at the exterior. Such a layer is produced either by dipping the graphitic molded article into melted silicon, dipping it into a succession of suspensions of carbon and either silicon or zirconium, with a greater silicon or zirconium content in each successive dip, the suspensions also including a binder resin, or by applying layers of a paste of carbon and either silicon or zirconium, also with some resin, each successive layer having a higher silicon or zirconium content.

Abstract: A process for preparing ultrafine carbide powder of silicon or titanium and other carbide which are used as refractory materials comprises the steps of passing electric current to a carbon member held in contact with a material such as silicon in a vacuum vessel into which an inert gas at a desired pressure is introduced and collecting a carbide powder of the material fuming into the gas as a result of a high-temperature reaction between the material and carbon member in contact, thus producing carbide powder of ultrafine particles and of high-purity with high efficiency. A preheater facilitates the passing of electricity through the material by reducing the resistance thereof and leads to efficient preparation of the ultrafine carbide powder.

Abstract: A process for forming a WC-Mo C solid solution alloy starts by first intensely milling, such as dry attritor milling, Mo and W metal powders, followed by a homogenization heat treatment of about 1400.degree. to 1500.degree. C. to form an Mo-W solid solution alloy. The Mo-W solid solution alloy is then crushed to form a fine powder and mixed by ball milling with the appropriate amount of carbon plus cobalt. The milled alloy powder is then heated at approximately 1100.degree. to 1400.degree. C. to form the desired WC-Mo C alloy.

Abstract: The present invention relates to a process for the production of an alloy powder (Mo, W) for powder metallurgy, which comprises chemically or mechanically mixing molybdenum and tungsten in the form of compounds and reducing the mixed powder with hydrogen, and a process for the production of a hard solid solution (Mo, W)C from the alloy powder (Mo, W), which comprises carburizing the alloy powder (Mo, W).

Abstract: Fine grain metal carbide powders are conveniently prepared from the corresponding metal oxide by heating in an atmosphere of methane in hydrogen. Sintered articles having a density approaching the theoretical density of the metal carbide itself can be fabricated from the powders by cold pressing, hot pressing or other techniques.

Abstract: A process for the production of a tungsten carbide catalyst by carburization of tungsten oxides, comprises, directing a mixture of carbon monoxide and carbon dioxide over tungsten oxide while heating it in a heated reactor at a heating rate and gas flow rate such that the reduction of the tungsten oxide occurs more slowly than the diffusion of the carbon into the tungsten and into tungsten carbide which is formed during the reaction with the diffusion being faster than the separation of carbon from the gaseous phase according to the rate of adjustment of the Boudouard equilibrium. The carbon monoxide is charged at a rate of 560 1tr/h and the carbon dioxide is charged at a rate of 40 1tr/h and, after a reactor containing the sample of tungstic acid is positioned in a closed reactor, the reactor is flushed with the gases for around ten minutes and then placed into a muffle furnace. The reactor is heated to a temperature of 670.degree. C.

Abstract: A plasma-arc process is disclosed for the production of powders of various chemical products, according to endothermic reactions, such as TiC and the like. The process consists essentially in carrying out, in a furnace with an anodic function without dissipative cooling, a series of steps comprising:(a) forming a chemically reactive fluidodynamic mass having a high thermal content and a high concentration of the desired reactive species, by injecting into the electronic column of a plasma-arc of a noble gas at least one reactant selected from the class consisting of metal and metalloid halides, the injection taking place, with mixing through a choker-injector-mixer nozzle which is electrically insulated;(b) causing the electronic condensation of said mass inside a main nozzle anode without dissipative cooling; and(c) injecting into said electronically condensed mass the residual part of said reactants necessary to the desired main chemical reaction for producing the chemical powder.

Abstract: Flexible metal carbide fabrics are produced by a process that involves the steps of:(a) impregnating a preformed organic polymeric fabric with a solution of a metal compound;(b) heating the impregnated fabric to evolve volatile decomposition products and to leave a carbonaceous relic containing the metal in finely dispersed form; and(c) further heating the relic to 1000.degree.-2400.degree. C. in a non-oxidizing atmosphere to form the metal carbide. Boron carbide and silicon carbide fabrics produced by this process are attractive for high temperature structural applications.

Abstract: A process for preparing titanium carbide in accordance with the present invention comprises ignition of a mixture consisting of 80-88% by weight of a powder of commercial titanium and 20-12% by weight of finely divided carbon followed by an exothermal reaction of said mixture under the conditions of layer-by-layer combustion with the formation of gaseous by-products; the process is conducted in a porous casing which prevents the mixture from scattering in the course of its intensive cooling, and removing the gaseous products therethrough.The process according to the present invention makes it posible to produce titanium carbide with a content of combined carbon approaching the stoichiometric value (19.5-19.8% by weight), the content of free carbon of 0.08% by weight and oxygen 0.1% by weight. The process according to the invention makes it also possible to use, as the starting materials, commercial products, i.e. products containing impurities.

Abstract: A composition of material is disclosed which comprises sintered carbide-binder metal alloys. The carbide is a solid solution of hexagonal tungsten monocarbide and molybdenum monocarbide of stoichiometric composition containing between 10 and 100 mole percent molybdenum monocarbide. The binder is selected from the metals of the iron group, and comprises between 3 and 50 weight percent of the composition. A method for making the hexagonal carbide is also disclosed.

Abstract: A process for preparation of a metal carbide-containing molded product which comprises heating a molded composition comprising at least one powdery metal selected from the group consisting of B, Ti, Si, Zr, Hf, V, Nb, Ta, Mo, W, Cr, Fe and U and having an average particle size of not more than about 50 .mu. and an acrylonitrile polymer at a temperature of about 200.degree. to 400.degree. C and then calcining the resulting product at a temperature of about 900.degree. to 2500.degree. C in an inert atmosphere.

Abstract: The method of preparing very dense tungsten carbide bodies. A substantially stoichiometric mixture is prepared from tungsten particles and a carbon precursor, the precursor being a vinylidene chloride based polymeric material such as SARAN. A green body is pressed from the mixture, and said body is initially heated at a controlled rate to decompose on the order of 20% of the polymeric material, providing HCl gas which reacts with oxide contaminants on the metal particles to provide a clean, reactive metal surface for later reaction with the carbon. An intermediate baking step is provided to controllably evolve the gaseous products that result from continued decomposition of the polymeric material. After subsequent heating to 800.degree.-1300.degree. C, the body may be cooled to room temperature and machined to provide threads, apertures or the like. When the body is subsequently heated to about 2000.degree. C, it shrinks to provide a very hard, dense body with a typical density between 14 and 15 g/cc.

Abstract: Process for the preparation of reactive tungsten comprising reducing a tungsten compound in a reducing atmosphere at temperatures ranging from about 450.degree. C to 700.degree. C. The reactive tungsten can be readily converted to WC, W.sub.2 C or WN.

Abstract: If cemented carbide products such as hot rolling-mill rolls, plugs and dies can be made of the powder reclaimed from scrapped cemented carbide products and the virgin powder of cemented carbide, it is possible to obtain cemented carbide products lower in price and capable of meeting the requirements of severe working conditions.

Abstract: Finely divided borides, carbides, and nitrides of metals of Groups III-VI of the Periodic Table, formed by reacting vaporous metal halide and a boron, carbon, or nitrogen source reactant at high temperatures, e.g., 1500.degree. C., are separated from gaseous reactor effluent stream at temperatures between about 200.degree. C. and 1500.degree. C. with the use of a porous sintered filter. By separating the finely divided product from the effluent stream before the stream cools to below about 200.degree. C., adsorption of impurities, e.g., unreacted metal halide or metal subhalides, on the product is reduced. The use of a filter, e.g., a porous sintered filter, avoids the size classification of product which may result when cyclones and a bag filter are used to collect product.

Abstract: Refractory, hard carbide alloys, intended primarily as replacement for the cast eutectic WC + W.sub.2 C tungsten carbides currently used as hard components in wear-resistant facings, consist of fine-grained and hard two-phase mixtures of subcarbide, (Mo,W).sub.2 C, and hexagonal monocarbide (Mo,W)C, solid solutions, and are formed by solid state decomposition of the pseudocubic, .eta.-(Mo,W).sub.3 C.sub.2, or cubic .alpha.-(Mo,W)C.sub.1-x solid solutions. The carbide alloys of the invention can be combined with low-melting metal binders to form cemented carbide alloys of at least equivalent wear-resistance to alloys using the eutectic tungsten carbides.

Abstract: A composition of material is disclosed which comprises sintered carbide-binder metal alloys. The carbide is a solid solution of hexagonal tungsten monocarbide and molybdenum monocarbide of stoichiometric composition containing between 10 and 100 mole percent molybdenum monocarbide. The binder is selected from the metals of the iron group, and comprises between 3 and 50 weight percent of the composition. A method for making the hexagonal carbide is also disclosed.

Abstract: Chromium or other metal carbides are recovered from chromates or equivalent soluble metal salts in substantially pure form by solid state carburization. The chromates may be derived from low grade ore to provide an overall non-smelting procedure which is non polluting. The carbide may be formed into sponge metal.

Abstract: A process for the production of tungsten carbide or mixed metal carbides, which comprises mixing tungsten oxide powder of mixed high melting point metal oxide powders with carbon powder in an amount sufficient to form the corresponding carbide, heating the mixture at a temperature of higher than 1000.degree. C in an inert atmosphere or in vacuum to reduce the oxygen content and then heating at a temperature of higher than 1400.degree. C in hydrogen atmosphere, thereby to form tungsten carbide or mixed metal carbides directly from the corresponding oxide.

Abstract: Metal values present as oxides, hydroxides or carbonates in ores or processed concentrates thereof are converted to the corresponding carbide by a solid state reaction with carbon, the carbide then is separated in substantially pure form and may be used directly as ferroalloy or may be converted to the metal.

Abstract: The preparation of metal and metalloid carbides, borides, nitrides silicides and sulfides by reaction in the vapor phase of the corresponding vaporous metal halide, e.g., metal chloride, with a source of carbon, boron, nitrogen, silicon or sulfur respectively in a reactor is described. Reactants can be introduced into the reactor through a reactant inlet nozzle assembly. Inhibition and often substantial elimination of product growth on exposed surfaces of such assembly is accomplished by introducing the corresponding substantially anhydrous hydrogen halide, e.g., hydrogen chloride, into the principal reactant mixing zone.

Abstract: Pure monocarbides, or pure mononitrides or carbonitrides of metals are prepared by first forming a mixture of carbon with an oxalate of the metals and thermally decomposing the metal oxalate in the presence of the carbon by a stream of hydrogen. The hydrogen is removed and monocarbides are then formed by heating the decomposition products in vacuo to carbothermally reduce them. Mononitrides and carbonitrides can be formed by replacing the hydrogen with nitrogen and heating the decomposition products in the nitrogen.

Abstract: There is disclosed a process for reclaiming cemented metal carbide material by first subjecting the metal carbide material to catastrophic oxidation to produce a mixture of metal oxide and the oxide of the cement, reducing the metal oxide either mixed with the cement oxide or after being separated from it, and finally carburizing the reduced metal.

Abstract: A process suitable for recovering refractory metal carbide values from contaminated uncemented refractory metal carbides containing an iron group metal comprises heating an admixture of the powders of the contaminated refractory metal carbides and glacial acetic acid to the boiling point of the admixture for at least about 30 minutes, the weight of the powders divided by the weight of the acid is less than 5, thereafter removing the resulting carbide solids from the acid and washing the solids with sufficient water to remove the residual acid and drying the solids.

Abstract: Whisker crystalline silicon carbide is prepared by heating a silicon-containing material for example, elemental silicon, silicon oxides, silicon hydroxides, silicon salts and the like with a halogen and carbon-containing material, such as a mixture of hydrocarbon and chlorine-containing material selected from chlorine, hydrogen chloride, tetrachloromethane and phosgene and halogenated hydrocarbon at a temperature of 800.degree.C or higher under a substantial oxygen and nitrogen gas-free condition.

Abstract: Fine grain metal carbide powders are conveniently prepared from the corresponding metal oxide by heating in an atmosphere of methane in hydrogen. Sintered articles having a density approaching the theoretical density of the metal carbide itself can be fabricated from the powders by cold pressing, hot pressing or other techniques.