Refractory Metal Containing Patents (Class 423/440)
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Patent number: 5110768Abstract: A process for producing a refractory material having the form TB.sub.o, e.g. zirconium nitride (ZrN), includes a first step of mixing a first salt having the form TX.sub.n, e.g. zirconium tetrachloride (ZrCl.sub.4) and a second salt having the form A.sub.m B, e.g. lithium nitride (Li.sub.3 N) in a ratio of n/m in a container. The process also includes a second step of igniting the mixture of the first and second salts, e.g. ZrCl.sub.4 and Li.sub.3 N, whereby the refractory material, e.g. ZrN, is produced along with byproducts having forms nAX and (n/m-o)B, e.g. 4LiCl and (1/6)N.sub.2, respectively. The process further includes a third step of separating the refractory material from the byproducts by solvent extraction. The stoichiometric ratio of the second salt to the first salt is n/m, e.g. 4/3. T is selected from the group consisting of transition metals, e.g. zirconium, and tetrelides, i.e. carbon, silicon, germanium, tin and lead.Type: GrantFiled: January 28, 1991Date of Patent: May 5, 1992Inventors: Richard B. Kaner, Philippe R. Bonneau, Edward G. Gillan, John B. Wiley, Robert F. Jarvis, Jr., Rande Treece
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Patent number: 5102646Abstract: The invention relates to a method of fabrication in the powdered state of ceramic compounds formed between a metalloid and a refractory metal, characterized in that it involves the following steps:a) said metalloid is caused to react with a reducing metal within a liquid bath constituted at least partly by a fused salt of said reducing metal in order to obtain a saltlike intermediate compound which combines said reducing metal and the metalloid, in solution in said bath,b) a reducible salt of said refractory metal is then injected into said bath in a divided form which is directly distributed throughout the bath in order to produce said powder by reaction of the reducible salt with said intermediate compound of the reducing metal.Type: GrantFiled: April 20, 1990Date of Patent: April 7, 1992Assignee: CerexInventor: Gerard Bienvenu
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Patent number: 5096689Abstract: A molten blend of an alkali metal halide containing tungsten is treated with solid particulate carbonaceous reactants, such as natural flake graphite. Tungsten monocarbide is produced having a large percentage of relatively coarse crystals. The crystal morphology is blocky or thick bladed with some equant forms and the carbon is present in the correct stoichiometric amount of 6.13% by weight, thus eliminating any need for carbon additions prior to sintering.Type: GrantFiled: February 19, 1991Date of Patent: March 17, 1992Assignee: Kennametal Inc.Inventors: Charles J. Terry, Harold C. Newman
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Patent number: 5089447Abstract: A powdered admixture of a metal and its boron, carbon, nitrogen or silicon derivative is, when subjected to densification conditions, partially reacted and converted to a hard, wear resistant material. Such a material, when formed from an admixture of tungsten carbide and tungsten, contains tungsten monocarbide and (di-tungsten) carbide. Other choices of metal and metal derivatives produce at least one compound having a stoichiometry which differs from that of starting metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.Type: GrantFiled: October 9, 1990Date of Patent: February 18, 1992Assignee: The Dow Chemical CompanyInventors: Edward E. Timm, Ann M. McCombs
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Patent number: 5080927Abstract: A thin film formation method includes the steps of holding a substrate in a reduced-pressure vapor phase reaction chamber having means for irradiating light in visible and ultraviolet ranges, supplying an organo-titanium compound containing a tri-azo group, and vapor-depositing a titanium nitride film on a surface of the substrate by an excitation reaction caused by light.Type: GrantFiled: July 6, 1990Date of Patent: January 14, 1992Assignee: Nippon Telegraph and Telephone Corp.Inventors: Koichi Ikeda, Masahiko Maeda, Yoshinobu Arita
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Patent number: 5061661Abstract: A method is disclosed for producing tungsten carbide and a cemented tungsten carbide article therefrom which consists essentially of forming a uniform mixture of tungsten metal powder and carbon wherein the tungsten metal powder has an aveage particle size of from about 1 to about 4 micrometers in diameter, wherein the surface area of the carbon is no greater than about 12 m.sup.2 /g, and wherein the amount of the carbon is sufficient to react with essentially all of the tungsten to produce tungsten carbide in the subsequent heating step, heating the mixture in a non-oxidizing atmosphere at a temperature of at least about 1200.degree. C. for a sufficient time to produce tungsten carbide wherein the amount of free carbon is less than about 0.Type: GrantFiled: July 23, 1990Date of Patent: October 29, 1991Assignee: GTE Products CorporationInventors: David R. Moyle, Geoffrey L. Harris, Robert F. Northrop
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Patent number: 5045121Abstract: A method is disclosed for removing carbon from the surface of a cemented tungsten carbide article which comprises contacting a cemented tungsten carbide article with an aqueous solution of hydrogen peroxide having a concentration of at least about 5% by volume hydrogen perioxide for a sufficient length of time to remove the major portion of the carbon from the surfaces of the article.Type: GrantFiled: February 4, 1991Date of Patent: September 3, 1991Assignee: GTE Products CorporationInventors: Timothy J. Hoffman, Robert G. Mendenhall, Michael J. Cheresnowsky
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Patent number: 5017525Abstract: A process for the production of a precursor which is a polymeric material comprising at least one metallic or non-metallic element, oxygen and carbon and from which a ceramic material, e.g. a carbide, nitride, boride, or silicide, may be produced by pyrolysis, which process comprises reacting(1) a first reactant which comprises a compound or compounds of at least one metallic or non-metallic element having two or more groups reactive with hydroxyl groups, and(2) a second reactant which comprises at least one organic compound having two or more hydroxyl groups,said reaction being effected in a liquid medium in which the reactants are soluble and/or dispersible and in which the polymeric material which is produced by the reaction is insoluble or in which the polymeric material may be caused to be insoluble, precipitating the polymeric material in the liquid medium in particulate form, and recovering the polymeric material from the liquid medium in particulate form.Type: GrantFiled: March 17, 1988Date of Patent: May 21, 1991Assignee: Imperial Chemical Industries PLCInventors: James D. Birchall, Mary J. Mockford, David R. Stanley, Paul M. L. Asher, William R. McCarthy
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Patent number: 4983354Abstract: A tungsten carbide powder and cemented tungsten carbide article made from the powder are disclosed. The powder has a particle size of greater than 20 micrometers in diameter and no particles less than one-half the average particle size or greater than two and one-half times the average particle size.Type: GrantFiled: February 10, 1989Date of Patent: January 8, 1991Assignee: GTE Products CorporationInventors: David A. Reeder, Carlos Lopez, Jack L Burwick
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Patent number: 4980201Abstract: The invention relates to a chemical vapor deposition (CVD) method for forming tungsten carbide, W.sub.3 C, by subjecting a gas mixture of tungsten hexafluoride, hydrogen and an aromatic hydrocarbon, e.g. benzene, to vapor phase reaction at an elevated temperature. The reaction temperature can be lowered to the extent of 250.degree. C. and the reaction can be carried out even at normal pressure, not necessarily under reduced pressure, by proportioning tungsten hexafluoride, hydrogen and the hydrocarbon such that in the gas mixture the atomic ratio of C to W falls in the range from 2 to 10 while the atomic ratio of H to C is not lower than 3. By this method a W.sub.3 C film excellent in glossiness can be deposited on various metal parts without adversely affecting the metal parts by the elevated temperature.Type: GrantFiled: March 7, 1989Date of Patent: December 25, 1990Assignee: Central Glass Company, LimitedInventors: Nobuyuki Tokunaga, Yasushi Kita
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Patent number: 4961913Abstract: The present invention relates to high performance ceramics and methods for their production using supercritical temperatures and supercritical pressures. Furthermore, the present invention relates to high performance ceramics for use in the automobile industry.Type: GrantFiled: August 31, 1988Date of Patent: October 9, 1990Inventor: Thomas M. Sullivan
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Process for the preparation of finely divided carbides and nitrides from ceramic precursor-compounds
Patent number: 4948762Abstract: Carbides, nitrides or carbonitrides of elements from the main groups III and IV and sub-groups III, IV, V and VI of the periodic system of elements are prepared by(i) reacting compounds of the formula MX.sub.m or R.sub.n MX.sub.m-n with a reactive hydrocarbon-containing compound or a mixture of compounds which is polymerizable and which contains a reactive compound with one C--OH-group in whichM is an element of the main group III or IV or sub-group of III, IV, V or VI of the periodic system of elements,X is a halogen,R is hydrogen or alkyl or aryl,m is an integer corresponding to the valency stage of M,n is an integer from 1 to one less than the velency stage of M, and(ii) thermally decomposing the resulting product from (i) to the corresponding carbide or to the corresponding nitrides or carbonitrides with further nitridation.Type: GrantFiled: September 18, 1989Date of Patent: August 14, 1990Assignee: Bayer AktiengesellschaftInventors: Wolfgang Krumbe, Benno Laubach, Gerhard Franz -
Patent number: 4948573Abstract: A process for forming carbides of silicon or metals in fine powder or whisker form. The process comprises forming a substantially uniform and non-agglomerated dispersion of a microfine powder of an oxide of silicon or a carbide-forming metal within a matrix of a polymer, carbonizing the oxide-containing polymer in an inert atmosphere and heating the carbonized product at high temperature to cause the oxide to react with carbon to form a carbide. The polymer must have a molecular weight of at least 10,000, a high carbon yield of at least 30% by weight, and a chemical structure which is infusible or capable of being rendered infusible. The preferred polymers are polyacrylonitrile, cellulose and polyvinyl alcohol, but other polymers with similar characteristics can be employed. The process is relatively inexpensive and gives an extremely finely divided product of high purity.Type: GrantFiled: May 16, 1989Date of Patent: August 14, 1990Assignee: Alcan International LimitedInventors: Sadashiv Nadkarni, Mukesh Jain, Jean-Paul Huni
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Patent number: 4921531Abstract: The present invention relates to a process for the production of fine powder materials and the products of that process. The process involves the in-situ precipitation of second phase particles, such as ceramic or intermetalics, within a metal matrix, followed by separation of the particles from the matrix to yield a powder comprising the second phase particles. Particles formed by this process are typically in the size range of 0.01 to 10 microns and have controlled morphology, narrow size distribution, well defined stoichiometery and relatively high purity. Exemplary of second phase particles formed by this process are metal borides, carbides, nitrides, oxides, silicides and beryllides, including TiB.sub.2, ZrB.sub.2, VB.sub.2, MoB.sub.2, TiC, WC, VC, TiN, ZrSi.sub.2, MoSi.sub.2, Ti.sub.5 Si.sub.3, and TiBe.sub.12.Type: GrantFiled: August 30, 1989Date of Patent: May 1, 1990Assignee: Martin Marietta CorporationInventors: Dennis C. Nagle, John M. Brupbacher, Leontios Christodoulou
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Patent number: 4914070Abstract: The invention is directed to a process for the production of fine grains of silicon carbide which are formed by an agglomerate of submicronic grains having a specific surface area that is at least 100 m.sup.2 .multidot.g.sup.-1, which are intended in particular to serve as a carrier for catalysts for petrochemistry, and for catalytic reactions at elevated temperature which can attain 1000.degree. C., the process comprising reacting vapors of silicon monoxide SiO on carbon, being characterized by: generating vapors of SiO in a first reaction zone by heating a mixture SiO.sub.2 +Si at a temperature of between 1100.degree. and 1400.degree. C., under a pressure of between 0.1 and 1.5 hPa; and, in a second reaction zone, contacting the SiO vapors with reactive carbon in the divided state with a specific surface area that is at least equal to 200 m.sup.2 .multidot.g.sup.-1 at a temperature of between 1100.degree. and 1400.degree. C.Type: GrantFiled: October 6, 1988Date of Patent: April 3, 1990Assignee: Pechiney ElectrometallurgieInventors: Marc J. Ledoux, Jean-Louis Guille, Sylvain Hantzer, Dominique Dubots
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Patent number: 4886652Abstract: Production of carbide shapes of silicon, titanium or vanadium by reaction of carbon with the metal in liquid phase such being carried out by heating a mixture of particles of carbon and particles of the metal rapidly to the melting point of the metal, thereby minimizing solid state reaction, and holding at a temperature and for a time sufficient to cause reaction. The metal and carbon particles are about 0.05 to 10 mm in diameter. An organic binder is used which volatilizes or dissociates upon heating.Type: GrantFiled: April 22, 1988Date of Patent: December 12, 1989Assignee: Osaka Gas Co., Ltd.Inventors: Gopala Krishnan, Michael Gusman, Sylvia M. Johnson, David J. Rowcliffe, Hajime Nakano
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Patent number: 4866012Abstract: A method of forming a carbothermally reduced powder of nitrides or carbides is disclosed. The product powder consists principally of unagglomerated particles and is formed by providing a collection of precursor particles in colloidal dispersion, adding to the dispersion a polymerizable monomer, polymerizing the monomer to matrix the precursor particles in discrete, well dispersed positions and carbothermally reducing the particles followed by removing excess carbon by burning. The polymer matrix acts an an agglomerate-inhibiting carbon source during carbothermal reduction.Type: GrantFiled: February 3, 1988Date of Patent: September 12, 1989Assignee: Engelhard CorporationInventor: Lance D. Silverman
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Patent number: 4853299Abstract: A silicon carbide sintered body containing not less than 0.03% by weight of boron, a total of not more than 0.3% by weight of metallic element impurities including the boron, not more than 1.0% by weight of free carbon, a total of not more than 0.15% by weight of non-metal impurities other than the free carbon, and the balance essentially consisting of silicon carbide, and having a density of not less 3.10 g/cm.sup.3. The sintered body is manufactured by heating a molding of a mixture containing a silicon carbide powder, a boron-containing sintering assistant, and a carbon-containing oxygen scavenger to a sintering temperature. The molded body is maintained at a temperature lower than the sintering temperature during the heating process until an oxide film covering the silicon carbide powder is substantially removed by the oxygen scavenger, and the molded body is then sintered at the sintering temperature under a non-pressurized condition.Type: GrantFiled: September 3, 1986Date of Patent: August 1, 1989Assignee: Kabushiki Kaisha ToshibaInventors: Toshiaki Mizutani, Takeyuki Yonezawa, Hiroshi Inoue, Akihiko Tsuge, Yoshiyuki Ohnuma
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Patent number: 4851206Abstract: Methods and compostions produced thereby are provided concerning the preparation and use of high specific surface area carbides and nitrides. The carbides and nitrides can be obtained by thermal reduction of oxides in the presence of a source of carbon and nitrogen respectively, with relatively slow progressive temperature increases prior to completion of the reaction, followed by quenching. Novel metastable carbides can be obtained by carburization of nitrides having high surface area, which nitrides can be prepared by the above-described process.Type: GrantFiled: October 5, 1987Date of Patent: July 25, 1989Assignee: The Board of Trustees of the Leland Stanford Junior University, Stanford UniversityInventors: Michel Boudart, Shigeo T. Oyama, Leo Volpe
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Patent number: 4851262Abstract: A method of making metal carbide, nitride, or boride powders and mixtures thereof by direct reduction of metal compounds comprises (a) forming a reactant mixture, (b) heating the reactant mixture to temperatures that cause solid reactants to vaporize and above which the metal precursor compounds are reduced, (c) passing the heated reactant mixture through a converging-diverging nozzle designed to reduce the temperature of the mixture to a temperature and for a time sufficient for further product species to form and for nuclei to form and grow by condensation to form the product powders, and (d) exhausting the mixture and product powders from the nozzle into an expansion chamber.Type: GrantFiled: May 27, 1987Date of Patent: July 25, 1989Assignee: Carnegie-Mellon UniversityInventor: John S. McFeaters
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Patent number: 4851203Abstract: Metal carbide and metal nitride powders produced by the carbothermal reduction of one or more metal oxides reacted with a binder material and a carbonaceous additive or optionally, a binder capable of supplying carbon to the reaction. The metal oxides are selected from among SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, HfO.sub.2 and B.sub.2 O.sub.3 and are combined with the binder in the presence of carbon to form granules having a controlled pore volume. The granules are then subjected to a carbothermal reduction reaction, in the presence of a nitrogen or a neutral atmosphere, to produce metal nitrides or metal carbides respectively, having an excess of carbon incorporated therein. The product is subsequently heated to react the excess carbon within the compound with oxygen from the atmosphere to form carbon monoxide gas, which may be removed by an optional exhaust system.Type: GrantFiled: March 25, 1987Date of Patent: July 25, 1989Assignee: AtochemInventors: Roland Bachelard, Philippe Joubert
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Patent number: 4834963Abstract: In the alumino-thermit method of producing tungsten monocarbide powders, metallic iron is added to the reaction charge in quantities to control the calculated reaction temperature within the range of about 4372.degree. to about 4500.degree. F. It has been found that this process can now be controlled to produce macrocrystalline tungsten carbide powders which are very low in Ti, Ta and Nb content and have a very narrow range of total carbon contents.Type: GrantFiled: December 16, 1986Date of Patent: May 30, 1989Assignee: Kennametal Inc.Inventors: Charles J. Terry, Jack D. Frank
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Patent number: 4828814Abstract: A process is disclosed for producing a solid material which, in some cases, may have a resultant purity of 99.999% or better which comprises contacting the solid material at a temperature approaching the melting point of the solid material with a purifying agent which is substantially nonreactive with the solid material to cause the impurities in the solid material to enter the material. After cooling, the purified solid material may be separated from the purifying agent and the impurities therein by leaching.Type: GrantFiled: March 7, 1986Date of Patent: May 9, 1989Assignee: SRI InternationalInventors: Angel Sanjurjo, Sylvia Pressacco
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Patent number: 4826666Abstract: Preparation of metal carbides, nitrides, borides, silicides and phosphides, also metal alloys and pure metals, by providing a precursor in which there are organic ligands bonded to the metal or metals, such precursor having the element X also bonded directly or indirectly to the metal or metals, the ligand-metal bonding being weaker than the X-metal bonding whereby on pyrolysis the product M.sub.a X.sub.b results in which M represents the metal or metals, X represents C, N, B, Si, P and a and b represent the atomic proportions of M and X. The subscript b may be zero if an alloy or pure metal is to be prepared. The product M.sub.a x.sub.b can be prepared by relatively low temperature pyrolysis and the precursor can be used as a solution or a low melting solid. This enables one to apply a surface coating or to shape the precursor into a fiber, rod or other shape and to pyrolyze the coating or shaped article. M is a transition, lanthanide or actinide metal or tin.Type: GrantFiled: March 22, 1988Date of Patent: May 2, 1989Assignee: SRI InternationalInventor: Richard M. Laine
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Patent number: 4812301Abstract: A process for producing substantially oxygen-free titanium carbide, nitride or carbonitride in powder form comprises treating a gas phase reaction mixture of titanium halide, desirably TiCl.sub.4, a reductant vapor, desirably sodium or magnesium, and a reactive gas capable of furnishing carbon, nitrogen or mixtures thereof at the reaction temperature, desirably nitrogen, methane or ammonia, to a temperature in the range from 500.degree. to 1250.degree. C., preferably 800.degree. to 1100.degree. C., whereby the titanium halide is substantially simultaneously reduced and carbided, nitrided or carbonitrided. The process may also be practiced using volatile metal halides of metals such as zironium, hafnium, vanadium, niobium, tantalum and silicon for forming substantially oxygen-free carbides, nitrides or carbonitrides thereof in powder form.Type: GrantFiled: April 24, 1986Date of Patent: March 14, 1989Assignee: The United States of America as represented by the Secretary of the InteriorInventors: Charles F. Davidson, Monte B. Shirts, Donna D. Harbuck
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Patent number: 4789534Abstract: Transition metal carbides in which the carbon is in excess and is covalently bound to the metal are produced by pyrolyzing transition metal amides that have two or more metal atomos, such as hexakis(dimethylamido) ditungsten or dimolybdenum.Type: GrantFiled: November 6, 1987Date of Patent: December 6, 1988Assignee: SRI InternationalInventor: Richard M. Laine
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Patent number: 4784839Abstract: Metal carbide and metal nitride powders produced by the carbothermal reduction of one or more metal oxides reacted with a binder material and a carbonaceous additive or optionally, a binder capable of supplying carbon to the reaction. The metal oxides are selected from among SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, HfO.sub.2 and B.sub.2 O.sub.3 and are combined with the binder in the presence of carbon to form granules having a controlled pore volume. The granules are then subjected to a carbothermal reduction reaction, in the presence of a nitrogen or a neutral atmosphere, to produce metal nitrides or metal carbides respectively, having an excess of carbon incorporated therein. The product is subsequently heated to react the excess carbon within the compound with oxygen from the atmosphere to form carbon monoxide gas, which may be removed by an optional exhaust system.Type: GrantFiled: March 25, 1987Date of Patent: November 15, 1988Assignee: ATOCHEMInventors: Roland Bachelard, Philippe Joubert
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Patent number: 4756791Abstract: A chemical vapor deposition process for producing single crystal whiskers of metal carbides, nitrides, or carbonitrides involving flushing a reaction chamber including a suitable substrate surface heated to 1025.degree.-1125.degree. C., and flowing reactant gases past the substrate to form whiskers. The reactants comprise a halide of Ti, Zr, Hf, Nb, Ta or W and one or more of nitrogen, ammonia and suitable aliphatic hydrocarbons. The atomic ratio of carbon and/or nitrogen to metal is about 5:1 to 16:1; the volume ratio of hydrocarbon and/or nitrogen and/or ammonia to hydrogen is about 1:50-1:20. The preferred substrate materials are nickel or a high nickel alloy coated with TiC or TiN, or, for carbide whiskers, nickel impregnated graphite. The reactor walls and internal fixtures preferably provide the substrate surfaces. A more efficient batch process and a continuous process for whisker growth are disclosed.Type: GrantFiled: August 25, 1986Date of Patent: July 12, 1988Assignee: GTE Laboratories IncorporatedInventors: Charles D'Angelo, Joseph G. Baldoni, II, Sergej-Tomislav Buljan
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Patent number: 4752456Abstract: A carbon-containing mixture is obtained by collecting a dispersed phase mixture from an aerosol which has been formed by introducing a decomposable carbon compound and a decomposable metallic compound into a hot gas containing steam.Since this carbon-containing mixture is extremely high in uniformity and consists of extremely fine particles, it can afford after heat treatment a metal carbide of high quality.Type: GrantFiled: July 16, 1986Date of Patent: June 21, 1988Assignee: Mitsui Toatsu Chemicals, Inc.Inventors: Yukihiro Yoda, Makoto Horita, Kensaku Maruyama, Hideaki Miyashita, Norihiro Murakawa, Kazuyoshi Isogaya, Fumio Nakamura, Norimasa Kawamura, Noriaki Kuramitsu
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Patent number: 4668583Abstract: A carbide coating for a surface intended to be subjected to stringencies of temperature and erosion, such as rocket nozzles, turbine blades, heat shields, and hypersonic structures, formed on a carbon substrate from a halide of hafnium, silicon, tantalum or zirconium, followed by deposition from a said halide and a hydrocarbon. The layer has a high melting point, can be made very thin, and resists cracking and spalling.Type: GrantFiled: November 13, 1984Date of Patent: May 26, 1987Assignee: Hi-Shear CorporationInventor: Donald E. Olander
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Patent number: 4664899Abstract: Tungsten carbide is produced by mixing tungsten oxide or ammonium paratungstate with carbon to form a mixture which is substantially reduced in a non-reducing atmosphere in the presence of sufficient carbon to produce a carbon content in the resulting mixture of less than seven percent by weight, and adding sufficient carbon to the resulting reduced mixture to increase the carbon content to at least the stoichiometric amount needed to form monotungsten carbide prior to carburization of the mixture to monotungsten carbide.Type: GrantFiled: June 15, 1983Date of Patent: May 12, 1987Assignee: GTE Products CorporationInventors: Edward R. Kimmel, Mary E. Shaffer, Thomas R. Pinkowski, Geoffrey L. Harris
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Patent number: 4652436Abstract: Nitrides and carbides are prepared by intercalating a monomer, a starting material of condensate, or a prepolymer into the interlamellar spaces or the vacant spaces of the crystalline structure of a natural mineral or an inorganic compound to prepare an intercalated compound and baking the intercalated polymer compound at a temperature in the range of 1100.degree.-1700.degree. C. under a nitrogen or reducing atmosphere. The present invention provides a method for readily preparing nitrides and carbides having the increased crystallinity at a low calcination temperature. Whiskers with larger diameters of 2 to 5 .mu.m can be prepared by adding carbon powder to the intercalated compound complex.Type: GrantFiled: July 8, 1985Date of Patent: March 24, 1987Assignee: Osaka Yuki Kagaku Kogyo Kabushiki KaishaInventor: Chuzo Kato
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Patent number: 4622215Abstract: A method for preparing finely divided titanium carbide powder in which an organotitanate is reacted with a carbon precursor polymer to provide an admixture of the titanium and the polymer at a molecular-level due to a crosslinking reaction between the organotitanate and the polymer. The resulting gel is dried, pyrolyzed to drive off volatile components and provide carbon. The resulting solids are then heated at an elevated temperature to convert the titanium and carbon to high-purity titanium carbide powder in a submicron size range.Type: GrantFiled: March 12, 1985Date of Patent: November 11, 1986Assignee: The United States of America as represented by the United States Department of EnergyInventor: Mark A. Janey
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Patent number: 4610857Abstract: A method for making ultra-fine ceramic particles, in which metal powder constituting a portion of the ultra-fine ceramic particles intended for production is injected at a rate of not less than 70 grams per minute into a plasma jet so that the metal powder is vaporized. The vaporized metal powder is then mixed with a reactive gas, which includes an element consituting the other portion of the ultra-fine ceramic particles, filled in the surrounding area of the plasma jet, and thereby the vaporized metal powder and the reactive gas produce a synthetic reaction. The ultra-fine ceramic particles are produced continuously because of the reaction flame.Type: GrantFiled: February 14, 1985Date of Patent: September 9, 1986Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masahiro Ogawa, Susumu Abe
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Patent number: 4606902Abstract: Refractory borides or carbides are prepared by contacting an alkali-metal ducible metal chloride or silicon tetrachloride with boron trichloride or carbon tetrachloride in an inert solvent in the presence of an alkali metal, the metal chloride or silicon tetrachloride and the boron trichloride or carbon tetrachloride being present in an amount about stoichiometrically equivalent to the boride or carbide to be prepared and the alkali metal being present in an amount about stoichiometrically equivalent to the amount of chloride in the metal chloride or silicon tetrachloride and the boron trichloride or carbon tetrachloride, until all chloride present has reacted with the alkali metal to form alkali metal chloride, separating the inert solvent to leave a solid residue containing a metal boride, silicon carbide or metal carbide precursor together with the alkali metal chloride, and calcining the residue while separating the alkali metal chloride until the precursor is converted to the refractory boride or carbideType: GrantFiled: October 3, 1985Date of Patent: August 19, 1986Assignee: The United States of America as represented by the Secretary of CommerceInventor: Joseph J. Ritter
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Patent number: 4595545Abstract: Refractory metal borides, carbides, nitrides and mixtures thereof of the Group IVb, Vb and VIb metals are produced from a glass or microcrystalline gel formed from organo-metallic precursors. Typically TiO.sub.2.B.sub.2 O.sub.3 glass is produced by hydrolysis of titanium butoxide and trimethyl borate, followed by gelling/drying. The glass may have carbon inclusions or may be mixed with carbon or aluminum powder or a mixture thereof, and reacted. In the case of aluminothermic and carboaluminothermic reduction, there is a residual aluminum-containing phase in the product. Composites can also be produced by including inert materials in the reaction mixture.Type: GrantFiled: December 30, 1982Date of Patent: June 17, 1986Assignee: ELTECH Systems CorporationInventor: Ajit Y. Sane
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Patent number: 4594235Abstract: A process is provided for the production of vanadyl hydrate including solvent extraction and stripping steps. The vanadyl hydrate is then reacted with carbon to produce vanadium carbide.Type: GrantFiled: June 19, 1985Date of Patent: June 10, 1986Assignee: Union Carbide CorporationInventor: Harry E. Gardner
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Patent number: 4594330Abstract: Fine spherical amorphous powder represented by the general formula:SiCxNyHzwherein 0.1<x<2.0, 0.1<y<1.5 and 0<z<4, is prepared by vapor phase oxidation of organosilicon compound substantially free from halogen atoms and oxygen atoms. An ultimately crystalline, uniform and fine powder of silicon nitride and silicon carbide is prepared by heat treatment of the fine spherical amorphous powder. The powder and the crystalline uniform, and fine powder are used as raw materials for composite ceramics and as functional materials for solar cell.Type: GrantFiled: March 15, 1985Date of Patent: June 10, 1986Assignee: Mitsubishi Gas Chemical Company, Inc.Inventors: Takashi Suzuki, Takamasa Kawakami, Takeshi Koyama, Masami Orisaku, Kansei Izaki, Rieko Nakano, Akira Mori
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Patent number: 4579713Abstract: The present invention provides a method for controlling the carbon content of dewaxed carbide preforms in a carbon containing furnace. The method includes the steps of placing the preforms in a carbon containing furnace and then heating the furnace to a predetermined temperature range between 800 and 1100 degrees Centigrade. At that temperature, a mixture of methane and hydrogen is introduced into the furnace chamber such that the amount of methane is between 10 and 90 percent of the amount of methane present at equilibrium for the reaction C.sub.solid +2H.sub.2 .revreaction.CH.sub.4. The furnace chamber is maintained at its temperature for a first time period sufficient for the chemical reaction XC+2H2.revreaction.X+CH.sub.4 (where X is selected from the group of W, Ti, Ta, Hf and No) substantially reaches equilibrium but shorter than the a second time period in which the reaction C.sub.solid +2H2.revreaction.CH.sub.Type: GrantFiled: April 25, 1985Date of Patent: April 1, 1986Assignee: Ultra-Temp CorporationInventor: Roy C. Lueth
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Patent number: 4540562Abstract: A process is provided for the production of vanadyl hydrate including solvent extraction and stripping steps. The vanadyl hydrate is then reacted with carbon to produce vanadium carbide.Type: GrantFiled: May 27, 1983Date of Patent: September 10, 1985Assignee: Umetco Minerals CorporationInventor: Harry E. Gardner
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Patent number: 4515763Abstract: Method and compositions produced thereby concerning high specific surface area carbides and nitrides. The carbides and nitrides are obtained by thermal reduction of oxides in the presence of a source of carbon or nitrogen respectively, with relatively slow progressive temperature increases prior to completion of the reaction, followed by quenching.Type: GrantFiled: December 14, 1982Date of Patent: May 7, 1985Assignee: Board of Trustees of Leland Stanford Jr. UniveristyInventors: Michel Boudart, Shigeo T. Oyama, Leo Volpe
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Patent number: 4505787Abstract: Means and method for utilizing radiated electromagnetic energy to elevate at least one of two or more reactants 16 to a temperature at which a chemical reaction will take place so as to provide a desired reaction product 161. In practice, at least one of reactants 16 must be, or be made, susceptible to heating when radiated with electromagnetic energy. Electromagnetic energy source 12 provides sufficient power to raise the temperature of said at least one reactant 16 to cause that reactant to further raise the temperature of associated reactant materials making them further susceptible to heating under the influence of the impinging electromagnetic energy waves. The electromagnetic energy is provided at sufficient power to raise the temperature to the point at which reactants 16 will react chemically to produce a desired reaction product. Since the heating action is localized, little or no energy is wasted in raising the wall temperatures of the reaction vessel 11 in which the material 16 is radiated.Type: GrantFiled: July 13, 1981Date of Patent: March 19, 1985Assignee: Super Fuel Systems IncorporatedInventors: Tom E. Fuller, Lewis R. Finell
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Patent number: 4492652Abstract: The pyrolysis of aromatic compounds with fused rings in the aromatic system which form free radicals on the peri position, for example, by eliminating a stable inorganic gas produces desirable products. These products include electrically conductive inert films. Further, with the addition of suitable inorganic compounds to the reactant, superconducting materials are obtainable. The addition of sulfur to the pyrolysis reactant also is possible and allows production of compounds useful as donors for the production of organic electrically conducting compositions.Type: GrantFiled: January 31, 1983Date of Patent: January 8, 1985Assignee: AT&T LaboratoriesInventor: Martin L. Kaplan
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Patent number: 4489044Abstract: Tungsten monocarbide is prepared by sparging a molten composition comprising an alkali metal halide and an oxygen compound of tungsten with a gas comprising a gaseous hydrocarbon, particularly methane.Type: GrantFiled: January 27, 1984Date of Patent: December 18, 1984Assignee: The United States of America as represented by the Secretary of the InteriorInventors: John M. Gomes, Andrea E. Raddatz, Elizabeth G. Baglin
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Patent number: 4478611Abstract: A novel method is disclosed for preparing a tungsten carbide grit. The method comprises blending tungsten carbide powder with a binder, forming agglomerates of the powder and sintering the agglomerates to form the tungsten carbide grit.Type: GrantFiled: December 14, 1979Date of Patent: October 23, 1984Assignee: Hughes Tool CompanyInventor: Gary F. Selden
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Patent number: 4472367Abstract: An apparatus and process are disclosed for utilizing solar radiation and the energy contained therein for the carbothermic reduction of a metal oxide to a metal carbide. The apparatus comprises a reflective surface which collects and focuses solar radiation onto a focal mirror which consequentially reflects and focuses the solar light rays into a reaction chamber through a Fresnel lens and a transparent window provided on the chamber. The solar light rays are focused by the reflective surface focal mirror and Fresnel lens such that the energy absorbed by reactants in the reaction chamber is sufficient for the carbothermic reduction of the metal oxide.Type: GrantFiled: September 8, 1980Date of Patent: September 18, 1984Assignee: Geruldine GibsonInventors: James O. Gibson, Mark G. Gibson
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Patent number: 4470956Abstract: Metal carbide is reclaimed from scrap by sorting the scrap to separate pieces of cemented carbide having similar composition and grain size and treating the separated portion to form metal carbide grains which may be resintered with metal binder to obtain cemented carbides having grain characteristics similar to the starting material.Type: GrantFiled: October 18, 1982Date of Patent: September 11, 1984Assignee: GTE Products CorporationInventors: Richard F. Cheney, Anil Bansal
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Patent number: 4466945Abstract: Metal carbide is reclaimed from scrap by sorting the scrap to separate pieces of cemented carbide having similar composition and grain size and treating the separated portion to form metal carbide grains which may be resintered with metal binder to obtain cemented carbides having grain characteristics similar to the starting material.Type: GrantFiled: August 8, 1983Date of Patent: August 21, 1984Assignee: GTE Products CorporationInventors: Richard F. Cheney, Anil Bansal
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Patent number: 4460697Abstract: Non-oxide powders such as carbides, nitrides, carbides/nitrides and borides are obtained by reducing an oxide powder in a reducing atmosphere, and after or concurrently with the reduction, treating the reduced powder in a carbonizing atmosphere, a nitrogenizing atmosphere, a carbonizing and nitrogenizing atmosphere, or a boronizing atmosphere. As the above oxide powder, there is used a brittle material obtained by rapid cooling of a melted oxide. The non-oxide powders obtained are utilized as a hard component of cemented carbides and cermet. These powders are fine particles having a particle size of 1.0 .mu.m or smaller and a high purity.Type: GrantFiled: May 21, 1982Date of Patent: July 17, 1984Assignee: Hitachi Metals, Ltd.Inventors: Hisao Hara, Hirohide Yamada
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Patent number: RE32612Abstract: Tungsten monocarbide is prepared by sparging a molten composition comprising an alkali metal halide and an oxygen compound of tungsten with a gas comprising a gaseous hydrocarbon, particularly methane.Type: GrantFiled: April 24, 1986Date of Patent: February 23, 1988Assignee: The United States of America as represented by the Secretary of the InteriorInventors: John M. Gomes, Andrea E. Raddatz, Elizabeth G. Baglin