Sintering Which Includes A Chemical Reaction Patents (Class 419/45)
  • Patent number: 4946643
    Abstract: Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.
    Type: Grant
    Filed: September 26, 1989
    Date of Patent: August 7, 1990
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Stephen D. Dunmead, Joseph B. Holt, Donald D. Kingman, Zuhair A. Munir
  • Patent number: 4941918
    Abstract: A magnesium-based composite material having improved mechanical strength, and in particular an improved modulus of elasticity, and a relatively low density. The material is provided by pressing and sintering a mixture of magnesium or magnesium-based alloy particles or a particulate combination of magnesium particles and particles of one or more additional metals, with a reinforcement additive of boron, or boron-coated B.sub.4 C, Si.sub.3 N.sub.4, SiC, Al.sub.2 O.sub.3 or MgO particles.
    Type: Grant
    Filed: December 12, 1988
    Date of Patent: July 17, 1990
    Assignee: Fujitsu Limited
    Inventors: Eiji Horikoshi, Tsutomu Iikawa, Takehiko Sato
  • Patent number: 4938798
    Abstract: A high melting metal silicide sputtering target which comprises a fine texture whose stoichiometric composition grains of MSi.sub.2, where M represents a high melting metal, have a maximum grain size of 20 .mu.m, whose free silicon grains have a maximum grain size of 50 .mu.m and whose oxygen content is not more than 200 ppm and has a density ratio to the theoretical density of 99% or more has good film characteristics including the reduction in the number of grains formed on the sputtered film and is useful as an electrode material or a wiring material in semi-conductor devices.
    Type: Grant
    Filed: March 7, 1988
    Date of Patent: July 3, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yoshitaka Chiba, Noriyoshi Hirao, Toru Sugihara, Kenji Hasegawa
  • Patent number: 4923512
    Abstract: Cobalt-bound tungsten carbide metal matrix composites having a unique microstructure are produced by consolidating partially sintered greenware under high pressures, e.g., 120,000 psi, at temperatures less than those used for conventional liquid phase sintering in a relatively short time, e.g., from less than one minute to less than about one hour. The composites have a binder phase which contains less than about 80 weight percent of the tungsten found in a composite prepared from the same or similar compositions via liquid phase sintering. These composites provide cutting tools with both toughness and wear resistance which exceed that of cutting tools made from the same or similar compositions via liquid phase sintering.
    Type: Grant
    Filed: April 7, 1989
    Date of Patent: May 8, 1990
    Assignee: The Dow Chemical Company
    Inventors: Ed E. Timm, Douglas B. Schwarz
  • Patent number: 4915902
    Abstract: The present invention relates to the formation of whisker reinforced metal matrix composites in which complex boride or carbide whiskers are distributed throughout a metal, metal alloy, or intermetallic matrix. Exemplary complex boride whiskers include TiNbB, TiTaB, TiVB, NbHfB, and TiNbMoB. Exemplary complex carbide whiskers include TiNbC, TiVC, TiZrC, TiHfC, and TiTaC. A method for the in-situ formation of complex boride and complex carbide whiskers within metallic matrices is disclosed which involves reacting a mixture of individual complex ceramic-forming constituents in the presence of a metal to precipitate the desired complex ceramic whiskers in a metal matrix.
    Type: Grant
    Filed: February 17, 1988
    Date of Patent: April 10, 1990
    Assignee: Martin Marietta Corporation
    Inventors: John M. Brupbacher, Leontios Christodoulou, Dennis C. Nagle
  • Patent number: 4915738
    Abstract: An alloy target for making a magneto-optical recording medium by sputtering comprises an alloy containing 10 to 50 atom % of at least one rare earth element selected from among Sm, Nd, Gd, Tb, Dy, Ho, Tm and Er, with a balance consisting substantially of at least one transition metal selected from among Co, Fe and Ni. The alloy has a mixed structure composed of at least one phase of an intermetallic compound formed by the rare earth element and the transition metal and a phase of the rare earth element along.
    Type: Grant
    Filed: April 29, 1988
    Date of Patent: April 10, 1990
    Assignee: Sumitomo Metal Mining Company Limited
    Inventors: Toshio Morimoto, Tatsuo Nate
  • Patent number: 4915737
    Abstract: An alloy target for making a magneto-optical recording medium by sputtering comprises an alloy containing 10 to 50 atom % of at least one rare earth element selected from among Sm, Nd, Gd, Tb, Dy, Ho, Tm and Er, with a balance consisting substantially of at least one transition metal selected from among Co, Fe and Ni. The alloy has a mixed structure composed of at least three phases of intermetallic compounds formed by the rare earth element and the transition metal.
    Type: Grant
    Filed: April 29, 1988
    Date of Patent: April 10, 1990
    Assignee: Sumitomo Metal Mining Company Limited
    Inventors: Toshio Morimoto, Keizo Kazama, Yasuhiro Okajima, Yasuhiro Tsugita, Shinobu Endo
  • Patent number: 4910868
    Abstract: A contact part is shaped to form a cavity in which a sintered or agglomerated block is placed before the assembly is placed on a welding press causing fixing and shaping of the block to form the contact pad. The protuberance of the pad may result from a deformation of the support in the course of the fixing operation, by a pin supported by the electrode of the welding machine coming up against the face opposite to the pad of the support.
    Type: Grant
    Filed: February 16, 1989
    Date of Patent: March 27, 1990
    Assignee: Merlin Gerin
    Inventors: Georges Fevrier, Jacques Vanin, Jean-Paul Favre-Tissot
  • Patent number: 4911989
    Abstract: A coated cemented carbide alloy having jointly a high toughness and high wear resistance is produced by specifying the cooling rate during sintering in efficient manner, which alloy comprises a cemented carbide substrate consisting of a hard phase of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of Group IVa, Va and VIa metals of Periodic Table and a binder phase consisting of at least one member selected from the iron group metals, and a monolayer or multilayer, provided thereon, consisting of at least one member selected from the group consisting of carbides, nitrides, oxides and borides of Group IVa, Va and VIa metals of Periodic Table, solid solutions thereof and aluminum oxide, in which the hardness of the cemented carbide substrate in the range of 2 to 5 .mu.m from the interface between the coating layer and substrate is 800 to 1300 kg/mm.sup.
    Type: Grant
    Filed: April 10, 1989
    Date of Patent: March 27, 1990
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Nakano Minoru, Tobioka Masaaki, Nomura Toshio
  • Patent number: 4909983
    Abstract: A method of producing intermetallic phases from powdery ductile components that are mixed in a predetermined mixture ratio and are subsequently precompacted by cold pressing. Subsequently, the precompacted components are pressed, via compaction, to such an extent that the degree of deformation is greater than 80%; thereafter, the thus-produced material is thermally treated.
    Type: Grant
    Filed: July 5, 1989
    Date of Patent: March 20, 1990
    Assignee: GKSS-Forschungszentrum Geesthacht GmbH
    Inventor: Michael Dahms
  • Patent number: 4906295
    Abstract: The present invention relates to a method of sintering ceramics and ceramics obtained by said method. According to the present invention, the synthesis and sintering of ceramics can be simultaneously carried out by utilizing the reaction heat generated when at least one metallic element selected from metallic elements of IIIb, IVa, Vb and VIb groups of the Periodic Table is combined with at least one nonmetallic element such as B, C, N and Si without heat or by preliminarily heating the ceramics at temperatures remarkably lower than the usual sintering temperature ceramics, thus-produced are superior in abrasion resistance and corrosion resistance.
    Type: Grant
    Filed: February 16, 1988
    Date of Patent: March 6, 1990
    Assignees: Sumitomo Electric Industries, Ltd., Yoshinari Miyamoto, Osamu Yamada, Mitsue Koizumi
    Inventors: Yoshinari Miyamoto, Osamu Yamada, Mitsue Koizumi, Osamu Komura, Eiji Kamijo, Masaaki Honda, Akira Yamakawa
  • Patent number: 4891182
    Abstract: A process for making a porous mass of a metal of iron- or titanium-group comprises steps of forming a sinter of solvent-soluble particles, pressing in a molten metal of the iron- or titanium- group into open interstices in the sinter, and eluting the particles from the composite of the sinter and metal. Solvent-soluble magnesia particles whose surface is either covered or not with a film of boric anhydride or solvent-soluble calcia particles whose surface is either covered or not with film of calcium chloride are sintered and machined into the desired shape. The formed sinter is put in a case of a heat-insulating material that can withstand the melting temperature of a metal of iron- or titanium-group. After being heated to a given temperature together with the case, the sinter is immediately put in a metal mold where a molten metal of iron- or titanium-group is pressed into open interstices in the sinter. Then, only the particles are eluted from the sinter-metal composite by a solvent.
    Type: Grant
    Filed: March 20, 1989
    Date of Patent: January 2, 1990
    Assignee: Agency of Industrial Science & Technology
    Inventors: Michiru Sakamoto, Akira Kitahara, Hidetoshi Ueno, Sumio Nagata
  • Patent number: 4886637
    Abstract: A presinter treatment is provided to reduce oxygen contamination prior to sintering a predominantly iron powder compact comprising carbon powder and a liquating diffusible boron source, such as nickel boride powder optionally in combination with iron boride powder. A preferred treatment is carried out at a temperature effective to dissociate iron oxide within the compact but not to initiate a liquid phase by said boron source and further is carried out in a vacuum to evacuate oxygen released thereby from compact pores prior to sintering. The presinter treatment enhances carbon and boron diffusion into the iron during sintering. In a preferred embodiment, the fraction of borocementite particles formed by diffused carbon and boron in the sintered iron structure is increased by the presinter treatment of this invention.
    Type: Grant
    Filed: April 17, 1989
    Date of Patent: December 12, 1989
    Assignee: General Motors Corporation
    Inventors: William F. Jandeska, Jr., Vadim Rezhets, Carlo Ligotti
  • Patent number: 4879262
    Abstract: A self-sustaining combustion synthesis process for producing hard, tough, lightweight B.sub.4 C/TiB.sub.2 composites is based on the thermodynamic dependence of adiabatic temperature and product composition on the stoichiometry of the B.sub.4 C and TiB.sub.2 reactants. For lightweight products the composition must be relatively rich in the B.sub.4 C component. B.sub.4 C-rich composites are obtained by varying the initial temperature of the reactants. The product is hard, porous material whose toughness can be enhanced by filling the pores with aluminum or other metal phases using a liquid metal infiltration process. The process can be extended to the formation of other composites having a low exothermic component.
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: November 7, 1989
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Danny C. Halverson, Beverly Y. Lum, Zuhair A. Munir
  • Patent number: 4871437
    Abstract: Cermet electrode compositions and methods for making are disclosed which comprise NiO--NiFe.sub.2 O.sub.4 --Cu--Ni. Addition of an effective amount of a metallic catalyst/reactant to a composition of a nickel/iron/oxide, NiO, copper, and nickel produces a stable electrode having significantly increased electrical conductivity. The metallic catalyst functions to disperse the copper and nickel as an alloy continuously throughout the oxide phase of the cermet to render the electrode compositon more highly electrically conductive than were the third metal not present in the base composition. The third metal is preferably added to the base composition as elemental metal and includes aluminum, magnesium, sodium and gallium. The elemental metal is converted to a metal oxide during the sintering process.
    Type: Grant
    Filed: November 3, 1987
    Date of Patent: October 3, 1989
    Assignee: Battelle Memorial Institute
    Inventors: Steven C. Marschman, Norman C. Davis
  • Patent number: 4871438
    Abstract: Cermet electrode compositions comprising NiO-NiFe.sub.2 O.sub.4 -Cu-Ni, and methods for making, are disclosed. Addition of nickel metal prior to formation and densification of a base mixture into the cermet allows for an increase in the total amount of copper and nickel that can be contained in the NiO-NiFe.sub.2 O.sub.4 oxide system. Nickel is present in a base mixture weight concentration of from 0.1% to 10%. Copper is present in the alloy phase in a weight concentration of from 10% to 30% of the densified composition. Such cermet electrodes can be formed to have electrical conductivities well in excess of 100 ohm.sup.-1 cm.sup.-1. Other alloy and oxide system cermets having high content metal phases are also expected to be manufacturable in accordance with the invention.
    Type: Grant
    Filed: November 3, 1987
    Date of Patent: October 3, 1989
    Assignee: Battelle Memorial Institute
    Inventors: Steven C. Marschman, Norman C. Davis
  • Patent number: 4849164
    Abstract: A sintering aid is disclosed for use in a powder metallurgical method for manufacturing an iron alloy article by compacting and sintering a predominantly iron powder mixture comprising carbon powder and a boron-containing additive, such as nickel boride. The sintering aid comprises an oxygen getter to inhibit boron oxidation that, if formed, is believed to retard carbon diffusion. The sintering aid also preferably includes a second constituent to produce, in combination with the getter, a melting point suitable for forming a transient liquid phase during the early stages of sintering. Preferred sintering aids include intermetallic iron titanium compounds, intermetallic ferro-vanadium compound and intermetallic nickel magnesium compound.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: July 18, 1989
    Assignee: General Motors Corporation
    Inventors: William F. Jandeska, Vadim Rezhets, Carlo Ligotti
  • Patent number: 4778649
    Abstract: A method of producing a material having a layer of ceramic as a first component, a layer of a metal as a second component and an intermediate layer lying between said layers and including said first and second components in continuous gradient ratios so that the properties of the material may change continuous, including a step of forming said intermediate layer by igniting a powder mixture of metallic and nonmetallic constitutive elements of said ceramic component and said metal component so as to cause a synthetic reaction in the powder mixture.
    Type: Grant
    Filed: August 7, 1987
    Date of Patent: October 18, 1988
    Assignees: Agency of Industrial Science and Technology, Daikin Industries, Ltd.
    Inventors: Masayuki Niino, Nobuyuki Yatsuyanagi, Jun Ikeuchi, Nobuhiro Sata, Tohru Hirano, Kanichiro Sumiyoshi
  • Patent number: 4772449
    Abstract: A method of making a cathode suitable for an electrochemical cell of the type having a molten sodium anode, a beta"-alumina separator, and a cathode which comprises one or more transition metals selected from the group comprising Fe, Ni, Co, Cr and Mn. The method comprises heating a particulate starting material comprising at least one member of the group of transition metals in an oxidizing atmosphere to cause its particles to become at least partially oxidized, and to adhere together to form a unitary porous matrix. This matrix is then heated in a reducing atmosphere at least partially to reduce the oxide formed during the formation of the matrix, and the reduced matrix is then impregnated with a sodium aluminium chloride molten salt electrolyte. Sodium chloride in dispersed form is incorporated into the matrix, preferably by mixing sodium chloride in particulate form with the particulate transition metal starting material, before the heating in an oxidizing atmosphere to form the matrix.
    Type: Grant
    Filed: June 5, 1987
    Date of Patent: September 20, 1988
    Assignee: Lilliwyte Societe Anonyme
    Inventors: Roger J. Bones, David A. Teagle, Stephen D. Brooker
  • Patent number: 4770701
    Abstract: Amorphous metal-ceramic and microcrystalline metal-ceramic composites are synthesized by solid state reaction-formation methods. These metal-ceramic composites are characterized by a composition that ranges from about 75 to about 99.9 percent ceramic in about 0.1 to about 25 percent amorphous or microcrystalline metal binder phase.
    Type: Grant
    Filed: April 30, 1986
    Date of Patent: September 13, 1988
    Assignee: The Standard Oil Company
    Inventors: Richard S. Henderson, Michael A. Tenhover
  • Patent number: 4762558
    Abstract: Reactive sintering process for producing a shaped body containing the nickel aluminide compound Ni.sub.3 Al, which comprises sintering a compacted shaped mass containing an intimate mixture of substances, e.g. including elemental nickel powder and elemental aluminum powder in a stoichiometric atomic ratio generally corresponding to the compound Ni.sub.3 Al, by heating the mass, e.g. in a vacuum, to an elevated sintering temperature, e.g. 500-750.degree. C., sufficiently to initiate an exothermic reaction, and at a heating rate sufficiently for consequent progressive generation of a transient liquid below the melting point of the aluminum powder and at the corresponding eutectic temperature, and upon initiation of the exothermic reaction continuing the sintering sufficiently to form a densified shaped body containing the nickel aluminide compound Ni.sub.
    Type: Grant
    Filed: May 15, 1987
    Date of Patent: August 9, 1988
    Assignee: Rensselaer Polytechnic Institute
    Inventors: Randall M. German, Animesh Bose, David Sims
  • Patent number: 4762677
    Abstract: This invention deals with a method of producing a bulk amorphous metal alloy article. The method involves mechanically alloying an amorphous matrix material and a crystalline element which is a fast diffuser in the matrix material to give a powder mixture which is at least 50% but less than 100% amorphous. This powder mixture is then formed into a bulk amorphous metal alloy article by ordinary forming methods such as hot-pressing. The resultant bulk amorphous metal alloy article can be heated above its glass transition temperature to provide a bulk crystalline metal alloy article.
    Type: Grant
    Filed: November 3, 1987
    Date of Patent: August 9, 1988
    Assignee: Allied-Signal Inc.
    Inventor: Benjamin P. Dolgin
  • Patent number: 4752333
    Abstract: The invention concerns alloys comprising a matrix based on at least one conductor metal M, formed by a homogeneous dispersion in the matrix of stable coherent particles of one or more associations of ions of type M, M', O in which M represents the metal or metals of the matrix, M' represents a different metal from M, which is capable of undergoing internal oxidation, and O represents oxygen.It also concerns the process for the production of such alloys which comprises subjecting a starting alloy powder to the action of an oxidizing agent formed by a powder with a granulometry of the order of 1 .mu.m of a metal oxide capable by thermal decomposition of providing the oxygen necessary for the internal oxidization of M', the starting alloy being based on at least one metal M, if appropriate hardened by one or more elements R or A as defined hereinbefore.Use of such alloys for the electrical, electronic and connection arts.
    Type: Grant
    Filed: January 9, 1987
    Date of Patent: June 21, 1988
    Assignee: Trefimetaux
    Inventors: Jules Caisso, Martine Cahoreau, Edmond Dedieu, Michel Grosbras
  • Patent number: 4750932
    Abstract: A refractory metal silicide sputtering target is made by reacting refractory metal and silicon to about 70 to 90% completion of the reaction, comminuting the material, and then vacuum hot pressing the comminuted material to a high density compact.
    Type: Grant
    Filed: December 18, 1986
    Date of Patent: June 14, 1988
    Assignee: GTE Products Corporation
    Inventors: Edward D. Parent, Charles S. Purinton, Charles W. Sutter
  • Patent number: 4746363
    Abstract: Cermet body formed by reaction sintering at pressures ranging from subatmospheric to superatmospheric of admixed and shaped particulate exothermic reactants, which have maximum particle size substantially not greater than 150 .mu.m and can be elements, compounds, intermetallic compounds and/or alloys, in stoichiometric proportions to substantially form 40-95 mole percent of first phase or phases being boride, nitride, silicide, sulfide or combination thereof of one or more of the elements of Groups 2a, 3a exclusive of B, 4a, 2b, 3b including lanthanide and actinide series elements, 4b, 5b, 6b, 7b and 8, and 5-60 mole percent of second phase or phases being metal, alloy, intermetallic compound or combination thereof of one or more of the elements of Groups 3a exclusive of B, 4a, 2b, 4b, 5b, 6b, 7b, iron, cobalt and nickel, wherein the maximum grain size of the first phase or phases is substantially not greater than 10 .mu.m and which body contains 0 to 4 weight percent oxygen.
    Type: Grant
    Filed: June 19, 1987
    Date of Patent: May 24, 1988
    Assignee: Corning Glass Works
    Inventor: Thomas P. DeAngelis
  • Patent number: 4735770
    Abstract: By the inventive method, an amorphous material in powder form can be produced, whereby at least two starting components in powder form are mechanically alloyed by means of a milling process so that a boron component which cannot be alloyed mechanically can nevertheless be alloyed. According to the invention, a boron component in powder form is admixed to the starting components; this powder mixture is subjected to the milling process, an amorphous alloying component being formed from the starting components with embedded or deposited fine particles of the boron components; and the mixture powder so produced is subjected to an annealing treatment below the crystallization temperature of the amorphous alloy component for diffusing the boron into the amorphous alloy component.
    Type: Grant
    Filed: January 29, 1987
    Date of Patent: April 5, 1988
    Assignee: Siemens Aktiengesellschaft
    Inventors: Ludwig Schultz, Egon Hellstern
  • Patent number: 4726842
    Abstract: A cermet material comprises an intergrown network of a minor proportion of ceramic such as TiB.sub.2 in a metal matrix such as Al. The cermet is prepared by forming a minor proportion by weight of a ceramic phase in situ in a molten metal phase and holding the mixture of elevated temperature for a time to effect formation of an intergrown ceramic network.
    Type: Grant
    Filed: December 3, 1985
    Date of Patent: February 23, 1988
    Assignee: Alcan International Limited
    Inventors: Martin R. Reeve, Adam J. Gesing, Graham Stratford
  • Patent number: 4704250
    Abstract: A method for synthesizing low density cermets of boron carbide and a metal binder, using decomposition of a metallic compound at controlled temperature and pressure.
    Type: Grant
    Filed: November 4, 1986
    Date of Patent: November 3, 1987
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Carl F. Cline, Fred J. Fulton
  • Patent number: 4702770
    Abstract: Low-density composites are produced consisting chiefly of boron carbide and aluminum, or aluminum alloy, and minor amounts of ceramic material. The method allows control of the rate of reaction between boron carbide and metal so that the final components of the composite, and hence the mechanical properties, are controlled. The invention includes modification of the carbon content of the boron carbide composition, dispersion of boron carbide and formation of a compact, infiltration of the compact by aluminum or aluminum alloy, and heat treatments. The invention produces low-density boron carbide-aluminum composites with a homogeneous microstructure possessing desired mechanical properties.
    Type: Grant
    Filed: July 26, 1985
    Date of Patent: October 27, 1987
    Assignee: Washington Research Foundation
    Inventors: Aleksander J. Pyzik, Ilhan A. Aksay
  • Patent number: 4698481
    Abstract: A system to prevent, retard or reverse the decomposition of silicon carbide articles during high temperature plasma sintering. Preferably, the system comprises sintering a silicon carbide refractory or ceramic green body in a closed sintering environment, such as a closed tube, with strategic placement of the plasma torch or torches, exhaust outlet and tube. As sintering proceeds, a silicon vapor pressure builds up within the tube, retarding the decomposition of the silicon carbide body. The plasma torch, exhaust outlet, and tubes are positioned so that buoyant convective flow is maximized to increase the heat transfer and energy efficiency. In another embodiment, a "sacrificial" source of silicon carbide is placed into the sintering furnace. The silicon carbide in the sacrificial source starts to decompose before the silicon carbide refractory or ceramic article, creating a supersaturated atmosphere of silicon vapor species in the furnace.
    Type: Grant
    Filed: March 25, 1986
    Date of Patent: October 6, 1987
    Assignee: Kennecott Corporation
    Inventors: Jonathan J. Kim, Joel D. Katz
  • Patent number: 4695321
    Abstract: This invention relates to high-hardness, high-toughness, high-density composite materials containing diamond, and a process for making such materials comprising applying shock compression to the composite powders and inducing an exothermic chemical reaction. The process is useful in making metal, ceramic and cermet diamond composite materials.
    Type: Grant
    Filed: May 1, 1986
    Date of Patent: September 22, 1987
    Assignee: New Mexico Tech Research Foundation
    Inventors: Tamotsu Akashi, Akira Sawaoka
  • Patent number: 4693863
    Abstract: A powder metallurgy consolidation process and apparatus for carrying out said process produces integral metal bodies by heating metal powder of a predetermined composition to a temperature sufficient to cause solid state interparticle bonding, while simultaneously maintaining a reactive fluid in contact with the metal powder. The metal powder is compacted to a density greater than 90% of the full theoretical density of the composition after the reactive fluid has been removed. The reactive fluid is selected to modify the powder particle surface chemistry in order to improve bondability and to obtain other properties as desired. Metal bodies which have been consolidated by the process are sufficiently dense to be mechanically hot worked and exhibit exceptionally low retained gas content.
    Type: Grant
    Filed: April 9, 1986
    Date of Patent: September 15, 1987
    Assignee: Carpenter Technology Corporation
    Inventors: Gregory J. Del Corso, Robert E. Carnes, David Esposito
  • Patent number: 4687632
    Abstract: A reduction process for the production of a product metal which includes the step of reacting at least one reducible metal compound and a reducing metal in a sealed reaction zone by heating the reactants without any substantial agitation from a temperature below the melting point of the reducing metal to a temperature which is both above the melting point of the reducing metal and below the temperature at which the reduction reaction between the metal compound(s) and the reducing metal will proceed spontaneously; initiating a reduction reaction between the reducible metal compound(s) and a molten reducing metal by causing the surface of the molten reducing metal to be suddenly disrupted, thereupon releasing the reaction mixture from said first reaction zone into a product collection zone while permitting the reduction reaction to continue to thereby produce a reduced metal or alloy in zero valent state; and apparatus for conducting the above process.
    Type: Grant
    Filed: May 11, 1984
    Date of Patent: August 18, 1987
    Inventors: Frank W. Hurd, deceased, by Susan M. Hurd, executor, by Harland C. Hurd, executor
  • Patent number: 4673550
    Abstract: There is disclosed a process for synthesizing TiB.sub.2 composite materials containing a metallic phase. The preparation of these composites comprises providing mixtures of titanium alloys which in addition to at least 30 wt. % titanium also contain F, Ni, Al, Mo, Cr, Co, Cu or mixtures thereof, and boron or ferroboron, reacting these mixtures by local igniting and exothermic reaction or by heating or melting, resulting in the synthesis of composite material containing fine TiB.sub.2 crystals dispersed in a fine metallic phase which is derived from the metallic element previously alloyed or combined with the titanium of the titanium alloys or the metallic element or elements contained in the ferroboron. By leaching out the metallic phase, fine TiB.sub.2 powders may be obtained. Parts and coatings can also be obtained. The parts are normally obtained by treating the TiB.sub.2 material by powder metallurgic techniques. Coatings may be obtained by thermo or plasma spray depositing on a substrate.
    Type: Grant
    Filed: September 24, 1986
    Date of Patent: June 16, 1987
    Inventors: Serge Dallaire, Blaise Champagne
  • Patent number: 4671822
    Abstract: A ZrB.sub.2 -containing sintered cermet comprising zirconium diboride partially substituted by at least one member selected from the group consisting of chromium boride, molybdenum boride and tungsten boride, and a binding component containing at least one member selected from the group consisting of metals of Group VIII of the periodic table.
    Type: Grant
    Filed: June 4, 1986
    Date of Patent: June 9, 1987
    Assignee: Asahi Glass Company, Ltd.
    Inventors: Kazuo Hamashima, Makoto Imakawa, Yukinori Kutsukake
  • Patent number: 4668470
    Abstract: A method for forming intermetallic and intermetallic-type precursor alloys for subsequent mechanical alloying applications. Elemental powders are blended in proportions approximately equal to their respective intermetallic compounds. Heating of the blend results in the formation of intermetallic compounds whereas lack of heating results in intermetallic-type powder without the intermetallic structure. The resultant powder is then blended to form a final alloy. Examples involving aluminum-titanium alloys are discussed.
    Type: Grant
    Filed: December 16, 1985
    Date of Patent: May 26, 1987
    Assignee: Inco Alloys International, Inc.
    Inventors: Paul S. Gilman, Arun D. Jatkar, Stephen Donachie, Winfred L. Woodard, III, Walter E. Mattson
  • Patent number: 4655830
    Abstract: This invention relates to the manufacture of compacts of ceramic composition, cermets, and other high hardness materials by applying explosive shock during exothermic sintering of such powders.
    Type: Grant
    Filed: June 21, 1985
    Date of Patent: April 7, 1987
    Inventors: Tomotsu Akashi, Akira Sawaoka
  • Patent number: 4649002
    Abstract: A system to prevent, retard or reverse the decomposition of silicon carbide articles during high temperature plasma sintering. Preferably, the system comprises sintering a silicon carbide refractory or ceramic green body in a closed sintering environment, such as a covered crucible, with strategic placement of the plasma torch or torches, exhaust outlet and crucibles. As sintering proceeds, a silicon vapor pressure builds up within the crucible, retarding the decomposition of the silicon carbide body. The plasma torch, exhaust outlet, and crucibles are positioned so that buoyant convective flow is maximized to increase the heat transfer and energy efficiency. In another embodiment, a "sacrificial" source of silicon carbide is placed into the sintering furnace. The silicon carbide in the sacrificial source starts to decompose before the silicon carbide refractory or ceramic article, creating a supersaturated atmosphere of silicon vapor species in the furnace.
    Type: Grant
    Filed: April 1, 1985
    Date of Patent: March 10, 1987
    Assignee: Kennecott Corporation
    Inventors: Jonathan J. Kim, Joel D. Katz
  • Patent number: 4642218
    Abstract: A method for producing high technology ceramics with minimal porosity comsing the steps of filling a can with a constituent powder of a ceramic, creating a vacuum in the can and maintaining the vacuum throughout the entire process; outgassing the powder in the can by placing a furnace around the area of the can that encloses the powder and heating the furnace to at least 100.degree. C.; removing the furnace after a minimum of five minutes of heating; cold rolling the can in a rolling system; igniting the powder so a localized propagation reaction front is created; and hot rolling the can in the rolling system so the propagation reaction front is maintained between the rolls of the rolling system.
    Type: Grant
    Filed: October 19, 1984
    Date of Patent: February 10, 1987
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Roy W. Rice
  • Patent number: 4640816
    Abstract: Bulk metastable, amorphous or fine crystalline alloy materials are produced by reacting cold-worked, mechanically deformed filamentary precursors such as metal powder mixtures or intercalated metal foils. Cold-working consolidates the metals, increases the interfacial area, lowers the free energy for reaction, and reduces at least one characteristic dimension of the metals. For example, the grains (13) of powder or the sheets of foil are clad in a container (14) to form a disc (10). The disc (10) is cold-rolled between the nip (16) of rollers (18,20) to form a flattened disc (22). The grains (13) are further elongated by further rolling to form a very thin sheet (26) of a lamellar filamentary structure (FIG. 4) containing filaments having a thickness of less than 0.01 microns.
    Type: Grant
    Filed: August 31, 1984
    Date of Patent: February 3, 1987
    Assignee: California Institute of Technology
    Inventors: Michael Atzmon, William L. Johnson, John D. Verhoeven
  • Patent number: 4620872
    Abstract: A novel composite target material that is composed of a rare earth metal and a transition metal (iron-group metal) and which is used in the formation of a thin magnetooptical recording film by sputtering is disclosed. Also disclosed is a process for producing such composite target material.The process comprises the steps of providing a rare earth metal and an iron-group transition metal as separate entities, mixing these metals without alloying, and hot-forming the mixture at a temperature lower than the eutectic point of the system of metallic components in the mixture, thereby forming an intermetallic compound at the interface between the rare earth metal and the transition metal while causing said metals to be bonded together.The target material produced by this process contains 30-50 wt % of the rare earth metal, with the balance being made of the iron-group transition metal and incidental impurities.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: November 4, 1986
    Assignee: Mitsubishi Kinzoku Kabushiki Kaisha
    Inventors: Kenichi Hijikata, Katsuyuki Sato, Hitoshi Maruyama, Ryoko Furuhashi
  • Patent number: 4615863
    Abstract: A process for producing readily sinterable aluminum nitride powder, which comprises mixing(i) alumina powder and/or powder of a compound capable of forming alumina by heat treatment,(ii) carbon powder and/or powder of a compound capable of forming carbon by heat treatment, and(iii) powder of at least one compound selected from the group consisting of alkaline earth metal oxides, compounds capable of forming said alkaline earth metal oxides by heat treatment, rare earth element oxides and compounds capable of forming said rare earth element oxides by heat treatment,and calcining the resulting mixture in a nitrogen-containing non-oxidative atmosphere, provides an aluminum nitride powder which is readily sinterable without further mixing with a sintering aid.
    Type: Grant
    Filed: August 22, 1985
    Date of Patent: October 7, 1986
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Inoue, Akihiko Tsuge, Katsutoshi Komeya
  • Patent number: 4610726
    Abstract: A cermet is produced by providing a bulk reaction mixture of particulate reactants plus elemental metal, which reaction mixture is in admixture with a ceramic diluent that is the same as ceramic material formed during sintering of the reaction mixture. Sintering produces a boride-oxide ceramic with the oxide being a metal oxide of the elemental metal. However, the elemental metal is present in the reaction mixture in substantial excess over that amount stoichiometrically required. Sintering is conducted under inert atmosphere, generally after pressing. The invention is particularly directed to boride-based ceramics containing aluminum, which materials are suitable as components of electrolytic cells for the production of aluminum by molten salt electrolysis.
    Type: Grant
    Filed: June 29, 1984
    Date of Patent: September 9, 1986
    Assignee: Eltech Systems Corporation
    Inventor: Harry L. King
  • Patent number: 4610931
    Abstract: Cemented carbide substrates having substantially A or B type porosity and a binder enriched layer near its surface are described. A refractory oxide, nitride, boride, and/or carbide coating is deposited on the binder enriched surface of the substrate. Binder enrichment is achieved by incorporating Group IVB or VB transition elements. These elements can be added as the metal, the metal hydride, nitride or carbonitride.
    Type: Grant
    Filed: March 8, 1984
    Date of Patent: September 9, 1986
    Assignee: Kennametal Inc.
    Inventors: Bela J. Nemeth, George P. Grab
  • Patent number: 4599277
    Abstract: In a process for sintering a metal member bonded to a substrate during which the metal member undergoes densification at a temperature which is different from the curing temperature of the substrate, an improvement is provided which comprises causing the densification temperature of the metal member to be closer to or identical with the curing temperature of the substrate by adding to said metal member prior to sintering an amount of organometallic compound which undergoes decomposition before the densification temperature of the metal member has been reached to provide under the sintering conditions employed a densification temperature-modifying amount of a metal or metal oxide which can be the same as or different from the metal of the aforesaid metal member.The improved sintering process of the present invention is particularly adapted for use in the fabrication of multilayer ceramic substrates which serve as circuit modules for seminconductor chips.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: July 8, 1986
    Assignee: International Business Machines Corp.
    Inventors: James M. Brownlow, Robert Rosenberg
  • Patent number: 4594220
    Abstract: A method of manufacturing a scandate dispenser cathode having a matrix at least the top layer of which at the surface consists substantially of tungsten (W) and scandium oxide (Sc.sub.2 O.sub.3) and with emitter material in or below said matrix. If said method comprises the following steps:(a) compressing a porous plug of tungsten powder(b) heating said plug in a non-reactive atmosphere and in contact with scandium to above the melting temperature of scandium,(c) cooling the plug in a hydrogen (H.sub.2) atmosphere(d) pulverizing the plug to fragments(e) heating said fragments to approximately 800.degree. C. and firing them at this temperature for a few to a few tens of minutes in a hydrogen atmosphere and slowly cooling in said hydrogen atmosphere(f) grinding the fragments to scandium hydride-tungsten powder (ScH.sub.2 /W)(g) compressing a matrix or a top layer on a matrix of pure tungsten from said ScH.sub.
    Type: Grant
    Filed: December 24, 1984
    Date of Patent: June 10, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Jan Hasker, Pieter Hokkeling, Johannes van Esdonk, Josef J. van Lith
  • Patent number: 4585618
    Abstract: A cermet is produced by providing a bulk reaction mixture of particulate reactants which react to produce a self-sustaining ceramic body, and carrying out the reaction with the bulk reaction mixture in contact with molten metal which moderates the reaction and infiltrates the resulting ceramic body. The method is particularly applicable for boride-based ceramics infiltrated with aluminum, suitable as components of electroytic cells for the production of aluminum by molten salt electrolysis.
    Type: Grant
    Filed: February 15, 1984
    Date of Patent: April 29, 1986
    Assignee: ELTECH Systems Corporation
    Inventors: Jean-Marie Fresnel, Pierre-Etienne Debely, Jean-Pierre Waefler
  • Patent number: 4585617
    Abstract: Amorphous metal alloy compositions are synthesized by solid state incorporation/reduction reactions wherein a high-surface area support is brought in contact with a precursor metal-bearing compound in such a manner that the compound is incorporated into the support or caused to deposit metal onto the surface of the support. The composition obtained is an amorphous alloy composition or can be made so by heat treating at a temperature below the crystallization temperature of the amorphous metal alloy desired to be formed.
    Type: Grant
    Filed: July 3, 1985
    Date of Patent: April 29, 1986
    Assignee: The Standard Oil Company
    Inventors: Michael A. Tenhover, Richard S. Henderson, Robert K. Grasselli
  • Patent number: 4584172
    Abstract: An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily.
    Type: Grant
    Filed: May 3, 1984
    Date of Patent: April 22, 1986
    Assignee: Aluminum Company of America
    Inventors: Siba P. Ray, Robert A. Rapp
  • Patent number: RE32714
    Abstract: A method of producing .Iadd.permanent magnet material for .Iaddend.high performance permanent magnets is disclosed in which particles of a master alloy consisting of Fe.sub.2 B having a maximum particle size of 50 microns is admixed with Fe powder and particles of a rare earth capable of combining with Fe and B to form a tetragonal compound of Fe.sub.14 R.sub.2 B type. The admixture is compacted and a magnetic material is formed of the master alloy, Fe powder and .[.rate.]. .Iadd.rare .Iaddend.earth particles which includes a major phase of at least one intermetallic compound of the Fe-R-B type having a crystal structure of the substantially tetragonal system and while the particle size of the crystal structure is controlled by sintering the compacted admixture at a temperature of about 700.degree. C. to 1000.degree. C. for from a fraction of an hour to 36 hours. The magnetic material is then annealed at a temperature of about 550.degree. C. to 650.degree. C. for a fraction of an hour to 2 hours.
    Type: Grant
    Filed: April 21, 1986
    Date of Patent: July 19, 1988
    Assignee: North Carolina State University
    Inventors: Hans H. Stadelmaier, Nadia A. ElMasry