Fusing Or Melting Inorganic Material Patents (Class 264/332)
  • Patent number: 4943398
    Abstract: A method for manufacturing a fused cast refractory article including the steps of pouring a molten refractory material into a cavity of a mold including a casting sand held by a negative pressure applied through the sand and against a thermoplastic film which surrounds the mold cavity, casting and cooling off the refractory material, wherein the negative pressure is maintained after the casting. The mold includes an upper mold portion including a frame, a casting sand, and a thermoplastic film; a bottom mold portion including a frame, a casting sand and a thermoplastic film; and a cavity defined by the thermoplastic film between the upper and bottom mold portion and having an inlet opening.
    Type: Grant
    Filed: November 12, 1987
    Date of Patent: July 24, 1990
    Assignee: Toshiba Monofrax Co., Ltd.
    Inventors: Shigeo Endo, Haruo Kawashima, Kimio Hirata, Yasuo Saito, Takao Uchiya, Hideo Yanagi
  • Patent number: 4943320
    Abstract: A process for preparing ceramic-metal composites without melting the metal is disclosed. A compact or green body is made from a ceramic and a metal, and the compact is sealed in a vacuum in a container such as a glass envelope. The compact is then heated to a temperature below the melting point of the metal, but high enough so that the vapor pressure of the metal is significant, and the metal redistributes through the ceramic by evaporation and condensation. The composite thereby forms a body having ceramic particles uniformly coated by the metal. Products formed by the process and fabrication of a B.sub.4 C/Cr composite are also disclosed.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: July 24, 1990
    Assignee: The Regents of the University of California
    Inventors: Alexander Pechnik, M. Dean Matthews
  • Patent number: 4925608
    Abstract: A method of joining two pre-sintered pieces of silicon carbide is disclosed. It entails polishing the surfaces to be joined to a mirror-finish, fitting the polished surfaces together to form a composite structure, and then subjecting the composite structure to hot isostatic pressing under conditions which are sufficient to form a joint which is essentially indistinguishable from the original silicon carbide pieces.
    Type: Grant
    Filed: September 27, 1988
    Date of Patent: May 15, 1990
    Assignee: Norton Company
    Inventors: Guilio A. Rossi, Paul J. Pelletier
  • Patent number: 4921655
    Abstract: In the preparation of compact, crystalline and pore-free moldings from an oxide ceramic, amorphous oxide powders of beryllium, magnesium, aluminum, boron, zirconium, thorium or silicon or mixed oxides of silicon with these elements, in which some of the oxygen is replaced by bound nitrogen, are used as starting materials. These amorphous oxide powders containing bound nitrogen are compressed in a first stage at above the glass transition temperature but below the crystallization temperature to give a glassy molding, and the latter is then heated in a second stage to above the crystallization temperature. In the case of the individual oxides, from 5 to 30% of the oxygen are replaced by bound nitrogen, and in the case of the mixed oxides of silicon with these elements from 50 to 90% of the oxygen are replaced by bound nitrogen.
    Type: Grant
    Filed: April 29, 1988
    Date of Patent: May 1, 1990
    Assignee: BASF Aktiengesellschaft
    Inventor: Hans-Josef Sterzel
  • Patent number: 4917843
    Abstract: For joining shaped bodies of silicon nitride together, silicon nitride surfaces to be joined are first polished and then put into an apparatus for applying sputtered layers where they are first cleaned by ion bombardment in argon, followed immediately by sputtering with silicon in a nitrogen atmosphere such that a layer is deposited having a nitrogen content exceeding the Si.sub.3 N.sub.4 stoichiometric ratio. This readily provides a layer of the composition Si.sub.3 N.sub.5.5. A complementary nitrogen deficient layer is also provided in the joint before hot pressing, either in the form of a silicon layer that goes between the nitrogen-rich silicon nitride layers or in the form of a nitrogen-deficient silicon nitride layer sputtered onto a polished silicon nitride surface at relatively low nitrogen pressure. The parts are isostatically hot pressed together at 1500.degree. to 1750.degree. C. in a nitrogen atmosphere. The layers which are usually thinner than 1 .mu.
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: April 17, 1990
    Assignee: Kernforschungsanlage Julich Gesellschaft mit beschrankter Haftung
    Inventors: Erno Gyarmati, Xiliang Qiu
  • Patent number: 4906426
    Abstract: A process for producing an improved quality alumina-silica-chromia fiber from a mixture of an alumina powder, a silica powder and a powder of a solid solution of chromia in alumina, providing a flowing melt, and forming fibers.
    Type: Grant
    Filed: February 8, 1989
    Date of Patent: March 6, 1990
    Inventor: Masafumi Yamamoto
  • Patent number: 4879263
    Abstract: A sliding member formed of sintered silicon nitride shows improvement in strength and abrasion resistance when substantially all the .beta.-phase type fine silicon nitride particles present as a main component in the sintered silicon nitride have major diameters not exceeding 60 .mu.m and aspect ratios of not less than 5 and the aforementioned fine silicon nitride particles have a relative density of not less than 98%.
    Type: Grant
    Filed: September 17, 1985
    Date of Patent: November 7, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsutoshi Komeya, Hashimoto, Masahiro, Katsutoshi Nishida, Michiyasu Komatsu
  • Patent number: 4859531
    Abstract: A method for bonding a cubic boron nitride sintered compact to other cubic boron nitride sintered compact or to a body of shank material is disclosed. The method comprises forming a Ti layer of 0.01-1 .mu.m in thickness over a bonding interface between two cubic boron nitride sintered compacts or between a cubic boron nitride sintered compact and a body of shank material, forming a layer of Ni or Cu over the Ti layer to a thickness of 0.01-5 .mu.n, putting together the two cubic boron nitride sintered compacts or the cubic boron nitride sintered compact and the body of shank material with a 10-1,000 .mu.m foil of Al, Al-Ni alloy or Ag--Cu--In alloy being placed over the boding interface, and heating the cubic boron nitride sintered compact structure to temperatures above the meeting point of the metal foil and not exceeding 750.degree. C. in an inert atmosphere or in a vacuum.
    Type: Grant
    Filed: July 27, 1988
    Date of Patent: August 22, 1989
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kazuwo Tsuji, Hitoshi Sumiya, Yoshiaki Kumazawa, Nobuo Urakawa, Keiichi Satoh
  • Patent number: 4849142
    Abstract: The invention relates to producing relatively flaw free zirconia ceramic shapes requiring little or no matching by superplastic forging of a fully sintered or partially sintered preform. The preform is prepared by providing a starting powder comprising by weight from about 70% to about 100% zirconia and from about 0 to about 30% of stabilizing additives, e.g. commerically available TZ-3Y powder, cold pressing to obtain a preform of green density ranging from about 30% of theoretical density to about 75% of theoretical density and partially or fully sintering at atmospheric pressure, e.g. in argon or air at a temperature ranging from about 900.degree. C. to about 1900.degree. C. The superplastic forging is carried out by isothermally pressing the partially or fully sintered preform into substantially final shape utilizing a temperature and strain rate such that surface cracks do not occur, e.g. utilizing a temperature of 1310.degree. C.
    Type: Grant
    Filed: January 3, 1986
    Date of Patent: July 18, 1989
    Assignees: Jupiter Technologies, Inc., Cornell Research
    Inventors: Prakash C. Panda, Edgar R. Seydel, Rishi Raj
  • Patent number: 4848984
    Abstract: A method of making a reaction bonded/hot pressed silicon nitride comprising object is disclosed. Second phase crystallites are formed prior to hot pressing. A mixture of silicon, SiO.sub.2, and 0.4-2.3 molar percent (by weight of the silicon) of oxygen carrying agents, i.e., Y.sub.2 O.sub.3 and Al.sub.2 O.sub.3, is performed and reaction nitrided to form discs or billets having at least 60% alpha Si.sub.3 N.sub.4 and a high proportion of second phase crystallites which displace substantially all silicate glass except for a controlled small quantity. The reactive amounts of Y.sub.2 O.sub.3, Al.sub.2 O.sub.3 and SiO.sub.2 are controlled to assure formation of substantially Y.sub.1 SiO.sub.2 N as the second phase crystallite. Al.sub.2 O.sub.3 is controlled in an amount of 0.4-4% by weight to ensure that the small proportion of glass serves to protect the oxynitrides against linear oxidation kinetics. The hot pressed material has no visual mottle porosity associated therewith.
    Type: Grant
    Filed: September 20, 1984
    Date of Patent: July 18, 1989
    Assignee: Ceradyne, Inc.
    Inventors: Andre Ezis, Elaine C. Beckwith
  • Patent number: 4847031
    Abstract: Self-resistance heated, electrically conductive, refractory evaporating boats containing titanium diboride can be reclaimed for reuse. If there is aluminum adhering to the boats, they are first leached in hot caustic solution to remove the aluminum. After rinsing and drying, the boats are ground to powder which is then screened. The screened powder is used to manufacture new boats.
    Type: Grant
    Filed: December 16, 1987
    Date of Patent: July 11, 1989
    Assignee: GTE Products Corporation
    Inventors: Edward D. Parent, Edwin J. Spooner, Robert F. Scoledge, Jr.
  • Patent number: 4843042
    Abstract: An aluminum nitride ceramic body with a thermal conductivity of at least 0.5 W/cm.K at 25.degree. C. is produced by shaping a particulate mixture of aluminum nitride powder and an additive selected from the group consisting of CaF.sub.2, SrF.sub.2, BaF.sub.2 and mixtures thereof into a compact and liquid phase sintering the compact.
    Type: Grant
    Filed: June 30, 1986
    Date of Patent: June 27, 1989
    Assignee: General Electric Company
    Inventors: Stephen L. Dole, Ronald H. Arendt, Wayne D. Pasco
  • Patent number: 4839119
    Abstract: Compact pore-free silicon carbide moldings are produced by compressing amorphous silicon carbide powder in the absence of sintering assistants at from 1400.degree. to 1800.degree. C. and under from 100 to 2000 kp/cm .sup.2 to give dense, glassy moldings. In a subsequent stage the resulting glassy moldings are converted into crystalline .alpha.-silicon carbide at from 1950.degree. to 2200.degree. C.
    Type: Grant
    Filed: February 26, 1988
    Date of Patent: June 13, 1989
    Assignee: BASF Aktiengesellschaft
    Inventor: Hans-Josef Sterzel
  • Patent number: 4834917
    Abstract: Waste material such as toxic compounds, radioactive waste materials and spent nuclear fuel rods are encapsulated in a container system which is subjected to a hot pressure process to cause a protective powder material located around the waste material to form a dense matrix and function as a highly corrosion resistant and protective shroud. Embodiments include hot isostatic pressing and hot uniaxial pressing, the use of metal powder such as copper powder for the protective powder material or alternatively ceramic powder and, depending upon the embodiment chosen, the use of a single container or dual container system in which a first container is located within an outer container. Either or both of such containers may be cylindrical with a bellows-like side wall to facilitate compression thereof in an axial direction.
    Type: Grant
    Filed: June 23, 1987
    Date of Patent: May 30, 1989
    Assignees: Australian Nuclear Science & Technology Organization, The Australian National University
    Inventors: Eric J. Ramm, Albert E. Ringwood
  • Patent number: 4832893
    Abstract: A method for producing PLZT generally expressed as (Pb.sub.1-x La.sub.x) (Zr.sub.1-y Ti.sub.y).sub.1-x/4 O.sub.3 (0<x.ltoreq.0.3, 0.ltoreq.y.ltoreq.1.0) comprises the steps of forming a coprecipitated body by reacting solution containing at least one of Pb, La and Ti with a zirconium-containing solution and a precipitation-forming solution, or (a) forming a solution containing at least one of Pb, La and Ti forming PLZT generally expressed as (Pb.sub.1-x La.sub.x) (Zr.sub.1-y Ti.sub.y).sub.1-x/4 O.sub.3 (0<x.ltoreq.0.3, 0.ltoreq.y.ltoreq.1.0) and a zirconium-containing solution and carrying out a hydrolysis reaction to produce a sol body, (b) drying and then presintering the coprecipitated body at a temperature of from 700.degree. to 1300.degree. C. to form a modified zirconia powder, (c) mixing the presintered body with a compound having a remaining component composition of a required PLZT composition, (d) presintering the mixture at a temperature of from 500.degree. to 1000.degree. C.
    Type: Grant
    Filed: December 16, 1987
    Date of Patent: May 23, 1989
    Assignees: Nippondenso Co., Ltd., Science and Technology Agency National Institute
    Inventors: Michio Hisanaga, Kazunori Suzuki, Masataka Naito, Shinichi Shirasaki
  • Patent number: 4812272
    Abstract: A process for compacting a porous ceramic structural member having a compated shape and an optional size by encapsulation with material of the same type and capable of sintering and subsequently subjected to hot-isostatic pressing; immersing the preformed body in a suspension of a material of the same type in a solvent but which contains no sintering aid and forming a first encapsulating layer; evaporating the solvent; immersing the thus obtained body in a second suspension of a material in a solvent of the same type capable of sintering and which contains one or more sintering aids, and forming a second encapsulating layer; evaporating the solvent; subjecting the thus obtained body at an elevated temperature in an atmosphere of a protective gas for a sufficient period of time to sinter the same; isostatically compacting the body provided with a tight-sintered surface; and mechanically removing the encapsulating layers.
    Type: Grant
    Filed: February 5, 1987
    Date of Patent: March 14, 1989
    Assignee: Duetsche Forchungs- und Versuchsanstalt fur Luft- und Raumfahrt e.V.
    Inventors: Jurgen Heinrich, Manfred Bohmer
  • Patent number: 4812280
    Abstract: A process for manufacturing large, fully dense, high purity TiB.sub.2 articles by pressing powders with a sintering aid at relatively low temperatures to reduce grain growth. The process requires stringent temperature and pressure applications in the hot-pressing step to ensure maximum removal of sintering aid and to avoid damage to the fabricated article or the die.
    Type: Grant
    Filed: April 17, 1986
    Date of Patent: March 14, 1989
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: Arthur J. Moorhead, E. S. Bomar, Paul F. Becher
  • Patent number: 4808337
    Abstract: A compressible bellows type metal canister is used in a hot pressing process for immobilizing high level radioactive nuclear waste material in the form of synthetic rock, the canister comprises a base wall and a corrugated bellows side wall of generally circular cross-section, concentrically arranged within the corrugated side wall is a cylindrical liner. In the center of the base wall a conically-tapered aperture is provided with a filter plug. Diametrically opposed apertures are provided in the base wall and are connected by an outlet pipe for removal of waste gases.
    Type: Grant
    Filed: July 14, 1986
    Date of Patent: February 28, 1989
    Inventors: Eric J. Ramm, Wilhelmus J. Bukyx, John G. Padgett, Alfred E. Ringwood
  • Patent number: 4806279
    Abstract: A vibratory processing arrangement including an apparatus comprising three main stages. Namely, a high level waste vibrating impregnator, a vibrating calciner and a vibratory powder mixer.The waste impregnator comprises a downwardly inclined trough having flexible mountings and a vibrator at its upstream end, a hood structure and a series of liquid sprays connected to a high level waste supply tube.The vibratory calciner comprises a downwardly inclined tube connected to a downstream discharge tube. The discharge tube has an inlet pipe for entry of reducing gas. The reducing gas passes upwardly through the tubes to a gas discharge take-off tube near the upstream end of the downwardly inclined tube. A vibrator is tuned to provide the desired flow rate through the downwardly inclined tube.Calcined discharged powder falls downwardly into the vibratory mixer, which has a vibratory actuator and flexible mountings.
    Type: Grant
    Filed: December 1, 1986
    Date of Patent: February 21, 1989
    Assignees: Australian Atomic Energy Commission, Australian National University
    Inventor: Eric J. Ramm
  • Patent number: 4792468
    Abstract: A process of forming a refractory mass on a surface, which process includes spraying against that surface a mixture of refractory particles and oxidisable particles which react exothermically with oxygen to generate sufficient heat to soften or melt at least the surfaces of the refractory particles and so bring about formation of said refractory mass, and causing the sprayed mixture to be heated sufficiently to cause the oxidisable particles to undergo such exothermic reaction, the granulometry of the particles which are sprayed in the mixture being such that the mean of the 80% and 20% grain sizes of the refractory particles is greater than the mean of the 80% and 20% grain sizes of the oxidisable particles and that the size range spread factor of the refractory particles is at least 1.2.
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: December 20, 1988
    Assignee: Glaverbel
    Inventors: Pierre Robyn, L/e/ on-Philippe Mottet, Pierre Deschepper
  • Patent number: 4786448
    Abstract: There are disclosed a plastic processing method of the pressure of pressureless sintered ceramic body composed of at least one aluminum-containing compound selected from the group consisting of aluminum oxide, aluminum nitride and aluminum oxynitride and at least one hard compound selected from the group consisting of carbides, nitrides and oxides of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten and silicon and mutual solid solutions thereof, the content of said at least one aluminum-containing compound is 5 to 95% by volume, comprising subjecting the ceramic body to plastic deformation at a temperature of 1300.degree. C. or higher, under a stress of 15 kg/mm.sup.2 or smaller and at a strain rate of 10.sup.-3 /sec or less in a reducing atmosphere or in vacuum, and a ceramics-made molded material comprising a composite ceramic body composed of the same as mentioned above.
    Type: Grant
    Filed: August 27, 1986
    Date of Patent: November 22, 1988
    Assignee: Toshiba Tunglogy Co., Ltd.
    Inventors: Mikio Fukuhara, Yuji Katsumura, Akira Fukawa, Mutsuo Asakawa, Tomio Urushihata, Isao Miyakawa, Kazuhiro Sawada
  • Patent number: 4786304
    Abstract: A method of molding a hollow, fiber reinforced glass matrix composite article. Reinforcing fibers are placed in a mold cavity. A billet of high temperature stable glass matrix material is heated above its flow point. The thus heated matrix materials is flowed into the mold cavity from a point inside of the article being formed and at the relative midpoint along its vertical axis. Improved article tolerance control and minimized article preform fiber disturbance is achieved.
    Type: Grant
    Filed: August 10, 1987
    Date of Patent: November 22, 1988
    Assignee: United Technologies Corporation
    Inventor: Otis Y. Chen
  • Patent number: 4784818
    Abstract: A shaped article of superplastic ceramic composed of zirconia toughened ceramic containing, or not containing, fine alumina powder is produced by deforming the ceramic under the action of stress at a temperature in the range of superplastic temperatures thereof.
    Type: Grant
    Filed: March 28, 1986
    Date of Patent: November 15, 1988
    Assignees: Agency of Industrial Science & Technology, Ministry of International Trade & Industry
    Inventors: Fumihiro Wakai, Shuzo Kanzaki, Shuji Sakaguchi
  • Patent number: 4778626
    Abstract: A dry, pourable particulate mixture of nuclear waste and synthetic rock-forming components is produced by supplying the rock forming components in dry particulate form to a mixer, supplying the nuclear waste in liquid phase and operating the mixer to distribute the waste substantially uniformly through the synthetic rock components; the mixture is calcined to produce a precursor powder which is adapted to be used in a hot pressing process to form synthetic rock throughout which the radioactive nuclear waste is distributed and immobilized. A reducing gas atmosphere is preferably maintained in the calcining process stage, the gas being for example pure hydrogen or a mixture of hydrogen in nitrogen in proportions which are non-explosive. A screw type or paddle type conveyor can be used for the mixing and calcining stages although the calcining can be effected in a vertically downwardly directed tube device having associated heating means such as microwave heating.
    Type: Grant
    Filed: October 27, 1986
    Date of Patent: October 18, 1988
    Assignees: Australian Nat'l Univ. of Acton, Australia Nuclear Science & Technology Organisation
    Inventors: Eric J. Ramm, Wilhelmus J. Buykx, Alfred E. Ringwood
  • Patent number: 4762656
    Abstract: The hot pressing of beryllium oxide powder into high density compacts with little or no density gradients is achieved by employing a homogeneous blend of beryllium oxide powder with a lithium oxide sintering agent. The lithium oxide sintering agent is uniformly dispersed throughout the beryllium oxide powder by mixing lithium hydroxide in an aqueous solution with beryllium oxide powder. The lithium hydroxide is converted in situ to lithium carbonate by contacting or flooding the beryllium oxide-lithium hydroxide blend with a stream of carbon dioxide. The lithium carbonate is converted to lithium oxide while remaining fixed to the beryllium oxide particles during the hot pressing step to assure uniform density throughout the compact.
    Type: Grant
    Filed: October 10, 1986
    Date of Patent: August 9, 1988
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Ambrose H. Ballard, Thomas G. Godfrey, Jr., Erb H. Mowery
  • Patent number: 4759887
    Abstract: A process for the manufacture of shaped bodies from silicon granulates for producing silicon melts includes first incipiently melting silicon grains on their surfaces, so that they bond with their neighbors in the process and, after solidifying, form a porous compound shaped body which only then may be melted completely. Such compound shaped bodies can be manufactured continuously or semi-continuously and converted without difficulty by a subsequent step into the molten state. An apparatus for producing shaped bodies is also provided which preferably employs an electron beam, to supply energy to incipiently melt the granulate.
    Type: Grant
    Filed: May 12, 1986
    Date of Patent: July 26, 1988
    Assignee: Heliotronic Forschungs- und Entwicklungs-gesellschaft fur Solarzellen-Grundstoffe mbH
    Inventors: Joachim Geissler, Deiter Helmreich, Roland Luptovits, Maximilian Semmler, Burkhard Walter
  • Patent number: 4752427
    Abstract: A method for plastic working of ceramics comprising the steps of causing a sintered or pre-sintered body of polycrystalline ceramics containing at 20.degree. C. tetragonal-phase zirconia crystals to undergo plastic deformation at a temperature of about 1,000.degree. C. to about 1,600.degree. C. and then heating the ceramics body at a temperature of about 1,300.degree. C. to about 1,650.degree. C.
    Type: Grant
    Filed: July 11, 1986
    Date of Patent: June 21, 1988
    Assignees: Agency of Industrial Science and Technology, Nippon Kagaku Togyo Co., Ltd.
    Inventors: Fumihiro Wakai, Shuji Sakaguchi, Hiroshi Ohnishi, Hiroshi Tomatsu
  • Patent number: 4749539
    Abstract: A process is disclosed for producing corrosion resistant silicon nitride bodies from compositions of pure silicon nitride, lanthanum oxide with and without aluminum oxide by hot pressing.
    Type: Grant
    Filed: May 29, 1984
    Date of Patent: June 7, 1988
    Assignee: GTE Products Corporation
    Inventor: Martin Y. Hsieh
  • Patent number: 4744943
    Abstract: A process for preparing dense, consolidated bodies, the process comprising compressing in a forging press an isostatic die assembly, the assembly comprising a preform surrounded by a fluid pressure-transmitting medium, the medium and the preform being contained in a shell having an open top; under sufficient conditions of temperature, time and pressure that a dense, consolidated body of desired shape is formed, and then recovering the body by separating the body from the fluid pressure-transmitting medium.
    Type: Grant
    Filed: December 8, 1986
    Date of Patent: May 17, 1988
    Assignee: The Dow Chemical Company
    Inventor: Edward E. Timm
  • Patent number: 4734234
    Abstract: Pore-free, compact moldings of silicon nitride are produced by a method in which amorphous silicon nitride powder is compressed in a first stage at from 1200.degree. to 1350.degree. C. and from 50 to 600 kp/cm.sup.2 to give a glassy molding, and the silicon nitride is converted in a second stage to crystalline silicon nitride at from 1400.degree. to 1800.degree. C. without the use of pressure.
    Type: Grant
    Filed: January 21, 1986
    Date of Patent: March 29, 1988
    Assignee: BASF Aktiengesellschaft
    Inventor: Hans-Josef Sterzel
  • Patent number: 4732719
    Abstract: The invention relates to producing relatively flaw free silicon nitride ceramic shapes requiring little or no machining by superplastic forgingThis invention herein was made in part under Department of Energy Grant DE-AC01-84ER80167, creating certain rights in the United States Government. The invention was also made in part under New York State Science and Technology Grant SB1R 1985-10.
    Type: Grant
    Filed: January 3, 1986
    Date of Patent: March 22, 1988
    Assignee: Jupiter Technologies, Inc.
    Inventors: Prakash C. Panda, Edgar R. Seydel, Rishi Raj
  • Patent number: 4715892
    Abstract: The present invention is directed to a cermet material comprising a matrix of metal or alloy with ceramic particles distributed therein. The cermet includes a glass binder for bonding between the metal or alloy and the ceramic particles.
    Type: Grant
    Filed: October 30, 1986
    Date of Patent: December 29, 1987
    Assignee: Olin Corporation
    Inventor: Deepak Mahulikar
  • Patent number: 4705659
    Abstract: A process is disclosed for fabricating a free-standing thin or thick film structure. One embodiment of the process includes the steps of providing a substrate of a first refractory material, forming a layer of carbon on the substrate, and depositing a film of a second refractory material on top of the layer of carbon. This sandwich structure is heated in an oxidizing ambient to cause the oxidation of the carbon layer leaving the second refractory material as a free-standing film.
    Type: Grant
    Filed: July 7, 1986
    Date of Patent: November 10, 1987
    Assignee: Motorola, Inc.
    Inventors: Jonathan J. Bernstein, T. Bruce Koger, Charles S. Chanley
  • Patent number: 4692288
    Abstract: A method including embedding a porous silicon ceramic compact, or workpiece, in a powder which is not sinterable at the process temperature, and subjecting the powder and embedded compact to heat and pressure in a hot isostatic press. The powder transmits the pressure to the compact. The powder may be the same material as the compact, except without a sintering agent, or the powder may be graphite powder. The grain size of the powder is between 2 .mu.m and 50 .mu.m. The powder and embedded compact are placed in a container prior to hot pressing; the container may be made of thin sheet metal or of quartz glass.
    Type: Grant
    Filed: October 21, 1980
    Date of Patent: September 8, 1987
    Assignee: MTU Motoren-und Turbinen-Union Munchen GmbH
    Inventors: Axel Rossmann, Werner Huther
  • Patent number: 4690797
    Abstract: A method for the manufacture of large area silicon crystal bodies suitable for use in the manufacture of solar cells wherein silicon powder having a small grain size is used as the starting material. This powder is compressed to form a thin layer in a suitable form, the form having at least a surface composed of silicon or a silicon compound. The form is filled to a depth approximating the final dimensions of the article. The powder is sintered in the form, and the compressed, sintered layer is converted into a self-supporting silicon foil. This foil is melted partially up to at least half its thickness and recrystallized in a two-stage temperature treatment. The melting occurs by means of a single-sided energy irradiation. The silicon foil is not deteriorated in terms of its mechanical stability and shaped by means of the single-sided, optical type heating.
    Type: Grant
    Filed: September 17, 1986
    Date of Patent: September 1, 1987
    Assignee: Siemens Aktiengesellschaft
    Inventors: Achim Eyer, Armin Raeuber, Norbert Schillinger
  • Patent number: 4689196
    Abstract: An electrical contact comprises 5 to 20 weight percent tungsten carbide, 0.5 to 3 weight percent graphite, balance silver. The contact has low erosion rate, low contact resistance, and anti-welding properties.
    Type: Grant
    Filed: February 26, 1987
    Date of Patent: August 25, 1987
    Assignee: GTE Products Corporation
    Inventor: Chi H. Leung
  • Patent number: 4689188
    Abstract: Alternate layers of mats of specially coated SiC fibers and silicon monotapes are hot pressed in two stages: In the first a die is heated to about 600.degree. C. in a vacuum furnace and maintained at this temperature for about one-half hour to remove fugitive binder.In the second stage the die temperature is raised to about 1000.degree. C. and the layers are pressed at between 35 MPa and 138 MPa. The resulting preform is placed in a rector tube where a nitriding gas is flowed past the preform at 1100.degree. C. to 1400.degree. C. to nitride the same.
    Type: Grant
    Filed: July 16, 1986
    Date of Patent: August 25, 1987
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Ramakrishna T. Bhatt
  • Patent number: 4683118
    Abstract: A process and apparatus for producing a pressed powder body from at least two different kinds of ultrafine particles. Ultrafine particles of at least two different materials are uniformly mixed together and the mixture is sprayed onto an objective surface whereby the spray pressure causes the particles to adhere and form the pressed powder body. The apparatus includes mixing means, means for conveying the mixture of ultrafine particles, and a pressed powder body forming chamber including nozzle means for spraying the mixture of ultrafine particles, an objective surface and means for evacuating the chamber and introducing an inert gas therein.
    Type: Grant
    Filed: October 9, 1985
    Date of Patent: July 28, 1987
    Assignee: Research Development Corporation of Japan
    Inventors: Chikara Hayashi, Seiichiro Kashu
  • Patent number: 4678761
    Abstract: Magnesium oxide ceramic bodies may be strengthened by inclusion of zirconium oxide particles, and may be further sintered to a density approaching theoretical density by conventional sintering techniques by inclusion of sintering aids, such as manganese oxide and iron oxide.
    Type: Grant
    Filed: October 29, 1985
    Date of Patent: July 7, 1987
    Assignee: The Dow Chemical Company
    Inventors: Anil Virkar, Thomas C. Yuan
  • Patent number: 4671917
    Abstract: Molten oxide of grinding material, refractory material, etc., being poured into a circular casting space formed between coaxially arranged inner and outer cylinders and cooled by the water contained in the inner cylinder. Thus, the molten oxide is cooled radially from the center of the inner cylinder and solidified. The outer cylinder includes two segments which separate from each other for facilitating putting the molten oxide into the casting space and taking the resulting solidified product out of the casting space.
    Type: Grant
    Filed: July 30, 1985
    Date of Patent: June 9, 1987
    Assignee: Japan Abrasive Co., Ltd.
    Inventors: Akira Iwata, Masahiro Tamamaki, Genji Tanaka, Masaaki Taniguchi, Kouji Tsuda
  • Patent number: 4666645
    Abstract: The present invention discloses a process of forming glass, glass-ceramic or ceramic matrix, fiber reinforced composite articles. The method comprises preparing both the matrix and the reinforcement into fibers, which are then chopped into relatively short lengths. These chopped fibers are then formed into hybrid felt papers comprising a mixture of both reinforcing fibers and matrix fibers. These felt papers are then cut into preforms and stacked one on top of the other to form a lay-up. The lay-up is then placed in a die and densified to form the composite article.
    Type: Grant
    Filed: April 20, 1984
    Date of Patent: May 19, 1987
    Assignee: United Technologies Corporation
    Inventors: Karl M. Prewo, George K. Layden
  • Patent number: 4664705
    Abstract: A polycrystalline diamond (PCD) body with improved thermal stability is disclosed which comprises a PCD body which has had at least one of its previously empty pores infiltrated by a silicon containing alloy. According to the process of the invention, a porous PCD body is obtained, preferably by acid leaching a PCD body which was formed in the presence of a metal catalyst such as cobalt. The porous PCD body is then surrounded by either the desired silicon containing alloy, or by the constituents of that alloy, each preferably in powdered form. The PCD body with its surrounding material is then heated and pressed to temperatures sufficient to melt the surrounding material (thereby forming the silicon alloy if not already formed) and to cause it to infiltrate into the pores. After the infiltration, it is preferred to remove the excess silicon containing alloy from the external surfaces of the PCD body, such as by an acid bath. It is also preferred to include several porous PCD bodies per process cycle.
    Type: Grant
    Filed: July 30, 1985
    Date of Patent: May 12, 1987
    Assignee: Sii Megadiamond, Inc.
    Inventors: M. Duane Horton, Gary R. Peterson
  • Patent number: 4664731
    Abstract: A method of making fiber reinforced glass composite articles utilizes preregnated preforms which are bound with a temporary plastic binder. The binder is removed in a gradient oven and the frit or preform is drawn through a pultrusion die assembly heated to the degree necessary to render the frit workable. Deformation in the heated die assembly is maintained during cooling, resulting in a formed glass composite article.
    Type: Grant
    Filed: January 7, 1985
    Date of Patent: May 12, 1987
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: George K. Layden, Karl M. Prewo
  • Patent number: 4657754
    Abstract: Fine alumina powders for making alumina bodies are produced by seeding of a non-alpha alumina with submicron alpha alumina particles, firing, and crushing and milling the fired product to a fine powder. The powder so produced may be formed by conventional techniques such as pressing, granulating, slip casting, tape casting, and extrusion, and sintered to produce the desired fired product.
    Type: Grant
    Filed: November 21, 1985
    Date of Patent: April 14, 1987
    Assignee: Norton Company
    Inventors: Ralph Bauer, Arup K. Khaund, Ronald W. Trischuk, Joseph Similia
  • Patent number: 4657878
    Abstract: A novel method of making a refractory material is disclosed comprising the steps of providing an electrical arc metal furnace, charging that furnace with a charge of refractory oxide, and selecting voltage, amperage and electrode spacings to create novel "hum and scum" melt conditions. This hum and scum condition is maintained until said charge is substantially melted. The described technique is particularly useful for melting magnesia chrome materials to produce fusion cast refractory products which are highly reduced and quite dense. The elaboration of this product requires higher energy input per pound concurrent with an increased consumption of reducing materials compared with standard preparation conditions. The resulting product exhibits higher oxidation weight gains, higher densities, lower porosities, high cold crush strengths, more thermal shock resistance, and better corrosion-erosion resistance than similar magnesia chrome refractory products fused using prior "arc and bark" processes.
    Type: Grant
    Filed: February 8, 1985
    Date of Patent: April 14, 1987
    Assignee: Corhart Refractories
    Inventors: Thomas A. Clishem, Leonard W. Pokallus
  • 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: 4645624
    Abstract: Particulate material is poured into a container which is decay and heat resistant, the container is sealed and subjected to axial compression at elevated temperature to cause densification of the material, there being an arrangement for preventing substantial radially outward deformation of the container during compression. An important application is to immobilization of nuclear reactor waste in a synthetic rock structure formed during the high temperature compression step, and advantageously the containers are secured within an outer metal cannister for subsequent safe handling and disposal. An important embodiment includes a bellows container which advantageously is upwardly pressed into an inverted metal cannister restrained by an upper abutment, the bellows container becoming an interference fit within the metal cannister during the final portion of compression, but the bellows container wall itself being substantially sufficient to prevent gross outward deformation of the bellows container.
    Type: Grant
    Filed: August 19, 1983
    Date of Patent: February 24, 1987
    Assignees: Australian Atomic Energy Commission, The Australian National University
    Inventors: Eric J. Ramm, Alfred E. Ringwood
  • Patent number: 4643859
    Abstract: A process for producing fine non-oxide powder from an alkoxide selected from the group consisting of a silicon alkoxide and an aluminum alkoxide, which comprises dispersing carbon powder in the alkoxide, hydrolyzing the dispersion, and heating the hydrolyzate mixture thereby obtained, in a nitrogen atmosphere at a temperature of from 1350.degree. C. to 1650.degree. C. for from 30 minutes to 30 hours.
    Type: Grant
    Filed: October 17, 1985
    Date of Patent: February 17, 1987
    Assignee: National Institute for Researches in Inorganic Materials
    Inventors: Mamoru Mitomo, Yuji Yoshioka
  • Patent number: 4642204
    Abstract: A method of containing radioactive or other dangerous material separately or intermixed with a bonding compound of a material, resistant to leaching by water, in a gas-tight container and of converting the material by hot isostatic pressing (HIP) into a dense body. The material is filled into a cylindrical container having a corrugated bellows-like wall. The dangerous material is prevented from filling up the annular spaces formed by the corrugations, by means of a barrier means placed inside the container. A metallic netting combined with a paper-like sheet of ceramic material makes a suitable barrier means.
    Type: Grant
    Filed: January 23, 1984
    Date of Patent: February 10, 1987
    Assignee: ASEA Aktiebolag
    Inventors: Martin Burstrom, Ragnar Tegman
  • 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