Special Atmosphere Patents (Class 419/57)
  • Patent number: 5812925
    Abstract: A method for joining a first metal surface to a second metal surface that includes providing powder metal particles substantially all of which have hardnesses lower than the hardnesses of the first and second metal surfaces, at normal temperatures; locating the particles in a layer between the first and second metallic surfaces, to form an assembly; heating the assembly to an elevated temperature or temperatures below the softening temperature of the first and second metallic surfaces; and effecting compression of the layer by and between the first and second surfaces at a pressure level or levels below the compressive yield strengths of the first and second surfaces, and above the compressive yield strengths of the particles, and for a time duration to effect a bond between the first and second metallic surfaces.
    Type: Grant
    Filed: October 23, 1996
    Date of Patent: September 22, 1998
    Inventor: Gunes M. Ecer
  • Patent number: 5777247
    Abstract: Fine powders of iron with less than 5% by weight graphite, copper, and an organic binder can be formed into shapes having a green density of up to about 7.4 g/cc and sintered in a hydrogen containing atmosphere to yield parts having minimum variations in physical properties. Incorporation of small quantities of copper, e.g. 1% or less by weight, negates variations in physical properties of sintered parts that were subjected to variations in the hydrogen content of the sintering atmosphere.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: July 7, 1998
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Kerry Renard Berger, James Garfield Marsden
  • Patent number: 5773733
    Abstract: The present invention provides an alumina-aluminum nitride-nickel (Al.sub.2 O.sub.3 -AlN-Ni) composite which can be prepared by pressureless sintering Al.sub.2 O.sub.3 and NiAl alloy powders or by pressureless sintering Al.sub.2 O.sub.3, Ni and Al powders in a nitrogen-containing atmosphere. The mechanical properties and the thermal conductivity of the obtained composite are better than those of alumina alone, while the electrical resistivity of the composite remains high. The composite thus is suitable for use as an electronic substrate or package.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: June 30, 1998
    Assignee: National Science Council
    Inventors: Wei-Hsing Tuan, Wen-Bing Chou, Shun-Tai Chang
  • Patent number: 5761593
    Abstract: A cemented carbide insert with improved toughness and resistance against plastic deformation containing WC and cubic phases of carbide and/or carbonitride in a binder phase based on Co and/or Ni with a binder phase enriched surface zone is disclosed. The binder phase content in the insert is 3.5-12 weight-%. In a zone below the binder phase enriched surface zone, the binder phase content is 0.85-1 of the binder phase content in the inner portion of the insert and the content of cubic phases is essentially constant and equal to the content in the inner portion of the insert. The insert is formed by sintering a cemented carbide containing a nitrogen-containing material in a vacuum or inert atmosphere and heat treating the sintered insert in nitrogen at 40-400 mbar at a temperature of 1280.degree.-1430.degree. C. for a time of 5-100 min.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: June 2, 1998
    Assignee: Sandvik AB
    Inventors: Ake Ostlund, Ulf Oscarsson, Per Gustafson, Leif Akesson
  • Patent number: 5758253
    Abstract: A process for producing sintered titanium-graphite having improved wear resistance and low frictional characteristics is described. The said process which produces titanium-graphite composites having a triphasic structure with controlled porosity and a graphite lubricating film, comprises sintering a mixture of titanium and graphite powders in which the percentage of graphite may vary from 4 to 8 percent at temperatures from about 800.degree. C. to 1600.degree. C., for about 1/2 to 2 hours, under a compaction pressure of 0.17 to 0.62 MPa. The composites have applications in biomedical engineering and other fields of engineering due to their biocompatibility, strength and improved wear resistance.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: May 26, 1998
    Assignee: National University of Singapore
    Inventors: Swee Hin Teoh, Rajendran Thampuran, James Cho Hong Goh, Winston Kar Heng Seah
  • Patent number: 5752156
    Abstract: High-temperature-stable, fiber-reinforced beryllium metal matrix composite materials are fabricated using coating, infiltration and hot-pressing procedures. High-temperature-stable fibers of metal oxides, carbon or silicon carbide are coated with reaction barrier coatings which prevent chemical reactions from occurring at the interface with the surrounding metallic beryllium matrix at temperatures up to close to the melting point of beryllium. Coatings such as yttria, YAG and mixtures of yttria and YAG or of yttria and beryllia are employed exterior of metal oxide fibers, such as alumina or alumina-silica fibers. Suitable reaction barrier coatings are also employed over carbon fibers (or silicon carbide fibers) which preferably include an interior coating of elemental silicon upon the exterior surface of the carbon fibers. Oxide coatings are preferably applied by immersion in a liquid bath containing a suitable coating solution, preferably an alcohol solvent alkoxide sol-gel.
    Type: Grant
    Filed: March 4, 1996
    Date of Patent: May 12, 1998
    Assignee: General Atomics
    Inventors: Kuo-Chun Chen, Paul W. Trester, Khodabakhsh S. Mazdiyasni
  • Patent number: 5736092
    Abstract: A microwave susceptor bed useful for sintering ceramics, ceramic composites and metal powders is described. The susceptor bed includes granules of a major amount of a microwave susceptor material, and a minor amount of a refractory parting agent, either dispersed in the susceptor material, or as a coating on the susceptor material. Alumina is the preferred susceptor material. Carbon is the most preferred parting agent. Also described is a sintering process using the bed and to novel silicon nitride products produced thereby.
    Type: Grant
    Filed: June 17, 1996
    Date of Patent: April 7, 1998
    Assignee: Microwear Corporation
    Inventors: Prasad Shrikrishna Apte, Larry Roy Morris
  • Patent number: 5732323
    Abstract: The invention relates to a method for the fabrication of dimensionally accurate metal pieces by sintering a material which, before the sintering, consists of a blend of three pulverous ingredients, of which the first ingredient is in the main an iron-group metal, the second ingredient is in the main copper and phosphorus, and the third ingredient is an alloy of copper and some other metal. The shape of the piece is produced by layer-by-layer freeform selected area laser sintering, wherein a layer of the said powder blend is spread on a base, those regions of the layer which correspond to this cross-sectional surface of the piece are heated by a laser beam to the sintering temperature. Thereafter further successive powder layers are spread one on top of another, and in each layer in turn those areas which correspond to the cross-sectional surface of the piece in that layer are laser sintered.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: March 24, 1998
    Assignee: Aktiebolaget Electrolux
    Inventor: Olli Juhani Nyrhila
  • Patent number: 5729823
    Abstract: The present invention relates to a cemented carbide insert, comprising a cemented carbide substrate and a coating. The substrate contains WC and cubic carbonitride phase in a binder phase based of Co and/or Ni and has a binder phase enriched surface zone essentially free of cubic phase. The binder phase enriched surface zone prevails over the edge. As a result, an insert according to the invention has improved edge toughness and resistance against plastic deformation and is particularly useful for machining of sticky work piece materials such as stainless steel.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: March 17, 1998
    Assignee: Sandvik AB
    Inventors: Per Gustafson, Leif kesson
  • Patent number: 5723799
    Abstract: The present invention provides metal-based composite with oxide particle dispersion and a method for producing the same.The present invention relates to a method for producing metal-based composite with oxide particle dispersion, comprising sintering of metal-based ultrafine powders (with an average grain size of about 20 nm to 100 nm and a grain size distribution of about 5 nm to 300 nm and with the surface oxidized for handling) in vacuum, in an inert gas or in a reducing atmosphere by rapid sintering, crystallizing the ultrafine powders with a grain size of about 50 nm or less to metal oxide during sintering and simultaneously removing the oxygen on the surface of the ultrafine powders with the grain size of about 50 nm or more, and the metal-based composite with oxide particle dispersion produced according to the said method.
    Type: Grant
    Filed: July 5, 1996
    Date of Patent: March 3, 1998
    Assignee: Director General of Agency of Industrial Science and Technology
    Inventors: Norimitsu Murayama, Yasuyoshi Torii
  • Patent number: 5694639
    Abstract: A sintered body of titanium based carbonitride alloy containing hard constituents based on, in addition to titanium, one or more of the metals Zr, Hf, V, Nb, Ta, Cr, No or W in 5-30% binder phase based on Co and/or Ni is disclosed. The body has a binder phase enriched surface zone with a higher binder phase content than in the inner portion of the body in combination with an enrichment of simple hard constituents, i.e., the share of grains with core-rim structure is lower in the surface zone than in the inner of the body.A method of manufacturing the sintered carbonitride alloy is also provided which comprises forming a powder mixture containing binder phase containing Co and/or Ni and hard constituents of carbides and nitrides with titanium as a main component, the mixture having composition which is substoichiometric regarding an interstitial balance and sintering the mixture to completely transform the substoichiometric phases to stoichiometric by heating a) in vacuum to 1100-1200 C.
    Type: Grant
    Filed: January 30, 1996
    Date of Patent: December 2, 1997
    Assignee: Sandvik AB
    Inventors: Rolf Gregor Oskarsson, Gerold Weinl
  • Patent number: 5686676
    Abstract: The sinterability of a copper/tungsten green compact is improved by using copper oxide, tungsten oxide or both as the copper and/or tungsten source. Sinterability is further enhanced by including steam in the sintering atmosphere.
    Type: Grant
    Filed: May 7, 1996
    Date of Patent: November 11, 1997
    Assignee: Brush Wellman Inc.
    Inventors: David E. Jech, Juan L. Sepulveda, Anthony B. Traversone
  • Patent number: 5678162
    Abstract: A mold useful for injection molding, comprising: a porous network of metal and oxidized metal and a cured epoxy resin dispersed in the porous network. The mold can be prepared by a process comprising the sequential steps of (a) forming a mixture of a metal powder and a polymer binder; (b) heating the mixture at a temperature in the range from about 100.degree. C. to about 300.degree. C. to remove a majority of the polymer binder from the mixture; (c) heating the mixture resulting from step (b) at a temperature greater than about 300.degree. C. and less than the melting point of the metal in the presence of oxygen to oxidize at least a portion of the metal to form a self-adhering porous network of metal and oxidized metal; (d) contacting the self-adhering porous network with an epoxy resin to fill at least a portion of the porous network with epoxy resin; and (e) curing the body resulting from step (d) to form the mold. The shape of the mold can be performed by selective laser sintering of the mixture.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: October 14, 1997
    Assignee: Board of Regents, Univ. of Texas System
    Inventors: Joel W. Barlow, Balasubramanian Badrinarayan, Joseph J. Beaman, David L. Bourell, Richard H. Crawford, Harris L. Marcus, James R. Tobin, Neal K. Vail
  • Patent number: 5666636
    Abstract: The present invention provides a process for preparing titanium nitride sintered masses having no residual pores and consisting of TiN solid solution particles and Ni solid solution matrix, in which a granulated powder of the following composition:TiN-pMo.sub.2 C-qC-rNi-sMeCwherein:p is 5 to 20 wt %;q is 0 to 1.5 wt %;r is 15 to 30 wt %;s is 0 to 5 wt %;MeC is one or more carbides selected from VC, WC, TaC and NbC;with the proviso that q and s are not 0 wt % simultaneously;is compacted and sintered. The process according to the present invention can provide sintered TiN cermets of high density and a small grain size.
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: September 9, 1997
    Assignee: Korea Institute of Science and Technology
    Inventors: Jong Ku Park, Sung Tae Park
  • Patent number: 5641921
    Abstract: This invention is directed toward a material which is used to coat or create a surface for machine cutting tools, all types of drill bit teeth, saw teeth, bearing surfaces valve seats, nozzles and the like, thereby producing surfaces which are highly abrasion and erosion resistant. Furthermore, this invention includes some of the possible methods for producing such a material given that the methods and apparatus required provide a significant cost reduction over those required for producing prior art surface materials with similar abrasion and erosion resistant properties. More specifically, the material set forth can be formed at relatively low temperatures and relatively low pressures by sintering mixtures for a relatively short period of time.
    Type: Grant
    Filed: August 22, 1995
    Date of Patent: June 24, 1997
    Assignee: Dennis Tool Company
    Inventors: Mahlon Denton Dennis, Barton Hampshire
  • Patent number: 5628046
    Abstract: A process for fabrication of sintered articles from a molybdenum-containing steel alloy by atomization, pressing, and sintering. The melt used for atomization has a molybdenum content determined as a function of the sintering temperature which lies in a range of 1050.degree.-1350.degree. C. The carbon content of the powder mixture is no more than 0.05% by weight and the reduction annealing takes place in a temperature range of 850.degree.-950.degree. C.
    Type: Grant
    Filed: October 31, 1995
    Date of Patent: May 6, 1997
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Norbert Dautzenberg, Karl-Heinz Lindner, Klaus Vossen
  • Patent number: 5607780
    Abstract: Disclosed are a target material for magneto-optical recording medium having a structure formed by sintering of an RE-TM phase (A) having a composition with an RE content higher than that of the composition of an intermetallic compound represented by the chemical formula TM.sub.2 RE, and a TM-RE phase (B) having a composition with an RE content equal to or lower than that of the composition of an intermetallic compound represented by the chemical formula TM.sub.2 E, wherein RE denotes at least one rare earth element selected from the group of elements consisting of Nd, Gd, Tb, Dy, Ho and Er, and TM denotes at least one element selected from the group of metals of the iron group which consists of Fe, Co and Ni; and a process for producing the same.
    Type: Grant
    Filed: May 20, 1994
    Date of Patent: March 4, 1997
    Assignee: Hitachi Metals, Ltd.
    Inventors: Kaoru Masuda, Takashi Meguro
  • Patent number: 5603073
    Abstract: A high density, high strength and high compressive strain tungsten heavy alloy consists essentially of tungsten in the amount of approximately 90% by weight, and the rest Mn and Ni in an amount sufficient to cause sintering at between 1100.degree. and 1400.degree. C. The W--Ni--Mn alloy exhibits characteristics of intense shear bands (which could indicate failure by adiabatic shear during high strain-rate dynamic testing) thus making it an attractive material for kinetic energy penetrators. Moreover, the alloy provides an inexpensive high density material which can be produced in furnaces for conventional ferrous powder metal part manufacturing and other conventional non-ferrous powder metal part manufacturing by lowering the sintering temperature by 200.degree. to 300.degree. C.
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: February 11, 1997
    Assignee: Southwest Research Institute
    Inventor: Animesh Bose
  • Patent number: 5603072
    Abstract: Fe-based alloy powder suitable for manufacturing sintered products with excellent corrosion resistance for example, which comprises by weight percentage of not more than 0.03% of C; not more than 2% of Si; not more than 0.5% of Mn; from 8 to 28% of Ni; from 15 to 25% of Cr; from 3 to 8% of Mo; optionally at least one of not more than 5% of Cu; not more than 3 % of Sn; not more than 2% of Nb and not more than 2% of Ti; and the balance being Fe and incidental impurities. The Fe-based alloy powder is sintered in an inert gas such as Ar or H.sub.2, or in an atmosphere of N.sub.2 with pressure of 1 to 10 torr after being compacted. A sintered compact sintered in an atmosphere of N.sub.2 with pressure of higher than 10 torr and not higher than 200 torr is cooled at cooling rate of higher than 50.degree. C./min.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: February 11, 1997
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Tomio Kouno, Mitsuaki Asano
  • Patent number: 5590388
    Abstract: A method of producing a molded ceramic article comprises the first step mixing powdery raw materials and a liquid additive, thereby obtaining a mixed raw material, the second step press-molding the mixed raw material obtained in the first step in a hydrostatically applied condition of pressure, thereby removing an excess of the liquid additive to obtain a preform, and the third step calcining the preform obtained in the second step to obtain a molded ceramic article. The molded ceramic article comprises, as a principal component, copper and, as essential components, Cr and Ni within composition ranges of 0.1.ltoreq.Cr<2 wt. % and 0.1.ltoreq.Ni<10 wt. % and further at least one additive component selected from the group consisting of the following composition ratios: the following composition ratios: 0<Fe<5 wt. %, 0.ltoreq.Co<5 wt. %, 0.ltoreq.Al<10 wt. %, 0.ltoreq.Ti<20 wt. %, 0.ltoreq.Mo<3 wt. %, 0.ltoreq.Si<3 wt. %, 0.ltoreq.V<3 wt. %, 0.ltoreq.Mg<1 wt. %, and 0.ltoreq.
    Type: Grant
    Filed: September 1, 1994
    Date of Patent: December 31, 1996
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Mitsuo Kuwabara, Kiyoshi Ikegami, Teruaki Yoshida, Koji Takahashi, Tamotsu Harada, Takeshi Komiyama, Fumio Hirai, Masamichi Hayashi
  • Patent number: 5540884
    Abstract: Heat multilayer aluminum nitride greenware, a composite of layers of aluminum nitride green tape having refractory metal ink patterns deposited thereon, in a nonoxidizing atmosphere, at atmospheric pressure to effect liquid phase sintering of both the aluminum nitride greenware and the refractory metal ink. The resultant cofired structure is substantially free of warpage and has satisfactory thermal conductivity, surface finish, mechanical properties and resistance to delamination.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: July 30, 1996
    Assignee: The Dow Chemical Company
    Inventor: Yi-Hung Chiao
  • Patent number: 5540883
    Abstract: A method of producing bearing surfaces from powder metal blanks comprising: blending carbon and ferro alloys and lubricant with compressible elemental iron powder, pressing the blending mixture to form the powder metal blank, high temperature sintering the blank in a reducing atmosphere, compressing the powder metal blanks so as to produce a densified layer having a bearing surface, and then heat treating the densified layer.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: July 30, 1996
    Assignee: Stackpole Limited
    Inventors: Peter Jones, Keith Buckley-Golder
  • Patent number: 5525292
    Abstract: A process is disclosed for producing an aluminum or an aluminum alloy sintering, comprising successive steps of maintaining a rare gas atmosphere inside a sintering furnace while heating a compact of aluminum particles or aluminum alloy particles, together with a magnesium source; reducing the pressure inside the sintering furnace while heating further for thereby sublimating magnesium nitrogen to generate Mg.sub.3 N.sub.2 and bringing the generated Mg.sub.3 N.sub.2 into contact with Al.sub.2 O.sub.3 in the surface of the compact for the reduction of Al.sub.2 O.sub.3, thereby effecting heating and sintering at a temperature lower than the melting point of aluminum. The process increases the bonding strength of the aluminum alloy particles while fully taking the advantage of a sintering process. Thus, it enables aluminum sinterings or aluminum-alloy sinterings improved in yield point, strength, and elongation.
    Type: Grant
    Filed: July 13, 1995
    Date of Patent: June 11, 1996
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Yasuhiro Nakao, Kunitoshi Sugaya, Shigehisa Seya, Takeshi Sakuma
  • Patent number: 5494635
    Abstract: Processes are disclosed in which cemented carbide parts, having a wide range of initial carbon levels, and a wide range of sizes, can be carburized to a critical carbon level, and then slow cooled at various rates, to yield stratified enriched zones in the near-surface region of said parts. The enriched zones are characterized by the cobalt content decreasing, and the microhardness increasing, continuously through the enriched zones, and approaching values characteristic of the interior. The combination of stratified enriched zones in the near surface region and the 6% binder interior provide the toughness and deformation resistance required for heavy roughing applications.A wide variety of cemented carbides, having different compositions and WC grain sizes, can also be carburized and slow cooled using the same techniques to yield stratified binder enriched zones having the same hardness profiles and cobalt content profiles as described above.
    Type: Grant
    Filed: May 20, 1993
    Date of Patent: February 27, 1996
    Assignee: Valenite Inc.
    Inventor: Stephen L. Bennett
  • Patent number: 5489411
    Abstract: A high strength titanium alloy or titanium aluminide metal foil having improved strength and density is produced, preferably in coilable strip form, by plasma-depositing the selected titanium-based material on a receiving surface, separating the deposited material from the receiving surface to provide two metal foil preforms each having a relatively smooth side as cast against the receiving surface and a relatively rough, opposite side as deposited from the plasma, disposing the two metal preforms together with the relatively rough sides of the two metal preforms in facing engagement with each other, and squeezing the two preforms together between pressure bonding rolls to metallurgically bond the preforms to each other and to consolidate the materials of the preforms to form a fully dense metal foil.
    Type: Grant
    Filed: September 23, 1991
    Date of Patent: February 6, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Sunil C. Jha, James A. Forster, Robert W. Howard
  • Patent number: 5478522
    Abstract: The present invention relates to a method for manufacturing a heating element, the method including the steps of: a) providing powders of two metals; b) mixing the powders; c) grinding the mixed powders; d) compacting the mixed powders to form a green compact; e) sintering the green compact in a first atmosphere; f) plastically working and process annealing the green compact; g) etching a surface of the green compact to cause pores thereon; and h) sintering the etched green compact in an oxidizing atmosphere. A Ni-Cr heating element manufactured by the present method has improved high temperature properties and a fusion temperature 300.degree. C. greater than those of conventional Ni-Cr heating elements.
    Type: Grant
    Filed: November 15, 1994
    Date of Patent: December 26, 1995
    Assignee: National Science Council
    Inventor: S. Wang
  • Patent number: 5476632
    Abstract: A process of forming a sintered article of powder metal comprising: selecting elemental iron powder; determining the desired properties of said sintered article and selecting, a quantity of carbon, and ferro alloy from the group of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium, ferro silicon and ferro boron; grinding said ferro alloy to a mean particle size of approximately 8 to 12 microns; introducing a lubricant while blending the carbon, ferro alloy, with said elemental iron powder; pressing the mixture to form the article; and then high temperature sintering the article at a temperature between 1,250.degree. C. and 1,350.degree. C. in a neutral or reducing atmosphere; so as to produce the sintered article of powdered metal; and includes the product formed thereby.
    Type: Grant
    Filed: January 14, 1994
    Date of Patent: December 19, 1995
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Peter Jones
  • Patent number: 5476633
    Abstract: An INVAR 36 material having long-term dimensional stability is produced by sintering a blend of powders of nickel and iron under pressure in an inert atmosphere to form an alloy containing less than 0.01 parts of carbon and less than 0.1 part aggregate and preferably 0.01 part individually of Mn, Si, P, S, and Al impurities. The sintered alloy is heat treated and slowly and uniformly cooled to form a material having a coefficient of thermal expansion of less than 1 ppm/.degree.C. and a temporal stability of less than 1 ppm/year.
    Type: Grant
    Filed: July 6, 1994
    Date of Patent: December 19, 1995
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Witold M. Sokolowski, Marc S. Lane, Cheng H. Hsieh, Timothy P. O'Donnell
  • Patent number: 5466311
    Abstract: A method of manufacturing an Ni--Al intermetallic compound matrix composite comprising steps of a) providing an aluminum powder, b) providing a reinforced material, c) providing a reducing solution containing a reducing agent and nickel ions to be reduced, d) adding the aluminum powder and the reinforced material into the reducing solution, and e) permitting the reducing agent to reduce the nickel ions to be respectively deposited on the aluminum powder and the reinforced material. Such method permits the Ni--Al, Ni--Al+B intermetallic compound matrix composite to be produced inexpensively/efficiently/fastly.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: November 14, 1995
    Assignee: National Science Council
    Inventors: Chen-Ti Hu, Wen-Chih Chiou
  • Patent number: 5460775
    Abstract: The invention provides aluminum sintered alloys with high dimensional accuracy and high density which are superior in mechanical and physical characteristics as well as wear resistance, and a method of producing such alloys not by plastic working but by atmospheric sintering with high economy. Rapidly solidified aluminum alloy powder resulting from solidifying aluminum alloy molten metal containing 0.4 to 4.0% by weight of Mg at a solidification rate of 10.sup.2 .degree. C./sec or more is press molded in the cold, after annealing in the temperature range of 250 to 450.degree. C. if necessary, and then the molded product is sintered by generating nitrogen compounds on the powder surface at atmospheric pressure with a nitrogen partial pressure of 0.8 atm or more and a steam partial pressure of 0.01 atm or less in which a reducing gas component has been added as a nitrogen-combining acceleration gas component by 0.01 atm or more. Thus, a nitrogen-combined aluminum sintered alloy containing 0.4 to 4.
    Type: Grant
    Filed: July 2, 1993
    Date of Patent: October 24, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tetsuya Hayashi, Yoshinobu Takeda
  • Patent number: 5456878
    Abstract: In a producing process of a sintered porous anode body of valve-metal for a solid-state electrolytic capacitor, molded pieces of the powder of valve-metal is sintered at a high temperature and at a lowered pressure in an atmosphere of an inert gas supplied at a fixed flow rate. Thanks to the usage of the inert gas, partial pressures of impurity elements can be suppressed and a gas emitted from the molded pieces in the sintering process can be washed out. Consequently, there is obtained a solid-state electrolytic capacitor in which the lead wire of the anode body is not easily bent down and which has a reduced leakage current and an increased withstand voltage.
    Type: Grant
    Filed: December 2, 1991
    Date of Patent: October 10, 1995
    Assignee: NEC Corporation
    Inventors: Hirokazu Tadokoro, Arihiro Goto
  • Patent number: 5445786
    Abstract: A heat-resistant metallic monolith manufactured by forming metal powders into a honeycomb structure and by sintering the structure, a heat-resistant metal oxide coated on the surface of the cell walls and that of the pores thereof. Such a heat-resistant metallic monolith is manufactured by mixing metal powders, an organic binder and water to prepare a mixture, by forming the mixture into a shape of a desired honeycomb configuration, by sintering the shape in a non-oxidizing atmosphere at a temperature between 1000.degree. and 145.degree. C. and then by coating a heat-resistant metal oxide on a surface of the cell walls and that of the pores of the obtained sintered body.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: August 29, 1995
    Assignee: NGK Insulators, Ltd.
    Inventors: Takashi Harada, Hiroshige Mizuno, Fumio Abe, Tsuneaki Ohashi
  • Patent number: 5441694
    Abstract: In a method for preparing a high .alpha.-type silicon nitride powder by adding to and mixing with metallic silicon powder a copper catalyst and nitriding the mixture in a non-oxidizing gas atmosphere containing nitrogen or ammonia at 1,000.degree. to 1,500.degree. C., the amount of copper catalyst is limited to from 0.05 % to less than 0.5 % by weight of copper based on the weight of the metallic silicon. There is obtained silicon nitride powder of high purity at low cost and high efficiency since the copper catalyst can be efficiently removed from the silicon nitride powder through conventional acid treatment.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: August 15, 1995
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Masanori Fukuhira, Hirofumi Fukuoka, Yoshiharu Konya, Masaki Watanabe
  • Patent number: 5439744
    Abstract: This invention relates generally to a novel directed metal oxidation process which is utilized to produce self-supporting bodies. In some of the more specific aspects of the invention, a parent metal (e.g., a parent metal vapor) is induced to react with at least one solid oxidant-containing material to result in the directed growth of a reaction product which is formed from a reaction between the parent metal and the solid oxidant-containing material. The inventive process can be utilized to form bodies having substantially homogeneous compositions, graded compositions, and macrocomposite bodies.
    Type: Grant
    Filed: February 25, 1993
    Date of Patent: August 8, 1995
    Assignee: Lanxide Technology Company, LP
    Inventors: Terry D. Claar, Vilupanur A. Ravi, Philip J. Roach
  • Patent number: 5437833
    Abstract: This invention relates generally to a novel method of manufacturing a composite body, such as a ZrB.sub.2 --ZrC--Zr (optional) composite body, by utilizing a post-treatment process and to the novel products made thereby. More particularly, the invention relates to a method of modifying a composite body comprising one or more boron-containing compounds (e.g., a boride or a boride and a carbide) which has been made by the reactive infiltration of a molten parent metal into a bed or mass containing boron carbide, and optionally one or more inert fillers, to form the body.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: August 1, 1995
    Assignee: Lanxide Technology Company, LP
    Inventors: Terry D. Claar, Gerhard H. Schiroky, William B. Johnson
  • Patent number: 5429793
    Abstract: A process for producing metal oxide dispersion-strengthened anodes for use in fuel cells in which a metal alloy powder comprising at least one metal powder and at least one metal oxide forming phase is formed into a "green" cohesive structure. The "green" cohesive structure is heated in a sintering furnace resulting in simultaneous sintering and internal oxidizing of the oxide forming phase within the "green" cohesive structure, forming an oxide dispersion-strengthened structure. To promote simultaneous sintering of the "green" cohesive structure and internal oxidation of the oxide forming phase within the "green" cohesive structure, an oxidizing agent is disposed within the "green" cohesive structure or is applied to the exterior of the cohesive structure.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: July 4, 1995
    Assignee: Institute of Gas Technology
    Inventors: Estela T. Ong, Nellie Burton-Gorman
  • Patent number: 5422069
    Abstract: Master alloys and methods of producing same are disclosed, wherein an intermetallic compound, for example Al.sub.3 Cb is first prepared via thermite processing, then size reduced, then mixed with other components in amounts yielding a mixture in the desired proportion for the master alloy. The mixture is compacted, then heated to produce the master alloy by fusion.
    Type: Grant
    Filed: December 29, 1993
    Date of Patent: June 6, 1995
    Assignee: Reading Alloys, Inc.
    Inventor: Frederick H. Perfect, deceased
  • Patent number: 5407634
    Abstract: A method of inhibiting grain growth and restricting grain size during heat-treatment and hot-working of metallic materials. A small volume of inert gas is added to a metallic material so that the inert gas is dispersed throughout the metallic material. The metallic material is then heated sufficiently high so that the inert gas forms micropores within the metallic material; the micropores interact with grain boundaries to inhibit grain growth. If desired, all or part of the residual microporosity may be eliminated from the metallic material during the final step of a deformation processing cycle.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: April 18, 1995
    Assignee: McDonnell Douglas Corporation
    Inventors: Ricky L. Martin, Richard J. Lederich
  • Patent number: 5405570
    Abstract: A method of preparing a durable air-permeable mold having dimensional accuracy and without cracks clue to the segregation of the ingredients of the aggregate and without a surface irregularity, which comprises compounding 100 parts by weight of an aggregate obtained by compounding metal powders with metal oxide powders in a weight ratio of 5:95 to 30:70, the metal of said metal oxide powders being the same as that of the metal powders, 80% or more of said metal powders and said metal oxide powders having grain sizes of 300 .mu.m or less, with 10 to 35 by weight of an auxiliary hardening material that is softened and melted during the sintering process, and 10 to 25 by weight of a binder that contains an evaporable component, mixing them to form a slurry mixture, pouring it in a pattern mold to obtain a mold, drying the thus-obtained mold, and sintering the dried mold in an oxidative atmosphere at a temperature of 600.degree. to 1200.degree. C.
    Type: Grant
    Filed: March 16, 1994
    Date of Patent: April 11, 1995
    Assignee: Sintokogio, Ltd.
    Inventors: Toyoji Fuma, Kazuyuki Nishikawa, Yojiro Hayashi, Naoshi Makiguchi, Takehiro Inagaki, Koji Nishioka, Mituo Kawaguchi
  • Patent number: 5403374
    Abstract: A watch exterior part is formed of cemented carbide or stellite alloy, and has a three-dimensionally curved as-sintered surface or a small hole with an as-sintered interior peripheral surface, or has a three-dimensionally curved polished surface obtained by polishing an as-sintered surface. The watch exterior part is manufactured by a method in which organic binder is milled into a material powder, and a molded body obtained by injection molding is subjected to a binder removing process and then sintered. By the manufacturing method, a watch exterior part formed of cemented carbide or stellite alloy has a high strength and a complicated configuration such as a three-dimensional curved surface and a small hole, without applying secondary machining operations such as discharge operations.
    Type: Grant
    Filed: May 28, 1992
    Date of Patent: April 4, 1995
    Assignees: Sumitomo Electric Industries, Ltd., Namiki Precision Jewel Co., Ltd.
    Inventors: Nobuyuki Kitagawa, Toshio Nomura, Yoichi Yaguchi, Hidehiro Uchiumi, Naoko Iwashimizu
  • Patent number: 5403542
    Abstract: Method of manufacturing a sintered carbonitride alloy comprising wet milling powders of forming binder phase containing Co, Ni and mixture thereof and powder forming hard constituents of nitrides and carbonitrides with Ti as the main component to a mixture with desired composition; compacting said mixture to form compact; heating the compact at 100-300 C. in oxygen or air and subjecting said compact in multiple heating steps to effect sintering.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: April 4, 1995
    Assignee: Sandvik AB
    Inventors: Gerold Weinl, Rolf G. Oskarsson, Per Gustafsson
  • Patent number: 5384087
    Abstract: The present invention relates to a process for making an aluminum silicon carbide composite material in strip form. The process comprises blending a powdered aluminum matrix material and a powdered silicon carbide material, roll compacting the blended powdered materials in an inert atmosphere to form a green strip having a first thickness, and directly hot working the blended and roll compacted materials to bond the aluminum matrix material particles and the silicon carbide particles and to form a thin strip material having a desired thickness.
    Type: Grant
    Filed: April 6, 1992
    Date of Patent: January 24, 1995
    Assignee: Ametek, Specialty Metal Products Division
    Inventor: Clive Scorey
  • Patent number: 5380482
    Abstract: A method of manufacturing ingots for use in making objects having heat, thermal shock, corrosion and wear resistance by formulating a composition of about 17-80% TiB.sub.2 powder, about 0.0 to 4.0% Y.sub.2 O.sub.3 powder, and the balance of NiAl powder, the powders being thoroughly admixed, and placing the admixture into a mold in which it is subjected to a pressure of about 7000 psi and a temperature of about 1400.degree. C. for 20 to 140 minutes in an inert atmosphere, after which the mold is cooled and the ingot is removed and ready for use in manufacturing an object. In some applications the use of a ceramic filler material mixed with the powder is employed to improve the physical characteristics of the finished ingot.
    Type: Grant
    Filed: April 2, 1993
    Date of Patent: January 10, 1995
    Assignee: Aspen Research, Inc.
    Inventors: David B. Maginnis, Frank Maginnis
  • Patent number: 5372776
    Abstract: A density element (12) for use in ruminal delivery devices (10) which is manufactured by partial sintering in such a manner as to fragment upon contact with the many parts in rendering machinery without damage to the blades. The density element (12) has density of at least about 1.5 gm/cm.sup.3 and a transverse rupture strength greater than about 3000 psi no greater than about 30,000 psi. The part is sintered under conditions which do not permit full weld bond strength to be obtained and may thereafter be heat treated or impregnated with an inert hydrophobic material to increase corrosion resistance.
    Type: Grant
    Filed: March 2, 1994
    Date of Patent: December 13, 1994
    Assignee: Alza Corporation
    Inventors: John R. Peery, James B. Eckenhoff
  • Patent number: 5368629
    Abstract: The rapidly solidified aluminum alloy powder is preformed in a cold or warm environment to form a powder compact having a relative density of 75-93%. Then, the preformed compact is heated and degassed in the atmosphere of an inert gas at temperature of 300.degree. C. to 560.degree. C. for 0.25-3 hours. Immediately thereafter, the compact is subjected to hot coining at 300.degree.-560.degree. C. to obtain a solidified compact having pores at a rate of 2-5%. The solidified compact is then subjected to sizing. Since the inorganic gas prevents reaction between the evaporated water and aluminum while preheating the compact, the hot coining can be carried out in a state where solid state diffusion easily occurs. Thus, the powder particles can be bonded together strongly with a single forging. Also, at the end of hot coining, pores remain in the solidified compact at the rate of 2-5%. Utilizing these pores, the compact can be subjected to sizing to improve its dimensional accuracy.
    Type: Grant
    Filed: December 3, 1992
    Date of Patent: November 29, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Katsuyoshi Kondo, Yoshinobu Takeda
  • Patent number: 5364586
    Abstract: A filter membrane and a process for making the filter membrane are provided. The filter membrane comprises a metal substrate having a filtering layer thereon comprising sintered ultra-fine particles of metal or ceramic compounds. The filtering layer preferably has an average pore size of from about 30 nanometers to about 200 nanometers. The filter membranes can withstand pressure drops of up to about 0.6 MPa and are useful for a variety of filtering applications.
    Type: Grant
    Filed: August 17, 1993
    Date of Patent: November 15, 1994
    Assignee: Ultram International L.L.C.
    Inventors: Lev I. Trusov, Vladimir N. Lapovok, Victor I. Novikov
  • Patent number: 5352404
    Abstract: A process for forming contact material of an electrode comprises the steps of preparing chromium of which oxygen content is substantially reduced, forming a molten mixture of the chromium and copper, atomizing the molten mixture into fine particles to obtain Cu-Cr alloyed powder, compacting Cu-Cr alloyed powder under desired pressure, and sintering the compacted alloyed powder. The oxygen content of the chromium may be reduced until less than 0.1 wt %. In a course of the process, a metal having melting point lower then copper may be blended. The metal may be blended in Cu-Cr alloyed powder, or blended in the molten mixture of copper and chromium. Alternatively, the process further includes the steps of forming a second molten mixture of copper and a metal having melting point lower than copper, atomizing the second molten mixture into fine particles to obtain alloyed powder of copper and the metal, and blending Cu-Cr alloyed powder with the alloyed powder of copper and the metal.
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: October 4, 1994
    Assignee: Kabushiki Kaisha Meidensha
    Inventors: Nobuyuki Yoshioka, Toshimasa Fukai, Yasushi Noda, Nobutaka Suzuki
  • Patent number: 5348800
    Abstract: A composite soft magnetic material is produced from soft magnetic metal (e.g., Sendust) particles by coating the particles with a non-magnetic metal oxide (e.g., .alpha.-alumina) in a mechano-fusion manner, or heat treating the particles to form a diffusion layer of .alpha.-alumina thereon, coating the coated particles with a high resistance soft magnetic substance (e.g., ferrite), and sintering the double coated particles under pressure as by hot pressing or plasma activated sintering. It exhibits high saturation magnetic flux density, magnetic permeability, and electric resistivity. The non-magnetic metal oxide intervening between the soft magnetic metal and the high resistance soft magnetic substance is effective in reducing core loss.
    Type: Grant
    Filed: February 1, 1993
    Date of Patent: September 20, 1994
    Assignee: TDK Corporation
    Inventors: Hideharu Moro, Yasuharu Miyauchi
  • Patent number: 5342573
    Abstract: A method of producing a tungsten heavy alloy product according to a powder metallurgical procedure utilizing the injection molding technique which enables production of tungsten heavy alloy products having high dimensional accuracy and complex configuration and yet having high physical strength and toughness in high productivity and at low cost. A powder mixture of tungsten powder and nickel powder, iron powder or copper powder is mixed with an organic binder and they are kneaded together. The kneaded mixture is injection molded into a predetermined shape, and thereafter the binder is removed from the molded product. Subsequently, the molded product is sintered in a temperature range of from the melting point of the bond phase of nickel, iron or copper to +50.degree. C. relative to the melting point.
    Type: Grant
    Filed: August 20, 1992
    Date of Patent: August 30, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoshinari Amano, Masahiro Omati, Junzo Matsumura
  • Patent number: 5338506
    Abstract: A process for making a non magnetic Ni-WC cemented carbide composition and articles made from the same. The process comprises:(a) dewaxing a green Ni-WC cemented carbide substrate in the presence of hydrogen gas at a pressure less than about 1000 torr and at a sufficient flow rate and a sufficient time to affect the saturation magnetization and magnetic permeability of the Ni-WC cemented carbide substrate;(b) pumping out the hydrogen gas and introducing argon at a pressure in the range of about 1 torr to 1000 torr;(c) increasing the temperature up to the sintering temperature to facilitate sintering of the Ni-WC cemented carbide substrate; and;(d) cooling the furnace to room temperature.The articles made according to this invention are useful as wear parts for electronic instruments and as punches form aluminum beverage cans.
    Type: Grant
    Filed: December 21, 1992
    Date of Patent: August 16, 1994
    Assignee: Valenite Inc.
    Inventors: John W. Friederichs, Prakash K. Mirchandani, Paul J. Krudy