Powder Pretreatment (prior To Consolidation Or Sintering) Patents (Class 419/30)
  • Patent number: 4676829
    Abstract: Improvements in the positive temperature dependence of yield strength and in the work hardening rate of tri-nickel aluminide base alloys are achieved. The novel alloy composition has seven alloying ingredients as follows:______________________________________ Concentration Ingredient in Atomic % ______________________________________ Ni balance Co 8-12 Al 16-20 Si 4-6 Nb 0.26-0.30 Zr 0.02-0.04 B 0.2-0.7 ______________________________________The novel composition may be prepared by forming a melt of the composition and atomizing the melt with an inert gas to form fine particles with Ll.sub.2 type crystal structure. The powder is densified by heat and pressure to a novel alloy composition having the improvements in positive temperature dependence of yield strength and work hardening rate as noted above.
    Type: Grant
    Filed: October 3, 1985
    Date of Patent: June 30, 1987
    Assignee: General Electric Company
    Inventors: Keh-Minn Chang, Alan I. Taub, Shyh-Chin Huang
  • Patent number: 4670215
    Abstract: There is disclosed a process for forming a wear-resistant, sintered layer on a metallic substrate. The process comprises steps of adhesively attaching to a surface of metallic substrate an alloy particle sheet containing 94 to 99 weight % of ternary eutectic alloy particles and 6 to 1 weight % of acryl binder, heating in a non-oxidating atmosphere to a temperature of 150.degree. to 380.degree. C. and holding at the temperature for at least 5 minutes, and heating a sintering temperature of the alloy particles.
    Type: Grant
    Filed: February 19, 1985
    Date of Patent: June 2, 1987
    Inventors: Tsuyoshi Morishita, Sigemi Osaki, Noriyuki Sakai, Yukio Shimizu, Toshiharu Konishi, Takahumi Sakuramoto
  • Patent number: 4659379
    Abstract: A nickel anode electrode fabricated by oxidizing a nickel alloying material to produce a material whose exterior contains nickel oxide and whose interior contains nickel metal throughout which is dispersed the oxide of the alloying material and by reducing and sintering the oxidized material to form a product having a nickel metal exterior and an interior containing nickel metal throughout which is dispersed the oxide of the alloying material.
    Type: Grant
    Filed: April 16, 1985
    Date of Patent: April 21, 1987
    Assignee: Energy Research Corporation
    Inventors: Prabhakar Singh, Mark Benedict
  • Patent number: 4657734
    Abstract: A method for preparing a sliding face of a machine tool, comprising the steps of: providing a flat surface as a slide surface to a slide component of a machine proper by gluing a plastic material prepared from a kneaded mixture of sintered metal powder and a synthetic resin binder to the slide component; and thermally dissolving out said synthetic resin binder contained in the plastic material and sintering said metal powder.
    Type: Grant
    Filed: April 16, 1985
    Date of Patent: April 14, 1987
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Hiroyasu Yamada, Motoatsu Shiraishi
  • Patent number: 4614544
    Abstract: A high strength powder metal part formed from an alloy of iron, nickel, molybdenum and carbon and having an ultimate tensile strength of at least 175,000 pounds per square inch. The powder metal part is made by mixing the alloy with a lubricant, forming the mixture into the desired part shape, sintering in a dissociated ammonia atmosphere, and cryogenically cooling the sintered part.
    Type: Grant
    Filed: October 22, 1985
    Date of Patent: September 30, 1986
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Chaman Lall
  • Patent number: 4613480
    Abstract: Improvements in the strength of atomized and consolidated boron doped tri-nickel aluminides are made possible. The improved strength is achieved by cold rolling and annealing a HIPped aluminide. The improvements are to room temperature properties.
    Type: Grant
    Filed: October 3, 1985
    Date of Patent: September 23, 1986
    Assignee: General Electric Company
    Inventors: Keh-Minn Chang, Shyh-Chin Huang, Alan I. Taub
  • Patent number: 4613371
    Abstract: A fine amorphous metallurgical powder suitable for compacting and sintering into amorphous densified articles which consist essentially of a major portion by weight a transition metal or combination thereof and less than a minor amount of an additional component for enhancing the amorphous characteristics of densified articles produced by directing a stream of molten droplets at a repellent surface to produce the smooth surfaced and melt solidified particles having an average particle size of less than about ten micrometers.
    Type: Grant
    Filed: February 21, 1984
    Date of Patent: September 23, 1986
    Assignee: GTE Products Corporation
    Inventors: Richard F. Cheney, Richard H. Pierce
  • Patent number: 4613368
    Abstract: A tri-nickel aluminide base composition is provided which has good ductility at all temperatures. The composition has a relatively high concentration of cobalt substituent and is doped by boron. It also has minor concentrations of at least two other substituent metals selected from the group consisting of niobium, hafnium, vanadium, molybdenum and zirconium.
    Type: Grant
    Filed: October 3, 1985
    Date of Patent: September 23, 1986
    Assignee: General Electric Company
    Inventors: Keh-Minn Chang, Shyh-Chin Huang, Alan I. Taub
  • Patent number: 4608227
    Abstract: A process is provided for the preparation and fabrication of sintered titanium horseshoes whereby titanium powder is processed so that its characteristics are such that it is ideally suited for horseshoes.The sintered powder titanium horseshoes have many advantages over the present state of the art some of their advantages being that they are light weight, have high strength, are flexible, have excellent wearing characteristics, are abrasion resistant and are easily formed and shaped into the desired configuration.
    Type: Grant
    Filed: September 9, 1985
    Date of Patent: August 26, 1986
    Inventor: Mildred Preiss
  • Patent number: 4606884
    Abstract: The present invention concerns the manufacture of bars, wires or profiled elements by hot transformation which may be followed by cold transformation. The invention particularly concerns a new process for the manufacture of a composite billet for hot transformation as well as a method for the manufacture of products which are difficult to transform by making use of such a composite billet.
    Type: Grant
    Filed: July 3, 1984
    Date of Patent: August 19, 1986
    Assignees: Microfusion, Commissariat a l'Energie Atomique
    Inventors: Jean Gavinet, Bruno Childeric
  • Patent number: 4602956
    Abstract: Composite cermets having a central core of a first cermet composition and one or more surrounding layers of different cermet compositions are formed by a multi-step pressing operation, followed by sintering. A tungsten/alumina or molybdenum/alumina composite cermet is useful as an end closure for alumina arc tubes of metal halide discharge lamps.
    Type: Grant
    Filed: December 17, 1984
    Date of Patent: July 29, 1986
    Assignee: North American Philips Lighting Corporation
    Inventors: Deborah P. Partlow, Shih-Ming Ho
  • Patent number: 4601874
    Abstract: A process for forming a titanium base alloy comprises compacting a powder formed of particles of titanium or of a mother alloy thereof and of a dispersion of fine particles of a product curbing the growth of the grain size, in a proportion per volume which is less than that which would lead to the formation of a continuous layer of fine particles about the particles of titanium powder. Then the alloy is heat treated at a temperature higher than the point of transformation into phase .beta. and quenched. The product is typically selected among S, P, B, As, Se, Te, Y and the lanthanides.
    Type: Grant
    Filed: July 8, 1985
    Date of Patent: July 22, 1986
    Assignee: Office National d'Etudes et de Recherche Aerospatiales (ONERA)
    Inventors: Michel Marty, Henri Octor, Andre Walder
  • Patent number: 4599110
    Abstract: A process for the production of valve seat rings by powder metallurgy wherein molybdenum disulfide in the range of about 0.5% to 1.5% by weight is added to a powder mixture containing 0.8% to 1.5% by weight graphite, 1.0% to 4% by weight lead, 0.5% to 5% by weight nickel, 1.2% to 1.8% by weight molybdenum, 9.6% to 14.4% by weight cobalt, and the remainder iron. The resulting powder mixture is pressed into valve seat rings at a pressing force between 40 and 60 and preferably 50 KN/cm.sup.2. The rings are then sintered in a neutral atmosphere at a temperature of 1100.degree. C. to 1200.degree. C., finally compressed at a pressing force above 120 KN/cm.sup.2 and heat-treated if required. The resulting valve seat rings have greatly improved wear properties when used in internal combustion engines using lead-free gasoline.
    Type: Grant
    Filed: April 11, 1985
    Date of Patent: July 8, 1986
    Assignee: Bleistahl G.m.b.H.
    Inventors: Michael Kohler, Wolfgang Petry
  • Patent number: 4597792
    Abstract: High strength and high toughness are combined in an aluminum-based metallic product by dispersing particles of an aluminum-based metal having a toughness of at least about 20 foot-pounds through a matrix of aluminum-based metal having a yield strength of at least about 30 ksi.
    Type: Grant
    Filed: June 10, 1985
    Date of Patent: July 1, 1986
    Assignee: Kaiser Aluminum & Chemical Corporation
    Inventor: Donald Webster
  • Patent number: 4592781
    Abstract: A fine aluminum metallurgical powder suitable for compacting and sintering into densified articles which includes a dispersed phase is produced by directing a stream of molten droplets at a repellent surface to produce smooth surfaced and melt solidified particles having an average particle size of less than about ten micrometers.
    Type: Grant
    Filed: February 21, 1984
    Date of Patent: June 3, 1986
    Assignee: GTE Products Corporation
    Inventors: Richard F. Cheney, Richard H. Pierce
  • Patent number: 4584169
    Abstract: In the installation, a strip is shaped from a split tube which is welded or seamed to give a closed tube in a welding or seaming station. Associated with the welding or seaming station is a suction mechanism used for the removal of on the one hand the cold air flow produced by the moving open tube and on the other the air flow heated during welding and flowing back from the closed tube, as a result of the reduction of the internal cross-section thereof. This obviates air turbulence in the welding or seaming station, which could whirl up the pulverulent material introduced into the open tube in a dosing station and could be deposited on the longitudinal edges of the split tube. This could unfavorably influence the seaming or welding process.
    Type: Grant
    Filed: April 17, 1985
    Date of Patent: April 22, 1986
    Assignee: Schweissindustrie Oerlikon Buhrle AG
    Inventors: Alexander Werner, Heinz Pfenninger
  • Patent number: 4582536
    Abstract: The present invention provides a method for consolidating rapidly solidified, transition metal alloys which includes the step of compacting a plurality of alloy bodies at a temperature ranging from about 0.90-0.99 Tm (melting temperature in .degree.C.) for a time period ranging from about 1 min to 24 hours. The alloy bodies contain at least two transition metal elements and consist essentially of the formula (Fe,Co and/or Ni).sub.bal (W, Mo, Nb and/or Ta).sub.a (Al and/or Ti).sub.b (Cr).sub.c (B and/or C).sub.d (Si and/or P).sub.e, wherein "a" ranges from about 0-40 at. %, "b" ranges from about 0-40 at. %, "c" ranges from about 0-40 at. %, "d" ranges from about 5-25 at. %, and "e" ranges from about 0-15 at. %. The alloy bodies also have a substantially homogeneous and optically featureless structure.
    Type: Grant
    Filed: December 7, 1984
    Date of Patent: April 15, 1986
    Assignee: Allied Corporation
    Inventor: Derek Raybould
  • Patent number: 4569823
    Abstract: A powder metallurgical method of producing metal bodies using spherical powder, produced by inert gas atomization, from magnetizable material with a particle size distribution closely approximating the so called Fuller curve for maximum density packing of spherical particles. Said powder is magnetized and filled into a form, which may take place before or after magnetization, said mixed and magnetized powder then sintered in said form with the exclusion of air, to produce a sintered body without communicating porosity.
    Type: Grant
    Filed: March 23, 1984
    Date of Patent: February 11, 1986
    Assignee: Kloster Speedsteel Aktiebolag
    Inventor: Leif Westin
  • Patent number: 4556532
    Abstract: A composite camshaft having a plurality of fitting members, such as cam lobes and journals, fabricated from metal powders having a composition of an Fe-C-Cu system which contains 17-35% by weight of Cu and joined to a steel shaft by a binding effect of Cu, which melts out of the fitting member and full penetrate a clearance between the fitting member and the steel shaft to join them as one body.
    Type: Grant
    Filed: January 10, 1985
    Date of Patent: December 3, 1985
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventors: Genkichi Umeha, Shigeru Urano, Satoru Kato
  • Patent number: 4534935
    Abstract: Sponge titanium powder is compacted, advantageously by roll compaction to a density in the range of about 60% to 80% of the density of solid titanium metal, thereafter heat treated in vacuum at about 500.degree. C. to 750.degree. C., cooled in vacuum to 300.degree. C. and quenched to 100.degree. C. to provide a substrate for electrodes useful in electrolytic processes.
    Type: Grant
    Filed: January 9, 1984
    Date of Patent: August 13, 1985
    Assignee: INCO Limited
    Inventors: John Ambrose, Douglas K. Charles, Bruce R. Conard, Carlos Diaz, Charles E. O'Neill, Wayne P. Leavoy
  • Patent number: 4519839
    Abstract: A sintered high vanadium high speed steel with an excellent hardness and ductility of composition C 1.4-6.2%, W+2 Mo (W-equivalent) 10.0-24.0%, Cr 3.0-6.0%, V 8.5-28%, Co less than 17%, the remainder Fe and inevitable impurities, and a method of producing same.It can be produced by the steps of commingling the alloy constituents in the form of pulverulent oxides and carbon powder, heating the mixture in a stream of hydrogen, thereby reducing the mixture by the carbon and hydrogen simultaneously to yield an alloy powder, adjusting the composition and the grain size of the obtained alloy powder, pressing the alloy powder to a compact, sintered the compact in a vacuum, and finally converting the matrix of the sintered body into martensite by heat treatment.
    Type: Grant
    Filed: October 3, 1984
    Date of Patent: May 28, 1985
    Assignees: The Furukawa Electric Co., Ltd., Kanto Denka Kogyo Co., Ltd., Fujidie Co., Ltd.
    Inventors: Ishibachi Toyoaki, Yoshihara Minoru, Takuma Takashi, Fuke Yasunori, Maeda Masayuki
  • Patent number: 4515864
    Abstract: Apparatus for the production of a metal article comprises means for maintaining a reservoir of molten metal with a free surface, means for rotating the free surface of the reservoir about an axis such that the molten metal is atomized and thrown outwardly away from the said surface by centrifugal action, and a substrate in the path of the atomized particles of said molten metal, whereby a solid article may be built up on the substrate by solidifying the atomized particles thereon. The molten metal may be produced by melting an electrode or otherwise.An annular solid metal article is disclosed having excellent mechanical properties. The solid metal article is produced in a single step by a spray deposition process. Molten metal is centrifugally atomized to splat and build up on a cooled mold surface disposed around the centrifuge means. Controlled relative reciprocatory movement in the direction of the rotational axis of the centrifuge is provided.
    Type: Grant
    Filed: July 30, 1982
    Date of Patent: May 7, 1985
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom
    Inventor: Alfred R. E. Singer
  • Patent number: 4491477
    Abstract: An anti-wear sintered alloy comprising from 2.5 to 25.0% of Cr, from 0.10 to 3.0% of Mn, from 0.1 to 0.8% of P, from 1.0 to 5.0% of Cu, from 0.5 to 2.0% of Si, from 0 to 3% of Mo, 1.5 to 3.5% of C, one selected from the group consisting of from 0.5 to 3.0% of S and from 1.0 to 5.0% of Pb, and the balance being Fe with less than 2% of impurities, wherein S or Pb is distributed uniformly in the sintered alloy in form of sulfide or lead particle of less than 100 .mu.m and a manufacturing process thereof.
    Type: Grant
    Filed: August 24, 1982
    Date of Patent: January 1, 1985
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Tetsuya Suganuma, Koji Kazuoka, Shuichi Fujita, Yoshitaka Takahashi, Takeshi Okujo
  • Patent number: 4483819
    Abstract: A process for the production of agglomerated valve metal powder which comprises heating an admixture of a valve metal powder and a reducing agent in the presence of an inert gas or under high vacuum for a sufficient time and at a sufficiently elevated temperature that agglomeration of the valve metal powder occurs, and removing the reaction products of the reducing agent and the valve metal and any unreacted reducing agent from the agglomerated valve metal powder by subsequent reaction with an inorganic acid. The agglomerated powder can be sintered to prepare valve metal electrodes, e.g., anodes, which can also be prepared by direct sintering of the admixture of the metal powder and the reducing agent.
    Type: Grant
    Filed: July 19, 1982
    Date of Patent: November 20, 1984
    Assignee: Hermann C. Starck Berlin
    Inventors: Wolf-Wigand Albrecht, Uwe Papp
  • Patent number: 4474732
    Abstract: An alloy steel is provided along with a method of making the same. The alloy is heat, wear, corrosion and oxidation resistant, and is preferably made utilizing powder metallurgy techniques. The method involves the addition of carbon and silicon to an iron base alloy containing chromium to improve the properties of the steel.
    Type: Grant
    Filed: October 24, 1979
    Date of Patent: October 2, 1984
    Assignee: Amsted Industries Incorporated
    Inventor: Jean C. Lynn
  • Patent number: 4473402
    Abstract: New cobalt base alloys containing chromium and carbon are disclosed. The alloys are subjected to rapid solidification processing (RSP) technique which produces cooling rates between 10.sup.5 to 10.sup.7 .degree. C./sec. The as-quenched ribbon, powder etc. consists predominantly of amorphous phase. The amorphous phase is subjected to suitable heat treatments so as to produce a transformation to a microcrystalline alloy which includes carbides; this heat treated alloy exhibits superior mechanical properties for numerous industrial applications.
    Type: Grant
    Filed: April 11, 1983
    Date of Patent: September 25, 1984
    Inventors: Ranjan Ray, Viswanathan Panchanathan
  • Patent number: 4470953
    Abstract: The object of the invention is a process of manufacturing a sintered compact of sinterable pulverulent material, in which the powder is moulded against a moulding surface and sintered in contact with the moulding surface and in which the pores in at least local areas of the compact are sealed by infiltration with an infiltration material which during a stage of the infiltration process is in liquid form and which by temperature decrease is caused to solidify in the pores, and the characteristic features of the invention are that the moulding takes place on the moulding surface in such a way that the moulding surface is covered with relatively fine-grained sinterable powder which by its own adhesion or by adhesion intensified by additives is caused to form an at least temporarily retained fine powder layer (3) on the moulding surface, and that at least one layer (5) of sinterable coarse powder is applied to the fine powder layer, and that both layers are sintered and infiltration is effected such that the infi
    Type: Grant
    Filed: February 5, 1982
    Date of Patent: September 11, 1984
    Assignee: Uddeholms Aktiebolag
    Inventor: Lars M. Bruce
  • Patent number: 4470847
    Abstract: A process to produce passified Group IVb transition metal based metal particles having a controlled particle size distribution is disclosed which produces particles suitable for metallurgy usage without additional particle size reduction. Such particles are also substantially free of halides and are produced at temperatures considerably below that of arc melting temperatures of Group IVb transition metals and alloys based thereon.
    Type: Grant
    Filed: November 8, 1982
    Date of Patent: September 11, 1984
    Assignee: Occidental Research Corporation
    Inventors: Robert A. Hard, Joseph A. Megy
  • Patent number: 4464205
    Abstract: A powder metallurgical process for producing a wrought product characterized by a low level of residual impurities. The process comprises the steps of: comminuting metal powder to effect a reduction in particle size, at least 60% of the comminuted particles being capable of passing through a -270 mesh Tyler screen; blending the metal powder with a softer metal-bearing powder; heating the blended powder particles at an elevated temperature, the particles adhering and forming a mass during heating; crushing the mass of powder particles; cold-isostatically pressing the crushed mass of powder; sintering the powder in the absence of an encapsulating member under conditions which effect a reduction in the nitrogen, oxygen and carbon levels of the powder; and hot working the sintered powder into a wrought product. The wrought product has less than 0.015% carbon.
    Type: Grant
    Filed: November 25, 1983
    Date of Patent: August 7, 1984
    Assignee: Cabot Corporation
    Inventors: Prabhat Kumar, Ronald D. Rivers, Anthony J. Hickl
  • Patent number: 4464206
    Abstract: A process for producing a wrought product of improved ductility from substantially noncompactible prealloyed metal powder. The process comprises the steps of: comminuting substantially noncompactible prealloyed metal powder so as to flatten the particles thereof; heating the comminuted particles of metal powder at an elevated temperature, the particles adhering and forming a mass during heating; crushing the mass of metal powder; compacting the crushed mass of metal powder; sintering the metal powder; and hot working the metal powder into a wrought product. The wrought product has a chemistry which is substantially the same, with the exception of carbon and certain residuals, as the chemistry of the prealloyed powder.
    Type: Grant
    Filed: November 25, 1983
    Date of Patent: August 7, 1984
    Assignee: Cabot Corporation
    Inventors: Prabhat Kumar, Ronald D. Rivers, Anthony J. Hickl
  • Patent number: 4463058
    Abstract: The invention features a method and resultant article of the method, wherein deagglomerated silicon carbide whiskers are uniformly dispersed and/or distributed in a matrix material, generally a metal. The uniform distribution achieved by the invention greatly enhances the mechanical properties of the composite, such as the ultimate strength. The method comprises the deagglomeration of silicon carbide whiskers prior to mixing with matrix materials.
    Type: Grant
    Filed: June 16, 1981
    Date of Patent: July 31, 1984
    Assignee: Atlantic Richfield Company
    Inventors: Paul E. Hood, John O. Pickens
  • Patent number: 4451429
    Abstract: A method of reclaiming precious metal incidentally sputtered into vacuum chamber walls, fixtures, and the like. The incidentally sputtered precious metal is reclaimed by grinding it into a metal powder that is useful as an electrical conductor in a cermet ink. Power can also be made by pulverizing the principally sputtered metal too.
    Type: Grant
    Filed: July 8, 1982
    Date of Patent: May 29, 1984
    Assignee: General Motors Corporation
    Inventor: Morris Berg
  • Patent number: 4432795
    Abstract: A sintered powdered titanium alloy article is provided which has a density approaching theoretical and which is characterized by having physical properties similar to those of a wrought titanium alloy article having the same chemical composition.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: February 21, 1984
    Assignee: Imperial Clevite Inc.
    Inventor: Phillip J. Andersen
  • Patent number: 4432935
    Abstract: A porous body, for a solid electrolytic capacitor, is made from a combination of titanium and aluminum in order to reduce dependence upon tatalum, a material which is now in extremely short supply. First, the titanium hydride and aluminum are milled into an extremely fine micro-powder. Then, the powders are mixed with the aluminum content in the range of 45%-65%, compressed into the desired body shape, and given a three-step heat treatment. In the first step, the body is heated at a temperature of 400.degree. to 500.degree. C. for a dehydrogenation. In the second step, the dehydrogenated body is heated to an alloying temperature which is higher than 500.degree. C., but lower than the melting point of aluminum. In the third step, the alloyed body is heated to a temperature which is higher than the melting point of aluminum (about 1000.degree. C.).
    Type: Grant
    Filed: March 31, 1981
    Date of Patent: February 21, 1984
    Assignee: Nippon Electric Co., Ltd.
    Inventors: Yoshimi Kubo, Shigeaki Shimizu, Tetsuo Suzuki, Hitoshi Igarashi
  • Patent number: 4423004
    Abstract: Tantalum powder for electrolytic capacitors is treated with a non-aqueous solution of ammonium thiocyanate in N,N'-dimethylformamide or N-methylpyrrolidinone after the powder has been subjected to a thermal treatment in the absence of oxygen step and before the powder is exposed to an oxygen-containing fluid to prevent oxygen uptake by the powder. The thermal treatment step is carried out at 700.degree. C. and above.
    Type: Grant
    Filed: March 24, 1983
    Date of Patent: December 27, 1983
    Assignee: Sprague Electric Company
    Inventor: Sidney D. Ross
  • Patent number: 4415527
    Abstract: A method for producing a low carbon ferrous powder melt stock with a sulfur content of less than 5 parts per million is disclosed comprising the steps of atomizing molten steel into a powder, exposing the powder to a temperature of at least 2100.degree. F. in a hydrogen containing atmosphere until the sulfur content has been reduced to the desired level, and cooling the desulfurized powder to ambient temperature in a non-oxidizing atmosphere. During heat treatment an interconnected porosity of at least 10% is maintained for the powder.
    Type: Grant
    Filed: December 17, 1980
    Date of Patent: November 15, 1983
    Assignee: Allegheny Ludlum Steel Corporation
    Inventor: Orville W. Reen
  • Patent number: 4362484
    Abstract: Hot briquetting apparatus for ferrous or non-ferrous particles has a furnace having upper and lower chambers. The particles are supplied to the lower chamber and leave the lower chamber through a discharge tube to enter a briquetting press. A passage is performed between the lower and upper chambers and sensing means sense the constituents of the gases in that passage. Control means control the air-to-fuel ratio of a zone of the lower chamber. The control means are connected to the output of the sensing means so as to maintain the atmosphere within the zone as a reducing atmosphere, the whole of the lower chamber being a reducing atmosphere.
    Type: Grant
    Filed: August 24, 1981
    Date of Patent: December 7, 1982
    Assignee: Ecobric Foundry Limited
    Inventor: Martin A. Stephens