Abstract: A copper-tungsten mixture net-shaped product produced using powder metallurgical techniques with injection molding and liquid phase sintering. The product has a very low leak rate in helium gas, a high thermal conductivity and a rate of thermal expansion which is substantially the same as some glass and ceramic materials.

Abstract: A process for producing a thin film of a base metal on a substrate which comprises thermally decomposing in oxidative atmosphere an organic or inorganic compound containing a base metal compound formed on a substrate to form the oxide of the metal and then reducing the oxide by heat-treating it in reductive atmosphere. A temperature sensor, magnetic sensor, and ceramic wiring substrate utilizing the base metal thin film.

Abstract: A superplastic composite material is produced by thoroughly and homogeneously mixing particles or whiskers of silicon nitride and aluminum metal powder in a solvent, then removing the solvent from the resultant mixture, sintering the residual mixture at an elevated temperature, further compressing it at an elevated temperature, then hot extrusion-molding the compressed mixture thereby forming a shaped article, and heat-treating this shaped article.

Abstract: There is disxlosed a process for preparing a novel superconducting material. This material has the formula YBa.sub.2 Cu.sub.3 O.sub.7-x wherin x is equal to or less than 0.3, the material has a bulk density of from about 90 to about 96 percent, and the hardness of the material is in excess of 5.0 GigaPascals.In the first step of the process, there is provided a pure powder comprised of barium, yttrium, and copper in a mole ratio of 2/1/3. Such powder is comprised of less than 1.0 mole percent of impurity.In the second step of the process, the powder is compacted. Thereafter, the compacted powder is fired at a temperature of from about 1,000 to about 1,300 degrees Clesius for a period not exceeding 12 hours.In the third step of the process, the temperature of the fired powder is reduced at least 20 degrees Celsius to a first reduced temperature within the range of from about 960 to about 990 degrees Celsius, and the powder is than held within this reduced temperature range for at least 1 hour.

Abstract: A superconductor material having a current density, J, of from about 30,000 to about 85,000 amps/cm.sup.2 at zero magnetic field and 77.degree. K. is disclosed. The 123 superconductor is of the formula L.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. wherein L is preferably yttrium. The process comprises compacting the solid state reaction product of L.sub.1 Ba.sub.2 Cu.sub.3 O and then sintering the reaction product at a temperature between about 40.degree. C. to about 90.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. at a temperature of approximately 940.degree. C. The composition is then heated in a preheated chamber maintained at approximately 1090.degree. C. to about 1,200.degree. C. (approximately 1,100.degree. C. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.) until it has been decomposed, and is then rapidly cooled to a temperature between about 10.degree. C. to about 30.degree. C. above its melting point, i.e. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.

Abstract: A sintering metal powder consisting of metal particles having a particle diameter distribution including a plurality of peaks. The larger of the two particle diameters at every adjoining two, respectively, of the peaks has a ratio of between 5 and 10 to the smaller. The height of one of every adjoining two of the peaks has a ratio of between 1 and 5 to that of the other that is not higher than the one peak. The particle diameter at one of every adjoining two of the peaks which is not higher than the other is smaller than that at the other peak. The particle diameter at the highest peak is between 30 and 80 microns. A process for making a sintered product from such a powder is also disclosed.

Abstract: A sintered hard metal body having improved heat resistance and higher cutting performance is produced by a process including mixing together at least one hard substance, at least one binder material, and at least one of at least one complex carbide and at least one complex nitride to form a starting mixture each constituent of which is in powdered form. The at least one hard substance is selected from the group consisting of carbides, nitrides, and carbonitrides of transition metals of Groups IVB, VB and VIB of the Periodic Table of Elements, is present as at least one of a carbide, a mixed carbide, a nitride, a mixed nitride, a carbonitride, and a mixed carbonitride, and has a cubic crystal form. The at least one binder metal is selected from the group including iron, nickel and cobalt.

Abstract: A high melting metal silicide sputtering target which comprises a fine texture whose stoichiometric composition grains of MSi.sub.2, where M represents a high melting metal, have a maximum grain size of 20 .mu.m, whose free silicon grains have a maximum grain size of 50 .mu.m and whose oxygen content is not more than 200 ppm and has a density ratio to the theoretical density of 99% or more has good film characteristics including the reduction in the number of grains formed on the sputtered film and is useful as an electrode material or a wiring material in semi-conductor devices.

Abstract: Method of producing powder-metallurgical objects, specifically elongate objects such as rods, sections, tubes or the like, wherein a powder of metal and/or metal alloys of great hardness, particularly tool steel or high-speed steel powder, is charged into a thin-walled capsule, said capsule is then sealed so as to be airtight, is heated, and subjected to isostatic compression to produce a blank which will then undergo hot-working, specifically extrusion, for the production of the finished product. In a first alternative, the airtight and sealed capsule is initially heated to a temperature higher than 1,000.degree. C. Following through-heating of the capsule, the latter is maintained at an elevated temperature for a prolonged period. Then the capsule is slowly cooled and subjected to cold isostatic compression prior to final shaping. In a second alternative, the capsule is sealed so as to be airtight, and then subjected to an initial cold isostatic compression.

Abstract: A carefully controlled amount of hydrogen is diffused into titanium or its alloys at an elevated temperature above the transformation temperature. After the elevated temperature is maintained for an approprate duration of time, eutectoid transformation is performed in an inert atmosphere, again for an appropriate period of time, during which or alternatively after which the hydrogen is removed and the metal cooled to room temperature. A sintered titanium alloy component of the type intended for use as a joint replacement subjected to such a treatment displays a fatigue strength which is noticeably improved over a similar article with an equiaxed or lamellar microstructure.

Abstract: An improved method for the continuous fabrication of metal-hydride, electrochemical, hydrogen storage alloy, negative electrodes for use in rechargeable nickel metal hydride cells. The improved method comprises the steps of reducing the size of a high hardness, metal hydride, hydrogen storage alloy by shattering it along natural fracture line thereof. The process next includes providing measured amounts of powered metal hydride electrochemical hydrogen storage alloy material and disposing said material upon a continuous wire mesh screen substrate. Thereafter, the powdered metal hydride electrochemical hydrogen storage alloy and wire mesh screen are subjected to a compaction process wherein they are rolled and pressed so as to form a single integral electrode web which is subsequently exposed to a high temperature sintering process in a chemically inert environment.

Abstract: A process for the powder metallurgical production of structural parts of high strength and hardness from silicon-manganese or silicon-manganese-carbon alloyed steels. The alloying elements Si and Mn or Si, Mn and C are mixed, in powder form, by way of the alloy carriers ferrosilicon, ferromanganese or a silicon-manganese-iron master alloy containing silicon and manganese in the ranges from 10 to 30 weight percent Si, 20 to 70 weight percent Mn, remainder Fe, with an iron powder and when carbon is present with graphite, to form a powder mixture. The powder mixture is compressed and sintered at a temperature in a range from 1150.degree. C. to 1250.degree. C. and then cooled.

Abstract: A surface structure of A1N substrate comprising:an A1N substrate,an intermediate layer disposed on the A1N substrate, anda metallized layer disposed on said intermediate layer, said intermediate layer comprising at least aluminum, nitrogen and oxygen. The metallized layer has a main component of one of Mo-Mn alloy, Mo and W, and has a thickness of 1-20 .mu.m,This surface structure is produced by coating a surface of A1N substrate with metallizing layer components, heat treating the resultant coated substrate at a temperature of 200.degree.-500.degree. C. under an oxidizing atmosphere, and further heating the heat treated coated substrate at a temperature of 1200.degree.-1400.degree. C. under a nonoxidizing atmosphere having a dew point of -35.degree.to 5.degree. C.

Abstract: A presinter treatment is provided to reduce oxygen contamination prior to sintering a predominantly iron powder compact comprising carbon powder and a liquating diffusible boron source, such as nickel boride powder optionally in combination with iron boride powder. A preferred treatment is carried out at a temperature effective to dissociate iron oxide within the compact but not to initiate a liquid phase by said boron source and further is carried out in a vacuum to evacuate oxygen released thereby from compact pores prior to sintering. The presinter treatment enhances carbon and boron diffusion into the iron during sintering. In a preferred embodiment, the fraction of borocementite particles formed by diffused carbon and boron in the sintered iron structure is increased by the presinter treatment of this invention.

Abstract: A manufacturing method for a multilayered ceramic body using Cu, Ni, Co or Fe as a conductor material, and a conductor forming paste of particular composition of CuO, NiO, CoO or Fe.sub.2 O.sub.3 as the main component, the paste being applied to the multilayered body. The manufacturing method comprises: a process of forming the multilayered body with conductor paste of CuO, NiO, CoO or Fe.sub.2 O.sub.3 as the main component and insulating paste formed of glass and/or ceramic, so that a binder is removed from the laminate by heat treatment in an oxidizing atmosphere; a process of heat treatment for reducing the oxide; and a sintering process for sintering the laminate in a nitrogen atmosphere.

Abstract: An economical alloyed powder for dental amalgams exhibiting good working properties is obtained from pressed and sintered molded bodies by mechanical comminution. The formed body is produced by mixing and pressing powders of elemental silver, copper and tin with a subsequent sintering between 150.degree. C. and the solidus temperature of the alloy being formed. The sintering is performed until a homogeneous distribution of the tin has been achieved in the silver and copper particles.

Abstract: Method of manufacturing cams for camsshafts by powder metallurgy, wherein the formed cams have constant properties over the volume thereof and are well polishable, includes molding into a cam blank a powder mixture made up of iron powder alloyed with carbide-forming elements of the fifth and sixth secondary groups of the periodic table, and graphite powder in a quantity necessary for carbide formation; sintering the blank at a temperature of at most 50 K above a solidus temperature of the blank; and compacting the blank by hot-isostatic compression at a temperature below the solidus temperature to at least 99% of a theoretical density.

Abstract: Spiral parts, such as orbiting and fixed scroll plates having involute wraps, for use in scroll compressors, the parts having low coefficient of thermal expansion and high tensile strength and Young's modulus, are formed by combining a self-lubricating power into aluminum raw material powder prior to compression and forging. As an alternative to and in conjunction with the foregoing, temperatures during preform heating and in the die for forging are controlled to be in respective ranges of 300.degree. to 500.degree. C. and 150.degree. to 500.degree. C. Aluminum alloy fine powder preferably has a particle diameter no larger than 350 .mu.m. The self-lubricating powder preferably forms 1 to 25% of the mix by volume, and contains at least one member selected from the group consisting of graphite, BN, and MoS.sub.2.

Abstract: In a method of sintering an injection-molded article of raw material powder and organic binder, the injection-molded article already debinderized is initially heated up to a certain reaction temperature at which residual binder is removed from it. In subsequent decarburizing step, the residual binder is removed from the molded article under atmospheric or reduced pressure, while being supplied with H.sub.2 gas. Thereafter, in a reducing and sintering step, the molded article is heated up to a sintering temperature and is held at this temperature under reduced pressure for a predetermined period, with H.sub.2 gas being supplied. H.sub.2 content of the atmosphere in the decarburizing step is kept higher than that in the reducing and sintering step.

Abstract: A process for producing permanent magnet materials, which comprises the steps of:forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30% R (provided that R is at least one of rare earth elements including Y), 2-28% B, and the balance being Fe and inevitable impurities,sintering the formed body at a temperature of 900.degree.-1200.degree. C.,subjecting the sintered body to a primary heat treatment at a temperature of 750.degree.-1000.degree. C.,then cooling the resultant body to a temperature of no higher than 680.degree. C. at a cooling rate of 3.degree.-2000.degree. C./min, andfurther subjecting the thus cooled body to a secondary heat treatment at a temperature of 480.degree.-700.degree. C.35 MGOe, 40 MGOe or higher energy product can be obtained with specific compositions.

Abstract: Method in producing a molding of an iron alloy, wherein the molding is produced by hot isostat pressing of a prealloyed powder comprising 0.5 to 2.8% coal by weight, 24 to 35% chromium by weight, from effective amount to 2% silicon by weight, from effective amount to 1.5% manganese by weight, 0 to 2.3% nickel weight, and 0 to 3.0% molybdenum by weight, and the residue iron.

Abstract: An improved method for the continuous fabrication of metal-hydride, electrochemical, hydrogen storage alloy, negative electrodes for use in rechargeable nickel metal hydride cells. The improved method comprises the steps of providing measured amounts of powdered metal hydride electrochemical hydrogen storage alloy material and disposing said material upon a continuous wire mesh screen substrate. Thereafter, the powdered metal hydride electrochemical hydrogen storage alloy and wire mesh screen are subjected to a compaction process wherein they are rolled and pressed so as to form a single integral electrode web which is subsequently exposed to a high temperature sintering process in a chemically inert environment. The sintering process is designed to drive off excess moisture in the material while discouraging oxidation of the electrode web and set the electrode web state of charge.

Abstract: A process is disclosed for producing a sheet of tungsten heavy alloy which comprises forming metal particles of the alloy wherein each metal particle is a uniform admixture of the alloy components, entraining the particles in a carrier gas, passing the particles and the carrier gas into a high temperature zone at a temperature above the melting point of the matrix phase of the particles and maintaining the particles in the zone for a sufficient time to melt at least the matrix phase of the particles and form spherical particles, followed by rapidly and directly solidifying the high temperature treated material while the material is in flight. A slurry is formed of this high temperature treated material and a liquid medium, the liquid medium is removed from the material and a planar cake is formed of the material, the cake is dried, and sintered to a density equal to or greater than about 90% of the theoretical density of the alloy to form the sheet.

Abstract: A low density tungsten alloy article is disclosed and the method for producing the article. The method involves compacting a relatively uniform tungsten alloy powder with the tungsten content comprising no greater than about 90% by weight of the alloy and the balance a matrix phase to produce a preformed article which is then sintered in a reducing atmosphere at a temperature below the melting point of the matrix phase for a sufficient time to form a densified article which is mechanically worked to produce the final article.

Abstract: A process is disclosed for producing a sheet of tungsten heavy alloy which involves uniformly blending metal powder compnents of the alloy by forming a slurry of the powder components and one or more chemical compounds of at least one of the components of the alloy as an inorganic binder in a liquid medium, the chemical compound being soluble in the liquid medium and capable of being decoposed into one or more of the metal components of the alloy below the melting point of the metal powder components, removing the liquid medium from the powder components and forming a planar cake of the powder components and said inorganic binder, drying the cake, heating the cake to a temperature sufficient to decompose the inroganic binders into their elemental components or oxides, followed by heating the cake in a reducing atmosphere at a temperature sufficient to reduce any oxides forming during the previous steps to the metals, and sintering the cake to a density equal to or greater than about 90% of the theoretical den

Abstract: There is provided a process for infiltrating a compacted ferrous powder metal body with copper or a copper alloy which process is characterized by presintering the ferrous metal body at a temperature of from about 1875.degree. F. to a temperature below the melting point of the infiltrant, and then in the same furnace, raising the temperature above the melting point of the copper or copper alloy infiltrant for a period sufficient to infiltrate the powder metal body. This process is more economical than the prior double run infiltration processes and provides excellent impact strengths and tensile strengths.

Abstract: A process for manufacturing powder metallurgy (P/M) preforms which are conditioned for optimum intrinsic workability is described which comprises steps of heating a quantity of P/M material in a can to a first preselected temperature under vacuum to degas the material, compacting the canned material at a second preselected temperature under pressure to provide a compact of the material; or cold compacting the powder to about 75% density and degassing it at suitable temperature and then vacuum hot pressing the powder at about 0.

Abstract: Composite powder particles which are essentially spherical in shape are disclosed which consist essentially of particles of a matrix phase which consists essentially of a metal selected from the group consisting of aluminum and aluminum based alloys and a reinforcement phase which is relatively uniformly dispersed in and bonded to the matrix, the reinforcement phase comprising titanium diboride.A process is disclosed for producing the above composite particles which involves entraining in a carrier gas a plurality of agglomerated powders, at least one of the powders supplying aluminum, at least one of the powders supplying titanium without boron and at least one of the powders supplying boron without titanium. The powders are fed through a high temperature zone to cause essentially complete melting and coalescence of the powders wherein at least a part of the titanium and at least a part of the boron combine to form titanium diboride and thereafter resolidified to form the composite powder particles.

Abstract: A method of powder metallurgically manufacturing an article with near net shape is disclosed, the method comprisingfilling the mould cavity (3) of an open ceramic open mould (1), the inside walls of the cavity being precision copying cast surfaces (2), with fine particulate metal powder (5),placing the mould with its content of metal powder in an outer mould (6), and covering the ceramic open mould containing the metal powder with a bed of finely distributed particulate pressure medium (7),heating the bed of pressure medium and ceramic mould and particulate metal powder therein and subjecting the particulate pressure medium to pressure provided by at least one surface acting in an axial direction against the opening (4) of the ceramic mould, so that pressure is transferred by the particulate pressure medium to the metal powder in the mould to consolidate the metal powder to a completely dense body (21) with surfaces (22) which have been shaped by the precision cast surfaces of the mould cavity.

Abstract: A process is disclosed for producing tungsten heavy alloy billets. The process involves forming a uniform blend of elemental powders to form a tungsten alloy having a tungsten content of equal to or less than about 91% by weight and wherein the particle size of the tungsten is no less than about 2 micrometers in diameter. This blend is uniformly packed into a container having thermal expansion similar to that of the powder. The blend is then sintered in a hydrogen atmosphere at a temperature sufficient to impart strength to the powder and to reduce oxides and remove volatile impurities from the powder without significant densification in the powder. The powder is then solid state sintered in a reducing atmosphere at a sufficient temperature to densify the powder to at least about 90% of the theoretical density but at a temperature below the liquid phase sintering temperature of the powder, to form the billet.

Abstract: This invention provides a shaped, graded, cermet article comprising at least one continuous ceramic phase and at least one discontinuous metal phase, the ratio of ceramic/metal being controlled and varied over the thickness of the article. The ceramic phase preferably is microcrystalline.

Abstract: The present invention is concerned with a method of molding metallic powders, in which a binder fluid having a specific freezing point, typically water, is added to the metallic powder to be molded to form a mixture, after which a die having the desired cavity is filled with said mixture. The mixture is then pressure molded and rapidly cooled, freezing the binder fluid to produce a frozen molded shape, which is then dried to remove the binder fluid and sintered.The amount of the binder fluid of specific freezing point to be added to the said metallic powder is the minimum amount that will satisfy the dual demands of flowability during molding and shape retention after the removal of the binder fluid, with from 25 to 50 vol% generally being appropriate. Molding is achieved by injection molding, compression molding or other technique in which pressure is applied to the material in the mold.

Abstract: Metal or alloy articles having complicated shapes can be produced with high precision by injection molding a kneaded mixture of a metal or alloy powder and an organic binder comprising a special methylcellulose, a plasticizer, a lubricant and water, followed by removal of the organic binder and sintering.

Abstract: An alloy of nickel and titanium in the atomic ratio of 49:51 to 56:44 can be prepared at a temperature much lower than the eutectic point of the corresponding alloy. Thus, a green compact of a powdery mixture of the component metals is subjected to a heat treatment under high vacuum first at a rate of temperature elevation of 5.degree. to 30.degree. C./minute up to a temperature of, for example, 600.degree. C. and then at a rate of temperature elevation of at least 40.degree. C./minute up to a temperature of 815.degree.-900.degree. C. The surface of the metal particles is activated at the first stage along with degassing and the surface-activated metal particles are brought into an exothermic reaction at the second stage to cause explosive fusion and alloying.

Abstract: A method of sintering compacts of metals, ceramics and the like in powder form. At least the surface portion of the compact is sintered in a plasma atmosphere having a pressure of 10 Torr or less thereby eliminating the open voids and then the compact is subjected to a hot isostatic press process.

Abstract: A process for producing titanium alloy articles by Hot Isostatic Pressing of a rapidly-solidified titanium alloy powder is provided wherein such pressing is carried out at a pressure greater than 30 ksi, and a temperature of about 60 to 80 percent of the beta-transus temperature of the alloy, in degrees C. Hot Isostatic Pressing under these conditions allows retention of the fine microstructure of the rapidly-solidified powder. The compacted article may be subjected to heat treatment to alter its microstructure.

Abstract: The powdered material contains oxygen in the oxide and/or adsorbed form and the oxygen present is reduced in a first pre-sintering stage and the cohesion of the material is ensured in a second sintering stage. The pre-sintering stage is carried out under a reducing atmosphere based on hydrogen and neutral gas whose flow rate F.sub.G is higher than or equal to: ##EQU1## in which relation: S.sub.P =section of the layer of powder to be sintered in sq.mD.sub.P =voluminal mass of the powder in kg/cu mX(O.sub.2)i=percentage of oxygen mass in the powder before the pre-sintering stage, in the oxide and/or adsorbed form,P(H.sub.2)i=voluminal percentage of hydrogen in the gas introduced into the furnace,P(H.sub.2)f=the smallest voluminal percentage of hydrogen in the atmosphere in the furnace at a point where the oxides have been completely reduced,v.sub.S =speed of feed of the material in the furnace expressed in m/hr,.alpha. is a constantF.sub.G being expressed in cu.m/hr.

Abstract: A process for manufacturing structural parts of complicated shape from intermetallic phases capable of sintering by means of special additives which serve at the same time as sintering assist and increase the ductility of the finished structural part. The process includes the steps of making by melting a pre-alloy of the intermetallic phase, comminuting the pre-alloy into fine powder and mixing the fine powder with one or more additives into a mass which can then be shaped and subsequently sintered at a temperature of 70 to 95% of the absolute melting point of the intermetallic phases into a structural part of increased ductility and a density greater than 95% of the theoretical density which might possibly be subjected to subsequent pressing operations.

Abstract: Very fine grain metal billets are produced by loading alloy metal powder of desired composition into a metal extrusion container in successive layers of two or four inches deep. Each layer after loading is compacted by a high energy rate forming ram so as to introduce energy on the order of 3.times.10.sup.6 psi per layer and at least 18.times.10.sup.6 psi total. An inner plate is then loosely placed on the compacted powder. On top of the inner plate is placed a cover plate which is welded to the container. The filled container is then heated in a furnace to an extrusion temperature below the melting point of the alloy and is extruded in an extrusion press having a ratio of about 3:1 with a force of about 3,000 tons. The inner plate does not move at the same rate as the container and in effect is partially extruded against the powder so as to raise the density of the extruded billet to substantially 100% of its theoretical density.

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.

Abstract: A sintered tungsten carbide material and method for manufacturing same in which the method includes the steps of combining metal particles composed of from 75 to 95 percent by weight of a composition containing at least 70 percent by weight of tungsten carbide and from 5 to 25 percent by weight of a binder metal composition, the binder metal composition consisting essentially of from 5 to 15 percent by weight of chromium and from 85 to 95 percent by weight of nickel; pressing the metal particles into a pressed body; sintering the pressed body in a sintering chamber for a period ranging from 20 to 200 minutes, at a temperature ranging from 1400.degree. to 1500.degree. C., and in a protective atmosphere which is one of a vacuum, a noble gas, a mixture of noble gases, and hydrogen gas to form a sintered body; and treating the sintered body for a period ranging from 20 to 200 minutes, at a temperature ranging from 1300.degree. to 1400.degree. C.

Abstract: A method of manufacturing a porous body using particulate material as a starting stock. The particles are inserted in a can, the can evacuated and inert gas admitted to a predetermined back-fill pressure. After hot isostatic pressing, the compact so formed is cooled and subsequently heat treated to permit the pores formed in pressing to expand and form a porous body.

Abstract: An improved fabrication process for cobalt-enriched cemented carbide substrates is disclosed, in which an article is generally comprised of tungsten carbide, cobalt, and carbides, nitrides or carbonitrides of titanium, tantalum, and niobium, or mixtures thereof. In one aspect of the invention the article is contacted with nitrogen gas and then sintered in the absence of nitrogen gas to form a cobalt-enriched, B-1 phase-depleted zone. The article is then sintered in nitrogen gas to form a B-1 phase enriched layer on the surface of the article. Additionally, a metal oxide wear layer can be provided on the article.

Abstract: Methods and apparatus are disclosed for consolidating loose or pre-compressed particulate materials, such as metal powder or metal flakes, in press equipment utilizing a reusable canister means that is sealed in vacuum from the atmosphere and heated prior to consolidation in the press equipment at elevated pressures and temperatures, thereby improving utilization of the press equipment.

Abstract: This invention relates to a hard alloy comprising two phases: a hard phase consisting of at least one compound having a crystal structure of simple hexagonal MC type (M: metal; C: carbon) selected from the group consisting of mixed carbides, carbonitrides and carboxynitrides of molybdenum and tungsten, and a binder phase consisting of at least one element selected from the group consisting of iron, cobalt and nickel. The hard phase is prepared by carburizing an (Mo, W) alloy obtained by reducing oxides of molybdenum and tungsten with a particle size of at most 1 micron, is composed of coarse particles with a mean particle size of at least 3 microns, and has a uniform molybdenum to tungsten ratio in the particles. The hard alloy has a gross composition within the range of the shaded portion ABCDEA in FIG. 1.

Abstract: Metal powder of the desired composition having a particle size of -80 mesh is charged into an extrusion container, preferably a piece of carbon steel pipe, in successive layers about two inches thick. Each layer is compacted after deposition by a high energy rate forming ram so as to raise the tap density of the powder to about 80% of theoretical. An inner cover plate is then placed loosely on the compacted powder in the extrusion container, and is not attached to the container shell. On top of this inner plate is placed an outer cover plate which is welded to the container shell. Both plates are also of carbon steel, but are much thicker than the container wall. The container so prepared is heated in a heating furnace to a temperature below the melting temperature of the container and the powder alloy thus raising the density of the powder to about 90-93% of theoretical.

Abstract: Powder metallurgy products of high tensile strength are formed in a pore-free state by a novel process which entirely avoids the use of canisters. An open-pore specimen is purged with depurative gas, backfilled with a reactive gas and, while still immersed in the reactive gas, compressed isostatically to an extent necessary to close the pores. The specimen may then be compressed to full density without the need for either high vacuum or a depurative or reactive gas atmosphere.

Abstract: An improvement is disclosed in a method for producing a metal article of high density comprising pressing a metal powder at a sufficient pressure to form a green article and sintering said green article at a sufficient temperature for a sufficient time to form a sintered article, the improvement being pressing the sintered article at a sufficient temperature for a sufficient time at a sufficient pressure of a non-oxidizing atmosphere to produce the final high density article.

Abstract: The specification discloses a powder process in which metal or ceramic particles are mixed with a binder such as ultra high molecular weight polyethylene powder and are compacted. The compacted shape is heated to a temperature near the melting point of the binder to consolidate the binder and produce a green shape. The green shape is formed and the binder is removed. Thereafter, the shape is sintered to form a final part.

Abstract: A method of producing a high density tungsten alloy sheet product is disclosed which utilizes as a starting material a thin-gage sheet or foil substrate of a first alloy constituent, such as pure iron or an alloy thereof. A prescribed mixture of tungsten metal powder and a second metal alloy constitutent powder, such as nickel, is loaded on the substrate and partially consolidated in a protective atmosphere furnace to form a porous tungsten alloy skeleton which is also partially bonded to the substrate. The product is then preferably cooled in a protective atmosphere and sheared into desired lengths. The sized pieces are then further heated in a protective atmosphere at gradually increasing temperatures to a point above the melting point of the substrate, whereupon the substrate sheet or foil melts and infiltrates the porous tungsten alloy skeleton to complete the densification of the product.