Abstract: A cathode is made from a mixture of tungsten and iridium powders using a ction product formed from reacting barium peroxide with an excess of tungsten as the impregnant.

Abstract: An object is manufactured of a powdered material by isostatic pressing of a body (10), preformed from the powdered material, whereby the preformed body is surrounded by a casing (16) which at least for the main part is transferred to molten phase, before the isostatic pressing is carried out while sintering the powder. As material in the casing there is used glass or a material forming glass when being heated and containing 48-52 percent by weight B.sub.2 O.sub.3, 46-50 percent by weight SiO.sub.2 and 1.5-2.5 percent by weight Al.sub.2 O.sub.3. It can be removed from the finished object by water or water vapor and has a low coefficient of thermal expansion at temperatures below the melting temperature of the glass. To counteract the penetration of molten glass from the casing into the preformed body, a barrier layer (18) may be arranged on the preformed body inside the casing. (FIG.

Abstract: A process for improving the swelling resistance of a titanium-modified austenitic stainless steel that involves a combination of rapid solidification and dynamic compaction techniques.

Abstract: A cathode is made from a mixture of tungsten and iridium powders using a ium iridiate formed from barium peroxide and iridium oxide as the impregnant.

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: An Al-alloy containing Si, Fe, Cu and Mg and at least one of Mn and Co in the basic composition range of 8.0.ltoreq.Si.ltoreq.30.0 wt. %, 2.0.ltoreq.Fe.ltoreq.33.0 wt. %, 0.8.ltoreq.Cu.ltoreq.7.5 wt. %, 0.3.ltoreq.Mg.ltoreq.3.5 wt. %, 0.5.ltoreq.Mn.ltoreq.5.0 wt. % and/or 0.5.ltoreq.Co.ltoreq.3.0 wt. %, provided in a powder state. A sindered member formed of these Al-alloys displays high strength, excellent heat-resistivity and stress corrosion cracking resistivity. A structural member made of the sintered Al-alloy is manufactured through the steps of subjecting a powder press-shaped body formed at a temperature of 350.degree. C. or lower and at a pressure of 1,5.about.5.0 ton/cm to hot extrusion working at a temperature of 300.degree..about.400.degree. C. to form a raw material for forging, and then forge shaping the raw material at a temperature of 300.degree..about.495.degree. C.

Abstract: A cathode is made from a mixture of tungsten and iridium powders using a ium peroxide containing material as the impregnant.

Abstract: In the manufacture of an object of a powdered material by isostatic pressing of a body (10) preformed from the powdered material with a gaseous pressure medium, the preformed body is provided with a casing (13) of glass which is made gas-impenetrable by heating before carrying out the isostatic pressing. Inside the glass casing there is arranged on the preformed body an intermediate layer (12) which counteracts the penetration of molten glass from the casing into the preformed body. The intermediate layer comprises a layer of one or more intermediate phases in the system Al.sub.2 O.sub.3 --SiO.sub.2, for example mullite 3Al.sub.2 O.sub.3.2SiO.sub.2, or a layer containing one or more such intermediate phases as main constituent. In a preferred embodiment a layer of boron nitride is arranged inside the intermediate layer. In a preferred embodiment, the powdered object consists of aluminium oxide or an aluminium oxide-based ceramic.

Abstract: The present invention provides a method of producing a bulk amorphous metal alloy article. The method involves mechanically alloying a matrix metal and a fast diffuser element into a powder mixture consisting of particles having a modulated structure and whereby the powder is at least 50% but less than 100% amorphous. The resultant powder mixture is formed into a bulk amorphous metal alloy article by standard forming methods such as cold or hot-pressing. This bulk article can be further processed into a bulk crystalline metal alloy article by heating at a temperature above the glass transition temperature of the amorphous metal alloy article.

Abstract: A tungsten-nickel-iron-cobalt high density alloy having unexpected improved strength and hardness properties and the method of making such alloy are disclosed. The alloy has from about 85-98% by weight tungsten with the remainder being a nickel-iron-cobalt binder in which the cobalt is present in amounts of from at least about 5% up to 47.5% by weight of the binder and the amount of cobalt being equal to or less than the amount of nickel. After the powders of the elements in the indicated amounts are homogeneously blended, compacted into a shape and sintered, the sintered shape is subjected to a heat treatment in a flowing argon atmosphere for a period of time and at a temperature at least sufficiently high to solubilize the intermetallic or .mu. phase, Co.sub.7 W.sub.

Abstract: Sinter alloys based on high-speed steel are proposed, which can be used for producing wearing parts in machinery and vehicle contruction. The sinter alloys comprise a mixture of a powder of a high-speed steel and an unalloyed or a low-alloy iron powder. While the high-speed steel powder forms liquid phases upon sintering, the mixture components can be drawn from either the group of iron alloys that do not form liquid phases or the group of iron alloys that do form liquid phases. The proposed alloys cannot be sintered to the density of the high-speed steels, nor do they quite attain the strength values of such steels, but in the cases where these limit values for strength are not critical they have the decisive advantage that they can be sintered without deformation in standard protective gas furnaces lacking extreme temperature constancy and that they furthermore exhibit only very slight shrinkage.

Abstract: An electrochemical cell comprising a zinc electrode in an electrolyte solution wherein the electrode is formed from a zinc powder compacted to a density of at least about 6.5 g/cc to substantially reduce the corrosion of the zinc electrode and the consequent evolution of hydrogen gas without resorting to the addition of mercury to the electrode.

Abstract: A workpiece consisting of a heat-resistant aluminum alloy is produced by a powder-metallurgical process wherein an alloy containing 8 to 14% by weight Fe, 0.5 to 2% by weight V and 0.2 to 1% by weight Mn is melted, the melt is cooled in a gas stream at a rate of at least 10.sup.5 .degree.C/s and is atomized to form particles having a diameter of 1 to 40 .mu.m, whereupon the powder is consolidated a temperature of 350.degree. to 450.degree. C. at a pressure of 2000 to 6000 bar, to form a pressed article. In this process, the intermetallic compound Al.sub.6 Fe stabilized by Mn occurs in fine distribution. This dispersoid imparts high ductility and toughness to the grain.

Abstract: To increase service life and suppress interferences in high voltage electrodes for the ignition distributing system of internal combustion engines, the electrodes consist of molded and sintered mixture of 50-90% by weight iron powder and 50-10% by weight calcium silicide. Preferably, the electrode has tipstretched contact area of nonalloyed iron.

Abstract: A powder metal composite made up of first and second powder metal bodies assembled in a mold cavity with the bodies separated by a divider ring and with the bodies being in concentric relationship such that the assembled bodies and divider ring can be simultaneously compacted and subsequently simultaneously sintered to form the desired composite metal article. In practicing the method of forming a composite metal article one of the bodies may be selected from a base powder metal and the other body may be selected from a high performance alloy powder metal, and the divider ring may be selected from a low melting point metal such as copper that will dissolve itself into the powders during sintering and enhance mechanical properties of the sintered compact article.

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: When manufacturing an object of powdered material by isostatic pressing of a body (10), preformed from the powdered material, with a gaseous pressure medium, the preformed body is provided with a casing (19) of glass which is made gas-impermeable by heating before carrying out the isostatic pressing. Inside the glass casing there is arranged on the preformed body a barrier layer (11) which counteracts the penetration of melted glass from the enclosure in the preformed body. The barrier layer is built up of at least two layers, of which one layer (12) at least substantially consists of powdered boron nitride and one layer (13) of a mixture of powdered boron nitride and a powdered material with the ability, upon contact with glass from the casing in melted form, to make a layer containing boron nitride tighter.

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: Mill scale, iron ore, or taconite is utilized in a powder metallurgy process to form steel articles having approximately the same density as that of conventional rolled steel. Particulate iron is mixed with manganese, carbon, additional alloying ingredients, and a binder to form a particulate admixture. The particulate admixture is then compressed, preferably under extreme pressure until the density of the compressed particulate admixture is from about 0.2408 lbs/in.sup.3 (6.67 g/cm.sup.3) to about 0.2833 lbs/in.sup.3 (7.83 g/cm.sup.3), which corresponds to a density of from about 85% to about 100% of the density of conventional rolled steel. The resultant coherent mass is subjected to sintering and below fusion heating to form an alloyed article which can be swaged, rolled, drawn, or worked at elevated temperature to decrease the grain size of the alloyed article. The resultant end-product will preferably have a density of from about 0.2408 lbs/in.sup.3 (6.67 g/cm.sup.3) to about 0.2833 lbs/in.sup.3 (7.

Abstract: A cBN sintered compact for an end mill obtained by sintering mixed powder prepared by mixing about 35 to 50 percent by volume of cubic boron nitride powder smaller than about 2 .mu.m in average particle size with about 50 to 65 percent by volume of a binder under cBN-stable superhigh pressure conditions. The binder contains about 20 to 30 percent by weight of Al and one or more Ti compounds selected from a group of TiN.sub.z, Ti(C,N).sub.z, TiC.sub.z, (Ti,M)C.sub.z, (Ti,M) (C,N).sub.z and (Ti,M)N.sub.z (where M indicates a transition metal element of the group IVa, Va or VIa of the periodic table excepting Ti and z is within a range of about 0.7.ltoreq.z.ltoreq. about 0.

Abstract: The invention resides in a process of preparing an inhomogeneous sintered body by adjoining metal powder with refractory ceramic powder at normal powder metallurgical pressures and sintering conditions. The invention is characterized thereby that the sintered body is manufactured in one layer or several layers having displaced mixing ratio between the ceramics and the metal and that the binding between ceramics and metal is strengthened with monoaluminium phosphate or a monoaluminium phosphate former. The sintered body can be used for example as heat shielding.

Abstract: A method is disclosed for making a fuel pellet for a nuclear reactor. A mixture is prepared of PuO.sub.2 and UO.sub.2 powders, where the mixture contains at least about 30% PuO.sub.2, and where at least about 12% of the Pu is the Pu.sup.240 isotope. To this mixture is added about 0.3 to about 5% of a binder having a melting point of at least about 250.degree. F. The mixture is pressed to form a slug and the slug is granulated. Up to about 4.7% of a lubricant having a melting point of at least about 330.degree. F. is added to the granulated slug. Both the binder and the lubricant are selected from a group consisting of polyvinyl carboxylate, polyvinyl alcohol, naturally occurring high molecular weight cellulosic polymers, chemically modified high molecular weight cellulosic polymers, and mixtures thereof. The mixture is pressed to form a pellet and the pellet is sintered.

Abstract: Method for applying a corrosion-protection layer to the base body (1) of a gas turbine blade by embedding particles (3) of SiC in a metallic matrix by means of powder, paste or electrolytic/electrophoretic methods and compacting, welding or fusing and bonding the matrix-forming material to the base body (1) by means of hot-pressing, hot isostatic pressing or laser beam, electron beam or electric arc. Protective layers are formed which do not flake off and with high silicon content which is at least partially contained in the embedded, partly modified SiC particles (6) as a reservoir for the operation.

Abstract: A refractory hard metal-metal composite is formed by impregnating a porous refractory hard metal article with molten metal.

Abstract: A method for producing a sintered ferrous alloy containing at least one alloying element whose standard free energy for oxide formation at 1,000.degree. C. is 11,000 cal/g mol O.sub.2 or less is described. The method comprises a sintering procedure comprising steps of elevating the temperature of a green compact comprising said at least one alloying element, sintering it in a sintering furnace and cooling it, wherein the pressure in the sintering furnace is maintained at between about 0.2 and 500 Torr by supplying a reducing gas during at least a part of the sintering procedure under reduced pressure.

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.

Abstract: Powder metal compositions of nickel, molybdenum, boron, carbon, phosphorus and iron which exhibit low shrinkage on sintering.

Abstract: A cermet is produced by providing a bulk reaction mixture of particulate reactants plus elemental metal, which reaction mixture is in admixture with a ceramic diluent that is the same as ceramic material formed during sintering of the reaction mixture. Sintering produces a boride-oxide ceramic with the oxide being a metal oxide of the elemental metal. However, the elemental metal is present in the reaction mixture in substantial excess over that amount stoichiometrically required. Sintering is conducted under inert atmosphere, generally after pressing. The invention is particularly directed to boride-based ceramics containing aluminum, which materials are suitable as components of electrolytic cells for the production of aluminum by molten salt electrolysis.

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.

Abstract: An improvement is disclosed in a process for recovery of cobalt from cobalt bearing material to obtain fine cobalt metal powder of high purity, the improvement being mechanically compacting the powder into a billet and sintering the billet in a hydrogen atmosphere at a sufficient temperature for a sufficient time to densify the billet and form a high purity cobalt article having an oxygen content of no greater than about 500 weight parts per million.

Abstract: A process for producing a composite billet employing powder metallurgical techniques in which a first alloy powder of a preselected composition is compacted in a tubular container producing a preliminarily compacted tubular mass which thereafter is finished on the interior surface thereof to desired final dimensions. The resultant tubular mass is placed in a second container and the core thereof is filled with a powder of a desired second alloy composition and the contents are sealed. The second alloy powder is subsequently hot compacted to a density approaching 100 percent theoretical density without incurring any appreciable distortion or dimensional change of the tubular mass. Thereafter, the preliminary composite compacted billet is subjected under elevated temperature to an axial extrusion step producing a final composite extruded billet having a concentric outer layer of a first alloy and an inner core layer of a second alloy metallurgically bonded together.

Abstract: A magnetic powder core, suitable for use in a low frequency power device, is prepared by a method including the steps of coating an atomized iron powder from an aqueous solution of potassium dichromate, drying the powder, compressing the powder to form a compact and heat treating the compact until it becomes partially sintered. Cores having coercivities below 240.sup.A /m, saturation inductions exceeding 1.3 Tesla and resistivities exceeding 500 microhm cm are disclosed.

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.

Abstract: A method of manufacturing a scandate dispenser cathode having a matrix at least the top layer of which at the surface consists substantially of tungsten (W) and scandium oxide (Sc.sub.2 O.sub.3) and with emitter material in or below said matrix. If said method comprises the following steps:(a) compressing a porous plug of tungsten powder(b) heating said plug in a non-reactive atmosphere and in contact with scandium to above the melting temperature of scandium,(c) cooling the plug in a hydrogen (H.sub.2) atmosphere(d) pulverizing the plug to fragments(e) heating said fragments to approximately 800.degree. C. and firing them at this temperature for a few to a few tens of minutes in a hydrogen atmosphere and slowly cooling in said hydrogen atmosphere(f) grinding the fragments to scandium hydride-tungsten powder (ScH.sub.2 /W)(g) compressing a matrix or a top layer on a matrix of pure tungsten from said ScH.sub.

Abstract: The present invention provides a method for producing a consolidated article composed of a transition metal alloy. The method includes the step of selecting a rapidly solidified alloy which is at least about 50% glassy. The alloy is formed into a plurality of alloy bodies, and these alloy bodies are compacted at a pressing temperature of not more than about 0.6 Ts (solidus temperature in .degree.C.) to consolidate and bond the alloy bodies together into a glassy metal compact having a density of at least about 90% T.D. (theoretical density). The compacted glassy alloy bodies are then heat treated at a temperature generally ranging from about 0.55-0.85 Ts, but, in any case, above the alloy crystallization temperature, for a time sufficient to produce a fine grain crystalline alloy structure in the compacted article.

Abstract: A process for making a strip or sheet comprising dispersion strengthened metal or dispersion strengthened metal alloy which comprises rolling directly from dispersion strengthened metal powder to a green strip or sheet density of from at least 90% to 95% of theoretical density, sintering the green strip or sheet in an inert atmosphere at a temperature and for a period of time sufficient to form a rigid body; reducing the thickness of the strip or sheet by at least 25% by cold rolling or hot rolling and resintering at sintering temperature of at least about 1800.degree. F. for 40 to 75 or more minutes.

Abstract: The invention relates to a powder metallurgical method for producing high speed steel products, the shape of which is close to the desired final shape of the product, i.e. according to the so called near net shape technique.

Abstract: A thin-walled elastic envelope or mold element is arranged within a divisible outer supporting mold of porous material and a vacuum is applied to the outer supporting mold. Thereupon powdered metal or ceramic is introduced into the elastic mold element and the mold element is closed and pressurized to form a preform. The preform is then subjected to cold isostatic pressurization which is applied to the outer surface of the elastic mold element. Prior to the cold isostatic pressurization, the vacuum applied to the outer supporting mold is terminated and a vacuum is produced within the elastic mold element.

Abstract: An object is manufactured from a powdered material by isostatic pressing of a body, preformed from the powdered material, with a pressure medium, whereby the preformed body, in which at least the surface layer consists of a ceramic material in the form of a nitride, is surrounded by a casing which is rendered impenetrable to the pressure medium, before the isostatic pressing is carried out and the powder sintered. As the material in the casing there is used boron oxide or a glass containing boron oxide or a material forming glass while being heated, in which the content of boron oxide is sufficiently high for the glass--or the glass formed during heating--to be removable by water. The preformed body surrounded by the casing is subjected to a heat treatment for the formation of boron nitride on the surface of the preformed body, before the isostatic pressing is carried out. The casing is removed from the finished product by means of water or water vapor.

Abstract: The present invention relates to a method for manufacturing a high-strength sintered silicon carbide article and more particularly, to a method for a sintered silicon carbide article having high mechanical strength by mixing a finely divided silicon carbide powder with the definite amounts of a specific carbon-containing material, a boron compound and silicon powder as densification aids, shaping and then sintering said shaped article under an inert atmosphere.

Abstract: A stainless steel powder is mixed with at least a Ni--Mn and a Ni--Cr powder, and the powder mixture is formed by loose packing into a required configuration. The powder mixture is sintered in a non-oxidizing atmosphere at the melting point of the Ni--Mn powder or at a higher temperature thereby to obtain a porous body.

Abstract: A voltage limiting composition, actually a nonlinear resistor, especially suitable for use in a gapless surge arrester is disclosed herein. This composition includes a predetermined amount of zinc oxide as its primary ingredient and one or more specifically selected additives. All of these constituents are combined and sintered so that the composition displays a nonlinear exponent .alpha. at least equal to about 35 over the current range of 1 ma to 5000 amps and such that its energy absorption capability is at least equal to about 50 joules/cm.sup.3.

Abstract: The present invention relates to a method of manufacturing widgets from components and/or particulate; and to a can for containing such components and/or particulate during the consolidation into widgets. The method of the present invention can be used to form widgets from metals, ceramics, plastics, polymers, and/or combinations thereof. The materials used to form the widgets can be in the form of particulate, pellets, shard, and/or ribbon. The method of the present invention can also be used to join widgets and/or to heal ingot cracks.

Abstract: The disclosed electrode composition for a vacuum switch comprises copper, as a principal ingredient, a low melting point metal such as Bi, Pb, In, Li, Sn or any of their alloys, in a content not exceeding 20% by weight, a first additional metal such as Te, Sb, La, Mg or any of their alloys and a refractory metal such as Cr, Fe, Co, Ni, Ti, W or any of their alloys in a content less than 40% by weight.

Abstract: A load-bearing thermal insulator, for example a brake piston thrust transmission element, which comprises platelets or flakes of thermally insulating material dispersed in a metal matrix and oriented normal to the direction of heat flow so as to impede the flow of heat through the matrix in one direction.

Abstract: The present invention provides a method of preventing the segregation of powders of different specific gravities in a metal powder composition. The powder metal is admixed with the powders of lesser specific gravities, and furfuryl alcohol is added at the same time. While mixing, an acid is added to react with the furfuryl alcohol to convert the alcohol to a solid resin film on the powder metal particles. The powders of lesser specific gravities are bonded to the metal powder particles by the resin, and segregation of the metal powder and the lighter powders is eliminated.

Abstract: A flowable material, or slurry, comprising a liquid vehicle and solid particulate material dispersed therein which will flow out flat in the form of a sheet. The material, upon exposure to the atmosphere, and either with or without the application of heat, will set up in a dimensionally stable form and can, thereafter, be sintered to form a solid article. The fraction of the vehicle of the composition which remains after the solvent evaporates, vaporizes during sintering and the final product consists only of the particulate material in sintered form.

Abstract: There is described a new material for jewelry and commodities which has a relatively low density and also is low carat but resistant to oxidation and corrosion. It consists of a noble metal or alloy and 1 to 70 volume % glass, whereby as glass there is used a glass frit having a transformation temperature of 300.degree. to 500.degree. C. and a softening interval of over 80.degree. C. There is also described a process for its production.

Abstract: A porous sintered body, preferably a filter or filter material, with good corrosion resistance and with a pore volume which can be predicted within specified comparatively narrow limits, is made by loose sintering of a preferably gas-atomized spherical powder a ferritic-austenitic stainless steel.

Abstract: Pressureless consolidation of metallic powders is achieved by sintering, in a nonoxidizing atmosphere, a blend of the metallic powder with a small amount of finely divided lithium tetraborate.