Abstract: Disclosed is a roller for use in a rotary compressor, which roller comprising a sintered body consisting essentially of 0.5-2.0% by weight of C, 1.0-5.0% by weight of Cu, 0.5-3.5% by weight of Cr, 0.1-1.0% by weight of Co, 0.1-1.0% by weight of W and a balance Fe and unavoidable impurities. Hard particles of Cr-Co-W alloy are dispersed in one of pearlitic and tempering martensitic matrix, and sintered pores of the sintered body are sealed with tri-iron tetroxide. Resultant sintered body has high wear resistance and scuffing resistance capable of being used as an inverter type compressor.

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: A process is described for making a composite article without shrinkage, particularly of ceramic and metal wherein the article includes complex internal surfaces or cavities. The process requires forming an insert body that includes an external surface that corresponds to an internal cavity of the article. The insert body consists of a material having a melting temperature less than that of the article. The process further requires forming a porous compact about the insert body wherein the compact is formed into the substantially the net shape of the article. The compact is made of a material that is wetted by liquid insert material and has a sintering temperature greater than the wetting temperature of the insert material. The process further requires heating the article to a temperature such that the inserts substantially melts and infiltrates the porous compact forming the finished composite article.

Abstract: A contact forming material for a vacuum valve or vacuum circuit breaker comprising (a) a conductive material consisting of copper and/or silver, and (b) an arc-proof material consisting of chromium, titanium, zirconium, or an alloy thereof wherein the amount of said arc-proof material present in said conductive material matrix is no more than 0.35% by weight. This contact forming material is produced by a process which comprises the steps of compacting arc-proof material powder into a green compact, sintering said green compact to obtain a skeleton of the arc-proof material, infiltrating the voids of said skeleton with a conductive material, and cooling the infiltrated material. The contact forming material can provide contacts for a vacuum valve or vacuum circuit breaker which has excellent characteristics such as temperature rise characteristic and contact resistance characteristic.

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

Abstract: A method for working high-purity, mechanically strong targets containing brittle phases in the equilibrium state. First a porous body is manufactured from part of the component with a higher melting point and thereafter the porous body is impregnated with an impregnating composition corresponding to the remainder of the components required to form the ultimate composition of the target. The composition of the impregnation material must be selected in such a manner that the reaction between the impregnation material and the porous body shall produce no phases of low melting points.

Abstract: A method of making a cathode suitable for an electrochemical cell of the type having a molten sodium anode, a beta"-alumina separator, and a cathode which comprises one or more transition metals selected from the group comprising Fe, Ni, Co, Cr and Mn. The method comprises heating a particulate starting material comprising at least one member of the group of transition metals in an oxidizing atmosphere to cause its particles to become at least partially oxidized, and to adhere together to form a unitary porous matrix. This matrix is then heated in a reducing atmosphere at least partially to reduce the oxide formed during the formation of the matrix, and the reduced matrix is then impregnated with a sodium aluminium chloride molten salt electrolyte. Sodium chloride in dispersed form is incorporated into the matrix, preferably by mixing sodium chloride in particulate form with the particulate transition metal starting material, before the heating in an oxidizing atmosphere to form the matrix.

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 dental material and method for forming, reinforcing or repairing a dental restoration comprising a combination of a high fusing temperature metal component in a major proportion and a low fusing temperature component in a minor proportion. A binder may be added to form a putty-like consistency. The dental material is molded into a predetermined shape and heat treated at a temperature which will substantially melt the low fusing metal components but below the melting temperature of the high fusing metal component for forming a porous, sponge-like mass of interconnected particles of the high fusing temperature metal component. A filler material having a low melting temperature is then added to the porous mass and the mass is again treated to form a solid mass.

Abstract: A valve-seat insert for internal combustion engines comprises a double-layered, sintered alloy composed of a valve-seat layer on which a valve is seated, and a base layer integrated with the valve-seat layer and adapted to be seated in a cylinder head of an engine. The valve-seat layer is composed of a sintered alloy of a high heat resistance and a high wear resistance having a composition comprising, by weight, 4 to 8% Co, 0.6 to 1.5% Cr, 4 to 8% Mo, 1 to 3% Ni, 0.3 to 1.5% C, 0.2 to 0.6% Ca, and the balance of Fe and inevitable impurities, the additives, Co, Cr and Mo being present mainly in a form of a Co-Cr-Mo hard alloy and a hard Fe-Mo alloy dispersed in the Fe matrix. The base layer is composed of a sintered alloy of a higher heat resistance and a higher creep resistance than those of the valve-seat layer and having a composition comprising, by weight, 11 to 15% Cr, 0.4 to 2.0% Mo, 0.05 to 0.3% C, and the balance of Fe and inevitable impurities.

Abstract: The present invention relates to a composite bearing material comprising three layers: (1) a metal backing, (2) a porous metal interlayer bonded to the metal backing which includes bronze or other copper alloy particles from two distinct particle size ranges and (3) a PTFE based composition intermixed with and overlying the porous metal interlayer. In accordance with the method of the present invention, the porous metal interlayer substantially comprises a relatively non-homogeneous mixture of particles from the two distinct particle size ranges, wherein a substantial portion of the relatively fine powder is segregated adjacent the metal backing. The present invention includes a significant thickness of the PTFE based composition applied to and remaining above the surface of the porous metal backing.

Abstract: A diamond-coated tungsten carbide-base sintered hard alloy material for inserts of cutting tools, which has greatly improved bond strength or degree of bonding of the diamond coating layer to the matrix and therefore is capable of exhibiting excellent cutting performance over a long period of time.The sintered hard alloy material comprises:(1) a matrix of a sintered hard alloy consisting essentially of 1-4 percent by weight cobalt, and the balance of tungsten carbide and inevitable impurities, the tungsten carbide having a coarse grain structure having an average grain size of 2-10 microns; and(2) a diamond coating layer formed over surfaces of the matrix by forming an etching layer over the matrix surfaces and then forming the diamond coating layer over the matrix surfaces via the etching layer by a low pressure vapor-phase synthesization method.If required, the matrix may further contain CO1-CO8 (ISO) free carbon.

Abstract: A copper or copper alloy infiltrated ferrous powder metal part, and method for making the same, characterized as having after infiltration an overall density of at least 7.50 g/cm.sup.3 and a diffusion depth of copper into the steel matrix of less than about 4 micrometers as determined by chemical etching or less than about 8 micrometers as determined by electron dispersive X-ray analysis (EDXA), wherein said ferrous metal is plain carbon steel having a combined carbon content in the range of about 0.15% to about 1.25%, or a low alloy steel.

Abstract: A microcomposite material having a matrix of a titanium-base alloy, the material further including about 10-80% by weight TiC substantially uniformly dispersed in the matrix. Several methods of cladding a macrocomposite structure including pressing quantities of a matrix material and a microcomposite material composed of the matrix material and a compatible stiffener material into layers to form a multi-layered compact and sintering the multi-layered compact to form an integral metallurgical bond between the layers of the compact with diffusion but essentially no composition gradient between the layers. A multi-layered macrocomposite article composed of an alloy layer of a matrix material and a layer of a microcomposite material composed of the matrix material and a compatible stiffener material bonded together at the interface region between the layers, the interface region being essentially free of a composition gradient.

Abstract: A method of manufacturing by a powder metallurgy process a rotary drill bit including a bit body having an external surface on which cutting elements are mounted, and a passage for supplying drilling fluid to the surface of the bit. The method comprises forming a hollow mould for moulding at least a portion of the bit body, packing at least part of the mould with powdered matrix material, and infiltrating the material with a metal alloy in a furnace to form a matrix. Before the mould is packed with the powdered material, formers are positioned on the interior surface of the mould to project into the interior of the mould space and form sockets to receive nozzles, or studs on which the cutting elements are mounted. According to the invention, the formers are formed from material, such as austenitic stainless steel, having a coefficient of thermal expansion not less than that of the matrix material.

Abstract: A sintered, metal infiltrated article and a method for preparing same is disclosed. The method permits mass production by injection molding, of metal infiltrated sintered articles of complex shape without excessive machining of the final product. The articles so produced have desirable physical properties such as abrasion resistance, high hardness, and high resistance to erosion at extreme temperatures encountered in use.

Abstract: Low-density composites are produced consisting chiefly of boron carbide and aluminum, or aluminum alloy, and minor amounts of ceramic material. The method allows control of the rate of reaction between boron carbide and metal so that the final components of the composite, and hence the mechanical properties, are controlled. The invention includes modification of the carbon content of the boron carbide composition, dispersion of boron carbide and formation of a compact, infiltration of the compact by aluminum or aluminum alloy, and heat treatments. The invention produces low-density boron carbide-aluminum composites with a homogeneous microstructure possessing desired mechanical properties.

Abstract: A porous, sintered powdered metal article having excellent corrosion resistance is provided. A porous metal such as prepared from a sintered iron powder and suitable for further treatment is phosphatized with a solvent phosphatizing composition. The phosphatized metal is then coated with a chromium-containing coating composition. The thus treated powdered metal part may be further topcoated and, in either case, exhibits outstanding corrosion resistance.

Abstract: A novel contact electrode material for vacuum interrupters is disclosed, by which the chopping current value inherent in contact material can be reduced so that it is possible to stably interrupt small lagging current due to inductive loads without generating surge voltages. The material is equivalent or superior to the conventional Cu-0.5Bi material in large current interrupting capability and dielectric strength. The material consists essentially of copper, chromium, iron or molybdenum and chromium carbide or molybdenum carbide. The metallographical microstructure is such that copper is infiltrated into a porous matrix formed by mutually bonding chromium powder, iron or molybdenum powder and metal carbide powder in diffusion state.

Abstract: A material which is intended for use in sliding surface bearings comprises a metallic backing, a porous metallic substrate layer applied to said backing, and a PTFE-filler mixture, which completely fills the pores of the substrate layer and constitutes an antifriction layer. The bond strength between the antifriction layer and the substrate layer is improved by coating that surface of the substrate layer which faces the antifriction layer with a primer.

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.

Abstract: Fabrication of a high precision mirror using a discontinuous metal matrix mposite is described. A metal matrix composite (MMC) is obtained by using one of the three methods described herein or any other method. The MMC material so obtained is machined to form a mirror substrate which is then coated and the coating so obtained is converted into the mirror surface. The mirror so obtained has better characteristics over the conventional high precision beryllium mirrors used for this purpose and is fabricated out of a nontoxic material which is cheaper and more easily available than the beryllium metal.

Abstract: An article is disclosed comprising particles of a silicon nitride based material and a lubricating material, the lubricating material occupying interconnected spaces within the article, the spaces being at least about 3% by volume of the article.

Abstract: A novel target material for use in the sputter formation of a metal silicide film in electrode wiring in a semiconductor device, and a process for producing such target material are disclosed.The process for producing the target material is characterized by first impregnating molten silicon into a calcined body containing at least one silicide forming metal component and a silicon component and then forming a sintered body with a reduced oxygen content containing both a metal silicide and silicon.The target material prepared in accordance with the invention is extremely low not only in oxygen content but also in the concentrations of other impurities and has high deflective strength as compared with the conventional sintered target.The film formed by sputtering the target of the invention has appreciably reduced impurity levels and hence, very low electric resistivities. The target of the invention enables sputtering to be performed 5 times as fast as in the case using the conventional sintered target.

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

Abstract: A hollow charge, or plate charge, lining, and a projectile charge coating, made from a composite material of tungsten and copper. Indicated are material proportions, grain sizes, and manufacturing methods.

Abstract: A copper infiltrated ferrous powder metal part infiltrated with copper or a copper alloy characterized as having after infiltration a residual uninfiltrated porosity of less than about 7 volume percent and a maximum pore size of the residual uninfiltrated porosity of less than about 125 micrometers, said porosity and pore size values being taken from a worst field of view in a functionally critical area of said metal part.

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.

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: Disclosed is a method for preparing a sintered body containing cubic boron nitride which comprise the steps ofcontacting a starting material containing boron nitride and/or a starting material containing at least one selected from the group consisting of metals of groups IVa, Va and VIa of the periodic table, silicon, aluminum, iron group metals and compounds of the aforesaid metals with at least one selected from the group consisting of borazine, a borazine derivative and a compound composed of boron, nitrogen and hydrogen as will release hydrogen by a thermal decomposition under pressure to form boron nitride; andsintering the material under conditions of a predetermined pressure and temperature under which cubic boron nitride is kept stable. Also disclosed is a method for preparing cubic boron nitride which comprises, in addition to the above steps, recovering cubic boron nitride from the obtained sintered body by a chemical and/or physical manner.

Abstract: An article comprising a first portion which is formed porously by sintering of an alloy or cermet material and a second portion which is formed of a metal and intimately bonds to the first portion. For example, the article is a rocker arm for an automotive internal combustion engine, in which first portion is the wear-resistant tip portion and the second portion the body portion. The second portion is formed by molten metal forging, with the sintered first portion set in the mould as an insert, such that the molten metal under pressure is forced to infiltrate into the pores of the sintered first portion at least in a region contiguous to the interface between the first and second portions. This article features very high strength of the bond at the interface between the first and second portions.

Abstract: A canless method for hot working a nickel-base gas atomized alloy powder. The powder is blended with nickel powder, consolidated and sintered to a sufficient green strength. The surface of the resultant form is sealed to create an oxygen impervious layer so as to prevent oxidation therein. The sealed surface, in a sense, acts as a can. The form is then reheated and hot worked.

Abstract: A method of producing rocket combustors wherein in forming an outer cylin by a powder metallurgical method on the outer side of a cylinder provided on its outer periphery with a cooling wall of channel construction having a plurality of grooves (14), an Ni electroforming layer is formed on the outer side of the outer cylinder, and also a method of producing rocket combustors wherein an outer cylinder is of multilayer construction having two or more layers.

Abstract: A precision molded article, such as a die cavity, is made by combining granules of a first metal or alloy and a second metal or alloy, the second metal or alloy having a homogeneous appearance at some temperature below its melting point, and a higher Rockwell Hardness than the first metal or alloy, mixing the granules with a heat fugitive organic binder, molding the granule-binder mixture into a green molded preform, thermally degrading and removing essentially all the binder to form a skeletal preform, and infiltrating the preform with a third metal or alloy which will wet the second metal or alloy and has a lower Rockwell Hardness than the second metal or alloy, thereby forming a molded article having granules of first metal or alloy the majority of which are fully enveloped within a single skeleton of the second metal or alloy, the skeleton of second metal or alloy being surrounded by layers or matrices of softer metals.

Abstract: A valve seat for ball valves comprises a ring-shaped or annular body fabricated of sintered metal particles having interparticulate spaces which are substantially completely filled with graphite. The seat is fabricated by pumping a dispersion of colloidal graphite in a liquid carrier through the matrix of a preformed ring-shaped sintered metal body, thereafter heating the body to drive off any portion of the liquid carrier which remains in the interparticulate spaces of the body, and then coining the body to collapse any voids which remain in the body and to mechanically bind into the body the graphite which has been trapped in said interparticulate spaces during the pumping step.

Abstract: A sintered alloy for a valve seat comprising, in weight percent, 0.5 to 1.7% C, 0.5 to 2.5% Ni, 3.0 to 8.0% Cr, 0.1 to 0.9% Mo, 1.0 to 3.8% W and 4.5 to 8.5% Co, the balance being substantially Fe provided by a base atomized powder; said alloy containing 8 to 14% by volume of 250 mesh or less C-Cr-W-Co-Fe and Fe-Mo hard grains and 6 to 13% by volume of cells, with the continuous cells being infiltrated by a copper alloy.

Abstract: In the method according to the invention, Cr powder is poured into a degased mold, which can be made of graphite. On this Cr powder a piece of low-oxygen copper is placed. Subsequently, the mold is closed with a porous cover, which can also be made of graphite. Then the mold is degased in a high-vacuum furnace at room temperature until a pressure of better than 10.sup.-4 mb is reached. Thereafter, the furnace temperature is increased to as high as possible a temperature below the melting point of copper. This furnace temperature is maintained constant until an internal pressure in the furnace of better than 10.sup.-4 mb is reached. Subsequently, without intermediate cooling, the furnace temperature is further increased slowly to a final value of 100 degrees K. to 200 degrees K. above the melting temperature of the copper. This temperature is then maintained until the porosity contained in the Cr powder is completely filled up by the liquid copper.

Abstract: A precision molded article, such as a die cavity, is made by combining iron powder granules and optional manganese granules with a heat fugutive organic binder, molding the granule-binder mixture into a green molded preform, thermally degrading and removing essentially all the binder to form a skeletal preform, and infiltrating the preform with an infiltrant which has a lower melting point than the iron powder granules and which optionally contains manganese, with the proviso that either the above decribed manganese granules are employed or manganese-containing infiltrant is employed, thereby forming a molded article having a skeleton of ferroalloy granules having a martensitic or perlitic core and an outer layer of austenitic manganese steel, the skeleton being surrounded by infiltrant.

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

Abstract: The shrinkage normally encountered when molding a mixture of spherical cobalt-containing particles and thermoplastic binder, heating the resulting molded article to degrade the binder and form a porous preform, and infiltrating the same is counteracted by adding finely divided elemental iron or elemental nickel to the spherical cobalt-containing particles. In addition to improving dimensional control, the elemental powder addition increases impact strength while maintaining hardness.

Abstract: Article produced in a mould for a plastics moulding tool having a mould surface defining the contours of the article, with the article comprising a body formed from a composition comprising a sinterable material having a sintering temperature which material, before sintering, is shapable into a desired shape and which during sintering forms a porous body having pores, the sinterable material being at least partially sintered in the mould, and also comprising a matrix having a lower melting point than the sintering temperature of the sinterable material, with the matrix comprising a matrix metal which is infiltrated in the porous body to substantially fill the pores.

Abstract: A method of preparing electrical contacts and electrical contact materials comprises the steps of blending a conductive metallic component, such as silver, with nickel and zirconium diboride which is substantially completely free of oxides, pressing the powder mixture to form a pre-sintered compact, and thereafter liquid phase sintering the compact to a densified body.The zirconium diboride is mixed with about 2 weight percent of a reducing agent, preferably mixed carbon and boron powders, and heated to remove oxides from the surface of the zirconium diboride powder particles prior to the steps of pressing and sintering.

Abstract: The invention relates to a method for manufacturing tubes by sintering and infiltration, the characteristic features of the invention being that the tube wall is formed from a metal powder on a mandrel and is sintered and that the tube wall, during one sintering stage, is sealed by infiltration by means of an infiltration material which solidifies in situ when the temperature is lowered after sintering and which is capable, when in the liquid state, of wetting the metal powder particles, the molding of the tube from the metal powder being preferably carried out by a wet or dry pressing process or by extrusion of the metal powder.

Abstract: A method for producing compact of diamond particles, comprising: providing a mass of diamond particles and a metallic material capable of dissolving carbon, as infiltrant, with a substantially identical cross section, placing said diamond and infiltrant metal close to but separated with each other with an intervening layer of high melting metal, as barrier, which has a cross section of 85 to 97% relative to that of the diamond and infiltrant metal, and subjecting the whole to an elevated pressure and temperature condition within the diamond stability region of carbon phase diagram, thus allowing a regulated amount of fused infiltrant metal to flow in among the mass of diamond to join adjacent particles with each other, and recovering a compact of thus joined diamond particles.

Abstract: A method of the preparation of an improved high-density sintered alloy composed mainly or iron and up to 50 wt. % of copper, in which boron is added in an amount of no less than 0.03% to suppress or limit the copper growth phenomenon during sintering. The alloys prepared by the present method undergo less dimensional changes during sintering and are thus of a very high density as compared with the conventional alloys of the same type.

Abstract: A molded, non-refractory metal article is made by molding in a flexible mold a plastic mixture of non-refractory, spherical metal powders and a heat-fugitive binder comprising thermoplastic material to form a green article of predetermined shape and dimensions, heating the green article to remove said binder and consolidate the non-refractory spherical powders in the form of a porous, monolithic skeleton of necked particles of non-refractory metal, infiltrating the skeleton with a molten metal having a melting point that is at least 25.degree. C. less than the melting point of the lowest melting of said spherical, non-refractory metal particles, and cooling the infiltrated skeleton thereby forming a homogeneous, void-free, non-refractory metal article of two intermeshed metal matrices.

Abstract: A method is disclosed for making wear resistant, ferrous based parts (10) by molding a uniform mixture of ferrous based powder and binder material into a compacted shape, heating the compacted shape to remove the binder and to partially sinter the mixture to a strength of 1000-8000 psi, while maintaining a porosity of 20-40% at least along the outer region of the part, depositing a fluid suspension of wear resistant particles onto a surface zone of the shape, and heating the coated shape to bond the particles to the surface and fully sinter the part.

Abstract: The invention provides a novel method for firmly bonding a porous body, e a sintered body prepared by the powder metallurgical techniques with a metal powder, and a fusion-made body, e.g. an iron casting body, hitherto undertaken by the method of pressure welding or diffusion bonding. The inventive method utilizes the principle of infiltration and an infiltrater material is placed at the contacting portion between the porous body and the fusion-made body and heated at a temperature to exceed the melting point of the infiltrater material in vacuum so that the molten infiltrater material is infiltrated into the porous body leading to strong bonding upon solidification to have the porous body and the fusion-made body integrally bonded together.

Abstract: Sintered metal articles especially sealing rings of less than 25 mm diameter are formed by plating sintered metal skeletons with a metal of lower melting point than the metal of the skeletons, for example, copper. The plated skeletons are then heated, preferably in a stack, to melt the plated metal, which infiltrates the skeletons. The articles so produced are stronger than and have greater elasticity than the skeletons themselves due to the presence of the plated metal in the skeletons.