Abstract: Pressure assisted sintering achieves full densification in short sinter times with low grain growth. This result is enabled by a stage of sintering to a condition of closed porosity (14) followed by a pressure assisted sinter (PAS) stage (16) carried out at a temperature close to, but just below, sinter temperature. Advantageously a small melt formation is induced by a brief temperature spiking (18) during the PAS stage to enable collapse of voids.

Abstract: A hot isostatic pressing system including a hot isostatic pressing station having a high pressure container constituted by a vertical pressure-resistant cylinder closed at the top end thereof and a lower lid detachably fitted to the bottom of the pressure resistant cylinder and a treating chamber internally provided with a heater and enclosed by a heat insulating wall, and a mechanism for adjusting an atmospheric gas pressure and temperature of the pressing station into a condition suitable for the hot isostatic pressing of a work item accommodated in the treating chamber; a plurality of auxiliary stations each provided with an opening for receiving from beneath thereof the heat insulating wall of the treating chamber accommodating the internal heater and a work item, a support structure for supporting the heat insulating wall, and a mechanism for cooling the work item and internal heater in an inert gas atmosphere; a carriage for transferring the lower lid and work item or the lower lid, work item, heat insu

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: 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 dual alloy turbine wheel manufacture of a cast integral blade ring pressure-sealed to a wrought alloy hub and thereafter bonded thereto by hot isostatic pressing.

Abstract: A sintered stainless steel and sintered seamless steel pipe exhibiting improved resistance to stress corrosion cracking are disclosed. The metallurgical structure comprises a matrix phase and a dispersing phase, which are different from each other in their metallurgical structures, the matrix phase comprising a substantially single ferritic structure, and the dispersing phase comprising a structure selected from the group consisting of an austenitic structure, an austenitic+ferritic dual phase structure, an austenitic+martensitic dual phase structure, and an austenitic+ferritic+martensitic triple phase structure. The sintered seamless stainless steel pipes are useful as heat exchanging tubes and piping to which sea water or industrial water is fed.

Abstract: A method is provided for preparing computer disk substrates having low surface amplitude which comprises: (a) forming a liquid suspension containing aluminum powder, an aluminum alloying element and a borate composition by initially admixing the borate composition with a volatile liquid medium to obtain a borate solution and thereafter admixing the aluminum powder and aluminum alloying element with the borate solution to produce the liquid suspension; (b) heating the liquid suspension to remove the liquid medium and to obtain a dry aluminum powder composition; (c) isostatically pressurizing the dry aluminum powder composition and roller compacting the same into sheet form; (d) heating and sintering the sheet form in a non-oxidizing atmosphere; and (e) cutting and compressing the sintered sheet into computer disk substrate configuration.

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: A method of making powder-metallurgical articles, in which powder of metal and/or metal alloys is filled into a thin-walled casing, whereupon the casing is closed and subjected to cold-isostatic pressure. Thereby the powder within the casing is compacted to form a strong or, respectively, dimensionally stable article. When the casing wall includes a joining weld seam, said casing wall is provided with an elastically expandable layer in the close vicinity of the weld seam in order to prevent formation of a fold, preferably in such a way that an approximately uniform prestress is applied to the wall surface.

Abstract: An electrically conducting cermet for use in a closure assembly in a high pressure sodium discharge lamp which cermet comprises a sintered compact of refractory oxide granules and a conducting network extending throughout the cermet wherein said network is provided by a layer of niobium and, optionally, at least one other specified metal. The cermet is, because of the niobium content of the metallic network, permeable to hydrogen and lamps incorporating this cermet can therefore be stabilized in acceptable times.

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: This invention relates to a process for sintering aluminum alloy powders under pressure.It consists in placing the powder in a capsule, in coating the capsule with an easily melted, stable vitreous material with a viscosity between 10.sup.2 and 10.sup.5 poises at the sintering temperature and in pressing it in a unidirectional press.It applies, in powder metallurgy, to the obtaining of castings that exhibit homogeneous mechanical properties, these castings being able to be roughcasts or finished castings.

Abstract: Sponge titanium powder is compacted, advantageously by roll compaction to a density in the range of about 60% to 80% of the density of solid titanium metal, thereafter heat treated in vacuum at about 500.degree. C. to 750.degree. C., cooled in vacuum to 300.degree. C. and quenched to 100.degree. C. to provide a substrate for electrodes useful in electrolytic processes.

Abstract: The invention is refractory, electrically conductive, mixed materials based on hexagonal boron nitride and at least one electrically conductive component such as titanium boride and zirconium boride, and having a density of at least about 95% of the theoretical density and nondirection-dependent properties, which have been manufactured from powder mixtures that are practically free of oxygen and metal and comprisefrom about 10 to 60% by weight of boron nitride,from about 0 to 60% by weight of aluminum nitride and/or silicon nitride, andfrom about 30 to 70% by weight of an electrically conductive component,without the concomitant use of sintering aids by means of isostatic hot pressing in a vacuum-tight casing at temperatures of from about 1400.degree. to 1700.degree. C. and under a pressure of from about 100 to 300 MPa. The powder mixtures are pre-densified to form green bodies in block form and are then introduced into casings or coated with a material forming a vacuum-tight casing.

Abstract: The disclosure relates to a method of manufacturing a turbine wheel using an elastomeric mold for the acceptance of powdered metal. The powdered metal is cold isostatically pressed and thereafter heated to effect metallurgical bonding thereof.

Abstract: A tubular composite element of metal, particularly steel, whereby at least the two opposite ends of the tubular composite element consist of different materials, for example carbon steel and stainless steel, and a process and a pressing for simultaneously producing two or more of such composite elements, at least two powders each consisting of one of the different materials, which have been produced by atomizing melts of the materials in question, are introduced alternately and separately from one another into three or more sections each extending over a predetermined axial length of a metallic hollow cylindrical casing and are condensed by vibration and/or ultrasound to around 60 to 70% of the theoretical density and by cold isostatic pressing of the closed casing under a pressure of at least about 3000 bars to at least 80% of the theoretical density and the pressing thus obtained is heated, subsequently hot-extruded to form a tube and the tube thus formed is divided up into the two or more composite element

Abstract: A process for making a workpiece suitable for being hot worked to produce a wrought metal poduct is described. Aluminum alloy powder is cold compacted and then heated in an inert environment to provide a sinter-sealed shape. The resultant workpiece may then be subjected to conventional processing to produce the desired wrought product.

Abstract: Disclosed is a method of making a pellet from a powder by placing the powder in a heat-shrinkable container, sealing the container and isostatically pressing the container at a temperature which causes it to shrink, followed by decomposition of the container and sintering of the powder. In preparing nuclear fuel pellets, a free-flowing fissile powder is mixed with a free-flowing fertile powder and the mixture is placed in the heat-shrinkable container. The container is sealed, heated and isostatically pressed, then decomposed and the powder is sintered.

Abstract: A method of manufacturing metal pieces by casting and sintering of a metal alloy powder of the type that includes two phases, a conforming phase during which a load of powder is heated inside a formal casting to execute a rigid preform which is porous and a compacting and sintering phase during which the preform is heated under isostatic pressure. The method and resulting metal piece is characterized in that the conforming phase is conducted so that the preform has open pores and the isostatic pressure is applied by way of an envelope that distorts and is airtight. The method is applied advantageously in the execution of complex formal pieces made of superalloys or made of a titanium alloy.

Abstract: A particulate mass to be sintered is imbedded in a mold which comprises a porous mass of particulate refractory material enclosed within a flexible membrane. Six press units are provided for applying compressive pressures externally to the mold, together or in sequence, whereby to subject the sinterable mass to pressures in the respective directions, under the control of a preprogrammed control unit which receives clock pulses from a source and stimulates the respective press units. A flexible heating coil imbedded in the mold is supplied with alternating current from a source to inductively heat up the sinterable mass and the adjacent mold material, to enable sintering to occur. The sinterable mass may have been precompacted into a self-supporting so-called "green compact", or it may be supported in a self-supporting shell carried within and forming part of the mold. The mold preferably comprises three layers having characteristics chosen so as to assist in heating up the sinterable mass uniformly.

Abstract: This invention relates to a capsule for pressings pressed by isostatic pressure and to these pressings used for extruding metallic objects, particularly tubes, of stainless steel, the outer and inner wall of the capsule consisting of thin-walled sheet metal, and at least the outer wall having substantially the same strength properties in the axial direction over its circumference and particularly consisting of a spiral-welded tube and being preferrably provided with a bulge which is directed outwardly against the shrinkage occurring during isostatic pressing, and at least on the front end of the capsule an insert being provided, which consists of one or more pieces of a ductile solid material or a ductile material pressed from powder. The invention further relates to a process for the production of such capsules and pressings and to a process for extruding tubes and to the tubes obtained according to this process.

Abstract: A process for the after-treatment of powder-metallurgically produced extruded tubes of stainless steel or highly alloyed nickel steels, pressings initially being produced by introducing into a capsule of thin sheet steel a powder consisting predominantly of spherical particles which have been produced from the required starting material by sputtering and, after the capsule has been closed, the density of the powder is increased to at least about 80% to about 93% of the theoretical density by cold isostatic pressing and the pressings obtained are then extruded into tubes at temperatures around 1200.degree. C.

Abstract: Process for manufacturing a forged article in which a preform is generated by filling a semi-rigid liner with powdered metal, providing the liner with a sealing element, and isostactically compressing the liner and its contents. The liner is then removed from the green preform, the preform is sintered, and the resulting sintered preform is forged.