Abstract: A method for manufacturing a sintered body is provided, comprising the steps of dispersing powdery silicon nitride and a sintering assistant into a first dispersion medium composed mainly of substance capable of being extracted by supercritical fluid to form a first slurry and casting the first slurry to form a compact; dispersing powdery material into a second medium composed mainly of substance capable of being extracted by the supercritical fluid to form a second slurry and coating the second slurry on the surface of the compact to form a film layer; dipping the compact covered with the film layer in the supercritical fluid to extract the first dispersion medium and the second dispersion medium, respectively from the compact and the film layer; heating the compact from which the first and second dispersion mediums have been removed to form the film layer into a film layer impermeable to gas; and sintering the compact covered with the film layer impermeable.

Abstract: A method of producing a sintered, very high density dental prosthesis from a suspension containing noble-metal powder mixtures with bi or multimodal particle-size distribution and a mixing liquid. The suspension is molded to the desired shape and then the dental prosthesis is dried. The molded dental prosthesis is then heat-treated 5 to 45 minutes between 100.degree. and 400.degree. C., then heated with an average temperature elevation of 50 to 300 K/min. to 800.degree. C. and then brought to the sintering temperature T at 20 to 200 K/min. The sintering temperature T is between T.sub.solidus - 200) and T.sub.solidus - 70), whereby T.sub.solidus is the solidus temperature of the sintered alloy. The cooling-down of the dental prosthesis takes place under a vacuum or a protective gas.

Abstract: Method for manufacturing a sintered body with high density comprises: turning first powder into a first slurry by dispersing the first powder in a first dispersion medium composed mainly of substances capable of being extracted by supercritical fluid and forming a compact which contains the first dispersion medium, by casting the first slurry; turning second powder into a second slurry by dispersing the second powder in a second dispersion medium composed mainly of substances capable of being extracted by supercritical fluid, and forming a film layer by coating the surface of the compact with the second slurry; extracting and removing the substances contained in the compact and the substances contained in the film layer by means of the supercritical fluid; turning the film layer on the surface of the compact into an impermeable film layer to gas by heating the compact, from which the substances have been extracted and removed; and applying a hot isostatic pressing process to the compact, the film layer on the

Abstract: A new method for making a heat pipe wick and arteries includes drilling. Radial holes around the circumference of the heat pipe container at its ends and stringing monofilament polymer lines inside the container between corresponding holes. The container is rotated at a slow rate while a slurry of nickel powder mixed into a viscous binder of water, Polyox and Methocel is injected inside the container to cover the inside surface of the container and the lines. The rotational rate of the container is then increased to force the slurry to level out to an uniform depth set by the thickness of sleeves attached at each end of the container. Forced air is blown through the inside of the rotating pipe to dry the slurry and form a green wick. After stopping rotation of the pipe, it is then heated inside a sintering oven in a reducing atmosphere to disintegrate the binder and polymer lines and to leave a sintered metal wick having hollow longitudinal arteries.

Abstract: A slip or casting composition useful in molding or sheet casting comprising:a mixture of inorganic particulate material, an organic solvent and a dispersant for said particulate material having the structure set forth below: ##STR1## where R.sub.1, R.sub.2, R.sub.3 are linear or branched hydrocarbon chains, where no more than one of the R Groups is CH.sub.3 and the remaining R groups are each at least 6 to 30 carbon atoms long;Y is selected from the group consisting of (CH.sub.2).sub.n where n=1 to 10 and ##STR2## where m=1 to 5; and X is selected from the group consisting of COO-, SO.sub.3 -, PO.sub.3 -.

Abstract: A method is disclosed for producing metal carbide grade powders, which comprises forming a wax mixture consisting essentially of in percent by weight about 10 to 60 of an organic compound additive which is a solid at room temperature and contains a C.dbd.

Abstract: A method of producing dispersion hardened metal alloys which incorporate highly reactive metals or their alloys whose oxides are not adapted to be easily reduced. According to the method, the highly reactive metals of their alloys are added as powder particles to a solution of a salt of a reducible metal which is to form a metallic matrix in which the reactive metals or their alloys are to be integrated, after which the solution is atomized to form particles from which the solvent is removed to yield the final product of the metal matrix with the highly reactive metals or their alloys integrated therein as a second phase.

Abstract: A method is disclosed for producing metal carbide grade powders, which comprises dry milling metal carbide powder which can be tungsten carbide, titanium carbide, tantalum carbide, niobium carbide, vanadium carbide, chromium carbide, and combinations thereof to increase the surface area of the powder particles to result in essetially all of the powders being converted to single crystals, forming a mixture of the resulting dry milled carbide powder, a binder metal which can be cobalt, nickel, and combinations thereof, and a wax, while heating the carbide powder, the binder metal and the wax to a temperature above the melting point of the wax and maintaining the temperature to result in a uniform distribution of the wax on the carbide and binder metal particles, forming a slurry of the mixture and water, attritor milling the slurry at a temperature below the melting point of the wax, and removing the water from the resulting attritor milled mixture and aggiomerating the mixture to produce the metal carbide grad

Abstract: A new method for making a sintered metal heat pipe wick is practiced by mixing nickel powder into a slurry with a viscous binder comprising water. Polyox and Methocel. The mixture is then injected inside a rotating stainless steel cylindrical heat pipe container, or pipe, to completely coat the inside surface of the pipe. The rotational rate of the pipe is then increased to force the slurry to level out to a uniform depth set by the thickness of sleeves attached at each end of the pipe. Forced air is then blown through the inside of the rotating pipe to dry the slurry and form a green wick. After stopping rotation of the pipe, it is then heated inside a sintering oven in a reducing atmosphere to disintegrate the binder and leave a sintered metal final composition of the wick. Thus produced wicks prevent "hot spots" because they have a more uniform thickness and are attached more evenly and securely than prior art heat pipe wicks to the inside walls of the heat pipe container.

Abstract: In a method for forming a cast article by slip casting through casting of a slip of powders of ceramics, etc. as disporsed in a solvent such as water, etc. into a solvent-absorbable, porous casting mold of gypsum, etc., the casting mold as made is heated to considerably lower the strength of the casting mold in a shape-maintainable range, the slip is cast into the cavity of the casting mold and after solidification of the slip into a green body the casting mold is removed to obtain a defect-free green body. The casting mold can be removed with much ease.

Abstract: In a casting method comprising casting a slip containing water or an organic solvent as the medium into a mold and removing the mold after solidification of the slip, use of a mold formed with an organic binder soluble in the medium of the slip allows the slip to quickly solidify and afford a green body due to absorption of the medium in the slip by the mold. In this case, the mold softens with loss of the binding power thereof simultaneously with the absorption of the medium. Therefore, no cracks appear at all in the green body, and removal of the mold is very easy.

Abstract: A process for producing flat products from gas atomised particulate material comprises the steps of forming a relatively smooth castable slurry comprising a suspension of such particulate material in a solution of film-forming binder material, depositing a coating of the slurry onto a substrate or support surface and drying the coating to form a flexible flat product. The dried flat product may be bonded onto the substrate or support surface by the drying process or, alternatively, may be removed therefrom and roll-bonded to a suitable substrate for subsequent compaction and sintering.

Abstract: A process is disclosed for producing a sheet of tungsten heavy alloy which involves uniformly blending elemental powder components of the alloy by forming a slurry of the powder components in a liquid medium, removing the liquid medium from the powders and forming a planar cake of the powders, drying the cake, sintering the cake to a density equal to or greater than about 90% of the theoretical density of the alloy to form the sheet.

Abstract: A method for making seamless, porous metal articles comprising:(a) rotating a mold containing a stabilized suspension of a metal particulate at a rate and for a time such that the particulate is separated from the suspension and distributed on the interior wall of the mold, thereby forming a structure conforming to the interior wall of the mold, the rate of rotation being sufficiently high that at least about 100 Gs of centrifugal acceleration is achieved at the interior wall of the structure,(b) drying the formed structure to provide a structure having green or unsintered strength, and(c) sintering the dried structure to remove volatile material and fuse the individual particles of the particulate to each other to form the seamless, porous metal article.Metal articles in accordance with the invention have substantially uniform diameters, thicknesses and pore structures, have Bubble Point ratios of 1.5 or less, and find particular use as filters.

Abstract: A process is disclosed for producing a sheet of tungsten heavy alloy which involves forming a solution of chemical compounds containing the metal values of the alloy in the correct proportion as in the alloy, crystallizing the compounds from solution and drying the compounds, reducing the compounds to their respective metals wherein each particle is an admixture of the allow components; forming a slurry of the metals and a liquid medium, removing the liquid medium from the metals and forming a planar cake of the metals, drying the cake, and sintering the cake to a density equal to or greater than about 90% of the theoretical density of the alloy to form the sheet.

Abstract: A molded composite material comprising a plural number of constituents is provided in which at least two of the constituents are distributed with a relative existing ratio varying at least in one direction in the composite material. A process for producing the composite material is also provided.

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 sintered metal part which has a pressed and sintered core; the part is coated with a sintered metal surface layer; the layer has a property different from that of the metal part; the interior regions of the core are free of the metal constituting the coating; and process for making the parts.

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: A process for producing flat products from particulate material comprises the steps of forming relatively smooth, castable slurry comprising a suspension of particulate material in an aqueous solution, a film-forming binder material and a dispersion of a particulate synthetic resin in an aqueous solution, depositing a coating of this slurry onto a support surface and, heating the deposited coating to a temperature at which a component of the synthetic resin volatilises. The coating may be removed from the support surface as a flat product either before or after heating to volatilize a component of the synthetic resin.

Abstract: A method for utilizing a powder metallurgy ("P/M") slurry by employing water atomized metallic powders and subsequently reducing the oxide levels therein to acceptable levels. The slurry comprises a carbon containing binder. The slurry is consolidated and sintered under controlled conditions to reduce the oxide levels.

Abstract: In a forming method and a mold wherein a slip is cast into the mold and wherein the mold is removed after hardening of the slip, the mold is patterned by the use of a water-soluble binder. The mold absorbs a water content in the slip to soften and to become easy of removal, while the slip has the water content absorbed to harden promptly. Therefore, the forming method and the mold are especially suited to produce a cast article of complicated shape.

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 method for consolidating powder utilizing slurry extrusion or rolling techniques. A metallic powder, binder and boron containing activator are mixed together to form a slurry. The slurry is introduced into an active forming apparatus whereupon it is formed into an object of predetermined shape and sintered.

Abstract: A process for producing strip from particulate metallic material in which a slurry comprising a suspension of particulate metallic material in a solution of water containing a film forming binder material is deposited as a coating onto a support surface and is heated to gel the binder and to dry the slurry coating, the dried strip subsequently being removed from the support surface and rolled to effect compaction thereof. The ratio of particulate metallic material to water content of the slurry lies within the range 3.4:1 and 4.2:1 to ensure good flowability of the slurry coating and to produce the required flat profile in the rolled strip.

Abstract: Hard, tough, lightweight boron-carbide-reactive metal composites, particularly boron-carbide-aluminum composites, are produced. These composites have compositions with a plurality of phases. A method is provided, including the steps of wetting and reacting the starting materials, by which the microstructures in the resulting composites can be controllably selected. Starting compositions, reaction temperatures, reaction times, and reaction atmospheres are parameters for controlling the process and resulting compositions. The ceramic phases are homogeneously distributed in the metal phases and adhesive forces at ceramic-metal interfaces are maximized. An initial consolidation step is used to achieve fully dense composites. Microstructures of boron-carbide-aluminum cermets have been produced with modulus of rupture exceeding 110 ksi and fracture toughness exceeding 12 ksi.sqroot.in. These composites and methods can be used to form a variety of structural elements.

Abstract: A metal powder sheet for use for forming a sintered layer on a metal substrate. The sheet includes powders of a metal which provides a required physical property such as wear-resistance and ultra-fine powders of a metal having a powder size finer than 1 micron. These powders are kneaded with an addition of an acryl resin as a binder. The ultra-fine powders make it possible to carry out the sintering process at a lower temperature.

Abstract: A process is disclosed for producing a composite in the form of a sheet which involves forming a slurry of a brazing alloy powder and a vehicle, applying the slurry as a pattern or as a layer to a structural substrate, removing the vehicle from the slurry, and melting the alloy uniformly into a homogeneous mass without melting the substrate, and thereafter cooling the same to solidify it into a self supporting sheet.

Abstract: A process for producing a flat product such as a coin includes the steps of forming a slurry comprising a suspension of particulate material in a film-forming cellulose derivative, depositing a quantity of this slurry onto a support surface, drying the slurry to form a self-supporting flat product, and removing the dried product from the support surface. The particulate material essentially comprises metallic particles and matter whose chemical composition and physical properties differ from those of the metallic particles such that the added matter is not or only partially taken into solution with the metallic particles on heat treatment of the product whereby the presence of the added matter can readily be detected following such heat treatment.

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: The method disclosed in this specification is one of reducing the green density of an article cast in a slip casting operation. The article is cast from a casting slip containing silicon metal particles, yttrium containing particles, and a small amount of a fluoride salt which is effective to suppress flocculation of the silicon metal particles by y.sup.+3 ions derived from the yttrium containing particles. The method is characterized by the following step. A small amount of compound which produces a cation which will partly flocculate the particles of silicon metal is added to the casting slip. The small amount of this compound is added so that when the casting slip is slip cast into a casting mold, the partly flocculated particles of silicon will interrupt an otherwise orderly packing of the particles of silicon and particles of yttrium. In this manner, the green density of the slip cast article is reduced and the article may be more easily nitrided.

Abstract: Honeycomb structures, such as those used in turbine engine abradable seals, are provided with a uniform density filling of a suitable abradable material. The abradable material is prepared as a tape preform using an organic binder. The preform is forced into the honeycomb using a rubber tool.

Abstract: Copper end terminations of excellent electrical and mechanical properties are provided on multielectrode ceramic capacitors by applying copper, glass frit metallizations to the ends of a ceramic capacitor and firing the applied metallization in an atmosphere of nitrogen which contains a controlled partial pressure of oxygen.

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: 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: Ceramic substrates are pinned using powdered metallurgy pins formed in situ on the substrate.

Abstract: A process for making capacitors using electrode compositions of finely divided particles of noble metals and certain inorganic metal oxides dispersed in an inert organic medium. Suitable inorganic metal oxides are MoO.sub.3, GeO.sub.2, Pb.sub.5 Ge.sub.3 O.sub.11, Nb.sub.2 O.sub.5, NiO, ZnO, SnO.sub.2, CdO, metal phosphates, metal fluorides, phosphate glasses, germanate glasses, fluoride glasses and mixtures and precursors thereof.

Abstract: A green body comprised of a mixture of nickel powder and lithium oxide is fired in air to produce a porous lithium nickel oxide structure useful as a cathode in a molten carbonate fuel cell.