Abstract: A process is proposed which serves to produce layer systems for gas sensors, the electrodes essentially being composed of a finely divided ceramic material and finely divided electron-conducting material. The process comprises adding stabilizer oxides to the electrode material in proportions above those necessary for full stabilization. As a result, a layer system having outstanding mechanical properties and high electrode load carrying capacity is obtained by a simple manufacturing process.

Abstract: Disclosed are heat resistant aluminum alloy powders and alloys including Ni, Si, either at least one of Fe and Zr or at least one of Zr and Ti. For instance, the alloy powders or alloys consist essentially of Ni in an amount of from 5.7 to 20% by weight, Si in an amount of from 0.2 to 25% by weight, at least one of Fe in an amount of from 0.6 to 8.0% by weight and Cu in an amount of from 0.6 to 5.0% by weight, and the balance of Al. The alloy powders or alloys are optimum for a matrix of heat and wear resistant aluminum alloy-based composite materials including at least one of nitride particles and boride particles in an amount of 0. 5 to 10% by weight with respect to the whole composite material taken as 100% by weight. The alloy powders, alloys and composite materials are satisfactory applicable to the component parts of the recent automobile engines which should produce a high output.

Abstract: A high temperature heat-treating jig characterized by forming a tungsten layer or a tungsten alloy layer on the surface of a heat-resistant base to avoid discoloration and color shading during the heat treatment at a high temperature.

Abstract: Metal carbides may be formed by mixing metal powder with a stoichiometric amount of graphite, compressing the same in a mould/die and then sintering. High temperatures (and maybe a bonding agent) are required to effect the final step and finished product. These disadvantages are overcome by exploiting dry high energy milling to bring the starting materials into a very finely divided and reactive state, with regions of metal, carbon and metal based solid solution ranging from 3 to 100 nanometers in diameter. As an alternative source of carbon, cationic organic surfactants may be used instead of graphite in the appropriate proportion. Compacting the milled mixture, followed by sintering at lower temperatures by a margin of at least 400.degree. C., will produce very strong dense carbides at low cost. The method may be extended to include metal based composites, which also includes cermets, by incorporating an appropriate excess of metal powder(s) in the starting materials.

Abstract: A method for producing an article including a refractory compound by infiltrating a preform with a liquid infiltrant and initiating a reaction between the preform and the liquid infiltrant to establish a reaction front which propagates in a direction opposite to the direction of flow of the liquid infiltrant is provided, as are articles prepared according to this method.

Abstract: A filter membrane and a process for making the filter membrane are provided. The filter membrane comprises a metal substrate having a filtering layer thereon comprising sintered ultra-fine particles of metal or ceramic compounds. The filtering layer preferably has an average pore size of from about 30 nanometers to about 200 nanometers. The filter membranes can withstand pressure drops of up to about 0.6 MPa and are useful for a variety of filtering applications.

Abstract: It is the object of the invention to reduce the propagation of noises, in particular shifting noises, in mechanical transmissions. The invention consists in the use of a sintered shaped part formed in an individualized configuration as a noise-damped component, and in particular a gearwheel for a transmission. In the novel configuration, an axially symmetrical sintered shaped part has individual, approximately annular zones of material, for example, an inner rim zone close to the axis and an outer rim zone remote from the axis, the inner and outer rim zones having a high strength and being largely free from voids and a central region being highly porous and comparatively ductile.

Abstract: A method and apparatus for fabricating three-dimensional objects according to the selective laser sintering process are disclosed. In order to reduce inconsistencies in structural and textural integrity, and in thermal effects that can cause distortion, methods for ensuring that overlapping laser scans are accomplished in a consistent manner relative to the thermal flow from the sintered locations are utilized. Methods are disclosed for achieving this by limiting the extent to which the laser scans object areas in the powder layers so that the time-to-return for adjacent overlapping scans is minimized; such minimization results in significantly less variation in the time-to-return overall.

Abstract: A surface hardened aluminum part having excellent heat resistance and abrasion resistance obtained by forming, on the surface of an aluminum base material, an alloy layer that has a uniform composition and uniform hardness, being free from cracks. An aluminum alloy powder made of aluminum and metals each of which forms an intermetallic compound of high hardness with aluminum is prepared. This aluminum alloy powder is supplied onto the aluminum base material and the aluminum or aluminum alloy contained in the aluminum base material is alloyed with the aluminum alloy powder using a high-density energy heat source to form an alloy layer. The alloy layer thus formed has an intermetallic compound of high hardness uniformly distributed throughout the layer so that the hardness of the alloy layer is uniform and cracking is unlikely to occur.

Abstract: A method of manufacturing a protective insert (1) on a metal part (2) in which a foil (3) that serves as a barrier for gases is fixed between the part (2) and the insert (1), the edges of a metal capsule (4) are fixed to the edges of the foil (3), the space (5) between the capsule (4) and the part (2) is filled with a metal or ceramic powder and the ends of the capsule (4) are closed, the part (2) together with the filled capsule (4) are inserted in an isostatic pressing oven under a controlled atmosphere, with the pressure and the temperature being selected so that the powder is pressed in situ. The part (2) is cooled and then the capsule is removed before giving the part (2) together with its insert (1) the desired final shape. The method is very simple and it enables reliable products to be obtained.

Abstract: A slurry compound prepared by a sintering powdery material and a binder is press-molded to obtain a contour for the final product applicable to a bone-implant such as hip prosthesis. The molded body is given a programmed movement of rotation and/or swinging to impart a centrifugal force to the sintering particles which direct toward the inner wall of the mold cavity. The final product obtained after sintering has a hollow interior having no communication to the outside. Imparting conditions of rotating/swinging movement may be changed or programmed in order to achieve a desired structure or constitution of the final product. By way of example, larger particles concentrate near the inner wall of the mold to provide a rough, porous surface of the body, whereas it has a dense core consisting mainly of sintered fine particles. A hip prosthesis having a ceramic-rich femoral head and a metal-rich stem may also be produced by so programming the movement imparting conditions.

Abstract: A method for manufacturing of a cemented carbide body for cutting tools, rock drilling tools or wear parts with complicated geometry characterized in that the body is sintered together from simpler pressed but unsintered parts to form a body with desired complex geometry.

Abstract: A method for brazing together two parts at least one of which comprises a titanium aluminide material is described wherein a metallic layer of foil or powder is inserted between the parts in laminar contact with respective confronting surfaces thereof to be joined, the metallic layer comprising a metal which forms with titanium a eutectic composition having a characteristic fusion temperature lower than the fusion temperature of the metal, and the metallic layer and confronting surfaces of the parts are heated to a temperature of about the characteristic fusion temperature of the eutectic composition.

Abstract: A coating film of a carbon allotrope is formed on a substrate by continuously supplying a fine carbon powder onto the substrate and simultaneously irradiating the fine carbon powder with a laser beam of a high output level thereby inducing sublimation of the fine carbon powder, and quenching the sublimated fine carbon powder to cause deposition thereof on the substrate.

Abstract: A process for making a component by depositing a first layer of a fluent porous material, such as a powder, in a confined region and then depositing a binder material to selected regions of the layer of powder material to produce a layer of bonded powder material at the selected regions. Such steps are repeated a selected number of times to produce successive layers of selected regions of bonded powder material so as to form the desired component. The unbonded powder material is then removed. In some cases the component may be further processed as, for example, by heating it to further strengthen the bonding thereof.

Abstract: A prepack well screen assembly has a resistance welded outer screen concentrically mounted in radially spaced relation on a perforated mandrel, thereby defining an annulus in which a sintered metal prepack sleeve is loaded. The longitudinal spacing distance between adjacent turns of the outer screen selectively exclude sand fines of a predetermined minimum size. The porosity of the sintered metal prepack sleeve is selected to pass sand fines in the size range of from about 20 microns to about 150 microns. The effective inlet flow area through the sintered metal prepack sleeve is substantially greater than the effective inlet flow area through the outer screen. The sintered metal prepack screen excludes sand fines from inflowing formation fluid during the initial production phase following a gravel pack operation, without limiting production of formation fluid.

Abstract: A porous intermediate compact is first prepared from metal particles, carbon and a temporary binder. The compact is then heated to remove the binder and then infiltrated with the vapor of a metal having a melting point lower than the compact.

Abstract: A process for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry.

Abstract: A process for making molded objects utilizes powder injection molding techniques. Powder is mixed with a binder and then cast into a compact. The compact is then subjected to a first debinding step in the presence of a wicking agent under gentle heating. In this first stage, at least 40% of the binder is removed. Additional binder is then removed in a subsequent higher temperature stage to produce a compact which is free of binder and free of cracks.

Abstract: A heat-resistant aluminum alloy sinter comprises 5 to 12% by weight of Cr, less than 10% by weight of at least one selected from the group consisting of Co, Ni, Mn, Zr, V, Ce, Fe, Ti, Mo, La, Nb, Y and Hf, and the balance of Al containing unavoidable impurities. A silicon carbide fiber is included for reinforcing the sinter in a fiber volume fraction range of 2 to 30%.

Abstract: A method for molding high temperature composites that transmits more uniform pressures to the surface of the composites. A compliant glass, glass-ceramic, or ceramic layer is caused to apply pressure to a composite precursor and heat is applied to the composite precursor to form a composite.

Abstract: Apparatus and methods for compressing a mass utilizing a plurality of interfitting anvils mounted for movement relative to one another along co-planar paths and include faces which, when the anvils are operatively moved relative to one another, exert compression on a mass positioned between the faces in at least two directions in a plane simultaneously. The faces of the apparatus can be so shaped that the cross section of the mass being compressed is urged toward a shape other than that of a regular polygon. Methods of the invention include the consolidation of a mass of compactable material enclosed within a hollow tube having deformable walls, the extraction of juice or oil from fruit or seeds and the internal fracturing of solids so as to swell materials such as solid rocket propellants.

Abstract: A light-weight yet sturdy ceramic article, is manufactured by initially forming at least one fugitive core including a main portion and at least one holding portion projecting from the main portion and then positioning the fugitive core in a mold cavity bounded by a multitude of bounding surfaces so that the holding portion holds the main portion at predetermined spacings from all of the bounding surfaces. This is followed by filling the mold cavity around the fugitive core with a dense slip constituted by ceramic or metal particles in mixture with a liquid medium to form a ceramic or metal preform embedding the fugitive core in its interior and freezing the ceramic or metal preform, then the fugitive core is dissolved and escapes from the interior of the frozen ceramic or metal preform and finally the ceramic preform is converted into the ceramic article.

Abstract: A moulded body having an inner support matrix is enveloped at least partially with a plastic envelope making up the mould. The support matrix is formed at least partially from metal wire pieces and/or metal chips, which are compression moulded and sintered.

Abstract: A composite tool with a higher bonding strength and higher heat resistance is provided comprising an insert of a hard material such as composite diamond or BN compacts and a support of a hard metal or alloy such as steel and cemented carbides, having a larger volume than the insert, the insert and support being bonded by friction welding through an interlayer of a high strength metal or alloy such as Co and Ni with a thickness of at most 1 mm.

Abstract: Near net shape metal articles are cast from powder feedstock using a focused high energy beam which melts successive layers of powder as it repetitively traces the shape of the article over a substrate without the necessity for refocusing. Powder is fed into a cavity in which the article is formed at a rate to maintain a depth which provides lateral support for, and therefore forms a mold for, a thick layer of powder which is melted by the energy beam to add each layer to the article. The high energy laser or electron beam has a power density sufficient to penetrate the melted layer of powder and melt the surface of the underlying substrate or layer just enough to provide a good metallurgical bond for the layer being added. A copper fixture which supports the substrate while the article is being formed, serves as a heat sink and forms the cavity which confines the powder to the vicinity of the article being formed.

Abstract: A method of joining two porous bodies of silicon carbide is disclosed. It entails utilizing an aqueous slip of a similar silicon carbide as was used to form the porous bodies, including the sintering aids, and a binder to initially join the porous bodies together. Then the composite structure is subjected to cold isostatic pressing to form a joint having good handling strength. Then the composite structure is subjected to pressureless sintering to form the final strong bond. Optionally, after the sintering the structure is subjected to hot isostatic pressing to further improve the joint and densify the structure. The result is a composite structure in which the joint is almost indistinguishable from the silicon carbide pieces which it joins.

Abstract: An improved process and an improved composite bearing material produced thereby comprising a hard metal backing strip having leaded-bronze bearing lining tenaciously bonded to at least one face surface thereof and wherein the bearing lining is characterized by having the lead constituent thereof substantially uniformly distributed throughout the lining matrix in the form of extremely fine-sized particles providing improved operating characteristics to the bearing materials fabricated therefrom.

Abstract: A titanium composite having a coil-shaped skeletal structure on the surface, comprising a titanium or titanium alloy substrate and one or more layers of a coil-shaped skeletal titanium or titanium alloy structure that is firmly attached to the surface of said substrate and a process for producing a titanium composite having a coil-shaped skeletal structure on a surface of a titanium or titanium alloy substrate, which comprises: providing a coating composition which is a mixture of a titanium or titanium alloy powder with a binder; applying said composition in such a manner that titanium or titanium alloy coils which are to form the coil-shaped skeletal structure are firmly attached to both themselves and to the titanium or titanium alloy substrate; the heating the assembly either in vacuo or in an inert atmosphere so that the titanium or titanium alloy powder in the applied coating composition is sintered to have the coil-shaped skeletal titanium or titanium alloy structure attached firmly onto the titanium o

Abstract: Disclosed is a method of making drills, endmills and other rotating-and-cutting tools comprising the steps of: extruding super-hard metal powder into a spiral rod; sintering the spiral rod; forming a-ferrous metal powder layer around the rear end of the spiral rod sinter; and heating and then cooling the ferrous metal powder layer in such a way that voids may be caused to appear in the ferrous metal powder layer, which is integrally connected to the spiral rod sinter to make up its shank. Thanks to the existence of the voids in the shank layer, any inner strain will be dissipated, assuring that crack-free products result.

Abstract: A tubular compact (14) obtained by compacting a powder is applied with one circumferential surface (16) at a minimum distance required for said application, from an abutment surface (15) corresponding to said one circumferential surface (16). The space between said one circumferential surface (16) and the abutment surface (15) is evacuated, such that the compact (14), while undergoing a certain deformation to bridge said space, is sucked against the abutment surface (15) so as to be firmly retained against it.

Abstract: A self-sustaining combustion synthesis process for producing hard, tough, lightweight B.sub.4 C/TiB.sub.2 composites is based on the thermodynamic dependence of adiabatic temperature and product composition on the stoichiometry of the B.sub.4 C and TiB.sub.2 reactants. For lightweight products the composition must be relatively rich in the B.sub.4 C component. B.sub.4 C-rich composites are obtained by varying the initial temperature of the reactants. The product is hard, porous material whose toughness can be enhanced by filling the pores with aluminum or other metal phases using a liquid metal infiltration process. The process can be extended to the formation of other composites having a low exothermic component.

Abstract: An improved method for encasing objects in metal is disclosed as are the novel encased objects so prepared. An object is wrapped with a sheet comprising sinterable particulate or powdered metal and an organic binder, and is the fired to volatilize the binder and to sinter the particulate metal into a unitary metal structure. In the preferred embodiment of this invention, the object to be encased is a green sinterable particulate object which undergoes sintering simultaneously with the particulate metal casing during the firing step.

Abstract: A method for producing porous bearing shells with a compacted surface for gas-static bearings from sintered hollow blanks includes heating a blank with an inside diameter smaller than a rated diameter of a bearing and slipping the blank in the heated state onto a mandrel having an outside diameter equal to the rated diameter of the bearing. Subsequently the blank is cooled to the operating temperature of the bearing. The blank is reheated and the blank is finally pulled off the mandrel.

Abstract: A process is described in which hollow spheres or hollow-sphere composites (moldings) having high-strength walls are produced. Additional layers are applied to metallized spherical lightweight particles having a core of foamed polymer. In order to increase the strength of the wall of the spherical particle and the strength of the molding, metallized lightweight spherical particles having a metal wall thickness of 5 to 20 microns are treated (coated) with a dispersion of particulate metal or metal oxide or particulate ceramic or refractory material, the lightweight spherical particles coated in a thickness from 15 to 500 microns are dried, the dried particles are heated to a temperature of about 400.degree. C. to effect a pyrolysis of the polymer core, and the particles are subsequently sintered at a temperature from 900.degree. to 1400.degree. C.

Abstract: The bonding of nickel, cobalt, copper or any number of metals to oxide ceramics is achieved whereby the substrate and associated metallurgy are co-sintered. The invention teaches the use of an intermediary oxide such as Al2O3, Cr2O3, TiO2 or ZrO2 which will adhere to the substrate and in the presence of firing ambients form a complex ternary oxide with the overlying metal thereby creating the desired bond. The eutectic can be created during the firing cycle without the undesired consequence of oxidizing the metal. The so-called intermediary oxides can be oxidized in situ, deposited as oxides, or introduced into either the ceramic composition or the metal paste.

Abstract: Disclosed herein is a metal-ceramic composite article which includes a metallic member made of a precipitation hardenable alloy and a ceramic member, wherein a projection of the ceramic member is fitted into a hole or a through hole formed in the metallic member and the metallic member of the composite article is hardened through precipitation hardening. A process for manufacturing such a metal-ceramic composite article is also disclosed. The manufacturing process includes the steps of: fitting a projection formed at a ceramic member into a hole formed in the metallic member made of a precipitation hardenable alloy in a state in which precipitation-hardening is not carried out to form a metal-ceramic joint body, and subjecting the thus formed metal-ceramic composite body to a precipitation hardening treatment to harden the metallic member.

Abstract: A metal-ceramic composite article produced by fitting a projection formed on a ceramic member into a hole formed in a metallic member having a hardened region and an unhardened region on its surface such that the ceramic member is monolithically bonded to the metallic member and the deformed region of the metallic member resulting from the fitting is located within its unhardened range, has a high bonding force between the ceramic member and the metallic member and is adapted to be used in engine parts, such as turbocharger rotor, gas turbine rotor and the like, and other structural parts exposed to high temperature or to repeating loads, by utilizing the heat resistance, wear resistance and high strength of the ceramic.

Abstract: In the cooling wall of a regenerative cooling rocket combustion chamber, the throat portion thereof in which the heat load is highest is formed of a porous material having a perspiring cooling action. The other portion in which the heat load is relatively low is designed to be cooled by conventional forced convection. By such a composite cooling system, a high cooling effect is provided and yet the pressure loss in the cooling passages is small and light weight and long life of the engine are attained concurrently.

Abstract: The invention relates to a method for connecting reaction sintered silicon carbide parts to iron and other metal parts of importance is that the connection involves the use of a binder comprising a mixture of silicon and a metal and preferrably it is a eutectic mixture.

Abstract: A method of producing coolant channels in a metallic object such as a cutting tool whereby a blank is formed by at least one working step such as compaction etc. and the channels are formed by cores whereby the working takes place as a compaction at a temperature of at least 950.degree. C. and that the core thereafter is removed in a separate step.

Abstract: Process for modifying in situ the electrical and/or optical properties of an electrochemically-deposited interlayer within a polyimide film, the interlayer being comprised of particulate silver and/or gold, by heating the interlayer, either in its entirety or in a spatially selective manner, so as to sinter the particulate silver and/or gold without adversely affecting the properties of the polyimide, and the film structure produced thereby.

Abstract: A composite compact component made of a composite compact consisting of a diamond or BN powder bonded to a hard sintered alloy base during a sintering operation, and a substrate composed of steel or a hard sintered alloy bonded to the base of the composite compact through a high strength filler metal or alloy having a melting point of at least the liquidus point of the hard sintered alloy base. A process of making set composite compact component is also disclosed as well as a drill bit containing said composite compact component and variations thereof.

Abstract: There is disclosed a process for forming a wear-resistant, sintered layer on a metallic substrate. The process comprises steps of adhesively attaching to a surface of metallic substrate an alloy particle sheet containing 94 to 99 weight % of ternary eutectic alloy particles and 6 to 1 weight % of acryl binder, heating in a non-oxidating atmosphere to a temperature of 150.degree. to 380.degree. C. and holding at the temperature for at least 5 minutes, and heating a sintering temperature of the alloy particles.

Abstract: Alloy powder is packed into a mold which comprises a complex-shaped solid aphite inner core and a similarly complex-shaped thin glass outer wall. The mold is evacuated, sealed, and then heated to the alloy sintering temperature, the glass softens and applies an isostatic pressure on the alloy as the alloy particles consolidate. After the consolidation step, the mold and its contents are cooled and the glass and graphite materials are removed from the alloy object. This method is particularly useful for preparing complex fittings of Nitinol shape memory alloys.

Abstract: This specification is directed to a method of making a current collector (14) for a sodium/sulfur battery (10). The current collector so-made is electronically conductive and resistant to corrosive attack by sulfur/polysulfide melts. The method includes the step of forming the current collector for the sodium/sulfur battery from a composite material (16) formed of aluminum filled with electronically conductive fibers selected from the group of fibers consisting essentially of graphite fibers having a diameter up to 10 microns and silicon carbide fibers having a diameter in a range of 500-1000 angstroms.

Abstract: An article in rod, tube, strip, sheet or plate shape with reversible thermomechanical properties is produced by joining of at least two parts consisting of a total of at least one shape memory alloy having a two-way effect, whereby each part has a memory effect by itself. In the case of at least two shape memory alloys (1, 2) with different transition temperatures but the same mode of movement, the joining of the individual parts can take place prior to the deformation in the low temperature range necessary to inducing the two-way effect. In the case of differing types and degrees of movement of the individual parts (25, 26), their joining can first be accomplished only after the individual deformations of each part for itself in the low temperature range are accomplished regardless of how many shape memory alloys with different transition temperatures are used in the structure of the article.

Abstract: Amorphous metal powders or ribbons are fabricated into solid shapes of appreciable thickness by the application of compaction energy. The temperature regime wherein the amorphous metal deforms by viscous flow is measured. The metal powders or ribbons are compacted within the temperature range.

Abstract: An improved bond between diamond and a metallic matrix can be achieved by hot pressing the metallic matrix onto a cleaned polycrystalline diamond (PCD) element. The PCD is degreased and then maintained substantially free from subsequent oxidation. The cleaned nonoxidized PCD is then disposed within a hot press and bonded under pressure and temperature with a conventional metallic matrix to form a cutting element. The cutting element thus formed is comprised of a PCD portion and a metallic portion with a high strength bond formed therebetween, on at least one surface of the diamond and, preferably, two adjacent surfaces. Typically, the metallic matrix is a carbide-forming metal or mixture of carbide-forming metals, and the diamond is a thermally stable porous, sintered polycrystalline product. The insert is subsequently placed within a bit mold and a bit is fabricated according to conventional powder metallurgical infiltration techniques.

Abstract: A composition for fixing a metal powder molding at sintering, which is used, in the case of disposing a metal powder molding formed by rolling a mixture of a metal powder and a synthetic resin-based binder on a metal base material and sintering the metal powder molding in a non-oxidizing atmosphere, by interposing between the metal powder molding and the base material, comprising a thermosetting resin composition containing a thermosetting resin as the essential component, the amount of the residual carbon of which after the completion of sintering is at least about 0.5% by weight.