Abstract: There is provided a method of fabricating a laminated composite material and laminated composite materials fabricated thereby wherein the method includes the initial step of forming a pre-laminate by overlaying a first layer characterized by a first thermal expansion coefficient and a first ductility parameter with a second layer characterized by a second thermal expansion coefficient and a second ductility parameter. The pre-laminate is heated to a temperature at which the first ductility parameter becomes substantially equivalent in value to the second ductility parameter. The first and second layers of the heated prelaminate are then pressed together, preferably by use of a rolling mill technique, with sufficient compression force to cause the layers to adhere one to the other, thus forming a core laminate. Preferably, the core laminate is divided, either by cutting or folding, into a plurality of divided laminate members.

Abstract: A process for producing sintered titanium-graphite having improved wear resistance and low frictional characteristics is described. The said process which produces titanium-graphite composites having a triphasic structure with controlled porosity and a graphite lubricating film, comprises sintering a mixture of titanium and graphite powders in which the percentage of graphite may vary from 4 to 8 percent at temperatures from about 800.degree. C. to 1600.degree. C., for about 1/2 to 2 hours, under a compaction pressure of 0.17 to 0.62 MPa. The composites have applications in biomedical engineering and other fields of engineering due to their biocompatibility, strength and improved wear resistance.

Abstract: A method for fabricating a high-activity cermet electrode which is applied on an exhaust gas sensor including an oxygen ion conducting solid electrolyte, which is composed of a cermet material composed of at least one catalytically active material and at least one oxygen ion conducting ceramic material, which is bonded to the solid electrolyte of the exhaust sensor by co-sintering the cermet electrode and the solid electrolyte at a temperature ranging from 1300.degree. to 1600.degree. C. to provide a porous cermet electrode, and which contains at least one further catalytically active material which is embedded in the pores of the porous cermet electrode after co-sintering, the method including bonding together an unsintered solid electrolyte which conducts oxygen ions and a cermet electrode by co-sintering at from 1300.degree. to 1600.degree. C. to provide a porous cermet electrode; and subsequently introducing at least one further catalytically active material into pores of the porous cermet electrode.

Abstract: An apparatus and process for making metal oxide sputtering targets from volatile and thermally unstable metal oxide powder by enveloping the metal oxide powder in at least one layer of a barrier material while the powder is hot-pressed using a graphite die assembly.

Abstract: A method of producing a composite powder by providing particles of (I) tungsten, niobium, zirconium, titanium or mixtures thereof, (II) silicon and (III) carbon in a proportion relative to each other so as to possess an overall chemical composition in that segment of the ternary diagram of FIGS. 2(a), 2(b), 2(c) and 2(d) designated A, and subjecting the particles to a mechanical alloying process under conditions and for a time sufficient to produce the composite powder. Also disclosed is a method of forming a substantially oxygen-free composition of matter comprising a matrix substance of WSi.sub.2, NbSi.sub.2, ZrSi.sub.2, TiSi.sub.2 or alloys thereof having SiC dispersed therein, the method comprising consolidating the above-described composite powder. Also disclosed is a method of forming oxidation- and wear-resistant coatings by subjecting the composite powder whose composition lies in segment A to a metallurgical process such as plasma spraying.

Abstract: A densified titanium diboride based ceramic composition is provided having W and Co therein and a fine grain size. The composition has particular usefulness as a cutting tool for the machining of titanium based alloys at high speeds.

Abstract: Graphite or carbon particles with a graphitic skin are intercalated with a compound including an oxidized form of a metal and then reduced in a hydrogen atmosphere. This process reduces the driving force for the galvanic reaction between the particles and active metals in aqueous environments. The particles may be present as a reinforcement for a metal matrix (e.g., graphite/aluminum metal matrix composites) or as a reinforcement for a non-metallic material (e.g., graphite/polyimide, graphite/polyester or graphite/cyanate composites). In the latter case, the composite is adjacent to a metal in a structure.By way of example, the graphite or carbon particle may be a fiber, the metal subject to attack may be aluminum or magnesium, and the intercalation compound may be NiCl.sub.2.

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: Microlaminated composite articles are made by combining one or more sheets of flexible sintered crystalline ceramic foil with one or multiple inorganic substrate layers, e.g., of metal foil, to form a stack which is then heated below the melting temperatures of the foil and substrate layers, and under slight or moderate pressure, to provide a well-bonded composite article which is essentially free of interlaminar cementing or sealing materials.

Abstract: There is now provided a method of manufacturing a sintered body of titanium-based carbonitride alloy comprising hard constituents in 5-25% binder phase where the hard constituents contain, in addition to Ti, one or more of the metals V, Nb, Ta, Cr, Mo or W and the binder phase is based on cobalt and/or nickel by powder metallurgical methods, i.e., milling, pressing and sintering. The composition of the hard constituents is:0.88<a<0.96;0.04<b<0.08;0.ltoreq.c<0.04;0.ltoreq.d<0.04;0.60<f<0.73;0.80<x<0.90; and0.31<h<0.40.and the overall composition of the hard constituents phase is expressed by the formula:(Ti.sub.a,Ta.sub.b,Nb.sub.c,V.sub.d).sub.x (Mo.sub.e,W.sub.f).sub.y (C.sub.g,N.sub.h).sub.z.

Abstract: A pressure molding device having a powder supporting flat face formed by the end face of a pressure ram or a pressure-submissive block and a reciprocating vertical sleeve. The layer of powder formed on the flat face and having a uniform density is cut with the vertical sleeve's end for molding. A molded body has a uniform density in all portions and deformation does not occur in the course of sintering for producing semiconducting or insulating base boards.

Abstract: The bonding of a porous metal layer to at least one surface of a cermet is accomplished, without a supporting metal netting in the green cermet blank, by using a reducible metal oxide in the green cermet blank and a reducible metal oxide layer on the surface or surfaces of the green blank. In the following reducing sintering step the metal component in the green blank and the porous metal layer are formed simultaneously resulting in an intimate strong bond between the cermet blank and the porous metal layer. Both reducible metal oxides may be the same. The resulting product, such as an electrode-diaphragm-electrode structure is well suited for use in water electrolysis, chlorine alkaline electrolysis, and in fuel cells.

Abstract: Ceramic precursor compositions, such as metal hydroxides and oxides, are electrochemically deposited in a biased electrochemical cell. The cell typically generates hydroxide ions that precipitate metallic or semimetallic ions to form insoluble solids that may be separated from the cell, then dried, calcined and sintered to form a ceramic composition.

Abstract: A highly loaded, uniform ceramic composite can be made by first preparing a highly loaded suspension. Due to the particle-particle interactions of a highly concentrated system, virtually any dopant can be added, including other suspensions, fibers, and whiskers. The process is particularly useful for making composites of materials which coagulate when mixed at low concentration.

Abstract: A method of producing self-supporting ceramic bodies having a modified metal-containing component includes first providing a self-supporting ceramic body comprising (i) a polycrystalline oxidation reaction product formed upon oxidation of a molten parent metal precursor with an oxidant, and (ii) an interconnected metal-containing component at least partially accessible from one or more surfaces of said ceramic body. The surface or surfaces of the ceramic body is contacted with a quantity of foreign metal different from said interconnected metal-containing component at a temperature and for a time sufficient to allow for interdiffusion, whereby at least a portion of said metal-containing component is displaced by said foreign metal. The resulting ceramic body, having an altered metal-containing component, exhibits modified or improved properties.

Abstract: There is disclosed an improved process for preparing a superconducting composition having the formula MBa.sub.2 Cu.sub.3 O.sub.x wherein M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said composition having a superconducting transition temperature of about 90 K; said process consisting essentially of preparing a precursor solution, drying the solution of obtain a solid material, and heating and cooling the solid material under specified conditions to obtain the desired product. In another embodiment, a shaped superconducting MBa.sub.2 Cu.sub.3 O.sub.x article is prepared by impregnating an article of cellulose material with the precursor solution, drying the impregnated article, and heating and cooling the impregnated article under prescribed conditions to obtain the desired product.

Abstract: A method to produce an article of commerce comprising a self-supporting ceramic body by oxidation of a molten parent metal with a vapor-phase oxidant, includes applying to a surface of the parent metal a layer at least one dopant material therein. The layer is thin relative to the thickness of the ceramic body. Upon heating the parent metal to a molten state in the presence of the oxidant, e.g., air, an oxidation reaction product is formed on the molten metal which, because of the effect of the dopant material, migrates through the growing oxidation reaction product so as to be exposed to the oxidant to form additional oxidation reaction product to and beyond the depth of the applied dopant material layer. Suitable temperature and oxidizing conditions are maintained for a time sufficient to produce a self-supporting ceramic body.

Abstract: A silicon carbide sintered body containing not less than 0.03% by weight of boron, a total of not more than 0.3% by weight of metallic element impurities including the boron, not more than 1.0% by weight of free carbon, a total of not more than 0.15% by weight of non-metal impurities other than the free carbon, and the balance essentially consisting of silicon carbide, and having a density of not less 3.10 g/cm.sup.3. The sintered body is manufactured by heating a molding of a mixture containing a silicon carbide powder, a boron-containing sintering assistant, and a carbon-containing oxygen scavenger to a sintering temperature. The molded body is maintained at a temperature lower than the sintering temperature during the heating process until an oxide film covering the silicon carbide powder is substantially removed by the oxygen scavenger, and the molded body is then sintered at the sintering temperature under a non-pressurized condition.

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 continuous, bicomponent, non-vitreous ceramic fiber comprises components existing in a longitudinal side by side relationship wherein each of the components is derived from the different fiber-forming precursor liquid. The precursor liquids are formed into a fiber and gelled or hydrolyzed to provide a bicomponent non-refractory green fiber. Firing the bicomponent green fibers in a reducing atmosphere can provide ceramic/cermet or cermet/cermet fibers wherein each cermet component has a graded composition.

Abstract: A method is provided of producing a self-supporting ceramic composite structure having one or more encasement members, such as an encasing steel sleeve, joined to it by growth of the ceramic material to engagement surface(s) of the encasement member(s). A parent metal is contacted with a body of filler which is encased by the encasement member(s). The resulting assembly is heated to melt and oxidize the parent metal, e.g., aluminum, to form a polycrystalline material comprising an oxidation reaction product which grows through the doby of filler and stops at the engagement surface(s) of the encasement member(s) which thereby determines the surface geometry of the grown ceramic matrix. Upon cooling, the encasement member(s) is shrink-fitted about the ceramic composite body. The invention also provides the resultant articles, for example, a ceramic composite body having a stainless steel member affixed thereto.

Abstract: The present invention is directed to a cermet material comprising a matrix of aluminum alloy with ceramic particles distributed therein. The cermet is adapted for use as a semiconductor substrate and is manufactured using powder technology procedures. The cermet comprises from about 40 to about 60 volume % of aluminum or aluminum alloy, from an effective amount up to about 10 volume % of binder for enhancing bonding between the aluminum alloy and ceramic particles, and the balance essentially ceramic particles.

Abstract: A method of manufacture of objects by consolidation of powdered metals, alloys, ceramics, or their mixtures is disclosed. The method comprises the steps of preparing a shaped, preferably ceramic, shell, placing it inside a metal or ceramic can, filling both the shell and space between the shell and the can with powder, outgassing and sealing the can if necessary, heating the full can and pressing it to consolidate the powder into a dense form; and separating the densified object within the shell from the densified shapes between the shell and the can. During pressing, the ceramic shell does not consolidate or bond to the surrounding powder, thus acting as an easy parting surface as well as being a shape defining container for the object being consolidated. The method permits easy definition of desired shell shape and permits manufacture of complex shaped, fully densified objects in near-net-shape form.

Abstract: This invention relates to the manufacture of compacts of ceramic composition, cermets, and other high hardness materials by applying explosive shock during exothermic sintering of such powders.

Abstract: The method of consolidating a metallic, metallic and ceramic, or ceramic body in any of initially powdered, sintered, fibrous, sponge, or other form capable of compaction, includes the steps:(a) providing a bed of flowable particles within a contained zone, said particulate primarily including flowable and resiliently compressible carbonaceous particles,(b) positioning said body in said bed,(c) and effecting pressurization of said bed to cause pressure transmission via said particles to said body, thereby to compact the body into desired shaped, increasing its density,(d) said body and bed being at elevated temperatures prior to said pressurization step.

Abstract: The present invention relates to a method of manufacturing a metal-impregnated body by immersing a porous ceramic or ceramic powder in a solution containing a chemical compound having an OH radical selected from the group consisting of water and aqueous solutions of methanol, ethanol, butanol, acetone, acetic acid and ammonium hydroxide; drying and molding it into a porous body; and then impregnating said porous body with a molten metal.