Abstract: Often, metal matrix composites (MMC's) lack adequate machinability and possess excessive abrasiveness because hard ceramic materials, such as silicon carbide, are used as the reinforcement phase. To make a metal matrix composite body having a more machinable and less abrasive surface, an MMC comprising an aluminum nitride reinforcement is formed on the surface of the body. In one embodiment, a layer is provided to a permeable mass or preform at the surface at issue, the layer featuring at least a reduced loading of ceramic filler material, and sometimes no ceramic material at all. The reduced loading is achieved by incorporating a fugitive material into the coating layer. Molten matrix metal is caused to infiltrate the permeable mass or preform and the coating layer to produce a macrocomposite body comprising a metal matrix composite coating and substrate.

Abstract: The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the composite body such that any undesirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. The getterer materials) may form at least one compound which acts as a passivation layer, and/or is able to move by bulk transport (e.g., by viscous flow as a glassy material) to a crack, and sealing the crack, thereby further enhancing the oxidation protection of the composite body.

Abstract: The present invention relates to a novel method for forming cast metal matrix composite bodies. In particular, the present invention relates to a novel method for forming or recycling metal matrix composite bodies so as to render such bodies in a condition for casting or recasting as a cast metal matrix composite body. Specifically, a scrap metal matrix composite body and preferably a scrap cast metal matrix composite body is placed into a crucible, optionally along with unreinforced matrix metal and/or virgin metal matrix composite material. Whether the scrap and/or virgin materials are placed into the crucible in solid or molten form, the contents of the crucible are ultimately rendered molten to form a composite melt.

Abstract: The present invention is directed to compositions derived from polymers containing metal-nitrogen bonds, which compositions exhibit, among other things, desirable oxidation resistance, corrosion resistance and hydrolytic stability when exposed to adverse environments, whether at ambient or at elevated temperatures, and which may be useful as, for example, protective coatings on surfaces.

Abstract: This invention relates generally to a novel directed metal oxidation process which is utilized to produce self-supporting bodies. In some of the more specific aspects of the invention, a parent metal (e.g., a parent metal vapor) is induced to react with at least one solid oxidant-containing material to result in the directed growth of a reaction product which is formed from a reaction between the parent metal and the solid oxidant-containing material. The inventive process can be utilized to form bodies having substantially homogeneous compositions, graded compositions, and macrocomposite bodies.In a preferred embodiment, the reaction product may be chemically modified or a different reaction product may be coated thereon. Specifically, once a first reaction product is formed on a solid oxidant-containing material, the formed body may be exposed to a vapor-phase parent metal different from the first parent metal.

Abstract: The present invention relates to porous mat gas fired radiant burner panels utilizing improved reverberatory screens. The purpose of these screens is to boost the overall radiant output of the burner relative to a burner using no screen and the same fuel-air flow rates. In one embodiment, the reverberatory screen is fabricated from ceramic composite material, which can withstand higher operating temperatures than its metallic equivalent. In another embodiment the reverberatory screen is corrugated. The corrugations add stiffness which helps to resist creep and thermally induced distortions due to temperature or thermal expansion coefficient differences. As an added benefit, it has been unexpectedly discovered that the corrugations further increase the radiant efficiency of the burner. In a preferred embodiment, the reverberatory screen is both corrugated and made from ceramic composite material.

Abstract: This invention relates to the discovery of organometallic ceramic precursor binders used to fabricate shaped bodies by different techniques. Exemplary shape making techniques which utilize hardenable, liquid, organometallic, ceramic precursor binders include the fabrication of negatives of parts to be made (e.g., sand molds and sand cores for metalcasting, etc.), as well as utilizing ceramic precursor binders to make shapes directly (e.g., brake shoes, brake pads, clutch parts, grinding wheels, polymer concrete, refractory patches and liners, etc.). In a preferred embodiment, this invention relates to thermosettable, liquid ceramic precursors which provide suitable-strength sand molds sand cores at very low binder levels and which, upon exposure to molten metalcasting exhibit low emissions toxicity as a result of their high char yields of ceramic upon exposure to heat.

Abstract: The present invention relates to modifying the properties of a metal matrix composite body by a post formation process treatment and/or a substantially contiguous modification treatment. The post formation process treatment may be applicable to a variety of metal matrix composite bodies produced by various techniques, and is particularly applicable to modifying the properties of a metal matrix composite body produced by a spontaneous infiltration technique. The substantially contiguous modification process may also be used primarily in conjunction with metal matrix composite bodies produced according to a spontaneous infiltration technique. Particularly, at least a portion of the matrix metal of the metal matrix composite body and/or the filler material of the metal matrix composite body is modified or altered during and/or after the formation process.

Abstract: The present invention is directed to compositions derived from polymers containing metal-nitrogen bonds, which compositions exhibit, among other things, desirable oxidation resistance, corrosion resistance and hydrolytic stability when exposed to adverse environments, whether at ambient or at elevated temperatures, and which may be useful as, for example, protective coatings on surfaces.

Abstract: The compositions of this invention comprise uncrosslinked reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one metal-containing polymer comprising a metal-nitrogen polymer.Preferred compositions of this invention comprise reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one of: silicon-nitrogen polymers, aluminum-nitrogen polymers and boron-nitrogen and polymer combinations thereof comprising a multiplicity of sequentially bonded repeat units the compositions comprising the reaction products of the reaction mixtures, and the compositions obtained by crosslinking the reaction products of the reaction mixtures. The crosslinking may be effected through at least one of thermal-based, radiation-based free radical-based or ionic-based crosslinking mechanisms.

Abstract: The compositions of this invention comprise uncrosslinked reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one metal-containing polymer comprising a metal-nitrogen polymer.Preferred compositions of this invention comprise reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one of: silicon-nitrogen polymers, aluminum-nitrogen polymers and boron-nitrogen and polymer combinations thereof comprising a multiplicity of sequentially bonded repeat units the compositions comprising the reaction products of the reaction mixtures, and the compositions obtained by crosslinking the reaction products of the reaction mixtures. The crosslinking may be effected through at least one of thermal-based, radiation-based free radical-based or ionic-based crosslinking mechanisms.

Abstract: The present invention relates to coated optical devices, such as optical fibers and optical wave guides, and methods for forming coated optical devices. Methods for forming coated optical devices comprise providing at least one optical device and contacting at least a portion of at least one optical device with at least one coating composition comprising at least one metal-nitrogen polymer. The at least one coating composition may further comprise at least one multifunctional organic electrophile comprising at least one monomer, oligomer, or polymer comprising a plurality of organic electrophilic substituents. The coating composition contacting at least a portion of an optical device is at least partially crosslinked, thereby forming coated optical devices which exhibit enhanced resistance to, for example, deterioration resulting from, among other things, exposure to chemicals and environmental factors.

Abstract: The compositions of this invention comprise uncrosslinked reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one metal-containing polymer comprising a metal-nitrogen polymer.Preferred compositions of this invention comprise reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one of: silicon-nitrogen polymers, aluminum-nitrogen polymers and boron-nitrogen and polymer combinations thereof comprising a multiplicity of sequentially bonded repeat units the compositions comprising the reaction products of the reaction mixtures, and the compositions obtained by crosslinking the reaction products of the reaction mixtures. The crosslinking may be effected through at least one of thermal-based, radiation-based free radical-based or ionic-based crosslinking mechanisms.

Abstract: The compositions of this invention comprise uncrosslinked reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one metal-containing polymer comprising a metal-nitrogen polymer.Preferred compositions of this invention comprise reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one of: silicon-nitrogen polymers, aluminum-nitrogen polymers and boron-nitrogen and polymer combinations thereof comprising a multiplicity of sequentially bonded repeat units the compositions comprising the reaction products of the reaction mixtures, and the compositions obtained by crosslinking the reaction products of the reaction mixtures. The crosslinking may be effected through at least one of thermal-based, radiation-based free radical-based or ionic-based crosslinking mechanisms.

Abstract: The compositions of this invention comprise uncrosslinked reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one metal-containing polymer comprising a metal-nitrogen polymer.Preferred compositions of this invention comprise reaction mixtures comprising (1) at least one organic monomer, oligomer or polymer comprising a multiplicity of organic, electrophilic substituents, and (2) at least one of: silicon-nitrogen polymers, aluminum-nitrogen polymers and boron-nitrogen and polymer combinations thereof comprising a multiplicity of sequentially bonded repeat units the compositions comprising the reaction products of the reaction mixtures, and the compositions obtained by crosslinking the reaction products of the reaction mixtures. The crosslinking may be effected through at least one of thermal-based, radiation-based free radical-based or ionic-based crosslinking mechanisms.

Abstract: A ceramic-forming prepreg tape is prepared by (a) dispersing in water a ceramic-forming powder and a fiber, (b) flocculating the dispersion by adding a cationic wet strength resin and an anionic polymer, (c) dewatering the flocculated dispersion to form a sheet, (d) wet pressing and drying the sheet, and (e) coating or impregnating the sheet with an adhesive selected from the group consisting of a polymeric ceramic precursor, and a dispersion of an organic binder and the materials used to form the sheet. The tape can be used to form laminates, which are then fired to consolidate the tapes to a ceramic.

Abstract: The present invention relates to a process of depositing metals onto various substrates. Applications for which the present invention may be useful include the formation of catalysts such as those used in electrochemical applications, including fuel cells and the like, refining applications such as oil refining, automotive applications such as automotive catalytic converters, and other similar applications.

Abstract: Coated ceramic filler materials comprised of ceramic particles, fibers, whiskers, etc. having at least two substantially continuous coatings thereon are provided. The coatings are selected so that the interfacial shear strength between the ceramic filler material and the first coating, between coatings, or between the outer coating and the surrounding matrix material, are not equal so as to permit debonding and pull-our when fracture occurs. The resultant, multi-coated ceramic filler materials may be employed to provide composites, especially ceramic matrix composites, with increased fracture toughness. The ceramic filler materials are designed to be particularly compatible with ceramic matrices formed by directed oxidation of precursor metals, but such ceramic filler materials are also adaptable for use in many other composite material systems.In a preferred embodiment, the coatings are applied to the ceramic fiber plies or preforms by CVD.

Abstract: This invention relates generally to a novel directed metal oxidation process which is utilized to produce self-supporting bodies. In some of the more specific aspects of the invention, a parent metal (e.g., a parent metal vapor) is induced to react with at least one solid oxidant-containing material to result in the directed growth of a reaction product which is formed from a reaction between the parent metal and the solid oxidant-containing material. The inventive process can be utilized to form bodies having substantially homogeneous compositions, graded compositions, and macrocomposite bodies. In a preferred embodiment, the reaction product may be chemically modified or a different reaction product may be coated thereon. Specifically, once a first reaction product is formed on a solid oxidant-containing material, the formed body may be exposed to a vapor-phase parent metal different from the first parent metal.

Abstract: The present invention relates to novel methods for shaping a filler material into a porous preform and subsequently filling at least a portion of the porous preform with a second material to form a composite body. Specific aspects of the invention include novel combinations of materials to form the preform in combination with novel processing techniques for shaping the combinations of materials into a porous preform.