Abstract: The present invention relates, generally, to a self-supporting porous ceramic composite body and to methods for producing such articles to net or near net shape, which bodies exhibit superior thermal and mechanical properties. The invention also relates to the manufacture of ceramic-metal or ceramic-ceramic macrocomposite bodies which have the porous ceramic articles incorporated therein or thereon.

Abstract: A silicon carbide ceramic having crystalline grain boundary phases is prepared by heating a composition comprising silicon carbide, a silicate glass and a high metal content transition metal silicide, to a temperature of 1300.degree. C. to 2100.degree. C. under vacuum until oxygen is removed from the glass as SiO gas, and the glass that remains within the silicon carbide ceramic crystallizes.

Abstract: A method of making self-supporting ceramic composite structures having filler embedded therein includes infiltrating a permeable mass of filler with polycrystalline material comprising an oxidation reaction product obtained by oxidation of a parent metal such as aluminum. The self-supporting ceramic composite structure optionally contains therein non-oxidized constituents of the parent metal. The structure is formed by placing a parent metal adjacent to a permeable filler and heating the assembly to melt the parent metal and provide a molten body of parent metal which is contacted with a suitable oxidant. Within a certain temperature region and optionally, aided by one or more dopants in or on the parent metal, molten parent metal will migrate through previously formed oxidation reaction product into contact with the oxidant, causing the oxidation reaction product to grow so as to embed the adjacent filler and provide the composite structure.

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 and 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. Another preferred embodiment of the invention involves the fabrication of preforms used in the formation of composite articles.

Abstract: The present invention relates to a novel method for forming metal matrix composite bodies and novel products produced by the method. Particularly, a permeable mass of filler material or a preform is provided which has included therein at least some matrix metal powder. Moreover, an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are in communication with the filler material or preform, at least at some point during the process, which permits molten matrix metal, upon contact with the filler material or preform, to spontaneously infiltrate the filler material or preform. The presence of powdered matrix metal in the preform or filler material reduces the relative volume fraction of filler material to matrix metal.

Abstract: The present invention broadly relates to novel aluminum nitride matrix ceramic composite bodies for use as refractory materials and methods for making the same. The refractory materials are useful in environments which are corrosive, erosive, abrasive and/or which generate thermal shock. Such environments include furnaces, and associated apparatus which house or contact molten masses including, for example, molten metals, molten glasses, etc. The preferred method for making the aluminum nitride matrix ceramic composites comprises a directed oxidation of molten metal.

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: There is disclosed a method for producing a self-supporting ceramic body by oxidation of a molten precursor metal with a vapor-phase oxidant to form an oxidation reaction product and inducing a molten flux comprising said molten precursor metal through said oxidation reaction product. A second metal is incorporated into said molten flux during the oxidation reaction. The resulting ceramic body includes sufficient second metal such that one or more properties of said ceramic body are at least partially affected by the presence and properties of said second metal in the metallic constituent.

Abstract: This invention relates to metal and ceramic matrix composite brake rotors comprising an interconnected matrix embedding at least one filler material. In the case of metal matrix composite materials, the at least one filler material comprises at least about 26% by volume of the brake rotor for most applications, and at least about 20% by volume for applications involving passenger cars and trucks. In a preferred embodiment of the present invention, the metal matrix composite brake rotor comprises an interconnected metal matrix containing at least about 28% by volume of a particulate filler material and more preferably at least about 30% by volume. Moreover, the composite rotors of the present invention exhibit a maximum operating temperature of at least about 900.degree. F. and preferably at least about 950.degree. F. and even more preferably at least about 975.degree. F. and higher.

Abstract: The present invention relates to the formation of a metal matrix composite body by the spontaneous infiltration of a molten matrix metal into a three-dimensionally interconnected material. Moreover, the three-dimensionally interconnected material may contain filler material within at least a portion of its porosity. Particularly, an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are in communication with a filler material and/or a three-dimensionally interconnected material and/or a matrix metal at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the three-dimensionally interconnected material and any filler material contained within at least a portion of the porosity of the three-dimensionally interconnected material.

Abstract: The present invention relates to the formation of a macrocomposite body by spontaneously infiltrating a permeable mass of filler material or a preform with molten matrix metal and bonding the spontaneously infiltrated material to at least one second material such as a ceramic or ceramic containing body and/or a metal or metal containing body. Particularly, an infiltration enhancer and/or infiltration enhancer precursor and/or infiltrating atmosphere are in communication with a filler material or a preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the filler material or preform. Moreover, prior to infiltration, the filler material or preform is placed into contact with at least a portion of a second material such that after infiltation of the filler material or preform, the infiltrated material is bonded to the second material, thereby forming a macrocomposite body.

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: This invention relates generally to a novel method of manufacturing a composite body and to novel products made thereby. More particularly, the invention relates to a method of producing a self-supporting composite body comprising one or more boron-containing compounds, e.g., a boride or a boride and carbide, by reactive infiltration of molten parent metal into a bed or mass containing boron carbide, and, optionally, one or more inert fillers and permitting residual or excess parent metal to remain bonded to the formed self-supporting composite body. The residual or excess metal is used to form a bond between the formed composite body and another body (e.g., a metal body, a ceramic body, or another composite body). In addition, this invention related to alternative methods of disposing metal on at least one surface of the above-described composite bodies (such as sputtering, CVD, etc.) to permit the composite bodies to be bonded to another body.

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.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: at least one of: a polymer selected from the group consisting of silicon-nitrogen polymers, aluminum-nitrogen polymers and boron-nitrogen polymers comprising a multiplicity of sequentially bonded repeat units.

Abstract: The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) of reinforcement materials 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. In a preferred embodiment of the present invention, the getterer material(s) form at least one compound (e.g., at least one glassy material) which acts as a crack sealant, thereby further enhancing the oxidation protection of the composite body. One or more ceramic filler materials which serve as reinforcements may have a plurality of superimposed coatings thereon, at least one of which coatings may function as a getterer.

Abstract: The present invention relates to a novel process for forming thin metal matrix composite bodies. Particularly, an infiltration enhancer and/or an infiltrating atmosphere are in communication with a filler material or preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the filler material or preform. Such spontaneous infiltration occurs without the application of any pressure or vacuum. In an embodiment of the present invention, the filler material may be sprayed upon a thin sheet of matrix metal. Alternatively, the filler material may be shaped via tape casting, slip casting, etc. to provide a thin preform. In another embodiment of the present invention, a body of matrix metal may be coated with a filler material such that upon spontaneous infiltration a metal matrix composite body is produced which inversely replicates the configuration of the original body of matrix metal.

Abstract: The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) of reinforcement materials in composite bodies. In a preferred embodiment of the invention, a coated ceramic filler material adaptable for use as a reinforcing component in a ceramic matrix composite is provided with a plurality of superimposed coatings. The coating system includes a first coating in substantially continuous contact with the ceramic filler material and one or more additional or outer coatings superimposed over the underlying coating and in substantially continuous contact therewith. Zonal junctions are formed between the filler and the first coating, between superimposed coatings, and between the outer coating and the ceramic matrix. The coatings are selected so that the interfacial shear strength of at least one of these several zones is weak relative to the other zones.

Abstract: An aluminum-nitrogen polymer is prepared by reacting an organic nitrile with a dialkylaluminum hydride to form an organoaluminum imine, and heating the imine to a temperature of 50.degree. to 200.degree. C. for at least 2 hours. The polymeric product can be subjected to an additional heat treatment to form a more highly cross-linked polymer. After either heat treatment the polymeric product can be further reacted with a primary amine or ammonia. The organoaluminum imine as well as the aminated or non-aminated polymers can be pyrolyzed to form an aluminum nitride-containing ceramic.

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 present invention relates to the use of a gating means in combination with a spontaneous infiltration process to produce a metal matrix composite body. Particularly, a permeable mass of filler material or a preform is spontaneously infiltrated by molten matrix metal to form a metal matrix composite body. A gating means is provided which controls or limits the areal contact between molten matrix metal and the filler material or preform. The use of a gating means provides for control of the amount of matrix metal which can contact the preform or filler material, which may result in less machining of a formed metal matrix composite body compared with a similar metal matrix composite body made without a gating mean. Moreover, the use of a gating means ameliorates the tendency of a formed metal matrix composite body to warp due to the contact between the formed composite body and matrix metal carcass.