Abstract: Novel self-supporting ceramic structures are produced by the oxidation reaction of a molten metal precursor with a vapor-phase oxidant to form an oxidation reaction product. The resulting ceramic material of the polycrystalline oxidation reaction product consists essentially of an oxidation reaction product and, optionally, one or more non-oxidized constituents of the metal precursor.

Abstract: The present invention relates to modifying the properties of a metal matrix composite body by a post formation process 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. 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 after the formation process. Preferably, the preform contains a second non-metal material, an infiltration enhancer of infiltration enhancer precursor, and an infiltration atmosphere.

Abstract: The present invention relates to novel ceramic-filled metal matrix composites and methods for making the same. Particularly, a permeable mass of filler material is spontaneously infiltrated by, for example, an aluminum alloy, in the presence of nitrogen-containing atmosphere. A reservoir feeding technique for forming metal matrix composite bodies is also disclosed. The reservoir feeding technique can also be used to form complex (e.g., a metal bonded to a metal matrix composite) metal matrix composite bodies.

Abstract: The present invention relates to a novel process for forming a plurality of 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 plurality of filler materials or preforms. Such spontaneous infiltration occurs without the application of any pressure or vacuum and occurs in a single step. 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: A method of producing a self-supporting ceramic composite body having therein at least one cavity which inversely replicates the geometry of a positive mold of parent metal. The method includes embedding the mold of parent metal within a conformable bed of filler to provide therein a cavity shaped and filled by the mold. The assembly is heated to melt the parent metal mold, e.g., an aluminum parent metal mold, and contacted with an oxidant to oxidize the molten parent metal to form a polycrystalline material which grows through the surrounding bed of filler, the molten metal being drawn through the growing polycrystalline material to be oxidized at the interface between the oxidant and previously formed oxidation reaction product whereby the cavity formerly filled by the mold of parent metal is eventually evacuated of the metal. There remains behind a cavity whose shape inversely replicates the original shape of the mold.

Abstract: A method for producing a self-supporting ceramic composite body which comprises preparing a polycrystalline material as the oxidation reaction product of a parent metal with a vapor-phase oxidant, comminuting the resulting material to a particulate, forming a permeable mass of said particulate as filler, and infiltrating said particulate with an oxidation reaction product of a parent metal with a vapor-phase oxidant, thereby forming said ceramic composite body.

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: In a method for producing ceramic body by oxidation of a parent metal having a graded microstructure characterized by a plurality of zones differing from each other in one or more properties by altering the process conditions during formation of said ceramic body such that a zone of the oxidation reaction product formed posterior to said altering has one or more properties different from a zone of the oxidation reaction product formed anterior to said altering.

Abstract: A method of producing self-supporting ceramic bodies having a modified metal-containing component includes first providing a 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: Two or more ceramic bodies are bonded together by oxidizing with a vapor-phase oxidant molten metal obtained from a body of precursor metal to form an oxidation reaction product bond. The oxidation reaction product is formed between adjacent facing, substantially congruent surfaces of the ceramic bodies and bridges the surfaces, thus bonding the ceramic bodies to each other. Promoters may optionally be used to facilitate formation of the oxidation reaction product.

Abstract: Self-supporting bodies are produced by reactive infiltration of a parent metal into a boron donor material and a carbon donor material. The reactive infiltration typically results in a composite comprising a boron-containing compound, a carbon-containing compound and residual metal, if desired. The mass to be infiltrated may contain one or more inert fillers admixed with the boron donor material and carbon donor material. The relative amounts of reactants and process conditions may be altered or controlled to yield a body containing a wide ranging varying volume percentage of ceramic, metal, and porosity.

Abstract: Ceramic bodies are bonded together via a layer of an oxidation reaction product of a molten metal, which metal is present in one or both of the ceramic bodies prior to bonding. At least one of the ceramic bodies comprises a ceramic product formed by the oxidation reaction of molten parent metal (e.g., alumina from molten aluminum) and grown as molten metal is transported through, and oxidized on the surface of, its own oxidation product. One or both of the ceramic bodies used in the bonding process contains surface-accessible channels of residual metal, i.e., metal channels which have resulted from molten-metal transport during the ceramic growth process. When the suitably assembled ceramic bodies are heated in the presence of an oxidant at a temperature above the melting point of the residual metal, molten metal at the surface of at least one of the ceramic bodies reacts with the oxidant to form a layer of oxidation reaction product, which may or may not incorporate at least one filler material.

Abstract: In the present invention there is provided a method for producing a self-supporting ceramic or ceramic composite body by the oxidation of a parent metal to form a polycrystalline ceramic material comprising the oxidation reaction product of said parent metal with an oxidant, including a vaporphase oxidant, and optionally one or more metallic constituents dispersed throughout the polylcrystalline ceramic material. The method comprises the steps of providing at least a portion of said parent metal for establishing at least one surface of the ceramic body, and heating said parent metal to a temperature above its melting point but below the melting point of the oxidation reaction product to form a body of molten metal. At that temperature, the molten metal is reacted with the oxidant, thus forming the oxidation reaction product.

Abstract: In the present invention there is provided a method for producing abrasive ceramic and ceramic composite material characterized by an abrasive grain as the comminuted form of a polycrystalline ceramic material. The abrasive grains of the present invention consist essentially of the oxidation reaction product of a parent metal precursor with a vapor phase oxidant, and, optionally one or more metallic constituents such as non-oxidized constituents of the parent metal. There is also provided a method for producing abrasive grains which additionally consist of one or more inert filler materials.

Abstract: A method for producing a self-supporting ceramic composite body having a negative pattern which inversely replicates the positive pattern of a parent metal precursor having thereon a positive pattern section which is emplaced in conforming engagement with a bed of conformable filler. The parent metal precursor, which also has a non-replicating section, is melted and reacted with an oxidant to form a polycrystalline oxidation reaction product which grows primarily only from the positive pattern section of the parent metal precursor and through the filler. The molten parent metal is drawn through the growing polycrystalline material and oxidized at the interface between the oxidant and previously formed oxidation reaction product. The reaction is continued for sufficient time to at least partially embed the filler within the oxidation reaction product and form the ceramic composite body containing a negative pattern which inversely replicates the positive pattern of the parent metal precursor.

Abstract: Self supporting ceramic composite structures having filler embedded therein produced by a method which 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 and optionally containing 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 vapor-phase 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: A method of producing a self-supporting ceramic composite body having therein at least one cavity which inversely replicates the geometry of a positive mold of parent metal. The method includes embedding the mold of parent metal within a conformable bed of filler to provide therein a cavity shaped and filled by the mold. The assembly is heated to melt the parent metal mold, e.g., an aluminum parent metal mold, and contacted with an oxidant to oxidize the molten parent metal to form a polycrystalline material which grows through the surrounding bed of filler, the molten metal being drawn through the growing polycrystalline material to be oxidized at the interface between the oxidant and previously formed oxidation reaction product whereby the cavity formerly filled by the mold of parent metal is eventually evacuated of the metal. There remains behind a cavity whose shape inversely replicates the original shape of the mold.

Abstract: In a method for producing ceramic body by oxidation of a parent metal having a graded microstructure characterized by a plurality of zones differing from each other in one or more properties by altering the process conditions during formation of said ceramic body such that a zone of the oxidation reaction product formed posterior to said altering has one or more properties different from a zone of the oxidation reaction product formed anterior to said altering.

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 infiltration of the filler material or preform, the infiltrated material is bonded to the second material, thereby forming a sealable electronic package.

Abstract: Self-supporting ceramic composite bodies of desired shape are produced by infiltrating a permeable self-supporting preform with polycrystalline matrix material comprising an oxidation reaction product obtained by oxidation of a parent metal precursor, such as aluminum, and optionally containing therein metallic constituents. The composite body is formed by contacting a zone of a permeable self-supporting preform, having at least one defined surface boundary spaced from said contacting zone, with a body of molten metal which is reacted with a suitable vapor-phase oxidant to form an oxidation reaction product.