Abstract: A method for manufacture of Group IVB metal carbide comprising a carbide of a metal selected from the group consisting of titanium, hafnium and zirconium ceramic composites is provided wherein a permeable mass of filler and carbon is contacted with a molten Group IVB metal. The molten metal is maintained in contact with the permeable mass for a sufficient period to infiltrate the permeable mass and to react the molten metal with the carbon source to form a Group IVB metal carbide composite. The permeable mass may comprise a Group IVB metal carbide, or other inert filler, or a combination of filler materials.

Abstract: A method is provided for producing a self-supporting ceramic composite body having a plurality of spaced apart wall members, each wall member having a bounded cross-section for defining substantially continuous, fluid passageways. The wall members generally inversely replicate in opposed directions the geometry of a positive pattern. Each of the wall members, which are axially aligned, comprises a ceramic matrix having a filler embedded therein, and is obtained by the oxidation reaction of a parent metal to form a polycrystalline material which consists essentially of the oxidation reaction product of the parent metal with an oxidant and, optionally, one or more metals, e.g. nonoxidized constituents of the parent metal.

Abstract: The present invention relates to a novel process for forming metal matrix composite bodies. Particularly, an infiltration enhancer and/or an infiltration enhancer precursor and/or an 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. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum.

Abstract: This invention relates generally to a reaction which occurs on the surface of a substrate body. Particularly, at least one solid oxidant is contacted with at least one parent metal to result in a reaction therebetween and the formation of a reaction product on the surface of a substrate body.

Abstract: The present invention relates to a novel process for forming macrocomposite bodies. Particularly, a suitable matrix metal, typically in a molten state, is in contact with a suitable mass of filler material or preform located adjacent to, or in contact with, at least one second material in the presence of a suitable reactive atmosphere in an impermeable container, at least at some point during the process, which permits a reaction to occur between the reactive atmosphere and the molten matrix metal and/or mass of filler material or preform and/or impermeable container, thereby causing molten matrix metal to infiltrate the mass of filler material or preform due to, at least in part, the creation of a self-generated vacuum. The impermeable container being sealed by a molten glassy material. Such self-generated vacuum infiltration occurs without the application of any external pressure or vacuum.

Abstract: The invention relates to a method for producing ceramic composites obtained by oxidation of a parent metal to form a polycrystalline ceramic material by providing a filler having a coating of a silicon source on at least a portion of the filler different in composition from the primary composition of the filler, said silicon source possessing intrinsic doping properties. A body of molten parent metal, adjacent a mass of the filter material, reacts with an oxidant to form an oxidation reaction product which infiltrates the adjacent mass of filler, thereby forming the ceramic composite.

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 vapor is induced to react with a solid oxidant to result in the directed growth of a reaction product which is formed from a reaction between the parent metal vapor and the solid oxidant. The inventive process can be utilized to form bodies having substantially homogeneous compositions, graded compositions, and macrocomposite bodies.

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.

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: The present invention relates to the formation of bodies having graded properties. Particularly, the invention provides a method for forming a metal matrix composite body having graded properties. The graded properties are achieved by, for example, locating differing amounts of filler material in different portions of a formed body and/or locating different compositions of filler material in different portions of a formed body and/or locating different sizes of filler materials in different portions of a formed body. In addition, the invention provides for the formation of macrocomposite bodies wherein, for example, an excess of matrix metal can be integrally bonded or attached to a graded metal matrix composite portion of a macrocomposite body.

Abstract: The present invention relates to forming a metal matrix composite between at least two bodies having a similar or a different chemical composition, the metal matrix composite functioning as a bonding means which bond to or fixes the bodies together. Particularly, a metal matrix composite is produced by a spontaneous infiltration technique by providing a filler material or preform with an infiltration enhancer and/or an infiltration enhancer precursor and/or and infiltrating atmosphere, which are in communication with the filler material or preform at least at some point during the process. Molten matrix metal then spontaneously infiltrates the filler material or preform, whereby the metal matrix composite serves to bond together two or more bodies.

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: 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: 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: This invention relates generally to a novel method for removing metal from a formed self-supporting body. A self-supporting body is made by reactively infiltrating a molten parent metal into a bed or mass containing a boron source material and a carbon source material (e.g., boron carbide) and/or a boron source material and a nitrogen source material (e.g., boron nitride) and, optionally, one or more inert fillers. Once the self-supporting body is formed, it is then placed, at least partially, into contact with another material which causes metallic constituent contained in the self-supporting body to be at least partially removed.

Abstract: This invention relates to a method for producing a self-supporting ceramic structure comprising an oxidation reaction product of a parent metal and a vapor-phase oxidant characterized by an altered microstructure attributable to the addition of one or more process modifiers relative to substantially the same oxidation reaction product produced without a process modifier.

Abstract: The present invention relates to a novel process for forming metal matrix composite bodies. Particularly, a suitable matrix metal, typically in a molten state, is in contact with a suitable filler material or preform in the presence of a suitable reactive atmosphere in a sealed impermeable container, at least at some point during the process, which permits a reaction to occur between the reactive atmosphere and the molten matrix metal and/or filler material or preform and/or impermeable container, thereby causing molten matrix metal to infiltrate the filler material or preform due to, at least in part, the creation of a self-generated vacuum. Such self-generated vacuum infiltration occurs without the application of any external pressure or vacuum.

Abstract: The present invention relates to a novel method for forming metal matrix composite bodies. A permeable mass of filler material is spontaneously infiltrated by a molten matrix metal. Particularly, an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltration atmosphere are in communication with the filler material, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the filler material. After infiltration has been completed to a desired extent, additional matrix metal is added to that matrix metal which has spontaneously infiltrated the filler material to result in a suspension of filler material and matrix metal, said suspension having a lower volume fraction of filler relative to matrix metal. The matrix metal then can be permitted to cool in situ or the mixture of matrix metal and filler material can be poured into a second container as a casting process to form a desired shape which corresponds to the second container.

Abstract: The present invention relates to methods for producing self-supporting ceramic and ceramic composite bodies having a protective surface region on at least a portion of the surface of the formed bodies, and bodies produced thereby.

Abstract: A refractory component for use in contact with molten metal comprising a ceramic matrix which is three-dimensionally interconnected, said matrix comprising an oxidation reaction product of aluminum parent metal, said ceramic matrix containing less than about 0.5% by weight residual parent metal, said ceramic matrix embedding at least one filler material, thereby forming a ceramic composite body, said ceramic composite body having a porosity which is interconnected, said interconnected porosity comprising openings having a mean diameter of less than about 6 microns.