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 oxdiation reaction of a parent metal to form a polycrystalline material which comprises 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: 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 carbide material which may contain one or both of 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 carbide material, boron-containing compound and/or carbon-containing compound. The relative amounts of reactants and process conditions may be altered or controlled to yield a body containing varying volume percents of ceramic, metal, ratios of one ceramic to another and porosity.

Abstract: Self-supporting bodies are produced by reactive infiltration of a parent metal into a boron donor material and a carbon 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 varying volume percents of ceramic, metal, ratios of one ceramic to another and porosity.

Abstract: A method is provided for producing a self-supporting ceramic or ceramic composite body by oxidation of a parent metal, the self-supporting body having a graded microstructure characterized by a plurality of zones differing from each other in one or more properties. The zones in the body are attained by altering the process conditions during formation of the body such that a zone of the oxidation reaction product formed posterior to said altering has at least one property different from a zone of the oxidation reaction product formed anterior to said altering.

Abstract: There is provided a method for producing a self-supporting ceramic composite comprising (1) a ceramic matrix obtained by oxidation of an aluminum zinc alloy to form a polycrystalline oxidation reaction product of the metal with an oxidant, and (2) one or more fillers embedded by the matrix. The metal alloy and permeable mass of filler having at least one defined surface boundary are oriented relative to each other so that formation of the oxidation reaction product will occur into said mass of filler and in a direction towards said defined surface boundary. On heating the metal to a first temperature above its melting point but below the melting point of said oxidation reaction product to form a body of molten parent metal, the molten metal reacts with said oxidant to form said oxidation reaction product which infiltrates said mass of filler to said defined surface boundary.

Abstract: A heat storage medium comprising a body of parent metal and an intrinsically cohesive ceramic layer formed integrally with the metal body and encapsulating said metal body is produced by the directed oxidation of a body of parent metal outwardly from the surface of said body to form integrally with the body of parent metal a layer of oxidation reaction product which encapsulates unreacted parent metal and forms a cavity resulting from the depletion of aprent metal.

Abstract: A method for producing materials having a high purity, which comprises forming an oxidation reaction product of a parent metal and an oxygen-containing vapor-phase oxidant, comminuting the resulting ceramic body and leaching any non-oxidation reaction product and/or corresponding filler materials therefrom, and recovering said substantially pure materials.

Abstract: An aluminum metal matrix composite comprises an aluminum metal matrix embedding a second filter, such as a ceramic second filler, and is formed by contacting, for example, a molten aluminum metal with a permeable mass of second filler within a ceramic impervious mold formed by growing a polycrystalline oxidation reaction product into a first filler. By hermetically sealing the second filler within the mold with a body of molten aluminum metal, the latter spontaneously infiltrates the mass of second filler at moderate temperatures, e.g. about 900.degree. C., without need of any other infiltration expedients. The molten mass containing the infiltrated ceramic filler is solidified to provide the metal matrix composite which may be recovered from the mold.

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: 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: 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 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 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: This invention relates to a new ceramic-metal composite body and a method for producing the same. Particularly, a compliant layer composition is utilized for preventing the rupture of a ceramic article and/or the yielding or failure of a metal during the pouring, solidification and cooling of a molten metal which has been cast around the ceramic. A slurry composition for the compliant layer includes plaster of paris, a liquid vehicle and a filler material. The slurry composition is coated on the ceramic article and thereafter is heat-treated to form a compliant layer. Ceramic-metal composite bodies comprising low strength hollow articles and high expansion coefficient metals may be manufactured according to the method of this invention.

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

Abstract: A method is provided for producing a self-supporting ceramic body comprising a polycrystalline material comprised of the oxidation reaction product of a parent metal and having therein one or more channels which inversely replicate the geometry of a configured fugitive metal. The method includes providing an assembly of the configured fugitive metal and the parent metal, optionally including a bed of permeable filler, and heating the assembly to form a body of molten parent metal. The molten parent metal is oxidized under selected conditions to grow the polycrystalline material to engulf the configured fugitive metal (and to infiltrate the filler, if the filler is present) and to cause the fugitive metal to disperse into the engulfing polycrystalline material thereby leaving behind as the one or more channels the space formerly occupied by the configured fugitive metal.

Abstract: The invention concerns self-supporting ceramic structures, including ceramic composite structures embedding a filler, and methods of making them. The ceramic structures comprise a polycrystalline material made by oxidation of a body of molten parent metal with an oxidant. The polycrystalline material has a first region substrate surmounted by a terminal region stratum which is integral with the first region. The terminal region stratum is harder and of denser, finer crystalline structure than the first region substrate and is formed in a reaction stage subsequent to the reaction stage in which the first region of polycrystalline material is formed. Growth of the first stage is attained by attenuating or interrupting the transport of molten parent metal to the first region under conditions which nonetheless leave or maintain therein enough oxidizable molten parent metal to form the polycrystalline material of the terminal region.

Abstract: A method of producing shaped, self-supporting ceramic bodies includes preparing a mold by applying a gas-permeable, conformable material to a shape-defining surface of a shaped parent metal. The gas-permeable material, when set or stable, provides a mold with a shaped surface which is defined by, and is therefore substantially congruent to, the shape-defining surface. Upon heating, the parent metal melts and flows from the mold into a receptacle without disturbing the mold. Oxidation reaction product is then grown by oxidation of the molten parent metal with a vapor-phase oxidant to form an oxidation reaction produce which grows into the mold cavity and is shaped by it. A ceramic body is recovered from the mold and has substantially the same shape as the pattern section of the original shaped parent metal.

Abstract: An assembly for the preparation of ceramic composite structures includes a segmented container within which a permeable filler is retained and a parent metal body is contacted with the bed of permeable filler. The segmented container is comprised of one or more segments made of a material, such as an INCONEL alloy, which has a coefficient of thermal expansion which is significantly greater than that of the filler. The segments are arranged to define between or among them one or more expansion joints which are effective to accommodate circumferential thermal expansion of the segments to thereby inhibit or prevent volumetric expansion of the container. A method of forming ceramic composite structures includes heating the resulting assembly in the presence of an oxidant to melt and oxidize the parent metal, e.g., aluminum, to form a polycrystalline material comprising an oxidation reaction product which grows through the mass of filler to embed it and thus form the composite structure.