Lanxide Technology Company, LP

H Daniel Lesher

Marc S Newkirk

Andrew W Urquhart

Harry Richard Zwicker

Ratnesh K Dwivedi

Robert C Kantner

Danny R White

Christopher R Kennedy

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. The method provides ceramic composite articles having therein at least one cavity inversely replicating the shape of the mold which supplied the parent metal for oxidation.

Inverse shape replication method of making ceramic composite articles

Self-supporting ceramic composite structures having filler embedded therein are taught as being 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.

Composite ceramic articles

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.

Ceramic composite articles obtained by inverse shape replication

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 inconnel alloy, which has a coefficient of thermal expansion which is significantly greater than that of the filler. The segments are arranged to defined 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.

Assembly for making ceramic composite structures and method of using the

A method is provided of producing a self-supporting ceramic composite structure having one or more encasement members, such as an encasing steel sleeve, joined to it by growth of the ceramic material to engagement surface(s) of the encasement member(s). A parent metal is contacted with a body of filler which is encased by the encasement member(s). The resulting assembly is heated to melt and oxidize the parent metal, e.g., aluminum, to form a polycrystalline material comprising an oxidation reaction product which grows through the body of filler and stops at the engagement surface(s) of the encasement member(s) which thereby determines the surface geometry of the grown ceramic matrix. Upon cooling, the encasement member(s) is shrink-fitted about the ceramic composite body. The invention also provides the resultant articles, for example, a ceramic composite body having a stainless steel member affixed thereto.

Ceramic composite structures having intrinsically fitted encasement

A method for producing a self-supporting ceramic composite structure which includes a ceramic matrix embedding a filler, includes oxidizing a parent metal to form a polycrystalline material comprising the oxidation reaction product of the parent metal with an oxidant and, optionally, one or more metallic constituents, and the filler embedded by the matrix. The method includes heating a first source of molten parent metal and a source of molten parent metal and contacting the first source of molten parent metal with a permeable bedding of filler. The first source of molten parent metal is reacted with the oxidant to form the oxidation reaction product and is replenished from the reservoir as the reacting continues for a time sufficient to grow the oxidation reaction product to a desired extent and thereby embed at least a portion of the bedding of filler within the oxidation reaction product to form the ceramic composite structure. The bedding of filler may have any suitable shape, including that of a hollow body, the interior of which is contacted by the first source of molten parent metal to grow the oxidation reaction product through the shaped, hollow body of filler.

Reservoir feed method of making ceramic composite structures and

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.

Methods of making composite ceramic articles

A method for producing a self-supporting ceramic composite structure, which includes a ceramic matrix embedding a filler, includes oxidizing a parent metal to form a polycrystalline material comprising the oxidation reaction product of the parent metal with an oxidant and, optionally, one or more metallic constituents, and the filler embedded by the matrix. The method includes heating a first source of molten parent metal and a reservoir source of molten parent metal and contacting the first source of molten parent metal with a permeable bedding of filler. The first source of molten parent metal is reacted with the oxidant to form the oxidation reaction product and is replenished from the reservoir as the reacting continues for a time sufficient to grow the oxidation reaction product to a desired extent and thereby embed at least a portion of the bedding of filler within the oxidation reaction product to form the ceramic composite structure. The bedding of filler may have any suitable shape, including that of a hollow body, the interior of which is contacted by the first source of molten parent metal to grow the oxidation reaction product through the shaped, hollow body of filler.

Methods of making composite ceramic articles having embedded filler

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.

Method of making ceramic composites

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.

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 there in 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. The method provides ceramic composite articles having therein at least one cavity inversely replicating the shape of the mold which supplied the parent metal for oxidation.

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Wilmington, DE, United States of America

H Daniel Lesher