Method of making ceramic composite bodies
AssigneeLanxide Technology Company, LP
InventorsBirol Sonuparlak, Kenneth S. Hatton, Dennis J. Landini, Sylvia J. Canino, Michael K. Aghajanian
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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.
Claims32
A method for producing a self-supporting ceramic structure comprising (i) a ceramic matrix obtained by oxidation of a parent metal to form a polycrystalline material comprising an oxidation reaction product and at least one additional constituent, and (ii) a protective surface region on at least a portion of a surface of the ceramic matrix comprising a primary chemical constituent different from the primary chemical constituent of the ceramic matrix, comprising the steps of:
- (a) heating a parent metal in the presence of an oxidant to a temperature above the melting point of said parent metal but below the melting point of said oxidation reaction product to form a body of molten parent metal;
- (b) reacting said body of molten parent metal with said oxidant at said temperature to permit said oxidation reaction product to form;
- (c) maintaining at least a portion of said oxidation reaction product in contact with and between said molten parent metal and said oxidant at said temperature to progressively draw molten parent metal through said oxidation reaction product towards said oxidant to permit fresh oxidation reaction product to continue to form at an interface between said oxidant and previously formed oxidation reaction product, thereby forming said polycrystalline material;
- (d) providing at least one external material on at least a portion of said polycrystalline material;
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- (e) heating said polycrystalline material to a second temperature, said second temperature being sufficient to induce at least two constituents of said polycrystalline material to react with at least a portion of said at least one external material to form at least one protective surface region on at least a portion of the surface of the ceramic matrix to form said ceramic structure.
A method for producing a self-supporting ceramic composite structure comprising (i) a ceramic matrix obtained by oxidation of a parent metal to form a polycrystalline material comprising an oxidation reaction product and at least one additional constituent, (ii) a filler material, and (iii) a protective surface region on at least a portion of a surface of the ceramic matrix comprising a primary chemical constituent different from the primary chemical constituent of the ceramic matrix, comprising the steps of:
- (a) heating a parent metal in the presence of an oxidant to a temperature above the melting point of said parent metal but below the melting point of said oxidation reaction product to form a body of molten parent metal;
- (b) providing a filler material in contact with said parent metal;
- (c) reacting said body of molten parent metal with said oxidant at said temperature to permit said oxidation reaction product to form which at least partially embeds said filler material;
- (d) maintaining at least a portion of said oxidation reaction product in contact with and between said molten parent metal and said oxidant at said temperature to progressively draw molten parent metal through said oxidation reaction product towards said oxidant to permit fresh oxidation reaction product to continue to form at an interface between said oxidant and previously formed oxidation reaction product, thereby forming said polycrystalline material at least partially embedding said filler material;
- (e) providing at least one external material on at least a portion of said polycrystalline material;
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- (f) heating said polycrystalline material at least partially embedding said filler material to a second temperature, said second temperature being sufficient to induce at least one of (i) at least two constituents of said polycrystalline material or (ii) at least one constituent of said polycrystalline material and at least a portion of said at least partially embedded filler material to react with at least a portion of said at least one external material to form at least one protective surface region on at least a portion of the surface of the ceramic matrix to form said ceramic composite structure.
A method for producing a self-supporting ceramic structure comprising (i) a ceramic matrix comprising alumina obtained by oxidation of an aluminum metal to form a polycrystalline material comprising an oxidation reaction product and at least one additional constituent, and (ii) a protective surface region on at least a portion of a surface of the ceramic matrix comprising a primary chemical constituent different from the primary chemical constituent of the ceramic matrix comprising alumina, comprising the steps of:
- (a) heating an aluminum metal in the presence of an oxidant comprising air to a temperature above the melting point of said aluminum metal but below the melting point of said oxidation reaction product to form a body of molten aluminum metal;
- (b) reacting said body of molten aluminum metal with said oxidant comprising air at said temperature to permit said oxidation reaction product to form;
- (c) maintaining at least a portion of said oxidation reaction product in contact with and between said molten aluminum metal and said oxidant comprising air at said temperature to progressively draw molten aluminum metal through said oxidation reaction product towards said oxidant to permit fresh oxidation reaction product to continue to form at an interface between said oxidant and previously formed oxidation reaction product, thereby forming said polycrystalline material;
- (d) providing at least one external material on at least a portion of said polycrystalline material;
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- (e) heating said polycrystalline material to a second temperature, said second temperature being sufficient to induce at least two constituents of said polycrystalline material to react to form at least one protective surface region on at least a portion of the surface of the ceramic matrix comprising alumina to form said ceramic structure.
Dependencies are inferred from the claim text.