Method of making ceramic composite articles with shape replicated surfaces

Claim 1

A method for producing a self-supporting ceramic composite body having a negative pattern inversely replicating a positive pattern of a parent metal body, said composite body comprising (1) a ceramic matrix obtained by oxidation of a parent metal to form a polycrystalline material comprising an oxidation reaction product of said parent metal with an oxidant; and (2) a filler embedded by said ceramic matrix, the method comprising the steps of: (a) providing a parent metal body having (1) a positive pattern section for inverse replication, and (2) a non-replicating section; (b) emplacing at least said positive pattern section of said parent metal body in conforming engagement with a bed of conformable filler and using a means for promoting growth of said oxidation reaction product from said positive pattern section into said filler material and a means for inhibiting oxidation reaction product growth from said non-replicating section, said conformable filler (i) being permeable to said oxidant when said oxidant contacts molten parent metal in step (c), and (ii) being permeable to infiltration by the growth of the oxidation reaction product through said conformable filler; (c) heating the parent metal body to a temperature region above its melting point but below the melting point of its oxidation reaction product to form a body of molten parent metal and, at said temperature, (1) reacting the molten parent metal with said oxidant to form said oxidation reaction product. (2) maintaining at least a portion of said oxidation reaction product in contact with and between said body of molten metal and said oxidant, to progressively draw molten metal from said body of molten metal through the oxidation reaction product and into contact with said oxidant within said bed of filler to concurrently form said negative pattern in said bed of filler as fresh oxidation reaction product Continues to form at the interface between said oxidant and previously formed oxidation reaction product, (3) and continuing said reacting for a time to at least partially embed said bed of conformable filler within said oxidation reaction product by growth of oxidation reaction product into said conformable filler to form said composite body with said negative pattern; and (d) separating the resulting self-supporting ceramic composite body from any excess filler and any unreacted parent metal.

Claim 2

A method for producing a self-supporting ceramic composite body having a negative pattern inversely replicating a positive pattern of a parent metal body, said composite body comprising (1) a ceramic matrix obtained by oxidation of a parent metal to form a polycrystalline material comprising an oxidation reaction product of said parent metal with an oxidant; and (2) a filler embedded by said ceramic matrix, the method comprising the steps of: (a) providing a parent metal body having (1) a positive pattern section for inverse replication, and (2) a non-replicating section; (b) emplacing at least said positive pattern section of said parent metal body in conforming engagement with a bed of conformable filler and using a means for promoting growth of said oxidation reaction product from said positive pattern section into said filler material and a means for inhibiting oxidation reaction product growth from said non-replicating section, said conformable filler (i) being permeable to said oxidant when said oxidant contacts molten parent metal in step (c), and (ii) being permeable to infiltration by the growth of the oxidation reaction product through said conformable filler; (c) heating the parent metal body to a temperature region above its melting point but below the melting point of its oxidation reaction product to form a body of molten parent metal and, at said temperature, (1) reacting the molten parent metal with said oxidant to form said oxidation reaction product. (2) maintaining at least a portion of said oxidation reaction product in contact with and between said body of molten metal and said oxidant, to progressively draw molten metal from said body of molten metal through the oxidation reaction product and into contact with said oxidant within said bed of filler to concurrently form said negative pattern in said bed of filler as fresh oxidation reaction product Continues to form at the interface between said oxidant and previously formed oxidation reaction product, (3) and continuing said reacting for a time to at least partially embed said bed of conformable filler within said oxidation reaction product by growth of oxidation reaction product into said conformable filler to form said composite body with said negative pattern; and (d) separating the resulting self-supporting ceramic composite body from any excess filler and any unreacted parent metal.

Claim 13

The method of any one of claims 1, 2, 3, 6, 7, 8, 9, 10 or 11, wherein said oxidant comprises a vapor-phase oxidant.

Claim 16

The method of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 14, wherein said parent metal body comprises an aluminum parent metal.

Claim 21

The method of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein said parent metal body comprises a metal selected from the group consisting of aluminum, silicon, titanium, tin, zirconium and hafnium parent metals and mixtures thereof.

Claim 22

The method of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein said oxidant comprises a material selected from the group consisting of at least one of an oxygen-containing gas, a nitrogen-containing gas, a halogen, sulfur, phosphorus, arsenic, carbon, boron, selenium, tellurium, silica, methane, ethane. propane, acetylene, ethylene, propylene, and mixtures thereof.

Claim 23

The method of any of claims I, 2, 3, 4, 5, 6, 7, 8 or 9, wherein said conformable filler comprises a material selected from the group consisting of hollow bodies, particulates, fibers, whiskers, spheres, steelwool, plates aggregate, wires, rods, bars, platelets, pellets, tubes, refractory fiber cloth, tubules, and mixtures thereof.

Claim 24

The method of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein said filler comprises a material selected from the group consisting of at least one of aluminum oxide, silica, silicon carbide, silicon aluminum oxynitride, zirconium oxide, barium titanate, boron nitride, silicon nitride, magnesium aluminate, ferrous alloys, iron-chromium-aluminum alloy, carbon, aluminum, and mixtures thereof.

Claim 25

A method for producing a self-supporting ceramic composite body having a negative pattern inversely replicating a positive pattern of a parent metal body, said composite body comprising (1) a ceramic matrix obtained by oxidation of an aluminum parent metal to form a polycrystalline material comprising an aluminum oxidation reaction product of said parent metal with air; and (2) a filler embedded by said ceramic matrix, the method of comprising the steps of: (a) providing an aluminum parent metal body having (1) a positive pattern section for inverse replication, and (2) a non-replicating section; (b) emplacing at least said positive pattern section of said parent metal precursor in conforming engagement with a bed of conformable filler and using a means for promoting growth of said oxidation reaction product primarily from said positive pattern section into said filler material and a means for inhibiting oxidation reaction product growth from said non-replicating section, said conformable filler (i) being permeable to air to enable contact of the molten parent metal by air in step (c), and (ii) being permeable to infiltration by the growth of the oxidation reaction product through said conformable filler; (c) heating the emplaced positive pattern to a temperature region of from about 850° C. to about 1450° C. to form a body of molten aluminum parent metal and, at said temperature, (1) reacting the molten parent metal with said air to form said alumina oxidation reaction product, (2) maintaining at least a portion of said alumina oxidation reaction product in contact with and between said body of molten metal and said air, to progressively draw molten metal from said body of molten metal through the alumina oxidation reaction product and into said bed of filler to concurrently from said negative pattern in said bed of conformable filler as fresh alumina oxidation reaction product continues to form at an interface between said air and previously formed alumina oxidation reaction product, and (3) continuing said reacting for a time to at least partially embed said bed of conformable filler within said alumina oxidation reaction product by growth of oxidation reaction product into said conformable filler to form said composite body with said composite body with said negative pattern; and (d) separating the resulting self-supporting ceramic composite body from any excess filler and any unreacted parent metal.

Claim 26

A method for producing a self-supporting ceramic composite body having a negative pattern inversely replicating a positive pattern of a parent metal body, said composite body comprising (1) a ceramic matrix obtained by oxidation of an aluminum parent metal to form a polycrystalline material comprising an aluminum oxidation reaction product of said parent metal with air; and (2) a filler embedded by said ceramic matrix, the method of comprising the steps of: (a) providing an aluminum parent metal body having (1) a positive pattern section for inverse replication, and (2) a non-replicating section; (b) emplacing at least said positive pattern section of said parent metal precursor in conforming engagement with a bed of conformable filler and using a means for promoting growth of said oxidation reaction product primarily from said positive pattern section into said filler material and a means for inhibiting oxidation reaction product growth from said non-replicating section, said conformable filler (i) being permeable to air to enable contact of the molten parent metal by air in step (c), and (ii) being permeable to infiltration by the growth of the oxidation reaction product through said conformable filler; (c) heating the emplaced positive pattern to a temperature region of from about 850° C. to about 1450° C. to form a body of molten aluminum parent metal and, at said temperature, (1) reacting the molten parent metal with said air to form said alumina oxidation reaction product, (2) maintaining at least a portion of said alumina oxidation reaction product in contact with and between said body of molten metal and said air, to progressively draw molten metal from said body of molten metal through the alumina oxidation reaction product and into said bed of filler to concurrently from said negative pattern in said bed of conformable filler as fresh alumina oxidation reaction product continues to form at an interface between said air and previously formed alumina oxidation reaction product, and (3) continuing said reacting for a time to at least partially embed said bed of conformable filler within said alumina oxidation reaction product by growth of oxidation reaction product into said conformable filler to form said composite body with said composite body with said negative pattern; and (d) separating the resulting self-supporting ceramic composite body from any excess filler and any unreacted parent metal.

Claim 27

The method of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 24, including doping said parent metal with at least one dopant material by at least one of (a) alloying at least one dopant into said parent metal, and (b) applying at least one dopant as a layer of dopant material onto at least a portion of a surface of said positive pattern of said parent metal body, and (c) providing at least one dopant at least partially within said conformable filler adjacent to said positive pattern.