Novel ceramic materials and methods for making same
AssigneeLanxide Technology Company, LP
InventorsMarc S. Newkirk, Steven F. Dizio
Life of this patent
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Abstract
Novel self-supporting ceramic structures are produced by the oxidation reaction of a molten metal precursor with a vapor-phase oxidant to form an oxidation reaction product. Molten metal is drawn through the oxidation reaction product towards the oxidant to cause continued growth of the product at the interface between oxidant and previously formed product. This reaction or growth is continued to form a thick, self-supporting ceramic body. The resulting ceramic material of the polycrystalline growth product consists essentially of an oxidation reaction product and, optionally, one or more non-oxidized constituents of the metal precursor.
Claims29
A method for producing a self-supporting ceramic body, adapted or fabricated for use as an article of commerce, by oxidation of a parent metal to form a polycrystalline material consisting essentially of (1) the oxidation reaction product of said parent metal with a vapor-phase oxidant, and (2) one or more non-oxidized constituents of the parent metal, which comprises:
- heating said parent metal to a temperature above the melting point of said parent metal but below the melting point of the oxidation reaction product to form a body of molten metal and, at said temperature;
- (a) reacting said body of molten metal with said vapor-phase oxidant to form said oxidation reaction product,
- (b) maintaining at least a portion of said oxidation reaction product in contact with and between said body of molten metal and said oxidant, to draw molten metal through the oxidation reaction produot towards the oxidant so that oxidation reaction product continues to form at the interface between the oxidant and previously formed oxidation reaction product, and leaving non-oxidized constituents of said parent metal dispersed through said polycrystalline material, and
- (c) continuing said reaction for a time sufficient to produce said ceramic body.
A method for producing a self-supporting ceramic body, adapted or fabricated for use as an article of commerce, by oxidation of a parent metal to form a polycrystalline material consisting essentially of (1) the oxidation reaction product of said parent metal with a vapor-phase oxidant, and (2) one or more non-oxidized constituents of the parent metal, which comprises:
- (a) choosing an oxidant and a parent metal which, when molten, will react with the oxidant to form a stable oxidation reaction product having a surface free energy relationship with the molten metal such that within some portion of a temperature region in which the parent metal is molten, at least some of the grain boundaries of said oxidation reaction product have a surface free energy greater than the alternative configuration of two substantially geometrically equivalent grain/metal interface boundaries resulting in the formation of channels of molten metal,
- (b) maintaining a body of said molten parent metal in contact with at least a portion of said oxidation reaction product and remote from said oxidant, to draw molten metal along said channels towards and into contact with said oxidant to continue to form oxidation reaction product, and leaving non-oxidized constituents of said parent metal dispersed through said polycrystalline material, and
- (c) continuing said reaction for a time sufficient to produce said ceramic body.
A method for producing a self-supporting ceramic body, adapted or fabricated for use as an article of commerce, by oxidation of a parent metal to form a polycrystalline material consisting consisting essentially of the oxidation reaction product of said parent metal with a vapor-phase oxidant, which comprises:
- heating said parent metal to a temperature above the melting point of said parent metal but below the melting point of the oxidation reaction product to form a body of molten metal and, at said temperature;
- (a) reacting said body of molten metal with said vapor-phase oxidant to form said oxidation reaction product,
- (b) maintaining at least a portion of said oxidation reaction product in contact with and between said body of molten metal and said oxidant, to draw molten metal through the oxidation reaction product towards the oxidant so that oxidation reaction product continues to form at the interface between the oxidant and previously formed oxidation reaction product, and
- (c) continuing said reaction for a time sufficient to product said ceramic body.
Dependencies are inferred from the claim text.