Methods of making ceramic articles with a modified metal-containing component

In a method for producing a self-supporting ceramic body by oxidation of a parent metal, which includes the steps of:

• heating said parent metal in the presence of a vapor-phase oxidant to form a body of molten parent metal and reacting said molten parent metal with said oxidant at said temperature to form an oxidation reaction product, which product is in contact with and extends between said body of molten metal and said oxidant, maintaining the temperature to keep the metal molten and progressively drawing molten metal through the oxidation reaction product towards the oxidant so that the oxidation reaction product continues to form at the interface between the oxidant and previously formed oxidation reaction product, and continuing said reaction for a time sufficient to produce said ceramic body comprising said oxidation reaction product and an interconnected metal-containing component, which component is at least partially interconnected and at least partially accessible from at least one external surface of the ceramic body, the improvement comprising:
• (A) contacting said at least one external surface of said ceramic body with a foreign metal different from said parent metal, so as to create a concentration gradient between said foreign metal and said interconnected metal-containing component, said contacting occuring for a sufficient amount of time to permit interdiffusion between said foreign metal and said interconnected metal-containing component, whereby at least a portion of said interconnected metal-containing component is displaced from said ceramic body by said foreign metal;
• and
• (B) recovering said ceramic body.

A method for producing a self-supporting ceramic composite body comprising the steps of:

• positioning a parent metal adjacent to a permeable mass of filler and orienting said parent metal and said filler relative to each other so that formation of an oxidation reaction product of the parent metal and an oxidant will occur and form in a direction towards and into said mass of filler;
• heating said parent metal to a temperature above its melting point but below the melting point of its oxidation reaction product to form a body of molten parent metal and reacting the molten parent metal with said oxidant at said temperature to form said oxidation reaction product, and at said temperature maintaining at least a portion of said oxidation reaction product in contact with and extending between said body of molten metal and said oxidant, to draw molten metal through the oxidation reaction product towards the oxidant and towards and into the adjacent mass of filler so that fresh oxidation reaction product continues to form within the mass of filler at an interface between the oxidant and previously formed oxidation reaction product;
• continuing said reacting for a time sufficient to embed at least a portion of the filler with said oxidation reaction product, thereby forming a ceramic composite body with a metal-containing component, which component is at least partially interconnected and at least partially accessible from at least one external surface of the ceramic composite body;
• contacting said at least one external surface of said ceramic composite body with a foreign metal different from said parent metal, so as to create a concentration gradient between said foreign metal and said interconnected metal-containing component, said contacting occurring for sufficient amount of time to permit interdiffusion between said formed metal and said interconnected metal-containing component, whereby at least a portion of said interconnected metal-containing component is displaced from said ceramic composite body by said foreign metal;
• and
• recovering said ceramic composite body.