US 5,494,868 AGranted

Inverse shape replication method of making ceramic composite articles

AssigneeLanxide Technology Company, LP

InventorsMarc S. Newkirk, Andrew W. Urquhart, H. Daniel Lesher

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Abstract

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.

Claims21

Dependent claims

A method for producing a self-supporting ceramic composite body comprising (1) a ceramic matrix obtained by oxidation of at least one parent metal to form a polycrystalline material comprising at least one oxidation reaction product of said at least one parent metal with at least one liquid-phase oxidant;

and (2) at least one filler embedded by said ceramic matrix, the method comprising the steps of:
(a) positioning said at least one parent metal adjacent to at least one permeable mass of said at least one filler and orienting said at least one parent metal and said at least one filler relative to each other so that formation of said at least one oxidation reaction product will occur in a direction towards and into said at least one permeable mass of said at least one filler;
(b) heating said at least one parent metal to a temperature above its melting point but below the melting point of its at least one oxidation reaction to form at least one body of molten parent metal and reacting the at least one molten parent metal with an oxidant consisting essentially of said at least one liquid-phase oxidant at said temperature to form said at least one oxidation reaction product, and at said temperature maintaining at least a portion of said at least one oxidation reaction product in contact with and extending between said at least one body of molten metal and said at least one liquid-phase oxidant, to draw molten metal through the at least one oxidation reaction product towards the at least one liquid-phase oxidant and towards and into the adjacent mass of the at least one filler so that fresh oxidation reaction product continues to form within the mass of at least one filler at an interface between the at least one liquid-phase oxidant and previously formed the at least one oxidation reaction product;
and
(c) continuing said reacting for a time sufficient to embed at least a portion of the at least one filler within said polycrystalline material.

2 more elements

and (2) at least one filler embedded by said matrix, the method comprising the steps of:
(a) positioning said at least one parent metal adjacent to at least one permeable mass of the at least one filler and orienting said at least one parent metal and said at least one filler relative to each other so that formation of said at least one oxidation reaction product will occur in a direction towards and into said at least one permeable mass of the at least one filler;
(b) heating said at least one parent metal to a temperature above its melting point but below the melting point of its at least one oxidation reaction to form at least one body of molten parent metal and reacting the molten parent metal with an oxidant consisting essentially of said at least one solid-phase oxidant at said temperature to form said at least one oxidation reaction product, and at said temperature maintaining at least a portion of said at least one oxidation reaction product in contact with and extending between said at least one body of molten metal and said at least one solid-phase oxidant, to draw molten metal through the at least one oxidation reaction product towards the at least one solid-phase oxidant and towards and into the adjacent mass of the at least one filler so that fresh oxidation reaction product continues to form within the mass of the at least one filler at an interface between the at least one solid-phase oxidant and previously formed oxidation reaction product;
and
(c) continuing said reacting for a time sufficient to embed at least a portion of the at least one filler within said polycrystalline material.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/176,058Filed 3 Jan 1994 · continuation
Priority: 27 Jan 1986
Granted: 27 Feb 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

C04B 35/117
Fine ceramics: composites
C04B 35/652
Reaction sintering of free metal- or free silicon-containing compositions: directional oxidation or solidification, e.g. Lanxide process
C04B 2235/3217
Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, hydroxides, chlorides: aluminum oxide or oxide…
C04B 2235/3418
Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, hydroxides,…:…

Family

Serial823,542Parent of this division · filed 27 Jan 1986
Serial329,794Parent of this continuation · filed 28 Mar 1989
US 4,828,785 AParent of this division · filed 9 May 1989
Serial763,681Parent of this continuation · filed 23 Sep 1991
US 5,051,382 AParent of this continuation · filed 24 Sep 1991
Serial983,191Parent of this continuation · filed 30 Nov 1992
US 5,168,081 AParent of this continuation · filed 1 Dec 1992
US 5,275,987 AParent of this continuation · filed 4 Jan 1994
US 5,494,868 AThis patent

From the US filing history. Foreign family members aren’t listed.