Patent EP0155831A2 successfully refreshed from Google Patents.
EP0155831A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Novel ceramic materials and methods of making same
Assignee: Lanxide Technology Co LP
•
Filing: 1985-03-15
•
Granted: —
•
Expires: 2005-03-15
Abstract
Abstract Novel self-supporting oxide ceramic materials are produced by the reaction of a molten metal with a vapor phase oxidizing environment using a novel oxidation mechanism. The process is practiced by creating conditions under which the molten is drawn into and through the oxide reaction product to cause continued growth of oxide at the oxide/ atmosphere interface. Under the special conditions of the process invention, molten metal is transported along certain of the intersections of the oxide crystallites by virtue of a preferred wetting phenomenon, such that interconnected channels of the liquid metal are formed where grain boundaries of relatively high surface energy would otherwise occur in the oxide. The resulting novel ceramic product consists of an oxide phase which is interconnected largely through relatively low energy grain boundaries and a metal phase (or porosity in place of the metal phase) also at least partially interconnected.
Inventors
- 👤 Marc Stevens Newkirk
- 👤 Steven Frank Dizio
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 08:34
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/653; C04B35/01; C04B35/10; C04B35/64; C04B35/65; C04B35/652; C22; C22C; C22C29/00; C22C29/12
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
240 words
A method for producing a self supporting ceramic structure by oxidation of a liquid phase parent metal or metal alloy with a vapor phase oxidizing environment comprising the steps of: a. choosing a combination of a parent metal or metal alloy and an oxidizing environment which will form a stable polycrystalline oxide as their reaction product, and which polycrystalline oxide reaction product has a surface energy relationship with the molten parent such that at least within some portion of the temperature region in which 1) the polycrystalline oxide reaction product is stable, and 2) the parent metal or metal alloy is molten, at least some of the grain boundaries of the polycrystalline oxide are such as to allow the molten parent metal or alloy to migrate through the polycrystalline oxide reaction product and b. maintaining said parent metal or alloy in said oxidizing environment and within said portion of said temperature region so as to allow the molten parent metal or alloy to migrate through said polycrystalline oxide reaction product as the reaction product forms, along the said oxide grain boundaries, thus resulting in the parent metal or alloy being transported through its oxide reaction product, and thereby present molten parent metal or alloy at the interface between said polycrystalline oxide reaction product and said oxidizing environment, and thereby growing a ceramic structure comprised of essentially said oxide reaction product and at least some of the parent metal or alloy.
Claim 2
Independent Claim
240 words
A method for producing a self supporting ceramic structure by oxidation of a liquid phase parent metal or metal alloy with a vapor phase oxidizing environment comprising the steps of: a. choosing a combination of a parent metal or metal alloy and an oxidizing environment which will form a stable polycrystalline oxide as their reaction product, and which polycrystalline oxide reaction product has a surface energy relationship with the molten parent such that at least within some portion of the temperature region in which 1) the polycrystalline oxide reaction product is stable, and 2) the parent metal or metal alloy is molten, at least some of the grain boundaries of the polycrystalline oxide are such as to allow the molten parent metal or alloy to migrate through the polycrystalline oxide reaction product and b. maintaining said parent metal or alloy in said oxidizing environment and within said portion of said temperature region so as to allow the molten parent metal or alloy to migrate through said polycrystalline oxide reaction product as the reaction product forms, along the said oxide grain boundaries, thus resulting in the parent metal or alloy being transported through its oxide reaction product, and thereby present molten parent metal or alloy at the interface between said polycrystalline oxide reaction product and said oxidizing environment, and thereby growing a ceramic structure comprised of essentially said oxide reaction product and at least some of the parent metal or alloy.
Claim 3
Dependent Claim
19 words
A method as claimed in Claim 1, wherein the parent metal or alloy is aluminum or an aluminum alloy.
Claim 4
Dependent Claim
16 words
A method as claimed in Claim 2, wherein the parent metal comprises at least two dopants.
Claim 5
Dependent Claim
21 words
A method as claimed in Claim 3, wherein one dopant is an initiator dopant and another dopant is an accelerator dopant.
Claim 6
Dependent Claim
22 words
A method as claimed in Claim 4, wherein the initiator dopant is magnesium and the accelerator dopant is a Group IVB element.
Claim 7
Dependent Claim
18 words
A method as claimed in Claim 5, wherien the Group IVB element is silicon, tin, germanium or lead.
Claim 8
Dependent Claim
46 words
A method as claimed in Claim 5 or 6, wherein the magnesium is present in an amount of from 0.3% to 10.0% and the Group IVB element is present in an amount of from .5% to 10% based on the total weight of the aluminum alloy.
Claim 9
Dependent Claim
21 words
A process as claimed in any one of Claims 2 to 7, wherein the process temperature is from 1000°C to 1450°C.
Claim 10
Independent Claim
17 words
A method as claimed in any one of the preceding claim, wherein the oxidizing environment is air.
Claim 11
Dependent Claim
16 words
A ceramic article produced by a method as claimed in any one of the preceding claims.
Claim 12
Dependent Claim
40 words
A material comprised of a three dimensionally interconnected polycrystalline oxide structure containing between 2% and 35% by volume of a metallic constituent, wherein substantially all of the grain boundaries of said oxide have an angular mis-match of less than 20°.
Claim 13
Dependent Claim
40 words
A material comprised of a three dimensionally interconnected polycrystalline oxide structure containing between 2% and 35% by volume of a metallic constituent, wherein substantially all of the grain boundaries of said oxide have an angular mis-match of less than 20°.
Claim 14
Dependent Claim
44 words
A material as claimed in Claim 11, wherein said oxide structure contains one or more metals dispersed through said oxide structure primiarily as non-interconnected inclusions within said oxide structure and wherein said metal or metals constitute less than 15 volume percent of said material.
Claim 15
Dependent Claim
19 words
A material as claimed in Claim 11 or Claim 12, which contains 10-35 volume percent of interconnected void space.
Claim 16
Dependent Claim
22 words
A material as claimed in Claim 13, wherein the void spaces are connected by passages of less than 1 micron in width.
Claim 17
Dependent Claim
40 words
A material as claimed in Claim 11, wherein said oxide structure contains one or more metals dispersed through said oxide structure in primarily an interconnected arrangement and wherein said metal or metals constitute about 15-35 volume percent of said material.
Claim 18
Dependent Claim
20 words
A material as claimed in Claim 15, wherein void space constitutes less than 5 percent of said material by volume.
Claim 19
Dependent Claim
20 words
A material as claimed in any one of Claims 11 to 16, wherein said interconnected oxide comprises alpha aluminum oxide.
Claim 20
Dependent Claim
29 words
A material as claimed in any one of Claims 11 to 17, wherein the metallic constituent comprises aluminum either alone or in combination with one or more other metals.
Claim 21
Dependent Claim
38 words
A material comprised of a three dimensionally interconnected polycrystalline oxide structure containing dispersed inclusion of one or more metals, which inclusions constitute from 2 to 12 percent of said material by volume and which inclusions are substantially non-interconnected.
Claim 22
Dependent Claim
38 words
A material comprised of a three dimensionally interconnected polycrystalline oxide structure containing dispersed inclusion of one or more metals, which inclusions constitute from 2 to 12 percent of said material by volume and which inclusions are substantially non-interconnected.
Claim 23
Dependent Claim
34 words
A material as claimed in Claim 19, containing from 3 to 12% void volume dispersed through the material and connected to provide a void space communicating between at least two surfaces of the material.
Claim 24
Dependent Claim
26 words
A material as claimed in Claim 19, containing less than 3% void volume, said void volume being comprised of essentially discrete voids dispersed through the material.
Claim 25
Dependent Claim
25 words
A material as in Claims 19, 20 or 21, wherein said polycrystalline oxide is alpha aluminum oxide and wherein one of said metals is aluminum.
Claim 26
Dependent Claim
16 words
The method of Claim 1 in which said oxide reaction product is interconnected in three dimensions.
Claim 27
Independent Claim
123 words
A method of producing a self supporting ceramic refractory structure comprising the steps of: (a) alloying aluminum with between about 0.3% to about 10.0% magnesium by weight of the aluminium together with between about .5% to about 10% by weight of the aluminum of a Group IVB metal; (b) reacting the alloy formed according to step (a) in an oxidizing environment at temperatures between about 1100°C to about 1450°C rendering the alloy molten and progessively growing an oxide layer on the surface of the alloy towards the oxidizing environment by transport of said aluminum along grain boundaries of the formed oxide layer; and (c) maintaining the reaction of step (b) for a time sufficient to grow a desired thickness of said oxide layer.
Claim 28
Independent Claim
123 words
A method of producing a self supporting ceramic refractory structure comprising the steps of: (a) alloying aluminum with between about 0.3% to about 10.0% magnesium by weight of the aluminium together with between about .5% to about 10% by weight of the aluminum of a Group IVB metal; (b) reacting the alloy formed according to step (a) in an oxidizing environment at temperatures between about 1100°C to about 1450°C rendering the alloy molten and progessively growing an oxide layer on the surface of the alloy towards the oxidizing environment by transport of said aluminum along grain boundaries of the formed oxide layer; and (c) maintaining the reaction of step (b) for a time sufficient to grow a desired thickness of said oxide layer.
Claim 29
Dependent Claim
28 words
A method as in Claim 24, wherein step (c) is practiced for a time substantially beyond the exhaustion of the molten alloy to produce a porous ceramic structure.
Claim 30
Dependent Claim
20 words
A method as in Claim 24, wherien step (c) is practiced to form inclusions of metal in said ceramic structure.
Claim 31
Dependent Claim
13 words
A ceramic article which is the produc of the process of Claim 24.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.