EP0169067A2
Expired / Lapsed
EP
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Methods of making self-supporting ceramic materials
Assignee: Lanxide Technology Co LP
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Filing: 1985-07-17
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Granted: —
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Expires: 2005-07-17
Abstract
Abstract A method to produce a self-supporting ceramic structure by oxidation of a liquid phase parent metal with a vapor phase oxidizing environment includes applying a layer having at least one dopant material to at least a portion of a parent metal of the type having an oxide skin which is normally impervious to an oxiding atmosphere. Upon temperature elevation, the parent metal becomes molten and due to the dopant material in the layer, is caused to migrate through the oxide skin and layer so as to be exposed to the oxidizing atmosphere whereupon an oxide of the parent metal is formed. Migration of the parent metal continues through the formed parent metal oxide to grow layer upon layer of parent metal oxide to thus achieve a self-supporting oxide structure.
Inventors
- 👤 Marc Stevens Newkirk
- 👤 Harry Richard Zwicker
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 18:15
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/622; C04B35/64; C04B35/65; C04B35/652
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
232 words
A method for producing a self-supporting ceramic structure by oxidation of a liquid phase parent metal with a vapor phase oxidizing environment comprising the steps of: (a) applying a layer including at least one dopant material to at least a portion of the surface of a parent metal of the type having an oxidised surface skin which is normally impervious to the oxidizing environment, said at least one dopant material being capable of causing the parent metal to migrate through any oxidiseú surface skin present to expose the migrated parent metal to the oxidizing environment when said parent metal is raised to a sufficient temperature, (b) elevating the temperature of the parent metal having the dopant material applied thereto to render the parent metal in a liquid phase and to cause the parent metal to migrate through the surface skin to present the migrated parent metal to the oxidizing environment; and (c) maintaining the parent metal at an elevated temperature and in the oxidizing atmosphere for a time sufficient to allow the presented parent metal to react with the oxidizing atmosphere to form an oxidation reaction product of the parent metal within and beyond the dopant- including layer and for a time sufficient to continually present parent metal to the oxidizing atmosphere to form additional oxidation reaction product of the parent metal thus forming a self-supporting ceramic polycrystalline oxidation reaction product structure.
Claim 2
Independent Claim
232 words
A method for producing a self-supporting ceramic structure by oxidation of a liquid phase parent metal with a vapor phase oxidizing environment comprising the steps of: (a) applying a layer including at least one dopant material to at least a portion of the surface of a parent metal of the type having an oxidised surface skin which is normally impervious to the oxidizing environment, said at least one dopant material being capable of causing the parent metal to migrate through any oxidiseú surface skin present to expose the migrated parent metal to the oxidizing environment when said parent metal is raised to a sufficient temperature, (b) elevating the temperature of the parent metal having the dopant material applied thereto to render the parent metal in a liquid phase and to cause the parent metal to migrate through the surface skin to present the migrated parent metal to the oxidizing environment; and (c) maintaining the parent metal at an elevated temperature and in the oxidizing atmosphere for a time sufficient to allow the presented parent metal to react with the oxidizing atmosphere to form an oxidation reaction product of the parent metal within and beyond the dopant- including layer and for a time sufficient to continually present parent metal to the oxidizing atmosphere to form additional oxidation reaction product of the parent metal thus forming a self-supporting ceramic polycrystalline oxidation reaction product structure.
Claim 3
Dependent Claim
24 words
A method claimed as in Claim 1 wherein an amount of the dopant material is also present as a constituent of the parent metal.
Claim 4
Dependent Claim
51 words
A method as claimed in Claim 1 or Claim 2, wherein at least two dopant materials are utilised, an initiator dopant and an accelerator dopont, and at least one of the said initiator and accelerator dopants is the said at least one dopant applied to the surfaces of the parent metal.
Claim 5
Independent Claim
21 words
A method as claimed in any one of the preceding claims wherein the parent metal is aluminum or an aluminum alloy.
Claim 6
Dependent Claim
27 words
A method as in Claim 4 wherein step (a) is practiced by applying at least one layer including an accelerator dopant material and an initiator dopant material.
Claim 7
Dependent Claim
33 words
A method as claimed in Claim 5 wherein a first layer including the accelerator dopant is first applied to the surface and then a second layer including the initiator dopant is subsequently applied.
Claim 8
Dependent Claim
33 words
A method as claimed in Claim 5 wherein a first layer including the initiator dopant is first applied to the surface and then a second layer including the accelerator dopant is subsequently applied.
Claim 9
Dependent Claim
31 words
A method as claimed in claim 5 wherein a layer comprising both the accelerator and initiator dopants is applied to at least a portion of the surface of the parent metal.
Claim 10
Dependent Claim
18 words
A method as claimed in any of Claim 5 to 8 wherein the initiator dopant material comprises magnesium.
Claim 11
Dependent Claim
50 words
A method as claimed in Claim 9 wherein the initiator dopant material is MgO or MgAl 2 O 4 . 11. A method as claimed in Claim 10 wherein the initiator dopant material is applied to the surface portion in an amount greater than 0.1 gram per cm 2 .
Claim 12
Independent Claim
22 words
A method as claimed in any one of claims 5 to 11 wherein the accelerator dopant material comprises a Group IVB element.
Claim 13
Dependent Claim
19 words
A method as claimed in Claim 12 wherein the accelerator dopant is an oxide of a Group IVB element.
Claim 14
Dependent Claim
22 words
A method as claimed in Claim 13 wherein the accelerator dopant comprises a sheet of silicon-containing glass overlayed on said surface portion.
Claim 15
Independent Claim
32 words
A method as claimed in any one of Claims 4 to 14, Where the temperature of the parent metal is maintained in step (c) at a temperature of from 1000°C to 1450°C
Claim 16
Dependent Claim
27 words
A method as claimed in Claim 15 wherein the temperature of the parent metal is maintained in step (c) at a temperature of from 1000°C to 1350°C.
Claim 17
Dependent Claim
41 words
1 7. A method as claimed in Claim 2 wherein the parent metal is alloyed with an initiator dopant and wherein step (b) is practiced by applying a layer including an accelerator dopant to the surface portion of the parent metal.
Claim 18
Dependent Claim
38 words
A method as in Claim 2 wherein the parent metal is alloyed with an accelerator dopant and whereine step (b) is practiced by applying a layer including an initiator dopant to the surface portion of the parent metal.
Claim 19
Independent Claim
42 words
A method as claimed in any one of Claims 4 to 16, wherein the product formed is a ceramic polycrystalline interconnected oxide structure containing some unoxidized constituents of the parent metal, said interconnected oxide confirming not less than 80% alpha aluminum oxide.
Claim 20
Dependent Claim
16 words
A ceramic material produced by a process as claimed in any one of the preceding claims.
References Cited (Backward Citations)
No citation records indexed.
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