US4948676A
Expired / Lapsed
US
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Cermet material, cermet body and method of manufacture
Assignee: Moltech Invent SA
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Filing: 1987-08-19
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Granted: 1990-08-14
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Expires: 2007-08-19
Abstract
Abstract The present invention provides a ceramic/metal composite material comprising cerium/aluminum mixed oxides as the ceramic phase and an alloy or intermetallic compond of cerium and at least one of aluminum, nickel, iron and cobalt as the metal phase. The ceramic phase may comprise interengaged crystal lattices of ceria and alumina. The material may be a self-sustaining body which may be used as substrate for a dimensionally stable anode in molten sale aluminum electrowinning cells, coated with a protective layer of cerium oxyfluoride in situ during electrolysis in molten cryolite containing cerium ions.
Inventors
- 👤 Dominique Darracq
- 👤 Jean-Jacques Duruz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:13
CPC Classifications
C; C22; C22C; C22C29/00; C22C29/12; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/65; C22C1/00; C22C1/04; C22C1/05; C22C1/051; C25; C25C; C25C3/00; C25C3/06; C25C3/08; C25C3/12
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
69 words
A ceramic/metal composite material of at least one ceramic phase and at least one metallic phase, comprising mixed oxides of cerium and at least one of aluminum, nickel, iron and copper in the form of a skeleton of interconnected ceramic oxide grains which skeleton is interwoven with a continuous metallic network of an alloy or intermetallic compound of cerium with at least one of aluminum, nickel, iron and copper.
Claim 2
Dependent Claim
69 words
A ceramic/metal composite material of at least one ceramic phase and at least one metallic phase, comprising mixed oxides of cerium and at least one of aluminum, nickel, iron and copper in the form of a skeleton of interconnected ceramic oxide grains which skeleton is interwoven with a continuous metallic network of an alloy or intermetallic compound of cerium with at least one of aluminum, nickel, iron and copper.
Claim 3
Dependent Claim
62 words
The composite material of claim 1, wherein the metallic phase comprises an alloy or intermetallic compound of cerium and aluminum and optionally at least one of silver and the noble metals, and wherein the ceramic phase comprises mixed oxides or mixtures of oxides of cerium and aluminum and optionally at least one of a sulphide, nitride and phosphide of cerium or aluminum.
Claim 4
Dependent Claim
16 words
The composite material of claim 1, wherein the cerium and/or aluminum oxides are doped with fluorine.
Claim 5
Dependent Claim
25 words
The composite material of claim 1, wherein the molar ratio between the cerium and the aluminum in the mixed oxide(s) is between 9:1 and 1:9.
Claim 6
Dependent Claim
25 words
The composite material of claim 4, wherein the molar ratio between the cerium and the aluminum in the mixed oxide(s) is between 2:1 and 1:5.
Claim 7
Dependent Claim
45 words
The composite material of claim 5, wherein the ceramic grains comprise a major amount of grains essentially of the composition Al 2 O 3 .Ce 2 O 3 and a minor amount essentially of the composition 2Al 2 O 3 .Ce 2 O 3 .
Claim 8
Dependent Claim
30 words
The composite material of claim 6, wherein the ceramic grains further comprise a smaller amount of grains essentially of the composition 3Al 2 O 3 .2Ce 2 O 3 .
Claim 9
Dependent Claim
23 words
The composite material of claim 1, wherein the atomic ratio between Ce and Al in the metallic phase is between 9:1 and 1:9.
Claim 10
Dependent Claim
23 words
The composite material of claim 8, wherein the atomic ratio between cerium and aluminum in the metallic phase is between 2:1 and 1:5.
Claim 11
Dependent Claim
23 words
The composite material of claim 8, wherein the atomic ratio between cerium and aluminum in the metallic phase is between 1:1 and 1:2.
Claim 12
Dependent Claim
20 words
The composite material of claim 1, wherein the ceramic phase comprises dopants for increasing its electrical conductivity and/or its density.
Claim 13
Dependent Claim
24 words
The composite material of claim 11, wherein the dopant of the ceramic phase comprises at least one of tantalum, niobium and other pentavalent elements.
Claim 14
Dependent Claim
25 words
The composite material of claim 11, wherein the ceramic phase comprises or further comprises dopants selected from yttrium, lanthanum, praseodymium and other rare earth metals.
Claim 15
Dependent Claim
25 words
The composite material of claim 1, wherein the cerium in the ceramic phase is present as a mixture of Ce 3+ and Ce 4+ .
Claim 16
Dependent Claim
14 words
The composite material of claim 1, wherein the metallic phase comprises CeAl 2 .
Claim 17
Dependent Claim
20 words
The composite material of claim 1, further comprising inert reinforcing fibers or tissues of carbon, alumina, ceria, zirconia and/or silica.
Claim 18
Dependent Claim
13 words
A self sustaining body made of the composite material according to claim 1.
Claim 19
Dependent Claim
10 words
The body of claim 17, comprising a protective surface layer.
Claim 20
Dependent Claim
13 words
The body according to claim 18, wherein the surface layer comprises cerium oxyfluoride.
Claim 21
Dependent Claim
22 words
A dimensionally stable anode of the composite body of claim 18, in a molten salt electrolysis cell in which aluminum is produced.
Claim 22
Dependent Claim
77 words
A method of manufacturing the ceramic/metal composite material or body of claim 1, which method comprises establishing a precursor mixture comprising powders of cerium and at least one metal selected from aluminum, nickel, iron and copper, and thereafter reactive sintering, reactive hot-pressing or reactive plasma spraying said precursor mixture, with said precursor mixture optionally containing at least one oxide, fluoride or boride of cerium and/or of at least one metal selected from aluminum, nickel, iron and copper.
Claim 23
Dependent Claim
42 words
The method of claim 21, wherein the precursor powders comprise metallic cerium and aluminum and at least one compound selected from CeO 2 , Ce 2 O 3 , CeF 3 , AlF 3 , AlB 2 , AlB 12 and Al-silicides.
Claim 24
Dependent Claim
41 words
The method of claim 22, wherein the precursor powders further comprise at least one doping additive selected from Ta 2 O 5 , Nb 2 O 5 and other pentavalent oxides for improvement of the electrical conductivity of the ceramic phase.
Claim 25
Dependent Claim
33 words
The method of claim 23, wherein the amount of doping additives in the precursor powder is equivalent to produce a concentration of dopants up to 5 mole % of the produced ceramic phase.
Claim 26
Dependent Claim
33 words
The method of claim 24, wherein the amount of doping additives in the precursor powder is equivalent to produce a concentration of dopants up to 1 mole % of the produced ceramic phase.
Claim 27
Dependent Claim
47 words
The method of claim 23. wherein the precursor mixture comprises at least one densifying agent selected from AlF 3 , CeF 3 , cryolite, AlB 2 , AlB 12 TiB 2 , CeB 4 , CeB 6 , TiN, CeN, BN, SiB 4 and SiB 6 .
Claim 28
Dependent Claim
22 words
The method of claim 21, wherein the sintering or hot-pressing is carried out at a temperature between 800° C. and 1800° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |