US3926567A
Expired / Lapsed
US
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Cermet composition and method of fabrication
Assignee: National Aeronautics and Space Administration
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Filing: 1973-04-05
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Granted: 1975-12-16
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Expires: 1993-04-05
Abstract
Abstract Cermet composition particularly adapted for production of high temperature resistant cermet insulator bodies, especially applicable as cermet electrical insulator seals for thermionic diodes, comprising particles of a high temperature metal or metal alloy, preferably niobium or niobium-zirconium alloy particles or spheres, dispersed in and bonded to a continuous matrix of a ceramic oxide, preferably yttria or alumina, the resulting cermet composition having improved strength provided by the metal content, with high electrical resistance at least comparable to or greater than the electrical resistance of the pure ceramic oxide, and high thermal shock resistance. Process for producing the above cermet composition comprises mixing particles of a high temperature resistant metal or metal alloy, e.g. niobium, with a ceramic oxide powder, e.g. yttria, and providing a substantially homogeneous mixture thereof, forming such composition into a desired shape, vacuum sealing the resulting composition and sintering such composition under high pressure in a high temperature autoclave operation.
Inventors
- 👤 James C Administrator Fletcher
- 👤 Wayne M Phillips
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:05
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/02; A61L27/04; A61L27/28; A61L27/30; A61L27/306; C; C04; C04B; C04B35/00; C04B35/71; C04B35/74; B; B22; B22F; B22F2999/00; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
68 words
A HIGH STRENGTH CERMENT COMPOSITION COMPRISING A SINTERED BODY CONSISTING OF HIGH TEMPERATURE RESISTANT METAL OR METAL ALLOY PARTICLES COATED WITH AND DISPERSED IN A CONTINUOUS MATRIX OF CERAMIC OXIDE, SAID METAL OR METAL ALLOY PARTICLES COMPRISING TWO DIFFERENT METALS, ONE OF SAID METALS BEING PRESENT IN A SMALL AMOUNT, SAID LAST MENTIONED METAL CORRESPONDING TO THE METAL OF AT LEAST ONE METAL OXIDE OF SAID CERAMIC OXIDE.
Claim 2
Dependent Claim
68 words
A HIGH STRENGTH CERMENT COMPOSITION COMPRISING A SINTERED BODY CONSISTING OF HIGH TEMPERATURE RESISTANT METAL OR METAL ALLOY PARTICLES COATED WITH AND DISPERSED IN A CONTINUOUS MATRIX OF CERAMIC OXIDE, SAID METAL OR METAL ALLOY PARTICLES COMPRISING TWO DIFFERENT METALS, ONE OF SAID METALS BEING PRESENT IN A SMALL AMOUNT, SAID LAST MENTIONED METAL CORRESPONDING TO THE METAL OF AT LEAST ONE METAL OXIDE OF SAID CERAMIC OXIDE.
Claim 3
Dependent Claim
14 words
A cermet composition as defined in claim 1, said body being compressed and sintered.
Claim 4
Dependent Claim
114 words
A HIGH STRENGTH CERMET COMPOSITION COMPRISING A SINTERED BODY CONSISTING OF HIGH TEMPERATURE RESISTANT METAL OR METAL ALLOY PARTICLES COATED WITH AND DISPERSED IN A CONTINUOUS MATRIX OF CERAMIC OXIDE, SAID METAL AND METAL ALLOY PARTICLES BEING SELECTED FROM THE GROUP CONSISTING OF NIOBIUM, NIOBIUM ALLOYS CONTAINING A SMALL AMOUNT OF METAL OF THE GROUP CONSISTING OF ZIRCONIUM, ALUMINUM AND YTTRIUM; NICKEL, IRON, CHROMIUM, COBALT, TANTALUM, TUNGSTEN, MOLYBDENUM, ALUMINUM AND MAGNESIUM, SAID CERAMIC OXIDE BEING SELELCTED FROM THE GROUP CONSISTING OF ALUMINA,, YTTRIA, ZIRONIA, AND MIXTURES THEREOF, ZIRCONIA IN COMBINATION WITH AN OXIDE OF THE GROUP CONSISTING OF CALCIUM OXIDE AND MAGNESIUM OXIDE; TITANIUM DIOXIDE, TANTALUM OXIDE, VANADIUM OXIDE, NIOBIUM OXIDE AND CHROMIUM OXIDE.
Claim 5
Dependent Claim
114 words
A HIGH STRENGTH CERMET COMPOSITION COMPRISING A SINTERED BODY CONSISTING OF HIGH TEMPERATURE RESISTANT METAL OR METAL ALLOY PARTICLES COATED WITH AND DISPERSED IN A CONTINUOUS MATRIX OF CERAMIC OXIDE, SAID METAL AND METAL ALLOY PARTICLES BEING SELECTED FROM THE GROUP CONSISTING OF NIOBIUM, NIOBIUM ALLOYS CONTAINING A SMALL AMOUNT OF METAL OF THE GROUP CONSISTING OF ZIRCONIUM, ALUMINUM AND YTTRIUM; NICKEL, IRON, CHROMIUM, COBALT, TANTALUM, TUNGSTEN, MOLYBDENUM, ALUMINUM AND MAGNESIUM, SAID CERAMIC OXIDE BEING SELELCTED FROM THE GROUP CONSISTING OF ALUMINA,, YTTRIA, ZIRONIA, AND MIXTURES THEREOF, ZIRCONIA IN COMBINATION WITH AN OXIDE OF THE GROUP CONSISTING OF CALCIUM OXIDE AND MAGNESIUM OXIDE; TITANIUM DIOXIDE, TANTALUM OXIDE, VANADIUM OXIDE, NIOBIUM OXIDE AND CHROMIUM OXIDE.
Claim 6
Dependent Claim
81 words
A high strength cermet composition comprising a sintered body consisting of high temperature resistant metal or metal alloy particles coated with and dispersed in a continuous matrix of ceramic oxide, said metal or metal alloy particles being selected from the group consisting of niobium and niobium alloys containing a small amount of a member selected from the group consisting of zirconium, aluminum and yttrium, and said ceramic oxide being selected from the group consisting of alumina, yttria, zirconia, and mixtures thereof.
Claim 7
Dependent Claim
81 words
A high strength cermet composition comprising a sintered body consisting of high temperature resistant metal or metal alloy particles coated with and dispersed in a continuous matrix of ceramic oxide, said metal or metal alloy particles being selected from the group consisting of niobium and niobium alloys containing a small amount of a member selected from the group consisting of zirconium, aluminum and yttrium, and said ceramic oxide being selected from the group consisting of alumina, yttria, zirconia, and mixtures thereof.
Claim 8
Dependent Claim
44 words
A cermet Composition as defined in claim 3, said metal or metal alloy particles being present in an amount ranging from about 5 to about 80%, and said ceramic oxide being present in an amount ranging from about 20 to about 95%, by volume.
Claim 9
Dependent Claim
44 words
A cermet composition as defined in claim 4, said metal or metal alloy particles being present in an amount ranging from about 5 to about 80%, and said ceramic oxide being present in an amount ranging from about 20 to about 95%, by volume.
Claim 10
Dependent Claim
44 words
A cermet composition as defined in claim 4, said metal or metal alloy particles being present in an amount ranging from about 25 to about 60%, and said ceramic oxide being present in an amount ranging from about 40 to about 75%, by volume.
Claim 11
Dependent Claim
49 words
A cermet composition as defined in claim 6, said metal or metal alloy particles having a diameter ranging from about 10 to about 1,000 microns, said ceramic oxide being in the form of particles of a size less than 1/10 the diameter of said metal or metal alloy particles.
Claim 12
Dependent Claim
34 words
A cermet composition as defined in claim 4, employing said niobium alloy particles containing said small amount of said metal corresponding to the metal of at least one metal oxide of said ceramic oxide.
Claim 13
Dependent Claim
86 words
A cermet composition as defined in claim 7, comprising a pressed sintered body consisting of particles of a member selected from the group consisting of niobium, niobium-1% zirconium, niobium-1% yttrium and niobium-1% aluminum, said particles homogenously distributed in a continuous matrix of said ceramic oxide, said metal or metal alloy particles having a diameter ranging from about 10 to about 1,000 microns, said ceramic oxide being in the form of particles of a size less than 1/10 the diameter of said metal or metal alloy particles.
Claim 14
Dependent Claim
29 words
A cermet composition as defined in claim 10, said ceramic oxide being a mixture of yttria and from 1 to about 20% of zirconia, by volume of such mixture.
Claim 15
Dependent Claim
50 words
A cermet composition as defined in claim 11, said particles being niobium-1% zirconium alloy, said particles having a diameter ranging from about 25 to about 100 microns and said ceramic oxide particles being of a size ranging from about 0.01 to about 0.05 the diameter of said metal alloy particles.
Claim 16
Dependent Claim
56 words
A cermet composition as defined in claim 10, said particles being niobium-1% yttrium alloy and said ceramic oxide being yttria, said particles having a diameter ranging from about 25 to about 100 microns and said ceramic oxide particles being of a size ranging from about 0.01 to about 0.05 the diameter of said metal alloy particles.
Claim 17
Dependent Claim
56 words
A cermet composition as defined in claim 10, said particles being niobium-1% aluminum alloy and said ceramic oxide being alumina, said particles having a diameter ranging from about 25 to about 100 microns and said ceramic oxide particles being of a size ranging from about 0.01 to about 0.05 the diameter of said metal alloy particles.
Claim 18
Dependent Claim
56 words
A cermet composition as defined in claim 10, said particles being niobium-1% zirconium alloy and said ceramic oxide containing zirconia, said particles having a diameter ranging from about 25 to about 100 microns and said ceramic oxide particles being of a size ranging from about 0.01 to about 0.05 the diameter of said metal alloy particles.
References Cited (Backward Citations)
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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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |