US4006891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crucible for melting super-alloys
Assignee: Rolls Royce PLC
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Filing: 1976-07-09
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Granted: 1977-02-08
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Expires: 1996-07-09
Abstract
Abstract A crucible for melting a nickel-based superalloy containing one or more of the elements aluminium, titanium and hafnium is made of magnesia grains bonded by tinania, hafnia or yttria. The purity of the magnesia is not less than 97%.
Inventors
- 👤 David Alan Ford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:48
CPC Classifications
F; F27; F27B; F27B14/00; F27B14/08; F27B14/10; C; C04; C04B; C04B35/00; C04B35/01; C04B35/03; C04B35/04; C04B35/043; C04B35/0435
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
79 words
A crucible for melting a nickel-based superalloy containing one or more of the elements of the group consisting of aluminium, titanium and hafnium, wherein the crucible is made of a material consisting by weight of 90 - 99% magnesia grains and 1 - 10% of an oxide being a bonding medium for the magnesia grains and being one of the group consisting of titania, hafnia and yttria, and wherein the purity of the magnesia is not less than 97%.
Claim 2
Dependent Claim
79 words
A crucible for melting a nickel-based superalloy containing one or more of the elements of the group consisting of aluminium, titanium and hafnium, wherein the crucible is made of a material consisting by weight of 90 - 99% magnesia grains and 1 - 10% of an oxide being a bonding medium for the magnesia grains and being one of the group consisting of titania, hafnia and yttria, and wherein the purity of the magnesia is not less than 97%.
Claim 3
Dependent Claim
32 words
Crucible according to claim 1, wherein the crucible material includes as a permissible impurity up to 3% of at least one of the oxides of the group consisting of calcia and silica.
Claim 4
Dependent Claim
44 words
Crucible according to claim 1, wherein the crucible material consists by weight of 94-96% magnesia grains, 1-3% titania powder as said bonding medium, and as a permissible impurity 3% of at least one of the oxides of the group consisting of calcia and silica.
Claim 5
Dependent Claim
18 words
Crucible according to claim 1, wherein the magnesia includes as a permissible impurity not more than 2% calcia.
References Cited (Backward Citations)
US3141917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-08 | 1980-08-09 | 1981-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-08 | 1984-08-09 | 1985-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-08 | 1988-08-09 | 1989-02-08 | $7700.00 | Window Closed / Lapsed |