US3853491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tungsten filament having uniform concentration gradient of thoria particles
Assignee: General Electric Co
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Filing: 1972-09-01
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Granted: 1974-12-10
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Expires: 1992-09-01
Abstract
Abstract An improved tungsten filament is disclosed containing approximately 1-2 percent by weight thoria particles distributed in the tungsten matrix as a dispersed phase. The thoria particles are distributed in the tungsten matrix to provide a slight but uniform compositional gradient which diminishes continuously with increasing distance from the exterior surface of the filament to the longitudinal central axis. Upon recrystallization of the filament or wire product there is also formed a tungsten grain structure having a more uniform size and shape of the individual tungsten grains than can be obtained by conventional powder metallurgy preparation.
Inventors
- 👤 T Dunham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:42
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/40; B23K35/402; C; C22; C22C; C22C32/00; C22C32/001; C22C32/0015; C22C32/0031; H; H01; H01K; H01K1/00; H01K1/02; H01K1/04; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12021
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
75 words
A THERMALLY AND MECHANICALLY WORKED DISPERSION ALLOY MEMBER CONSISTING ESSENTIALLY OF A RECRYSTALLIZED TUNGSTEN GRAIN STRUCTURE WHEREIN THE TUNGSTEN GRAINS ARE SMALL SIZE EQUIAXED CRYSTALS AND WHICH FURTHER CONTAINS AN AVERAGE 1-2 PERCENT BY WEIGHT THORIA PARTICLES OF SMALLER SIZE THAN THE TUNGSTEN GRAINS DISTRIBUTED IN A UNIFORMLY DIMINISHING CONCENTRATION GRADIENT HAVING THE MAXIMUM CONCENTRATION LOCATED AT THE EXTERIOR SURFACE OF SAID MEMBER WITH NO SHARP COMPOSITIONAL VARIATION OF THORIA PARTICLES ALONG SAID CONCENTRATION GRADIENT.
Claim 2
Dependent Claim
75 words
A THERMALLY AND MECHANICALLY WORKED DISPERSION ALLOY MEMBER CONSISTING ESSENTIALLY OF A RECRYSTALLIZED TUNGSTEN GRAIN STRUCTURE WHEREIN THE TUNGSTEN GRAINS ARE SMALL SIZE EQUIAXED CRYSTALS AND WHICH FURTHER CONTAINS AN AVERAGE 1-2 PERCENT BY WEIGHT THORIA PARTICLES OF SMALLER SIZE THAN THE TUNGSTEN GRAINS DISTRIBUTED IN A UNIFORMLY DIMINISHING CONCENTRATION GRADIENT HAVING THE MAXIMUM CONCENTRATION LOCATED AT THE EXTERIOR SURFACE OF SAID MEMBER WITH NO SHARP COMPOSITIONAL VARIATION OF THORIA PARTICLES ALONG SAID CONCENTRATION GRADIENT.
Claim 3
Dependent Claim
10 words
A swaged member having the alloy composition defined in claim
Claim 4
Dependent Claim
10 words
A rolled member having the alloy composition defined in claim
Claim 5
Dependent Claim
11 words
A drawn filament having the alloy composition defined in claim 1.
Claim 6
Dependent Claim
25 words
A dispersion alloy member as in claim 1 having improved strength and ductility compared with a conventionally prepared dispersion alloy member of the same composition.
Claim 7
Dependent Claim
11 words
A drawn filament having the physical characteristics defined in claim 5.
References Cited (Backward Citations)
US1082933A
Cited
US2798808A
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US2846339A
Cited
US3278281A
Cited
US3105290A
Cited
US3475159A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |