US3979234A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for fabricating articles of tungsten-nickel-iron alloy
Assignee: Energy Research and Development Administration ERDA
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Filing: 1975-09-18
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Granted: 1976-09-07
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Expires: 1995-09-18
Abstract
Abstract A high density W-Ni-Fe alloy of composition 85-96% by weight W and the remainder Ni and Fe in a wt. ratio of 5:5-8:2 having enhanced mechanical properties is prepared by compacting the mixed powders, sintering the compact in reducing atmosphere to near theoretical density followed by further sintering at a temperature where a liquid phase is present, vacuum annealing, and cold working to achieve high uniform hardness.
Inventors
- 👤 Walter G. Northcutt, Jr.
- 👤 William B. Snyder, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:54
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/24; B22F3/12; B22F3/16; C; C22; C22C; C22C1/00; C22C1/04; C22C1/045; F; F42; F42B; F42B12/00; F42B12/72; F42B12/74; B22F2998/00; B22F2998/10; B22F2999/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
142 words
A method of fabricating articles of W--Ni--Fe alloy comprising: a. providing a uniformly blended mixed powder of 85-96% by weight W and the remainder Ni and Fe in a Ni--Fe weight ratio of 5:5-8:2, b. pressing said powder into a compact, c. sintering said compact in reducing atmosphere at a temperature at least 1200°C and below the liquid phase temperature for a period of time sufficient to provide an article of at least 95% theoretical density, d. further heating the article to a temperature 0.1°-20°C above the liquid phase temperature for a period of time sufficient to cause the formation of a liquid phase, yet insufficient to cause slumping of the article, e. vacuum annealing the article by maintaining the article in a vacuum at 700°-1420°C for sufficient time to remove entrapped gases, and f. machining the article to the desired dimensions.
Claim 2
Independent Claim
142 words
A method of fabricating articles of W--Ni--Fe alloy comprising: a. providing a uniformly blended mixed powder of 85-96% by weight W and the remainder Ni and Fe in a Ni--Fe weight ratio of 5:5-8:2, b. pressing said powder into a compact, c. sintering said compact in reducing atmosphere at a temperature at least 1200°C and below the liquid phase temperature for a period of time sufficient to provide an article of at least 95% theoretical density, d. further heating the article to a temperature 0.1°-20°C above the liquid phase temperature for a period of time sufficient to cause the formation of a liquid phase, yet insufficient to cause slumping of the article, e. vacuum annealing the article by maintaining the article in a vacuum at 700°-1420°C for sufficient time to remove entrapped gases, and f. machining the article to the desired dimensions.
Claim 3
Dependent Claim
24 words
The method of claim 1 further comprising, after vacuum annealing and prior to the machining step, cold working the article to the desired hardness.
Claim 4
Dependent Claim
17 words
The method of claim 1 in which the sintering steps are carried out in H 2 atmosphere.
Claim 5
Dependent Claim
50 words
The method of claim 2 in which the sintering steps are carried out in H 2 atmosphere and said cold working is accomplished by swaging the article to a reduction of 25% to cause the article to exhibit uniform (±1 Rc unit) hardness of 42 on the Rockwell C scale.
Claim 6
Dependent Claim
28 words
An armor penetrating projectile having a composition of 90 wt. % W, 7 wt. % Ni and 3 wt. % Fe fabricated by the method of claim 4.
Claim 7
Dependent Claim
22 words
A method of enhancing the penetrating ability of a sintered W--Ni--Fe article comprising fabricating the article by the method of claim 4.
Claim 8
Dependent Claim
26 words
The method of claim 6 in which the composition of the article is 90% by weight W, 7% by weight Ni, and 3% by weight Fe.
References Cited (Backward Citations)
GB760113A
Cited
US3695868A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |