US4239159A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of fine metal powders
Assignee: Air Products and Chemicals Inc
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Filing: 1979-02-13
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Granted: 1980-12-16
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Expires: 1999-02-13
Abstract
Abstract Metal particles which are ductile at ambient temperature can be comminuted by being passed through a first impact mill at ambient temperature to increase their length to thickness ratio, embrittled, and then comminuted in a second impact mill.
Inventors
- 👤 Dereck R. Johns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:12
CPC Classifications
B; B02; B02C; B02C19/00; B02C19/18; B02C19/186; B22; B22F; B22F1/00; B22F1/14; B22F1/142; B22F9/00; B22F9/02; B22F9/04; Y; Y10; Y10S; Y10S241/00; Y10S241/37
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
60 words
A method of comminuting oversize ductile metal powder particles produced by water or gas atomization comprising the steps of impacting the particles to increase their length to thickness ratio thus producing generally elongated flattened particles, cooling the elongated particles to a temperature at which the elongated particles become embrittled and further comminuting the embrittled particles to produce relatively fine powder.
Claim 2
Independent Claim
60 words
A method of comminuting oversize ductile metal powder particles produced by water or gas atomization comprising the steps of impacting the particles to increase their length to thickness ratio thus producing generally elongated flattened particles, cooling the elongated particles to a temperature at which the elongated particles become embrittled and further comminuting the embrittled particles to produce relatively fine powder.
Claim 3
Dependent Claim
29 words
A method according to claim 1, wherein the ductile metal powder particles are impacted within a vibratory ball mill to produce length to thickness ratios in excess of 10.1.
Claim 4
Dependent Claim
27 words
A method according to claim 1 or 2, wherein said impacted particles are cooled to below their embrittlement temperature and then comminuted in a rotary impact mill.
References Cited (Backward Citations)
US4015780A
Cited
US4018633A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |