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US5055128A
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Sintered fe-co type magnetic materials
Assignee: JFE Steel Corp
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Filing: 1989-05-30
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Granted: 1991-10-08
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Expires: 2009-05-30
Abstract
Abstract Disclosed herein is an economical process for the production of a sintered Fe-Co type, Fe-Co-V type or Fe-Co-Cr type magnetic material, which comprises preparing an alloy powder of at least Fe and Co metals or a like powder, kneading it with an organic binder, conducting injection molding and debinding, and then conducting a two-stage sintering treatment consisting of low-temperature sintering and high-temperature sintering. Magnetic materials having a specific composition of the Fe-Co, Fe-Co-V or Fe-Co-Cr type and excellent magnetic properties and a low core loss value are also disclosed.
Inventors
- 👤 Yoshisato Kiyota
- 👤 Osamu Furukimi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:16
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20; H01F1/22; C; C22; C22C; C22C33/00; C22C33/02; C22C33/0207; C22C33/0257; C22C33/0278; C22C33/0285
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
56 words
A sintered Fe-Co type magnetic material comprising 15-60 wt. % of Co, not greater than 0.04 wt. % of O, not greater than 0.02 wt. % of C and the remainder of Fe and imperative impurities, having a sintered density ratio of at least 95% and an average crystal grain size of at least 50 μm.
Claim 2
Dependent Claim
56 words
A sintered Fe-Co type magnetic material comprising 15-60 wt. % of Co, not greater than 0.04 wt. % of O, not greater than 0.02 wt. % of C and the remainder of Fe and imperative impurities, having a sintered density ratio of at least 95% and an average crystal grain size of at least 50 μm.
Claim 3
Dependent Claim
61 words
A sintered Fe-Co type magnetic material comprising 15-60 wt. % of Co, 0.5-3.5 wt. % of V, not greater than 0.6 wt. % of O, not greater than 0.04 wt. % of C and the remainder of Fe and imperative impurities, having a sintered density ratio of at least 95% and an average crystal grain size of at least 50 μm.
Claim 4
Dependent Claim
61 words
A sintered Fe-Co type magnetic material comprising 15-60 wt. % of Co, 0.5-3.5 wt. % of V, not greater than 0.6 wt. % of O, not greater than 0.04 wt. % of C and the remainder of Fe and imperative impurities, having a sintered density ratio of at least 95% and an average crystal grain size of at least 50 μm.
Claim 5
Dependent Claim
61 words
A sintered Fe-Co type magnetic material comprising 20-50 wt. % of Co, 0.5-3.5 wt. % of Cr, not greater than 0.04 wt. % of O, not greater than 0.02 wt. % of C and the remainder of Fe and imperative impurities, having a sintered density ratio of at least 95% and an average crystal grain size of at least 50 μm.
Claim 6
Dependent Claim
61 words
A sintered Fe-Co type magnetic material comprising 20-50 wt. % of Co, 0.5-3.5 wt. % of Cr, not greater than 0.04 wt. % of O, not greater than 0.02 wt. % of C and the remainder of Fe and imperative impurities, having a sintered density ratio of at least 95% and an average crystal grain size of at least 50 μm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-07 | 1995-04-08 | 1995-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-07 | 1999-04-08 | 1999-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-07 | 2003-04-08 | 2003-10-08 | $7700.00 | Window Closed / Lapsed |