US3982971A
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Rare earth-containing permanent magnets
Assignee: Shin-Etsu Chemical Co Ltd
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Filing: 1975-02-20
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Granted: 1976-09-28
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Expires: 1995-02-20
Abstract
Abstract Permanent magnets are disclosed having a very high coercive force and a very great maximum energy product, and consisting essentially of a rare earth-cobalt based alloy. The alloy is expressed by the formula Sm1-uCeu(Co1-v-w-xCuvFewMnx)z where 0</=u</=0.20, 0.08</=v</=0.20, 0</=w</=0.08, 0.01</=x</=0.15 and 6.0</=z</=7.8, preferably 7.2</=z</=7.8. By using these alloys, the magnetic properties of the resultant permanent magnets are superiorly affected, and the magnet-preparing process is rendered much simplified. This is also because the conventional heat aging step may be eliminated, particularly when the z value is within the preferred range.
Inventors
- 👤 Yoshio Yamanaka
- 👤 Kazuyoshi Watanabe
- 👤 Masakatsu Honshima
- 👤 Hideaki Kikuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:14
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; C; C22; C22C; C22C19/00; C22C19/07; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/0555; H01F1/0557
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
110 words
A process for the preparation of a permanent magnet which comprises the steps of shaping the powder of an alloy expressed by the formula Sm 1 -u Ce u (Co 1 -v -w -x Cu v Fe w Mn x ) z where 0≦u≦0.20, 0.08≦v≦0.20, 0≦w≦0.08, 0.01≦x≦0.15, and 7.2≦z≦7.8, into a block by compression molding in a magnetic field, subjecting said block to sintering at a temperature in the range of from 1,170° to 1,270° C, and cooling the thus sintered block at a cooling velocity between 1° C/second and 30° C/second to a temperature of about 800° C, with subsequent cooling to room temperature without any intermediate aging step.
Claim 2
Dependent Claim
110 words
A process for the preparation of a permanent magnet which comprises the steps of shaping the powder of an alloy expressed by the formula Sm 1 -u Ce u (Co 1 -v -w -x Cu v Fe w Mn x ) z where 0≦u≦0.20, 0.08≦v≦0.20, 0≦w≦0.08, 0.01≦x≦0.15, and 7.2≦z≦7.8, into a block by compression molding in a magnetic field, subjecting said block to sintering at a temperature in the range of from 1,170° to 1,270° C, and cooling the thus sintered block at a cooling velocity between 1° C/second and 30° C/second to a temperature of about 800° C, with subsequent cooling to room temperature without any intermediate aging step.
Claim 3
Dependent Claim
116 words
A process for the preparation of a permanent magnet which comprises the steps of shaping the powder of an alloy expressed by the formula Sm 1 -u Ce u (Co 1 -v -w -x Cu v Fe w Mn x ) z where 0≦u≦0.20, 0.08≦v≦0.20, 0≦w≦0.08, 0.01≦x≦0.15, and 7.2≦z≦7.8, into a block by compression molding in a magnetic field, subjecting said block to sintering at a temperature in the range of from 1,170° to 1,270° C, and cooling the thus sintered block at a cooling velocity between 1° C/second and 30° C/second to a temperature of about 800° C, aging the thus cooled block at this temperature and thereafter cooling the aged block to room temperature.
Claim 4
Dependent Claim
116 words
A process for the preparation of a permanent magnet which comprises the steps of shaping the powder of an alloy expressed by the formula Sm 1 -u Ce u (Co 1 -v -w -x Cu v Fe w Mn x ) z where 0≦u≦0.20, 0.08≦v≦0.20, 0≦w≦0.08, 0.01≦x≦0.15, and 7.2≦z≦7.8, into a block by compression molding in a magnetic field, subjecting said block to sintering at a temperature in the range of from 1,170° to 1,270° C, and cooling the thus sintered block at a cooling velocity between 1° C/second and 30° C/second to a temperature of about 800° C, aging the thus cooled block at this temperature and thereafter cooling the aged block to room temperature.
Claim 5
Dependent Claim
10 words
A permanent magnet prepared by the process of claim 1.
Claim 6
Dependent Claim
10 words
A permanent magnet prepared by the process of claim 2.
Claim 7
Dependent Claim
21 words
The process as claimed in claim 1, wherein said cooling velocity is from 5° per second to 30° C per second.
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) | 1979-09-28 | 1980-03-29 | 1980-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-28 | 1984-03-29 | 1984-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-28 | 1988-03-29 | 1988-09-28 | $7700.00 | Window Closed / Lapsed |