US4221613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rare earth-cobalt system permanent magnetic alloys and method of preparing same
Assignee: Namiki Precision Jewel Co Ltd
•
Filing: 1979-01-24
•
Granted: 1980-09-09
•
Expires: 1999-01-24
Abstract
Abstract Permanent magnetic alloys comprising 11.5-12.5% rare earth components of which 6.3-12% is samarium and 0.5-6.2% is yttrium; 0.2-2.5% hafnium, 19.5-26.5% iron, 7-10.5% copper, and 52-70.7% cobalt, the ranges of the components being in atomic ratios. The alloys are prepared by obtaining 1-50 mu m. powders of the components, compacting the powder after magnetic field orientation sintering the compacted powders at 1160 DEG -1220 DEG for 1-10 hours, cooling the sintered body at a rate of at least 1 DEG C./second until the temperature is about 900 DEG C., and then annealing the body at 750 DEG -900 DEG C.
Inventors
- 👤 Nobuo Imaizumi
- 👤 Kazuo Wakana
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 21:36
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/0555; H01F1/0557; C; C22; C22C; C22C19/00; C22C19/07
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
36 words
Permanent magnetic alloys comprising 11.5-12.5% rare earth components of which 6.3-12% is samarium and 0.5-6.2% is yttrium; 0.2-2.5% hafnium, 19.5-26.5% iron, 7-10.5% copper, and 52-70.7% cobalt, the ranges of the aforesaid components being in atomic ratios.
Claim 2
Dependent Claim
36 words
Permanent magnetic alloys comprising 11.5-12.5% rare earth components of which 6.3-12% is samarium and 0.5-6.2% is yttrium; 0.2-2.5% hafnium, 19.5-26.5% iron, 7-10.5% copper, and 52-70.7% cobalt, the ranges of the aforesaid components being in atomic ratios.
Claim 3
Dependent Claim
84 words
A method of preparing the alloys of claim 1 comprising the steps of melting raw material containing said components, solidifying the resulting melt, pulverizing the resulting ingot into powders having a grain size of 1-50 μm, compacting the powders after magnetic field orientation thereof, sintering said compacted powders at 1160°-1220° C. for 1-10 hours, cooling the sintered body at a rate of at least 1° C./second at least until the temperature is about 900° C., and then annealing the resulting bulk at 750°-900° C.
Claim 4
Dependent Claim
18 words
The method as in claim 2 where said annealing occurs at about 850° C. for about 1/2 hour.
Claim 5
Dependent Claim
26 words
The method as in claim 2 where said melting is effected in an inert atmosphere with a high frequency induction furnace or an electric arc furnace.
Claim 6
Independent Claim
18 words
The method as in claims 2 or 4 where said cooling is effected by quenching the sintered body.
Claim 7
Dependent Claim
16 words
The method as in claim 2 where said grain size of the powders is 1-5 μm.
Claim 8
Dependent Claim
15 words
The method as in claim 2 where the sintered body is cooled to room temperature.
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) | 1983-09-09 | 1984-03-10 | 1984-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-09 | 1988-03-10 | 1988-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-09 | 1992-03-10 | 1992-09-09 | $7700.00 | Window Closed / Lapsed |