US4801340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing permanent magnets
Assignee: Namiki Precision Jewel Co Ltd
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Filing: 1987-06-11
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Granted: 1989-01-31
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Expires: 2007-06-11
Abstract
Abstract A method for manufacturing a permanent magnet using alloys of the formula R(T1-yMy)z, wherein R denotes one or two species of rare earth metals, including Y, T denotes transition metals, principally Fe or Fe and Co, M denotes metalloid elements, principally B, and wherein 0.02<y<0.15, and 5<z<9), to obtain permanent magnets with high orientation properties through the formation of 50-1000 mu m crude grains by spraying the alloys in a hot melt state using an inert gas atomization process, forming grains of less than 30 mu m by a mechanical pulverizing process after crystal texture in the crude grains has grown to over 30 mu m granules by a heat-treatment of the crude grains in a vacuum or in an inert atmosphere below 1000 DEG C., whereupon the grain powder is compression molded and heat treated at 500 DEG -900 DEG C. under a magnetic field to yield a compacted powder permanent magnet.
Inventors
- 👤 Nobuyuki Inoue
- 👤 Katsumi Takahashi
- 👤 Nobuo Imaizumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:14
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/057; H01F1/0571; H01F1/0574; H01F1/0575; H01F1/0576
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
A method for manufacturing compacted powder permanent magnets from alloys whose compositions are determined by the formula R (T 1-y M y )z wherein R denotes one or two species of rare earth metals including Y, T denotes a transition metal selected from the group consisting of Fe and Fe and Co, M denotes the metalloid element B, and wherein 0.02<y<0.15, and 5<z<9, said method comprising the steps of: a. obtaining 50-1000 um crude grains by spraying said alloys in a melt state using an inert gas atomization process, b. heat-treating said crude grains in a vacuum or in an inert atmosphere, c. forming grains of less than 30 um by a mechanical pulverizing process, and d. compression-molding said grains of (c) to form a compression molded body.
Claim 2
Independent Claim
128 words
A method for manufacturing compacted powder permanent magnets from alloys whose compositions are determined by the formula R (T 1-y M y )z wherein R denotes one or two species of rare earth metals including Y, T denotes a transition metal selected from the group consisting of Fe and Fe and Co, M denotes the metalloid element B, and wherein 0.02<y<0.15, and 5<z<9, said method comprising the steps of: a. obtaining 50-1000 um crude grains by spraying said alloys in a melt state using an inert gas atomization process, b. heat-treating said crude grains in a vacuum or in an inert atmosphere, c. forming grains of less than 30 um by a mechanical pulverizing process, and d. compression-molding said grains of (c) to form a compression molded body.
Claim 3
Dependent Claim
20 words
The method as defined by claim 1, wherein said heat-treatment is carried out in the temperature range of 900°-1000° C.
Claim 4
Dependent Claim
29 words
The method as defined in claim 1, wherein said compression molded body is heated in the temperature range of 500°-900° C. in a magnetic field of over 100 Oe.
Claim 5
Dependent Claim
26 words
The method as defined in claim 1, further comprising hardening said compression molded body by impregnating said body with resin to produce a resin-bonded permanent magnet.
Claim 6
Dependent Claim
23 words
The method as defined in claim 3, further comprising hardening said compression molded body by impregnating said body with resin following heat treatment.
Claim 7
Dependent Claim
52 words
The method as defined in claim 1, further comprising the steps of a. vacuum sealing said compression molded body in a metal container, b. compressing said vacuum sealed compression molded body formed in step (a) with hot isostatic pressure of over 50 kg/cm 2 in the temperature range of 600-900 degrees C.
Claim 8
Dependent Claim
33 words
The method as defined by claim 6, further comprising quenching and then mechanically pulverizing said compression molded body with a jet mill or a ball mill to form fine particles of 2-20 um.
Claim 9
Dependent Claim
23 words
The method as defined in claim 7, further comprising orienting said compression molded body by executing the compression-molding process in a magnetic field.
Claim 10
Dependent Claim
21 words
The method as defined in claim 1, in which said compression-molded body is sintered in the temperature range of 1000°-1200° C.
References Cited (Backward Citations)
US4585473A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-31 | 1992-08-01 | 1993-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-31 | 1996-08-01 | 1997-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-31 | 2000-08-01 | 2001-01-31 | $7700.00 | Window Closed / Lapsed |