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US4836868A
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Permanent magnet and method of producing same
Assignee: TDK Corp
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Filing: 1987-04-14
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Granted: 1989-06-06
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Expires: 2007-04-14
Abstract
Abstract In an R-Fe-B permanent magnet produced by a process including a rapid cooling, a composition of {R.sub.a (Ce.sub.b La.sub.1-b).sub.1-a }x(Fe.sub.1-z Co z ) 100-x-y-w B y M w (R is at least one rare earth element except for La and Ce but including Y, 5.5≦x<12, 2≦y<15, 0≦z≦0.7, 0<w≦10, 0.80≦a≦1.00, 0≦b≦1, M is Zr, Nb, Mo, Hf, Ta, W, Ti, and/or V) is proposed. The presence of the M element increases a ((BH)max) to a value higher than that of a composition wherein x is higher than 12 and makes the magnet more easily magnetizable.
Inventors
- 👤 Kohichi Yajima
- 👤 Osamu Kohmoto
- 👤 Tetsuhito Yoneyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:24
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; H01F1/0575; H01F1/0578; H05; H05K; H05K2201/00; H05K2201/10; H05K2201/10613; H05K2201/10954; H05K2201/10977
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
120 words
A permanent magnet which consists of a composition of {R a (Ce b La 1-b ) 1-a }x(Fe 1-z Co z ) 100-x-y-w B y M w (R is at least one rare earth element except for La and Ce but including Y, 5.5≦x<12, 2≦y<15, 0≦z≦0.7, 0.1≦w≦10, 0.80≦a≦1.00, 0≦b≦1, M is at least one element selected from the group consisting of Zr, Nb, Mo, Hf, Ta, W, Ti, and V, having a structure including fine crystals formed by a rapid cooling of a melt having said composition, and in which the presence of said at least one M element increases the maximum energy product (BH)max) to a value higher than that of a composition wherein x is higher than 12.
Claim 2
Dependent Claim
120 words
A permanent magnet which consists of a composition of {R a (Ce b La 1-b ) 1-a }x(Fe 1-z Co z ) 100-x-y-w B y M w (R is at least one rare earth element except for La and Ce but including Y, 5.5≦x<12, 2≦y<15, 0≦z≦0.7, 0.1≦w≦10, 0.80≦a≦1.00, 0≦b≦1, M is at least one element selected from the group consisting of Zr, Nb, Mo, Hf, Ta, W, Ti, and V, having a structure including fine crystals formed by a rapid cooling of a melt having said composition, and in which the presence of said at least one M element increases the maximum energy product (BH)max) to a value higher than that of a composition wherein x is higher than 12.
Claim 3
Dependent Claim
16 words
A permanent magnet according to claim 1, consisting of powder having said composition and said structure.
Claim 4
Dependent Claim
19 words
A permanent magnet according to claim 2, wherein said powder is pressed in the form of a magnet body.
Claim 5
Dependent Claim
21 words
A permanent magnet according to claim 2, wherein the powder is obtained by pulverizing a ribbon obtained by the rapid cooling.
Claim 6
Dependent Claim
24 words
A permanent magnet according to claim 1, consisting of powder having said composition and said structure and an organic resin binder or metallic binder.
Claim 7
Dependent Claim
21 words
A permanent magnet according to claim 5, wherein the powder is obtained by pulverizing a ribbon obtained by the rapid cooling.
Claim 8
Dependent Claim
31 words
A permanent magnet according to claim 1, 2, 3, 4, 5, or 6, having been magnetized at a field of approximately 20 kOe until a magnetization ratio of at least 95%.
Claim 9
Dependent Claim
25 words
A permanent magnet according to claim 1, 2, 3, 4, 5, or 6, wherein the content (x) of rare earth element is less than 10.
Claim 10
Dependent Claim
19 words
A permanent magnet according to claim 8, wherein the content (x) of rare earth element is at least 6.
Claim 11
Dependent Claim
15 words
A permanent magnet according to claim 8, wherein the content (y) of boron is 4≦y≦12.
Claim 12
Dependent Claim
33 words
A permanent magnet according to claim 1, 2, 3, 4, 5, or 6, wherein M is at least one element selected from the group consisting of Zr, Nb, Hf, Ta, W, and V.
Claim 13
Dependent Claim
11 words
A permanent magnet according to claim 11, wherein M is Zr.
Claim 14
Dependent Claim
11 words
A permanent magnet according to claim 11, wherein M is Nb.
Claim 15
Dependent Claim
11 words
A permanent magnet according to claim 11, wherein M is Mo.
Claim 16
Dependent Claim
11 words
A permanent magnet according to claim 11, wherein M is Hf.
Claim 17
Dependent Claim
11 words
A permanent magnet according to claim 11, wherein M it Ta.
Claim 18
Dependent Claim
11 words
a permanent magnet according to claim 11, wherein M is W.
Claim 19
Dependent Claim
11 words
A permanent magent according to claim 11, wherein M is V.
Claim 20
Dependent Claim
23 words
A permanent magnet according to claim 1, 2, 3, 4, 5, or 6, having a coercive force (iHc) of at least 7 kOe.
Claim 21
Dependent Claim
21 words
A permanent magnet according to claim claim 2 or 3, having a maximum energy product ((BH)max) of more than 8 MGOe.
Claim 22
Dependent Claim
16 words
A permanent magnet according to claim 1, wherein the content (w) of said M is 2≦w≦10.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |