Patent US4952239A successfully refreshed from Google Patents.
US4952239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetically anisotropic bond magnet, magnetic powder for the magnet and manufacturing method of the powder
Assignee: Proterial Ltd
•
Filing: 1989-06-14
•
Granted: 1990-08-28
•
Expires: 2009-06-14
Abstract
Abstract Magnetically anisotropic powder and resin-bonded magnets made therefrom have "flattened" crystal grains of an R-TM-B-M system alloy with preferably (c)/(a) greater than 2, where (c) is the grain size perpendicular to the C-axis and (a) the grain size parallel to the C-axis. The "flattened" grains are produced by plastically deforming a green compact of flakes formed by rapidly-quenching an alloy melt, and then crushing the plastically deformed body. In the alloy system, R is at least one of the rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is an additive selected from Si, Al, Nb, Zr, P and C.
Inventors
- 👤 Masatoki Tokunaga
- 👤 Yasuto Nozawa
- 👤 Katsunori Iwasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:56
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
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
126 words
Anisotropic magnetic powder for a magnetically anisotropic bond magnet comprising an alloy powder of the R-TM-B-M system, wherein R is at least one of rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is at least one additive selected from the group consisting of Si, Al, Nb, Zr, P and C, said powder having an average crystal size of 0.01-.05 μm, an average grain size of 1-1,000 μm, a flattened grain structure with (c) greater than (a) in which (c) is the average size of the grain in the direction perpendicular to the C-axis and (a) is the average size of the grain in the C-axis direction, and has magnetic anisotropy.
Claim 2
Dependent Claim
126 words
Anisotropic magnetic powder for a magnetically anisotropic bond magnet comprising an alloy powder of the R-TM-B-M system, wherein R is at least one of rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is at least one additive selected from the group consisting of Si, Al, Nb, Zr, P and C, said powder having an average crystal size of 0.01-.05 μm, an average grain size of 1-1,000 μm, a flattened grain structure with (c) greater than (a) in which (c) is the average size of the grain in the direction perpendicular to the C-axis and (a) is the average size of the grain in the C-axis direction, and has magnetic anisotropy.
Claim 3
Dependent Claim
45 words
The magnetic powder as set forth in claim 1, wherein the R-TM-B-M system alloy powder consists essentially of 11-18 at % of rare earth elements, 4-11 at % of boron, 3 at % or less of the additives, and the balance iron and unavoidable impurities.
Claim 4
Dependent Claim
26 words
The magnetic powder as set forth in claim 2, wherein the residual induction in the direction of the easy magnetizing axis is 8 kilo-Gauss or higher.
Claim 5
Dependent Claim
65 words
The magnetic powder as set forth in claim 1, wherein the R-TM-B-M system anisotropic alloy powder is produced by the process comprising the steps of rapidly-quenching the molten metal of the R-TM-B-M alloy to make flakes of the alloy, compacting the flakes to form a high density body, plastically deforming the body to cause magnetic anisotropy in the body, and crushing the plastically deformed body.
Claim 6
Dependent Claim
19 words
The magnetic powder as set forth in claim 4, wherein the anisotropy is caused by a hot upsetting process.
Claim 7
Dependent Claim
19 words
The magnet powder as in claim 4, wherein the deformation ratio of the body is at least about 2.4.
Claim 8
Dependent Claim
19 words
The magnet powder as in claim 4, wherein the deformation ratio of the body is at least about 3.0.
Claim 9
Dependent Claim
19 words
The magnet powder as in claim 4, wherein the deformation ratio of the body is at least about 4.1.
Claim 10
Dependent Claim
19 words
The magnet powder as in claim 4, wherein the deformation ratio of the body is at least about 5.6.
Claim 11
Dependent Claim
19 words
The magnet powder as in claim 4, wherein the deformation ratio of the body is at least about 6.3.
Claim 12
Dependent Claim
19 words
The magnet powder as in claim 4, wherein the deformation ratio of the body is at least about 7.2.
Claim 13
Dependent Claim
49 words
The magnetic powder as in claim 1, wherein the R-T-M-B-M system alloy powder consists essentially of 11-18 at % of rare earth elements, 4-11 at % of boron, 30 at % or less of Co, 3 at % or less of additives, and the balance iron and unavoidable impurities.
Claim 14
Dependent Claim
130 words
Magnetic powder for a magnetically anisotropic bond magnet comprising an alloy powder of the R-TM-B-M system, wherein R is at least one or rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is at least one additive selected from the group consisting of Si, Al, Nb, Zr, P and C, said powder having an average crystal grain size of 0.01-0.5 μm, having magnetic anisotropy, having an average grain size of 1-1,000 μm, and having grains which have been plastically deformed to a flattened shape having a reduced thickness relative to the other grain dimensions to provide said anisotropy, wherein the C-axis of easy magnetization of each flattened grain is substantially aligned with the thickness direction.
Claim 15
Dependent Claim
130 words
Magnetic powder for a magnetically anisotropic bond magnet comprising an alloy powder of the R-TM-B-M system, wherein R is at least one or rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is at least one additive selected from the group consisting of Si, Al, Nb, Zr, P and C, said powder having an average crystal grain size of 0.01-0.5 μm, having magnetic anisotropy, having an average grain size of 1-1,000 μm, and having grains which have been plastically deformed to a flattened shape having a reduced thickness relative to the other grain dimensions to provide said anisotropy, wherein the C-axis of easy magnetization of each flattened grain is substantially aligned with the thickness direction.
Claim 16
Dependent Claim
46 words
The magnetic powder as set forth in claim 13, wherein the R-TM-B-M system alloy powder consists essentially of 11-18 at % of rare earth elements, 4-11 at % of boron, 3 at % or less of the additives, and the balance of iron and unavoidable impurities.
Claim 17
Dependent Claim
26 words
The magnetic powder as set forth in claim 14, wherein the residual induction in the direction of the easy magnetizing axis is 8 kilogauss or higher.
Claim 18
Dependent Claim
65 words
The magnetic powder as set forth in claim 13, wherein the R-TM-B-M system anisotropic alloy powder is produced by the process comprising the steps of rapidly-quenching the molten metal of the R-TM-B-M alloy to make flakes of the alloy, compacting the flakes to form a high density body, plastically deforming the body to cause magnetic anisotropy in the body, and crushing the plastically deformed body.
Claim 19
Dependent Claim
18 words
The magnetic powder as set forth in claim 16, wherein the anisotropy is caused by hot upsetting process.
Claim 20
Dependent Claim
46 words
The magnetic powder as in claim 13, wherein the R-TM-B-M system alloy powder consists essentially of 11-18% of rare earth elements, 4-11 at % boron, 30 at % or less of Co, 3 at % or less of additives, and the balance iron and unavoidable impurities.
References Cited (Backward Citations)
US4192696A
Cited
US4402770A
Cited
JPS5946008A
Cited
JPS5964739A
Cited
JPS5964733A
Cited
EP0106948A2
Cited
EP0125752A2
Cited
US4597938A
Cited
US4601875A
Cited
JPS59219904A
Cited
JPS609852A
Cited
JPS6027105A
Cited
JPS60100402A
Cited
EP0133758A2
Cited
EP0174735A2
Cited
EP0187538A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |