EP0239031A1
Expired / Lapsed
EP
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Method of manufacturing magnetic powder for a magnetically anisotropic bond magnet
Assignee: Proterial Ltd
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Filing: 1987-03-20
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Granted: —
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Expires: 2007-03-20
Abstract
Abstract A magnetically anisotropic bond permanent magnet consists essentially of 15 to 40 vol-% of a resin binder, the balance being formed of R-TM-B-M system alloy powder. In this alloy system, R is at least one of the rear-earth elements including Y; TM is Te, which may be partly substituted by CO; and M is at least one of the elements Si, AI, Nb, Zr, Hf, Mo, P and C as an additive. B is boron. The alloy powder has an average crystal size of 0.01 to 0.5 µm and is magnetically anisotropic. The easy-magnetizing axes of the alloy powder are directed to a given direction. Such a permanent magnet has excellent thermal stability and magnetizing properties.
Inventors
- 👤 Masatoki Tokunaga
- 👤 Yasuto Nozawa
- 👤 Katsunori Iwasaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 06:53
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: 17
Claim 1
Independent Claim
111 words
A magnetically anisotropic bond magnet consisting essentially of 15 to 40 vol% of resin binder and the balance of R-TM-B-M system alloy powder (wherein R is at least one of the rare earth elements including Y; TM is Fe or Fe a part of which has been substituted by Co; B is boron; M is at least one selected from the group of Si, At, Nb, Zr, Hf, Mo, P and C as additives); wherein the R-TM-B-M system alloy powder has an average crystal size of 0.01 to 0.5 µm and is magnetically anisotropic; and wherein the R-TM-B-M system alloy powder's easy magnetizing axes have been directed to a given direction.
Claim 2
Dependent Claim
111 words
A magnetically anisotropic bond magnet consisting essentially of 15 to 40 vol% of resin binder and the balance of R-TM-B-M system alloy powder (wherein R is at least one of the rare earth elements including Y; TM is Fe or Fe a part of which has been substituted by Co; B is boron; M is at least one selected from the group of Si, At, Nb, Zr, Hf, Mo, P and C as additives); wherein the R-TM-B-M system alloy powder has an average crystal size of 0.01 to 0.5 µm and is magnetically anisotropic; and wherein the R-TM-B-M system alloy powder's easy magnetizing axes have been directed to a given direction.
Claim 3
Dependent Claim
46 words
The magnet of Claim 1, wherein the R-TM-B-M system alloy powder consists essentially of 11 to 18 atom-% of rare earth elements, 4 to 11 atom-% of boron, 30 atom-% or less of Co, 3 atom-% or less of additives, and the balance of unavoidable impurities.
Claim 4
Dependent Claim
56 words
The magnet of Claim 1, wherein the R-TM-B-M system anisotropic alloy powder is produced by a 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, and plastically deforming the body to cause magnetic anisotropy in the body.
Claim 5
Dependent Claim
15 words
The magnet of Claim 3, wherein the anisotropy is caused by a hot upsetting process.
Claim 6
Dependent Claim
95 words
A magnetic powder for a magnetically anisotropic bond magnet characterized in that the average grain size of the R-TM-B-M system alloy powder (wherein R is at least one of rare earth elements including Y; TM is Fe or Fe a part of which has been substituted by Co; B is boron; and M is at least one selected from the group of Si, Ai, Nb, Zr, Hf, Mo, P and C as additives) is 1 to 1,000 µm, that the average crystal grain size is 0.01 to 0.5 µm, and that it is magnetically anisotropic.
Claim 7
Dependent Claim
95 words
A magnetic powder for a magnetically anisotropic bond magnet characterized in that the average grain size of the R-TM-B-M system alloy powder (wherein R is at least one of rare earth elements including Y; TM is Fe or Fe a part of which has been substituted by Co; B is boron; and M is at least one selected from the group of Si, Ai, Nb, Zr, Hf, Mo, P and C as additives) is 1 to 1,000 µm, that the average crystal grain size is 0.01 to 0.5 µm, and that it is magnetically anisotropic.
Claim 8
Dependent Claim
48 words
The magnetic powder of Claim 5, wherein the R-TM-B-M system alloy powder consists essentially of 11 to 18 atom-% of rare earth elements, 4 to 11 atom-% of boron, 30 atom-% or less of Co, 3 atom-% or less of the additives, and the balance of unavoidable impurities.
Claim 9
Dependent Claim
23 words
The magnetic powder of Claim 6, wherein the residual induction in the direction of the easy magnetizing axis is 0.8 T or higher.
Claim 10
Dependent Claim
61 words
The magnetic powder of any of Claims 5 to 7, wherein the R-TM-B-M system anisotropic alloy powder is produced by a 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, and plastically deforming the body to cause magnetic anisotropy in the body.
Claim 11
Dependent Claim
16 words
The magnetic powder of Claim 8, wherein the anisotropy is caused by a hot upsetting process.
Claim 12
Dependent Claim
49 words
The magnetic powder of any of Claims 5 to 9, wherein the average ration c/a is 2 or more, in which (c) is the average size of the crystal grain in the direction perpendicular to C-axis and (a) is the average size of the crystal grain in C-axis direction.
Claim 13
Independent Claim
124 words
A method of manufacturing magnetic powder for a magnetically anisotropic bond magnet, comprising the steps of rapidly-quenching a molten metal of the R-TM-B-M alloy (wherein R is at least one of rare earth elements including Y; TM is Fe or Fe a part of which has been substituted by Co; B is boron; and M is at least one selected from the group of Si, AQ, Nb, Zr, Hf, Mo, P and C as additives) to make flakes of the alloy, compacting the flakes to form a high density body, plastically deforming the body to produce an alloy having an average crystal grain size of 0.01 to 0.5 µm and magnetic anisotropy, and heat-treating the alloy to enhance the coercive force of the alloy.
Claim 14
Independent Claim
124 words
A method of manufacturing magnetic powder for a magnetically anisotropic bond magnet, comprising the steps of rapidly-quenching a molten metal of the R-TM-B-M alloy (wherein R is at least one of rare earth elements including Y; TM is Fe or Fe a part of which has been substituted by Co; B is boron; and M is at least one selected from the group of Si, AQ, Nb, Zr, Hf, Mo, P and C as additives) to make flakes of the alloy, compacting the flakes to form a high density body, plastically deforming the body to produce an alloy having an average crystal grain size of 0.01 to 0.5 µm and magnetic anisotropy, and heat-treating the alloy to enhance the coercive force of the alloy.
Claim 15
Dependent Claim
42 words
The method of Claim 11, wherein the anisotropic R-TM-B-M system alloy is heated to a temperature of from 600°C to 900°C, retained at the temperature for no longer than 240 min, and then cooled at a cooling rate of 1°C/s or higher.
Claim 16
Dependent Claim
48 words
The method of Claim 12, wherein the R-TM-B-M system alloy consists essentially of 11 to 18 atom-% of rare earth elements, 4 to 11 atom-% of boron, 30 atom-% or less of Co, 3 atom-% or less of the additives and the balance of Fe and unavoidable impurities.
Claim 17
Dependent Claim
19 words
The invention of any of the preceding Claims, wherein M is preferably Si, Ai, Nb, Zr, P or C.
References Cited (Backward Citations)
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