EP0258609A2
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EP
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Permanent magnet with good thermal stability
Assignee: Proterial Ltd
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Filing: 1987-07-22
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Granted: —
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Expires: 2007-07-22
Abstract
Abstract A permanent magnet having good thermal stability, consisting essentially of the composition represented by the general formula: wherein R is Nd alone or one or more rare earth elements mainly composed of Nd, Pr or Ce, 0≦x≦0.7, 0.02≦y≦0.3, 0.001≦z≦0.15 and 4.0≦A≦7.5. This permanent magnet may contain one or more additional elements selected from Nb, W, V, Ta and Mo. This permanent magnet has high coercive force and Curie temperature and thus highly improved thermal stability.
Inventors
- 👤 Masaaki Tokunaga
- 👤 Minoru Endoh
- 👤 Hiroshi Kogure
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 09:05
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; H01F1/0577
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
42 words
I. A permanent magnet having good thermal stability, consisting essentially of the composition represented by the general formula: wherein R is Nd alone or one or more rare earth elements mainly composed of Nd, Pr or Ce, 0≦x≦0.7, 0.025≦y≦0.3, 0.001≦z≦0.15 and 4.05A57.5.
Claim 2
Dependent Claim
30 words
The permanent magnet having good thermal stability according to claim I, wherein R is Nd, part of which may be substituted by Pr and/or Ce, 0.01≦x≦0.4, 0.03≦y≦0.2, 0.002≦z≦0.1 and 4.55A57.0.
Claim 3
Dependent Claim
67 words
A permanent magnet having good thermal stability, consisting essentially of the composition represented by the general formula: wherein R is Nd alone or one or more rare earth elements mainly composed of Nd, Pr or Ce, part of which may be substituted by Dy, Tb or Ho, M is one or more elements selected from Nb, W, V, Ta and Mo, 0≦x≦0.7, 0.02≦y≦0.3, 0.001≦z≦0.15, 0.001≦u≦0.1 and 4.0≦A≦7.5.
Claim 4
Dependent Claim
18 words
The permanent magnet having good thermal stability according to claim 3, wherein 0.01≦x≦0.4, 0.03≦y≦0.2, 0.002≦z≦0.1, 0.002≦u≦0.04 and 4.5≦A≦7.0.
Claim 5
Dependent Claim
31 words
The permanent magnet having good thermal stability according to claim 3, wherein R is mainly composed of Nd and Dy, an atomic ratio of Nd to Dy being 0.97:0.03 to 0.6:0.4.
Claim 6
Dependent Claim
18 words
The permanent magnet having good thermal stability according to claim 5, wherein 0.01≦x≦0.4, 0.03≦y≦0.2, 0.002≦z≦0.1, 0.002≦u≦0.04 and 4.5≦A≦7.0.
Claim 7
Dependent Claim
18 words
The permanent magnet having good thermal stability according to any one of claims 3-6, wherein M is Nb.
References Cited (Backward Citations)
No citation records indexed.
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