EP0124655A2
Expired / Lapsed
EP
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Isotropic permanent magnets and process for producing same
Assignee: Proterial Ltd
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Filing: 1983-12-30
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Granted: —
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Expires: 2003-12-30
Abstract
Abstract Isotropic permanent magnet formed of a sintered body having a mean crystal grain size of 1-160 microns and a major phase of tetragonal system comprising, in atomic percent, 10-25% of R wherein R represents at least one of rare-earth elements including Y, 3-23% ofB and the balance being Fe. As additional elements M, Al, Ti, V, Cr, Mn, Zr, Hf, Nb, Ta, Mo, Ge, Sb, Sn, Bi, Ni or W may be incorporated. The magnets can be produced through a powder metallurgical process resulting in high magnetic properties, e.g., up to 7 MGOe or higher energy product.
Inventors
- 👤 Setsuo Hanazonodanchi 14-106 Fujimura
- 👤 Masato Sagawa
- 👤 Yutaka Matsuura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 02:23
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: 48
Claim 1
Independent Claim
46 words
An isotropic permanent magnet formed of a sintered body consisting essentially of, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities.
Claim 2
Dependent Claim
46 words
An isotropic permanent magnet formed of a sintered body consisting essentially of, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities.
Claim 3
Dependent Claim
62 words
An isotropic permanent magnet formed of a sintered body consisting essentially of, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities, in which the sintered body has a mean crystal grain size of 1 - 160 microns.
Claim 4
Dependent Claim
62 words
An isotropic permanent magnet formed of a sintered body consisting essentially of, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities, in which the sintered body has a mean crystal grain size of 1 - 160 microns.
Claim 5
Dependent Claim
71 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising the steps: melting and preparing alloys comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities, cooling the resultant molten alloys, pulverizing the resultant alloys, compacting the pulverized alloys, and sintering the resultant compact.
Claim 6
Dependent Claim
71 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising the steps: melting and preparing alloys comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities, cooling the resultant molten alloys, pulverizing the resultant alloys, compacting the pulverized alloys, and sintering the resultant compact.
Claim 7
Dependent Claim
77 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising the steps: compacting under pressure alloy powders comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities, and sintering the resultant compact under such conditions that the sintered bodies have a mean crystal grain size of 1 - 160 microns.
Claim 8
Dependent Claim
77 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising the steps: compacting under pressure alloy powders comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B and the balance being Fe and inevitable impurities, and sintering the resultant compact under such conditions that the sintered bodies have a mean crystal grain size of 1 - 160 microns.
Claim 9
Dependent Claim
102 words
A magnet as defined in Claim 1 or 2, in which, of said impurities, Cu is no more than 3.3 %, S is no more than 2.5 %, C is no more than 4.0 %, P is no more than 3.3 %, Ca is no more than 4.0 %, M g is no more than 4.0 %, O is no more than 2.0 %, and Si is no more than 5.0 %, wherein, when two or more of said elements are contained, the combined value thereof is no more than the maximum value among the aforesaid values of the actually contained elements.
Claim 10
Dependent Claim
101 words
A process as defined in Claim 3 or 4, in which, of said impurities, Cu is no more than 3.3 %, S is no more than 2.5 %, C is no more than 4.0 %, P is no more than 3.3 %, Ca is no more than 4.0 %, Mg is no more than 4.0 %, O is no more than 2.0 % and Si is no more than 5.0 %, wherein, when two or more of said elements are contained, the combined amount thereof is no more than the maximum value among the aforesaid values of the actually contained elements.
Claim 11
Dependent Claim
104 words
An isotropic permanent magnet formed of a sintered body consisting essentially of, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, given percents, specified below, of at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stands for: wherein, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M.
Claim 12
Dependent Claim
104 words
An isotropic permanent magnet formed of a sintered body consisting essentially of, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, given percents, specified below, of at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stands for: wherein, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M.
Claim 13
Dependent Claim
120 words
An isotropic permanent magnet formed of a sintered body, which comprises, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, given percents, specified below, at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stands for: wherein, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M, and provided that said sintered body has a mean crystal grain size of about 1 - 100 microns.
Claim 14
Dependent Claim
120 words
An isotropic permanent magnet formed of a sintered body, which comprises, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, given percents, specified below, at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stands for: wherein, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M, and provided that said sintered body has a mean crystal grain size of about 1 - 100 microns.
Claim 15
Dependent Claim
129 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising the steps: melting and preparing alloys comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, giver percents, specified below, of at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stand: for: and, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M, cooling the resultant molten alloys, pulverizing the resultant alloys, compacting the pulverized alloys, and sintering the resultant compact.
Claim 16
Dependent Claim
129 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising the steps: melting and preparing alloys comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, giver percents, specified below, of at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stand: for: and, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M, cooling the resultant molten alloys, pulverizing the resultant alloys, compacting the pulverized alloys, and sintering the resultant compact.
Claim 17
Dependent Claim
132 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising steps: compacting an alloys comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, given percents, specified below, of at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stands for: wherein, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M, and sintering the resultant compact under such conditions that the sintered bodies have a mean crystal grain size of 1 - 100 microns.
Claim 18
Dependent Claim
132 words
A process for preparing isotropic permanent magnets formed of sintered bodies comprising steps: compacting an alloys comprising, in atomic percent, 10 - 25 % of R wherein R represents at least one of rare-earth elements including Y, 3 - 23 % of B, given percents, specified below, of at least one of the following additional elements M exclusive of 0 % of M, and the balance being Fe and inevitable impurities, provided that M stands for: wherein, when two or more of said elements M are added, the combined amount thereof is no more than the maximum percent value among the aforesaid values of the actually added elements M, and sintering the resultant compact under such conditions that the sintered bodies have a mean crystal grain size of 1 - 100 microns.
Claim 19
Dependent Claim
112 words
A magnet as defined in Claim 7 or 8, in which, of said impurities(A), Cu is no more than 3.3 %, S is no more than 2.5 %, C is no more than 4.0 %, P is no more than 3.3 %, Ca is no more than 4.0 %, Mg is no more than 4.0 %, O is no more than 2.0 %, and Si is no more than 5.0 %, wherein, when one or two or more of said M and A, respectively, are contained, the combined value of (M + A) is no more than the maximum value among the aforesaid values of the elements M and A actually contained.
Claim 20
Dependent Claim
113 words
A process as defined in Claim 9 or 10, in which, of said impurities, Cu is no more than 3.3 %, S is no more than 2.5 %, C is no more than 4.0 %, P is no more than 3.3 %, Ca is no more than 4.0 %, Mg is no more than 4.0 %, O is no more than 2.0 % and Si is no more than 5.0 %, wherein, when one or two or more of said elements M and A, respectivelye are contained, the combined amount of (M + A) is no more than the maximum value among the aforesaid values of the elements M and A actually contained.
Claim 21
Dependent Claim
29 words
A magnet as defined in Claim 1, 2, 7 or 8, in which, in atomic %, R is 12 - 20% , and B is 5 - 18 %.
Claim 22
Dependent Claim
22 words
A magnet as defined in Claim 13, in which, R is 12 - 16 % and B is 6 - 18 %.
Claim 23
Dependent Claim
29 words
A process as defined in Claim 3, 4, 9 or 10, in which, in atomic %, R is 12 - 20 %, and B is 5 - 18 %.
Claim 24
Dependent Claim
25 words
A process as defined in Claim 15, in which, in atomic %, R is 12 - 16 %, and B is 6 - 18 %.
Claim 25
Dependent Claim
25 words
A magnets as defined in Claim 1, 2, 7 or 8, in which R contains 50 atomic % or higher of light rare earth elements.
Claim 26
Dependent Claim
20 words
A magnet as defined in Claim 17, in which R contains 50 atomic % or higher of (Nd + Pr).
Claim 27
Dependent Claim
22 words
A magnet as defined in Claim 18, in which R is about 15 atomic %, and B is about 8 atomic %.
Claim 28
Dependent Claim
25 words
A process as defined in Claim 3, 4, 9 or 10, in which R contains 50 atomic % or higher of light rare earth elements.
Claim 29
Dependent Claim
20 words
A process as defined in Claim 20, in which R contains 50 atomic % or higher of (Nd + Pr).
Claim 30
Dependent Claim
22 words
A process as defined in Claim 21, in which R is about 15 atomic %, and B is about 8 atomic %.
Claim 31
Dependent Claim
30 words
A magnet as defined in Claim 1, 2, 7 or 8, in which the major phase is formed by an FeBR type alloy having a substantially tetragonal system crystal structure.
Claim 32
Dependent Claim
23 words
A magnet as defined in Claim 1, 2, 7 or 8, which contains 1 vol. % or higher of a rare earth-rich phase.
Claim 33
Dependent Claim
21 words
A magnet as defined in Claim 1, 2, 7 or 8, which has (BH) max of no less than 2 MGOe.
Claim 34
Dependent Claim
16 words
A magnet as defined in Claim 13, which has (BH)max of no less than 4 MGOe.
Claim 35
Dependent Claim
16 words
A magnet as defined in Claim 14, which has (BH)max of no less than 7 MGOe.
Claim 36
Dependent Claim
57 words
A magnet as defined in Claim 7 or 8, in which the following elements M are contained in or below the following given %: provided that, when two or more of said elements M are added, the combined amount thereof is no more than the maximum value among the aforesaid values of said elements M actually added.
Claim 37
Dependent Claim
56 words
A process as defined in Claim 9 or 10, in which the following elements M are contained in or below the following given %: provided that, when two or more of said elements M are added, the combinedamount thereof is no more than the maximum value among the aforesaid values of said elements M actually added.
Claim 38
Dependent Claim
55 words
A magnet as defined in Claim 16, in which the following elements M are contained in or below the following given %: provided that, when two or more of said elements M are added, the combined amount thereof is no more than the maximum value among the aforesaid values of said elements M actually added.
Claim 39
Dependent Claim
55 words
A process as defined in Claim 17, in which the following elements M are contained in or below the following given %: provided that, when two or more of said elements M are added, the combined amount thereof is no more than the maximum value among the aforesaid values of said elements M actually added.
Claim 40
Dependent Claim
15 words
A magnet as defined in Claim 28, which has Br of no less than 4kG.
Claim 41
Dependent Claim
16 words
A magnet as defined in Claim 30, which has Br of no less than 6 kG.
Claim 42
Dependent Claim
30 words
A magnet as defined in Claim 7 or 8, in which M is one or more selected from the group consisting of V, Nb, Ta, Mo, W, Cr and Al.
Claim 43
Dependent Claim
27 words
A magnet as defined in Claim 1, 2, 7 or 8, in which the sintered body has a mean crystal grain size of 1 - 80 microns.
Claim 44
Dependent Claim
25 words
A magnet as defined in Claim 1 or 2, in which the sintered body has a mean crystal grain size of 3 - 10 microns.
Claim 45
Dependent Claim
25 words
A magnet as defined in Claim 7 or 8, in which the sintered body has a mean crystal grain size of 2 - 30 microns.
Claim 46
Dependent Claim
26 words
A process as defined in Claim 3, 4, 9 or 10, in which sintering is carried out at a temperature of 900 to 1200 degrees C.
Claim 47
Dependent Claim
19 words
A process as defined in Claim 38, in which sintering is carried out in a nonoxidizing or reducing atmosphere.
Claim 48
Dependent Claim
34 words
A process as defined in Claim 39, in which said atmosphere is vacuum or reduced pressure, or an inert gas of 99.9 % purity or higher under a pressure of 1 - 760 Torr.
References Cited (Backward Citations)
No citation records indexed.
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