EP0126802B1
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Process for producing of a permanent magnet
Assignee: Proterial Ltd
•
Filing: 1983-09-23
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Granted: 1988-12-14
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Expires: 2003-09-23
Abstract
No abstract record available.
Inventors
- 👤 Hitoshi Yamamoto
- 👤 Masato Sagawa
- 👤 Setsuo Hanazonodanchi 14-106 Fujimura
- 👤 Yutaka Matsuura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 05:14
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; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49075; Y10T29/49076
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
64 words
A process for producing a permanent magnet of the Fe-B-R type comprising: providing a sintered body having a composition comprising, by atomic percent, 8-30% R, wherein R is at least one rare earth element including Y, 2-28% boron (B), and the balance being iron (Fe), and heat treating the sintered body at a temperature ranging from 350 degrees C to the temperature for sintering.
Claim 2
Dependent Claim
64 words
A process for producing a permanent magnet of the Fe-B-R type comprising: providing a sintered body having a composition comprising, by atomic percent, 8-30% R, wherein R is at least one rare earth element including Y, 2-28% boron (B), and the balance being iron (Fe), and heat treating the sintered body at a temperature ranging from 350 degrees C to the temperature for sintering.
Claim 3
Dependent Claim
29 words
A process as defined in claim 1, wherein the sum of Nd and/or Pr amounts to no less than 50 at % of the overall rare earth elements R.
Claim 4
Dependent Claim
56 words
A process as defined in claim 1, wherein in said sintered body Nd and/or Pr amounts to no less than 50 at % of the overall rare earth elements R, and a part of the Fe is substituted for by Cobalt (Co), such that the sintered body comprises no more than 50 at % of Co.
Claim 5
Dependent Claim
64 words
A process as defined in one of the preceding claims, wherein said sintered body optionally comprises at least one additional element M of no more than the values by atomic percent as specified hereinbelow provided that, when two or more elements are added, the total amount thereof shall be no more than the largest value among said specified values of the elements actually added:
Claim 6
Dependent Claim
60 words
A process as defined in any of claims 1-4, wherein the step of providing said sintered body comprises: preparing a metallic powder having said composition and a mean particle size of 0.3-80 pm, and compacting said metallic powder in a magnetic field, and sintering the compacted body at a temperature of 900-1200 degrees C in a nonoxidizing or reducing atmosphere.
Claim 7
Dependent Claim
28 words
A process as defined in claim 5, wherein said sintered body comprises, by atomic percent, 10-25% R and 3-23% B, and is compacted without applying a magnetic field.
Claim 8
Dependent Claim
21 words
A process as defined in any of claims 1-6, wherein the heat treatment is carried out after cooling following the sintering.
Claim 9
Dependent Claim
19 words
A process as defined in any of claims 1-6, wherein the heat treatment is carried out following the sintering.
Claim 10
Dependent Claim
26 words
A process as defined in claim 7, wherein the cooling following the sintering is carried out at a cooling rate of 20 degrees C/min or higher.
Claim 11
Dependent Claim
20 words
A process as defined in any of claims 1-6, wherein heat treatment is carried out at least at one stage.
Claim 12
Dependent Claim
18 words
A process as defined in claim 10, wherein heat treatment is carried out in two or more stages.
Claim 13
Dependent Claim
38 words
A process as defined in any of claims 1-6, wherein the heat treatment is carried out as a cooling procedure at a cooling rate of 0.2-20 degrees C/min within a temperature range from 800 to 400 degrees C.
Claim 14
Dependent Claim
31 words
A process as defined in claim 11, wherein heat treatment at a subsequent stage following a preceding stage is carried out at a temperature lower than that of the preceding stage.
Claim 15
Dependent Claim
27 words
A process as defined in claim 11, wherein the heat treatment at the first stage is carried out at a temperature of 800 degrees C or higher.
Claim 16
Dependent Claim
29 words
A process as defined in claim 13, wherein the heat treatment at a second or further stage is carried out at a temperature of 800 degrees C or less.
Claim 17
Dependent Claim
24 words
A process as defined in claim 12, wherein said cooling procedure is carried out subsequent to the sintering or any preceding heat treatment stage.
Claim 18
Dependent Claim
26 words
A process as defined in any of claims 1-6, wherein the heat treatment is carried out in a vacuum, or in a reducing or nonoxidizing atmosphere.
Claim 19
Dependent Claim
25 words
A process as defined in claim 17, wherein the heat treatment is carried out in a vacuum of 0.133 Pa (10- 3 Torr) or less.
Claim 20
Dependent Claim
31 words
A process as defined in claim 17, wherein the heat treatment is carried out in a reducing or inert gas atmosphere having a gas purity of 99.99 mole % or higher.
Claim 21
Dependent Claim
27 words
A process as defined in claim 5 or 6, wherein the nonoxidizing or reducing atmosphere is comprised of a vacuum, an inert gas or a reducing gas.
Claim 22
Dependent Claim
24 words
A process as defined in claim 20, wherein the inert gas or the reducing gas has a purity of 99.9 mole % or higher.
Claim 23
Dependent Claim
18 words
A process as defined in claim 20, wherein the vacuum is 1.33 Pa (10- 2 Torr) or less.
Claim 24
Dependent Claim
21 words
A process as defined in claim 5 or 6, wherein the metallic powder is an alloy powder having said respective composition.
Claim 25
Dependent Claim
24 words
A process as defined in claim 5 or 6, wherein the metallic powder is a mixture of alloy powders making up said respective composition.
Claim 26
Dependent Claim
44 words
A process as defined in claim 5 or 6, wherein the metallic powder is a mixture of an alloy or alloys having a Fe-B-R base composition and a powdery metal having a complementary composition making up the respective final composition of said metallic powder.
Claim 27
Dependent Claim
24 words
A process as defined in claim 25, wherein said powdery metal comprises an alloy or alloys of the componental elements of said final composition.
Claim 28
Dependent Claim
19 words
A process as defined in claim 25, wherein said powdery metal comprises said componental elements of said final composition.
Claim 29
Dependent Claim
17 words
A process as defined in claim 9, wherein the cooling rate is 100 degrees C/min or higher.
Claim 30
Dependent Claim
42 words
A process as defined in claim 6, wherein said additional elements M amount to no more than the values specified below: and the total amount of the additional elements M shall be no more than the largest value among the specified values.
Claim 31
Dependent Claim
17 words
A process as defined in any of claims 1-4, wherein R is 12-24%, and B is 3--27%.
Claim 32
Dependent Claim
15 words
A process as defined in claim 30, wherein R is 12-20%, and B is 4-24%.
Claim 33
Dependent Claim
14 words
A process as defined in claim 31, wherein Ci is no more than 35%.
Claim 34
Dependent Claim
16 words
A process as defined in claim 2 or 4, wherein Co is no more than 25%.
Claim 35
Dependent Claim
15 words
A process as defined in claim 2 or 4, wherein Co is 5% or more.
Claim 36
Dependent Claim
15 words
A process as defined in claim 6, wherein R is 12-20%, and B is 5-18%.
Claim 37
Dependent Claim
15 words
A process as defined in claim 35, wherein R is 12-16%, and B is 6-18%.
Claim 38
Dependent Claim
30 words
A process as defined in claim 3, wherein the additional elements M comprise at least one selected from the group consisting of V, Nb, Ta, MO, W, Cr and Al.
Claim 39
Dependent Claim
23 words
A process as defined in claim 10, wherein the heat treatment is carried out at a temperature between 450 and 800 degrees C.
Claim 40
Dependent Claim
23 words
A process as defined in claim 38, wherein the heat treatment is carried out at a temperature between 500 and 700 degrees C.
Claim 41
Dependent Claim
24 words
A process as defined in claim 38 or 39, wherein the heat treatment is carried out approximately under an isothermic condition at each stage.
Claim 42
Dependent Claim
23 words
A process as defined in claim 28, wherein the sintered body is cooled down to a temperature of 800 degrees C or less.
Claim 43
Dependent Claim
20 words
A process as defined in any of claims 1-4, wherein further impurities including Si do not exceed 5 atomic percent.
Claim 44
Dependent Claim
30 words
A process as defined in claim 1 or 4, wherein at least 50 vol.-% of the sintered body is occupied by ferromagnetic Fe-B-R type compound having a tetragonal crystal structure.
Claim 45
Dependent Claim
30 words
A process as defined in claim 3 or 5, wherein at least 50 vol.-% of the sintered body is occupied by ferromagnetic Fe-Co-B-R type compound having a tetragonal crystal structure.
References Cited (Backward Citations)
No citation records indexed.
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