EP0153744A2
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EP
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Process for producing permanent magnets
Assignee: Proterial Ltd
•
Filing: 1985-02-27
•
Granted: —
•
Expires: 2005-02-27
Abstract
Abstract A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200°C, subjecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700°C. 35 MGOe, 40 MGOe or higher energy product can be obtained with specific compositions.
Inventors
- 👤 Hitoshi Yamamoto
- 👤 Masato Sagawa
- 👤 Setsuo Hanazonodanchi 14-106 Fujimura
- 👤 Yutaka Matsuura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:07
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; B; B22; B22F; B22F3/00; B22F3/24
Claims Analysis
Total Claims: 81
Claim 1
Independent Claim
117 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200°C, subj ecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700°C.
Claim 2
Dependent Claim
117 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200°C, subj ecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700°C.
Claim 3
Dependent Claim
129 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3 to 80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, no more than 50 % Co (except for 0 % Co), and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200°C, subjecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700°C.
Claim 4
Dependent Claim
129 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3 to 80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, no more than 50 % Co (except for 0 % Co), and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200°C, subjecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700°C.
Claim 5
Dependent Claim
172 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, no more than the given percentage of at least one of the additional elements M (except for 0 % M, and wherein M is: provided that in the case where two or more of M are contained, the sum thereof is no more than the maximun given percentage among the additional elements M as contained), and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200°C. subjecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700° C.
Claim 6
Dependent Claim
172 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, no more than the given percentage of at least one of the additional elements M (except for 0 % M, and wherein M is: provided that in the case where two or more of M are contained, the sum thereof is no more than the maximun given percentage among the additional elements M as contained), and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200°C. subjecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700° C.
Claim 7
Dependent Claim
197 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, no more than 50 % Co (except for 0 % Co), no more than the given percentage of at least one of the additional elements M (except for 0 % M, and wherein M is: no more than 5.0 % Si, and no more than 2.0 % Zn, provided that in the case where two or more of M are contained, the sun thereof is no more than the maximum given percentage among the additional elements M as contained), and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200° C, subjecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700° C.
Claim 8
Dependent Claim
197 words
A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, no more than 50 % Co (except for 0 % Co), no more than the given percentage of at least one of the additional elements M (except for 0 % M, and wherein M is: no more than 5.0 % Si, and no more than 2.0 % Zn, provided that in the case where two or more of M are contained, the sun thereof is no more than the maximum given percentage among the additional elements M as contained), and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200° C, subjecting the sintered body to a primary heat treatment at a temperature of 750-1000°C, then cooling the resultant body to a temperature of no higher than 680°C at a cooling rate of 3-2000°C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700° C.
Claim 9
Dependent Claim
24 words
A process as defined in any of Claims 1-4, wherein the cooling after sintering is conducted at a cooling rate of at least 20°C/min.
Claim 10
Dependent Claim
29 words
A process as defined in Claim 5, wherein the primary heat treatment is conducted subsequent to the sintering, or by reheating starting from any temperature below 750°C after cooling.
Claim 11
Dependent Claim
22 words
A process as defined in Claim 5, wherein said cooling after sintering is conducted at a cooling rate of at least 100°C/min.
Claim 12
Dependent Claim
20 words
A process as defined in any of CLaims 1-4, wherein the sintering is effected in a reducing or non-oxidizing atmosphere.
Claim 13
Dependent Claim
27 words
A process as defined in any of Claim 1-4, wherein the secondary heat treatment is conducted by reheating starting from any temperature of no higher than 680°C.
Claim 14
Dependent Claim
28 words
A process as defined in Claim 9, wherein the secondary heat treatment is conducted at any time after said cooling to a temperature of no higher than 680°C.
Claim 15
Dependent Claim
26 words
A process as defined in Claim 10, wherein the secondary heat treatment is conducted subsequent to said cooling to a temperature of no higher than 680°C.
Claim 16
Dependent Claim
21 words
A process as defined in any of Claims 1-4, wherein the primary heat treatment is conducted at a temperature between 770-950°C.
Claim 17
Dependent Claim
19 words
A process defined in Claim 8, wherein the primary heat treatment is conducted at a temperature between 790-920° C.
Claim 18
Dependent Claim
25 words
A process as defined in any of Claims 1-4, wherein said cooling after the primary heat treatment is conducted at a cooling rate of 10-1500°C/min.
Claim 19
Dependent Claim
13 words
A process as defined in Claim 14, wherein said cooling rate is 20-1000°C/min.
Claim 20
Dependent Claim
21 words
A process as defined in any of Claims 1-4, wherein the secondary heat treatment is conducted at a temperature between 520-670°C.
Claim 21
Dependent Claim
19 words
A process as defined in Claim 16, wherein the secondary heat treatment is conducted at a temperature between 550-650°C.
Claim 22
Dependent Claim
26 words
A process as defined in any of Claims 1-4, wherein the heat treatments are conducted in vacuum or in an atmosphere of inert or reducing gas.
Claim 23
Dependent Claim
17 words
A process as defined in Claim 18, wherein the vacuum is at 10 -3 Torr or less.
Claim 24
Dependent Claim
19 words
A process as defined in Claim 18, wherein the atmosphere gas has a purity of at least 99.99 %.
Claim 25
Dependent Claim
24 words
A process as defined in any of Claims 1-4, wherein the primary heat treatment is conducted at a temperature below the respective sintering temperature.
Claim 26
Dependent Claim
27 words
A process as defined in any of Claims 1-4, wherein R includes at least one selected from a group consisting of Nd, Pr, Dy, Tb and Ho.
Claim 27
Dependent Claim
36 words
A process as defined in Claim 22, wherein R includes at least one selected from a group consisting of Nd, Pr, Dy, Tb and Ho and at least one rare earth elements except for said group.
Claim 28
Dependent Claim
23 words
A process as defined in Claim 22, wherein at least 50 % of the entire R is the sum of Nd and Fr.
Claim 29
Dependent Claim
19 words
A process as defined in any of Claims 1-4, wherein R is 12-24 % and B is 3-27 %.
Claim 30
Dependent Claim
17 words
A process as defined in Claim 25, wherein R is 12-20 % and B is 5-24 %.
Claim 31
Dependent Claim
17 words
A process as defined in Claim 26, wherein R is 12.5-20 % and B is 5-15 %.
Claim 32
Dependent Claim
17 words
A process as defined in Claim 27, wherein R is 13-18 % and B is 5-15 %.
Claim 33
Dependent Claim
13 words
A process as defined in Claim 28, wherein B is 5-11 % .
Claim 34
Dependent Claim
16 words
A process as defined in Claim 29, wherein R is 13-16 and B is 6-11 %.
Claim 35
Dependent Claim
19 words
A process as defined in Claim 30, wherein R is 13-14.5 % and B is 6 - 7 %.
Claim 36
Dependent Claim
20 words
A process as defined in Claim 27, wherein Fe, or the sum of Fe, Co and M is 65-82.5 %.
Claim 37
Dependent Claim
21 words
A process as defined in Claim 28 , wherein Fe, or the sun of Fe, Co and M is 67-82 %.
Claim 38
Dependent Claim
23 words
A process as defined in Claim 24, wherein at least 80 % of the entire R is the sum of Nd and Pr.
Claim 39
Dependent Claim
13 words
A process as defined in Claim 34, wherein R is Nd and/or Pr.
Claim 40
Dependent Claim
14 words
A process as defined in Claim 2 or 4, wherein Co is 0.1-35 %.
Claim 41
Dependent Claim
12 words
A process as defined in Claim 36, wherein Co is 5-25 %.
Claim 42
Dependent Claim
15 words
A process as defined in Claim 36, wherein Co is no more than 23 %.
Claim 43
Dependent Claim
23 words
A process as defined in Claim 30, wherein Co is no more than 15 % and M is no more than 2 %.
Claim 44
Dependent Claim
23 words
A process as defined in Claim 31, wherein Co is no more than 10 % and M is no more than 1 %.
Claim 45
Dependent Claim
16 words
A process as defined in Claim 3 or 4, wherein M is at least 0.1 %.
Claim 46
Dependent Claim
45 words
A process as defined in Claim 41, wherein M is no more than the following given percentage provided that the sun of M is no more than the maximun given percentage among the respective additional elements M contained where two or more M are contained:
Claim 47
Dependent Claim
45 words
A process as defined in Claim 42, wherein M is no more than the following given percentage provided that the sum of M is no more than the maximum given percentage among the respective additional elements M contained where two or more M are contained:
Claim 48
Dependent Claim
38 words
A process as defined in Claim 43, wherein M is at least one selected from the group consisting of V, Nb, Ta, Mo, W, Cr and Al and the sum of M is no more than 3 %.
Claim 49
Dependent Claim
24 words
A process as defined in any of Claims 1-4, wherein the forming is effected in a magnetic field under a condition to provide anisotropy.
Claim 50
Dependent Claim
19 words
The product of the process as defined in Claim 45, wherein R is 13-18 %, B is 5-11 %.
Claim 51
Dependent Claim
24 words
The product of the process as defined in Claim 46, wherein F e or the sun of Fe, Co and M is 71-82 %.
Claim 52
Dependent Claim
16 words
The product of the process as def ined in CLaim 47, wherein Co is 5-23 %.
Claim 53
Dependent Claim
33 words
The product of the process as defined in Claim 47, wherein M is 0.1-3 % of at least one selected from the group consisting of V, Nb, Ta, Mo, W, Cr and Al.
Claim 54
Dependent Claim
26 words
The product of the process as defined in CLaim 47, wherein at least 50 % of the entire R is the sum of Nd and Pr.
Claim 55
Dependent Claim
68 words
The product of the process as defined in Claim 47, wherein R=R 1 +R 2 provided that R 1 is 0.2-3 % per the total material of at least one of Dy, Tb and Ho, and the balance being R 2 consisting of at least 80 % per the entire R of the sum of Nd plus Pr and other R than R 1 , Nd and Pr.
Claim 56
Dependent Claim
19 words
The product of the process as defined in Claim 50, wherein the energy product is at least 30 MGOe.
Claim 57
Dependent Claim
19 words
The product of the process as defined in Claim 51, wherein the energy product is at least 30 MGOe.
Claim 58
Dependent Claim
63 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, and the balance being Fe and inevitable impurities, wherein at least 80 % of the entire R is the sum of Nd and Pr.
Claim 59
Dependent Claim
63 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, and the balance being Fe and inevitable impurities, wherein at least 80 % of the entire R is the sum of Nd and Pr.
Claim 60
Dependent Claim
74 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of, in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, no more than 15 % Co (except for 0 % Co), and the balance being Fe and inevitable impurities, wherein at least 80 % of the entire R is the sum of Nd and Pr.
Claim 61
Dependent Claim
74 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of, in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, no more than 15 % Co (except for 0 % Co), and the balance being Fe and inevitable impurities, wherein at least 80 % of the entire R is the sum of Nd and Pr.
Claim 62
Dependent Claim
91 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of, in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, no more than 1 % of at least one of the additional elements M (except for 0 % N) selected from the group consisting of V, Nb, Ta, Mo, W, Cr, Al, Ti, Zr, Hf, Mn, Ni, Ge, Sn, Bi, Sb, Si and Zn and the balance being Fe with inevitable impurities.
Claim 63
Dependent Claim
91 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of, in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, no more than 1 % of at least one of the additional elements M (except for 0 % N) selected from the group consisting of V, Nb, Ta, Mo, W, Cr, Al, Ti, Zr, Hf, Mn, Ni, Ge, Sn, Bi, Sb, Si and Zn and the balance being Fe with inevitable impurities.
Claim 64
Dependent Claim
103 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of, in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, no more than 15 % Co (except for 0 % Co) , no more than 1 % of at least one of the additional elements M (except for 0 % M) selected from the group consisting of V, Nb, Ta, Ko, W, Cr, Al, Ti, Zr, Hf, Mn, Ni, Ge, Sn, Bi, Sb, Si and Zn and the balance being Fe With inevitable impurities.
Claim 65
Dependent Claim
103 words
An anisotropic sintered permanent magnet having energy product of at least 35 MGOe and consisting essentially of, in atomic percentage, 13-16 % R (provided that R is at least one of rare earth elements including Y), 6-11 % B, no more than 15 % Co (except for 0 % Co) , no more than 1 % of at least one of the additional elements M (except for 0 % M) selected from the group consisting of V, Nb, Ta, Ko, W, Cr, Al, Ti, Zr, Hf, Mn, Ni, Ge, Sn, Bi, Sb, Si and Zn and the balance being Fe With inevitable impurities.
Claim 66
Dependent Claim
26 words
A permanent magnet as defined in Claim 54, wherein R is 13-14.5 %, B is 6-7 % and the energy product is at least 40 MGOe.
Claim 67
Dependent Claim
30 words
A permanent magnet as defined in Claim 55, wherein R is 13-14.5 %, B is 5-7 % , Co is 0.1-10 and the energy product is at least 40 MGOe.
Claim 68
Dependent Claim
32 words
A permanent magnet as defined in Claim 56, wherein R is 13-14.5 % , B is 6-7 % , M is 0.1-1 %, and the energy product is at least 40 MGOe.
Claim 69
Dependent Claim
36 words
A permanent magnet as defined in Claim 57, wherein R is 13-14.5 % , B is 6-7 % , Co is 0.1-10 %, M is 0.1-1 % and the energy product is at least 40 MGOe.
Claim 70
Dependent Claim
20 words
A permanent magnet as defined in any of claims 54-61, wherein R is at least one of Nd and Pr.
Claim 71
Dependent Claim
39 words
A permanent magnet as defined in any of claims 54-61, wherein R includes 0.2-3 % per total magnet of at least one of Dy, Tb and Ho, the balance of R being at least one of Nd and Pr.
Claim 72
Dependent Claim
15 words
A permanent magnet as defined in Claim 63, wherein the balance of R is Nd.
Claim 73
Dependent Claim
29 words
A process as defined in any of Claims 1-4, wherein the forming is effected without applying magnetic fiela provided that R is 10-25 % and B is 3-23 %.
Claim 74
Dependent Claim
24 words
A process as defined in Claim 65, wherein R is 12-20 %, B is 5-18 % and Co is no more than 35 %.
Claim 75
Dependent Claim
24 words
A process as defined in Claim 66, wherein R is 12-16 %, B is 6-18 % and Co is no more than 25 %.
Claim 76
Dependent Claim
26 words
A process as defined in Claim 3 or 4, provided that with respect to V, W, Ti, Ni and Ge, the given percentage is as follows:
Claim 77
Dependent Claim
11 words
The isotropic product of the process as defined in Claim 67.
Claim 78
Dependent Claim
28 words
The isotropic product of the process as defined in Claim 68, wherein R is 12-16 %, B is 6-18 %, and Co is no more than 25 %.
Claim 79
Dependent Claim
34 words
The isotropic product of the process as defined in Claim 70, wherein M is 0.1-3 % of at least one selected from the group consisting of V, Nb, Ta, Mo, W, Cr and Al.
Claim 80
Dependent Claim
17 words
The isotropic product as defined in Claim 69, which has energy product of at least 7 MGOe.
Claim 81
Dependent Claim
17 words
The isotropic product as defined in Claim 71, which has energy product of at least 7 MGOe.
References Cited (Backward Citations)
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