EP0320064A1 - Hard magnetic material of a rare earth metal, iron and carbon - Google Patents
Hard magnetic material of a rare earth metal, iron and carbon Download PDFInfo
- Publication number
- EP0320064A1 EP0320064A1 EP88202784A EP88202784A EP0320064A1 EP 0320064 A1 EP0320064 A1 EP 0320064A1 EP 88202784 A EP88202784 A EP 88202784A EP 88202784 A EP88202784 A EP 88202784A EP 0320064 A1 EP0320064 A1 EP 0320064A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- magnetic material
- hard magnetic
- carbon
- iron
- composition
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000696 magnetic material Substances 0.000 title claims abstract description 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims description 32
- 229910052799 carbon Inorganic materials 0.000 title claims description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims description 17
- 229910052742 iron Inorganic materials 0.000 title claims description 13
- 229910052761 rare earth metal Inorganic materials 0.000 title claims description 3
- 150000002910 rare earth metals Chemical class 0.000 title claims description 3
- 238000005266 casting Methods 0.000 claims abstract description 14
- 238000001953 recrystallisation Methods 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims description 21
- 229910052779 Neodymium Inorganic materials 0.000 claims description 15
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 claims description 14
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 claims description 14
- 239000013078 crystal Substances 0.000 claims description 9
- 229910017052 cobalt Inorganic materials 0.000 claims description 6
- 239000010941 cobalt Substances 0.000 claims description 6
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 4
- 239000007858 starting material Substances 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 150000002500 ions Chemical class 0.000 claims 1
- 238000000137 annealing Methods 0.000 abstract description 10
- 229910001172 neodymium magnet Inorganic materials 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 150000001875 compounds Chemical group 0.000 description 2
- 238000000265 homogenisation Methods 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 150000001639 boron compounds Chemical class 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/058—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IVa elements, e.g. Gd2Fe14C
Definitions
- the invention relates to a hard magnetic material comprising neodymium, iron and carbon.
- Nd2Fe14B having the tetragonal crystal structure. It is known that in this compound substitution of B by C leads to an increased anisotropy (see, for example, Journal de Physique Colloque C6, supplphi au no. 9, T 46, Sept. 1985, page C6-305/308: "Magnetic Anisotropy of Carbon Doped Nd2Fe14B" by Bolzoni, Leccabue, Pareti and Sanchez). In this article it is stated on page 306 that it was impossible to obtain the tetragonal phase when borium was completely substituted by carbon in the compound Nd2Fe14B. This is also stated in an article in Solid State Communications Vol. 64, No. 5 p. 639-644 (1987).
- this object could be achieved by means of a material which has the tetragonal crystal structure and which consists of a recrystallization annealed cast material having a composition which does not or hardly deviate from the stoichiometric composition Nd2Fe14C.
- Fe may be substituted by Co up to a maximum of 6 at.% calculated on the overall composition. If more than 6 at.% of Fe is substituted by Co the quantity of hard magnetic material having the tetragonal crystal structure, which can be obtained in the annealing treatment decreases significantly.
- the hard magnetic material in accordance with the invention can be obtained as follows.
- the starting materials neodymium, iron, (possibly) cobalt and carbon are melted together in a substantially stoichiometric ratio, preferably, under an inert gas atmosphere such as argon.
- the melt is cast in a mould.
- the material has the Nd2Fe17 structure and is not hard magnetic; the carbon is dissolved in the lattice. It is assumed that the carbon in the lattice could substitute one or more iron atoms.
- the structure is rhombohedral. If desired, the casting obtained can be homogenization annealed at a temperature of 900° or higher.
- the material only comprises neodymium, iron and carbon it is annealed at a temperature between 840 and 890° C so that recrystallization takes place. It has been found that recrystallization takes place only within this temperature range, thereby forming the tetragonal Nd2Fe14C phase. Surprisingly it has been found that on weighing out the starting materials it is undesirable to clearly deviate from the stoichiometric composition as is required in the case of the corresponding boron compounds. A small positive deviation of no more than 20% in the quantity of neodymium and/or carbon relative to the stoichiometric composition and of 15% in the quantity of iron, however, has been found permissible.
- the tetragonal phase is not formed outside the indicated temperature range (above 890° C) or, if said phase is formed, predominantly, a second phase having the Nd2Fe17 structure remains in addition to the tetragonal phase (below 840° C). If annealing is carried out in the indicated temperature range the tetragonal phase is predominantly formed.
- a substantially single-phase material having optimum magnetic properties can be obtained if annealing is carried out at temperatures between 850 and 880° C, preferably at 870° C. If the material also comprises Co, the annealing process in which recrystallization takes place is preferably carried out at a temperature of approximately 850° C.
- Magnets can be obtained by directly casting the material in the desired shape. After casting and recrystallization annealing the material can be powdered and subsequently sintered to the desired shape in a magnetic field or be mixed with synthetic resin and pressed into the desired shape.
- part of the iron may be substituted by other 3d metals and/or aluminium, gallium, silicon etc.
- Part of the neodymium can be substituted by one or more rare earth metals.
- a casting was manufactured, the overall composition of which corresponded to the formula Nd2Fe13CoC. Subsequently, this casting was directly subjected to a recrystallization annealing process at 850° C for 150 hours without being previously homogeneization annealed.
- the material thus obtained is substantially single phase and has a tetragonal crystal structure.
- the material has a Curie temperature of 620 K.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Hard Magnetic Materials (AREA)
Abstract
A hard magnetic material having the substantially stoichiometric composition Nd2Fe14C. It can be obtained by casting and subsequently recrystallization annealing at a temperature between 840 and 890 DEG C. A part of Fe may be substituted by Co. In this case the magnetic material is obtained by casting and subsequently recrystallization annealing at a temperature of approximately 850 DEG C.
Description
- The invention relates to a hard magnetic material comprising neodymium, iron and carbon.
- A known material of this type is Nd₂Fe₁₄B having the tetragonal crystal structure. It is known that in this compound substitution of B by C leads to an increased anisotropy (see, for example, Journal de Physique Colloque C6, supplément au no. 9, T 46, Sept. 1985, page C6-305/308: "Magnetic Anisotropy of Carbon Doped Nd₂Fe₁₄B" by Bolzoni, Leccabue, Pareti and Sanchez). In this article it is stated on page 306 that it was impossible to obtain the tetragonal phase when borium was completely substituted by carbon in the compound Nd₂Fe₁₄B. This is also stated in an article in Solid State Communications Vol. 64, No. 5 p. 639-644 (1987). In this article "Synthesis and Magnetic Properties of Ternary Carbides R₂Fe₁₄C" by Gueramiom, Bezinge, Yvon and Muller it is stated on page 640 that the tetragonal structure in, amongst others, R = neodymium is not found by means of recrystallization annealing.
- It is an object of the invention to provide a hard magnetic material having a high crystal anisotropy, which comprises only carbon instead of boron and also a relatively high content of neodymium.
- It was found that this object could be achieved by means of a material which has the tetragonal crystal structure and which consists of a recrystallization annealed cast material having a composition which does not or hardly deviate from the stoichiometric composition Nd₂Fe₁₄C. In this composition Fe may be substituted by Co up to a maximum of 6 at.% calculated on the overall composition. If more than 6 at.% of Fe is substituted by Co the quantity of hard magnetic material having the tetragonal crystal structure, which can be obtained in the annealing treatment decreases significantly.
- The hard magnetic material in accordance with the invention can be obtained as follows. The starting materials neodymium, iron, (possibly) cobalt and carbon are melted together in a substantially stoichiometric ratio, preferably, under an inert gas atmosphere such as argon. The melt is cast in a mould. The material has the Nd₂Fe₁₇ structure and is not hard magnetic; the carbon is dissolved in the lattice. It is assumed that the carbon in the lattice could substitute one or more iron atoms. The structure is rhombohedral. If desired, the casting obtained can be homogenization annealed at a temperature of 900° or higher. If the material only comprises neodymium, iron and carbon it is annealed at a temperature between 840 and 890° C so that recrystallization takes place. It has been found that recrystallization takes place only within this temperature range, thereby forming the tetragonal Nd₂Fe₁₄C phase. Surprisingly it has been found that on weighing out the starting materials it is undesirable to clearly deviate from the stoichiometric composition as is required in the case of the corresponding boron compounds. A small positive deviation of no more than 20% in the quantity of neodymium and/or carbon relative to the stoichiometric composition and of 15% in the quantity of iron, however, has been found permissible. The tetragonal phase is not formed outside the indicated temperature range (above 890° C) or, if said phase is formed, predominantly, a second phase having the Nd₂Fe₁₇ structure remains in addition to the tetragonal phase (below 840° C). If annealing is carried out in the indicated temperature range the tetragonal phase is predominantly formed. A substantially single-phase material having optimum magnetic properties can be obtained if annealing is carried out at temperatures between 850 and 880° C, preferably at 870° C. If the material also comprises Co, the annealing process in which recrystallization takes place is preferably carried out at a temperature of approximately 850° C. It has been found that cobalt considerably increases the Curie temperature of the hard magnetic material, which may be desirable for certain applications. In the manufacture of the Co-containing hard magnetic materials in accordance with the invention, it has been found that on weighing out the individual elements a small deviation from the stoichiometric composition is not necessary, but it is permissible. A positive deviation of 20% in the quantity of neodymium and/or carbon as well as a positive deviation of 15% in the quantity of iron and/or cobalt is permissible. The experiments leading to the invention were also carried out using praseodymium instead of neodymium; it was found impossible to obtain a substantially single-phase material having the tetragonal crystal structure.
- As has been described above, castings were manufactured having the overall composition Nd₂Fe₁₄C. After casting the material had a Nd₂Fe₁₇ structure (rhombohedral). Without previous homogenization annealing the castings obtained were directly recrystallization annealed for 500 hours at 870° C. The material was single phase and had a tetragonal crystal structure. The lattice constants were measured. It was found that: A = 8.814 Å, C = 12.015 Å. The material in accordance with the invention has a Curie temperature of 535 K. The saturation magnetization at 20° C= 130 EMU per gram. Single-phase materials having the tetragonal crystal structure were obtained in the same manner using materials having the overall composition Nd12.1Fe81.8C₆ and Nd11.8Fe81.1C7.1.
- Magnets can be obtained by directly casting the material in the desired shape. After casting and recrystallization annealing the material can be powdered and subsequently sintered to the desired shape in a magnetic field or be mixed with synthetic resin and pressed into the desired shape.
In the said materials, part of the iron may be substituted by other 3d metals and/or aluminium, gallium, silicon etc. Part of the neodymium can be substituted by one or more rare earth metals. - A casting was manufactured, the overall composition of which corresponded to the formula Nd₂Fe₁₃CoC. Subsequently, this casting was directly subjected to a recrystallization annealing process at 850° C for 150 hours without being previously homogeneization annealed. The material thus obtained is substantially single phase and has a tetragonal crystal structure. The material has a Curie temperature of 620 K.
Claims (9)
1. A hard magnetic material comprising a rare earth metal, iron and carbon, characterized in that the material consists of a recrystallization annealed cast material having a tetragonal crystal structure and a composition which does not or hardly deviate from the stoichiometric composition Nd₂Fe₁₄C.
2. A hard magnetic material as claimed in Claim 1, characterized in that a maximum of 6 at.% of the Fe present in the hard magnetic material, calculated on the overall composition, has been substituted by Co.
3. A hard magnetic material as claimed in Claim 1, characterized in that as regards neodymium and carbon the composition's positive deviation from the stoichiometric composition does not exceed 20%, and as regards iron the positive deviation does not exceed 15%.
4. A hard magnetic material as claimed in Claim 3, characterized in that as regards Nd and C the composition's positive deviation from the stoichiometric composition does not exceed 20%, and as regards iron and cobalt the positive deviation does not exceed 15%.
5. A hard magnetic material as claimed in Claim 3, characterized in that the lattice constants amount to A = 8.814 Å and C = 12.015 Å.
6. A method of manufacturing a hard magnetic material comprising neodymium, iron and carbon, characterized in that the starting materials neodymium, ion and carbon are melted together in a quantity which deviates little from the stoichiometric ratio Nd₂Fe₁₄C, and cast in a mould, after which the casting is recrystallization annealed at a temperature between 840 and 890° C.
7. A method as claimed in Claim 6, characterized in that the material is annealed at a temperature between 850 and 880° C.
8. A method of manufacturing a hard magnetic material comprising neodymium, iron, cobalt and carbon, characterized in that the starting materials neodymium, iron, cobalt and carbon are melted together in a quantity which deviates little from the stoichiometric ratio Nd₂Fe14-xCoxC (wherein x < 1.02) and cast in a mould, after which the casting is recrystallization annealed at a temperature of approximately 850° C.
9. Magnetic castings comprising a hard magnetic material as claimed in anyone of the Claims 1 upto and including 5, and/or magnetic castings obtained by means of a method as claimed in anyone of the Claims 6 up to and including 8.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL8702991 | 1987-12-11 | ||
| NL8702991A NL8702991A (en) | 1987-12-11 | 1987-12-11 | Boron-free hard magnetic material comprising a tetragonal phase - by annealing castings of an alloy contg. neodymium, iron and carbon and having a specific stoichiometric compsns. |
| NL8800740A NL8800740A (en) | 1987-12-11 | 1988-03-24 | HARD-MAGNETIC MATERIAL FROM A RARE NATURAL METAL, IRON AND CARBON. |
| NL8800740 | 1988-03-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP0320064A1 true EP0320064A1 (en) | 1989-06-14 |
Family
ID=26646321
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP88202784A Withdrawn EP0320064A1 (en) | 1987-12-11 | 1988-12-05 | Hard magnetic material of a rare earth metal, iron and carbon |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0320064A1 (en) |
| JP (1) | JPH024940A (en) |
| KR (1) | KR890010944A (en) |
| CN (1) | CN1033494A (en) |
| NL (1) | NL8800740A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3928389A1 (en) * | 1989-08-28 | 1991-03-14 | Schramberg Magnetfab | PERMANENT MAGNET |
| US5062907A (en) * | 1989-05-10 | 1991-11-05 | U.S. Philips Corp. | Hard magnetic material and magnet manufactured from such hard magnetic material |
| EP0468449A1 (en) * | 1990-07-24 | 1992-01-29 | Kanegafuchi Kagaku Kogyo Kabushiki Kaisha | Bonded rare earth magnet and a process for manufacturing the same |
| US5240627A (en) * | 1990-07-24 | 1993-08-31 | Kanegafuchi Kagaku Kogyo Kabushiki Kaisha | Bonded rare earth magnet and a process for manufacturing the same |
| US5300156A (en) * | 1990-07-24 | 1994-04-05 | Kanegafuchi Kagaku Kogyo Kabushiki Kaisha | Bonded rare earth magnet and a process for manufacturing the same |
| DE4242839A1 (en) * | 1992-12-17 | 1994-06-23 | Siemens Ag | Mfr. of magnetic anisotropic power of rare earth based compound |
| DE4243048A1 (en) * | 1992-12-18 | 1994-06-23 | Siemens Ag | Manufacturing hard magnetic materials using Sm Fe C system |
| US5478411A (en) * | 1990-12-21 | 1995-12-26 | Provost, Fellows And Scholars Of The College Of The Holy And Undivided Trinity Of Queen Elizabeth Near Dublin | Magnetic materials and processes for their production |
| CN120933012A (en) * | 2025-07-23 | 2025-11-11 | 北京工业大学 | Rare earth iron carbon-based thermal deformation magnet and preparation method thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105603296A (en) * | 2015-12-23 | 2016-05-25 | 桂林电子科技大学 | Rare earth Fe-based electromagnetic shielding material and preparation method thereof |
-
1988
- 1988-03-24 NL NL8800740A patent/NL8800740A/en not_active Application Discontinuation
- 1988-12-05 EP EP88202784A patent/EP0320064A1/en not_active Withdrawn
- 1988-12-08 JP JP63308974A patent/JPH024940A/en active Pending
- 1988-12-08 CN CN88108583A patent/CN1033494A/en active Pending
- 1988-12-08 KR KR1019880016298A patent/KR890010944A/en not_active Withdrawn
Non-Patent Citations (4)
| Title |
|---|
| JOURNAL OF APPLIED PHYSICS, PROCEEDINGS OF THE THIRTY-FIRST ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, vol. 61, no. 8, part 11A, 15th Aptil 1987, pages 3574-3577, American Institute of Physics, New York, US; N.C. LIU et al.: "High intrinsic coercivities in iron-rare earth-carbon-boron alloys through the carbide or boro-carbide Fe14R2X(X=BxC1-x) * |
| MATERIALS LETTERS, vol. 4, nos. 8-9, August 1986, pages 377-380, Elsevier Science Publishers, N.V., Amsterdam, NL; N.C. LIU et al.: "High coercivity permanent magnet materials based on iron-rare-earth-carbon alloys" * |
| PATENT ABSTRACTS OF JAPAN, vol. 4, no. 109 (E-20)[591], 6th August 1980, page 92 E 20; & JP-A-55 67 110 (SUWA SEIKOSHA K.K.) 21-05-1980 * |
| SOLID STATE COMMUNICATIONS, vol. 64, no. 5, 1987, pages 639-644, Pergamon Journals Ltd, London, GB; M. GUERAMIAN et al.: "Synthesis and magnetic properties of ternary carbides R2Fe14C(R = Pr,Sm,Gd,Tb,Dy,Ho,Er,Tm,Lu) with Nd2Fe14B structure type" * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5062907A (en) * | 1989-05-10 | 1991-11-05 | U.S. Philips Corp. | Hard magnetic material and magnet manufactured from such hard magnetic material |
| DE3928389A1 (en) * | 1989-08-28 | 1991-03-14 | Schramberg Magnetfab | PERMANENT MAGNET |
| EP0468449A1 (en) * | 1990-07-24 | 1992-01-29 | Kanegafuchi Kagaku Kogyo Kabushiki Kaisha | Bonded rare earth magnet and a process for manufacturing the same |
| US5240627A (en) * | 1990-07-24 | 1993-08-31 | Kanegafuchi Kagaku Kogyo Kabushiki Kaisha | Bonded rare earth magnet and a process for manufacturing the same |
| US5300156A (en) * | 1990-07-24 | 1994-04-05 | Kanegafuchi Kagaku Kogyo Kabushiki Kaisha | Bonded rare earth magnet and a process for manufacturing the same |
| US5478411A (en) * | 1990-12-21 | 1995-12-26 | Provost, Fellows And Scholars Of The College Of The Holy And Undivided Trinity Of Queen Elizabeth Near Dublin | Magnetic materials and processes for their production |
| DE4242839A1 (en) * | 1992-12-17 | 1994-06-23 | Siemens Ag | Mfr. of magnetic anisotropic power of rare earth based compound |
| DE4243048A1 (en) * | 1992-12-18 | 1994-06-23 | Siemens Ag | Manufacturing hard magnetic materials using Sm Fe C system |
| CN120933012A (en) * | 2025-07-23 | 2025-11-11 | 北京工业大学 | Rare earth iron carbon-based thermal deformation magnet and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH024940A (en) | 1990-01-09 |
| KR890010944A (en) | 1989-08-11 |
| NL8800740A (en) | 1989-07-03 |
| CN1033494A (en) | 1989-06-21 |
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