EP3522178B1 - Rare earth magnet and production method thereof - Google Patents
Rare earth magnet and production method thereof Download PDFInfo
- Publication number
- EP3522178B1 EP3522178B1 EP18215888.1A EP18215888A EP3522178B1 EP 3522178 B1 EP3522178 B1 EP 3522178B1 EP 18215888 A EP18215888 A EP 18215888A EP 3522178 B1 EP3522178 B1 EP 3522178B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- rare earth
- phase
- earth magnet
- main phase
- modifier
- 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.)
- Active
Links
- 229910052761 rare earth metal Inorganic materials 0.000 title claims description 171
- 150000002910 rare earth metals Chemical class 0.000 title claims description 138
- 238000004519 manufacturing process Methods 0.000 title claims description 29
- 239000003607 modifier Substances 0.000 claims description 82
- 239000000203 mixture Substances 0.000 claims description 75
- 229910052684 Cerium Inorganic materials 0.000 claims description 70
- 229910052746 lanthanum Inorganic materials 0.000 claims description 67
- 229910052779 Neodymium Inorganic materials 0.000 claims description 53
- 229910045601 alloy Inorganic materials 0.000 claims description 37
- 239000000956 alloy Substances 0.000 claims description 37
- 239000012535 impurity Substances 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 27
- 230000009467 reduction Effects 0.000 claims description 21
- 238000002844 melting Methods 0.000 claims description 20
- 230000008018 melting Effects 0.000 claims description 20
- 229910052751 metal Inorganic materials 0.000 claims description 16
- 239000002184 metal Substances 0.000 claims description 16
- 229910052782 aluminium Inorganic materials 0.000 claims description 13
- 229910052802 copper Inorganic materials 0.000 claims description 12
- 238000010791 quenching Methods 0.000 claims description 11
- 230000000171 quenching effect Effects 0.000 claims description 11
- 229910052693 Europium Inorganic materials 0.000 claims description 10
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 10
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 10
- 229910052772 Samarium Inorganic materials 0.000 claims description 10
- 229910052733 gallium Inorganic materials 0.000 claims description 10
- 229910052737 gold Inorganic materials 0.000 claims description 10
- 229910052738 indium Inorganic materials 0.000 claims description 10
- 229910052709 silver Inorganic materials 0.000 claims description 10
- 229910052725 zinc Inorganic materials 0.000 claims description 10
- 229910052748 manganese Inorganic materials 0.000 claims description 9
- 239000000155 melt Substances 0.000 claims description 9
- 238000005275 alloying Methods 0.000 claims description 7
- 230000003247 decreasing effect Effects 0.000 claims description 7
- 239000012071 phase Substances 0.000 description 266
- 239000002243 precursor Substances 0.000 description 69
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 64
- 238000010586 diagram Methods 0.000 description 50
- 230000005291 magnetic effect Effects 0.000 description 48
- 238000004458 analytical method Methods 0.000 description 35
- 230000000052 comparative effect Effects 0.000 description 33
- 238000002360 preparation method Methods 0.000 description 23
- 230000005415 magnetization Effects 0.000 description 20
- 239000010949 copper Substances 0.000 description 19
- 238000010438 heat treatment Methods 0.000 description 18
- 239000013078 crystal Substances 0.000 description 16
- 230000000694 effects Effects 0.000 description 14
- 229910001172 neodymium magnet Inorganic materials 0.000 description 14
- 230000008595 infiltration Effects 0.000 description 13
- 238000001764 infiltration Methods 0.000 description 13
- 230000000007 visual effect Effects 0.000 description 13
- 230000007423 decrease Effects 0.000 description 9
- 239000010931 gold Substances 0.000 description 9
- 239000011572 manganese Substances 0.000 description 9
- 239000011701 zinc Substances 0.000 description 9
- 229910052742 iron Inorganic materials 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 238000007731 hot pressing Methods 0.000 description 7
- 239000010944 silver (metal) Substances 0.000 description 7
- 230000001965 increasing effect Effects 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 229910000881 Cu alloy Inorganic materials 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 5
- 229910052796 boron Inorganic materials 0.000 description 5
- 230000003993 interaction Effects 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 238000011156 evaluation Methods 0.000 description 4
- 238000002955 isolation Methods 0.000 description 4
- 230000001902 propagating effect Effects 0.000 description 4
- 229910000838 Al alloy Inorganic materials 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 3
- 229910000531 Co alloy Inorganic materials 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910052692 Dysprosium Inorganic materials 0.000 description 2
- 229910052691 Erbium Inorganic materials 0.000 description 2
- 229910052689 Holmium Inorganic materials 0.000 description 2
- 229910052765 Lutetium Inorganic materials 0.000 description 2
- 229910052771 Terbium Inorganic materials 0.000 description 2
- 229910052775 Thulium Inorganic materials 0.000 description 2
- 229910052769 Ytterbium Inorganic materials 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 2
- 230000005298 paramagnetic effect Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 229910052706 scandium Inorganic materials 0.000 description 2
- 229910052727 yttrium Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910052773 Promethium Inorganic materials 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- ZMIGMASIKSOYAM-UHFFFAOYSA-N cerium Chemical compound [Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce] ZMIGMASIKSOYAM-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002159 nanocrystal Substances 0.000 description 1
- 238000007709 nanocrystallization Methods 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- VQMWBBYLQSCNPO-UHFFFAOYSA-N promethium atom Chemical compound [Pm] VQMWBBYLQSCNPO-UHFFFAOYSA-N 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/12—Both compacting and sintering
- B22F3/14—Both compacting and sintering simultaneously
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/007—Ferrous alloys, e.g. steel alloys containing silver
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
-
- 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
-
- 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
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
-
- 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
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0572—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes with a protective layer
-
- 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
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0576—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together pressed, e.g. hot working
-
- 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
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0266—Moulding; Pressing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0273—Imparting anisotropy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0293—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/048—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by pulverising a quenched ribbon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C2202/00—Physical properties
- C22C2202/02—Magnetic
-
- 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
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
Definitions
- An R-Fe-B-based rare earth magnet has a main phase and a grain boundary phase present around the main phase.
- the main phase has a composition represented by R 2 Fe 14 B and is a magnetic phase. Due to this main phase, strong magnetism is exhibited.
- the grain boundary phase is present around the main phase and magnetically isolates the main phases from one another. The coercive force of the R-Fe-B-based rare earth magnet is enhanced by this magnetic isolation.
- the rare earth magnet of the present disclosure and the production method thereof include the following embodiments.
- the anisotropic magnetic field at room temperature is high, but the Curie point is 320°C and is not so high. Accordingly, even if the Curie point is not reached, at high temperatures, the anisotropic magnetic field of the Nd 2 Fe 14 B phase is reduced.
- the Fe-containing magnetic phase (for example, RFe 2 phase) is paramagnetic at a temperature higher than the normal temperature but has a possibility of propagating the interaction of magnetic spins between Nd 2 Fe 14 B phases (between crystal grains).
- the coercive force is high at room temperature, because the Fe-containing magnetic phase in the grain boundary phase has a small effect.
- Formation of the (Nd, Ce, La) 2 Fe 14 B phase brings about an increase in the total number of main phases, and consequent replacement of Nd by Ce and La compensates for the reduction in the anisotropic magnetic field and suppresses the reduction in the coercive force of the entire (Nd, Ce, La)-Fe-B-based rare earth magnet. This enhancement of coercive force is prominent at high temperatures.
- Ce or La is present at the position of Nd of the Nd 2 Fe 14 B phase.
- Nd stands for neodymium
- Ce stands for cerium
- La stands for lanthanum
- R 1 is one or more members selected from rare earth elements other than Nd
- Ce and La is one or more members selected from rare earth elements other than Nd
- Ce and La is one or more members selected from rare earth elements other than Nd
- Ce and La is one or more members selected from rare earth elements other than Nd
- Ce and La is one or more members selected from rare earth elements other than Nd
- Ce and La stands for lanthanum
- Fe stands for iron
- Co stands for cobalt
- B stands for boron
- M 1 represents one or more members selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an unavoidable impurity element.
- Ga stands for gallium
- Al stands for aluminum
- Cu stands for copper
- Au stands for gold
- Ag stands for silver
- Zn stands for zinc
- In stands for indium
- Mn stands for manganese
- R 2 is one or
- r B affects the content of the main phase and the content of the Fe-containing magnetic phase in the grain boundary phase. If the content of B is too small, the main phase represented by (Nd, Ce, La) 2 Fe 14 B is difficult to be formed. When the content r of B is 4.0 at% or more, it is unlikely that the main phase represented by (Nd, Ce, La) 2 Fe 14 B is difficult to be formed. From this viewpoint, r may be 4.5 at% or more, 5.0 at% or more, or 5.5 at% or more. On the other hand, if the content r of B is excessive, an Fe-containing magnetic phase such as RFe 4 B 4 phase is readily formed in the grain boundary phase. When r is 6.5 at% or less, an ⁇ -Fe phase is less likely to be formed in a large amount. From this viewpoint, r may be 6.3 at% or less, or 6.0 at% or less.
- the rare earth magnet 100 of the present disclosure has a main phase 10 and a grain boundary phase 20.
- the rare earth magnet 100 of the present disclosure further has an intermediate phase 30, in addition to a main phase 10 and a grain boundary phase 20.
- the rare earth magnet 100 may have a phase (not shown) other than the main phase 10, the grain bounder phase 20, and the intermediate phase 30.
- the phase other than the main phase 10, the grain bounder phase 20, and the intermediate phase 30 includes an oxide, a nitride, an intermetallic compound, etc.
- the grain boundary phase 20 is present around the main phase 10.
- the intermediate phase 30 is sandwiched between the main phase 10 and the grain boundary phase 20. Formation of the intermediate phase 30 is described by referring to the composition of the modifier.
- the precursor 100 contains mainly Nd, Ce and La as the rare earth element.
- the alloy in the modifier contains mainly R 2 that is one or more members selected from Pr, Nd, Pm, Sm, Eu, and Gd.
- R 2 of the modifier differs in the kind of one or more rare earth elements from Nd, Ce and La of the precursor 100, and therefore, although not bound by theory, R 2 infiltrates into the main phase 10 and forms the intermediate phase 30. Accordingly, the concentration of R 2 is higher in the intermediate phase 30 than in the main phase 10. Although not bound by theory, the reason for infiltration of R 2 into the main phase 10 is considered as follows.
- the value of w is ideally close to 0, but the value of w may be 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, or 0.05 or more.
- the value of w is preferably lower as long as a rise in the production cost is not caused, and the value may be 0.09 or less, 0.08 or less, 0.07 or less, or 0.06 or less.
- the peripheral velocity of the single roll may be, typically, 20 m/s or more, 24 m/s or more, or 28 m/s or more, and may be 40 m/s or less, 36 m/s or less, or 32 m/s or less.
- the pressure at the time of hot pressing may be, typically, 200 MPa or more, 300 MPa or more, or 350 MPa or more, and may be 600 MPa or less, 500 MPa or less, or 450 MPa or less.
- the pressing time at the time of hot pressing may be, typically, 5 seconds or more, 20 seconds or more, or 40 seconds or more, an may be 120 seconds or less, 100 seconds or less, or 80 seconds or less.
- the temperature at the time of plastic working may be 650°C or more, 700°C or more, or 720°C or more, and may be 850°C or less, 800°C or less, or 770°C or less.
- the plastic working is performed as hot working, and therefore, when the strain rate is low, this means that the contact part above is subjected to a high temperature over a long period of time. Consequently, atomic diffusion occurs via the contact part, and the main phase 10 undergoes grain growth.
- Ce and La, particularly, La are expelled to the grain boundary phase 20 from the main phase 10.
- Ce and La enter between main phases 10, and formation of the contact part above is suppressed.
- the melting point of the grain boundary phase 20 lowers.
- the plastic working is performed at a temperature allowing at least one grain boundary phase 20 to melt.
- the rare earth magnet precursor and the modifier are contacted with each other to obtain a contact body.
- the rare earth magnet precursor is the above-described compressed body. At this time, at least one surface of the rare earth magnet precursor and at least one surface of the modifier are put into contact with each other.
- the contact body above is heat-treated to infiltrate the melt of the modifier into the inside of the rare earth magnet precursor.
- the melt of the modifier thereby reaches the surface part of the main phase via the grain boundary phase of the rare earth magnet precursor, and R 2 in the modifier is infiltrated into the main phase to form an intermediate phase.
- the molded body was subjected to hot upsetting (hot-plastic working) to obtain a compressed body (plastically deformed body).
- hot-plastic working a sample of 15 mm in height was compressed to 4.5 mm.
- the working temperature was 780°C
- the strain rate was 0.01/s
- the reduction ratio was 70%. It was confirmed by scanning electron microscope (SEM) that the compressed body has oriented nanocrystals. This compressed body was used as a rare earth magnet precursor.
- Comparative Example 8 was prepared in the same manner as in Comparative Example 1 other than R of the rare earth magnet precursor was changed as in Table 1-3.
- Fig. 6 is a diagram illustrating the positions for texture observation and composition analysis with respect to the sample of Example 6.
- Fig. 7 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 6 (first visual field).
- Fig. 8 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 6 (second visual field).
- Fig. 9 is a diagram illustrating the positions for texture observation and composition analysis with respect to the sample of Example 12.
- Fig. 10 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 12 (first visual field).
- Fig. 11 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 12 (second visual field).
- Table 2-1 Composition of Rare Earth Magnet Precursor (at%) Modifier Ratio of Rare Earths Hot Upsetting Conditions Average Grain Size ( ⁇ m) Composition Ratio Infiltration Amount (at%) Percentage Ratio Strain Rate (/s) Reduction Ratio (%) Temperature (°C) Nd Ce La Fe B Ga Cu Nd Cu Nd Ce La La/Ce
- Example 12 7.866 3.1464 2.0976 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 60 24 16 2/3 0.01 70 780 579.33
- Example 39 6.555 3.933 2.622 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 50 30 20 2/3 0.001 70 780 595.82
- Example 40 7.866 3.1464 2.0976 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 60 24 16 2/3 0.001 70 780 6
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Power Engineering (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Hard Magnetic Materials (AREA)
Description
- The present disclosure relates to an R-Fe-B-based rare earth magnet, wherein R is a rare earth element, and a production method thereof. More specifically, the present disclosure relates to an R-Fe-B-based rare earth magnet protected from reduction in the coercive force at high temperatures, and a production method thereof.
- An R-Fe-B-based rare earth magnet has a main phase and a grain boundary phase present around the main phase. The main phase has a composition represented by R2Fe14B and is a magnetic phase. Due to this main phase, strong magnetism is exhibited. On the other hand, the grain boundary phase is present around the main phase and magnetically isolates the main phases from one another. The coercive force of the R-Fe-B-based rare earth magnet is enhanced by this magnetic isolation.
- In order to enhance the magnetic isolation effect, various attempts are being made. For example,
Patent Document 1 discloses a rare earth magnet using, as a precursor, a rare earth magnet having a main phase and a grain boundary phase, in which a modifier is infiltrated into the inside of the precursor. - In the rare earth magnet disclosed in
Patent Document 1, the coercive force of the entire rare earth magnet is enhanced by having an intermediate phase between the main phase and the grain boundary phase. - [Patent Document 1] International Publication No.
2014/196605A1 -
US 6 136 099 A discloses a rare earth-iron series magnet formed from an alloy ingot using a one-step hot working process. The alloy ingot includes between about 8 and 30 atomic percent of at least one rare earth element, between about 2 and 28 atomic percent of boron, less than about 50 atomic percent of cobalt, less than about 15 atomic percent of aluminum and the balance of iron and other impurities that are inevitably included during the preparation process. The alloy is cast to obtain a cast ingot and the hot working is performed on the cast ingot at a temperature of greater than about 500 DEG C. in order to make the crystal grains of the ingot fine and to align the axis of the grains in a desired direction. -
JP 2016 111136 A - The R-Fe-B-based rare earth magnet is of high performance, and therefore its use is expanding to a variety of fields. Consequently, the opportunity of using the R-Fe-B-based rare earth magnet under a high-temperature environment is increased. In addition, when the R-Fe-B-based rare earth magnet is used in a high-power motor and high output was maintained for a long time, the R-Fe-B-based rare earth magnet is sometimes subjected to high temperatures due to self-heating of the motor.
- It is known that when the R-Fe-B-based rare earth magnet is subjected to high temperatures, the coercive force may decrease.
- Accordingly, the present inventors have found a problem that an R-Fe-B-based rare earth magnet protected from reduction in the coercive force even at high temperatures is demanded. Incidentally, in the present description, the high temperature indicates a range from 130 to 170°C, particularly from 140 to 160°C, the room temperature indicates a range from 20 to 25°C, and the R-Fe-B-based rare earth magnet indicates a magnet having a main phase and a grain boundary phase present around the main phase, the main phase containing a phase having a composition represented by R2Fe14B.
- The present disclosure have been made to solve the problem above. An object of the present disclosure is to provide an R-Fe-B-based rare earth magnet protected from reduction in the coercive force even at high temperatures and a production method thereof.
- As a result of many intensive studies to attain the object above, the present inventors have accomplished the rare earth magnet of the present disclosure and the production method thereof. The rare earth magnet of the present disclosure and the production method thereof include the following embodiments.
- <1> A rare earth magnet including:
- a main phase, and
- a grain boundary phase present around the main phase,
- wherein the overall composition is represented by the formula,
- wherein Ndx(Ce, La)(1-x-y)R1y)pFe(100-p-q-r-s)CoqBrM1 s· (R2 zR3 wM2 1-z-w)t,
- wherein R1 is one or more members selected from rare earth elements other than Nd, Ce and La, R2 is one or more members selected from Pr, Nd, Pm, Sm, Eu and Gd, R3 is one or more members selected from rare earth elements other than R2, M1 represents one or more members selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an unavoidable impurity element, M2 represents an alloy element for decreasing the melting point of R2 zR3 wM2 1-z-w to be lower than the melting point of R2 by alloying with R2 and R3, and an unavoidable impurity element,
- wherein p, q, r, s, and t are, in at%,
- 5.0≤p≤20.0,
- 0≤q≤8.0,
- 4.0≤r≤6.5,
- 0≤s≤2.0, and
- 0≤t≤10.0, and
- wherein x, y, z, and w are, by molar ratio,
- 0.4≤x≤0.8,
- 0≤y≤0.1,
- 0.5≤z≤0.8, and
- 0≤w≤0.1, and
- wherein La is contained in an amount of 1/9 to 3 times by molar ratio relative to Ce, characterized in that an average grain size of the main phase is from 1 to 1,000 nm, wherein the average grain size of the main phase is calculated in accordance with the method defined in the description.
- <2> The rare earth magnet according to item <1>, wherein La is contained in an amount of 1/9 to 2 times by molar ratio relative to Ce.
- <3> The rare earth magnet according to item <1> or <2>,
- wherein: an intermediate phase is further provided between the main phase and the grain boundary phase,
- wherein t is 0.1≤t≤10.0, and
- wherein the concentration of R2 is higher in the intermediate phase than in the main phase.
- <4> The rare earth magnet according to any one of items <1> to <3>, wherein R2 is Nd.
- <5> The rare earth magnet according to item <3> or <4>, wherein the concentration of R2 is higher by 1.5 to 8.0 times in the intermediate phase than in the main phase.
- <6> The rare earth magnet according to any one of items <3> to <5>, wherein the thickness of the intermediate phase is from 2 to 100 nm.
- <7> A method for producing a rare earth magnet, including:
- preparing a molten metal having a composition represented by the formula: Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s,
- wherein R1 is one or more members selected from rare earth elements other than Nd, Ce and La, M1 represents one or more members selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an unavoidable impurity element,
- wherein p, q, r, and s are, in at%,
- 5.0≤p≤20.0,
- 0≤q≤8.0,
- 4.0≤r≤6.5, and
- 0≤s≤2.0, and
- wherein x and y are, by molar ratio,
- 0.4≤x≤0.8,and
- 0≤y≤0.1, and
- wherein La is contained in an amount of 1/9 to 3 times by molar ratio relative to Ce,
- quenching the molten metal to obtain a ribbon,
- compressing a plurality of ribbons by hot working to obtain a molded body, and
- compressing the molded body by hot working to obtain a compressed body, wherein an average grain size of the main phase (10) is from 1 to 1000 nm, wherein the average grain size of the main phase (10) is calculated in accordance with the method defined in the description.
- preparing a molten metal having a composition represented by the formula: Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s,
- <8> The method according to item <7>, wherein the molten metal contains La in an amount of 1/9 to 2 times by molar ratio relative to Ce.
- <9> The method according to item <7> or <8>, including:
- preparing a modifier containing an alloy represented by the formula: R2 zR3 wM2 1-z-w,
- wherein R2 is one or more members selected from Pr, Nd, Pm, Sm, Eu and Gd, R3 is one or more members selected from rare earth elements other than R2, M2 represents an alloy element for decreasing the melting point of R2 zR3 wM2 1-z-w to be lower than the melting point of R2 by alloying with R2 and R3, and an unavoidable impurity element,
- wherein z and w are, by molar ratio, 0.5≤z≤0.8 and 0≤w≤0.1,
- contacting the compressed body and the modifier with each other to obtain a contact body, and
- heat-treating the contact body to infiltrate a melt of the modifier into the inside of the compressed body.
- preparing a modifier containing an alloy represented by the formula: R2 zR3 wM2 1-z-w,
- <10> The method according to item <9>, wherein R2 is Nd.
- <11> The method according to any one of items <7> to <10>, wherein the molded body is compressed at a strain rate of 0.001/s or more and less than 0.1/s, a reduction ratio of 50 to 70%, and a temperature of 700 to 800°C to obtain a compressed body.
- According to the present disclosure, a rare earth magnet protected from reduction in the coercive force at high temperatures by causing Nd, Ce and La to be present together and setting the content ratio between Ce and La to a predetermined range, and a production method thereof can be provided.
-
- [
Fig. 1] Fig. 1 is a diagram illustrating the content ratio of Nd, Ce and La. - [
Fig. 2] Fig. 2 is a diagram schematically illustrating one embodiment of the texture of the rare earth magnet according to the present disclosure. - [
Fig. 3] Fig. 3 is a diagram illustrating another embodiment of the texture of the rare earth magnet according to the present disclosure. - [
Fig. 4] Fig. 4 is a graph illustrating the relationship between the temperature and the cohesive force with respect to the samples of Example 15 and Comparative Example 1. - [
Fig. 5] Fig. 5 is a diagram illustrating the relationship between the temperature and the residual magnetization with respect to the samples of Example 15 and Comparative Example 1. - [
Fig. 6] Fig. 6 is a diagram illustrating the positions for texture observation and component analysis with respect to the sample of Example 6. - [
Fig. 7] Fig. 7 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 6 (first visual field). - [
Fig. 8] Fig. 8 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 6 (second visual field). - [
Fig. 9] Fig. 9 is a diagram illustrating the positions for texture observation and composition analysis with respect to the sample of Example 12. - [
Fig. 10] Fig. 10 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 12 (first visual field). - [
Fig. 11] Fig. 11 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 12 (second visual field). - [
Fig. 12] Fig. 12 is a diagram illustrating the positions for texture observation and composition analysis with respect to the sample of Example 17. - [
Fig. 13] Fig. 13 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 17 (first visual field). - [
Fig. 14] Fig. 14 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 17 (second visual field). - [
Fig. 15] Fig. 15 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 39. - [
Fig. 16] Fig. 16 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 40. - [
Fig. 17] Fig. 17 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 6. - [
Fig. 18] Fig. 18 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 12. - [
Fig. 19] Fig. 19 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 39. - [
Fig. 20] Fig. 20 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 19 . - [
Fig. 21] Fig. 21 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 40. - [
Fig. 22] Fig. 22 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 21 . - [
Fig. 23] Fig. 23 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 6. - [
Fig. 24] Fig. 24 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 23 . - [
Fig. 25] Fig. 25 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 12. - [
Fig. 26] Fig. 26 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 25 . - The embodiments of the rare earth magnet according to the present disclosure and the production method thereof are described in detail below. Incidentally, the embodiments set forth below should not be construed to limit the rare earth magnet according to the present disclosure and the production method thereof, as long as remaining within the scope of the appended claims.
- In the R-Fe-B-based rare earth magnet, when 1) the grain size of the main phase is reduced, 2) the anisotropic magnetic field of the main phase is increased, and 3) main phases are magnetically isolated from one another, the coercive force is enhanced.
- In order to reduce the grain size of the main phase, in the R-Fe-B-based rare earth magnet, the main phase is nanocrystallized. Consequently, in the R-Fe-B-based rare earth magnet, a large amount of R2Fe14B phase is present as the main phase, and a grain boundary phase is present around the main phase. In the grain boundary phase, an R-rich phase containing excess R, and a small amount of magnetic phase containing Fe (for example, RFe2 phase) are present.
- In the Nd2Fe14B phase, the anisotropic magnetic field at room temperature is high, but the Curie point is 320°C and is not so high. Accordingly, even if the Curie point is not reached, at high temperatures, the anisotropic magnetic field of the Nd2Fe14B phase is reduced. On the other hand, the Fe-containing magnetic phase (for example, RFe2 phase) is paramagnetic at a temperature higher than the normal temperature but has a possibility of propagating the interaction of magnetic spins between Nd2Fe14B phases (between crystal grains). When a large amount of Nd2Fe14B phase is present as the main phase, the coercive force is high at room temperature, because the Fe-containing magnetic phase in the grain boundary phase has a small effect. However, at high temperature, the Fe-containing magnetic phase in the grain boundary phase has the effect of propagating the interaction of magnetic spins between Nd2Fe14B phases (between crystal grains), and the grain size of the main phase is thereby apparently increased, presenting the possibility of reducing the effect of nanocrystallization of the main phase. As a result, the coercive force rapidly decreases.
- When R of the R-Fe-B-based rare earth magnet contains Nd, Ce and La, the anisotropic magnetic field of (Nd, Ce, La)2Fe14B is lower than the anisotropic magnetic field of Nd2Fe14B at both room temperature and high temperature. Hereinafter, the R-Fe-B-based rare earth magnet containing Nd, Ce and La is sometimes referred to as "(Nd, Ce, La)-Fe-B-based rare earth magnet".
- Although not bound by theory, in the (Nd, Ce, La)-Fe-B-based rare earth magnet, when the content ratio between Ce and La is in a predetermined range, the stability of the Fe-containing magnetic phase (e.g., RFe2 phase) in the grain boundary phase decreases, compared with the Nd-Fe-B-based rare earth magnet. Consequently, in the (Nd, Ce, La)-Fe-B-based rare earth magnet, Fe in the grain boundary phase is likely to contribute to the production of a phase other than the Fe-containing magnetic phase. The phase other than the Fe-containing magnetic phase includes CeFe2 phase, etc.
- Formation of the (Nd, Ce, La)2Fe14B phase brings about an increase in the total number of main phases, and consequent replacement of Nd by Ce and La compensates for the reduction in the anisotropic magnetic field and suppresses the reduction in the coercive force of the entire (Nd, Ce, La)-Fe-B-based rare earth magnet. This enhancement of coercive force is prominent at high temperatures. Incidentally, in the present description, although not bound by theory, with respect to the (Nd, Ce, La)2Fe14B phase, Ce or La is present at the position of Nd of the Nd2Fe14B phase.
- In addition, when the (Nd, Ce, La)-Fe-B-based rare earth magnet is used as a precursor and a modifier containing R2 is infiltrated into the inside of the precursor, depending on the infiltration amount of the alloy from the modifier, an intermediate phase is formed between the main phase and the grain boundary phase.
- Although not bound by theory, it is considered that part of Ce and/or La present in the main phase of the precursor is replaced by R2 and an intermediate phase is thereby formed. Accordingly, in the intermediate phase, the concentration of R2 is higher than in the main phase of the precursor and in turn, the anisotropic magnetic field of the intermediate phase is higher than the anisotropic magnetic field of the main phase of the precursor. At high temperature, the anisotropic magnetic field of the intermediate phase is reduced. However, even at high temperature, the anisotropic magnetic field of the intermediate phase is higher than the anisotropic magnetic field of the main phase of the precursor by the amount corresponding to the R2 concentration that is increased compared with the main phase of the precursor. This contributes to the protection from reduction in the coercive force.
- From the matters described hereinbefore, the present inventors have found that with respect to the R-Fe-B-based rare earth magnet, the reduction in the coercive force at high temperatures can be suppressed.
- The configuration requirements of the rare earth magnet according to the present disclosure and the production method thereof, based on the finding above, are described below.
- First, the configuration requirements of the rare earth magnet of the present disclosure are described.
- The overall composition of the rare earth magnet of the present invention is represented by the formula: (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1s·(R2 zR3 wM2 1-z-w)t.
- In the formula above, (R2 zR3 wM2 1-z-w)t represents a composition derived from the later-described modifier. In the case of not infiltrating a modifier, t=0, and the overall composition of the rare earth magnet of the present disclosure is represented by (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s.
- On the other hand, in the case of infiltrating a modifier, t is a positive value and is not 0, and (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s represents a composition of the rare earth magnet precursor.
- In the formula above, Nd stands for neodymium, Ce stands for cerium, La stands for lanthanum, R1 is one or more members selected from rare earth elements other than Nd, Ce and La, Fe stands for iron, Co stands for cobalt, and B stands for boron. M1 represents one or more members selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an unavoidable impurity element. Ga stands for gallium, Al stands for aluminum, Cu stands for copper, Au stands for gold, Ag stands for silver, Zn stands for zinc, In stands for indium, and Mn stands for manganese. R2 is one or more members selected from Pr, Nd, Pm, Sm, Eu and Gd. Pr stands for praseodymium, Nd stands for neodymium, Pm stands for promethium, Sm stands for samarium, Eu stands for europium, and Gd stands for gadolinium. M2 represents an alloy element for decreasing the melting point of R2 zR3 wM2 1-z-w to be lower than the melting point of R2 by alloying with R2 and R3, and an unavoidable impurity element.
- In the present description, the rare earth element includes 17 elements of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Of these, Sc, Y, La, and Ce are a light rare earth element, Pr, Nd, Pm, Sm, Eu, and Gd are a medium rare earth element, and Tb, Dy, Ho, Er, Tm, Yb, and Lu are a heavy rare earth element. Incidentally, in general, the rarity of the heavy rare earth element is high, and the rarity of the light rare earth element is low. The rarity of the medium rare earth element is between the heavy rare earth element and the light rare earth element.
- Next, p, q, r, s and t, and x, y, z and w are described. In the following description, the case of infiltrating a modifier is explained. As for the case of not infiltrating a modifier, the "rare earth magnet precursor" is read as "rare earth magnet", and the description of items derived from a modifier is treated as non-existing.
- In the rare earth magnet precursor, p is the total content of Nd, Ce, La and R1, q is the content of Co, r is the content of B (boron), and s is the content of M1. With respect to the items derived from a modifier, t is the infiltration amount of an alloy from the modifier, relative to the rare earth magnet precursor, and is the total content of R2, R3 and M2. Each of the values of p, q, r, s and t is at%.
- In the rare earth magnet precursor, each of the values of x and y is the following content ratio (molar ratio). x represents the content ratio of Nd relative to the total content of Nd, Ce, La and R1, and y represents the content ratio of R1 relative to the total content of Nd, Ce, La and R1 . With respect to the items derived from a modifier, each of the values of z and w is the following content ratio (molar ratio). z is the content ratio of R2 relative to the total content of R2, R3 and M2, and w represents the content ratio of R3 relative to the total content of R2, R3 and M2.
- The constituent elements of the rare earth magnet precursor represented by the formula above are described below.
- Nd is an element essential for the rare earth magnet precursor of the present disclosure. By containing Nd, high magnetization can be exhibited at room temperature and high temperature. In addition, at room temperature, the Nd2Fe14B phase has a high anisotropic magnetic field.
- Ce is an element essential for the rare earth magnet precursor of the present disclosure. When Nd in the main phase (Nd2Fe14B phase) is replaced by Ce, an Fe-containing magnetic phase, i.e., a CeFe2 phase, in the grain boundary phase is readily formed. The CeFe2 phase is paramagnetic and is expected to have an effect of propagating the interaction of magnetic spins between main phases to reduce the coercive force. In order to suppress the reduction in the coercive force, it is necessary to reduce the stability of the Fe-containing magnetic phase in the grain boundary phase.
- In addition, Ce can have an atomic valence of trivalence or tetravalence. Although not bound by theory, a lot of Ce becomes trivalent due to an action of La. In the trivalent Ce, 4f electrons are localized, and therefore magnetization is advantageously enhanced.
- La is an element essential for the rare earth magnet precursor of the present disclosure. Nd in the main phase (Nd2Fe14B phase) is replaced by La, and the stability of the Fe-containing magnetic phase in the grain boundary phase is reduced, because compounds of a transition metal such as La and Fe are thermodynamically unstable as a whole and are not mixed with one another. That is, the addition of La is expected to provide an effect of forming an RFe2 phase. Accordingly, La greatly contributes to protection from reduction in the coercive force. Moreover, La is advantageously inexpensive compared with Nd. In addition, when Ce is added, a CeFe2 phase is likely to be formed, and the coercive force is reduced. However, when La is added together with Ce, the formation of CeFe2 phase is suppressed, and the propagation of interaction of magnetic spins between grains in the main phase is restricted.
- As described above, x is the content ratio of Nd. The saturation magnetization and anisotropic magnetic field are higher in the Nd2Fe14B phase than in Ce2Fe14B phase and La2Fe14B phase. Accordingly, when x is 0.40 or more, desired magnetization and coercive force are readily obtained in the rare earth magnet of the present disclosure. From this viewpoint, x may be 0.45 or more, 0.50 or more, or 0.55 or more. On the other hand, when x is 0.80 or less, it is unlikely that the content ratio of Ce and La is too small and the actions and effects of Ce and La are hardly obtained. From this viewpoint, x may be 0.75 or less, 0.70 or less, or 0.65 or less.
- In the rare earth magnet precursor, the content of La is, by molar ratio, from 1/9 to 3 times relative to the content of Ce.
Fig. 1 is a diagram illustrating the content ratio of Nd, Ce and La. InFig. 1 , the straight line denoted by (1) indicates a composition in which the content of La is, by molar ratio, 1/9 times relative to the content of Ce; the straight line denoted by (2) indicates a composition in which the content of La is, by molar ratio, 1/3 times relative to the content of Ce; the straight line denoted by (3) indicates a composition in which the content of La is, by molar ratio, 2/3 times relative to the content of Ce; and the straight line denoted by (4) indicates a composition in which the content of La is, by molar ratio, 3 times relative to the content of Ce. - More specifically, these are rephrased as follows. The straight line of (1) indicates a composition at Ce:La=1:1/9; the straight line of (2) indicates a composition at Ce:La=1:1/3; the straight line of (3) indicates a composition at Ce:La=1:2/3; and the straight line of (4) indicates a composition at Ce:La=1:3.
- As described above, the content ratio x of Nd is from 0.4 to 0.8, and therefore in
Fig. 1 , the composition of the rare earth magnet precursor of the present disclosure is denoted by a portion in which the region sandwiched by "Nd80" and "Nd40" and the region sandwiched by straight line (1) and straight line (4) are overlapped. - When the content of La is, by molar ratio, 1/9 times or more relative to the content of Ce, desired magnetization can be obtained at room temperature and high temperature. From this viewpoint, the content is preferably 1/8 times or more, more preferably 1/7 times or more. On the other hand, when the content of La is by molar ratio, 3 times or less relative to the content of Ce, Nd of the grain boundary phase is replaced by Ce and/or La, thereby reducing the stability of the Fe-containing magnetic phase (e.g., RFe2 phase), and the content (volume ratio) of the Fe-containing magnetic phase decreases. As a result, the grain boundary phase restricts the effect of propagating the interaction of magnetic spins between main phases and suppresses the reduction in the coercive force at high temperature. From this viewpoint, the content is preferably 5/2 times or less, more preferably 2 times or less.
- R1 is one or more members selected from rare earth elements other than Nd, Ce and La. The rare earth magnet of the present disclosure contains Nd, Ce and La as essential components. It is difficult for raw materials of these essential components not to contain the rare earth element R1 other than Nd, Ce and La at all. However, when the value of the content ratio y of R1 is from 0 to 0.1, the properties of the rare earth magnet of the present disclosure can be regarded as substantially the same as those when y is 0.
- Excessively increasing the purity of raw materials of essential components entails a rise in the production cost, and therefore the value of y may be 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, or 0.05 or more. On the other hand, the value of y is preferably lower as long as a rise in the production cost is not caused, and the value may be 0.09 or less, 0.08 or less, 0.07 or less, or 0.06 or less.
- When the total content p of Nd, Ce, La and R1 is 5.0 at% or more, the main phase represented by (Nd, Ce, La)2Fe14B is not difficult to be formed. From the viewpoint that the main phase represented by (Nd, Ce, La)2Fe14B is readily formed, p may be 7.0 at% or more, 9.0 at% or more, 11.0 at% or more, or 13.0 at% or more. On the other hand, when p is 20.0 at% or less, the existence ratio (volume ratio) of the grain boundary phase does not become excessive. From the viewpoint that the exsistence ratio of the grain boundary phase does not become excessive, the total content may be 19.0 at% or less, 18.0 at% or less, or 17.0 at% or less.
- B affects the content of the main phase and the content of the Fe-containing magnetic phase in the grain boundary phase. If the content of B is too small, the main phase represented by (Nd, Ce, La)2Fe14B is difficult to be formed. When the content r of B is 4.0 at% or more, it is unlikely that the main phase represented by (Nd, Ce, La)2Fe14B is difficult to be formed. From this viewpoint, r may be 4.5 at% or more, 5.0 at% or more, or 5.5 at% or more. On the other hand, if the content r of B is excessive, an Fe-containing magnetic phase such as RFe4B4 phase is readily formed in the grain boundary phase. When r is 6.5 at% or less, an α-Fe phase is less
likely to be formed in a large amount. From this viewpoint, r may be 6.3 at% or less, or 6.0 at% or less. - Co can substitute for iron in the main phase, grain boundary phase and intermediate phase. When Fe is referred to in the present description, part of Fe can be replaced by Co. For example, part of Fe of the (Nd, Ce, La)2Fe14B phase is replaced by Co to form the (Nd, Ce, La)2(Fe, Co)14B phase. In addition, the Fe-containing magnetic phase (e.g., R2Fe17 phase) in the grain boundary phase allows part of Fe thereof to be replaced by Co and becomes a magnetic phase (e.g., R2(Fe, Co)17 phase).
- In this way, part of Fe is replaced by Co, and the Curie point in each phase is thereby enhanced. In the case of preferring not to enhance the Curie point, Co may not be contained. It is not essential to contain Co. When the content q of Co is 0.5 at% or more, enhancement of the Curie point is substantially recognized. From the viewpoint of enhancing the Curie point, the content may be 1.0 at% or more, 2.0 at% or more, 3.0 at% or more, or 4.0 at% or more. On the other hand, Co is expensive, and therefore, in economic terms, the content q of Co may be 8.0 at% or less, 7.0 at% or less, or 0.6 at% or less.
- M1 may be contained within the range not compromising the properties of the rare earth magnet of the present disclosure. M1 may contain an unavoidable impurity element. The unavoidable impurity element indicates an impurity element that is unavoidably contained or causes a significant rise in the production cost for avoiding its inclusion, such as impurity element contained in raw materials of the rare earth magnet or impurity element mixed in the production step. The impurity element, etc. mixed in the production step encompass an element incorporated due to manufacturing reasons within a range not affecting the magnetic properties.
- The element that can be incorporated within a range not affecting the properties of the rare earth magnet of the present disclosure includes Ga, Al, Cu, Au, Ag, Zn, In, and Mn.
- Ga, Al, Zn, In, Au, Ag and Cu decrease the melting point of the grain boundary phase present inside of a ribbon, etc. obtained, for example, by a liquid quenching method. For this reason, in the case of obtaining a molded body from a plurality of ribbons and/or obtaining a compressed body from the molded body, such elements may be incorporated so as to, for example, enhance the mold life but are not essential. When the content of M1 is not more than the upper limit, the elements exert substantially no effect on the magnetic properties. In view of magnetic properties, these elements may be regarded as an unavoidable impurity element.
- Mn contributes to the stabilization of (Nd, Ce, La)2Fe14B phase by replacing part of Fe in the (Nd, Ce, La)2Fe14B phase.
- When the content s of M1 is 2.0 at% or less, the magnetic properties of the present disclosure are not compromised. From this viewpoint, the content s of M1 may be 1.5 at% or less, 1.0 at% or less, or 0.5 at% or less.
- In the case of not containing Ga, Al, Cu, Au, Ag, Zn, In, and Mn as M1, since it is impossible not to contain an unavoidable impurity element at all, the lower limit of the content s of M1 may be 0.05 at%, 0.1 at%, or 0.2 at%, and this poses no practical problem.
- Each of the values of p, q, r and s described hereinbefore is the same as that in the case of a normal R-Fe-B-based rare earth magnet.
- Fe is the remainder after removing Nd, Ce, La, R1, Co, B, and M1 described hereinbefore, and the content (at%) of Fe is represented by (100-p-q-r-s). When p, q, r and s are in the ranges above, a main phase and a grain boundary phase are obtained. In addition, when the rare earth magnet having a main phase and a grain boundary phase is used as a precursor and a modifier is sufficiently infiltrated into the precursor, an intermediate phase is obtained. The main phase, grain boundary phase and intermediate phase are described below.
-
Fig. 2 is a diagram schematically illustrating one embodiment of the texture of the rare earth magnet according to the present disclosure.Fig. 3 is a diagram illustrating another embodiment of the texture of the rare earth magnet according to the present disclosure. - In the embodiment illustrated in
Fig. 2 , therare earth magnet 100 of the present disclosure has amain phase 10 and agrain boundary phase 20. In the embodiment illustrated inFig. 3 , therare earth magnet 100 of the present disclosure further has anintermediate phase 30, in addition to amain phase 10 and agrain boundary phase 20. - The embodiment illustrated in
Fig. 2 is recognized when a modifier is not infiltrated or a very small amount of a modifier is infiltrated. Therare earth magnet 100 of the embodiment illustrated inFig. 2 is used as a rare earth magnet precursor into which a modifier is infiltrated. The embodiment illustrated inFig. 3 is recognized when a sufficient amount of a modifier is infiltrated. - The
rare earth magnet 100 may have a phase (not shown) other than themain phase 10, thegrain bounder phase 20, and theintermediate phase 30. The phase other than themain phase 10, thegrain bounder phase 20, and theintermediate phase 30 includes an oxide, a nitride, an intermetallic compound, etc. - The properties of the
rare earth magnet 100 are exerted mainly by themain phase 10, thegrain boundary phase 20, and theintermediate phase 30. Most of the phases other than themain phase 10, thegrain boundary phase 20, and theintermediate phase 30 are an impurity. Accordingly, the total content of themain phase 10, thegrain boundary phase 20, and theintermediate phase 30 is preferably 95 vol% or more, more preferably 97 vol% or more, still more preferably 99 vol% or more, relative to therare earth magnet 100. - The
main phase 10 is nanocrystallized. Being nanocrystallized means that the average grain size of themain phase 10 is from 1 to 1,000 nm. The average grain size may be 10 nm or more, 50 nm or more, or 100 nm or more, and may be 900 nm or less, 700 nm or less, 500 nm or less, or 300 nm or less. - The "average grain size" indicates an average value of longitudinal lengths t of
main phases 10, for example, illustrated inFig. 2 . For example, a given region is specified in a scanning electron microscope image or a transmission electron microscope image of therare earth magnet 100, and the average value of respective lengths t ofmain phases 10 present in the given region is calculated and defined as the "average grain size". In the case where the crosssectional shape of themain phase 10 is elliptic, t is denoted as the length of the long axis, and in the case where the cross-section of the main phase is quadrilateral, t is denoted as the length of a longer diagonal. In the case of the embodiment illustrated inFig. 3 , t is set including theintermediate phase 30, because, as described later, theintermediate phase 30 is derived from themain phase 10. - When the
rare earth magnet 100 illustrated inFig. 2 is used as a rare earth magnet precursor (hereinafter, sometimes referred to as "precursor 100") and a modifier is infiltrated thereinto, the modifier reaches the interface of themain phase 10 and thegrain boundary 20 via thegrain bounder phase 20. Then, R2 in the modifier infiltrates the inside of themain phase 10 from thegrain boundary phase 20 and, as illustrated inFig. 3 , anintermediate phase 30 is formed. - The
grain boundary phase 20 is present around themain phase 10. Theintermediate phase 30 is sandwiched between themain phase 10 and thegrain boundary phase 20. Formation of theintermediate phase 30 is described by referring to the composition of the modifier. - The modifier contains an alloy having a composition represented by R2 zR3 wM2 1-z-w. On the other hand, the
precursor 100 has a composition represented by (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s. - R2 is one or more members selected from Pr, Nd, Pm, Sm, Eu and Gd, and R3 is one or more members selected from rare earth elements other than R2. In addition, M2 represents an alloy element for decreasing the melting point of R2 zR3 wM2 1-z-w to be lower than the melting point of R2 by alloying with R2 and R3, and an unavoidable impurity element.
- The
precursor 100 contains mainly Nd, Ce and La as the rare earth element. On the other hand, the alloy in the modifier contains mainly R2 that is one or more members selected from Pr, Nd, Pm, Sm, Eu, and Gd. - R2 of the modifier differs in the kind of one or more rare earth elements from Nd, Ce and La of the
precursor 100, and therefore, although not bound by theory, R2 infiltrates into themain phase 10 and forms theintermediate phase 30. Accordingly, the concentration of R2 is higher in theintermediate phase 30 than in themain phase 10. Although not bound by theory, the reason for infiltration of R2 into themain phase 10 is considered as follows. - At the time of infiltrating the modifier into the
precursor 100, when the alloy in the modifier contains mainly the same rare earth element of themain phase 10, the rare earth element in the modifier is not easily infiltrated into themain phase 10. For example, at the time of infiltrating a modifier containing an Nd-Cu alloy into the Nd-Fe-B-based rare earth magnet precursor, Nd in the modifier is likely to stay in thegrain boundary phase 20 and hardly infiltrates into the main phase (Nd2Fe14B phase). - On the other hand, when the alloy in the modifier contains mainly a rare earth element different from the
main phase 10, the rare earth element in the modifier readily infiltrates into themain phase 10. For example, at the time of infiltrating a modifier containing an Nd-Cu alloy into the (Nd, Ce, La)-Fe-B-based rare earth magnet, Nd in the modifier readily infiltrates into themain phase 10 due to the presence of Ce and La. From the viewpoint of enhancing the saturation magnetization and anisotropic magnetic field of theintermediate phase 30 in a balanced manner, R2 is preferably Nd. - The composition of the alloy in the modifier is represented by R2 zR3 wM2 1-z-w. R3 is one or more members selected from rare earth elements other than R2. The rare earth element contained in the alloy in the modifier is R2, and it is difficult not to contain the rare earth element R3 other than R2 at all. However, when the value of the content ratio w of R3 is from 0 to 0.1, the properties as the modifier can be regarded as substantially the same as those when w is 0.
- The value of w is ideally close to 0, but the value of w may be 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, or 0.05 or more. On the other hand, the value of w is preferably lower as long as a rise in the production cost is not caused, and the value may be 0.09 or less, 0.08 or less, 0.07 or less, or 0.06 or less.
- In the formula: (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s·(R2 zR3 wM2 1-z-w)t of the overall composition, the value of t corresponds to the infiltration amount (at%) of the alloy from the modifier relative to the
precursor 100. The concentration of R2 in theintermediate phase 30 and the thickness of theintermediate phase 30 are changed according to the value of t. - In
Fig. 3 , when the concentration of R2 is higher by 1.5 times or more in theintermediate phase 30 than in themain phase 10, the magnetic isolation can be clearly recognized. On the other hand, even when the concentration of R2 is higher by 8.0 times in theintermediate phase 30 than in themain phase 10, the effect of magnetic isolation is not saturated. Accordingly, the concentration of R2 is preferably higher by 1.5 to 8.0 times in theintermediate phase 30 than in themain phase 10. The concentration of R2 may be higher by 1.5 to 5.0 times, or by 1.5 to 3.0 times. - In order to clearly recognize the function as the
intermediate phase 30, the thickness of theintermediate phase 30 is preferably 2 nm or more, more preferably 10 nm or more, still more preferably 20 nm or more. On the other hand, the thickness of theintermediate phase 30 depends on the infiltration amount of the modifier. The modifier contains M2 not contributing to magnetization, and therefore, if the infiltration amount of M2 is too large, the volume fraction of the grain boundary phase is increased, and magnetization of therare earth magnet 100 decreases. From this viewpoint, the thickness of theintermediate phase 30 is preferably 100 nm or less, more preferably 70 nm or less, still more preferably 40 nm or less. - The production method of the rare earth magnet of the present disclosure is described below.
- A molten metal having a composition represented by the formula: (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s and containing La in an amount of 1/9 to 3 times by molar ratio relative to Ce is prepared. Alternatively, a molten metal containing La in an amount of 1/9 to 2 times by molar ratio relative to Ce may be prepared. Descriptions regarding Nd, Ce, La, R1, Fe, Co, B, and M1 and regarding x, y, p, q, r, and s are the same as those in the rare earth magnet. Incidentally, in the case where a specific component is consumed during preparation of the molten metal or in the subsequent step, the component may be blended by taking into account the consumption.
- The method for preparing a molten metal is not limited and includes, for example, induction heating of raw materials by using high frequency current. The preparation of a molten metal is preferably performed in an inert gas atmosphere so as to prevent oxidation of the raw materials during melting or the molten metal during storage.
- The molten metal above is quenched to obtain a ribbon. As long as the main phase in the ribbon can be nanocrystallized, the quenching method is not particularly limited and includes, for example, a liquid quenching method. In order to nanocrystallize the main phase in the ribbon, the molten metal-cooling rate may be, typically, 1×102 K/sec or more, 1×103 K/sec or more, or 1×104 K/sec or more, and may be 1×107 K/sec or less, 1×106 K/sec or less, or 1×105 K/sec or less.
- As to the conditions in the liquid quenching method, for example, a molten metal is discharged toward a copper-made single roll in an inert gas atmosphere under reduced pressure of 50 kPa or less to obtain a ribbon, but the conditions are not limited thereto.
- The molten metal discharging temperature may be, typically, 1,300°C or more, 1,350°C or more, or 1,400°C or more, and may be 1,600°C or less, 1,550°C or less, or 1500°C or less.
- The peripheral velocity of the single roll may be, typically, 20 m/s or more, 24 m/s or more, or 28 m/s or more, and may be 40 m/s or less, 36 m/s or less, or 32 m/s or less.
- The ribbon obtained by liquid quenching is compressed by hot working to obtain a molded body. The molded body is obtained from a plurality of ribbons. The method for compression is not particularly limited but includes, for example, a method where ribbons are charged into a die and hot-pressed. Before hot pressing, the ribbon may be pulverized to 10 µm or less. The temperature at the time of hot pressing may be a temperature at which a molded body is obtained, but may also be a temperature at which part of the grain boundary phase in the ribbon melts, that is, the ribbon may be liquid phase sintered. The atmosphere during hot pressing is preferably an inert gas atmosphere so as to prevent oxidation of the ribbon and molded body. In addition, as for the hot pressing, a powder obtained by pulverizing the ribbon may be compacted to obtain a compact, and the compact may then be sintered (including liquid phase sintering).
- The pressure at the time of hot pressing may be, typically, 200 MPa or more, 300 MPa or more, or 350 MPa or more, and may be 600 MPa or less, 500 MPa or less, or 450 MPa or less.
- The temperature at the time of hot pressing may be, typically, 550°C or more, 600°C or more, or 630°C or more, and may be 750°C or less, 700°C or less, or 670°C or less.
- The pressing time at the time of hot pressing may be, typically, 5 seconds or more, 20 seconds or more, or 40 seconds or more, an may be 120 seconds or less, 100 seconds or less, or 80 seconds or less.
- The above-described molded body is further plastically worked by hot working to obtain a compressed body (plastically deformed body). The method for hot-plastic working (hereinafter, sometimes simply referred to as "plastic working") is not particularly limited as long as a compressed body having anisotropy is obtained. The method includes, for example, a method where the molded body is charged into a cemented carbide-made mold and plastically worked at a reduction ratio of 10 to 75%. The method for plastic working includes upsetting, backward extrusion, etc. The reduction ratio may be set to obtain desired anisotropy. The temperature at the time of plastic working may be set such that the compressed body is not broken and the crystal grain in the compressed body is not coarsened.
- The reduction ratio at the time of plastic working may be, typically, 10% or more, 30% or more, 50% or more, or 60% or more, and may be 75% or less, 70% or less, or 65% or less.
- The temperature at the time of plastic working may be 650°C or more, 700°C or more, or 720°C or more, and may be 850°C or less, 800°C or less, or 770°C or less.
- The strain rate at the time of plastic working may be 0.001/s or more, 0.01/s or more, 0.1/s or more, or 1.0/s or more, and may be 10.0/s or less, 5.0/s or less, or 3.0/s or less.
- Although not bound by theory, it is considered that the followings are generated inside the molded body during plastic working. The molded body has a
main phase 10 and agrain boundary phase 20 present around the main phase 10 (see,Fig. 2 ). When the molded body is plastically worked, themain phase 10 is deformed. At this time, in at least part of themain phase 10, a portion allowing for direct contact betweenmain phases 10 is likely to be produced due to the deformation. This contact part may work out to origin of the grain growth of themain phase 10. If the strain rate at the time of plastic working is low, themain phase 10 readily undergoes grain growth from the contact part as a starting point. The plastic working is performed as hot working, and therefore, when the strain rate is low, this means that the contact part above is subjected to a high temperature over a long period of time. Consequently, atomic diffusion occurs via the contact part, and themain phase 10 undergoes grain growth. On the other hand, in the initial stage of plastic working, Ce and La, particularly, La, are expelled to thegrain boundary phase 20 from themain phase 10. At the time of deformation of themain phase 10 resulting from expelling of Ce and La, Ce and La enter betweenmain phases 10, and formation of the contact part above is suppressed. In addition, due to expelling of Ce and La, the melting point of thegrain boundary phase 20 lowers. The plastic working is performed at a temperature allowing at least onegrain boundary phase 20 to melt. Lowering of the melting point of thegrain boundary phase 20 causes reduction in the viscosity of the melt of thegrain boundary phase 20 during plastic working. As a result, themain phase 10 undergoing deformation is readily rotated in the melt to facilitate orientation of themain phase 10 in a specific direction. For this reason, when the strain rate is low, typically, even when the strain rate is 0.001/s or more and less than 0.01/s, the grain growth of themain phase 10 is restricted to suppress reduction in the coercive force and at the same time, orientation of themain phase 10 is promoted to enhance the magnetization. From this viewpoint, the strain rate may be from 0.001/s to 0.008/s, or from 0.001/s to 0.005/s. - The compressed body obtained in this way may be directly used as a rare earth magnet, or by using the compressed body as a rare earth magnet precursor, subsequent steps may be performed.
- A modifier containing an alloy having a composition represented by the formula: R2 zR3 wM2 1-z-w is prepared. Descriptions regarding R2 and R3 and regarding w are the same as those for the rare earth magnet.
- M2 represents an alloy element for decreasing the melting point of R2 zR3 wM2 1-z-w to be lower than the melting point of R2 by alloying with R2 and R3, and an unavoidable impurity element. Due to this element, even when the temperature of the later-described heat treatment is not raised excessively, the alloy in the modifier can be melted. As a result, the alloy in the modifier can be infiltrated into the rare earth magnet precursor without coarsening the texture of the rare earth magnet precursor. M2 may contain an unavoidable impurity element. The unavoidable impurity element indicates an impurity element that is unavoidably contained or causes a significant rise in the production cost for avoiding its inclusion, such as impurity element contained in raw materials.
- As M2, one or more members selected from Cu, Al, and Co, and an unavoidable element are preferred, because Cu, Al, and Co have little adverse effect on the magnetic properties, etc. of the rare earth magnet.
- The alloy having a composition represented by the formula: R2 zR3 wM2 1-z-w includes an Nd-Cu alloy, a Pr-Cu alloy, an Nd-Pr-Cu alloy, an Nd-Al alloy, a Pr-Al alloy, an Nd-Pr-Al alloy, an Nd-Co alloy, a Pr-Co alloy, and an Nd-Pr-Co alloy.
- The content ratio z of R2 is described. When z is 0.50 or more, the content of R2 in the alloy is large, and therefore R2 is easily infiltrated into the
main phase 10 and theintermediate phase 30. From this viewpoint, z is preferably 0.55 or more, more preferably 0.60 or more. On the other hand, when z is 0.80 or less, the melting point of the alloy in the modifier appropriately lowers and in turn, the temperature of the later-described heat treatment is made appropriate. As a result, the texture of the rare earth magnet precursor can be prevented from coarsening. From the viewpoint of making the melting point of the alloy appropriate, z is preferably 0.75 or less, more preferably 0.70 or less. When R2 is two or more elements, z is the total thereof. The same applies to M2. - The production method of the modifier is not particularly limited. The production method of the modifier includes a casting method, a liquid quenching method, etc. From the viewpoint that the alloy composition less varies depending on the region of the modifier and the content of an impurity such as oxide is small, a liquid quenching method is preferred.
- The infiltration amount of the alloy in the modifier is denoted by t (at%) in the formula of the overall composition. When t is 0.05 at% or more, the effect due to infiltration of the modifier is seen, for example, on the enhancement of magnetic properties. In order to clearly recognize the
intermediate phase 30 as illustrated inFig. 3 , t is preferably 0.1 at% or more, more preferably 1.0 at% or more, still more preferably 1.5 at% or more. On the other hand, the modifier contains M2, and therefore, if the infiltration amount of the modifier is excessive, the magnetization of the rare earth magnet after infiltration of the modifier decreases. When t is 10.0 at% or less, the decrease of magnetization poses no problem in practice. From this viewpoint, t is preferably 9.0 at% or less, more preferably 8.0 at% or less, still more preferably 7.0 at% or less. - The rare earth magnet precursor and the modifier are contacted with each other to obtain a contact body. The rare earth magnet precursor is the above-described compressed body. At this time, at least one surface of the rare earth magnet precursor and at least one surface of the modifier are put into contact with each other.
- The contact body above is heat-treated to infiltrate the melt of the modifier into the inside of the rare earth magnet precursor. The melt of the modifier thereby reaches the surface part of the main phase via the grain boundary phase of the rare earth magnet precursor, and R2 in the modifier is infiltrated into the main phase to form an intermediate phase.
- The heat treatment temperature is not particularly limited as long as the modifier is melted and the melt of the modifier can be infiltrated into the main phase of the rare earth magnet precursor.
- As the heat treatment temperature is higher, the melt of the modifier, particularly, R2, is more easily infiltrated into the main phase of the rare earth magnet precursor. From this viewpoint, the heat treatment temperature is preferably 580°C or more, more preferably 600°C or more, still more preferably 620°C or more. On the other hand, as the heat treatment temperature is lower, the texture of the rare earth magnet precursor, particularly, the main phase, is more likely to be restricted from coarsening. From this viewpoint, the heat treatment temperature is preferably 800°C or less, more preferably 775°C or less, still more preferably 725°C or less.
- The heat treatment atmosphere is not particularly limited, but from the viewpoint of preventing oxidation of the rare earth magnet precursor and the modifier, an inter gas atmosphere is preferred.
- The rare earth magnet of the present disclosure and the production method thereof are described more specifically below by referring to Examples. Incidentally, the rare earth magnet of the present disclosure and the production method thereof are not limited to the conditions employed in the following Examples.
- First, a rare earth magnet precursor is prepared. A molten alloy having a composition represented by R13.11Fe80.43Cu0.10B5.99Ga0.37 was liquid-quenched by a single roll method to obtain a ribbon. R is as in Table 1-1 later. As for the conditions of liquid quenching, the molten alloy temperature (discharge temperature) was 1,420°C, and the peripheral velocity of the roll was 30 m/s. At this time, the cooling rate of the molten alloy was 106 K/sec. The liquid quenching was performed in an argon gas reduced-pressure atmosphere. It was confirmed by transmission electron microscope (TEM) observation that the ribbon is nanocrystallized.
- The ribbon was roughly pulverized into a powder, and the powder was charged into die, pressurized and heated to obtain a molded body. As for the pressurizing and heating conditions, the applied pressure was 400 MPa, the heating temperature was 650°C, and the holding time for pressurization and heating was 60 seconds.
- The molded body was subjected to hot upsetting (hot-plastic working) to obtain a compressed body (plastically deformed body). In the hot-plastic working, a sample of 15 mm in height was compressed to 4.5 mm. As for the hot upsetting conditions, the working temperature was 780°C, the strain rate was 0.01/s, and the reduction ratio was 70%. It was confirmed by scanning electron microscope (SEM) that the compressed body has oriented nanocrystals. This compressed body was used as a rare earth magnet precursor.
- An Nd70Cu30 alloy was prepared as the modifier. Nd powder and Cu powder, manufactured by Kojundo Chemical Lab. Co., Ltd., were weighed, arc-melted, and liquid-quenched to obtain a ribbon.
- The rare earth magnet precursor and the modifier were put into contact with each other and heat-treated in a heating furnace. The amount of the modifier was 1.59 at%, 3.72 at%, and 5.32 at%, relative to the rare earth magnet precursor (see, Table 1-1). As for the heat treatment conditions, the heat treatment temperature was 625°C, and the heat treatment time was 165 minutes.
- The sample was prepared in the same manner as in Examples 1 to 26 other than the composition of the alloy for preparing the rare earth magnet precursor was Nd13.11Fe80.43Cu0.10B5.99Ga0.37 and the modifier was not infiltrated into the rare earth magnet precursor.
- The samples were prepared in the same manner as in Examples 1 to 26 except that R of the rare earth magnet precursor was changed as in Table 1-3.
- The samples were prepared in the same manner as in Examples 1 to 26 other than R of the rare earth magnet precursor was changed as in Table 1-3 and the modifier was not infiltrated into the rare earth magnet precursor.
- The samples were prepared in the same manner as in Examples 1 to 26 other than the composition of the alloy for preparing the rare earth magnet precursor was R13.11Fe80.80Cu0.10B5.99 and R of the rare earth magnet precursor was changed as in Table 1-3.
- The sample was prepared in the same manner as in Example 6 other than the strain rate at the time of hot upsetting of the molded body was changed to 0.001/s.
- The sample was prepared in the same manner as in Example 12 except that the strain rate at the time of hot upsetting of the molded body was changed to 0.001/s.
- The sample was prepared in the same manner as in Examples 1 to 26 other than the composition of the alloy for manufacturing the rare earth magnet precursor was Nd13.11Fe80.43CU0.10B5.99Ga0.37.
- The samples were prepared in the same manner as in Examples 1 to 26 other than R of the rare earth magnet precursor was changed as in Table 1-3.
- The sample of Comparative Example 8 was prepared in the same manner as in Comparative Example 1 other than R of the rare earth magnet precursor was changed as in Table 1-3.
- The sample of Comparative Example 9 was prepared in the same manner as in Comparative Example 2 other than R of the rare earth magnet precursor was changed as in Table 1-3 and the infiltrating amount of the modifier was 3.72 at% relative to the rare earth magnet precursor. The sample of Comparative Example 9 is the same as the sample in which the modifier of 3.72 at% is infiltrated into Sample of Comparative Example 8.
- The sample of Comparative Example 10 was prepared in the same manner as in Comparative Example 1 other than R of the rare earth magnet precursor was changed as in Table 1-3.
- The sample of Comparative Example 11 was prepared in the same manner as in Comparative Example 2 other than R of the rare earth magnet precursor was changed as in Table 1-3 and the infiltrating amount of the modifier was 3.72 at% relative to the rare earth magnet precursor. The sample of Comparative Example 11 is the same as the sample in which the modifier of 3.72 at% is infiltrated into Sample of Comparative Example 10.
- The sample of Comparative Example 12 was prepared in the same manner as in Comparative Example 2 other than R of the rare earth magnet precursor was changed as in Table 1-3 and the infiltrating amount of the modifier was 3.72 at% relative to the rare earth magnet precursor.
- With respect to the samples of Examples 1 to 40 and Comparative Examples 1 to 12, the coercive force and residual magnetization were measured. In the measurement, a pulse excitation-type magnetic properties measuring apparatus (maximum applied magnetic field: 15T) manufactured by Toei Industry Co., Ltd. was used. Both the coercive force and the residual magnetization were measured at 23°C, 100°C, 140°C and 160°C.
- The results are shown in Tables 1-1 to 1-4 and Tables 2-1 and 2-2. In Tables 1-1 and Table 1-3, the composition of each sample is shown together. As for the coercive force and the residual magnetization, the gradient ΔHc from 23 to 160°C and the gradient ΔBr from 23 to 160°C are shown together, respectively. In Table 2-1, the conditions in hot upsetting and the average grain size are shown together. Here, the average grain size means the average grain size t of a crystal grain composed of a
main phase 10 and an intermediate phase 30 (see,Fig. 3 ).Fig. 4 is a graph illustrating the relationship between the temperature and the cohesive force with respect to the samples of Example 15 and Comparative Example 1.Fig. 5 is a diagram illustrating the relationship between the temperature and the residual magnetization with respect to the samples of Example 15 and Comparative Example 1. - With respect to the samples of Examples 6, 12, 17, 39 and 40, the texture was observed using a scanning transmission electron microscope (STEM), and the component analysis (EDX analysis) was performed.
-
Figs. 6 to 26 illustrate the evaluation results. Of these,Figs. 6 to 14 are evaluation results regarding Examples and Comparative Examples shown in Tables 1-1 to 1-4, andFigs. 15 to 26 are the evaluation results regarding Examples shown in Tables 2-1 and 2-2. -
Fig. 6 is a diagram illustrating the positions for texture observation and composition analysis with respect to the sample of Example 6.Fig. 7 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 6 (first visual field).Fig. 8 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 6 (second visual field).Fig. 9 is a diagram illustrating the positions for texture observation and composition analysis with respect to the sample of Example 12.Fig. 10 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 12 (first visual field).Fig. 11 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 12 (second visual field).Fig. 12 is a diagram illustrating the positions for texture observation and composition analysis with respect to the sample of Example 17.Fig. 13 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 17 (first visual field).Fig. 14 is a diagram illustrating the results of texture observation and composition analysis with respect to the sample of Example 17 (second visual field). -
Fig. 15 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 39.Fig. 16 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 40.Fig. 17 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 6.Fig. 18 is a diagram illustrating one example of the grain size t of a crystal grain with respect to the sample of Example 12. In each ofFigs. 15 to 18 , the average grain size of Table 2 is an average of respective grain sizes t of crystal grains included in the visual field. -
Fig. 19 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 39.Fig. 20 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 19 .Fig. 21 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 40.Fig. 22 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 21 .Fig. 23 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 6.Fig. 24 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 23 .Fig. 25 is a diagram illustrating the results of texture observation and the positions for composition analysis with respect to the sample of Example 12.Fig. 26 is a diagram illustrating the results of composition analysis at a position indicated by a white line inFig. 25 . Furthermore, with respect to Examples 39, 40, 6 and 12, the peak concentrations of La and Ce in the grain boundary phase and the total peak concentration thereof are determined fromFigs. 20 ,22 ,24 and26 , and the results are shown in Table 3. - [Table 1-1]
Table 1-1 Composition of Rare Earth Magnet Precursor (at%) Modifier Ratio of Rare Earths Composition Ratio Infiltration Amount (at%) Percentage Ratio Nd Ce La Fe B Ga Cu Nd Cu Nd Ce La La/Ce Example 1 6.555 5.8995 0.6555 80.43 5.99 0.37 0.1 0.7 0.3 1.593 50 45 5 1/9 Example 2 6.555 5.8995 0.6555 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 50 45 5 1/9 Example 3 6.555 5.8995 0.6555 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 50 45 5 1/9 Example 4 6.555 3.933 2.622 80.43 5.99 0.37 0.1 0.7 0.3 1.593 50 30 20 2/3 Example 5 6.555 3.933 2.622 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 50 30 20 2/3 Example 6 6.555 3.933 2.622 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 50 30 20 2/3 Example 7 7.866 4.7196 0.5244 80.43 5.99 0.37 0.1 0.7 0.3 1.593 60 36 4 1/9 Example 8 7.866 4.7196 0.5244 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 60 36 4 1/9 Example 9 7.866 4.7196 0.5244 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 60 36 4 1/9 Example 10 7.866 3.1464 2.0976 80.43 5.99 0.37 0.1 0.7 0.3 1.593 60 24 16 2/3 Example 11 7.866 3.1464 2.0976 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 60 24 16 2/3 Example 12 7.866 3.1464 2.0976 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 60 24 16 2/3 Example 13 9.177 3.5397 0.3933 80.43 5.99 0.37 0.1 0.7 0.3 1.593 70 27 3 1/9 Example 14 9.177 3.5397 0.3933 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 70 27 3 1/9 Example 15 9.177 3.5397 0.3933 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 70 27 3 1/9 Example 16 9.177 2.9498 0.9833 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 70 22.5 7.5 1/3 Example 17 9.177 2.9498 0.9833 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 70 22.5 7.5 1/3 Example 18 9.177 2.3598 1.5732 80.43 5.99 0.37 0.1 0.7 0.3 1.593 70 18 12 1/3 Example 19 9.177 2.3598 1.5732 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 70 18 12 2/3 Example 20 9.177 2.3598 1.5732 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 70 18 12 2/3 Example 21 5.244 5.8995 1.9665 80.43 5.99 0.37 0.1 0.7 0.3 1.593 40 45 15 2/3 Example 22 5.244 5.8995 1.9665 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 40 45 15 1/3 Example 23 5.244 5.8995 1.9665 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 40 45 15 1/3 Example 24 10.488 1.9665 0.6555 80.43 5.99 0.37 0.1 0.7 0.3 1.593 80 15 5 1/3 Example 25 10.488 1.9665 0.6555 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 80 15 5 1/3 Example 26 10.488 1.9665 0.6555 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 80 15 5 1/3 Comp. Ex. 1 13.11 0 0 80.43 5.99 0.37 0.1 0.7 0.3 0 100 0 0 0 Table 1-2 Hc (kA/m) ΔHc Br(T) ΔBr 23°C 100°C 140°C 160°C 23°C 100°C 140°C 160°C Example 1 814.419 535.629 399.056 331.710 -3.523 1.078 0.969 0.891 0.804 -0.001997 Example 2 1028.451 664.597 486.864 394.509 -4.627 1.086 0.972 0.880 0.808 -0.002026 Example 3 992.544 602.112 450.800 328.810 -4.845 1.156 1.037 0.905 0.826 -0.002408 Example 4 624.456 460.678 351.232 331.162 -2.141 1.071 0.939 0.809 0.746 -0.002378 Example 5 993.877 654.091 531.552 452.211 -3.954 1.041 0.910 0.835 0.785 -0.001874 Example 6 1056.989 718.458 554.758 473.301 -4.260 1.087 0.964 0.882 0.840 -0.001803 Example 7 1024.061 626.259 447.194 375.379 -4.735 1.072 0.910 0.832 0.791 -0.002048 Example 8 1145.189 720.261 536.178 441.157 -5.139 1.078 0.991 0.934 0.893 -0.001350 Example 9 1091.798 662.166 500.819 412.070 -4.962 1.308 1.139 1.061 1.038 -0.001972 Example 10 671.026 461.698 378.515 288.120 -2.795 1.243 1.147 1.060 0.945 -0.002175 Example 11 1123.707 774.906 599.760 514.147 -4.449 1.088 0.999 0.933 0.868 -0.001608 Example 12 1259.810 828.061 634.413 537.040 -5.276 1.097 0.964 0.911 0.826 -0.001982 Example 13 1015.358 610.109 454.955 373.106 -4.688 1.320 1.192 1.082 1.040 -0.002041 Example 14 1298.931 814.498 610.030 503.485 -5.806 1.173 1.091 1.018 0.930 -0.001776 Example 15 1250.872 753.659 555.621 465.461 -5.733 1.327 1.162 1.039 0.987 -0.002483 Example 16 1380.781 932.803 723.162 609.482 -5.630 1.121 1.027 0.953 0.950 -0.001247 Example 17 1559.062 1022.101 780.158 638.960 -6.716 1.103 0.978 0.927 0.861 -0.001762 Example 18 918.613 612.147 472.674 427.437 -3.585 1.166 1.019 0.924 0.913 -0.001844 Example 19 1252.048 807.128 628.219 530.611 -5.266 1.285 1.159 1.047 0.976 -0.002256 Example 20 1460.435 933.822 721.123 608.854 -6.216 1.114 1.026 0.972 0.896 -0.001589 Example 21 456.288 337.826 271.656 224.067 -1.695 1.181 1.078 0.903 0.869 -0.002275 Example 22 893.054 593.880 459.346 379.221 -3.751 1.116 0.989 0.915 0.767 -0.002549 Example 23 977.178 631.120 460.286 385.728 -4.317 1.034 0.931 0.824 0.747 -0.002097 Example 24 736.254 489.216 367.931 344.882 -2.857 0.971 0.900 0.841 0.757 -0.001561 Example 25 640.606 446.174 358.366 312.032 -2.398 0.900 0.855 0.807 0.778 -0.000894 Example 26 956.480 613.323 476.829 430.730 -3.838 0.885 0.781 0.715 0.695 -0.001388 Comp. Ex. 1 2111.200 1278.200 0.000 753.600 -9.909 1.227 1.061 1.020 -0.001511 - [Table 1-3]
Table 1-3 Composition of Rare Earth Magnet Precursor (at%) Modifier Ratio of Rare Earths Composition Ratio Infiltration Amount (at%) Percentage Ratio Nd Ce La Fe B Ga Cu Nd Cu Nd Ce La La/Ce Example 27 9.177 0.9833 2.9498 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 70 7.5 23 3 Example 28 9.177 0.9833 2.9498 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 70 7.5 23 3 Example 29 7.866 1.3110 3.9330 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 60 10 30 3 Example 30 7.866 1.3110 3.9330 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 60 10 30 3 Example 31 6.555 1.6388 4.9163 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 50 12.5 38 3 Example 32 6.555 1.6388 4.9163 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 50 12.5 38 3 Example 33 9.177 0.9833 2.9498 80.43 5.99 0.37 0.1 0 0 0 70 7.5 23 3 Example 34 7.866 1.3110 3.9330 80.43 5.99 0.37 0.1 0 0 0 60 10 30 3 Example 35 9.177 2.9498 0.9833 80.43 5.99 0.37 0.1 0 0 0 70 22.5 7.5 1/3 Example 36 6.555 1.6388 4.9163 80.43 5.99 0.37 0.1 0 0 0 50 12.5 38 3 Example 37 9.177 2.9498 0.9833 80.80 5.99 0 0.1 0.7 0.3 3.7218 70 22.5 7.5 1/3 Example 38 9.177 2.9498 0.9833 80.80 5.99 0 0.1 0.7 0.3 5.3184 70 22.5 7.5 1/3 Comp. Ex. 1 13.110 0 0 80.43 5.99 0.37 0.1 0.7 0.3 0 100 0 0 0 Comp. Ex. 2 13.110 0 0 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 100 0 0 0 Comp. Ex. 3 9.833 3.2775 0 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 75 25 0 0 Comp. Ex. 4 6.555 6.5550 0 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 50 50 0 0 Comp. Ex. 5 3.278 9.8325 0 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 25 75 0 0 Comp. Ex. 6 0 13.1100 0 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 0 100 0 0 Comp. Ex. 7 0 9.8325 3.2775 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 0 75 25 1/3 Comp. Ex. 8 12.979 0 0.1311 80.43 5.99 0.37 0.1 0 0 0 99 0 1 - Comp. Ex. 9 12.979 0 0.1311 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 99 0 1 - Comp. Ex. 10 12.455 0 0.6555 80.43 5.99 0.37 0.1 0 0 0 95 0 5 - Comp. Ex. 11 12.455 0 0.6555 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 95 0 5 - Comp. Ex. 12 10.488 0 2.6220 80.43 5.99 0.37 0.1 0.7 0.3 3.7218 80 0 20 - Table 1-4 Hc (kA/m) ΔHc Br (T) ΔBr 23°C 100°C 140°C 160°C 23°C 100°C 140°C 160°C Example 27 1209.320 773.416 610.893 538.765 -4.895 1.140 1.000 0.963 0.909 -0.001688 Example 28 1321.902 874.709 676.984 587.216 -5.363 1.070 0.990 0.915 0.845 -0.001644 Example 29 843.584 553.896 451.270 393.333 -3.287 1.113 1.028 0.937 0.876 -0.001726 Example 30 1011.438 655.267 527.789 469.067 -3.959 1.003 0.892 0.812 0.760 -0.001773 Example 31 227.909 174.283 138.376 120.266 -0.786 1.167 1.007 0.954 0.885 -0.002055 Example 32 759.147 513.050 422.654 380.318 -2.765 1.068 0.903 0.819 0.768 -0.002194 Example 33 309.445 192.002 157.662 143.394 -1.212 1.188 0.903 0.833 0.797 -0.002857 Example 34 204.389 140.493 112.896 87.651 -0.852 1.179 1.023 0.856 0.859 -0.002335 Example 35 464.050 300.899 245.706 226.890 -1.731 1.299 1.141 1.007 0.948 -0.002561 Example 36 172.166 87.886 79.890 69.776 -0.747 1.141 1.079 1.022 0.999 -0.001037 Example 37 924.101 555.778 407.837 338.923 -4.271 1.312 1.162 1.021 0.993 -0.002331 Example 38 978.118 572.242 438.178 350.134 -4.584 1.267 1.105 0.969 0.940 -0.002383 Comp. Ex. 1 2111.200 1278.200 857.905 753.600 -9.909 1.227 1.132 1.061 1.020 -0.001511 Comp. Ex. 2 2213.500 1380.240 956.376 850.460 -9.949 1.110 1.016 0.960 0.930 -0.001314 Comp. Ex. 3 1593.680 962.400 708.184 589.760 -7.328 1.090 0.999 0.922 0.875 -0.001569 Comp. Ex. 4 1344.000 756.000 524.000 378.080 -7.051 1.040 0.953 0.880 0.835 -0.001497 Comp. Ex. 5 518.160 353.440 250.400 196.640 -2.347 0.845 0.614 0.541 0.432 -0.003012 Comp. Ex. 6 405.600 262.400 160.800 105.600 -2.190 0.805 0.619 0.546 0.383 -0.003081 Comp. Ex. 7 405.600 262.400 160.800 105.600 -2.190 0.851 0.581 0.544 0.431 -0.003064 Comp. Ex. 8 1076.746 648.603 489.373 412.541 -4.848 1.347 1.217 1.117 1.062 -0.002078 Comp. Ex. 9 1745.654 1101.520 775.611 691.174 -7.697 1.235 1.102 1.031 1.003 -0.001694 Comp. Ex. 10 1085.370 663.813 517.440 445.234 -4.673 1.341 1.201 1.085 1.016 -0.002374 Comp. Ex. 11 1766.587 1114.926 855.344 707.403 -7.731 1.238 1.127 1.092 1.026 -0.001547 Comp. Ex. 12 1337.739 845.701 670.085 578.435 -5.542 1.222 1.057 0.978 0.931 -0.002123 - It could be confirmed from Tables 1-1 to 1-4 that in all of the samples of Examples 1 to 38, the absolute value of ΔHc is smaller than in Comparative Examples 1 to 4. In addition, it could be confirmed that in all of the samples of Examples 1 to 38, the absolute value of ΔBr is very small. Furthermore, it could be confirmed that in Comparative Examples 5 to 7, the decrease of magnetization at high temperatures is large. These results could verify that in the rare earth magnet of the present disclosure, reduction in the coercive force at high temperatures can be suppressed without greatly affecting the magnetization. The same could also be verified in
Figs. 4 and 5 . In addition, fromFigs. 6 to 11 , formation of anintermediate phase 30 could be confirmed. - With regard to the samples in which the modifier are infiltrated, the samples of Examples 1 to 32 and Examples 37 to 38 are compared with the samples of Comparative Examples 9, 11, and 12. Then, it could be confirmed that, with regard to rare earth elements, the absolute value of ΔHc is smaller in the samples of Examples 1 to 32 and Examples 37 to 38 that contain Nd, Ce, and La than in the samples of Comparative Examples 9, 11, and 12 that contain only Nd and La. With regard to the samples in which the modifier are not infiltrated, the same could also be confirmed between the samples of Examples 33 to 36 and the samples of Comparative Examples 8 and 10.
- [Table 2-1]
Table 2-1 Composition of Rare Earth Magnet Precursor (at%) Modifier Ratio of Rare Earths Hot Upsetting Conditions Average Grain Size (µm) Composition Ratio Infiltration Amount (at%) Percentage Ratio Strain Rate (/s) Reduction Ratio (%) Temperature (°C) Nd Ce La Fe B Ga Cu Nd Cu Nd Ce La La/Ce Example 6 6.555 3.933 2.622 80.43 5.99 0.37 0.7 0.3 5.3184 50 30 20 2/3 0.01 70 780 527.72 Example 12 7.866 3.1464 2.0976 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 60 24 16 2/3 0.01 70 780 579.33 Example 39 6.555 3.933 2.622 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 50 30 20 2/3 0.001 70 780 595.82 Example 40 7.866 3.1464 2.0976 80.43 5.99 0.37 0.1 0.7 0.3 5.3184 60 24 16 2/3 0.001 70 780 638.27 Table 2-2 Hc (kA/m) ΔHc Br (T) ΔBr 23°C 100°C 140°C 160°C 23 °C 100°C 140°C 160°C Example 6 1056.989 718.458 554.758 473.301 -4.260 1.087 0.964 0.882 0.840 -0.001803 Example 12 1259.810 828.061 634.413 537.040 -5.276 1.097 0.964 0.911 0.826 -0.001982 Example 39 857.696 543.939 406.739 336.650 -3.803 1.221 1.110 0.979 0.887 -0.002436 Example 40 1054.088 637.862 479.888 399.840 -4.776 1.244 1.124 1.023 0.971 -0.001993 -
Table 3 Example 6 Example 12 Example 39 Example 40 Ce (at%) 13.85 11.01 9.46 9.21 La (at%) 11.52 5.73 16.19 16.91 Ce+La (at%) 25.37 16.74 25.65 26.12 - It could be confirmed from Table 2 that even when the strain rate is low, the increase in the average grain size of a crystal grain is suppressed and consequently, the coercive force is not deteriorated. In addition, it could be confirmed that when the strain rate is low, the magnetization is enhanced. Furthermore, it could be confirmed from Table 3 that the concentrations of Ce and La, particularly La, in the
grain boundary phase 20 are high when the strain rate is low, compared with the case where the strain rate is high, and the maintenance of coercive force and the enhancement of magnetization possibly have high relevance to the expelling of Ce and La to thegrain boundary phase 20 from themain phase 10. - From the results above, the effects of the rare earth magnet of the present disclosure and the production method thereof could be verified.
-
- 10
- Main phase
- 20
- Grain boundary phase
- 30
- Intermediate phase
- 100
- Rare earth magnet (precursor)
Claims (11)
- A rare earth magnet comprising:a main phase (10), anda grain boundary phase (20) present around the main phase (10),wherein the overall composition is represented by the formula: (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s · (R2 zR3 wM2 1-z-w)t,wherein R1 is one or more members selected from rare earth elements other than Nd, Ce and La, R2 is one or more members selected from Pr, Nd, Pm, Sm, Eu and Gd, R3 is one or more members selected from rare earth elements other than R2, M1 represents one or more members selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an unavoidable impurity element, M2 represents an alloy element for decreasing the melting point of R2 zR3 wM2 1-z-w to be lower than the melting point of R2 by alloying with R2 and R3, and an unavoidable impurity element,wherein p, q, r, s, and t are, in at%,5.0≤p≤20.0,0≤q≤8.0,4.0≤r≤6.5,0≤s≤2.0, and0≤t≤10.0, andwherein x, y, z, and w are, by molar ratio,0.4≤x≤0.8,0≤y≤0.1,0.5≤z≤0.8, and0≤w≤0.1), andwherein La is contained in an amount of 1/9 to 3 times by molar ratio relative to Ce, and whereinan average grain size of the main phase (10) is from 1 to 1000 nm wherein theaverage grain size of the main phase (10) is calculated in accordance with the methoddefined in the description.
- The rare earth magnet according to claim 1, wherein La is contained in an amount of 1/9 to 2 times by molar ratio relative to Ce.
- The rare earth magnet according to claim 1 or 2,wherein an intermediate phase (30) is further provided between the main phase (10) and the grain boundary phase (20),wherein t is 0.1≤t≤10.0, andwherein the concentration of R2 is higher in the intermediate phase (30) than in the main phase (10).
- The rare earth magnet according to any one of claims 1 to 3, wherein R2 is Nd.
- The rare earth magnet according to claim 3 or 4, wherein the concentration of R2 is higher by 1.5 to 8.0 times in the intermediate phase (30) than in the main phase (10).
- The rare earth magnet according to any one of claims 3 to 5, wherein the thickness of the intermediate phase (30) is from 2 to 100 nm.
- A method for producing a rare earth magnet, comprising:preparing a molten metal having a composition represented by the formula: (Ndx(Ce, La)(1-x-y)R1 y)pFe(100-p-q-r-s)CoqBrM1 s,wherein R1 is one or more members selected from rare earth elements other than Nd, Ce and La, M1 represents one or more members selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an unavoidable impurity element,wherein p, q, r, and s are, in at%,5.0≤p≤20.0,0≤q≤8.0,4.0≤r≤6.5,and0≤s≤2.0,andwherein x and y are, by molar ratio,0.4≤x≤0.8, and0≤y≤0.1, andwherein La is contained in an amount of 1/9 to 3 times by molar ratio relative to Ce, and quenching the molten metal to obtain a ribbon,compressing a plurality of ribbons by hot working to obtain a molded body, andcompressing the molded body by hot working to obtain a compressed body, wherein an average grain size of the main phase (10) is from 1 to 1000 nm, wherein the average grain size of the main phase (10) is calculated in accordance with the method defined in the description.
- The method according to claim 7, wherein the molten metal contains La in an amount of 1/9 to 2 times by molar ratio relative to Ce.
- The method according to claim 7 or 8, comprising:preparing a modifier containing an alloy represented by the formula: R2 zR3 wM2 1-z-w,wherein R2 is one or more members selected from Pr, Nd, Pm, Sm, Eu and Gd, R3 is one or more members selected from rare earth elements other than R2, M2 represents an alloy element for decreasing the melting point of R2 zR3 wM2 1-z-w to be lower than the melting point of R2 by alloying with R2 and R3, and an unavoidable impurity element, andwherein z and w are, by molar ratio, 0.5≤z≤0.8 and 0≤w≤0.1,contacting the compressed body and the modifier with each other to obtain a contact body, andheat-treating the contact body to infiltrate a melt of the modifier into the inside of the compressed body.
- The method according to claim 9, wherein R2 is Nd.
- The method according to any one of claims 7 to 10,
wherein the molded body is compressed at a strain rate of 0.001/s or more and less than 0.01/s, a reduction ratio of 50 to 70%, and a temperature of 700 to 800°C to obtain a compressed body.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017254475 | 2017-12-28 | ||
JP2018151433 | 2018-08-10 | ||
JP2018221584A JP7247548B2 (en) | 2017-12-28 | 2018-11-27 | Rare earth magnet and manufacturing method thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
EP3522178A1 EP3522178A1 (en) | 2019-08-07 |
EP3522178B1 true EP3522178B1 (en) | 2022-02-23 |
Family
ID=64901904
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP18215888.1A Active EP3522178B1 (en) | 2017-12-28 | 2018-12-24 | Rare earth magnet and production method thereof |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP3522178B1 (en) |
KR (1) | KR102156629B1 (en) |
CN (1) | CN109979699B (en) |
BR (1) | BR102018077206A2 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11721479B2 (en) * | 2019-08-29 | 2023-08-08 | Toyota Jidosha Kabushiki Kaisha | Rare earth magnets |
JP7252105B2 (en) * | 2019-09-10 | 2023-04-04 | トヨタ自動車株式会社 | Rare earth magnet and manufacturing method thereof |
JP7298533B2 (en) * | 2020-04-21 | 2023-06-27 | トヨタ自動車株式会社 | Rare earth magnet and manufacturing method thereof |
JP7303157B2 (en) * | 2020-06-01 | 2023-07-04 | トヨタ自動車株式会社 | Rare earth magnet and manufacturing method thereof |
JP7409285B2 (en) * | 2020-10-22 | 2024-01-09 | トヨタ自動車株式会社 | Rare earth magnet and its manufacturing method |
US20230282399A1 (en) * | 2021-02-08 | 2023-09-07 | Korea Institute Of Materials Science | Method for manufacturing anisotropic rare earth bulk magnet, and anisotropic rare earth bulk magnet manufactured thereby |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6136099A (en) * | 1985-08-13 | 2000-10-24 | Seiko Epson Corporation | Rare earth-iron series permanent magnets and method of preparation |
JPS63119204A (en) * | 1986-11-07 | 1988-05-23 | Tdk Corp | High-performance rare earth magnet |
JP3033127B2 (en) * | 1990-05-16 | 2000-04-17 | 大同特殊鋼株式会社 | Rare earth magnet alloy with good hot workability |
US10468165B2 (en) * | 2013-06-05 | 2019-11-05 | Toyota Jidosha Kabushiki Kaisha | Rare-earth magnet and method for manufacturing same |
JP6791614B2 (en) * | 2014-12-04 | 2020-11-25 | トヨタ自動車株式会社 | motor |
CN104882266A (en) * | 2015-06-16 | 2015-09-02 | 北京科技大学 | Method for preparing high-coercivity Nd-Fe-B magnet from light rare earth-Cu alloy through grain boundary permeation |
-
2018
- 2018-12-12 KR KR1020180160146A patent/KR102156629B1/en active IP Right Grant
- 2018-12-24 EP EP18215888.1A patent/EP3522178B1/en active Active
- 2018-12-27 BR BR102018077206-6A patent/BR102018077206A2/en not_active Application Discontinuation
- 2018-12-28 CN CN201811619581.1A patent/CN109979699B/en active Active
Also Published As
Publication number | Publication date |
---|---|
CN109979699A (en) | 2019-07-05 |
CN109979699B (en) | 2021-10-22 |
EP3522178A1 (en) | 2019-08-07 |
KR102156629B1 (en) | 2020-09-16 |
BR102018077206A2 (en) | 2019-07-16 |
KR20190080748A (en) | 2019-07-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3522178B1 (en) | Rare earth magnet and production method thereof | |
JP4702546B2 (en) | Rare earth permanent magnet | |
JP6089535B2 (en) | R-T-B sintered magnet | |
EP2388350B1 (en) | Method for producing r-t-b sintered magnet | |
RU2697265C2 (en) | SINTERED R-Fe-B MAGNET AND METHOD FOR PRODUCTION THEREOF | |
JP6119548B2 (en) | Manufacturing method of rare earth sintered magnet | |
RU2389098C2 (en) | Functional-gradient rare-earth permanent magnet | |
TWI421886B (en) | Manufacture method of rare earth metal permanent magnet material | |
JP5472236B2 (en) | Rare earth magnet manufacturing method and rare earth magnet | |
WO2013191276A1 (en) | Sintered magnet | |
EP2779179B1 (en) | R-T-B-based rare earth magnet particles, process for producing the R-T-B-based rare earth magnet particles, and bonded magnet | |
JP5692231B2 (en) | Rare earth magnet manufacturing method and rare earth magnet | |
KR102631761B1 (en) | Neodymium iron boron magnetic material, raw material composition, manufacturing method and application | |
US20180182515A1 (en) | Rare earth magnet and production method thereof | |
JP7247548B2 (en) | Rare earth magnet and manufacturing method thereof | |
EP3355320B1 (en) | Rare earth magnet and method of producing the same | |
JP7167709B2 (en) | Rare earth magnet and manufacturing method thereof | |
CN105448444B (en) | A kind of method and rare earth permanent-magnetic material of the rare earth permanent-magnetic material that processability improves | |
JP4700578B2 (en) | Method for producing high resistance rare earth permanent magnet | |
EP2623235B1 (en) | Alloy material for r-t-b system rare earth permanent magnet, method for producing r-t-b system rare earth permanent magnet | |
JP7167665B2 (en) | Rare earth magnet and manufacturing method thereof | |
JP2007266199A (en) | Manufacturing method of rare earth sintered magnet | |
EP3792939A1 (en) | Rare earth magnet and production method thereof | |
JP2019179796A (en) | Rare earth magnet and manufacturing method thereof | |
EP3989244A1 (en) | Rare earth magnet and method for producing thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20181224 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20211125 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 1471077 Country of ref document: AT Kind code of ref document: T Effective date: 20220315 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602018031175 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG9D |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20220223 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 1471077 Country of ref document: AT Kind code of ref document: T Effective date: 20220223 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220623 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220523 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220523 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220524 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220623 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602018031175 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20221124 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
P01 | Opt-out of the competence of the unified patent court (upc) registered |
Effective date: 20230427 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R084 Ref document number: 602018031175 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20221231 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20221224 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: 746 Effective date: 20230926 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20221231 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20221224 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20221231 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20221231 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20231102 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20231108 Year of fee payment: 6 Ref country code: DE Payment date: 20231031 Year of fee payment: 6 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20181224 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20220223 |