EP0601943B1 - R-Fe-B type magnet powder, sintered magnets therefrom and preparation process - Google Patents
R-Fe-B type magnet powder, sintered magnets therefrom and preparation process Download PDFInfo
- Publication number
- EP0601943B1 EP0601943B1 EP93420483A EP93420483A EP0601943B1 EP 0601943 B1 EP0601943 B1 EP 0601943B1 EP 93420483 A EP93420483 A EP 93420483A EP 93420483 A EP93420483 A EP 93420483A EP 0601943 B1 EP0601943 B1 EP 0601943B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- powder
- mpa
- weight
- content
- hydrogen
- 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.)
- Expired - Lifetime
Links
- 239000000843 powder Substances 0.000 title claims abstract description 124
- 238000002360 preparation method Methods 0.000 title description 2
- 239000000203 mixture Substances 0.000 claims abstract description 102
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 73
- 229910052796 boron Inorganic materials 0.000 claims abstract description 28
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 21
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000006247 magnetic powder Substances 0.000 claims abstract description 18
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 18
- 229910052802 copper Inorganic materials 0.000 claims abstract description 17
- 239000012535 impurity Substances 0.000 claims abstract description 15
- 229910052742 iron Inorganic materials 0.000 claims abstract description 12
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 11
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 10
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 10
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 10
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 9
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 7
- 229910052779 Neodymium Inorganic materials 0.000 claims abstract description 7
- 229910052777 Praseodymium Inorganic materials 0.000 claims abstract description 7
- 229910052772 Samarium Inorganic materials 0.000 claims abstract description 7
- 229910052735 hafnium Inorganic materials 0.000 claims abstract description 7
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 7
- 229910052715 tantalum Inorganic materials 0.000 claims abstract description 7
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 7
- 230000007704 transition Effects 0.000 claims abstract description 7
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 7
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 7
- 238000004519 manufacturing process Methods 0.000 claims abstract description 6
- 229910052693 Europium Inorganic materials 0.000 claims abstract description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 36
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 31
- 239000001257 hydrogen Substances 0.000 claims description 31
- 229910052739 hydrogen Inorganic materials 0.000 claims description 31
- 229910045601 alloy Inorganic materials 0.000 claims description 28
- 239000000956 alloy Substances 0.000 claims description 28
- 229910052786 argon Inorganic materials 0.000 claims description 18
- 239000011261 inert gas Substances 0.000 claims description 18
- 230000005291 magnetic effect Effects 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 18
- 238000011282 treatment Methods 0.000 claims description 17
- 239000007789 gas Substances 0.000 claims description 16
- 230000036961 partial effect Effects 0.000 claims description 13
- 238000001816 cooling Methods 0.000 claims description 11
- 239000000654 additive Substances 0.000 claims description 9
- 230000000996 additive effect Effects 0.000 claims description 9
- 239000001307 helium Substances 0.000 claims description 6
- 229910052734 helium Inorganic materials 0.000 claims description 6
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 3
- 229910052748 manganese Inorganic materials 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 239000001301 oxygen Substances 0.000 claims description 3
- 229910052760 oxygen Inorganic materials 0.000 claims description 3
- 238000001033 granulometry Methods 0.000 claims 5
- 238000003801 milling Methods 0.000 claims 2
- 239000002245 particle Substances 0.000 abstract description 20
- 238000002156 mixing Methods 0.000 abstract description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 22
- 230000006835 compression Effects 0.000 description 20
- 238000007906 compression Methods 0.000 description 20
- 239000010949 copper Substances 0.000 description 18
- 229910017052 cobalt Inorganic materials 0.000 description 13
- 239000010941 cobalt Substances 0.000 description 13
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 13
- 238000000280 densification Methods 0.000 description 12
- 238000005260 corrosion Methods 0.000 description 11
- 230000007797 corrosion Effects 0.000 description 11
- 230000004927 fusion Effects 0.000 description 9
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 8
- 229910052757 nitrogen Inorganic materials 0.000 description 8
- 238000002844 melting Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 7
- 238000011049 filling Methods 0.000 description 6
- 238000000227 grinding Methods 0.000 description 6
- 238000005245 sintering Methods 0.000 description 6
- 238000012423 maintenance Methods 0.000 description 5
- 101100166838 Caenorhabditis elegans ces-2 gene Proteins 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 239000004411 aluminium Substances 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229910000765 intermetallic Inorganic materials 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000003754 machining Methods 0.000 description 3
- 229910020598 Co Fe Inorganic materials 0.000 description 2
- 229910017061 Fe Co Inorganic materials 0.000 description 2
- 241000861223 Issus Species 0.000 description 2
- 240000008042 Zea mays Species 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 230000005496 eutectics Effects 0.000 description 2
- 239000007970 homogeneous dispersion Substances 0.000 description 2
- 238000004845 hydriding Methods 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000002688 persistence Effects 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000010408 sweeping Methods 0.000 description 2
- 101100353517 Caenorhabditis elegans pas-2 gene Proteins 0.000 description 1
- 101100084503 Caenorhabditis elegans pas-3 gene Proteins 0.000 description 1
- 241001080024 Telles Species 0.000 description 1
- 230000003416 augmentation Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 150000004678 hydrides Chemical class 0.000 description 1
- 230000001976 improved effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 238000010010 raising Methods 0.000 description 1
- 238000007712 rapid solidification Methods 0.000 description 1
- -1 rare earth hydride Chemical class 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000004621 scanning probe microscopy Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 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
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/0433—Nickel- or cobalt-based alloys
- C22C1/0441—Alloys based on intermetallic compounds of the type rare earth - Co, Ni
-
- 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
-
- 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
- H01F1/0573—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 obtained by reduction or by hydrogen decrepitation or embrittlement
-
- 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
Definitions
- the invention relates to a magnetic powder and permanent magnets. sintered containing essentially at least one rare earth TR, at least one transition element T and boron, the magnetic powder being obtained by the mixture of at least 2 initial powders of chemical composition and different particle sizes and their method of preparation.
- the problem is therefore to find a manufacturing method simpler and less expensive according to the conventional route of powder metallurgy to obtain sintered magnets having better magnetic characteristics, especially good afterglow and good resistance to atmospheric corrosion.
- the magnets can then undergo all the usual operations machining and surface coatings if necessary.
- phase T1 More precisely, they have a structure made up of grains of phase T1, representing more than 94% of the structure, and of size substantially uniform between 2 and 20 ⁇ m. These are surrounded a thin and continuous secondary phase border rich in TR, thick substantially uniform, not locally having a width ⁇ 5 ⁇ m. This secondary phase contains more than 10% cobalt.
- the Applicant has noticed that the coercivity, the afterglow and specific energy, although satisfactory, could be further improved by obtaining the powder (B) by a mixture of two powders (C) and (D), without affecting the other properties of use of the sintered magnets, in particular resistance to oxidation and atmospheric corrosion and machining to tolerances by grinding.
- a suitable choice of powder (D) allowed to significantly reduce the temperature and the duration of the sintering.
- the magnets can then undergo all the usual operations machining and surface coatings if necessary.
- the powders (A) and (B) thus obtained were mixed in the weight proportions indicated in Table IV, then they have been then compressed under field (// or ⁇ ), sintered and processed in conditions given in Table V, which also shows the density and the magnetic characteristics obtained on the magnets.
- Figs. 1 and 2 schematically represent 2 micrographic sections performed in scanning microscopy equipped with an analytical probe and were carried out on two magnets of the same composition corresponding to the examples Ml and Sl: Ml being used according to the invention and Sl being produced according to the prior art by a mono-alloy technique.
- the powders (A) and (B) thus obtained were mixed in the weight proportions indicated in Table XI, then they have been then compressed under field ( ⁇ ), sintered and processed in conditions shown in Table XII, where also the magnetic characteristics obtained on the magnets.
- examples M5 -M6 M9 - M10 - M13 - M14 - M21 - M22 - M25 - M26 - M29 - M30 are from powder (A) with a high boron content (1.06%) and their persistence is less than 1.32 T.
- Examples M31 and M32 correspond to cases where although originating from powder (B) containing powder (D) and powder (A) with low content boron (0.98% by weight), the magnets have a slight remanence less than 1.32 T, because the powder (B) has a B content> 1.5%.
- the magnets according to the invention have the same structural characteristics as those of application FR 92-14995: absence of phase Nd 1 + ⁇ Fe 4 B 4 , homogeneous structure of grains in size and in slightly angular shape, secondary phase uniformly distributed in fine edges and where cobalt is preferentially localized.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Power Engineering (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Hard Magnetic Materials (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
L'invention concerne une poudre magnétique et des aimants permanents frittés contenant essentiellement au moins une terre rare TR, au moins un élément de transition T et du bore, la poudre magnétique étant obtenue par le mélange d'au moins 2 poudres initiales de composition chimique et de granulométrie différentes et leur méthode de préparation.The invention relates to a magnetic powder and permanent magnets. sintered containing essentially at least one rare earth TR, at least one transition element T and boron, the magnetic powder being obtained by the mixture of at least 2 initial powders of chemical composition and different particle sizes and their method of preparation.
On connaít les demandes de brevets suivantes qui enseignent l'utilisation d'un mélange de 2 alliages initiaux pour la fabrication d'aimants frittés.
- La demande JP 63-114939 décrit des aimants du type ci-dessus obtenus à partir d'un mélange de 2 poudres, l'une apportant des grains magnétiques de type TR2 T14B, et l'autre, qui constituera la "matrice" contenant soit des éléments à bas point de fusion, soit des éléments à haut point de fusion. Il est également indiqué que cette deuxième poudre doit être rendue extrêmement fine (de 0,02 à 1 µm) ce qui est économiquement pénalisant.
- La demande JP-2-31402 rapporte l'utilisation d'une deuxième poudre constituée de TR-Fe-B ou TR-Fe à l'état amorphe ou microcristallin, c'est-à-dire obtenue par solidification rapide, ce qui exige des équipements spécifiques peu courants.
- La demande EP 0447567 décrit un aimant résistant à la corrosion ayant une texture comprenant une phase principale TR2 T14B (T étant Fe Co et/ou Ni) et une phase secondaire à base de composés intermétalliques des séries TR-T, d'eutectiques TR-T ou d'intermétalliques TR-T-B (T étant Ni ou un mélange de Ni avec Fe ou Co), obtenu par frittage d'un mélange de poudre de TR2 T14B et de poudre à bas point de fusion constitué de composés intermétalliques des séries TR-T, d'eutectiques TR-T ou d'intermétalliques TR-T-B.
- Application JP 63-114939 describes magnets of the above type obtained from a mixture of 2 powders, one providing magnetic grains of type TR 2 T 14 B, and the other, which will constitute the "matrix "containing either elements with a low melting point or elements with a high melting point. It is also indicated that this second powder must be made extremely fine (from 0.02 to 1 μm) which is economically disadvantageous.
- Application JP-2-31402 reports the use of a second powder consisting of TR-Fe-B or TR-Fe in the amorphous or microcrystalline state, that is to say obtained by rapid solidification, which requires unusual equipment.
- EP 0447567 describes a corrosion resistant magnet having a texture comprising a main phase TR 2 T 14 B (T being Fe Co and / or Ni) and a secondary phase based on intermetallic compounds of the TR-T series, TR-T eutectics or TR-TB intermetallics (T being Ni or a mixture of Ni with Fe or Co), obtained by sintering a mixture of powder TR 2 T 14 B and powder with low melting point consisting TR-T series intermetallic compounds, TR-T eutectics or TR-TB intermetallics.
Le problème qui se pose est donc de trouver une méthode de fabrication plus simple et moins onéreuse selon la voie conventionnelle de la métallurgie des poudres en vue d'obtenir des aimants frittés ayant de meilleures caractéristiques magnétiques, en particulier une bonne rémanence et une bonne résistance à la corrosion atmosphérique. The problem is therefore to find a manufacturing method simpler and less expensive according to the conventional route of powder metallurgy to obtain sintered magnets having better magnetic characteristics, especially good afterglow and good resistance to atmospheric corrosion.
Sauf indications contraires, les teneurs données ci-après sont les teneurs pondérales.Unless otherwise indicated, the contents given below are the contents by weight.
Selon l'invention, la poudre initiale est constituée par un mélange de 2
poudres de nature et de granulométrie différentes, et est caractérisée en
ce que :
Sa teneur totale en TR est comprise entre 26,7 et 30% et de préférence entre 28 et 29%; la teneur en Co est de préférence limitée à 5% maximum, et même 2%. La teneur en Al est de préférence comprise entre 0,2 et 0,5%, ou mieux entre 0,25 et 0,35%; la teneur en Cu est tenue de préférence entre 0,02 et 0,05%, et plus particulièrement entre 0,025 et 0,035%. La teneur en B est comprise entre 0,96 et 1,1%, et de
La poudre (A) est ensuite broyée finement à l'aide d'un broyeur à jet de gaz, de préférence de l'azote, amené à une pression (absolue) comprise entre 0,4 et 0,8 MPa en ajustant les paramètres de sélection granulométrique de façon à obtenir une poudre dont la granulométrie Fisher est comprise entre 3,5 et 5 µm.
TR 52-70%; comprenant au moins 40% (en valeur absolue) d'une (ou plusieurs) terre(s) rare(s) légère(s) choisie(s) dans le groupe constitué par les éléments : La, Ce, Pr, Nd, Sm, Eu; une teneur en H2 (en ppm en poids) supérieure à 130x%TR; Co 20-35%; Fe 0-20%; B 0-0,2%; Al 0,1-4%; et des impuretés inévitables, de granulométrie Fisher comprise entre 2,5 et 3,5 µm.
Il est préférable que la poudre (B) ait une granulométrie Fisher inférieure d'au moins 20% à celle de la poudre (A). Cette poudre (B) donnant essentiellement naissance à une phase secondaire, il est souhaitable que la température de fusion complète (liquidus) de l'alliage (B) soit inférieure à 1080°C.
Its total TR content is between 26.7 and 30% and preferably between 28 and 29%; the Co content is preferably limited to 5% maximum, and even 2%. The Al content is preferably between 0.2 and 0.5%, or better still between 0.25 and 0.35%; the Cu content is preferably kept between 0.02 and 0.05%, and more particularly between 0.025 and 0.035%. The B content is between 0.96 and 1.1%, and preferably 1.0-1.06%. The rest consists of Fe. The powder (A) can be obtained from an alloy produced by fusion (ingots) or by co-reduction (coarse powder), the ingots or coarse powders being preferably subjected to a treatment under H 2 under the following conditions: evacuation or sweeping of the enclosure, application of an inert gas pressure of between 0.1 and 0.12 MPa, temperature rise at a speed between 10 ° C / h and 500 ° C / h until a temperature between 350 and 450 ° C is reached, application of an absolute partial pressure of hydrogen between 0.01 and 0.12 MPa and maintenance of these conditions from 1 to 4 hours, evacuating and applying an inert gas pressure of 0.1 to 0.12 MPa, cooling to room temperature at a speed between 5 ° C / h and 100 ° C / h . The inert gas used is preferably argon or helium or a mixture of these 2 gases.
The powder (A) is then finely ground using a gas jet mill, preferably nitrogen, brought to a pressure (absolute) of between 0.4 and 0.8 MPa by adjusting the parameters of particle size selection so as to obtain a powder whose Fisher particle size is between 3.5 and 5 μm.
TR 52-70%; comprising at least 40% (in absolute value) of one (or more) light rare earth (s) chosen from the group made up of the elements: La, Ce, Pr, Nd, Sm , Eu; an H 2 content (in ppm by weight) greater than 130x% TR; Co 20-35%; Fe 0-20%; B 0-0.2%; Al 0.1-4%; and unavoidable impurities, with a Fisher particle size between 2.5 and 3.5 μm.
It is preferable that the powder (B) has a Fisher particle size at least 20% less than that of the powder (A). This powder (B) essentially giving rise to a secondary phase, it is desirable that the complete melting temperature (liquidus) of the alloy (B) be less than 1080 ° C.
Les aimants peuvent ensuite subir toutes les opérations habituelles d'usinage et de revêtements de surface si nécessaire.The magnets can then undergo all the usual operations machining and surface coatings if necessary.
Les aimants selon l'invention qui appartiennent à la famille TR-T-B où TR
désigne au moins une terre-rare, T au moins un élément de transition tel
que Fe et/ou Co, B, le bore, pouvant contenir éventuellement d'autres
éléments mineurs, sont essentiellement constitués de grains de phase
quadratique TR2 Fe14 B dite "Tl", d'une phase secondaire contenant
essentiellement des terres-rares, et d'autres phases mineures
éventuelles. Ces aimants possèdent les caractéristiques suivantes :
De façon plus précise, ils possèdent une structure constituée de grains de phase T1, représentant plus de 94% de la structure, et de taille sensiblement uniforme comprise entre 2 et 20 µm. Ceux-ci sont entourés d'un liseré fin et continu de phase secondaire riche en TR, d'épaisseur sensiblement uniforme, ne présentant pas, localement, une largeur ≥ 5 µm. Cette phase secondaire contient plus de 10% de cobalt.More precisely, they have a structure made up of grains of phase T1, representing more than 94% of the structure, and of size substantially uniform between 2 and 20 µm. These are surrounded a thin and continuous secondary phase border rich in TR, thick substantially uniform, not locally having a width ≥ 5 µm. This secondary phase contains more than 10% cobalt.
Cependant, la demanderesse s'est aperçue que la coercitivité, la rémanence et l'énergie spécifique, bien que satisfaisantes, pouvaient encore être améliorées en obtenant la poudre (B) par un mélange de deux poudres (C) et (D), sans affecter les autres propriétés d'emploi des aimants frittés, en particulier la résistance à l'oxydation et à la corrosion atmosphérique et l'usinage aux tolérances par rectification. De plus, la demanderesse s'est aperçue qu'un choix adapté de la poudre (D) permettait de réduire sensiblement la température et la durée du frittage.However, the Applicant has noticed that the coercivity, the afterglow and specific energy, although satisfactory, could be further improved by obtaining the powder (B) by a mixture of two powders (C) and (D), without affecting the other properties of use of the sintered magnets, in particular resistance to oxidation and atmospheric corrosion and machining to tolerances by grinding. Of more, the applicant has noticed that a suitable choice of powder (D) allowed to significantly reduce the temperature and the duration of the sintering.
Selon l'invention, la poudre additive (B) est obtenue par le mélange de
deux poudres grossières (C) et (D) d'alliages de nature différente et
broyées simultanément. Par poudre grossière on entend une poudre dont les
particules passent au tamis de 1 mm.
La poudre (A) est ensuite broyée finement à l'aide d'un broyeur à jet de gaz, de préférence de l'azote, amené à une pression (absolue) comprise
The powder (A) is then finely ground using a gas jet mill, preferably nitrogen, brought to a pressure (absolute) of between 0.4 and 0.8 MPa by adjusting the parameters of particle size selection so as to obtain a powder whose Fisher particle size is between 3.5 and 5 μm.
Les aimants peuvent ensuite subir toutes les opérations habituelles d'usinage et de revêtements de surface si nécessaire.The magnets can then undergo all the usual operations machining and surface coatings if necessary.
Les aimants selon l'invention qui appartiennent à la famille TR-T-B résultant de l'emploi des poudres (A) et (B), où TR
désigne au moins une terre rare, T au moins un élément de transition tel
que Fe et/ou Co, B, le bore, pouvant contenir éventuellement d'autres
éléments mineurs, sont essentiellement constitués de grains de phase
quadratique TR2Fe14B dite "Tl", d'une phase secondaire contenant
essentiellement des terres rares, et d'autres phases mineures
éventuelles. Ces aimants possèdent les caractéristiques très élevées
suivantes :
De façon plus précise, ils possèdent une structure constituée de grains de phase Tl, représentant plus de 94 % de la structure, et de taille sensiblement uniforme comprise entre 2 et 20 µm. Ceux-ci sont entourés d'un liseré fin et continu de phase secondaire riche en TR, d'épaisseur sensiblement uniforme, ne présentant pas, localement, une largeur ≥ 5 µm. Cette phase secondaire contient plus de 10 % de cobalt.More precisely, they have a structure made up of grains of phase Tl, representing more than 94% of the structure, and of size substantially uniform between 2 and 20 µm. These are surrounded a thin and continuous secondary phase border rich in TR, thick substantially uniform, not locally having a width ≥ 5 µm. This secondary phase contains more than 10% cobalt.
L'invention sera mieux comprise à l'aide des exemples suivants illustrés par les fig. 1 et 2.
- La figure 1 représente schématiquement une coupe micrographique d'un aimant fritté selon l'invention (Ml)
- La figure 2 représente schématiquement une coupe micrographique d'un aimant fritté de même composition obtenu selon la technique du mono-alliage (Sl).
- FIG. 1 schematically represents a micrographic section of a sintered magnet according to the invention (Ml)
- FIG. 2 schematically represents a micrographic section of a sintered magnet of the same composition obtained according to the mono-alloy technique (S1).
-
Les 8 alliages (A) dont la composition est reportée au Tableau I ont
été préparés de la façon suivante :
- coulée des lingots sous vide
- traitement à l'hydrogène dans les conditions suivantes :
- mise sous vide
- introduction d'Argon sous une pression absolue de 0,1 MPa
- chauffage à 50°C/h jusqu'à 400°C
- mise sous vide
- remplissage par un mélange Argon + hydrogène sous les pressions partielles absolues de 0,06 MPa (H2) et 0,07 MPa (Ar) et maintien durant 2 h
- mise sous vide
- remplissage d'Argon sous 0,1 MPa et refroidissement à la température ambiante à 10°C/h
- broyage avec broyeur à jet de gaz sous azote jusqu'aux granulométries Fisher indiquées au tableau III.
- casting ingots under vacuum
- hydrogen treatment under the following conditions:
- vacuum
- introduction of Argon under an absolute pressure of 0.1 MPa
- heating at 50 ° C / h up to 400 ° C
- vacuum
- filling with an Argon + hydrogen mixture under absolute partial pressures of 0.06 MPa (H 2 ) and 0.07 MPa (Ar) and holding for 2 h
- vacuum
- Argon filling at 0.1 MPa and cooling to room temperature at 10 ° C / h
- grinding with a gas jet mill under nitrogen up to the Fisher particle sizes indicated in Table III.
-
Les 10 alliages (B), dont la composition est reportée au tableau II,
ont été préparés de la façon suivante :
- fusion sous vide de lingots
- traitement à l'hydrogène
- mise sous vide
- application d'un mélange Ar+H2, sous les pressions partielles absolues de 0,06 MPa (H2) et 0,07 MPa (A) à la température ambiante pendant 2h
- chauffage à 400°C à raison de 50°C/h dans la même atmosphère et maintien pendant 2 h
- mise sous vide
- remplissage d'argon sous 0,1 MPa absolu et refroidissement à la température ambiante à 10°C/h
- broyage au broyeur à jet de gaz sous azote jusqu'aux granulométries Fisher indiquées au Tableau III.
- vacuum melting of ingots
- hydrogen treatment
- vacuum
- application of an Ar + H 2 mixture, under absolute partial pressures of 0.06 MPa (H 2 ) and 0.07 MPa (A) at room temperature for 2 h
- heating to 400 ° C at a rate of 50 ° C / h in the same atmosphere and holding for 2 h
- vacuum
- Argon filling at 0.1 MPa absolute and cooling to room temperature at 10 ° C / h
- grinding with a gas jet mill under nitrogen up to the Fisher particle sizes indicated in Table III.
Les poudres (A) et (B) ainsi obtenues ont été mélangées dans les proportions pondérales indiquées au Tableau IV, puis elles ont été ensuite comprimées sous champ (// ou ⊥), frittées et traitées dans les conditions reportées au Tableau V, où figurent également la densité et les caractéristiques magnétiques obtenues sur les aimants.The powders (A) and (B) thus obtained were mixed in the weight proportions indicated in Table IV, then they have been then compressed under field (// or ⊥), sintered and processed in conditions given in Table V, which also shows the density and the magnetic characteristics obtained on the magnets.
Les aimants M1, M2, M3, M4, M5, M9 et M13 correspondent à l'invention; les autres exemples sortent du domaine de l'invention pour les raisons suivantes :
- M6 -
- la poudre (B) contient 1% de B, valeur supérieure à la limite autorisée et la densification est très insuffisante.
- M7 -
- la proportion de la poudre (B) dans le mélange (A)+(B) est trop faible et conduit à une mauvaise dispersion de cette poudre (B) et à une mauvaise densification.
- M8 -
- la coercitivité inférieure à 1050 kA/m due à l'utilisation d'un alliage (B) à trop faible teneur en TR.
- M10-
- la présence de V dans l'alliage (B) - 9% en poids - ne permet pas de conduire à de bonnes propriétés.
- M11-
- la présence simultanée de B et de V dans la poudre (B) fait perdre sur toutes les propriétés de l'aimant.
- S1,S2,S3-
- ces compositions sont obtenues à l'aide de la méthode mono-alliage ne permettant pas d'obtenir une densification suffisante ce qui se traduit par de faibles propriétés magnétiques.
- M12-
- la composition est identique à celle de la composition M1, mais obtenue avec une poudre (Al) mélangée à une poudre (B9) qui n'a pas reçu de traitement à l'hydrogène mais un concassage mécanique sous atmosphère inerte avant introduction dans le broyeur à jet de gaz.
- M6 -
- the powder (B) contains 1% B, value greater than the authorized limit and the densification is very insufficient.
- M7 -
- the proportion of the powder (B) in the mixture (A) + (B) is too low and leads to poor dispersion of this powder (B) and to poor densification.
- M8 -
- the coercivity below 1050 kA / m due to the use of an alloy (B) with too low a TR content.
- M10-
- the presence of V in the alloy (B) - 9% by weight - does not lead to good properties.
- M11-
- the simultaneous presence of B and V in the powder (B) causes all the properties of the magnet to be lost.
- S1, S2, S3-
- these compositions are obtained using the mono-alloy method which does not allow sufficient densification to be obtained, which results in weak magnetic properties.
- M12-
- the composition is identical to that of composition M1, but obtained with a powder (Al) mixed with a powder (B9) which has not received a hydrogen treatment but a mechanical crushing under an inert atmosphere before introduction into the mill gas jet.
Les fig. 1 et 2 représentent schématiquement 2 coupes micrographiques effectuées en microscopie à balayage équipée d'une sonde analytique et ont été réalisées sur deux aimants de même composition correspondant aux exemples Ml et Sl : Ml étant mis en oeuvre selon l'invention et Sl étant réalisé selon l'art antérieur par une technique mono-alliage.Figs. 1 and 2 schematically represent 2 micrographic sections performed in scanning microscopy equipped with an analytical probe and were carried out on two magnets of the same composition corresponding to the examples Ml and Sl: Ml being used according to the invention and Sl being produced according to the prior art by a mono-alloy technique.
Les différences sont les suivantes :
- L'aimant Ml possède une structure homogène de grains fins de phase magnétique TR2 Fe14 B -l- dont la taille moyenne est de 9 µm et 95% des grains ayant une taille inférieure à 14 µm et dont la géométrie est peu anguleuse.
- La phase secondaire, qui est riche en TR -2-, est uniformément répartie en fins liserés autour des grains de phase magnétique TR2 Fe14 B, sans présence de poches dont la taille excède 4 µm.
- On ne note pas la présence de phase TR1+ε Fe4 B4, la porosité intergranulaire -3- est très faible et le diamètre d'une telle porosité n'excède pas 2 µm. La présence de phase oxyde intergranulaire -4- est faible, la taille de ces oxydes n'excède pas 3 µm.
- Une analyse quantitative en cobalt de grains de phase Tl (TR2 Fe14 B) et de la phase secondaire montre que le cobalt est principalement localisé dans la phase secondaire intergranulaire avec une teneur moyenne supérieure à 10% en poids et que la phase magnétique TR2 Fe14 B -1- n'en contient qu'une très faible teneur.
- L'aimant Sl se caractérise par une microstructure constituée de grains de phase magnétique TR2 Fe14 B -1- dont la taille moyenne est de 12 µm avec une population importante de grains dont la taille est de 20 µm, certains pouvant atteindre 30 µm. De plus, les grains ont une forme générale anguleuse. Il est à noter la présence de phase TR Fe4 B4 -5- et de nombreuses et larges porosités -3- pouvant atteindre un diamètre > 5 µm.
- Des amas d'oxydes -4- sont d'autre part détectés principalement dans les joints triples pouvant atteindre une taille > 5 µm.
- La teneur en Co de la phase secondaire riche en TR est très faible et correspond à la teneur moyenne dans l'alliage, tout comme dans la phase magnétique TR2 Fe14 B.
- The magnet M1 has a homogeneous structure of fine grains of magnetic phase TR 2 Fe 14 B -l- whose average size is 9 μm and 95% of the grains having a size less than 14 μm and whose geometry is not very angular.
- The secondary phase, which is rich in TR -2-, is uniformly distributed in fine edgings around the grains of magnetic phase TR 2 Fe 14 B, without the presence of pockets whose size exceeds 4 µm.
- The presence of phase TR 1 + ε Fe 4 B 4 is not noted, the intergranular porosity -3- is very small and the diameter of such porosity does not exceed 2 μm. The presence of intergranular oxide phase -4- is low, the size of these oxides does not exceed 3 μm.
- A quantitative analysis of cobalt from grains of phase Tl (TR 2 Fe 14 B) and of the secondary phase shows that the cobalt is mainly located in the intergranular secondary phase with an average content greater than 10% by weight and that the magnetic phase TR 2 Fe 14 B -1- contains only a very low content.
- The magnet Sl is characterized by a microstructure consisting of grains of magnetic phase TR 2 Fe 14 B -1- whose average size is 12 µm with a large population of grains whose size is 20 µm, some of which can reach 30 µm . In addition, the grains have a generally angular shape. Note the presence of TR Fe 4 B 4 -5- phase and many large porosities -3- which can reach a diameter> 5 µm.
- On the other hand, clusters of oxides -4- are mainly detected in triple joints which can reach a size> 5 µm.
- The Co content of the secondary phase rich in TR is very low and corresponds to the average content in the alloy, as in the magnetic phase TR 2 Fe 14 B.
Le procédé de mélange de deux poudres (A) et (B) correspondant à la méthode revendiquée possède par rapport aux procédés de l'art antérieur, les avantages suivants :
- la méthode d'obtention de poudres (B) contenant essentiellement du Co et des TR conduit, grâce au traitement à l'hydrogène, à l'obtention d'une dispersion fine et homogène de ses constituants. Il en résulte une meilleure densification, même pour les teneurs totales en TR inférieures à celles de l'art antérieur, et des propriétés magnétiques élevées (Br,HcJ) ainsi qu'une meilleure résistance à la corrosion;
- la composition de la poudre (B) permet de donner à la phase secondaire riche en TR des propriétés particulières telles que la résistance à la corrosion atmosphérique, apportée par le Co, ou une meilleure frittabilité apportée par le Cu et l'Al.
- the method for obtaining powders (B) containing essentially Co and TR leads, thanks to the hydrogen treatment, to obtain a fine and homogeneous dispersion of its constituents. This results in better densification, even for total TR contents lower than those of the prior art, and high magnetic properties (Br, HcJ) as well as better corrosion resistance;
- the composition of the powder (B) makes it possible to give the secondary phase rich in TR particular properties such as resistance to atmospheric corrosion, brought by Co, or better sinterability brought by Cu and Al.
Ainsi, par exemple, des aimants frittés préparés selon l'invention (TR=30,5% en poids) et selon l'art antérieur obtenus à la même densité par une technique de métallurgie des poudres mono-alliage (TR=32% en poids) maintenus en autoclave sous une pression relative de 1,5 bar (0,15 MPa) pendant 120h à 100°C sous atmosphère humide (100% d'humidité relative) accusent les pertes de poids suivantes :
invention 2 à 7,10-3 g/cm2art antérieur 3 à 7,10-2 g/cm2
-
invention 2 at 7.10 -3 g / cm 2 -
prior art 3 to 7.10 -2 g / cm 2
Pour des aimants dont la composition de la base et les éléments d'addition sont comparables, on voit que le gain sur la tenue à la corrosion est significativement différent un facteur de 10 à l'avantage des aimants obtenus selon l'invention.
- la microstructure de l'aimant fritté est plus homogène en ce qui concerne la taille des grains de Tl et la bonne répartition d'une quantité plus faible de phase riche en TR confère une augmentation importante de la coercivité.
- the microstructure of the sintered magnet is more homogeneous as regards the size of the grains of Tl and the good distribution of a smaller quantity of phase rich in TR confers a significant increase in coercivity.
Dans l'intervalle de proportion de mélange des poudres (A) et (B) défini, les variations de la teneur en bore et des TR correspondent pratiquement à l'optimum du rapport TR/B évitant la formation importante de la phase TR1+εFe4 B4 et confirment ainsi une grande souplesse de la méthode pour ajuster la composition de la poudre et maximaliser les propriétés magnétiques.Within the defined proportion of the mixture of powders (A) and (B), the variations in the boron content and the TR correspond practically to the optimum of the TR / B ratio avoiding the significant formation of the TR 1+ phase. ε Fe 4 B 4 and thus confirm a great flexibility of the method for adjusting the composition of the powder and maximizing the magnetic properties.
-
Les 2 alliages (A) dont la composition est reportée au Tableau VI ont
été préparés de la façon suivante :
- coulée des lingots sous vide
- traitement à l'hydrogène dans les conditions suivantes :
- mise sous vide
- introduction d'Argon sous une pression absolue de 0,1 MPa
- chauffage à 50°C/h jusqu'à 400°C
- remplissage par un mélange Argon + hydrogène sous les pressions partielles absolues de 0,06 MPa (H2) et 0,07 MPa (Ar) et maintien durant 2 h
- mise sous vide
- remplissage d'Argon sous 0,1 MPa et refroidissement à la température ambiante à 10°C/h
- broyage avec broyeur à jet de gaz sous azote jusqu'aux granulométries Fisher indiquées au Tableau X.
- casting ingots under vacuum
- hydrogen treatment under the following conditions:
- vacuum
- introduction of Argon under an absolute pressure of 0.1 MPa
- heating at 50 ° C / h up to 400 ° C
- filling with an Argon + hydrogen mixture under absolute partial pressures of 0.06 MPa (H 2 ) and 0.07 MPa (Ar) and holding for 2 h
- vacuum
- Argon filling at 0.1 MPa and cooling to room temperature at 10 ° C / h
- grinding with a gas jet mill under nitrogen up to the Fisher particle sizes indicated in Table X.
-
Les 2 alliages (C), dont la composition est reportée au Tableau VII,
ont été préparés de la façon suivante :
- fusion sous vide de lingots
- traitement à l'hydrogène
- mise sous vide
- application d'un mélange Ar+H2, sous les pressions partielles absolues de 0,06 MPa (H2) et 0,07 MPa (A) à la température ambiante pendant 2 H
- chauffage à 400°C à raison de 50°C/h dans la même atmosphère et maintien pendant 2 h
- mise sous vide
- remplissage d'argon sous 0,1 MPa absolu et refroidissement à la température ambiante à 10°C/h
- vacuum melting of ingots
- hydrogen treatment
- vacuum
- application of an Ar + H 2 mixture, under absolute partial pressures of 0.06 MPa (H 2 ) and 0.07 MPa (A) at room temperature for 2 H
- heating to 400 ° C at a rate of 50 ° C / h in the same atmosphere and holding for 2 h
- vacuum
- Argon filling at 0.1 MPa absolute and cooling to room temperature at 10 ° C / h
La taille maximale de la poudre grossière ainsi obtenue est inférieure à 900 µm.
- L'alliage (D) dont la composition est reportée au Tableau VIII a été
traité de la façon suivante :
- concassage mécanique d'un lingot sous atmosphère particulière d'azote jusqu'à une granulométrie < 3 mm
- prébroyage dans un broyeur à jet de gaz sous azote jusqu'à une granulométrie < 500 µm.
- Les 8 mélanges (B) de (C)+(D) dont les compositions sont reportées dans
le Tableau IX ont été préparés de la façon suivante :
- mélange des poudres grossières (C) et (D) dans les proportions pondérales réparties dans le Tableau IX
- homogénéisation dans un mélangeur rotatif
- broyage avec un broyeur à jet de gaz sous azote jusqu'aux granulométries indiquées au Tableau X.
- The alloy (D), the composition of which is given in Table VIII, has been treated as follows:
- mechanical crushing of an ingot under a particular nitrogen atmosphere up to a particle size <3 mm
- pre-grinding in a gas jet mill under nitrogen to a particle size <500 µm.
- The 8 mixtures (B) of (C) + (D) whose compositions are given in Table IX were prepared as follows:
- mixture of coarse powders (C) and (D) in the weight proportions distributed in Table IX
- homogenization in a rotary mixer
- grinding with a gas jet mill under nitrogen up to the particle sizes indicated in Table X.
Les poudres (A) et (B) ainsi obtenues ont été mélangées dans les proportions pondérales indiquées au Tableau XI, puis elles ont été ensuite comprimées sous champ (⊥), frittées et traitées dans les conditions reportées au Tableau XII, où figurent également les caractéristiques magnétiques obtenues sur les aimants.The powders (A) and (B) thus obtained were mixed in the weight proportions indicated in Table XI, then they have been then compressed under field (⊥), sintered and processed in conditions shown in Table XII, where also the magnetic characteristics obtained on the magnets.
Les aimants M7-M8 ; M11-M12 ; M23-M24 ; M27 ; M28 correspondent à
l'invention, les autres exemples sortent du domaine de l'invention pour
les raisons suivantes :
Bien qu'issus de poudres (B) contenant la poudre (D), les exemples M5 -M6 M9 - M10 - M13 - M14 - M21 - M22 - M25 - M26 - M29 - M30 sont issus de poudre (A) dont la teneur en bore est élevée (1,06 %) et leur rémanence est inférieure à 1,32 T.Although produced from powders (B) containing the powder (D), examples M5 -M6 M9 - M10 - M13 - M14 - M21 - M22 - M25 - M26 - M29 - M30 are from powder (A) with a high boron content (1.06%) and their persistence is less than 1.32 T.
Les exemples M31 et M32 correspondent à des cas où bien qu'issus de poudre (B) contenant de la poudre (D) et de poudre (A) à faible teneur en bore (0,98 % poids), les aimants présentent une rémanence légèrement inférieure à 1,32 T, car la poudre (B) a une teneur en B > 1,5%.Examples M31 and M32 correspond to cases where although originating from powder (B) containing powder (D) and powder (A) with low content boron (0.98% by weight), the magnets have a slight remanence less than 1.32 T, because the powder (B) has a B content> 1.5%.
Les aimants selon l'invention possèdent les mêmes caractéristiques structurales que ceux de la demande FR 92-14995 : absence de phase Nd1+ε Fe4B4, structure homogène de grains en taille et en forme peu anguleuse, phase secondaire uniformément répartie en fins liserés et où le cobalt se localise préférentiellement.The magnets according to the invention have the same structural characteristics as those of application FR 92-14995: absence of phase Nd 1 + ε Fe 4 B 4 , homogeneous structure of grains in size and in slightly angular shape, secondary phase uniformly distributed in fine edges and where cobalt is preferentially localized.
Le procédé, objet de l'invention présente les avantages suivants :
- Par
comparaison avec l'Exemple 1, on obtient donc une meilleure densification avec un frittage réalisé à plus basse température et/ou pour une durée moindre, ce qui améliore l'induction rémanente et la coercitivité. - La poudre additive (B) contient tous les éléments d'addition permettant, au cours de l'opération de frittage, pratiquée à basse température (1050°C - 1070°C), de former la phase riche en TR, liquide, contenant du cobalt et d'autres éléments tels que l'aluminium, le cuivre, le silicium et impuretés et au cours du refroidissement après frittage de donner naissance à la formation de phase magnétique TR2Fe14B additionnelle, sans nécessiter la dissolution difficile de la phase TR1+ε Fe4B4 nécessaire dans l'art antérieur, et conduisant ainsi a l'obtention de propriétés magnétiques très élevées.
- On constate par ailleurs que l'aimant fritté selon l'invention ne contient pas de phase TR1+ε Fe4B4.
- le traitement d'hydruration de la poudre (C) permet, comme dans l'art antérieur, l'obtention d'une fine et homogène dispersion de ses constituants et de faciliter ainsi la densification lors du frittage à basse température même pour les basses teneurs en TR et l'obtention de propriétés magnétiques élevées (Br, Hcj) ainsi qu'une meilleure résistance à la corrosion.
- l'adjonction de la poudre (D) contenant le bore dans la poudre (C)
permet un ajustement fin de la teneur finale de cet élément afin de
maximaliser la rémanence de l'aimant final.
Compositions (A) (en poids %) Nd Dy B Al V Cu Fe A1 27,0 1,5 1,06 0,3 0 0,03 ba1 A2 27,5 1,0 1,06 0,3 0 0,03 ba1 A3 26,0 1,5 1,06 0,3 0 0,03 ba1 A4 27,0 1,5 1,0 0,3 0 0,03 ba1 A5 27,0 1,5 1,15 0,3 0 0,03 ba1 A6 28,1 0 1,17 0 1,0 0,03 69,43 A7 28,1 0 1,13 0 0 0,03 70,7 A8 28,1 0 1,0 0 0 0,03 70,9 Compositions (B) (en poids %) Nd Dy Co Fe Al V Cu B B1 59,1 1,5 32,0 7,1 0,3 0 0,03 0 B2 59,8 1,0 32,0 6,9 0,3 0 0,03 0 B3 59,0 1,5 32,0 6,1 0,3 0 0,03 1,05 B4 67,2 1,5 31,0 0 0,3 0 0,03 0 B5 50,0 1,5 33,0 15,2 0.3 0 0,03 0 B6 52,0 10,0 33,0 2,0 3,0 0 0,03 0 B7 52,0 10,0 24,0 2,0 3,0 9,0 0,03 0 B8 52,0 10,0 24,0 1,0 3,0 9,0 0,03 1,10 B9 59,1 1,5 32,0 7,1 0,3 0 0,03 0 B10 59,1 1,5 32,0 6,9 0,3 0 0,03 0,2 Caractéristiques des poudres Repère FSSS 02 ppm A1 4,5 2900 A2 4,7 3100 A3 4,5 2800 A4 4,7 2800 A5 4,8 3000 A6 4,2 3000 A7 4,5 3200 A8 4,6 2900 B1 3,2 5100 B2 3,3 4800 B3 3,9 6000 B4 3,1 5200 B5 3,4 4800 B6 3,5 5000 B7 3,4 4900 B8 3,3 5200 B9 3,4 10200 B10 3,3 5500 Compositions (A) -en poids %- Nd Dy B Al Cu Si Fe A1 27,0 1,5 1,06 0,3 0,03 0,05 reste A2 27,0 1,5 0,98 0,3 0,03 0,05 reste Compositions (C) -en poids %- Nd Dy B Co Al Cu Si Fe C1 59,1 1,5 0 32,0 0,3 0,03 0,05 reste C2 59,1 1,5 0,2 32,0 0,3 0,03 0,05 reste Composition (D) -en poids %- B Al Cu Si Fe D1 17,0 2,0 0,5 0,5 reste Caractéristiques des poudres fines Repères FSSS O2 ppm A1 4,1 2 800 A2 4,2 3 100 B1 3,0 4 300 B2 2,8 5 500 B3 3,3 4 600 B4 3,1 4 800 B5 2,8 4 700 B6 2,5 6 200 B7 3,1 5 000 B8 2,9 5 100
- By comparison with Example 1, a better densification is therefore obtained with a sintering carried out at a lower temperature and / or for a shorter duration, which improves the residual induction and the coercivity.
- The additive powder (B) contains all of the addition elements allowing, during the sintering operation, carried out at low temperature (1050 ° C - 1070 ° C), to form the phase rich in TR, liquid, containing cobalt and other elements such as aluminum, copper, silicon and impurities and during cooling after sintering give rise to the formation of additional magnetic phase TR 2 Fe 14 B, without requiring the difficult dissolution of the phase TR 1 + ε Fe 4 B 4 necessary in the prior art, and thus leading to obtaining very high magnetic properties.
- It can also be seen that the sintered magnet according to the invention does not contain a TR 1 + ε Fe 4 B 4 phase.
- the hydriding treatment of the powder (C) makes it possible, as in the prior art, to obtain a fine and homogeneous dispersion of its constituents and thus to facilitate densification during sintering at low temperature even for low contents in TR and obtaining high magnetic properties (B r , H cj ) as well as better corrosion resistance.
- the addition of the powder (D) containing the boron in the powder (C) allows a fine adjustment of the final content of this element in order to maximize the persistence of the final magnet.
Compositions (A) (by weight%) Nd Dy B Al V Cu Fe A1 27.0 1.5 1.06 0.3 0 0.03 ba1 A2 27.5 1.0 1.06 0.3 0 0.03 ba1 A3 26.0 1.5 1.06 0.3 0 0.03 ba1 A4 27.0 1.5 1.0 0.3 0 0.03 ba1 AT 5 27.0 1.5 1.15 0.3 0 0.03 ba1 A6 28.1 0 1.17 0 1.0 0.03 69.43 A7 28.1 0 1.13 0 0 0.03 70.7 AT 8 28.1 0 1.0 0 0 0.03 70.9 Compositions (B) (by weight%) Nd Dy Co Fe Al V Cu B B1 59.1 1.5 32.0 7.1 0.3 0 0.03 0 B2 59.8 1.0 32.0 6.9 0.3 0 0.03 0 B3 59.0 1.5 32.0 6.1 0.3 0 0.03 1.05 B4 67.2 1.5 31.0 0 0.3 0 0.03 0 B5 50.0 1.5 33.0 15.2 0.3 0 0.03 0 B6 52.0 10.0 33.0 2.0 3.0 0 0.03 0 B7 52.0 10.0 24.0 2.0 3.0 9.0 0.03 0 B8 52.0 10.0 24.0 1.0 3.0 9.0 0.03 1.10 B9 59.1 1.5 32.0 7.1 0.3 0 0.03 0 B10 59.1 1.5 32.0 6.9 0.3 0 0.03 0.2 Characteristics of powders Landmark FSSS 02 ppm A1 4.5 2900 A2 4.7 3100 A3 4.5 2800 A4 4.7 2800 AT 5 4.8 3000 A6 4.2 3000 A7 4.5 3200 AT 8 4.6 2900 B1 3.2 5100 B2 3.3 4800 B3 3.9 6000 B4 3.1 5200 B5 3.4 4800 B6 3.5 5000 B7 3.4 4900 B8 3.3 5200 B9 3.4 10200 B10 3.3 5500 Compositions (A) - by weight% - Nd Dy B Al Cu Yes Fe A1 27.0 1.5 1.06 0.3 0.03 0.05 rest A2 27.0 1.5 0.98 0.3 0.03 0.05 rest Compositions (C) - by weight% - Nd Dy B Co Al Cu Yes Fe C1 59.1 1.5 0 32.0 0.3 0.03 0.05 rest C2 59.1 1.5 0.2 32.0 0.3 0.03 0.05 rest Composition (D) - by weight% - B Al Cu Yes Fe D1 17.0 2.0 0.5 0.5 rest Characteristics of fine powders Landmarks FSSS O 2 ppm A1 4.1 2,800 A2 4.2 3,100 B1 3.0 4,300 B2 2.8 5,500 B3 3.3 4,600 B4 3.1 4,800 B5 2.8 4,700 B6 2.5 6,200 B7 3.1 5,000 B8 2.9 5,100
Claims (29)
- A magnetic powder for the manufacture of sintered magnets of the RE-T-B family, where RE represents at least one rare earth, T represents at least one transition element such as Fe and/or Co, B represents boron, the powder possibly containing other minor elements, the powder having a structure consisting mainly of grains of quadratic phase RE2T14B, a secondary phase consisting mainly of RE, and possibly comprising other minor phases, the initial magnetic powder being constituted by a mixture of two powders (A) and (B) :a) Powder (A) consists of grains with a quadratic structure RE2T14B, T being primarily iron with Co/Fe < 8 %, and which may also contain up to 0.5 % Al, up to 0.05 % Cu and up to 4 % in total of at least one element of the group V, Nb, Hf, Mo, Cr, Ti, Zr, Ta, W and unavoidable impurities, the Fisher granulometry being between 3.5 and 5 µm;b) Powder (B) is rich in RE, contains Co, and has the following composition by weight:
RE 52-70 %, comprising at least 40 % (absolute value) of one or more light rare earth(s) selected from the group La, Ce, Pr, Nd, Sm, Eu; a hydrogen content (in ppm by weight) greater than 130 x %RE; Co 20-35 %; Fe 0-20 %; B ≤ 0-0.2 %; Al 0.1-4 %; and unavoidable impurities, the powder having a Fisher granulometry of between 2.5 and 3.5 µm. - Magnetic powder according to claim 1 characterised in that the granulometry of powder (B) is lower than that of powder (A) by at least 20 %.
- Magnetic powder according to claim 1 or claim 2, characterised in that powder (B) is practically free of boron.
- Magnetic powder according to any one of claims 1 to 3, characterised in that the liquidus temperature of powder (B) is less than or equal to 1080°C.
- Magnetic powder according to claim 4, characterised in that the liquidus temperature is less than 1050°C.
- Magnetic powder according to any one of claims 1 to 5, characterised in that powder (A) represents 88 to 95 % (by weight) of the mixture (A) + (B).
- Magnetic powder according to claim 6, characterised in that powder (A) represents 90 to 94 % (by weight) of the mixture (A) + (B).
- Method of manufacture of a powder (B) as defined in any one of claims 1 to 4, wherein the initial alloy is treated with hydrogen before milling under the following conditions: put under vacuum, introduction of an inert gas at a pressure of between 0.1 and 0.12 MPa, raise temperature at a rate of between 10°C/h and 500°C/h up to a temperature of between 350 and 450°C, introduction of hydrogen at an absolute partial pressure of between 0.01 and 0.12 MPa and maintain these conditions for 1 to 4 hours, then put under vacuum and introduction of an inert gas at a pressure of 0.1 to 0.12 MPa, cooling to room temperature at a rate of between 5°C/h and 100°C/h.
- Method according to claim 8, characterised in that the hydrogen treatment is preceded by a prior hydrogen treatment step consisting of holding the initial alloy at an absolute partial pressure of hydrogen of between 0.01 and 0.12 MPa for 1 to 3 hours at room temperature.
- Method according to claim 8 or claim 9,
characterised in that the prior (cold) and principal (hot) treatment steps under hydrogen are repeated up to two times. - Method according to any one of claims 8 to 10, characterised in that the inert gas is argon or helium or a mixture of the two gases.
- Method of manufacture of powder (A) as defined in claim 1, wherein the initial alloy is treated with hydrogen before milling under the following conditions: put under vacuum, introduction of an inert gas at a pressure of between 0.1 and 0.12 MPa, raise temperature at a rate of between 10°C/h and 500°C/h up to a temperature of between 350 and 450°C, introduction of hydrogen at an absolute partial pressure of between 0.01 and 0.12 MPa and maintain these conditions for 1 to 4 hours, then put under vacuum and introduction of an inert gas at a pressure of 0.1 to 0.12 MPa, cooling to room temperature at a rate of between 5°C/h and 100°C/h.
- Method according to claim 12, characterised in that the inert gas is argon or helium or a mixture of the two gases.
- Magnetic powder produced in accordance with claim 1, characterised in that the RE content is between 29 and 32 % by weight.
- Magnetic powder according to claim 14, characterised in that the O2 content is less than 3500 ppm.
- Magnetic powder according to claim 14, characterised in that the RE content is between 29 and 31 % by weight.
- Sintered magnet of the RE-T-B family, resulting from the use of the powder of claim 1 where RE represents at least one rare earthn, T represents at least one transition element such as Fe and/or Co, B represents boron, the powder possibly containing other minor elements, the powder having a structure consisting mainly of quadratic phase (T1) RE2T14B, a secondary phase consisting mainly of RE, and possibly other minor phases, characterised in that the Co is mainly located in the secondary phase with an average Co content ≥ 10% by weight.
- Magnet according to claim 17, characterised in that it contains less than 3500 ppm of oxygen.
- Additive powder (B) according to any one of claims 1 or 2, this additive powder consisting of a mixture of powders (C) and (D):a) powder (C) is rich in RE, contains Co and has the following composition by weight :
RE 52-70% ; comprising at least 40 % (absolute) of one or more light rare earth(s) selected from the group La, Ce, Pr, Nd, Sm, Eu; a hydrogen content (ppm by weight) of greater than 130 x %RE; Co-20-35 % ; Fe 0-20% ; B 0-0.2% ; Al 0.1-4%; and unavoidable impurities.b) powder (B) is composed of B alloyed with at least one of the following elements :Al, Si, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo,and containing between 5 and 70 % by weight of boron along with unavoidable impurites. - Additive powder (B) according to claim 19, characterised in that the B content is between 0.4 and 1.2%.
- Magnetic powder consisting of a mixture of 88 to 95% of powder (A) and 5 to 12% of powder (B) according to any one of claims 19 or 20, powder (A) consisting of quadratic grains RE2T14B, T consisting mainly of iron with Co/Fe ≤ 8% and containing 0.95 to 1.05% B and possibly also containing up to 0.5% Al, up to 0.05 % Cu. and up to 4% in total of at least one element of the group V, Nb, Hf, Mo, Cr, Ti, Zr, Ta, W, and unavoidable impurities, the powder having a Fisher granulometry of between 3.5 and 5µm.
- Additive powder (B) according to any one of claims 19 to 21, characterised in that RE rich powder (C) is practically free of boron.
- Additive powder (B) according to claim 22, characterised in that the liquidus temperature is lower than or equal to 1050°C.
- Additive powder (B) according to claim 22, characterised in that it is mixed with a powder (A) which has a composition very close to that of the magnetic phase RE2 T14B
- Magnetic powder according to claim 24, characterised in that the granulometry of powder (B) is at least 20% lower than that of powder (A).
- Sintered permanent magnet resulting in particular from the use of the powder of claim 1 and comprising 29 to 32% RE, 0.93 to 1.04% B, 1 to 4.3% Co, 0.2 to 0.5% Al, 0.02 to 0.05% Cu, the remainder consisting of Fe and unavoidable impurities, characterised in that the remanance is greater than 1.32 T.
- Permanent magnet according to claim 26, characterised in that the remanance is greater than 1.35 T.
- Permanent magnet according to claim 26 or claim 27, characterised in that the intrinsic coercivity is greater than 1150 kA/m.
- Permanent magnet according to any one of claims 26 to 28, characterised in that the oxygen content is less than 3500 ppm.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9214995A FR2698999B1 (en) | 1992-12-08 | 1992-12-08 | Magnetic powder of Fe-TR-B type and corresponding sintered magnets and their method of preparation. |
FR9214995 | 1992-12-08 | ||
FR9308586 | 1993-07-07 | ||
FR9308586A FR2707421B1 (en) | 1993-07-07 | 1993-07-07 | Additive powder for the manufacture of sintered magnets type Fe-Nd-B, manufacturing method and corresponding magnets. |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0601943A1 EP0601943A1 (en) | 1994-06-15 |
EP0601943B1 true EP0601943B1 (en) | 1998-05-20 |
Family
ID=26229947
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP93420483A Expired - Lifetime EP0601943B1 (en) | 1992-12-08 | 1993-12-07 | R-Fe-B type magnet powder, sintered magnets therefrom and preparation process |
Country Status (9)
Country | Link |
---|---|
US (1) | US5482575A (en) |
EP (1) | EP0601943B1 (en) |
JP (1) | JP3594326B2 (en) |
AT (1) | ATE166488T1 (en) |
CA (1) | CA2110846A1 (en) |
DE (1) | DE69318682T2 (en) |
ES (1) | ES2117117T3 (en) |
FI (1) | FI113209B (en) |
SI (1) | SI9300639A (en) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69434323T2 (en) * | 1993-11-02 | 2006-03-09 | Tdk Corp. | Preparation d'un aimant permanent |
DE19541948A1 (en) * | 1995-11-10 | 1997-05-15 | Schramberg Magnetfab | Magnetic material and permanent magnet of the NdFeB type |
EP0789367A1 (en) * | 1996-02-09 | 1997-08-13 | Crucible Materials Corporation | Method for producing selected grades of rare earth magnets using a plurality of particle batches |
DE19636285C2 (en) * | 1996-09-06 | 1998-07-16 | Vakuumschmelze Gmbh | Process for producing an SE-Fe-B permanent magnet |
JP3901259B2 (en) * | 1996-09-30 | 2007-04-04 | 本田技研工業株式会社 | SmFe-based magnetostrictive material |
US6425961B1 (en) * | 1998-05-15 | 2002-07-30 | Alps Electric Co., Ltd. | Composite hard magnetic material and method for producing the same |
US20050062572A1 (en) * | 2003-09-22 | 2005-03-24 | General Electric Company | Permanent magnet alloy for medical imaging system and method of making |
JP4534553B2 (en) * | 2004-03-30 | 2010-09-01 | Tdk株式会社 | R-T-B system sintered magnet and manufacturing method thereof |
JP5115511B2 (en) * | 2008-03-28 | 2013-01-09 | Tdk株式会社 | Rare earth magnets |
JP2011258935A (en) * | 2010-05-14 | 2011-12-22 | Shin Etsu Chem Co Ltd | R-t-b-based rare earth sintered magnet |
JP7099924B2 (en) * | 2018-09-21 | 2022-07-12 | トヨタ自動車株式会社 | Rare earth magnets and their manufacturing methods |
KR102589893B1 (en) * | 2019-09-26 | 2023-10-16 | 주식회사 엘지화학 | Method for preparing sintered magnet and sintered magnet |
CN110957125B (en) * | 2019-12-24 | 2021-11-05 | 厦门钨业股份有限公司 | Sintering method of neodymium iron boron permanent magnet material and neodymium iron boron permanent magnet material |
CN111180158A (en) * | 2019-12-30 | 2020-05-19 | 宁波韵升股份有限公司 | R-T-B series sintered permanent magnet and preparation method thereof |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0447567A1 (en) * | 1989-10-12 | 1991-09-25 | Kawasaki Steel Corporation | Corrosion-resistant tm-b-re type magnet and method of production thereof |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2201426B (en) * | 1987-02-27 | 1990-05-30 | Philips Electronic Associated | Improved method for the manufacture of rare earth transition metal alloy magnets |
JPS6448403A (en) * | 1987-08-19 | 1989-02-22 | Mitsubishi Metal Corp | Rare earth-iron-boron magnet powder and manufacture thereof |
US5123974A (en) * | 1987-09-16 | 1992-06-23 | Giancola Dominic J | Process for increasing the transition temperature of metallic superconductors |
US5000800A (en) * | 1988-06-03 | 1991-03-19 | Masato Sagawa | Permanent magnet and method for producing the same |
JP2787580B2 (en) * | 1988-10-06 | 1998-08-20 | 眞人 佐川 | Nd-Fe-B based sintered magnet with excellent heat treatment |
US5200001A (en) * | 1989-12-01 | 1993-04-06 | Sumitomo Special Metals Co., Ltd. | Permanent magnet |
JPH0735521B2 (en) * | 1990-08-30 | 1995-04-19 | 住友特殊金属株式会社 | Raw material powder for R-Fe-B permanent magnets |
JPH04120238A (en) * | 1990-09-11 | 1992-04-21 | Tdk Corp | Manufacture of rare earth sintered alloy and manufacture of permanent magnet |
JP3092672B2 (en) * | 1991-01-30 | 2000-09-25 | 三菱マテリアル株式会社 | Rare earth-Fe-Co-B anisotropic magnet |
EP0517179B1 (en) * | 1991-06-04 | 1995-05-17 | Shin-Etsu Chemical Co., Ltd. | Method of making two phase Rare Earth permanent magnets |
JP3254229B2 (en) * | 1991-09-11 | 2002-02-04 | 信越化学工業株式会社 | Manufacturing method of rare earth permanent magnet |
US5387291A (en) * | 1992-03-19 | 1995-02-07 | Sumitomo Special Metals Co., Ltd. | Process for producing alloy powder material for R-Fe-B permanent magnets and alloy powder for adjusting the composition therefor |
-
1993
- 1993-12-02 US US08/160,652 patent/US5482575A/en not_active Expired - Fee Related
- 1993-12-07 DE DE69318682T patent/DE69318682T2/en not_active Expired - Fee Related
- 1993-12-07 ES ES93420483T patent/ES2117117T3/en not_active Expired - Lifetime
- 1993-12-07 AT AT93420483T patent/ATE166488T1/en active
- 1993-12-07 EP EP93420483A patent/EP0601943B1/en not_active Expired - Lifetime
- 1993-12-07 FI FI935472A patent/FI113209B/en not_active IP Right Cessation
- 1993-12-07 CA CA002110846A patent/CA2110846A1/en not_active Abandoned
- 1993-12-08 SI SI9300639A patent/SI9300639A/en unknown
- 1993-12-08 JP JP30808493A patent/JP3594326B2/en not_active Expired - Fee Related
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0447567A1 (en) * | 1989-10-12 | 1991-09-25 | Kawasaki Steel Corporation | Corrosion-resistant tm-b-re type magnet and method of production thereof |
Also Published As
Publication number | Publication date |
---|---|
FI113209B (en) | 2004-03-15 |
SI9300639A (en) | 1994-06-30 |
EP0601943A1 (en) | 1994-06-15 |
JP3594326B2 (en) | 2004-11-24 |
JPH06231916A (en) | 1994-08-19 |
FI935472A0 (en) | 1993-12-07 |
ES2117117T3 (en) | 1998-08-01 |
ATE166488T1 (en) | 1998-06-15 |
DE69318682D1 (en) | 1998-06-25 |
US5482575A (en) | 1996-01-09 |
DE69318682T2 (en) | 1998-11-26 |
CA2110846A1 (en) | 1994-06-09 |
FI935472A (en) | 1994-06-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10160037B2 (en) | Rare earth magnet and its preparation | |
EP0601943B1 (en) | R-Fe-B type magnet powder, sintered magnets therefrom and preparation process | |
CN107871581B (en) | Method for preparing R-Fe-B sintered magnet | |
EP1879201B1 (en) | Rare earth sintered magnet and process for producing the same | |
US10510483B2 (en) | Production method for R-T-B sintered magnet | |
US8361242B2 (en) | Powders for rare earth magnets, rare earth magnets and methods for manufacturing the same | |
US8317937B2 (en) | Alloy for sintered R-T-B-M magnet and method for producing same | |
US10593472B2 (en) | Production method for R-T-B sintered magnet | |
FR2632766A1 (en) | PERMANENT MAGNET AND METHOD FOR MANUFACTURING THE SAME | |
US20230118859A1 (en) | R-t-b-based permanent magnet and method for producing same, motor, and automobile | |
WO2017089488A1 (en) | Sintered permanent magnet | |
JP2024023206A (en) | Anisotropic rare earth sintered magnet and manufacturing method thereof | |
JP7533424B2 (en) | Manufacturing method of rare earth sintered magnet | |
EP1082733B1 (en) | Method for preparing a magnetic material by forging and magnetic material in powder form | |
FR2698999A1 (en) | Two-part magnetic material | |
FR2707421A1 (en) | Additive powder for the manufacture of Fe-Nd-B-type sintered magnets, method of manufacture and corresponding magnets | |
JP2001155912A (en) | Method of manufacturing rare earth based alloy powder for permanent magnet, material alloy of intermediate product of the powder and manufacturing method therefor | |
JP3562138B2 (en) | Raw material alloy for manufacturing rare earth magnet powder | |
WO2021111921A1 (en) | Rare-earth sintered magnet | |
EP4246539A1 (en) | Method for manufacturing a magnet from recycled magnets | |
WO2021117672A1 (en) | Rare earth sintered magnet | |
JP5445125B2 (en) | Method for producing surface-modified R-Fe-B sintered magnet | |
JPH0817613A (en) | Material alloy for manufacturing rare earth magnet powder and its manufacture | |
JPH07316753A (en) | Raw material alloy for producing rare earth magnet powder | |
JPH04345003A (en) | Manufacture of rare earth-transient metal base magnet |
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 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH DE ES FR GB IE IT LI NL SE |
|
17P | Request for examination filed |
Effective date: 19940701 |
|
17Q | First examination report despatched |
Effective date: 19950810 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH DE ES FR GB IE IT LI NL SE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
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: 19980520 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: 19980520 |
|
REF | Corresponds to: |
Ref document number: 166488 Country of ref document: AT Date of ref document: 19980615 Kind code of ref document: T |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) |
Effective date: 19980603 |
|
REF | Corresponds to: |
Ref document number: 69318682 Country of ref document: DE Date of ref document: 19980625 |
|
ITF | It: translation for a ep patent filed | ||
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2117117 Country of ref document: ES Kind code of ref document: T3 |
|
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: 19980820 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D Free format text: FRENCH |
|
NLV1 | Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19981208 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FD4D |
|
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: 19981231 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19981231 Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19981231 |
|
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 | ||
BERE | Be: lapsed |
Owner name: S.A. UGIMAG Effective date: 19981231 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20051201 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20051207 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20051208 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20060118 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20061231 Year of fee payment: 14 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20070703 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20061207 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20070831 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20061207 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 20061209 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20070102 Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20061209 |
|
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 NON-PAYMENT OF DUE FEES Effective date: 20071207 |