EP0447567A1 - Aimant a base de tm-b-re resistant a la corrosion et procede de production de cet aimant - Google Patents

Aimant a base de tm-b-re resistant a la corrosion et procede de production de cet aimant Download PDF

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Publication number
EP0447567A1
EP0447567A1 EP90914967A EP90914967A EP0447567A1 EP 0447567 A1 EP0447567 A1 EP 0447567A1 EP 90914967 A EP90914967 A EP 90914967A EP 90914967 A EP90914967 A EP 90914967A EP 0447567 A1 EP0447567 A1 EP 0447567A1
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Prior art keywords
phase
series
intermetallic compound
powder
re2tm14b
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EP90914967A
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German (de)
English (en)
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EP0447567B1 (fr
EP0447567A4 (en
Inventor
Yukiko Kawasaki Steel Corporation Technical Ozaki
Michio Kawasaki Steel Corp. Shimotomai
Yasutaka Kawasaki Steel Corporation Fukuda
Akira Kawasaki Steel Corporation Fujita
Yoko Kawasaki Steel Corporation Kitano
Junichi Kawasaki Steel Corporation Shimomura
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JFE Steel Corp
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Kawasaki Steel Corp
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    • 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
    • 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
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C19/00—Alloys based on nickel or cobalt
    • C22C19/07—Alloys based on nickel or cobalt based on cobalt
    • 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

  • This invention relates to rare earth metal-transition metal series magnets having not only excellent magnetic properties but also improved corrosion resistance and temperature-dependent properties and a method of producing the same.
  • Alnico magnets As a typical permanent magnet manufactured at the present, there are mentioned Alnico magnets, ferrite magnets, rare earth metal magnets and the like.
  • the Alnico magnets are manufactured from the old time, but their demand is lowering in accordance with the development of cheap ferrite magnets and rare earth metal magnets having higher magnetic properties.
  • the ferrite magnets are chemically stable and low in the cost because oxides are used as a main starting material, so that they are the main current as a magnet material even at the present, but they have a drawback that maximum energy product is small.
  • Sm-Co series magnets having a combination of magnetic isotropy inherent to rare earth metal ion and magnetic moment inherent to transition metal element have been developed, whereby the conventional value of maximum energy product is largely increased.
  • the Sm-Co series magnet is mainly composed of resourceless Sm and Co, so that it is obliged to become expensive.
  • Nd-Fe-B series magnets contain greater amounts of a light rare earth element such as ND having very high activity or the like and a corrosive Fe as a main component, so that the corrosion resistance is poor and hence the magnetic properties are degraded to damage the reliability as an industrial material.
  • Such magnets are excellent in the corrosion resistance and high in the Curie point, so that the reliability as a magnet material is largely increased.
  • the invention is concerned with rare earth metal-transition metal series magnets of two phase structure further developed from the above magnet.
  • magnets having excellent magnetic properties through two alloying process in which rare earth rich phase and rare earth poor phase are mixed and sintered at liquid phase state have previously been proposed as Nd series magnet of two phase structure (Japanese Patent laid open No. 63-93841 and No. 63-164403).
  • Nd series magnet of two phase structure Japanese Patent laid open No. 63-93841 and No. 63-164403
  • the magnetic properties are improved, but there is still remained a problem on the corrosion resistance.
  • the invention is to advantageously solve the aforementioned problems and to propose rare earth metal-transition metal series magnets of two phase structure being excellent in not only the magnetic properties but also the corrosion resistance and a method of advantageously producing the same.
  • the inventors have made various metallographical studies on the above magnet using high resolution electron microscope or the like, and confirmed that this magnet contains Nd2(Fe, Co, Ni)14B phase having a large saturated magnetic flux density, and intergranular phases surrounding crystal grains of the above phase and developing a strong coercive force such as Nd2(Fe, Co, Ni)17, Nd(Fe, Co, Ni)5, Nd2(Fe, Co, Ni)7, Nd(Fe, Co, Ni)4B and Nd(Fe, Co, Ni)12B6 and further Nd 1-x TM x of CrB structure (TM is mainly Ni) and the like.
  • TM is mainly Ni
  • Nd-Fe-B ternary phase diagram is shown in Fig. 1 (N. F. Chaban, Yu. B. Kuzma, N. S. Bilonizhko, O. O. Kachmar and N. U. Petrov, Akad Nauk, SSSR, SetA, Fiz.-Mat. Tekh, Nauki No. 10 (1979) 873), and Nd-Co-B ternary phase diagram is shown in Fig. 2 (N. S. Bilonizhko and Yu. B. Kuzma, Izv. Akad. Nauk SSSR Neorg.
  • Nd2Fe14B phase and Nd2Co14B phase are misinterpreted as Nd2Fe9B phase and Nd2Co9B phase, so that they are corrected in Figs. 1 and 2).
  • a phase of number 1 is Nd2Fe14B phase, and NdFe4B4 phase (phase of number 2), Nd phase, Nd2Fe17 phase and Fe phase appear as a composition near thereto.
  • Nd2Co17 phase, NdCo5 phase, Nd2Co7 phase, NdCo4B phase (phase of number 2) and NdCo12B6 phase (phase of number 7) appear in a magnet prepare from a composition near to Nd2Co14B phase of number 1, and Nd phase does not naturally appear at an equilibrium state.
  • Nd phase is not only a point of causing rust but also a magnetically useless phase, so that it should be eliminated.
  • an object of the invention to provide permanent magnets having excellent magnetic properties and corrosion resistance by using magnetically useful two phases, i.e. RE2TM14B phase having a high residual magnetic flux density and a low melting point RE-TM phase or RE-TM-B phase enhancing the sinterability and possessing a cleaning action against grain boundary of main phase and further forming an electrochemically noble composition as a starting material to prepare a two phase magnet.
  • magnetically useful two phases i.e. RE2TM14B phase having a high residual magnetic flux density and a low melting point RE-TM phase or RE-TM-B phase enhancing the sinterability and possessing a cleaning action against grain boundary of main phase and further forming an electrochemically noble composition as a starting material to prepare a two phase magnet.
  • the invention lies in a corrosion-resistant rare earth metal-transition metal series permanent magnet consisting essentially of RE: not less than 10 at% but not more than 25 at% (where RE: one or more of Y, Sc and lanthanoid, B: not less than 2 at% but not more than 20 at% and the reminder being substantially TM (TM is one or more of Fe, Co and Ni), whose texture being comprised of a phase of RE2TM14B (TM is the same as mentioned above) having Nd2Fe14B structure, RE-TM series intermetallic compound phase (TM is Ni or a mixture of Ni and Fe or Co) or RE-TM series eutectic structure (TM is the same as mentioned above) and/or RE-TM-B series intermetallic compound phase (TM is the same as mentioned above) having a melting point lower than that of the above phase.
  • RE rare earth metal-transition metal series permanent magnet
  • the invention lies in a method of producing a corrosion-resistant rare earth metal-transition metal series magnet, which comprises subjecting a mixture of powder composed mainly of RE2TM14B series intermetallic compound phase (TM is one or more of Fe, Co and Ni) and powder having a melting point lower than that of the above powder and composed of mainly of RE-TM series intermetallic compound phase (TM is Ni or a mixture of Ni and Fe or Co) or RE-TM series eutectic structure (TM is the same as mentioned above) and/or RE-TM-B series intermetallic compound phase (TM is the same as mentioned above) to a compression molding and then sintering it.
  • TM RE2TM14B series intermetallic compound phase
  • TM is one or more of Fe, Co and Ni
  • RE-TM series intermetallic compound phase TM is Ni or a mixture of Ni and Fe or Co
  • RE-TM series eutectic structure TM is the same as mentioned above
  • RE-TM-B series intermetallic compound phase TM is the same as
  • the intergranular phase electrochemically more noble than the main phase in order to more improve the corrosion resistance, it is effective to make the intergranular phase electrochemically more noble than the main phase, so that it is preferable that a ratio of Ni and/or Co in TM of the low melting point RE-TM and RE-TM-B series phases is higher than that in RE2TM14B phase.
  • the increase of Ni ratio is effective to the improvement of corrosion resistance and the reduction of cost.
  • a ratio of RE2TM14B intermetallic compound phase to RE-TM, RE-TM-B series intermetallic compound phase is about 95:5 to 40:60 as a formula unit. Because, when this ratio is outside the above range, there is caused a disadvantage of bringing about considerable degradation of coercive force and saturated magnetic flux density.
  • the term "formula unit" used herein corresponds to a case that Nd2Fe14B is considered as one molecule (this is called as formula in case of solid).
  • the particle size of each of the above powders to be mixed is desirable to be about 0.5-5 ⁇ m for handling easiness and homogeneous mixing.
  • a typical composition of RE-TM series intermetallic compound phase (inclusive of eutectic structure, same as above) and RE-TM-B series intermetallic compound phase having a melting point lower than that of RE2TM14B intermetallic compound phase is as follows. ⁇ RE-TM series RE2TM17, RETM5, RE2TM7, RETM3, RETM2, RE1TM 1-x , RE7TM3, RE3TM and RE-TM eutectic structure ⁇ RE-TM-B series RETM4B, RE3TM11B4, RE2TM5B2, RE2TM7B3, RE2TM5B3, RETM12B6, RETM2B2, RETM9B4, RE2TMB3
  • powder composed mainly of the above RE2TM14B, RE-TM series and RE-TM-B series intermetallic compound phases can be obtained as follows.
  • constitutional elements are weighed so as to have a given composition and shaped into an ingot by arc melting or high frequency melting under vacuum or in an inert gas atmosphere. Then, the ingot is held at a temperature of 600-1000°C under vacuum or in an inert gas atmosphere for 1-30 days to form a single phase of intermetallic compound.
  • the intermetallic compound phase has frequently a solid solution range to a certain extent ( ⁇ 20%), so that the starting composition is allowed to have a composition width in accordance therewith.
  • the single phase of the intermetallic compound is roughly ground by means of a hammer mill and then finely divided into a particle size of 0.5-5 ⁇ m by using a jet mill or an attritor .
  • hydrogen brittleness is previously carried out within a temperature range of room temperature to about 350°C for several hours before the grinding with a hammer mill, whereby the subsequent pulverization is made easy.
  • powder composed mainly of the previously prepared intermetallic compound having a composition of RE2TM14B is mixed with at least one powder composed mainly of the previously prepared RE-TM series intermetallic compound and RE-TM-B series intermetallic compound phases having a melting point lower than that of the above powder, pressed and sintered, whereby high magnetic properties and high corrosion resistance can simultaneously be provided.
  • Nd and Pr are desirable as RE from viewpoints of magnitude of magnetic moment and magnetic coupling with TM atm as well as the cost, but it is needless to say that the other RE or a combination of Nd, Pr therewith may be used.
  • TM one or more of Fe, Co and Ni is sufficient, and particularly it is preferable to increase the ratio of Ni from a viewpoint of high corrosion resistance of the magnet.
  • RE2TM14B phase bears the saturated magnetic flux density of the magnet, so that the ratios of Fe, Co and Ni in TM are desirable to be not less than 10 at% but less than 73 at% in Fe, not less than 7 at% but not more than 50 at% in Co and not less than 5 at% but not more than 30 at% in Ni.
  • the corrosion resistance of the permanent magnet according to the invention is superior to that of the conventional RE-TM-B magnet, so that the above phase can naturally be used as a main phase in accordance with the use purpose of the magnet.
  • light rare earth element such as La, Ce, Pr, Nd or the like is advantageously adaptable importantly considering the cost, and middle to heavy rare earth elements from Sm to Lu and Y, Sc and the like are adaptable for more enhancing the corrosion resistance.
  • TM the presence of Ni and/or Co, particularly Ni is effective to improve the corrosion resistance, so that according to the invention Ni is necessarily contained as TM.
  • the content in TM is preferable to be not less than about 8%.
  • the corrosion resistance can be more improved because the phases of these powders tend to preferentially corrode in the grain boundary as compared with RE2TM14B phase in the sintered body if the structure of TM is same and is advantageously acted by previously making electrochemically noble. Furthermore, the magnetically useless Nd phase can be eliminated, so that the residual magnetic flux density increases and hence the maximum energy product (BH) max also increases.
  • BH maximum energy product
  • the effect of the invention is not lost even when a part of RE and TM is replaced with at least one of Mg, Al, Si, Ti, V, Cr, Mn, Cu, Ag, Au, Cd, Rh, Pd, Ir, Pt, Zn, Ga, Ge, Zr, Nb, Mo, In, Sn, Hf, Ta and W in an amount up to 8 at% of a full magnet.
  • the production method there may be carried out a method wherein a mixture of powder of RE2TM14B composition and powder composed mainly of low melting point RE-TM series and/or RE-TM-B series intermetallic compound phases is placed in an iron pipe under vacuum and then sintered while hot rolling as a method of producing large size magnets in addition to the method in which the above powder mixture is subjected to compression molding and then sintered.
  • An alloy button was prepared by arc melting neodymium, transition metal and boron at an atomic ratio of 2:14:1, which was subjected to a normalizing treatment in a vacuum furnace at 950°C for 7 days and further to rough grinding and fine pulverization, whereby fine powder having a particle size of few microns was obtained.
  • the ratios of Fe, Co, Ni in the transition metal were varied to produce a plurality of alloy powders.
  • powder having a ratio of neodymium or (neodymium + dysprosium) to nickel of 1:1 was prepared.
  • the normalizing treatment conditions were 680°C and 5 days.
  • powders selected from the above two groups were mixed at a mixing ratio shown in Table 1, pressed while applying a magnetic field of 15 kOe, sintered at 1000°C under vacuum for 2 hours and then quenched to room temperature.
  • the magnetic properties and corrosion property of the thus obtained samples were measured to obtain results shown in Table 1. Moreover, the corrosion property was evaluated by exposing the sample to an environment at a temperature of 70°C and a humidity of 95% for 48 hours and measuring a rusted area ratio on the surface of the sample.
  • the rare earth metal-transition metal series magnets of two phase structure according to the invention considerably improve not only the magnetic properties but also corrosion resistance as compared with those obtained by melting the full composition from the first as in the conventional technique.
  • An alloy button was prepared by arc melting neodymium, transition metal and boron at an atomic ratio of 2:14:1, which was subjected to a normalizing treatment in a vacuum furnace at 950°C for 7 days and further to rough grinding and fine pulverization, whereby fine powder having a particle size of few microns was obtained.
  • the ratios of Fe, Co, Ni in the transition metal were varied to produce a plurality of alloy powders.
  • powder having a ratio of neodymium and/or dysprosium or praseodymium to nickel or (nickel + cobalt) of 3:1 was prepared.
  • the normalizing treatment conditions were 485°C and 5 days.
  • the rare earth metal-transition metal series magnets of two phase structure according to the invention are excellent in the magnetic properties and corrosion resistance. Furthermore, when Acceptable Example 8 is compared with Acceptable Example 13, it is apparent that the corrosion resistance is improved as the Ni ratio in RE3(Ni, Co)1 becomes particularly higher. Moreover, in the conventional example, the magnetic properties are good, but the corrosion resistance is poor because Ni is not contained.
  • a fine alloy powder of RE2TM14B composition was prepared by the same manner as in Example 1, while a fine alloy powder in which ratios of Ni and Co in TM were made higher than those of RE2TM14B powder was prepared as a starting powder. After these powders were mixed, a sintered magnet was produced by the same manner as in Example 1.
  • the rare earth metal-transition metal series magnets having improved corrosion resistance and magnetic properties can be produced as compared with the conventional production method.
  • the corrosion resistance is improved, so that the considerable improvement of reliability as an industrial material is realized.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)

Abstract

Aimant permanent biphasé présentant d'excellentes caractéristique magnétiques ainsi qu'une grande résistance à la corrosion. On le fabrique en utilisant deux phases magnétiquement favorables en tant que matériaux de départ. L'une est une phase RE2TM14B possédant une densité élevée du flux résiduel; l'autre est une phase RE-TM à bas point de fusion et/ou une phase RE-TM-B contribuant à l'amélioration de l'aptitude au frittage et présentant une fonction de nettoyage de la frontière de grain de la phase principale, permettant au matériau résultant d'être une composition électrochimiquement noble.
EP90914967A 1989-10-12 1990-10-11 Aimant a base de tm-b-re resistant a la corrosion et procede de production de cet aimant Expired - Lifetime EP0447567B1 (fr)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
JP263946/89 1989-10-12
JP26394689 1989-10-12
JP335028/89 1989-12-26
JP33502889 1989-12-26
JP2269635A JP2675430B2 (ja) 1989-10-12 1990-10-09 耐蝕性希土類―遷移金属系磁石およびその製造方法
JP269635/90 1990-10-09
PCT/JP1990/001315 WO1991006107A1 (fr) 1989-10-12 1990-10-11 Aimant en metal de transition de terres rares resistant a la corrosion et procede de production de cet aimant

Publications (3)

Publication Number Publication Date
EP0447567A1 true EP0447567A1 (fr) 1991-09-25
EP0447567A4 EP0447567A4 (en) 1992-05-20
EP0447567B1 EP0447567B1 (fr) 1996-05-29

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Application Number Title Priority Date Filing Date
EP90914967A Expired - Lifetime EP0447567B1 (fr) 1989-10-12 1990-10-11 Aimant a base de tm-b-re resistant a la corrosion et procede de production de cet aimant

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EP (1) EP0447567B1 (fr)
JP (1) JP2675430B2 (fr)
KR (1) KR960013029B1 (fr)
CA (1) CA2044171C (fr)
DE (1) DE69027201T2 (fr)
WO (1) WO1991006107A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0553527A1 (fr) * 1992-01-29 1993-08-04 Sumitomo Special Metals Co., Ltd. Matériau en poudre pour des aimants permanents à base de terre rare-fer-bore
EP0561650A2 (fr) * 1992-03-19 1993-09-22 Sumitomo Special Metal Co., Ltd. Matière en poudre d'alliage pour aimants permanents R-Fe-B
EP0583041A1 (fr) * 1992-08-13 1994-02-16 Koninklijke Philips Electronics N.V. Procédé pour la fabrication d'un aimant permanent à base de NdFeB
EP0601943B1 (fr) * 1992-12-08 1998-05-20 Ugimag S.A. Poudre magnétique de type Fe-TR-B et aimants frittés correspondants et leur méthode de préparation
CN1044940C (zh) * 1992-08-13 1999-09-01 Ybm麦格奈克斯公司 基于钕铁硼的生产永久磁铁的方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5405455A (en) * 1991-06-04 1995-04-11 Shin-Etsu Chemical Co. Ltd. Rare earth-based permanent magnet
DE69202515T2 (de) * 1991-06-04 1995-09-21 Shinetsu Chemical Co Verfahren zur Herstellung von zweiphasigen Dauermagneten auf der Basis von Seltenen Erden.
CN1934283B (zh) 2004-06-22 2011-07-27 信越化学工业株式会社 R-Fe-B基稀土永磁体材料

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0261579A1 (fr) * 1986-09-16 1988-03-30 Tokin Corporation Méthode pour la fabrication d'un aimant permanent terre métal rare-fer-bore utilisant une poudre en alliage refroidi brusquement
EP0311049A2 (fr) * 1987-10-08 1989-04-12 Kawasaki Steel Corporation Aimant à métal de verre-rare résistant à la corrosion

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Publication number Priority date Publication date Assignee Title
JP2700643B2 (ja) * 1987-04-11 1998-01-21 株式会社トーキン 耐酸化性に優れた希土類永久磁石の製造方法
JPH0621324B2 (ja) * 1986-10-04 1994-03-23 信越化学工業株式会社 希土類永久磁石合金用組成物
JPS63127505A (ja) * 1986-11-17 1988-05-31 Taiyo Yuden Co Ltd 磁石及びその製造方法
JPH063763B2 (ja) * 1986-12-26 1994-01-12 信越化学工業株式会社 希土類永久磁石の製造方法
JP2948223B2 (ja) * 1987-03-31 1999-09-13 住友特殊金属 株式会社 耐食性のすぐれた高性能永久磁石及びその製造方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0261579A1 (fr) * 1986-09-16 1988-03-30 Tokin Corporation Méthode pour la fabrication d'un aimant permanent terre métal rare-fer-bore utilisant une poudre en alliage refroidi brusquement
EP0311049A2 (fr) * 1987-10-08 1989-04-12 Kawasaki Steel Corporation Aimant à métal de verre-rare résistant à la corrosion

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9106107A1 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0553527A1 (fr) * 1992-01-29 1993-08-04 Sumitomo Special Metals Co., Ltd. Matériau en poudre pour des aimants permanents à base de terre rare-fer-bore
EP0561650A2 (fr) * 1992-03-19 1993-09-22 Sumitomo Special Metal Co., Ltd. Matière en poudre d'alliage pour aimants permanents R-Fe-B
EP0561650B1 (fr) * 1992-03-19 1998-08-05 Sumitomo Special Metals Company Limited Procédé de fabrication des aimants permanents R-Fe-B
EP0583041A1 (fr) * 1992-08-13 1994-02-16 Koninklijke Philips Electronics N.V. Procédé pour la fabrication d'un aimant permanent à base de NdFeB
CN1044940C (zh) * 1992-08-13 1999-09-01 Ybm麦格奈克斯公司 基于钕铁硼的生产永久磁铁的方法
EP0601943B1 (fr) * 1992-12-08 1998-05-20 Ugimag S.A. Poudre magnétique de type Fe-TR-B et aimants frittés correspondants et leur méthode de préparation

Also Published As

Publication number Publication date
EP0447567B1 (fr) 1996-05-29
KR920701999A (ko) 1992-08-12
WO1991006107A1 (fr) 1991-05-02
DE69027201T2 (de) 1996-10-10
CA2044171A1 (fr) 1991-04-13
CA2044171C (fr) 2000-12-12
JP2675430B2 (ja) 1997-11-12
KR960013029B1 (ko) 1996-09-25
EP0447567A4 (en) 1992-05-20
JPH03250607A (ja) 1991-11-08
DE69027201D1 (de) 1996-07-04

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