Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • 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
  • H01F1/059—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and Va elements, e.g. Sm2Fe17N2
• • 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
  • H01F1/0302—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity characterised by unspecified or heterogeneous hardness or specially adapted for magnetic hardness transitions
  • H01F1/0306—Metals or alloys, e.g. LAVES phase alloys of the MgCu2-type

Definitions

• the present invention motors, speakers, relates Bond permanent magnet material used in such Akuchiyue one coater, a hard magnetic phase as represented by S m 2 F ei 7 N x in the same tissue, F e or F
• Bond permanent magnet material used in such Akuchiyue one coater, a hard magnetic phase as represented by S m 2 F ei 7 N x in the same tissue, F e or F
• An exchange spring magnet is a force that behaves as a single hard magnetic material due to the strong exchange coupling force between the two phases.At the same time, in the second quadrant of the demagnetization curve, the magnetization reversibly changes with the change in the external magnetic field. It shows a peculiar behavior of spring knocking and has attracted attention in recent years for applications that make optimal use of its effects.
• the method belonging to the first category is to start from a molten alloy having a adjusted composition and separate the phases during cooling and solidification or during subsequent heat treatment.
• Nd-Fe-B system An excessive amount of Fe is melted, solidified, and heat-treated to obtain a fine crystal aggregate of a Fe 3 B phase (soft magnetic phase) and a Nd 2 Fe 4 B phase (hard magnetic layer).
• a method belonging to the second category is a method in which acicular iron powder is used as a base material, and the surface portion is changed into a hard magnetic phase by chemical treatment and heat treatment, as disclosed in Japanese Patent Application Laid-Open No. 7-2712913.
• FeOOH gateite
• As a manufacturing method FeOOH (gateite) is heated to 300 to 500 ° C. in a hydrogen atmosphere in a state where needle crystals are coated with aluminum phosphate.
• the present invention particularly relates to an improvement of an exchange spring magnet by a method belonging to the above second category, and by stably diffusing and forming a hard magnetic layer on the surface of needle-like iron fine particles, it is possible to obtain a stable magnet. It is an object of the present invention to provide a permanent magnet powder having excellent magnetic properties, a method for producing the same, and an anisotropic permanent magnet using the powder.
• a powder for a permanent magnet of the present invention is characterized in that the base material is acicular fine particles of Fe or an alloy containing Co in Fe, and Fe, Sm and It is characterized by comprising a hard magnetic layer containing N, and an isolation layer made of a rare earth element oxide outside the hard magnetic layer.
• the powder for permanent magnet of the present invention has a hard magnetic layer on the surface of such acicular Fe fine particles, and is composed of acicular fine particles having an isolation layer outside the hard magnetic layer. It is characterized by being composed of sintered powder having a diameter of 100 to 100 / m. By providing such an isolation layer, the bonding between iron phases is suppressed during sintering, and a high-density sintered body with good dispersibility can be obtained.
• the isolation layer is coated with one or more metals of Zn, Sn, and Pb, an intermetallic compound is formed between Sm and these low-melting metals, and the coercive force is increased. Significantly improved.
• the matrix is needle-like fine particles of alloy containing Fe or Co in Fe, and the surface of the needle-like fine particles is Fe, Sm or the like.
• a powder for a permanent magnet comprising a hard magnetic layer containing N and N, and an isolation layer made of a rare earth element oxide outside the hard magnetic layer.
• the rare earth element one or more of Nd, La, Ce, Pr, Sm and Y can be used.
• a second aspect of the present invention is a permanent magnet powder comprising a sintered body powder having a particle size of 10 to 100 ⁇ m and comprising acicular fine particles provided with an isolation layer made of a rare earth oxide on the outside.
• a permanent magnet powder in which the isolation layer is coated with one or more metals of Zn, Sn, and Pb is defined as a third invention.
• needle-shaped Fe particles or Fe with a major axis of 0.1 to 3 ⁇ and a minor axis of 0.03 to 0.4 ⁇ m are used.
• Needle-like Fe-Co alloy particles containing Co are coated with a rare-earth element hydroxide by wet deposition, filtered, dried, and then hydrogen gas or inert gas or both. Heat treatment is performed in a mixed gas atmosphere, and the obtained needle-like Fe fine particles or needle-like Fe-Co alloy fine particles coated with a rare earth oxide are obtained at 500 to 100 ° C in a vacuum.
• a method for producing a powder for permanent magnets characterized by performing nitriding treatment at a fourth invention, is defined as a fourth invention.
• the major axis is 0; 3 —? 60 OH needle-shaped fine particles or ⁇ -F e ⁇ ⁇ H fine particles with Co-doped ⁇ -F e ⁇ ⁇ ⁇ Needle-like fine particles
• the surface of the element is coated with a hydroxide of a rare earth element by a wet deposition method, filtered, dried, and then heat-treated in an atmosphere containing hydrogen gas, and the obtained needle-shaped F coated with an oxide of the rare earth element is obtained.
• a fifth invention provides a method for producing powder for permanent magnets, which comprises forming a compound layer containing Fe and Sm on the surfaces of alloy fine particles, and then performing a nitriding treatment in a nitrogen-containing gas.
• Still another manufacturing method is a needle-like Fe fine particle having a major axis of 0.1 to 3 m and a minor axis of 0.03 to 0.4 ⁇ m or a needle-like F containing Co in Fe.
• the surface of e-Co alloy fine particles is coated with a rare earth element hydroxide by wet deposition, filtered, dried, and then heat treated in an atmosphere of hydrogen gas or inert gas or a mixture of both. Then, the obtained needle-like Fe fine particles or needle-like Fe—Co alloy fine particles coated with the oxide of the rare earth element are coated with Sm at 500 to 100 ° C. in a vacuum.
• a heat treatment is performed to form a compound layer containing Fe and Sm on the surface of the acicular Fe fine particles or acicular Fe-Co alloy fine particles, and then the acicular fine particles are exposed to a magnetic field.
• Permanent magnet characterized by sintering at 700 to 1000 C, then pulverizing to a particle size of 100 to 100 m, and nitriding in a nitrogen-containing gas.
• the manufacturing method of use powder shall be the sixth invention.
• ⁇ -FeOOH needle-shaped fine particles having a major axis of 0.1 to 3 / m and a minor axis of 0.03 to 0.4 ⁇ are used.
• the surface of the a-FeOOH needle-shaped fine particles in which fine particles are doped with Co is coated with a rare-earth element hydroxide by a wet deposition method, filtered, dried, and then heat-treated in an atmosphere containing hydrogen gas.
• a seventh invention provides a method for producing powder for permanent magnets, characterized by pulverizing to a particle size of 100 to 100 / m and further performing nitriding treatment in a nitrogen-containing gas.
• the permanent magnet according to the fourth or fifth invention further comprising, after the nitriding treatment, a treatment of coating the surface with one or more metals of Zn, Sn, and Pb.
• the method for producing the powder for use is the eighth invention.
• the base is needle-like fine particles of Fe or an alloy containing Co in Fe, and Fe
• S A permanent magnet powder comprising a hard magnetic layer containing m and N and an isolating layer made of a rare earth element oxide on the outside of the hard magnetic layer is kneaded with a resin, and is subjected to heat compression molding in a magnetic field.
• the resulting anisotropic permanent magnet is a ninth invention.
• the base is a needle-like fine particle of Fe or an alloy containing Co in Fe, and a hard magnetic layer containing Fe, Sm and N on the surface of the needle-like fine particle.
• a permanent magnet powder composed of sintered powder having a particle size of 10 to 100 / m and comprising acicular fine particles having an isolation layer made of an oxide of a rare earth element outside the hard magnetic layer;
• a tenth invention is directed to an anisotropic permanent magnet obtained by kneading the powder with a resin and subjecting the mixture to heat compression molding in a magnetic field.
• the base is needle-like fine particles of Fe or an alloy containing Co in Fe, and a hard magnetic layer containing Fe, Sm, and N on the surface of the needle-like fine particles.
• An anisotropic permanent magnet obtained by kneading a powder for a permanent magnet coated with one or more metals of Pb with a resin and subjecting it to heat compression molding in a magnetic field is described in the eleventh paragraph. Invention.
• the base is needle-like fine particles of Fe or an alloy containing Co in Fe, and a hard magnetic layer containing Fe, Sm, and N on the surface of the needle-like fine particles.
• a permanent magnet provided with an isolating layer made of a rare earth oxide outside the hard magnetic layer, and coating the isolating layer with one or more metals of Zn, Sn, and Pb;
• a twelfth invention is directed to an anisotropic permanent magnet obtained by subjecting powder for use to heating and compression molding using the metal as a binder.
• the long axis of the needle-like fine particles of Fe or Fe—Co alloy is set to 0.;! To 3 / im, the short axis is set to 0.03 to 0.4 ⁇ ,
• the aspect ratio is preferably set to 2 or more. However, when the aspect ratio exceeds 15, twins are generated, and the fluidity of the fine particles is poor, making handling difficult. If the minor axis is less than 0.3 ⁇ , it is difficult to control the thickness of the Sm diffusion layer in the subsequent formation of the Fe—Sm compound layer, and stable magnetic properties cannot be obtained.
• the method for producing the needle-like Fe fine particles include a reduction method using FeOOH as a raw material, an electrolytic deposition method, and the like.
• the element constituting the isolation layer a rare earth element or CaO is preferable, but among the rare earth elements, Pr or Nd can be suitably used from the viewpoint of adhesion.
• the purpose of the separating layer is to separate needle-like fine particles from each other as described above, and to suppress a decrease in the aspect ratio.
• the isolation layer constituent elements have a higher oxygen affinity than the constituent elements of the hard magnetic layer. Also prevents peeling during the heat treatment process Therefore, it is preferable that the isolation layer has high adhesion.
• the needle-like fine particles of the Fe or Fe-Co alloy rather than completely covering the needle-like fine particles of the Fe or Fe-Co alloy with an isolating layer of rare earth element oxide of a certain thickness, it is porous isolation with fine particle oxides of rare earth elements. It is important to form a layer, which leads to uniform deposition of Sm and a uniform hard magnetic layer on the fine particles of Fe or Fe-Co alloy needles. is there.
• a salt of a rare earth element is added to a suspension of FeOOH needle-like fine particles, needle-like Fe fine-particles or Fe—Co needle-like fine particles, and NH 4
• the solution can be made alkaline by adding OH or the like, and the surface of the needle-like fine particles can be coated by precipitating a hydroxide of a rare earth element.
• Known wet precipitation methods such as forward addition, reverse addition, simultaneous addition, gas precipitation, hydrothermal treatment, and coprecipitation can be used.
• the thickness of the Fe-Sm compound layer formed on the surface of the acicular Fe fine particles or Fe-Co needle-like fine particles is 0.01 to 0.1 ⁇ m, preferably 0, as the sum of both sides. 0.02 to 0.08 ⁇ , more preferably 0.02 to 0.05 ⁇ . The reason is that when the iron fine particles exceed 0 in the minor axis direction, the domain wall is stably present, and the coercive force is significantly reduced.
• the isolation layer When the isolation layer is coated with one or more metals of Zn, Sn, and Pb, an intermetallic compound of Sm of the hard magnetic layer and these low-melting metals is generated, and the coercive force Is greatly improved.
• low melting point metals such as Zn, Sn, and Pb are nonmagnetic
• the thickness of the low melting point metal coating exceeds 0.3 / m, the value of magnetization is significantly reduced.
• the thickness of the low-melting-point metal coating is less than 0.01 / zm, the effect of improving the coercive force cannot be obtained.
• the permanent magnet powder comprising the sintered compact powder according to the second invention when the sintering temperature is less than 700 ° C., the density does not increase. If the temperature exceeds 100 ° C., the particles become coarse, and the magnetic characteristics are degraded. In order to pulverize the sintered acicular fine particles to obtain a sintered body powder, it is preferable to pulverize the particles into a particle size of 10 to 100 ⁇ m. This is because a high orientation is difficult to obtain below 100 im, and a green compact density lower than 100 im.
• a powder for a permanent magnet having stable and excellent magnetic properties can be obtained.
• the production method and an anisotropic permanent magnet using the powder can be provided.
• FIG. 1 is a diagram schematically showing a change in raw material particles until a magnet molded body is obtained from a magnet raw material.
• FIG. 2 is a diagram showing a flow of processing steps until a magnet molded body is obtained from a magnet raw material.
• Talox Synthetic Iron Oxide Yellow LL-XLO manufactured by Titanium Industry Co., Ltd.
• major axis average 7.3 ⁇ m
• minor axis average 0.0
• Obtained by electrolysis of iron salt solution with fine needle-like ⁇ -FeOOH fine particles of 7 ⁇ or mercury cathode see US Pat. No. 2,239,144.
• Long axis 0.5 to 1.0 m
• Fine needle-like electrodeposited Fe fine particles having a minor axis of about 0.03 ⁇ m were used as a raw material.
• in aqueous ammonia was added to F e ion and C o ion (F e o. 7 C o 3) (OH) coprecipitated in 2 forms, which was air oxidized in solution at 7 0 ° C (F e .. 7 Co 3 ) into needle-like fine particles of OOH, filtered and dried to obtain a starting material.
• Fig. 1 (a) shows a schematic diagram of the raw material needle-shaped fine particles.
• FIG. 2 is a flowchart showing the details of each process described below.
• FIG. 1 (b) shows a schematic diagram of the coated Fe-FeOOH needle-shaped fine particles.
• ⁇ -FeOOH needle-like fine particles were used as the starting material. Therefore, to obtain needle-like Fe fine particles coated with an oxide of a rare earth element, it was necessary to use heat treatment during the heat treatment.
• the atmosphere is a force that uses a gas containing hydrogen gas.When the needle-like Fe fine particles are used as a starting material, it is not always necessary to use an atmosphere containing hydrogen gas, and an inert gas such as nitrogen or Ar is used as an atmosphere gas. It can also be adopted as
• Fig. 1 (e) shows a schematic diagram of such acicular Fe fine particles.
• zinc coating is performed by photodecomposition of zinc (a needle-like Fe fine particle is put in a solution of getyl zinc / n-hexane and irradiated with ultraviolet rays to decompose getyl zinc.
• a method of covering with zinc metal can also be used.
• low melting point metals other than zinc such as tin and lead
• the pellet-shaped material is put into a hot press machine.
• a green compact as shown in FIG. 1 (f) was obtained by hot compression at 420 ° C. for 2 hours at a pressure of 7 ton / cm 2 .
• the pellet-shaped body was hot-rolled at 300 ° C to a thickness of 2 cm by a rolling mill, and the resulting molded product was cut and ground. A molded body as shown in Fig. (F) was obtained.
• the pelletized body was hot-extruded at 300 ° C by an extruder, and the resulting molded product was cut.
• the nitridized zinc-coated acicular Fe fine particles prepared up to A (5) described above are mixed and kneaded with an epoxy resin (about 3% by weight of the raw material fine particles), and are oriented in a magnetic field of 15 kOe. Pressing was performed at a pressure of ton / cm 2 , and then a curing treatment was performed at 120 ° C. for 1 hour to obtain a resin-bonded permanent magnet.
• the magnets were manufactured by the above method, and six kinds of starting materials were used as shown in Table 1 below.
• Table 1 the analysis results of the metal elements after the formation of the Sm-Fe compound layer are shown in terms of the atomic ratio. Then, all of the magnets obtained were processed to a cross section of 10 mm XIO mm, and a DC BH tracer (manufactured by Toshiba Corporation) was used to measure the magnet performance of each magnet. The results are shown in Table 2 below.

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

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• 1996
  • 1996-11-06 JP JP29404996A patent/JP3647995B2/ja not_active Expired - Fee Related
• 1997
  • 1997-11-04 WO PCT/JP1997/004012 patent/WO1998020507A1/ja not_active Ceased
  • 1997-11-04 US US09/284,446 patent/US6328817B1/en not_active Expired - Fee Related
  • 1997-11-04 EP EP97909739A patent/EP0938105B1/en not_active Expired - Lifetime
  • 1997-11-04 DE DE69725750T patent/DE69725750T2/de not_active Expired - Lifetime
  • 1997-11-04 AT AT97909739T patent/ATE252764T1/de not_active IP Right Cessation

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