WO2016175069A1 - 希土類磁石の製造方法 - Google Patents

希土類磁石の製造方法 Download PDF

Info

Publication number
WO2016175069A1
WO2016175069A1 PCT/JP2016/062215 JP2016062215W WO2016175069A1 WO 2016175069 A1 WO2016175069 A1 WO 2016175069A1 JP 2016062215 W JP2016062215 W JP 2016062215W WO 2016175069 A1 WO2016175069 A1 WO 2016175069A1
Authority
WO
WIPO (PCT)
Prior art keywords
powder
rare earth
magnet body
sintered magnet
producing
Prior art date
Application number
PCT/JP2016/062215
Other languages
English (en)
French (fr)
Inventor
幸弘 栗林
尚吾 神谷
治和 前川
慎太郎 田中
Original Assignee
信越化学工業株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 信越化学工業株式会社 filed Critical 信越化学工業株式会社
Priority to MYPI2017703918A priority Critical patent/MY182702A/en
Priority to US15/570,233 priority patent/US11084059B2/en
Priority to CN201680023920.2A priority patent/CN107533909B/zh
Priority to EP16786346.3A priority patent/EP3291263B1/en
Publication of WO2016175069A1 publication Critical patent/WO2016175069A1/ja
Priority to PH12017501970A priority patent/PH12017501970B1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/02—Processes for applying liquids or other fluent materials performed by spraying
    • B05D1/04—Processes for applying liquids or other fluent materials performed by spraying involving the use of an electrostatic field
    • B05D1/06—Applying particulate materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/025—Discharge apparatus, e.g. electrostatic spray guns
    • B05B5/053—Arrangements for supplying power, e.g. charging power
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/08—Plant for applying liquids or other fluent materials to objects
    • B05B5/082—Plant for applying liquids or other fluent materials to objects characterised by means for supporting, holding or conveying the objects
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/24—After-treatment of workpieces or articles
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
    • H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • 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
    • H01F1/06—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 in the form of particles, e.g. powder
    • H01F1/08—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 in the form of particles, e.g. powder pressed, sintered, or bound together
    • H01F1/086—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 in the form of particles, e.g. powder pressed, sintered, or bound together sintered
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/0293—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B13/00—Machines or plants for applying liquids or other fluent materials to surfaces of objects or other work by spraying, not covered by groups B05B1/00 - B05B11/00
    • B05B13/02—Means for supporting work; Arrangement or mounting of spray heads; Adaptation or arrangement of means for feeding work
    • B05B13/0221—Means for supporting work; Arrangement or mounting of spray heads; Adaptation or arrangement of means for feeding work characterised by the means for moving or conveying the objects or other work, e.g. conveyor belts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/025—Discharge apparatus, e.g. electrostatic spray guns
    • B05B5/035—Discharge apparatus, e.g. electrostatic spray guns characterised by gasless spraying, e.g. electrostatically assisted airless spraying
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys

Definitions

  • the present invention applies a powder containing a rare earth compound to a sintered magnet body and heat-treats it to absorb the rare earth element in the sintered magnet body.
  • the present invention relates to a method for producing a rare earth magnet that can be efficiently applied to obtain a rare earth magnet excellent in magnetic properties.
  • Rare earth permanent magnets such as Nd—Fe—B are increasingly used for their excellent magnetic properties.
  • a rare earth compound powder is applied to the surface of the sintered magnet body and heat treated, and the rare earth element is absorbed and diffused into the sintered magnet body to obtain a rare earth permanent magnet.
  • Patent Document 1 Japanese Patent Laid-Open No. 2007-53351
  • Patent Document 2 International Publication No. 2006/043348
  • the coercive force is reduced while suppressing a decrease in residual magnetic flux density. It can be increased.
  • the rare earth compound is applied by immersing the sintered magnet body in a slurry in which the powder containing the rare earth compound is dispersed in water or an organic solvent, or spraying the slurry onto the sintered magnet body.
  • the drying method is generally used, but it is difficult to control the amount of powder applied by the dipping method or spray method, and the rare earth element cannot be sufficiently absorbed. In some cases, valuable rare earth elements are wasted.
  • the film thickness of the coating film tends to vary and the film density is not high, an excessive coating amount is required to increase the coercive force to saturation.
  • the adhesive force of the coating film made of powder is low, workability from the coating process to the completion of the heat treatment process is not necessarily good.
  • the present invention has been made in view of the above circumstances.
  • R 1 is one or more selected from rare earth elements including Y and Sc.
  • R 2 is one or more selected from rare earth elements including Y and Sc.
  • the present inventors have an R 1 —Fe—B-based composition (R 1 is one or more selected from rare earth elements including Y and Sc).
  • the sintered magnet body surface, oxides of R 2 is selected fluorides from acid fluorides, hydroxides or hydrides (R 2 is at least one element selected from rare earth elements inclusive of Y and Sc)
  • R 1 is one or more selected from rare earth elements including Y and Sc
  • the sintered magnet body surface, oxides of R 2 2 is selected fluorides from acid fluorides, hydroxides or hydrides
  • R 2 is at least one element selected from rare earth elements inclusive of Y and Sc
  • a rare earth permanent magnet is manufactured by applying a powder containing one or more kinds and heat-treating the powder, the powder is sprayed onto a grounded sintered magnet body, and the powder is applied to the sintered magnet body.
  • electrostatic coating the powder can be applied uniformly and efficiently, and the coating amount can be controlled to form a dense powder coating film with good adhesion, with better magnetic properties
  • a sintered magnet body having an R 1 —Fe—B-based composition (R 1 is one or more selected from rare earth elements including Y and Sc), an oxide of R 2 , a fluoride, an acid
  • a powder containing one or more selected from fluorides, hydroxides or hydrides (R 2 is one or more selected from rare earth elements including Y and Sc) is applied and heat-treated to form R
  • the sintered magnet body is held in a grounded and highly conductive jig, and the charged powder is sprayed onto the sintered magnet body. And providing the powder to the sintered magnet body by electrostatic coating the powder onto the sintered magnet body.
  • the present inventors have found that charging by the corona discharge is preferable for charging the powder, and applying a liquid to the coating film of the powder to make it wet once, and then drying this
  • the coercive force can be further improved by performing a heat treatment after being applied, a suitable jig mode, a suitable applied voltage when charging the powder using a corona gun, and a suitable amount of powder applied thereby Etc.
  • the present invention provides the following inventions [2] to [8] as preferred embodiments.
  • [2] The method for producing a rare earth magnet according to [1], wherein the electrostatic coating is performed by charging the powder by corona discharge.
  • [3] The above-mentioned powder is corona-charged and sprayed using a corona gun, and the electrostatic coating is performed. At that time, the applied voltage to the tip of the corona gun is set to -60 kV or more and the powder is applied to the sintered magnet [2]
  • [6] The method for producing a rare earth magnet according to [4] or [5], wherein the spray amount of the liquid is 1 ml / dm 2 or more.
  • [7] The method for producing a rare earth magnet according to any one of [4] to [6], wherein the liquid is pure water.
  • the jig is made of a material selected from copper, copper alloy, aluminum, iron, iron alloy, and titanium, and the sintered magnet body is sandwiched and held by a holding portion having a sharp tip.
  • powder application can be performed without requiring complicated operations and steps such as preparing a slurry by dispersing a rare earth compound powder in a solvent, and the charge potential and spray amount of the powder can be reduced.
  • the coating amount can be controlled easily and surely to form a dense powder coating film with good adhesion, and in addition, non-adhering powder can be easily and easily compared with the case where slurry is applied. It can be recovered efficiently.
  • the rare earth compound powder can be uniformly applied to the surface of the sintered magnet body and the coating operation can be performed very efficiently, the coercive force is excellent.
  • a rare earth magnet excellent in increased magnetic properties can be efficiently produced.
  • the method for producing a rare earth magnet of the present invention is applied to a sintered magnet body having an R 1 —Fe—B-based composition
  • R 1 is one or more selected from rare earth elements including Y and Sc.
  • oxide of R 2 fluoride, acid fluoride, hydroxide or hydride
  • R 2 is at least one element selected from rare earth elements inclusive of Y and Sc
  • powder is applied heat treatment containing
  • R 2 is absorbed by the sintered magnet body to produce a rare earth magnet.
  • R 1 —Fe—B based sintered magnet body one obtained by a known method can be used.
  • a mother alloy containing R 1 , Fe, B is roughly pulverized, finely pulverized, according to a conventional method. It can be obtained by molding and sintering.
  • R 1 is one or more selected from rare earth elements including Y and Sc, specifically, Y, Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb. , Dy, Ho, Er, Yb and Lu.
  • the R 1 —Fe—B based sintered magnet body is formed into a predetermined shape by grinding or the like, if necessary, and the surface thereof has an R 2 oxide, fluoride, oxyfluoride, hydroxide, A powder containing one or more hydrides is applied and heat treated to absorb and diffuse (granular boundary diffusion) into the sintered magnet body to obtain a rare earth magnet.
  • R 2 is one or more selected from rare earth elements including Y and Sc, and Y, Sc, La, Ce, Pr, Nd, Sm, Eu are selected in the same manner as R 1. , Gd, Tb, Dy, Ho, Er, Yb and Lu.
  • one or a plurality of R 2 contains Dy or Tb in a total of 10 atomic% or more, more preferably 20 atomic% or more, particularly 40 atomic% or more.
  • R 2 contains 10 atomic% or more of Dy and / or Tb, and the total concentration of Nd and Pr in R 2 is lower than the total concentration of Nd and Pr in R 1 . More preferred.
  • the particle diameter of the powder containing one or more of the oxides, fluorides, oxyfluorides, hydroxides, and hydrides of R 2 is not particularly limited, and absorption diffusion (grain boundary diffusion)
  • the particle size of the rare-earth compound powder used in (1) is generally 100 ⁇ m or less, more preferably 10 ⁇ m or less.
  • the lower limit is not particularly limited, but is preferably 1 nm or more.
  • This average particle diameter can be determined as a mass average value D 50 (that is, a particle diameter or a median diameter when the cumulative mass is 50%), for example, using a particle size distribution measuring apparatus using a laser diffraction method or the like.
  • the powder is applied to the sintered magnet body by holding the sintered magnet body and spraying the charged powder to the grounded sintered magnet body. This is done by painting.
  • the method for charging the powder may be a friction charging method for frictionally charging the powder or a corona charging method for charging the powder by corona discharge, but can be charged without being affected by the material of the powder.
  • the corona charging method is preferably used because the optimum coating conditions are easily obtained as compared with frictional charging.
  • powder can be charged and sprayed using a commercially available electrostatic coating gun.
  • a corona charging system an automatic powder gun “X-3a” manufactured by Asahi Sunac Co., Ltd.
  • friction As a charging method an automatic powder gun “T-3a” manufactured by Asahi Sunac Corporation can be used.
  • the amount of powder applied can be adjusted by adjusting the voltage applied to the tip of the corona gun and the amount of powder supplied. Can be adjusted relatively.
  • the applied voltage to the tip of the corona gun is set to ⁇ 60 kV or more, particularly ⁇ 70 kV to ⁇ 80 kV, and a predetermined amount of powder is quantitatively supplied using a quantitative supply device or the like. By doing so, it is preferable to adjust the amount applied to the sintered magnet body to be 850 mg / dm 2 or more.
  • the sintered magnet body is held by a highly conductive jig, and is subjected to the electrostatic coating while being grounded via the jig.
  • the highly conductive material for forming the jig is not particularly limited, but copper, copper alloy, aluminum, iron, iron alloy, titanium, and the like are preferably used.
  • tool What is necessary is just to set it as a suitable form according to the shape, size, etc. of a sintered magnet body.
  • a jig configured to sandwich and hold the sintered magnet body in a holding portion having a sharp tip formed can be suitably used.
  • reference numeral 1 in FIG. 1 is a square frame base, and four holding arms 2 are erected on the base 1.
  • the holding arm 2 is a holding portion 21 whose tip is bent like a bowl and whose tip is formed in a sharp conical shape.
  • Two holding arms 2 are set as one set, and two sets are erected with the holding portions 21 facing each other.
  • the sintered magnet body 3 is held by the holding portions 21 of the holding arms 2.
  • This jig is made of the above-mentioned highly conductive material.
  • the powder is formed in portions other than the contact with the sintered magnet body 3 of the holding portion 21 and the electrical contact for grounding (not shown). It is preferable to coat with plastisol or the like so as not to adhere.
  • the sintered magnet body in which the powder is applied in this way to form a coating film of the powder is absorbed and diffused into the sintered magnet body by the heat treatment in the next step.
  • the powder adhering to the surface is likely to be scattered as it is, and even if the amount is small until the heat treatment, the effect of increasing the coercive force and the uniformity may be slightly reduced due to the scattering of the powder.
  • the liquid to be applied include alcohols such as ethyl alcohol and pure water, but pure water is particularly preferably used from the viewpoint of cost.
  • the application of the liquid can be performed by spraying.
  • a liquid such as pure water is sprayed on the surface of the sintered magnet body, and the sintered magnet is in a state where the pure water is present on the surface.
  • a sufficient liquid application effect can be obtained both before and after electrostatic coating.
  • a liquid such as pure water is sprayed on the surface of the sintered magnet body before electrostatic coating.
  • a better effect can be obtained.
  • the amount of liquid such as pure water to be applied is not particularly limited and is appropriately set according to the size and shape of the sintered magnet body, the particle size of the powder, the thickness of the coating film to be formed, etc. It is preferably 1 ml / dm 2 or more, particularly 2 to 3 ml / dm 2 .
  • the powder coating by electrostatic coating is performed by transporting the sintered magnet body held by the jig using, for example, a hanger transport rail and continuously performing the electrostatic coating processing on a plurality of sintered magnet bodies. It can cope with mass production. For example, the manufacturing facility shown in FIG. 2 can be illustrated.
  • reference numeral 4 in FIG. 2 denotes a hanger transport rail for transporting the sintered magnet body attached to the jig at a predetermined speed.
  • the load / unload unit 5 attaches the sintered magnet body to the jig and attaches the hanger.
  • the sintered magnet body was transported along the transport rail 4 and passed through the pretreatment unit 6, the electrostatic coating unit 7 and the drying unit 8 in order to form a coating film of the powder, and this coating film was formed.
  • the sintered magnet body is recovered by the load / unload unit 5.
  • the pretreatment section 6 is provided with a surface treatment booth 61 and a back treatment booth 62, and pure water is sprayed on both the front and back surfaces of the sintered magnet body by the pure water spray gun 63 in these treatment booths 61 and 62. .
  • the electrostatic coating unit 7 is provided with a surface coating booth 71 and a backside coating booth 72. In these coating booths 61 and 62, electrostatic coating is applied to the sintered magnet body grounded via the jig. The powder charged by the gun 73 is sprayed, and the powder is electrostatically coated on both the front and back surfaces of the sintered magnet body. Further, the drying unit 8 is subjected to a drying process at a temperature of about 50 to 70 ° C. for 5 to 10 minutes.
  • the sintered magnet body coated with the rare earth compound powder is heat-treated, and the R 2 in the rare earth compound is absorbed and diffused in the sintered magnet body, thereby obtaining a rare earth permanent magnet. Is.
  • the heat treatment for absorbing and diffusing rare earth elements represented by R 2 may be performed according to a known method. Further, after the heat treatment, known post-treatment can be performed as necessary, such as aging treatment under appropriate conditions or further grinding into a practical shape.
  • Example 1 A thin plate-like alloy in which Nd is 14.5 atomic%, Cu is 0.2 atomic%, B is 6.2 atomic%, Al is 1.0 atomic%, Si is 1.0 atomic%, and Fe is the balance.
  • strip casting method in which Nd, Al, Fe, Cu metal with a purity of 99% by mass or more, high-frequency dissolution in an Ar atmosphere using 99.99% by mass of Si, ferroboron, and then poured into a single copper roll A thin plate-like alloy was used. The obtained alloy was exposed to hydrogenation of 0.11 MPa at room temperature to occlude hydrogen, then heated to 500 ° C. while evacuating to partially release hydrogen, cooled and sieved, A coarse powder of 50 mesh or less was obtained.
  • the coarse powder was finely pulverized by a jet mill using high-pressure nitrogen gas to a weight-median particle size of 5 ⁇ m.
  • the obtained mixed fine powder was molded into a block shape at a pressure of about 1 ton / cm 2 while being oriented in a magnetic field of 15 kOe under a nitrogen atmosphere.
  • This compact was put into a sintering furnace in an Ar atmosphere and sintered at 1060 ° C. for 2 hours to obtain a magnet block.
  • This magnet block was ground on the whole surface using a diamond cutter, then washed with alkali solution, pure water, nitric acid, pure water in this order and dried to obtain 40 mm ⁇ 20 mm ⁇ 5 mm (direction of magnetic anisotropy).
  • a block magnet was obtained.
  • the sintered magnet body is attached to a jig in which a plurality of jigs shown in FIG. 1 are arranged and grounded, and dysprosium fluoride is used by using an electrostatic powder coating apparatus “XR4-100PS” manufactured by Asahi Sannak Co., Ltd.
  • the powder was corona charged and sprayed and applied at 850 mg / dm 2 or more to form a coating film of dysprosium fluoride powder on the surface of the sintered magnet body.
  • the set voltage at the tip of the corona gun was 75 kV ⁇ 80 ⁇ A.
  • the sintered magnet body By subjecting the sintered magnet body, on which the dysprosium fluoride coating film has been formed, to heat treatment at 900 ° C. for 5 hours in an Ar atmosphere and then to absorption treatment, followed by aging treatment at 500 ° C. for 1 hour and quenching. A rare earth magnet was obtained. With respect to the three samples, a magnet body was cut out to 2 mm ⁇ 2 mm ⁇ 5 mm from nine locations at the center and end of the magnet shown in FIG. 3, and its coercive force was measured. Table 1 shows the average value of the nine coercive forces for each sample.
  • Example 2 The sintered magnet body obtained in the same manner as in Example 1 is held in a jig, and pure water is sprayed to give 3 ml / dm 2 of pure water to the surface of the sintered magnet body to wet the surface of the sintered magnet body. It was in the state.
  • a dysprosium fluoride powder was applied to the sintered magnet body in the same manner as in Example 1 to form a coating film of the dysprosium fluoride powder. After drying this at 60 ° C. for 5 minutes, a heat treatment was performed in the same manner as in Example 1 to obtain a rare earth magnet, and the coercive force was measured in the same manner. The results are shown in Table 1.
  • Example 3 After applying the dysprosium fluoride powder to the sintered magnet body obtained in the same manner as in Example 1 to form a coating film of dysprosium fluoride powder, this sintered magnet body was obtained. Pure water was sprayed on to give 3 ml / dm 2 of pure water to make the coating film wet. After drying this at 60 ° C. for 5 minutes, a heat treatment was performed in the same manner as in Example 1 to obtain a rare earth magnet, and the coercive force was measured in the same manner. The results are shown in Table 1.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)

Abstract

接地された良導電性の治具に上記焼結磁石体を保持し、この焼結磁石体に希土類化合物の粉末を帯電させて噴霧し、該粉末を上記焼結磁石体に静電塗装することにより、上記焼結磁石体に上記粉末を塗布し、熱処理して希土類磁石を製造する。これにより、希土類化合物の粉末を均一に焼結磁石体表面に塗布することができ、しかもその塗布操作を極めて効率的に行うことができる。

Description

希土類磁石の製造方法
　本発明は、焼結磁石体に、希土類化合物を含有する粉末を塗布し熱処理して希土類元素を焼結磁石体に吸収させ、希土類永久磁石を製造する際に、上記希土類化合物の粉末を均一かつ効率的に塗布して磁気特性に優れた希土類磁石を効率的に得ることができる希土類磁石の製造方法に関する。
　Ｎｄ－Ｆｅ－Ｂ系などの希土類永久磁石は、その優れた磁気特性のために、ますます用途が広がってきている。従来、この希土類磁石の保磁力を更に向上させる方法として、焼結磁石体の表面に希土類化合物の粉末を塗布して熱処理し、希土類元素を焼結磁石体に吸収拡散させて希土類永久磁石を得る方法が知られており（特許文献１：特開２００７－５３３５１号公報、特許文献２：国際公開第２００６／０４３３４８号）、この方法によれば、残留磁束密度の減少を抑制しつつ保磁力を増大させることが可能である。
　しかしながら、この方法は更に改善の余地を残している。即ち、従来上記希土類化合物の塗布には、該希土類化合物を含む粉末を水や有機溶媒に分散させたスラリーに焼結磁石体を浸漬して、又は該スラリーを焼結磁石体にスプレーして塗布し、乾燥させる方法が一般的であるが、浸漬法やスプレー法では、粉末の塗着量をコントロールすることが難しく、希土類元素を十分に吸収させることができなかったり、逆に必要以上の粉末が塗布され貴重な希土類元素を無駄に消費してしまう場合もある。また、塗膜の膜厚にバラツキが生じやすく、膜の緻密性も高くないため、保磁力増大を飽和にまで高めるには過剰な塗着量が必要になる。更に、粉末からなる塗膜の密着力が低いために塗着工程から熱処理工程が完了するまでの作業性が必ずしも良好なものではない。
　このため、希土類化合物の粉末を均一かつ効率的に塗布することができ、しかも塗着量をコントロールして緻密な粉末の塗膜を密着性よく形成することができる塗布方法の開発が望まれる。
特開２００７－５３３５１号公報 国際公開第２００６／０４３３４８号
　本発明は、上記事情に鑑みなされたもので、Ｒ1－Ｆｅ－Ｂ系組成（Ｒ1はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）からなる焼結磁石体表面に、Ｒ2の酸化物、フッ化物、酸フッ化物、水酸化物又は水素化物（Ｒ2はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）から選ばれる１種又は２種以上を含有する粉末を塗布し熱処理して希土類永久磁石を製造する際に、粉末を均一かつ効率的に塗布することができ、しかも塗着量をコントロールして緻密な粉末の塗膜を密着性よく形成することができ、より磁気特性に優れた希土類磁石を効率的に得ることができる希土類磁石の製造方法を提供することを目的とする。
　本発明者らは、上記目的を達成するため鋭意検討を行った結果、Ｒ1－Ｆｅ－Ｂ系組成（Ｒ1はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）からなる焼結磁石体表面に、Ｒ2の酸化物、フッ化物、酸フッ化物、水酸化物又は水素化物（Ｒ2はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）から選ばれる１種又は２種以上を含有する粉末を塗布し熱処理して希土類永久磁石を製造する場合に、上記粉末を帯電させて接地した焼結磁石体に噴霧し、該粉末を上記焼結磁石体に静電塗装することによって、該粉末を均一かつ効率的に塗布することができ、しかも塗着量をコントロールして緻密な粉末の塗膜を密着性よく形成することができ、より磁気特性に優れた希土類磁石を効率的に得ることができることを見い出し、本発明を完成したものである。
　従って、本発明は、
［１］　Ｒ1－Ｆｅ－Ｂ系組成（Ｒ1はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）からなる焼結磁石体に、Ｒ2の酸化物、フッ化物、酸フッ化物、水酸化物又は水素化物（Ｒ2はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）から選ばれる１種又は２種以上を含有する粉末を塗布し熱処理してＲ2を焼結磁石体に吸収させる希土類永久磁石の製造方法において、接地された良導電性の治具に上記焼結磁石体を保持し、帯電させた上記粉末をこの焼結磁石体に噴霧して該粉末を上記焼結磁石体に静電塗装することにより、上記焼結磁石体に上記粉末を塗布することを特徴とする希土類磁石の製造方法
を提供する。
　また、本発明者らは、更に検討を進めた結果、上記粉末の帯電にはコロナ放電による帯電が好ましいこと、上記粉末の塗膜に液体を付与して一旦湿らせた状態とし、これを乾燥させた後に熱処理を行うことにより更に保磁力を向上させ得ること、好適な治具の態様、更にコロナガンを用いて上記粉末を帯電させる際の好適な印加電圧と、それによる好適な粉末の塗布量などを見い出した。
　従って、本発明は好適な実施態様として、下記［２］～［８］の発明を提供する。
［２］　コロナ放電により上記粉末を帯電させて上記静電塗装を行う［１］の希土類磁石の製造方法。
［３］　コロナガンを用いて上記粉末をコロナ帯電させて噴霧し上記静電塗装を行うと共に、その際にコロナガン先端部への印加電圧を－６０ｋＶ以上とし、上記粉末の焼結磁石体への塗布量を８５０ｍｇ／ｄｍ2以上とする［２］の希土類磁石の製造方法。
［４］　上記静電塗装を施す前に上記焼結磁石体表面に液体をスプレーし、該焼結磁石体表面に液体が存在した状態で上記静電塗装を施して上記粉末の塗膜を形成し、これを乾燥させた後、上記熱処理を行う［１］～［３］のいずれかの希土類磁石の製造方法。
［５］　上記静電塗装を行った後、上記焼結磁石体表面に形成された上記粉体の塗膜に液体をスプレーして該塗膜を湿らせ、これを乾燥させた後、上記熱処理を行う［１］～［３］のいずれかの希土類磁石の製造方法。
［６］　上記液体のスプレー量が、１ｍｌ／ｄｍ2以上である［４］又は［５］の希土類磁石の製造方法。
［７］　上記液体が純水である［４］～［６］のいずれかの希土類磁石の製造方法。
［８］　上記治具が、銅、銅合金、アルミニウム、鉄、鉄合金、チタニウムから選ばれる材料からなり、先端が尖鋭に形成された保持部に上記焼結磁石体を挟持して保持するように構成されていると共に、該保持部の焼結磁石体との接点及び接地用の電気的接続点以外の部位がプラチゾルでコーティングされたものである［１］～［７］のいずれかの希土類磁石の製造方法。
　本発明によれば、希土類化合物の粉末を溶媒に分散させてスラリーを調製するなどの煩雑な作業や工程を要することなく、粉末の塗布を行うことができ、しかも粉末の帯電電位や噴霧量を調節することにより、容易かつ確実に塗着量をコントロールして緻密な粉末の塗膜を密着性よく形成することができ、その上、スラリーを塗布する場合に比べて未付着の粉末を容易かつ効率的に回収することができる。
　従って、本発明によれば、このように希土類化合物の粉末を均一に焼結磁石体表面に塗布することができ、しかもその塗布操作を極めて効率的に行うことができるので、保磁力が良好に増大された磁気特性に優れた希土類磁石を効率的に製造することができるものである。
本発明の製造方法に用いられる治具の一例を示概略図であり、（Ａ）は概略平面図、（Ｂ）は（Ａ）のＢ－Ｂ線に沿った概略断面図である。 本発明の製造方法における粉末塗布を実施する静電塗装設備の一例を示す概略図である。 実施例における保磁力の測定位置を示す説明図である。
　本発明の希土類磁石の製造方法は、上記のとおり、Ｒ1－Ｆｅ－Ｂ系組成（Ｒ1はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）からなる焼結磁石体に、Ｒ2の酸化物、フッ化物、酸フッ化物、水酸化物又は水素化物（Ｒ2はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）を含有する粉末を塗布し熱処理してＲ2を焼結磁石体に吸収させて希土類磁石を製造するものである。
　上記Ｒ1－Ｆｅ－Ｂ系焼結磁石体は、公知の方法で得られたものを用いることができ、例えば常法に従ってＲ1、Ｆｅ、Ｂを含有する母合金を粗粉砕、微粉砕、成形、焼結させることにより得ることができる。なお、Ｒ1は上記のとおり、Ｙ及びＳｃを含む希土類元素から選ばれる１種又は２種以上で、具体的にはＹ、Ｓｃ、Ｌａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｙｂ及びＬｕが挙げられる。
　本発明では、このＲ1－Ｆｅ－Ｂ系焼結磁石体を、必要に応じて研削等によって所定形状に成形し、表面にＲ2の酸化物、フッ化物、酸フッ化物、水酸化物、水素化物の１種又は２種以上を含有する粉末を塗布し、熱処理して焼結磁石体に吸収拡散（粒界拡散）させ、希土類磁石を得る。
　上記Ｒ2は、上記のように、Ｙ及びＳｃを含む希土類元素から選ばれる１種又は２種以上であり、上記Ｒ1と同様にＹ、Ｓｃ、Ｌａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｙｂ及びＬｕが例示される。この場合、特に制限されるのではないが、Ｒ2中の１又は複数に合計で１０原子％以上、より好ましくは２０原子％以上、特に４０原子％以上のＤｙ又はＴｂを含むことが好ましい。このようにＲ2に１０原子％以上のＤｙ及び／又はＴｂが含まれ、かつＲ2におけるＮｄとＰｒの合計濃度が前記Ｒ1におけるＮｄとＰｒの合計濃度より低いことが本発明の目的からより好ましい。
　上記Ｒ2の酸化物、フッ化物、酸フッ化物、水酸化物、水素化物の１種又は２種以上を含有する粉末の粒径は、特に制限されるものではなく、吸収拡散（粒界拡散）に用いられる希土類化合物粉末として一般的な粒度とすることができ、具体的には、平均粒子径１００μｍ以下が好ましく、より好ましくは１０μｍ以下である。その下限は特に制限されないが１ｎｍ以上が好ましい。この平均粒子径は、例えばレーザー回折法などによる粒度分布測定装置等を用いて質量平均値Ｄ50（即ち、累積質量が５０％となるときの粒子径又はメジアン径）などとして求めることができる。
　本発明において上記粉末の塗布は、上記のように、上記焼結磁石体を保持し、帯電させた上記粉末を接地した焼結磁石体に噴霧して該粉末を上記焼結磁石体に静電塗装することにより行われる。
　この場合、上記粉末を帯電させる方式は、粉末を摩擦帯電させる摩擦帯電方式でも粉末をコロナ放電により帯電させるコロナ帯電方式でもよいが、特に粉体の材質に影響されずに帯電させることができるので、最適な塗布条件が摩擦帯電に比較して簡単に求められるとの理由からコロナ帯電方式が好ましく用いられる。いずれの方式においても、市販の静電塗装ガンを用いて粉体を帯電させ噴霧することができ、例えばコロナ帯電方式としては旭サナック（株）社の粉体自動ガン「Ｘ－３ａ」、摩擦帯電方式としては旭サナック（株）社の粉体自動ガン「Ｔ－３ａ」などを用いることができる。
　ここで、コロナガン（コロナ帯電方式の静電塗装ガン）を用いて上記粉末を帯電させて噴霧する場合は、コロナガン先端部への印加電圧と粉末の供給量を調節することにより、粉末の塗布量を比較的ように調節することができる。本発明においては、特に制限されるものではないが、コロナガン先端部への印加電圧を－６０ｋＶ以上、特に－７０ｋＶ～－８０ｋＶとすると共に、所定量の粉末を定量供給装置などを用いて定量供給することにより、上記焼結磁石体への塗布量が８５０ｍｇ／ｄｍ2以上となるように調節することが好ましい。
　一方、上記焼結磁石体は良導電性の治具に保持され、該治具を介して接地された状態で上記静電塗装に供される。この治具を成形する良導電性の材料としては、特に制限されるものではないが、銅、銅合金、アルミニウム、鉄、鉄合金、チタニウムなどが好適に用いられる。また、治具の形態に制限は無く、焼結磁石体の形状や大きさ等に応じて適宜な形態とすればよい。例えば、先端が尖鋭に形成された保持部に上記焼結磁石体を挟持して保持するように構成された治具を好適に使用することができる。
　このような治具としてより具体的には、図１に示した形態の治具を例示することができる。即ち、図１中の参照符号１は四角枠状の基台であり、この基台１に４本の保持アーム２が立設されている。保持アーム２は、先端部が鉤状に屈曲していると共に、その先端が尖鋭な円錐状に形成された保持部２１となっている。この保持アーム２を２本１組として２組が互いの保持部２１を対向させた状態で立設されている。そして、この各保持アーム２の保持部２１で上記焼結磁石体３を挟持した状態に保持するようになっている。なお、この治具は、上記良導電性の材料で形成されるが、上記保持部２１の焼結磁石体３との接点、及び図示しない接地用の電気的接点以外の部分は、上記粉末が付着しないようにプラスチゾルなどでコーティングすることが好ましい。
　このようにして上記粉末を塗布して該粉末の塗膜を形成した焼結磁石体は、次工程の熱処理により焼結磁石体に吸収拡散されるが、上記静電塗装により焼結磁石体表面に付着した上記粉末は、そのままでは飛散しやすく加熱処理までの間に少量ではあっても粉末の飛散により保磁力の増大効果や均一性に若干の低下を招く場合がある。このため、特に制限されるものではないが、塗布した上記粉末の塗膜に液体を付与して該塗膜を一旦湿らせて乾燥させた後に上記加熱処理を施すことが好ましい。付与する液体としては、エチルアルコール等のアルコール類や純水などを例示することができるが、特にコスト等の点で純水が好ましく用いられる。
　上記液体の付与はスプレーにより行うことができ、この場合上記静電塗装を行う前に焼結磁石体表面に純水等の液体をスプレーし、表面に純水等が存在した状態で焼結磁石体に上記静電塗装を施しても、また上記静電塗装を行った後に形成された塗膜に対して純水等の液体をスプレーするようにしてもよい。なお、静電塗装の前後いずれにおいても十分な液体付与の効果が得られるが、後述する実施例のとおり、静電塗装前に焼結磁石体表面に純水等の液体をスプレーしておく方がより良好な効果が得られる。なお、付与する純水等の液体の量は、焼結磁石体の大きさや形状、粉末の粒径や形成する塗膜の厚さなどに応じて適宜設定され特に制限されるものではないが、１ｍｌ／ｄｍ2以上、特に２～３ｍｌ／ｄｍ2とすることが好ましい。
　この静電塗装による粉末の塗布は、上記治具に保持した焼結磁石体を例えばハンガー搬送レールなどを用いて搬送し、複数の焼結磁石体に連続的に上記静電塗装処理を施して量産化に対応することができる。例えば図２に示した製造設備を例示することができる。
　即ち、図２中の４は上記治具に取り付けられた焼結磁石体を所定速度で搬送するハンガー搬送レールであり、ロード・アンロード部５で該治具に焼結磁石体を取り付けてハンガー搬送レール４に沿って該焼結磁石体を搬送し、前処理部６、静電塗装部７及び乾燥部８を順次通過させて上記粉末の塗膜を形成し、この塗膜が形成された焼結磁石体を上記ロード・アンロード部５で回収するものである。
　上記前処理部６には、表面処理ブース６１及び裏面処理ブース６２が設けられており、これら処理ブース６１，６２で純水スプレーガン６３により焼結磁石体の表裏両面に純水がスプレーされる。また、上記静電塗装部７には表面塗装ブース７１及び裏面塗装ブース７２が設けられており、これら塗装ブース６１，６２において、上記治具を介して接地された焼結磁石体に静電塗装ガン７３により帯電した上記粉末が噴霧され、焼結磁石体の表裏両面に上記粉末が静電塗装される。更に、上記乾燥部８では、５０～７０℃程度の温度で５～１０分間の乾燥処理が施されるようになっている。
　本発明の製造方法は、このようにして希土類化合物の粉末を塗布した焼結磁石体を熱処理し、希土類化合物中の上記Ｒ2を焼結磁石体に吸収拡散させることにより、希土類永久磁石を得るものである。
　上記Ｒ2で示されるで希土類元素を吸収拡散させる上記熱処理は公知の方法に従って行えばよい。また、上記熱処理後、適宜な条件で時効処理を施したり、更に実用形状に研削するなど、必要に応じて公知の後処理を施すこともできる。
　以下、本発明のより具体的な態様について実施例をもって詳述するが、本発明はこれに限定されるものではない。
　　［実施例１］
　Ｎｄが１４．５原子％、Ｃｕが０．２原子％、Ｂが６．２原子％、Ａｌが１．０原子％、Ｓｉが１．０原子％、Ｆｅが残部からなる薄板状の合金を、純度９９質量％以上のＮｄ、Ａｌ、Ｆｅ、Ｃｕメタル、純度９９．９９質量％のＳｉ、フェロボロンを用いてＡｒ雰囲気中で高周波溶解した後、銅製単ロールに注湯するいわゆるストリップキャスト法により薄板状の合金とした。得られた合金を室温にて０．１１ＭＰａの水素化に曝して水素を吸蔵させた後、真空排気を行ないながら５００℃まで加熱して部分的に水素を放出させ、冷却してから篩いにかけて、５０メッシュ以下の粗粉末とした。
　上記粗粉末を、高圧窒素ガスを用いたジェットミルで粉末の重量中位粒径５μｍに微粉砕した。得られたこの混合微粉末を窒素雰囲気下１５ｋＯｅの磁界中で配向させながら、約１ｔｏｎ／ｃｍ2の圧力でブロック状に成形した。この成形体をＡｒ雰囲気の焼結炉内に投入し、１０６０℃で２時間焼結して磁石ブロックを得た。この磁石ブロックをダイヤモンドカッタ－を用いて全面研削加工した後、アルカリ溶液、純水、硝酸、純水の順で洗浄し乾燥させて、４０ｍｍ×２０ｍｍ×５ｍｍ（磁気異方性化した方向）のブロック状磁石体を得た。
　図１の治具を複数連設した治具に上記焼結磁石体を取り付け接地させ、旭サンナック（株）社製の粉体静電塗装装置「ＸＲ４－１００ＰＳ」を用い、フッ化ディスプロシウム粉末をコロナ帯電させ噴霧して８５０ｍｇ／ｄｍ2以上塗布し、上記焼結磁石体の表面にフッ化ディスプロシウム粉末の塗膜を形成した。なお、コロナガン先端部の設定電圧は７５ｋＶ×８０μＡとした。
　フッ化ディスプロシウム粉末の塗膜を形成した上記焼結磁石体を、Ａｒ雰囲気中、９００℃で５時間熱処理して吸収処理を施し、更に５００℃で１時間時効処理して急冷することにより希土類磁石を得た。３個のサンプルにつき、図３に示した磁石の中央部及び端部の９点の場所から２ｍｍ×２ｍｍ×５ｍｍに磁石体を切り出し、その保磁力を測定した。各サンプルにつき上記９点の保磁力の平均値を表１に示す。
　　［実施例２］
　実施例１と同様にして得た焼結磁石体を治具に保持し、純水をスプレーして焼結磁石体表面に３ｍｌ／ｄｍ2の純水を付与して焼結磁石体表面を湿った状態とした。この焼結磁石体に実施例１と同様にしてフッ化ディスプロシウム粉末を塗布しフッ化ディスプロシウム粉末の塗膜を形成した。これを６０℃で５分間乾燥させた後に実施例１と同様に加熱処理を行って希土類磁石を得、同様に保磁力を測定した。結果を表１に示す。
　　［実施例３］
　実施例１と同様にして得た焼結磁石体に、実施例１と同様にフッ化ディスプロシウム粉末を塗布してフッ化ディスプロシウム粉末の塗膜を形成した後、この焼結磁石体に純水をスプレーして３ｍｌ／ｄｍ2の純水を付与し、塗膜が湿った状態とした。これを６０℃で５分間乾燥させた後に実施例１と同様に加熱処理を行って希土類磁石を得、同様に保磁力を測定した。結果を表１に示す。
Figure JPOXMLDOC01-appb-T000001
１　基台
２　保持アーム
２１　保持部
３　焼結磁石体
４　ハンガー搬送レール
５　ロード・アンロード部
６　前処理部
６１　表面処理ブース
６２　裏面処理ブース
６３　純水スプレーガン
７　静電塗装部
７１　表面塗装ブース
７２　裏面塗装ブース
７３　静電塗装ガン
８　乾燥部

Claims (8)

  1. 　Ｒ1－Ｆｅ－Ｂ系組成（Ｒ1はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）からなる焼結磁石体に、Ｒ2の酸化物、フッ化物、酸フッ化物、水酸化物又は水素化物（Ｒ2はＹ及びＳｃを含む希土類元素から選ばれる１種又は２種以上）から選ばれる１種又は２種以上を含有する粉末を塗布し熱処理してＲ2を焼結磁石体に吸収させる希土類永久磁石の製造方法において、
    接地された良導電性の治具に上記焼結磁石体を保持し、帯電させた上記粉末をこの焼結磁石体に噴霧して該粉末を上記焼結磁石体に静電塗装することにより、上記焼結磁石体に上記粉末を塗布することを特徴とする希土類磁石の製造方法。
  2. 　コロナ放電により上記粉末を帯電させて上記静電塗装を行う請求項１記載の希土類磁石の製造方法。
  3. 　コロナガンを用いて上記粉末をコロナ帯電させて噴霧し上記静電塗装を行うと共に、その際にコロナガン先端部への印加電圧を－６０ｋＶ以上とし、上記粉末の焼結磁石体への塗布量を８５０ｍｇ／ｄｍ2以上とする請求項２記載の希土類磁石の製造方法。
  4. 　上記静電塗装を施す前に上記焼結磁石体表面に液体をスプレーし、該焼結磁石体表面に液体が存在した状態で上記静電塗装を施して上記粉末の塗膜を形成し、これを乾燥させた後、上記熱処理を行う請求項１～３のいずれか１項に記載の希土類磁石の製造方法。
  5. 　上記静電塗装を行った後、上記焼結磁石体表面に形成された上記粉体の塗膜に液体をスプレーして該塗膜を湿らせ、これを乾燥させた後、上記熱処理を行う請求項１～３のいずれか１項に記載の希土類磁石の製造方法。
  6. 　上記液体のスプレー量が、１ｍｌ／ｄｍ2以上である請求項４又は５記載の希土類磁石の製造方法。
  7. 　上記液体が純水である請求項４～６のいずれか１項に記載の希土類磁石の製造方法。
  8. 　上記治具が、銅、銅合金、アルミニウム、鉄、鉄合金、チタニウムから選ばれる材料からなり、先端が尖鋭に形成された保持部に上記焼結磁石体を挟持して保持するように構成されていると共に、該保持部の焼結磁石体との接点及び接地用の電気的接続点以外の部位がプラスチゾルでコーティングされたものである請求項１～７のいずれか１項に記載の希土類磁石の製造方法。
PCT/JP2016/062215 2015-04-28 2016-04-18 希土類磁石の製造方法 WO2016175069A1 (ja)

Priority Applications (5)

Application Number Priority Date Filing Date Title
MYPI2017703918A MY182702A (en) 2015-04-28 2016-04-18 Method for producing rare-earth magnet
US15/570,233 US11084059B2 (en) 2015-04-28 2016-04-18 Method for producing rare-earth magnet
CN201680023920.2A CN107533909B (zh) 2015-04-28 2016-04-18 稀土类磁铁的制造方法
EP16786346.3A EP3291263B1 (en) 2015-04-28 2016-04-18 Method for producing rare-earth magnet
PH12017501970A PH12017501970B1 (en) 2015-04-28 2017-10-27 Method for producing rare-earth magnet

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015092061A JP6350380B2 (ja) 2015-04-28 2015-04-28 希土類磁石の製造方法
JP2015-092061 2015-04-28

Publications (1)

Publication Number Publication Date
WO2016175069A1 true WO2016175069A1 (ja) 2016-11-03

Family

ID=57199193

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/062215 WO2016175069A1 (ja) 2015-04-28 2016-04-18 希土類磁石の製造方法

Country Status (7)

Country Link
US (1) US11084059B2 (ja)
EP (1) EP3291263B1 (ja)
JP (1) JP6350380B2 (ja)
CN (1) CN107533909B (ja)
MY (1) MY182702A (ja)
PH (1) PH12017501970B1 (ja)
WO (1) WO2016175069A1 (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107146670A (zh) * 2017-04-19 2017-09-08 安泰科技股份有限公司 一种稀土永磁材料的制备方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11018567B2 (en) * 2017-09-29 2021-05-25 Ford Global Technologies, Llc Permanent magnet rotor with enhanced demagnetization protection
JP7087830B2 (ja) * 2018-03-22 2022-06-21 日立金属株式会社 Ｒ－ｔ－ｂ系焼結磁石の製造方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55108723A (en) * 1979-02-14 1980-08-21 Citizen Watch Co Ltd Method for manufacture of coil core
JPH11238620A (ja) * 1998-02-23 1999-08-31 Seiko Epson Corp 永久磁石およびその製造方法
JP2002126612A (ja) * 2000-10-23 2002-05-08 Denso Corp ヨーク製造方法
JP2004079782A (ja) * 2002-08-19 2004-03-11 Matsushita Electric Ind Co Ltd 電子部品の製造方法
JP2010242136A (ja) * 2009-04-02 2010-10-28 Kazufumi Ogawa 金属微粒子、メッキ液、リード線及び関連する方法
JP2015065218A (ja) * 2013-09-24 2015-04-09 大同特殊鋼株式会社 ＲＦｅＢ系磁石の製造方法

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2245089A (en) * 1939-10-25 1941-06-10 John M Hargrave Welder's clamp
US2599010A (en) * 1949-09-09 1952-06-03 Pernitz Kalman Rotatably supported adjustable painter's work holder
DE10144652A1 (de) 2000-09-12 2002-06-13 Denso Corp Verfahren zur Herstellung eines Jochs für eine Drehfeldmaschine
JP3863029B2 (ja) 2002-02-07 2006-12-27 大成化工株式会社 肩部を有する容器内面への粉体塗装装置並びに粉体塗装方法
US20080213496A1 (en) * 2002-02-14 2008-09-04 Applied Materials, Inc. Method of coating semiconductor processing apparatus with protective yttrium-containing coatings
CN100388434C (zh) * 2003-03-12 2008-05-14 东京毅力科创株式会社 半导体处理用的基板保持结构和等离子体处理装置
JP3897724B2 (ja) * 2003-03-31 2007-03-28 独立行政法人科学技術振興機構 超小型製品用の微小、高性能焼結希土類磁石の製造方法
CN100433204C (zh) * 2004-07-28 2008-11-12 株式会社日立制作所 稀土类磁铁
JP4654709B2 (ja) * 2004-07-28 2011-03-23 株式会社日立製作所 希土類磁石
US7375946B2 (en) * 2004-08-16 2008-05-20 Applied Materials, Inc. Method and apparatus for dechucking a substrate
CN1898757B (zh) 2004-10-19 2010-05-05 信越化学工业株式会社 稀土永磁材料的制备方法
JP4656325B2 (ja) 2005-07-22 2011-03-23 信越化学工業株式会社 希土類永久磁石、その製造方法、並びに永久磁石回転機
US7559996B2 (en) 2005-07-22 2009-07-14 Shin-Etsu Chemical Co., Ltd. Rare earth permanent magnet, making method, and permanent magnet rotary machine
CN102483980B (zh) * 2010-03-04 2016-09-07 Tdk株式会社 稀土烧结磁体和电动机
CN103258633B (zh) * 2013-05-30 2015-10-28 烟台正海磁性材料股份有限公司 一种R-Fe-B系烧结磁体的制备方法
JP5959488B2 (ja) * 2013-10-09 2016-08-02 旭サナック株式会社 粉体塗装方法
CN103996525A (zh) * 2014-05-27 2014-08-20 安徽大地熊新材料股份有限公司 一种防腐耐磨烧结钕铁硼磁体的制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55108723A (en) * 1979-02-14 1980-08-21 Citizen Watch Co Ltd Method for manufacture of coil core
JPH11238620A (ja) * 1998-02-23 1999-08-31 Seiko Epson Corp 永久磁石およびその製造方法
JP2002126612A (ja) * 2000-10-23 2002-05-08 Denso Corp ヨーク製造方法
JP2004079782A (ja) * 2002-08-19 2004-03-11 Matsushita Electric Ind Co Ltd 電子部品の製造方法
JP2010242136A (ja) * 2009-04-02 2010-10-28 Kazufumi Ogawa 金属微粒子、メッキ液、リード線及び関連する方法
JP2015065218A (ja) * 2013-09-24 2015-04-09 大同特殊鋼株式会社 ＲＦｅＢ系磁石の製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3291263A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107146670A (zh) * 2017-04-19 2017-09-08 安泰科技股份有限公司 一种稀土永磁材料的制备方法

Also Published As

Publication number Publication date
EP3291263B1 (en) 2020-04-08
PH12017501970A1 (en) 2018-03-19
JP6350380B2 (ja) 2018-07-04
US11084059B2 (en) 2021-08-10
MY182702A (en) 2021-02-02
CN107533909A (zh) 2018-01-02
EP3291263A1 (en) 2018-03-07
JP2016207985A (ja) 2016-12-08
US20180133751A1 (en) 2018-05-17
PH12017501970B1 (en) 2018-03-19
CN107533909B (zh) 2020-07-10
EP3291263A4 (en) 2018-12-19

Similar Documents

Publication Publication Date Title
EP3438997B1 (en) Method for grain boundary diffusion of r-fe-b rare earth sintered magnets, hre diffusion source and preparation method therefor
JP6385551B1 (ja) Ｎｄ−Ｆｅ−Ｂ系磁性体の保磁力増強方法
Soderžnik et al. High-coercivity Nd-Fe-B magnets obtained with the electrophoretic deposition of submicron TbF3 followed by the grain-boundary diffusion process
Soderžnik et al. The grain-boundary diffusion process in Nd–Fe–B sintered magnets based on the electrophoretic deposition of DyF3
EP3182423B1 (en) Neodymium iron boron magnet and preparation method thereof
EP3614403B1 (en) Method for preparing rare earth permanent magnet material
KR102219024B1 (ko) 희토류 영구 자석의 제조방법
DE102012000421B4 (de) Verfahren zum Herstellen von gesinterten Nd-Fe-B-Magneten mit Dy oder Tb
KR102101309B1 (ko) 희토류 영구자석의 제조 방법
WO2014034854A1 (ja) 希土類永久磁石の製造方法
CN106920669B (zh) 一种R-Fe-B系烧结磁体的制备方法
KR102137726B1 (ko) 희토류 영구자석의 제조 방법
WO2016175069A1 (ja) 希土類磁石の製造方法
CN104599829A (zh) 一种提高烧结钕铁硼磁体磁性能的方法
CN106920611A (zh) 一种制作高矫顽力烧结r-t-b永磁材料的方法及r-t-b系永磁材料
WO2017018252A1 (ja) 希土類系焼結磁石の製造方法
JP6939337B2 (ja) Ｒ−ｔ−ｂ系焼結磁石の製造方法
JP2019121792A (ja) Ｒ−Ｆｅ−Ｂ系焼結磁性体の製造方法及びその製造装置
JP6946905B2 (ja) 拡散源
JP6946904B2 (ja) 拡散源
JP6760169B2 (ja) Ｒ−ｔ−ｂ系焼結磁石の製造方法
JP7528437B2 (ja) Ｒ－ｔ－ｂ系焼結磁石の製造方法
JP2020150262A (ja) Ｒ−ｔ−ｂ系焼結磁石
EP4138101A1 (en) Method for producing rare earth sintered magnet

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16786346

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 15570233

Country of ref document: US

Ref document number: 12017501970

Country of ref document: PH

NENP Non-entry into the national phase

Ref country code: DE