WO2013054845A1 - R-t-b系合金薄片、並びにr-t-b系焼結磁石及びその製造方法 - Google Patents
R-t-b系合金薄片、並びにr-t-b系焼結磁石及びその製造方法 Download PDFInfo
- Publication number
- WO2013054845A1 WO2013054845A1 PCT/JP2012/076324 JP2012076324W WO2013054845A1 WO 2013054845 A1 WO2013054845 A1 WO 2013054845A1 JP 2012076324 W JP2012076324 W JP 2012076324W WO 2013054845 A1 WO2013054845 A1 WO 2013054845A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- rtb
- alloy
- sintered magnet
- crystal
- based sintered
- Prior art date
Links
Images
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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0611—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by a single casting wheel, e.g. for casting amorphous metal strips or wires
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
-
- 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
- H01F1/0536—Alloys characterised by their composition containing rare earth metals 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
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/06—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
- H01F41/0266—Moulding; Pressing
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C2202/00—Physical properties
- C22C2202/02—Magnetic
-
- 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
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
Definitions
- the present invention relates to an RTB-based alloy flake, an RTB-based sintered magnet, and a manufacturing method thereof.
- drive motors used in various fields are required to be smaller and lighter and to be more efficient.
- a technique capable of further improving the magnetic characteristics of a sintered magnet used in a drive motor is required.
- an RTB-based rare earth sintered magnet As a sintered magnet having high magnetic properties, an RTB-based rare earth sintered magnet has been conventionally used. This RTB-based sintered magnet has been attempted to improve the magnetic characteristics by using heavy rare earth metals such as Dy and Tb having a large anisotropic magnetic field HA . However, with the recent rise in prices of rare earth metal raw materials, it is strongly desired to reduce the amount of expensive heavy rare earth elements used. Under such circumstances, attempts have been made to improve the magnetic properties by refining the structure of the RTB-based sintered magnet.
- the RTB-based sintered magnet is manufactured by a powder metallurgy method.
- the manufacturing method by the powder metallurgy method first, the raw material is melted and cast to obtain an alloy flake containing an RTB-based alloy. Next, the alloy flakes are pulverized to prepare an alloy powder having a particle size of several ⁇ m to several tens of ⁇ m. Next, this alloy powder is molded and sintered to produce a sintered body. Thereafter, the obtained sintered body is processed into a predetermined dimension. In order to improve corrosion resistance, the sintered body may be plated as necessary to form a plating layer. In this way, an RTB-based sintered magnet can be obtained.
- the strip casting method is a method of preparing alloy flakes by cooling a molten alloy with a cooling roll.
- an attempt has been made to control the alloy structure by adjusting the cooling rate in the above-described strip casting method.
- Patent Document 1 proposes to obtain an alloy flake composed of chill crystals, granular crystals, and columnar crystals having a predetermined particle size by strip casting.
- FIG. 15 and FIG. 16 are metallographic micrographs showing the surface of an RTB-based alloy flake produced by a conventional strip casting method at 100 times magnification. As shown in FIGS. 15 and 16, the RTB-based alloy flakes are composed of crystals of various sizes containing an R 2 T 14 B phase.
- HcJ coercive force
- Br residual magnetic flux density
- ⁇ is a coefficient indicating the independence of crystal grains
- HA represents an anisotropic magnetic field depending on the composition
- N represents a local demagnetizing field depending on the shape, etc.
- Ms is the main The saturation magnetization of the phase.
- ⁇ represents the sintered density
- ⁇ 0 represents the true density
- f represents the volume fraction of the main phase
- f represents the volume fraction of the main phase
- A represents the degree of orientation of the main phase.
- H A , Ms and f depend on the composition of the sintered magnet
- N depends on the shape of the sintered magnet.
- the coercive force can be improved by increasing ⁇ in the above formula (1). From this fact, the coercive force can be improved by controlling the structure of the alloy powder used in the compact for sintered magnets.
- the present invention has been made in view of the above circumstances, and an object thereof is to provide an alloy flake capable of improving the coercive force of an RTB-based sintered magnet. Another object of the present invention is to provide an RTB-based sintered magnet having a sufficiently excellent coercive force without using an expensive heavy rare earth element, and a method for producing the same.
- the present inventors have made various studies focusing on the structure of the alloy flakes in order to improve the magnetic properties of the RTB-based sintered magnet. As a result, it has been found useful to specify the microstructure of the surface of the alloy flakes.
- the present invention is an RTB-based alloy flake containing a dendrite-like crystal containing an R 2 T 14 B phase, wherein the average width of the dendrite-like crystal is 60 ⁇ m or less on at least one surface.
- An RTB-based alloy flake is provided in which the number of crystal nuclei of the dendritic crystal is 500 or more per 1 mm square (1 mm ⁇ 1 mm).
- the RTB-based alloy flakes of the present invention have a predetermined number or more of crystal nuclei per unit area on at least one surface. Such dendrite-like crystals are suppressed from growing in the plane direction of the RTB-based alloy flakes. For this reason, the R 2 T 14 B phase grows in a columnar shape in the thickness direction. An R-rich phase is generated around the R 2 T 14 B phase grown in a columnar shape, and this R-rich phase is preferentially broken during pulverization. Therefore, when the RTB-based alloy flakes having such a structure are pulverized, an alloy powder in a uniformly dispersed state can be obtained without segregating the R-rich phase as compared with the prior art. Further, by firing such an alloy powder, an R-TB-based sintered magnet having a high coercive force can be obtained by suppressing aggregation of R-rich phase and abnormal grain growth of crystal grains.
- the aspect ratio of a crystal group composed of a plurality of dendritic crystals is preferably 0.8 or more on at least one surface.
- the average value of the dendrite-like crystal width in the RTB-based alloy flakes of the present invention is preferably 25 ⁇ m or more. Thereby, the growth of the R 2 T 14 B phase in the thickness direction of the alloy flakes can be further promoted. Therefore, an alloy powder having a small particle size and a small variation in particle size can be obtained.
- the present invention provides an RTB-based sintered magnet obtained by molding and firing an alloy powder obtained by pulverizing the RTB-based alloy flakes described above.
- This RTB-based sintered magnet has a sufficiently excellent coercive force because it uses an alloy powder having a small particle size and an R-rich phase uniformly dispersed as a raw material.
- the present invention provides a step of pulverizing the alloy flakes described above to prepare an alloy powder, a step of forming and firing the alloy powder, and producing an RTB-based sintered magnet, A method for producing an RTB-based sintered magnet is provided.
- an RTB-based sintered magnet having a sufficiently excellent coercive force can be obtained because an alloy powder having a small particle size and an R-rich phase uniformly dispersed is used.
- an alloy flake that can improve the coercive force of an RTB-based sintered magnet. Further, it is possible to provide an RTB-based sintered magnet having a sufficiently excellent coercive force, and a method for producing the same.
- FIG. 3 is a metallographic micrograph (magnification: 100 times) of one surface of an RTB-based alloy flake according to an embodiment of the present invention.
- FIG. 3 is a plan view schematically showing a dendrite-like crystal contained in an RTB-based alloy flake according to an embodiment of the present invention.
- It is a schematic diagram which shows an example of the manufacturing method of the alloy flakes of this invention.
- It is an enlarged plan view which shows an example of the roll surface of the cooling roll used for manufacture of the alloy flakes of this invention.
- It is a schematic cross section which shows an example of the cross-sectional structure of the roll surface vicinity of the cooling roll used for manufacture of the alloy flakes of this invention.
- FIG. 1 is a cross-sectional view schematically showing an example of a cross-sectional structure of an RTB-based sintered magnet according to an embodiment of the present invention. It is explanatory drawing which shows the internal structure of a motor provided with the RTB type sintered magnet which concerns on one Embodiment of this invention.
- 2 is a metal micrograph (magnification: 100 times) of one surface of an RTB-based alloy flake of Example 1.
- FIG. 4 is a metallographic micrograph (magnification: 100 times) of one surface of an RTB-based alloy flake of Example 2.
- FIG. 2 is a metallographic micrograph (magnification: 100 times) of one surface of an RTB-based alloy flake of Comparative Example 1.
- FIG. 4 is a metallographic micrograph (magnification: 100 times) of one surface of an RTB-based alloy flake of Comparative Example 2.
- 4 is a metallographic micrograph (magnification: 100 times) of one surface of an RTB-based alloy flake of Comparative Example 3.
- 2 is a metal micrograph (magnification: 100 times) of one surface of a conventional RTB-based alloy flake.
- FIG. 2 is a metal micrograph (magnification: 100 times) of one surface of a conventional RTB-based alloy flake. It is a figure which shows the element map data which painted the triple point area
- FIG. FIG. 10 is a diagram showing element map data in which a triple point region of an RTB-based sintered magnet of Comparative Example 4 is painted black.
- FIG. 1 is a metallographic micrograph (magnification: 100 times) of one surface of an RTB-based alloy flake of this embodiment.
- the alloy flakes of this embodiment contain an R 2 T 14 B phase crystal phase and an R rich phase.
- R represents an element containing at least one selected from rare earth elements
- T represents an element containing at least one of iron and cobalt
- B represents boron.
- the rare earth element refers to scandium (Sc), yttrium (Y), and lanthanoid elements belonging to Group 3 of the long-period periodic table.
- lanthanoid elements include lanthanum (La) and cerium.
- Ce praseodymium
- Pr neodymium
- Sm samarium
- Eu europium
- Gd gadolinium
- Tb terbium
- Dy dysprosium
- Ho holmium
- Er erbium
- Tm thulium
- Yb lutetium
- one surface of the RTB-based metal foil piece of the present embodiment is composed of a large number of petal-like dendritic crystals containing an R 2 T 14 B phase.
- FIG. 2 is an enlarged plan view schematically showing a dendrite-like crystal constituting one surface of the RTB-based alloy flake.
- the dendritic crystal 40 has a crystal nucleus 42 at the center, and the filler crystal 44 extends radially from the crystal nucleus 42 as a starting point.
- the width P of the dendrite-like crystal 40 is obtained as the maximum distance in the distance between the ends of two different filler-like crystals 44. Usually, the width P is the distance between the end portions of the two filler crystals 44 that are substantially opposed to each other via the crystal nucleus 42.
- the average value of the width P of the dendritic crystal 40 is determined as follows. In an image obtained by enlarging one surface of the metal foil piece 200 times with a metal microscope, 100 dendrite crystals 40 are arbitrarily selected, and the width P of each dendrite crystal 40 is measured. The arithmetic average value of these measured values is the average value of the width P of the dendritic crystal 40.
- the average value of the width P of the dendritic crystal 40 is preferably 25 to 60 ⁇ m.
- the upper limit of the average value of the width P is preferably 55 ⁇ m, more preferably 50 ⁇ m, and even more preferably 48 ⁇ m. Thereby, the dendrite-like crystal 40 becomes small, and a finer alloy powder can be obtained.
- the lower limit of the average value of the width P is preferably 30 ⁇ m, more preferably 35 ⁇ m, and still more preferably 38 ⁇ m. This further promotes the growth of the R 2 T 14 B phase in the thickness direction of the alloy flakes. Therefore, an alloy powder having a small particle size and a small variation in particle size can be obtained.
- the surface of the RTB-based alloy flakes of this embodiment shown in FIG. 1 is larger per unit area on one surface than the surface of the conventional RTB-based alloy flakes as shown in FIGS.
- the number of crystal nuclei 42 is large, and the width of the dendritic crystal 40 is small.
- interval M of the filler-like crystal 44 which comprises the dendrite-like crystal 40 is small, and the magnitude
- the uniformity of the dendrite-like crystal 40 is greatly improved.
- the uniformity of the length S and the width Q of the filler-like crystal 44 on the surface of the RTB-based alloy flake of this embodiment is also greatly improved.
- the dendrite-like crystal 40 as a whole is continuous in one direction (vertical direction in FIG. 1) on one surface of the RTB-based alloy flake, forming a crystal group.
- the aspect ratio is calculated as C2 / C1, where C1 is the length of the long axis in the crystal group of dendritic crystals and C2 is the length of the short axis perpendicular to the long axis.
- the average aspect ratio calculated in this way is preferably 0.8 or more, more preferably 0.7 to 1.0, still more preferably 0.8 to 0.98, Preferably, it is 0.88 to 0.97.
- the average value of the aspect ratio is an arithmetic average value of the ratio (C2 / C1) in 100 crystal groups arbitrarily selected.
- the average aspect ratio in this specification is determined as follows. In an image obtained by enlarging one surface of a metal foil piece 200 times with a metal microscope, 100 crystal groups are arbitrarily selected, and the major axis length C1 and minor axis length C2 of each crystal group are respectively set. taking measurement. The arithmetic average value of the crystal group ratio (C2 / C1) is the average aspect ratio.
- the number of dendrite-like crystal nuclei 42 generated is 500 or more per 1 mm square, preferably 600 or more, more preferably 700 or more. More preferably, it is 763 or more. Since a large number of crystal nuclei 42 are generated in this way, the size per crystal nucleus 42 is reduced, and an RTB-based alloy flake having a fine structure can be obtained.
- the RTB-based alloy flakes of this embodiment may have at least one surface having the above-described structure. If at least one surface has the above-described structure, an alloy powder having a small particle size and an R-rich phase uniformly dispersed can be obtained. Next, an example of a method for producing the RTB-based alloy flakes of this embodiment will be described below.
- FIG. 3 is a schematic view of an apparatus for producing an RTB-based alloy flake of the embodiment.
- the RTB-based alloy flakes of this embodiment can be manufactured by a strip cast method using a manufacturing apparatus as shown in FIG.
- the method for producing the alloy flakes of this embodiment includes a melting step of preparing a molten alloy of an RTB-based alloy, and pouring the molten alloy onto the roll surface of a cooling roll that rotates in the circumferential direction.
- a first cooling step for cooling the roll surface to generate crystal nuclei and solidifying at least a part of the molten alloy and a second cooling step for further cooling the alloy containing the crystal nuclei to obtain alloy flakes.
- a raw material containing at least one kind of rare earth metal, rare earth alloy, pure iron, ferroboron, and these alloys is introduced into the high-frequency melting furnace 10.
- the molten alloy 12 is prepared by heating the raw material to 1300 to 1400 ° C.
- the molten alloy 12 is transferred to the tundish 14. Thereafter, molten alloy is poured from the tundish 14 onto the roll surface of the cooling roll 56 rotating at a predetermined speed in the direction of arrow A. The molten alloy 12 comes into contact with the roll surface 17 of the cooling roll 16 and is removed by heat exchange. As the molten alloy 12 is cooled, crystal nuclei are generated in the molten alloy and at least a part of the molten alloy 12 is solidified. For example, an R 2 T 14 B phase (melting temperature of about 1100 ° C.) is first generated, and then at least a part of the R rich phase (melting temperature of about 700 ° C.) is solidified.
- an R 2 T 14 B phase melting temperature of about 1100 ° C.
- FIG. 4 is a schematic view showing a part of the roll surface 17 in a planar shape and enlarged.
- the roll surface 17 is formed with a mesh-like groove, which forms a concavo-convex pattern.
- the roll surface 17 is substantially divided into a plurality of first recesses 32 arranged at a predetermined interval a along the circumferential direction (direction of arrow A) of the cooling roll 16 and the first recesses 32.
- a plurality of second recesses 34 that are orthogonal and parallel to the axial direction of the cooling roll 16 and arranged at a predetermined interval b are formed.
- the 1st recessed part 32 and the 2nd recessed part 34 are substantially linear grooves, and have a predetermined depth.
- a convex portion 36 is formed by the first concave portion 32 and the second concave portion 34.
- the angle ⁇ formed by the first recess 32 and the second recess 34 is preferably 80 to 100 °, more preferably 85 to 95 °.
- FIG. 5 is a schematic cross-sectional view showing an enlarged cross-section along the line VV in FIG. That is, FIG. 5 is a schematic cross-sectional view showing a part of the cross-sectional structure when the cooling roll 16 is cut by a plane passing through the axis and parallel to the axial direction.
- the height h1 of the convex portion 36 is obtained as the shortest distance between the straight line L1 passing through the bottom of the first concave portion 32 and parallel to the axial direction of the cooling roll 16 and the apex of the convex portion 36 in the cross section shown in FIG. be able to.
- the interval w1 between the convex portions 36 can be obtained as the distance between the apexes of the adjacent convex portions 36 in the cross section shown in FIG.
- FIG. 6 is a schematic cross-sectional view showing an enlarged cross section taken along line VI-VI in FIG. That is, FIG. 6 is a schematic cross-sectional view showing a part of the cross-sectional structure when the cooling roll 16 is cut along a plane parallel to the side surface.
- the height h2 of the convex portion 36 is obtained as the shortest distance between the straight line L2 passing through the bottom of the second concave portion 34 and perpendicular to the axial direction of the cooling roll 16 and the apex of the convex portion 36 in the cross section shown in FIG. be able to.
- the interval w2 between the convex portions 36 can be obtained as the distance between the apexes of the adjacent convex portions 36 in the cross section shown in FIG.
- the average value H of the heights of the convex portions 36 and the average value W of the intervals between the convex portions 36 are obtained as follows. Using a laser microscope, a cross-sectional profile image (magnification: 200 times) in the vicinity of the roll surface 17 of the cooling roll 16 as shown in FIGS. In these images, the height h1 and the height h2 of the arbitrarily selected convex portion 36 are each measured at 100 points. At this time, only those whose heights h1 and h2 are 3 ⁇ m or more are measured, and those whose height is less than 3 ⁇ m are not included in the data. The arithmetic average value of the measurement data of a total of 200 points is set as the average value H of the height of the convex portion 36.
- the uneven pattern of the roll surface 17 can be prepared by processing the roll surface 17 with a short wavelength laser, for example.
- the average value H of the heights of the convex portions 36 is preferably 7 to 20 ⁇ m. Thereby, the molten alloy can be sufficiently permeated into the recesses 32 and 34, and the adhesion between the molten alloy 12 and the roll surface 17 can be sufficiently increased.
- the upper limit of the average value H is more preferably 16 ⁇ m and even more preferably 14 ⁇ m from the viewpoint of allowing the molten alloy to more fully penetrate the recesses 32 and 34.
- the lower limit of the average value H is more preferable from the viewpoint of obtaining crystals of the R 2 T 14 B phase oriented more uniformly in the thickness direction of the alloy flakes while sufficiently increasing the adhesion between the molten alloy and the roll surface 17. Is 8.5 ⁇ m, more preferably 8.7 ⁇ m.
- the average value W of the interval between the convex portions 36 is 40 to 100 ⁇ m.
- the upper limit of the average value W is preferably 80 ⁇ m, more preferably 70 ⁇ m, and still more preferably from the viewpoint of obtaining a magnet powder having a small particle size by further reducing the width of the columnar crystals of the R 2 T 14 B phase. 67 ⁇ m.
- the lower limit of the average value W is preferably 45 ⁇ m, more preferably 48 ⁇ m. As a result, an RTB-based sintered magnet having higher magnetic characteristics can be obtained.
- the surface roughness Rz of the roll surface 17 is preferably 3 to 5 ⁇ m, more preferably 3.5 to 5 ⁇ m, and further preferably 3.9 to 4.5 ⁇ m. If Rz is excessive, the thickness of the flakes varies and the variation in cooling rate tends to increase. On the other hand, when Rz is too small, the adhesiveness between the molten alloy and the roll surface 17 becomes insufficient, and the molten alloy or the alloy flakes tend to peel from the roll surface 17 earlier than the target time. In this case, the heat removal from the molten alloy does not proceed sufficiently, and the molten alloy moves to the secondary cooling unit 20. For this reason, there exists a tendency for the malfunction which the alloy flakes 18 stick in the secondary cooling part 20 generate
- the surface roughness Rz in this specification is a ten-point average roughness, and is a value measured according to JIS B 0601-1994. Rz can be measured using a commercially available measuring device (for example, a surf test manufactured by Mitutoyo Corporation).
- the cooling roll 16 having the roll surface 17 as shown in FIGS. 4 to 6 since the cooling roll 16 having the roll surface 17 as shown in FIGS. 4 to 6 is used, when the molten alloy 12 is poured onto the roll surface 17 of the cooling roll 16, the molten alloy 12 is first convex. The part 36 is contacted. Starting from this contact portion, a dendrite-like crystal 40 including an R 2 T 14 B phase as shown in FIG. 2 is generated. A large number of such dendrite-like crystals 40 are formed on the roll surface 17, and the width P of each dendrite-like crystal 40 is sufficiently small, so that it grows in a columnar shape in the thickness direction of the alloy flakes.
- the roll surface 17 of the cooling roll 16 has convex portions 36 having a predetermined height and arranged at predetermined intervals. As a result, a large number of crystal nuclei 42 of the R 2 T 14 B phase are generated on the roll surface 17, and then a dendrite-like crystal 40 is formed. The dendrite-like crystal 40 also grows in the thickness direction of the RTB-based alloy flakes to form columnar crystals of the R 2 T 14 B phase.
- the cooling rate in the first cooling step is preferably 1000 to 3000 ° C./second, more preferably 1500 to 2500 ° C./second, from the viewpoint of suppressing the occurrence of heterogeneous phases while making the structure of the obtained alloy flakes sufficiently fine.
- Seconds When the cooling rate is less than 1000 ° C./second, the ⁇ -Fe phase tends to precipitate, and when the cooling rate exceeds 3000 ° C./second, chill crystals tend to precipitate.
- a chill crystal is an isotropic fine crystal having a particle size of 1 ⁇ m or less. When a large amount of chill crystals are produced, the magnetic properties of the RTB-based sintered magnet finally obtained tend to be impaired.
- the cooling rate can be controlled, for example, by adjusting the temperature and flow rate of the cooling water flowing through the inside of the cooling roll 16.
- the cooling rate can be adjusted by changing the material of the roll surface 17 of the cooling roll 16.
- a copper plate having a purity of 95% by mass can be used as the material of the cooling roll.
- the second cooling step is a step of further cooling the alloy flakes 18 including the crystal nuclei generated in the first cooling step by the secondary cooling unit 20.
- the cooling method in the second cooling step is not particularly limited, and a conventional cooling method can be employed.
- the secondary cooling unit 60 for example, a gas pipe 19 having a gas blowing hole 19a is provided, and a cooling gas is blown from the gas blowing hole 19a to an alloy flake deposited on a rotary table rotating in the circumferential direction. Is mentioned. Thereby, the alloy flakes 18 can be sufficiently cooled. The alloy flakes are recovered after being sufficiently cooled by the secondary cooling unit 20.
- the thickness of the RTB-based alloy flakes of this embodiment is preferably 0.5 mm or less, more preferably 0.1 to 0.5 mm. If the thickness of the alloy flakes is too large, the heat removal effect will be insufficient and the structure of the columnar crystals will be uneven. In addition, precipitation of ⁇ -Fe phase is observed in the vicinity of the free surface. When the alloy flakes on which the ⁇ -Fe phase is precipitated are pulverized, there is a tendency for the magnetic properties to decrease and the particle diameter variation of the alloy powder after pulverization to increase.
- the RTB-based alloy flakes of this embodiment contain an R 2 T 14 B phase as a main phase and an R rich phase as a different phase.
- the main phase is a crystal phase contained most in the alloy flakes
- the heterogeneous phase is a crystal phase different from the main phase and mainly present at the grain boundary of the main phase.
- the R-rich phase is non-magnetic and has a higher concentration of rare earth elements such as Nd than the R 2 T 14 B phase.
- the RTB-based alloy flakes of this embodiment may contain an ⁇ -Fe phase and a chill crystal in addition to the R-rich phase as a different phase.
- the total content of the different phases is preferably 10% by mass or less, more preferably 7% by mass or less, and further preferably 5% by mass or less with respect to the entire RTB-based alloy flake. .
- an RTB-based sintered magnet having both excellent residual magnetic flux density and coercive force can be obtained.
- FIG. 7 is a photograph of an SEM (scanning electron microscope) -BEI (reflection electron image) image showing a cross section of the RTB-based alloy flake along the thickness direction.
- FIG. 7A is a SEM-BEI image photograph (magnification: 300 times) showing a cross section along the thickness direction of the RTB-based alloy flakes of this embodiment.
- FIG. 7B is a photograph (magnification: 300 times) of a SEM-BEI image showing a cross section of the conventional RTB-based alloy flake along the thickness direction.
- the lower surface of the RTB-based alloy flake is a contact surface (casting surface) with the roll surface 17.
- white portions are R 2 T 14 B phase crystals
- black portions are R rich phases.
- the conventional RTB-based alloy flakes have fewer R 2 T 14 B phase crystal nucleus precipitates than in FIG. 7A.
- the R 2 T 14 B phase crystal grows not only in the vertical direction but also in the horizontal direction. For this reason, the width (lateral width) in a direction perpendicular to the longitudinal direction of the R 2 T 14 B phase crystal is larger than that in FIG. If the RTB-based alloy flake has such a structure, a fine alloy powder cannot be obtained.
- the manufacturing method of the RTB-based sintered magnet of the present embodiment includes a melting step of preparing a molten alloy of the RTB-based alloy, and a roll surface of a cooling roll that rotates the molten alloy in the circumferential direction.
- the molten alloy is cooled by the roll surface to form crystal nuclei, and at least a part of the molten alloy is solidified, and the alloy containing the crystal nuclei is further cooled to obtain RTB
- the grinding method in the grinding process is not particularly limited.
- the pulverization may be performed in the order of coarse pulverization and fine pulverization, for example.
- the coarse pulverization is preferably performed in an inert gas atmosphere using, for example, a stamp mill, a jaw crusher, a brown mill, or the like.
- hydrogen occlusion and pulverization may be performed after hydrogen is occluded.
- coarse pulverization an alloy powder having a particle size of about several hundred ⁇ m can be prepared.
- the alloy powder prepared by coarse pulverization is finely pulverized using a jet mill or the like, for example, until the average particle diameter becomes 1 to 5 ⁇ m.
- the pulverization of the alloy flakes is not necessarily performed in two stages of coarse pulverization and fine pulverization, and may be performed in one stage.
- the R-rich phase portion of the alloy flakes is preferentially broken.
- the particle size of the alloy powder depends on the interval between the R-rich phases.
- the alloy flakes used in the manufacturing method of the present embodiment have dendrite-like crystals 42 having a larger number of crystal precipitates on the surface and a smaller size than conventional ones. And an alloy powder in which the R-rich phase is more uniformly dispersed can be obtained.
- the alloy powder is formed in a magnetic field to obtain a formed body. Specifically, first, the alloy powder is filled in a mold disposed in an electromagnet. Thereafter, the magnetic field is applied by an electromagnet to pressurize the alloy powder while orienting the crystal axes of the alloy powder. In this manner, molding is performed in a magnetic field to produce a molded body.
- the molding in the magnetic field may be performed, for example, at a pressure of about 0.7 to 1.5 ton / cm 2 in a magnetic field of 12.0 to 17.0 kOe.
- a molded body obtained by molding in a magnetic field is fired in a vacuum or an inert gas atmosphere to obtain a sintered body.
- Firing conditions are preferably set as appropriate according to conditions such as composition, pulverization method, and particle size.
- the firing temperature can be 1000 to 1100 ° C.
- the firing time can be 1 to 5 hours.
- the RTB-based sintered magnet obtained by the manufacturing method of the present embodiment uses an alloy powder that is sufficiently fine and in which the R-rich phase is more uniformly dispersed, so that the structure is finer and more uniform than before.
- an RTB-based sintered magnet having a sufficiently excellent coercive force can be obtained.
- the aging treatment can be performed, for example, in two stages, and it is preferable to perform the aging treatment under two temperature conditions near 800 ° C. and 600 ° C. When an aging treatment is performed under such conditions, a particularly excellent coercive force tends to be obtained.
- the RTB-based sintered magnet thus obtained has the following composition, for example. That is, the RTB-based sintered magnet contains R, B, Al, Cu, Zr, Co, O, C, and Fe, and the content ratio of each element is R: 25 to 37% by mass, B : 0.5 to 1.5% by mass, Al: 0.03 to 0.5% by mass, Cu: 0.01 to 0.3% by mass, Zr: 0.03 to 0.5% by mass, Co: 3 % By mass or less (excluding 0% by mass), O: 0.5% by mass or less, and Fe: 60 to 72% by mass.
- the composition of the RTB-based sintered magnet is usually the same as that of the RTB alloy flake.
- the RTB-based sintered magnet contains inevitable impurities such as Mn, Ca, Ni, Si, Cl, S, and F at about 0.001 to 0.5 mass%. Also good. However, the total content of these impurities is preferably less than 2% by mass, and more preferably less than 1% by mass.
- the RTB-based sintered magnet contains an R 2 T 14 B phase as a main phase and an R-rich phase as a different phase.
- This RTB-based sintered magnet is obtained by using an alloy powder having a small particle size and a small variation in particle size, so that the uniformity of the structure is improved and sufficiently excellent. Has coercivity.
- FIG. 8 is a schematic cross-sectional view showing an enlarged part of the cross section of the RTB-based sintered magnet of the present embodiment.
- the RTB-based sintered magnet 100 preferably includes at least Fe as the transition element (T), and more preferably includes a combination of Fe and a transition element other than Fe. Examples of transition elements other than Fe include Co, Cu, and Zr.
- the RTB-based sintered magnet 100 preferably contains at least one element selected from Al, Cu, Ga, Zn and Ge. As a result, the coercive force of the RTB-based sintered magnet 100 can be further increased.
- the RTB-based sintered magnet 100 preferably contains at least one element selected from Ti, Zr, Ta, Nb, Mo, and Hf. By including such an element, it is possible to suppress grain growth during firing, and the coercive force of the RTB-based sintered magnet 100 can be further increased.
- the content of rare earth elements in the RTB-based sintered magnet 100 is preferably 25 to 37% by mass, more preferably 28 to 35% by mass, from the viewpoint of further improving the magnetic properties.
- the content of B in the RTB-based sintered magnet 100 is preferably 0.5 to 1.5% by mass, more preferably 0.7 to 1.2% by mass.
- the rare earth elements in the RTB-based sintered magnet 100 are scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), At least one selected from europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu) Contains elements.
- the RTB-based sintered magnet 100 may contain heavy rare earth elements such as Dy, Tb, and Ho as R.
- the content of the heavy rare earth element in the total mass of the RTB-based sintered magnet 100 is preferably 1.0% by mass or less, more preferably 0.5% by mass in total of the heavy rare earth elements. % Or less, and more preferably 0.1% by mass or less. According to the RTB-based sintered magnet 100 of the present embodiment, a high coercive force can be obtained even if the content of the heavy rare earth element is thus reduced.
- the amount of R 2 T 14 B phase which is the main phase of the RTB-based sintered magnet 100, decreases, and ⁇ -Fe having soft magnetism, etc. Tends to precipitate, and HcJ may be reduced. On the other hand, if it exceeds 37% by mass, the volume ratio of the R 2 T 14 B phase may decrease, and the residual magnetic flux density may decrease.
- the RTB-based sintered magnet 100 contains 0.2 to 2 mass% in total of at least one element selected from Al, Cu, Ga, Zn and Ge from the viewpoint of further increasing the coercive force. It is preferable. From the same viewpoint, the RTB-based sintered magnet 100 contains at least one element selected from Ti, Zr, Ta, Nb, Mo and Hf in a total amount of 0.1 to 1% by mass. It is preferable.
- the content of the transition element (T) in the RTB-based sintered magnet 100 is the remainder of the rare earth element, boron, and additive element described above.
- Co When Co is contained as a transition element, the content is preferably 3% by mass or less (excluding 0), more preferably 0.3 to 1.2% by mass. Co forms the same phase as Fe, but by containing Co, the Curie temperature and the corrosion resistance of the grain boundary phase can be improved.
- the content of oxygen in the RTB-based sintered magnet 100 is preferably 300 to 3000 ppm, more preferably from the viewpoint of achieving both magnetic properties and corrosion resistance at a higher level.
- 500 to 1500 ppm the content of nitrogen in the RTB-based sintered magnet 100 is 200 to 1500 ppm, more preferably 500 to 1500 ppm.
- the carbon content in the RTB-based sintered magnet 100 is 500 to 3000 ppm, and more preferably 800 to 1500 ppm.
- the crystal grains 120 in the RTB-based sintered magnet 100 preferably include an R 2 T 14 B phase.
- the triple point region 140, than R 2 T 14 B phase, the content of R of mass contains a higher phase than R 2 T 14 B phase.
- the average value of the area of the triple point region 140 in the cross section of the RTB-based sintered magnet 100 is an arithmetic average of 2 ⁇ m 2 or less, preferably 1.9 ⁇ m 2 or less. Further, the standard deviation of the area distribution is 3 or less, preferably 2.6 or less.
- the area of the triple point region 140 is small. The variation in area is also small. For this reason, both Br and HcJ can be maintained high.
- the average value of the area of the triple point region 140 in the cross section and the standard deviation of the area distribution can be obtained by the following procedure. First, the RTB-based sintered magnet 100 is cut and the cut surface is polished. An image of the polished surface is observed with a scanning electron microscope. Then, image analysis is performed to determine the area of the triple point region 140. The arithmetic average value of the obtained areas is the average area. The standard deviation of the area of the triple point region 140 can be calculated based on the area of each triple point region 140 and the average value thereof.
- the rare earth element content in the triple point region 140 is preferably 80 to 99% by mass from the viewpoint of an RTB-based sintered magnet having sufficiently high magnetic properties and sufficiently excellent corrosion resistance. More preferably, it is 85 to 99% by mass or more, and still more preferably 90 to 99% by mass. From the same viewpoint, the rare earth element content in each triple point region 140 is preferably the same. Specifically, the standard deviation of the content distribution of the triple point region 140 in the RTB-based sintered magnet 100 is preferably 5 or less, more preferably 4 or less, and even more preferably 3 It is as follows.
- the average grain size of the crystal grains 120 in the RTB-based sintered magnet 100 is preferably 0.5 to 5 ⁇ m, more preferably 2 to 4.5 ⁇ m, from the viewpoint of further improving the magnetic characteristics.
- This average grain size is obtained by performing image processing of an electron microscope image obtained by observing a cross section of the RTB-based sintered magnet 100, measuring the grain size of each crystal grain 120, and arithmetically averaging the measured values. Can be obtained.
- R-T-B based sintered magnet 100 includes a dendrite-like crystal grains 2 containing R 2 T 14 B phase, a grain boundary region 4 including a phase high content of R than R 2 T 14 B phase , And a pulverized product of RTB-based alloy flakes having an average interval interval of 3 ⁇ m or less having a higher R content than the R 2 T 14 B phase in the cross section is obtained by firing. It is preferable.
- Such an RTB-based sintered magnet 100 is obtained by using a pulverized product that is sufficiently fine and has a sharp particle size distribution. Therefore, the RTB is composed of fine crystal grains. A system sintered body is obtained.
- the ratio of the phase having a higher R content than the R 2 T 14 B phase is present not in the pulverized product but in the outer peripheral portion, the R content is higher than that of the sintered R 2 T 14 B phase.
- the dispersed state of the phase having a high amount tends to be good. For this reason, the structure of the RTB-based sintered body becomes finer and the uniformity is improved. Therefore, the magnetic properties of the RTB-based sintered body can be further enhanced.
- FIG. 9 is an explanatory view showing the internal structure of a motor including the RTB-based sintered magnet 100 obtained by the above-described manufacturing method.
- a motor 200 shown in FIG. 9 is a permanent magnet synchronous motor (SPM motor 200), and includes a cylindrical rotor 60 and a stator 50 disposed inside the rotor 60.
- the rotor 60 includes a cylindrical core 62 and a plurality of RTB-based sintered magnets 100 such that N poles and S poles alternate along the inner peripheral surface of the cylindrical core 62.
- the stator 50 has a plurality of coils 52 provided along the outer peripheral surface. The coil 52 and the RTB-based sintered magnet 100 are disposed so as to face each other.
- the SPM motor 200 includes the RTB-based sintered magnet 100 in the rotor 60.
- the RTB-based sintered magnet 100 has both high magnetic characteristics and excellent corrosion resistance at a high level. Therefore, the SPM motor 200 including the RTB-based sintered magnet 100 can continuously exhibit a high output over a long period of time.
- the RTB-based alloy flakes of this embodiment have crystal nuclei 42 of the R 2 T 14 B phase on only one surface, but these crystal nuclei 42 are formed of the RTB-based alloy flakes. You may have on the surface (both surfaces) which opposes. In this case, it is preferable that both surfaces have a structure as shown in FIG.
- the RTB-based alloy flakes having the dendrite-like crystals 40 as shown in FIG. 1 are arranged in such a manner that two cooling rolls having the above-mentioned uneven pattern are arranged, and the molten alloy is poured between them. It can be obtained by roll casting.
- Example 1 Preparation of alloy flakes> Using the alloy flake manufacturing apparatus as shown in FIG. 3, the strip casting method was performed according to the following procedure. First, raw material compounds of the respective constituent elements are blended so that the composition of the alloy flakes is the ratio (mass%) of the elements shown in Table 2, and heated to 1300 ° C. in the high-frequency melting furnace 10 to obtain RTB A molten alloy 12 having a system composition was prepared. This molten alloy 12 was poured onto a roll surface 17 of a cooling roll 16 rotating at a predetermined speed through a tundish. The cooling rate of the molten alloy 12 on the roll surface 17 was 1800 to 2200 ° C./second.
- the roll surface 17 of the cooling roll 16 includes a linear first recess 32 extending along the rotation direction of the cooling roll 16 and a linear second recess 34 orthogonal to the first recess 32. Had an uneven pattern.
- the average height H of the convex portions 36, the average value W of the intervals between the convex portions 36, and the surface roughness Rz were as shown in Table 1, respectively. Note that a measurement device (trade name: Surf Test) manufactured by Mitutoyo Corporation was used for measuring the surface roughness Rz.
- the alloy flakes obtained by cooling with the cooling roll 16 were further cooled by the secondary cooling section 60 to obtain alloy flakes having an RTB-based composition.
- the composition of this alloy flake was as shown in Table 2.
- FIG. 10 is a metallographic micrograph of the cast surface of the RTB-based alloy flake of Example 1 (magnification: 100 times).
- the cast surface of the alloy flakes is observed with a metallographic microscope, the average value of the width P of the dendritic crystals, the ratio of the minor axis length C2 to the major axis length C1 of the dendritic crystal group (aspect ratio), The area occupancy of the R 2 T 14 B phase crystal with respect to the entire visual field, and the number of crystal nuclei of dendritic crystals per unit area (1 mm 2 ) were examined. These results are shown in Table 1.
- the area occupancy of the R 2 T 14 B phase crystal is the area ratio of the dendrite-like crystal to the entire image in the metal micrograph of the cast surface of the RTB-based alloy flake.
- the dendrite-like crystal corresponds to the white part.
- the average value of the aspect ratio of the dendrite-like crystal group is an arithmetic average value of the ratio (C2 / C1) in 100 crystal groups arbitrarily selected.
- the RTB-based alloy flakes were cut along the thickness direction, and SEM-BEI observation (magnification: 300 times) of the cut surface was performed. In this observation image, the thickness of the alloy flake was determined. This thickness was as shown in Table 1.
- the alloy flakes were pulverized by a jet mill to obtain an alloy powder having an average particle size of 2.0 ⁇ m.
- the alloy powder was filled in a mold placed in an electromagnet and molded in a magnetic field to produce a molded body. Molding was performed by applying a pressure of 1.2 t / cm 2 while applying a magnetic field of 15 kOe. Thereafter, the molded body was fired at 930 to 1030 ° C. for 4 hours in a vacuum, and then rapidly cooled to obtain a sintered body.
- the obtained sintered body was subjected to two-stage aging treatment at 800 ° C. for 1 hour and at 540 ° C. for 1 hour (both in an argon gas atmosphere) to obtain the RTB-based sintering of Example 1. A magnet was obtained.
- Example 1 Example 1 with the exception that the roll surface of the cooling roll was processed and the average height H of the convex portions, the average value W of the convex portion intervals, and the surface roughness Rz were changed as shown in Table 1. Similarly, alloy flakes of Examples 2 to 6 and Examples 16 to 19 were obtained. In the same manner as in Example 1, the alloy flakes of Examples 2 to 6 and Examples 16 to 19 were evaluated. FIG. 11 is a metallurgical micrograph of the cast surface of the RTB-based alloy flakes of Example 2 (magnification: 100 times). In the same manner as in Example 1, RTB-based sintered magnets of Examples 2 to 6 were produced and evaluated. These results are shown in Table 1.
- Examples 7 to 15 and Examples 20 to 32 The roll surface of the cooling roll is processed, and the average value of the heights of the protrusions, the average value of the interval between the protrusions, and the surface roughness Rz are changed as shown in Table 1, and the alloy flakes are changed by changing the raw materials
- the alloy flakes of Examples 7 to 15 and Examples 20 to 32 were obtained in the same manner as in Example 1 except that the composition was changed as shown in Table 2.
- the alloy flakes of Examples 7 to 15 and Examples 20 to 32 were evaluated.
- the RTB-based sintered magnets of Examples 7 to 15 and Examples 20 to 32 were produced and evaluated in the same manner as Example 1. These results are shown in Table 1.
- Comparative Example 1 An alloy flake of Comparative Example 1 was obtained in the same manner as in Example 1 except that a cooling roll having only a linear first recess extending in the rotation direction of the roll was used on the roll surface. This cooling roll did not have the 2nd recessed part.
- interval, and surface roughness Rz were calculated
- the average value H of the heights of the convex portions is an arithmetic average value of the heights of 100 convex portions
- the average value W of the intervals between the convex portions is a value obtained by measuring the interval between adjacent convex portions at 100 different points. Is the arithmetic mean of
- FIG. 12 is a metallographic micrograph of the cast surface of the RTB-based alloy flake of Comparative Example 1 (magnification: 100 times). In the same manner as in Example 1, the alloy flakes of Comparative Example 1 were evaluated. In the same manner as in Example 1, the RTB-based sintered magnet of Comparative Example 1 was produced and evaluated. These results are shown in Table 1.
- Example 1 (Comparative Examples 2 and 3) Example 1 with the exception that the roll surface of the cooling roll was processed and the average height H of the convex portions, the average value W of the convex portion intervals, and the surface roughness Rz were changed as shown in Table 1. Similarly, RTB-based alloy flakes of Comparative Examples 2 and 3 were obtained. Then, the RTB-based alloy flakes of Comparative Examples 2 and 3 were evaluated in the same manner as in Example 1.
- FIG. 13 is a metallographic micrograph of the cast surface of the RTB-based alloy flake of Comparative Example 2 (magnification: 100 times).
- FIG. 14 is a metallographic micrograph of the cast surface of the RTB-based alloy flake of Comparative Example 3 (magnification: 100 times). In the same manner as in Example 1, RTB-based sintered magnets of Comparative Examples 2 and 3 were produced and evaluated. These results are shown in Table 1.
- Comparative Example 4 Except having used the cooling roll which has only the linear 1st recessed part extended in the rotation direction of a roll on the roll surface, and having changed the raw material and changing the composition of the alloy flakes as shown in Table 2. In the same manner as in Example 1, an RTB-based alloy flake of Comparative Example 4 was obtained. These cooling rolls did not have the second recess. In addition, the average value H of the convex part height of these cooling rolls, the average value W of the convex part space
- Example 1 In the same manner as in Example 1, the alloy flakes of Comparative Example 4 were evaluated. Then, an RTB-based sintered magnet of Comparative Example 4 was produced and evaluated in the same manner as in Example 1. These results are shown in Table 1.
- FIG. 17 is a diagram showing element map data in which the triple point region is blacked out in the rare earth sintered magnet of Example 10.
- FIG. 18 is a diagram showing element map data in which the triple point region of the RTB-based sintered magnet of Comparative Example 4 is blacked out.
- Example 10 to 15 image analysis was performed in the same manner as in Example 10, and the average value of the area of the triple point region and the standard deviation of the distribution of the area were calculated. These results are shown in Table 3. As shown in Table 3, the average values and standard deviations of the triple point area of the RTB-based sintered magnets of Examples 10 to 15 were sufficiently smaller than those of Comparative Example 4. From these results, it was confirmed that in Examples 10 to 15, segregation of the phase having a higher R content than the R 2 T 14 B phase was sufficiently suppressed.
- Example 10 has a higher RT coercivity than RT.
- a -B sintered magnet was obtained. This is because the RTB-based sintered magnet of Example 10 not only has a fine grain size but also has a uniform grain size and shape, and therefore segregates in the triple point region. This is thought to be due to the suppression of
- an alloy flake that can improve the coercive force of an RTB-based sintered magnet. Further, it is possible to provide an RTB-based sintered magnet having a sufficiently excellent coercive force, and a method for producing the same.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Hard Magnetic Materials (AREA)
- Powder Metallurgy (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
- Continuous Casting (AREA)
Abstract
Description
HcJ=α・HA-N・Ms (1)
Br=Ms・(ρ/ρ0)・f・A (2)
図1は、本実施形態のR-T-B系合金薄片の一表面の金属顕微鏡写真(倍率:100倍)である。本実施形態の合金薄片は、R2T14B相の結晶相とRリッチ相とを含有する。本明細書において、Rは希土類元素から選ばれる少なくとも1種を含む元素、Tは鉄及びコバルトの少なくとも一方を含む元素、及びBはホウ素をそれぞれ示す。
図3は、実施形態のR-T-B系合金薄片を製造するための装置の模式図である。本実施形態のR-T-B系合金薄片は、図3に示すような製造装置を用いたストリップキャスト法によって製造することができる。本実施形態の合金薄片の製造方法は、R-T-B系合金の合金溶湯を調製する溶融工程と、合金溶湯を、円周方向に回転する冷却ロールのロール面に注いで合金溶湯を該ロール面によって冷却して結晶核を生成させ、合金溶湯の少なくとも一部を凝固させる第1の冷却工程と、結晶核を含む合金をさらに冷却して合金薄片を得る第2の冷却工程と、を有する。以下、各工程の詳細について説明する。
次に、R-T-B系焼結磁石の製造方法の好適な実施形態を説明する。本実施形態のR-T-B系焼結磁石の製造方法は、R-T-B系合金の合金溶湯を調製する溶融工程と、合金溶湯を、円周方向に回転する冷却ロールのロール面に注いで合金溶湯を該ロール面によって冷却して結晶核を生成させ、合金溶湯の少なくとも一部を凝固させる第1の冷却工程と、結晶核を含む合金をさらに冷却してR-T-B系合金薄片を得る第2の冷却工程と、R-T-B系合金薄片を粉砕してR-T-B系の合金粉末を得る粉砕工程と、合金粉末を成形して成形体を作製する成形工程と、成形体を焼成してR-T-B系焼結磁石を得る焼成工程と、を有する。すなわち、本実施形態のR-T-B系焼結磁石の製造方法は、上述の製造方法で得られたR-T-B系合金薄片を用いており、溶融工程から第2の冷却工程までは、上述の合金薄片の製造方法と同様に行うことができる。したがって、ここでは粉砕工程以降の工程を説明する。
<合金薄片の作製>
図3に示すような合金薄片の製造装置を用いて、次の手順でストリップキャスト法を行った。まず、合金薄片の組成が表2に示す元素の割合(質量%)となるように、各構成元素の原料化合物を配合し、高周波溶解炉10で1300℃に加熱して、R-T-B系の組成を有する合金溶湯12を調製した。この合金溶湯12を、タンディッシュを介して所定の速度で回転している冷却ロール16のロール面17上に注いだ。ロール面17上における合金溶湯12の冷却速度は、1800~2200℃/秒とした。
図10は、実施例1のR-T-B系合金薄片の鋳造面の金属顕微鏡写真である(倍率:100倍)。合金薄片の鋳造面を金属顕微鏡で観察して、デンドライト状結晶の幅Pの平均値、デンドライト状結晶の結晶群の長軸の長さC1に対する短軸の長さC2の比(アスペクト比)、全視野に対するR2T14B相の結晶の面積占有率、及び単位面積当たり(1mm2)におけるデンドライト状結晶の結晶核の発生数を調べた。これらの結果を表1に示す。なお、R2T14B相の結晶の面積占有率は、R-T-B系合金薄片の鋳造面の金属顕微鏡写真における、画像全体に対するデンドライト状の結晶の面積比率である。図10において、デンドライト状結晶は白色部分に相当する。デンドライト状結晶の結晶群のアスペクト比の平均値は、任意に選択された100個の結晶群における比(C2/C1)の算術平均値である。
次に、合金薄片をジェットミルで粉砕して平均粒径が2.0μmの合金粉末を得た。この合金粉末を、電磁石中に配置された金型内に充填し、磁場中で成形して成形体を作製した。成形は、15kOeの磁場を印加しながら1.2t/cm2に加圧して行った。その後、成形体を、真空中、930~1030℃で4時間焼成した後、急冷して焼結体を得た。得られた焼結体に、800℃で1時間、及び、540℃で1時間(ともにアルゴンガス雰囲気中)の2段階の時効処理を施して、実施例1のR-T-B系焼結磁石を得た。
B-Hトレーサーを用いて、得られたR-T-B系焼結磁石のBr(残留磁束密度)及びHcJ(保磁力)を測定した。測定結果を表1に示す。
冷却ロールのロール面を加工して、凸部の高さの平均値H、凸部の間隔の平均値W、及び表面粗さRzを表1のとおりに変更したこと以外は、実施例1と同様にして実施例2~6及び実施例16~19の合金薄片を得た。そして、実施例1と同様にして、実施例2~6及び実施例16~19の合金薄片の評価を行った。図11は、実施例2のR-T-B系合金薄片の鋳造面の金属顕微鏡写真である(倍率:100倍)。実施例1と同様にして実施例2~6のR-T-B系焼結磁石を作製し、評価を行った。これらの結果を表1に示す。
冷却ロールのロール面を加工して、凸部の高さの平均値、凸部の間隔の平均値、及び表面粗さRzを表1のとおりに変更したこと、及び原料を変更して合金薄片の組成を表2のとおりに変更したこと以外は、実施例1と同様にして実施例7~15及び実施例20~32の合金薄片を得た。実施例1と同様にして、実施例7~15及び実施例20~32の合金薄片の評価を行った。そして、実施例1と同様にして実施例7~15及び実施例20~32のR-T-B系焼結磁石を作製し、評価を行った。これらの結果を表1に示す。
ロール面に、ロールの回転方向に延在する直線状の第1の凹部のみを有する冷却ロールを用いたこと以外は実施例1と同様にして比較例1の合金薄片を得た。この冷却ロールは第2の凹部を有していなかった。なお、この冷却ロールの凸部の高さの平均値H、凸部の間隔の平均値W、及び表面粗さRzは、次の通りにして求めた。すなわち、冷却ロールを、冷却ロールの軸を通り軸方向に平行な面で切断したときの切断面においてロール面近傍の断面構造を観察して求めた。凸部の高さの平均値Hは、100個の凸部の高さの算術平均値であり、凸部の間隔の平均値Wは、隣り合う凸部の間隔を異なる100箇所で測定した値の算術平均値である。
冷却ロールのロール面を加工して、凸部の高さの平均値H、凸部の間隔の平均値W、及び表面粗さRzを表1のとおりに変更したこと以外は、実施例1と同様にして比較例2,3のR-T-B系合金薄片を得た。そして、実施例1と同様にして、比較例2,3のR-T-B系合金薄片の評価を行った。図13は、比較例2のR-T-B系合金薄片の鋳造面の金属顕微鏡写真である(倍率:100倍)。図14は、比較例3のR-T-B系合金薄片の鋳造面の金属顕微鏡写真である(倍率:100倍)。実施例1と同様にして比較例2,3のR-T-B系焼結磁石を作製し、評価を行った。これらの結果を表1に示す。
ロール面に、ロールの回転方向に延在する直線状の第1の凹部のみを有する冷却ロールを用いたこと、及び原料を変更して合金薄片の組成を表2のとおりに変更したこと以外は実施例1と同様にして比較例4のR-T-B系合金薄片を得た。これらの冷却ロールは第2の凹部を有していなかった。なお、これらの冷却ロールの凸部の高さの平均値H、凸部の間隔の平均値W、及び表面粗さRzは、比較例1と同様にして求めた。
(三重点領域の面積と標準偏差)
実施例10のR-T-B系焼結磁石について、電子線マイクロアナライザ(EPMA:JXA8500F型FE-EPMA)を用いて元素マップデータを収集した。測定条件は加速電圧15kV、照射電流0.1μA、Count-Time:30msecとし、データ収集領域は、X=Y=51.2μm、データ点数は、X=Y=256(0.2μm-step)とした。この元素マップデータにおいて、まず、3つ以上の結晶粒に囲まれている三重点領域を黒く塗りつぶし、これを画像解析することにより、三重点領域の面積の平均値と当該面積の分布の標準偏差を求めた。図17は、実施例10の希土類焼結磁石において三重点領域を黒く塗りつぶした元素マップデータを示す図である。
さらに、同様の電子顕微鏡の観察画像において、画像解析によってR2T14B相の結晶粒の形状を認識させ、個々の結晶粒の直径を求めて、その算術平均値を求めた。これを、R2T14B相の結晶粒の平均粒径とした。結果を表3に示す。
EPMAを用いて、実施例10~15及び比較例4のR-T-B系焼結磁石の三重点領域における希土類元素の質量基準の含有量を求めた。測定は、10点の三重点領域において行い、希土類元素の含有量の範囲と標準偏差を求めた。これらの結果を表3に示す。
一般的なガス分析装置を用いて、実施例10~15及び比較例4のR-T-B系焼結磁石のガス分析を行って、酸素、窒素及び炭素の含有量を求めた。その結果を表3に示す。
Claims (5)
- R2T14B相を含むデンドライト状結晶を含有するR-T-B系合金薄片であって、
少なくとも一つの表面において、
前記デンドライト状結晶の幅の平均値が60μm以下であり、
前記デンドライト状結晶の結晶核の数が1mm四方当たり500個以上である、R-T-B系合金薄片。 - 前記デンドライト状結晶の幅の平均値が25μm以上である、請求項1に記載のR-T-B系合金薄片。
- 複数の前記デンドライト状結晶からなる結晶群のアスペクト比の平均値が0.8以上である、請求項1又は2に記載のR-T-B系合金薄片。
- 請求項1~3のいずれか一項に記載のR-T-B系合金薄片を粉砕して得た合金粉末を成形し、焼成して得られるR-T-B系焼結磁石。
- 請求項1~3のいずれか一項に記載の合金薄片を粉砕して合金粉末を調製する工程と、
前記合金粉末を成形して焼成し、R-T-B系焼結磁石を作製する工程と、を有する、R-T-B系焼結磁石の製造方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013538567A JP5880569B2 (ja) | 2011-10-13 | 2012-10-11 | R−t−b系合金薄片及びその製造方法、並びにr−t−b系焼結磁石の製造方法 |
US14/351,119 US9607742B2 (en) | 2011-10-13 | 2012-10-11 | R-T-B based alloy strip, and R-T-B based sintered magnet and method for producing same |
DE112012004288.3T DE112012004288T5 (de) | 2011-10-13 | 2012-10-11 | R-T-B-basiertes Legierungsband, R-T-B-basierter gesinterter Magnet und Verfahren zu deren Herstellung |
CN201280050558.XA CN103875046B (zh) | 2011-10-13 | 2012-10-11 | R-t-b系合金薄片、r-t-b系烧结磁体及其制造方法 |
Applications Claiming Priority (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011-226042 | 2011-10-13 | ||
JP2011226042 | 2011-10-13 | ||
JP2011226040 | 2011-10-13 | ||
JP2011-226040 | 2011-10-13 | ||
JP2011248978 | 2011-11-14 | ||
JP2011-248980 | 2011-11-14 | ||
JP2011-248978 | 2011-11-14 | ||
JP2011248980 | 2011-11-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013054845A1 true WO2013054845A1 (ja) | 2013-04-18 |
Family
ID=48081895
Family Applications (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/076327 WO2013054847A1 (ja) | 2011-10-13 | 2012-10-11 | R-t-b系焼結磁石及びその製造方法、並びに回転機 |
PCT/JP2012/076346 WO2013054854A1 (ja) | 2011-10-13 | 2012-10-11 | R-t-b系合金薄片、並びにr-t-b系焼結磁石及びその製造方法 |
PCT/JP2012/076310 WO2013054842A1 (ja) | 2011-10-13 | 2012-10-11 | R-t-b系焼結磁石及びその製造方法、並びに回転機 |
PCT/JP2012/076324 WO2013054845A1 (ja) | 2011-10-13 | 2012-10-11 | R-t-b系合金薄片、並びにr-t-b系焼結磁石及びその製造方法 |
Family Applications Before (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/076327 WO2013054847A1 (ja) | 2011-10-13 | 2012-10-11 | R-t-b系焼結磁石及びその製造方法、並びに回転機 |
PCT/JP2012/076346 WO2013054854A1 (ja) | 2011-10-13 | 2012-10-11 | R-t-b系合金薄片、並びにr-t-b系焼結磁石及びその製造方法 |
PCT/JP2012/076310 WO2013054842A1 (ja) | 2011-10-13 | 2012-10-11 | R-t-b系焼結磁石及びその製造方法、並びに回転機 |
Country Status (5)
Country | Link |
---|---|
US (4) | US20140247100A1 (ja) |
JP (4) | JP5949776B2 (ja) |
CN (4) | CN103890867B (ja) |
DE (4) | DE112012004298T5 (ja) |
WO (4) | WO2013054847A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015022946A1 (ja) * | 2013-08-12 | 2015-02-19 | 日立金属株式会社 | R-t-b系焼結磁石およびr-t-b系焼結磁石の製造方法 |
JP2023512541A (ja) * | 2020-04-30 | 2023-03-27 | 烟台正海磁性材料股▲フン▼有限公司 | 微細結晶、高保磁力のネオジム鉄ボロン系焼結磁石及びその製造方法 |
JP7452159B2 (ja) | 2020-03-24 | 2024-03-19 | 株式会社プロテリアル | R-t-b系焼結磁石の製造方法 |
Families Citing this family (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006305231A (ja) * | 2005-05-02 | 2006-11-09 | Tokai Ind Sewing Mach Co Ltd | 刺繍ミシン及び刺繍スタート位置設定方法。 |
DE112012004298T5 (de) * | 2011-10-13 | 2014-07-03 | Tdk Corporation | Gesinterter R-T-B-Magnet und Verfahren zu seiner Herstellung sowie Rotationsmaschine |
EP2985768B8 (en) * | 2013-03-29 | 2019-11-06 | Hitachi Metals, Ltd. | R-t-b-based sintered magnet |
JP6005257B2 (ja) * | 2013-03-29 | 2016-10-12 | 和歌山レアアース株式会社 | R−t−b系磁石用原料合金およびその製造方法 |
JP2014223652A (ja) * | 2013-05-16 | 2014-12-04 | 住友電気工業株式会社 | 希土類−鉄系合金材の製造方法、希土類−鉄系合金材、希土類−鉄−窒素系合金材の製造方法、希土類−鉄−窒素系合金材、及び希土類磁石 |
JP6314380B2 (ja) * | 2013-07-23 | 2018-04-25 | Tdk株式会社 | 希土類磁石、電動機、及び電動機を備える装置 |
JP6314381B2 (ja) * | 2013-07-23 | 2018-04-25 | Tdk株式会社 | 希土類磁石、電動機、及び電動機を備える装置 |
WO2015068681A1 (ja) * | 2013-11-05 | 2015-05-14 | 株式会社Ihi | 希土類永久磁石および希土類永久磁石の製造方法 |
JP6413302B2 (ja) * | 2014-03-31 | 2018-10-31 | Tdk株式会社 | R−t−b系異方性磁性粉及び異方性ボンド磁石 |
JP6380738B2 (ja) * | 2014-04-21 | 2018-08-29 | Tdk株式会社 | R−t−b系永久磁石、r−t−b系永久磁石用原料合金 |
US9755462B2 (en) * | 2015-02-24 | 2017-09-05 | GM Global Technology Operations LLC | Rotor geometry for interior permanent magnet machine having rare earth magnets with no heavy rare earth elements |
JP6582940B2 (ja) * | 2015-03-25 | 2019-10-02 | Tdk株式会社 | R−t−b系希土類焼結磁石及びその製造方法 |
US10923256B2 (en) | 2015-06-25 | 2021-02-16 | Hitachi Metals, Ltd. | R-T-B-based sintered magnet and method for producing same |
CN105513737A (zh) | 2016-01-21 | 2016-04-20 | 烟台首钢磁性材料股份有限公司 | 一种不含重稀土元素烧结钕铁硼磁体的制备方法 |
CN107527698B (zh) * | 2016-06-20 | 2019-10-01 | 有研稀土新材料股份有限公司 | 一种热变形稀土永磁材料及其制备方法和应用 |
CN106298138B (zh) * | 2016-11-10 | 2018-05-15 | 包头天和磁材技术有限责任公司 | 稀土永磁体的制造方法 |
WO2018121112A1 (zh) * | 2016-12-29 | 2018-07-05 | 北京中科三环高技术股份有限公司 | 细晶粒稀土类合金铸片、制备方法、旋转冷却辊装置 |
CN108257752B (zh) * | 2016-12-29 | 2021-07-23 | 北京中科三环高技术股份有限公司 | 一种制备细晶粒稀土类烧结磁体用合金铸片 |
CN108246992B (zh) * | 2016-12-29 | 2021-07-13 | 北京中科三环高技术股份有限公司 | 一种制备细晶粒稀土类合金铸片的方法及旋转冷却辊装置 |
CN108257751B (zh) * | 2016-12-29 | 2021-02-19 | 北京中科三环高技术股份有限公司 | 一种制备细晶粒稀土类烧结磁体用合金铸片 |
JP6863008B2 (ja) * | 2017-03-30 | 2021-04-21 | Tdk株式会社 | R−t−b系希土類焼結磁石用合金およびr−t−b系希土類焼結磁石の製造方法 |
CN107707051A (zh) * | 2017-11-24 | 2018-02-16 | 安徽美芝精密制造有限公司 | 用于电机的永磁体和具有其的转子组件、电机及压缩机 |
JP2021501560A (ja) * | 2017-11-24 | 2021-01-14 | 安徽美芝精密制造有限公司Anhui Meizhi Precision Manufacturing Co., Ltd. | モータ用の永久磁石、それを有するロータアセンブリ、モータ及び圧縮機 |
JP7167484B2 (ja) * | 2018-05-17 | 2022-11-09 | Tdk株式会社 | R-t-b系希土類焼結磁石用鋳造合金薄片 |
JP6989713B2 (ja) * | 2018-12-25 | 2022-01-05 | ダイセルミライズ株式会社 | 表面に粗面化構造を有する希土類磁石前駆体または希土類磁石成形体とそれらの製造方法 |
DE112019007700T5 (de) * | 2019-09-10 | 2022-06-15 | Mitsubishi Electric Corporation | Seltenerd-magnetlegierung, verfahren zu ihrer herstellung, seltenerd-magnet, rotor und rotierende maschine |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09260122A (ja) * | 1996-03-19 | 1997-10-03 | Hitachi Metals Ltd | 焼結型永久磁石 |
WO2005095024A1 (ja) * | 2004-03-31 | 2005-10-13 | Santoku Corporation | 希土類焼結磁石用合金鋳片の製造法、希土類焼結磁石用合金鋳片及び希土類焼結磁石 |
JP2006019521A (ja) * | 2004-07-01 | 2006-01-19 | Inter Metallics Kk | 磁気異方性希土類焼結磁石の製造方法及び製造装置 |
JP2011210838A (ja) * | 2010-03-29 | 2011-10-20 | Tdk Corp | 希土類焼結磁石及びその製造方法、並びに回転機 |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3932143B2 (ja) * | 1992-02-21 | 2007-06-20 | Tdk株式会社 | 磁石の製造方法 |
US5595608A (en) * | 1993-11-02 | 1997-01-21 | Tdk Corporation | Preparation of permanent magnet |
JP3693838B2 (ja) | 1999-01-29 | 2005-09-14 | 信越化学工業株式会社 | 希土類磁石用合金薄帯、合金微粉末及びそれらの製造方法 |
JP4032560B2 (ja) * | 1999-05-26 | 2008-01-16 | 日立金属株式会社 | 永久磁石用希土類系合金粉末の製造方法 |
EP1059645B1 (en) * | 1999-06-08 | 2006-06-14 | Shin-Etsu Chemical Co., Ltd. | Thin ribbon of rare earth-based permanent magnet alloy |
CN1220220C (zh) * | 2001-09-24 | 2005-09-21 | 北京有色金属研究总院 | 钕铁硼合金快冷厚带及其制造方法 |
CN1255235C (zh) | 2002-03-06 | 2006-05-10 | 北京有色金属研究总院 | 合金快冷厚带设备和采用该设备的制备方法及其产品 |
US7311788B2 (en) * | 2002-09-30 | 2007-12-25 | Tdk Corporation | R-T-B system rare earth permanent magnet |
US7314531B2 (en) * | 2003-03-28 | 2008-01-01 | Tdk Corporation | R-T-B system rare earth permanent magnet |
JP4449900B2 (ja) * | 2003-04-22 | 2010-04-14 | 日立金属株式会社 | 希土類合金粉末の製造方法および希土類焼結磁石の製造方法 |
US20050098239A1 (en) * | 2003-10-15 | 2005-05-12 | Neomax Co., Ltd. | R-T-B based permanent magnet material alloy and R-T-B based permanent magnet |
CN100400199C (zh) * | 2004-03-31 | 2008-07-09 | 株式会社三德 | 稀土类烧结磁铁用合金铸片及其制造方法和稀土类烧结磁铁 |
US20060165550A1 (en) * | 2005-01-25 | 2006-07-27 | Tdk Corporation | Raw material alloy for R-T-B system sintered magnet, R-T-B system sintered magnet and production method thereof |
JP4955217B2 (ja) * | 2005-03-23 | 2012-06-20 | Tdk株式会社 | R−t−b系焼結磁石用原料合金及びr−t−b系焼結磁石の製造方法 |
CN101256859B (zh) * | 2007-04-16 | 2011-01-26 | 有研稀土新材料股份有限公司 | 一种稀土合金铸片及其制备方法 |
US8152936B2 (en) * | 2007-06-29 | 2012-04-10 | Tdk Corporation | Rare earth magnet |
JP5299737B2 (ja) * | 2007-09-28 | 2013-09-25 | 日立金属株式会社 | R−t−b系焼結永久磁石用急冷合金およびそれを用いたr−t−b系焼結永久磁石 |
JP5303738B2 (ja) * | 2010-07-27 | 2013-10-02 | Tdk株式会社 | 希土類焼結磁石 |
JP5729051B2 (ja) * | 2011-03-18 | 2015-06-03 | Tdk株式会社 | R−t−b系希土類焼結磁石 |
DE112012004298T5 (de) * | 2011-10-13 | 2014-07-03 | Tdk Corporation | Gesinterter R-T-B-Magnet und Verfahren zu seiner Herstellung sowie Rotationsmaschine |
-
2012
- 2012-10-11 DE DE112012004298.0T patent/DE112012004298T5/de active Pending
- 2012-10-11 DE DE112012004275.1T patent/DE112012004275T5/de active Pending
- 2012-10-11 CN CN201280050510.9A patent/CN103890867B/zh active Active
- 2012-10-11 WO PCT/JP2012/076327 patent/WO2013054847A1/ja active Application Filing
- 2012-10-11 WO PCT/JP2012/076346 patent/WO2013054854A1/ja active Application Filing
- 2012-10-11 US US14/350,728 patent/US20140247100A1/en not_active Abandoned
- 2012-10-11 WO PCT/JP2012/076310 patent/WO2013054842A1/ja active Application Filing
- 2012-10-11 US US14/351,119 patent/US9607742B2/en active Active
- 2012-10-11 CN CN201280050562.6A patent/CN103858185B/zh active Active
- 2012-10-11 DE DE112012004260.3T patent/DE112012004260T5/de active Pending
- 2012-10-11 US US14/351,199 patent/US9613737B2/en active Active
- 2012-10-11 JP JP2013538572A patent/JP5949776B2/ja active Active
- 2012-10-11 DE DE112012004288.3T patent/DE112012004288T5/de active Pending
- 2012-10-11 WO PCT/JP2012/076324 patent/WO2013054845A1/ja active Application Filing
- 2012-10-11 US US14/350,438 patent/US9620268B2/en active Active
- 2012-10-11 CN CN201280050553.7A patent/CN103875045B/zh active Active
- 2012-10-11 JP JP2013538567A patent/JP5880569B2/ja active Active
- 2012-10-11 JP JP2013538565A patent/JP6079633B2/ja active Active
- 2012-10-11 JP JP2013538569A patent/JP5949775B2/ja active Active
- 2012-10-11 CN CN201280050558.XA patent/CN103875046B/zh active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09260122A (ja) * | 1996-03-19 | 1997-10-03 | Hitachi Metals Ltd | 焼結型永久磁石 |
WO2005095024A1 (ja) * | 2004-03-31 | 2005-10-13 | Santoku Corporation | 希土類焼結磁石用合金鋳片の製造法、希土類焼結磁石用合金鋳片及び希土類焼結磁石 |
JP2006019521A (ja) * | 2004-07-01 | 2006-01-19 | Inter Metallics Kk | 磁気異方性希土類焼結磁石の製造方法及び製造装置 |
JP2011210838A (ja) * | 2010-03-29 | 2011-10-20 | Tdk Corp | 希土類焼結磁石及びその製造方法、並びに回転機 |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015022946A1 (ja) * | 2013-08-12 | 2015-02-19 | 日立金属株式会社 | R-t-b系焼結磁石およびr-t-b系焼結磁石の製造方法 |
CN105453195A (zh) * | 2013-08-12 | 2016-03-30 | 日立金属株式会社 | R-t-b系烧结磁体及r-t-b系烧结磁体的制造方法 |
JPWO2015022946A1 (ja) * | 2013-08-12 | 2017-03-02 | 日立金属株式会社 | R−t−b系焼結磁石およびr−t−b系焼結磁石の製造方法 |
US10388442B2 (en) | 2013-08-12 | 2019-08-20 | Hitachi Metals, Ltd. | R-T-B based sintered magnet and method for producing R-T-B based sintered magnet |
JP7452159B2 (ja) | 2020-03-24 | 2024-03-19 | 株式会社プロテリアル | R-t-b系焼結磁石の製造方法 |
JP2023512541A (ja) * | 2020-04-30 | 2023-03-27 | 烟台正海磁性材料股▲フン▼有限公司 | 微細結晶、高保磁力のネオジム鉄ボロン系焼結磁石及びその製造方法 |
Also Published As
Publication number | Publication date |
---|---|
DE112012004275T5 (de) | 2014-07-10 |
CN103890867A (zh) | 2014-06-25 |
CN103890867B (zh) | 2017-07-11 |
US9620268B2 (en) | 2017-04-11 |
DE112012004298T5 (de) | 2014-07-03 |
WO2013054842A1 (ja) | 2013-04-18 |
US20140308152A1 (en) | 2014-10-16 |
CN103875046B (zh) | 2016-10-05 |
DE112012004260T5 (de) | 2014-07-17 |
DE112012004288T5 (de) | 2014-07-31 |
US9607742B2 (en) | 2017-03-28 |
WO2013054854A1 (ja) | 2013-04-18 |
US20140286815A1 (en) | 2014-09-25 |
JPWO2013054854A1 (ja) | 2015-03-30 |
CN103875045B (zh) | 2016-08-31 |
US20140286816A1 (en) | 2014-09-25 |
CN103858185A (zh) | 2014-06-11 |
CN103875045A (zh) | 2014-06-18 |
US9613737B2 (en) | 2017-04-04 |
JP6079633B2 (ja) | 2017-02-15 |
US20140247100A1 (en) | 2014-09-04 |
CN103858185B (zh) | 2017-05-03 |
JP5949775B2 (ja) | 2016-07-13 |
JP5880569B2 (ja) | 2016-03-09 |
JPWO2013054847A1 (ja) | 2015-03-30 |
CN103875046A (zh) | 2014-06-18 |
JPWO2013054842A1 (ja) | 2015-03-30 |
WO2013054847A1 (ja) | 2013-04-18 |
JP5949776B2 (ja) | 2016-07-13 |
JPWO2013054845A1 (ja) | 2015-03-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5880569B2 (ja) | R−t−b系合金薄片及びその製造方法、並びにr−t−b系焼結磁石の製造方法 | |
JP4832856B2 (ja) | R−t−b系合金及びr−t−b系合金薄片の製造方法、r−t−b系希土類永久磁石用微粉、r−t−b系希土類永久磁石 | |
EP2128290A1 (en) | R-t-b base alloy, process for production thereof, fine powder for r-t-b base rare earth permanent magnet, and r-t-b base rare earth permanent magnet | |
JPWO2009075351A1 (ja) | R−t−b系合金及びr−t−b系合金の製造方法、r−t−b系希土類永久磁石用微粉、r−t−b系希土類永久磁石 | |
EP1395381B1 (en) | Centrifugal casting method und centrifugal casting apparatus | |
KR101922188B1 (ko) | 희토류 소결 자석용 원료 합금 주편 및 그 제조 방법 | |
JP4879503B2 (ja) | R−t−b系焼結磁石用合金塊、その製造法および磁石 | |
JP4479944B2 (ja) | 希土類磁石用合金薄片およびその製造方法 | |
WO2009125671A1 (ja) | R-t-b系合金及びr-t-b系合金の製造方法、r-t-b系希土類永久磁石用微粉、r-t-b系希土類永久磁石、r-t-b系希土類永久磁石の製造方法 | |
JP2004181531A (ja) | 希土類含有合金薄片の製造方法、希土類磁石用合金薄片、希土類焼結磁石用合金粉末、希土類焼結磁石、ボンド磁石用合金粉末、及びボンド磁石並びに金属組織評価方法 | |
EP1652606B1 (en) | Centrifugal casting method, centrifugal casting apparatus, and cast alloy produced by same | |
JP2004043921A (ja) | 希土類含有合金薄片、その製造方法、希土類焼結磁石用合金粉末、希土類焼結磁石、ボンド磁石用合金粉末およびボンド磁石 | |
JP2019112720A (ja) | R−t−b系希土類焼結磁石用合金、r−t−b系希土類焼結磁石 | |
JPH08176755A (ja) | 希土類磁石用合金及びその製造方法 |
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: 12839781 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2013538567 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14351119 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1120120042883 Country of ref document: DE Ref document number: 112012004288 Country of ref document: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12839781 Country of ref document: EP Kind code of ref document: A1 |