[go: up one dir, main page]

WO2005031023A1 - Alliage de matiere premiere pour aimant permanent r-t-b et aimant permanent r-t-b - Google Patents

Alliage de matiere premiere pour aimant permanent r-t-b et aimant permanent r-t-b Download PDF

Info

Publication number
WO2005031023A1
WO2005031023A1 PCT/JP2004/014580 JP2004014580W WO2005031023A1 WO 2005031023 A1 WO2005031023 A1 WO 2005031023A1 JP 2004014580 W JP2004014580 W JP 2004014580W WO 2005031023 A1 WO2005031023 A1 WO 2005031023A1
Authority
WO
WIPO (PCT)
Prior art keywords
alloy
rich phase
raw material
rich
thin plate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2004/014580
Other languages
English (en)
Japanese (ja)
Inventor
Futoshi Kuniyoshi
Yuji Kaneko
Hiroshi Hasegawa
Shiro Sasaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Resonac Holdings Corp
Proterial Ltd
Original Assignee
Showa Denko KK
Neomax Co Ltd
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 Showa Denko KK, Neomax Co Ltd filed Critical Showa Denko KK
Priority to JP2005514309A priority Critical patent/JP4366360B2/ja
Publication of WO2005031023A1 publication Critical patent/WO2005031023A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • 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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575—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 a raw material alloy for an RTB-based permanent magnet, and more particularly to a raw alloy flake for an RTB-based permanent magnet manufactured by a strip casting method. Still, the present invention relates to an R—T—B-based permanent magnet produced from the above-mentioned raw material alloy for an R-T-B-based permanent magnet.
  • R-T-B permanent magnets which have the largest magnetic energy product among permanent magnets, are used for HD (hard disk), MRI (magnetic resonance imaging), and various motors due to their high characteristics. ing.
  • HD hard disk
  • MRI magnetic resonance imaging
  • various motors due to their high characteristics. ing.
  • the demand for energy-saving lugi in the market has increased, and the ratio of motors, including automobiles, has increased.
  • R in “RT—B-based permanent magnet” is mainly the one in which a part of Nd is replaced by other rare earth elements such as Pr and Dy, and Y is a rare earth element. It is at least one of the elements. “Ding” is a substitution of a part of Fe with another transition metal such as Co or Ni. "B” is boron, part of which is C Or those substituted with N.
  • the "RT-B-based permanent magnet” is composed of "Nd_Fe-B-based magnet” or "R-Fe-B-based magnet” because its main components are Nd, Fe, and B.
  • RT—B permanent magnet refers to Cu
  • One or more of elements such as Al, Ti, V, Cr, Ga, Mn, Nb, Ta, Mo, W, Ca, Sn, Z It is known that magnets added in combination can be used to improve various properties such as magnetic properties.
  • R-T-B alloys have a main phase of R 2 T i 4 B phase, which is a ferromagnetic phase that contributes to the magnetizing action, and coexist with a nonmagnetic, rare earth-enriched, low melting point R-rich phase. Alloy. Since R-T-B alloys are active metals, they are generally melted in a vacuum or inert gas. In addition, in order to manufacture a sintered magnet from the manufactured R—T—B series alloy ingot by powder metallurgy, the alloy ingot is crushed to about 3 m (FSSS: measurement with a fisher subsizer). After the alloy powder is formed, it is pressed in a magnetic field.
  • FSSS measurement with a fisher subsizer
  • the powder compact obtained by press molding is sintered at a high temperature of about 100 ° C to 110 ° C in a sintering furnace. It is general that the sintered body produced in this way is subjected to hemp heat treatment, machining, and plating to improve corrosion resistance as necessary.
  • the R-rich phase in R—T—B sintered magnets plays an important role as follows.
  • the melting point of the R-rich phase is low and becomes a liquid phase during sintering, contributing to the higher density of magnets and the improvement of magnetization.
  • the dispersion state of the R-rich phase in the formed magnet is poor, local sintering failure and magnetism will be reduced, so that the R-rich phase is uniformly dispersed in the formed magnet. Is important.
  • the distribution of the R-rich phase in the RTB-based sintered magnet is greatly affected by the microstructure of the RTB-based alloy as the raw material.
  • a strip cast method (hereinafter abbreviated as “SC method”) has been developed as a method for producing R—T-B alloys, and is used in actual processes.
  • SC method a thin section of about 0.1 to 1 mm in thickness is produced by flowing molten metal of an alloy on a copper roll and rapidly cooling and solidifying the molten alloy.
  • the SC method since the crystal structure of the alloy is refined, it is possible to produce an RTB alloy having a structure in which the R-rich phase is finely dispersed.
  • the alloy manufactured by the SC method since the internal R-rich phase is finely dispersed, the dispersibility of the R-rich phase in the magnet after pulverization and sintering is good. Thus, the magnetic properties of the magnet can be improved.
  • the alloy flakes produced by the SC method have excellent structural homogeneity.
  • the homogeneity of the structure can be compared by the dispersion state of the crystal grain size and the R-rich phase.
  • chill crystals equiaxed crystals
  • the ⁇ -shaped surface side the production roll side of the alloy flakes, but the whole is quenched.
  • a moderately fine and homogeneous structure obtained by solidification can be obtained.
  • the R-T-B alloy produced by the SC method has a finely dispersed R-rich phase and excellent structure homogeneity. As a result, the homogeneity of the R-rich phase in the final magnet is improved, and the magnetic properties can be improved.
  • the R—T—B-based alloy ingot produced by the SC method has an excellent structure for producing a sintered magnet. However, as the properties of the magnet improve, the raw material mixture becomes more and more. There is a growing demand for advanced control of the gold structure, especially the state of the R-rich phase.
  • the present inventors studied the relationship between the structure of the manufactured R—T—B system alloy and the behavior during hydrogen cracking and fine grinding. It is important to control the dispersion state of the R-rich phase in order to control the grain size of the alloy powder uniformly.
  • Japanese Patent Application Laid-Open No. 2003-188806 Japanese Patent Application Laid-Open No. 2003-188806.
  • the region in which the dispersion state of the R-rich phase formed on the side of the mold in the alloy is extremely fine (fine R-rich phase region) is finely pulverized and the pulverization stability of the alloy is reduced.
  • fine R-rich phase region is finely pulverized and the pulverization stability of the alloy is reduced.
  • the present invention provides an R—T—B-based permanent magnet raw material alloy capable of improving magnetic properties by controlling the R-rich phase present in the alloy on a more microscopic scale.
  • the purpose is to: Disclosure of the invention
  • the present inventors observed the R-rich phase present in the RTB-based alloy on a more microscopic scale, and found that there was a great relationship between the shape of the R-rich phase and the magnetic properties.
  • the present invention is as follows. (1) R-T-B-based permanent magnet material alloy containing R 2 T 4 B columnar crystal and R-rich phase (R is at least one rare earth element containing ⁇ , T is F e or at least one of the transition metal elements other than Fe and Fe, and B is boron or boron and carbon), and in the alloy structure observed in any cross section including the normal direction of the thin plate, The aspect ratio of the R-rich phase whose aspect ratio is 10 or more and its major axis direction is 90 ⁇ 30 ° to the surface of the thin plate is 3096 or more of all the R-rich phases present in the alloy.
  • a raw material alloy for R-T-B series permanent magnets characterized by the following characteristics.
  • the area ratio of the R-rich phase whose aspect ratio is 90 or more and its major axis direction is 90 ⁇ 30 ° to the surface of the thin plate, is the ratio of all R-rich phases present in the alloy.
  • the area ratio of the R-rich phase whose aspect ratio is 10 or more and its major axis direction is 90 ⁇ 3 ⁇ ° to the surface of the thin plate is equal to the ratio of all the R-rich phases present in the alloy.
  • R-T-B-based permanent magnets containing R 2 T 4 B columnar crystals and an R-rich phase (R is at least one rare earth element containing Y, T is Fe or at least one of the transition metal elements other than Fe and Fe, B is boron or boron and carbon) and was observed in any cross section including the normal direction of the thin plate
  • R-rich phase whose aspect ratio is 1% or more and whose major axis direction is 3% or less or 15% or more with respect to the surface of the thin plate is determined by A raw material alloy for R-T-B-based permanent magnets, characterized in that it accounts for 50% or less of all R-rich phases present in the steel.
  • the area ratio of the R-rich phase having an aspect ratio of 1% or more and its major axis direction being 30 ° or less or 150 ° or more with respect to the sheet surface exists in the alloy.
  • R-T-B-based permanent magnet raw alloy containing R 2 T 4 B columnar crystals and R-rich phase (R is at least one rare earth element containing ⁇ , T is F e or at least one of the transition metal elements other than Fe and Fe, and B is boron or boron and carbon), and the alloy structure observed in any cross section including the normal direction of the thin plate
  • the area ratio of the R-rich phase with an aspect ratio of 1% or more and its major axis direction being 90 ⁇ 30 ° with respect to the surface of the thin plate is found in the alloy. 3% or more of all R rich phases present, and the aspect ratio is 1% or more and the major axis direction is 30 ° or less or 150 ° or more with respect to the sheet surface R-T-B material alloy for permanent magnets, characterized in that the area ratio of the R-rich phase is 50% or less of all the R-rich phases present in the alloy.
  • the area ratio of the R-rich phase having an aspect ratio of 1 mm or more and its major axis direction being 9 ° ⁇ 30 ° with respect to the surface of the thin plate is equal to the ratio of all R-rich phases present in the alloy.
  • the area ratio of the R-rich phase whose aspect ratio is 10 ° or more and the major axis direction is 30 ° or less or 150 ° or more with respect to the surface of the thin plate.
  • FIG. 1 is a diagram showing a cross-sectional structure of a rare-earth magnet alloy flake containing an agglomerated R-rich phase manufactured by a conventional SC method.
  • FIG. 2 is a view showing a cross-sectional structure of a rare-earth magnet alloy flake containing an R-rich phase having a higher-order dendrite manufactured by a conventional SC method.
  • FIG. 3 is a view showing a cross-sectional structure of a rare-earth magnet alloy flake according to the present invention.
  • FIG. 4 is a schematic view of a manufacturing apparatus of the strip cast method. BEST MODE FOR CARRYING OUT THE INVENTION
  • an embodiment of a raw material alloy for an RTB-based permanent magnet according to the present invention will be described with reference to the drawings.
  • FIG. 1 and FIG. show the cross section of a thin section of a Nd-Fe-B alloy (Nd31.5 mass%) recorded by the conventional SC method and observed by SEM (scanning electron microscope). It is an electronic image.
  • the left side of the drawing is the mold side of the alloy, and the right side is the free side of the alloy.
  • the white part in Fig. 1 indicates the Nd rich phase (when R is Nd, the R rich phase is called the “Nd rich phase”). There is. ).
  • the Nd rich phase is aggregated in a pool.
  • Fig. 2 shows that in order to produce a sintered magnet from an R-TB-based alloy in which a very fine Nd-rich phase exists in a dendritic form, the R-T-B-based alloy was ground. Then, it is necessary to produce a compact by pressing.
  • As a method of pulverizing the RTB alloy it is preferable to first embrittle the RTB alloy by hydrogen absorption and then pulverize it finely.
  • R-T-B alloys are coarsely crushed (crushed) by embrittlement due to hydrogen storage.
  • hydrogen is absorbed from the R-rich phase, expands, becomes brittle, and becomes hydride. Therefore, in hydrogen crushing, fine cracks are introduced into the alloy along the R-rich phase or starting from the R-rich phase.
  • fine cracks generated by hydrogen disintegration caused the alloy to break, so that the dispersion state of the R-rich phase tended to affect the pulverization efficiency and fine powder shape. . Therefore, the present inventors observed the R-rich phase on a more microscopic scale, and found that the shape of each R-rich phase and the fine cracks formed by hydrogen disintegration are related to the magnetic properties. I found that.
  • the very fine R-rich phase existing in the form of dendrites has a small distance between adjacent fine-branched R-rich phases for general sintered magnets. It is smaller than the ground particle size. For this reason, the proportion of fine branch-shaped R-rich phases incorporated into the fine powder after jet milling increases. As described above, the R-rich phase becomes a liquid phase during sintering and contributes to sintering. For this purpose, the R-rich phase exists on the surface of each fine powder, and it is necessary to wet the fine powder during sintering. However, such an effect cannot be expected for the R-rich phase that has entered the powder, and it cannot provide a sufficient effect even if it oozes out on the surface. Causes decline.
  • FIG. 3 shows a reflected electron image when a cross section of a piece of the Nd—Fe—B alloy according to the present invention was observed by SEM (scanning electron microscope).
  • the Nd-rich phase in the cross-sectional photograph shows a layered (lamella-like) Nd-rich phase extending within a limited angle range centered on the thickness direction.
  • the dominant proportion is dominant.
  • the pool-shaped R-rich phase shown in Fig. 1 and the twig-shaped R-rich phase shown in Fig. 2 are slightly present, but their abundance is low. If an alloy having such a structure is pulverized by jet milling after hydrogen disintegration, the problems with alloys having the structures shown in FIGS. 1 and 2 may be caused by changes in composition and increases in oxygen and nitrogen concentrations. It is possible to solve problems such as lower magnetic properties, lower sintering density and lower degree of orientation. As a result, it is possible to obtain an optimal raw material alloy for R—T-B permanent magnets that can sufficiently fulfill the essential role of the R-rich phase, and use such a raw material alloy. This makes it possible to obtain an RTB permanent magnet having high magnetic properties.
  • Fig. 4 shows a schematic view of an apparatus for forming by the strip cast method.
  • RT-B alloys are melted in a vacuum or an inert gas atmosphere using a refractory material 1 due to their active properties. After the molten alloy is held at 130 ° C to 150 ° C for a predetermined time, the inside is water-cooled via a tundish 2 equipped with a rectification mechanism and a slag removal mechanism as necessary. It is supplied to the produced rotating roll 3 for production.
  • the supply speed of the molten metal and the number of rotations of the rotating rolls should be controlled appropriately according to the required thickness of the alloy.
  • the rotating peripheral speed of the rotating roll is preferably set to about 0.5 to 3 m / s. Yes. Copper or copper alloy is suitable for the material of the manufacturing rotary roll because it has good thermal conductivity and is easily available. Depending on the material of the rotating roll and the surface condition of the roll, the metal may adhere to the surface of the rotating roll for manufacturing, causing the metal to adhere to the surface of the rotating roll. The quality of the base alloy is stable.
  • the alloy 4 solidified on the rotating roll separates from the roll on the opposite side of the tandem tissue and is recovered in the recovery container 5. By providing a heating and cooling mechanism in this collection container, the state of the R-rich phase structure can be controlled.
  • the next cooling is, specifically, to set the temperature of the alloy at 60 ° to 85 ° C. when leaving the production roll. ⁇ It is necessary that the temperature of the alloy when leaving the casting hole be higher than the melting point of the R-rich phase.
  • the melting point of the R-rich phase is slightly higher or lower depending on the composition, but is more than 600 ° C. ⁇ If the temperature of the alloy when it is separated from the forming roll is lower than the melting point of the R-rich phase, the solidification of the R-rich phase has been completed and the structure will be as shown in Fig. 2. On the other hand, when the temperature is higher than 850 ° C, the R-rich phase aggregates into a pool after the roll detaches, and the structure becomes as shown in Fig.
  • the dispersion state and shape of the R-rich phase greatly depend on TRE (total rare earth content).
  • TRE total rare earth content
  • ⁇ the amount of heat cut off on the forming roll is small
  • ⁇ the alloy temperature tends to increase when the forming roll is removed
  • the R rich phase aggregates and pools. The tendency to form.
  • alloys with a high TRE and a high R-rich phase have a high tendency to generate a structure having higher-order dendritic arms due to a large amount of heat cut on the ⁇ roll.
  • the alloy thickness must be reduced when the TRE is small, and thickened when the TRE is large.
  • the average thickness of the alloy is preferably set to 0.10 to 0.30 mm in order to increase the degree of primary cooling. More preferably, it is 0.15 to 0.27 mm. More preferably, the standard of the TRE, which is 0.20 to 0.25 mm, is 30 to 33 wt%, and the preferable average thickness of the alloy is 0.25 to 0.35 mm. More preferably, it is 0.26 to 0.32 mm.
  • the target of TRE is 33 wt% or more, the preferable average thickness of the alloy is from 0.2 to 0.5 mm. More preferably 0.28 ⁇ . ⁇ It is 35 mm.
  • the degree of primary cooling can also be controlled by appropriately selecting the surface roughness of the mirror forming roll and controlling the heat loss from the alloy on the forming roll. This method is especially effective when the TRE is less than 33 wt% or more than 33 wt%. ⁇ Unnecessary heat cutting can be suppressed by increasing the surface roughness of the forming roll. When the TRE is 33 wt% or more, high heat transfer to the forming roll caused by a large amount of the R-rich phase can be appropriately suppressed by roughening the surface roughness of the forming roll. it can. Surface roughness of the guide in this case is 2 0 microns or more in ten-point mean roughness R Z.
  • the surface roughness should be about 2 ⁇ m or less to prevent primary cooling on the roll, and excessive aggregation of the R-rich phase should be prevented. Is preferred. However, the surface roughness is affected by other factors such as the roll surface material, and is not limited to the above values.
  • the surface temperature of the forming roll affects the wettability of the molten alloy and the roll. If the temperature is too low, the wettability of the molten alloy and the roll tends to be poor, and there is a tendency for macroscopic nonuniformity in contact between the alloy and the alloy. When the temperature is too high, the wettability between the molten alloy and the roll is good if the temperature is too high. Tona May cause partial burn-in. The seizure of the alloy on the roll surface causes a change in heat transfer and wettability in that area, and causes a change in the alloy structure. It is difficult to generate. In addition, if the amount of seized alloy is further increased, stable operation becomes difficult, and the production efficiency is reduced.
  • the production roll surface temperature is suitably from 50 to 400 ° C, preferably from 100 to 300 ° C. More preferably, it is 150 to 200 ° C.
  • the temperature of the roll surface shown here is the temperature at which the molten metal comes into contact with the roll, and it is difficult to measure it directly. It is possible to calculate from the thermocouple measurement value by touching the roll surface of the part.
  • a partition plate is installed in the collection container, the interval between the partition plates is set appropriately, and the inside of the partition plate is cooled with an inert gas water such as A Therefore, it is effective to control the cooling rate of the recovered alloy.
  • the temperature of the alloy when recovered in the recovery container is 65 ° C to 700 ° C, it is preferable that the temperature be up to 600.
  • the cooling rate is 3 to 30 ° CZ min, more preferably 3 to 20 ° CZ min. If the temperature of the alloy when collected in the collection container is 00 to 8 ° C 0 ° C, 6 ° 0 ° C C is preferred, cooling rate is 10 ⁇ 4 ⁇ CZ min, more preferably 1 ⁇ 3 o ° c min. When the temperature of the alloy when collected in the collection container is 80 ⁇ to 85 ⁇ C, the preferred cooling rate up to 60 ⁇ is 20 to 5 ⁇ CZ minutes, more preferably 3 to 5 ⁇ CZ. Minutes. In these temperature ranges, if the temperature exceeds the upper limit, the structure shown in Fig. 2 becomes more likely. Below the lower limit, the structure shown in Fig. 1 becomes more likely.
  • the alloy of the present invention defines the structure, and the production method is not limited to the above method.
  • the thickness of the alloy flake of the present invention is preferably 0.1 mm or more and 0.5 mm or less.
  • the thickness of the alloy flakes is less than 0.1 mm, the solidification rate increases excessively, and the dispersion of the R-rich phase becomes too fine. If the thickness of the alloy flakes is more than 0.5 mm, problems such as a decrease in the dispersibility of the R-rich phase due to a decrease in the solidification rate are caused.
  • the present invention relates to a raw material alloy for a R-T-B-based permanent magnet in the form of a thin plate containing R 2 ⁇ 4 B columnar crystals and an R- rich phase
  • R is at least one kind of rare earth element containing ⁇
  • T is Fe or at least one of the transition metal elements other than Fe and Fe
  • B is boron or boron and carbon.
  • the R-rich phase which has an aspect ratio of 1% or more and whose major axis direction is 90 ⁇ 30 ° with respect to the surface of the sheet, is observed in any cross section including the normal direction of the sheet. Area ratio is determined by all R It is 30% or more of the horn phase.
  • the aspect ratio of the R-rich phase in the alloy is less than 1%
  • the R-rich phase is agglomerated and in the form of a pool, and when the proportion of the R-rich phase increases, it is pulverized.
  • the composition change due to dropout of the R-rich phase and over-milling increases.
  • the R-rich phase is more than necessary, Is likely to be
  • the five R-rich phases can be described as higher-order dendrites in metallography, but in actual alloy structures, primary dendrites and higher-order dendrites higher than the second order are considered. Since there is a high possibility that individual differences will occur in the identification of birds, it is determined geometrically and this range is defined.
  • the area ratio of the R-rich phase having an aspect ratio of at least 10 and its major axis direction being 90 ⁇ 3 ° with respect to the surface of the thin plate is reduced by all R 30% or less of the rich phase As a result, the magnetic properties are significantly reduced.
  • the area ratio of the R-rich phase having an aspect ratio of at least 10 and its major axis direction being 90 ⁇ 3 ° relative to the surface of the thin plate is equal to all R-rich phases present in the alloy. More than 50% of the phase. More preferably, the area ratio of the R-rich phase having an aspect ratio of 10 or more and its major axis direction being 9 ⁇ 30 ° with respect to the surface of the thin plate is equal to all R-rich phases present in the alloy. It must be at least 0% of the Tsuchi phase.
  • the aspect ratio is 2% or more. More preferably, the above alloy has an aspect ratio of 30 or more.
  • the area ratio of the R-rich phase whose aspect ratio is 1 mm or more and the major axis direction is 30 ° or less or 150 ° or more with respect to the surface of the thin plate is reduced to all R-rich phases present in the alloy. It should be less than 50% of the phase. Even when the aspect ratio is 10 or more, the R-rich phase whose major axis direction is 30 ° or less or 15 °° or more with respect to the thin plate surface is a twig-shaped high-order dendritic arm with a small interval. It is particularly likely.
  • the area ratio of the R-rich phase having an aspect ratio of not less than 10 and the major axis direction thereof being not more than 30 ° or not less than 150 ° with respect to the surface of the thin plate is all present in the alloy. This is less than 30% of the R-rich phase of the above.
  • the aspect ratio is 1 mm or more and its major axis
  • the area ratio of the R-rich phase which is 90 ° 30 ° with respect to the surface of the thin plate, is 30% or more of all the R-rich phases present in the alloy, and
  • the ratio of the area of the R rich phase whose ratio is 10 or more and its major axis direction is 30 ° or less or 150 ° or more with respect to the sheet surface is equal to all the R rich phases present in the alloy. Less than 50% of the total.
  • the area ratio of the R-rich phase having an aspect ratio of at least 10 and its major axis direction being 90 ⁇ 30 ° with respect to the surface of the thin plate is the same as that of all the R-rich phases present in the alloy.
  • the R-rich phase with an aspect ratio of at least 10 and a major axis direction of 30 ° or less or “150 ° or more” with respect to the metal surface is less than 30% of all R-rich phases present in the alloy.
  • the above-mentioned R-rich phase with an aspect ratio of 10 or more, an aspect ratio of 2 or more, or an aspect ratio of 30 or more has a major axis dimension of 5% or more, preferably 10% or more of the thin plate thickness dimension. It preferably has a length.
  • the aspect ratio of the R-rich phase in the alloy, the angle in the major axis direction to the sheet surface, and the area ratio of such an R-rich phase are different from those of the main phase. Since the brightness is high in BEI, it is possible to analyze after distinguishing the main phase and the R-rich phase with the image analyzer. For example, randomly selected and photographed the BEI of the cross section of 10 alloy flakes at an appropriate magnification, In each of the photographs, the total area of the R-rich phase in the photograph and the total area of the R-rich phase whose major axis is within a predetermined angle range at a predetermined aspect ratio are image-analyzed.
  • the total of the total areas of the R-rich phases whose major axis directions are within a predetermined angle range at a predetermined aspect ratio determined in each photograph was calculated for each of the 10 images.
  • the area ratio of the predetermined R-rich phase can be considered.
  • the thin plate-shaped raw material alloy for RTB-based permanent magnet according to the present invention has a main phase of R 2 Ti 4 B phase which is a ferromagnetic phase.
  • the R 2 T 4 B phase is columnar, and the R 2 T 4 B columnar crystal preferably has a major axis within an angle of 90 ⁇ 30 ° with respect to the thin plate surface.
  • the length of the long axis is preferably 30% or more, and more preferably 5% or more of the thickness of the thin plate.
  • the above-mentioned preferable R 2 Tt 4 B columnar crystal is contained in 30% or more, preferably 50% or more of R 2 T 14 B columnar crystal in the whole thin plate.
  • the R 2 T i 4 B columnar crystal refers to a column 1 in which the crystal orientations observed by a polarizing microscope using the magnetic K err effect are uniform.
  • Example 1 Nd: 31.5% by mass>, B: 1.0% by mass, Co: 1.0% by mass, AI: 0.30% by mass, Cu: 0.1 Metal neodymium, ferropolon, cobalt, aluminum, copper, and iron are combined so that 0% by mass and the balance is iron, the raw materials are melted in a high-frequency melting furnace, and the molten metal is subjected to a strip casting method. To produce alloy flakes.
  • the diameter of the rotating roll for production is 300 mm
  • the material is pure copper with a thickness of 50 mm
  • the inside is water-cooled
  • the peripheral speed of the roll during production is 1. 1 mZ s
  • the average thickness is 0.2.
  • Mm alloy flakes were produced. At that time, the average roughness of the surface of the roll was 12 microns in Rz. By visual observation, the alloy was evenly placed on the ⁇ ⁇ ⁇ roll, and no seizure on the ⁇ ⁇ ⁇ roll was observed.
  • thermocouple was brought into contact with the bottom of the production roll surface, and the surface temperature of the production roll during the production was measured.
  • amount of cooling water for the production hole and the temperature difference between the entrance and exit, and the temperature of the water discharged from the production roll were measured.From these measured values, the molten tundish was in contact with the production roll.
  • the surface temperature of the structure roll at the location was calculated to be 1 ° C.
  • the area ratio of the R-rich phase with an aspect ratio of 10 or more and its major axis direction being 90 ⁇ 30 ° with respect to the metal surface was found in the alloy. 80% of all R-rich phases present in In addition, the area ratio of the R-rich phase having an aspect ratio of at least 20 and its major axis direction being 90 ⁇ 3 ° with respect to the metal surface is determined by the ratio of all R-rich phases present in the alloy. 65% of the touch phase. On the other hand, the area ratio of the R-rich phase whose aspect ratio is 10 or more and whose major axis direction is 30 ° or less or 150 ° or more with respect to the metal surface exists in the alloy. 6% of all R-rich phases.
  • the raw materials were blended in the same composition as in Example 1, and dissolution and production by the SC method were performed in the same manner as in Example 1.
  • the thickness of the ⁇ roll is 90 mm, and the average roughness of the ⁇ ⁇ ⁇ roll surface is 7 ⁇ m in Rz.
  • the average thickness of the alloy flakes was ⁇ . 35 mm.
  • the surface temperature of the production roll at a position where the molten metal of the tundish was in contact with the production roll was 400 C, which was obtained in the same manner as in Example 1.
  • the temperature of the alloy flakes without seizure was measured by removing the roll with an infrared thermometer and found to be 820 ° C. No special cooling mechanism has been installed in the collection container that stores the alloy flakes that have been separated from the rolls. When the temperature change of the alloy was measured with a thermocouple inserted from the side of the recovery container into the inside, the maximum temperature was 810 ° C, and the average cooling rate up to 600 ° C was 6 ° CZ minutes. Ah .
  • the obtained alloy flakes without seizure were evaluated in the same manner as in Example 1. As a result, many of the R-rich phases aggregated to form a pool. The area fraction of one R-rich phase is 26% of all R-rich phases present in the alloy.
  • the raw materials were blended in the same composition as in Example 1, and dissolution and production by the SC method were performed in the same manner as in Example 1.
  • the thickness of the ⁇ ⁇ ⁇ roll is 25 mm, and the average roughness of the ⁇ ⁇ ⁇ roll surface is 10 microns in Rz.
  • the average thickness of the alloy flakes was 0.22 mm. According to the visual observation, a part of the alloy on the ⁇ roll had a slightly higher temperature.
  • the molten tundish obtained in the same manner as in Example 1 The surface temperature of the forming roll at a position in contact with the forming roll was 80 ° C.
  • the average temperature of the alloy flakes measured by removing the roll with an infrared thermometer was 67 ° C.
  • a partition plate through which water is circulated is installed in the collection container that stores the alloy flakes that have separated from the roll.
  • the obtained alloy flakes were evaluated in the same manner as in Example 1.
  • the R-rich phase contained a large amount of twig-like high-order dendrites, and the aspect ratio was 10 or more and its major axis direction
  • the area ratio of the R-rich phase which is 90 ⁇ 30 ° with respect to the metal surface was 23% of all the R-rich phases present in the alloy.
  • the area ratio of the R-rich phase having an aspect ratio of 10 or more and its major axis direction being 30 ° or less or 15 °° or more with respect to the metal surface is determined by all the alloys present in the alloy. It was 54% of the R-rich phase.
  • the alloy flakes obtained in Example 1 were coarsely pulverized by a known hydrogen pulverization treatment, and 0.01% of zinc stearate powder was added to the obtained coarsely pulverized powder, and the mixture was added to a rocking mixer. More After mixing in an elementary atmosphere, the mixture was finely pulverized by a jet mill apparatus. The atmosphere during the jet mill pulverization was a nitrogen atmosphere mixed with 100 ppm of oxygen. The oxygen concentration of the body was 50 ⁇ 0 ppm.
  • the obtained powder was mixed with a cold leap embedding resin, cured, polished, and the cross section of the powder was observed by SEM-BEI to investigate the dispersion state of the R-rich phase in the powder. As a result, the R-rich phase was attached to the surface of the grains mainly composed of the main phase.
  • the obtained powder was press-molded under a magnetic field of 1.5 T of orientation magnetic field at a pressure of 1.0 Ot / cm 2 , and the compact was held at 160 ° C. for 4 hours for sintering. did.
  • the resulting sintered body has a sintering density of at least S g Z cm 3, which is a sufficient density. Further, this sintered body was heat-treated at 560 ° C. for 1 hour in an argon atmosphere to produce a sintered magnet.
  • Table 1 shows the results of measuring the magnetic properties of this sintered magnet with a BH curve tracer.
  • Example 2 The alloy flake obtained in Comparative Example 1 was ground in the same manner as in Example 2 to obtain a fine powder. At this time, the cross section of the powder was observed in the same manner as in Example 2, and most of the R-rich phase was separated from the main phase and existed as relatively small grains composed of only the R-rich phase. I confirmed that. Further, through the same molding and sintering steps as in Example 2, a sintered magnet was produced. The magnetic properties of the sintered magnet produced in Comparative Example 3 were measured with a BH cap tracer, and the results are shown in Table 1.
  • Example 2 The alloy flake obtained in Comparative Example 2 was ground in the same manner as in Example 2 to obtain fine powder. At this time, the cross section of the powder was observed in the same manner as in Example 2, and it was confirmed that the ratio of grains in which the R-rich phase was present was about 7 times that of Example 2. Further, through the same molding and sintering steps as in Example 2, a sintered magnet was produced.
  • Table 1 shows the results of measuring the magnetic properties of the sintered magnet produced in Comparative Example 4 using a BH force implanter.
  • Comparative Example 3 As shown in Table 1, the density of Comparative Example 3 is lower than that of Example 2, and the magnetization and coercive force are also low in characteristics. This is due to the poor dispersion of the R-rich phase in the alloy stage, so that the R-rich phase is separated as an active fine powder in the grinding process in the cyclone of the pulverizer and the TRE tends to decrease. And the R-rich phase It is presumed that the bias did not function effectively during sintering due to the decrease in sinterability. On the other hand, Comparative Example 4 showed the same behavior, though not as much as Comparative Example 3, indicating that the contribution of the R-rich phase to sintering was insufficient. Industrial applicability
  • the R-rich phase in the alloy can be utilized to the utmost extent. Also exhibit excellent magnet properties.
  • the R-Rich cannot fully fulfill its original role, there is little variation in composition during fine grinding in the sintered magnet manufacturing process, there is no decrease in magnetic properties due to an increase in oxygen concentration, and there is a reduction in sintering density. It has excellent effects that cannot be obtained with conventional alloys, such as a decrease in the degree of orientation and the like. Further, by using the above-mentioned alloy, an RTB-based permanent magnet having high magnetic properties can be obtained.
  • the present invention can be suitably used for various kinds of electronic equipment and electric machines that require a high-performance sintered magnet.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Power Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)
  • Continuous Casting (AREA)

Abstract

L'invention concerne un alliage de matière première pour un aimant permanent R-T-B sous forme de feuille mince comprenant un cristal en forme de basalte R2T14B et une phase enrichie R, R représentant au moins un élément de terre rare contenant Y, T signifiant Fe ou Fe et au moins un élément de métal de transition autre que Fe, B désignant bore ou bore et carbone. Dans une structure de l'alliage observé sur une section quelconque comprenant le sens normal de la feuille mince, le rapport d'allongement est égal ou supérieur à 10 et le rapport de section de la phase enrichie R, dont le sens longitudinal est de 90±30° relativement à la surface de la feuille mince, est égal ou supérieur à 30 %, sur la base de toutes les phase enrichies R existant dans l'alliage.
PCT/JP2004/014580 2003-09-30 2004-09-28 Alliage de matiere premiere pour aimant permanent r-t-b et aimant permanent r-t-b Ceased WO2005031023A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2005514309A JP4366360B2 (ja) 2003-09-30 2004-09-28 Ｒ−ｔ−ｂ系永久磁石用原料合金およびｒ−ｔ−ｂ系永久磁石

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2003-339374 2003-09-30
JP2003339374 2003-09-30

Publications (1)

Publication Number Publication Date
WO2005031023A1 true WO2005031023A1 (fr) 2005-04-07

Family

ID=34386181

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2004/014580 Ceased WO2005031023A1 (fr) 2003-09-30 2004-09-28 Alliage de matiere premiere pour aimant permanent r-t-b et aimant permanent r-t-b

Country Status (3)

Country Link
JP (1) JP4366360B2 (fr)
CN (1) CN1860248A (fr)
WO (1) WO2005031023A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008114571A1 (fr) 2007-03-22 2008-09-25 Showa Denko K.K. Alliage à base de r-t-b, procédé de fabrication de celui-ci, fine poudre pour un aimant permanent en terre rare à base de r-t-b et aimant permanent en terre rare à base de r-t-b
JP2015073991A (ja) * 2013-10-04 2015-04-20 大同特殊鋼株式会社 希土類磁石用合金リボンの製造方法
JP2015193925A (ja) * 2014-03-27 2015-11-05 日立金属株式会社 Ｒ−ｔ−ｂ系合金粉末およびｒ−ｔ−ｂ系焼結磁石
JP2018170483A (ja) * 2017-03-30 2018-11-01 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
CN115148436A (zh) * 2021-03-30 2022-10-04 Tdk株式会社 R－t－b系永久磁铁用合金和r－t－b系永久磁铁的制造方法

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010073533A1 (fr) * 2008-12-26 2010-07-01 昭和電工株式会社 Alliage pour aimant permanent à base de terres rares du système r-t-b, procédé de fabrication dudit aimant, et moteur
JP5982680B2 (ja) * 2011-10-28 2016-08-31 Tdk株式会社 Ｒ−ｔ−ｂ系合金粉末、並びに異方性ボンド磁石用コンパウンド及び異方性ボンド磁石
CN104576022B (zh) * 2014-12-03 2017-06-27 中国科学院宁波材料技术与工程研究所 稀土永磁体的制备方法
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
WO2018121112A1 (fr) 2016-12-29 2018-07-05 北京中科三环高技术股份有限公司 Pièce de coulée en alliage de terres rares à grains fins, procédé de préparation et dispositif de rouleau de refroidissement rotatif
DE102019107726B4 (de) 2018-04-04 2024-09-26 Asahi Kasei Kabushiki Kaisha Zusatz für bitumenhaltige Dichtungsbahn, Verfahren zur Herstellung einer bitumenhaltigen Dichtungsbahn, Bitumenzusammensetzung und Verwendung der Bitumenzusammensetzung
JP7645121B2 (ja) * 2021-03-30 2025-03-13 Tdk株式会社 Ｒ－ｔ－ｂ系永久磁石用合金およびｒ－ｔ－ｂ系永久磁石の製造方法
CN115555525A (zh) * 2022-10-14 2023-01-03 四川大学 一种实时测量快速凝固薄带凝固速度的装置及测量方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07272929A (ja) * 1994-03-29 1995-10-20 Kobe Steel Ltd 希土類元素−Ｆｅ−Ｂ系薄膜永久磁石
JP2003077717A (ja) * 2001-09-03 2003-03-14 Showa Denko Kk 希土類磁石用合金塊、その製造方法および焼結磁石
JP2003213383A (ja) * 2002-01-22 2003-07-30 Sumitomo Metal Ind Ltd 希土類合金とその製造方法および永久磁石

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07272929A (ja) * 1994-03-29 1995-10-20 Kobe Steel Ltd 希土類元素−Ｆｅ−Ｂ系薄膜永久磁石
JP2003077717A (ja) * 2001-09-03 2003-03-14 Showa Denko Kk 希土類磁石用合金塊、その製造方法および焼結磁石
JP2003213383A (ja) * 2002-01-22 2003-07-30 Sumitomo Metal Ind Ltd 希土類合金とその製造方法および永久磁石

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008114571A1 (fr) 2007-03-22 2008-09-25 Showa Denko K.K. Alliage à base de r-t-b, procédé de fabrication de celui-ci, fine poudre pour un aimant permanent en terre rare à base de r-t-b et aimant permanent en terre rare à base de r-t-b
JP2015073991A (ja) * 2013-10-04 2015-04-20 大同特殊鋼株式会社 希土類磁石用合金リボンの製造方法
JP2015193925A (ja) * 2014-03-27 2015-11-05 日立金属株式会社 Ｒ−ｔ−ｂ系合金粉末およびｒ−ｔ−ｂ系焼結磁石
JP2018170483A (ja) * 2017-03-30 2018-11-01 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
US10964463B2 (en) 2017-03-30 2021-03-30 Tdk Corporation Alloy for R—T—B based rare earth sintered magnet and method for producing the R—T—B based rare earth sintered magnet
CN115148436A (zh) * 2021-03-30 2022-10-04 Tdk株式会社 R－t－b系永久磁铁用合金和r－t－b系永久磁铁的制造方法

Also Published As

Publication number Publication date
CN1860248A (zh) 2006-11-08
JP4366360B2 (ja) 2009-11-18
JPWO2005031023A1 (ja) 2006-12-07

Similar Documents

Publication Publication Date Title
US11145443B2 (en) R-T-B-based magnet material alloy and method for producing the same
JP5274781B2 (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
JP3267133B2 (ja) 希土類磁石用合金及びその製造方法並びに永久磁石の製造方法
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
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
JP4366360B2 (ja) Ｒ−ｔ−ｂ系永久磁石用原料合金およびｒ−ｔ−ｂ系永久磁石
WO2003066922A1 (fr) Aimant constitue par de la poudre d'alliage de bore et de fer des terres rares
JP4479944B2 (ja) 希土類磁石用合金薄片およびその製造方法
JPH1036949A (ja) 希土類磁石用合金及びその製造方法
JP3505261B2 (ja) Ｓｍ−Ｃｏ系永久磁石材料、永久磁石及びその製造法
US20050098239A1 (en) R-T-B based permanent magnet material alloy and R-T-B based permanent magnet
JP4879503B2 (ja) Ｒ−ｔ−ｂ系焼結磁石用合金塊、その製造法および磁石
US7846273B2 (en) R-T-B type alloy, production method of R-T-B type alloy flake, fine powder for R-T-B type rare earth permanent magnet, and R-T-B type rare earth permanent magnet
JP4276541B2 (ja) Ｓｍ−Ｃｏ系磁石用合金、その製造方法、焼結磁石及びボンド磁石
JP4318204B2 (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
JP3721831B2 (ja) 希土類磁石用合金及びその製造方法
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
JP2002208509A (ja) 希土類磁石およびその製造方法
JP3278431B2 (ja) 希土類金属−鉄−ボロン系異方性永久磁石用粉末
WO2009125671A1 (fr) Alliage à base r-t-b, procédé de production de l'alliage à base r-t-b, fines pour un aimant permanent à élément des terres rares en alliage à base r-t-b, aimant permanent à élément des terres rares en alliage à base r-t-b et procédé de production d'un aimant permanent à élément des terres rares en alliage à base r-t-b
JP3953768B2 (ja) 耐食性のすぐれたＲ−Ｆｅ−Ｂ−Ｃ系磁石合金用鋳片
JP3536943B2 (ja) 希土類磁石用合金及びその製造方法
JPH0920954A (ja) 耐食性のすぐれたＲ−Ｆｅ−Ｂ−Ｃ系磁石合金用鋳片及びその製造方法
JP2003077717A (ja) 希土類磁石用合金塊、その製造方法および焼結磁石
JP3256413B2 (ja) 耐食性のすぐれたＲ−Ｆｅ−Ｂ−Ｃ系磁石合金用鋳片及びその製造方法

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200480028521.2

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2005514309

Country of ref document: JP

122 Ep: pct application non-entry in european phase