CN105189805A - Raw material alloy for R-T-B-based magnet - Google Patents

Raw material alloy for R-T-B-based magnet Download PDF

Info

Publication number
CN105189805A
CN105189805A CN201480023759.XA CN201480023759A CN105189805A CN 105189805 A CN105189805 A CN 105189805A CN 201480023759 A CN201480023759 A CN 201480023759A CN 105189805 A CN105189805 A CN 105189805A
Authority
CN
China
Prior art keywords
phase
rich
magnet
alloy
raw material
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.)
Granted
Application number
CN201480023759.XA
Other languages
Chinese (zh)
Other versions
CN105189805B (en
Inventor
清水隆之
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.)
Santoku Corp
Original Assignee
Chuo Denki Kogyo 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 Chuo Denki Kogyo Co Ltd filed Critical Chuo Denki Kogyo Co Ltd
Publication of CN105189805A publication Critical patent/CN105189805A/en
Application granted granted Critical
Publication of CN105189805B publication Critical patent/CN105189805B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • 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

Abstract

A raw material alloy for a R-T-B-based magnet (wherein R represents at least one of rare earth elements including Y; and T represents at least one of transition elements including Fe as the essential element), said alloy containing a R2T14B phase as the main phase and R-rich phases in each of which R is concentrated, wherein the distance between the R-rich phases is 10 microns or more and the ellipsoidal aspect ratio of each of the R-rich phases is 0.6 or more. A fine powder produced by milling the raw material alloy has excellent fluidability, and enables the production of a sintered magnet having a complicated shape. When the raw material alloy for a R-T-B-based magnet contains Dy and/or Tb as R, it is desirable that the percentage ratio (A/B) produced by dividing the total concentration (A) of Dy and Tb in the main phase by the total concentration (B) of Dy and Tb in each of the R-rich phases is 180% or more. It is also desirable that the percentage ratio (D/C) produced by dividing the concentration (D) of an impurity in each of the R-rich phases by the concentration (C) of the impurity in the main phase is 230% or more.

Description

R-T-B series magnet raw alloy
Technical field
The present invention relates to the R-T-B series magnet raw alloy used in the raw material of rare-earth magnet.More specifically, relate to utilizing and pulverize and make the micro mist of mobility excellence, the R-T-B series magnet raw alloy of the sintered magnet of complicated shape can be obtained.In addition, relate to and can omit melt process or reduce melt process required time thus obtain the R-T-B series magnet raw alloy of bonded permanent magnet.
Background technology
In recent years, as the alloy used in the raw material of rare-earth magnet, there is the R-T-B system alloy of magnet characteristics excellence.Herein, " R " in " R-T-B system alloy " represents rare earth element, " T " represents using Fe as necessary transition metal, " B " represents boron.R-T-B series magnet raw alloy comprises above-mentioned R-T-B system alloy, becomes the raw material of rare-earth magnet.This R-T-B series magnet raw alloy can by the alloy strip manufacture utilizing thin strap continuous casting method to cast.
The mode chart of the casting device that Fig. 1 uses when being and representing and utilize thin strap continuous casting method casting alloy band.Casting device shown in this figure possesses chamber 5, crucible 1, tundish 2 and cooling roller 3.By being decompression state or non-active gas atmosphere by the inner sustain of chamber 5, thus prevent alloy molten solution and the alloy strip of casting oxidized.
When using this casting device and utilize thin strap continuous casting method to cast the alloy strip formed by R-T-B system alloy, such as, can utilize following steps to carry out.
(A) raw material is loaded in crucible 1, use induction heating device (not shown) by this heating raw materials.Thus, raw material melted and form alloy molten solution.
(B) by tundish 2, this alloy molten solution is supplied to the periphery of cooling roller 3.The inside of cooling roller 3 has the structure that refrigeration agent is circulated, therefore alloy molten solution cooling roller 3 periphery quenching and solidify.
(C) operation carrys out the alloy thin band 4 that cast thickness is 0.2 ~ 1.0mm like this.Cooling roller 3 along this figure the arrow being applied with hachure shown in direction rotate, therefore alloy strip 4 is peeled off from cooling roller 3 along with this rotation.
The alloy strip utilizing thin strap continuous casting method to cast, is cooled according to the condition of regulation after making alloy slice by fragmentation.In order to prevent the oxidation of alloy slice, usually under reduced pressure or under non-active gas atmosphere, carry out the fragmentation of alloy strip and the cooling of alloy slice.It should be noted that, in thin strap continuous casting method, sometimes obtain alloy slice by the thin slice of casting alloy.In addition, also sometimes alloy slice is obtained by carrying out fragmentation after the thin slice of casting alloy further.
Such operation and the R-T-B series magnet raw alloy (hereinafter also referred to as " raw material for magnet ") obtained have by R 2t 14the crystallization phases (principal phase) that B phase is formed and the concentrated crystalline structure having the rich R phase of rare earth element (mainly Nd) to coexist.Principal phase is the ferromagnetism phase contributing to magnetization, and rich R phase is the non-magnetic phase being helpless to magnetization.The crystalline structure comprising principal phase and rich R phase can use the interval of rich R phase to evaluate.The interval of rich R phase is the mean value at the interval from a rich R phase to the rich R phase of consecutive position in the section of thickness direction.
This raw material for magnet is mainly used as the raw material of R-T-B based sintered magnet (hereinafter also referred to as " sintered magnet "), R-T-B system bonded permanent magnet (hereinafter also referred to as " bonded permanent magnet ").
R-T-B based sintered magnet such as can be obtained by following manufacturing process.
(1) in pulverizing process, after R-T-B series magnet raw alloy being carried out hydrogenolysis broken (coarse reduction), jet mill etc. is utilized to carry out Crushing of Ultrafine and make micro mist.Carry out classification (such as air classification, screen sizing), to remove the particle that the particle of the not enough lower value of particle diameter and particle diameter exceed higher limit from this micro mist.
(2) in molding procedure, classified micro mist is carried out extrusion forming with mould in magnetic field, thus obtains powder compact.
(3), in sintering circuit, after the powder compact of extrusion forming is sintered in a vacuum, thermal treatment (tempering) is implemented to sintered compact.Obtain R-T-B based sintered magnet thus.
The shape of the sintered magnet obtained by this manufacturing process presents different shape according to its purposes.As method sintered magnet being processed into different shape, such as, sometimes cutting process is set after sintering circuit, utilizes perforate processing, machining to be refined to arbitrary shape.In addition, arbitrary shape (near-net-shape, nearnetshape) is finish-machined to when also sometimes carrying out extrusion forming in molding procedure.
In the method arranging cutting process, the yield rate of goods can reduce because of machining.On the other hand, utilize extrusion forming to be finish-machined in the method for arbitrary shape, if the mobility of micro mist is low, then when complicated shape, when there is thin-walled, micro mist cannot be filled in mould equably, density significantly can change because of the difference at position.Like this, when being filled to mould under the state of Density inhomogeneity, sintering becomes insufficient, its result, and the magnetic properties of sintered magnet worsens.
About R-T-B based sintered magnet, such as, as shown in patent documentation 1 ~ 3, proposed various motion in the past.The manufacture method of the sintered magnet proposed in patent documentation 1 is to have carried out the powdered alloy of thermal reunite process as object.In this powdered alloy, add the binding agent comprising the organic solvent of methylcellulose gum, polyacrylamide, polyvinyl alcohol and so on and carry out mixing, thus making pulp-like.This slurry spray drying unit is made the spherical pelletizing that median size is 20 ~ 400 μm.If use this pelletizing carry out shaping, sintering and obtain sintered magnet, even then thin wall profile, complicated shape also can realize higher magnetic properties.This is because pelletizing has excellent mobility for the binding agent self that spherical and pelletizing that mobility is high comprises.
In addition, the manufacture method of the sintered magnet proposed in patent documentation 2 is to have carried out the fine powdered alloy of wet type as object.In the slurry of this powdered alloy, add the binding agent comprising organic solvent and carry out mixing in the same manner as patent documentation 1, thus making pulp-like.This is carried out mixing slurry spray drying unit and made the spherical pelletizing that median size is 20 ~ 400 μm.If use this pelletizing carry out shaping, sintering and obtain sintered magnet, even then thin wall profile, complicated shape also can realize higher magnetic properties.This is because pelletizing has excellent mobility for the binding agent self that spherical and pelletizing that mobility is high comprises.
But the manufacture method of the sintered magnet proposed in patent documentation 1 and 2 all utilizes binding agent to the micro powder granule that bonds, and is therefore difficult to carry out magnetic field orientating.In addition, comprise organic solvent in binding agent, therefore this organic solvent is difficult to be completely removed when sintering, thus residual a part of in gained sintered magnet.Therefore, the carbon be mixed into from organic solvent, oxygen can form rare earth compound, and its result makes magnetic properties worsen.
For the sintered magnet raw alloy proposed in patent documentation 3, observe in the microscopic examination image on the surface contacted with roller cooling surface of this alloy utilizing the multiplying power of 100 times, to cross the nucleus origination point of the line segment being equivalent to 880 μm as center, the length-to-diameter ratio that dendrite grows into round shape is 0.5 ~ 1.0 and the crystallization quantity of particle diameter more than 30 μm is more than 5.In addition, for this sintered magnet raw alloy, that observes this alloy utilizing the multiplying power of 200 times is approximately perpendicular in the microscopic examination image of the section on the surface contacted with roller cooling surface, and the equispaced of rich R phase is 10 ~ 30 μm.
The sintered magnet raw alloy proposed in this patent documentation 3 utilizes the pulverizing process of the manufacturing process of sintered magnet and powder size can be made to become even.But the mobility of even-grained micro mist (micro mist of narrow particle size distribution) might not be good.During the epigranular of the micro mist obtained by raw material for magnet, easily through its particle, therefore there is the tendency being difficult to fluidization in atmosphere.Therefore, the mobility of micro mist reduces, its result, and the magnetic properties of sintered magnet reduces.
On the other hand, R-T-B system bonded permanent magnet such as by powder and the bonding agent (resin, low melting point metal) by pulverizing raw material for magnet mixture (mixture) carries out compressed moulding, injection molding is solidified, thus manufacture.As bonded permanent magnet powder, the so-called MQ powder of conventional マ グ ネ Network エ Application チ Inc..In addition, as bonded permanent magnet powder, the also conventional powder obtained implementing pulverization process after raw material for magnet enforcement HDDR (inhaling hydrogen-disproportionation-dehydrogenation-compound again, HydrogenationDisproportionationDesorptionRecombination) process.
When using HDDR process, raw material for magnet is required that principal phase (crystal grain) is thick.Make the thick principal phase generation decomposition of this raw material for magnet by HDDR process and combine again.Can split principal phase thus imperceptibly and the direction of unified easy magnetizing axis, its result, can improve coercive force and the remanence of bonded permanent magnet.
In pulverization process after HDDR process, even if by HDDR process, after making principal phase be split imperceptibly, also the easy rich R phase along alloy is become powder by pulverizing.When being undertaken shaping by the mixture comprising this powder and bonding agent, if the particle diameter of powder is little, then forming pressure rises and is difficult to shaping.In order to prevent the powder diameter obtained by pulverization process from diminishing, also need to carry out coarsening to principal phase.Therefore, in the manufacture of bonded permanent magnet in the past, as the pre-treatment of HDDR process, the thermal treatment of melt process is called as to raw material for magnet enforcement and makes principal phase generation coarsening.
But in melt process, due to the stripping from raw material for magnet (alloy slice) of rich R phase, therefore alloy slice is fused to other alloy slice sometimes.In addition, the composition of alloy slice is sometimes also unstable.Therefore, in melt process, process raw material for magnet (alloy slice) is difficult to.
Prior art document
Patent documentation
Patent documentation 1: Japanese Unexamined Patent Publication 8-107034 publication
Patent documentation 2: Japanese Unexamined Patent Publication 8-88111 publication
Patent documentation 3: International Publication WO2012/002531 publication
Summary of the invention
the problem that invention will solve
As mentioned above, in the molding procedure of the manufacturing process of R-T-B based sintered magnet, importantly, the mobility of the micro mist pulverized by raw material for magnet.Propose in patent documentation 1 and 2 and micro mist made median size and be the spherical pelletizing of 20 ~ 400 μm thus improve mobility.But owing to using the binding agent comprising organic solvent during granulation, therefore a part for organic solvent residues in sintered magnet and forms rare earth compound, and result causes magnetic properties to worsen.In addition, the sintered magnet raw alloy proposed in patent documentation 3 becomes evenly (making size-grade distribution become narrow) owing to making the granularity of micro mist, and the therefore mobility reduction of micro mist, the magnetic properties of sintered magnet worsen.
On the other hand, for R-T-B system bonded permanent magnet, when using HDDR process, made the principal phase generation coarsening of raw material for magnet by melt process.But, in melt process, be difficult to process raw material for magnet (alloy slice).
The present invention carries out in light of this situation, its object is to, and provides by pulverizing the micro mist and the R-T-B series magnet raw alloy that can obtain the sintered magnet of complicated shape that can make mobility excellence.In addition, its object is to, provide and can omit melt process or reduce melt process required time and obtain the R-T-B series magnet raw alloy of bonded permanent magnet.
for the scheme of dealing with problems
The present inventor studies for the mobility improving the micro mist pulverized by raw material for magnet, found that: in raw material for magnet, make principal phase generation coarsening, make being spaced apart more than 10 μm and making the oval length ratio of rich R phase be more than 0.6 of rich R phase.Find thus: the size-grade distribution of pulverized micro mist broadens, mobility improves.
In addition, raw material for magnet contains Dy and Tb (also they being referred to as " heavy rare earths " below) sometimes as R.Now, the present inventor finds: make along with the coarsening of principal phase principal phase distribute with the heavy rare earths of rich R phase and change, make the heavy rare earths comprised in rich R phase be expelled to principal phase and spread.The coercive force of rare-earth magnet can be improved thus.
And then the present inventor finds: by the coarsening along with principal phase, impurity (such as Mn, Si etc.) is expelled to rich R phase from principal phase, can improves the coercive force of rare-earth magnet.
The present invention completes based on above-mentioned opinion, and its purport is the R-T-B series magnet raw alloy of following (1) ~ (3).
(1) a kind of R-T-B series magnet raw alloy, it is characterized in that, its be R-T-B series magnet raw alloy (wherein, R be comprise Y rare earth element among at least a kind, T is using Fe as more than necessary a kind transition element), comprise the R as principal phase 2t 14the rich R phase that B phase and R have been concentrated, rich R phase be spaced apart more than 10 μm and the oval length ratio of rich R phase is more than 0.6.
(2) the R-T-B series magnet raw alloy according to above-mentioned (1), it is characterized in that, any one or both that aforementioned R-T-B series magnet raw alloy contains in Dy and Tb are used as R, and the per-cent that the total concn A (quality %) of Dy and the Tb in aforementioned principal phase obtains divided by the total concn B (quality %) of Dy and the Tb in aforementioned rich R phase is more than 180%.
(3) the R-T-B series magnet raw alloy according to above-mentioned (1) or (2), it is characterized in that, the per-cent that the impurity concentration D (quality %) of aforementioned rich R phase obtains divided by the impurity concentration C (quality %) of aforementioned principal phase is more than 230%.
In the present invention, " the oval length ratio of rich R phase is more than 0.6 " refers to, as described later, and rich R phase thicker (broadening) and the shape be deformed into close to positive round.The oval length of rich R phase calculates with the ratio (with reference to aftermentioned formula (1)) of the section second moment (Ix, Iy) in the center of gravity of the rich R phase system of coordinates that is initial point than using like that as described later.
the effect of invention
The rich R of R-T-B series magnet raw alloy of the present invention is alternate is divided into more than 10 μm and the oval length ratio of rich R phase is more than 0.6.Therefore, the size-grade distribution being pulverized the micro mist obtained in the manufacturing process of sintered magnet by raw material for magnet broadens and mobility raising, and its result, can obtain the sintered magnet of complicated shape.In addition, time melt process can omitted or reduce needed for melt process in the manufacturing process of bonded permanent magnet.
Accompanying drawing explanation
The mode chart of the casting device that Fig. 1 uses when being and representing and utilize thin strap continuous casting legal system to make alloy strip.
Fig. 2 is that (a) of the figure of the determination step of the oval length ratio that rich R phase is described, this figure represents the image reflected electron image of alloy section being carried out 2 values, and (b) of this figure represents the image of the position of centre of gravity obtaining each rich R phase.
Fig. 3 is the image of the plot analysis result of the EPMA represented in the conventional example 2 of embodiment, the photo that (a) expression of this figure is taken with electron microscope, (b) of this figure represents the analytical results of Dy, (c) of this figure represents that the analytical results of Si, (d) of this figure represent the analytical results of Mn.
Fig. 4 is the image of the plot analysis result of the EPMA represented in the example of the present invention 7 of embodiment, the photo that (a) expression of this figure is taken with electron microscope, (b) of this figure represents the analytical results of Dy, (c) of this figure represents that the analytical results of Si, (d) of this figure represent the analytical results of Mn.
Embodiment
Below, be described for R-T-B series magnet raw alloy of the present invention.
1. R-T-B series magnet raw alloy of the present invention
The feature of raw material for magnet of the present invention is, it comprises the R as principal phase 2t 14the rich R phase that B phase and R have been concentrated, rich R phase be spaced apart more than 10 μm and the oval length ratio of rich R phase is more than 0.6.
Being spaced apart more than 10 μm and referring to of rich R phase a: part for rich R phase is diffused in principal phase and disappears thus the state of principal phase generation coarsening.In addition, the oval length ratio of the rich R phase of raw material for magnet of the present invention is more than 0.6.
Herein, the oval length of rich R phase is than the index of correlation of shape, especially rugosity (width) being rich R phase, and its measuring method refers to aftermentioned.The oval length of rich R phase is 0 < R≤1 than R according to its definition, its value more close to the shape of 1 rich R phase more close to positive round, this value is more close to 0, then the shape of rich R phase becomes thinner (narrowing).
The oval length ratio of rich R phase is more than 0.6 to refer to: along with the coarsening of principal phase, a part for rich R phase is thicker (broadening), from thermodynamic (al) viewpoint, is be deformed into the shape close to stablizing positive round.
About this raw material for magnet of the present invention, as shown in aftermentioned embodiment, when raw material for magnet being pulverized in the pulverizing process of the manufacturing process of sintered magnet, the micro mist of mobility excellence can be obtained.Its reason is still not clear, but infers it is based on following effect.Broadened by the size-grade distribution of the micro mist obtained carrying out classification after raw material for magnet pulverizing, due to the thicker particle comprised in micro mist, atmosphere easily retains between particles.Like this, the atmosphere retained between particles plays function as lubricant, micro mist generation fluidization, its result, and the mobility of micro mist is improved.
Therefore, even if when raw material for magnet of the present invention has a complicated shape in the molding procedure of the manufacturing process of sintered magnet, when there is thin-walled portion, also micro mist can be filled in mould equably, the magnetic properties of sintered magnet can be suppressed to worsen.
In addition, the principal phase of raw material for magnet of the present invention there occurs coarsening, therefore when being used as the raw material of bonded permanent magnet, and time melt process can omitted or reduce needed for melt process.Therefore, raw material for magnet of the present invention can improve manufacture efficiency in the manufacture of bonded permanent magnet.In addition, the alloy slice in melt process can be suppressed to form and to become unstable, stably can obtain the bonded permanent magnet of high-quality.
When the interval of the rich R phase of raw material for magnet of the present invention is more than 40 μm, the time needed for the coarsening of principal phase increases and manufactures degradation in efficiency, and that therefore expects rich R phase is spaced apart less than 40 μm.The oval length of rich R phase becomes the upper limit than by its definition with 1.0.
About heavy rare earths it is known that: in raw material for magnet, sometimes add the heavy rare earths of Dy and Tb and so on as R.Known passing through adds heavy rare earths, can prevent reversal magnetization, its result in rare-earth magnet, and coercive force improves.Also known in addition: by making added heavy rare earths, in rich R phase, denseization occur, the generation of the nucleation site becoming reversal magnetization basic point can be prevented, prevent reversal magnetization.But, raw material for magnet of the present invention make rich R phase be spaced apart more than 10 μm, make principal phase generation coarsening, the effect therefore utilizing the dense chemoprevention of heavy rare earths in rich R phase to stop reversal magnetization diminishes relatively.
Therefore, in the raw material for magnet of the present invention of principal phase generation coarsening, be diffused in principal phase by making heavy rare earths and improve coercitive effect and relatively become large.Therefore, in raw material for magnet of the present invention containing any one in Dy and Tb or both as R time, per-cent that the total concn A (quality %) of Dy and the Tb in principal phase obtains divided by the total concn B (quality %) of Dy and the Tb in rich R phase (A/B, hereinafter also referred to as " partition ratio of heavy rare earths ") expectation is more than 180%.
When the partition ratio of heavy rare earths is more than 180%, presents the heavy rare earths comprised in a part of rich R phase along with the coarsening of principal phase and be discharged to principal phase and the state spread.Like this, by making heavy rare earths be diffused in principal phase, the coercive force of rare-earth magnet can be improved.
About impurity, when comprising the impurity such as Mn, Si in the principal phase of raw material for magnet, produce the position that the coercive force of rare-earth magnet is low because of this impurity.The easy reversal magnetization in the position that coercive force is low and cause the coercive force of rare-earth magnet to reduce, therefore expects impurity to be expelled to rich R phase from principal phase for raw material for magnet.
Therefore, the per-cent (D/C, hereinafter also referred to as " partition ratio of impurity ") that the impurity concentration D (quality %) of the rich R phase of raw material for magnet of the present invention obtains divided by the impurity concentration C (quality %) of principal phase expects to be more than 230%.When the partition ratio of impurity is more than 230%, present impurity is discharged to rich R phase state from principal phase, the coercive force of the rare-earth magnet caused by impurity can be suppressed to reduce.
In the present invention, impurity refer to industrially alloying time, headed by raw material, the material be inevitably mixed into due to the various factors of manufacturing process, such as headed by above-mentioned Mn, Si, O (oxygen), C, N, H, Ca, Mg, S, P, Na, K, Ar etc. meet.
2. chemical constitution
R-T-B series magnet raw alloy of the present invention has following composition: the R containing at least a kind among the rare earth element comprising Y, using Fe as T and B (boron) of more than necessary a kind transition element.It is intended that about R-T-B series magnet raw alloy of the present invention, in atom %, as R in the total content of Nd and Pr containing more than 11.6% and Nd and Pr of less than 16.4% and containing more than 5.0% and the B of less than 10%, surplus forms as more than necessary a kind transition element and T and impurity by using Fe.Its scope limiting reason and more expect below is described.
Be desirably in comprise Y rare earth element among be used as R, this is because they are at various R containing Nd and Pr 2fe 14saturation magnetization among B compound is the highest.Now, when the total content of Nd and Pr is less than 11.6 atom %, when raw material for magnet is used as the raw material of sintered magnet, the rare earth element amount needed for sound sintering, coercive force minimizing cannot be guaranteed in sintering circuit.On the other hand, when the total content of Nd and Pr is more than 16.4 atom %, principal phase tails off relatively, remanence Br reduces.Therefore, expect to make the total content of Nd and Pr be 11.6 more than atom % and the total content of 16.4 below atom %, Nd and Pr is more expected to be 12.2 more than atom % and 15.2 below atom %.
When B is containing quantity not sufficient 5.0 atom %, in Rare Earth magnet, sometimes can not get sufficient coercive force, remanence.When B content is more than 10 atom %, in Rare Earth magnet, sometimes can not get sufficient remanence.B content is more expected to be 5.6 more than atom % and 7.5 below atom %.
In addition, if substitute a part of T and containing Dy and Tb as R, then can improve the coercive force of rare-earth magnet.During containing Dy and Tb, improve coercitive effect to obtain, their total content expects to be 1 more than atom %.On the other hand, when their total content is more than 4.1 atom %, remanence significantly reduces, and therefore expects to make the upper limit be 4.1 atom %.
If when substituting a part of T and contain Al, the effect of can be improved coercive force and weathering resistance, so expect.During in order to obtain this effect containing Al, expect to make Al content be 0.1 more than atom %.On the other hand, when Al content is more than 2.0 atom %, magneticflux-density and coercive force together reduce, and therefore expect to make that the upper limit is 2.0 atom %, the upper limit more expects to be 0.7 atom %.
3. measuring method
The interval of aforementioned rich R phase and the oval length of rich R phase are than using the image taken by scanning electron microscope to measure in the present invention.
The sample used in the image utilizing scanning electron microscope to take is made by following steps in the present invention.
(1) take 10 raw material for magnet (alloy slice), this alloy is imbedded heat-curing resin to be fixed.
(2) making by grinding the section of the thickness direction of the alloy slice fixed by resin expose, making this section present mirror status.
(3) the alloy section of nital to mirror status is utilized to implement the etching in 5 seconds.
[interval of rich R phase]
The interval of rich R phase utilizes following step to measure in the present invention.
(1) use the sample made by above-mentioned steps, for the section of each alloy slice, utilize scanning electron microscope with 1000 times of shooting reflected electron images.Now, by the section of alloy slice along thickness direction to be divided into 3 part at equal intervals time, take reflected electron image in the mode that is all included of region being positioned at central authorities.
(2) for captured 10 images, reading to image analysis apparatus, is that benchmark carries out 2 values with brightness, carries out the process for identifying rich R phase and principal phase.
(3) for 10 images having carried out 2 values, draw the straight line parallel with the face of contact cooling roller in the middle position of thickness, be determined at rich R phase adjacent on straight line interval each other and obtain mean value, as the interval of the rich R phase of this alloy slice.
(4) mean value is obtained by the interval of the rich R phase of 10 alloy slices, using the interval of this mean value as the rich R phase of this raw material for magnet.
The reason of taking reflected electron image for middle section when being divided into 3 part in above-mentioned (1) is as follows.In the region of the side, face contacted with cooling roller during casting, likely partially have the fine position of excessive tissue.On the other hand, in the region of opposing face side, likely partially have the thick position of excessive tissue.This excessively fine position, excessively thick position belong to so-called outlier statistically.Therefore, by taking reflected electron image for middle section when being divided into 3 part, for the interval of rich R phase, outlier can be removed to measure typical value.Herein, " opposing face " refers to the face relative to contacting with cooling roller during casting, is positioned at the face (face let cool) of its opposition side.
[the oval length ratio of rich R phase]
Fig. 2 is that (a) of the figure of the determination step of the oval length ratio that rich R phase is described, this figure represents the image reflected electron image of alloy section having been carried out 2 values, and (b) of this figure represents the image of the position of centre of gravity obtaining each rich R phase.In this figure, principal phase 8 Dark grey represents, rich R phase 9 represents by light gray.
The oval length of rich R phase utilizes following steps to measure than in the present invention.
(1) use the sample made by above-mentioned steps, for the section of each alloy slice, use scanning electron microscope with 1000 times of shooting reflected electron images.Now, during by the section of alloy slice in a thickness direction to be divided into 3 part at equal intervals, take reflected electron image in the mode that the region being positioned at central authorities is all included.
(2) for captured image, read to image analysis apparatus, carry out 2 values using brightness as benchmark, carry out the process identifying rich R phase and principal phase, obtain shown in (a) 10 images of this figure.
(3) for 10 each images having carried out 2 values, as shown in (b) of this figure, image analysis software is used to obtain center of gravity 9a for each rich R phase in image.
(4) for the rich R phase of each in each image, above-mentioned image analysis software is used to calculate section second moment (Ix, Iy) respectively.Now, for each rich R phase, rectangular coordinate system is set as: the face that initial point is the center of gravity 9a of rich R phase, X-axis is parallel to the contact cooling roller when casting, Y-axis are parallel to thickness direction.
(5) for the rich R phase of each in each image, using the value the greater among section second moment (Ix, Iy) as major axis, smaller will be worth as minor axis, calculate the ratio r of minor axis and major axis.Specifically, following formula (1) is utilized to calculate ratio r.
r＝Min{Ix、Iy}/Max{Ix、Iy}···(1)
Herein, inputted a value and b value carry out contrasting and export the function of the value of larger one by Max{a, b}.In addition, inputted a value and b value carry out contrasting and export the function of the value of less one by Min{a, b}.
(6) for the ratio r of each the rich R phase utilizing above-mentioned formula (1) to calculate in each image, mean value is calculated, as the oval length ratio of the rich R phase of this alloy slice.
(7) mean value is obtained by the oval length ratio of the rich R phase of 10 alloy slices, using the oval length ratio of its mean value as the rich R phase of this raw material for magnet.
The situation of taking the reason of reflected electron image and the interval of the rich R phase of mensuration for middle section when being divided into 3 part in above-mentioned (1) is identical.By taking reflected electron image to middle section when being divided into 3 part, for the oval length ratio of rich R phase, outlier can be removed to measure typical value.
Total concn B, the impurity concentration D of rich R phase of Dy and the Tb in the total concn A of Dy and the Tb in aforementioned principal phase, rich R phase and the impurity concentration C of principal phase use in the present invention and measure based on the plot analysis of EPMA and linear analysis.
Utilize following step in the present invention to make based on the sample used in the plot analysis of EPMA and linear analysis.
(1) take 9 raw material for magnet (alloy slice), this alloy is imbedded heat-curing resin to be fixed.
(2) making by grinding the section of the thickness direction of the alloy slice fixed by resin expose, making this section present mirror status.
(3) in a vacuum carbon evaporation is carried out to the alloy section of mirror status.
[concentration of element]
In the present invention, the concentration of each element utilizes following steps to measure.
(1) use the sample made by above-mentioned steps, utilize EPMA, plot analysis is carried out to the concentration of element of each alloy and obtains image.Now, among the section of alloy slice, the middle body for thickness direction is analyzed, and obtains image.
(2) to comprise the mode in the region of being carried out plot analysis by EPMA, utilize electron microscope with 1000 times of shooting reflected electron images.
(3) according to the image of plot analysis and the image of electron microscope, EPMA is utilized, for the enterprising line linearity analysis of line in the face of contact cooling roller when comprising principal phase and rich both R phases and be parallel to casting.
(4) according to the image of electron microscope, the result of linear analysis is divided into principal phase and rich R phase, using respective mean value as the principal phase concentration of this alloy slice and rich R phase concentration.
(5) obtain mean value by the principal phase concentration of 9 alloy slices, be denoted as the principal phase concentration of this raw material for magnet.In addition, obtain mean value by the rich R phase concentration of 9 alloy slices, be denoted as the rich R phase concentration of this raw material for magnet.
4. the manufacture method of R-T-B series magnet raw alloy of the present invention
As the commercial run of the alloy of manufacture coarse grain, have and use the slow mold of speed of cooling to carry out the method for casting.In addition, also have following method: the comparatively faster atomization of speed of cooling, utilize thin strap continuous casting method or melt spin-ning method (meltspinmethod) casting alloy after implement heat-treating methods.In R-T-B series magnet raw alloy, the general thin strap continuous casting method that it is possible to the alloy strip obtaining advantageous crystalline orientation.Raw material for magnet of the present invention also can bring making by the alloy utilizing thin strap continuous casting method to cast.The alloy strip of the R-T-B system alloy utilizing thin strap continuous casting method to cast under reduced pressure or carry out fragmentation under non-active gas atmosphere and make alloy slice.
R-T-B series magnet raw alloy of the present invention can by high operating temperatures direct with more than 950 DEG C and less than 1140 DEG C keep carrying out cooling making after the specified times, and do not cool this alloy slice.By by the alloy slice of the condition of high temperature with more than 950 DEG C and less than 1140 DEG C keep the specified time, the rich R phase of the part of alloy slice diffuses to principal phase and disappears.Its result, principal phase generation coarsening and make the interval of rich R phase reach more than 10 μm.In addition, along with the coarsening of principal phase, the rich R phase thicker (width is wide) of a part comparatively thin (width is narrow), its shape is close to positive round.Its result, the oval length ratio of rich R phase reaches more than 0.6.
When alloy slice contains heavy rare earths, by by the alloy slice of the condition of high temperature with more than 950 DEG C and less than 1140 DEG C keep the specified time, the heavy rare earths comprised in rich R phase is discharged to principal phase and spreads.Its result, can make the partition ratio of heavy rare earths be more than 180%.
In addition, by by the alloy slice of the condition of high temperature with more than 950 DEG C and less than 1140 DEG C keep the specified time, the impurity such as Mn, Si are discharged to rich R phase from principal phase.Its result, can make the partition ratio of impurity be more than 230%.
When keeping the temperature of alloy slice less than 950 DEG C, the oval length of rich R phase than becoming less than 0.6, the mobility of chippy micro mist becomes insufficient.On the other hand, when keeping the temperature of alloy slice more than 1140 DEG C, alloy slice is fused to other alloy slice and assembles.
Alloy slice is remained more than 950 DEG C and the time of less than 1140 DEG C can the interval of rich R phase required by raw material for magnet, the chemical constitution of alloy, speed of cooling etc. on cooling roller suitably set.
About by alloy slice with more than 950 DEG C and less than 1140 DEG C keep after cooling, the speed of cooling from the temperature range kept till temperature to 500 DEG C is set to less than 65 DEG C/min to carry out.This is because: when the speed of cooling of said temperature scope is more than 65 DEG C/min, as shown in aftermentioned embodiment, gained raw material for magnet can not inhale hydrogen, cannot pulverize.The cooling of the alloy slice of the temperature range less than 500 DEG C is not particularly limited.
Embodiment
In order to verify the effect brought by raw material for magnet of the present invention, test.In this test, by making raw material for magnet and pulverizing and obtain micro mist, confirm the mobility of this micro mist.
[test method]
In this test (conventional example, the present invention's example and comparative example), use the casting device shown in earlier figures 1, utilize the step of aforementioned (A) ~ (C), carried out the strip of casting alloy by the R-T-B system alloy molten solution being heated to regulation melt temperature.The alloy strip cast is carried out fragmentation at the back segment of cooling roller and makes alloy slice.During casting alloy band, the adjustment reservoir quantity of liquation and the rotating speed of cooling roller, make the thickness of cast alloy strip be about 0.3mm or be about 0.5mm.Atmospheric condition is set as the argon gas atmosphere as non-active gas, and its pressure is set to 300torr.
In this test, by list of modification surface temperature, atmospheric condition, the speed of cooling on cooling roller is adjusted to 850 DEG C/sec ~ 1500 DEG C/sec.Herein, speed of cooling is calculated divided by the time (second) of peeling off till position that a bit arrives from fluid injection position on the periphery of cooling roller by the difference of melt temperature (DEG C) with the alloy strip temperature (DEG C) peeling off position.In addition, cooling roller employs using Cu as principal constituent and the irregular cooling roller of surface formation.Herein, positional representation peels off alloy strip position from cooling roller is peeled off.
In the prior embodiment, broken alloy slice is fed in water-cooled container, in this container, is cooled to alloy slice reaches till 150 DEG C.Atmospheric condition is now set to non-active gas and argon gas atmosphere in the same manner as casting, and its pressure is set to 300torr.When the temperature of alloy slice reaches 150 DEG C, discharge alloy slice from container, let cool to normal temperature in an atmosphere, thus obtain raw material for magnet.
In the present invention's example and comparative example, after broken alloy slice enforcement thermal treatment, then implement cooling process.In thermal treatment, broken alloy slice is directly fed in barrel shape well heater at high operating temperatures, keeps the hold-time of regulation with the Heating temperature specified.Now, utilize the rotation of bucket to stir input alloy slice, and utilize well heater to heat.Heat treated atmospheric condition is set to non-active gas and argon gas atmosphere, its pressure is set to 300torr in the same manner as casting.
In cooling process, alloy slice is fed in barrel shape water cooler, utilizes the rotation of bucket to stir input alloy slice, and cooled by the water coolant that circulates in the wall of bucket.Speed of cooling in barrel shape water cooler is adjusted to 45 ~ 70 DEG C/min by the feed rate changing water coolant.The atmospheric condition of barrel shape water cooler is set to non-active gas and argon gas atmosphere, its pressure is set to 300torr in the same manner as casting.When the temperature of alloy slice reaches 500 DEG C, alloy slice is discharged from barrel shape water cooler, lets cool to normal temperature in non-active gas, thus obtain raw material for magnet.
In this test, by changing raw material compounding, the chemical constitution of gained raw material for magnet is denoted as any one in A ~ C.The chemical constitution A of its alloy ~ C is shown in table 1.
[table 1]
Table 1
In this test, taked the sample of regulation sheet number by gained raw material for magnet, utilize the step recorded in aforementioned " 3. measuring method ", measure the interval of rich R phase and the oval length ratio of rich R phase.In addition, taked the sample of regulation sheet number by gained raw material for magnet, utilize the step recorded in aforementioned " 3. measuring method ", for principal phase and rich R phase, measure the concentration of impurity Si and Mn respectively, calculate the partition ratio of Si and Mn.In addition, in the raw material for magnet of chemical constitution B and C, as heavy rare earths only containing Dy, therefore utilize the step recorded in aforementioned " 3. measuring method ", measure respectively for the Dy concentration A of principal phase and the Dy concentration B of rich R phase.Use its measurement result, calculate the partition ratio (A/B) of heavy rare earths.
In addition, the pulverizing process in the manufacturing process of simulation sintered magnet, after carrying out hydrogenolysis broken (coarse reduction), utilizes jet mill carry out Crushing of Ultrafine and make micro mist, carries out classification to this micro mist gained raw material for magnet.During hydrogenolysis is broken, makes hydrogen attract deposit after raw material for magnet at normal temperature under the hydrogen atmosphere of 90kPa ~ 100kPa (660 ~ 760torr), carry out the Dehydroepiandrosterone derivative of 600 DEG C × 1 hour in an ar atmosphere.Non-active gas (the N that the broken coarse meal obtained of hydrogenolysis is below 150ppm at amount of oxygen will be utilized 2gas) in atmosphere with gaseous tension 6kgf/cm 2, feed rate 200g/min condition jet mill carry out pulverizing and making micro mist.The classification of micro mist uses centrifuge separator to utilize air classification to carry out, in order to remove particle and the particle of particle diameter less than 1 μm that particle diameter is more than 40 μm.
Use gained micro mist, utilize following step to measure angle of repose and avalanche angle in an ar atmosphere.
(1) be that the circular slab of 80mm is placed in pedestal by diameter, at the central position of its circular slab configuration funnel.Now, the distance between the front end of funnel and the upper surface of circular slab is set to 130mm, uses the funnel that the internal diameter in pipe portion is 6mm.Make micro mist be fallen by funnel in this condition, before the mountain formed by the micro mist fallen is by avalanche, stop falling of micro mist.
(2) for the mountain of the micro mist formed on circular slab, in three mensuration base angles, place (angle that the inclined-plane on mountain and circular slab upper surface are), using its mean value as angle of repose.
(3) make weight be that the counterweight of 109g falls from the height of 160mm to pedestal to giving impact 3 times, thus the landslide on circular slab is collapsed.
(4) for the mountain of avalanche, at 3 mensuration base angles, place, using its mean value as avalanche angle.
The angle of repose of micro mist represents the scope that micro mist is expanded in mould when micro mist being filled to mould, and angle of repose is less, then more micro mist can be filled in mould on a large scale in, mobility is more excellent.In addition, avalanche angle represents and micro mist is filled to mould and gives the scope that when impacting, micro mist is expanded in mould, and avalanche angle is less, then more micro mist can be filled in mould on a large scale in, mobility is more excellent.
[test-results]
Table 2 illustrates the chemical constitution of raw material for magnet, casting condition (speed of cooling on melt temperature, cooling roller, the thickness of alloy strip), heat-treat condition (Heating temperature, hold-time) and cooling process condition (speed of cooling in cooling process) for each test.In addition, table 2 illustrates angle of repose and the avalanche angle of gained micro mist.And then table 2 illustrates the interval of rich R phase, the oval length ratio of rich R phase, the partition ratio of heavy rare earths and the partition ratio of impurity (Si and Mn) for gained raw material for magnet.
[table 2]
According to table 2, in conventional example 1 ~ 3, cast alloy strip is carried out fragmentation and makes alloy slice, thermal treatment is not implemented in the cooling of this alloy slice.Its result, the interval of the rich R phase of gained raw material for magnet reaches 3.0 ~ 6.7 μm, oval length ratio reaches 0.30 ~ 0.41.The angle of repose of the micro mist pulverized by this raw material for magnet is 55 ~ 58 °, avalanche angle is 34 or 35 °.
On the other hand, in example 1 ~ 10 of the present invention, cast alloy strip is carried out fragmentation and makes alloy slice, after direct involutory gold plaque implements thermal treatment at high operating temperatures, implement cooling process, the interval of the rich R phase of gained raw material for magnet reaches more than 10 μm and oval length ratio reaches more than 0.6.The angle of repose of micro mist that this raw material for magnet is pulverized is reached 40 ~ 46 °, avalanche angle reaches 20 ~ 25 °.
Like this, compared with conventional example 1 ~ 3, angle of repose and the avalanche angle of example 1 ~ 10 of the present invention diminish, the mobility of micro mist improves.Therefore, can clearly by make the rich R phase of raw material for magnet be spaced apart more than 10 μm and oval length ratio is more than 0.6, for the micro mist pulverized by this raw material for magnet, can mobility be improved.
Then, for the partition ratio of heavy rare earths and the partition ratio of impurity, the analytical results with reference to EPMA is verified.
Fig. 3 is the image of the plot analysis result of the EPMA representing conventional example 2, the photo that (a) expression of this figure is taken with electron microscope, (b) of this figure represents the analytical results of Dy, (c) of this figure represents that the analytical results of Si, (d) of this figure represent the analytical results of Mn.
Fig. 4 is the image of the plot analysis result of the EPMA representing example 7 of the present invention, the photo that (a) expression of this figure is taken with electron microscope, (b) of this figure represents the analytical results of Dy, (c) of this figure represents that the analytical results of Si, (d) of this figure represent the analytical results of Mn.
In the electron micrograph of (a) of Fig. 3 and (a) of Fig. 4, grey portion is principal phase, white portion is rich R phase.In addition, in (b) ~ (d) of Fig. 3 and (b) ~ (d) of Fig. 4, the concentration of Dy, Si or Mn is represented by the depth, the concentration in white portion is the highest, along with darkening, concentration step-down, the concentration of black part is minimum.(b) ~ (d) of Fig. 3 represents that the concentration distribution of each element in (a) of Fig. 3 shown region, (b) ~ (d) of Fig. 4 represent the concentration distribution of each element in (a) of Fig. 4 shown region respectively respectively.
About the partition ratio of heavy rare earths, the test containing heavy rare earths as R is conventional example 2 and 3 and example of the present invention 6 ~ 10.In conventional example 2 wherein, according to (a) and (b) of Fig. 3, compared with in rich R phase, Dy in principal phase with the distributions of high density in entirety.On the other hand, in example 7 of the present invention, according to (a) and (b) of Fig. 4, the concentration difference of Dy in principal phase and rich R phase expands, in principal phase with the distributions of high density in entirety, distribute with the state that concentration is extremely low in rich R phase.
On the other hand, according to table 2, in conventional example 2 and 3, the partition ratio of heavy rare earths is 160% and 140%, but in example of the present invention 6 ~ 10, the partition ratio of heavy rare earths is more than 180%.Thus can be clear and definite: in the raw material for magnet of example 6 ~ 10 of the present invention, along with the coarsening of principal phase, the heavy rare earths comprised in rich R phase is discharged to principal phase, and presents heavy rare earths and be diffused in state in principal phase.
About the partition ratio of impurity, in conventional example 2, according to (a) and (c) of Fig. 3, compared with in principal phase, Si in rich R phase with the distributions of high density in entirety.On the other hand, in example 7 of the present invention, according to (a) and (c) of Fig. 4, the concentration difference of Si in rich R phase and principal phase expands, and distribute with the state of very high concentrations in rich R phase, the state with lower concentration in principal phase distributes.About Mn, according to (a) and (d) of Fig. 3 and (a) and (d) of Fig. 4, distribute with the state identical with Si.
According to table 2, in conventional example 1 ~ 3, the partition ratio of Si reaches 130% and 160%, the partition ratio of Mn reaches 200% and 210%.On the other hand, in example 1 ~ 10 of the present invention, the partition ratio of Si and Mn all reaches more than 230%.Thus can be clear and definite: the raw material for magnet of example 1 ~ 10 of the present invention presents impurity is discharged to rich R phase state from principal phase.
On the other hand, in comparative example 1, heat treated maintenance temperature is set to 930 DEG C, the oval length of rich R phase is than less than 0.6.Therefore, in comparative example 1, compared with example 1 ~ 10 of the present invention, the angle of repose of micro mist and avalanche angle become large, the mobility of micro mist reduces.In addition, in comparative example 2, the speed of cooling of cooling process is set to 70 DEG C/min, its result, to raw material for magnet carry out hydrogenolysis broken time, alloy can not inhale hydrogen, cannot obtain micro mist.In comparative example 3, heat treated maintenance temperature is set to 1150 DEG C, alloy slice welding and condensing in barrel shape well heater.Therefore raw material for magnet cannot be obtained.
Can confirm thus: for alloy slice broken for alloy strip to be implemented with more than 950 DEG C and after the thermal treatment of less than 1140 DEG C maintenance specified times, implement with 65 DEG C/min from the cooling process keeping temperature to be cooled to the temperature range till 500 DEG C, thus raw material for magnet of the present invention can be obtained.
utilizability in industry
If R-T-B series magnet raw alloy of the present invention is used for sintered magnet, then utilize the micro mist pulverized and can make mobility excellence, therefore, it is possible to obtain the sintered magnet of complicated shape.On the other hand, if for bonded permanent magnet, then can omit melt process or time of reducing needed for melt process and obtain bonded permanent magnet.Therefore, R-T-B series magnet raw alloy of the present invention can effectively utilize in the manufacture field of sintered magnet and bonded permanent magnet.
description of reference numerals
1: crucible, 2: tundish, 3: cooling roller, 4: alloy strip,
5: chamber, 6: liquation, 8: principal phase, 9: rich R phase,
9a: the center of gravity of rich R phase.

Claims (3)

1. a R-T-B series magnet raw alloy, is characterized in that, its be R-T-B series magnet raw alloy (wherein, R be comprise Y rare earth element among at least a kind, T is using Fe as more than necessary a kind transition element),
Comprise the R as principal phase 2t 14the rich R phase that B phase and R have been concentrated,
Rich R phase be spaced apart more than 10 μm and the oval length ratio of rich R phase is more than 0.6.
2. R-T-B series magnet raw alloy according to claim 1, is characterized in that, any one or both that described R-T-B series magnet raw alloy contains in Dy and Tb are used as described R,
The per-cent that the total concn in mass % of Dy and the Tb in described principal phase obtains divided by the total concn in mass % of Dy and the Tb in described rich R phase is more than 180%.
3. R-T-B series magnet raw alloy according to claim 1 and 2, is characterized in that, the per-cent that the impurity concentration D in mass % of described rich R phase obtains divided by the impurity concentration C in mass % of described principal phase is more than 230%.
CN201480023759.XA 2013-04-24 2014-04-15 R T B series magnet raw alloys Active CN105189805B (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2013-090819 2013-04-24
JP2013090819 2013-04-24
PCT/JP2014/002123 WO2014174795A1 (en) 2013-04-24 2014-04-15 Raw material alloy for r-t-b-based magnet

Publications (2)

Publication Number Publication Date
CN105189805A true CN105189805A (en) 2015-12-23
CN105189805B CN105189805B (en) 2017-06-30

Family

ID=51791384

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201480023759.XA Active CN105189805B (en) 2013-04-24 2014-04-15 R T B series magnet raw alloys

Country Status (3)

Country Link
JP (1) JP6005263B2 (en)
CN (1) CN105189805B (en)
WO (1) WO2014174795A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108133796A (en) * 2017-12-11 2018-06-08 北京科技大学 A kind of preparation method of sintered magnet NdFeB magnetic powder
CN108831648A (en) * 2018-06-21 2018-11-16 宁波招宝磁业有限公司 The method of spray drying preparation performance Nd Fe B sintered magnet

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7251157B2 (en) * 2019-01-16 2023-04-04 Tdk株式会社 Evaluation method of raw material alloy for rare earth magnet, apparatus for evaluating raw material alloy for rare earth magnet, and manufacturing method of rare earth magnet

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08269643A (en) * 1995-03-29 1996-10-15 Sumitomo Special Metals Co Ltd Cast strip for r-fe-b magnetic alloy and its production
CN1457497A (en) * 2001-05-30 2003-11-19 住友特殊金属株式会社 Method of making sintered compact for rare earth magnet
WO2013008756A1 (en) * 2011-07-08 2013-01-17 昭和電工株式会社 Alloy for r-t-b-based rare earth sintered magnet, process for producing alloy for r-t-b-based rare earth sintered magnet, alloy material for r-t-b-based rare earth sintered magnet, r-t-b-based rare earth sintered magnet, process for producing r-t-b-based rare earth sintered magnet, and motor

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2817624B2 (en) * 1994-06-29 1998-10-30 昭和電工株式会社 Rare earth magnet alloy manufacturing method
JP3536943B2 (en) * 1994-12-21 2004-06-14 昭和電工株式会社 Alloy for rare earth magnet and method for producing the same
JPH08264363A (en) * 1995-03-24 1996-10-11 Hitachi Metals Ltd Manufacture of rare earth permanent magnet
JP4442597B2 (en) * 2001-06-22 2010-03-31 日立金属株式会社 Rare earth magnet and manufacturing method thereof
JP4689652B2 (en) * 2002-11-22 2011-05-25 昭和電工株式会社 Method for evaluating metal structure of RTB-based magnet alloy
EP1749599B1 (en) * 2004-04-30 2015-09-09 Hitachi Metals, Ltd. Methods for producing raw material alloy for rare earth magnet, powder and sintered magnet
US20100230013A1 (en) * 2007-12-13 2010-09-16 Showa Denko K.K. R-t-b alloy, process for production of r-t-b alloy, fine powder for r-t-b rare earth permanent magnets, and r-t-b rare earth permanent magnet
JP2011199069A (en) * 2010-03-19 2011-10-06 Tdk Corp Method for manufacturing rare earth sintered magnet, and material for the rare earth sintered magnet
JP5753481B2 (en) * 2011-11-28 2015-07-22 中央電気工業株式会社 Rare earth alloy and method for producing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08269643A (en) * 1995-03-29 1996-10-15 Sumitomo Special Metals Co Ltd Cast strip for r-fe-b magnetic alloy and its production
CN1457497A (en) * 2001-05-30 2003-11-19 住友特殊金属株式会社 Method of making sintered compact for rare earth magnet
WO2013008756A1 (en) * 2011-07-08 2013-01-17 昭和電工株式会社 Alloy for r-t-b-based rare earth sintered magnet, process for producing alloy for r-t-b-based rare earth sintered magnet, alloy material for r-t-b-based rare earth sintered magnet, r-t-b-based rare earth sintered magnet, process for producing r-t-b-based rare earth sintered magnet, and motor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108133796A (en) * 2017-12-11 2018-06-08 北京科技大学 A kind of preparation method of sintered magnet NdFeB magnetic powder
CN108133796B (en) * 2017-12-11 2019-10-22 北京科技大学 A kind of preparation method of sintered magnet NdFeB magnetic powder
CN108831648A (en) * 2018-06-21 2018-11-16 宁波招宝磁业有限公司 The method of spray drying preparation performance Nd Fe B sintered magnet

Also Published As

Publication number Publication date
JP6005263B2 (en) 2016-10-12
CN105189805B (en) 2017-06-30
WO2014174795A1 (en) 2014-10-30
JPWO2014174795A1 (en) 2017-02-23

Similar Documents

Publication Publication Date Title
US7431070B2 (en) Rare earth magnet alloy ingot, manufacturing method for the same, R-T-B type magnet alloy ingot, R-T-B type magnet, R-T-B type bonded magnet, R-T-B type exchange spring magnet alloy ingot, R-T-B type exchange spring magnet, and R-T-B type exchange spring bonded magnet
CN103858185B (en) R-T-B based sintered magnet and production method for same, and rotary machine
KR101036968B1 (en) R-t-b type alloy and production method thereof, fine powder for r-t-b type rare earth permanent magnet, and r-t-b type rare earth permanent magnet
JP6005257B2 (en) Raw material alloy for RTB-based magnet and method for producing the same
KR20090033829A (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
CN101888909A (en) R-T-B alloy, process for production of R-T-B alloy, fine powder for r-t-b rare earth permanent magnets, and R-T-B rare earth permanent magnets
US6797081B2 (en) Centrifugal casting method, centrifugal casting apparatus, and cast alloy produced by same
JP4879503B2 (en) Alloy block for RTB-based sintered magnet, manufacturing method thereof and magnet
CN105189805A (en) Raw material alloy for R-T-B-based magnet
JP4479944B2 (en) Alloy flake for rare earth magnet and method for producing the same
CN104114305B (en) R-T-B-Ga series magnet raw alloy and manufacture method thereof
JP4689652B2 (en) Method for evaluating metal structure of RTB-based magnet alloy
TW567104B (en) The method for controlling inside texture of alloy containing rare earth elements, the powder of aforementioned alloy and the magnetic stone made by it
JP4449900B2 (en) Method for producing rare earth alloy powder and method for producing rare earth sintered magnet
WO2003020993A1 (en) Rare earth magnet alloy ingot, manufacturing method for the same, r-t-b type magnet alloy ingot, r-t-b type magnet, r-t-b type bonded magnet, r-t-b type exchange spring magnet alloy ingot, r-t-b type exchange spring magnet, and r-t-b type exchange spring bonded magnet
CN1860248A (en) Raw material alloy for r-t-b permanent magnet and r-t-b permanent magnet
JP2003183787A (en) Principal phase-based alloy for rare earth magnet, manufacturing method therefor, mixed powder for sintered rare earth magnet, and rare earth magnet
CN109420771B (en) Thixotropic molding material, method for producing thixotropic molding material, and molded article
JP4754739B2 (en) Alloy ingot for rare earth magnet, method for producing the same, and sintered magnet
JP2004181531A (en) Method for producing rare-earth containing alloy flake, alloy flake for rare-earth magnet, alloy powder for rare-earth sintered magnet, rare-earth sintered magnet, alloy powder for bonded magnet and bonded magnet, and evaluation method for metallic structure
JP4574820B2 (en) Method for producing magnet powder for rare earth bonded magnet
EP1652606B1 (en) Centrifugal casting method, centrifugal casting apparatus, and cast alloy produced by same
JP2003303709A (en) Manufacturing method of nitrogen-atom bearing alloy for rare earth metal - iron-based permanent magnet
JP2005136355A (en) Method of manufacturing sintered rare-earth magnet

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C41 Transfer of patent application or patent right or utility model
TA01 Transfer of patent application right

Effective date of registration: 20160530

Address after: Wakayama County

Applicant after: Wakayama Rare Earth Co., Ltd.

Address before: Tokyo, Japan, Japan

Applicant before: Chuo Denki Kogyo Co., Ltd.

TA01 Transfer of patent application right
TA01 Transfer of patent application right

Effective date of registration: 20170524

Address after: Hyogo

Applicant after: Santoku Corp.

Address before: Wakayama County

Applicant before: Wakayama Rare Earth Co., Ltd.

GR01 Patent grant
GR01 Patent grant