CN105976958A - R-T-B series rare earth sintered magnet and alloy used for R-T-B series rare earth sintered magnet - Google Patents
R-T-B series rare earth sintered magnet and alloy used for R-T-B series rare earth sintered magnet Download PDFInfo
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- H—ELECTRICITY
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- 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
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Abstract
The invention relates to an R-T-B series rare earth sintered magnet. The R-T-B series rare earth sintered magnet is formed by rare earth element R, transition metal T using Fe as the main component, metal element M containing one than one kind of metal selected from Al, Ga, and Cu, and B and inevitable impurities. The rare earth sintered magnet contains 13-15.5 atom% of R, 5.0-6.0 atom% of B, 0.1-2.4 atom% of M, and with the balance being T and inevitable impurities. The transition metal T contains 0.015-0.10 atom% Zr.
Description
Technical field
The present invention relates to R-T-B based rare earth sintered magnet and R-T-B based rare earth sintered magnet alloy.
The Japanese Patent Application that the present invention filed an application in Japan based on March 13rd, 2015 No. 2015-051353 and 2015
The Japanese Patent Application 2015-236922 CLAIM OF PRIORITY that December is filed an application in Japan on the 3rd, is incorporated herein its content.
Background technology
In the past, R-T-B based rare earth sintered magnet (being the most sometimes abbreviated as " R-T-B based magnet ") was used for hard disk drive
The motor such as the electromotor motor of voice coil motor, hybrid vehicle or electric automobile.
R-T-B based magnet is by obtaining the R-T-B series alloy powder molding with Nd, Fe, B as main constituent sintering.
Generally, in R-T-B system alloy, R is Nd and the part replacing Nd with other rare earth element such as Pr, Dy, Tb.T
It is Fe and the part with other Transition metal substituted Fe such as Co, Ni.B is boron, can replace one part with C or N.
The tissue of general R-T-B based magnet is mainly made up of with rich R phase principal phase.Principal phase is made up of R2T14B.Rich R phase is
It is present in the crystal boundary of principal phase and the Nd concentration phase higher than principal phase.Rich R phase is also referred to as Grain-Boundary Phase.
For the composition of R-T-B system alloy, generally for the ratio of the principal phase in the tissue improving R-T-B based magnet, Nd
With the ratio of Fe and B to carry out (for example, referring to non-patent literature 1) in the way of R2T14B as far as possible.
Additionally, the R-T-B based magnet used in automobile motor is exposed under high temperature, therefore it is required that high is stupid in motor
Magnetic force (Hcj).
As the technology of the coercive force improving R-T-B based magnet, there is the skill that the R of R-T-B system alloy is substituted by Dy from Nd
Art.But, Dy not only resource is uneven, and yield is the most limited, therefore to its supply instability.Therefore, research has does not increases R-
The content of the Dy contained by T-B system alloy and make the technology that the coercive force of R-T-B based magnet improves.
The present inventor etc. have studied the composition of R-T-B system alloy, and it is it was found that be less than conventional R-T-B system
During the specific B concentration of alloy, coercive force improves.Then, even if the content successfully developing Dy is zero or considerably less, it is possible to
Obtain the R-T-B system alloy (for example, referring to patent documentation 1) of the R-T-B based magnet of high coercive force.
The R-T-B based magnet of the R-T-B system alloy manufacture that use the present inventor etc. is developed has by R2T14B
The principal phase that constitutes and compared with principal phase Grain-Boundary Phase containing a large amount of R.In this R-T-B based magnet, as Grain-Boundary Phase, contain
Divided by beyond the Grain-Boundary Phase (rich R phase) that the rare earth element concentration toward accreditation is high, also containing terres rares compared with conventional Grain-Boundary Phase
The Grain-Boundary Phase (rich transition metal phase) that concentration of element is low and transition metal concentration is high.Rich transition metal be mutually can undertake stupid
The phase of magnetic force, therefore rich transition metal is present in the R-T-B based magnet of Grain-Boundary Phase mutually is overturn conventional general knowledge epoch-making
Magnet.
Prior art literature
Patent documentation
Patent documentation 1: Japanese Unexamined Patent Publication 2013-216965 publication
Patent documentation 2: Japanese Unexamined Patent Publication 2014-27268 publication
Non-patent literature
Non-patent literature 1: assistant river true man, permanent magnet-material science and application on November 30th, 1, first edition the 2nd time
Printing distribution, page 256～page 261
Summary of the invention
The R-T-B based magnet that the present inventor etc. are developed shows high coercive force while the content of suppression Dy
(Hcj), but require improve coercive force further.
The present invention completes in view of the foregoing, and the purpose of the present inventor is to above-mentioned developed R-T-
B based magnet and R-T-B based rare earth sintered magnet alloy are improved further, thus provide one to have higher magnetic remanence
The R-T-B based rare earth sintered magnet of power (Hcj) and R-T-B based rare earth sintered magnet alloy.
The present invention is to solve above-mentioned problem, have employed following means.
(1) a kind of R-T-B based rare earth sintered magnet, it is characterised in that by rare earth element R, with Fe as main constituent
Transition metal T, metallic element M and B of more than the a kind metal contained in Al, Ga, Cu and inevitable impurity are constituted, and contain
The R of 13～15.5 atom %, containing the B of 5.0～6.0 atom %, M, T and inevitable impurity containing 0.1～2.4 atom % are it
Remaining part is divided, and, the Zr containing 0.015～0.10 atom % is as above-mentioned transition metal T.
(2) the R-T-B based rare earth sintered magnet as described in (1), it is characterised in that in Grain-Boundary Phase, above-mentioned Zr not with
Above-mentioned B forms compound.
(3) the R-T-B based rare earth sintered magnet as described in (1) or (2), it is characterised in that meet following (formula 1):
0.32≤B/TRE≤0.40 (formula 1)
In (formula 1), B represents the concentration (atom %) of boron element, and TRE represents rare earth element total concentration (atom %).
(4) a kind of R-T-B based rare earth sintered magnet alloy, it is characterised in that by rare earth element R, based on Fe
The transition metal T of composition, metallic element M and B containing more than a kind metal in Al, Ga, Cu and inevitable impurity
Constitute, containing the R of 13～15.5 atom %, containing the B of 5.0～6.0 atom %, the M, T containing 0.1～2.4 atom % with inevitable
Impurity is remainder, and the Zr containing 0.015～0.10 atom % is as above-mentioned transition metal T.
(5) the R-T-B based rare earth sintered magnet alloy as described in (4), it is characterised in that meet following (formula 1):
0.32≤B/TRE≤0.40 (formula 1)
In (formula 1), B represents the concentration (atom %) of boron element, and TRE represents rare earth element total concentration (atom %).
R-T-B based rare earth sintered magnet according to the present invention and R-T-B based rare earth sintered magnet alloy, Ke Yiti
Supply the R-T-B based rare earth sintered magnet with high coercive force and the R-T-B based rare earth sintering magnetic of the content of a kind of Dy of suppression
Ferrum alloy.
Accompanying drawing explanation
Fig. 1 is the front schematic view of the example manufacturing device representing alloy.
Fig. 2 be the embodiment 1 about the R-T-B based magnet being not added with Dy～6 and the content of Zr of comparative example 1～4 with stupid
The figure of the relation of magnetic force.
Fig. 3 is to represent the embodiment 1 about the R-T-B based magnet being not added with Dy～6 and the content of Zr of comparative example 1～4
Figure with the relation of rectangularity (Hk/Hcj).
Fig. 4 be represent the embodiment 7 about the R-T-B based magnet adding Dy～12 and comparative example 5～7 Zr content with
The figure of the relation of coercive force.
Fig. 5 be represent the embodiment 7 about the R-T-B based magnet adding Dy～12 and comparative example 5～7 Zr content with
The figure of the relation of rectangularity (Hk/Hcj).
Fig. 6 is the figure representing the observed result utilizing FE-EPMA, and (a) is the figure of embodiment 1, and (b) is the figure of comparative example 3.
Symbol description
1 ... manufacture device, 2 ... casting device, 3 ... heater, 4 ... storage container, 5 ... container, 6 ... chamber, 6a ...
Casting chamber, 6b ... tempering storage room, 7 ... hopper, 21 ... breaker, 31 ... heater, 32 ... open and close type mounting table group,
33 ... open and close type mounting table.
Detailed description of the invention
Hereinafter, the R-T-B based rare earth sintered magnet of an embodiment of the invention is described in detail.This
The bright embodiment being not limited to following description, suitably can change in the range of its purport and reality not changing
Execute.The R-T-B based rare earth sintered magnet of the present invention can also be without departing from containing other element in the range of the purpose of the present invention.
" R-T-B based rare earth sintered magnet "
The R-T-B based rare earth sintered magnet (being the most sometimes abbreviated as " R-T-B based magnet ") of present embodiment is by rare earth
Dvielement R, transition metal T with Fe as main constituent, metallic element M containing more than a kind metal in Al, Ga, Cu and
B and inevitable impurity are constituted.The R-T-B based magnet of the present embodiment R containing 13～15.5 atom %, former containing 5.0～6.0
The B of sub-%, M, T and inevitable impurity containing 0.1～2.4 atom % are remainder, as transition metal T containing 0.015～
The Zr of 0.10 atom %.
If the content of the R contained by R-T-B based magnet is less than 13 atom %, then the coercive force of R-T-B based magnet becomes not fill
Point.If additionally, the content of R is more than 15.5 atom %, then the residual magnetization step-down of R-T-B based magnet.
The R-T-B based magnet of present embodiment can be with or without Dy.As can be contained in R-T-B based magnet except Dy with
Outer rare earth element, can enumerate Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb, Lu.These rare earths
Dvielement particularly preferably uses Nd, Pr, Dy, Tb.Additionally, the R of R-T-B based magnet is preferably with Nd as main constituent.
Metallic element M contained by R-T-B based magnet is the metal of more than a kind in Al, Ga, Cu.Metallic element M institute
The metal of more than in Al, Ga, Cu a kind contained promotes the generation of rich transition metal phase when manufacturing R-T-B based magnet.Its
As a result, the coercive force (Hcj) making R-T-B based magnet is effectively improved.
In R-T-B based magnet, metallic element M contains 0.1～2.4 atom %.Therefore, when manufacturing R-T-B based magnet, promote
The generation of rich transition metal phase.If the metallic element M contained by R-T-B based magnet is less than 0.1 atom %, then promote rich transition metal
The generation of phase not sufficiently effective.It is as a result, it is possible to be formed without rich transition metal phase, R in R-T-B based magnet2T17Separate out mutually, R-
The coercive force (Hcj) of T-B based magnet becomes insufficient.
In order to generate rich transition metal phase fully, the content of the metallic element M contained by R-T-B based magnet is preferably 0.7
More than atom %.If additionally, the metallic element M contained by R-T-B based magnet is more than 2.4 atom %, the then magnetization of R-T-B based magnet
(Br), the magnetic characteristic such as Maximum Energy Product (BHmax) declines.In order to ensure magnetization and the Maximum Energy Product of R-T-B based magnet, R-T-
The content of the metallic element M contained by B based magnet is preferably 2.4 below atom %.
When metallic element M is containing Cu, become easy, for preferably for manufacturing the sintering of R-T-B based magnet.Metallic element M contains
During Cu, if the concentration of the Cu in R-T-B based magnet is less than 1.0 atom %, then the residual magnetization (Br) of R-T-B based magnet is good.
B contained by R-T-B based magnet is boron, can replace a part with C or N.B content is 5.0～6.0 atom %.Enter
And, the R-T-B based magnet of present embodiment preferably meets following (formula 1).In the present embodiment, if B content be above-mentioned scope,
Preferably B/TRE serves as reasons the scope that (formula 1) represents, then become the R-T-B based magnet that coercive force is high.The presumption of its reason is as follows.
0.32≤B/TRE≤0.40 (formula 1)
In (formula 1), B represents the concentration (atom %) of boron element, and TRE represents rare earth element total concentration (atom %).
If B content is above-mentioned scope, be preferably B/TRE is above-mentioned scope, then contained in R-T-B based magnet transition metal
Relative with the content of rare earth element become many.Its result, in the manufacturing process of R-T-B based magnet, utilizes metallic element M effective
Ground promotes the generation of rich transition metal phase.Therefore, R-T-B based magnet become generate fully have a rich transition metal phase there is height
The Magnet of coercive force.
It is additionally, if the content of the B in R-T-B based magnet is more than 6.0 atom %, then containing rich B phase in R-T-B based magnet, stupid
Magnetic force becomes insufficient.Therefore, the content of the B in R-T-B based magnet is set to 6.0 below atom %, is preferably set to 5.5 atom %
Below.
Additionally, the B/TRE represented by above-mentioned (formula 1) is 0.32～0.40, R-T-B based magnet is in order to obtain high magnetic remanence
Power, is further preferably set to 0.34～0.38.
Transition metal T contained by R-T-B based magnet, with Fe as main constituent, contains the Zr of 0.015～0.10 atom % further.
The lower limit of the content of Zr is preferably 0.017 atom %, more preferably 0.018 atom %.The upper limit of the content of Zr is preferably 0.04
Atom %, more preferably 0.03 atom %, more preferably 0.02 atom %.
By the content of Zr is set to this scope, while can making the high rectangularity of maintenance (Hk/Hcj), coercive force is high
R-T-B based magnet.
Known Zr plays the effect of the grain growth of suppression principal phase when for manufacturing the sintering of R-T-B based magnet.
The present inventor etc. conduct in-depth research, when it is it was found that the content of Zr is above-mentioned scope, and Ke Yiwei
Coercive force is improved while holding high rectangularity.That is, the content of Zr is reduced to the maximum amount not carrying out grain growth
Found that in the narrowest above-mentioned scope, while maintaining high rectangularity, improve coercive force.
The mechanism that when being above-mentioned scope to the content of Zr, coercive force uprises is speculated as follows.
Zr exists with 2 forms in R-T-B based magnet.One form in Fe site being to replace principal phase, another
The individual form being to be present in Grain-Boundary Phase as boride.If Zr replaces the Fe site of principal phase, then in sintering circuit, suppress crystal grain
Growth, therefore the coercive force of R-T-B based magnet improves.Additionally, boride carries out reacting by the B in Zr and Grain-Boundary Phase and gives birth to
Become, but Magnet characteristic is not affected.
In the manufacturing process of R-T-B based magnet, carry out replacement and the generation of boride in the Fe site of Zr simultaneously.At this
In embodiment, the content of B is low compared with common R-T-B based magnet, therefore there's almost no B in Grain-Boundary Phase.Therefore, excellent
First carry out the replacement in the Fe site of Zr.When the content of Zr is above-mentioned scope, carry out the replacement in the Fe site of Zr, suppress sintering circuit
In grain growth.
If the change compared with the higher limit of above-mentioned scope of the content of Zr is many, then Zr reacts with the B in principal phase, raw in Grain-Boundary Phase
Become boride.By this reaction, principal phase is decomposed, and therefore magnetization and the coercive force both of which of R-T-B based magnet declines.
If additionally, the content of Zr tails off compared with the lower limit of above-mentioned scope, then cannot suppress the crystalline substance of principal phase when sintering
Grain growth, its result, coercive force step-down.
The content of Zr compared with above-mentioned scope too much or very few time, coercive force all declines, therefore, its result, be clipped in it
During above-mentioned scope between, coercive force uprises.
The R-T-B based magnet of present embodiment content of B compared with conventional Magnet is low, is therefore practically free of at Grain-Boundary Phase
B.Therefore, Zr is mostly used in replacement Fe site, and the Zr reacted with the B of Grain-Boundary Phase is zero (nothing) or only has a small amount of.Therefore, recognize
For the content with the Zr less than conventional R-T-B based magnet, can get and make coercive force improve while maintaining high rectangularity
Effect.
In this manual " Zr does not forms compound with B " refer to Zr do not generate together with B compound situation and
Zr with B only generate cannot be observed in the observation image of electric field emission type electron ray microscopic analyzer (FE-EPMA) right
Should be in the situation of the compound of the amount of the degree of the bright spot of this compound.More specifically, refer to not observe in patent documentation 2
To being equivalent to constitute the situation of the bright spot corresponding to the compound of the phase containing Zr, B and C.
As the transition metal in addition to Fe, Zr contained by the T of R-T-B based magnet, it is possible to use various 3～11 units of race
Element.Specifically, such as, Co, Nb etc. can be enumerated.When the T of R-T-B based magnet also contains Co in addition to Fe, Tc (Curie can be improved
Temperature) and corrosion resistance, the most preferably.Additionally, as it has been described above, the T of R-T-B based magnet in addition to Fe also containing in the case of Nb,
When for manufacturing the sintering of R-T-B based magnet, the grain growth of principal phase is also suppressed, the most preferably.
T content ratio (T/B) relative to B content contained by R-T-B based magnet is preferably 13～15.5.If R-T-B system magnetic
The T/B of ferrum is above-mentioned scope, then the coercive force of R-T-B based magnet uprises further.If additionally, the T/B of R-T-B based magnet is 13
～15.5, then in the manufacturing process of R-T-B based magnet, the generation of rich transition metal phase is more effectively promoted.If R-T-B system
The T/B of Magnet is less than 15.5, more preferably less than 15, R the most during fabrication2T17R-T-B based magnet is difficult to generate, can
Obtain good coercive force and rectangularity.If additionally, the T/B of R-T-B based magnet is more than 13, more preferably more than 13.5, then
The residual magnetization of R-T-B based magnet is good.
The R-T-B based magnet of present embodiment possesses by R2T14B constitute principal phase and compared with principal phase containing a large amount of R's
Grain-Boundary Phase.Grain-Boundary Phase has the rich transition metal that the concentration of rich R phase and R is high less than the concentration of rich R phase and transition metal
Phase.Rich R phase is the phase that total atom concentration is 50 more than atom % of rare earth element.Rich transition metal is rare earth element mutually
Total atom concentration is the phase of 25～35 atom %.
The area occupation ratio of the rich transition metal phase contained by R-T-B based magnet is more preferably 0.005 area %～3 area %.If
In the area occupation ratio of rich transition metal phase is above-mentioned scope, then can more effectively obtain by caused mutually containing rich transition metal in Grain-Boundary Phase
Coercive force improve effect.On the other hand, if the area occupation ratio of rich transition metal phase is less than 0.005 area %, then R2T17Xiang Youke
Can separate out, the effect making coercive force (Hcj) improve becomes insufficient.If additionally, the area occupation ratio of rich transition metal phase is more than 3
Long-pending %, it is likely that cause the impact that under residual magnetization (Br), Maximum Energy Product ((BH) max), degradation is bad on magnetic characteristic, because of
This is the most preferred.
The area occupation ratio of the rich transition metal phase of R-T-B based magnet can be studied by method shown below.First, will
The resin of R-T-B based magnet embedment electric conductivity, cuts the face parallel with differently-oriented directivity, carries out mirror ultrafinish.It follows that with reflecting
Electronic image is observed through the surface of mirror ultrafinish with the multiplying power of about 1500 times, by its contrast differentiate principal phase, rich R phase,
Rich transition metal phase.Thereafter, the area occupation ratio in the middle of the cross section of rich transition metal phase is calculated.
The area occupation ratio of rich transition metal phase can be used as Magnet alloy (or the Magnet alloy and changing of raw material by regulation
Property alloy) composition, or adjust in sintering circuit described later, the 1st heat treatment step, the 2nd heat treatment step arbitrary
Individual heat treatment condition easily adjusts.
Rich transition metal mutually in the atomic concentration of Fe be preferably 50～70 atom %.If rich transition metal mutually in Fe
In atomic concentration is above-mentioned scope, is then improved effect by the coercive force caused mutually containing rich transition metal and become more notable.
" manufacture method of R-T-B based rare earth sintered magnet "
The manufacture method of the R-T-B based rare earth sintered magnet of the following description present invention.
(alloy manufacturing process)
The alloy of the R-T-B based rare earth sintered magnet of the present invention such as can pass through SC (thin strap continuous casting) method will such as
The alloy melt of the composition requirement of the temperature of about 1450 DEG C carries out casting and manufacturing casting alloy thin slice.At this time it is also possible to will
The rate of cooling of the casting alloy thin slice after casting carries out the expansion of the composition in promotion alloy at 700～900 DEG C of temporary delays
The process (temperature holding operation) dissipated.
Thereafter, by utilizing hydrogen crush method etc. to crush the casting alloy thin slice of gained, pulverizer is utilized to carry out powder
Broken and obtain R-T-B system alloy.
R-T-B based rare earth sintered magnet alloy by rare earth element R, transition metal T with Fe as main constituent, containing choosing
Metallic element M and B and the inevitable impurity of more than a kind metal in Al, Ga, Cu are constituted.Magnet with alloy containing 13～
The R of 15.5 atom %, containing the B of 5.0～6.0 atom %, M, T and inevitable impurity containing 0.1～2.4 atom % are its remaining part
Point, as the transition metal T Zr containing 0.15～0.10 atom %.R-T-B based rare earth sintered magnet alloy without containing Dy, but
Can also contain to obtain the coercive force of regulation.
And then, R-T-B based rare earth sintered magnet alloy preferably meets following (formula 1).
0.32≤B/TRE≤0.40 (formula 1)
In (formula 1), B represents the concentration (atom %) of boron element, and TRE represents rare earth element total concentration (atom %).
If the content of the R contained by R-T-B based rare earth sintered magnet alloy is less than 13 atom %, then it is used to obtain
The coercive force of R-T-B based magnet become insufficient.If additionally, the content of R is more than 15.5 atom %, then using the R-that it manufactures
The residual magnetization step-down of T-B based magnet.
As the rare earth element contained by R-T-B based rare earth sintered magnet alloy, can enumerate Sc, Y, La, Ce, Pr,
Nd、Pm、Sm、Eu、Gd、Dy、Tb、Ho、Er、Tm、Yb、Lu.Nd, Pr, Dy, Tb is particularly preferably used among these.Additionally, Magnet
With the R of alloy preferably with Nd as main constituent.
Metallic element M contained by R-T-B based rare earth sintered magnet alloy is more than a kind in Al, Ga, Cu
Metal.The metal of more than in Al, Ga, Cu a kind contained by metallic element M promotes rich mistake when manufacturing R-T-B based magnet
Cross the generation of metal phase.Its result, makes the coercive force (Hcj) of R-T-B based magnet be effectively improved.
R-T-B based rare earth sintered magnet alloy contains the metallic element M of 0.1～2.4 atom %.Therefore, by by magnetic
Ferrum alloy is sintered, heat treatment, can obtain containing rich R phase and the R-T-B based magnet of rich transition metal phase.If Magnet alloy
Contained metallic element M is less than 0.1 atom %, then the generation of the rich transition metal phase of promotion is not sufficiently effective.Itself as a result, it is possible to
Being formed without rich transition metal phase in R-T-B based magnet, the coercive force (Hcj) of R-T-B based magnet becomes insufficient.In order to fully
Generating rich transition metal phase, the content of the metallic element M contained by Magnet alloy is preferably 0.7 more than atom %.If additionally, magnetic
Metallic element M contained by ferrum alloy is more than 2.4 atom %, the then magnetization (Br) of R-T-B based magnet, Maximum Energy Product
Etc. (BHmax) magnetic characteristic declines.In order to ensure magnetization and the Maximum Energy Product of R-T-B based magnet, the gold contained by Magnet alloy
The content belonging to element M is preferably 2.4 below atom %.
When metallic element M is containing Ga, Ga is due to suppression R2T17The effect of the generation of phase is high, is therefore possible to prevent by generating R2T17
Coercive force caused by mutually, the decline of rectangularity.Therefore, metallic element M is preferably containing Ga.
When metallic element M is containing Cu, the sintering of Magnet alloy becomes easy, the most preferably.When metallic element M is containing Cu, if
The concentration of the Cu in Magnet alloy is less than 1.0 atom %, then use the remaining magnetic of the R-T-B based magnet of Magnet alloy manufacture
Change (Br) good.
B contained by R-T-B based rare earth sintered magnet alloy is boron, can replace a part with C or N.B content is
5.0～6.0 atom %, and rare earth element concentration meets above-mentioned (formula 1) relative to the ratio i.e. B/TRE of B concentration.Therefore, at this
In embodiment, the coercive force using the R-T-B based magnet that this Magnet alloy manufactures is high.Estimate its reason as follows.
If the B content of R-T-B based rare earth sintered magnet alloy and B/TRE are above-mentioned scope, then Magnet is used to close
The R-T-B based magnet that gold manufactures becomes the equally distributed Magnet of Grain-Boundary Phase, available high coercive force.Further, if Magnet closes
B content and the B/TRE of gold are above-mentioned scope, then contained in Magnet alloy transition metal is relative with the content of rare earth element
Change is many.Its result, in the manufacturing process of R-T-B based magnet, is effectively facilitated the generation of rich transition metal phase.Therefore, use
The R-T-B based magnet of this Magnet alloy manufacture becomes the Magnet generating rich transition metal phase fully, has high magnetic remanence
Power.
If the content of the B in R-T-B based rare earth sintered magnet alloy is less than 5.0 atom %, the most sometimes R2T17Xiang
Separating out in R-T-B Magnet, coercive force is not enough.If the content of the B in Magnet alloy is more than 6.0 atom %, then it is used to manufacture
R-T-B based magnet in containing rich B phase, coercive force becomes insufficient.Therefore, to be set to 6.0 former for the content of the B in Magnet alloy
Sub-below %, is preferably set to 5.5 below atom %.
T contained by R-T-B based rare earth sintered magnet alloy is with Fe as main constituent, former containing 0.015～0.10 further
The Zr of sub-%.The lower limit of the content of Zr is preferably 0.017 atom %, more preferably 0.018 atom %.The upper limit of the content of Zr is excellent
Elect 0.04 atom %, more preferably 0.03 atom %, more preferably 0.02 atom % as.
By Zr is set to this scope, use the R-T-B based magnet of this Magnet alloy manufacture can make maintenance rectangle
The R-T-B based magnet of high coercive force while property (Hk/Hcj).
T content ratio (T/B) relative to B content contained by R-T-B based rare earth sintered magnet alloy be preferably 13～
15.5.If the T/B of Magnet alloy is above-mentioned scope, then the coercive force of the R-T-B based magnet of Magnet alloy manufacture is used to enter
One step uprises.If additionally, the T/B of Magnet alloy is 13～15.5, then in the manufacturing process of R-T-B based magnet, more effectively
Ground promotes the generation of rich transition metal phase.If the T/B of Magnet alloy be less than 15.5, more preferably less than 15, then can be
Use and the R-T-B based magnet of Magnet alloy manufacture prevents from generate R2T17Phase, and can prevent coercive force, rectangularity from declining.This
Outward, if the T/B of Magnet alloy is more than 13, more preferably more than 13.5, then the R-T-B system magnetic that Magnet manufactures is used with alloy
The residual magnetization of ferrum becomes good.
If the total concentration of the oxygen, nitrogen and the carbon that contain as impurity etc. in R-T-B based rare earth sintered magnet alloy is high,
Then in sintering circuit, these elements are bonded with rare earth element R and consume rare earth element R.Thus, institute in Magnet alloy
As rich transition in the 1st heat treatment step carried out after sintering circuit in the rare earth element R contained and the 2nd heat treatment step
The quantitative change of the rare earth element R that the raw material of metal phase utilizes is few.Its result, the growing amount of rich transition metal phase likely tails off,
The coercive force of R-T-B based magnet becomes insufficient.
Therefore, it is former that the total concentration of contained in R-T-B based rare earth sintered magnet alloy oxygen, nitrogen and carbon is preferably 2
Sub-below %.It is former by the total concentration of oxygen, nitrogen and carbon contained in R-T-B based rare earth sintered magnet alloy is set to 2
Sub-below %, can suppress to consume rare earth element R in sintering circuit, it can be ensured that the growing amount of rich transition metal phase.Cause
This, the R-T-B based magnet that available coercive force (Hcj) is high.
R-T-B based rare earth sintered magnet alloy possesses by R2T14Principal phase that B is constituted and compared with principal phase containing a large amount of
The Grain-Boundary Phase of R.
As the example of operation of the alloy of the R-T-B based rare earth sintered magnet manufacturing the present invention, to use
The method manufacturing device manufacture shown in Fig. 1 illustrates.
(the manufacture device of alloy)
Fig. 1 is the front schematic view of the example manufacturing device representing alloy.
The manufacture device 1 of the alloy shown in Fig. 1 possesses: casting device 2, breaker 21, be configured at breaker 21
The heater 3 of lower section and be configured at the storage container 4 of lower section of heater 3.
The casting alloy block cast by casting device 2 is carried out broken and makes casting alloy thin slice by breaker 21.
As it is shown in figure 1, possess between breaker 21 and open and close type mounting table group 32, casting alloy thin slice is guided to heater 3
Open and close type mounting table group 32 on hopper 7.
Heater 3 is made up of heater 31 and container 5.Container 5 possesses storage container 4 and is arranged at storage container 4
The open and close type mounting table group 32 on top.Open and close type mounting table group 32 is made up of multiple open and close type mounting tables 33.Open and close type loads
Platform 33 loads the casting alloy thin slice supplied by breaker 21 when " closing ", makes the output of casting alloy thin slice to storage when "ON"
Hide container 4.
Additionally, manufacture device 1 possess the ribbon conveyer 51 (movable fixture) making container 5 can move freely, utilize band
Formula conveyer 51 makes container 5 to move by left and right directions in FIG.
Additionally, the manufacture device 1 shown in Fig. 1 possesses chamber 6.Chamber 6 possesses casting chamber 6a and is arranged at casting chamber 6a
Lower section and the tempering storage room 6b that connects with casting chamber 6a.Casting chamber 6a is accommodated with casting device 2, tempering storage room 6b
It is accommodated with heater 3.
In the present embodiment, for manufacturing the alloy of R-T-B based rare earth sintered magnet, first, do not scheming
The dissolver shown is prepared the alloy melt of the composition requirement of the temperature of about 1450 DEG C.It follows that the alloy of gained is melted
Body uses not shown tundish supply to make it solidify to the chill roll 22 being made up of water-cooled copper roller of casting device 2, makes
Casting alloy.Thereafter, make casting alloy depart from from chill roll 22, by crushing between the breaker roll of breaker 21,
Thus make casting alloy thin slice.
Broken casting alloy thin slice by hopper 7, be piled up in be configured at hopper 7 lower section be in open and close type mounting table
In the open and close type mounting table 33 of the state of " the closing " of group 32.The casting alloy thin slice being piled up in open and close type mounting table 33 is utilized
Heater 31 heats.
In the present embodiment, to the casting alloy more than 800 DEG C manufactured till its temperature become less than 500 DEG C
Period maintains the temperature of 10 seconds～120 seconds to keep operation at a certain temperature.In the present embodiment, carry at open and close type
Put the casting alloy thin slice within the temperature range of supplying 800 DEG C～500 DEG C on platform 33, be piled up in open and close type from casting alloy thin slice
Moment in mounting table 33 starts with heater 31 and heats.Thus, start to maintain casting alloy with certain temperature
The temperature of 10 seconds～120 seconds keeps operation.
Then, the casting alloy thin slice being piled up in open and close type mounting table 33 was made out in the moment of the time through regulation
Enclosed mounting table 33 becomes "open" state and falls to storage container 4.Thus, the heat of heater 31 cannot arrive casting alloy
Thin slice, recovers the cooling of casting alloy thin slice, and temperature keeps operation to terminate.
Estimating when carrying out temperature and keeping operation, the element contained by casting alloy is by the element of movement in casting alloy
Be reconfigured at, promote the replacement of the composition of metallic element M and B containing more than a kind metal in Al, Ga, Cu.Thus,
The part of the B contained by region that presumption becomes alloy Grain-Boundary Phase moves to principal phase, becomes the metal unit contained by the region of principal phase
A part of element M moves to alloy Grain-Boundary Phase.Thus, presumption can play principal phase Magnet characteristic originally, therefore uses its
The coercive force of R-T-B based magnet uprises.
When temperature keeps the temperature of the casting alloy in operation more than 800 DEG C, it is possible to alloy structure coarsening.Additionally,
Maintain time of certain temperature more than 120 seconds time, sometimes productivity ratio is caused obstacle.
Additionally, in the case of temperature keeps the temperature of the casting alloy in operation to be set to less than 500 DEG C or maintaining one
In the case of the time of fixed temperature was less than 10 seconds, sometimes cannot fully obtain carrying out temperature and keep the element of operation generation again
The effect of configuration.
It addition, in the present embodiment, load by open and close type will be piled up within the temperature range of 800 DEG C～500 DEG C
Casting alloy thin slice on platform 33 carries out temperature with the method that heater 31 carries out heating and keeps operation, as long as temperature keeps operation
Period till the temperature that the casting alloy more than 800 DEG C becomes less than 500 DEG C maintains 10 seconds～120 at a certain temperature
Second, it is not limited to the method.
Additionally, in the manufacture method of the alloy of the R-T-B based rare earth sintered magnet of present embodiment, preferably will system
The reduced pressure atmosphere of non-active gas it is set in making the chamber 6 of R-T-B system alloy.And then, in the present embodiment, preferably will casting
At least some of of operation is carried out in the environment containing helium.Helium is high from the ability of casting alloy heat extraction compared with argon, can be easily
Accelerate the rate of cooling of casting alloy.
As by least some of method carried out in the environment containing helium of casting process, such as, can enumerate at chamber 6
Casting chamber 6a in using regulation flow as non-active gas supply helium method.In this case, become in casting chamber 6a
For the environment containing helium, therefore can cool down efficiently and utilize casting device 2 to carry out casting and utilize chill roll 22 to carry out being quenched
In casting alloy with chill roll 22 not in contact with face.Therefore, the rate of cooling of casting alloy accelerates, and the particle diameter of alloy structure is micro-
Refinement, comminuted excellence, it is readily derived the fine alloy structure being spaced apart below 3 μm of alloy Grain-Boundary Phase, can improve
Use the coercive force of the R-T-B based magnet that it manufactures.Additionally, will be set to containing helium in casting chamber 6a environment time, casting alloy
Rate of cooling accelerates, and therefore can easily the temperature of the casting alloy thin slice being piled up in open and close type mounting table 33 be made
Less than 800 DEG C.
Additionally, in the manufacture method of the R-T-B system alloy of present embodiment, preferably temperature is kept the casting after operation
Alloy sheet cools down in the environment containing helium.Thus, the casting alloy thin slice of the casting alloy after operation is kept as temperature
Rate of cooling accelerates, therefore the further miniaturization of alloy structure, can be readily derived comminuted excellence, the interval of alloy Grain-Boundary Phase
It it is the fine alloy structure of below 3 μm.As temperature is kept the casting alloy thin slice after operation in the environment containing helium cold
But method, such as, can enumerate to contain in the storage container 4 of the casting alloy thin slice fallen from open and close type mounting table 33 with
The method of the flow supply helium of regulation.
It addition, in the present embodiment, use SC legal system is made the situation of the alloy of R-T-B based rare earth sintered magnet
It is illustrated, but the alloy of the R-T-B based rare earth sintered magnet used in the present invention is not limited to use SC legal system
The alloy made.Such as, the alloy of R-T-B based rare earth sintered magnet can also use centre spinning, booking etc. to enter
Row casting.
Hydrogen crush method is such as carried out by following method: at room temperature make hydrogen adsorption in casting alloy thin slice, at 300 DEG C
After the hydrogen of the temperature of left and right carries out heat treatment, carry out reducing pressure and the hydrogen degassing that will enter between the lattice of principal phase, thereafter,
Carry out heat treatment at a temperature of about 500 DEG C, remove the hydrogen being bonded with the rare earth element in Grain-Boundary Phase.Hydrogen crush method is inhaled
With the casting alloy thin slice of hydrogen due to volumetric expansion, therefore easily inside alloy, produce a large amount of be full of cracks (crackle) and crush.
Additionally, as the method pulverized by the casting alloy thin slice broken through hydrogen, jet mill etc. can be used.To break through hydrogen
Broken casting alloy thin slice is put into jet mill pulverizer, uses the elevated pressure nitrogen micropowder of such as 0.6MPa to be broken to particle mean size 1
～4.5 μm and make powder.The particle mean size reducing powder can make the coercive force of sintered magnet improve.But, if excessively subtracting
Small grain size, then powder surface is oxidized easily, and coercive force declines on the contrary.
(using the Magnet manufacturing process of alloy)
Then, the alloy using so obtained R-T-B based rare earth sintered magnet is manufactured the side of R-T-B based magnet
Method illustrates.
As the method for the R-T-B based magnet manufacturing present embodiment, such as, can enumerate and sinter magnetic at R-T-B based rare earth
The powder of the alloy of ferrum adds the zinc stearate of 0.02 mass %～0.03 mass % as lubricant, use transverse magnetic field
Middle forming machines etc. carry out extruded, sinter in a vacuum, thereafter, carry out heat-treating methods etc..
(sintering circuit)
After sintering, at 400 DEG C～800 DEG C, heat is carried out at 800 DEG C～1200 DEG C, more preferably at 900 DEG C～1200 DEG C
During process, R-T-B based magnet the most easily generates rich transition metal phase, available coercive force higher R-T-B based magnet.
In the present embodiment, in R-T-B system alloy, R is generated by meeting above-mentioned (formula 1)2T17Phase.Speculate R2T17
Heat treatment after R-T-B system alloy sintering is made R-T-B based magnet is used as the raw material of rich transition metal phase.
It can also be more than 2 times that heat treatment after sintering can simply be 1 time.Such as, the heat treatment after 1 sintering is only carried out
Time, preferably at 500 DEG C～530 DEG C, carry out heat treatment.During additionally, carry out the heat treatment after 2 sintering, preferably at 600 DEG C～
Heat treatment is carried out at a temperature of 2 stages of the temperature of the temperature of 950 DEG C and 400 DEG C～500 DEG C.
When carrying out heat treatment with the temperature in 2 stages, estimating as follows, the generation of rich transition metal phase is promoted, therefore
The R-T-B based magnet that available coercive force is more excellent.
That is, when carrying out heat treatment with the temperature in 2 stages, in the heat treatment of 600～950 DEG C of the 1st time, rich R phase becomes
Liquid phase and be surrounded on around principal phase.Thus, in the heat treatment of 400～500 DEG C of the 2nd time, rich R phase and R2T17Phase and metal
The reaction of element M is promoted, and the generation of rich transition metal phase is promoted.
In the manufacture method of the R-T-B based magnet of present embodiment, use B content to meet above-mentioned (formula 1) and containing 0.1～
The alloy of the metallic element M of 2.4 atom % is as R-T-B system alloy, therefore main containing R by possessing2Fe14The principal phase of B and with
Principal phase is compared the sintered body of the Grain-Boundary Phase containing a large amount of R and is constituted, and the total atom concentration of available Grain-Boundary Phase containing rare earth element is 70
This of the rich R phase of more than atom % and rich transition metal phase that the total atom concentration of rare earth element is 25～35 atom %
Bright R-T-B based magnet.
And then, by by the kind of the metallic element contained by the R-T-B system alloy of present embodiment or usage amount, containing R2T17
The area occupation ratio in the region of phase, the composition of R-T-B system alloy regulate within the scope of the invention, and adjust sintering temperature or sintering
After the condition such as heat treatment, the area occupation ratio of the rich transition metal phase in R-T-B based magnet can be easily adjusted be 0.005～
The preferred scope of 3 area %.Then, by adjusting the area occupation ratio of the rich transition metal phase in R-T-B based magnet, can be suppressed
There is while the content of Dy the R-T-B based magnet of the coercive force of the regulation according to purposes.
Additionally, speculate in the R-T-B based magnet of the present invention, first the effect making the coercive force (Hcj) of gained improve is
Owing to being formed with the rich transition metal phase containing Fe with high concentration in Grain-Boundary Phase.Rich mistake contained by the R-T-B based magnet of the present invention
Cross the area occupation ratio of metal phase and be preferably 0.005～3 area %, more preferably 0.1%～2 area %.
If in the area occupation ratio of rich transition metal phase is above-mentioned scope, then can more effectively obtain by Grain-Boundary Phase contains rich transition
The coercive force raising effect that metal is caused mutually.On the other hand, if the area occupation ratio of rich transition metal phase is less than 0.005 area %, then
There is a possibility that the effect that coercive force (Hcj) improves becomes insufficient.If additionally, the area occupation ratio of rich transition metal phase is more than 3
Long-pending %, then cause the degradation harmful effect to magnetic characteristic under residual magnetization (Br), Maximum Energy Product ((BH) max), the most excellent
Choosing.
And then, thus it is speculated that in the R-T-B based magnet of the present invention, make effect that the coercive force (Hcj) of gained improves next to that
Transition metal T contained by R-T-B based magnet, with Fe as main constituent, contains the Zr of 0.015～0.10 atom % further, thus
The grain growth of principal phase during suppression sintering, and reduce the formation at Grain-Boundary Phase Yu the compound of boron (B).
Rich transition metal mutually in the atomic concentration of Fe be preferably 50～70 atom %.If rich transition metal mutually in Fe
In atomic concentration is above-mentioned scope, then can more effectively obtain by the effect caused mutually containing rich transition metal.On the other hand, if rich
The atomic concentration of the Fe of transition metal phase is less than above-mentioned scope, it is likely that by caused stupid mutually containing rich transition metal in Grain-Boundary Phase
Magnetic force (Hcj) improves effect and becomes insufficient.If additionally, the atomic concentration of the Fe of rich transition metal phase is more than above-mentioned scope, then
Likely separate out R2T17Mutually or Fe and magnetic characteristic is had undesirable effect.
B/TRE content is met above-mentioned (formula 1) and containing 0.1～2.4 atom % by the R-T-B based magnet of present embodiment
The R-T-B system alloy of metallic element M is shaped and sinters, and Grain-Boundary Phase is containing rich R phase and rich transition metal phase, rich transition
Metal is the phase that the total atom concentration of rare earth element is higher than rich R phase less than the atomic concentration of rich R phase, Fe mutually, therefore in suppression
While the content of Dy, there is high coercive force, there is the excellent magnetic characteristic being suitable for motor.
It addition, in the present embodiment, Dy metal or Dy compound is made to be attached to the surface of the R-T-B based magnet after sintering
And carry out heat treatment, make Dy be spread in inside sintered magnet, such that it is able to make the Dy concentration on sintered magnet surface higher than inside
The R-T-B based magnet of Dy concentration, make coercive force improve further.
The method being higher than the R-T-B based magnet of internal Dy concentration as the Dy concentration manufacturing sintered magnet surface, specifically
For, method shown below can be enumerated.Such as, by by ethanol equal solvent and dysprosium fluoride (DyF3) mix with the ratio of regulation
R-T-B based magnet after impregnation sintering in the coating fluid closed, by coating solution in R-T-B based magnet.Thereafter, to coating
The R-T-B based magnet having coating fluid is diffused operation, and this diffusing procedure carries out the heat treatment in 2 stages.Specifically, carry out by
It is coated with the R-T-B based magnet of the liquid temperature with 900 DEG C in argon environment and heats the 1st heat treatment of about 1 hour, by the
R-T-B based magnet after 1 heat treatment is temporarily cooled to room temperature.Thereafter, carry out again by R-T-B based magnet in argon environment with
The temperature of 500 DEG C heats the 2nd heat treatment of about 1 hour, is cooled to room temperature.
It is attached to the surface of R-T-B based magnet as make Dy metal or the Dy compound after sintering in addition to the method described above
Method, it is possible to use make Metal gasification and make these films be attached to the method for magnet surface, make organic metal decompose and make film
It is attached to the method etc. on surface.
Alternatively, it is also possible to the surface of R-T-B based magnet after sintering, Tb metal or Tb compound are replaced Dy metal or
Dy compound and make it adhere to and carry out heat treatment.In this case, such as, by the coating solution of the fluoride containing Tb in
The surface of the R-T-B based magnet after sintering and carry out heat treatment, make Tb in sintered magnet diffusion inside, such that it is able to make sintering
The Tb concentration of magnet surface, higher than the R-T-B based magnet of internal Tb concentration, can make coercive force improve further.
Furthermore, it is possible to make metal Dy, metal Tb be deposited with carry out heat treatment in the surface of R-T-B based magnet, Dy, Tb is made to exist
Sintered magnet diffusion inside, so that coercive force improves further.Can be the most any to the R-T-B based magnet of present embodiment
Obstacle ground uses this technology.
The coercive force (Hcj) of R-T-B based magnet is the highest more preferred, and the motor at the electric motor driven power steering as automobile etc. is used
Magnet time, preferably more than 20kOe, during as the Magnet of the motor of electric automobile, preferably more than 30kOe.Electronic
If coercive force (Hcj) is less than 30kOe in the Magnet of the motor of automobile, the thermostability as motor is not enough the most sometimes.
Embodiment
" embodiment 1～12, comparative example 1～7 "
By Nd metal (more than purity 99wt%), Pr metal (more than purity 99wt%), Dy metal (purity 99wt% with
On), ferro-boron (Fe80%, B20w%), iron block (more than purity 99%wt), Al metal (more than purity 99wt%), Ga metal (pure
Degree more than 99wt%), Cu metal (purity 99wt%), Co metal (more than purity 99wt%), Zr metal (purity 99wt% with
On) weigh in the way of becoming the alloy composition of alloy A～S shown in Tables 1 and 2, fill in alumina crucible.
Table 1 represents the alloy without Dy, and table 2 represents the alloy containing Dy.
[table 1]
It is not added with Dy Magnet composition at%
| Alloy name | TFE | Nd | Pr | Al | Fe | Ga | Cu | Co | Zr | B | |
| Comparative example 1 | A | 15.34 | 11.35 | 3.99 | 0.51 | bal. | 0.48 | 0.14 | 0.99 | 0.000 | 5.16 |
| Comparative example 2 | B | 15.29 | 11.33 | 3.96 | 0.40 | bal. | 0.47 | 0.12 | 1.04 | 0.008 | 5.14 |
| Embodiment 1 | C | 15.30 | 11.33 | 3.96 | 0.40 | bal. | 0.47 | 0.12 | 1.04 | 0.015 | 5.16 |
| Embodiment 2 | D | 15.32 | 11.34 | 3.98 | 0.40 | bal. | 0.50 | 0.12 | 1.04 | 0.017 | 5.18 |
| Embodiment 3 | E | 15.32 | 11.32 | 4.00 | 0.41 | bal. | 0.50 | 0.12 | 1.05 | 0.018 | 5.17 |
| Embodiment 4 | F | 15.35 | 11.33 | 3.97 | 0.41 | bal. | 0.48 | 0.12 | 1.03 | 0.036 | 5.19 |
| Embodiment 5 | G | 15.32 | 11.35 | 3.97 | 0.41 | bal. | 0.48 | 0.12 | 1.00 | 0.071 | 5.15 |
| Embodiment 6 | H | 15.34 | 11.36 | 3.98 | 0.40 | bal. | 0.47 | 0.12 | 1.02 | 0.100 | 5.16 |
| Comparative example 3 | I | 15.41 | 11.37 | 4.03 | 0.44 | bal. | 0.49 | 0.13 | 1.00 | 0.119 | 5.19 |
| Comparative example 4 | J | 15.32 | 11.32 | 4.00 | 0.41 | bal. | 0.50 | 0.12 | 1.05 | 0.305 | 5.17 |
[table 2]
Add Dy Magnet composition at%
| TRE | Nd | Pr | Dy | Al | Fe | Ga | Cu | Co | Zr | B | ||
| Comparative example 5 | K | 14.63 | 10.19 | 3.63 | 0.81 | 0.43 | bal. | 0.48 | 0.15 | 0.99 | 0.000 | 5.33 |
| Embodiment 7 | L | 14.65 | 10.19 | 3.63 | 0.82 | 0.43 | bal. | 0.48 | 0.15 | 0.99 | 0.015 | 5.33 |
| Embodiment 8 | M | 14.60 | 10.15 | 3.62 | 0.83 | 0.42 | bal. | 0.48 | 0.14 | 1.00 | 0.017 | 5.34 |
| Embodiment 9 | N | 14.66 | 10.18 | 3.64 | 0.84 | 0.42 | bal. | 0.48 | 0.15 | 0.99 | 0.018 | 5.30 |
| Embodiment 10 | O | 14.66 | 10.20 | 3.63 | 0.83 | 0.42 | bal. | 0.48 | 0.14 | 0.99 | 0.026 | 5.28 |
| Embodiment 11 | P | 14.59 | 10.16 | 3.60 | 0.83 | 0.42 | bal. | 0.48 | 0.14 | 1.00 | 0.065 | 5.36 |
| Embodiment 12 | Q | 14.62 | 10.17 | 3.61 | 0.84 | 0.42 | bal. | 0.48 | 0.14 | 1.00 | 0.100 | 5.30 |
| Comparative example 6 | R | 14.58 | 10.10 | 3.61 | 0.86 | 0.42 | bal. | 0.48 | 0.13 | 0.99 | 0.117 | 5.40 |
| Comparative example 7 | S | 14.57 | 10.12 | 3.62 | 0.83 | 0.41 | bal. | 0.47 | 0.14 | 0.99 | 0.399 | 5.35 |
Thereafter, alumina crucible is arranged in high-frequency vacuum electric induction furnace, will replace with Ar in stove.Then, by high frequency
Vacuum induction furnace is heated to 1450 DEG C and makes alloy molten make motlten metal.Thereafter, melted gold is injected to water-cooled copper roller
Belong to, cast casting alloy by SC (thin strap continuous casting) method.Now, the peripheral speed of water-cooled copper roller is set to the 1.0m/ second, will be molten
The average thickness melting metal is set to about 0.3mm.Thereafter, casting alloy is crushed and obtain casting alloy thin slice.
Then, casting alloy thin slice is crushed by hydrogen crush method shown below.First, by casting alloy thin slice
In the way of becoming diameter about 5mm, carry out coarse pulverization, be inserted in the hydrogen of room temperature and make hydrogen adsorption.It follows that carry out slightly
The heat treatment pulverized and make the casting alloy thin slice of hydrogen adsorption be heated to 300 DEG C in hydrogen.Thereafter, break by the following method
Broken: to carry out reducing pressure and the hydrogen between the lattice of principal phase is deaerated, carry out being heated to the heat treatment of 500 DEG C further and release removing crystalline substance
Boundary mutually in hydrogen, be cooled to room temperature.
Then, the casting alloy thin slice broken through hydrogen is added zinc stearate 0.025wt% as lubricant, utilization injection
Grinding machine (Hosokawa Micron 100AFG) uses the elevated pressure nitrogen of 0.6MPa by the casting alloy thin slice Crushing of Ultrafine broken through hydrogen
R-T-B series alloy powder is obtained to particle mean size (d50) 4.5 μm.
Then, so obtained R-T-B series alloy powder is added 0.02 mass %～the zinc stearate of 0.03 mass %
As lubricant, in use transverse magnetic field, forming machine is with briquetting pressure 0.8t/cm2Carry out extruded and make molded body.
Thereafter, the molded body being made up of alloy is arranged in the pallet of carbon, the tray arrangement of molded body will have been put into
In heat-treatment furnace, it is decompressed to 0.01Pa.It follows that carry out heat treatment at 500 DEG C for the purpose of organic removing, with
Being decomposed into purpose of hydride and at 800 DEG C, carry out heat treatment, at 1000～1100 DEG C, carry out heat to be sintered to purpose
Process, obtain sintered body (sintering circuit).
Thereafter, at a temperature of 2 stages of 800 DEG C and 500 DEG C, sintered body is carried out heat treatment, cooling, thus obtain reality
Execute example 1～12 and the R-T-B based magnet of comparative example 1～7.
It follows that by the embodiment 1 of gained～12 and the respective magnetic characteristic of R-T-B based magnet of comparative example 1～7 with arteries and veins
Stamp BH curve plotter (east English industry TPM2-10) measures.The results are shown in table 3.
[table 3]
Coercive force, Hk/Hci catalog
| Alloy name | Coercive force (kOe) | Hk/Hcj | |
| Comparative example 1 | A | 18.56 | 0.48 |
| Comparative example 2 | B | 20.05 | 0.63 |
| Embodiment 1 | C | 20.17 | 0.92 |
| Embodiment 2 | D | 20.19 | 0.92 |
| Embodiment 3 | E | 20.22 | 0.92 |
| Embodiment 4 | F | 19.74 | 0.91 |
| Embodiment 5 | G | 19.64 | 0.91 |
| Embodiment 6 | H | 19.55 | 0.90 |
| Comparative example 3 | I | 19.45 | 0.89 |
| Comparative example 4 | J | 19.20 | 0.88 |
| Comparative example 5 | K | 19.91 | 0.88 |
| Embodiment 7 | L | 21.75 | 0.90 |
| Embodiment 8 | M | 21.92 | 0.91 |
| Embodiment 9 | N | 22.15 | 0.92 |
| Embodiment 10 | O | 22.30 | 0.92 |
| Embodiment 11 | P | 22.04 | 0.92 |
| Embodiment 12 | Q | 21.80 | 0.92 |
| Comparative example 16 | R | 21.60 | 0.92 |
| Comparative example 7 | S | 21.30 | 0.90 |
" Hcj " refers to coercive force in table 3, and " Hk/Hcj " refers to based on Br, (" Br " refers to residual magnetization.) it is 90%
The rectangularity of the ratio of Hk Yu Hcj that calculates of the form of H.The value of these magnetic characteristics is the mensuration of 3 R-T-B based magnets respectively
Be worth is average.
Fig. 2 is to represent the embodiment 1 about the R-T-B based magnet being not added with Dy～6 and the containing of Zr of comparative example 1～4
The figure of the relation of amount and coercive force.
As shown in Figure 2, coercive force reduces along with the content of Zr from 0.305 atom % and slowly uprises, former 0.02
Become maximum during sub-%, drastically decline when minimizing from 0.01 atom %.Understand before and after 0.02 atom %, there is display spy
The Zr concentration range of not high coercive force.
Fig. 3 is to represent the embodiment 1 about the R-T-B based magnet being not added with Dy～6 and the content of Zr of comparative example 1～4
Figure with the relation of rectangularity (Hk/Hcj).
From the figure 3, it may be seen that rectangularity (Hk/Hcj) reduces along with the content of Zr from 0.305 atom % and slowly uprises,
Become maximum near 0.02 atom %, drastically decline when minimizing from 0.015 atom %.Before understanding near 0.02 atom %
Rear there is the Zr concentration range that rectangularity is the best.Rectangularity is preferably more than 0.9 in practical.
Fig. 4 be represent the embodiment 7 about the R-T-B based magnet adding Dy～12 and comparative example 5～7 Zr content with
The figure of the relation of coercive force.
As shown in Figure 4, coercive force reduces along with the content of Zr from 0.399 atom % and slowly uprises, and is being reduced to less
When 0.03 atom %, become maximum, the degree identical with the coercive force of 0.10 atom % when 0.015 atom %, from
0.015 atom % is remarkably decreased when playing minimizing.For add Dy R-T-B based magnet, also know that with the R-T-B being not added with Dy
Near the content of the Zr of based magnet same degree, coercive force becomes maximum.
Fig. 5 be represent the embodiment 7 about the R-T-B based magnet adding Dy～12 and comparative example 5～7 Zr content with
The figure of the relation of rectangularity (Hk/Hcj).
As shown in Figure 5, rectangularity (Hk/Hcj) is even if the content minimizing of Zr is also maintained at high shape from 0.399 atom %
State, begins to decline when being reduced to less than 0.02 atom %, is 0.9 when 0.015 atom %, is subtracting from 0.015 atom %
Time few, decline monotonously till being 0.88 when at 0 atom %.
After being ground respectively by the R-T-B based magnet of each sample, utilize electric field emission type electron ray microscopic analyzer (FE-
EPMA) observe abradant surface, carry out forming map analysis.
Fig. 6 (a), (b) are the figures representing the observed result utilizing FE-EPMA, and Fig. 6 (a) is the figure of embodiment 1, Fig. 6 (b)
It it is the figure of comparative example 3.
In Fig. 6 (b), as be depicted with arrows, Grain-Boundary Phase observe substantial amounts of with containing Zr and the chemical combination of boron (B)
Bright bright spot corresponding to thing, on the other hand, in Fig. 6 (a), that does not observes with corresponding to this compound is bright bright
Point.
Claims (7)
1. a R-T-B based rare earth sintered magnet, it is characterised in that by rare earth element R, with Fe as main constituent transition gold
Belong to T, metallic element M and B containing more than a kind metal in Al, Ga, Cu and inevitable impurity to constitute, containing 13～
The R of 15.5 atom %, containing the B of 5.0～6.0 atom %, M, T and inevitable impurity containing 0.1～2.4 atom % are its remaining part
Point,
Further, the Zr containing 0.015～0.10 atom % is as described transition metal T.
2. R-T-B based rare earth sintered magnet as claimed in claim 1, it is characterised in that in Grain-Boundary Phase, described Zr not with
Described B forms compound.
3. R-T-B based rare earth sintered magnet as claimed in claim 1 or 2, it is characterised in that meet following formula 1:0.32≤
B/TRE≤0.40 formula 1
In formula 1, B represents the concentration in terms of atom % of boron element, and TRE represents the denseest in terms of atom % of rare earth element
Degree.
4. the R-T-B based rare earth sintered magnet as according to any one of claims 1 to 3, it is characterised in that containing 0.015～
The Zr of 0.02 atom %.
5. a R-T-B based rare earth sintered magnet alloy, by rare earth element R, transition metal T with Fe as main constituent,
Metallic element M and B and inevitable impurity containing more than a kind metal in Al, Ga, Cu are constituted, former containing 13～15.5
The R of sub-%, containing the B of 5.0～6.0 atom %, M, T and inevitable impurity containing 0.1～2.4 atom % are remainder, its
It is characterised by,
Zr containing 0.015～0.10 atom % is as described transition metal T.
6. R-T-B based rare earth sintered magnet alloy as claimed in claim 5, it is characterised in that meet following formula 1:
0.32≤B/TRE≤0.40 formula 1
In formula 1, B represents the concentration in terms of atom % of boron element, and TRE represents the denseest in terms of atom % of rare earth element
Degree.
7. the R-T-B based rare earth sintered magnet alloy as described in claim 5 or 6, it is characterised in that containing 0.015～
The Zr of 0.02 atom %.
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| JP2015236922A JP6672753B2 (en) | 2015-03-13 | 2015-12-03 | RTB based rare earth sintered magnet and alloy for RTB based rare earth sintered magnet |
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