JPH05315120A - Rare earth sintered magnet and its manufacture - Google Patents
Rare earth sintered magnet and its manufactureInfo
- Publication number
- JPH05315120A JPH05315120A JP4115845A JP11584592A JPH05315120A JP H05315120 A JPH05315120 A JP H05315120A JP 4115845 A JP4115845 A JP 4115845A JP 11584592 A JP11584592 A JP 11584592A JP H05315120 A JPH05315120 A JP H05315120A
- Authority
- JP
- Japan
- Prior art keywords
- phase
- rare earth
- coercive force
- temperature
- sintered magnet
- 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.)
- Pending
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/0009—Antiferromagnetic materials, i.e. materials exhibiting a Néel transition temperature
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Powder Metallurgy (AREA)
- Hard Magnetic Materials (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、R(ただしRはPr,
Ndを主成分とする希土類元素),Fe,B,Cuを原
料基本成分とする希土類焼結磁石とその製造方法に関す
るものである。The present invention relates to R (where R is Pr,
The present invention relates to a rare earth sintered magnet containing Nd as a main component, Fe, B, and Cu as raw material basic components, and a method for manufacturing the same.
【0002】[0002]
【従来の技術】R−Fe−B系永久磁石は、極めて高い
保磁力とエネルギー積を持つ永久磁石として、1983年の
発表以来、多くの研究開発がなされている。2. Description of the Related Art R-Fe-B system permanent magnets have been much researched and developed since the announcement in 1983 as permanent magnets having extremely high coercive force and energy product.
【0003】R−Fe−B系異方性永久磁石の製造方法
として挙げられるのは、粉末冶金的な手段による焼結
法、急冷薄帯をプレスして機械的に配向させるダイアッ
プセット法、鋳造インゴットを直接熱間加工して配向さ
せる鋳造・熱間加工法があるが、このうち工業的に確立
されているのは焼結法によるものである。Examples of the method for producing the R-Fe-B anisotropic permanent magnet include a sintering method by a powder metallurgical means, a die upset method of pressing a quenched ribbon and mechanically orienting it. There is a casting / hot working method in which a cast ingot is directly hot worked and oriented, and the industrially established method is the sintering method.
【0004】R−Fe−B系焼結磁石に関する代表的文
献としてはM.Sagawa, S. Fujimura,N. Togawa, H.Yamam
oto and Y. Matsuura;J. Appl. Phys. Vol.55(6),15 Ma
rch1984,p2083 等が挙げられる。特許としては特開昭59
-46008号公報などが挙げられ、原子百分比で8〜30%のR
(ただしRはYを含む希土類元素の少なくとも1種)、
2〜28%のB及び残部Feからなる磁気異方性焼結体であ
ることを特徴とする永久磁石が粉末冶金法に基づく焼結
によって製造されることが開示されている。Representative documents concerning the R-Fe-B system sintered magnet are M. Sagawa, S. Fujimura, N. Togawa, H. Yamam.
oto and Y. Matsuura; J. Appl. Phys. Vol.55 (6), 15 Ma
rch1984, p2083 and the like. As a patent, JP 59
-46008 publication and the like, 8% to 30% R in atomic percentage
(Where R is at least one rare earth element including Y),
It is disclosed that a permanent magnet, which is a magnetic anisotropic sintered body composed of 2 to 28% B and the balance Fe, is manufactured by sintering based on a powder metallurgy method.
【0005】この焼結法では、溶解・鋳造により合金イ
ンゴットを作製し、粉砕して適当な粒度(数μm)の磁
性粉を得る。磁性粉は成形助剤のバインダーと混練さ
れ、磁場中でプレス成形されて成形体が出来上がる。成
形体はアルゴン中で1100℃前後の温度で1〜5時間程度
焼結され、その後室温まで急冷される。焼結後、600 ℃
前後の温度で熱処理する事により永久磁石はさらに保磁
力を向上させる。また、この焼結磁石の熱処理に関して
は特開昭61-217540号公報、特開昭62-165305 号公報等
に、多段熱処理の効果が開示されている。In this sintering method, an alloy ingot is produced by melting and casting and crushed to obtain a magnetic powder having an appropriate particle size (several μm). The magnetic powder is kneaded with a binder, which is a molding aid, and press-molded in a magnetic field to form a molded body. The compact is sintered in argon at a temperature of about 1100 ° C. for about 1 to 5 hours and then rapidly cooled to room temperature. 600 ° C after sintering
The permanent magnet further improves the coercive force by heat treatment at the temperature around. Regarding the heat treatment of this sintered magnet, the effects of multi-stage heat treatment are disclosed in JP-A-61-217540 and JP-A-62-165305.
【0006】保磁力向上の手段として、各種の添加元素
による効果も探索された。この中で最も効果のあったも
のは重希土類元素のDyの添加であった。Dyの添加に
より主相であるR2Fe14B相の磁気異方性定数が増大
し、結果として得られる磁石に於て高い保磁力が得られ
る。このようなDy添加の効果により、R−Fe−B系
焼結磁石は広範囲の用途に使用されつつある。As a means for improving the coercive force, the effects of various additive elements were also searched for. The most effective of these was the addition of the heavy rare earth element Dy. The addition of Dy increases the magnetic anisotropy constant of the R 2 Fe 14 B phase, which is the main phase, and a high coercive force can be obtained in the resulting magnet. Due to such an effect of adding Dy, the R—Fe—B system sintered magnet is being used for a wide range of applications.
【0007】また特開昭61-295355号公報などには、各
種ホウ化物相を含むR−Fe−B系焼結磁石が開示され
ている。これはホウ化物相が主相結晶粒の粒成長を抑制
する効果を有しており、そのため保磁力が向上するとい
うものである。Further, Japanese Patent Application Laid-Open No. 61-295355 discloses R-Fe-B based sintered magnets containing various boride phases. This is because the boride phase has the effect of suppressing the grain growth of the main phase crystal grains, and therefore the coercive force is improved.
【0008】[0008]
【発明が解決しようとする課題】上述したように、R−
Fe−B系焼結磁石においてDyの添加は高保磁力化の
非常に有効な手段である。しかし重希土類元素であるD
yは、その生産量・埋蔵量共に非常に少なく貴重な元素
であるため、その使用により大幅なコストアップを招
く。また希土類元素の資源バランスを考えた上でも、D
yを多量に使用することは好ましくない。As described above, R-
The addition of Dy is a very effective means of increasing the coercive force in the Fe-B system sintered magnet. However, D, which is a heavy rare earth element
Since y is a rare element which has a very small amount of production and reserves, its use causes a significant cost increase. In addition, considering the resource balance of rare earth elements, D
It is not preferable to use a large amount of y.
【0009】またホウ化物添加による主相結晶粒の粒成
長抑制効果による保磁力の向上は僅かである。製法上
も、ホウ化物の添加によって焼結性が劣化したり、軟磁
性相であるR2Fe17相が発生したりして磁気特性の低
下を引き起こすという欠点がある。Further, the improvement of the coercive force due to the grain growth suppressing effect of the main phase crystal grains by adding the boride is slight. Also in the manufacturing method, there is a drawback that the addition of the boride deteriorates the sinterability and the R 2 Fe 17 phase which is a soft magnetic phase is generated to deteriorate the magnetic properties.
【0010】本発明は以上の従来技術の欠点を解決する
ものであり、その目的とするところは、供給量の多い元
素を使用し、高特性とくに高保磁力を有する希土類焼結
磁石と、工業的に生産の容易なその製造方法を提供する
ところにある。The present invention solves the above-mentioned drawbacks of the prior art, and an object of the present invention is to use a rare earth sintered magnet having a high characteristic, particularly a high coercive force, by using an element supplied in a large amount, and an industrial method. It provides a manufacturing method that is easy to produce.
【0011】[0011]
【課題を解決するための手段】本発明者らは、上記課題
を解決するために、添加元素としてCuに着目し、得ら
れたR−Fe−B−Cu系焼結磁石の構成組織と磁気特
性の相関について詳細な研究を行なった。その結果、最
終的に得られる磁石の構成組織において、粒界相中にR
6Fe13Cuなる化合物相が存在している場合に良好な
保磁力が安定して得られることが明らかとなった。この
化合物は後述するような結果から、正方晶で室温に於て
反強磁性を示す化合物であることも判明した。またR6
Fe13Cu相を最終的な磁石組織中に出現させるために
は適当な熱処理条件を選ばなくてはならないことも明ら
かとなった。In order to solve the above-mentioned problems, the present inventors focused their attention on Cu as an additional element, and obtained the R-Fe-B-Cu-based sintered magnet structure and magnetism. A detailed study was conducted on the correlation of properties. As a result, in the structure of the finally obtained magnet, R is contained in the grain boundary phase.
It has been clarified that good coercive force can be stably obtained when the compound phase of 6 Fe 13 Cu is present. From the results as described later, this compound was also found to be a tetragonal compound showing antiferromagnetism at room temperature. See also R 6
It was also clarified that appropriate heat treatment conditions had to be selected in order for the Fe 13 Cu phase to appear in the final magnet structure.
【0012】即ち、本発明の希土類焼結磁石はR(ただ
しPr,Ndを主成分とする希土類元素),Fe,B,
Cuを原料基本成分とし、構成相として正方晶の反強磁
性化合物であるR6Fe13Cu相を有することを特徴と
するもので、その製造方法は前記基本成分からなる合金
粉末を成形し焼結した後に、400℃以上でかつR6Fe13
Cu相の包晶温度以下の温度範囲で熱処理する事を特徴
とするものである。That is, the rare earth sintered magnet of the present invention is R (provided that the rare earth element is Pr, Nd as a main component), Fe, B,
It is characterized by having Cu as a raw material basic component and having a R 6 Fe 13 Cu phase which is a tetragonal antiferromagnetic compound as a constituent phase. After binding, the temperature is 400 ° C or higher and R 6 Fe 13
It is characterized in that the heat treatment is carried out in a temperature range below the peritectic temperature of the Cu phase.
【0013】以下、本発明の構成について詳細に説明す
る。The structure of the present invention will be described in detail below.
【0014】まず本発明の根幹を成すR6Fe13Cu相
の同定過程について述べる。サンプル中においてのこの
相の存在の有無は偏光光学顕微鏡による組織観察によっ
て簡単に判別することができる。後述の表1のサンプル
No.1に関して、偏光光学顕微鏡によって確認した相の
EPMAによる組成分析を行なった。その結果、この相
はおよそPr30at%、Fe66at%、Cu4at%と他の微量な
元素からなる組成を有し、PrとFeとCuの原子比が
ほぼ6:13:1であることがわかった。この結果を受
けて類似の化合物に関する研究について調査を行なっ
た。その結果、M=Si,Sn,Ga,In,Al,Tlに関してR6Fe
14-xMxなる相(ただしM=Si,Sn,In,Tlの場合x=1、
M=Ga,Alの場合x=3)に関する報告があった。参考
文献としては以下のようなものが挙げられる。First, the process of identifying the R 6 Fe 13 Cu phase that forms the basis of the present invention will be described. The presence or absence of this phase in the sample can be easily determined by observing the structure with a polarization optical microscope. Sample of Table 1 below
Regarding No. 1, the composition analysis by EPMA of the phase confirmed by the polarization optical microscope was performed. As a result, it was found that this phase had a composition of approximately 30 at% Pr, 66 at% Fe, 6 at% Cu, and other trace elements, and the atomic ratio of Pr: Fe: Cu was approximately 6: 13: 1. Based on this result, research on similar compounds was conducted. As a result, R 6 Fe for M = Si, Sn, Ga, In, Al, Tl
14-x M x phase (when M = Si, Sn, In, Tl, x = 1,
There was a report regarding x = 3) when M = Ga and Al. The following can be cited as references.
【0015】J. Allemand et al; J. Less-Common Me
t. 166(1990)73 K. G. Knoch et al; IEEE Trans. Mag. MAG-25(198
9),No.5,3426 J. Fidler; 6th International Symposium on Magnet
ic Anisotropy andCoercivity in RE-TM Alloys Paper
No. S2.7 B. Grieb et al; IEEE Trans. Mag. MAG-26(1990)136
7 P. Schrey et al; J. Mag. Magn. Mat. 101(1991)417 F. Weitzer et al; J. Less-Common Met. 167(1990)1
35 参考文献にはNd6Fe13Siに関するX線回折結果
から、その結晶構造の提唱が行なわれている。しかしC
uを構成元素として含む同種の化合物に関する報告はい
まだ行なわれていない。本発明者らは上述したようなE
PMAで確認したPr、Fe、Cuからなる化合物相に
関してX線回折を行なった。その結果、得られた回折ピ
ークは空間群I4/mcmに属する正方晶のものと良く一致
した。またその格子定数はa=b=0.81nm,c=2.31nmと測定
された。図1にX線回折結果と各ピークの同定結果を示
す。以上のようにX線回折とEPMAによる分析から、
この相は正方晶化合物のPr6Fe13Cu相であること
が明らかとなった。J. Allemand et al; J. Less-Common Me
t. 166 (1990) 73 KG Knoch et al; IEEE Trans. Mag. MAG-25 (198
9), No.5,3426 J. Fidler; 6th International Symposium on Magnet
ic Anisotropy and Coercivity in RE-TM Alloys Paper
No. S2.7 B. Grieb et al; IEEE Trans. Mag. MAG-26 (1990) 136
7 P. Schrey et al; J. Mag. Magn. Mat. 101 (1991) 417 F. Weitzer et al; J. Less-Common Met. 167 (1990) 1
In the 35 reference, the crystal structure of Nd 6 Fe 13 Si is proposed based on the X-ray diffraction results. But C
No report has been made yet regarding the same type of compound containing u as a constituent element. The present inventors have adopted E as described above.
X-ray diffraction was performed on the compound phase consisting of Pr, Fe and Cu confirmed by PMA. As a result, the obtained diffraction peak was in good agreement with that of a tetragonal crystal belonging to the space group I4 / mcm. The lattice constants were measured as a = b = 0.81 nm and c = 2.31 nm. FIG. 1 shows the X-ray diffraction result and the identification result of each peak. From the above X-ray diffraction and EPMA analysis,
It was revealed that this phase was a tetragonal compound Pr 6 Fe 13 Cu phase.
【0016】本発明者らはPr6Fe13Cuに関しての
磁性の評価も併せて行なった。図2に磁化曲線を示す。
図から解るように得られた曲線はヒステリシスループを
描かず、磁化が磁場にほぼ比例する常磁性的な変化を示
している。また図3には磁化の温度依存性(M-Tカー
ブ)を示したが、得られる磁化は非常に小さく、118℃
付近に磁化のピークがみられた。図4にはメスバウアー
分光分析の結果得られたスペクトル図を示す。この結果
から結晶構造中の各サイトに占める鉄原子の内部磁場
は、各サイトにおいて200kOe程度の比較的大きな値とな
ることがわかった。以上の結果からPr6Fe13Cuは
強磁性を示さないものの結晶中の鉄原子はかなり大きな
磁気モーメントを持っていることとなり、反強磁性化合
物であると判断できる。上述したM-Tカーブ中の118℃
というピーク温度はネール点と考えられる。なおNdに
関しても同様なNd6Fe13Cu相が存在することを確
認した。The inventors of the present invention also evaluated the magnetism of Pr 6 Fe 13 Cu. The magnetization curve is shown in FIG.
As can be seen from the figure, the curve obtained does not draw a hysteresis loop but shows a paramagnetic change in which the magnetization is almost proportional to the magnetic field. Fig. 3 shows the temperature dependence of magnetization (MT curve). The obtained magnetization is very small, 118 ° C.
A peak of magnetization was seen in the vicinity. FIG. 4 shows a spectrum diagram obtained as a result of Moessbauer spectroscopy. From this result, it was found that the internal magnetic field of iron atoms occupying each site in the crystal structure has a relatively large value of about 200 kOe at each site. From the above results, although Pr 6 Fe 13 Cu does not show ferromagnetism, the iron atom in the crystal has a considerably large magnetic moment, and it can be judged that it is an antiferromagnetic compound. 118 ℃ in the MT curve mentioned above
The peak temperature is considered to be the Neel point. Regarding Nd, it was confirmed that a similar Nd 6 Fe 13 Cu phase was present.
【0017】以上述べたようなR6Fe13Cu相が、主
相であるR2Fe14B化合物結晶粒界や粒界三重点に均
一に分散している場合に、良好な磁気特性、特に高保磁
力が得られる。When the R 6 Fe 13 Cu phase as described above is uniformly dispersed in the grain boundaries of the R 2 Fe 14 B compound or the triple points of the grain boundaries, which is the main phase, good magnetic properties, particularly High coercive force can be obtained.
【0018】R6Fe13Cu相を最終的に得られる磁石
組織中に出現させるためには、まず最初にインゴットの
合金組成を適切に選ぶ必要がある。基本的には鉄原子が
すべて主相として消費されずに粒界相中にも適当な量だ
け存在することが必要であり、かつ軟磁性相であるR2
Fe17相を出現させないことが必要である。具体的に
は、合金組成をRxFeyBzCu(100-x-y-z)と表わした
際に、y−14z>0,z≧4であることが必要であ
る。In order to make the R 6 Fe 13 Cu phase appear in the finally obtained magnet structure, it is first necessary to properly select the alloy composition of the ingot. Basically, it is necessary that all the iron atoms are not consumed as the main phase but exist in an appropriate amount also in the grain boundary phase, and R 2 which is the soft magnetic phase.
It is necessary not to allow the Fe 17 phase to appear. Specifically, when the alloy composition is expressed as R x Fe y B z Cu (100-xyz) , it is necessary that y-14z> 0 and z ≧ 4.
【0019】また合金組成を適切に決定しても必ずしも
最終的な磁石組織としてR6Fe13Cu相が得られるも
のではなく、熱処理条件も適当に選ぶ必要がある。なぜ
ならばR6Fe13Cu相はある一定の温度領域でしか安
定に存在しないためである。例えばPr6Fe13Cu相
は、Pr2Fe17+l(液相)→Pr6Fe13Cuなる包
晶反応で形成され、その包晶温度は熱分析の結果からす
ると650℃付近と推定される。Rの種類や他の不純物元
素により包晶温度は変化するが、基本的にはこの包晶温
度以下での熱処理を最後に施さないとR6Fe13Cu相
が出現しないことになり、このため保磁力は低い値にと
どまってしまう。また逆に熱処理温度が低くなりすぎる
と熱処理時間が非常に長くなり、量産性に支障を来す。
このため400℃以上の温度で熱処理を行なうことが望ま
しい。またより良くは、上記の包晶反応式中のl(液
相)が出現する温度以上での熱処理が望ましい。このよ
うな温度領域では原子の拡散が容易となって反応が促進
されるため熱処理時間の短縮が可能となる。例を挙げる
とR=Prの場合にはPr相とPrCu相の共晶反応温
度(約470℃)以上で熱処理を行なうことが望ましい。
ただしこのような温度はRの種類や不純物元素により変
化する。Further, even if the alloy composition is appropriately determined, the R 6 Fe 13 Cu phase is not always obtained as the final magnet structure, and the heat treatment conditions must be appropriately selected. This is because the R 6 Fe 13 Cu phase stably exists only in a certain temperature range. For example, the Pr 6 Fe 13 Cu phase is formed by a peritectic reaction of Pr 2 Fe 17 +1 (liquid phase) → Pr 6 Fe 13 Cu, and the peritectic temperature is estimated to be around 650 ° C. from the results of thermal analysis. .. The peritectic temperature changes depending on the type of R and other impurity elements, but basically, the R 6 Fe 13 Cu phase does not appear unless the heat treatment below this peritectic temperature is finally performed. The coercive force remains low. On the contrary, if the heat treatment temperature is too low, the heat treatment time becomes very long, which impairs mass productivity.
Therefore, it is desirable to perform heat treatment at a temperature of 400 ° C or higher. More preferably, the heat treatment is performed at a temperature at or above at which 1 (liquid phase) in the peritectic reaction formula appears. In such a temperature range, the diffusion of atoms is facilitated and the reaction is promoted, so that the heat treatment time can be shortened. For example, in the case of R = Pr, it is desirable to perform the heat treatment at the eutectic reaction temperature (about 470 ° C.) or higher of the Pr phase and the PrCu phase.
However, such temperature changes depending on the type of R and the impurity element.
【0020】熱処理に先立つ成形・焼結時の諸条件は既
に特許等で公知となっている条件で行なって問題ない。There are no problems if the molding and sintering conditions prior to the heat treatment are carried out under the conditions already known from patents and the like.
【0021】[0021]
【作用】上述したようにR6Fe13Cu相を持つR-Fe
-B-Cu系焼結磁石においては良好な磁気特性、特に高
い保磁力を得ることができる。このような本発明による
磁気特性の向上は、次のような効果によるものと考えら
れる。Function As described above, R-Fe having the R 6 Fe 13 Cu phase
In the -B-Cu system sintered magnet, good magnetic properties, especially high coercive force can be obtained. It is considered that the improvement of the magnetic characteristics according to the present invention is due to the following effects.
【0022】第1の効果は粒界相部分における強磁性相
の消滅ということである。従来のR-Fe-B-Cu系磁
石においては、粒界相部分にα-FeあるいはR2Fe17
などの保磁力の小さな強磁性相の点在が見られた。この
ような強磁性相は磁化反転の核になり、そのため保磁力
が激減してしまう。しかしR6Fe13Cu相が形成され
る場合にはこのような強磁性相が消滅する。R6Fe13
Cu相は反強磁性相であるので、磁化反転の核のように
主相に磁気的な影響を与えることはわずかで、このため
良好な保磁力が得られるものと考えられる。The first effect is that the ferromagnetic phase disappears in the grain boundary phase portion. In the conventional R-Fe-B-Cu based magnet, α-Fe or R 2 Fe 17 is contained in the grain boundary phase portion.
Scattering of ferromagnetic phase with small coercive force was observed. Such a ferromagnetic phase becomes the nucleus of the magnetization reversal, so that the coercive force is drastically reduced. However, when the R 6 Fe 13 Cu phase is formed, such a ferromagnetic phase disappears. R 6 Fe 13
Since the Cu phase is an antiferromagnetic phase, it rarely exerts a magnetic influence on the main phase like a nucleus of magnetization reversal, and it is considered that good coercive force can be obtained for this reason.
【0023】第2の効果は、主相結晶粒同士の分離の促
進と主相結晶粒の粒成長の抑制ということである。後述
の実施例において見られるように、粒界にR6Fe13C
u相が存在しない場合には主相粒同士が接触して存在す
る部分が多くみられる。このような部分は磁化反転が容
易となり、保磁力の低下を招く。これに対してR6Fe1
3Cu相が粒界相部分に均一に分散して存在する場合
は、この相によって主相同士の磁気的な孤立化がうまく
成されており、このため磁化反転が起こり難くなって高
い保磁力が実現できるものと考えられる。また組織写真
から判断すると、最終の磁石組織としてR6Fe13Cu
相が存在している場合には、主相結晶粒径はR6Fe13
Cu相が存在しない場合よりも小さくなっている。R6
Fe13Cu相が主相結晶粒径の微細化に直接寄与してい
るかどうかは不明であるが、このように結果的には微細
な主相粒が得られ、高保磁力が実現される。The second effect is to promote the separation of the main phase crystal grains from each other and to suppress the grain growth of the main phase crystal grains. As can be seen in the examples described below, R 6 Fe 13 C is formed at the grain boundaries.
When the u phase does not exist, there are many areas where the main phase grains are in contact with each other. In such a portion, the magnetization reversal becomes easy and the coercive force is lowered. On the other hand, R 6 Fe 1
3 When the Cu phase is uniformly dispersed in the grain boundary phase portion, this phase is successful in magnetically isolating the main phases from each other, which makes it difficult for magnetization reversal to occur, resulting in a high coercive force. It is thought that can be realized. Judging from the structure photograph, the final magnet structure is R 6 Fe 13 Cu.
When a phase is present, the crystal grain size of the main phase is R 6 Fe 13
It is smaller than when the Cu phase is not present. R 6
It is not known whether the Fe 13 Cu phase directly contributes to the refinement of the main phase crystal grain size, but as a result, fine main phase grains are obtained and a high coercive force is realized.
【0024】第3の効果はR6Fe13Cu相の出現によ
る主相結晶粒界面の清浄化ということである。顕微鏡写
真から判断すると、主相とR6Fe13Cu相は互いに接
触して存在することが多いが、その界面はかなり直線的
で、凹凸の少ない界面となっている。上記参考文献に
おいて、Schreyらは、主相とNd6Fe13Sn相の界面
をTEMで観察した結果、その界面が非常にクリーンで
あり、これが保磁力向上に寄与していると述べている
が、本発明の磁石の場合にも同様な現象が起きて高保磁
力が実現されていると考えられる。The third effect is that the main phase crystal grain interface is cleaned by the appearance of the R 6 Fe 13 Cu phase. Judging from the photomicrograph, the main phase and the R 6 Fe 13 Cu phase often exist in contact with each other, but the interface is fairly linear and has few irregularities. In the above reference, Schrey et al. Stated that the interface between the main phase and the Nd 6 Fe 13 Sn phase was observed by TEM, and as a result, the interface was very clean, which contributes to the improvement of the coercive force. It is considered that the same phenomenon occurs in the case of the magnet of the present invention, and a high coercive force is realized.
【0025】次に本発明の実施例について述べる。Next, examples of the present invention will be described.
【0026】[0026]
(実施例1)表1に示す組成の合金を、アルゴン雰囲気
中で高周波誘導加熱溶解炉を用いて溶解し、次いで金型
中に鋳造した。希土類、鉄及び銅の原料としては99.9%
の純度のものを用い、ボロンはフェロボロン合金を用い
た。得られたインゴットをスタンプミルにより35メッシ
ュスルーに粉砕し、ついでジェットミルにより窒素ガス
を用いて微粉砕を行ない、平均粒径が約3μmの粉末を
得た。このようにして得られた粉末を成形助剤のステア
リン酸亜鉛と混練した後、10kOeの磁界中で1.5t/cm2の
圧力で成形した。得られた圧粉体を1050℃においてアル
ゴン雰囲気中で3時間焼結した。(Example 1) An alloy having the composition shown in Table 1 was melted in an argon atmosphere using a high frequency induction heating melting furnace, and then cast in a mold. 99.9% as raw material for rare earth, iron and copper
Of the above-mentioned purity, and a ferroboron alloy was used as boron. The obtained ingot was crushed into 35 mesh through with a stamp mill, and then finely crushed with a jet mill using nitrogen gas to obtain a powder having an average particle size of about 3 μm. The powder thus obtained was kneaded with zinc stearate as a molding aid and then molded under a magnetic field of 10 kOe at a pressure of 1.5 t / cm 2 . The green compact obtained was sintered at 1050 ° C. in an argon atmosphere for 3 hours.
【0027】この後、アルゴン雰囲気中600℃において1
0時間の熱処理を施した。Then, at 600 ° C. in an argon atmosphere, 1
Heat treatment was performed for 0 hours.
【0028】この時の組織を偏光をかけて光学顕微鏡で
観察したところ、主相以外の粒界相としてR6Fe13C
u相が存在するものとしないものの両方が観察された。
ここで両者の代表的な組織観察結果の模式図を図5およ
び図6に示す。図5は粒界相としてR6Fe13Cu相が
存在するもので主相同士の分離が促進され、粒径も小さ
い組織となっている。図6は粒界相としてR6Fe13C
u相が存在しない組織であり、主相同士の孤立化がうま
く成されておらず、また主相粒径も粗大化している。When the structure at this time was observed by an optical microscope with polarized light, R 6 Fe 13 C was observed as a grain boundary phase other than the main phase.
Both the presence and absence of the u phase were observed.
Here, a schematic view of the representative results of the structure observation of both is shown in FIG. 5 and FIG. In FIG. 5, the R 6 Fe 13 Cu phase is present as a grain boundary phase, the separation of the main phases is promoted, and the grain size is small. FIG. 6 shows R 6 Fe 13 C as a grain boundary phase.
This is a structure in which the u phase does not exist, the main phases are not well isolated from each other, and the main phase grain size is coarse.
【0029】表2には表1に示した合金組成の焼結磁石
における磁気特性と、光学顕微鏡観察を行なった結果か
ら判断したR6Fe13Cu相の有無を示す。この場合の
磁気特性はサンプルを40kOeのパルス磁場で着磁した
後、最大印加磁場25kOeでB-Hトレーサーにより測定し
た。Table 2 shows the magnetic characteristics of the sintered magnets having the alloy compositions shown in Table 1 and the presence / absence of the R 6 Fe 13 Cu phase judged from the result of observation with an optical microscope. The magnetic characteristics in this case were measured by a BH tracer with a maximum applied magnetic field of 25 kOe after the sample was magnetized with a pulsed magnetic field of 40 kOe.
【0030】[0030]
【表1】 [Table 1]
【0031】[0031]
【表2】 [Table 2]
【0032】以上のように構成相としてR6Fe13Cu
相を持つR-Fe-B-Cu系焼結磁石は高い磁気特性、
特に高保磁力を実現することができる。As described above, R 6 Fe 13 Cu is used as the constituent phase.
R-Fe-B-Cu based sintered magnets with phases have high magnetic characteristics,
In particular, a high coercive force can be realized.
【0033】(実施例2)表1のNo.1に示した合金組成
のインゴットについて実施例1と同様の成形・焼結条件
を施し、その後200〜800℃の各温度で10時間の熱処理を
施した。このようにして得られた圧延磁石について磁気
特性を測定した。熱処理温度と磁気特性の関係を図7に
示す。(Example 2) The ingot having the alloy composition shown in No. 1 of Table 1 was subjected to the same molding and sintering conditions as in Example 1, and then heat-treated for 10 hours at each temperature of 200 to 800 ° C. gave. The magnetic characteristics of the rolled magnet thus obtained were measured. FIG. 7 shows the relationship between the heat treatment temperature and the magnetic characteristics.
【0034】図から明らかなように熱処理温度を400〜6
50℃の範囲で高い磁気特性が得られることがわかった。
またこれらの磁石サンプルについて光学顕微鏡による組
織観察を行ったところ、高特性の得られる400〜650℃の
温度で熱処理をしたものについてのみ、R6Fe13Cu
相の存在が確認された。As is apparent from the figure, the heat treatment temperature is 400 to 6
It was found that high magnetic properties were obtained in the range of 50 ° C.
Further, when the structure of these magnet samples was observed with an optical microscope, it was found that only those heat-treated at a temperature of 400 to 650 ° C. at which high characteristics were obtained were R 6 Fe 13 Cu.
The existence of phases was confirmed.
【0035】[0035]
【発明の効果】叙上のごとく本発明のようなR,Fe,
B,Cuを原料基本成分とし、焼結後熱処理を施すこと
によって製造され、構成相として正方晶の反強磁性化合
物であるR6Fe13Cu相を持つ希土類永久磁石におい
ては高い磁気特性、特に高保磁力が得られる。このよう
に供給量の多い添加元素であるCuを添加することによ
っても、高価なDyを使用することなく低コストな高性
能希土類焼結磁石を得ることができる。According to the present invention, as described above, R, Fe,
The rare earth permanent magnet having a R 6 Fe 13 Cu phase, which is a tetragonal antiferromagnetic compound as a constituent phase, is manufactured by subjecting B and Cu to the raw material basic components and performing a heat treatment after sintering, and particularly, has a high magnetic property. High coercive force can be obtained. By adding Cu, which is an additional element that is supplied in a large amount, a low-cost high-performance rare earth sintered magnet can be obtained without using expensive Dy.
【図1】 R6Fe13Cuに関するX線回折結果図。FIG. 1 is an X-ray diffraction result diagram of R 6 Fe 13 Cu.
【図2】 R6Fe13Cuの磁化曲線図。FIG. 2 is a magnetization curve diagram of R 6 Fe 13 Cu.
【図3】 R6Fe13Cuの磁化と温度の関係図。FIG. 3 is a relational diagram of magnetization and temperature of R 6 Fe 13 Cu.
【図4】 R6Fe13Cuのメスバウアースペクトル
図。FIG. 4 is a Moessbauer spectrum diagram of R 6 Fe 13 Cu.
【図5】 R6Fe13Cu相の存在する焼結磁石組織の
模式図。FIG. 5 is a schematic diagram of a sintered magnet structure in which an R 6 Fe 13 Cu phase exists.
【図6】 R6Fe13Cu相が存在しない焼結磁石組織
の模式図。FIG. 6 is a schematic diagram of a sintered magnet structure in which no R 6 Fe 13 Cu phase is present.
【図7】 熱処理温度と磁気特性の関係図。FIG. 7 is a diagram showing the relationship between heat treatment temperature and magnetic properties.
1 R2Fe14B相 2 R-リッチ相 3 R6Fe13Cu相1 R 2 Fe 14 B phase 2 R-rich phase 3 R 6 Fe 13 Cu phase
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 FI 技術表示箇所 H01F 41/02 G 8019−5E (72)発明者 伊原 清二 長野県諏訪市大和3丁目3番5号セイコー エプソン株式会社内 (72)発明者 秋岡 宏治 長野県諏訪市大和3丁目3番5号セイコー エプソン株式会社内 (72)発明者 梅田 高照 東京都文京区本郷7−3−1東京大学工学 部金属工学科内 (72)発明者 永山 勝久 東京都文京区本郷7−3−1東京大学工学 部金属工学科内 (72)発明者 梶谷 敏之 東京都文京区本郷7−3−1東京大学工学 部金属工学科内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification number Reference number within the agency FI Technical indication location H01F 41/02 G 8019-5E (72) Inventor Seiji Ihara 3-3-5 Yamato, Suwa City, Nagano Prefecture No. Seiko Epson Corporation (72) Inventor Koji Akioka 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Takateru Umeda 7-3-1 Hongo, Bunkyo-ku, Tokyo University of Tokyo Engineering Department of Metal Engineering (72) Inventor Katsuhisa Nagayama 7-3-1 Hongo, Bunkyo-ku, Tokyo University of Tokyo Department of Metal Engineering (72) Inventor Toshiyuki Kajiya 7-3-1 Hongo, Bunkyo-ku, Tokyo Metal Department of Engineering, Tokyo University Department of Engineering
Claims (2)
る希土類元素),Fe,B,Cuを原料基本成分とし、
構成相として正方晶の反強磁性化合物であるR6Fe13
Cu相を有することを特徴とする希土類焼結磁石。1. R (where R is a rare earth element containing Pr and Nd as main components), Fe, B and Cu as raw material basic components,
R 6 Fe 13 which is a tetragonal antiferromagnetic compound as a constituent phase
A rare earth sintered magnet having a Cu phase.
る合金粉末を成形して焼結した後に、400℃〜R6Fe13
Cu相の包晶反応温度の温度範囲に於て熱処理を施すこ
とを特徴とする請求項1記載の希土類焼結磁石の製造方
法。2. An alloy powder containing R, Fe, B, and Cu as raw material basic components is molded and sintered, and then 400 ° C. to R 6 Fe 13
The method for producing a rare earth sintered magnet according to claim 1, wherein the heat treatment is performed within a temperature range of peritectic reaction temperature of the Cu phase.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4115845A JPH05315120A (en) | 1992-05-08 | 1992-05-08 | Rare earth sintered magnet and its manufacture |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4115845A JPH05315120A (en) | 1992-05-08 | 1992-05-08 | Rare earth sintered magnet and its manufacture |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH05315120A true JPH05315120A (en) | 1993-11-26 |
Family
ID=14672563
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4115845A Pending JPH05315120A (en) | 1992-05-08 | 1992-05-08 | Rare earth sintered magnet and its manufacture |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH05315120A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004079922A (en) * | 2002-08-22 | 2004-03-11 | Hitachi Ltd | Magnet and motor using it |
US20170025207A1 (en) * | 2011-07-08 | 2017-01-26 | Showa Denko K.K. | Alloy for r-t-b-based rare earth sintered magnet, process of 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 of producing r-t-b-based rare earth sintered magnet, and motor |
JP2022535480A (en) * | 2019-11-21 | 2022-08-09 | フージャン チャンティン ゴールデン ドラゴン レア-アース カンパニー リミテッド | Neodymium-iron-boron magnet material, raw material composition, manufacturing method, and application |
-
1992
- 1992-05-08 JP JP4115845A patent/JPH05315120A/en active Pending
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004079922A (en) * | 2002-08-22 | 2004-03-11 | Hitachi Ltd | Magnet and motor using it |
CN100346427C (en) * | 2002-08-22 | 2007-10-31 | 株式会社日立制作所 | Magnet and electric motor using the same |
US7399368B2 (en) * | 2002-08-22 | 2008-07-15 | Hitachi, Ltd. | Motor using magnet |
US20170025207A1 (en) * | 2011-07-08 | 2017-01-26 | Showa Denko K.K. | Alloy for r-t-b-based rare earth sintered magnet, process of 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 of producing r-t-b-based rare earth sintered magnet, and motor |
US11024448B2 (en) * | 2011-07-08 | 2021-06-01 | Tdk Corporation | Alloy for R-T-B-based rare earth sintered magnet, process of 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 of producing R-T-B-based rare earth sintered magnet, and motor |
JP2022535480A (en) * | 2019-11-21 | 2022-08-09 | フージャン チャンティン ゴールデン ドラゴン レア-アース カンパニー リミテッド | Neodymium-iron-boron magnet material, raw material composition, manufacturing method, and application |
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