JP2001313206A - R-t-n anisotropic magnetic powder, its manufacturing method, and r-t-n anisotropic bonded magnet - Google Patents
R-t-n anisotropic magnetic powder, its manufacturing method, and r-t-n anisotropic bonded magnetInfo
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- JP2001313206A JP2001313206A JP2000129784A JP2000129784A JP2001313206A JP 2001313206 A JP2001313206 A JP 2001313206A JP 2000129784 A JP2000129784 A JP 2000129784A JP 2000129784 A JP2000129784 A JP 2000129784A JP 2001313206 A JP2001313206 A JP 2001313206A
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- magnetic powder
- dehydrogenation
- based anisotropic
- anisotropic
- recrystallized
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Classifications
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- 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
- H01F1/059—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and Va elements, e.g. Sm2Fe17N2
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- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Hard Magnetic Materials (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、改良されたR−T
−N系異方性磁粉(RはYを含む希土類元素の少なくと
も1種でありSmを必ず含み、TはFeまたはFeとC
oである)およびその製造方法に関する。また本発明
は、前記R−T−N系異方性磁粉およびバインダーから
なる高性能のR−T−N系異方性ボンド磁石に関する。TECHNICAL FIELD The present invention relates to an improved R-T
-N-based anisotropic magnetic powder (R is at least one kind of rare earth element containing Y and always contains Sm, T is Fe or Fe and C
o) and a method for producing the same. The present invention also relates to a high-performance RTN-based anisotropic bonded magnet comprising the RTN-based anisotropic magnetic powder and a binder.
【0002】[0002]
【従来の技術】希土類元素(R)、Feおよび窒素から
なるR−T−N系永久磁石はNd−Fe−B系永久磁石
に匹敵する高い磁気特性を有するが、約700℃超の温度
域で熱分解するので焼結磁石としての実用化が困難であ
る。このため、近年ボンド磁石への実用化が進められて
いる。R−T−N系ボンド磁石はSrフェライト異方性
焼結磁石に比べてボンド磁石特有の形状自由度および加
工性に優れ、かつ高い磁気特性を有することから、今後
各種磁石応用製品分野へ採用されていくものと期待され
ている。2. Description of the Related Art An RTN-based permanent magnet composed of a rare earth element (R), Fe and nitrogen has high magnetic properties comparable to Nd-Fe-B-based permanent magnets, but has a temperature range exceeding about 700 ° C. Therefore, practical use as a sintered magnet is difficult. For this reason, practical application to bond magnets has recently been promoted. R-T-N bonded magnets are superior to Sr ferrite anisotropic sintered magnets in shape flexibility and workability unique to bonded magnets, and have high magnetic properties. It is expected to be done.
【0003】従来のSm−Fe−N系異方性ボンド磁石
は、例えば特許第2739860号公報に記載されるように、
窒化したSm−Fe−N系合金を平均粒径で約2μmの
単磁区微粒子に微粉砕し、次いで前記微粉とバインダー
とを混練してコンパウンドとし、次いでコンパウンドを
磁場中で圧縮または射出成形して異方性化したものであ
る。しかし、この異方性ボンド磁石に配合されるSm−
Fe−N系磁粉が平均粒径で約2μmの微粉粒子である
ため、急激に酸化されて磁気特性が大きく低下する他、
異方性ボンド磁石中への磁粉の充填性が低下し成形体密
度の顕著な低下を招き、最大エネルギー(BH)maxの向上
が困難であるという問題を有している。A conventional Sm—Fe—N anisotropic bonded magnet is disclosed in, for example, Japanese Patent No. 2739860.
The nitrided Sm-Fe-N-based alloy is pulverized into single magnetic domain fine particles having an average particle size of about 2 μm, and then the fine powder and a binder are kneaded to form a compound, and then the compound is compressed or injection-molded in a magnetic field. It is anisotropic. However, the Sm-
Since the Fe-N-based magnetic powder is a fine powder having an average particle size of about 2 μm, it is rapidly oxidized and magnetic properties are significantly reduced.
There is a problem that the filling property of the magnetic powder in the anisotropic bonded magnet is reduced, and the density of the compact is remarkably reduced, and it is difficult to improve the maximum energy (BH) max.
【0004】特開平4−260302号公報には、Smを5〜
15原子%、M(MはZr,Hf,Nb、Ta、W、M
o、Ti、V、Cr、Ga、Al、Sn、PbおよびS
iの少なくとも1種である)を10原子%以下、Nを0.5
〜15原子%および残部がFeまたはFeおよびCoであ
り、複数の結晶粒を含み、平均結晶粒径が1μm以下の
Sm−Fe−N系異方性磁粉が開示されている。また、
特開平8−37122号公報には、R(RはYを含む希土類
元素の少なくとも1種でかつSmを50%以上含有)10〜
12at%、T(TはFeあるいはFeの一部を50at%以下
のCoで置換)80〜90at%、M(MはAl,Ti,V,
Cr,Ni,Ga,Zr,Nb,Mo,In,Sn,H
f,TaおよびWの少なくとも1種)10at%以下からな
る鋳塊を溶体化処理後、平均粒度が20μm〜10mmの少
なくとも80vol.%以上がTh2Zn17型構造を有する
化合物からなる粗粉砕粉となした後、前記粗粉砕粉を1.
0×104〜1.0×6Pa(0.1〜10atm)のH2ガスまたはそ
れに等しいH2分圧を有する不活性ガス(N2ガスを除
く、但し全圧力は1.0×6Pa(10atm)以下)中で、750
〜900℃に30分〜8時間加熱保持し、さらにH 2分圧1.3
Pa(1×10−2Torr)以下にて750〜900℃に30分〜8時
間加熱保持する脱H2処理を行い、次いで冷却して平均
結晶粒径が0.05〜3μmであり、かつ個々の粉末を形成
する微細結晶の方位が一定の方向にそろった集合組織を
有する粉体となし、次に前記粉体をN2圧力5×104〜
1.0×108Pa (0.5〜1000atm)のN2ガス中で300〜650
℃に30分〜50時間保持し、R8〜10at%、T65〜82at
%、M10at%以下、N8〜15at%を含有し、Th2Zn
17型構造を有する合金粉末を得た後、3〜500μmに
粉砕、整粒し、次いで樹脂を混合して磁場中で成形す
る、R−T−M−N系異方性ボンド磁石を製造する方法
が開示されている。しかし、特開平4−260302号公報お
よび特開平8−37122号公報のいずれにも、本発明の製
造方法の特徴である脱水素・再結合反応処理時の真空度
(水素分圧)をy(Pa)、脱水素時間をx(秒)とし
たとき、xが60〜1000秒のときにy=Axz(ただし−
0.5≦z≦−0.01であり、Aは脱水素条件により決定さ
れる定数である)で表される指数関数の条件下で脱水素
・再結合反応処理を行う旨の開示はない。また、この脱
水素条件を採用した場合に最終的に得られるR−T-N
系異方性磁粉が実質的に2−17型の硬質磁性相のシャー
プな粒径分布を有する微結晶粒からなり、同時に角形
(Hk)および最大エネルギー積(BH)maxを顕著に向上で
きる旨の開示はなく、示唆も認められない。Japanese Patent Application Laid-Open No. Hei 4-260302 discloses that Sm is 5 to 5.
15 atomic%, M (M is Zr, Hf, Nb, Ta, W, M
o, Ti, V, Cr, Ga, Al, Sn, Pb and S
i is at least one kind), 10% by atom or less, and N is 0.5%
-15 atomic% and the balance Fe or Fe and Co
Containing a plurality of crystal grains and having an average crystal grain size of 1 μm or less.
An Sm-Fe-N-based anisotropic magnetic powder is disclosed. Also,
JP-A-8-37122 discloses R (R is a rare earth element containing Y
At least one element and containing 50% or more of Sm)
12at%, T (T is Fe or a part of Fe at 50at% or less
80 to 90 at%, M (M is Al, Ti, V,
Cr, Ni, Ga, Zr, Nb, Mo, In, Sn, H
f, Ta and W) at least 10 at% or less.
After the solution treatment of the cast ingot, the average particle size is 20 μm to 10 mm.
Th is at least 80vol.% Or more2Zn17Has a mold structure
After forming the coarsely pulverized powder comprising the compound,
0x104~ 1.0 ×6H of Pa (0.1-10atm)2Gas or its
H equal to2Inert gas with partial pressure (N2Remove gas
However, the total pressure is 1.0 ×6Pa (10atm) or less)
900900 ° C for 30 minutes to 8 hours. 21.3 partial pressure
Pa (1 × 10-2Torr) or below at 750-900 ° C for 30 minutes to 8:00
H2Process, then cool and average
The crystal grain size is 0.05 ~ 3μm and forms individual powder
Texture in which the orientation of the microcrystals
Powder, and then convert the powder to N2Pressure 5 × 104~
1.0 × 108N of Pa (0.5 to 1000atm)2300-650 in gas
C for 30 minutes to 50 hours, R8-10at%, T65-82at
%, M10at% or less, N8-15at%, Th2Zn
17After obtaining the alloy powder having the mold structure, to 3 ~ 500μm
Crush and size, then mix the resin and mold in a magnetic field
For manufacturing an R-T-M-N anisotropic bonded magnet
Is disclosed. However, JP-A-4-260302 and
And Japanese Patent Application Laid-Open No. 8-37122,
Degree of vacuum during dehydrogenation / recombination reaction processing, which is a feature of the fabrication method
(Hydrogen partial pressure) as y (Pa) and dehydrogenation time as x (second)
, When x is 60 to 1000 seconds, y = Axz(However,-
0.5 ≦ z ≦ −0.01, and A is determined by the dehydrogenation conditions.
Under the condition of an exponential function expressed by
-There is no disclosure that the recombination reaction treatment will be performed. Also,
RTN finally obtained when hydrogen conditions are adopted
-Based anisotropic magnetic powder is substantially a 2-17 type hard magnetic phase shear.
Composed of fine crystal grains with
(Hk) and maximum energy product (BH) max significantly improved
There is no disclosure to the effect and no suggestion is found.
【0005】次に、着磁性は実用に供するSm−Fe−
N系異方性ボンド磁石において極めて重要な特性であ
る。通常、Sm−Fe−N系異方性ボンド磁石の着磁磁
場強度は着磁電源等の制限から室温の1989.5kA/m(25k
Oe)以下に制限される場合がほとんどであるので、本
発明では着磁性を、室温の1989.5kA/m (25kOe)で着
磁した場合の最大エネルギー積(BH)maxで評価した。[0005] Next, magnetizing is performed using Sm-Fe-
This is an extremely important property in an N-based anisotropic bonded magnet. Usually, the strength of the magnetizing magnetic field of the Sm-Fe-N based anisotropic bonded magnet is limited to room temperature of 299.5 kA / m (25 k
Oe) In most cases, the magnetization is limited to the following, and in the present invention, the magnetization was evaluated by the maximum energy product (BH) max when magnetized at room temperature of 199.5 kA / m (25 kOe).
【0006】[0006]
【発明が解決しようとする課題】本発明の解決しようと
する課題は、従来の平均粒径が5μm未満のSm−Fe
−N系異方性磁粉に比べて磁気特性の耐熱性が優れてお
り、かつ高い(BH)max、さらには良好な着磁性を有する
R−T−N系異方性磁粉およびその製造方法を提供する
ことである。また本発明の課題は、前記R−T−N系異
方性磁粉を用いた高性能のR−T−N系異方性ボンド磁
石を提供することである。An object of the present invention is to provide a conventional Sm-Fe having an average particle size of less than 5 μm.
R-T-N-based anisotropic magnetic powder, which has excellent heat resistance of magnetic properties as compared with -N-based anisotropic magnetic powder, and has high (BH) max, and furthermore has good magnetism, and a method for producing the same. To provide. Another object of the present invention is to provide a high-performance RTN-based anisotropic bonded magnet using the R-TN-based anisotropic magnetic powder.
【0007】[0007]
【課題を解決するための手段】上記課題を解決した本発
明のR−T−N系異方性磁粉は、主要成分組成が、重量
百分率で、R(RはYを含む希土類元素の少なくとも1
種であり、Smを必ず含む)20〜30%、N2.5〜3.5%、
残部T(TはFeまたはFeとCoである)および不可
避的不純物からなる、平均粒径が5〜300μmのR−T
−N系異方性磁粉であって、前記R−T−N系異方性磁
粉は微細な2−17型硬質磁性相の再結晶粒の集合体から
実質的になり、平均再結晶粒径が0.02〜5μmでありか
つ再結晶粒径が5μm以下の再結晶粒の面積比率が90%
以上のものである。このため、従来の平均粒径が5μm
未満のSm−Fe−N系異方性磁粉に比べて磁気特性の
耐熱性が良好であり、かつ角形(Hk)および(BH)maxを
高めることができる。Hkは4πI-H減磁曲線上において
0.7Brの位置におけるHの値であり、減磁曲線の矩形性
の尺度である。Brは残留磁束密度、Hは磁界の強さ、4
πIは磁化の強さである。The RTN-based anisotropic magnetic powder of the present invention which has solved the above-mentioned problems has a main component composition in which R is a weight percentage of R (R is at least one of rare earth elements including Y).
It is a seed and always contains Sm) 20-30%, N2.5-3.5%,
R-T having an average particle size of 5 to 300 μm, comprising a balance T (T is Fe or Fe and Co) and unavoidable impurities
-N-based anisotropic magnetic powder, wherein the RTN-based anisotropic magnetic powder is substantially composed of an aggregate of recrystallized grains of a fine 2-17 type hard magnetic phase, and has an average recrystallized grain size. Is 0.02 to 5 μm and the area ratio of recrystallized grains having a recrystallized grain size of 5 μm or less is 90%
That's all. Therefore, the conventional average particle size is 5 μm.
As compared with the Sm-Fe-N-based anisotropic magnetic powder having less than 50%, the heat resistance of the magnetic properties is good, and the square (Hk) and (BH) max can be increased. Hk on the 4πI-H demagnetization curve
The value of H at the position of 0.7Br, which is a measure of the rectangularity of the demagnetization curve. Br is the residual magnetic flux density, H is the strength of the magnetic field, 4
πI is the intensity of magnetization.
【0008】本発明のR−T−N系異方性磁粉におい
て、主要成分組成が、重量百分率で、R(RはYを含む
希土類元素の少なくとも2種であり、SmおよびLaを
必ず含み、La含有量が0.1〜3.5%である)20〜30%、
N2.5〜3.5%、残部T(TはFeまたはFeとCoであ
る)および不可避的不純物からなる場合に着磁性を向上
できる。本発明者らの検討により、本発明のR−T−N
系異方性磁粉のうち平均結晶粒径が0.02〜0.5μmのも
のはピンニング型と判断される磁化反転機構を示すこと
がわかった。これに対し、平均粒径が2μm程度の2−
17型Sm−Fe−N系異方性磁粉の磁化反転機構はニュ
ークリエーション型である。着磁性はニュークリエーシ
ョン型に比べてピンニング型が悪い。この着磁性の悪さ
を改善するために本発明者らが鋭意検討した結果、本発
明のR−T−N系異方性磁粉に所定量のLaを含有する
とき、平均粒径が約2μmのSm−Fe−N系異方性磁
粉に相当する着磁性が得られることがわかった。RがS
m、Laおよび不可避的不純物からなり、重量百分率
で、(Sm+La)含有量が20〜30%であり、かつLa
含有量が0.1〜3.5%のときに、着磁性を改善することが
できる。La含有量が0.1%未満では着磁性の改善効果
が認められず、3.5%超では角形(Hk)が逆に低下す
る。これは前記La含有量範囲のときに異方性磁界はや
や低下するが、室温の1989.5kA/m (25kOe)以下で着
磁した場合の(BH)maxおよびHkが高められるからであ
る。In the R-T-N-based anisotropic magnetic powder of the present invention, the main component composition is represented by a weight percentage of R (R is at least two kinds of rare earth elements including Y, and always contains Sm and La; La content is 0.1-3.5%) 20-30%,
Magnetization can be improved when N2.5 to 3.5%, balance T (T is Fe or Fe and Co), and unavoidable impurities. According to the study of the present inventors, the RTN of the present invention
It was found that among the anisotropic magnetic powders, those having an average crystal grain size of 0.02 to 0.5 μm exhibited a magnetization reversal mechanism judged to be pinning type. On the other hand, the average particle size of 2-
The magnetization reversal mechanism of the 17-type Sm-Fe-N-based anisotropic magnetic powder is a nucleation type. The magnetization is worse in the pinning type than in the nucleation type. As a result of intensive studies conducted by the present inventors to improve the poor magnetization, when the RTN-based anisotropic magnetic powder of the present invention contains a predetermined amount of La, the average particle size is about 2 μm. It was found that magnetism corresponding to Sm-Fe-N-based anisotropic magnetic powder was obtained. R is S
m, La and unavoidable impurities, having a (Sm + La) content of 20 to 30% by weight and La
When the content is 0.1 to 3.5%, the magnetization can be improved. If the La content is less than 0.1%, no effect of improving magnetism is observed, and if it exceeds 3.5%, the square (Hk) is conversely reduced. This is because the anisotropic magnetic field slightly decreases when the La content is in the above range, but (BH) max and Hk when magnetized at room temperature of not more than 199.5 kA / m (25 kOe) are increased.
【0009】R−T−N系異方性磁粉とバインダーとか
らなる本発明の異方性ボンド磁石は、良好な磁気特性の
耐熱性および高い(BH)max等を有し、さらに良好な着磁
性を具備することができるので、各種磁石応用製品分野
(回転機、アクチュエータまたはマグネットロール等)
において極めて有用である。The anisotropic bonded magnet of the present invention comprising an RTN-based anisotropic magnetic powder and a binder has good magnetic properties such as heat resistance and a high (BH) max. Because it can have magnetism, various magnet application product fields (rotating machines, actuators, magnet rolls, etc.)
Is extremely useful in
【0010】また本発明は、主要成分組成が、重量百分
率で、R(RはYを含む希土類元素の少なくとも1種で
あり、Smを必ず含む)が20〜30%、残部T(TはFe
またはFeとCoである)および不可避的不純物からな
るR−T系母合金を平均粒径5〜300μmに粉砕し、次
いで水素化・分解反応処理、脱水素・再結合反応処理お
よび窒化を行うR−T−N系異方性磁粉の製造方法にお
いて、脱水素・再結合反応処理時の真空度(水素分圧)
をy(Pa)、脱水素時間をx(秒)としたとき、xが
60〜1000秒のときにy=Axz(ただし−0.5≦z≦−
0.01、Aは脱水素条件により決定される定数)で表され
る指数関数の条件下で脱水素処理を行う、R−T−N系
異方性磁粉の製造方法である。本発明者らは窒化用のR
−T系母合金に対し、脱水素時の相変態速度が磁気異方
性化度に顕著な影響を与えると考え、種々の脱水素条件
下で実験を繰り返した。その結果、脱水素工程に規則性
があることを発見した。つまり脱水素工程を脱水素・再
結合反応処理の開始後60〜1000秒の間における一次脱水
素工程とそれ以降の二次脱水素工程に分けられること、
および最終的に得られるR−T−N系異方性磁粉の磁気
特性が一次脱水素工程の脱水素速度によりほぼ決定され
ることがわかった。二次脱水素工程は一次脱水素工程を
終了後、格子間に残った余分な水素を放出させるための
工程であるので、不可避ではあるが一次脱水素工程に比
べて磁気特性への影響度は小さい。一次脱水素工程にお
ける真空度(水素分圧)をy(Pa)、xを脱水素時間
(秒)とした場合、x=60〜1000秒ではyとxとの関係が
対数グラフ上でほぼ直線に近似でき、y=Axzなる指
数関数(Aは脱水素条件により決定される定数)で表せ
ることがわかった。また、二次脱水素工程では急激に真
空度が高まることがわかった。ここでxを前記範囲に特
定した理由は、xが60秒未満ではR−T系母合金以外の
炉内水素雰囲気分を脱気するための時間を含んでおり、
正味のSm 2T17生成のための相変態状態に至らない
からである。xの上限の1000秒はR−T系母合金の入炉
量(処理量)、真空排気装置の性能によって変動するも
のの、x=1000秒が一次脱水素工程がほぼ完了する目安
となるからである。本発明者らはR−T系母合金の入炉
量を調整し、zを意図的に変化させる検討を行った。そ
の結果、zが−0.5未満では保磁力iHcは高いが、残留磁
束密度Brおよび最大エネルギー積(BH)maxが顕著に低下
した。この現象を詳細に説明すると、一次脱水素工程を
高速で行うため再結晶粒の成長に必要な核の生成方向が
ランダムになり、ランダムな配向状態で再結晶粒が成長
するために磁気的にほぼ等方性になると判断される。し
たがってBr、(BH)maxは等方性磁粉相当の値になる。一
方、zが−0.01を超えると再結晶化速度が極めて遅くな
るので、脱水素処理時間が非常に長くなり工業生産効率
が大きく低下する。したがって脱水素速度を−0.5≦z
≦−0.01 の速度勾配に調整することにより、再結晶化
の相変態が異方性が十分付与される好適な速度で進行す
るため、従来にない高いBr、(BH)maxを有し、かつシャ
ープな再結晶粒径分布を有する微細な2−17型硬質磁性
相から実質的になるR−T−N系異方性磁粉を得られる
と判断される。一次脱水素工程における脱水素速度の制
御は容易である。例えば炉内容積および真空排気ポンプ
の排気能力が決まれば、窒化用のR−T系母合金の入炉
量を調整することにより自在に制御できる。あるいは炉
内と真空排気ポンプを接続する配管中に圧力コントロー
ラを設置することにより制御することができる。あるい
はバルブの開閉により所定の真空度y(Pa)で所定時
間x(秒)保持する一次脱水素工程を1ステップとし
て、次第に真空度y(Pa)を低下させるようにして段
階的に複数のステップの一次脱水素工程を行い、平均的
な一次脱水素工程における脱水素速度がx=60〜1000秒
でかつy=Axzなる指数関数で表されるように行って
もよい。In the present invention, the composition of the main components is preferably
R (R is at least one rare earth element including Y
20% to 30% with Sm, and the balance T (T is Fe
Or Fe and Co) and unavoidable impurities.
The RT-based master alloy is pulverized to an average particle size of 5 to 300 μm.
Hydrogenation / decomposition reaction treatment, dehydrogenation / recombination reaction treatment
In the method of producing an RTN-based anisotropic magnetic powder for
And the degree of vacuum during the dehydrogenation / recombination reaction (hydrogen partial pressure)
Is y (Pa) and the dehydrogenation time is x (seconds), x is
Y = Ax for 60 to 1000 secondsz(However, -0.5≤z≤-
0.01, A is a constant determined by dehydrogenation conditions)
R-T-N system that performs dehydrogenation under exponential function conditions
This is a method for producing anisotropic magnetic powder. We have identified R for nitriding.
The phase transformation rate during dehydrogenation is magnetically anisotropic for -T
Various dehydrogenation conditions considered to have a significant effect on the degree of
The experiment was repeated below. As a result, the dehydrogenation process has regularity
I found that there is. In other words, the dehydrogenation process is
Primary dehydration between 60 and 1000 seconds after the start of the binding reaction
Divided into the elementary process and the subsequent secondary dehydrogenation process,
And magnetic properties of the finally obtained RTN-based anisotropic magnetic powder
Characteristics are almost determined by the dehydrogenation rate in the primary dehydrogenation process.
I found out. The secondary dehydrogenation step is the primary dehydrogenation step
After finishing, release excess hydrogen remaining between lattices
Although it is a process, it is inevitable, but compared to the primary dehydrogenation process.
The degree of influence on the magnetic properties is small. In the primary dehydrogenation process
The degree of vacuum (hydrogen partial pressure) to be applied is y (Pa) and x is the dehydrogenation time
(Seconds), the relationship between y and x is at x = 60-1000 seconds.
It can be approximated to a straight line on a logarithmic graph, and y = AxzBecome finger
Express as a number function (A is a constant determined by dehydrogenation conditions)
I found out. In the secondary dehydrogenation process,
It turned out that the airiness increased. Here, x is within the above range.
The reason is that when x is less than 60 seconds, other than the RT master alloy is used.
Includes time to degas the hydrogen atmosphere in the furnace,
Net Sm 2T17Does not reach phase transformation state for formation
Because. The upper limit of x is 1000 seconds for RT-based master alloy
Amount (processing amount) varies depending on the performance of the evacuation system
However, x = 1000 seconds is an indication that the primary dehydrogenation process is almost completed
This is because The present inventors have proposed an RT-type master alloy furnace.
A study was made to adjust the amount and intentionally change z. So
As a result, when z is less than -0.5, the coercive force iHc is high,
Notably reduced flux density Br and maximum energy product (BH) max
did. To explain this phenomenon in detail, the primary dehydrogenation step
The nucleation direction required for the growth of recrystallized grains
Become random, recrystallized grains grow in random orientation
Is determined to be magnetically substantially isotropic. I
Therefore, Br and (BH) max are values equivalent to isotropic magnetic powder. one
On the other hand, when z exceeds -0.01, the recrystallization rate becomes extremely slow.
As a result, the dehydrogenation time becomes very long and the industrial production efficiency
Greatly decreases. Therefore, the dehydrogenation rate is set to -0.5 ≦ z
Recrystallization by adjusting the velocity gradient to ≤-0.01
Phase transformation proceeds at a suitable speed to give sufficient anisotropy
Therefore, it has unprecedentedly high Br and (BH) max, and
2-17 type hard magnet with sharp recrystallized particle size distribution
An R-T-N-based anisotropic magnetic powder consisting essentially of phases can be obtained
Is determined. Control of dehydrogenation rate in primary dehydrogenation process
It is easy. For example, furnace volume and vacuum pump
Once the exhaust capacity of the furnace is determined, the RT-based master alloy for nitriding
It can be controlled freely by adjusting the amount. Or furnace
Pressure control in the piping connecting the inside and the vacuum pump
It can be controlled by installing a laser. There
Is a predetermined degree of vacuum y (Pa) by opening and closing the valve
The primary dehydrogenation process that holds x (seconds) for one
And gradually reduce the degree of vacuum y (Pa).
Perform the primary dehydrogenation process in multiple steps on a
Dehydrogenation rate in the primary dehydrogenation process is x = 60-1000 seconds
And y = AxzGoing to be represented by an exponential function
Is also good.
【0011】[0011]
【発明の実施の形態】以下に本発明のR−T−N系異方
性磁粉の組成限定理由を説明するが、%と単に記してい
るのは重量%を意味している。BEST MODE FOR CARRYING OUT THE INVENTION The reasons for limiting the composition of the RTN-based anisotropic magnetic powder of the present invention will be described below, but the simple description of% means% by weight.
【0012】R含有量は20〜30%が好ましく、22〜28が
より好ましい。R含有量が20%未満ではiHcが397.9kA/m
(5kOe)未満になり、30%超では(BH)maxが大きく低
下する。RにはSmを必ず含み、SmおよびLa以外に
Y、Ce、Pr、Nd、Eu、Gd、Tb、Dy、H
o、Er、Tm、YbおよびLuの少なくとも1種を含
むことが許容される。Smミッシュメタルやジジム等の
2種以上の希土類元素の混合物を用いてもよい。Rとし
て、より好ましくはSmまたはSmおよびLaとY、C
e、Pr、Nd、Gd、DyおよびErの少なくとも1
種の組み合わせ、さらに好ましくはSmまたはSmおよ
びLaとY、Ce、PrおよびNdの少なくとも1種と
の組み合わせ、特にRがSmまたはSmおよびLaから
なることが好ましい。Smの純度でいえば、iHc≧397.9
kA/m(5kOe)とするために、Rに占めるSm比率を、
好ましくは50原子%以上、さらに好ましくは70原子%以
上とすることがよい。Rには、製造上混入が避けられな
いO、H、C、Al、Si、Na、MgおよびCa等の
不可避的不純物を合計でRのうちの10原子%以下含有す
ることが許容される。The R content is preferably from 20 to 30%, more preferably from 22 to 28. If the R content is less than 20%, iHc is 397.9kA / m
(5 kOe), and when it exceeds 30%, (BH) max is greatly reduced. R always contains Sm, and in addition to Sm and La, Y, Ce, Pr, Nd, Eu, Gd, Tb, Dy, H
It is permissible to include at least one of o, Er, Tm, Yb and Lu. A mixture of two or more rare earth elements such as Sm misch metal and dymium may be used. R is more preferably Sm or Sm and La and Y, C
at least one of e, Pr, Nd, Gd, Dy and Er
A combination of species, more preferably a combination of Sm or Sm and La with at least one of Y, Ce, Pr and Nd, particularly preferably R comprises Sm or Sm and La. In terms of Sm purity, iHc ≧ 397.9
To obtain kA / m (5 kOe), the ratio of Sm to R is
It is preferably at least 50 atomic%, more preferably at least 70 atomic%. R is allowed to contain unavoidable impurities such as O, H, C, Al, Si, Na, Mg and Ca, which cannot be avoided in production, in a total of 10 atomic% or less of R.
【0013】本発明のR−T−N系異方性磁粉にM元素
(MはB、Ti、NbおよびGaの少なくとも1種)を
0.1〜5%含有するとき、iHcが高められて磁気特性の耐
熱性が向上する。M元素の含有量が0.1%未満では磁気
特性の耐熱性を向上する効果が認められず、5%超では
(BH)maxが大きく低下する。An M element (M is at least one of B, Ti, Nb and Ga) is added to the RTN based anisotropic magnetic powder of the present invention.
When the content is 0.1 to 5%, iHc is increased, and the heat resistance of magnetic properties is improved. If the content of the element M is less than 0.1%, the effect of improving the heat resistance of the magnetic properties is not recognized.
(BH) max is greatly reduced.
【0014】窒素の含有量は2.5〜3.5%が好ましく、2.
7〜3.3%がより好ましい。窒素含有量が2.5%未満およ
び3.5%超ではiHcおよび(BH)maxが大きく低下する。The nitrogen content is preferably 2.5-3.5%, and 2.
7 to 3.3% is more preferred. When the nitrogen content is less than 2.5% or more than 3.5%, iHc and (BH) max are greatly reduced.
【0015】Feの一部を0.1〜25のCoで置換するこ
とが好ましく、1〜15原子%のCoで置換することがよ
り好ましい。所定量のCoを含有することによりキュリ
ー温度およびiHcの温度係数が向上するが、Co含有量
が25%超では(BH)maxおよびiHcが顕著に低下し、0.1%
未満では添加による磁気特性の改善効果が認められな
い。It is preferable that a part of Fe is substituted with 0.1 to 25 Co, and more preferably 1 to 15 atomic% of Co. The Curie temperature and the temperature coefficient of iHc are improved by containing a predetermined amount of Co. However, when the Co content is more than 25%, (BH) max and iHc are remarkably reduced, and 0.1%
If it is less than 1, the effect of improving the magnetic properties by addition is not recognized.
【0016】窒化に供するR−T系母合金として、還元
/拡散法、高周波溶解法またはアーク溶解法等によるR
−T系母合金溶湯を鋳型鋳造法またはストリップキャス
ト法により凝固せしめたものを使用することができる。
ストリップキャスト法による場合、R−T系母合金溶湯
の急冷凝固に用いる冷却用ロールの周速を、好ましくは
0.05〜10m/秒、より好ましくは0.1〜8m/秒とする
ことが急冷凝固したR−T系母合金のαFeの発生量を
低減し、かつ最終的に得られるR−T−N系磁粉のαF
e量の低減を実現し、丸みを帯び、充填性に富んだ粒子
形態にするためによい。As an RT type mother alloy to be subjected to nitriding, reduction
/ R by diffusion method, high frequency melting method or arc melting method
It is possible to use a solidified T-based mother alloy by a mold casting method or a strip casting method.
In the case of the strip casting method, the peripheral speed of the cooling roll used for rapid solidification of the molten RT-based master alloy is preferably
0.05 to 10 m / sec, more preferably 0.1 to 8 m / sec, reduces the amount of αFe generated in the rapidly solidified RT master alloy and reduces the amount of finally obtained RTN magnetic powder. αF
It is good for realizing a reduction in the amount of e, for forming a rounded, highly-packed particle form.
【0017】還元/拡散法によるR−T系母合金を用い
て、本発明のR−T−N系異方性磁粉を作製する場合の
好ましい製造条件を以下に説明する。まず、Rの酸化物
とTまたはTの酸化物を用いて、R−T−N系磁粉に対
応したR−T系母合金の主要成分組成に配合する。さら
にRの酸化物および必要に応じてTの酸化物が化学反応
式上100%還元される量(これを化学量論的必要量とい
う)の0.5〜2倍に相当する量の還元剤(Ca、Mg、
CaH2およびMgH 2の少なくとも1種)を前記配合
物に添加後、混合する。続いて、混合物を不活性ガス雰
囲気中で1000〜1300℃×1〜20時間加熱してRの酸化物
等を還元し、続いて還元したRとTとを十分に相互拡散
させた後室温まで冷却する。還元剤の添加量が化学量論
的必要量の0.5倍未満では工業生産上有益な還元反応が
実現されず、2倍超では最終的にR−T−N系磁粉に残
留する還元剤量が増大して磁気特性の低下を招く。ま
た、不活性ガス雰囲気中での加熱条件が1000℃×1時間
未満では工業生産上有益な還元/拡散反応が進行せず、
1300℃×20時間超では還元/拡散反応炉の劣化が顕著に
なる。次に、反応物を洗浄液中に投入してCaO等の反
応副生成物を洗い流した後、脱水および真空乾燥を行っ
て還元/拡散法によるR−T系母合金が得られる。次
に、必要に応じて前記R−T系母合金を、窒素を含まな
い不活性ガス雰囲気中で1010〜1280℃×1〜40時間加熱
する均質化熱処理を行い、αFe等の偏析相を固溶させ
た後、室温まで冷却する。均質化熱処理の条件が1010℃
×1時間未満ではαFeやSmFe3等の偏析相の固溶
が進まず、1280℃×40時間超では均質化熱処理の効果が
飽和し、Sm等の蒸発による組成ずれが顕著になる。こ
うして得られたR−T系母合金は、Ca含有量が好まし
くは0.4重量%以下、より好ましくは0.2重量%以下、特
に好ましくは0.1重量%以下であり、酸素含有量が好ま
しくは0.8重量%以下、より好ましくは0.4重量%以下、
特に好ましくは0.2重量%以下であり、炭素含有量が好
ましくは0.3重量%以下、より好ましくは0.2重量%以
下、特に好ましくは0.1重量%以下のものである。次
に、0.005Pa〜1.0×106Pa(4.9×10−8〜10atm)の水
素ガス中または水素ガス分圧を有する不活性ガス(窒素
ガスを除く)中で500〜900℃に加熱する水素化・分解反
応処理、および続いて650〜900℃でかつ後述の脱水素条
件下で脱水素・再結合反応処理を行う。水素化・分解反
応によりR−T系母合金は希土類元素Rの水素化物RH
x、αFe、FeCo相などに分解する。続いて、脱水
素・再結合反応により、R2T 17相に再結晶させて平
均再結晶粒径が0.02〜5μmでありかつ再結晶粒径が5
μm以下の再結晶粒の面積比率が90%以上のR−T系母
合金粒子が得られる。各R−T系母合金粒子を構成する
個々の再結晶粒はほぼ一致した磁化容易軸を有するの
で、窒化後のものは良好な磁場配向性を示す。水素化・
分解反応処理の水素分圧が0.005Pa(4.9×10−8atm)
未満では分解反応が起こらず、1.0×106Pa(10atm)超
では高圧設備を必要とするのでコスト増を招く。また水
素化・分解反応処理の加熱条件が500℃未満ではR−T
系母合金が水素を吸収するのみでRHx相などへの分解
が起こらず、900℃超では脱水素後のR−T系母合金が
粗大粒化し、R−T−N系異方性ボンド磁石のiHc、Hk
が大きく低下する。脱水素・再結合反応処理の加熱温度
が650℃未満ではRHx等の分解が進行せず、900℃超で
は再結晶組織が粗大粒化してiHc、Hkが大きく低下す
る。次に必要に応じて粉砕を行い、その後窒化すること
により本発明のR−T−N系異方性磁粉が得られる。窒
化前に必要に応じて分級または篩分し、粒径分布を調整
することが均一な窒化組織を実現し、かつR−T−N系
異方性ボンド磁石の成形容易性および密度を向上するた
めに好ましい。窒化は、2.0×104〜1.0×106Pa (0.2
〜10atm)の窒素ガス、水素が1〜95モル%で残部が窒素
からなる(水素+窒素)の混合ガス、NH3のモル%が
1〜50%で残部水素からなる(NH3+水素)の混合ガ
スのいずれかの雰囲気中で300〜650℃×0.1〜30時間加
熱するガス窒化が実用性に富んでいる。ガス窒化の加熱
条件は300〜650℃×0.1〜30時間が好ましく、400〜550
℃×0.5〜20時間がより好ましい。300℃×0.1時間未満
では窒化が進行せず、650℃×30時間超では逆にRN相
を生成しiHcが低下する。窒化における窒素単独ガスま
たは窒素含有ガスの圧力は2.0×104〜1.0×106Pa
(0.2〜10atm)が好ましく、5.0×104〜5.0×105Pa
(0.5〜5atm)がより好ましい。2.0×104Pa(0.2at
m)未満では窒化反応が非常に遅くなり、1.0×106Pa
(10atm)超では高圧ガス設備によるコスト増を招く。
窒化後に、真空中あるいは不活性ガス中(窒素ガスを除
く)で300〜600℃×0.5〜50時間の熱処理を行うとiHcを
さらに高めることができる。こうして得られたR−T−
N系磁粉には10〜500ppm(重量比)の水素の含有が許容
される。水素含有量が10ppm未満のものは工業生産上製
造が困難であり、500ppm超では実用に耐える有用な磁気
特性を実現することが困難である。Using an RT master alloy by a reduction / diffusion method
Thus, when preparing the RTN-based anisotropic magnetic powder of the present invention,
Preferred manufacturing conditions are described below. First, the oxide of R
And R or T-N oxide powder using
The main component composition of the corresponding RT master alloy is blended. Further
Chemical reaction of R oxide and T oxide if necessary
The amount reduced by 100% in the formula (this is called the stoichiometric requirement)
Of the reducing agent (Ca, Mg,
CaH2And MgH 2At least one of the above)
After adding to the mixture, mix. Subsequently, the mixture is brought to an inert gas atmosphere.
Heat in an atmosphere at 1000-1300 ° C for 1-20 hours to make R oxide
Etc., and then the reduced R and T are sufficiently interdiffused.
After cooling, cool to room temperature. Stoichiometric amount of reducing agent added
If the target amount is less than 0.5 times the reduction required for industrial production,
Not realized, and more than twice ultimately remains in RTN-based magnetic powder
As a result, the amount of the reducing agent to be retained increases, and the magnetic properties are lowered. Ma
In addition, the heating condition in an inert gas atmosphere is 1000 ° C × 1 hour
If it is less than 1, the reduction / diffusion reaction useful for industrial production does not proceed,
If the temperature exceeds 1300 ° C x 20 hours, deterioration of the reduction / diffusion reactor is remarkable
Become. Next, the reactant is introduced into the cleaning solution to react with CaO or the like.
After washing off by-products, dehydrate and vacuum dry.
To obtain an RT master alloy by a reduction / diffusion method. Next
If necessary, the RT master alloy may be replaced with no nitrogen.
1010-1280 ° C x 1-40 hours in an inert gas atmosphere
Heat treatment to dissolve segregated phases such as αFe
Then, cool to room temperature. Homogenization heat treatment condition is 1010 ℃
× If less than 1 hour, αFe or SmFe3Solution of segregated phases such as
If the temperature exceeds 1280 ° C x 40 hours, the effect of the homogenization heat treatment
The composition is saturated and the composition shift due to evaporation of Sm or the like becomes remarkable. This
The obtained RT alloy has a preferable Ca content.
0.4% by weight or less, more preferably 0.2% by weight or less,
Is preferably 0.1% by weight or less, and the oxygen content is preferably
0.8% by weight or less, more preferably 0.4% by weight or less,
Particularly preferably, the content is 0.2% by weight or less, and the carbon content is good.
Preferably 0.3% by weight or less, more preferably 0.2% by weight or less
Below, particularly preferably 0.1% by weight or less. Next
, 0.005Pa ~ 1.0 × 106Pa (4.9 × 10-8~ 10atm) water
Inert gas in hydrogen gas or having a partial pressure of hydrogen gas (nitrogen
(Excluding gas) heated to 500 ~ 900 ℃
Followed by dehydrogenation at 650-900 ° C and described below.
Dehydrogenation and recombination reaction treatment is performed under the conditions. Hydrogenation and decomposition
In response, the RT alloy becomes a hydride RH of the rare earth element R.
Decomposes into x, αFe, FeCo phase, etc. Followed by dehydration
By the elementary-recombination reaction, R2T 17Recrystallize into phases
The average recrystallized particle size is 0.02 to 5 μm and the recrystallized particle size is 5
RT based mother having an area ratio of recrystallized grains of μm or less of 90% or more
Alloy particles are obtained. Construct each RT-based master alloy particle
Individual recrystallized grains have nearly coincident easy axes
And after nitriding shows good magnetic field orientation. Hydrogenation
The hydrogen partial pressure of the decomposition reaction treatment is 0.005 Pa (4.9 × 10-8atm)
If less than 1.0 × 106Over Pa (10atm)
In this case, high pressure equipment is required, which leads to an increase in cost. Also water
If the heating condition of the soaking / decomposition reaction is less than 500 ° C, RT
Decomposition into RHx phase etc. only by the system master alloy absorbing hydrogen
When the temperature exceeds 900 ° C, the RT-based master alloy after dehydrogenation
IHc and Hk of R-T-N anisotropic bonded magnet
Greatly decreases. Heating temperature for dehydrogenation / recombination reaction treatment
Is less than 650 ° C, decomposition of RHx etc. does not proceed,
Means that the recrystallized structure is coarse and iHc and Hk are greatly reduced
You. Next, if necessary, pulverize and then nitridate
As a result, the RTN-based anisotropic magnetic powder of the present invention is obtained. Nitrification
Classification or sieving as necessary before sizing to adjust particle size distribution
To achieve a uniform nitrided structure, and an RTN system
To improve the moldability and density of anisotropic bonded magnets
Preferred for Nitriding is 2.0 × 104~ 1.0 × 106Pa (0.2
~ 10atm) nitrogen gas, hydrogen is 1 ~ 95mol% and the balance is nitrogen
Gas mixture of (hydrogen + nitrogen), NH3Mole% of
1-50% consisting of the balance hydrogen (NH3+ Hydrogen)
In an atmosphere of 300 to 650 ° C x 0.1 to 30 hours
Heated gas nitriding is very practical. Heating of gas nitriding
The conditions are preferably 300 to 650 ° C x 0.1 to 30 hours, and 400 to 550
C. x 0.5 to 20 hours is more preferable. 300 ° C x less than 0.1 hour
Nitridation does not progress in the case of 650 ° C. for more than 30 hours.
And iHc decreases. Nitrogen alone gas in nitriding
Or the pressure of the nitrogen-containing gas is 2.0 × 104~ 1.0 × 106Pa
(0.2 to 10 atm), preferably 5.0 × 104~ 5.0 × 105Pa
(0.5 to 5 atm) is more preferable. 2.0 × 104Pa (0.2at
Below m), the nitridation reaction becomes very slow,6Pa
If it exceeds (10 atm), the cost will increase due to the high pressure gas equipment.
After nitriding, vacuum or inert gas (excluding nitrogen gas)
Heat treatment at 300-600 ° C x 0.5-50 hours at
Can be even higher. The R-T- thus obtained
N-based magnetic powder can contain 10-500ppm (weight ratio) of hydrogen
Is done. Those with a hydrogen content of less than 10 ppm are manufactured on industrial production
Useful magnets that are difficult to produce
It is difficult to achieve the characteristics.
【0018】本発明のR−T−N系異方性磁粉の平均粒
径は5〜300μmが好ましく、5〜100μmがより好まし
く、10〜50μmが特に好ましい。平均粒径が5μm未満
では酸化が顕著になり、磁気特性の耐熱性および(BH)ma
x等が大きく低下し、平均粒径が300μm超では表面性が
悪化して磁気回路のギャップの小さい用途への適用が困
難になる。The average particle size of the RTN-based anisotropic magnetic powder of the present invention is preferably 5 to 300 μm, more preferably 5 to 100 μm, and particularly preferably 10 to 50 μm. If the average particle size is less than 5 μm, the oxidation becomes remarkable, and the heat resistance of the magnetic properties and (BH) ma
When x and the like are greatly reduced, and when the average particle size exceeds 300 μm, the surface properties are deteriorated, and it is difficult to apply the magnetic circuit to applications having a small gap.
【0019】R−T−N系異方性磁粉の主相は2-17型
結晶構造の硬質磁性相であり、高い(BH)maxおよび良好
なHkを具備するために、前記硬質磁性相の平均再結晶粒
径が0.02〜5μmのときは面積比率で90%以上の前記硬
質磁性相の再結晶粒の粒径を5μm以下にすることが好
ましく、前記硬質磁性相の平均再結晶粒径が0.02〜1μ
mのときは面積比率で90%以上の前記硬質磁性相の再結
晶粒の粒径を1μm以下にすることがさらに好ましく、
前記硬質磁性相の平均再結晶粒径が0.02〜0.5μmのと
きは面積比率で90%以上の前記硬質磁性相の再結晶粒の
粒径を0.5μm以下にすることが特に好ましい。磁気特
性を高めるために、R−T−N系異方性磁粉のαFeの
含有比率を、面積比率の平均値で5%以下にすることが
好ましく、3%以下がより好ましく、1%以下が特に好
ましい。硬質磁性相、αFeの同定および各相の面積比
率の算出は、電子顕微鏡、光学顕微鏡等により撮影した
断面組織写真、電子回折結果およびx線回折結果等を考
慮して求める。例えば、対象とするR−T−N系磁粉粒
子の断面を撮影した透過型電子顕微鏡写真およびその断
面組織の同定結果を符合させて求めることができる。The main phase of the RTN-based anisotropic magnetic powder is a hard magnetic phase having a 2-17 type crystal structure, and has a high (BH) max and good Hk. When the average recrystallized particle size is 0.02 to 5 μm, the particle size of the recrystallized particles of the hard magnetic phase having an area ratio of 90% or more is preferably set to 5 μm or less. 0.02-1μ
When m, it is further preferable that the grain size of the recrystallized grains of the hard magnetic phase having an area ratio of 90% or more is 1 μm or less,
When the average recrystallized grain size of the hard magnetic phase is 0.02 to 0.5 μm, it is particularly preferable to set the grain size of the recrystallized grains of the hard magnetic phase having an area ratio of 90% or more to 0.5 μm or less. In order to enhance the magnetic properties, the content ratio of αFe of the RTN-based anisotropic magnetic powder is preferably 5% or less, more preferably 3% or less, and more preferably 1% or less in the average value of the area ratio. Particularly preferred. The identification of the hard magnetic phase and αFe and the calculation of the area ratio of each phase are determined in consideration of a cross-sectional structure photograph taken by an electron microscope, an optical microscope or the like, an electron diffraction result, an x-ray diffraction result, and the like. For example, it can be determined by matching a transmission electron micrograph of a cross section of the target RTN-based magnetic powder particle with the identification result of the cross-sectional structure.
【0020】本発明のR−T−N系異方性ボンド磁石の
バインダーとして熱硬化性樹脂、熱可塑性樹脂またはゴ
ム材料が好適である。圧縮成形法、射出成形法またはカ
レンダーロール法による場合はバインダーとして熱可塑
性樹脂または熱硬化性樹脂を用いることが好ましい。A thermosetting resin, a thermoplastic resin or a rubber material is suitable as a binder of the RTN anisotropic bonded magnet of the present invention. In the case of the compression molding method, the injection molding method or the calender roll method, it is preferable to use a thermoplastic resin or a thermosetting resin as the binder.
【0021】[0021]
【実施例】以下、実施例により本発明を詳細に説明する
が、それら実施例により本発明が限定されるものではな
い。 (実施例1)表1の実施例1の窒化磁粉組成に対応する
主要成分組成に調整したSm−Fe系母合金を高周波溶
解し、鋳型鋳造した。次いで、αFe等の偏析相を固溶
させるために、鋳造したSm−Fe系母合金をアルゴン
ガス雰囲気中で1100℃×10時間加熱後、室温まで冷却す
る均質化熱処理を行った。次いで、水素化・分解反応処
理および続いて脱水素・再結合反応処理を以下の条件で
行った。まず、640dm3/分(640リットル/分)の排気能力を
有する真空ポンプを備えた所定容積の雰囲気制御炉に、
均質化熱処理済みのR−Fe系母合金を10kg入炉した。
次いで、室温で85kPa(0.85atm)の水素雰囲気とし、こ
の水素雰囲気を保ちながら室温から5℃/分の昇温速度
で820℃まで加熱し、次いで820℃で3時間保持した。続
いて820℃で到達真空度が10Pa(7.5×10−2Torr)以
下になるまで排気する脱水素・再結合反応処理を行っ
た。脱水素・再結合反応処理後、炉内をアルゴンガス雰
囲気に置換し、その後室温まで冷却した。前記脱水素・
再結合反応処理の開始後60秒を経過した時点から炉内の
真空度(水素分圧)を測定し、対数グラフ上にプロット
した。結果を図1に示す。図1において、10kgと記した
ものがこの実施例のデータである。図1より、脱水素を
開始後60〜1000秒までの一次脱水素工程の真空度は直線
に近似でき、1000秒超の二次脱水素工程で急激に真空度
が高くなる(水素分圧が低くなる)ことがわかる。次
に、水素化・分解反応処理および脱水素・再結合反応処
理を完了したSm−Fe系母合金をアルゴンガス雰囲気
中で粉砕後、75μmアンダーに篩分した。次いで、窒化
ガス雰囲気中で450℃×10時間加熱する窒化処理を施
し、その後室温まで冷却し、平均粒径が38μmの本発明
のSm−Fe−N系異方性磁粉を得た。この異方性磁粉
は平均再結晶粒径が0.15μmでありかつ0.3μm以下の
再結晶粒が面積比率で96%である硬質磁性相(Th2Z
n17型)とごく少量のαFeとからなっており、αF
eは面積比率の平均値で1%未満であり非常に少なかっ
た。平均再結晶粒径は、前記Sm−Fe−N系磁粉粒子
を顕微鏡観察用樹脂中に埋め込み、研磨後、前記Sm−
Fe−N系磁粉粒子の研磨断面を電子顕微鏡により撮影
した。次いで、撮影した断面写真の代表的な視野におい
て30個の結晶粒を貫通する直線を引き、(30個分の結晶
粒が貫通する線分長さ)を(貫通する結晶粒の数:30
個)で除して求めた。また、平均再結晶粒の粒径分布は
測定した前記30個の結晶粒径値の分布から求めた。次
に、前記Sm−Fe−N系磁粉:95.3重量部、シランカ
ップリング剤:0.5重量部、液状エポキシ樹脂:3.5重量
部、硬化剤DDS(ジアミノジフェニルスルフォン):0.7
重量部を配合し、混合した。次いで混合物を約90℃に加
熱した二軸混練機に投入して混練し、コンパウンドを作
製した。次いで、コンパウンドを所定の成形機に投入
し、磁場中で圧縮成形した。次いで加熱硬化後、室温ま
で冷却して本発明のSm−Fe−N系異方性ボンド磁石
を得た。表1にSm−Fe系母合金の入炉量、脱水素時
間x=10〜1000秒におけるz値およびA値、作製したS
m−Fe−N系異方性ボンド磁石の密度および室温にお
ける磁気特性((BH)max、iHc)を示す。次に、前記コン
パウンドを用いて磁場中で圧縮成形し、パーミアンス係
数(Pc)が2;(厚み)/(直径)=0.7 の中実円筒状
の異方性ボンド磁石(試料)を得た。次いで加熱硬化を
行い、その後室温まで冷却した。次に、前記試料を、20
℃、2387.4kA/m(30kOe)で着磁後、総磁束量(Φ)を
測定した。次いで、大気中で120℃×1時間加熱後室温
まで冷却し、総磁束量(Φ1)を測定した。磁気特性の
耐熱性の指標として、下記式で定義した不可逆減磁率
(総磁束量の変化率)を用いて評価した。 (不可逆減磁率)=(Φ−Φ1)/(Φ)×100(%) その結果、この異方性ボンド磁石の磁気特性の耐熱性
(不可逆減磁率)は2.1%であり、十分実用に耐えるこ
とがわかった。また、この異方性ボンド磁石の減磁曲線
の角形性は良好であった。 (比較例1)実施例1において作製したコンパウンドを
成形機に投入し、磁場を印加せずに無磁場で圧縮成形し
て等方性のSm−Fe−N系ボンド磁石を得た。この等
方性ボンド磁石の評価結果を表1に示す。 (実施例2〜4、比較例2、3)入炉量を表1の値に変
えた以外は実施例1と同様にして実施例2〜4、比較例
2、3の各Sm−Fe−N系磁粉を作製し、Sm−Fe
−N系異方性ボンド磁石を作製した。なお、図1におけ
る3kg〜65gは実施例2〜4および比較例2、3のそ
れぞれにおける入炉量を示している。実施例2〜4のS
m−Fe−N系異方性磁粉は平均粒径が35〜53μmおよ
び平均再結晶粒径が0.15〜0.3μmでありかつ0.3μm以
下の再結晶粒が面積比率で90〜96%である硬質磁性相
(Th2Zn17型)とごく少量のαFeとからなって
いた。αFeは面積比率の平均値で1%未満であり非常
に少なかった。また、実施例2〜4の異方性ボンド磁石
の不可逆減磁率は2.1〜2.3%であり良好であった。ま
た、これらの異方性ボンド磁石の減磁曲線の角形性は良
好であった。 (比較例4)実施例1の均質化熱処理済みのSm−Fe
系母合金に対し、水素化・分解反応処理および脱水素・
再結合反応処理を施さずに、そのままアルゴンガス雰囲
気中で粉砕し、75μmアンダーに篩分した。次いで、窒
化ガス雰囲気中で450℃×10時間加熱する窒化処理を施
し、その後室温まで冷却した。次に、窒素ガスを粉砕媒
体とするジェットミルで微粉砕し、平均粒径1.9μmの
Sm−Fe−N系異方性磁粉を得た。以降は、この磁粉
を用いた以外は実施例1と同様にして異方性ボンド磁石
を作製し、不可逆減磁率を求めた。その結果、不可逆減
磁率は8.3%であり、磁気特性の耐熱性が非常に悪いこ
とがわかった。また、この異方性ボンド磁石の減磁曲線
の角形性は悪く、上記実施例のものに比べてHkは2.3〜
4%低かった。EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. (Example 1) An Sm-Fe-based master alloy adjusted to a main component composition corresponding to the composition of the magnetic nitride powder of Example 1 in Table 1 was subjected to high frequency melting and casting. Next, in order to dissolve a segregated phase such as αFe, the cast Sm—Fe-based mother alloy was heated in an argon gas atmosphere at 1100 ° C. for 10 hours, and then subjected to a homogenizing heat treatment of cooling to room temperature. Next, a hydrogenation / decomposition reaction treatment and a subsequent dehydrogenation / recombination reaction treatment were performed under the following conditions. First, an atmosphere control furnace of a predetermined volume equipped with a vacuum pump having a pumping capacity of 640 dm 3 / min (640 liter / min),
10 kg of the homogenized heat-treated R-Fe-based master alloy was introduced into the furnace.
Next, a hydrogen atmosphere of 85 kPa (0.85 atm) was set at room temperature, and while maintaining this hydrogen atmosphere, heating was performed from room temperature to 820 ° C. at a rate of 5 ° C./min, and then maintained at 820 ° C. for 3 hours. Subsequently, a dehydrogenation / recombination reaction treatment was carried out at 820 ° C. until the ultimate vacuum reached 10 Pa (7.5 × 10 −2 Torr) or less. After the dehydrogenation / recombination reaction treatment, the inside of the furnace was replaced with an argon gas atmosphere, and then cooled to room temperature. The dehydrogenation
60 seconds after the start of the recombination reaction treatment, the degree of vacuum (hydrogen partial pressure) in the furnace was measured and plotted on a logarithmic graph. The results are shown in FIG. In FIG. 1, what is indicated as 10 kg is the data of this embodiment. From FIG. 1, the degree of vacuum in the primary dehydrogenation process from 60 to 1000 seconds after the start of dehydrogenation can be approximated to a straight line, and the degree of vacuum rapidly increases in the secondary dehydrogenation process over 1000 seconds (the hydrogen partial pressure increases. Lower). Next, the Sm—Fe-based master alloy that had been subjected to the hydrogenation / decomposition reaction treatment and the dehydrogenation / recombination reaction treatment was pulverized in an argon gas atmosphere, and then sieved to 75 μm under. Next, nitriding treatment was performed by heating at 450 ° C. for 10 hours in a nitriding gas atmosphere, and then cooled to room temperature to obtain an Sm—Fe—N-based anisotropic magnetic powder of the present invention having an average particle size of 38 μm. This anisotropic magnetic powder has a hard magnetic phase (Th 2 Z) having an average recrystallized particle size of 0.15 μm and a recrystallized particle size of 0.3 μm or less having an area ratio of 96%.
n 17-inch) and has become from a very small amount of αFe, αF
e was less than 1% on average of the area ratio, which was very small. The average recrystallized particle diameter is determined by embedding the Sm-Fe-N-based magnetic powder particles in a resin for microscopic observation, polishing,
The polished cross section of the Fe—N-based magnetic powder particles was photographed with an electron microscope. Next, a straight line penetrating 30 crystal grains is drawn in a representative visual field of the photographed cross-sectional photograph, and (the length of a line segment through which 30 crystal grains penetrate) is calculated by (number of crystal grains penetrating: 30).
). The particle size distribution of the average recrystallized grains was determined from the distribution of the measured 30 crystal grain size values. Next, the Sm-Fe-N-based magnetic powder: 95.3 parts by weight, a silane coupling agent: 0.5 parts by weight, a liquid epoxy resin: 3.5 parts by weight, a curing agent DDS (diaminodiphenylsulfone): 0.7.
Parts by weight were blended and mixed. Next, the mixture was put into a twin-screw kneader heated to about 90 ° C. and kneaded to prepare a compound. Next, the compound was charged into a predetermined molding machine and compression-molded in a magnetic field. Next, after heat curing, the mixture was cooled to room temperature to obtain an Sm-Fe-N-based anisotropic bonded magnet of the present invention. Table 1 shows the amount of furnace, the z value and the A value at a dehydrogenation time x of 10 to 1000 seconds, and the S
The density and the magnetic characteristics ((BH) max, iHc) at room temperature of the m-Fe-N based anisotropic bonded magnet are shown. Next, the compound was compression-molded in a magnetic field to obtain a solid cylindrical anisotropic bonded magnet (sample) having a permeance coefficient (Pc) of 2; (thickness) / (diameter) = 0.7. Next, heat curing was performed, and then the temperature was cooled to room temperature. Next, the sample was
After magnetizing at 2387.4 kA / m (30 kOe) at ℃, the total magnetic flux (Φ) was measured. Next, after heating in air at 120 ° C. for 1 hour, the mixture was cooled to room temperature, and the total magnetic flux (Φ1) was measured. The evaluation was performed using an irreversible demagnetization rate (change rate of the total magnetic flux amount) defined by the following equation as an index of heat resistance of magnetic properties. (Irreversible demagnetization rate) = (Φ−Φ1) / (Φ) × 100 (%) As a result, the heat resistance (irreversible demagnetization rate) of the magnetic properties of this anisotropic bonded magnet is 2.1%, which is sufficient for practical use. I understand. Further, the squareness of the demagnetization curve of this anisotropic bonded magnet was good. (Comparative Example 1) The compound produced in Example 1 was put into a molding machine, and compression-molded without a magnetic field without applying a magnetic field to obtain an isotropic Sm-Fe-N-based bonded magnet. Table 1 shows the evaluation results of the isotropic bonded magnet. (Examples 2 to 4, Comparative Examples 2 and 3) Sm-Fe- of Examples 2 to 4 and Comparative Examples 2 and 3 in the same manner as in Example 1 except that the furnace input amount was changed to the value shown in Table 1. N-based magnetic powder was prepared and Sm-Fe
An -N based anisotropic bonded magnet was produced. Note that 3 kg to 65 g in FIG. 1 indicate the furnace input amounts in Examples 2 to 4 and Comparative Examples 2 and 3, respectively. S of Examples 2 to 4
The m-Fe-N type anisotropic magnetic powder is hard having an average particle size of 35 to 53 μm, an average recrystallized particle size of 0.15 to 0.3 μm, and recrystallized particles of 0.3 μm or less in an area ratio of 90 to 96%. It consisted of a magnetic phase (Th 2 Zn 17 type) and a very small amount of αFe. αFe was very small, less than 1% on average of the area ratio. The irreversible demagnetization rates of the anisotropic bonded magnets of Examples 2 to 4 were 2.1 to 2.3%, which was good. The squareness of the demagnetization curves of these anisotropic bonded magnets was good. (Comparative Example 4) Homogenized heat-treated Sm-Fe of Example 1
Hydrogenation and decomposition reaction treatment and dehydrogenation
Without subjecting to a recombination reaction treatment, it was pulverized in an argon gas atmosphere as it was, and sieved to under 75 μm. Next, a nitriding treatment was performed by heating at 450 ° C. × 10 hours in a nitriding gas atmosphere, and then cooled to room temperature. Next, the powder was finely pulverized with a jet mill using nitrogen gas as a pulverizing medium to obtain an Sm-Fe-N-based anisotropic magnetic powder having an average particle size of 1.9 µm. Thereafter, an anisotropic bonded magnet was produced in the same manner as in Example 1 except that this magnetic powder was used, and the irreversible demagnetization rate was obtained. As a result, the irreversible demagnetization rate was 8.3%, indicating that the heat resistance of the magnetic properties was very poor. In addition, the squareness of the demagnetization curve of this anisotropic bonded magnet is poor, and Hk is 2.3 to
It was 4% lower.
【0022】[0022]
【表1】 [Table 1]
【0023】図1より、脱水素を開始後60〜1000秒まで
の一次脱水素工程の真空度はいずれも直線に近似でき、
1000秒超の二次脱水素工程において入炉するR−Fe系
母合金量が減少するほど急激に真空度が高くなることが
わかる。また一次脱水素工程における各近似直線から求
めた勾配(z値)は入炉量が多いほど増大しており、入
炉量が多いほど脱水素速度が遅くなることがわかる。ま
た表1より、脱水素速度が早いほど(BH)maxは小さくな
り、脱水素速度が遅いほど(BH)maxが大きくなることが
わかる。特に、実施例1、2のSm−Fe−N系異方性
ボンド磁石は非常に高い(BH)maxを有している。From FIG. 1, the degree of vacuum in the primary dehydrogenation step from 60 to 1000 seconds after the start of dehydrogenation can be approximated to a straight line.
It can be seen that the degree of vacuum sharply increases as the amount of the R-Fe-based master alloy entering the furnace decreases in the secondary dehydrogenation step for more than 1000 seconds. Also, it can be seen that the gradient (z value) obtained from each approximation straight line in the primary dehydrogenation step increases as the furnace input amount increases, and the dehydrogenation rate decreases as the furnace input amount increases. Table 1 also shows that (BH) max decreases as the dehydrogenation rate increases, and (BH) max increases as the dehydrogenation rate decreases. In particular, the Sm-Fe-N based anisotropic bonded magnets of Examples 1 and 2 have very high (BH) max.
【0024】(実施例5)Sm23.7Febal.T
ixB0.2N3.1, Sm23.7Feba l.B
xN3.1,Sm23.7Febal.GaxN3.1
およびSm23. 7Febal.NbxN3.1(いず
れもx=0〜7%)で示される主要成分組成の各窒化磁
粉に対応するSm−Fe−M系母合金を作製した。次い
で、実施例1と同様の均質化熱処理および水素化・分解
反応処理を施した。続いて各水素化・分解反応処理後の
ものに対し、それぞれ脱水素・再結合反応処理における
入炉量(処理量)を10kgとした以外は実施例1と同様に
して、脱水素・再結合反応処理を行った。各々の一次脱
水素工程におけるz値は−0.20〜−0.28であった。以降
は実施例1と同様にして前記の各Sm−Fe―M−N系
異方性磁粉を作製した。これらの異方性磁粉は平均粒径
が33〜55μmであり、平均再結晶粒径は0.2〜0.35μm
でありかつ0.35μm以下の再結晶粒が面積比率で91〜95
%である硬質磁性相(Th2Zn17型)とごく少量の
αFeとからなっていた。αFeは面積比率の平均値で
1%未満であり非常に少なかった。前記各Sm−Fe−
M−N系異方性磁粉をそれぞれ用いた以外は実施例1と
同様にして異方性ボンド磁石を作製した。これらの異方
性ボンド磁石の室温における(BH)maxと配合した各磁粉
のM元素(TiB、B、GaまたはNb)含有量x(w
t%)との関係を図2に示す。図2より、高い(BH)max
を保持するために、B含有量は3%以下、Ti、Gaま
たはNb含有量は5%以下が望ましいことがわかる。ま
た、実施例1と同様にして評価した不可逆減磁率は、B
含有量が0.1〜3%のもの、Ti含有量が0.1〜5%のも
の、Ga含有量が0.1〜5%のものおよびNb含有量が
0.1〜5%のものでいずれもが1.7%以下であり、磁気特
性の耐熱性が向上していた。Example 5 Sm 23.7 Fe bal. T
i x B 0.2 N 3.1, Sm 23.7 Fe ba l. B
x N 3.1, Sm 23.7 Fe bal . Ga x N 3.1
And Sm 23. 7 Fe bal. An Sm-Fe-M base alloy corresponding to each magnetic nitride powder having a main component composition represented by Nb x N 3.1 (x = 0 to 7%) was produced. Next, the same homogenization heat treatment and hydrogenation / decomposition reaction treatment as in Example 1 were performed. Subsequently, the dehydrogenation / recombination was performed in the same manner as in Example 1 except that the furnace amount (processing amount) in the dehydrogenation / recombination reaction treatment was changed to 10 kg for each of the hydrogenation / decomposition reaction treatments. Reaction treatment was performed. The z value in each primary dehydrogenation step was -0.20 to -0.28. Thereafter, each of the above-described Sm-Fe-MN-based anisotropic magnetic powders was produced in the same manner as in Example 1. These anisotropic magnetic powders have an average particle size of 33 to 55 μm, and an average recrystallized particle size of 0.2 to 0.35 μm.
And 0.35 μm or less of recrystallized grains in an area ratio of 91 to 95
% Of the hard magnetic phase (Th 2 Zn 17 type) and a very small amount of αFe. αFe was very small, less than 1% on average of the area ratio. Each of the above Sm-Fe-
An anisotropic bonded magnet was produced in the same manner as in Example 1 except that the MN-based anisotropic magnetic powder was used. At room temperature of these anisotropic bonded magnets, (BH) max and the M element (TiB, B, Ga or Nb) content x (w
2 is shown in FIG. As shown in FIG. 2, the higher (BH) max
It can be seen that the B content is desirably 3% or less and the Ti, Ga or Nb content is desirably 5% or less in order to maintain the following. The irreversible demagnetization rate evaluated in the same manner as in Example 1 was B
When the content is 0.1-3%, when the Ti content is 0.1-5%, when the Ga content is 0.1-5%, and when the Nb content is
Each of the alloys having a content of 0.1 to 5% was 1.7% or less, and the heat resistance of the magnetic properties was improved.
【0025】(実施例6)Sm23.7−xLaxFe
bal.N3.1(x=0〜7%)で示される主要成分
組成の窒化磁粉に対応するSm−La−Fe系母合金を
作製後、実施例1と同様の均質化熱処理および水素化・
分解反応処理を施した。続いて、入炉量を10kgとした以
外は実施例1と同様にして脱水素・再結合反応処理を行
った。これらの一次脱水素工程におけるz値は−0.24〜
−0.28であった。次いで実施例1と同様にして粉砕、窒
化を行い本発明のSm−La−Fe−N系異方性磁粉を
得た。これら磁粉は平均粒径が33〜52μmであり、平均
再結晶粒径は0.18〜0.31μmでありかつ0.31μm以下の
再結晶粒が面積比率で90〜94%である硬質磁性相(Th
2Zn17型)とごく少量のαFeとからなっていた。
αFeは面積比率の平均値で1%未満であり非常に少な
かった。以降は各Sm−La−Fe−N系異方性磁粉を
用いた以外は実施例1と同様にして異方性ボンド磁石を
作製し、室温の1989.5kA/m (25kOe)で着磁し、室温
の(BH)maxを測定した。これら異方性ボンド磁石の(BH)m
axと配合した各Sm−La−Fe−N系異方性磁粉のL
a含有量x(wt%)との関係を図3に示す。図3よ
り、La含有量が0.1〜3.5%のときにx=0に比べて(B
H)maxが高められる(着磁性が改善される)ことがわか
る。また、このLa含有量が0.1〜3.5%のときの着磁性
は比較例4のものと同等以上であり良好であった。Example 6 Sm 23.7-x La x Fe
bal. N 3.1 After producing the Sm-La-Fe-based mother alloy corresponding to nitride magnetic powder of the main component composition represented by (x = 0~7%), similar homogenizing heat treatment and hydro-Example 1
A decomposition reaction treatment was performed. Subsequently, a dehydrogenation / recombination reaction treatment was performed in the same manner as in Example 1 except that the furnace input amount was changed to 10 kg. The z value in these primary dehydrogenation steps is -0.24 to
-0.28. Then, pulverization and nitriding were performed in the same manner as in Example 1 to obtain an Sm-La-Fe-N-based anisotropic magnetic powder of the present invention. These magnetic powders have an average particle size of 33 to 52 μm, an average recrystallized particle size of 0.18 to 0.31 μm, and a hard magnetic phase (Th) in which recrystallized particles of 0.31 μm or less have an area ratio of 90 to 94%.
2 Zn 17 type) and a very small amount of αFe.
αFe was very small, less than 1% on average of the area ratio. Thereafter, an anisotropic bonded magnet was prepared in the same manner as in Example 1 except that each Sm-La-Fe-N-based anisotropic magnetic powder was used, and magnetized at room temperature of 199.5 kA / m (25 kOe). The (BH) max at room temperature was measured. (BH) m of these anisotropic bonded magnets
L of each Sm-La-Fe-N-based anisotropic magnetic powder blended with ax
FIG. 3 shows the relationship with the a content x (wt%). From FIG. 3, when the La content is 0.1 to 3.5%, (B
It can be seen that H) max is increased (magnetization is improved). When the La content was 0.1 to 3.5%, the magnetization was equal to or better than that of Comparative Example 4 and was good.
【0026】(実施例7)Sm23.7Febal.C
oxN3.1(x=0〜35%)で示される主要成分組成
の窒化磁粉に対応するSm−Fe−Co系母合金を作製
後、実施例1と同様の均質化熱処理および水素化・分解
反応処理を施した。続いて、入炉量を10kgとした以外は
実施例1と同様にして脱水素・再結合反応処理を行っ
た。これらの一次脱水素工程におけるz値は−0.21〜−
0.27であった。次いで実施例1と同様にして粉砕、 窒
化を行い本発明のSm−Fe−Co−N系異方性磁粉を
得た。これら磁粉は平均粒径が30〜46μmであり、平均
再結晶粒径は0.19〜0.33μmでありかつ0.33μm以下の
再結晶粒が面積比率で90〜95%である硬質磁性相(Th
2Zn17型)とごく少量のαFeとからなっていた。
αFeは面積比率の平均値で1%未満であり非常に少な
かった。以降は各Sm−Fe−Co−N系異方性磁粉を
用いた以外は実施例1と同様にして異方性ボンド磁石を
作製し、室温の(BH)maxを測定した。これら異方性ボン
ド磁石の(BH)maxと配合した各異方性磁粉のCo含有量
x(wt%)との関係を図4に示す。図4より、高い(B
H)maxを有するために、Co含有量は25%以下が好まし
く、20%以下がより好ましく、10%以下が特に好ましい
ことがわかる。(Embodiment 7) Sm23.7Febal.C
oxN3.1(X = 0-35%) main component composition represented by
Of Sm-Fe-Co based alloy corresponding to magnetic nitride powder
Then, the same homogenization heat treatment and hydrogenation / decomposition as in Example 1
Reaction treatment was performed. Next, except that the furnace input was 10 kg
A dehydrogenation / recombination reaction treatment was performed in the same manner as in Example 1.
Was. The z value in these primary dehydrogenation steps is -0.21 to-
It was 0.27. Then, pulverization and nitriding were performed in the same manner as in Example 1.
To obtain the Sm-Fe-Co-N-based anisotropic magnetic powder of the present invention.
Obtained. These magnetic powders have an average particle size of 30 to 46 μm,
Recrystallized grain size is 0.19 ~ 0.33μm and 0.33μm or less
Hard magnetic phase (Th) in which recrystallized grains have an area ratio of 90 to 95% (Th
2Zn17Mold) and a very small amount of αFe.
αFe is less than 1% on average of the area ratio, which is very small.
won. Hereinafter, each Sm-Fe-Co-N-based anisotropic magnetic powder
An anisotropic bonded magnet was prepared in the same manner as in Example 1 except that the magnet was used.
It was prepared and the (BH) max at room temperature was measured. These anisotropic bon
Content of each anisotropic magnetic powder blended with (BH) max of the magnet
FIG. 4 shows the relationship with x (wt%). From FIG. 4, higher (B
H) to have max, Co content is preferably less than 25%
And more preferably 20% or less, particularly preferably 10% or less
You can see that.
【0027】[0027]
【発明の効果】以上記述の通り、本発明によれば、従来
に比べて、磁気特性の耐熱性に優れ、かつ高い(BH)max
を有するR−T−N系異方性ボンド磁石およびそれに用
いるR−T−N系異方性磁粉ならびにその製造方法を提
供することができる。As described above, according to the present invention, the heat resistance of the magnetic characteristics is excellent and the (BH) max
And an RTN-based anisotropic magnetic powder used for the same, and a method for producing the same.
【図1】脱水素時間と炉内真空度の関係の一例を示すグ
ラフである。FIG. 1 is a graph showing an example of a relationship between a dehydrogenation time and a degree of vacuum in a furnace.
【図2】Sm−Fe−M−N系異方性磁粉のM元素の含
有量と異方性ボンド磁石の(BH)maxの相関の一例を示す
グラフである。FIG. 2 is a graph showing an example of a correlation between the content of the M element in the Sm—Fe—M—N anisotropic magnetic powder and (BH) max of the anisotropic bonded magnet.
【図3】Sm−La−Fe−N系異方性磁粉のLa含有
量と異方性ボンド磁石の(BH)maxの相関の一例を示すグ
ラフである。FIG. 3 is a graph showing an example of the correlation between the La content of an Sm-La-Fe-N-based anisotropic magnetic powder and (BH) max of an anisotropic bonded magnet.
【図4】Sm−Fe−Co−N系異方性磁粉のCo含有
量と異方性ボンド磁石の(BH)maxの相関の一例を示すグ
ラフである。FIG. 4 is a graph showing an example of a correlation between the Co content of an Sm—Fe—Co—N-based anisotropic magnetic powder and (BH) max of an anisotropic bonded magnet.
───────────────────────────────────────────────────── フロントページの続き Fターム(参考) 5E040 AA03 AA19 CA01 HB17 HB19 NN17 5E062 CD05 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E040 AA03 AA19 CA01 HB17 HB19 NN17 5E062 CD05
Claims (5)
はYを含む希土類元素の少なくとも1種であり、Smを
必ず含む)20〜30%、N2.5〜3.5%、残部T(TはFe
またはFeとCoである)および不可避的不純物からな
る、平均粒径が5〜300μmのR−T−N系異方性磁粉
であって、 前記R−T−N系異方性磁粉は微細な2−17型硬質磁性
相の再結晶粒の集合体から実質的になり、平均再結晶粒
径が0.02〜5μmでありかつ再結晶粒径が5μm以下の
再結晶粒の面積比率が90%以上であることを特徴とする
R−T−N系異方性磁粉。(1) The composition of the main component is represented by R (R
Is at least one kind of rare earth element containing Y, and necessarily contains Sm) 20 to 30%, N 2.5 to 3.5%, and the balance T (T is Fe
Or Fe and Co) and unavoidable impurities, and has an average particle size of 5 to 300 μm, wherein the R-TN-based anisotropic magnetic powder is fine. It consists essentially of an aggregate of recrystallized grains of the 2-17 type hard magnetic phase, has an average recrystallized grain size of 0.02 to 5 μm, and has an area ratio of recrystallized grains having a recrystallized grain size of 5 μm or less of 90% or more. R-T-N-based anisotropic magnetic powder, characterized in that:
はYを含む希土類元素の少なくとも2種であり、Smお
よびLaを必ず含み、La含有量が0.1〜3.5%である)
20〜30%、N2.5〜3.5%、残部T(TはFeまたはFe
とCoである)および不可避的不純物からなる請求項1
に記載のR−T−N系異方性磁粉。2. A composition according to claim 1, wherein the main component composition is R (R
Is at least two kinds of rare earth elements containing Y, and always contains Sm and La, and has a La content of 0.1 to 3.5%.
20-30%, N2.5-3.5%, balance T (T is Fe or Fe
And Co) and unavoidable impurities.
R-T-N-based anisotropic magnetic powder described in 1 above.
はYを含む希土類元素の少なくとも1種であり、Smを
必ず含む)20〜30%、残部T(TはFeまたはFeとC
oである)および不可避的不純物からなるR−T系母合
金を平均粒径5〜300μmに粉砕し、次いで水素化・分
解反応処理、脱水素・再結合反応処理および窒化を行う
R−T−N系異方性磁粉の製造方法において、 脱水素・再結合反応処理時の真空度(水素分圧)をy
(Pa)、脱水素時間をx(秒)としたとき、xが60〜
1000秒のときにy=Axz(ただし−0.5≦z≦−0.01
であり、Aは脱水素条件により決定される定数である)
で表される指数関数の条件下で脱水素を行うことを特徴
とするR−T−N系異方性磁粉の製造方法。3. A composition according to claim 1, wherein the main component composition is R (R
Is at least one kind of rare earth element containing Y and always contains Sm) 20 to 30%, and the balance T (T is Fe or Fe and C
o) and an unavoidable impurity are pulverized to an average particle size of 5 to 300 μm, and then subjected to hydrogenation / decomposition reaction treatment, dehydrogenation / recombination reaction treatment and nitriding. In the method for producing N-based anisotropic magnetic powder, the degree of vacuum (hydrogen partial pressure) during the dehydrogenation / recombination reaction treatment is set to y.
(Pa), when the dehydrogenation time is x (seconds), x is 60 to
At the time of 1000 seconds y = Ax z (where -0.5 ≦ z ≦ -0.01
Where A is a constant determined by dehydrogenation conditions)
A method for producing an RTN-based anisotropic magnetic powder, comprising performing dehydrogenation under the condition of an exponential function represented by:
はYを含む希土類元素の少なくとも1種であり、Smを
必ず含む)20〜30%、N2.5〜3.5%、残部T(TはFe
またはFeとCoである)および不可避的不純物からな
るとともに、微細な2−17型硬質磁性相の再結晶粒の集
合体から実質的になり、平均再結晶粒径が0.02〜5μm
でありかつ再結晶粒径が5μm以下の再結晶粒の面積比
率が90%以上である、平均粒径が5〜300μmのR−T
−N系異方性磁粉と、バインダーとからなることを特徴
とするR−T−N系異方性ボンド磁石。4. A composition according to claim 1, wherein the main component composition is R (R
Is at least one kind of rare earth element containing Y, and necessarily contains Sm) 20 to 30%, N 2.5 to 3.5%, and the balance T (T is Fe
Or Fe and Co) and unavoidable impurities, and consist essentially of aggregates of recrystallized grains of a fine 2-17 type hard magnetic phase, and have an average recrystallized grain size of 0.02 to 5 μm.
And an RT having an average particle size of 5 to 300 μm, wherein the area ratio of recrystallized particles having a recrystallized particle size of 5 μm or less is 90% or more.
An RTN-based anisotropic bonded magnet comprising -N-based anisotropic magnetic powder and a binder.
組成が、重量百分率で、R(RはYを含む希土類元素の
少なくとも2種であり、SmおよびLaを必ず含み、L
a含有量が0.1〜3.5%である)20〜30%、N2.5〜3.5
%、残部T(TはFeまたはFeとCoである)および
不可避的不純物からなる請求項4に記載のR−T−N系
異方性ボンド磁石。5. The composition of a main component of the R-T-N-based anisotropic magnetic powder is represented by weight percentage of R (R is at least two kinds of rare earth elements including Y, and always contains Sm and La;
a content is 0.1-3.5%) 20-30%, N2.5-3.5
The R-T-N-based anisotropic bonded magnet according to claim 4, wherein the R-T-N-based anisotropic bonded magnet is composed of%, the balance T (T is Fe or Fe and Co), and unavoidable impurities.
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005243883A (en) * | 2004-02-26 | 2005-09-08 | Shin Etsu Chem Co Ltd | Rare earth permanent magnet |
US7713360B2 (en) | 2004-02-26 | 2010-05-11 | Shin-Etsu Chemical Co., Ltd. | Rare earth permanent magnet |
CN103328134A (en) * | 2011-01-21 | 2013-09-25 | 户田工业株式会社 | Ferromagnetic granular powder and method for manufacturing same, as well as anisotropic magnet, bonded magnet, and pressed-powder magnet |
US11676748B2 (en) * | 2015-12-24 | 2023-06-13 | Nichia Corporation | Anisotropic magnetic powders and method of producing the same |
US11685654B2 (en) | 2017-05-17 | 2023-06-27 | Nichia Corporation | Secondary particles for anisotropic magnetic powder |
-
2000
- 2000-04-28 JP JP2000129784A patent/JP2001313206A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005243883A (en) * | 2004-02-26 | 2005-09-08 | Shin Etsu Chem Co Ltd | Rare earth permanent magnet |
US7713360B2 (en) | 2004-02-26 | 2010-05-11 | Shin-Etsu Chemical Co., Ltd. | Rare earth permanent magnet |
CN103328134A (en) * | 2011-01-21 | 2013-09-25 | 户田工业株式会社 | Ferromagnetic granular powder and method for manufacturing same, as well as anisotropic magnet, bonded magnet, and pressed-powder magnet |
US11676748B2 (en) * | 2015-12-24 | 2023-06-13 | Nichia Corporation | Anisotropic magnetic powders and method of producing the same |
US11685654B2 (en) | 2017-05-17 | 2023-06-27 | Nichia Corporation | Secondary particles for anisotropic magnetic powder |
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