JP2868062B2 - Manufacturing method of permanent magnet - Google Patents
Manufacturing method of permanent magnetInfo
- Publication number
- JP2868062B2 JP2868062B2 JP5300773A JP30077393A JP2868062B2 JP 2868062 B2 JP2868062 B2 JP 2868062B2 JP 5300773 A JP5300773 A JP 5300773A JP 30077393 A JP30077393 A JP 30077393A JP 2868062 B2 JP2868062 B2 JP 2868062B2
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- weight
- alloy
- oxygen
- gallium
- 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.)
- Expired - Fee Related
Links
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
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は永久磁石の製造方法に関
し、特に希土類鉄系の永久磁石の製造に使用されるもの
である。
【０００２】
【従来の技術】従来から知られている希土類磁石として
は、ＲＣｏ5 型、Ｒ2 （Ｃｏ，Ｃｕ，Ｆｅ，Ｍ）17型
（ただし、ＲはＳｍ，Ｃｅ等の希土類元素、ＭはＴｉ，
Ｚｒ，Ｈｆ等の遷移元素）等の希土類コバルト系のもの
が知られている。しかしながら、この系の永久磁石で
は、最大エネルギー積が３０ＭＧＯｅ程度であり、また
比較的高価なＣｏを大量に使用しなければならないとい
う問題点があった。
【０００３】近年、上記希土類コバルト系の代わりに、
比較的安価な希土類鉄系の永久磁石が研究されている
（特開昭５９−４６００８号、特開昭５９−６４７３３
号等）。これはＮｄ−Ｆｅ−Ｂ系等の構成元素からなる
ものであり、Ｆｅ使用によるコスト低下に加え、最大エ
ネルギー積が３０ＭＧＯｅを超えるものが得られるため
非常に有効な材料である。
【０００４】しかしながら、この希土類鉄系永久磁石は
製造条件により磁石特性、特に保磁力が３００Ｏｅから
１０ｋＯｅを超えるものまで現われるというように大き
なバラツキを示し、安定した磁石特性を得ることができ
ないという問題点がある。このことは工業上非常に重要
な問題であり、再現性よく安定な磁石特性を有する希土
類鉄系の永久磁石を得ることができれば、その実用性は
大きく向上する。
【０００５】また、高保磁力かつ高（ＢＨ）max の要求
は強く、より高性能化に向けて研究が進められている。
【０００６】本発明は以上の点を考慮してなされたもの
であり、高い保持力、高い（ＢＨ）max を有し、良好な
磁石特性を有する永久磁石を再現性よく製造し得る永久
磁石の製造方法を提供することを目的とする。
【０００７】
【課題を解決するための手段及び作用】本発明者らは上
記問題点を解消すべく鋭意研究を重ねた結果、希土類鉄
系の永久磁石においてはＧａの添加が磁石特性、特に保
磁力に顕著な影響を与えるという事実を見出した。
【０００８】本願発明はこれに基づいてなされたもので
あり、１０〜４０重量％のＲ（ただし、ＲはＹ及び希土
類元素から選ばれた少なくとも１種）、０．１〜８重量
％の硼素、１３重量％以下のガリウム、０．００５〜
０．０３重量％の酸素、残部が主として鉄からなる組成
を有する永久磁石合金を出発原料とし、該合金を粉砕、
磁場中プレス、焼結することを特徴とする永久磁石の製
造方法である。
【０００９】本願発明において、各元素の含有率を上記
範囲に限定したのはそれぞれ以下のような理由による。
【００１０】Ｒが１０重量％未満ではｉＨｃの増大が得
られず、４０重量％を超えるとＢｒが低下するため、い
ずれの場合でも（ＢＨ）max が低下してしまう。したが
って、Ｒの含有率は１０〜４０重量％とする。好ましく
は２５〜３５重量％である。なお、希土類元素のうちで
もＮｄ及びＰｒは特に高い（ＢＨ）max を得るのに有効
な元素であり、Ｒとしてこの２元素のうち少なくとも１
種を必須元素として含有することが好ましい。このＮ
ｄ、ＰｒのＲ量中の割合は７０％以上（Ｒ量全部でもよ
い）であることが望ましい。
【００１１】特にＮｄが９０重量％以上である時、優れ
た特性を得ることができる。
【００１２】硼素（Ｂ）が０．１重量％未満ではｉＨｃ
が低下し、８重量％を超えるとＢｒの低下が顕著とな
る。よって、硼素の含有率は０．１〜８重量％とする。
高保磁力化のためには１．２重量％以上であることが好
ましい。なお、Ｂの一部をＣ、Ｎ、Ｓｉ、Ｐ、Ｇｅ等で
置換してもよい。これにより焼結性の向上、ひいてはＢ
ｒ、（ＢＨ）max の増大を図ることができる。この場合
の置換量はＢの８０％程度までとすることが望ましい。
【００１３】ガリウム（Ｇａ）は保磁力（ｉＨｃ）の向
上に有効な元素である。少量の添加で効果があるが、
０．１重量％以上、好ましくは０．２重量％以上でｉＨ
ｃの増大が顕著である。１３重量％を超えるとＢｒの低
下が顕著となる。よって、ガリウムの含有率は１３重量
％以下とする。このＧａの９０重量％までをＡｌで置換
することが可能である。
【００１４】本願磁石はその他酸素等の不可避的不純物
を含有する。所定の組成の永久磁石合金を用いて粉砕・
焼結する場合において最も重要な点は永久磁石合金中の
酸素含有量である。酸素が０．００５重量％未満では永
久磁石の製造時に要求される２〜１０μｍ程度の微粉砕
が困難となる。このため、粒径が不均一となり磁場中成
形時の配向性が悪くなり、Ｂｒの低下、ひいては（Ｂ
Ｈ）max の低下をもたらす。また、製造コストも大幅に
上昇する。一方、０．０３重量％を超えると保磁力が低
下し、高（ＢＨ）max を得ることができない。よって、
永久磁石合金中の酸素の含有率は０．００５〜０．０３
重量％が好ましい。焼結後の永久磁石中においては若干
増量することがある。
【００１５】永久磁石合金中における酸素の働きは明ら
かではないものの、以下のような振舞により高性能の永
久磁石を得ることができるものと推測される。
【００１６】すなわち、溶融合金中の酸素の一部は主成
分元素であるＲ、Ｆｅ原子と結合して酸化物となり、残
りの酸素とともに合金結晶粒界等に偏析して存在してい
ると考えられる。Ｒ−Ｆｅ−Ｂ系磁石が微粒子磁石であ
り、その保磁力が主として逆磁区発生磁場により決定さ
れることを考慮すると、酸化物、偏析等の欠陥が多い場
合、これらが逆磁区発生源として作用することにより保
磁力が低下してしまうと考えられる。また、欠陥が少な
い場合は粒界破壊等が起りにくくなるため、粉砕性が劣
化すると予想される。
【００１７】永久磁石合金中の酸素量は高純度の原料を
用いるとともに、原料合金溶融時の炉中酸素量を厳密に
調節することにより制御することができる。
【００１８】本願発明に係る永久磁石を構成する上記の
各元素以外の残部は主として鉄であるが、Ｆｅの一部を
Ｃｏ、Ａｌ、Ｃｒ、Ｔｉ、Ｚｒ、Ｈｆ、Ｎｂ、Ｔａ、
Ｖ、Ｍｎ、Ｍｏ、Ｗ、Ｒｕ、Ｒｈ、Ｒｅ、Ｐｄ、Ｏｓ、
Ｉｒ等で置換することもできる。その量は３０重量％程
度までであり、多すぎると（ＢＨ）max の低下等特性劣
化の要因となる。特にＣｏはキュリー温度上昇に有効で
あり、永久磁石中では１〜３０重量％、特に１０〜２０
重量％の添加が好ましい。
【００１９】このＣｏはＧａと複合添加で保磁力特性等
に極めて顕著な効果を奏する。
【００２０】次に製法について詳細に説明する。
【００２１】まず、所定量のＦｅ、Ｒ、Ｇａ、Ｂを含有
する永久磁石合金を製造する。次に、ボールミル等の粉
砕手段を用いて永久磁石合金を粉砕する。この際、後工
程の成形と焼結を容易にし、かつ磁気特性を良好にする
ために、粉末の平均粒径が２〜１０μｍとなるように微
粉砕することが望ましい。粒径が１０μｍを超えるとｉ
Ｈｃの低下をもたらし、一方２μｍ未満にまで粉砕する
ことは困難であるうえに、Ｂｒ等の磁気特性の低下を招
く。
【００２２】次いで、微粉砕された永久磁石合金粉末を
所望の形状にプレス成形する。成形の際には通常の焼結
磁石を製造するのと同様に、例えば１５ｋＯｅ程度の磁
場を印加し、配向処理を行なう。つづいて、例えば１０
００〜１１４０℃，０．５〜５時間程度の条件で成形体
を焼結する。この焼結は合金中の酸素濃度を増加させな
いように、Ａｒガス等の不活性ガス雰囲気中、もしくは
真空中で行なうことが望ましい。
【００２３】こうして得られた焼結体に必要に応じ５５
０〜７５０℃の温度範囲で０．１〜１０時間程度の時効
処理を行なう。
【００２４】時効処理温度が５５０℃未満又は７５０℃
を超えると、ｉＨｃの減少又は角形性の劣化を招き、磁
気特性は大幅に低下する。よって、時効処理温度は５５
０〜７５０℃の範囲が好ましい。
【００２５】以上のような方法によれば、Ｂｒ、ｉＨ
ｃ、（ＢＨ）max 等の磁気特性に優れた永久磁石を特性
のバラツキを招くことなく、再現性よく製造することが
できる。
【００２６】
【実施例】以下、本発明の実施例を説明する。
【００２７】実施例１
所定の組成で原料を混合し、Ａｒ雰囲気中で水冷銅ボー
トを用いてアーク溶解した。得られた磁石合金（酸素濃
度０．０２ｗｔ％）をＡｒ雰囲気中で粗粉砕し、更にジ
ェットミルにより約３．０μｍの粒度まで微粉砕した。
【００２８】この微粉末を所定の押型に充填して２０ｋ
Ｏｅの磁界を印加しつつ、２ｔｏｎ／ｃｍ2 の圧力で圧
縮成形した。この成形体をＡｒ雰囲気中、１０２０〜１
１２０℃で１ｈ焼結し、室温まで急冷した後、真空中で
５５０〜７５０℃，３〜１０時間時効処理を行ない、室
温まで急冷した。
【００２９】その結果を表１に示す。Ｎｄ量はＲ中の９
０重量％以上となっている。
【００３０】
【表１】
実施例２
組成がネオジウム３０．８重量％、ボロン０．８６重量
％、ガリウム１．０重量％、残部鉄となるように各元素
を配合し、２ｋｇをアルゴン雰囲気下、水冷銅ボート中
でアーク溶融した。その際、炉中の酸素量を厳密に調節
することにより、調整合金中の酸素を増減させた。
【００３１】得られた永久磁石合金をＡｒ雰囲気中で粗
粉砕し、更にステンレスボールミルにて３〜５μｍの粒
径まで微粉砕した。
【００３２】この微粉末を所定の押し型に充填して２０
０００Ｏｅの粒界を印加しつつ、２ｔｏｎ／ｃｍ2 の圧
力で圧縮成形した。得られた成形体をアルゴン雰囲気
中、１０８０℃で１時間焼結し、室温まで急冷した。そ
の後、真空中、６００℃で１時間時効処理を行ない、室
温まで急冷した。
【００３３】得られた永久磁石について、永久磁石合金
中の酸素濃度と、粗粉を３〜５μｍの粒度まで微粉砕す
るに必要な時間、残留磁束密度（Ｂｒ）、保磁力（ｉＨ
ｃ）及び最大エネルギー積（（ＢＨ）max ）との関係を
図１に示す。
【００３４】図１から明らかなように、合金の粉砕性及
び永久磁石の磁石特性は合金中の酸素濃度に大きく依存
している。すなわち、酸素濃度が０．００５重量％未満
では粉砕性が極端に悪くなり、この結果磁場中成形時の
配向性も悪くなるためＢｒが低下している。一方、酸素
濃度が０．０３重量％を超えると保磁力が極端に低下し
ている。
【００３５】実施例３
実施例２と同様な方法により、組成がネオジム３１．０
重量％、ボロン０．８４重量％、コバルト１４．６重量
％、ガリウム１．１重量％、酸素０．０３重量％、残部
鉄からなる組成を有する永久磁石合金を得た。
【００３６】得られた永久磁石合金を用い実施例１と同
様にして粉砕、圧縮成形、焼結を行なった。
【００３７】焼結後の試料を３００〜９００℃の各温度
で１時間時効処理した後、急冷して保磁力を調べた。こ
の結果を図２に示す。
【００３８】図２から明らかなように、時効温度は保磁
力に大きく影響し、５５０〜７５０℃で最も優れた特性
が得られることがわかる。
【００３９】希土類鉄系永久磁石はＮｄ2 Ｆｅ14Ｂ型の
正方晶系の強磁性Ｆｅリッチ相を主相とし、その他Ｎｄ
97Ｆｅ3 、Ｎｄ95Ｆｅ5 等のＲ成分を８０重量％以上含
有する立方晶系の非磁性Ｒリッチ相、Ｎｄ2 Ｆｅ7 Ｂ6
等の正方晶系の非磁性Ｂリッチ相、更に酸化物等を含有
することが知られている。本願発明のガリウムはＲリッ
チ相に濃縮して存在しているようである。
【００４０】
【発明の効果】以上詳述した如く本発明によれば、高い
保磁力、（ＢＨ）max を有する希土類鉄系の永久磁石を
安定して得ることができ、工業的価値が極めて大なるも
のである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a permanent magnet, and more particularly to a method for producing a rare earth iron-based permanent magnet. Conventionally known rare earth magnets include RCo 5 type and R 2 (Co, Cu, Fe, M) 17 type (where R is a rare earth element such as Sm, Ce, etc.) Is Ti,
Rare-earth cobalt-based materials such as transition elements such as Zr and Hf) are known. However, this type of permanent magnet has a problem that the maximum energy product is about 30 MGOe and that relatively expensive Co must be used in large quantities. In recent years, in place of the rare earth cobalt-based materials,
Research has been conducted on relatively inexpensive rare earth iron-based permanent magnets (JP-A-59-46008, JP-A-59-64733).
No.). This is made of a constituent element such as an Nd—Fe—B system, and is a very effective material because it can reduce the cost due to the use of Fe and can obtain a material having a maximum energy product exceeding 30 MGOe. However, the rare-earth iron-based permanent magnet has a large variation such that the coercive force appears from 300 Oe to more than 10 kOe depending on the manufacturing conditions, and a stable magnet property cannot be obtained. There is. This is a very important industrial problem. If a rare-earth iron-based permanent magnet having stable and reproducible magnet properties can be obtained, its practicality will be greatly improved. Further, there is a strong demand for a high coercive force and a high (BH) max , and research is being conducted for higher performance. [0006] The present invention has been made in view of the above, high holding force, high (BH) have a max, may be prepared rather by reproducible permanent magnet having good magnetic properties permanently
An object of the present invention is to provide a method for manufacturing a magnet . The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, it has been found that the addition of Ga to the rare earth iron-based permanent magnet can improve the magnet properties, especially the preservation of the magnet properties. We found the fact that it has a significant effect on magnetic force. [0008] The present invention has been made based on this, wherein R is 10 to 40 wt% (R is at least one selected from Y and rare earth elements), 0.1 to 8 wt% boron , 13% by weight or less of gallium, 0.005 to
0.03 wt% of oxygen, a permanent magnet alloy having a set formed remainder ing mainly of iron as a starting material, pulverizing the alloy,
This is a method for producing a permanent magnet, which is characterized by pressing and sintering in a magnetic field. In the present invention, the content of each element is limited to the above range for the following reasons. If R is less than 10% by weight, no increase in iHc can be obtained, and if R exceeds 40% by weight, Br decreases, and in any case, (BH) max decreases. Therefore, the content of R is set to 10 to 40% by weight. Preferably it is 25 to 35% by weight. Among the rare earth elements, Nd and Pr are effective elements for obtaining a particularly high (BH) max , and R is at least one of these two elements.
It is preferable to include a seed as an essential element. This N
It is desirable that the ratio of d and Pr in the R amount is 70% or more (all R amounts may be used). Particularly when Nd is 90% by weight or more, excellent characteristics can be obtained. When boron (B) is less than 0.1% by weight, iHc
And when it exceeds 8% by weight, the decrease of Br becomes remarkable. Therefore, the content of boron is set to 0.1 to 8% by weight.
For higher coercive force, the content is preferably 1.2% by weight or more. Note that a part of B may be replaced with C, N, Si, P, Ge, or the like. As a result, the sinterability is improved, and thus B
r, (BH) max can be increased. In this case, the replacement amount is desirably up to about 80% of B. Gallium (Ga) is an element effective for improving the coercive force (iHc). Although effective with a small amount of addition,
IH at 0.1% by weight or more, preferably 0.2% by weight or more
The increase of c is remarkable. If it exceeds 13% by weight, the decrease of Br becomes remarkable. Therefore, the content of gallium is set to 13% by weight or less. It is possible to replace up to 90% by weight of this Ga with Al. The magnet of the present invention contains other unavoidable impurities such as oxygen. Grinding using a permanent magnet alloy of the specified composition
The most important point in sintering is the oxygen content in the permanent magnet alloy. If the oxygen content is less than 0.005% by weight, it becomes difficult to finely pulverize a permanent magnet of about 2 to 10 μm, which is required. For this reason, the particle size becomes non-uniform, and the orientation during molding in a magnetic field is deteriorated, so that the Br decreases, and (B
H) leads to a reduction in max . Also, the manufacturing cost increases significantly. On the other hand, if it exceeds 0.03% by weight, the coercive force decreases, and a high (BH) max cannot be obtained. Therefore,
The content of oxygen in the permanent magnet alloy is 0.005 to 0.03.
% By weight is preferred. The amount may increase slightly in the sintered permanent magnet. Although the function of oxygen in the permanent magnet alloy is not clear, it is presumed that a high-performance permanent magnet can be obtained by the following behavior. That is, it is considered that a part of oxygen in the molten alloy is combined with R and Fe atoms, which are main components, to form an oxide, and segregates along with the remaining oxygen in the alloy crystal grain boundaries and the like. Can be Considering that the R-Fe-B-based magnet is a fine particle magnet and its coercive force is determined mainly by the reverse magnetic domain generation magnetic field, when there are many defects such as oxides and segregation, these act as reverse magnetic domain generation sources. It is considered that the coercive force is reduced by doing so. In addition, when the number of defects is small, grain boundary destruction and the like are unlikely to occur, so that it is expected that crushability is deteriorated. The amount of oxygen in the permanent magnet alloy can be controlled by using a high-purity raw material and strictly adjusting the amount of oxygen in the furnace when the raw material alloy is melted. The balance other than the above elements constituting the permanent magnet according to the present invention is mainly iron, but a part of Fe is Co, Al, Cr, Ti, Zr, Hf, Nb, Ta,
V, Mn, Mo, W, Ru, Rh, Re, Pd, Os,
It can be replaced by Ir or the like. The amount is up to about 30% by weight, and if it is too large, it causes a deterioration in characteristics such as a decrease in (BH) max . In particular, Co is effective for raising the Curie temperature, and is 1 to 30% by weight, particularly 10 to 20% by weight in the permanent magnet.
Addition by weight is preferred. This Co has an extremely remarkable effect on the coercive force characteristics and the like when added in combination with Ga. Next, the production method will be described in detail. First, a permanent magnet alloy containing predetermined amounts of Fe, R, Ga, and B is manufactured. Next, the permanent magnet alloy is pulverized using a pulverizing means such as a ball mill. At this time, it is desirable that the powder is finely pulverized so that the average particle diameter of the powder is 2 to 10 μm in order to facilitate molding and sintering in the subsequent steps and to improve magnetic properties. When the particle size exceeds 10 μm, i
This leads to a decrease in Hc, while it is difficult to grind it to less than 2 μm, and also a decrease in magnetic properties such as Br. Next, the finely ground permanent magnet alloy powder is pressed into a desired shape. At the time of molding, an orientation treatment is performed by applying a magnetic field of, for example, about 15 kOe as in the case of manufacturing a normal sintered magnet. Then, for example, 10
The compact is sintered under the conditions of 00 to 1140 ° C. for about 0.5 to 5 hours. This sintering is desirably performed in an inert gas atmosphere such as Ar gas or in a vacuum so as not to increase the oxygen concentration in the alloy. If necessary, 55
Aging treatment is performed in a temperature range of 0 to 750 ° C. for about 0.1 to 10 hours. The aging temperature is less than 550 ° C. or 750 ° C.
If it exceeds, iHc is reduced or the squareness is deteriorated, and the magnetic properties are significantly reduced. Therefore, the aging temperature is 55
The range of 0-750 degreeC is preferable. According to the above method, Br, iH
c, a permanent magnet having excellent magnetic properties such as (BH) max can be manufactured with good reproducibility without causing variation in properties. Embodiments of the present invention will be described below. Example 1 Raw materials having a predetermined composition were mixed and arc-melted using a water-cooled copper boat in an Ar atmosphere. The obtained magnet alloy (oxygen concentration: 0.02 wt%) was roughly pulverized in an Ar atmosphere, and further finely pulverized by a jet mill to a particle size of about 3.0 μm. This fine powder is filled in a predetermined pressing die and the
Compression molding was performed at a pressure of 2 ton / cm 2 while applying an Oe magnetic field. This molded body is placed in an Ar atmosphere at 1,200 to 1,
After sintering at 120 ° C. for 1 hour and quenching to room temperature, aging treatment was performed in vacuum at 550 to 750 ° C. for 3 to 10 hours, and quenched to room temperature. The results are shown in Table 1. Nd amount in R 9
0% by weight or more. [Table 1] Example 2 Each element was blended so that the composition was 30.8% by weight of neodymium, 0.86% by weight of boron, 1.0% by weight of gallium, and the balance was iron, and 2 kg was arced in a water-cooled copper boat under an argon atmosphere. Melted. At that time, the oxygen in the conditioning alloy was increased or decreased by strictly adjusting the amount of oxygen in the furnace. The obtained permanent magnet alloy was roughly pulverized in an Ar atmosphere and further finely pulverized by a stainless steel ball mill to a particle size of 3 to 5 μm. This fine powder is filled in a predetermined pressing mold and
While applying a 000 Oe grain boundary, compression molding was performed at a pressure of 2 ton / cm 2 . The obtained molded body was sintered at 1080 ° C. for 1 hour in an argon atmosphere, and rapidly cooled to room temperature. Thereafter, aging treatment was performed at 600 ° C. for 1 hour in a vacuum, and rapidly cooled to room temperature. Regarding the obtained permanent magnet, the oxygen concentration in the permanent magnet alloy, the time required for finely pulverizing the coarse powder to a particle size of 3 to 5 μm, the residual magnetic flux density (Br), the coercive force (iH)
FIG. 1 shows the relationship between c) and the maximum energy product ((BH) max ). As is clear from FIG. 1, the crushability of the alloy and the magnetic properties of the permanent magnet are greatly dependent on the oxygen concentration in the alloy. That is, when the oxygen concentration is less than 0.005% by weight, the pulverizability becomes extremely poor, and as a result, the orientation during molding in a magnetic field also becomes poor, so that Br is lowered. On the other hand, when the oxygen concentration exceeds 0.03% by weight, the coercive force is extremely reduced. Example 3 In the same manner as in Example 2, the composition was neodymium 31.0
Thus, a permanent magnet alloy having a composition consisting of, by weight, 0.84% by weight of boron, 14.6% by weight of cobalt, 1.1% by weight of gallium, 0.03% by weight of oxygen and the balance iron was obtained. Using the obtained permanent magnet alloy, pulverization, compression molding and sintering were performed in the same manner as in Example 1. After sintering the sample after sintering at each temperature of 300 to 900 ° C. for 1 hour, it was quenched and examined for coercive force. The result is shown in FIG. As is apparent from FIG. 2, the aging temperature has a large effect on the coercive force, and the most excellent characteristics can be obtained at 550 to 750 ° C. The rare-earth iron-based permanent magnet has a Nd 2 Fe 14 B-type tetragonal ferromagnetic Fe-rich phase as a main phase, and other Nd-Fe 14 B-type permanent magnets.
Nd 2 Fe 7 B 6 , a cubic nonmagnetic R-rich phase containing 80% by weight or more of R components such as 97 Fe 3 and Nd 95 Fe 5
It is known to contain a nonmagnetic B-rich phase of a tetragonal system such as, for example, an oxide. The gallium of the present invention appears to be present in a concentrated form in the R-rich phase. As described in detail above, according to the present invention, a rare earth iron-based permanent magnet having high coercive force and (BH) max can be stably obtained, and the industrial value is extremely large. It becomes.
【図面の簡単な説明】
【図１】 本発明の実施例２の永久磁石における酸素濃
度と、粉砕時間、残留磁束密度、保持力及び最大エネル
ギー積との関係を示す特性図。
【図２】 本発明の実施例３の永久磁石における時効温
度と保持力との関係を示す特性図。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a characteristic diagram showing a relationship among oxygen concentration, grinding time, residual magnetic flux density, coercive force and maximum energy product in a permanent magnet according to a second embodiment of the present invention. FIG. 2 is a characteristic diagram showing a relationship between an aging temperature and a holding force in a permanent magnet according to a third embodiment of the present invention.
フロントページの続き (72)発明者 溝口 徹彦 神奈川県川崎市幸区小向東芝町１ 株式 会社東芝 総合研究所内 (72)発明者 猪俣 浩一郎 神奈川県川崎市幸区小向東芝町１ 株式 会社東芝 総合研究所内 (56)参考文献 特開 昭62−136551（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) H01F 1/00 - 1/08 Continuing on the front page (72) Inventor Tetsuhiko Mizoguchi 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside Toshiba Research Institute Co., Ltd. (72) Inventor Koichiro Inomata 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Corporation (56) References JP-A-62-136551 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) H01F 1/00-1/08
Claims (1)
元素から選ばれた少なくとも１種）、０．１〜８重量％
の硼素、１３重量％以下のガリウム、０．００５〜０．
０３重量％の酸素、残部が主として鉄からなる組成を有
する永久磁石合金を出発原料とし、該合金を粉砕、磁場
中プレス、焼結することを特徴とする永久磁石の製造方
法。 ２．前記焼結の後、５５０〜７５０℃の温度で時効処理
することを特徴とする請求項１記載の永久磁石の製造方
法。 ３．前記永久磁石合金中のガリウムの９０重量％以下を
Ａｌで置換したことを特徴とする請求項１または２記載
の永久磁石の製造方法。 ４．前記永久磁石合金がＣｏを３０重量％以下含有する
ことを特徴とする請求項１または２記載の永久磁石の製
造方法。５．前記永久磁石合金中のガリウムが０．２重量％以上
であることを特徴とする請求項１または２記載の永久磁
石の製造方法。 (57) Claims 1.10 to 40% by weight of R (R is at least one selected from Y and rare earth elements), 0.1 to 8% by weight
Boron, 13% by weight or less of gallium, 0.005 to 0.
03 wt% of oxygen, a permanent magnet alloy having a set formed ing from mainly iron balance as a starting material, pulverizing the alloy, a magnetic field during pressing, manufacturing method of a permanent magnet, characterized by sintering. 2. The method for producing a permanent magnet according to claim 1, wherein after the sintering, aging treatment is performed at a temperature of 550 to 750C. 3. 90% by weight or less of gallium in the permanent magnet alloy
3. The method for producing a permanent magnet according to claim 1, wherein the permanent magnet is substituted with Al . 4. The process according to claim 1 or 2, wherein the permanent magnet the permanent magnet alloy characterized in that it contains less than 30 wt% Co. 5. Gallium in the permanent magnet alloy is 0.2% by weight or more
The permanent magnet according to claim 1 or 2, wherein
Stone manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5300773A JP2868062B2 (en) | 1993-11-08 | 1993-11-08 | Manufacturing method of permanent magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5300773A JP2868062B2 (en) | 1993-11-08 | 1993-11-08 | Manufacturing method of permanent magnet |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62041364A Division JP2577373B2 (en) | 1986-06-12 | 1987-02-26 | Sintered permanent magnet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0722227A JPH0722227A (en) | 1995-01-24 |
| JP2868062B2 true JP2868062B2 (en) | 1999-03-10 |
Family
ID=17888920
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5300773A Expired - Fee Related JP2868062B2 (en) | 1993-11-08 | 1993-11-08 | Manufacturing method of permanent magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2868062B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7199690B2 (en) | 2003-03-27 | 2007-04-03 | Tdk Corporation | R-T-B system rare earth permanent magnet |
| CN103812281A (en) * | 2014-03-01 | 2014-05-21 | 南通万宝实业有限公司 | Preparing process for built-up magnet for energy-saving permanent magnet alternating current synchronous motor |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH066775B2 (en) * | 1984-04-18 | 1994-01-26 | セイコーエプソン株式会社 | Rare earth permanent magnet |
| JPH066776B2 (en) * | 1984-05-14 | 1994-01-26 | セイコーエプソン株式会社 | Rare earth permanent magnet |
| JPH062930B2 (en) * | 1984-05-14 | 1994-01-12 | セイコーエプソン株式会社 | Rare earth permanent magnet |
| JPS60243247A (en) * | 1984-05-15 | 1985-12-03 | Namiki Precision Jewel Co Ltd | Permanent magnet alloy |
| JPS62136551A (en) * | 1985-12-10 | 1987-06-19 | Daido Steel Co Ltd | Permanent magnet material |
| JPS62136558A (en) * | 1985-12-10 | 1987-06-19 | Daido Steel Co Ltd | Permanent magnet material |
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1993
- 1993-11-08 JP JP5300773A patent/JP2868062B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0722227A (en) | 1995-01-24 |
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