JPH0422011B2

JPH0422011B2 -

Info

Publication number: JPH0422011B2
Application number: JP58199810A
Authority: JP
Inventors: Masao Togawa; Atsushi Hamamura; Masato Sagawa; Setsuo Fujimura; Yutaka Matsura; Hitoshi Yamamoto
Original assignee: Sumitomo Special Metals Co Ltd
Current assignee: Proterial Ltd
Priority date: 1983-10-25
Filing date: 1983-10-25
Publication date: 1992-04-15
Also published as: JPS6091601A

Description

【発明の詳細な説明】[Detailed description of the invention]

この発明は、Ｒ（但し、ＲはＹを包含する希土
類元素のうち少なくとも１種）、Ｂ、Feを主成分
とする永久磁石用合金粉末の製造方法に係り、磁
気特性がすぐれ、かつ安定した品質の上記系永久
磁石用合金微粉末が得られる湿式粉砕法の改良に
関する。永久磁石材料は、一般家庭の各種電気製品から
大型コンピユータの周辺端末機器まで、幅広い分
野で使用される極めて重要な電気・電子材料の一
つである。近年の電気・電子機器の小形化、高効
率化の要求にともない、永久磁石材料は益々高性
能化が求められるようになつた。現在の代表的な永久磁石材料は、アルニコ、ハ
ードフエライトおよび希土類コバルト磁石であ
る。近年のコバルトの原料事情の不安定化に伴な
い、コバルトを20〜30wt％含むアルニコ磁石の
需要は減り、鉄の酸化物を主成分とする安価なハ
ードフエライトが磁石材料の主流を占めるように
なつた。一方、希土類コバルト磁石はコバルトを
50〜60wt％も含むうえ、希土類鉱石中にあまり
含まれていないSmを使用するため大変高価であ
るが、他の磁石に比べて、磁気特性が格段に高い
ため、主として小型で付加価値の高い磁気回路に
多用されるようになつた。そこで、本発明者は先に、高価なSmやCoを含
有しない新しい高性能永久磁石としてFe−Ｂ−
Ｒ系（ＲはＹを含む希土類元素のうち少なくとも
１種）永久磁石を提案した（特願昭57−145072
号）。また、さらに、Fe−Ｂ−Ｒ系の磁気異方性
焼結体からなる永久磁石の温度特性を改良するた
めに、Feの一部をCoで置換することにより、生
成合金のキユリー点を上昇させて温度特性を改善
したFe−Co−Ｂ−Ｒ系異方性焼結体からなる永
久磁石を提案した（特願昭57−166663号）。上記の新規なFe−Ｂ−Ｒ系、Fe−Co−Ｂ−Ｒ
系（ＲはＹを含む希土類元素のうち少なくとも１
種）永久磁石を、製造するための出発原料の希土
類金属は、一般にCa還元法、電解法により製造
される金属塊であり、この希土類金属塊を用い
て、例えば次の工程により、上記の新規な永久磁
石が製造される。出発原料として、純度99.9％の電解鉄、
B19.4％を含有し残部はFe及びAl、Si、Ｃ等の
不純物からなるフエロボロン合金、純度99.7％
以上の希土類金属、あるいはさらに、純度99.9
％の電解Coを高周波溶解し、その後水冷銅鋳
型に鋳造する、スタンプミルにより35メツシユスルーまでに
粗粉砕し、次にボールミルにより、例えば粗粉
砕粉300ｇを６時間湿式微粉砕して３〜10μmの
微細粉となす、磁界（10KOe）中配向して、成形（1.5t／cm²
にて加圧）する、焼結、1000℃〜1200℃、１時間、Ar中の焼
結後に放冷する。時効処理、500℃〜1000℃、Ar中。上記の如く、上記永久磁石用合金粉末は、所要
組成の鋳塊を機械的粉砕及び湿式微粉砕を行なつ
て得られるが、この湿式微粉砕方法は35メツシユ
スルーに粗粉砕された該系粉末を、メタノール、
エタノール、イソアミルアルコール、１・１・
１・トリクロルエタン等の溶媒と共に、ボール・
ミルあるいはアトライター等の粉砕機に投入し、
粉砕機または機内の回転翼を鋼球と一緒に回転さ
せて10μm以下の微粉末に粉砕するもので、粉砕
作業上や得られる永久磁石の磁気特性上で種々の
問題があつた。すなわち、上記溶媒のメタノール、エタノール
は吸湿性に富み、微粉砕された粉末が酸化されや
すく、またトリクロルエタンは大気中あるいは粉
砕粉末中の含有水により分解されて該粉末と反応
しやすく、さらには上記溶媒は有毒かつ危険物で
あるため、その取り扱いに細心の注意を払う必要
があるなど作業上での問題があり、一方、かかる
溶媒を使用して微粉砕した粉末をプレス、焼結し
て得られた永久磁石はその磁気特性が劣化した
り、また、ばらつきを招来する問題もあつた。この発明は、安定した品質でかつすぐれた磁気
特性の得られる希土類、ボロン、鉄系の永久磁石
用合金粉末を製造する湿式粉砕方法を目的とし、
安全で取り扱いの容易な溶媒を用いる湿式微粉砕
法を目的としている。すなわち、この発明は、Ｒ（但し、ＲはＹを包
含する希土類元素のうち少なくとも１種）10原子
％〜30原子％、B2原子％〜28原子％、Fe65原子
％〜82原子％を主成分とし、粒度が10メツシユス
ルー（1800μm以下）の合金粉末を、沸点が35℃
以上で常温で液体の弗素化炭化水素と共に粉砕機
内に装入し、平均粒度が1μm〜10μmの粉末に微
粉砕することを特徴とする希土類・ボロン・鉄系
永久磁石用合金粉末の粉砕方法である。この発明は、Ｒ、Ｂ、Feを主成分とする永久
磁石用合金の湿式微粉砕に使用する溶媒を種々検
討した結果、沸点が35℃以上で常温で液体の弗素
化炭化水素が最適であることを知見したもので、
弗素化炭化水素は、トリクロロトリフルオロエタ
ン、パーフルオロトリブチルアミン、テトラクロ
ロジフルオロエタン、ベンゾトリフルオリド、ペ
ルフルオロベンゼン、ペルフルオロメチルデカリ
ン等であり、また、弗素化炭化水素で沸点が35℃
未満のものは、溶剤として使用すると蒸発するた
め、35℃以上の沸点であることが必要で、また、
湿式微粉砕を行なうため常温で液体である必要が
ある。また、この発明で微粉砕前の合金粉末の粒度を
10メツシユスルー（1800μm以下）としたのは、
10メツシユスルー（1800μm以下）を越える粗粒
では微粉砕に長時間を要し、微粉砕後の粉末中に
粗粒が混在する恐れがあるためである。以下に、この発明における希土類・鉄・ボロン
系永久磁石用原料合金粉末の組成限定理由を説明
する。この発明の永久磁石用原料合金粉末に含有され
る希土類元素Ｒは、イツトリウム（Ｙ）を包含し
軽希土類及び重希土類を包含する希土類元素であ
る。Ｒとしては、軽希土類をもつて足り、特にNd、
Prが好ましい。又通例Ｒのうち１種をもつて足
りるが、実用上は２種以上の混合物（ミツシユメ
タル、ジジム等）を入手上の便宜等の理由により
用いることができ、Sm、Ｙ、La、Ce、Gd、等
は他のＲ、特にNd、Pr等との混合物として用い
ることができる。なお、このＲは純希土類元素で
なくてもよく、工業上入手可能な範囲で製造上不
可避な不純物を含有するものでも差支えない。Ｒ（Ｙを含む希土類元素のうち少なくとも１種）
は、新規な上記系永久磁石を製造する合金粗粉砕
粉末として、必須元素であつて、10原子％未満で
は、高磁気特性、特に高保磁力が得られず、30原
子％を越えると、残留磁束密度（Br）が低下し
て、すぐれた特性の永久磁石が得られない。よつ
て、希土類元素は、10原子％〜30原子％の範囲と
する。Ｂは、新規な上記系永久磁石を製造する合金粗
粉砕粉末として、必須元素であつて、２原子％未
満では、高い保磁力（_IHc）は得られず、28原子
％を越えると、残留磁束密度（Br）が低下する
ため、すぐれた永久磁石が得られない。よつて、
Ｂは、２原子％〜28原子％の範囲とする。 Feは、新規な上記系永久磁石を製造する合金
粗粉砕粉末として、必須元素であるが、65原子％
未満では残留磁束密度（Br）が低下し、82原子
％を越えると、高い保磁力が得られないので、
Feは65原子％〜82原子％に限定する。また、Feの一部をCoで置換する理由は、永久
磁石の温度特性を向上させる効果が得られるため
であり、CoはFeの50％を越えると、高い保磁力
が得られず、すぐれた永久磁石が得られない。よ
つて、Coは50％を上限とする。この発明の合金粗粉砕粉末において、高い残留
磁束密度と高い保磁力を共に有するすぐれた永久
磁石を得るためには、R10原子％〜25原子％、
B4原子％〜26原子％、Fe68原子％〜80原子％が
好ましい。また、この発明による合金粗粉砕粉末は、Ｒ、
Ｒ、Feの他、工業的生産上不可避的不純物の存
在を許容できるが、Ｂの一部を4.0原子％以下の
Ｃ、3.5原子％のＰ、2.5原子％以下のＳ、3.5原子
％以下のCuのうち少なくとも１種、合計量で4.0
原子％以下で置換することにより、磁石合金の製
造性改善、低価格化が可能である。さらに、前記Ｒ、Ｂ、Fe合金あるいはCoを含
有するＲ、Ｂ、Fe合金に、 9.5原子％以下のAl、4.5原子％以下のTi、 9.5原子％以下のＶ、8.5原子％以下のCr、 8.0原子％以下のMn、５原子％以下のBi、 12.5原子％以下のNb、10.5原子％以下のTa、 9.5原子％以下のMo、9.5原子％以下のＷ、 2.5原子％以下のSb、７原子％以下のGe、 35原子％以下のSn、5.5原子％以下のZr、 5.5原子％以下のHfのうち少なくとも１種を添
加含有させることにより、永久磁石合金の高保磁
力化が可能になる。結晶相は主相が正方晶であることが、微細で均
一な合金粉末を得るのに不可欠である。この発明による合金微粉末の粒度は、平均粒度
が10μmを越えると、永久磁石の作製時にすぐれ
た磁気特性、とりわけ高い保磁力が得られず、ま
た、平均粒度が1μm未満では、永久磁石の作製工
程、すなわち、プレス成形、焼結、時効処理工程
における酸化が著しく、すぐれた磁気特性が得ら
れないため、平均粒度１〜10μmの合金微粉末が
最も望ましい。この発明による永久磁石用合金微粉末を使用し
て得られる磁気異方性永久磁石合金は、保磁力_I
Hc≧1K Oe、残留磁束密度Br＞4KG、を示し、
最大エネルギー積（BH）maxはハードフエライ
トと同等以上となり、最も好ましい組成範囲で
は、（BH）max≧10MG Oeを示し、最大値は
25MG Oe以上に達する。また、この発明による合金微粉末の組成が、
R10原子％〜30原子％、B2原子％〜28原子％、
Co45原子％以下、Fe65原子％〜82原子％の場合、
得られる磁気異方性永久磁石合金は、上記磁石合
金と同等の磁気特性を示し、残留磁束密度の温度
係数が、0.1％／℃以下となり、すぐれた特性が
得られる。また、合金粉末のＲの主成分がその50％以上を
軽希土類金属が占める場合で、R12原子％〜20原
子％、B4原子％〜24原子％、Fe65原子％〜82原
子％の場合、あるいはさらにCo5原子％〜45原子
％を含有するとき最もすぐれた磁気特性を示し、
特に軽希土類金属がNdの場合には、（BH）max
はその最大値が33MG Oe以上に達する。また、この発明による合金微粉末は、無磁界中
で加圧成型することにより、等方性永久磁石を製
造することができる。以下に実施例を説明する。実施例１出発原料として、純度99.9％の電解鉄、B19.4
％を含有し残部はFe及びＣ等の不純物からなる
フエロボロン合金、純度99.7％以上のNdを高周
波溶解し、その後水冷銅鋳型に鋳造し、
15Nd8B77Fe（at％）なる組成の鋳塊１Kgを得た。この鋳塊を機械的粉砕により35メツシユスルー
までに粗粉砕した。ついで、粗粉砕粉より採取し
た300ｇを、外径150mm×内径120mm×長さ150mm寸
法のボールミルに、10mm外径の鋼球2.8Kgととも
に装入し、溶媒としてトリクロロトリフルオロエ
タン600c.c.を用い、回転数100rpmで5.5時間の微
粉砕を行ない、平均粒度3.3μmの合金粉末を得
た。この合金粉末を用いて、磁界10KOe中で配向
し、2t／cm²にて加圧成型し、その後、1100℃、１
時間、の条件で焼結し、さらに、Ar中で600℃、
１時間の時効処理を施して、永久磁石を作製し
た。得られた永久磁石の磁気特性を測定し第１表
に示す。比較のため、同一組成の鋳塊を、微粉砕時の溶
媒にメタノール600c.c.を使用する以外は上記のこ
の発明方法と同一条件として永久磁石を作製し、
同様に磁気特性を測定し、第１表に測定結果を示
す。実施例２出発原料として、純度99.9％の電解鉄、B19.4
％を含有し残部はFe及びＣ等の不純物からなる
フエロボロン合金、純度99.7％以上のNd金属及
びDy金属を高周波溶解し、その後水冷銅鋳型に
鋳造し、15Nd、1.5Dy 7B76.5Fe（at％）なる組
成の鋳塊１Kgを得た。この鋳塊を機械的粉砕により35メツシユスルー
までに粗粉砕した。ついで、粗粉砕粉より採取し
た300ｇを、外径150mm×内径120mm×長さ150mm寸
法のボールミルに、10mm外径の鋼球2.8Kgととも
に装入し、溶媒としてフロリナート FC−72（商
品名住友スリーエム社製造）600c.c.を用い、回
転数100rpmで5.5時間の微粉砕を行ない、平均粒
度3.35μmの合金粉末を得た。この合金粉末を用いて、磁界10KOe中で配向
し、2t／cm²にて加圧成型し、その後、1100℃、１
時間、の条件で焼結し、さらに、Ar中で600c.c.、
１時間の時効処理を施して、永久磁石を作製し
た。得られた永久磁石の磁気特性を測定し第２表
に示す。比較のため、同一組成の鋳塊を、微粉砕時の溶
媒に１・１・１・トリクロルエタン600c.c.を使用
する以外は上記のこの発明方法と同一条件として
永久磁石を作製し、同様に磁気特性を測定し、第
２表に測定結果を示す。実施例３出発原料として、純度99.9％の電解鉄、B19.4
％を含有し残部はFe及びＣ等の不純物からなる
フエロボロン合金、純度99.7％以上のPrを高周波
溶解し、その後水冷銅鋳型に鋳造し、20Pr
8B72Fe（at％）なる組成の鋳塊１Kgを得た。この鋳塊を機械的粉砕により35メツシユスルー
までに粗粉砕した。ついで、粗粉砕粉より採取し
た300ｇを、外径 150mm×内径 120mm×長さ
150mm寸法のボールミルに、10mm外径の鋼球2.8Kg
とともに装入し、溶媒としてパーフルオロトリブ
チルアミン600c.c.を用い、回転数100rpmで5.5時
間の微粉砕を行ない、平均粒度3.1μmの合金粉末
を得た。この合金粉末を用いて、磁界10KOe中で配向
し、2t／cm²にて加圧成型し、その後、1100℃、１
時間、の条件で焼結し、さらに、Ar中で600℃、
１時間の時効処理を施して、永久磁石を作製し
た。得られた永久磁石の磁気特性を測定し第３表
に示す。比較のため、同一組成の鋳塊を、微粉砕時の溶
媒にイソアミルアルコール600c.c.を使用する以外
は上記のこの発明方法と同一条件として永久磁石
を作製し、同様に磁気特性を測定し、第３表に測
定結果を示す。第１表から第３表の結果より明らかなとおり、
本発明による粉砕方法で得られた微粉末を使用し
た永久磁石は、磁気特性がすぐれていると共に、
磁気特性のばらつきが極めて少なく工業生産上、
頗る有効である。 This invention relates to a method for producing an alloy powder for permanent magnets whose main components are R (where R is at least one rare earth element including Y), B, and Fe, and which has excellent magnetic properties and is stable. The present invention relates to an improvement in a wet pulverization method for obtaining the above-mentioned alloy fine powder for permanent magnets of high quality. Permanent magnetic materials are extremely important electrical and electronic materials used in a wide range of fields, from various household appliances to peripheral terminal equipment for large computers. With the recent demand for smaller size and higher efficiency of electrical and electronic equipment, permanent magnet materials are required to have increasingly higher performance. Current typical permanent magnet materials are alnico, hard ferrite and rare earth cobalt magnets. As the cobalt raw material situation has become unstable in recent years, the demand for alnico magnets containing 20 to 30 wt% cobalt has decreased, and inexpensive hard ferrite, whose main component is iron oxide, has become the mainstream magnet material. Summer. On the other hand, rare earth cobalt magnets contain cobalt.
It is very expensive because it contains 50-60wt% Sm, which is not included in rare earth ores, but it has much higher magnetic properties than other magnets, so it is mainly small and has high added value. It came to be widely used in magnetic circuits. Therefore, the present inventor first developed Fe-B- as a new high-performance permanent magnet that does not contain expensive Sm or Co.
Proposed an R-based permanent magnet (R is at least one rare earth element including Y) (Patent application 145072/1982)
issue). Furthermore, in order to improve the temperature characteristics of permanent magnets made of Fe-BR-based magnetically anisotropic sintered bodies, some of the Fe is replaced with Co, thereby raising the Curie point of the resulting alloy. We proposed a permanent magnet made of an anisotropic sintered Fe-Co-B-R system with improved temperature characteristics (Japanese Patent Application No. 166663/1982). The above novel Fe-BR system, Fe-Co-BR
system (R is at least one rare earth element including Y
The rare earth metal that is the starting material for manufacturing permanent magnets is generally a metal lump produced by Ca reduction method or electrolysis method, and using this rare earth metal lump, for example, the following process permanent magnets are manufactured. As a starting material, electrolytic iron with a purity of 99.9%,
Feroboron alloy containing 19.4% B and the remainder consisting of Fe and impurities such as Al, Si, and C, purity 99.7%
Rare earth metals of more than 99.9 purity
% of electrolytic Co is high-frequency melted, and then cast into a water-cooled copper mold. Coarsely pulverized with a stamp mill to a mesh throughput of 35%, and then wet-pulverized, for example, 300 g of coarsely pulverized powder with a ball mill for 6 hours to form a powder of 3 to 10 μm. Fine powder is oriented in a magnetic field (10KOe) and molded (1.5t/cm ²
Sintering at 1000°C to 1200°C for 1 hour. After sintering in Ar, allow to cool. Aging treatment, 500℃~1000℃, in Ar. As mentioned above, the alloy powder for permanent magnets is obtained by mechanically pulverizing and wet pulverizing an ingot of the desired composition, but this wet pulverizing method uses the powder that has been coarsely pulverized to a 35 mesh throughput. ,methanol,
Ethanol, isoamyl alcohol, 1.1.
1. With a solvent such as trichloroethane, a ball
Put it into a crusher such as a mill or attritor,
The grinder or rotary blade inside the machine is rotated together with the steel balls to grind them into fine powder of 10 μm or less, and there have been various problems with the grinding process and the magnetic properties of the resulting permanent magnet. That is, the above-mentioned solvents methanol and ethanol are highly hygroscopic and easily oxidize the finely ground powder, and trichloroethane is easily decomposed by the water contained in the air or the ground powder and reacts with the powder. Since the above-mentioned solvents are toxic and dangerous, there are problems in working with them, such as the need to be extremely careful when handling them. The obtained permanent magnets had problems in that their magnetic properties deteriorated and also caused variations. The purpose of this invention is to provide a wet pulverization method for producing rare earth, boron, and iron alloy powder for permanent magnets that has stable quality and excellent magnetic properties.
The purpose is a wet pulverization method that uses a safe and easy-to-handle solvent. That is, this invention mainly consists of R (wherein R is at least one kind of rare earth elements including Y) 10 to 30 atom%, B2 to 28 atom%, and Fe65 to 82 atom%. An alloy powder with a particle size of 10 mesh through (1800μm or less) and a boiling point of 35℃
A method for pulverizing rare earth/boron/iron alloy powder for permanent magnets, which is characterized in that the above is charged into a pulverizer together with a fluorinated hydrocarbon that is liquid at room temperature, and pulverized into powder with an average particle size of 1 μm to 10 μm. be. This invention was developed after studying various solvents for wet pulverization of alloys for permanent magnets whose main components are R, B, and Fe, and it was found that fluorinated hydrocarbons, which have a boiling point of 35°C or higher and are liquid at room temperature, are optimal. I learned that
Fluorinated hydrocarbons include trichlorotrifluoroethane, perfluorotributylamine, tetrachlorodifluoroethane, benzotrifluoride, perfluorobenzene, perfluoromethyldecalin, etc.Fluorinated hydrocarbons have a boiling point of 35℃
Anything below this value will evaporate when used as a solvent, so it must have a boiling point of 35°C or higher, and
Since wet pulverization is performed, it must be liquid at room temperature. In addition, with this invention, the particle size of alloy powder before pulverization can be reduced.
The reason for the 10 mesh throughput (1800μm or less) is that
This is because coarse particles exceeding 10 mesh throughput (1800 μm or less) require a long time to be pulverized, and coarse particles may be mixed in the powder after pulverization. The reasons for limiting the composition of the raw material alloy powder for rare earth/iron/boron permanent magnets in this invention will be explained below. The rare earth element R contained in the raw material alloy powder for permanent magnets of this invention is a rare earth element that includes yttrium (Y) and includes light rare earths and heavy rare earths. As R, a light rare earth element is sufficient, especially Nd,
Pr is preferred. Also, it is usually sufficient to have one type of R, but in practice, a mixture of two or more types (Mitsushimetal, dididim, etc.) can be used for reasons such as convenience of availability, and Sm, Y, La, Ce, Gd , etc. can be used as a mixture with other R, especially Nd, Pr, etc. Note that this R does not have to be a pure rare earth element, and may contain impurities that are unavoidable in production within an industrially available range. R (at least one rare earth element including Y)
is an essential element for the coarsely pulverized alloy powder used to manufacture the new above-mentioned permanent magnets.If it is less than 10 atomic%, high magnetic properties, especially high coercive force, cannot be obtained, and if it exceeds 30 atomic%, the residual magnetic flux will decrease. The density (Br) decreases, making it impossible to obtain a permanent magnet with excellent characteristics. Therefore, the rare earth element is in the range of 10 atomic % to 30 atomic %. B is an essential element for the coarsely pulverized alloy powder used to manufacture the new above-mentioned permanent magnets, and if it is less than 2 atom%, high coercive force ( _I Hc) cannot be obtained, and if it exceeds 28 atom%, the residual Excellent permanent magnets cannot be obtained because the magnetic flux density (Br) decreases. Then,
B is in the range of 2 atomic % to 28 atomic %. Fe is an essential element for the alloy coarsely ground powder used to manufacture the new above-mentioned permanent magnets, and 65 at.%
If it is less than 82 at%, the residual magnetic flux density (Br) will decrease, and if it exceeds 82 at%, high coercive force cannot be obtained.
Fe is limited to 65 at% to 82 at%. In addition, the reason why a part of Fe is replaced with Co is that it has the effect of improving the temperature characteristics of a permanent magnet. If Co exceeds 50% of Fe, high coercive force cannot be obtained, and the excellent Permanent magnets cannot be obtained. Therefore, the upper limit for Co is 50%. In order to obtain an excellent permanent magnet having both high residual magnetic flux density and high coercive force in the coarsely pulverized alloy powder of this invention, R10 at % to 25 at %,
B4 atomic% to 26 atomic% and Fe68 atomic% to 80 atomic% are preferable. Further, the coarsely pulverized alloy powder according to the present invention has R,
In addition to R and Fe, the presence of unavoidable impurities in industrial production can be tolerated, but a part of B can be replaced by 4.0 atom% or less of C, 3.5 atom% of P, 2.5 atom% or less of S, and 3.5 atom% or less of S. At least one of Cu, total amount 4.0
By substituting at atomic % or less, it is possible to improve the manufacturability and reduce the cost of the magnetic alloy. Furthermore, in the R, B, Fe alloy or R, B, Fe alloy containing Co, Al of 9.5 atomic % or less, Ti of 4.5 atomic % or less, V of 9.5 atomic % or less, Cr of 8.5 atomic % or less, 8.0 atomic% or less Mn, 5 atomic% or less Bi, 12.5 atomic% or less Nb, 10.5 atomic% or less Ta, 9.5 atomic% or less Mo, 9.5 atomic% or less W, 2.5 atomic% or less Sb, 7 By adding at least one of Ge at % or less, Sn at 35 atomic% or less, Zr at 5.5 atomic% or less, and Hf at 5.5 atomic% or less, it is possible to increase the coercive force of the permanent magnet alloy. It is essential that the main crystal phase be tetragonal in order to obtain a fine and uniform alloy powder. If the average particle size of the fine alloy powder according to the present invention exceeds 10 μm, excellent magnetic properties, especially high coercive force, cannot be obtained when producing a permanent magnet, and if the average particle size is less than 1 μm, it will not be possible to obtain a permanent magnet. Fine alloy powder with an average particle size of 1 to 10 μm is most desirable because oxidation is significant during the steps, ie, press forming, sintering, and aging treatment steps, making it impossible to obtain excellent magnetic properties. The magnetically anisotropic permanent magnet alloy obtained using the alloy fine powder for permanent magnets according to the present invention has a coercive force _I
Indicates Hc≧1K Oe, residual magnetic flux density Br>4KG,
The maximum energy product (BH)max is equal to or higher than that of hard ferrite, and in the most preferable composition range, (BH)max≧10MG Oe, and the maximum value is
Reaching more than 25MG Oe. Further, the composition of the alloy fine powder according to the present invention is
R10 atomic% ~ 30 atomic%, B2 atomic% ~ 28 atomic%,
For Co45 atomic% or less, Fe65 atomic% to 82 atomic%,
The resulting magnetically anisotropic permanent magnet alloy exhibits magnetic properties equivalent to those of the above-mentioned magnet alloy, and has a temperature coefficient of residual magnetic flux density of 0.1%/°C or less, providing excellent properties. In addition, when the main component of R in the alloy powder is 50% or more of light rare earth metals, R12 at% to 20 at%, B4 at% to 24 at%, Fe65 at% to 82 at%, or Furthermore, it exhibits the best magnetic properties when containing 5 to 45 at% of Co.
Especially when the light rare earth metal is Nd, (BH)max
The maximum value reaches more than 33MG Oe. Further, the alloy fine powder according to the present invention can be press-molded in the absence of a magnetic field to produce an isotropic permanent magnet. Examples will be described below. Example 1 As a starting material, electrolytic iron with a purity of 99.9%, B19.4
% and the remainder is impurities such as Fe and C, Nd with a purity of 99.7% or more is melted by high frequency, and then cast in a water-cooled copper mold.
1 kg of ingot having a composition of 15Nd8B77Fe (at%) was obtained. This ingot was mechanically crushed to a roughness of 35 mesh throughput. Next, 300 g of the coarsely ground powder was charged into a ball mill with outer diameter of 150 mm x inner diameter of 120 mm x length of 150 mm along with 2.8 kg of steel balls of 10 mm outer diameter, and 600 c.c. of trichlorotrifluoroethane was added as a solvent. Fine pulverization was carried out for 5.5 hours at a rotational speed of 100 rpm to obtain an alloy powder with an average particle size of 3.3 μm. Using this alloy powder, it was oriented in a magnetic field of 10KOe, pressure molded at 2t/ ^cm2 , and then heated at 1100℃ for 1
sintered under the conditions of 600℃ in Ar,
A permanent magnet was produced by performing an aging treatment for 1 hour. The magnetic properties of the obtained permanent magnet were measured and are shown in Table 1. For comparison, a permanent magnet was prepared using an ingot of the same composition under the same conditions as the method of this invention described above, except that methanol 600 c.c. was used as the solvent during pulverization.
The magnetic properties were similarly measured, and the measurement results are shown in Table 1. Example 2 As a starting material, electrolytic iron with a purity of 99.9%, B19.4
Ferroboron alloy containing 15Nd, 1.5Dy 7B76.5Fe (at% ) 1 kg of ingot with the following composition was obtained. This ingot was mechanically crushed to a roughness of 35 mesh throughput. Next, 300 g of the coarsely ground powder was charged into a ball mill with dimensions of 150 mm outside diameter x 120 mm inside diameter x 150 mm length, along with 2.8 kg of steel balls with an outside diameter of 10 mm, and Fluorinert FC-72 (product name: Sumitomo 3M) was used as a solvent. Using a 600cc. Using this alloy powder, it was oriented in a magnetic field of 10KOe, pressure molded at 2t/ ^cm2 , and then heated at 1100℃ for 1
sintered under the conditions of 600 c.c. in Ar,
A permanent magnet was produced by performing an aging treatment for 1 hour. The magnetic properties of the obtained permanent magnet were measured and are shown in Table 2. For comparison, a permanent magnet was prepared from an ingot of the same composition under the same conditions as the method of this invention described above, except that 1.1.1.trichloroethane 600 c.c. was used as the solvent during pulverization, and The magnetic properties were measured and the measurement results are shown in Table 2. Example 3 As a starting material, electrolytic iron with a purity of 99.9%, B19.4
% and the remainder is impurities such as Fe and C. A ferroboron alloy with a purity of 99.7% or more is melted by high frequency, and then cast in a water-cooled copper mold to form a 20Pr alloy.
1 kg of an ingot with a composition of 8B72Fe (at%) was obtained. This ingot was mechanically crushed to a roughness of 35 mesh throughput. Next, 300g collected from the coarsely crushed powder was sized to an outer diameter of 150mm x inner diameter of 120mm x length.
2.8 kg of steel balls with an outer diameter of 10 mm are placed in a ball mill with dimensions of 150 mm.
Using 600 c.c. of perfluorotributylamine as a solvent, fine pulverization was performed at a rotation speed of 100 rpm for 5.5 hours to obtain an alloy powder with an average particle size of 3.1 μm. Using this alloy powder, it was oriented in a magnetic field of 10KOe, pressure molded at 2t/ ^cm2 , and then heated at 1100℃ for 1
sintered under the conditions of 600℃ in Ar,
A permanent magnet was produced by performing an aging treatment for 1 hour. The magnetic properties of the obtained permanent magnet were measured and are shown in Table 3. For comparison, a permanent magnet was prepared from an ingot of the same composition under the same conditions as the method of this invention described above, except that 600 c.c. of isoamyl alcohol was used as the solvent during pulverization, and the magnetic properties were similarly measured. , Table 3 shows the measurement results. As is clear from the results in Tables 1 to 3,
A permanent magnet using the fine powder obtained by the pulverization method according to the present invention has excellent magnetic properties, and
There is very little variation in magnetic properties, making it suitable for industrial production.
It is extremely effective.

【表】【table】

Claims

【特許請求の範囲】[Claims]

１Ｒ（但し、ＲはＹを包含する希土類元素のう
ち少なくとも１種）10原子％〜30原子％、B2原
子％〜28原子％、Fe65原子％〜82原子％を主成
分とする合金粉末を、沸点が35℃以上で常温で液
体の弗素化炭化水素と共に粉砕機内に装入し、平
均粒度が1μm〜10μｍの粉末に微粉砕することを
特徴とする希土類・ボロン・鉄系永久磁石用合金
粉末の粉砕方法。1 R (however, R is at least one kind of rare earth elements including Y) alloy powder whose main components are 10 atomic % to 30 atomic %, B2 atomic % to 28 atomic %, and Fe65 atomic % to 82 atomic %. , a rare earth/boron/iron alloy for permanent magnets, which is charged into a pulverizer together with a fluorinated hydrocarbon that has a boiling point of 35°C or higher and is liquid at room temperature, and is pulverized into powder with an average particle size of 1 μm to 10 μm. How to grind powder.