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JPH06207204A - Production of rare earth permanent magnet - Google Patents

Production of rare earth permanent magnet

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Publication number
JPH06207204A
JPH06207204A JP15976691A JP15976691A JPH06207204A JP H06207204 A JPH06207204 A JP H06207204A JP 15976691 A JP15976691 A JP 15976691A JP 15976691 A JP15976691 A JP 15976691A JP H06207204 A JPH06207204 A JP H06207204A
Authority
JP
Japan
Prior art keywords
phase
alloy
rare earth
mixed
phases
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.)
Granted
Application number
JP15976691A
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Japanese (ja)
Other versions
JP2853839B2 (en
Inventor
Masao Kusunoki
的生 楠
Masao Yoshikawa
昌夫 吉川
Takehisa Minowa
武久 美濃輪
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Shin Etsu Chemical Co Ltd
Original Assignee
Shin Etsu Chemical Co Ltd
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Publication date
Application filed by Shin Etsu Chemical Co Ltd filed Critical Shin Etsu Chemical Co Ltd
Priority to JP3159766A priority Critical patent/JP2853839B2/en
Priority to EP92109366A priority patent/EP0517179B1/en
Priority to DE1992602515 priority patent/DE69202515T2/en
Priority to US08/119,641 priority patent/US5405455A/en
Publication of JPH06207204A publication Critical patent/JPH06207204A/en
Application granted granted Critical
Publication of JP2853839B2 publication Critical patent/JP2853839B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032Magnets 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
    • H01F1/04Magnets 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
    • H01F1/047Alloys characterised by their composition
    • H01F1/053Alloys characterised by their composition containing rare earth metals
    • H01F1/055Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571Alloys 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
    • H01F1/0575Alloys 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
    • H01F1/0577Alloys 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

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  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Powder Metallurgy (AREA)
  • Hard Magnetic Materials (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)

Abstract

PURPOSE:To produce the rare earth permanent magnet having excellent magnetic characteristic by specifying the constituting alloys, subjecting these alloys to press molding and sintering, then to an aging heat treatment. CONSTITUTION:An alloy mainly consisting of an R2Fc14 phase is used for the alloy A and an alloy contg. R, Co, Fc and B and consisting of an R2T<1>14 phase and/or R rich phase and a phase mixture composed of one or >=2 kinds among 5 phases; RT24B phase, RT<2>3 phase, RT<2>2 phase and R2T<2>7 phase and RT<2>5 phase as a construction phase in the alloy is used for the alloy B. The alloy B powder is mixed at 1 to 30wt.% with 99 to 70wt.% alloy A powder and the alloy mixture powder is press molded in a magnetic field. The molding is sintered in a vacuum or inert gaseous atmosphere and is then subjected to the aging heat treatment at the sintering temp. or below. As a result, the rare earth permanent magnet having excellent magnetic characteristics is produced.

Description

【発明の詳細な説明】 【0001】 【産業上の利用分野】本発明は、各種電気、電子機器に
用いられる、磁気特性に優れた希土類永久磁石の製造方
法に関するものである。 【0002】 【従来の技術】希土類磁石の中でもNd-Fe-B系磁石は、
主成分であるNdが資源的に豊富でコストが安く、磁気特
性に優れているために、近年益々その利用が広がりつつ
ある。磁気特性向上のための開発研究も、Nd系磁石の発
明以来精力的に行われてきており、数多くの研究や発明
が提案されている。Nd系焼結磁石の製造方法の1つであ
る2種類の組成の異なった合金粉体を混合、焼結して高
性能Nd磁石を製造する方法(以下、2合金法という)に
関しても数々の発明考案が提案されている。 【0003】これまでに提案されている2合金法を大き
く分けると、3種類に分類することができる。第1の方
法は、混合する原料合金粉体の一方を液体急冷法によっ
て非晶質あるいは微細結晶合金を作製し、それに通常の
希土類合金粉末を混合するか、あるいは両方の原料合金
粉体を共に液体急冷法で作製混合する方法[特開昭63-9
3841、 特開昭63-115307、特開昭63-252403、特開昭663-2
78208、特開平1-108707、 特開平1-146310、 特開平1-1463
09、 特開平1-155603各号公報参照]である。この液体急
冷法による合金を使用する2合金法については、最近50
MGOeを越える磁気特性が得られたと報告[E.Otuki,T.Otu
ka and T.Imai;11th.Int.Workshopon Rare Earth Magne
ts,Pittsburgh,Pennsylvania,USA,October(1990),p.328
参照 ]されている。 【0004】第2の方法は、混合する2種類の原料合金
粉体を共に主としてR2 Fe14
B化合物とし含有される希土類元素の種類、含有量を変
えた合金を作製して混合焼結する方法である。即ち、含
有するNdリッチ相の量比あるいは希土類元素の種類を変
えた合金を2種類混合する方法[特開昭61-81603、 特開
昭61-81604、 特開昭61-81605、 特開昭61-81606、 特開昭
61−81607、 特開昭61-119007、特開昭61-20754
6、特開昭63-245昭3、特開平1-177335各号公報参照]であ
る。 【0005】第3の方法は、一方の合金を主としてR 2
Fe14
B化合物からなる合金粉末とし、これに各種低融点元素
、低融点合金、希土類合金、炭化物、硼化物、水素化物
等の粉末を混合焼結して、Nd系希土類磁石を製造する方
法 [特開昭60-230959、特開昭61-263201、特開昭62-18140
2、特開昭62-182249、特開昭62-206802、特開昭62-270746、
特開昭63-6808、特開昭63-104406、特開昭63-114939、特開
昭63-272006、特開平1-111843、 特開平1-146308各号公報
参照] である。 【0006】 【発明が解決しようとする課題】従来技術による2合金
法ではNd系磁石合金の真に優れた磁気特性を実現させる
のに適切でなかったり不充分だったりする点が多く存在
する。即ち、前述した第1の方法では磁石合金のエネル
ギ−積は高いが保磁力は約9kOe 程度で、温度上昇によ
って低下するというNd磁石特有の欠点を持ち、実用的に
は不充分な磁石特性である。最も大きな問題点は、磁場
配向性である。第1の方法でも組成を適当に選ぶことに
よって、室温で保磁力を示す合金を得ることができるが
、液体急冷法によって得られる合金は非晶質アモルファ
ス相あるいは微細結晶となるため、微粉にして磁場中で
配向させても特定の結晶方位を磁場方向に配向させるこ
とができない。従って、混合した原料合金粉体を磁場中
成形しても得られる成形体の配向性は悪く、焼結後充分
な磁石特性が得られないことになる。 【0007】第2の方法においては、磁石合金中のR 2
Fe14B化合物と共存する相はNdリッチ相あるいはNd1+
χFe44
相であり、この両相とも室温では磁性を示さない。従
って、磁性を持たない化合物を混合した場合と同様に、
非磁性粒子の混在が配向性を乱して、磁気特性の優れた
磁石は得られない。また、混合する粉体として各種元素
や種々の化合物を用いる第3の方法においてもこれらの
化合物は磁性をもたないために、磁場中配向時に反磁場
が大きくなって有効磁場強度が減少し、そのため磁場方
向への磁性粒子の回転が不充分となって配向が乱れる。 【0008】
第3の方法において、混合する粉体に低融点の元素ある
いは合金を利用して磁気特性を向上させようとする提案
があるが、これは焼結中に混合した低融点相が、R 2 Fe
14
B化合物の粒界に存在する格子欠陥や酸化物相などのニ
ュークリエーションサイトを除去し、粒界をクリーニン
グして保磁力を向上させるという考え方によるものであ
る。しかし、低融点相の存在は次に述べるような理由か
ら、実際には磁気特性の向上に対して逆に不利な条件と
なっている。低融点相が例えば660 ℃付近から融液とな
っていると、実際の焼結温度1,100 ℃では低融点相の粘
度はかなり小さくなってしまう。その結果、成形体は液
相焼結によって収縮しながら同時に粒の周囲を囲む融液
の粘度が小さいために磁性粒子の回転が容易に起り、配
向が乱れて磁気特性が劣化する。つまり、Nd磁石の液相
焼結における望ましい液相成分は、適当な粘度を保って
粒子の配向を乱さず、かつまた成形体を緻密化し、粒界
を十分にクリーニングアップできることが必要なのであ
る。従来の2合金法においては、液相成分が関与する磁
場配向性と保磁力向上の両方の役割を充分に考慮し、こ
れらが最適な条件となるよう液相合金成分の磁性と融点
を適切に調整してはいなかった。本発明は2合金法にお
ける前述したような欠点を改良し、バランスのとれた磁
気特性に優れた希土類永久磁石の製造方法を提供しよう
とするものである。 【0009】 【課題を解決するための手段】本発明者等は、かかる課
題を解決するために2合金法を基本的に見直し、磁性体
構成相の種類、特性等を適切に選択し組合せることによ
り充分満足できるバランスのとれた磁気特性が得られる
ことを見出し、製造条件を詳細に検討して本発明を完成
させた。 本発明の要旨は、A合金を主としてR 2 Fe14
B相(ここにRは、Nd、Pr、Dyを主体とする少なくとも1
種以上の希土類元素を表す)から成る合金とし、B合金
をR、Co、Fe、 Bを含有し、かつ合金中の構成相としてR
2 114
B相および/またはRリッチ相(ここにRは上記に同
じ、T 1 はFe、Co を主体とする遷移金属元素を表す)並
びにRT24B相、RT 23相、RT 22相、R2 27
相およびRT 25相(ここにRは上記に同じ、T 2 はFe、C
o を主体とする遷移金属元素、同遷移金属およびBを表
す)の5相の内1種または2種以上の相との混合相から
成る合金とし、A合金粉末99〜70重量%に対してB合金
粉末を1〜30重量%混合し、該混合合金粉末を磁場中加
圧成形し、該成形体を真空または不活性ガス雰囲気中で
焼結し、さらに焼結温度以下の低温で時効熱処理するこ
とを特徴とする希土類永久磁石の製造方法であり、更に
詳しくは、B合金に含まれるRT24B相、RT 23
相、RT 22相、R2 27相およびRT 25
相の5つの構成相の内少なくとも1種以上の相の融点が
700 ℃以上1,155 ℃以下の金属間化合物であり、少
なくとも1種以上の相が室温以上のキューリー温度を有
する磁性体であり、少なくとも1種以上の相が室温以上
のキューリー温度ならびに結晶磁気異方性を有する磁性
体であることを特徴とする希土類磁石の製造方法である
【0010】以下本発明を詳細に説明する。本発明は所
謂2合金法と称する希土類永久磁石(以下、磁石合金C
という)の製造方法であり、原料となるA合金は主とし
てR 2 Fe14
B化合物相からなり、RはYを含む La,Ce,Pr,Nd,Pm,Sm
,Eu,Gd,Tb,Dy,Ho,Er,Tm,YbおよびLuから選択されるNd、P
r、Dyを主体とする少なくとも1種類以上の希土類元素で
ある。A合金は原料金属を真空または不活性ガス、好ま
しくはAr雰囲気中で溶解し鋳造する。原料金属は純希土
類元素、純鉄、フェロボロン等を使用するが、一般的な
工業生産において不可避な微量不純物は含まれるものと
する。得られたインゴットは、R2Fe14
B相がαFeと希土類リッチ相との包晶反応によって形成
されるため、鋳造後も凝固偏析によってαFe相、Rリッ
チ相、あるいはBリッチ相等が残留する場合がある。本
発明においてはA合金中のR2 Fe14
B相が多いほうが望ましいので、必要に応じて溶体化処
理を行う。その条件は真空またはAr雰囲気下、700 〜1,
200 ℃の温度領域で1時間以上熱処理すれば良い。 【0011】B合金は主としてR、Co、Fe、 Bから成る合
金で、組成式R aFebCocd
(ここにRは、Yを含む La,Ce,Pr,Nd,Pm,Sm,Eu,Gd,Tb
,Dy,Ho,Er,Tm,YbおよびLuから選択されるNd、Pr、Dyを主
体とする少なくとも1種以上の希土類元素、15≦a ≦40
、0≦b ≦80、 5≦c ≦85、 0≦d ≦20、 a+b+c+d=100 (
各原子%) )で表わされ
、A合金と同様に原料金属を真空または不活性ガス、好
ましくはAr雰囲気中で溶解し鋳造する。原料金属として
は純希土類元素、純鉄、純コバルト、フェロボロン等を
使用するが、一般的な工業生産において不可避な微量不
純物は含まれるものとする。希土類元素Rの量a が15原
子%未満ではRが少な過ぎるために焼結工程において十
分な量の液相が得られず、焼結体の密度が上がらなくな
り、40原子%を越えると合金の融点が低くなり過ぎて磁
気特性の向上効果がなくなる。Coの量c が5原子%未満
ではRT 24B相、RT 23相、RT 22相、R2 27
相およびRT 25
相等の各相が出現しなくなり、磁気特性の向上効果が得
られない。また、液体急冷法によって得られた薄帯を熱
処理してもB合金を作製することができる。即ち、液体
急冷法において、急冷後のB合金はアモルファス相或は
微細結晶相となっており、これを結晶化温度以上の温度
で一定時間以上加熱することにより、結晶化或は再結晶
成長させて、本発明の所定の構成相を析出させることが
出来る。 【0012】この組成範囲においてB合金中に主に出現
する相は、R 2 114 B相(主としてR2 Fe14
B相)、Rリッチ相(ここにRは上記に同じ、T 1 はF
e、Co を主体とする遷移金属元素を表す)並びにRT24
B相、RT 23相、RT 22相、R2 27相およびRT 25
相(ここにRは上記に同じ、T 2 はFe、Co を主体とする
遷移金属元素、同遷移金属およびBを表す)等であり、
本発明では前2相および後5相の内少なくとも1種また
は2種以上の相を含むB合金を使用することに特徴があ
る。なおRリッチ相と表記した相は、R成分が35原子%
以上となるRに富んだ各種の相全てを表すものとする。
これら7種類の相のうち、R2 Fe14B相、Rリッチ相の
2相は、従来公知の2合金法や、通常の希土類鉄ボロン
系磁石合金の製造法によっても出現していた相である。
残りのRT24B相、RT 23相、RT 22相、R2 27
相、RT 25
相の5種類の相は、B合金に5原子%以上のCoを添加す
ることにより出現し、本発明の2合金法において特有の
ものである。これら5相はCoを5原子%以上添加するこ
とによって初めてB合金中に平衡相として出現したもの
である。
図1は本発明のB合金の鋳造組織写真を走査電子顕微鏡
により撮影し、組成をEPMA( 電子プローブX線マイクロ
アナライザー )およびX線解析により求めた1例でR
24B相、RT 23相、RT 22
相、Rリッチ相の存在が明確に表されている。本発明
による2合金法は、B合金中にこれら5相のうち、少な
くとも1種以上含むことを特徴とし、これらの相の存在
によって2合金法で作製された磁石合金に高い磁気特性
を実現することができた。 【0013】本発明では以上述べたA合金、B合金を特
定割合に混合し、所謂2合金法によって磁石合金Cを作
製し、高い磁気特性を発現させることができた。以下、
B合金におけるこれら混合相の存在が磁石合金の高い磁
気特性をもたらした理由について述べる。まず第1の理
由として、これら混合相が室温以上のキューリー温度を
持つことが挙げられ、これは添加元素Coによって達成さ
れた。さらに、これらの相は特定の結晶方向に結晶磁気
異方性を持つ。従って、主な構成相としてこれらの相の
1種以上を含有するB合金粉末を主にR 2Fe14
B相から成るA合金粉末に混合して磁場中配向させる
と、B合金も強磁性体で磁気異方性を持つため、加えた
磁場方向にほぼ全ての粒子が結晶方向を揃えて配向し、
高い磁気特性が得られることになる。 【0014】第2の理由は、これらの相の融点がNd系希
土類磁石の液相焼結にとって適当な温度範囲、即ち700
℃以上1,155 ℃以下の範囲となることである。この温度
範囲はNdリッチ相の融点(500 〜 650℃)よりは高く、
しかもR 2Fe14
B相の融点(1,155 ℃)以下の温度である。従って、
通常の焼結温度においてNdリッチ相のみが存在していて
融液の粘度が下がり過ぎてしまい、その結果粒子の配向
を乱してしまうようなことがなく、かつまた液相となっ
て粒界をクリーニングしながら密度を上げ、焼結後高い
磁石特性を実現することになる。Co添加によるもう1つ
の効果として、耐食性の向上が挙げられる。B合金はA
合金より希土類元素を多く含有するため酸化劣化しやす
くなるが、Coを添加する
ことにより酸化劣化を防止することができ、安定した磁
気特性が得られる。B合金に添加されるDyは、焼結後も
粒界近傍に多く存在し、磁石合金Cの保磁力を向上させ
る効果がある。 【0015】次に2合金法による磁石合金Cの製造方法
を述べる。上記のようにして得られたA合金およびB合
金は、各インゴットを別々に粉砕した後、所定割合に混
合される。粉砕は、湿式又は乾式粉砕にて行われる。希
土類合金は非常に活性であり、粉砕中の酸化を防ぐこと
を目的に、乾式粉砕の場合はAr又は窒素などの雰囲気中
で、湿式粉砕の場合はフロンなどの非反応性の有機溶媒
中で行われる。混合工程も必要に応じて不活性雰囲気又
は溶媒中で行われる。粉砕は一般に粗粉砕、微粉砕と段
階的に行われるが、混合はどの段階で行われても良い。
即ち粗粉砕後に所定量混合し引続いて微粉砕を行っても
よいし、全ての粉砕を完了した後に所定の割合に混合し
てもよい。A、B両合金がほぼ同じ平均粒径で均一に混
合されることが必要で、平均粒径は0.5 〜20μmの範囲
が良く、0.5 μm未満では酸化され劣化し易く、20μm
を越えると焼結性が悪くなる。 【0016】A合金粉末とB合金粉末の混合割合は、A
合金粉末99〜70重量%に対してB合金粉末を1〜30重量
%の範囲で混合するのが良く、B合金粉末が1重量%未
満では焼結密度が上がらなくなり保磁力が得られないし
、30重量%を越えると焼結後の非磁性相の割合が大きく
なり過ぎて、残留磁束密度が小さくなってしまう。得ら
れたA合金とB合金の混合微粉は、次に磁場中成型プレ
スによって所望の寸法に成型され、さらに焼結熱処理す
る。焼結は900 〜1,200 ℃の温度範囲で真空又はアルゴ
ン雰囲気中にて30分以上行ない、続いて焼結温度以下の
低温で30分以上時効熱処理する。焼結後、磁石合金Cの
成形体の密度は対真密度比で95%以上に緻密化しており
高い残留磁束密度が得られる。 【0017】 【実施例】以下、本発明の具体的な実施態様を実施例を
挙げて説明するが、本発明はこれらに限定されるもので
はない。 (実施例1、比較例1)純度99.9重量%のNd、 Feメタル
とフェロボロンを用いて組成式12.5Nd-6B-81.5Fe(各原
子%)の合金を、高周波溶解炉のAr雰囲気中にて溶解鋳
造した後、このインゴットを1,070 ℃、Ar雰囲気中にて
20時間溶体化した。これをA1合金とする。次に同じ
く純度99.9重量%のNd、Dy、Fe、Co メタルとフェロボロン
を用いて組成式20Nd-10Dy-20Fe-6B-44Coの合金を高周波
溶解炉を用いAr雰囲気にて溶解鋳造し、これをB1合金
とした。A1合金インゴットとB1合金インゴットをそ
れぞれ別々に窒素雰囲気中にて粗粉砕して30メッシュ以
下とし、次にA1合金粗粉90重量%にB1合金粗粉を10
重量%秤量して、窒素置換したVブレンダー中で30分間
混合した。この混合粗粉を高圧窒素ガスを用いたジェッ
トミルにて、平均粒径約5μmに微粉砕した。得られた
混合微粉末を15kOe の磁場中で配向させながら、約1To
n/cm 2 の圧力でプレス成型した。次いで、この成形体は
Ar雰囲気の焼結炉内で1,070 ℃で1時間焼結され、さら
に530 ℃で1時間時効熱処理して急冷し、磁石合金C1
を作製した。 【0018】比較のため実施例1と同じ組成となる合金
を従来の1合金法にて製造し、比較例1とした。即ち、
A1、B1両合金混合後と同じ組成(磁石合金C1)を
最初から秤量し、溶解、粉砕、焼結、時効熱処理して2
合金法による磁石(実施例1の磁石組成C1)と磁気特
性を比較した。この磁石合金C1の組成は、2合金法に
よる実施例1、1合金法による比較例1共に、13.1Nd-
0.8Dy-3.5Co-6.0B-76.6Feである。表1に実施例1と比
較例1の両焼結体磁石において得られた磁気特性の値と
焼結体密度を示す。実施例1の磁気特性は比較例1に比
較して、焼結体密度は殆ど同じであるが、残留磁束密
度、保磁力、最大エネルギ−積等、全ての値において実
施例1が大きく勝っている。このように磁石合金Cの組
成が全く同一でも磁気特性にはかなりの差が生じてお
り、2合金法がNd磁石の磁気特性向上のために極めて有
効な方法であることを示している。B1合金の鋳造状態
での金属組織を、図1に走査電子顕微鏡の反射電子像写
真によって示した。写真の明暗から判る通りB1合金中
の主な構成相は4つある。各相は、EPMA(電子プローブ
X線マイクロアナライザー)およびX線解析によって、
図中に示したようにRT24B相、RT 23相、RT 22
相、Rリッチ相であることが判明した。 【0019】(実施例2〜11、比較例2〜11)表1に示
したように実施例2〜11の合金組成に対応して、A合金
としてA1、A2の組成合金をを作り、B合金としてB
2〜B9の組成合金を作製し、以下実施例1と同様の方
法で粉砕、所定の比率に混合、磁場中成形、焼結(1,05
0 〜1,120 ℃×1時間)、時効処理(500 〜600 ℃×1
〜10時間)を行い2合金法磁石合金C2〜C11を製造し
、その磁気特性を測定して表1、2に示した。比較のた
め実施例2〜11と同じ組成となる合金を1合金法により
作製した以外は実施例2〜11と同条件により磁石合金C
2〜C11を製造し、磁気特性を測定して比較例2〜11と
し、表1、表2に示した。 【0020】 【表1】 【表2】 【0021】 【発明の効果】
本発明により作製した希土類永久磁石は、高価な添加元
素を有効に活用して、従来法の同一組成の希土類磁石と
比べて磁気特性が数段優れており、高保磁力、高残留磁
束密度、さらには高エネルギー積のバランスのとれた高
性能磁石を提供することが可能となった。従って今後、
各種電気、電子機器用の高性能磁石として広汎に利用さ
れることが期待される。
Detailed Description of the Invention [0001] The present invention relates to various electric and electronic devices.
Manufacturing method of rare earth permanent magnets with excellent magnetic properties
It is about law. [0002] 2. Description of the Related Art Among rare earth magnets, Nd-Fe-B magnets are
Nd, which is the main component, is abundant in resources, low in cost, and magnetic.
Due to its superiority, its use is expanding more and more in recent years.
is there. Research and development for improving magnetic properties has also been carried out using Nd-based magnets.
It has been energetically carried out since the early days, and many researches and inventions have been made.
Is proposed. One of the manufacturing methods for Nd-based sintered magnets
Two alloy powders with different compositions are mixed and sintered to obtain high
Performance Nd magnet manufacturing method (hereinafter referred to as 2-alloy method)
A number of inventions have been proposed regarding this. The two-alloy method proposed so far is
It can be classified into three types. First person
In this method, one of the raw material alloy powders to be mixed is subjected to the liquid quenching method.
To produce an amorphous or fine crystal alloy,
Rare earth alloy powder mixed, or both raw alloys
A method in which both powders are produced and mixed by a liquid quenching method [Japanese Patent Laid-Open No. 63-9
3841, JP-A-63-115307, JP-A-63-252403, JP-A-663-2
78208, JP-A-1-108707, JP-A-1-146310, JP-A-1-1463
09, refer to Japanese Unexamined Patent Publication No. 1-155603]. This liquid steep
For the two-alloy method using alloys by the cold method, 50
Reported that magnetic properties exceeding MGOe were obtained [E.Otuki, T.Otu
ka and T.Imai; 11th.Int.Workshopon Rare Earth Magne
ts, Pittsburgh, Pennsylvania, USA, October (1990), p.328
Has been referred to]. The second method is to mix two kinds of raw material alloys.
R mainly for powder2Fe14
Change the type and content of rare earth elements contained as B compounds
This is a method of producing the alloy and mixing and sintering it. That is, including
Change the amount ratio of the Nd-rich phase or the type of rare earth element
A method of mixing two kinds of the obtained alloys [JP-A-61-81603, JP-A-61-81603]
61-81604, JP-A-61-81605, JP-A-61-81606, JP-A-61-81606
61-81607, JP-A-61-119007, JP-A-61-20754
6, see JP-A-63-245, Sho-3 and JP-A-1-177335.]
It In the third method, one alloy is mainly used for R 2
Fe14
Alloy powder consisting of B compound and various low melting point elements
, Low melting point alloys, rare earth alloys, carbides, borides, hydrides
For manufacturing Nd rare earth magnets by mixing and sintering powders such as
Method [JP-A-60-230959, JP-A-61-263201, JP-A-62-18140
2, JP-A-62-182249, JP-A-62-206802, JP-A-62-270746,
JP 63-6808, JP 63-104406, JP 63-114939, JP
Sho 63-272006, JP 1-111843, JP 1-146308
Reference]. [0006] Two alloys according to the prior art
Method achieves the truly excellent magnetic properties of Nd-based magnet alloys
There are many points that are not appropriate or insufficient for
To do. That is, in the first method described above, the energy of the magnet alloy is
The Gee product is high, but the coercive force is about 9 kOe, and
It has a drawback that is unique to Nd magnets
Is an insufficient magnet characteristic. The biggest problem is the magnetic field
It is oriented. Even in the first method, the composition should be selected appropriately.
Therefore, it is possible to obtain an alloy that exhibits a coercive force at room temperature.
, Alloys obtained by liquid quenching method are amorphous amorphous
In the magnetic field, it becomes fine powder because it becomes fine phase or fine crystals.
Even if it is oriented, a certain crystal orientation should be oriented in the magnetic field direction.
I can't. Therefore, the mixed raw alloy powder is
The orientation of the obtained molded product is poor even after molding, and it is sufficient after sintering.
It is not possible to obtain good magnet characteristics. In the second method, R in the magnet alloy is used. 2
Fe14Phase coexisting with B compound is Nd rich phase or Nd1+
χFeFourBFour
It is a phase and neither of them exhibits magnetism at room temperature. Servant
Therefore, as in the case of mixing non-magnetic compounds,
Mixing of non-magnetic particles disturbs the orientation, resulting in excellent magnetic properties.
I can't get a magnet. In addition, various elements as powder to be mixed
And in the third method using various compounds
Since the compound does not have magnetism, the demagnetizing field is generated during orientation in the magnetic field.
Becomes larger, the effective magnetic field strength decreases, and
The rotation of the magnetic particles in the opposite direction is insufficient, and the orientation is disturbed. [0008]
In the third method, the powder to be mixed contains an element having a low melting point.
Proposal to improve magnetic properties by using iron alloy
There is a low melting point phase mixed during sintering 2Fe
14
B compounds such as lattice defects existing at grain boundaries and oxide phases
Removes creation sites and cleans grain boundaries
The idea is to increase the coercive force by
It However, the existence of the low-melting phase is as follows.
In fact, on the contrary, there are disadvantageous conditions for improving the magnetic characteristics.
Has become. The low-melting phase starts to melt from around 660 ° C, for example.
Therefore, at the actual sintering temperature of 1,100 ° C, the viscosity of the low melting point phase
The degree will be quite small. As a result, the molded body is liquid
Melt that shrinks by phase sintering and simultaneously surrounds the periphery of grains
Since the viscosity of the magnetic particles is small, the magnetic particles easily rotate and
The magnetic properties are deteriorated due to disordered orientation. That is, the liquid phase of the Nd magnet
Desirable liquid phase component in sintering should maintain proper viscosity.
The orientation of the particles is not disturbed and the compact is densified,
Is required to be fully cleaned up.
It In the conventional two-alloy method, the magnetism involving the liquid phase component
Carefully consider both the roles of field orientation and coercive force improvement.
Magnetic properties and melting points of liquid phase alloy components so that these are optimal conditions.
Was not properly adjusted. The present invention is based on the two-alloy method.
The above-mentioned drawbacks are improved and a well-balanced magnetism is obtained.
Let's provide a manufacturing method of rare earth permanent magnets with excellent vapor characteristics
It is what [0009] [Means for Solving the Problems]
In order to solve the problem, we basically reviewed the two-alloy method,
By properly selecting and combining the types and characteristics of constituent phases
Well-balanced magnetic properties can be obtained
Found that, completed the present invention by examining the manufacturing conditions in detail
Let The gist of the present invention is that the alloy is mainly R 2Fe14
Phase B (where R is at least 1 mainly composed of Nd, Pr and Dy)
An alloy consisting of one or more kinds of rare earth elements), and B alloy
Containing R, Co, Fe, B, and R as a constituent phase in the alloy
2T 114
B phase and / or R rich phase (where R is the same as above)
T, T 1 Represents a transition metal element mainly composed of Fe and Co)
Every RT2FourPhase B, RT 23Phase, RT 22Phase, R2T 27
Phase and RT 2FivePhase (where R is the same as above, T 2 Is Fe, C
The transition metal element mainly consisting of o, the same transition metal and B
From the mixed phase with one or more of the five phases
Alloy consisting of 99% to 70% by weight of A alloy powder and B alloy
The powder is mixed in an amount of 1 to 30% by weight, and the mixed alloy powder is applied in a magnetic field.
Pressure molding and molding the molded body in a vacuum or an inert gas atmosphere.
Sinter, and then perform an aging heat treatment at a temperature lower than the sintering temperature.
And a method for manufacturing a rare earth permanent magnet characterized by:
For details, RT included in B alloy2FourPhase B, RT 23
Phase, RT 22Phase, R2T 27Phase and RT 2Five
The melting point of at least one of the five constituent phases of the phase
It is an intermetallic compound with a temperature of 700 ℃ or more and 1,155 ℃ or less.
At least one phase has a Curie temperature above room temperature
Is a magnetic substance that has at least one phase at room temperature or higher.
With Curie temperature and crystalline magnetic anisotropy
A method of manufacturing a rare earth magnet characterized by being a body
. The present invention will be described in detail below. The present invention is
Rare earth permanent magnet called so-called two-alloy method (hereinafter, magnet alloy C
That is, the production method is
R 2Fe14
La, Ce, Pr, Nd, Pm, Sm consisting of B compound phase and R containing Y
, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu selected Nd, P
At least one kind of rare earth element mainly composed of r and Dy
is there. For alloy A, raw metal is vacuum or inert gas, preferably
It is preferably melted and cast in Ar atmosphere. Raw metal is pure rare earth
Uses elemental elements, pure iron, ferroboron, etc.
Including a trace amount of impurities that are inevitable in industrial production
To do. The obtained ingot is R2Fe14
B phase is formed by peritectic reaction between αFe and rare earth rich phase
Therefore, the αFe phase and R
The H-phase or B-rich phase may remain. Book
In the invention, R in A alloy2Fe14
Since it is desirable to have a large amount of phase B, solution treatment may be performed if necessary.
Do the work. The conditions are 700 to 1, under vacuum or Ar atmosphere.
The heat treatment may be performed in the temperature range of 200 ° C for 1 hour or more. B alloy is a compound mainly composed of R, Co, Fe and B.
Gold, composition formula R aFebCocBd
(Where R is Y including La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb
, Dy, Ho, Er, Tm, Yb and Lu selected from Nd, Pr, Dy
At least one or more rare earth elements forming the body, 15 ≦ a ≦ 40
, 0 ≤ b ≤ 80, 5 ≤ c ≤ 85, 0 ≤ d ≤ 20, a + b + c + d = 100 (
Each atom%))
, A alloy as well as the source metal is vacuum or inert gas,
More preferably, it is melted and cast in Ar atmosphere. As a raw metal
Is pure rare earth element, pure iron, pure cobalt, ferroboron, etc.
Used, but inevitable in general industrial production.
Pure items shall be included. The amount a of rare earth element R is 15
If the content is less than%, the amount of R is too small, and the sintering process is insufficient.
A sufficient amount of liquid phase cannot be obtained, and the density of the sintered body does not increase.
If it exceeds 40 atom%, the melting point of the alloy becomes too low and
The effect of improving the air quality is lost. Co content c is less than 5 atomic%
Then RT 2FourPhase B, RT 23Phase, RT 22Phase, R2T 27
Phase and RT 2Five
Each phase such as phase disappears, and the effect of improving magnetic properties is obtained.
I can't. In addition, heat the ribbon obtained by the liquid quenching method.
The B alloy can be produced even by the treatment. That is, liquid
In the quenching method, the B alloy after quenching has an amorphous phase or
It has a fine crystalline phase, which is a temperature above the crystallization temperature.
Crystallize or recrystallize by heating for a certain time at
Can be grown to precipitate certain constituent phases of the present invention.
I can. Appearing mainly in B alloy in this composition range
The phase to do is R 2T 114Phase B (mainly R2Fe14
B phase), R rich phase (where R is the same as above, T 1 Is F
e represents a transition metal element mainly composed of Co) and RT2Four
Phase B, RT 23Phase, RT 22Phase, R2T 27Phase and RT 2Five
Phase (where R is the same as above, T 2 Is mainly Fe, Co
Transition metal element, representing the same transition metal and B), etc.,
In the present invention, at least one of the front two phases and the rear five phases or
Is characterized by using a B alloy containing two or more phases.
It The R-rich phase has 35 atomic% of R component.
It represents all of the various R-rich phases described above.
Of these seven phases, R2 Fe14B phase, R rich phase
The two phases are the conventionally known two-alloy method and ordinary rare earth iron boron.
It is a phase that has also appeared by the manufacturing method of the base magnet alloy.
Remaining RT2FourPhase B, RT 23Phase, RT 22Phase, R2T 27
Phase, RT 2Five
Five types of phases are added to the B alloy with Co of 5 atomic% or more.
Which is unique to the two-alloy method of the present invention.
It is a thing. For these five phases, Co should be added in an amount of 5 atomic% or more.
First appeared as an equilibrium phase in B alloy due to
Is.
FIG. 1 is a scanning electron microscope showing a photograph of the cast structure of the B alloy of the present invention.
Photographed with EPMA (electron probe X-ray micro
R) in one example obtained by analyzer) and X-ray analysis
T 2FourPhase B, RT 23Phase, RT 22
The existence of the phase and the R-rich phase is clearly shown. The present invention
The two-alloy method by
The presence of at least one of these phases, characterized by the inclusion of at least one
Magnetic properties of magnet alloys produced by the two-alloy method by
Could be realized. In the present invention, the A alloy and B alloy described above are special
The magnet alloy C is produced by the so-called two-alloy method by mixing in a fixed ratio.
It was manufactured and was able to exhibit high magnetic properties. Less than,
The presence of these mixed phases in the B alloy is due to the high magnetism of the magnet alloy.
The reason why the qi characteristics are brought about will be described. First the first reason
The reason is that these mixed phases have a Curie temperature above room temperature.
To have, which is achieved by the additive element Co
It was Furthermore, these phases are crystalline magnetic in a specific crystallographic direction.
Has anisotropy. Therefore, of these phases as the main constituent phases
Mainly R alloy containing B alloy powder containing one or more kinds 2Fe14
Oriented in a magnetic field by mixing with A alloy powder consisting of B phase
, And B alloy is also a ferromagnetic material and has magnetic anisotropy.
Almost all particles are oriented with their crystal directions aligned in the magnetic field direction,
High magnetic characteristics can be obtained. The second reason is that the melting points of these phases are Nd rare metals.
Suitable temperature range for liquid phase sintering of earth magnets, ie 700
It should be in the range of ℃ to 1,155 ℃. This temperature
The range is higher than the melting point of Nd-rich phase (500-650 ℃),
Moreover, R 2Fe14
The temperature is lower than the melting point of phase B (1,155 ° C). Therefore,
Only Nd-rich phase is present at normal sintering temperature
The melt viscosity becomes too low, which results in particle orientation.
It does not disturb the
And increase the density while cleaning the grain boundaries, and high after sintering
The magnet characteristics will be realized. Another by adding Co
The effect of is that the corrosion resistance is improved. B alloy is A
Since it contains more rare earth elements than alloys, it is prone to oxidative deterioration
But add Co
By doing so, oxidative deterioration can be prevented and a stable magnetic
Qi characteristics are obtained. Dy added to B alloy is
It exists in the vicinity of the grain boundary, and improves the coercive force of magnet alloy C.
There is an effect. Next, a method for producing a magnet alloy C by the two-alloy method
State. A alloy and B alloy obtained as described above
Gold is crushed separately from each ingot and then mixed in a specified proportion.
Are combined. The crushing is performed by wet or dry crushing. Rare
Earth alloys are very active and prevent oxidation during grinding
For dry crushing, in an atmosphere of Ar or nitrogen, etc.
In case of wet grinding, non-reactive organic solvent such as CFC
Done in. The mixing process may also be performed in an inert atmosphere or as needed.
Is carried out in a solvent. Grinding is generally coarse grinding, fine grinding and step grinding.
Mixing can be done at any stage, although it is done hierarchically.
That is, even if a predetermined amount is mixed after coarse pulverization and then fine pulverization is performed.
Well, after all the grinding is completed
May be. Both A and B alloys are mixed uniformly with almost the same average grain size.
The average particle size is in the range of 0.5 to 20 μm.
Is less than 0.5 μm, it easily oxidizes and deteriorates.
If it exceeds, the sinterability will deteriorate. The mixing ratio of the A alloy powder and the B alloy powder is A
1 to 30 weight% of B alloy powder for 99 to 70 weight% of alloy powder
It is better to mix in the range of 10%, and if the B alloy powder is less than 1% by weight.
If it is full, the sintered density will not increase and coercive force will not be obtained.
%, The proportion of non-magnetic phase after sintering becomes large.
And the residual magnetic flux density becomes small. Got
The mixed fine powder of the A alloy and the B alloy thus prepared is then subjected to a molding pretreatment in a magnetic field.
Molded to the desired size and then sintered and heat treated.
It Sintering is performed in vacuum or argon in the temperature range of 900 to 1,200 ° C.
For 30 minutes or more, and
Aging heat treatment at low temperature for 30 minutes or more. After sintering, the magnet alloy C
The density of the compact is 95% or more in terms of the true density ratio.
A high residual magnetic flux density can be obtained. [0017] EXAMPLES Specific embodiments of the present invention will be described below.
However, the present invention is not limited to these.
There is no. (Example 1, Comparative Example 1) Nd, Fe metal having a purity of 99.9% by weight
And ferroboron are used to formulate 12.5Nd-6B-81.5Fe (
% Alloy) by melting casting in an Ar atmosphere of a high frequency melting furnace
After fabrication, this ingot is heated at 1,070 ℃ in Ar atmosphere.
Solution-ized for 20 hours. This is an A1 alloy. Then the same
99.9% by weight of Nd, Dy, Fe, Co metal and ferroboron with high purity
High frequency alloy with composition formula 20Nd-10Dy-20Fe-6B-44Co
Melt casting in an Ar atmosphere using a melting furnace, and use this for B1 alloy
And A1 alloy ingot and B1 alloy ingot
Coarsely crushed separately in a nitrogen atmosphere and 30 mesh or less
Below, 90% by weight of A1 alloy coarse powder and 10% of B1 alloy coarse powder
Weigh% by weight, and in a nitrogen-substituted V blender for 30 minutes
Mixed. This mixed coarse powder is jetted using high pressure nitrogen gas.
It was finely pulverized with a Tomil to an average particle size of about 5 μm. Got
While orienting the mixed fine powder in a magnetic field of 15 kOe,
n / cm 2  It was press molded under the pressure of. Then, this molded body
Sintered in an Ar atmosphere sintering furnace at 1,070 ° C for 1 hour and then
Aging heat treatment at 530 ℃ for 1 hour and quenching, magnet alloy C1
Was produced. For comparison, an alloy having the same composition as in Example 1
Was manufactured by the conventional 1-alloy method, and was designated as Comparative Example 1. That is,
The same composition (magnet alloy C1) after mixing both A1 and B1 alloys
Weigh from the beginning, melt, crush, sinter, heat treat with aging 2
The magnet by the alloy method (magnet composition C1 of Example 1) and magnetic characteristics
Sex was compared. The composition of this magnet alloy C1 is based on the two-alloy method.
In both Example 1 and Comparative Example 1 by the alloy method, 13.1 Nd-
It is 0.8Dy-3.5Co-6.0B-76.6Fe. Table 1 shows the comparison with Example 1.
The values of the magnetic characteristics obtained in both sintered magnets of Comparative Example 1
The sintered body density is shown. The magnetic characteristics of Example 1 are higher than those of Comparative Example 1.
In comparison, the sintered body density is almost the same, but the residual magnetic flux density
Degree, coercive force, maximum energy product, etc.
Example 1 is a big win. In this way, a set of magnet alloy C
Even if the composition is exactly the same, there is a considerable difference in the magnetic characteristics.
2 alloy method is extremely effective for improving the magnetic properties of Nd magnets.
It is an effective method. Casting state of B1 alloy
Fig. 1 shows the back-scattered electron image of the metallographic structure at
Indicated by truth. As you can see from the light and dark in the photograph, in B1 alloy
There are four main constituent phases. Each phase is EPMA (electronic probe
X-ray microanalyzer) and X-ray analysis
RT as shown in the figure2FourPhase B, RT 23Phase, RT 22
Phase and R-rich phase. (Examples 2 to 11, Comparative Examples 2 to 11)
As described above, corresponding to the alloy compositions of Examples 2 to 11, the A alloy
As a composition alloy of A1 and A2,
2 to B9 composition alloys were prepared and the same method as in Example 1 was performed.
Crushed by a method, mixed in a predetermined ratio, molded in a magnetic field, sintered (1,05
0 to 1,120 ° C x 1 hour, aging treatment (500 to 600 ° C x 1)
~ 10 hours) to produce the two-alloy method magnet alloys C2 to C11
The magnetic properties were measured and shown in Tables 1 and 2. Comparison
Therefore, an alloy having the same composition as in Examples 2 to 11 was prepared by the 1-alloy method.
Magnet alloy C under the same conditions as in Examples 2 to 11 except that it was manufactured.
2 to C11 were manufactured, and the magnetic characteristics were measured to obtain Comparative Examples 2 to 11.
The results are shown in Tables 1 and 2. [0020] [Table 1] [Table 2] [0021] 【The invention's effect】
The rare earth permanent magnet produced by the present invention is an expensive additive source.
By effectively utilizing the element, the rare earth magnet with the same composition of the conventional method
Magnetic properties are several orders of magnitude better than other products, and high coercive force and high remanence
Balanced high of flux density and even high energy product
It has become possible to provide high performance magnets. Therefore, in the future,
Widely used as a high-performance magnet for various electric and electronic devices.
Expected to be

【図面の簡単な説明】 【図1】実施例1のB1合金の鋳造状態での金属組織を
示す走査電子顕微鏡写真である。 【符号の説明】 RT 24B相 RT 2 3 RT 2 2 Rリッチ相
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the metallurgical structure of the B1 alloy of Example 1 in the cast state.
It is a scanning electron micrograph shown. [Explanation of symbols] RT 2 4 B phase RT 2 3 phase RT 2 2 phase R rich phase

─────────────────────────────────────────────────────
【手続補正書】 【提出日】平成3年7月12日 【手続補正1】 【補正対象書類名】明細書 【補正対象項目名】0006 【補正方法】変更 【補正内容】 【0006】 【発明が解決しようとする課題】従来技術による2合金
法ではNd系磁石合金の真に優れた磁気特性を実現させ
るのに適切でなかったり不充分だったりする点が多く存
在する。即ち、前述した第1の方法では磁石合金のエネ
ルギー積は高いが保磁力は約9k0e程度で、温度上昇
によって保磁力が低下するというNd磁石特有の欠点の
ために、実用的には不充分な磁石特性である。最も大き
な問題点は、磁場配向性である。第1の方法でも組成を
適当に選ぶことによって、室温で磁性を示す合金を得る
ことができるが、液体急冷法によって得られる合金は非
晶質アモルファス相あるいは微細結晶となるため、微粉
にして磁場中で配向させても特定の結晶方位を磁場方向
に配向させることができない。従って、混合した原料合
金粉体を磁場中成形しても得られる成形体の配向性は悪
く、焼結後充分な磁石特性が得られないことになる。 【手続補正2】 【補正対象書類名】明細書 【補正対象項目名】0007 【補正方法】変更 【補正内容】 【0007】第2の方法においては、磁石合金中のR
Fe14B化合物と共存する相はNdリッチ相あるいは
Nd1+xFe相であり、この両相とも室温では
磁性を示さない。従って、磁性を持たない化合物を混合
しても非磁性粒子が配向性を乱して、磁気特性の優れた
磁石は得られない。また、混合する粉体として各種元素
や種々の化合物を用いる第3の方法においてもこれらの
化合物は磁性をもたないために、磁場中配向時に反磁場
が大きくなって有効磁場強度が減少し、そのため磁場方
向への磁性粒子の回転が不充分となって配向が乱れる。 【手続補正3】 【補正対象書類名】明細書 【補正対象項目名】0010 【補正方法】変更 【補正内容】 【0010】以下本発明を詳細に説明する。本発明は所
謂2合金法と称する希土類永久磁石(以下、磁石合金C
という)の製造方法であり、原料となるA合金は主とし
てRFe14B化合物相からなり、RはYを含むL
a,Ce,Pr,Nd,Pm,Sm,Eu,Gd,T
b,Dy,Ho,Er,Tm,YbおよびLuから選択
されるNd,Pr,Dyを主体とする少なくとも1種類
以上の希土類元素である。A合金は原料金属を真空また
は不活性ガス、好ましくはAr雰囲気中で溶解し鋳造す
る。原料金属は純希土類元素および希土類台金、純鉄、
フェロボロン、さらにはこれらの合金等を使用するが、
一般的な工業生産において不可避な微量不純物は含まれ
るものとする。得られたインゴットは、RFe14
相がαFeと希土類リッチ相との包晶反応によって形成
されるため、鋳造後も凝固偏析によってαFe相、Rリ
ッチ相、あるいはBリッチ相等が残留する場合がある。
本発明においてはA合金中のRFe14B相が多いほ
うが望ましいので、必要に応じて溶体化処理を行う。そ
の条件は真空またはAr雰囲気下、700〜1,200
℃の温度領域で1時間以上熱処理すれば良い。 【手続補正4】 【補正対象書類名】明細書 【補正対象項目名】0011 【補正方法】変更 【補正内容】 【0011】B合金は主としてR,Co、Fe、Bから
成る合金で、組成式RFeCo(ここにR
は、Yを含むLa,Ce,Pr,Nd,Pm,Sm,E
u,Gd,Tb,Dy,Ho,Er,Tm,Ybおよび
Luから選択されるNd、Pr,Dyを主体とする少な
くとも1種以上の希土類元素、15≦a≦40、O≦b
≦80、5≦c≦85、0≦d≦20、a+b+c+d
=100(各原子%))で表わされ、A合金と同様に原
料金属を真空または不活性ガス、好ましくはAr雰囲気
中で溶解し鋳造する。原料金属としては純希土類元素、
および希土類合金、純鉄、純コバルト、純ガリウム、フ
ェロボロン、さらにはこれらの合金等を使用するが、一
般的な工業生産において不可避な微量不純物は含まれる
ものとする。希土類元素Rの量aが15原子%未満では
Rが少な過ぎるために焼結工程において十分な量の液相
が得られず、焼結体の密度が上がらなくなり、40原子
%を越えると合金の融点が低くなり過ぎて磁気特性の向
上効果がなくなる。Coの量cが5原子%未満ではRT
L相、RT 相、RT 相、R 相およ
びRT 相等の各相が出現しなくなり、磁気特性の向
上効果が得られない。また、液体急冷法によって得られ
た薄帯を熱処理してもB合金を作製することができる。
即ち、液体急冷法において、急冷後のB合金はアモルフ
ァス相或は微細結晶相となっており、これを結晶化温度
以上の温度で一定時間以上加熱することにより、結晶化
或は再結晶成長させて、本発明の所定の構成相を析出さ
せることが出来る。 ─────────────────────────────────────────────────────
【手続補正書】 【提出日】平成4年7月10日 【手続補正1】 【補正対象書類名】明細書 【補正対象項目名】0003 【補正方法】変更 【補正内容】 【0003】これまでに提案されている2合金法を大き
く分けると、3種類に分類することができる。第1の方
法は、混合する原料合金粉体の一方を液体急冷法によっ
て非晶質あるいは微細結晶合金を作製し、それに通常の
希土類合金粉末を混合するか、あるいは両方の原料合金
粉体を共に液体急冷法で作製混合する方法[特開昭63-9
3841、 特開昭63-115307、特開昭63-252403、特開昭63-278
208、特開平1-108707、特開平1-146310、 特開平1-146309、
特開平1-155603各号公報参照]である。この液体急冷
法による合金を使用する2合金法については、最近50MG
Oeを越える磁気特性が得られたと報告[E.Otuki,T.Otuka
and T.Imai;11th.Int.Workshop on Rare Earth Magnet
s,Pittsburgh,Pennsylvania,USA,October(1990),p.328
参照 ]されている。 【手続補正2】 【補正対象書類名】明細書 【補正対象項目名】0004 【補正方法】変更 【補正内容】 【0004】第2の方法は、混合する2種類の原料合金
粉体を共に主としてR2 Fe14B化合物とし含有される希
土類元素の種類、含有量を変えた合金を作製して混合焼
結する方法である。即ち、含有するNdリッチ相の量比あ
るいは希土類元素の種類を変えた合金を2種類混合する
方法[特開昭61-81603、 特開昭61-81604、 特開昭61-816
05、 特開昭61-81606、 特開昭61-81607、 特開昭61-11900
7、特開昭61-207546、特開昭63-245903、特開平1-177335各
号公報参照]である。
─────────────────────────────────────────────────── ───
[Procedure Amendment] [Date of submission] July 12, 1991 [Procedure Amendment 1] [Document name for amendment] Specification [Item name for amendment] 0006 [Correction method] Change [Correction content] [0006] [Invention However, there are many points that the two-alloy method according to the prior art is not appropriate or insufficient for realizing the truly excellent magnetic characteristics of the Nd-based magnet alloy. That is, the first energy product is high coercivity of the magnet alloy in the method about 9k0e described above, the Nd magnet specific drawbacks that the coercive force is lowered by the temperature rise
For practical a magnet properties insufficient to. The biggest problem is magnetic field orientation. In the first method, an alloy exhibiting magnetism at room temperature can be obtained by appropriately selecting the composition. However, since the alloy obtained by the liquid quenching method becomes an amorphous amorphous phase or a fine crystal, it is made into a fine powder and a magnetic field. Even if it is oriented inside, a specific crystal orientation cannot be oriented in the magnetic field direction. Therefore, even if the mixed raw material alloy powder is molded in a magnetic field, the resulting molded body has poor orientation, and sufficient magnet characteristics cannot be obtained after sintering. [Procedure Amendment 2] [Name of Document to Amend] Specification [Name of Item to Amend] 0007 [Correction Method] Change [Content of Amendment] In the second method, R 2 in the magnet alloy is used.
The phase coexisting with the Fe 14 B compound is the Nd-rich phase or the Nd 1+ xFe 4 B 4 phase, and neither of these phases exhibits magnetism at room temperature. Therefore, mix compounds without magnetism
Even disturbs the orientation of the non-magnetic particles child by not obtained excellent magnet magnetic properties. Further, even in the third method in which various elements and various compounds are used as the powder to be mixed, since these compounds do not have magnetism, the demagnetizing field becomes large during the orientation in the magnetic field and the effective magnetic field strength decreases, Therefore, the rotation of the magnetic particles in the magnetic field direction is insufficient and the orientation is disturbed. [Procedure Amendment 3] [Document Name of Amendment] Specification [Name of Item Amendment] 0010 [Method of Amendment] Change [Content of Amendment] [0010] The present invention will be described in detail below. The present invention is a so-called two-alloy method, which is a rare earth permanent magnet (hereinafter referred to as magnet alloy C).
A) as a raw material is mainly composed of an R 2 Fe 14 B compound phase, and R is L containing Y.
a, Ce, Pr, Nd, Pm, Sm, Eu, Gd, T
It is at least one kind of rare earth element mainly composed of Nd, Pr and Dy selected from b, Dy, Ho, Er, Tm, Yb and Lu. The alloy A is cast by melting the raw material metal in a vacuum or an inert gas, preferably Ar atmosphere. Raw metals are pure rare earth elements and rare earth base metals, pure iron,
Ferroboron, and even these alloys are used,
Trace impurities that are inevitable in general industrial production shall be included. The obtained ingot is R 2 Fe 14 B
Since the phase is formed by the peritectic reaction between αFe and the rare earth-rich phase, the αFe phase, the R-rich phase, the B-rich phase, etc. may remain after the casting due to the solidification segregation.
In the present invention, since it is desirable that the amount of R 2 Fe 14 B phase in the A alloy is large, solution treatment is performed if necessary. The conditions are 700 to 1,200 under vacuum or Ar atmosphere.
It suffices to perform heat treatment for 1 hour or more in the temperature range of ° C. [Procedure Amendment 4] [Document name for amendment] Specification [Item name for amendment] 0011 [Correction method] Change [Correction] B alloy is an alloy mainly composed of R, Co, Fe and B, and has a composition formula R a Fe b Co c B d (here R
Is La, Ce, Pr, Nd, Pm, Sm, E including Y
u, Gd, Tb, Dy, Ho, Er, Tm, Yb and at least one rare earth element mainly composed of Nd, Pr and Dy selected from Lu, 15 ≦ a ≦ 40, O ≦ b
≦ 80, 5 ≦ c ≦ 85, 0 ≦ d ≦ 20, a + b + c + d
= 100 (each atomic%)), and the raw material metal is melted and cast in a vacuum or an inert gas, preferably Ar atmosphere, like the A alloy. Pure rare earth element as raw material metal,
Further, rare earth alloys , pure iron, pure cobalt, pure gallium, ferroboron, and alloys thereof are used, but trace impurities that are inevitable in general industrial production are included. If the amount a of the rare earth element R is less than 15 atomic%, the amount R is too small to obtain a sufficient amount of liquid phase in the sintering process, and the density of the sintered body cannot be increased. The melting point becomes too low, and the effect of improving magnetic properties is lost. If the amount c of Co is less than 5 atomic%, RT
2 4 L-phase, RT 2 3-phase, RT 2 2-phase, R 2 T 2 phases of 7 phase and RT 2 5 equality is no longer appear, not be obtained the effect of improving the magnetic properties. Further, the B alloy can be produced by heat-treating the ribbon obtained by the liquid quenching method.
That is, in the liquid quenching method, the B alloy after quenching has an amorphous phase or a fine crystalline phase, and is heated at a temperature not lower than the crystallization temperature for a certain period of time to cause crystallization or recrystallization growth. Thus, the predetermined constituent phase of the present invention can be precipitated. ─────────────────────────────────────────────────── ───
[Procedure amendment] [Date of submission] July 10, 1992 [Procedure Amendment 1] [Document name for amendment] Specification [Item name for amendment] 0003 [Correction method] Change [Content of amendment] [0003] Until now The two-alloy method proposed in (1) can be roughly classified into three types. The first method is to prepare an amorphous or fine crystal alloy by liquid quenching one of the raw material alloy powders to be mixed, and mix it with a normal rare earth alloy powder, or to mix both raw material alloy powders together. Method of preparing and mixing by liquid quenching method [Japanese Patent Laid-Open No. 63-9
3841, JP 63-115307, JP 63-252403, JP Akira 63 -278
208, JP-A-1-108707, JP-A-1-146310, JP-A-1-146309,
See Japanese Patent Laid-Open No. 1-155603]. Regarding the two-alloy method using the alloy by this liquid quenching method, recently, 50MG
Reported that magnetic properties exceeding Oe were obtained [E.Otuki, T.Otuka
and T.Imai; 11th.Int.Workshop on Rare Earth Magnet
s, Pittsburgh, Pennsylvania, USA, October (1990), p.328
Has been referred to]. [Procedure Amendment 2] [Document name for amendment] Specification [Item name for amendment] 0004 [Correction method] Change [Correction content] The second method is mainly for mixing two kinds of raw material alloy powders. This is a method in which alloys having different kinds and contents of rare earth elements contained as R 2 Fe 14 B compounds are produced and mixed and sintered. That is, a method of mixing two kinds of alloys in which the amount ratio of the contained Nd-rich phase or the kind of rare earth element is changed [JP-A-61-81603, JP-A-61-81604, and JP-A-61-816].
05, JP 61-81606, JP 61-81607, JP 61-11900
7, JP 61-207546, JP 63-245 90 3, Hei 1-177335 is the JP reference.

Claims (1)

【特許請求の範囲】 【請求項1】A合金を主としてR2 Fe14B相(ここにR
は、Nd、Pr、Dyを主体とする少なくとも1種以上の希土類
元素を表す)から成る合金とし、B合金をR、Co、Fe、 B
を含有し、かつ合金中の構成相としてR2114
B相および/またはRリッチ相(ここにRは上記に同
じ、T 1 はFe、Co を主体とする遷移金属元素を表す)並
びにRT24B相、RT 23相、RT 22相、R2 27
相およびRT 25相(ここにRは上記に同じ、T 2 はFe、C
o を主体とする遷移金属元素、同遷移金属およびBを表
す)の5相の内1種または2種以上の相との混合相から
成る合金とし、A合金粉末99〜70重量%に対してB合金
粉末を1〜30重量%混合し、該混合合金粉末を磁場中加
圧成形し、該成形体を真空または不活性ガス雰囲気中で
焼結し、さらに焼結温度以下の低温で時効熱処理するこ
とを特徴とする希土類永久磁石の製造方法。 【請求項2】請求項1に記載のB合金に含まれるRT24
B相、RT 23相、RT 22相、R2 27相およびRT 25
相の5つの構成相の内少なくとも1種以上の相の融点が
700 ℃以上1,155 ℃以下の金属間化合物であること
を特徴とする希土類永久磁石の製造方法。 【請求項3】請求項1または2に記載のB合金に含まれ
る5つの構成相の内、少なくとも1種以上の相が室温以
上のキューリー温度を有する磁性体であることを特徴と
する希土類磁石の製造方法。 【請求項4】請求項1または2または3に記載のB合金
に含まれる5つの構成相の内、少なくとも1種以上の相
が室温以上のキューリー温度ならびに結晶磁気異方性を
有する磁性体であることを特徴とする希土類磁石の製造
方法。 【請求項5】請求項1に記載のA合金、B合金およびA
B混合合金粉末の平均粒径が、0.5 〜20μmの範囲内で
あることを特徴とする希土類磁石の製造方法。
Claims: 1. A alloy mainly composed of R 2 Fe 14 B phase (where R
Is an alloy of at least one or more rare earth elements mainly composed of Nd, Pr and Dy), and B alloy is R, Co, Fe, B
And contains R 2 T 1 14 as a constituent phase in the alloy.
B phase and / or R rich phase (where R is the same as above)
T 1 represents a transition metal element mainly composed of Fe and Co), RT 2 4 B phase, RT 2 3 phase, RT 2 2 phase, and R 2 T 2 7
Phase and RT 2 5 phase (here R is as defined above, T 2 is Fe, C
an alloy consisting of a transition metal element mainly consisting of o, representing the same transition metal and B) and a mixed phase with one or more of the five phases, and 99 to 70% by weight of the A alloy powder. B alloy powder is mixed in an amount of 1 to 30% by weight, the mixed alloy powder is pressure-molded in a magnetic field, the molded body is sintered in a vacuum or an inert gas atmosphere, and the aging heat treatment is performed at a temperature lower than the sintering temperature. A method for producing a rare earth permanent magnet, comprising: 2. RT 2 4 contained in the B alloy according to claim 1.
B phase, RT 2 3-phase, RT 2 2-phase, R 2 T 2 7 phase and RT 2 5
The melting point of at least one of the five constituent phases of the phase
It must be an intermetallic compound of 700 ℃ or more and 1,155 ℃ or less
A method for producing a rare earth permanent magnet, characterized by: 3. The B alloy according to claim 1 or 2.
Out of the five constituent phases, at least one or more phases are at room temperature or above.
Characterized by being a magnetic material having a Curie temperature above
A method for manufacturing a rare earth magnet. 4. The B alloy according to claim 1, 2 or 3.
Of at least one of the five constituent phases contained in
Has a Curie temperature above room temperature and magnetocrystalline anisotropy.
Of rare earth magnets characterized by having a magnetic substance
Method. 5. The A alloy, B alloy and A according to claim 1.
When the average particle size of the B mixed alloy powder is within the range of 0.5 to 20 μm
A method for manufacturing a rare earth magnet, characterized by being present.
JP3159766A 1991-06-04 1991-06-04 Manufacturing method of rare earth permanent magnet Expired - Lifetime JP2853839B2 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP3159766A JP2853839B2 (en) 1991-06-04 1991-06-04 Manufacturing method of rare earth permanent magnet
EP92109366A EP0517179B1 (en) 1991-06-04 1992-06-03 Method of making two phase Rare Earth permanent magnets
DE1992602515 DE69202515T2 (en) 1991-06-04 1992-06-03 Process for the production of two-phase permanent magnets based on rare earths.
US08/119,641 US5405455A (en) 1991-06-04 1993-09-13 Rare earth-based permanent magnet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3159766A JP2853839B2 (en) 1991-06-04 1991-06-04 Manufacturing method of rare earth permanent magnet

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Publication Number Publication Date
JPH06207204A true JPH06207204A (en) 1994-07-26
JP2853839B2 JP2853839B2 (en) 1999-02-03

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US9520230B2 (en) 2010-10-25 2016-12-13 Toyota Jidosha Kabushiki Kaisha Production method of rare earth magnet
WO2013027109A1 (en) 2011-08-23 2013-02-28 Toyota Jidosha Kabushiki Kaisha Method for producing rare earth magnets, and rare earth magnets
US9761358B2 (en) 2011-08-23 2017-09-12 Toyota Jidosha Kabushiki Kaisha Method for producing rare earth magnets, and rare earth magnets

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