JPH0319296B2 - - Google Patents
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- Publication number
- JPH0319296B2 JPH0319296B2 JP57166663A JP16666382A JPH0319296B2 JP H0319296 B2 JPH0319296 B2 JP H0319296B2 JP 57166663 A JP57166663 A JP 57166663A JP 16666382 A JP16666382 A JP 16666382A JP H0319296 B2 JPH0319296 B2 JP H0319296B2
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- rare earth
- magnets
- present
- less
- 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 - Lifetime
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- 229910052761 rare earth metal Inorganic materials 0.000 claims description 32
- 229910052779 Neodymium Inorganic materials 0.000 claims description 22
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 19
- 239000000203 mixture Substances 0.000 claims description 16
- 229910052742 iron Inorganic materials 0.000 claims description 11
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 9
- 238000006467 substitution reaction Methods 0.000 claims description 9
- 229910052684 Cerium Inorganic materials 0.000 claims description 7
- 229910052772 Samarium Inorganic materials 0.000 claims description 7
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 6
- 229910052775 Thulium Inorganic materials 0.000 claims description 6
- 229910052769 Ytterbium Inorganic materials 0.000 claims description 6
- 229910052691 Erbium Inorganic materials 0.000 claims description 5
- 229910052693 Europium Inorganic materials 0.000 claims description 4
- 229910052746 lanthanum Inorganic materials 0.000 claims description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 36
- 229910045601 alloy Inorganic materials 0.000 description 13
- 239000000956 alloy Substances 0.000 description 13
- 230000005415 magnetization Effects 0.000 description 10
- 150000002910 rare earth metals Chemical class 0.000 description 10
- 229910052796 boron Inorganic materials 0.000 description 9
- 229910017052 cobalt Inorganic materials 0.000 description 9
- 239000010941 cobalt Substances 0.000 description 9
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 9
- 150000001875 compounds Chemical class 0.000 description 7
- 229910000828 alnico Inorganic materials 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 229910001047 Hard ferrite Inorganic materials 0.000 description 5
- 230000008859 change Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000012535 impurity Substances 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 229910052727 yttrium Inorganic materials 0.000 description 5
- 229910052689 Holmium Inorganic materials 0.000 description 4
- 229910052765 Lutetium Inorganic materials 0.000 description 4
- 229910052771 Terbium Inorganic materials 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 230000004907 flux Effects 0.000 description 4
- 239000000696 magnetic material Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- 239000010409 thin film Substances 0.000 description 4
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 3
- 229910000640 Fe alloy Inorganic materials 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 230000005347 demagnetization Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000004663 powder metallurgy Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000010298 pulverizing process Methods 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 229910000521 B alloy Inorganic materials 0.000 description 2
- 229910000722 Didymium Inorganic materials 0.000 description 2
- 241000224487 Didymium Species 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical group [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910017061 Fe Co Inorganic materials 0.000 description 1
- 229910000808 amorphous metal alloy Inorganic materials 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012776 electronic material Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- 230000005381 magnetic domain Effects 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000002074 melt spinning Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000000700 radioactive tracer Substances 0.000 description 1
- 229910000938 samarium–cobalt magnet Inorganic materials 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Description
本発明は、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まで、幅広い分野で使
われるきわめて重要な電気・電子材料の一つであ
る永久磁石の改良に係り、特にCo添加Fe−Ｂ−
Ｒ系永久磁石に関する。
近年の電気、電子機器の小型化、高効率化の要
求にともない、永久磁石はますます高性能化が求
められるようになつた。
現在の代表的な永久磁石はアルニコ、ハードフ
エライト及び希土類コバルト磁石である。最近の
コバルトの原料事情の不安定化にともない、コバ
ルトを20〜30重量％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50〜65重
量％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く使
われるようになつた。
希土類コバルト磁石はRCo5，R2Co17（Ｒは
Sm，Ceを中心とする希土類元素）にて示される
２元系化合物をベースとする永久磁石であり、
Coの一部を少量のCu，Feの他Zr，Ti，Ｖ，Hf
等の遷移金属元素にて置換することによつて磁気
特性の向上が図られてきたものである。
他方近時、コバルトを含まない磁性材料として
FeとＲ（以下本発明においてＲは希土類元素を示
す符号として用いる）を主成分とするスパツタ薄
膜又は超急冷リボンの磁性材料が提案されてい
る。例えば、クラークによるスパツタした薄膜ア
モルフアスTbFe2，DyFe2，SmFe2合金の磁気特
性が報告されているA.B.Clark：Appl.PhYs.
Lett.vol.23No.11 1December1973 642〜644頁）。
また超急冷リボンの磁性材料としてクロートによ
るPrFe系合金（J.J.Croat：Appl.Phys.Lett.37
(12)，15December19801096〜1098頁）があり、さ
らにクーン等による（Fe0.82B0.18）0.9Tb0.05La0.05
合金（N.C.Koon他：Appl.Phys.Lett.39(10)，
15November1981，840〜842頁）、カバコフ等に
よる（Fe0.8B0.2）1-xPrx（ｘ＝０〜0.3原子比）合金
（L.Kabakoff他：J.Appl.Phys.53(3)，
March1982，2255〜2257頁）等が報告されてい
る。さらに前記クロートは軽希土類鉄合金は低コ
スト永久磁石の魅力的な候補として長い間考えら
れてきたが、これら合金を粉末冶金法によつて磁
気的に硬化する試みは成功しなかつたことを報告
するとともに、Pr−Fe及びNd−Fe合金が溶融紡
糸（超急冷）によつて磁気的に硬化され得ること
を見い出したと報告している（J.J.Croat：J.
Appl.Phys.53(4)，April1982，3161頁）。
希土類を用いた磁石がもつと広い分野で安価
に、かつ多量に使われるようになるためには、高
価なコバルトを含まず、かつ希土類金属として、
鉱石中に多量に含まれている軽希土類を主成分と
することが必要とされよう。
一方既述のようにＲ−FeないしＲ−Fe−Ｂ合
金を磁性材料として有用化するためには、スパツ
タ薄膜化又は超急冷ないしアモルフアス化が不可
欠であるとされている。
しかし、これらのスパツタ薄膜又は超急冷リボ
ンからは任意の形状・寸法を有するバルク状の実
用永久磁石を得ることができなかつた。これまで
に報告されたFe−Ｂ−Ｒ系リボンの磁化曲線は
角形性が悪く、従来慣用の磁石に対抗できる実用
永久磁石とはみなされえない。また、上記スパツ
タ薄膜及び超急冷リボンは、いずれも本質上等方
性であり、これらから磁気異方性の実用永久磁石
を得ることは、事実上不可能であつた。
本発明は、このような要請に応えるべき新規な
実用高性能永久磁石を提供することを基本目的と
する。特に、本発明は、室温以上で良好な磁気特
性を有し、任意の形状・実用寸法に成形でき、磁
化曲線の角形性が高く、さらに磁気異方性を有す
る実用永久磁石であつて、しかもＲとして資源的
に豊富な軽希土類元素を有効に使用できるもの得
ることを目的とする。
このような永久磁石として、本発明者は、先
に、Nd，Prを中心とする特定の希土類元素とFe
とＢとを特定比をもつて必須とし、かつ磁気異方
性焼結体である。全く新しい種類の実用高性能永
久磁石を開発し、本願と同一出願人により出願し
た（特願昭57−145072）。このFe−Ｂ−R3元系磁
石は、従来知られているRCo5やR2Co17化合物と
は異なる新しい化合物を基礎とし、粉末冶金法に
て適当なミクロ組織を形成することによつて得ら
れる磁気異方性焼結永久磁石であり、特にボロン
(B)は、従来の、例えば非晶質合金作成時の非晶質
促進元素又は粉末冶金法における焼結促進元素と
して添加されるものではなく、このFe−Ｂ−Ｒ
系永久磁石の実体的内容を構成する磁気的に安定
で高い磁気異方性定数を有するＲ−Fe−Ｂ化合
物の必須構成元素であることを明らかにした。
上述のFe−Ｂ−Ｒ系磁気異方性焼結永久磁石
は必ずしもCoを含む必要がなく、またＲとして
は好適な実施態様として資源的に豊富なNd，Pr
を主体とする軽希土類を用いることができ、必ず
しもSmを必要とせず或いはSmを主体とする必要
もないので原料が安価であり、きわめて有用であ
る。しかも、磁気特性はハードフエライト磁石以
上の特性を有し（保磁力iHc≧1kOe，残留磁束
密度Br≧4kG、最大エネルギー積（BH）max≧
4MGOe）特に好ましい組成範囲においては希土
類コバルト磁石と同等以上の極めて高いエネルギ
ー積を示すことができる。
以上の通りこのFe−Ｂ−Ｒ系永久磁石は磁気
異方性に基づく高磁気特性、任意成形性、資源的
により豊富な材料を用いることができる等の点で
高いコストパフオーマンスを有し、Ｒ−Co系磁
石にも代わり得る工業上極めて有用なものである
が、一方、このFe−Ｂ−Ｒ系永久磁石のキユリ
ー点（温度）は、特願昭57−145072に開示の通り
一般に300℃前後、最高370℃である。このキユリ
ー点は、従来のアルニコ系ないしＲ−Co系の永
久磁石の約800℃のキユリー点と比べてかなり低
いものである。従つて、Fe−Ｂ−Ｒ系永久磁石
は、従来のアルニコ系やＲ−Co系磁石に比して
磁気特性の温度依存性が大であり、高温において
は磁気特性の低下が生ずる。本発明者の研究の結
果によれば、Fe−Ｂ−Ｒ系焼結磁石は約100℃以
上の温度で使用するとその温度特性が劣化するた
め、約70℃以下の通常の温度範囲で使用すること
が適当であることが判明した。
この様に永久磁石にとつて磁気特性の温度依存
性が大きい、即ちキユリー点が低いことはその使
用範囲が狭められることとなり、Fe−Ｂ−Ｒ系
永久磁石を広範囲の用途に使用するためにはキユ
リー点を上昇せしめ、温度特性を改善することが
必要であつた。
本発明は、前記基本目的と共にさらにかかる
Fe−Ｂ−Ｒ系磁気異方性焼結体永久磁石におい
て、その温度特性を改良することを併せて目的と
する。
本発明者は、各種の実験及び検討の結果、Fe
−Ｂ−Ｒ系永久磁石においてFeのCoによる置換
により前記基本目的を達成すると共に、それが
Fe−Ｂ−Ｒ系永久磁石の温度特性の改善、即ち
キユリー点の上昇及び残留磁束密度Brの温度係
数（温度依存変化率）の減少に有効であることを
見出した。即ち、本発明の永久磁石は次の通りで
ある。
本願の第１発明：原子百分比で、希土類元素
（Ｒ）としてNd，Pr，Dy，Ho，Tbのうち少な
くとも一種８〜30％、B2〜28％及び残部実質的
にFeからなるFe−Ｂ−Ｒ系磁気異方性焼結体永
久磁石において、前記Feの一部を全組成に対し
て50％以下（０％を除く）のCoで置換したこと
を特徴とする永久磁石。
本願の第２発明：原子百分比で、希土類元素
（Ｒ）としてNd，Pr，Dy，Ho，Tbのうち少な
くとも一種とLa，Ce，Pm，Sm，Eu，Gd，Er，
Tm，Yb，Lu，Ｙのうち少なくとも一種の合計
８〜30％、B2〜28％及び残部実質的にFeからな
るFe−Ｂ−Ｒ系磁気異方性焼結体永久磁石にお
いて、前記Feの一部を全組成に対して50％以下
（０％を除く）のCoで置換したことを特徴とする
永久磁石。
一般に、Fe合金へのCoの添加の際、Co添加量
の増大に従いキユリー点（Tc）が上昇するもの
と下降するものと両方が認められている。そのた
め、FeをCoで置換することは、一般的には複雑
な結果を生来し、その結果の予測は困難である。
例えば、RFe3化合物のFeをCoで置換して行く
と、Co量の増大に伴いTcはまず上昇するが、Fe
を1/2置換したＲ（Fe0.5Co0.5）3付近で極大に達し、
その後低下してしまう。またFe2B合金の場合に
は、FeのCoによる置換によりTcは単調に低下す
る。
Fe−Ｂ−Ｒ系におけるFeのCoによる置換にお
いては、第１図に示す通り、Co置換量の増大に
伴いTcは当初急速に増大し、以後徐々に増大す
ることが明らかとなつた。このFe−Ｂ−Ｒ系合
金においては、Ｒの種類によらず同様な傾向が確
認される。Coの置換量はわずか（例えば0.1〜１
原子％）でもTc増大に有効であり、第１図とし
て例示する系（77−ｘ）Fe−xCo−8B−15Ndに
おいて明らかな通り、ｘの調整により400〜800℃
の任意のTcをもつ合金が得られる。かくて本発
明は、高い磁気異方性を有する新規なFe−Ｂ−
Ｒ化合物をベースとしたFe−Ｂ−Ｒ系磁気異方
性焼結体永久磁石のFeの一部をCoで置換するこ
とにより合金組成中にCoを50％以下含有せしめ、
（Fe，Co）−Ｂ−Ｒ化合物をベースとしたFe−Co
−Ｂ−Ｒ系磁気異方性焼結体永久磁石を提供する
ものである。
本発明によれば、Coを含有することによりFe
−Ｂ−Ｒ系永久磁石の温度特性を実質的に従来の
アルニコ磁石、Ｒ−Co系磁石と同等程度に改善
する上、さらにその他の利点を保持する。
即ち、特に希土類元素Ｒとして資源的に豊富な
NdやPrなどの軽希土類を用いた場合、従来のＲ
−Co系磁石と比較すると、資源的、価格的いず
れの点においても有利であり、磁気特性の上から
もさらに優れたものが得られる。
また、本発明のCo添加Fe−Ｂ−Ｒ系永久磁石
はCoを含有しないFe−Ｂ−Ｒ系永久磁石と比較
してBrはほぼ同程度、iHcは同等或いは少し低い
がCo添加により角形性が改善されるため、かな
りの範囲で（BH）maxは同等か或いはそれ以上
とすることが可能である。さらに、CoはFeに比
べて耐食性を有するので、Fe−Ｂ−Ｒ系永久磁
石と比較してCoを添加することにより耐食性を
付与することも可能となる。
かくて、本発明は工業上極めて有用な新規な実
用高性能永久磁石を提供できる。
本発明において必須元素のうちＢ，Ｒの含有量
は基本的にFe−Ｂ−Ｒ系永久磁石（Coを含まな
い系）の場合と同様である。即ち（以下％は合金
中、原子百分率を示す）、保磁力Hc≧1kOeを満
たすためにＢは２％以上とし、ハードフエライト
の残留磁束密度Br約4kG以上とするためにＢは
28％以下とする。Ｒは、保磁力1kOe以上とする
ために８％以上必要であり、また燃え易く工業的
取扱、製造上の困難のため（かつまた高価である
ため）、30％以下とする。
本発明の永久磁石に用いる希土類元素ＲはＹを
包含し、軽希土類及び重希土類を包含する希土類
元素であり、そのうち所定の一種以上を用いる。
即ちこのＲとしては、Nd，Pr，La，Ce，Tb，
Dy，Ho，Er，Eu，Sm，Gd，Pm，Tm，Yb，
Lu及びＹが包含される。Ｒとしては、Nd，Prを
主体とする軽希土類（特にNd，Pr）が好まし
い。通例Ｒのうち所定のもの一種をもつて足りる
（Nd，Pr，Dy，Ho，Tb等）が、La，Ce，Pm，
Sm，Eu，Gd，Er，Tm，Yb，Lu，Ｙ等は他の
Ｒ、特にNd，Pr，Dy，Ho，Tb（一種以上）と
の混合物として用いることができる。実用上は二
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
る。Sm，La，Er，Tm，Ce，Gd，Ｙは単独で
はiHcが低いため好ましくなく、Eu，Pm，Yb，
Luは微量にしか存在せず高価である。従つてこ
れらの希土類元素は、前述の通り、Nd，Pr等の
他のＲ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ともよく、工業
上入手可能な範囲で製造上不可避な不純物（他の
希土類元素、Ca，Mg，Fe，Ti，Ｃ，Ｏ等）を
含有するもので差支えない。
Ｂ（ホウ素）としては、純ボロン又はフエロボ
ロンを用いることができ、不純物としてAl，Si，
Ｃ等を含むものも用いることができる。
残部は実質的にFeとCoからなり、本発明の特
徴とするCoの置換量は、後述する磁気特性等の
要求に応じて適宜選択することが望ましい。
本発明永久磁石はFe，Co，Ｂ，Ｒの外、Ｃ，
Ｓ，Ｐ，Ca，Mg，Ｏ，Si，Al等工業的に製造上
不可避な不純物の存在を許容できる。これらの不
純物は、原料或いは製造工程から混入することが
多く、合計は５％以下とすることが好ましい。
又、Al，Ti，Ｖ，Cr，Mn，Zn，Zr，Nb，Mo，
Ta，Ｗ，Sn，Bi，Sbの一種以上を添加すること
により高保磁力化が可能となり、又Ni添加によ
り、耐食性改善も可能となる。
本発明のFe−Co−Ｂ−Ｒ系永久磁石は、既述
のＲ、即ちNd，Pr，Dy，Ho，Tbのうち少なく
とも一種、又はこれらNd，Pr，Dy，Ho，Tbの
うち少なくとも一種とLa，Ce，Pm，Sm，Eu，
Gd，Er，Tm，Yb，Lu，Ｙのうち少なくとも一
種の合計８〜30％、２〜28％Ｂ，Co50％以下、
残部Feにおいて保磁力iHc≧1kOe、残留磁束密
度Br≧4kGの磁気特性を示し、最大エネルギー
積（BH）maxはハードフエライト（〜4MGOe
程度）と同等以上となる。
さらに、ＲとしてNd，PrをＲの主成分（即ち
全Ｒ中Nd，Prの１種以上が50％以上）とし、12
〜20％Ｒ、４〜24％Ｂ、45％以下Co、残部Feの
組成は、最大エネルギー積（BH）max≧
10MGOeを示し、特にCoが35％以下では最大エ
ネルギー積（BH）maxは20MGOe以上となり、
最高33MGOe以上に達する。又Coは５％未満で
もTc増大に寄与し、特に５％以上ではBrの温度
係数約0.1％／℃以下を示し、25％以下で他の磁
気特性を実質的に損うことなくTc増大に寄与す
る。
本発明のFe−Co−Ｂ−Ｒ系永久磁石も、先に
出願したFe−Ｂ−Ｒ系永久磁石と同様な磁気異
方性焼結体として得られる。典型的には、合金を
溶成、冷却（例えば鋳造）し、生成合金を粉末化
した後、磁界中にて成形し焼結することにより本
発明の永久磁石を得ることができる。
＜実施例＞
以下本発明を実施例に従つて説明する。但し、
この実施例は本発明をこれらに限定するものでは
ない。
第１図に代表例として77Fe−8B−15NdのFe
の一部をCo（ｘ）で置換した系、（77−ｘ）Fe−
xCo−8B−15Ndのｘを０〜77に変化させた場合
のキユリー点Tcの変化を示す。この試料は次の
工程により作製した。
(1) 合金を高周波溶解し水冷銅鋳型に鋳造、出発
原料はFeとして純度99.9％の電解鉄、Ｂとして
フエロボロン合金（19.38％Ｂ、５，32％Al、
0.74％Si、0.03％Ｃ、残部Fe）、Ｒとして純度
99.7％以上（不純物は主として他の希土類元
素）を使用、Coは純度99.9％の電解Coを使用
した。なお純度は重量％で示す；
(2) 粉砕、スタンプミルにより35メツシユスルー
まで粗粉砕し、次いでボールミルにより３時間
微粉砕（３〜10μｍ）；
(3) 磁界（10kOe）中配向、成形（1.5t／cm2にて
加圧）；
(4) 焼結1000〜1200℃１時間Ar中、焼結後放冷。
焼結体から約0.1ｇのブロツク（多結晶）を切
出し、VSMにより次のようにしてキユリー点を
測定した。即ち、試料には10kOeの磁界を印加
し、25℃〜600℃までの温度範囲で4πIの温度変化
を測定し、4πIがほぼ０になる温度をキユリー点
Tcとした。
上記の系でFeに対するCo置換量の増大に伴い
Tcは急速に増大し、Coが30％以上ではTcは600
℃以上に達する。
一般に永久磁石材料において、Tcの増大は磁
気特性の温度変化の減少のための最も重要な要因
とされている。この点の確認のため、Tc測定用
試料と同じ工程により第１表の永久磁石試料を作
製して、Brの温度特性を次のように測定した。
即ち25℃、60℃、100℃の各温度でBHトレーサ
により磁化曲線を測定し、25〜60℃と60〜100℃
におけるBrの温度変化を平均した。各種Fe−Ｂ
−Ｒ系及びFe−Ce−Ｂ−Ｒ系磁石のBr温度係数
の測定結果を第１表に示す。
第１表から、Fe−Ｂ−Ｒ系磁石にCoを含有す
ることにより、Brの温度変化が改善されること
は明らかである。
第１表には各試料の室温における磁気特性も併
記した。大部分の組成で、保磁力iHcはCo置換に
より低下するが、減磁曲線の角形性の向上によ
り、（BH）maxは上昇する。しかし、Co置換量
が多くなるとiHcの低下が著しく、永久磁石材料
としてiHc≧1KOeを得るために、Co量は50％以
下とする。
Ｂの下限、上限、Ｒの下限について既述の限定
理由が第１表から（さらに第３，４図から）確か
められる。
The present invention relates to the improvement of permanent magnets, which are one of the extremely important electrical and electronic materials used in a wide range of fields, from various household electrical appliances to peripheral terminals of large computers. −
Regarding R-based permanent magnets. In recent years, with the demand for smaller size and higher efficiency of electrical and electronic equipment, permanent magnets are required to have even higher performance. Current typical permanent magnets are alnico, hard ferrite, and rare earth cobalt magnets. With the recent instability in the raw material situation for cobalt, the demand for alnico magnets containing 20 to 30% cobalt by weight has decreased, and cheap hard ferrite, whose main component is iron oxide, has become the mainstream magnet material. Summer.
On the other hand, rare earth cobalt magnets contain 50 to 65% cobalt by weight and are very expensive because they use Sm, which is not often found in rare earth ores, but they have much higher magnetic properties than other magnets. Therefore, it has come to be used mainly in small, high value-added magnetic circuits. Rare earth cobalt magnets are RCo 5 , R 2 Co 17 (R is
It is a permanent magnet based on a binary compound represented by rare earth elements (mainly Sm and Ce).
Part of Co is replaced by small amounts of Cu, Fe, Zr, Ti, V, Hf
It has been attempted to improve the magnetic properties by substituting transition metal elements such as. On the other hand, recently, as a magnetic material that does not contain cobalt,
A sputtered thin film or ultra-quenched ribbon magnetic material containing Fe and R (hereinafter in the present invention, R is used as a symbol representing a rare earth element) as main components has been proposed. For example, the magnetic properties of sputtered thin film amorphous TbFe 2 , DyFe 2 , and SmFe 2 alloys have been reported by Clark: Appl. PhYs.
Lett.vol.23No.11 1December1973 pp. 642-644).
In addition, as a magnetic material for ultra-quenched ribbons, PrFe-based alloys by Croat (JJCroat: Appl.Phys.Lett.37
(12), 15December19801096-1098), and also by Kuhn et al. (Fe 0.82 B 0.18 ) 0.9 Tb 0.05 La 0.05
Alloys (NCKoon et al.: Appl.Phys.Lett.39(10),
(Fe 0.8 B 0.2 ) 1-x Pr x (x=0-0.3 atomic ratio) alloy by Kabakoff et al. (L. Kabakoff et al.: J.Appl.Phys.53(3),
March 1982, pp. 2255-2257), etc. have been reported. Furthermore, Kloth reported that although light rare earth iron alloys have long been considered attractive candidates for low-cost permanent magnets, attempts to magnetically harden these alloys by powder metallurgy were unsuccessful. They also reported that they found that Pr-Fe and Nd-Fe alloys can be magnetically hardened by melt spinning (ultra-quenching) (JJCroat: J.
Appl.Phys.53(4), April1982, p.3161). In order for magnets using rare earth metals to be used inexpensively and in large quantities in a wide range of fields, it is necessary to use magnets that do not contain expensive cobalt and are rare earth metals.
It would be necessary to have light rare earth elements, which are contained in large amounts in ores, as the main component. On the other hand, as mentioned above, in order to make R-Fe or R-Fe-B alloy useful as a magnetic material, it is said that sputter thinning, ultra-quenching, or amorphous formation is essential. However, it has not been possible to obtain bulk practical permanent magnets having arbitrary shapes and dimensions from these sputtered thin films or ultra-quenched ribbons. The magnetization curves of the Fe-B-R ribbons reported so far have poor squareness and cannot be considered as practical permanent magnets that can compete with conventional magnets. Furthermore, both the sputtered thin film and the ultra-quenched ribbon are essentially isotropic, and it has been virtually impossible to obtain a practical permanent magnet with magnetic anisotropy from them. The basic object of the present invention is to provide a new practical high-performance permanent magnet that should meet such demands. In particular, the present invention provides a practical permanent magnet that has good magnetic properties above room temperature, can be formed into any shape and practical size, has a highly square magnetization curve, and has magnetic anisotropy. The purpose of the present invention is to obtain a material that can effectively use resource-rich light rare earth elements as R. In order to create such a permanent magnet, the present inventor first developed a method using specific rare earth elements, mainly Nd and Pr, and Fe.
and B in a specific ratio, and is a magnetically anisotropic sintered body. A completely new type of practical high-performance permanent magnet was developed and filed by the same applicant as the present application (Japanese Patent Application No. 145072/1982). This Fe-B-R ternary magnet is based on a new compound different from the conventionally known RCo 5 and R 2 Co 17 compounds, and is obtained by forming an appropriate microstructure using powder metallurgy. It is a magnetically anisotropic sintered permanent magnet, especially boron.
(B) is not added as a conventional amorphous promoting element when creating an amorphous alloy or as a sintering promoting element in powder metallurgy, but in this Fe-B-R
It was revealed that it is an essential constituent element of the R-Fe-B compound, which is magnetically stable and has a high magnetic anisotropy constant, which constitutes the substantial content of permanent magnets. The above-mentioned Fe-BR-based magnetically anisotropic sintered permanent magnet does not necessarily need to contain Co, and as a preferable embodiment, Nd and Pr, which are abundant in resources, are used as R.
It is possible to use light rare earths mainly composed of Sm and does not necessarily require Sm or mainly Sm, so the raw material is inexpensive and extremely useful. Moreover, the magnetic properties are better than those of hard ferrite magnets (coercive force iHc≧1kOe, residual magnetic flux density Br≧4kG, maximum energy product (BH) max≧
4MGOe) In a particularly preferred composition range, it can exhibit an extremely high energy product equal to or higher than that of rare earth cobalt magnets. As mentioned above, this Fe-B-R permanent magnet has high cost performance in terms of high magnetic properties based on magnetic anisotropy, arbitrary formability, and the ability to use more abundant materials in terms of resources. -It is extremely useful industrially as a substitute for Co-based magnets, but on the other hand, the Curie point (temperature) of this Fe-BR-based permanent magnet is generally 300°C as disclosed in Japanese Patent Application No. 57-145072. The maximum temperature is 370℃ before and after. This Kyrie point is considerably lower than that of conventional alnico-based or R-Co-based permanent magnets, which is about 800°C. Therefore, the magnetic properties of Fe-BR permanent magnets have greater temperature dependence than conventional alnico-based or R-Co-based magnets, and their magnetic properties deteriorate at high temperatures. According to the results of research conducted by the present inventor, Fe-BR-based sintered magnets deteriorate in temperature characteristics when used at temperatures above about 100°C, so they should be used within the normal temperature range of about 70°C or below. It turned out to be appropriate. As described above, the large temperature dependence of the magnetic properties of permanent magnets, that is, the low Curie point, narrows the range of their use. It was necessary to raise the Kyrie point and improve the temperature characteristics. In addition to the above-mentioned basic object, the present invention further achieves
Another object of the present invention is to improve the temperature characteristics of Fe-BR-based magnetically anisotropic sintered permanent magnets. As a result of various experiments and studies, the inventor has discovered that Fe
-Achieve the above basic objective by replacing Fe with Co in a B-R permanent magnet, and also
It has been found that this method is effective in improving the temperature characteristics of Fe-BR-based permanent magnets, that is, raising the Curie point and reducing the temperature coefficient (temperature-dependent rate of change) of the residual magnetic flux density Br. That is, the permanent magnet of the present invention is as follows. First invention of the present application: Fe-B- consisting of 8 to 30% of at least one of Nd, Pr, Dy, Ho, and Tb as a rare earth element (R), B2 to 28%, and the remainder substantially Fe, in atomic percentage. A permanent magnet characterized in that, in an R-based magnetically anisotropic sintered permanent magnet, a portion of the Fe is replaced with 50% or less (excluding 0%) of Co based on the total composition. Second invention of the present application: At least one of Nd, Pr, Dy, Ho, Tb and La, Ce, Pm, Sm, Eu, Gd, Er, as rare earth elements (R) in atomic percentage
In the Fe-BR-based magnetically anisotropic sintered permanent magnet consisting of a total of 8 to 30% of at least one of Tm, Yb, Lu, and Y, B2 to 28%, and the remainder substantially Fe, the Fe A permanent magnet characterized in that a portion of the total composition is replaced with 50% or less (excluding 0%) of Co. Generally, when Co is added to an Fe alloy, it is recognized that the Curie point (Tc) both increases and decreases as the amount of Co added increases. Therefore, replacing Fe with Co generally produces complex results that are difficult to predict.
For example, when Fe in an RFe 3 compound is replaced with Co, Tc initially increases as the amount of Co increases, but Fe
It reaches a maximum near R(Fe 0.5 Co 0.5 ) 3 , which is 1/2 substituted with
After that, it decreases. In addition, in the case of Fe 2 B alloy, Tc monotonically decreases due to the substitution of Co for Fe. In the substitution of Fe for Co in the Fe-BR system, as shown in FIG. 1, it was revealed that as the amount of Co substitution increased, Tc increased rapidly at first, and then gradually increased. In this Fe-BR-based alloy, a similar tendency is confirmed regardless of the type of R. The amount of Co substitution is small (e.g. 0.1 to 1
atomic%) is also effective in increasing Tc, and as is clear in the system (77-x) Fe-xCo-8B-15Nd illustrated in Figure 1, the temperature can be increased from 400 to 800°C by adjusting x.
Alloys with arbitrary Tc can be obtained. Thus, the present invention provides novel Fe-B-
By substituting a part of Fe in the Fe-B-R magnetic anisotropic sintered permanent magnet based on the R compound with Co, the alloy composition contains 50% or less Co,
Fe-Co based on (Fe, Co)-B-R compound
-BR system magnetically anisotropic sintered permanent magnet is provided. According to the present invention, by containing Co, Fe
- The temperature characteristics of the B-R permanent magnet are improved to substantially the same level as conventional alnico magnets and R-Co magnets, and other advantages are maintained. That is, especially as a rare earth element R, it is abundant in resources.
When using light rare earths such as Nd and Pr, conventional R
-Compared with Co-based magnets, it is advantageous in terms of both resources and cost, and even better magnetic properties can be obtained. In addition, the Co-added Fe-B-R permanent magnet of the present invention has almost the same Br and the same or slightly lower iHc than the Fe-B-R permanent magnet that does not contain Co, but the addition of Co improves the squareness. is improved, so that (BH)max can be made equal to or even higher to a considerable extent. Furthermore, since Co has more corrosion resistance than Fe, it is also possible to impart corrosion resistance by adding Co compared to Fe-BR permanent magnets. Thus, the present invention can provide a novel practical high-performance permanent magnet that is extremely useful industrially. In the present invention, the contents of B and R among the essential elements are basically the same as in the case of Fe--B--R permanent magnets (systems that do not contain Co). That is, (hereinafter % indicates atomic percentage in the alloy), B should be 2% or more to satisfy the coercive force Hc≧1kOe, and B should be 2% or more to make the residual magnetic flux density Br of hard ferrite about 4kG or more.
28% or less. R is required to be 8% or more in order to have a coercive force of 1 kOe or more, and is set to 30% or less because it is easily flammable and difficult to handle and manufacture industrially (and is expensive). The rare earth element R used in the permanent magnet of the present invention includes Y, and is a rare earth element including light rare earths and heavy rare earths, among which one or more predetermined types are used.
That is, this R includes Nd, Pr, La, Ce, Tb,
Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb,
Lu and Y are included. As R, light rare earths mainly composed of Nd and Pr (particularly Nd and Pr) are preferable. Generally, it is sufficient to have one of the specified R (Nd, Pr, Dy, Ho, Tb, etc.), but La, Ce, Pm,
Sm, Eu, Gd, Er, Tm, Yb, Lu, Y, etc. can be used as a mixture with other R, especially Nd, Pr, Dy, Ho, Tb (one or more). In practice, a mixture of two or more types (Mitsushimetal, didymium, etc.) can be used for reasons such as convenience of availability. Sm, La, Er, Tm, Ce, Gd, Y are unfavorable because their iHc is low when used alone; Eu, Pm, Yb,
Lu exists only in trace amounts and is expensive. Therefore, as described above, these rare earth elements can be used as a mixture with other R such as Nd and Pr. Note that this R does not have to be a pure rare earth element, and may contain impurities that are unavoidable in manufacturing (other rare earth elements, Ca, Mg, Fe, Ti, C, O, etc.) within the industrially available range. do not have. As B (boron), pure boron or ferroboron can be used, and as impurities Al, Si,
Those containing C or the like can also be used. The remainder essentially consists of Fe and Co, and the amount of Co substitution, which is a feature of the present invention, is desirably selected as appropriate depending on the requirements for magnetic properties, etc., which will be described later. In addition to Fe, Co, B, and R, the permanent magnet of the present invention is C,
The presence of industrially unavoidable impurities such as S, P, Ca, Mg, O, Si, and Al can be tolerated. These impurities are often mixed in from raw materials or manufacturing processes, and the total amount is preferably 5% or less.
Also, Al, Ti, V, Cr, Mn, Zn, Zr, Nb, Mo,
By adding one or more of Ta, W, Sn, Bi, and Sb, it is possible to increase the coercive force, and by adding Ni, it is also possible to improve corrosion resistance. The Fe-Co-B-R permanent magnet of the present invention has at least one of the above-mentioned R, that is, Nd, Pr, Dy, Ho, and Tb, or at least one of these Nd, Pr, Dy, Ho, and Tb. and La, Ce, Pm, Sm, Eu,
A total of 8 to 30% of at least one of Gd, Er, Tm, Yb, Lu, Y, 2 to 28% B, Co50% or less,
The residual Fe exhibits magnetic properties of coercive force iHc ≥ 1kOe and residual magnetic flux density Br ≥ 4kG, and the maximum energy product (BH) max is similar to that of hard ferrite (~4MGOe).
degree) will be equivalent to or higher than that. Furthermore, as R, Nd and Pr are the main components of R (i.e., at least 50% of Nd and Pr in all R), and 12
The composition of ~20%R, 4~24%B, 45% or less Co, and the balance Fe is the maximum energy product (BH) max≧
10MGOe, and especially when Co is less than 35%, the maximum energy product (BH) max is more than 20MGOe,
Reach a maximum of 33MGOe or more. Also, Co contributes to an increase in Tc even when it is less than 5%, and in particular, when it is more than 5%, the temperature coefficient of Br is about 0.1%/℃ or less, and when it is less than 25%, it increases Tc without substantially impairing other magnetic properties. Contribute. The Fe-Co-B-R permanent magnet of the present invention can also be obtained as a magnetically anisotropic sintered body similar to the Fe-B-R permanent magnet filed earlier. Typically, the permanent magnet of the present invention can be obtained by melting the alloy, cooling it (for example, casting), pulverizing the resulting alloy, and then shaping and sintering it in a magnetic field. <Examples> The present invention will be described below with reference to Examples. however,
This example is not intended to limit the invention. Figure 1 shows a representative example of 77Fe−8B−15Nd Fe.
A system in which part of is replaced with Co(x), (77−x)Fe−
The graph shows the change in the Curie point Tc when x of xCo-8B-15Nd is changed from 0 to 77. This sample was produced by the following steps. (1) The alloy is melted by high frequency and cast in a water-cooled copper mold.The starting materials are electrolytic iron with a purity of 99.9% as Fe, and ferroboron alloy as B (19.38% B, 5,32% Al,
0.74%Si, 0.03%C, balance Fe), purity as R
99.7% or more (impurities are mainly other rare earth elements), and electrolytic Co with a purity of 99.9% was used. Purity is expressed in weight%; (2) Grinding, coarsely pulverizing with a stamp mill to a mesh throughput of 35, and then finely pulverizing with a ball mill for 3 hours (3 to 10 μm); (3) Orienting and molding in a magnetic field (10 kOe) (1.5 t) ( 4 ) Sintering: 1000-1200°C in Ar for 1 hour, then allowed to cool after sintering. About 0.1 g of a block (polycrystal) was cut out from the sintered body, and its Curie point was measured using VSM as follows. In other words, a magnetic field of 10 kOe is applied to the sample, a temperature change of 4πI is measured in the temperature range from 25℃ to 600℃, and the temperature at which 4πI is almost 0 is defined as the Curie point.
Tc. As the amount of Co substitution for Fe increases in the above system,
Tc increases rapidly, and when Co is 30% or more, Tc is 600
Reaching temperatures above ℃. Generally, in permanent magnet materials, increasing Tc is considered to be the most important factor for reducing temperature changes in magnetic properties. In order to confirm this point, permanent magnet samples shown in Table 1 were prepared using the same process as the samples for Tc measurement, and the temperature characteristics of Br were measured as follows.
That is, the magnetization curve was measured with a BH tracer at each temperature of 25℃, 60℃, and 100℃, and
The temperature change of Br was averaged. Various Fe-B
Table 1 shows the measurement results of the Br temperature coefficients of the -R and Fe-Ce-B-R magnets. From Table 1, it is clear that the temperature change of Br is improved by containing Co in the Fe-BR magnet. Table 1 also lists the magnetic properties of each sample at room temperature. For most compositions, the coercive force iHc decreases due to Co substitution, but (BH)max increases due to the improved squareness of the demagnetization curve. However, when the amount of Co substitution increases, the iHc decreases significantly, so in order to obtain iHc≧1KOe as a permanent magnet material, the amount of Co is set to 50% or less. The reasons for the limitations described above regarding the lower limit and upper limit of B and the lower limit of R can be confirmed from Table 1 (and from FIGS. 3 and 4).
【表】【table】
【表】
第１表には、ＲとしてNd，Pr等の主として軽
希土類を用いたものを多数掲げてあるが、夫々高
い磁気特性を示し、FeのCoによる置換によつて
さらに温度特性が改善されている。Ｒとしては、
２種以上の希土類元素の混合物も有用であること
が判る。
更に得られた焼結体（第１表No.C2、No.８、No.
24）を80℃、相対湿度90％の恒温恒湿槽に200時
間置き、酸化による重量変化を測定した処、本発
明に係る試料（No.８、No.24）はCoを含まない試
料（No.C2）に比べて重量増加の割合が著しく低
く、又Coの添加量に応じてその効果が顕著に認
められた。
次にFeの一部をCoで置換したFe−Co−Ｂ−Ｒ
系焼結磁石の代表例として57Fe−20Co−8B−
15Ndの室温における磁化曲線を第２図に示す。
初磁化曲線１は低磁界で急峻に立上がり、飽和に
達する。減磁曲線は極めて角形性が高く、本発明
磁石は典型的な高性能異方性磁石であることを示
している。初磁化曲線１の形から推察すると、本
発明磁石はその保磁力が反転磁区の核発生によつ
て決定される、いわゆるニユークリエーシヨン型
永久磁石である。なお、第１表に示す、他の試料
（比較例を除く）はいずれも、第２図と同様な磁
化曲線を示した。
前述の工程と同様にして製造した試料により、
（82−ｘ）Fe−10Co−8B−xNdの系においてｘ
を０〜40に変化させてNd量とBr，iHCとの関係
を調べた。その結果を第３図に示す。さらに、
（75−ｘ）Fe−10Co−xB−15Ndの系においてｘ
を０〜35に変化させてＢ量とBr，iHcとの関係を
調べ、その結果を第４図に示す。第３図、第４図
からも本発明のＲ，Ｂの数値限定の理由が明らか
である。
さらに、同様の工程により、Fe−Co−Ｂ−Ｒ
四成分系において、一例として（95−ｘ−ｙ）
Fe−5Co−yB−xNdの系についてFe，Ｂ，Nd三
成分を変化させて磁気特性を調べ、その結果を
（BH）maxについて第５図に示す。
本発明のFe−Co−Ｂ−Ｒ系永久磁石は、Ｒと
して軽希土類、特にNd，Prを中心とする軽希土
類、重希土類の混合物、例えばミツシユメタンや
ジジムのように安価なＲ原料を用いて高い磁気特
性が得られ、かつCoの含有量も重量百分率で45
％以下（原子％で50％以下）で十分であり、
SmCo系磁石がSmを必須とし50〜65重量％のCo
を含有するのと比較すれば、Smを必須とせずか
つCoを節約可能であり、温度特性はFe−Ｂ−Ｒ
系磁石に比べて顕著に改善できた。
以上詳述の通り、本発明は、新規なFe−Co−
Ｂ−Ｒ系磁気異方性焼結体から成る実用永久磁石
を提供し、従来レベル以上の磁気特性をＲとして
必ずしもSmを用いることなくまたCoを多量に用
いることなく実現したものである。本発明は、そ
の実施の態様においてさらに従来磁石よりも優れ
た高保磁力、高エネルギ積を備えると共に実質的
に従来のアルニコ、Ｒ−Co系磁石に匹敵する温
度特性を備えた実用高性能永久磁石を提供し、好
適な態様として従来にない最高のエネルギ積をも
実現したものである。加えて、ＲとしてNd，Pr
等の軽希土類を希土類の中心として用いることが
できることにより、資源、価格、磁気特性いずれ
の点においても優れた永久磁石であり、工業利用
性の極めて高いものである。またFe−Ｂ−Ｒ系
磁石と対比してみると、Coの含有により実用上
充分高いキユリー点を備え、応用範囲を拡げ実用
的価値を高めている。[Table] Table 1 lists many materials using mainly light rare earth elements such as Nd and Pr as R. Each of them shows high magnetic properties, and the temperature properties are further improved by replacing Fe with Co. has been done. As R,
Mixtures of two or more rare earth elements also prove useful. Furthermore, the obtained sintered bodies (Table 1 No. C2, No. 8, No.
24) was placed in a constant temperature and humidity chamber at 80°C and 90% relative humidity for 200 hours, and weight changes due to oxidation were measured. The rate of weight increase was significantly lower than that of No. C2), and the effect was noticeable depending on the amount of Co added. Next, Fe-Co-B-R in which part of Fe was replaced with Co
57Fe−20Co−8B− is a typical example of sintered magnet.
Figure 2 shows the magnetization curve of 15Nd at room temperature.
The initial magnetization curve 1 rises steeply in a low magnetic field and reaches saturation. The demagnetization curve has extremely high squareness, indicating that the magnet of the present invention is a typical high-performance anisotropic magnet. Judging from the shape of the initial magnetization curve 1, the magnet of the present invention is a so-called nucleation type permanent magnet whose coercive force is determined by the nucleation of reversal magnetic domains. Note that all of the other samples shown in Table 1 (excluding the comparative example) showed magnetization curves similar to those shown in FIG. 2. With a sample manufactured in the same manner as the above-mentioned process,
(82−x)x in the Fe−10Co−8B−xNd system
The relationship between the amount of Nd and Br and iHC was investigated by changing the value from 0 to 40. The results are shown in FIG. moreover,
(75−x)x in the system Fe−10Co−xB−15Nd
The relationship between the amount of B and Br, iHc was investigated by changing the value from 0 to 35, and the results are shown in FIG. The reason for limiting the numerical values of R and B in the present invention is also clear from FIGS. 3 and 4. Furthermore, by the same process, Fe-Co-B-R
In a four-component system, as an example (95-x-y)
The magnetic properties of the Fe-5Co-yB-xNd system were investigated by changing the three components Fe, B, and Nd, and the results are shown in FIG. 5 for (BH)max. The Fe-Co-B-R permanent magnet of the present invention uses an inexpensive R raw material as R, such as a mixture of light rare earths, especially light rare earths centered on Nd and Pr, and heavy rare earths, such as Mitsushimethane and didymium. High magnetic properties are obtained, and the Co content is 45% by weight.
% or less (50% or less in atomic %) is sufficient,
SmCo magnets require Sm and 50 to 65% Co by weight.
Compared to containing Fe-B-R, Sm is not required and Co can be saved, and the temperature characteristics are similar to that of Fe-B-R.
This was a marked improvement compared to other magnets. As detailed above, the present invention provides a novel Fe-Co-
The present invention provides a practical permanent magnet made of a BR-based magnetically anisotropic sintered body, and achieves magnetic properties higher than conventional levels without necessarily using Sm as R or using a large amount of Co. In its embodiment, the present invention further provides a practical high-performance permanent magnet that has a high coercive force and a high energy product superior to conventional magnets, and has temperature characteristics substantially comparable to conventional alnico and R-Co magnets. In a preferred embodiment, it also achieves the highest energy product ever achieved. In addition, as R, Nd, Pr
By using a light rare earth such as as the core of the rare earth, it is a permanent magnet that is excellent in terms of resources, price, and magnetic properties, and has extremely high industrial applicability. Furthermore, when compared with Fe-BR-based magnets, the inclusion of Co provides a sufficiently high Kurie point for practical use, expanding the range of applications and increasing practical value.
第１図は、（77−ｘ）Fe−xCo−8B−15Nd系
において、Co量（横軸原子％）とキユリー点と
の関係を示すグラフ、第２図は、57Fe−20Co−
8B−15Ndの磁石の室温における磁化曲線（初磁
化曲線１、減磁曲線２、縦軸は磁化4πI（kG）、横
軸は磁界Ｈ（kOe））、第３図は、（82−ｘ）Fe−
10Co−8B−xNd系において、Nd量（横軸原子
％）とiHc，Brとの関係を示すグラフ、第４図
は、（75−ｘ）Fe−10Co−xB−15Nd系におい
て、Ｂ量（横軸原子％）とiHc，Brとの関係を示
すグラフ、及び第５図は、Fe−5Co−Ｂ−Nd系
において、（95−ｘ−ｙ）Fe−yB−xR三成分の
組成と（BH）maxとの関係を示す三成分系ダイ
ヤフラム、を夫々示す。
Figure 1 is a graph showing the relationship between the amount of Co (atomic % on the horizontal axis) and the Kyrie point in the (77-x)Fe-xCo-8B-15Nd system, and Figure 2 is a graph showing the relationship between the amount of Co (atomic % on the horizontal axis) and the Curie point in the (77-x)Fe-xCo-8B-15Nd system.
Magnetization curve of 8B-15Nd magnet at room temperature (initial magnetization curve 1, demagnetization curve 2, vertical axis is magnetization 4πI (kG), horizontal axis is magnetic field H (kOe)), Figure 3 is (82-x) Fe−
Figure 4 is a graph showing the relationship between the amount of Nd (atomic % on the horizontal axis) and iHc, Br in the 10Co-8B-xNd system. The graph showing the relationship between iHc and Br (horizontal axis atomic %) and Figure 5 show the relationship between the composition of the (95-x-y) Fe-yB-xR ternary component and ( BH) A three-component diaphragm showing the relationship with max is shown.
Claims (1)
Pr，Dy，Ho，Tbのうち少なくとも一種８〜30
％、B2〜28％及び残部実質的にFeからなるFe−
Ｂ−Ｒ系磁気異方性焼結体永久磁石において、前
記Feの一部を全組成に対して50％以下（０％を
除く）のCoで置換したことを特徴とする永久磁
石。 ２ 原子百分比で、前記希土類元素（Ｒ）12〜20
％（但し前記希土類元素（Ｒ）の50％以上はNd
とPrの１種又は２種）、B4〜24％及び残部実質的
にFeからなり、前記Feの一部を全組成に対して
45％以下のCoで置換したことを特徴とする特許
請求の範囲第１項記載の永久磁石。 ３ 原子百分比で、希土類元素（Ｒ）としてNd，
Pr，Dy，Ho，Tbのうち少なくとも一種とLa，
Ce，Pm，Sm，Eu，Gd，Er，Tm，Yb，Lu，
Ｙのうち少なくとも一種の合計８〜30％、B2〜
28％及び残部実質的にFeからなるFe−Ｂ−Ｒ系
磁気異方性焼結体永久磁石において、前記Feの
一部を全組成に対して50％以下（０％を除く）の
Coで置換したことを特徴とする永久磁石。 ４ 原子百分比で、前記希土類元素（Ｒ）12〜20
％（但し前記希土類元素（Ｒ）の50％以上はNd
とPrの１種又は２種）、B4〜24％及び残部実質的
にFeからなり、前記Feの一部を全組成に対して
45％以下のCoで置換したことを特徴とする特許
請求の範囲第３項記載の永久磁石。[Claims] 1 Nd as a rare earth element (R) in atomic percentage;
At least one of Pr, Dy, Ho, Tb 8-30
%, B2~28% and the balance essentially consisting of Fe-
A permanent magnet characterized in that a part of the Fe is replaced with 50% or less (excluding 0%) of Co based on the total composition in a B-R magnetically anisotropic sintered permanent magnet. 2 The rare earth element (R) 12 to 20 in atomic percentage
% (However, more than 50% of the rare earth elements (R) are Nd
and Pr (1 or 2 types), B4 to 24% and the balance substantially consists of Fe, and a part of the Fe is added to the total composition.
The permanent magnet according to claim 1, wherein the permanent magnet is replaced with 45% or less of Co. 3 Nd as a rare earth element (R) in atomic percentage,
At least one of Pr, Dy, Ho, Tb and La,
Ce, Pm, Sm, Eu, Gd, Er, Tm, Yb, Lu,
A total of 8-30% of at least one type of Y, B2-
In an Fe-B-R magnetically anisotropic sintered permanent magnet consisting of 28% Fe and the remainder substantially Fe, a portion of the Fe is 50% or less (excluding 0%) of the total composition.
A permanent magnet characterized by substitution with Co. 4 The rare earth element (R) 12 to 20 in atomic percentage
% (However, more than 50% of the rare earth elements (R) are Nd
and Pr (1 or 2 types), B4 to 24% and the balance substantially consists of Fe, and a part of the Fe is added to the total composition.
4. The permanent magnet according to claim 3, wherein the permanent magnet is replaced with 45% or less of Co.
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57166663A JPS5964733A (en) | 1982-09-27 | 1982-09-27 | Permanent magnet |
| US06/516,841 US4792368A (en) | 1982-08-21 | 1983-07-25 | Magnetic materials and permanent magnets |
| CA000433188A CA1315571C (en) | 1982-08-21 | 1983-07-26 | Magnetic materials and permanent magnets |
| EP83107351A EP0106948B1 (en) | 1982-09-27 | 1983-07-26 | Permanently magnetizable alloys, magnetic materials and permanent magnets comprising febr or (fe,co)br (r=vave earth) |
| DE8383107351T DE3379084D1 (en) | 1982-09-27 | 1983-07-26 | Permanently magnetizable alloys, magnetic materials and permanent magnets comprising febr or (fe,co)br (r=vave earth) |
| SG48390A SG48390G (en) | 1982-09-27 | 1990-07-02 | Permanently magnetizable alloys,magnetic materials and permanent magnets comprising febr or(fe,co)br(r=vave earth) |
| HK68490A HK68490A (en) | 1982-09-27 | 1990-08-30 | Permanently magnetizable alloys,magnetic materials and permanent magnets comprising febr or(fe,co)br(r=vave earth) |
| US08/194,647 US5466308A (en) | 1982-08-21 | 1994-02-10 | Magnetic precursor materials for making permanent magnets |
| US08/485,183 US5645651A (en) | 1982-08-21 | 1995-06-07 | Magnetic materials and permanent magnets |
| US08/848,283 US5766372A (en) | 1982-08-21 | 1997-04-29 | Method of making magnetic precursor for permanent magnets |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57166663A JPS5964733A (en) | 1982-09-27 | 1982-09-27 | Permanent magnet |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62314249A Division JPS63213637A (en) | 1987-12-14 | 1987-12-14 | Ferromagnetic alloy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5964733A JPS5964733A (en) | 1984-04-12 |
| JPH0319296B2 true JPH0319296B2 (en) | 1991-03-14 |
Family
ID=15835422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57166663A Granted JPS5964733A (en) | 1982-08-21 | 1982-09-27 | Permanent magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5964733A (en) |
Families Citing this family (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0663056B2 (en) * | 1984-01-09 | 1994-08-17 | コルモーゲン コーポレイション | Non-sintered permanent magnet alloy and manufacturing method thereof |
| JPS60228652A (en) * | 1984-04-24 | 1985-11-13 | Nippon Gakki Seizo Kk | Magnet containing rare earth element and its manufacture |
| JPS60230959A (en) * | 1984-04-28 | 1985-11-16 | Tohoku Metal Ind Ltd | Permanent magnet and its manufacture |
| JPS60240105A (en) * | 1984-05-14 | 1985-11-29 | Shin Etsu Chem Co Ltd | Plastic magnet composition |
| FR2566758B1 (en) * | 1984-06-29 | 1990-01-12 | Centre Nat Rech Scient | NOVEL MAGNETIC RARE EARTH / IRON / BORON AND RARE EARTH / COBALT / BORON HYDRIDES, THEIR MANUFACTURING AND MANUFACTURING PROCESS FOR POWDER DEHYDRIDE PRODUCTS, THEIR APPLICATIONS |
| JPS6187825A (en) * | 1984-10-05 | 1986-05-06 | Hitachi Metals Ltd | Manufacture of permanent magnet material |
| JPH0791564B2 (en) * | 1984-12-10 | 1995-10-04 | 住友特殊金属株式会社 | Rare earth containing alloy powder |
| JPH0630295B2 (en) * | 1984-12-31 | 1994-04-20 | ティーディーケイ株式会社 | permanent magnet |
| USRE34838E (en) * | 1984-12-31 | 1995-01-31 | Tdk Corporation | Permanent magnet and method for producing same |
| JPS61195954A (en) * | 1985-02-26 | 1986-08-30 | Santoku Kinzoku Kogyo Kk | Permanent magnet alloy |
| JPS62165305A (en) * | 1986-01-16 | 1987-07-21 | Hitachi Metals Ltd | Permanent magnet of good thermal stability and manufacture thereof |
| JP2530641B2 (en) * | 1986-03-20 | 1996-09-04 | 日立金属株式会社 | Magnetically anisotropic bonded magnet, magnetic powder used therefor, and method for producing the same |
| JPH0621324B2 (en) * | 1986-10-04 | 1994-03-23 | 信越化学工業株式会社 | Rare earth permanent magnet alloy composition |
| KR900006533B1 (en) * | 1987-01-06 | 1990-09-07 | 히다찌 긴조꾸 가부시끼가이샤 | Anisotropic magnetic materials and magnets made with it and making method for it |
| US4983232A (en) * | 1987-01-06 | 1991-01-08 | Hitachi Metals, Ltd. | Anisotropic magnetic powder and magnet thereof and method of producing same |
| JPS63213637A (en) * | 1987-12-14 | 1988-09-06 | Sumitomo Special Metals Co Ltd | Ferromagnetic alloy |
| JPH0283905A (en) * | 1988-09-20 | 1990-03-26 | Sumitomo Special Metals Co Ltd | Corrosion-resistant permanent magnet and manufacture thereof |
| JP2843379B2 (en) * | 1988-10-04 | 1999-01-06 | 日立金属株式会社 | Isotropic heat-resistant bonded magnet, method of manufacturing the same, magnetic powder using the same, and PM-type motor using the same |
| US5269855A (en) * | 1989-08-25 | 1993-12-14 | Dowa Mining Co., Ltd. | Permanent magnet alloy having improved resistance |
| US5183630A (en) * | 1989-08-25 | 1993-02-02 | Dowa Mining Co., Ltd. | Process for production of permanent magnet alloy having improved resistence to oxidation |
| JPH0696927A (en) * | 1993-03-17 | 1994-04-08 | Seiko Epson Corp | Rare-earth sintered magnet |
| US5486224A (en) * | 1993-12-28 | 1996-01-23 | Sumitomo Metal Industries, Ltd. | Powder mixture for use in compaction to produce rare earth iron sintered permanent magnets |
| US6319336B1 (en) | 1998-07-29 | 2001-11-20 | Dowa Mining Co., Ltd. | Permanent magnet alloy having improved heat resistance and process for production thereof |
| CN1934283B (en) | 2004-06-22 | 2011-07-27 | 信越化学工业株式会社 | R-Fe-B-based rare earth permanent magnet material |
| KR101378089B1 (en) | 2007-05-02 | 2014-03-27 | 히다찌긴조꾸가부시끼가이사 | R-t-b sintered magnet |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57141901A (en) * | 1981-02-26 | 1982-09-02 | Mitsubishi Steel Mfg Co Ltd | Permanent magnet powder |
| JPS5964739A (en) * | 1982-09-03 | 1984-04-12 | ゼネラルモーターズコーポレーション | High energy rare earth metal-transition metal magnetic alloy |
-
1982
- 1982-09-27 JP JP57166663A patent/JPS5964733A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57141901A (en) * | 1981-02-26 | 1982-09-02 | Mitsubishi Steel Mfg Co Ltd | Permanent magnet powder |
| JPS5964739A (en) * | 1982-09-03 | 1984-04-12 | ゼネラルモーターズコーポレーション | High energy rare earth metal-transition metal magnetic alloy |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5964733A (en) | 1984-04-12 |
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