JPH04342104A - Magnetic powder for anisotropic bonded magnet; its manufacture - Google Patents
Magnetic powder for anisotropic bonded magnet; its manufactureInfo
- Publication number
- JPH04342104A JPH04342104A JP3142332A JP14233291A JPH04342104A JP H04342104 A JPH04342104 A JP H04342104A JP 3142332 A JP3142332 A JP 3142332A JP 14233291 A JP14233291 A JP 14233291A JP H04342104 A JPH04342104 A JP H04342104A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic powder
- bonded magnet
- average particle
- anisotropic
- anisotropic bonded
- 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.)
- Pending
Links
- 239000006247 magnetic powder Substances 0.000 title claims abstract description 59
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- 238000010438 heat treatment Methods 0.000 claims abstract description 25
- 239000002245 particle Substances 0.000 claims abstract description 23
- 239000000956 alloy Substances 0.000 claims abstract description 16
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 16
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 15
- 230000005415 magnetization Effects 0.000 claims abstract description 9
- 239000011261 inert gas Substances 0.000 claims abstract description 7
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 7
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims abstract description 7
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052796 boron Inorganic materials 0.000 claims abstract description 6
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 5
- 229910052742 iron Inorganic materials 0.000 claims abstract description 4
- 238000010298 pulverizing process Methods 0.000 claims description 17
- 238000000465 moulding Methods 0.000 claims description 9
- 239000000843 powder Substances 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 description 18
- 239000000203 mixture Substances 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 6
- 229910052692 Dysprosium Inorganic materials 0.000 description 5
- 229910052771 Terbium Inorganic materials 0.000 description 5
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 5
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 229910052779 Neodymium Inorganic materials 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 239000006249 magnetic particle Substances 0.000 description 4
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 4
- 230000004907 flux Effects 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000003822 epoxy resin Substances 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229910001172 neodymium magnet Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 229920000647 polyepoxide Polymers 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical compound FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- 229910052689 Holmium Inorganic materials 0.000 description 1
- JHWNWJKBPDFINM-UHFFFAOYSA-N Laurolactam Chemical compound O=C1CCCCCCCCCCCN1 JHWNWJKBPDFINM-UHFFFAOYSA-N 0.000 description 1
- 229910052765 Lutetium Inorganic materials 0.000 description 1
- 229920000299 Nylon 12 Polymers 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- 229910052773 Promethium Inorganic materials 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- OHSVLFRHMCKCQY-UHFFFAOYSA-N lutetium atom Chemical compound [Lu] OHSVLFRHMCKCQY-UHFFFAOYSA-N 0.000 description 1
- RVZRBWKZFJCCIB-UHFFFAOYSA-N perfluorotributylamine Chemical compound FC(F)(F)C(F)(F)C(F)(F)C(F)(F)N(C(F)(F)C(F)(F)C(F)(F)C(F)(F)F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)F RVZRBWKZFJCCIB-UHFFFAOYSA-N 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- VQMWBBYLQSCNPO-UHFFFAOYSA-N promethium atom Chemical compound [Pm] VQMWBBYLQSCNPO-UHFFFAOYSA-N 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 150000002910 rare earth metals Chemical group 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0576—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together pressed, e.g. hot working
Landscapes
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
【0001】0001
【産業上の利用分野】本発明はR(Rはイットリウムを
含む希土類元素の少なくとも1種)、ホウ素、M(Mは
Fe、Co、Niの少なくとも1種以上)を主成分とし
、優れた磁気特性を有する異方性ボンド磁石用磁粉及び
その製造方法に関する。[Industrial Application Field] The present invention has excellent magnetic The present invention relates to magnetic powder for anisotropic bonded magnets having characteristics and a method for manufacturing the same.
【0002】0002
【従来の技術】希土類ボンド磁石の材料としては、これ
まで大別してSm−Co系とNd−Fe−B系の磁粉が
提案されている。前者は全希土類中数原子%しか含まれ
ていないSmを使用すること、さらに原料供給が不安定
なCoを多量に含んでいることから資源上の問題を抱え
ている。後者は近年精力的に研究されている永久磁石材
料であり、高価なCoを含まず、資源的にもSmより豊
富なNdを主体とした永久磁石材料であることから注目
されている。これまで実用化されているNd−Fe−B
系ボンド磁石は特開昭59−64739号公報に代表さ
れるように、溶融合金を急冷薄帯製造装置によってアモ
ルファスリボンにし、その後熱処理、粉砕することによ
って得られた磁粉を用いるボンド磁石である。さらに、
この方法による異方性磁石粉の製造方法は特開昭60−
100402号公報に開示されているように上記の等方
性磁粉をホットプレスによって成形体とした後に、高温
下で塑性変形させることによって異方性のバルク磁石を
得、その後このバルク磁石を粉砕することによって異方
性のボンド磁石用磁粉を得ており、かかる異方性の磁粉
を用いることによって異方性ボンド磁石が得られている
。さらに、他の方法による異方性磁粉の製造方法として
焼結磁石を粉砕することによって異方性磁粉を得る方法
があるが、かかる方法は粉砕によって大巾に保磁力が低
下してしまい実用的な方法ではない。また、他の異方性
磁粉を得る方法として磁石合金を微粉末化することによ
って異方性磁粉を得る方法が提案されている。この方法
は溶解・鋳造した合金を粉砕するだけで異方性の磁粉が
得られるので工程が簡略化され、かつ磁気特性が安定し
ているばかりでなく、生産コスト的には有利な方法であ
ると考えられる。BACKGROUND OF THE INVENTION As materials for rare earth bonded magnets, Sm--Co based and Nd--Fe--B based magnetic powders have been proposed. The former has resource problems because it uses Sm, which contains only a few atomic percent of all rare earth elements, and also contains a large amount of Co, whose raw material supply is unstable. The latter is a permanent magnet material that has been actively researched in recent years, and is attracting attention because it does not contain expensive Co and is mainly composed of Nd, which is more abundant than Sm in terms of resources. Nd-Fe-B that has been put into practical use so far
As typified by Japanese Unexamined Patent Publication No. 59-64739, the bonded magnet uses magnetic powder obtained by turning a molten alloy into an amorphous ribbon using a quenching ribbon production device, followed by heat treatment and pulverization. moreover,
A method for producing anisotropic magnet powder using this method is disclosed in Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent No. 100402, the above-mentioned isotropic magnetic powder is formed into a compact by hot pressing, then plastically deformed at high temperature to obtain an anisotropic bulk magnet, and then this bulk magnet is crushed. By doing this, anisotropic magnetic powder for bonded magnets is obtained, and by using such anisotropic magnetic powder, anisotropic bonded magnets are obtained. Furthermore, as another method for producing anisotropic magnetic powder, there is a method of obtaining anisotropic magnetic powder by pulverizing a sintered magnet, but this method is impractical because the coercive force is greatly reduced by pulverization. Not in a good way. Furthermore, as another method of obtaining anisotropic magnetic powder, a method of obtaining anisotropic magnetic powder by pulverizing a magnet alloy has been proposed. This method simplifies the process because anisotropic magnetic powder can be obtained by simply crushing the melted and cast alloy, and the magnetic properties are not only stable, but also advantageous in terms of production costs. it is conceivable that.
【0003】0003
【発明が解決しようとする課題】しかしながら、上記の
鋳造合金を微粉砕化する方法によって得られる異方性磁
粉は保磁力を高くするためにはネオジウム(Nd)の一
部を重希土類元素であるジスプロシウム(Dy)、テル
ビウム(Tb)で置換する必要があり、このため磁粉の
飽和磁化が低下して高性能の磁粉が得られなくなり、加
えて高価なジスプロシウム(Dy)、テルビウム(Tb
)を用いるために磁粉の原料コストが大幅に高くなると
いう問題を有している。[Problems to be Solved by the Invention] However, in order to increase the coercive force of the anisotropic magnetic powder obtained by the above-mentioned method of pulverizing the cast alloy, part of the neodymium (Nd) must be replaced with a heavy rare earth element. It is necessary to replace dysprosium (Dy) and terbium (Tb), which reduces the saturation magnetization of the magnetic powder and makes it impossible to obtain high-performance magnetic powder.
), there is a problem in that the cost of raw materials for magnetic powder increases significantly.
【0004】0004
【課題を解決するための手段】本発明者らはこれらの従
来技術の問題を解決するために、高価な重希土類元素で
あるジスプロシウム(Dy)、テルビウム(Tb)の添
加量を少なくしても高い磁気特性を有する異方性ボンド
磁石用磁粉を安価な方法で提供できる方法を開発するた
めに、磁石合金を粉砕した後の磁粉の熱処理法について
、鋭意検討を行った結果本発明に至った。[Means for Solving the Problems] In order to solve the problems of these conventional techniques, the present inventors have developed a method that reduces the amount of expensive heavy rare earth elements dysprosium (Dy) and terbium (Tb). In order to develop a method that can inexpensively provide magnetic powder for anisotropic bonded magnets with high magnetic properties, we conducted intensive studies on heat treatment methods for magnetic powder after crushing a magnet alloy, and as a result we arrived at the present invention. .
【0005】即ち、本発明の第1はR(但し、Rはイッ
トリウムを含む希土類元素の少なくとも1種)10〜3
0原子%、ホウ素:2〜28原子%、M(但し、MはF
e、Co、Niの少なくとも1種以上):65〜82原
子%からなる合金を平均粒子径が0.5〜50μmに粉
砕した後に、磁場中でプレス成形を行って磁場印加方向
に磁化容易軸を揃えた成形体を得、その後、真空中もし
くは不活性ガス中もしくは還元雰囲気中で400〜90
0℃の温度下で熱処理を行い、該熱処理した成形体を粉
砕することによって得られる平均粒子径が0.5〜50
0μmの異方性ボンド磁石用磁粉であり、本発明の第2
はR(但し、Rはイットリウムを含む希土類元素の少な
くとも1種)10〜30原子%、ホウ素:2〜28原子
%、M(但し、MはFe、Co、Ni)の少なくとも1
種以上):65〜82原子%からなる合金を平均粒子径
が0.5〜50μmに粉砕した後に、磁場中でプレス成
形を行って磁場印加方向に磁化容易軸を揃えた成形体を
得、その後、真空中もしくは不活性ガス中もしくは還元
雰囲気中で400〜900度の温度下で熱処理を行い、
該熱処理した成形体を平均粒子径が0.5〜500μm
に粉砕する異方性ボンド磁石用磁粉の製造方法をその内
容とする。That is, the first aspect of the present invention is R (where R is at least one rare earth element including yttrium) 10 to 3
0 atom%, boron: 2 to 28 atom%, M (however, M is F
After grinding an alloy consisting of 65 to 82 atomic % of at least one of e, Co, and Ni) to an average particle size of 0.5 to 50 μm, press molding is performed in a magnetic field to form an axis of easy magnetization in the direction of application of the magnetic field. A molded body with a uniform temperature of 400 to 90
The average particle diameter obtained by performing heat treatment at a temperature of 0 ° C. and pulverizing the heat-treated molded product is 0.5 to 50.
This is magnetic powder for anisotropic bonded magnets with a diameter of 0 μm, and the second aspect of the present invention is
is R (wherein R is at least one rare earth element including yttrium) 10 to 30 at%, boron: 2 to 28 at%, and at least one of M (where M is Fe, Co, Ni).
species): After pulverizing an alloy consisting of 65 to 82 at% to an average particle size of 0.5 to 50 μm, press molding is performed in a magnetic field to obtain a molded body with the axis of easy magnetization aligned in the direction of application of the magnetic field, After that, heat treatment is performed at a temperature of 400 to 900 degrees in a vacuum, an inert gas, or a reducing atmosphere,
The heat-treated molded body has an average particle size of 0.5 to 500 μm.
The content is a method for manufacturing magnetic powder for anisotropic bonded magnets.
【0006】本発明における希土類元素(R)はイット
リウム(Y)を含む希土類元素の1種以上であって、ネ
オジウム(Nd),プラセオジウム(Pr),ランタン
(La),セリウム(Ce)、サマリウム(Sm),ガ
ドリニウム(Gd),プロメシウム(Pm),ユーロピ
ウム(Eu),ルテチウム(Lu),ジスプロシウム(
Dy),テルビウム(Tb),ホルミウム(Ho)、な
どが例示出来る。イットリウム(Y)は希土類元素では
ないが本発明では他の希土類元素と同様に扱える。希土
類元素(R)の含有量が10原子%以下であると、保磁
力(iHc)が低くくなり、30原子%以上であると残
留磁束密度(Br)が低くくなり高性能磁石となり得な
い。本発明において好ましい希土類元素はネオジウム(
Nd)であり、より高い保磁力を得るためにネオジウム
(Nd)の一部をジスプロシウム(Dy)もしくはテル
ビウム(Tb)で置換することが好ましい。これらのジ
スプロシウム(Dy)またはテルビウム(Tb)の置換
量が1原子%以下であると十分に高い保磁力が得られな
く、5原子%を上回ると高保磁力が得られるものの飽和
磁束密度が大きく低下し、高エネルギー積の磁粉が得ら
れない。また、ホウ素の含有量が2原子%未満であると
保磁力が低くくなり、28原子%以上であると残留磁束
密度が低くなる。The rare earth element (R) in the present invention is one or more rare earth elements including yttrium (Y), neodymium (Nd), praseodymium (Pr), lanthanum (La), cerium (Ce), samarium ( Sm), gadolinium (Gd), promethium (Pm), europium (Eu), lutetium (Lu), dysprosium (
Examples include Dy), terbium (Tb), and holmium (Ho). Although yttrium (Y) is not a rare earth element, it can be treated in the same manner as other rare earth elements in the present invention. If the rare earth element (R) content is less than 10 atomic%, the coercive force (iHc) will be low, and if it is 30 atomic% or more, the residual magnetic flux density (Br) will be low and it cannot be a high-performance magnet. . In the present invention, the preferable rare earth element is neodymium (
In order to obtain higher coercive force, it is preferable to replace a portion of neodymium (Nd) with dysprosium (Dy) or terbium (Tb). If the substitution amount of dysprosium (Dy) or terbium (Tb) is less than 1 atomic %, a sufficiently high coercive force cannot be obtained, and if it exceeds 5 atomic %, although a high coercive force can be obtained, the saturation magnetic flux density decreases significantly. However, magnetic particles with high energy product cannot be obtained. Further, if the boron content is less than 2 atomic %, the coercive force will be low, and if it is 28 atomic % or more, the residual magnetic flux density will be low.
【0007】本発明における異方性磁粉の製造方法は、
所定の組成に調製し溶解・鋳造した合金を50〜500
μm程度に粗粉砕した後に、有機溶剤中もしくは不活性
ガス中で0.5〜50μmとなるように粉砕する工程と
、微粉砕された磁粉を磁場中でプレス成形することによ
って磁粉の磁化容易軸を磁場印加方向に揃えた後に、真
空中もしくは不活性ガス中もしくは還元雰囲気中で一般
的な焼結温度より低い温度で熱処理し、該熱処理成形体
を再度0.5〜500μmに粉砕する工程とからなる製
造方法である。熱処理成形体の平均粒子径が0.5μm
を下回ると磁粉の酸化が激しくなり、保磁力が大幅に低
下してしまい、500μmを上回るとボンド磁石を作製
する際に空激が多くなってしまい好ましくない。ボンド
磁石を成形する方法として射出成形とプレス成形のどち
らにも使用できる磁粉としては0.5〜100μmの平
均粒子径であることがより好ましい。本発明におけるポ
イントは、粉砕後の磁粉を磁化容易軸方向に揃えた後に
、熱処理することにあり、熱処理によって磁粉粒子の粒
成長を抑えた状態で保磁力を増加させ、かつ磁粉の配向
性と角形性を向上させることにある。すなわち、通常の
焼結磁石の製造と違って、熱処理によって極力磁粉の粒
成長を抑えることが重要となる。通常のNdFeB系焼
結磁石は2−14−1相である主相とNd−rich相
、B−rich相の3相で緻密な構造をとっており、粉
砕したときに結晶粒そのものが破壊され、そのために保
磁力が大幅に低下するが、特に500μm以下に粉砕し
た場合その低下が大きい。一方、本発明のように低温熱
処理によって粒成長を抑えた成形体では、磁粉の粒界が
優先的に破壊される構造になり、そのため熱処理後の成
形体は容易に粉の状態に粉砕でき、かつ500μm以下
の粒子径となっても磁粉の保磁力を大幅に低下すること
を抑制できる。したがって、本発明における熱処理の温
度が900℃を越えると磁粉の粒成長が激しくなり、粉
砕後の保磁力が大幅に低下してしまい好ましくない。
又、熱処理温度が400℃以下の場合は前述の粒成長は
抑えられるものの保磁力の向上が十分でなく好ましくな
い。より好ましい熱処理温度は650℃〜750℃であ
る。さらに、熱処理後にそのまま成形体を室温まで急冷
してもかまわないが、より好ましくは0.5〜6℃/分
の冷却速度で所定の温度まで冷却した後に室温まで急冷
することが良い。さらに、磁場中プレスの成形圧力は成
形体を保持できる圧力でよいが、前述の熱処理時の磁粉
の粒成長を抑えるためには0.5〜3t/cm2 圧力
が好ましい。3t/cm2 を越える圧力で成形した場
合、磁粉の粒子間距離が短くなるため本発明の範囲の温
度で熱処理しても少なからず粒成長が発生するためであ
る。
また、本発明においては、熱処理後の成形体の粉砕は通
常の機械的粉砕法を用いることができるが、より粒界で
破壊させるためには成形体に水素を吸蔵させて崩壊させ
る水素吸蔵法による粉砕が好ましい。機械的粉砕法にお
いては粉砕時の磁粉の急激な酸化を防止するために不活
性ガス中または有機溶剤中において粉砕することがより
好ましい。[0007] The method for producing anisotropic magnetic powder in the present invention is as follows:
50 to 500 pieces of alloy prepared to a predetermined composition, melted and cast
The process of coarsely pulverizing the powder to about μm and then pulverizing it to 0.5 to 50 μm in an organic solvent or inert gas, and press-molding the finely pulverized magnetic powder in a magnetic field to achieve the axis of easy magnetization of the magnetic powder. After aligning the molded body in the direction of applying a magnetic field, heat treatment is performed at a temperature lower than the general sintering temperature in a vacuum, an inert gas, or a reducing atmosphere, and the heat-treated molded body is crushed again to 0.5 to 500 μm. This is a manufacturing method consisting of: The average particle diameter of the heat-treated molded product is 0.5 μm
If it is less than 500 μm, the oxidation of the magnetic powder will be severe and the coercive force will be significantly reduced, and if it exceeds 500 μm, there will be a lot of air shock when producing a bonded magnet, which is not preferable. It is more preferable that the magnetic powder has an average particle diameter of 0.5 to 100 μm, which can be used for both injection molding and press molding as a method for molding a bonded magnet. The key point of the present invention is to heat-treat the crushed magnetic powder after aligning it in the axis of easy magnetization.The heat treatment increases the coercive force while suppressing the grain growth of the magnetic particles, and improves the orientation of the magnetic particles. The purpose is to improve squareness. That is, unlike the production of normal sintered magnets, it is important to suppress grain growth of magnetic powder as much as possible through heat treatment. Normal NdFeB-based sintered magnets have a dense structure consisting of the main phase of 2-14-1 phase, Nd-rich phase, and B-rich phase, and when crushed, the crystal grains themselves are destroyed. Therefore, the coercive force decreases significantly, and the decrease is particularly large when the powder is pulverized to 500 μm or less. On the other hand, in a molded body in which grain growth is suppressed by low-temperature heat treatment as in the present invention, the grain boundaries of the magnetic powder are preferentially destroyed, so that the molded body after heat treatment can be easily ground into powder. Moreover, even if the particle size is 500 μm or less, the coercive force of the magnetic powder can be prevented from significantly decreasing. Therefore, if the temperature of the heat treatment in the present invention exceeds 900°C, the grain growth of the magnetic powder will become intense, and the coercive force after pulverization will decrease significantly, which is not preferable. Further, if the heat treatment temperature is 400° C. or lower, although the above-mentioned grain growth can be suppressed, the coercive force cannot be sufficiently improved, which is not preferable. A more preferable heat treatment temperature is 650°C to 750°C. Further, after the heat treatment, the molded body may be directly cooled to room temperature, but it is more preferable to cool it to a predetermined temperature at a cooling rate of 0.5 to 6° C./min, and then rapidly cool it to room temperature. Further, the compacting pressure of the press in the magnetic field may be a pressure capable of holding the compact, but a pressure of 0.5 to 3 t/cm2 is preferable in order to suppress grain growth of the magnetic powder during the heat treatment described above. This is because when molding is performed at a pressure exceeding 3 t/cm2, the distance between particles of the magnetic powder becomes short, so that even if heat treatment is performed at a temperature within the range of the present invention, grain growth will occur to some extent. In addition, in the present invention, a normal mechanical crushing method can be used to crush the molded body after heat treatment, but in order to cause more destruction at the grain boundaries, a hydrogen storage method is used in which the molded body absorbs hydrogen and disintegrates. Grinding is preferred. In the mechanical pulverization method, it is more preferable to pulverize in an inert gas or an organic solvent in order to prevent rapid oxidation of the magnetic powder during pulverization.
【0008】[0008]
【実施例】以下、本発明を実施例により説明するが、本
発明はこれらにより何ら制限されるものではない。[Examples] The present invention will be explained below with reference to Examples, but the present invention is not limited to these in any way.
【0009】実施例1〜3
出発原料としてNd12Dy3 Fe77B8 の組成
の合金をアーク溶解炉によって作製した。得られた合金
をスタンプミルによって50〜500μmに粗粉砕し、
住友スリーエム(株)社製のパーフルオロカーボン不活
性液体である「フロリナート(FC−72)」とともに
ボールミルによって90分間粉砕を行った。その後、磁
場中プレスによって印加磁場強度20kOe、成形圧力
1t/cm2 の条件で成形体を得た。かかる成形体を
表1に示すように600、700、800℃の温度で、
真空中1時間、Arガス中1時間の熱処理を行い、熱処
理後400℃まで4℃/分の冷却速度で冷却し、その後
室温まで急冷した。得られた熱処理成形体を平均粒子径
が0.5〜100μmになるようにハンマーミルによっ
て窒素中で粉砕し、本発明に係わる異方性磁粉を得た。
さらに、かかる磁粉とエポキシ樹脂を磁粉含率が97重
量%となるように混合し、ボンド磁石用組成物を得た。
続いて、20kOeの磁場中でこれらの混合物をプレス
成形し、異方性ボンド磁石を得た。得られたボンド磁石
の磁気特性を表1に示す。Examples 1 to 3 As a starting material, an alloy having a composition of Nd12Dy3 Fe77B8 was produced in an arc melting furnace. The obtained alloy was coarsely ground to 50 to 500 μm using a stamp mill,
Grinding was performed for 90 minutes in a ball mill together with "Florinert (FC-72)", a perfluorocarbon inert liquid manufactured by Sumitomo 3M Limited. Thereafter, a compact was obtained by pressing in a magnetic field under conditions of an applied magnetic field strength of 20 kOe and a compacting pressure of 1 t/cm2. As shown in Table 1, such molded bodies are heated at temperatures of 600, 700, and 800°C.
Heat treatment was performed in vacuum for 1 hour and in Ar gas for 1 hour, and after the heat treatment, it was cooled to 400°C at a cooling rate of 4°C/min, and then rapidly cooled to room temperature. The obtained heat-treated molded body was pulverized in nitrogen using a hammer mill so that the average particle size became 0.5 to 100 μm, thereby obtaining anisotropic magnetic powder according to the present invention. Furthermore, such magnetic powder and epoxy resin were mixed so that the magnetic powder content was 97% by weight to obtain a composition for a bonded magnet. Subsequently, the mixture was press-molded in a magnetic field of 20 kOe to obtain an anisotropic bonded magnet. Table 1 shows the magnetic properties of the obtained bonded magnet.
【0010】比較例1〜2
熱処理温度を表1に示したように1080℃、380℃
とする以外は実施例1と全く同様の方法で異方性磁粉を
得、ボンド磁石を作製した。得られたボンド磁石の磁気
特性を表1に示した。Comparative Examples 1 and 2 The heat treatment temperatures were 1080°C and 380°C as shown in Table 1.
Anisotropic magnetic powder was obtained in exactly the same manner as in Example 1 except that a bonded magnet was produced. Table 1 shows the magnetic properties of the obtained bonded magnet.
【0011】比較例3
出発原料としてNd12Dy3 Fe77B8 の組成
の合金をアーク溶解炉によって作製した。得られた合金
をスタンプミルによって50〜500μmに粗粉砕し住
友スリーエム(株)社製のパーフルオロカーボン不活性
液体である「フロリナート(FC−72)」とともにボ
ールミルによって90分間粉砕を行い、平均粒子径が3
.43μmの異方性磁粉を得た。かかる磁粉とエポキシ
樹脂を磁粉含率が97重量%となるように混合し、ボン
ド磁石用組成物を得た。続いて、20kOeの磁場中で
これらの混合物をプレス成形し異方性ボンド磁石を得た
。得られたボンド磁石の磁気特性を表1に示す。Comparative Example 3 An alloy having a composition of Nd12Dy3 Fe77B8 was prepared as a starting material in an arc melting furnace. The obtained alloy was coarsely ground to 50 to 500 μm using a stamp mill, and then ground for 90 minutes using a ball mill with Fluorinert (FC-72), a perfluorocarbon inert liquid manufactured by Sumitomo 3M Limited, to determine the average particle size. is 3
.. Anisotropic magnetic powder of 43 μm was obtained. The magnetic powder and epoxy resin were mixed so that the magnetic powder content was 97% by weight to obtain a composition for a bonded magnet. Subsequently, the mixture was press-molded in a magnetic field of 20 kOe to obtain an anisotropic bonded magnet. Table 1 shows the magnetic properties of the obtained bonded magnet.
【0012】0012
【表1】[Table 1]
【0013】表1に示した実施例1〜3はいずれも比較
例1〜3に比べて、高い保磁力(iHc)と良好なエネ
ルギー積((BH)max ) を有しており、本発明
のように粉砕磁粉の磁化容易軸を一定方向に配向させた
後に低温で熱処理することによって良好な磁気特性の異
方性ボンド磁石用磁粉が得られることがわかる。[0013] All of Examples 1 to 3 shown in Table 1 have higher coercive force (iHc) and better energy product ((BH) max) than Comparative Examples 1 to 3, and the present invention It can be seen that magnetic powder for anisotropic bonded magnets with good magnetic properties can be obtained by orienting the axis of easy magnetization of crushed magnetic powder in a certain direction and then heat-treating it at a low temperature.
【0014】実施例4
磁粉の熱処理までは実施例2と全く同様の方法で熱処理
成形体を得、熱処理後の粉砕磁粉の平均粒子径が0.5
〜100μmになるようにハンマーミルによって窒素中
で粉砕した後に、かかる磁粉とナイロン12を磁粉含率
が93重量%となるように混合し、ニーダーで混練して
ペレット化した。かかるペレットを印加磁場15kOe
の磁場配向射出成形機で成形し、本発明に係わる異方性
ボンド磁石を得た。得られたボンド磁石の磁気特性を表
2に示す。Example 4 A heat-treated molded body was obtained in exactly the same manner as in Example 2 up to the heat treatment of the magnetic powder, and the average particle diameter of the crushed magnetic powder after the heat treatment was 0.5.
After pulverizing in nitrogen using a hammer mill to a particle size of ~100 μm, the magnetic powder and nylon 12 were mixed to have a magnetic particle content of 93% by weight, and the mixture was kneaded with a kneader to form pellets. Such pellets are subjected to an applied magnetic field of 15 kOe.
An anisotropic bonded magnet according to the present invention was obtained by molding using a magnetic field orientation injection molding machine. Table 2 shows the magnetic properties of the obtained bonded magnet.
【0015】比較例4
実施例4において用いる磁粉を比較例3と同様とする以
外は実施例4と全く同様の方法で異方性の射出成形ボン
ド磁石を得た。得られたボンド磁石の磁気特性を表2に
示す。Comparative Example 4 An anisotropic injection-molded bonded magnet was obtained in exactly the same manner as in Example 4, except that the magnetic powder used in Example 4 was the same as in Comparative Example 3. Table 2 shows the magnetic properties of the obtained bonded magnet.
【0016】[0016]
【表2】[Table 2]
【0017】実施例4と比較例4の結果から、射出成形
ボンド磁石を作製する場合においても、本発明の異方性
磁粉は良好な磁気特性を有することがわかる。From the results of Example 4 and Comparative Example 4, it can be seen that the anisotropic magnetic powder of the present invention has good magnetic properties even when producing injection molded bonded magnets.
【0018】[0018]
【発明の効果】以上、詳述したように本発明によれば、
高い保磁力と良好なエネルギー積を有した異方性磁粉を
、良好な生産性をもって製造することが可能であり、工
業的価値は極めて高いといえる。[Effects of the Invention] As detailed above, according to the present invention,
It is possible to produce anisotropic magnetic powder with high coercive force and good energy product with good productivity, and it can be said that the industrial value is extremely high.
Claims (6)
土類元素の少なくとも1種)10〜30原子%、ホウ素
:2〜28原子%、M(但し、MはFe、Co、Niの
少なくとも1種以上):65〜82原子%からなる合金
を平均粒子径が0.5〜50μmに粉砕した後に、磁場
中でプレス成形を行って磁場印加方向に磁化容易軸を揃
えた成形体を得、その後、真空中もしくは不活性ガス中
もしくは還元雰囲気中で400〜900℃の温度下で熱
処理を行い、該熱処理した成形体を粉砕することによっ
て得られる平均粒子径が0.5〜500μmの異方性ボ
ンド磁石用磁粉。Claim 1: R (wherein R is at least one rare earth element including yttrium) 10 to 30 at%, boron: 2 to 28 at%, M (however, M is at least one of Fe, Co, and Ni) (above): After pulverizing an alloy consisting of 65 to 82 at% to an average particle size of 0.5 to 50 μm, press molding is performed in a magnetic field to obtain a compact with the axis of easy magnetization aligned in the direction of magnetic field application, and then Anisotropic particles with an average particle size of 0.5 to 500 μm obtained by heat treatment at a temperature of 400 to 900 °C in vacuum, in an inert gas, or a reducing atmosphere, and pulverizing the heat-treated molded body. Magnetic powder for bonded magnets.
ることを特徴とする請求項1記載の異方性ボンド磁石用
磁粉。2. Magnetic powder for an anisotropic bonded magnet according to claim 1, having an average particle diameter of 0.5 to 100 μm.
土類元素の少なくとも1種)10〜30原子%、ホウ素
:2〜28原子%、M(但し、MはFe、Co、Niの
少なくとも1種以上):65〜82原子%からなる合金
を平均粒子径が0.5〜50μmに粉砕した後に、磁場
中でプレス成形を行って磁場印加方向に磁化容易軸を揃
えた成形体を得、その後、真空中もしくは不活性ガス中
もしくは還元雰囲気中で400〜900度の温度下で熱
処理を行い、該熱処理した成形体を平均粒子径が0.5
〜500μmとなるように粉砕することを特徴とする異
方性ボンド磁石用磁粉の製造方法。3. R (wherein R is at least one kind of rare earth element including yttrium) 10 to 30 atomic %, boron: 2 to 28 atomic %, M (however, M is at least one of Fe, Co, and Ni) (above): After pulverizing an alloy consisting of 65 to 82 at% to an average particle size of 0.5 to 50 μm, press molding is performed in a magnetic field to obtain a compact with the axis of easy magnetization aligned in the direction of magnetic field application, and then , heat treatment is performed at a temperature of 400 to 900 degrees in a vacuum, an inert gas, or a reducing atmosphere, and the heat-treated molded product has an average particle size of 0.5.
A method for producing magnetic powder for an anisotropic bonded magnet, which comprises pulverizing the powder to a particle size of 500 μm.
るように粉砕することを特徴とする請求項3記載の異方
性ボンド磁石用磁粉の製造方法。4. The method for producing magnetic powder for an anisotropic bonded magnet according to claim 3, wherein the magnetic powder is pulverized to have an average particle diameter of 0.5 to 100 μm.
〜3t/cm2 であることを特徴とする請求項3記載
の異方性ボンド磁石用磁粉の製造方法。[Claim 5] The applied pressure for press forming in a magnetic field is 0.5.
4. The method for producing magnetic powder for an anisotropic bonded magnet according to claim 3, wherein the magnetic powder is 3 t/cm2.
分であることを特徴とする請求項3記載の異方性ボンド
磁石用磁粉の製造方法。[Claim 6] The cooling rate after heat treatment is 0.5 to 6°C/
4. The method for producing magnetic powder for an anisotropic bonded magnet according to claim 3, wherein
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3142332A JPH04342104A (en) | 1991-05-17 | 1991-05-17 | Magnetic powder for anisotropic bonded magnet; its manufacture |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3142332A JPH04342104A (en) | 1991-05-17 | 1991-05-17 | Magnetic powder for anisotropic bonded magnet; its manufacture |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04342104A true JPH04342104A (en) | 1992-11-27 |
Family
ID=15312895
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3142332A Pending JPH04342104A (en) | 1991-05-17 | 1991-05-17 | Magnetic powder for anisotropic bonded magnet; its manufacture |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04342104A (en) |
-
1991
- 1991-05-17 JP JP3142332A patent/JPH04342104A/en active Pending
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