JPH0547528A - Manufacturing method of anisotropical rare earth bonded magnet - Google Patents
Manufacturing method of anisotropical rare earth bonded magnetInfo
- Publication number
- JPH0547528A JPH0547528A JP3225162A JP22516291A JPH0547528A JP H0547528 A JPH0547528 A JP H0547528A JP 3225162 A JP3225162 A JP 3225162A JP 22516291 A JP22516291 A JP 22516291A JP H0547528 A JPH0547528 A JP H0547528A
- Authority
- JP
- Japan
- Prior art keywords
- resin
- magnet
- powder
- rare earth
- fired body
- 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
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
- H01F1/0578—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 bonded together
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は希土類（イットリウムを
含む）−遷移金属（鉄を必須元素とする）−ホウ素系樹
脂結合永久磁石の製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rare earth (including yttrium) -transition metal (iron is an essential element) -boron resin-bonded permanent magnet.
【０００２】Ｎｄ−Ｆｅ−Ｂで代表される該磁石は高性
能と低コストを兼備するために、その生産量は急激に増
加し、ＳｍＣｏ磁石の生産量を超えるに至った。以下、
Ｎｄ−Ｆｅ−Ｂ磁石により希土類−遷移金属−ホウ素系
永久磁石を代表させて説明を行う。Since the magnet represented by Nd-Fe-B has both high performance and low cost, the production amount thereof has rapidly increased and exceeds the production amount of SmCo magnet. Less than,
A rare earth-transition metal-boron-based permanent magnet will be described as a representative of Nd-Fe-B magnets.
【０００３】[0003]
【従来の技術】現在生産されているＮｄ−Ｆｅ−Ｂ磁石
のほとんどは焼結法による異方性磁石と、樹脂を結合剤
として磁石粉末を結合した等方性ボンド磁石（プラスチ
ック磁石とも言われる）である。前者は高エネルギ積
を、後者は任意の形状を作り得また寸法精度が良好なこ
とを主たる特長としている。2. Description of the Related Art Most of the Nd-Fe-B magnets produced at present are anisotropic magnets produced by a sintering method and isotropic bonded magnets (also called plastic magnets) in which magnet powders are bound with a resin as a binder. ). The former is characterized by a high energy product, and the latter is characterized mainly by the fact that it can produce an arbitrary shape and has good dimensional accuracy.
【０００４】Ｎｄ−Ｆｅ−Ｂ系合金を急冷凝固（メルト
スピンと称される）させて高保磁力を有する急冷リボン
を得、これを粉砕し、熱処理し、続いて樹脂と粉末を混
合して成形し、最後に樹脂硬化させて用いるＭＱ１と称
される磁石粉末がＧＭ社から発表されている。この結果
製造される等方性ボンド磁石の最大エネルギ積は５〜１
０ＭＧＯｅ程度である。ＭＱ１により等方性ボンド磁石
は現在多量に生産されている。A Nd-Fe-B type alloy is rapidly solidified (called melt spin) to obtain a rapidly cooled ribbon having a high coercive force, which is crushed and heat-treated, and subsequently, a resin and a powder are mixed and molded. Finally, a magnet powder called MQ1 which is used after resin curing is announced by GM. The resulting isotropic bonded magnet has a maximum energy product of 5 to 1
It is about 0 MGOe. A large amount of isotropic bonded magnets is currently produced by MQ1.
【０００５】希土類合金は一般に脆く加工し難いので、
Ｎｄ−Ｆｅ−Ｂ焼結磁石は焼結後の研摩加工などに多大
なコストがかかっていいるのが現状である。これに対し
てボンド磁石は、寸法精度が極めて高く、機械的強度が
大であり、極めて薄いリング、円盤などの製作が容易で
あるなどの特徴を有する。近年ステッピングモーターや
ラジアルブラシレスモーターにおいて、径方向に放射状
に異方性を有する極薄リング（以下、ラジアルリングと
呼ぶ）の需要が高まっている。ラジアルリングを焼結で
作ると、焼結後や焼結後に所定の寸法に加工するときに
割れや欠けが起こり、また加工ができたとしてもその後
の組立作業においても割れや欠けが起こり、結果として
歩留まりが非常に低くなってしまう。このような欠点が
ないボンド磁石はリング磁石として適している。ただし
Ｎｄ−Ｆｅ−Ｂボンド磁石は等方性リング磁石にするの
は問題が無いが、後述する理由で（放射方向に異方性を
有する）ラジアルリング磁石にするのは多大なコストア
ップを忍ばなければならない。Since rare earth alloys are generally brittle and difficult to process,
The present situation is that the Nd-Fe-B sintered magnet requires a great deal of cost for polishing after sintering. On the other hand, the bonded magnet has features such as extremely high dimensional accuracy, high mechanical strength, and easy manufacture of an extremely thin ring or disk. In recent years, in stepping motors and radial brushless motors, there is an increasing demand for ultra-thin rings having radial anisotropy in the radial direction (hereinafter referred to as radial rings). If the radial ring is made by sintering, cracks and chips will occur after sintering and when it is machined to a predetermined size after sintering, and even if it can be machined, it will also crack and chip during subsequent assembly work. As a result, the yield becomes very low. A bonded magnet without such a defect is suitable as a ring magnet. However, there is no problem in using an isotropic ring magnet for the Nd-Fe-B bond magnet, but a radial ring magnet (having anisotropy in the radial direction) causes a large cost increase for the reason described later. I have to
【０００６】以下異方性ボンド磁石の従来技術を説明す
る。ボンド磁石の原料粉末は保磁力が高いことが要求さ
れる。なぜならば焼結磁石では焼結やその後の熱処理工
程で保磁力の増大が期待できるが、ボンド磁石ではその
期待ができないからである。例えばＳｍＣｏ5 やフェラ
イト磁石の原料粉末は組成調整により高保磁力が得られ
る。Ｓｍ2 Ｃｏ17磁石の代表であるＳｍ1 （Ｆｅ，Ｃ
ｏ，Ｃｕ，Ｚｒ）7.4 ではインゴットに溶体化処理、急
冷、８５０℃×１時間時効、徐冷を施すことによって高
保磁力が得られる。このインゴットを粉砕しても保磁力
の低下はあまり起こらない。The prior art of anisotropic bonded magnet will be described below. Raw material powder for bonded magnets is required to have high coercive force. This is because a sintered magnet can be expected to increase the coercive force in the sintering and subsequent heat treatment steps, but a bonded magnet cannot. For example, a raw material powder of SmCo 5 or a ferrite magnet can have a high coercive force by adjusting the composition. Sm 1 (Fe, C) which is a typical Sm 2 Co 17 magnet
o, Cu, Zr) 7.4 , a high coercive force can be obtained by subjecting the ingot to solution treatment, rapid cooling, aging at 850 ° C. for 1 hour, and slow cooling. Even if the ingot is crushed, the coercive force does not decrease much.
【０００７】Ｎｄ−Ｆｅ−Ｂ系磁石ではＧＭ社からＭＱ
３と称される製品が発表されており、これは、急冷凝固
粉末のホットプレス品を磁場中で一軸圧縮（ダイアプセ
ット）により異方性化したものである。その後この異方
性体を粉砕し、樹脂で固めて異方性ボンド磁石とするこ
とができる。しかしながら、異方性化可能なＭＱ３磁性
粉を生産するには手間がかかり、生産コストが大幅に上
昇すること、保磁力の温度係数が低いというＭＱ１の特
徴がＭＱ３では失われる問題がある。ちなみに、ＭＱ３
による異方性ボンド磁石は市販されていず、ＭＱ１，Ｍ
Ｑ２による等方性磁石のみが市販されているとの記事が
社団法人応用磁気学会主催、応用磁気セミナー「磁石材
料とそのプロセス」テキスト、第９５頁に掲載されてい
る。For Nd-Fe-B system magnets, MQ from GM
A product referred to as No. 3 has been announced, which is a hot-pressed product of rapidly solidified powder that is anisotropy by uniaxial compression (diapset) in a magnetic field. Then, this anisotropic body can be crushed and hardened with a resin to form an anisotropic bonded magnet. However, it takes a lot of time to produce the MQ3 magnetic powder that can be anisotropy, the production cost increases significantly, and the characteristic of MQ1 that the temperature coefficient of coercive force is low is lost in MQ3. By the way, MQ3
Anisotropic bonded magnets by
An article that only isotropic magnets by Q2 are on the market is published in the Applied Magnetics Seminar "Magnetic Materials and their Processes" text, page 95, sponsored by Japan Society for Applied Magnetics.
【０００８】Ｎｄ−Ｆｅ−Ｂ樹脂含浸磁石の製法の一つ
である前記ＭＱ３において使用される原料粉末は高保磁
力を有し、粉砕により保磁力低下が少ないのでボンド磁
石の製造に適する。一方、Ｎｄ−Ｆｅ−Ｂ焼結体も高保
磁力を有するが、焼結体を粉砕するとボンド磁石製造前
に保磁力や角型比が極端に低下する。The raw material powder used in MQ3, which is one of the manufacturing methods for Nd-Fe-B resin-impregnated magnets, has a high coercive force and is less likely to decrease in coercive force due to pulverization, and therefore is suitable for producing bonded magnets. On the other hand, the Nd-Fe-B sintered body also has a high coercive force, but when the sintered body is crushed, the coercive force and the squareness ratio are extremely lowered before the bonded magnet is manufactured.
【０００９】鋳造インゴットを熱間圧延しその後粉砕に
より粉末を得、これを樹脂で結合する方法も提案されて
いるが、これも粉砕時の保磁力低下が著しい。A method has also been proposed in which a cast ingot is hot-rolled and then pulverized to obtain a powder, which is then bonded with a resin, but this also causes a remarkable decrease in coercive force during pulverization.
【００１０】一方、インゴットを微粉砕して磁界中配向
成形し、これを通常焼結磁石の製造に用いられる焼結温
度よりも低温で焼成することにより、多孔質の焼成体を
作り、これに樹脂を含浸させて異方性ボンド磁石を製造
する方法も提唱されている（特開昭５９−２１９９０４
号）。On the other hand, an ingot is finely pulverized and orientation-molded in a magnetic field, and the ingot is fired at a temperature lower than the sintering temperature usually used for producing a sintered magnet to form a porous fired body. A method of producing an anisotropic bonded magnet by impregnating a resin has also been proposed (Japanese Patent Laid-Open No. 59-219904).
issue).
【００１１】[0011]
【発明が解決しようとする課題】したがって、ＭＱ３の
方法により作られたホットプレス体を一軸圧縮後粉砕
し、得られた粉末を樹脂で固める方法が現在異方性Ｎｄ
−Ｆｅ−Ｂボンド磁石をラジアルリングなどとして使用
するに十分な磁気特性と寸法精度を提供する唯一の方法
であるといえる。なぜならば、磁気特性の面では急冷に
より得られたリボンは微結晶から構成されるので、その
粉砕により保磁力低下は起こるが、その低下程度は僅か
であり、十分な磁気特性が得られ、また寸法精度の面で
は樹脂と磁性粉末を射出成形等の方法で加工して得た製
品の寸法精度は極めて高いからである。しかしながら、
この方法では急冷凝固−粉砕−ホットプレス−一軸圧縮
（ダイアプセット）−粉砕−樹脂との混合の工程が必要
であるために、著しいコスト高になり、このためこの方
法によるＮｄ−Ｆｅ−Ｂボンド磁石は原料コストが安い
という利点を活用できていず、サンプル出荷又は研究段
階で足踏みしているのが現状である。Therefore, a method of uniaxially compressing a hot-pressed body produced by the method of MQ3 and then pulverizing it and hardening the obtained powder with a resin is currently anisotropic Nd.
It can be said that this is the only method that provides sufficient magnetic characteristics and dimensional accuracy to use a —Fe—B bonded magnet as a radial ring or the like. Because, in terms of magnetic properties, the ribbon obtained by quenching is composed of fine crystals, so a reduction in coercive force will occur due to pulverization, but the degree of reduction is slight, and sufficient magnetic properties can be obtained. This is because in terms of dimensional accuracy, the dimensional accuracy of the product obtained by processing the resin and magnetic powder by a method such as injection molding is extremely high. However,
This method requires the steps of rapid solidification-crushing-hot pressing-uniaxial compression (diapset) -crushing-mixing with the resin, resulting in a significant cost increase, and therefore the Nd-Fe-B bond produced by this method. Magnets have not been able to take advantage of the low raw material cost, and are currently at the stage of sample shipping or research.
【００１２】また、圧粉成形体を低温で焼成した後樹脂
を含浸させる方法では、焼成温度が低いため充分な保磁
力が得られず例えば前記特開昭５９−２１９９０４号で
は８８０℃で０．５時間焼成後の保磁力が５．５ｋＯｅ
に留まっている実施例が示されている。これよりも高温
で焼成すれば保磁力は向上するが、温度が一般に行われ
ている焼結磁石の焼結温度に近くなり、焼成体の収縮が
大きくなるため、多孔質体にならなくなる。従って樹脂
の含浸が不可能となり、ボンド磁石は得られない。Further, in the method in which a powder compact is fired at a low temperature and then impregnated with a resin, a sufficient coercive force cannot be obtained because the firing temperature is low. For example, in JP-A-59-219904 described above, a coercive force of 0. Coercive force after firing for 5 hours is 5.5 kOe
Examples are shown which remain at. If it is fired at a temperature higher than this, the coercive force will be improved, but the temperature will be close to the sintering temperature of the generally used sintered magnet, and the shrinkage of the fired body will increase, so that it will not become a porous body. Therefore, impregnation with the resin becomes impossible, and a bonded magnet cannot be obtained.
【００１３】ところで、異方性希土類ボンド磁石の主要
用途であるステッピングモーター、ブラシレスモーター
などのローターやステーターなどに使用される希土類異
方性ボンド磁石には異方性化が容易であり、１０〜１５
ＭＧＯｅの最大エネルギ積が得られるＳｍ2 Ｃｏ17磁石
が用いられている。ボンド磁石は機械加工費を節約でき
るため、全コストに対して加工コストの占める割合の大
きい小型精密製品用磁石として重要さを増している。も
し原料コストの高いＳｍやＣｏを安いＮｄとＦｅで置き
換えることができれば、ボンド磁石のコストは大幅に低
下し、需要は飛躍的に伸びることが期待される。By the way, rare earth anisotropic bonded magnets used for rotors and stators of stepping motors, brushless motors, etc., which are the main uses of anisotropic rare earth bonded magnets, can easily be made anisotropic. 15
An Sm 2 Co 17 magnet is used which gives the maximum energy product of MGOe. Since bonded magnets can save machining costs, they are becoming more important as magnets for small precision products, which account for a large proportion of the total cost. If Sm and Co, which have a high raw material cost, can be replaced with cheap Nd and Fe, the cost of the bonded magnet will be significantly reduced, and it is expected that demand will increase dramatically.
【００１４】本発明者は上記従来技術を詳しく検討し、
粉末の状態で高い保磁力を得ることに固執する限り異方
性ＳｍＣｏボンド磁石を代替できるＮｄ−Ｆｅ−Ｂボン
ド磁石を提供できないことに気が付いた。そして本発明
者等は圧粉体を焼成後、樹脂を含浸させる方法を改良
し、充分な保磁力の得られる方法を見出した。The present inventor has examined the above-mentioned conventional technique in detail,
We have found that we cannot provide Nd-Fe-B bonded magnets that can replace anisotropic SmCo bonded magnets as long as we stick to obtaining high coercive force in the powder state. Then, the present inventors have improved the method of impregnating the resin after firing the green compact and found a method of obtaining a sufficient coercive force.
【００１５】[0015]
【課題を解決するための手段】本発明は、ＮｄまたはＰ
ｒを必須元素とする希土類Ｒ（Ｙを含む）、Ｆｅを必須
元素とする遷移金属Ｔ、およびホウ素を基本成分とする
粉末に焼結阻止剤または気化剤を混合するか、あるいは
前記粉末の表面を酸化した後、前記粉末を磁界中で圧縮
して圧粉体を作り、該圧粉体を焼成して開放気孔を有す
る異方性焼成体を作り、該異方性焼成体に４００℃以上
かつ１０００℃以下の温度で熱処理を施した後、前記開
放気孔に樹脂を含浸後、前記樹脂を硬化することを特徴
とする異方性希土類ボンド磁石の製造方法であり、好ま
しくは、樹脂を含浸し該樹脂を硬化した後もしくは、該
樹脂を硬化し前記焼成体の表面を機械加工した後に前記
焼成体の表面に保護皮膜を形成し、さらに好ましくは、
焼結阻止剤がＤｙ又はＴｂを１０ａｔ％以上含むことを
特徴とする。The present invention is based on Nd or P
A rare earth R (including Y) containing r as an essential element, a transition metal T containing Fe as an essential element, and a powder containing boron as a basic component, mixed with a sintering inhibitor or a vaporizing agent, or on the surface of the powder. After the powder is oxidized, the powder is compressed in a magnetic field to form a green compact, and the green compact is fired to form an anisotropic fired body having open pores. And heat-treating at a temperature of 1000 ° C. or lower, impregnating the open pores with a resin, and then curing the resin. A method for producing an anisotropic rare earth bonded magnet, which is preferably impregnating with a resin After curing the resin, or after curing the resin and machining the surface of the fired body to form a protective film on the surface of the fired body, more preferably,
It is characterized in that the sintering inhibitor contains 10 at% or more of Dy or Tb.
【００１６】以下、Ｎｄ−Ｆｅ−Ｂ磁石に例を取って本
発明の構成を説明する。本発明では、粉末にあらかじめ
焼結阻止剤を混合し、その後磁界中配向成形を行う。焼
結阻止剤としては、ＢＮ，ＴｉＢ2 ，Ａｌ2 Ｏ3 ，Ｇａ
2 Ｏ3 ，ＳｉＯ2 ，などの酸化物、ＮｄＦ3 ，ＴｂＦ
3 ，ＤｙＦ3 ，等のフッ化物、ＮｄＣｌ3，ＴｂＣｌ
3 ，ＤｙＣｌ3 等の塩化物、その他のハロゲン化物、オ
キシハロゲン化物などを挙げることができる。これらは
いずれも焼成中に溶融を全く起こさないか、一部溶融す
る程度に留まり、これが焼成体内部に一様に分散するこ
とにより、焼成時に生じる希土類金属がｒｉｃｈな液相
の流動を妨げ、高温焼成を行っても焼成体が大きく収縮
しなくなる。その結果焼成温度が従来よりも高くでき、
高い保磁力が得られるようになる。その添加量は２０重
量％以下が好ましい。その添加量は０．１重量％未満で
は効果が少なく、２０重量％以上では残留磁化Ｂｒ及び
最大エネルギ（ＢＨ）max が低下する。The structure of the present invention will be described below by taking an Nd-Fe-B magnet as an example. In the present invention, the powder is mixed with a sintering inhibitor in advance, and then orientation molding is performed in a magnetic field. Examples of sintering inhibitors include BN, TiB 2 , Al 2 O 3 , and Ga.
Oxides such as 2 O 3 and SiO 2 , NdF 3 and TbF
Fluoride such as 3 , DyF 3 , NdCl 3 , TbCl
Examples thereof include chlorides such as 3 , DyCl 3 and other halides, oxyhalides and the like. All of these do not melt at all during firing, or remain only partially melted, and are uniformly dispersed inside the fired body, whereby the rare earth metal generated during firing hinders the flow of the rich liquid phase, Even if high temperature firing is performed, the fired body does not significantly contract. As a result, the firing temperature can be higher than before,
A high coercive force can be obtained. The addition amount is preferably 20% by weight or less. If the addition amount is less than 0.1% by weight, the effect is small, and if it is 20% by weight or more, the residual magnetization Br and the maximum energy (BH) max decrease.
【００１７】混合の方法は、磁石微粉砕粉にこれらの阻
止剤を添加し、ボールミルやロッキングンミキサー等で
混合してもよく、また微粉砕前の磁石原料粉末にあらか
じめこれらの阻止剤を添加しておき、その後微粉砕を行
ってもよい。またこれらの阻止剤は複数種を共添加する
ことができる。As the mixing method, these inhibitors may be added to the finely pulverized magnet powder and mixed by a ball mill, a rocking mixer, or the like, or these inhibitors may be added to the magnet raw material powder before fine pulverization in advance. Then, fine pulverization may be performed thereafter. Further, a plurality of these inhibitors can be added together.
【００１８】焼結阻止剤の代わりに、焼成前の圧粉体中
にあらかじめ大きい（最密充填の粉末間の隙間以上の）
空孔を生成しておくことも本発明の多孔質焼成体を作成
するのに有効である。このように大きな空孔を作成する
には、例えば磁性粉中にカンファーなどの焼成温度以下
で気化する物質の粉末を混合しておき、加熱によりカン
ファーを気化させる。このようにして生成された空孔は
より高温の焼成によっても消滅せず、焼成体中に残留
し、樹脂含浸に必要な気孔として働く。リンや硫黄やス
ズも焼成中に気化蒸発して、空孔を残留させるので同様
の効果が得られる。焼結阻止剤を添加する代わりに、粉
末を酸化させ、希土類元素を主体とする酸化物を形成さ
せた粉末を使用してもよい。In place of the sintering inhibitor, a large amount (previously larger than the gap between the close-packed powders) is formed in the green compact before firing.
Generating pores is also effective in producing the porous fired body of the present invention. In order to create such large pores, for example, powder of a substance that vaporizes at a firing temperature such as camphor or the like is mixed in magnetic powder, and the camphor is vaporized by heating. The voids generated in this way do not disappear even when fired at a higher temperature, remain in the fired body, and act as pores necessary for resin impregnation. Since phosphorus, sulfur, and tin also vaporize and evaporate during firing, leaving vacancies, the same effect can be obtained. Instead of adding the sintering inhibitor, a powder obtained by oxidizing the powder to form an oxide mainly composed of a rare earth element may be used.
【００１９】本発明の焼成体は磁場中圧縮と焼成の工程
を経たものであるが、従来の焼結体のように１００％近
い高密度にしないで、磁石粉末自体は全体で結合されス
ケルトンを作っているが、その内側には連続気孔が残っ
ている程度に焼成したものである。「焼成」とは磁石粉
末どうしは冶金的に結合しているが液体が侵入できる大
きさの気孔が残っている程度に加熱されたものを指す。
これに対して「圧粉体」は連続気孔が残っているが、粉
末どうしは主として機械的に付着しているにすぎない。
また「焼結体」は一般にＮｄリッチ相の液相の主相補修
効果を発揮させかつ結合を十分にするため、緻密な焼結
体となり連続孔は消失しているか、存在しても樹脂の含
浸は表面付近に限られ、製品内部には達していないた
め、その強度、加工性などは事実上変化しない。より具
体的には、Ｎｄ−Ｆｅ−Ｂ焼結磁石では少しでも磁気特
性を向上させるため焼結体の密度をできる限り高くする
ことが望ましく、密度が７．２ｇ／ｃｍ3 （真密度の９
６％）以下の焼結体は製造されていない。製造上このよ
うな焼結体は不良品として扱われている。これに対し
て、本発明法で得られた焼結体はその密度が真密度の９
５％以下であることが望ましい。これ以上の密度である
と樹脂の含浸はほとんどできなくなる。密度は９３％以
下であることがより望ましく、９２％以下であればさら
に望ましい。The fired body of the present invention has been subjected to the steps of compression and firing in a magnetic field. However, the magnetic powder itself is combined as a whole to form a skeleton without being made to have a high density close to 100% unlike the conventional sintered body. It is made, but it is fired to the extent that continuous pores remain inside. "Baking" refers to a method in which magnet powders are metallurgically bonded to each other but heated to such an extent that pores of a size that allows liquid to enter remain.
On the other hand, the “compacted powder” has continuous pores, but the powders are mainly mechanically adhered to each other.
In addition, the "sintered body" generally exhibits a main complementary repair effect of the liquid phase of the Nd-rich phase and has sufficient bonding, so that it becomes a dense sintered body and the continuous pores disappear, or even if the resin is present, Since the impregnation is limited to the vicinity of the surface and does not reach the inside of the product, its strength, workability, etc. are virtually unchanged. More specifically, in the Nd-Fe-B sintered magnet, it is desirable to increase the density of the sintered body as high as possible in order to improve the magnetic characteristics even a little, and the density is 7.2 g / cm 3 (the true density of 9
6%) or less of the sintered body has not been manufactured. Such a sintered body is treated as a defective product in manufacturing. On the contrary, the density of the sintered body obtained by the method of the present invention is 9% of the true density.
It is preferably 5% or less. If the density is higher than this, impregnation of the resin becomes almost impossible. The density is more preferably 93% or less, and further preferably 92% or less.
【００２０】続いて「スケルトン」と「開放気孔」につ
いて説明する。Ｎｄ−Ｆｅ−Ｂ粉末の焼成温度が高くな
るにつれて、粉末間の相互拡散が始まり、収縮が起こる
ようになる。収縮が起こる前は圧粉成形体の気孔は相互
に連続しかつ外部に開放されているが、収縮が始まると
孤立した気孔が多くなり、相互にかつ／または外部に連
通した気孔は少なくなる。このような過程に伴って粉末
は相互に一層密に結合し連続ネットワーク構造を作る。
Ｎｄ−Ｆｅ−Ｂ磁石の標準的な組成（例：Ｎｄ15Ｆｅ77
Ｂ8 、真密度７．６ｇ／ｍ3 ）では、約１０６０℃で密
度は７．３ｇ／ｍ3 以上になり空孔が互いに閉じるとと
もに、連続ネットワーク構造は消失して全方向で連続し
たソリッドの物質となる。それより低温では空孔の多く
は焼成体の外部と連絡しており、水などに浸漬すると泡
を発生して水がしみ込むのが認められる。本発明の磁石
ではこの状態で焼成を留め、外部に開放した気孔から樹
脂を含浸させる。これ以上焼成を進めると、閉じた気孔
のみを有する連続ネットワーク構造となる。かかる構造
も従来の焼結体としては不良品であり、焼成体の範疇に
入るが、樹脂の含浸には不適切である。したがって、本
発明で言う「スケルトン」とは粉末が一体構造を作って
いるが、その中には開放気孔が存在している状態を指
し、「開放気孔」とは焼成体の表面に孔の入口があり、
外部に開いた気孔である。このような開放気孔を有する
焼成体に樹脂を含浸させることによって焼成体が全体的
に強化される。Next, "skeleton" and "open pore" will be described. As the firing temperature of the Nd-Fe-B powder increases, interdiffusion between the powders starts and shrinkage occurs. Before the shrinkage occurs, the pores of the green compact are continuous with each other and open to the outside, but when the shrinkage starts, the number of isolated pores increases, and the pores communicating with each other and / or the outside decrease. With such a process, the powders are more closely bonded to each other to form a continuous network structure.
Standard composition of Nd-Fe-B magnets (eg Nd 15 Fe 77
B 8 and true density of 7.6 g / m 3 ) at about 1060 ° C., the density becomes 7.3 g / m 3 or more, the holes close to each other, the continuous network structure disappears, and the solid structure is continuous in all directions. Become a substance. At lower temperatures, many of the pores are in contact with the outside of the fired body, and when immersed in water or the like, bubbles are generated and it is observed that water permeates. In the magnet of the present invention, firing is stopped in this state, and the resin is impregnated through the pores opened to the outside. Further calcination results in a continuous network structure having only closed pores. Such a structure is also a defective product as a conventional sintered body and falls within the category of a fired body, but it is unsuitable for resin impregnation. Therefore, the "skeleton" referred to in the present invention refers to a state in which the powder forms an integral structure, but there are open pores therein, and "open pores" means the entrance of pores on the surface of the fired body. There is
It is an open pore. By impregnating a fired body having such open pores with a resin, the fired body is strengthened as a whole.
【００２１】本発明の焼成体は多孔質であり、気孔率
（全空孔体積の焼成体全体積に対する百分率）が５％以
上４０％以下、好ましくは７％以上３４％以下、より好
ましくは８％以上２０％以下のものであることが望まし
い。空孔率が大きすぎると最大エネルギ積（ＢＨ）max
が低下し、小さいと樹脂の含浸が困難になり、樹脂量が
少ないと強度低下や靭性低下が起こる。全空孔体積に対
する開放気孔の体積の割合を有効気孔率という。本発明
の焼成体では有効気孔率が高い程よい。The fired body of the present invention is porous and has a porosity (percentage of total pore volume relative to the total volume of the fired body) of 5% or more and 40% or less, preferably 7% or more and 34% or less, more preferably 8%. % Or more and 20% or less is desirable. If the porosity is too large, the maximum energy product (BH) max
When the amount of resin is small, it becomes difficult to impregnate the resin, and when the amount of resin is small, strength and toughness decrease. The ratio of the volume of open pores to the total pore volume is called effective porosity. In the fired body of the present invention, the higher the effective porosity, the better.
【００２２】続いて樹脂の含浸を説明する。使用できる
樹脂の種類は２種類ある。その一つは室温〜２００℃に
昇温して硬化（キュアリング）させる熱硬化性樹脂で
あり、他の一つはナイロン樹脂で代表される５０℃〜２
００℃の温度で液状になる熱可塑性樹脂である。これ
らの樹脂の中で室温から磁石の特性に変化を与える温
度、例えば２００℃以下の温度で焼成体に含浸可能な樹
脂なら何でもよい。Next, the resin impregnation will be described. There are two types of resins that can be used. One of them is a thermosetting resin which is heated to room temperature to 200 ° C. to cure (curing), and the other is a thermosetting resin represented by a nylon resin of 50 ° C. to 2
It is a thermoplastic resin that becomes liquid at a temperature of 00 ° C. Of these resins, any resin can be used as long as it can impregnate the fired body at a temperature that changes the magnet characteristics from room temperature, for example, a temperature of 200 ° C. or less.
【００２３】熱硬化性樹脂としては、エポキシ樹脂、
フェノール樹脂、フラン樹脂、ウレタン樹脂、不飽和ポ
リエステル樹脂などの１液または２液混合型樹脂を使用
することができる。これらの樹脂は溶媒により粘度を調
製後、含浸を行い、室温〜約１２０℃で硬化させて使用
する。樹脂としては、流動性が大きく、粘度の調節が容
易であり、温度を変えることにより硬化時間を調整で
き、硬化による寸法変化が小さい等の条件を満たすもの
が好ましい。As the thermosetting resin, epoxy resin,
One-part or two-part mixture type resins such as phenol resin, furan resin, urethane resin and unsaturated polyester resin can be used. These resins are used after being adjusted in viscosity with a solvent, impregnated, and cured at room temperature to about 120 ° C. It is preferable that the resin satisfy the conditions that it has a large fluidity, the viscosity can be easily adjusted, the curing time can be adjusted by changing the temperature, and the dimensional change due to the curing is small.
【００２４】熱可塑性樹脂としては、メチルメタアク
リレート、スチレン、アクリロニトリル、ポリエステ
ル、塩化ビニリデン、６．６ナイロン、６ナイロン、ジ
アリルフタレート、ｎ−ブチルメタクリレート等の固形
ポリマー、およびそれらの液状プレポリマーおよびモノ
マーを使用することができる。固形ポリマーは昇温によ
り流動性を与えた後、含浸を行い、冷却固化させる。液
状プレポリマーおよびモノマーはベンゾイルパーオキサ
イド、ｔーブチルベンゾエイドなどの重合触媒を添加
し、室温付近にて含浸を行った後、８０℃付近にて加熱
して重合固化をさせる。あるいは触媒を添加せずに液状
プレポリマーまたはモノマーの含浸を行い、γ線を照射
して重合固化させる。必要に応じて液状プレポリマーま
たはモノマーに、ジメチルアニリンなどの重合促進剤、
ハイドロキノンなどの禁止剤、トリメチルプロパントリ
メタアクリレートなどの架橋剤、ジオクチルフタレート
などの可塑剤、γ−メタアクリルオキシプロピルトリメ
トキシシランなどのカップリング剤を添加することがで
きる。これらの熱可塑性樹脂は、含浸、重合が容易であ
ること、磁石焼成体と化学反応を起こさないことなどの
条件を満たすものが好ましい。Examples of the thermoplastic resin include solid polymers such as methylmethacrylate, styrene, acrylonitrile, polyester, vinylidene chloride, 6.6 nylon, 6 nylon, diallyl phthalate and n-butyl methacrylate, and liquid prepolymers and monomers thereof. Can be used. The solid polymer is fluidized by heating and then impregnated and solidified by cooling. The liquid prepolymer and the monomer are added with a polymerization catalyst such as benzoyl peroxide and t-butylbenzoide, impregnated at around room temperature, and then heated at around 80 ° C. to polymerize and solidify. Alternatively, a liquid prepolymer or a monomer is impregnated without adding a catalyst, and is irradiated with γ-ray to polymerize and solidify. A liquid prepolymer or monomer, if necessary, a polymerization accelerator such as dimethylaniline,
An inhibitor such as hydroquinone, a crosslinking agent such as trimethylpropanetrimethacrylate, a plasticizer such as dioctylphthalate, and a coupling agent such as γ-methacryloxypropyltrimethoxysilane can be added. It is preferable that these thermoplastic resins satisfy the conditions that they are easily impregnated and polymerized, and that they do not cause a chemical reaction with the magnet fired body.
【００２５】「含浸」とは焼成体の開放気孔の入口から
該気孔内に流入した樹脂の状態を言う。含浸により体積
百分率で好ましくは２０％以上、より好ましくは４０％
以上％、最も好ましくは６０％以上の開放気孔に樹脂を
含浸する。含浸率が小さいと強度低下が起こる他に、空
孔中の空気による希土類の酸化によって腐食が起こる。"Impregnation" refers to the state of the resin that has flowed into the pores from the inlet of the open pores of the fired body. By impregnation, the volume percentage is preferably 20% or more, more preferably 40%.
% Or more, and most preferably 60% or more of the open pores are impregnated with resin. If the impregnation rate is small, the strength will decrease, and corrosion will occur due to the oxidation of the rare earth element by the air in the pores.
【００２６】本発明は磁石の化学組成には全く限定され
ず、永久磁石としての性能を発揮できるものであればあ
らゆる化学組成について本発明を適用することができ
る。係る化学組成を示す特許文献として特開昭５９−８
９４０１号、５９−２１７００３号、６２−２９１９０
１号、および特開平２−１１９１０５号を挙げる。コス
トと性能の面からは下記の化学組成が好ましい。 Ｎｄ＝１３〜１７ａｔ％，Ｂ＝６〜９ａｔ％，Ｃｏ＝０
〜３０ａｔ％，Ｄｙ＝０〜３ａｔ％，Ａｌ＝０．１〜４
ａｔ％，Ｖ＝０〜６ａｔ％，Ｎｂ＝０〜４ａｔ％，Ｍｏ
＝０〜４ａｔ％，Ｇａ＝０〜２ａｔ％，Ｃｒ＝０〜４ａ
ｔ％，Ｃｕ＝０ａｔ％The present invention is not limited to the chemical composition of the magnet, and the present invention can be applied to any chemical composition as long as it can exhibit the performance as a permanent magnet. As a patent document showing such a chemical composition, JP-A-59-8
9401, 59-217003, 62-29190.
No. 1 and JP-A No. 2-119105. The following chemical composition is preferable in terms of cost and performance. Nd = 13 to 17 at%, B = 6 to 9 at%, Co = 0
-30at%, Dy = 0-3at%, Al = 0.1-4
at%, V = 0 to 6 at%, Nb = 0 to 4 at%, Mo
= 0 to 4 at%, Ga = 0 to 2 at%, Cr = 0 to 4 a
t%, Cu = 0 at%
【００２７】なお希土類元素のうちＰｒは、Ｎｄの一部
または全部に置換できる。また、コスト低減の目的で、
ジジムやミッシュメタルをＮｄ原料の一部または全部と
して使用可能である。Of the rare earth elements, Pr can be substituted for part or all of Nd. Also, for the purpose of cost reduction,
Didymium or misch metal can be used as a part or all of the Nd raw material.
【００２８】以上のように焼成体に切削性及び接着性が
優れた樹脂を含浸することによりそのままで製品として
使用可能である。As described above, by impregnating the fired body with a resin having excellent cutting property and adhesiveness, it can be used as a product as it is.
【００２９】本発明の磁石は機械加工により最表面が仕
上されて使用されることがある。通常のボンド磁石は射
出成形又は圧縮成形により作られ、金型の寸法そのもの
の大きさであるから、寸法精度が非常に良い。本発明の
焼成体からなる磁石は焼成中の寸法変化があるので、場
合により機械加工を行い寸法精度を高める必要がある。
機械加工は通常の金属又はセラミックス加工用の平面研
削盤、両面研削盤、ボール盤、旋盤、フライス盤、セン
タレスグラインダーなどを用い、穴開け、研削、切削な
どを必要に応じて容易に行うことができる。場合によっ
ては切断のためダイアモンドカッタ等も用、また刃物と
して、通常のＮｄ−Ｆｅ−Ｂ焼結体加工のようにダイヤ
モンドや硬質砥石を使用する。The magnet of the present invention may be used after finishing the outermost surface by machining. A normal bonded magnet is made by injection molding or compression molding, and has the very same size as the size of the mold, so that the dimensional accuracy is very good. Since the magnet made of the fired body of the present invention has a dimensional change during firing, it is necessary to perform machining to increase the dimensional accuracy in some cases.
Machining can be carried out easily by using a general surface grinder, double-side grinder, boring machine, lathe, milling machine, centerless grinder, etc. for machining metal or ceramics, if necessary. Depending on the case, a diamond cutter or the like is also used for cutting, and a diamond or a hard grindstone is used as a blade as in the usual Nd-Fe-B sintered body processing.
【００３０】エポキシ樹脂などの切削性の良い樹脂を使
用すると、本発明の磁石は極めて良好な加工性を示し、
高速度鋼、超硬等の切削刃物を使用して能率よく低コス
トで切削できる。かかる機械加工を行うと表面の樹脂結
合やスケルトンの一部が壊れた加工劣化層が表面に存在
する。それ以外の焼成体全体ではスケルトン構造は壊れ
ずに樹脂が主相粒子を接着している。When a resin having good machinability such as epoxy resin is used, the magnet of the present invention exhibits extremely good workability,
High-speed steel and carbide cutting tools can be used for efficient and low-cost cutting. When such machining is performed, a resin-degraded layer on the surface or a processing-degraded layer in which a part of the skeleton is broken is present on the surface. In the other fired bodies as a whole, the skeleton structure is not broken and the resin bonds the main phase particles.
【００３１】また、本発明の焼成体磁石の表面あるいは
その最表面を機械加工した磁石の表面に防食あるいは粉
末飛散防止のための皮膜を形成して使用することがあ
る。防食は、表面に露出したスケルトンの酸化およびス
ケルトンに充填された樹脂を通って空気や水分が焼成体
内部に侵入して磁石が錆びることを防ぐためのものであ
る。また粉末飛散防止は相手材と接触、摺動あるいはス
ラスト接触することによりまた冷却のためのファンによ
る送風により磁石粉末が脱落し飛散することを防止する
ものである。Further, a film for corrosion protection or powder scattering prevention may be formed on the surface of the fired magnet of the present invention or the surface of the magnet whose outermost surface is machined for use. Anticorrosion is to prevent the magnets from rusting due to the air and moisture entering the inside of the fired body through the oxidation of the skeleton exposed on the surface and the resin filled in the skeleton. Further, the prevention of powder scattering is to prevent the magnet powder from falling off and scattering due to contact with, sliding contact with, or thrust contact with a mating member, or by blowing with a fan for cooling.
【００３２】これらの皮膜は従来の焼結磁石あるいは樹
脂含浸磁石に使用されている、クロメート皮膜、Ｎｉメ
ッキ、樹脂塗装皮膜（エポキシ樹脂、フラン樹脂、シリ
コン樹脂など）、電着塗装皮膜などであってよい。皮膜
の厚みは、例えば、Ｎｉメッキの場合は３〜３０μｍ、
樹脂塗装皮膜の場合は５〜２００μｍである。These coatings are chromate coatings, Ni platings, resin coatings (epoxy resin, furan resin, silicone resin, etc.), electrodeposition coatings, etc. used in conventional sintered magnets or resin-impregnated magnets. You may. The thickness of the film is, for example, 3 to 30 μm in the case of Ni plating,
In the case of a resin coating film, it is 5 to 200 μm.
【００３３】いずれの皮膜も樹脂含浸、感想後、もしく
は寸法調整のための加工を施した後に形成させる。樹脂
塗装皮膜は液状塗料を配合調整後、スプレーにより表面
に吹きつけて形成させる。Any film is formed after impregnation with a resin, impression, or after processing for size adjustment. The resin coating film is formed by spraying the surface of the resin coating with a spray after mixing and adjusting the liquid coating material.
【００３４】含浸された樹脂に付着した樹脂皮膜は、樹
脂どうしの結合により接着強度が高いので、スケルトン
が多少腐食しても皮膜がはがれない利点を有する。Ｎｉ
メッキは、加工を施さないものについては表面の大部分
が非導電性の含浸樹脂によっておおわれているため、例
えば予め無電解めっき層を付与して表面に導電性を施し
た後、電解メッキまたは無電解メッキにより所定の膜厚
を形成させる。無電解めっきのみによって膜を形成させ
てもよいが、この場合５μｍ以上の厚膜化が難しい。し
たがって耐食性がやや劣る。The resin film adhered to the impregnated resin has a high adhesive strength due to the bonding of the resins, and therefore has the advantage that the film does not peel off even if the skeleton corrodes to some extent. Ni
As for the plating, most of the non-processed surface is covered with a non-conductive impregnating resin.For example, after applying an electroless plating layer in advance to make the surface conductive, electrolytic plating or no plating is performed. A predetermined film thickness is formed by electrolytic plating. The film may be formed only by electroless plating, but in this case, it is difficult to increase the film thickness to 5 μm or more. Therefore, the corrosion resistance is slightly inferior.
【００３５】一方、加工を施したものについては、表面
はスケルトンの金属地肌が露出している部分と樹脂が露
出している部分の二つの部分から構成されている。Ｎｉ
メッキは無電解めっきにより樹脂部にも導電性を付与し
て、加工を施さないものと同様の手法により行うか、ス
ケルトン部の導電性を利用して直接メッキを行うことも
できる。スケルトン部に形成されたメッキ層は成長する
に伴い、次第に相互に合体して樹脂層もおおうようにな
る。On the other hand, in the case of the processed product, the surface is composed of two parts, that is, the part where the metal surface of the skeleton is exposed and the part where the resin is exposed. Ni
The electroless plating may be used to impart conductivity to the resin portion, and the plating may be performed by the same method as that used for non-processing, or the conductivity of the skeleton portion may be used for direct plating. As the plating layer formed on the skeleton portion grows, it gradually merges with each other to cover the resin layer.
【００３６】電着塗装皮膜についてもＮｉメッキと同
様、加工を施さないものについては活性化処理により樹
脂部にも導電性を与えてから行うか、皮膜を導電性のス
ケルトン部から優先的に形成、成長させ全面皮膜でおお
う。As with the Ni plating, the electrodeposition coating film is not processed, but the resin part is made conductive by activation treatment, or the film is preferentially formed from the conductive skeleton part. , Let it grow and cover it with the entire film.
【００３７】続いて本発明に係る異方性永久磁石を製造
する好ましい方法は、Ｎｄ−Ｆｅ−Ｂ合金の平均粒径２
μｍ以上２０μｍ以下での粉末に前記焼結阻止剤又は気
化剤を０．１〜２０重量％の範囲内で添加混合後、ある
いは粉末を酸化雰囲気内で放置又は混合し、表面を酸化
後、磁界中で配向、圧縮成形し、この成形体を５００℃
以上かつ１１４０℃以下の温度に加熱して、焼成体を作
り、この焼成体に４００℃以上かつ１０００℃以下の温
度で熱処理を施した後、樹脂を含浸することを特徴とす
る。Subsequently, a preferred method for producing the anisotropic permanent magnet according to the present invention is to use an Nd-Fe-B alloy having an average particle size of 2
After adding and mixing the sintering inhibitor or vaporizer within a range of 0.1 to 20% by weight to the powder having a particle size of μm or more and 20 μm or less, or leaving or mixing the powder in an oxidizing atmosphere to oxidize the surface, a magnetic field is applied. Oriented and compression molded in this
It is characterized in that it is heated to a temperature not lower than 1140 ° C. and below to form a fired body, and the fired body is subjected to heat treatment at a temperature not lower than 400 ° C. and not higher than 1000 ° C. and then impregnated with a resin.
【００３８】以下上記方法を説明する。原料粉の組成は
上述のとおりである。原料粉の粒径が２μｍより小さい
とその酸化が著しく、一方２０μｍより大きいと成形が
困難になることに加えて保磁力が低下する。The above method will be described below. The composition of the raw material powder is as described above. If the particle size of the raw material powder is smaller than 2 μm, its oxidation is remarkable, while if it is larger than 20 μm, molding becomes difficult and the coercive force is lowered.
【００３９】通常のＮｄ−Ｆｅ−Ｂ磁石粉末は粉砕によ
り保磁力が大幅に低下するが、本発明においては係る通
常の粉末を原料粉末として使用することができる。係る
原料粉を通常の方法で磁界中配向、圧縮成形する。配向
は通常、好ましくは５ｋＯｅ〜１５ｋＯｅの磁界中で行
う。磁界の強さは５ｋＯｅ以下では配向はよくなく、１
５ｋＯｅ以上の磁界発生は高コストで実際的でない。加
圧力は０．２ｔ／ｍ2〜５ｔ／ｍ2 の範囲内であること
が好ましい。加圧力が０．２ｔ／ｍ2 以下では成形体の
取り扱い困難であり、５ｔ／ｍ2 以上は金型の寿命が問
題となる。Ｎｄ−Ｆｅ−Ｂ系磁石合金を平均粒径３〜４
μｍに粉砕後、１〜４ｔ／ｍ2 の圧力下で圧粉体を作成
すると、この圧粉体は手で容易に割れるほど非常に脆
い。Ｎｄリッチ相は軟質金属相であり、圧粉時に主相と
圧着し、主相と結合している可能性もある。しかし、こ
の圧粉体の強度が非常に低いことは、その割合が無視し
えるほど非常に少ないか、またはその接着力が結合と呼
ばれるほど強いものではないことを示している。Although the coercive force of ordinary Nd-Fe-B magnet powder is significantly reduced by pulverization, such ordinary powder can be used as a raw material powder in the present invention. The raw material powder is oriented in a magnetic field and compression-molded by a usual method. Alignment is usually performed in a magnetic field of preferably 5 kOe to 15 kOe. If the magnetic field strength is less than 5 kOe, the orientation is not good, and 1
Generating a magnetic field of 5 kOe or more is expensive and impractical. Pressure is preferably in the range of 0.2t / m 2 ~5t / m 2 . When the applied pressure is 0.2 t / m 2 or less, it is difficult to handle the molded product, and when it is 5 t / m 2 or more, the life of the mold becomes a problem. Nd-Fe-B magnet alloy with an average particle size of 3-4
When the green compact is prepared under a pressure of 1 to 4 t / m 2 after being pulverized to μm, the green compact is so brittle that it can be easily cracked by hand. The Nd-rich phase is a soft metal phase, and it is possible that the Nd-rich phase is pressure-bonded to the main phase during compaction and bonded to the main phase. However, the very low strength of this green compact indicates that its proportion is so small that it can be ignored, or that its adhesive force is not so strong as to be called a bond.
【００４０】上述した圧粉体を続いて焼成する。焼成温
度は焼結阻止剤の添加量によって変わるが、５００℃〜
１１４０℃の範囲内である。焼結阻止剤のうちＴｂ及び
Ｄｙを含む化合物を使用した場合は、Ｔｂ及びＤｙが焼
成中にＮｄ2 Ｆｅ14Ｂ相内に拡散し、特にその表面付近
のＮｄがＴｂ及びＤｙと置換される。これによりＮｄ2
Ｆｅ14Ｂ相の表層部の異方性磁界が高められ、より保磁
力が向上するという副次的効果が得られる。この場合焼
成温度が比較的低くとも、保磁力は高められる。しかし
乍、ＴｂやＤｙを含まない化合物を使用する場合はこう
した効果が生じないために、９００℃以上の温度で焼成
するのが望ましい。また保磁力向上のためにＴｂやＤｙ
の金属粉末あるいは水素化化合物を焼成体の収縮があま
り大きくならない範囲で添加してもよい。焼成温度が１
１４０℃以上では主相が溶融し、本発明に望ましい多孔
質焼成体ができない。The green compact described above is subsequently fired. The firing temperature varies depending on the amount of the sintering inhibitor added, but is 500 ° C
It is within the range of 1140 ° C. When a compound containing Tb and Dy is used as a sintering inhibitor, Tb and Dy diffuse into the Nd 2 Fe 14 B phase during firing, and Nd near its surface is replaced with Tb and Dy. .. As a result, Nd 2
An anisotropic magnetic field of the surface layer portion of the Fe 14 B phase is increased, and a secondary effect that the coercive force is further improved is obtained. In this case, the coercive force can be increased even if the firing temperature is relatively low. However, when a compound containing no Tb or Dy is used, such an effect does not occur. Therefore, firing at a temperature of 900 ° C. or higher is desirable. Also, to improve coercive force, Tb and Dy
The metal powder or the hydrogenated compound may be added within the range in which the shrinkage of the fired body does not become so large. Firing temperature is 1
At 140 ° C. or higher, the main phase is melted and the porous fired body desired in the present invention cannot be obtained.
【００４１】一般に、Ｎｄ2 Ｆｅ14Ｂ型結晶構造を有す
る主相の高い保磁力を得るためには、合金中のＮｄリッ
チの相の拡散が活発になる５００℃よりは高温で加熱し
なくてはならない。主相Ｎｄ2 Ｆｅ14Ｂの粒子表面の欠
陥や不純物相（α−Ｆｅ，Ｆｅ2 Ｂ，Ｎｄ2 Ｆｅ17）を
除去し、高保磁力化をもたらすＮｄリッチ相は主相粒子
表面のできるだけ多くの部分にゆきわたることが望まし
い。Ｎｄリッチ相の分散が極めて良い粉末（Ｎｄ−Ｆｅ
−Ｂ合金の粉末はＮｄ2 Ｆｅ14Ｂ、Ｎｄリッチ相、Ｂリ
ッチ相その他の相の混合粉末からなる）では５００℃程
度の温度で高い保磁力が得られるが、一般には分散はそ
れほど理想的でないことが多いので、より高温での加熱
が必要である。Generally, in order to obtain a high coercive force of the main phase having the Nd 2 Fe 14 B type crystal structure, it is necessary to heat the alloy at a temperature higher than 500 ° C. at which the diffusion of the Nd-rich phase in the alloy becomes active. Don't The Nd-rich phase that removes defects and the impurity phase (α-Fe, Fe 2 B, Nd 2 Fe 17 ) on the particle surface of the main phase Nd 2 Fe 14 B and brings about high coercive force is present in as much as possible on the surface of the main phase particle. It is desirable to go to the part. Powder with very good dispersion of Nd-rich phase (Nd-Fe
-B alloy powder consists of mixed powder of Nd 2 Fe 14 B, Nd-rich phase, B-rich phase and other phases), a high coercive force can be obtained at a temperature of about 500 ° C., but dispersion is generally ideal. Often not, so higher temperature heating is required.
【００４２】上述した理由によって焼成温度は一般的に
言って５００〜１１４０℃の範囲内にある。この温度範
囲は一般に行われている焼結温度と同等もしくはややそ
れより高い範囲が含まれているが、焼結阻止剤により焼
成体はこうした温度範囲でも収縮しないために、本発明
で言う「焼成体」が得られる。For the reasons mentioned above, the firing temperature is generally in the range of 500 to 1140 ° C. This temperature range includes a range that is equal to or slightly higher than the sintering temperature that is generally used, but since the sintered body does not shrink even in such a temperature range due to the sintering inhibitor, the term "calcination" is used in the present invention. The body is obtained.
【００４３】開放空孔に樹脂を充填するには真空下また
は減圧化での真空含浸で行うか、または保磁力の低下を
招かない窒素ガスまたはアルゴンガスなどの不活性ガス
を使用して１．２気圧以上１００気圧以下での加圧含浸
を行ってもよい。また一度減圧後加圧含浸を行うことに
より含浸量および速度が増大する。The filling of the open pores with resin is performed by vacuum impregnation under vacuum or under reduced pressure, or by using an inert gas such as nitrogen gas or argon gas which does not reduce the coercive force. Pressure impregnation at 2 atm or more and 100 atm or less may be performed. In addition, once the pressure is reduced and then pressure impregnation is performed, the impregnation amount and speed are increased.
【００４４】Ｎｄ−Ｆｅ−Ｂ系合金では焼成温度が高い
ほど高い保磁力が得られるので、焼結阻止剤の使用や気
化による空孔の導入により空孔率を高め焼成温度を高く
することが保磁力向上の面で有利である。In the Nd-Fe-B type alloy, the higher the firing temperature is, the higher the coercive force is obtained. Therefore, it is possible to increase the porosity and raise the firing temperature by using a sintering inhibitor or introducing holes by vaporization. It is advantageous in improving coercive force.
【００４５】[0045]
【実施例】以下実施例により更に詳しく本発明を説明す
る。 実施例１ Ｎｄ16Ｆｅ76Ｂ8 を基本成分とし、その他Ａｌ、Ｃｕ，
Ｓｉなどの不可避的不純物を含むインゴットを高周波溶
解炉で溶製した。その後、そのインゴットをスタンプミ
ルで３０メッシュ以下の大きさに粗粉砕し、ジェットミ
ル粉砕機で平均粒径３．５μｍの微粉末を作成した。こ
の微粉末に各種焼結阻止剤を所定量添加し、不活性ガス
中ミキサーで３時間混合を行い、１２ｋＯｅの磁界中で
１．５t/cm2 の加圧を行い、１０×１０×８mm3 の直方
体の圧粉体を作成した。この圧粉体を１．０×１０-3to
rrの真空下３００〜１０７５℃の間の温度（表１参照）
で２〜８時間焼成を行い、本発明による永久磁石を作成
した。The present invention will be described in more detail with reference to the following examples. Example 1 Using Nd 16 Fe 76 B 8 as a basic component, other Al, Cu,
An ingot containing inevitable impurities such as Si was melted in a high frequency melting furnace. Then, the ingot was roughly crushed with a stamp mill to a size of 30 mesh or less, and a fine powder having an average particle size of 3.5 μm was prepared with a jet mill crusher. A predetermined amount of various sintering inhibitors was added to this fine powder, mixed for 3 hours in an inert gas mixer, and pressed under a magnetic field of 12 kOe at 1.5 t / cm 2 to obtain 10 × 10 × 8 mm 3 A rectangular parallelepiped green compact was prepared. 1.0 x 10 -3 to this green compact
Temperature between 300 and 1075 ° C under vacuum of rr (see Table 1)
It was fired for 2 to 8 hours to prepare a permanent magnet according to the present invention.
【００４６】焼成体の密度を不活性ガス雰囲気中で重量
と体積を測定することにより求めた。その後焼成体を真
空・加圧両用型含浸装置に入れ、１torrの真空引きの
後、エポキシ樹脂（室温硬化、二液混合型）を導入して
２時間真空含浸させ、その後２気圧までゆっくりと窒素
ガスを導入し、２時間加圧含浸させた。含浸装置から含
浸焼成体を取り出し後、１００℃で２時間窒素ガス雰囲
気中で硬化処理（キュアリング）を行い、硬化後取り出
し試験試料とした。この試験試料の保磁力（ｉＨｃ，ｋ
Ｏｅ）、密度（ｇ／ｍ3 ），最大エネルギ積（（ＢＨ）
max ＭＧＯｅ）を測定した。結果を表１、２に示す。The density of the fired body was determined by measuring the weight and volume in an inert gas atmosphere. After that, the fired body is put in a vacuum / pressurization type impregnation device, and after evacuation of 1 torr, an epoxy resin (room temperature curing, two-liquid mixing type) is introduced and vacuum impregnation is carried out for 2 hours, and then nitrogen is slowly added to 2 atm. Gas was introduced and pressure impregnation was performed for 2 hours. After taking out the impregnated fired body from the impregnating device, a curing treatment (curing) was performed in a nitrogen gas atmosphere at 100 ° C. for 2 hours, and after curing, an extraction test sample was obtained. The coercive force of this test sample (iHc, k
Oe), density (g / m 3 ), maximum energy product ((BH)
max MGOe) was measured. The results are shown in Tables 1 and 2.
【００４７】焼結阻止剤を添加したいずれの磁石も樹脂
含浸が可能になった。しかし焼結阻止剤を添加しない磁
石では含浸はできなかった。Resin impregnation became possible for any magnets to which a sintering inhibitor was added. However, impregnation was not possible with a magnet to which no sintering inhibitor was added.
【００４８】[0048]
【表１】 [Table 1]
【００４９】[0049]
【表２】 [Table 2]
【００５０】実施例２ 実施例１の試料番号１〜１２を両面研削盤研削機を用い
て７×５×３ｍｍの寸法をもつ直方体に研削した。研削
後の試料に下記の工程によりエポキシ樹脂スプレー塗装
皮膜を形成した。Example 2 Sample Nos. 1 to 12 of Example 1 were ground into a rectangular parallelepiped having dimensions of 7 × 5 × 3 mm by using a double-sided grinder grinder. An epoxy resin spray coating film was formed on the ground sample by the following steps.
【００５１】研削後の試料にショットブラストを施した
後、流水およびトリクロロエタンで十分洗浄し、表面の
残留研削粉を除去した。これにエポキシ樹脂塗装皮膜を
スプレーにより下記の工程に従って形成させた。After subjecting the sample after grinding to shot blasting, it was thoroughly washed with running water and trichloroethane to remove residual grinding powder on the surface. An epoxy resin coating film was formed thereon by spraying according to the following steps.
【００５２】１）エッチングプライマー皮膜（２液混合
型、リン酸亜鉛１０％含有）スプレー塗装 平均膜厚
１μｍ ２）乾燥 ８０℃、１５min ３）エポキシ・プライマー塗膜（含量体積率３０％）ス
プレー塗装 平均膜厚４０μｍ ４）乾燥１００℃、３hr1) Etching primer film (two-liquid mixed type, containing 10% zinc phosphate) spray coating average film thickness
1μm 2) Dry 80 ° C, 15min 3) Epoxy primer coating (30% volume ratio) Spray coating Average film thickness 40μm 4) Dry 100 ° C, 3hr
【００５３】皮膜形成後各試料を８０℃、相対湿度９０
％の雰囲気に５００hr放置した後、目視による発錆の有
無および碁盤目剥離試験による皮膜の密着力をしらべる
ことにより、耐候性の表かを行った。その結果上記コー
ティングを施した本発明の樹脂含浸焼成磁石には発錆は
全く認められず、剥離も全く起こらなかった。コーティ
ングを施さない上記磁石ではスケルトン部全面に錆の発
生が認められ、厳しい条件で本磁石を使用する場合には
コーティングが是非必要であることが確認された。After film formation, each sample was heated to 80 ° C. and relative humidity of 90.
After being left in an atmosphere of 100% for 500 hours, the presence or absence of rust was visually inspected and the adhesion of the film was examined by a cross-cut peeling test to determine the weather resistance. As a result, no rusting was observed in the resin-impregnated fired magnet of the present invention coated with the above coating, and no peeling occurred at all. It was confirmed that rust was found on the entire surface of the skeleton part in the above-mentioned uncoated magnet, and that coating is absolutely necessary when this magnet is used under severe conditions.
【００５４】実施例３ 実施例１の試料番号１〜１２を作製後、加工せず直接下
記の工程によってエポキシ樹脂塗装皮膜を形成させた。Example 3 After preparing Sample Nos. 1 to 12 of Example 1, an epoxy resin coating film was directly formed by the following steps without processing.
【００５５】１）エポキシ・プライマー塗膜（含量体積
率３０％）スプレー塗装平均膜厚４０μｍ ２）乾燥１００℃、３hr1) Epoxy primer coating (content volume ratio 30%) Spray coating average film thickness 40 μm 2) Drying 100 ° C., 3 hours
【００５６】皮膜形成後試料を８０℃、相対湿度９０％
の雰囲気に１０００hr放置した後、目視による発錆の有
無を調べた。その結果、上記コーティングを施した試料
では錆の発生は認められなかった。コーティングを施さ
ない上記磁石では、点状の錆がところどころに認めら
れ、厳しい条件で本磁石を使用する場合には加工しない
含浸のままの磁石でもコーティングが必要であることが
確認された。After forming the film, the sample was heated to 80 ° C. and relative humidity of 90%.
After left for 1000 hours in the atmosphere, the presence of rust was visually checked. As a result, no rust was observed in the sample coated with the above coating. In the above uncoated magnet, spot-like rust was observed here and there, and it was confirmed that when the present magnet is used under severe conditions, even the unimpregnated magnet which is not processed needs to be coated.
【００５７】[0057]
【発明の効果】本発明によれば、保磁力の高い異方性Ｎ
ｄ−Ｆｅ−Ｂボンド磁石を極めて簡単な方法により製造
することができる。異方性Ｎｄ−Ｆｅ−Ｂ磁石として開
発されたＭＱ３では急冷リボンを粉砕し、粉末を磁界中
圧縮しさらに一軸加工し、この加工体を粉砕し、得られ
た粉末を樹脂で固めていたために工程が長く、著しいコ
スト高になっていた。また、インゴットを微粉砕し、こ
れを磁界中配向後焼成して開放気孔を有する焼成体を作
り、これに樹脂を含浸して異方性ボンド磁石を得る方法
では、焼成体が高密度に収縮しないように低温で焼成し
ていたために、十分な保磁力が得られず、注目されなか
った。本発明は、工程が簡単な後者の方法に注目し、焼
結阻止剤の添加によりより高温での焼成を可能にするも
のである。また、焼結阻止剤としてＴｂ，Ｄｙを１０ａ
ｔ％以上を含むものを使用することによりさらに高い保
磁力が得られる。これにより極めて簡単な方法により従
来のＳｍ−Ｃｏ異方性ボンド磁石よりも低コストで、最
大エネルギ積が高い保磁力のＮｄ−Ｆｅ−Ｂボンド磁石
の製造が可能になった。According to the present invention, anisotropic N having a high coercive force is used.
A d-Fe-B bonded magnet can be manufactured by a very simple method. In MQ3, which was developed as an anisotropic Nd-Fe-B magnet, the quenched ribbon was crushed, the powder was compressed in a magnetic field and further uniaxially processed, and this processed body was crushed, and the obtained powder was solidified with resin. The process was long and the cost was extremely high. Further, in the method of pulverizing an ingot, orienting it in a magnetic field and firing it to make a fired body having open pores, and impregnating this with a resin to obtain an anisotropic bonded magnet, the fired body shrinks at a high density. Since it was fired at a low temperature so as not to do so, sufficient coercive force could not be obtained, and it was not noted. The present invention focuses on the latter method, which has a simple process, and enables the firing at a higher temperature by adding a sintering inhibitor. Further, as a sintering inhibitor, Tb and Dy are 10a
A higher coercive force can be obtained by using a material containing t% or more. As a result, it becomes possible to manufacture a Nd-Fe-B bonded magnet having a high coercive force with a high maximum energy product at a lower cost than the conventional Sm-Co anisotropic bonded magnet by a very simple method.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 // Ｃ２２Ｃ 33/02 Ｈ 7619−4Ｋ ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 5 Identification code Office reference number FI technical display location // C22C 33/02 H 7619-4K
Claims (3)
Ｒ（Ｙを含む）、Ｆｅを必須元素とする遷移金属Ｔ、お
よびホウ素を基本成分とする粉末に焼結阻止剤または気
化剤を混合するか、あるいは前記粉末の表面を酸化した
後、前記粉末を磁界中で圧縮して圧粉体を作り、該圧粉
体を焼成して開放気孔を有する異方性焼成体を作り、該
異方性焼成体に４００℃以上かつ１０００℃以下の温度
で熱処理を施した後、前記開放気孔に樹脂を含浸後、前
記樹脂を硬化することを特徴とする異方性希土類ボンド
磁石の製造方法。1. A rare earth element R (including Y) containing Nd or Pr as an essential element, a transition metal T containing Fe as an essential element, and a powder containing boron as a basic component are mixed with a sintering inhibitor or a vaporizer. Alternatively, after the surface of the powder is oxidized, the powder is compressed in a magnetic field to form a green compact, and the green compact is fired to form an anisotropic fired body having open pores. A method for producing an anisotropic rare earth bonded magnet, comprising: heat-treating a flexible fired body at a temperature of 400 ° C. or higher and 1000 ° C. or lower, impregnating the open pores with a resin, and then curing the resin.
しくは、該樹脂を硬化し前記焼成体の表面を機械加工し
た後に前記焼成体の表面に保護皮膜を形成することを特
徴とする請求項１記載の異方性希土類ボンド磁石の製造
方法。2. A protective film is formed on the surface of the fired body after the resin is impregnated and the resin is cured, or after the resin is cured and the surface of the fired body is machined. Item 2. A method for manufacturing an anisotropic rare earth bonded magnet according to Item 1.
以上含むことを特徴とする請求項１又は２項記載の異方
性希土類ボンド磁石の製造方法。3. The sintering inhibitor contains 10 at% of Dy or Tb.
The method for producing an anisotropic rare earth bonded magnet according to claim 1 or 2, further comprising the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3225162A JPH0547528A (en) | 1990-08-16 | 1991-08-09 | Manufacturing method of anisotropical rare earth bonded magnet |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2-215037 | 1990-08-16 | ||
| JP21503790 | 1990-08-16 | ||
| JP3225162A JPH0547528A (en) | 1990-08-16 | 1991-08-09 | Manufacturing method of anisotropical rare earth bonded magnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0547528A true JPH0547528A (en) | 1993-02-26 |
Family
ID=26520650
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3225162A Pending JPH0547528A (en) | 1990-08-16 | 1991-08-09 | Manufacturing method of anisotropical rare earth bonded magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0547528A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5641363A (en) * | 1993-12-27 | 1997-06-24 | Tdk Corporation | Sintered magnet and method for making |
| US6147265A (en) * | 1997-04-30 | 2000-11-14 | Mitsubishi Chemical Corporation | Process for producing alkylene glycol |
| WO2007135981A1 (en) * | 2006-05-18 | 2007-11-29 | Hitachi Metals, Ltd. | R-Fe-B POROUS MAGNET AND METHOD FOR PRODUCING THE SAME |
| WO2008065903A1 (en) * | 2006-11-30 | 2008-06-05 | Hitachi Metals, Ltd. | R-Fe-B MICROCRYSTALLINE HIGH-DENSITY MAGNET AND PROCESS FOR PRODUCTION THEREOF |
| JP2009123968A (en) * | 2007-11-15 | 2009-06-04 | Hitachi Metals Ltd | POROUS MATERIAL FOR R-Fe-B BASED PERMANENT MAGNET, AND MANUFACTURING METHOD THEREOF |
| US7592799B2 (en) | 2004-09-10 | 2009-09-22 | Ntn Corporation | Magnetic encoder and wheel support bearing assembly using the same |
| JP2010258412A (en) * | 2009-03-30 | 2010-11-11 | Tdk Corp | Method of producing rare-earth magnet |
| JP2013229360A (en) * | 2012-04-24 | 2013-11-07 | Tdk Corp | Ferrite magnet and method for producing the same |
| CN115976452A (en) * | 2022-12-21 | 2023-04-18 | 哈尔滨工业大学 | Treatment method for inhibiting surface discharge of magnet in plasma environment |
-
1991
- 1991-08-09 JP JP3225162A patent/JPH0547528A/en active Pending
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5641363A (en) * | 1993-12-27 | 1997-06-24 | Tdk Corporation | Sintered magnet and method for making |
| US6147265A (en) * | 1997-04-30 | 2000-11-14 | Mitsubishi Chemical Corporation | Process for producing alkylene glycol |
| US7592799B2 (en) | 2004-09-10 | 2009-09-22 | Ntn Corporation | Magnetic encoder and wheel support bearing assembly using the same |
| WO2007135981A1 (en) * | 2006-05-18 | 2007-11-29 | Hitachi Metals, Ltd. | R-Fe-B POROUS MAGNET AND METHOD FOR PRODUCING THE SAME |
| US8268093B2 (en) | 2006-05-18 | 2012-09-18 | Hitachi Metals, Ltd. | R-Fe-B porous magnet and method for producing the same |
| JP4873008B2 (en) * | 2006-05-18 | 2012-02-08 | 日立金属株式会社 | R-Fe-B porous magnet and method for producing the same |
| JPWO2008065903A1 (en) * | 2006-11-30 | 2010-03-04 | 日立金属株式会社 | R-Fe-B fine crystal high-density magnet and method for producing the same |
| US8128758B2 (en) | 2006-11-30 | 2012-03-06 | Hitachi Metals, Ltd. | R-Fe-B microcrystalline high-density magnet and process for production thereof |
| JP4924615B2 (en) * | 2006-11-30 | 2012-04-25 | 日立金属株式会社 | R-Fe-B fine crystal high-density magnet and method for producing the same |
| WO2008065903A1 (en) * | 2006-11-30 | 2008-06-05 | Hitachi Metals, Ltd. | R-Fe-B MICROCRYSTALLINE HIGH-DENSITY MAGNET AND PROCESS FOR PRODUCTION THEREOF |
| JP2009123968A (en) * | 2007-11-15 | 2009-06-04 | Hitachi Metals Ltd | POROUS MATERIAL FOR R-Fe-B BASED PERMANENT MAGNET, AND MANUFACTURING METHOD THEREOF |
| JP2010258412A (en) * | 2009-03-30 | 2010-11-11 | Tdk Corp | Method of producing rare-earth magnet |
| JP2013229360A (en) * | 2012-04-24 | 2013-11-07 | Tdk Corp | Ferrite magnet and method for producing the same |
| CN115976452A (en) * | 2022-12-21 | 2023-04-18 | 哈尔滨工业大学 | Treatment method for inhibiting surface discharge of magnet in plasma environment |
| CN115976452B (en) * | 2022-12-21 | 2023-06-16 | 哈尔滨工业大学 | Treatment method for inhibiting surface discharge of magnet in plasma environment |
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