JPH11238641A - Highly corrosion resistant r-fe-b bonded magnet and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly and highly efficiently form a conductive film on the surface of a bond magnet in a highly adhesive state and to easily attain electroplating for the bond magnet, in order to efficiently manufacture R-Fe-B bonded magnets of various shapes, such as a ring shape and a disc shape of which corrosion resistance is improved by a metallic film. SOLUTION: In this manufacturing method, an R-Fe-B bonded magnet is barrel-ground by a barrel grinding device by the use of a drying method through the use of metallic fine pieces, i.g., Fe, Ni, Co, and Cr metallic file pieces, of undefined shapes such as spherical, block-like and needle-like (wire) shapes of required dimensions as media. In this case, ground metallic fine pieces are pressed into and applied to a resin surface and air hole parts formed on the surface of the bonded magnet, magnetic powder surfaces are also coated with metallic fine pieces, and an extremely uniform conductive film is formed on the surface of the R-Fe-B bonded magnet, so that fine electroplating for the bonded magnet can be attained and an R-Fe-B bonded magnet plated product having high corrosion resistance and capable of reducing the deterioration of magnetic characteristics can be obtained.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】この発明は、リング形状や円
板状の種々の形状からなる清浄性の高い金属被膜にて耐
食性を改善したＲ−Ｆｅ−Ｂ系ボンド磁石に係り、Ｆ
ｅ，Ｎｉ，Ｃｏ，Ｃｒ金属片の不定形金属メディアによ
る乾式バレル研磨により、磨砕された前記金属微片をボ
ンド磁石表面の樹脂面および空孔部に圧入、被覆し、ま
た磁粉面に前記金属微片を被覆することにより、磁石表
面に十分な導電性を付与して、無電解めっきすることな
く直接電気めっきを実施可能とし、耐食性、密着性に優
れた高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石を得る製造方法
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an R--Fe--B bonded magnet having improved corrosion resistance by a highly clean metal coating having various shapes such as a ring shape and a disk shape.
e, Ni, Co, and Cr metal pieces are press-fitted and coated on the resin surface and pores of the bonded magnet surface by dry barrel polishing with an irregular metal medium on the surface of the bonded magnet. By coating metal particles, sufficient conductivity is imparted to the magnet surface to enable direct electroplating without electroless plating, and high corrosion resistance R-Fe-B system with excellent corrosion resistance and adhesion The present invention relates to a manufacturing method for obtaining a bonded magnet.

【０００２】[0002]

【従来の技術】今日、ゴム磁石あるいはプラスチック磁
石と呼ばれるボンド磁石には、従来の等方性ボンド磁石
から異方性ボンド磁石へ、またフェライト系ボンド磁石
より高磁力の希土類系ボンド磁石へと高性能化が図られ
てきた。2. Description of the Related Art Today, bond magnets called rubber magnets or plastic magnets have been changed from conventional isotropic bond magnets to anisotropic bond magnets, and to rare earth bond magnets having higher magnetic force than ferrite bond magnets. Performance has been improved.

【０００３】Ｒ−Ｆｅ−Ｂ系ボンド磁石はその組成に極
めて酸化しやすい成分相およびＦｅを多量に含むため、
錆びやすい問題があり、表面に種々の構成からなる樹脂
層を電着塗装、スプレー法、浸漬法、含浸法等で被着し
ていた。（例えば特開平１−１６６５１９、特開平１−
２４５５０４号）[0003] Since the R-Fe-B based bonded magnet contains a large amount of a component phase and Fe that are extremely oxidizable in its composition,
There is a problem that it is easily rusted, and resin layers having various structures have been applied to the surface by electrodeposition coating, spraying, dipping, impregnation, or the like. (For example, Japanese Patent Application Laid-Open No.
245504)

【０００４】これまでＲ−Ｆｅ−Ｂ系ボンド磁石の耐食
性向上のために用いられてきた樹脂塗装法、例えばスプ
レー法ではリング状ボンド磁石の場合、塗料のロスが大
きく、裏、表を反転する必要があるため工数が多く、ま
た膜厚の均一性も劣る問題があった。[0004] In the case of a resin coating method used to improve the corrosion resistance of R-Fe-B-based bonded magnets, for example, a spray method, a ring-shaped bonded magnet loses a large amount of paint and reverses the front and back. Since it is necessary, the number of steps is large, and the uniformity of the film thickness is poor.

【０００５】また、電着法では、膜厚は均一であるが、
磁石１個ごとにそれぞれ電極に取り付けるため、工数を
要して小物には不適であるほか、塗装後に外した電極部
跡の補修、すなわちタッチアップが必要であり、工数を
要して小物には不適であるという問題がある。In the electrodeposition method, the film thickness is uniform.
Since each magnet is attached to an electrode, it takes time and is not suitable for small items. In addition, it is necessary to repair the trace of the electrode part removed after painting, that is, touch up. There is a problem of being unsuitable.

【０００６】浸漬法では、一定の均一な膜厚の塗膜を得
るにはタレ等の問題により困難であり、またポーラスな
ボンド磁石では空孔が十分に埋まらず、乾燥時に膨れた
り、製品同士のくっつき等の問題がある。[0006] In the immersion method, it is difficult to obtain a coating film having a uniform and uniform film thickness due to sagging and other problems. In addition, pores are not sufficiently filled with a porous bonded magnet, and swelling occurs during drying, and the product may be damaged. There is a problem such as sticking.

【０００７】さらに最近においては、コンピューターの
ＨＤＤユニットに使用するＲ−Ｆｅ−Ｂ系ボンド磁石に
は極めて高い表面清浄性が求められ、従来の樹脂塗膜で
は対応できず、清浄性の高い金属被膜が求められてい
る。More recently, R-Fe-B-based bonded magnets used in HDD units of computers have been required to have extremely high surface cleanliness. Is required.

【０００８】[0008]

【発明が解決しようとする課題】金属被膜の生成方法に
ついては量産性を考慮すると、焼結Ｒ−Ｆｅ−Ｂ磁石で
行われている電気金属めっきを施すこと（特開昭６０−
５４４０６、特開昭６２−１２０００３号）が考えられ
るが、Ｒ−Ｆｅ−Ｂ系ボンド磁石表面はポーラスでかつ
導電性の低い樹脂部分が露出しているため、めっき液が
残存したり、樹脂部にめっき被膜が十分に生成せずピン
ホール（無めっき部）が生じて、発錆が起こる。With respect to the method of forming a metal film, in consideration of mass productivity, electrometal plating performed using a sintered R-Fe-B magnet is performed (Japanese Patent Application Laid-Open No. 60-1985).
54406, Japanese Patent Application Laid-Open No. 62-120003), but since the surface of the R—Fe—B based bonded magnet is porous and has a low-conductivity resin portion exposed, the plating solution remains or the resin portion does not remain. The plating film is not sufficiently formed on the surface, and pinholes (unplated portions) are generated, and rust occurs.

【０００９】そこで前処理として導電性を付与した後、
Ｒ−Ｆｅ−Ｂ系ボンド磁石に電気めっきを施す方法が提
案され、その主なものとしては、（１） Ｒ−Ｆｅ−Ｂ
系ボンド磁石の表面に無電解めっきを施した後、電気め
っきを行う方法、（２） Ｒ−Ｆｅ−Ｂ系ボンド磁石の
表面に樹脂と導電性粉末との混合物を塗装被覆後、電気
めっきを行う方法、（３） Ｒ−Ｆｅ−Ｂ系ボンド磁石
の表面に粘着性を有する樹脂層を形成し、金属粉体を付
着させた後、電気めっきを行う方法（特開平５−３０２
１７６号）、などがある。Therefore, after imparting conductivity as a pretreatment,
A method of electroplating an R—Fe—B-based bonded magnet has been proposed. The main ones are (1) R—Fe—B
A method of performing electroplating after applying electroless plating to the surface of a system-based bonded magnet, (2) coating and coating a mixture of a resin and conductive powder on the surface of the R-Fe-B-based bonded magnet, and then performing electroplating. (3) A method in which an adhesive resin layer is formed on the surface of an R—Fe—B-based bonded magnet, metal powder is adhered, and then electroplating is performed (Japanese Patent Laid-Open No. 5-302).
176).

【００１０】しかしながら、上記の（１）の無電解めっ
き法では、Ｒ−Ｆｅ−Ｂ系ボンド磁石表面にめっき液が
残存して発錆を生じる恐れがあり、かつ時間を要し成膜
効率の良いめっき法ではない。（３）は最表面層の金属
粉の付着力は弱く、電気めっき時に脱落して密着不良が
生じたり、接着層の樹脂部が一部露出する。また（２）
は樹脂層の中に導電性物質あるいは金属粉を含有させた
ものであり、表面において樹脂露出部はＲ−Ｆｅ−Ｂ系
ボンド磁石素材に比べると改善されているものの、製法
上、被膜樹脂露出部が少なからず存在し、表面に導電性
の低い部分が存在することから、均一な良好な導電性を
得ることは困難であり、電気めっき時にピンホールが生
じやすくなるなどの問題がある。However, in the electroless plating method (1), the plating solution may remain on the surface of the R—Fe—B-based bonded magnet to cause rust, and it takes a long time to increase the film forming efficiency. Not a good plating method. In (3), the adhesion of the metal powder on the outermost surface layer is weak, and the metal powder comes off during electroplating to cause poor adhesion, or the resin part of the adhesive layer is partially exposed. Also (2)
Is a resin layer in which a conductive substance or metal powder is contained, and the exposed resin portion on the surface is improved as compared with the R-Fe-B based bonded magnet material, but due to the manufacturing method, the exposed film resin is exposed. Since there are not a small number of portions and a portion having low conductivity on the surface, it is difficult to obtain uniform and good conductivity, and there is a problem that pinholes are easily generated during electroplating.

【００１１】この発明は、Ｒ−Ｆｅ−Ｂ系ボンド磁石に
電気めっきを施す方法において種々の問題を解消し、清
浄性の高い金属被膜にて耐食性を改善したリング形状や
円板状の種々の形状からなるＲ−Ｆｅ−Ｂ系ボンド磁石
を効率よく製造するため、ボンド磁石表面に導電性膜を
密着性良く、均一に高効率で形成して、容易に電気めっ
きが可能な高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石とその製
造方法の提供を目的としている。The present invention solves various problems in a method of electroplating an R—Fe—B-based bonded magnet, and provides various ring-shaped and disk-shaped magnets having improved corrosion resistance with a highly clean metal coating. In order to efficiently manufacture R-Fe-B based bonded magnets with a shape, a conductive film is formed on the surface of the bonded magnet with good adhesion, uniformity and high efficiency, and high corrosion resistance R- which can be easily electroplated. An object is to provide an Fe-B based bonded magnet and a method for manufacturing the same.

【００１２】[0012]

【課題を解決するための手段】発明者らは、耐食性およ
び表面清浄性に優れたＲ−Ｆｅ−Ｂ系ボンド磁石の電気
めっき技術について、素材表面にきわめて均一に導電性
を付与することが重要であることに着目し、その導電性
膜の形成方法について種々検討した結果、Ｒ−Ｆｅ−Ｂ
系ボンド磁石を、所要寸法の球状、塊状あるいは針状
（ワイヤー）等の不定形Ｆｅ，Ｎｉ，Ｃｏ，Ｃｒ金属微
片をメディアとして用いて、バレル装置にて乾式法のバ
レル研磨を施すことにより、ここで磨砕された金属微片
がボンド磁石表面の樹脂面および空孔部に圧入かつ被覆
され、また磁粉面にも金属微片が被覆されてＲ−Ｆｅ−
Ｂ系ボンド磁石表面に極めて均一に導電性膜が付与で
き、良好な電気めっきが可能となり、耐食性に優れ、磁
気特性の劣化の少ないＲ−Ｆｅ−Ｂ系ボンド磁石のめっ
き被膜品を得られることを知見し、この発明を完成し
た。Means for Solving the Problems The inventors of the present invention have found that it is important for the electroplating technology of R-Fe-B-based bonded magnets having excellent corrosion resistance and surface cleanliness to impart a very uniform conductivity to the material surface. Focusing on the fact that R-Fe-B
By subjecting the system-based bond magnet to barrel polishing by a dry method using a barrel device using irregular shaped Fe, Ni, Co, and Cr metal particles such as spherical, massive, or needle-shaped (wire) of required dimensions as media. The fine metal particles ground here are pressed into and coated on the resin surface and the holes on the surface of the bonded magnet, and the fine metal particles are also coated on the surface of the magnetic powder, so that R-Fe-
An electroconductive film can be applied to the surface of the B-based bonded magnet very uniformly, good electroplating can be performed, excellent corrosion resistance can be obtained, and a plated coated product of an R-Fe-B-based bonded magnet with little deterioration of magnetic properties can be obtained. And completed the present invention.

【００１３】すなわち、この発明は、Ｒ−Ｆｅ−Ｂ系ボ
ンド磁石の表面を構成する樹脂面及び空孔部にＦｅ，Ｎ
ｉ，Ｃｏ，Ｃｒ金属微片が圧入かつ被覆され、また表面
を構成する磁粉面に前記金属微片が被覆されて形成され
る当該磁石表面の前記金属被覆層と、この金属被覆層を
介して形成された電解めっき層とを有することを特徴と
する高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石である。That is, according to the present invention, the resin surface and the pores constituting the surface of the R—Fe—B bonded magnet are made of Fe, N
i, Co, Cr metal particles are press-fitted and coated, and the surface of the magnetic powder constituting the surface is coated with the metal particles. The metal coating layer on the surface of the magnet is formed via the metal coating layer. A highly corrosion-resistant R-Fe-B-based bonded magnet having an electrolytic plating layer formed thereon.

【００１４】また、発明者らは、上記構成の高耐食性Ｒ
−Ｆｅ−Ｂ系ボンド磁石において、磁粉面上に被覆され
る金属微片被覆層の厚さが０．２μｍ以下であること、
樹脂面及び空孔部に形成された金属微片圧入被覆層の厚
みが、０．１μｍ以上２μｍ以下であること、を各々特
徴とする高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石を併せて提
案する。Further, the inventors have proposed a high corrosion resistance R having the above structure.
-In the Fe-B-based bonded magnet, the thickness of the metal particle coating layer coated on the surface of the magnetic powder is 0.2 μm or less;
The present invention also proposes a high corrosion-resistant R-Fe-B-based bonded magnet, which is characterized in that the thickness of the metal fine particle press-fitting coating layer formed on the resin surface and the hole is 0.1 μm or more and 2 μm or less. .

【００１５】また、この発明は、バレル装置にＲ−Ｆｅ
−Ｂ系ボンド磁石と不定形Ｆｅ，Ｎｉ，Ｃｏ，Ｃｒ金属
微片を装入して乾式法にてバレル研磨を施し、Ｒ−Ｆｅ
−Ｂ系ボンド磁石の表面を構成する樹脂面及び空孔部に
磨砕された前記金属微片を圧入かつ被覆し、また表面を
構成する磁粉面に該金属微片を被覆し、当該磁石表面に
前記金属被覆層を形成した後、この導電性の金属被覆層
を介して、電解めっき層を形成することを特徴とする高
耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石の製造方法である。Further, the present invention provides a barrel device in which R-Fe
A B-bonded magnet and irregular Fe, Ni, Co, and Cr metal particles are charged and barrel-polished by a dry method to obtain R-Fe.
Press-fitting and covering the resin fine particles constituting the surface of the B-based bonded magnet and the metal fine particles ground into the pores, and coating the metal fine particles on the surface of the magnetic powder constituting the surface; And forming an electrolytic plating layer via the conductive metal coating layer after the metal coating layer is formed on the R-Fe-B bonded magnet.

【００１６】また、発明者らは、上記構成の高耐食性Ｒ
−Ｆｅ−Ｂ系ボンド磁石の製造方法において、不定形金
属微片の大きさ０．１ｍｍ〜５ｍｍの球状、塊状あるい
は針状であること、バレル研磨にて磨砕された前記金属
微片の大きさは長径５μｍ以下であること、回転、振
動、遠心バレルを用いて磁石と金属微片の容積比率（磁
石／前記金属微片）を３以下にてバレル研磨を行うこ
と、をそれぞれ特徴とする高耐食性Ｒ−Ｆｅ−Ｂ系ボン
ド磁石の製造方法を併せて提案する。Further, the present inventors have proposed a high corrosion resistance R having the above structure.
In the method for producing a Fe-B-based bonded magnet, the size of the amorphous metal fine particles is 0.1 mm to 5 mm, which is spherical, massive, or needle-like, and the size of the metal fine particles ground by barrel polishing. The feature is that the major axis is 5 μm or less, and barrel polishing is performed using a rotating, vibrating, or centrifugal barrel with a volume ratio of magnet and metal particles (magnet / the metal particles) of 3 or less. A method for producing a high corrosion resistant R—Fe—B-based bonded magnet is also proposed.

【００１７】[0017]

【発明の実施の形態】この発明において、Ｒ−Ｆｅ−Ｂ
系ボンド磁石は等方性、異方性ボンド磁石のいずれも対
象とし、例えば圧縮成型の場合は、所要組成、性状の磁
石粉末に熱硬化性樹脂、カップリング剤、潤滑剤を添加
混練した後、圧縮成型し加熱して樹脂を硬化して得ら
れ、又、射出成型、押し出し成型、圧延成型の場合は、
磁石粉末に熱可塑性樹脂、カップリング剤、潤滑剤を添
加混練したのち、射出成型、押し出し成型、圧延成型の
いずれかの方法にて成型して得られる。DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, R-Fe-B
The system bond magnet is intended for both isotropic and anisotropic bond magnets. For example, in the case of compression molding, after adding and kneading a thermosetting resin, a coupling agent and a lubricant to magnet powder of the required composition and properties , Obtained by compression molding, heating and curing the resin.In the case of injection molding, extrusion molding, and rolling molding,
It is obtained by adding and kneading a thermoplastic resin, a coupling agent, and a lubricant to the magnet powder, and then molding by any of injection molding, extrusion molding, and rolling molding.

【００１８】Ｒ−Ｆｅ−Ｂ系磁石粉末には、所要のＲ−
Ｆｅ−Ｂ系合金を溶解し鋳造後に粉砕する溶解粉砕法、
Ｃａ還元にて直接粉末を得る直接還元拡散法、所要のＲ
−Ｆｅ−Ｂ系合金を溶解ジェットキャスターでリボン箔
を得てこれを粉砕・焼鈍する急冷合金法、所要のＲ−Ｆ
ｅ−Ｂ系合金を溶解し、これをガスアトマイズで粉末化
して熱処理するガスアトマイズ法、所要原料金属を粉末
化したのち、メカニカルアロイングにて微粉末化して熱
処理するメカニカルアロイ法及び所要のＲ−Ｆｅ−Ｂ系
合金を水素中で加熱して分解並びに再結晶させる方法
（ＨＤＤＲ法）などの各種製法で得た等方性、異方性粉
末が利用できる。The required R-Fe-B-based magnet powder contains
A melting and pulverizing method in which an Fe-B alloy is melted and pulverized after casting,
Direct reduction diffusion method to obtain powder directly by Ca reduction, required R
A quenching alloy method in which a ribbon foil is obtained by melting a Fe-B-based alloy with a jet caster, and this is pulverized and annealed.
A gas atomizing method in which an EB-based alloy is melted and powdered by gas atomization and heat treatment is performed. Isotropic and anisotropic powders obtained by various methods such as a method of decomposing and recrystallizing a -B-based alloy by heating in hydrogen (HDDR method) can be used.

【００１９】この発明において、Ｒ−Ｆｅ−Ｂ系磁石粉
末に用いる希土類元素Ｒは、組成の１０原子％〜３０原
子％を占めるが、Ｎｄ，Ｐｒ，Ｄｙ，Ｈｏ，Ｔｂのうち
少なくとも１種、あるいはさらに、Ｌａ，Ｃｅ，Ｓｍ，
Ｇｄ，Ｅｒ，Ｅｕ，Ｔｍ，Ｙｂ，Ｌｕ，Ｙのうち少なく
とも１種を含むものが好ましい。また、通常Ｒのうち１
種をもって足りるが、実用上は２種以上の混合物（ミッ
シュメタル、シジム等）を入手上の便宜等の理由により
用いることができる。なお、このＲは純希土類元素でな
くてもよく、工業上入手可能な範囲で製造上不可避な不
純物を含有するものでも差し支えない。In the present invention, the rare earth element R used in the R—Fe—B-based magnet powder occupies 10 to 30 atomic% of the composition, and at least one of Nd, Pr, Dy, Ho, and Tb is used. Alternatively, La, Ce, Sm,
A material containing at least one of Gd, Er, Eu, Tm, Yb, Lu, and Y is preferable. Also, one of the normal Rs
Although seeds are sufficient, in practice, a mixture of two or more kinds (mish metal, sijim, etc.) can be used for reasons such as convenience in obtaining. Note that R may not be a pure rare earth element, and may contain impurities that are unavoidable in production within the industrially available range.

【００２０】Ｒは、上記系磁石粉末における必須元素で
あって、１０原子％未満では結晶構造がα−鉄と同一構
造の立方晶組織となるため、高磁気特性、特に高保磁力
が得られず、３０原子％を超えるとＲリッチな非磁性相
が多くなり、残留磁束密度（Ｂｒ）が低下してすぐれた
特性の永久磁石が得られない。よって、Ｒは、１０原子
％〜３０原子％の範囲が望ましい。R is an essential element in the above-mentioned system magnet powder, and if it is less than 10 atomic%, the crystal structure becomes a cubic structure having the same structure as α-iron, so that high magnetic properties, particularly high coercive force cannot be obtained. , More than 30 atomic%, the R-rich nonmagnetic phase increases, the residual magnetic flux density (Br) decreases, and a permanent magnet having excellent characteristics cannot be obtained. Therefore, R is desirably in the range of 10 at% to 30 at%.

【００２１】Ｂは、上記系磁石粉末における必須元素で
あって、２原子％未満では菱面体構造が主相となり、高
い保磁力（ｉＨｃ）は得られず、２８原子％を超えると
Ｂリッチな非磁性相が多くなり、残留磁束密度（Ｂｒ）
が低下するため、すぐれた永久磁石が得られない。よっ
て、Ｂは２原子％〜２８原子％の範囲が望ましい。B is an essential element in the above-mentioned system magnet powder. If it is less than 2 atomic%, the rhombohedral structure becomes the main phase, and a high coercive force (iHc) cannot be obtained. Increase in non-magnetic phase, residual magnetic flux density (Br)
, The excellent permanent magnet cannot be obtained. Therefore, B is desirably in the range of 2 to 28 atomic%.

【００２２】Ｆｅは、上記系磁石粉末において必須元素
であり、６５原子％未満では残留磁束密度（Ｂｒ）が低
下し、８０原子％を超えると高い保磁力が得られないの
で、Ｆｅは６５原子％〜８０原子％の含有が望ましい。Fe is an essential element in the above-mentioned system magnet powder. When the content is less than 65 atomic%, the residual magnetic flux density (Br) decreases. When the content is more than 80 atomic%, a high coercive force cannot be obtained. % To 80 atomic%.

【００２３】また、Ｆｅの一部をＣｏで置換すること
は、得られる磁石の磁気特性を損なうことなく、温度特
性を改善することができるが、Ｃｏ置換量がＦｅの２０
％を超えると、逆に磁気特性が劣化するため、好ましく
ない。Ｃｏの置換量がＦｅとＣｏの合計量で５原子％〜
１５原子％の場合は、（Ｂｒ）は置換しない場合に比較
して増加するため、高磁束密度を得るためには好まし
い。Further, by substituting a part of Fe with Co, the temperature characteristics can be improved without impairing the magnetic characteristics of the obtained magnet.
%, It is not preferable because the magnetic properties are deteriorated. The substitution amount of Co is 5 atomic% or more in total amount of Fe and Co.
In the case of 15 atomic%, since (Br) increases as compared with the case where no substitution is made, it is preferable to obtain a high magnetic flux density.

【００２４】また、Ｒ，Ｂ，Ｆｅのほか、工業的生産上
不可避的不純物の存在を許容でき、例えば、Ｂの一部を
４．０ｗｔ％以下のＣ、２．０ｗｔ％以下のＰ、２．０
ｗｔ％以下のＳ、２．０ｗｔ％以下のＣｕのうち少なく
とも１種、合計量で２．０ｗｔ％以下で置換することに
より、永久磁石の製造性改善、低価格化が可能である。In addition to R, B, and Fe, the presence of unavoidable impurities in industrial production can be tolerated. For example, a part of B may be 4.0 wt% or less of C, 2.0 wt% or less of P, .0
By replacing at least one of S by wt% or less and Cu by 2.0 wt% or less with a total amount of 2.0 wt% or less, it is possible to improve the productivity and reduce the cost of the permanent magnet.

【００２５】さらに、Ａｌ，Ｔｉ，Ｖ，Ｃｒ，Ｍｎ，Ｂ
ｉ，Ｎｂ，Ｔａ，Ｍｏ，Ｗ，Ｓｂ，Ｇｅ，Ｇａ，Ｓｎ，
Ｚｒ，Ｎｉ，Ｓｉ，Ｚｎ，Ｈｆのうち少なくとも１種
は、磁石粉末に対してその保磁力、減磁曲線の角型性を
改善あるいは製造性の改善、低価格化に効果があるため
添加することができる。なお、添加量の上限は、ボンド
磁石の（ＢＨ）ｍａｘや（Ｂｒ）値を所要値とするに必
要な該条件を満たす範囲が望ましい。Further, Al, Ti, V, Cr, Mn, B
i, Nb, Ta, Mo, W, Sb, Ge, Ga, Sn,
At least one of Zr, Ni, Si, Zn, and Hf is added to the magnet powder because it is effective for improving the coercive force and the squareness of the demagnetization curve or improving the productivity and reducing the price. be able to. The upper limit of the addition amount is desirably a range that satisfies the conditions necessary for setting the (BH) max and (Br) values of the bonded magnet to required values.

【００２６】またこの発明において、バインダーには射
出成形では、樹脂として６Ｐａ、１２Ｐａ、ＰＰＳ、Ｐ
ＢＴ、ＥＶＡ等、又押出成形、カレンダーロール、圧延
成形ではＰＶＣ、ＮＢＲ、ＣＰＥ、ＮＲ、ハイパロン
等、又圧縮成形には、エポキシ樹脂、ＤＡＰ、フェノー
ル樹脂等が利用でき、必要に応じて、公知の金属バイン
ダーを用いることができる。さらに、助材には成形を容
易にする滑剤や樹脂と無機フィラーの結合剤、シラン
系、チタン系等のカップリング剤などを用いることがで
きる。In the present invention, the binder is 6 Pa, 12 Pa, PPS, P
BT, EVA, etc., PVC, NBR, CPE, NR, Hypalon, etc. for extrusion molding, calender roll, roll molding, and epoxy resin, DAP, phenolic resin, etc. for compression molding. Metal binder can be used. Further, a lubricant that facilitates molding, a binder between a resin and an inorganic filler, a silane-based or titanium-based coupling agent, or the like can be used as the auxiliary material.

【００２７】この発明において、乾式バレルには、回転
式、振動式、遠心式等の公知のバレルが使用できる。バ
レル装置に装入するＦｅ，Ｎｉ，Ｃｏ，Ｃｒの金属微片
の形状については、球状、塊状あるいは針状（ワイヤ
ー）等の不定形が使用できる。前記金属微片の大きさ
は、０．１ｍｍ未満では十分な圧入、被覆に時間を要
し、実用的でなく、また５ｍｍを越えると表面凹凸が大
きくなり、表面全体に金属微片を被覆することができな
いため、金属微片の大きさは０．１ｍｍ〜５ｍｍが望ま
しく、さらに好ましい範囲は０．３ｍｍ〜３ｍｍであ
る。又、この発明において、乾式バレル内に装入される
金属微片は同一形状、寸法でもよく、又異形状、異寸法
のものを混合してもよい。又不定形金属微片に金属微粉
を混入してもよい。In the present invention, a known barrel of a rotary type, a vibration type, a centrifugal type, or the like can be used as the dry barrel. Regarding the shape of the fine metal particles of Fe, Ni, Co, and Cr to be charged into the barrel device, irregular shapes such as spherical, massive, and needle-like (wire) can be used. If the size of the metal fine particles is less than 0.1 mm, sufficient press-fitting and coating time is required, which is not practical, and if it exceeds 5 mm, the surface unevenness increases, and the entire surface is coated with the metal fine particles. Therefore, the size of the metal particles is preferably 0.1 mm to 5 mm, and more preferably 0.3 mm to 3 mm. Further, in the present invention, the metal fine pieces charged in the dry barrel may have the same shape and size, or may mix different shapes and sizes. Further, metal fine powder may be mixed into irregular shaped metal fine pieces.

【００２８】また、乾式バレル研磨に投入する比率は磁
石とＦｅ，Ｎｉ，Ｃｏ，Ｃｒの金属微片の容積比率（磁
石／前記金属微片）を３以下に限定したのは、３を越え
ると前記金属微片の圧入、被覆に時間を要し実用的でな
く、またボンド磁石表面から磁粉の脱粒が生じるため、
３以下とした。またバレル研磨機内に装入するボンド磁
石及び金属片の量は研磨機内容積の２０％〜９０％が好
ましく、２０％未満では、処理量が少なすぎて実用的で
なく、９０％を越えると、撹拌が不十分で、十分な研磨
ができない問題がある。また、圧入被覆される金属微片
の大きさは５μｍより大きい場合には、素材表面との密
着性が悪く、密着不良、剥離等を生ずるため５μｍ以下
とした。好ましい大きさは２μｍ以下である。The ratio of the volume of the magnet and the fine particles of Fe, Ni, Co and Cr (magnet / the above-mentioned fine metal particles) is limited to 3 or less. Press-fitting of the metal flakes, it takes time to coat and is not practical, and because the magnetic particles are shed from the bonded magnet surface,
3 or less. Also, the amount of the bonded magnet and the metal pieces to be charged into the barrel polishing machine is preferably 20% to 90% of the internal volume of the polishing machine. If it is less than 20%, the processing amount is too small to be practical. There is a problem that stirring is insufficient and sufficient polishing cannot be performed. When the size of the metal particles to be press-fitted is larger than 5 μm, the adhesion to the surface of the material is poor and poor adhesion and peeling are caused. A preferred size is 2 μm or less.

【００２９】金属微片の圧入、被覆については金属微片
は素材表面の樹脂面と磁粉面においては、柔らかい樹脂
面には圧入、被覆され、磁粉面には被覆される。樹脂面
に圧入される量は表面ほど多く、樹脂層内部に漸次的に
含有量が減少している。樹脂面の金属微片の圧入被覆層
の厚さを０．１μｍ以上２μｍ以下に限定したのは、
０．１μｍ未満では充分な導電性が得られず、２μｍよ
り大きいのは性能上の問題はないが作業に時間を要し、
実用的でない。With respect to the press-fitting and coating of the metal fine particles, the metal fine particles are press-fitted and coated on the soft resin surface and coated on the magnetic powder surface on the resin surface and the magnetic powder surface of the material surface. The amount pressed into the resin surface is larger at the surface, and the content gradually decreases inside the resin layer. The reason for limiting the thickness of the press-fitting coating layer of the metal particles on the resin surface to 0.1 μm or more and 2 μm or less is that
If it is less than 0.1 μm, sufficient conductivity cannot be obtained, and if it is more than 2 μm, there is no problem in performance, but it takes time to work,
Not practical.

【００３０】また、磁粉面の金属微片の被覆層の厚さを
０．２μｍ以下に限定したのは、磁粉面表面と金属微片
の反応は一種のメカノケミカル的反応であり、０．２μ
ｍより大きい場合には密着性が劣るためである。The reason why the thickness of the coating layer of the metal particles on the magnetic particle surface is limited to 0.2 μm or less is that the reaction between the magnetic particle surface and the metal particles is a kind of mechanochemical reaction.
If it is larger than m, the adhesion is inferior.

【００３１】この発明において、表面の平滑性が求めら
れる場合には、この発明の処理を行う前に、研磨材と植
物性媒体の混合物、研磨材と無機質粉体にて表面を改質
された植物性媒体の混合物をメディアとして研磨を行う
等の処理を行うことにより、平滑性が向上し、耐食性が
さらにすぐれたＲ−Ｆｅ−Ｂ系ボンド磁石を得ることが
できる。In the present invention, when surface smoothness is required, the surface is modified with a mixture of an abrasive and a vegetable medium, or with an abrasive and an inorganic powder before performing the treatment of the present invention. By performing a treatment such as polishing using a mixture of a vegetable medium as a medium, an R—Fe—B-based bonded magnet with improved smoothness and further excellent corrosion resistance can be obtained.

【００３２】この発明による乾式法バレル研磨の場合の
回転数は、回転バレルの場合は回転数２０〜５０ｒｐ
ｍ、遠心バレルの場合は回転数７０〜２００ｒｐｍ、ま
た振動バレル研磨法の場合は振動振幅０．５〜５０ｍｍ
が好ましい。The number of rotations in the case of dry barrel polishing according to the present invention is 20 to 50 rpm in the case of a rotary barrel.
m, in the case of a centrifugal barrel, the number of rotations is 70 to 200 rpm, and in the case of the vibration barrel polishing method, the vibration amplitude is 0.5 to 50 mm.
Is preferred.

【００３３】この発明において、電気めっき方法として
は、Ｎｉ，Ｃｕ，Ｓｎ，Ｃｏ，Ｚｎ，Ｃｒ，Ａｇ，Ａ
ｕ，Ｐｄ，Ｐｔ等から選ばれた少なくとも１種の金属ま
たはそれらの合金等にＢ，Ｓ，Ｐが含有されるめっき法
が好ましく、特にＣｕ、Ｎｉめっきが好ましい。めっき
厚は５０μｍ以下、好ましくは１０〜３０μｍである。
この発明では前記金属微片の圧入、被覆が有効の作用を
するため一般的なワット浴によってもめっき可能であ
り、優れた密着性、耐食性が得られる。In the present invention, Ni, Cu, Sn, Co, Zn, Cr, Ag, A
A plating method in which B, S, and P are contained in at least one metal selected from u, Pd, Pt, or the like, or an alloy thereof, is preferable, and Cu, Ni plating is particularly preferable. The plating thickness is 50 μm or less, preferably 10 to 30 μm.
In the present invention, since the press-fitting and coating of the metal fine particles have an effective function, plating can be performed even by a general watt bath, and excellent adhesion and corrosion resistance can be obtained.

【００３４】特にＮｉめっき浴のめっき方法としては、
洗浄→電気Ｎｉめっき→洗浄→乾燥の工程で行うのがよ
く、Ｎｉめっき浴のｐＨ調整は塩基性炭酸ニッケル、ｐ
Ｈ４．０〜４．６、浴温６０度の処理が好ましい。Ｎｉ
めっきは上述しためっき浴を用い、陽極を電解ニッケル
板を用いて所要電流を流し、電気Ｎｉめっきを行うが陽
極Ｎｉ板のＮｉの溶出を安定させるため、電極にＳを含
有したエストランドニッケルチップを使用することが望
ましい。In particular, as a plating method of the Ni plating bath,
It is preferable to carry out the steps of washing → electrical Ni plating → washing → drying.
H4.0-4.6, bath temperature of 60 degreeC processing is preferable. Ni
The plating is performed using the above-mentioned plating bath, the anode is subjected to a required current using an electrolytic nickel plate, and an electric Ni plating is performed. In order to stabilize the elution of Ni from the anode Ni plate, an Estland nickel chip containing S in the electrode is used. It is desirable to use

【００３５】めっき浴槽にはボンド磁石の形状に応じて
種々の浴槽を使用することができ、リング形状のボンド
磁石の場合はひっかけめっき処理、バレルめっき処理が
好ましい。Various bathtubs can be used for the plating bath depending on the shape of the bond magnet. In the case of a ring-shaped bond magnet, trapping plating and barrel plating are preferable.

【００３６】[0036]

【実施例】実施例１ 超急冷法で作製したＮｄ１２ａｔ％、Ｆｅ７７ａｔ％、
Ｂ６ａｔ％、Ｃｏ５ａｔ％の組成からなる平均粒径１５
０μｍの合金粉末にエポキシ樹脂２ｗｔ％を加えて混練
し、７ｔｏｎ／ｃｍ²の圧力で圧縮成型した後、１７０
℃で１時間キュアーし、外径２１ｍｍ×内径１８ｍｍ×
高さ４ｍｍのリング状ボンド磁石を作製した。得られた
ボンド磁石の特性はＢｒ６．８ｋＧ、ｉＨｃ９．１ｋＯ
ｅ、（ＢＨ）ｍａｘ９．２ＭＧＯｅであった。EXAMPLES Example 1 Nd 12 at%, Fe 77 at%, produced by a rapid quenching method
B6 at%, Co 5 at% composition, average particle size 15
After adding 2 wt% of epoxy resin to the 0 μm alloy powder and kneading, compression-molding at a pressure of 7 ton / cm ² , 170
Cure for 1 hour at ℃, outer diameter 21mm x inner diameter 18mm x
A ring-shaped bonded magnet having a height of 4 mm was produced. The characteristics of the obtained bonded magnet were Br 6.8 kG, iHc 9.1 kO.
e, (BH) max was 9.2 MGOe.

【００３７】得られたボンド磁石を振動バレルに入れ、
直径０．７ｍｍ、長さ０．５ｍｍの短円柱状Ｆｅ，Ｎ
ｉ，Ｃｏ，Ｃｒ片を用い、乾式バレル研磨処理を行い、
前記金属微片による導電被覆層を形成した。前記金属微
片の樹脂面、封孔部での圧入深さおよび磁粉面での被覆
厚さを第１表に示す。The obtained bonded magnet is put in a vibration barrel,
Short columnar Fe, N 0.7mm in diameter and 0.5mm in length
Dry barrel polishing using i, Co, Cr pieces
A conductive coating layer was formed using the metal particles. Table 1 shows the press-fitting depth at the resin surface, the sealing portion, and the coating thickness at the magnetic powder surface of the metal fine particles.

【００３８】なお、バレル研磨の処理条件は、容積３．
５ｌの振動バレルに入れ、５０ケのボンド磁石（見かけ
容積０．０１５ｌ、重量１００ｇ）と前記寸法の金属微
片（見かけ容積２ｌ、重量１０ｋｇ）を装入し、８時間
の処理を行った。The processing conditions for barrel polishing are as follows: volume 3.
It was placed in a 5 l vibration barrel, charged with 50 bonded magnets (apparent volume 0.015 l, weight 100 g) and metal particles of the above dimensions (apparent volume 2 l, weight 10 kg), and treated for 8 hours.

【００３９】その後洗浄を行い、ひっかけめっき方式で
電気Ｎｉめっきを行った。めっき後の膜厚は内径側１８
μｍ、外径側２１μｍであった。得られたリング状ボン
ド磁石を８０℃、相対湿度９０％、５００時間にて環境
試験（耐湿試験）を行った。その結果及び膜厚寸法精度
を表２〜表４に示す。Thereafter, cleaning was performed, and electric Ni plating was performed by a hook plating method. The film thickness after plating is 18 on the inner diameter side.
μm, 21 μm on the outer diameter side. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C. and a relative humidity of 90% for 500 hours. Tables 2 to 4 show the results and the film thickness dimensional accuracy.

【００４０】なお、電気Ｎｉめっきの条件は、電流密度
２Ａ／ｄｍ²、めっき時間６０分、ｐＨ４．１、浴温５
５℃であり、めっき液組成は硫酸ニッケル２３５ｇ／
ｌ、塩化ニッケル４５ｇ／ｌ、炭酸ニッケル適量（ｐＨ
調整）、ほう酸３５ｇ／ｌであった。The conditions of the electric Ni plating were as follows: current density 2 A / dm ² , plating time 60 minutes, pH 4.1, bath temperature 5
5 ° C., and the composition of the plating solution was 235 g of nickel sulfate /
l, nickel chloride 45g / l, nickel carbonate appropriate amount (pH
Adjustment), boric acid 35 g / l.

【００４１】比較例１ 実施例１と同様方法で得たリング状ボンド磁石を洗浄
後、無電解銅めっきを行った。めっき厚は６μｍであっ
た。無電解銅めっき後、実施例と同一の条件で電気Ｎｉ
めっきを行った。得られたリング状ボンド磁石を８０
℃、相対湿度９０％、５００時間にて環境試験（耐湿試
験）を行った。その結果を表１〜表３に示す。Comparative Example 1 A ring-shaped bonded magnet obtained in the same manner as in Example 1 was washed and then subjected to electroless copper plating. The plating thickness was 6 μm. After electroless copper plating, electric Ni
Plating was performed. The obtained ring-shaped bonded magnet was
An environmental test (moisture resistance test) was performed at 500 ° C. and a relative humidity of 90%. The results are shown in Tables 1 to 3.

【００４２】なお、無電解銅めっきの条件はめっき時間
２５分、ｐＨ１１．５、浴温２０℃であり、めっき液組
成は硫酸銅３５ｇ／ｌ、炭酸ナトリウム２５ｇ／ｌ、酒
石酸塩１５０ｇ／ｌ、水酸化ナトリウム４５ｇ／ｌ、３
７％ホルムアルデヒド１５０ｍｌであった。The conditions for the electroless copper plating were a plating time of 25 minutes, a pH of 11.5 and a bath temperature of 20 ° C. The composition of the plating solution was 35 g / l of copper sulfate, 25 g / l of sodium carbonate, 150 g / l of tartrate, Sodium hydroxide 45 g / l, 3
It was 150 ml of 7% formaldehyde.

【００４３】比較例２ 実施例１と同様方法で得たリング状ボンド磁石を洗浄
後、フェノール樹脂とＮｉ粉末を混合して、厚み１０μ
ｍの導電被膜を形成した。処理後、実施例と同一の条件
でＣｕ、Ｎｉめっきを行った。得られたリング状ボンド
磁石を８０℃、相対湿度９０％、５００時間にて環境試
験（耐湿試験）を行った。その結果を表２〜表４に示
す。Comparative Example 2 A ring-shaped bonded magnet obtained in the same manner as in Example 1 was washed, and a phenol resin and a Ni powder were mixed to form a 10 μm thick.
m of the conductive film was formed. After the treatment, Cu and Ni plating were performed under the same conditions as in the example. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C. and a relative humidity of 90% for 500 hours. The results are shown in Tables 2 to 4.

【００４４】なお、導電被覆処理条件は、処理時間３０
分、処理液組成はフェノール樹脂５ｗｔ％、Ｎｉ粉（粒
径０．７μｍ以下）７ｗｔ％、ＭＥＫ（メチルエチルケ
トン）８８ｗｔ％であった。The conductive coating treatment conditions were as follows.
The composition of the treatment liquid was 5 wt% of phenol resin, 7 wt% of Ni powder (particle diameter 0.7 μm or less), and 88 wt% of MEK (methyl ethyl ketone).

【００４５】比較例３ 実施例１と同様方法で得たリング状ボンド磁石を洗浄
後、浸漬法にて接着層としたフェノール樹脂層を予め形
成後、Ａｇ粉（粒径０．７μｍ以下）を表面に付着させ
た後、振動バレルにて７μｍの導電性被覆層を形成し
た。振動バレル処理後、実施例１と同一の条件で電気Ｎ
ｉめっきを行った。得られたリング状ボンド磁石を８０
℃、相対湿度９０％、５００時間にて環境試験（耐湿試
験）を行った。その結果を表２〜表４に示すComparative Example 3 A ring-shaped bonded magnet obtained in the same manner as in Example 1 was washed, a phenol resin layer serving as an adhesive layer was previously formed by a dipping method, and then Ag powder (particle diameter: 0.7 μm or less) was added. After adhering to the surface, a conductive coating layer of 7 μm was formed with a vibration barrel. After the vibration barrel treatment, electricity N was applied under the same conditions as in Example 1.
i-plating was performed. The obtained ring-shaped bonded magnet was
An environmental test (moisture resistance test) was performed at 500 ° C. and a relative humidity of 90%. The results are shown in Tables 2 to 4.

【００４６】なお、振動バレル処理条件は、容積３．５
ｌの振動バレルを用い、５０ケのボンド磁石を装入し、
見かけ容積が２ｌの３．０ｍｍ径のスチールボールをメ
ディアとして、２．５時間の処理を行った。The vibration barrel processing conditions were a volume of 3.5.
Using 50 vibrating barrels and loading 50 bonded magnets,
The treatment was performed for 2.5 hours using a 3.0 mm diameter steel ball having an apparent volume of 2 l as a medium.

【００４７】[0047]

【表１】 [Table 1]

【００４８】[0048]

【表２】 [Table 2]

【００４９】[0049]

【表３】 [Table 3]

【００５０】[0050]

【表４】 [Table 4]

【００５１】表２〜表４より明らかなごとく、比較例１
は約１３０時間後に点錆が認められ、比較例２は３５０
時間後、比較例３においても約３７０時間後に点錆が認
められたが、これに対して実施例１は５００時間後にお
いても３０倍の顕微鏡で認められる点錆はなかった。As is clear from Tables 2 to 4, Comparative Example 1
In about 130 hours, spot rust was observed after about 130 hours.
After about 370 hours, rust spots were observed in Comparative Example 3 after about 370 hours, whereas no rust spots were observed in the microscope of 30 times in Example 1 even after 500 hours.

【００５２】[0052]

【発明の効果】この発明は、Ｒ−Ｆｅ−Ｂ系ボンド磁石
を所要寸法の球状、塊状あるいは針状（ワイヤー）等の
不定形Ｆｅ，Ｎｉ，Ｃｏ，Ｃｒの金属微片を用いてバレ
ル装置にて乾式法にてバレル研磨を施し、磨砕された前
記金属微片をおよび空孔部に圧入、被覆し、また磁粉面
に前記金属微片を被覆することにより、Ｒ−Ｆｅ−Ｂ系
ボンド磁石表面に金属被覆層を形成して極めて高い導電
性を付与することができ、そのため緻密でピンホールの
ない電解めっき層を形成可能となり、極めて優れた耐食
性を有するＲ−Ｆｅ−Ｂ系ボンド磁石を得ることができ
る。また、この発明のボンド磁石は、高い表面清浄度を
要求されるコンピューターのＨＤＤユニット等には特に
有効である。According to the present invention, a barrel apparatus is provided by using an R-Fe-B-based bonded magnet by using irregular shaped Fe, Ni, Co, and Cr metal particles having a required size such as spherical, massive, or needle-like (wire). The barrel is polished by a dry method, and the crushed metal fine pieces are pressed into the holes and coated, and the magnetic fine particles are coated with the metal fine pieces to form an R-Fe-B system. An extremely high conductivity can be imparted by forming a metal coating layer on the surface of the bonded magnet, so that a dense and pinhole-free electrolytic plating layer can be formed, and an R-Fe-B-based bond having extremely excellent corrosion resistance You can get a magnet. Further, the bonded magnet of the present invention is particularly effective for HDD units of computers that require high surface cleanliness.

Claims (7)

【特許請求の範囲】[Claims] 【請求項１】 Ｒ−Ｆｅ−Ｂ系ボンド磁石の表面を構成
する樹脂面及び空孔部にＦｅ，Ｎｉ，Ｃｏ，Ｃｒ金属微
片が圧入かつ被覆され、また表面を構成する磁粉面に前
記金属微片が被覆されて形成された当該磁石表面の金属
被覆層と、この金属被覆層を介して形成される電解めっ
き層とを有する高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石。1. Fe, Ni, Co, and Cr metal particles are press-fitted and coated on a resin surface and a void portion constituting the surface of an R—Fe—B-based bonded magnet, and the magnetic powder surface constituting the surface is formed on the magnetic powder surface. A highly corrosion-resistant R-Fe-B-based bonded magnet having a metal coating layer on the surface of the magnet formed by coating metal fine pieces and an electrolytic plating layer formed through the metal coating layer. 【請求項２】 請求項１において、磁粉面上に被覆され
る金属被覆層の厚さが０．２μｍ以下である高耐食性Ｒ
−Ｆｅ−Ｂ系ボンド磁石。2. The high corrosion resistance R according to claim 1, wherein the thickness of the metal coating layer coated on the surface of the magnetic powder is 0.2 μm or less.
-Fe-B based bonded magnet. 【請求項３】 請求項１において、樹脂面及び空孔部に
形成された金属圧入被覆層の厚みが、０．１μｍ以上２
μｍ以下である高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石。3. The method according to claim 1, wherein the metal press-fitting coating layer formed on the resin surface and the hole has a thickness of 0.1 μm or more.
A highly corrosion-resistant R-Fe-B-based bonded magnet having a size of not more than μm. 【請求項４】 バレル装置にＲ−Ｆｅ−Ｂ系ボンド磁石
と不定形Ｆｅ，Ｎｉ，Ｃｏ，Ｃｒ金属微片を装入して乾
式法にてバレル研磨を施し、Ｒ−Ｆｅ−Ｂ系ボンド磁石
の表面を構成する樹脂面及び空孔部に磨砕された金属微
片を圧入かつ被覆し、また表面を構成する磁粉面に該金
属微片を被覆し、当該磁石表面に金属被覆層を形成した
後、前記導電性金属被覆層を介して、電解めっき層を形
成する高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石の製造方法。4. An R—Fe—B bond magnet and amorphous Fe, Ni, Co, and Cr metal particles are charged into a barrel device and barrel-polished by a dry method to obtain an R—Fe—B bond. Pressed and coated metal particles crushed on the resin surface and the pores constituting the surface of the magnet, and coated the metal particles on the magnetic powder surface constituting the surface, and provided a metal coating layer on the surface of the magnet. A method for producing a high corrosion resistant R-Fe-B-based bonded magnet in which an electrolytic plating layer is formed via the conductive metal coating layer after the formation. 【請求項５】 請求項４において、不定形金属微片が大
きさ０．１ｍｍ〜５ｍｍの球状、塊状あるいは針状であ
る高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石の製造方法。5. The method according to claim 4, wherein the irregular shaped metal particles are spherical, massive, or needle-shaped and have a high corrosion resistance of 0.1 to 5 mm. 【請求項６】 請求項４において、バレル研磨にて磨砕
された金属微片の大きさは長径５μｍ以下である高耐食
性Ｒ−Ｆｅ−Ｂ系ボンド磁石の製造方法。6. The method according to claim 4, wherein the metal fine particles ground by barrel polishing have a major axis of 5 μm or less in size. 【請求項７】 請求項４において、回転、振動または遠
心バレルを用いて、磁石と不定形金属微片の容積比率
（磁石／前記金属微片）を３以下にて乾式バレル研磨を
行う高耐食性Ｒ−Ｆｅ−Ｂ系ボンド磁石の製造方法。7. The high corrosion resistance according to claim 4, wherein dry barrel polishing is performed using a rotating, vibrating, or centrifugal barrel with a volume ratio of magnet to irregular metal particles (magnet / the metal particles) of 3 or less. A method for producing an R—Fe—B-based bonded magnet.