JPH10321427A - Rare-earth magnet of high electric resistance and manufacture thereof - Google Patents
Rare-earth magnet of high electric resistance and manufacture thereofInfo
- Publication number
- JPH10321427A JPH10321427A JP9143169A JP14316997A JPH10321427A JP H10321427 A JPH10321427 A JP H10321427A JP 9143169 A JP9143169 A JP 9143169A JP 14316997 A JP14316997 A JP 14316997A JP H10321427 A JPH10321427 A JP H10321427A
- Authority
- JP
- Japan
- Prior art keywords
- rare earth
- earth magnet
- powder
- electric resistance
- high electric
- 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]
【発明の属する技術分野】本発明は、高い電気抵抗を有
した希土類磁石およびその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare earth magnet having a high electric resistance and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】従来より永久磁石界磁式回転電機には、
安価なフェライト磁石が多用されてきたが、近年の回転
電機の小型化・高性能化の要求に伴い、より高性能な希
土類磁石の使用量が年々増加してきている。代表的な希
土類永久磁石としてはＳｍ−Ｃｏ系磁石、Ｎｄ−Ｆｅ−
Ｂ系磁石が挙げられ、さらなる高性能化が進行してい
る。2. Description of the Related Art Conventionally, permanent magnet field type rotary electric machines have
Although inexpensive ferrite magnets have been frequently used, the use of higher performance rare earth magnets has been increasing year by year due to the recent demand for smaller and higher performance rotating electric machines. Typical rare earth permanent magnets include Sm-Co based magnets and Nd-Fe-
B-based magnets are cited, and higher performance is being developed.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら希土類磁
石は金属磁石である為に電気抵抗が低く、回転電機に組
み込んだ場合渦電流損失が増大し、モータ効率を低下さ
せるという問題が発生する。そこで界磁用希土類磁石自
体の電気抵抗を高める提案がなされている。例えば樹脂
バインダーを使用したＮｄ−Ｆｅ−Ｂ系希土類ボンド磁
石の電気抵抗は10-2Ω・cmオーダーでありＮｄ−Ｆｅ−
Ｂ系希土類焼結磁石と比較して２オーダー高い電気抵抗
を有しているが、冷凍機などのコンプレッサ用モータに
使用した場合冷媒として用いる代替えフロン等により樹
脂バインダーが劣化する耐溶媒性が悪い問題がある。ま
た特開平５−１２１２２０号には、ボンド磁石粉をゾル
・ゲル法等により無機バインダーをコートした後に成形
金型中で直接圧縮通電し、フル密度磁石を得る方法が提
案されている。しかし、このものは磁石を硬化する際に
無機バインダーのガラス転移温度（約500℃）以上の加
熱を必要とする為にバインダーとの反応等による磁粉の
劣化が進行し、実用に供し得るに十分な磁気特性と高い
電気抵抗とを具備することは困難である。したがって本
発明の課題は、実用に供し得る磁気特性を維持しながら
高い電気抵抗と良好な耐溶媒性とを備えた高電気抵抗希
土類磁石およびその製造方法を提供することである。However, since the rare earth magnet is a metal magnet, its electric resistance is low, and when it is incorporated in a rotating electric machine, a problem arises that eddy current loss increases and motor efficiency decreases. Therefore, proposals have been made to increase the electric resistance of the field rare earth magnet itself. For example, the electric resistance of an Nd-Fe-B-based rare earth bonded magnet using a resin binder is of the order of 10 -2 Ω · cm, and Nd-Fe-B
Although it has an electrical resistance two orders of magnitude higher than that of B-based rare earth sintered magnets, when used in compressor motors such as refrigerators, the resin binder deteriorates due to chlorofluorocarbon substitutes used as refrigerants. Poor solvent resistance. There's a problem. Japanese Patent Application Laid-Open No. 5-121220 proposes a method of obtaining a full-density magnet by coating a bonded magnet powder with an inorganic binder by a sol-gel method or the like, and then applying a direct compression current in a molding die. However, this requires heating at a temperature higher than the glass transition temperature (about 500 ° C.) of the inorganic binder when the magnet is cured, so that the deterioration of the magnetic powder due to the reaction with the binder and the like progresses, which is sufficient for practical use. It is difficult to provide excellent magnetic properties and high electric resistance. Accordingly, an object of the present invention is to provide a high electric resistance rare earth magnet having high electric resistance and good solvent resistance while maintaining practical magnetic properties, and a method for manufacturing the same.
【０００４】[0004]
【課題を解決するための手段】上記課題を解決した本発
明は、希土類磁石粉末粒子をSiO2および／またはAl2O 3
粒子で結着したことを特徴とする高電気抵抗希土類磁石
である。したがって、樹脂バインダーを用いた希土類ボ
ンド磁石で問題となる耐溶媒性を大きく改善することが
できる。本発明では、希土類磁石粉末粒子がSiO2および
／またはAl2O3粒子で被覆されているとともにその被覆
厚みが１〜１０μｍであるように構成すると、高い電気
抵抗を獲得できると同時に単位体積に占める希土類磁石
粉末粒子の比率の減少を小さく抑えることが可能で高い
磁気特性を維持できるので好ましい。被覆厚みが１μｍ
未満では希土類磁石粉末粒子間の絶縁性が顕著に低下
し、１０μｍを越えると磁石体積率が減少して過度の磁
気特性低下を伴うので好ましくない。また、本発明の高
電気抵抗希土類磁石の表面が希土類磁石粉末粒子の耐食
性を向上させる樹脂（例えばフッ素樹脂等。）で５〜１
００μｍの被覆厚みで被覆されると、希土類磁石粉末が
R2T14B相,Rリッチ相を有した超急冷磁石粉末、R2T14Bを
主相とした異方性磁石粉末、R-Co系磁石粉末のうちのい
ずれか１種または２種以上である場合でも耐食性を改善
可能である。５μｍ未満では耐食性付与が困難であり、
１００μｍを越えると所定の寸法公差に形成できない場
合があるので好ましくない。[MEANS FOR SOLVING THE PROBLEMS]
Akira uses rare earth magnet powder particles as SiOTwoAnd / or AlTwoO Three
High electric resistance rare earth magnet characterized by binding with particles
It is. Therefore, rare earth elements using resin binder
Can greatly improve solvent resistance, which is a problem with
it can. In the present invention, the rare earth magnet powder particlesTwoand
/ Or AlTwoOThreeCoated with particles and its coating
If the thickness is configured to be 1 to 10 μm, high electricity
Rare earth magnet occupying unit volume while obtaining resistance
It is possible to keep the decrease in the ratio of powder particles small and high
This is preferable because magnetic properties can be maintained. The coating thickness is 1μm
If less than 10, the insulation between the rare earth magnet powder particles is significantly reduced.
If it exceeds 10 μm, the volume ratio of the magnet decreases
It is not preferable because the air quality is deteriorated. In addition, the present invention
Resistance of rare earth magnet powder particles
5 to 1 with a resin (for example, a fluororesin or the like) for improving the property
When coated with a coating thickness of 00 μm, the rare earth magnet powder
RTwoT14Super quenched magnet powder with B phase and R rich phase, RTwoT14B
Of the anisotropic magnet powder used as the main phase, R-Co magnet powder
Improves corrosion resistance even when one or two or more types are used
It is possible. If it is less than 5 μm, it is difficult to impart corrosion resistance,
If it exceeds 100 μm, it cannot be formed to the specified dimensional tolerance.
It is not preferable because there are cases.
【０００５】次に、本発明は、希土類磁石粉末に対して
液状無機バインダーを添加し混練後、その混練スラリー
を乾燥し、続いてその乾燥したものを粉砕した粉末を成
形し、さらにその成形体を室温から200℃の温度範囲に
おいて硬化させることを特徴とする高電気抵抗希土類磁
石の製造方法である。本発明では、液体無機バインダー
が粒径１０〜１００ｎｍの微細なSiO2および／またはAl
2O3粉末粒子をＰＨ８〜１２に調整した水溶液中に分散
させたものであり、混練スラリーを室温における真空脱
水で乾燥するとともに、成形時に前記粉砕粉に対してＰ
Ｈ７〜１２の水溶液、アルコール、アセトンのいずれか
を添加することが好ましい。本発明者等は、例えばR2T
14B相またはR2T17相を有する磁石粉末（但しRはYを含む
希土類元素のうち少なくとも１種、TはＦｅまたはＣｏ
を主体とする遷移金属のうちの少なくとも１種）に対
し、液状無機バインダーを添加・混練し、その混合スラ
リーを乾燥・粉砕した後に成形し200℃以内の温度範囲
において硬化することにより、10-2Ω・cm以上の電気抵
抗率を有し耐溶媒性の高いバルク状希土類磁石およびそ
の製造方法を見い出した。この液状無機バインダーは、
粒径１０〜１００μｍの微細SiO2および／またはAl2O3
粉末粒子をＰＨ８〜１２に調整した水溶液中に分散させ
たいわゆるコロイダルシリカおよび／またはコロイダル
アルミナであり、磁石粉末のR元素との反応を避けるた
め200℃以下で硬化させる（磁石粉末を結着させる）こ
とが好ましい。[0005] Next, the present invention relates to a method for adding a liquid inorganic binder to a rare earth magnet powder, kneading the mixture, drying the kneaded slurry, forming a pulverized powder from the dried slurry, and further molding the powder. Is cured in a temperature range from room temperature to 200 ° C. to produce a high electric resistance rare earth magnet. In the present invention, the liquid inorganic binder is fine SiO 2 and / or Al having a particle size of 10 to 100 nm.
2 O 3 powder particles are dispersed in an aqueous solution adjusted to PH 8 to 12, and the kneaded slurry is dried by vacuum dehydration at room temperature, and P
It is preferable to add an aqueous solution of H7-12, alcohol, or acetone. The present inventors, for example, R 2 T
Magnet powder having 14 B phase or R 2 T 17 phase (where R is at least one of rare earth elements including Y, T is Fe or Co
For at least one) of the transition metal mainly containing, by adding and kneading a liquid inorganic binder to cure at a temperature range within molded 200 ° C. After drying and pulverizing the mixture slurry, 10 - A bulk rare earth magnet having an electrical resistivity of 2 Ω · cm or more and high solvent resistance and a method for producing the same have been found. This liquid inorganic binder is
Fine SiO 2 and / or Al 2 O 3 with a particle size of 10 to 100 μm
It is a so-called colloidal silica and / or colloidal alumina in which powder particles are dispersed in an aqueous solution adjusted to pH 8 to 12, and is hardened at 200 ° C or lower to avoid reaction with the R element of the magnet powder (to bind the magnet powder) Is preferred.
【０００６】原料である希土類磁石粉末は、例えばR2T
14B相,Rリッチ相を有する超急冷磁石粉末、R2T14B主相
を含む異方性磁石粉末、R-Co系磁石粉末のいずれかをデ
ィスクミル等で粉砕し、粒径を500μm以下に調整したも
のを使用する。次に得られた磁石粉末に対して、上記粒
径範囲の微細なSiO2および／またはAl2O3粉末が分散し
ている液状無機バインダーを添加・混練し、室温におい
てロータリポンプ等により脱水・乾燥する。なお希土類
磁石粉末と液状無機バインダーとの混合比により、電気
抵抗率、磁気特性、強度等が変化するので、この混合比
は用途に応じて適宜選択すれば良い。例えば乾燥後の原
料を、再度ディスクミル等で粉砕し粒径を88〜500μmに
ふるい分けた後に所定の成形金型内に挿入し、等方性磁
粉を使用の場合は無磁場で、異方性磁粉を使用の場合は
磁場中において所定の形状に成形する。なお成形金型内
に給粉後、原料粉砕粉に対してPH7〜12の水溶液、アル
コール、アセトンのいずれかを10〜15wt%添加すること
で得られる希土類磁石の強度と電気抵抗率が大きくな
る。これは、乾燥により接着能力の低下した無機バイン
ダー成分を再度溶解させることで、（１）原料粉間の接
合力を高める、（２）粉砕工程において生じた活性な希
土類磁石粉末の非被覆面を再度被覆する、という２つの
効果が生じるためである。こうして得られた成形体を真
空または窒素等の不活性ガスフロー中において熱硬化処
理を行う。加熱温度は希土類磁石粉末のR元素との反応
を避けるため室温〜２００℃とすることが好ましい。以
上の工程を経て実用に供し得る高い電気抵抗率と磁気特
性と耐溶媒性を備えた希土類磁石が得られる。さらに、
本発明によれば、従来の樹脂バインダーで結着した希土
類ボンド磁石を凌駕する機械的強度の高電気抵抗希土類
磁石を提供できる。The rare earth magnet powder as a raw material is, for example, R 2 T
14 B phase, super-quenched magnet powder having R-rich phase, anisotropic magnet powder containing R 2 T 14 B main phase, or R-Co magnet powder is pulverized with a disc mill or the like to have a particle size of 500 μm. Use the one adjusted below. Next, to the obtained magnet powder, a liquid inorganic binder in which fine SiO 2 and / or Al 2 O 3 powder having the above-mentioned particle size range is dispersed is added and kneaded, and dewatered by a rotary pump or the like at room temperature. dry. The electric resistivity, magnetic properties, strength, and the like change depending on the mixing ratio of the rare earth magnet powder and the liquid inorganic binder. The mixing ratio may be appropriately selected depending on the application. For example, the dried raw material is again pulverized by a disc mill or the like, sieved to a particle size of 88 to 500 μm, and then inserted into a predetermined molding die.If using isotropic magnetic powder, no magnetic field, anisotropic When magnetic powder is used, it is formed into a predetermined shape in a magnetic field. After the powder is fed into the molding die, the strength and electric resistivity of the rare earth magnet obtained by adding 10 to 15 wt% of any of aqueous solution of PH7 to 12, alcohol and acetone to the raw material pulverized powder increase . This is because the inorganic binder component whose adhesive ability has been reduced by drying is redissolved to (1) increase the bonding strength between the raw material powders, and (2) remove the uncoated surface of the active rare earth magnet powder generated in the pulverizing step. This is because two effects of re-coating occur. The molded body thus obtained is subjected to a thermosetting treatment in a vacuum or an inert gas flow such as nitrogen. The heating temperature is preferably room temperature to 200 ° C. in order to avoid a reaction with the R element of the rare earth magnet powder. Through the above steps, a rare-earth magnet having high electric resistivity, magnetic properties and solvent resistance that can be put to practical use is obtained. further,
According to the present invention, it is possible to provide a high electric resistance rare earth magnet having mechanical strength superior to that of a conventional rare earth bonded magnet bound with a resin binder.
【０００７】[0007]
【発明の実施の形態】以下実施例により本発明を説明す
るが、下記実施例により本発明が限定されるものではな
い。 （実施例１）原料磁粉としてNd11.9FebalCo5.6B5.3Zr
0.04(at%)の組成を有する超急冷法によるMQI社製Nd-Fe-
B系等方性磁石粉末（B材）を用いた。また、PH12に調整
した水溶液中に平均粒径２０ｎｍのSiO2粒子を分散させ
た液状無機バインダー（SiO2含有量35.4wt%）を準備
し、以下の工程で本発明の高電気抵抗希土類磁石を製造
した。まず、（上記磁粉を粒径500μm以下に調整したも
の）：（上記液状無機バインダー）＝100：15の重量比
で秤量後、両者を混練し、室温２０℃においてロータリ
ーポンプにより脱水・乾燥した。なお乾燥後のものは半
硬化状態にある為、ディスクミルにて粉砕し成形可能な
粉砕原料粉とした。次にこの粉砕原料粉に対してＰＨ８
の純水を10wt%添加した後に、成形圧8ton/cm2において
成形し、得られた成形体をN2フロー中において95℃×2.
5h＋150℃×2.5hの加熱条件で硬化処理を施しバルク状
の高電気抵抗希土類磁石とした。表１に得られたこのバ
ルク状磁石の代表的な密度、および２０℃における電気
抵抗率と磁気特性と圧壊強度の測定結果を示す。また、
図１にこのバルク状磁石の代表的な破面を走査電子顕微
鏡により観察した組織を、図２には図１に対応したスケ
ッチを示す。また、圧壊強度の測定は図３に示す測定条
件で行った。圧壊強度測定用試料を直径（ｄ）１０．２
ｍｍ、厚み（ｔ）７ｍｍの円柱状に形成し、この試料の
径方向から加圧力Ｆ（ｋｇｆ）を加え、破壊に至る最大
加圧力Ｆｍａｘ（ｋｇｆ）に対して、 （圧壊強度）＝
（Ｆｍａｘ）÷（ｄ×ｔ） で定義した。 （比較例１）実施例１の磁粉をエポキシ樹脂で結着した
従来の樹脂ボンド磁石に対して実施例１と同様にして評
価した結果を表１に併記した。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. (Example 1) Nd 11.9 Febal Co 5.6 B 5.3 Zr as raw material magnetic powder
Nd-Fe- manufactured by MQI by ultra-quenching method having a composition of 0.04 (at%)
B type isotropic magnet powder (material B) was used. Further, a liquid inorganic binder (SiO 2 content: 35.4 wt%) in which SiO 2 particles having an average particle diameter of 20 nm were dispersed in an aqueous solution adjusted to PH12 was prepared, and the high electric resistance rare earth magnet of the present invention was prepared in the following steps. Manufactured. First, the magnetic powder was adjusted to a particle size of 500 μm or less, and the liquid inorganic binder was weighed at a weight ratio of 100: 15. Then, both were kneaded, and the mixture was dehydrated and dried with a rotary pump at room temperature of 20 ° C. Since the dried product was in a semi-cured state, it was pulverized with a disk mill to obtain a pulverizable raw material powder. Next, PH8
Pure water after the addition 10 wt%, molding pressure and molding at 8 ton / cm 2, the resulting molded body N 95 ° C. × 2 in a 2 flow.
A hardening treatment was performed under the heating conditions of 5 h + 150 ° C. × 2.5 h to obtain a bulk high electric resistance rare earth magnet. Table 1 shows typical densities of the obtained bulk magnets, and measurement results of electric resistivity, magnetic properties and crushing strength at 20 ° C. Also,
FIG. 1 shows the structure of a typical fracture surface of the bulk magnet observed by a scanning electron microscope, and FIG. 2 shows a sketch corresponding to FIG. The measurement of the crushing strength was performed under the measurement conditions shown in FIG. The sample for crushing strength measurement was 10.2 in diameter (d).
mm and a thickness (t) of 7 mm in a columnar shape. A pressing force F (kgf) is applied from the radial direction of the sample, and the maximum pressing force Fmax (kgf) that leads to fracture is: (crushing strength) =
(Fmax) ÷ (d × t). (Comparative Example 1) Table 1 also shows the results of evaluation of a conventional resin-bonded magnet obtained by binding the magnetic powder of Example 1 with an epoxy resin in the same manner as in Example 1.
【０００８】[0008]
【表１】 [Table 1]
【０００９】表１より、本発明品（実施例１）の電気抵
抗率は10-2Ω・cmのオーダーであり、Nd-Fe-B系焼結磁
石に比べ100倍以上の値である。これは図１および図２
から明らかなように、上記液状無機バインダーが希土類
磁石粉末粒子と良好な濡れ性を有し混練されることで希
土類磁石粉末粒子表面を無機バインダーが１〜１０μｍ
厚みに薄くほぼ均一に被覆した結果、希土類磁石粉末粒
子間の絶縁性を良好に維持するとともに、単位体積に占
める希土類磁石分の体積比率の低下を小さく抑えて実用
に供し得る磁気特性を確保することができているためと
判定される。また、この実施例１のバルク状磁石表面全
体をフッ素樹脂（ポリテトラフルオロエチレン）で被覆
平均厚み３０μｍにコーティングしたものを用いたコン
プレッサ用モータでは良好な耐溶媒性を示した。実施例
１に対して比較例１のものは磁気特性は同等であるが、
電気抵抗率は約１／３倍、圧壊強度は約２／３となって
いる。また、この比較例１のボンド磁石を用いたコンプ
レッサ用モータでは使用とともにそのボンド磁石の樹脂
バインダーの劣化が進行していた。上記の通り、本発明
の高電気抵抗希土類磁石は、樹脂バインダーを用いた従
来の希土類ボンド磁石では対応できない過酷な耐溶媒性
が要求される用途、さらには高い機械的強度を要求され
る用途に有用なものである。From Table 1, the electrical resistivity of the product of the present invention (Example 1) is on the order of 10 -2 Ω · cm, which is 100 times or more the value of the Nd-Fe-B sintered magnet. This is shown in FIG. 1 and FIG.
As is apparent from the above, the liquid inorganic binder is kneaded with the rare earth magnet powder particles and has good wettability, so that the surface of the rare earth magnet powder particles is 1 to 10 μm.
As a result of thin and almost uniform coating of the thickness, the insulation between the rare earth magnet powder particles is maintained well, and the reduction in the volume ratio of the rare earth magnet in the unit volume is kept small to secure magnetic properties that can be used practically. It is determined that it is possible. In addition, the motor for a compressor using the entire surface of the bulk magnet of Example 1 coated with a fluororesin (polytetrafluoroethylene) to have an average thickness of 30 μm exhibited good solvent resistance. The magnetic characteristics of Comparative Example 1 are the same as those of Example 1;
The electrical resistivity is about 1/3 times and the crushing strength is about 2/3. Further, in the compressor motor using the bonded magnet of Comparative Example 1, the resin binder of the bonded magnet deteriorated with use. As described above, the high electric resistance rare earth magnet of the present invention is used in applications requiring severe solvent resistance that cannot be handled by conventional rare earth bonded magnets using a resin binder, and further in applications requiring high mechanical strength. It is useful.
【００１０】（実施例２）原料磁粉としてNd12.5FebalC
o17.5B6.6Ga0.2Zr0.1Si0.1(at%)の組成を有するMQI社製
Nd-Fe-B系異方性磁石粉末（水素吸脱法によるR2Fe14B系
異方性磁石粉末）を用いた。また、無機バインダーとし
て実施例１のSiO2系液状無機バインダーを選択し、成形
条件を成形圧8ton/cm2、印加磁界11.5kOeの横磁場成形
とした以外は実施例１と同様にしてバルク状磁石を製造
し、得られたバルク状磁石の密度、電気抵抗率、磁気特
性、圧壊強度を測定した結果を表２に示す。 （比較例２）実施例２の原料磁粉をエポキシ樹脂で結着
した従来の樹脂ボンド磁石に対して実施例２と同様にし
て評価した結果を表２に併記した。(Example 2) Nd 12.5 Fe bal C as raw material magnetic powder
o 17.5 B 6.6 Ga 0.2 Zr 0.1 Made by MQI with a composition of 0.1 (at%)
Nd-Fe-B-based anisotropic magnet powder (R 2 Fe 14 B-based anisotropic magnet powder by a hydrogen absorption / desorption method) was used. In addition, except that the SiO 2 -based liquid inorganic binder of Example 1 was selected as the inorganic binder, and the molding conditions were a transverse magnetic field molding with a molding pressure of 8 ton / cm 2 and an applied magnetic field of 11.5 kOe, a bulk state was formed in the same manner as in Example 1. Table 2 shows the results of measuring the density, electric resistivity, magnetic properties, and crushing strength of the obtained bulk magnets after manufacturing the magnets. (Comparative Example 2) Table 2 also shows the results of evaluation of a conventional resin-bonded magnet in which the raw material magnetic powder of Example 2 was bound with an epoxy resin in the same manner as in Example 2.
【００１１】[0011]
【表２】 [Table 2]
【００１２】表２より、実施例２のものは比較例２に比
べてＢｒ、ｉＨｃ、電気抵抗率、圧壊強度が高いことが
わかった。From Table 2, it was found that Example 2 had higher Br, iHc, electrical resistivity and crushing strength than Comparative Example 2.
【００１３】（実施例３）原料磁粉としてSm10.7Co53.7
Fe28.5Cu5.68Zr1.43(at%)の組成を有する2-17型Sm-Co系
磁石粉末を用いた。また、無機バインダーとしてはPH8
に調整した水溶液中に３０ｎｍのAl2O3粒子を分散させ
たAl2O3系液状無機バインダー（Al2O3含有量7.9wt%）を
選択し、混合重量比は（前記液状無機バインダー）：
（前記磁粉）＝１：１とし、成形条件は印加磁界11.5kO
e,成形圧8ton/cm2における横磁場成形とした以外は実施
例１と同様にしてバルク状磁石を製作し、評価した密
度、電気抵抗率、磁気特性、圧壊強度の値を示す。 （比較例３）実施例３の原料磁粉をエポキシ樹脂で結着
した従来の樹脂ボンド磁石に対して実施例３と同様の評
価を行った結果を表３に併記した。Example 3 Sm 10.7 Co 53.7 as raw material magnetic powder
A 2-17 type Sm-Co magnet powder having a composition of Fe 28.5 Cu 5.68 Zr 1.43 (at%) was used. PH8 is used as an inorganic binder.
An Al 2 O 3 -based liquid inorganic binder (Al 2 O 3 content: 7.9 wt%) in which 30 nm Al 2 O 3 particles are dispersed in an aqueous solution adjusted to the above was selected, and the mixing weight ratio was (the liquid inorganic binder). :
(The above magnetic powder) = 1: 1, and the molding conditions were applied magnetic field of 11.5 kO.
e, A bulk magnet was manufactured in the same manner as in Example 1 except that the transverse magnetic field was molded at a molding pressure of 8 ton / cm 2, and the values of the evaluated density, electrical resistivity, magnetic properties, and crushing strength are shown. (Comparative Example 3) Table 3 also shows the results of the same evaluation as in Example 3 performed on a conventional resin-bonded magnet obtained by binding the raw material magnetic powder of Example 3 with an epoxy resin.
【００１４】[0014]
【表３】 [Table 3]
【００１５】表３より、比較例３に比べて実施例３のも
のが優れていることが明らかである。From Table 3, it is clear that Example 3 is superior to Comparative Example 3.
【００１６】[0016]
【発明の効果】上記の通り、本発明の高電気抵抗希土類
磁石は、絶縁層を構成する非磁性の無機バインダーが希
土類磁石粉末粒子の表面全体を薄く被覆しかつその磁石
粉末粒子同士を強固に結着しているので、良好な絶縁性
とともにバルク状磁石に占める磁石体積分の減少率を小
さく抑えられる結果磁気特性の低下を小さく抑えること
ができている。また、樹脂バインダーを用いていないの
で耐溶媒性に優れるとともに、高い機械的強度を有した
有用なものである。したがって、本発明の高電気抵抗希
土類磁石は上記のコンプレッサ用モータに代表される耐
溶媒性の過酷な用途や、回転電機の渦電流対策用途に極
めて有効である。As described above, in the high electric resistance rare earth magnet of the present invention, the nonmagnetic inorganic binder constituting the insulating layer thinly covers the entire surface of the rare earth magnet powder particles and firmly bonds the magnet powder particles to each other. Because of the binding, the reduction rate of the magnet volume occupied in the bulk magnet can be suppressed to a small degree with good insulating properties, and as a result, the deterioration of the magnetic properties can be suppressed to a small value. In addition, since the resin binder is not used, it is excellent in solvent resistance and has a high mechanical strength and is useful. Therefore, the high electric resistance rare earth magnet of the present invention is extremely effective for severe use of solvent resistance represented by the above-described compressor motor and for eddy current countermeasures of a rotating electric machine.
【図1】本発明の高電気抵抗希土類磁石の破断面の金属
組織である。FIG. 1 is a metal structure of a fracture surface of a high electric resistance rare earth magnet of the present invention.
【図２】図１に対応したスケッチである。FIG. 2 is a sketch corresponding to FIG.
【図３】圧壊強度の測定方法を説明する図である。FIG. 3 is a diagram illustrating a method for measuring crushing strength.
Claims (6)
はAl2O3粒子で結着したことを特徴とする高電気抵抗希
土類磁石。1. A high electric resistance rare earth magnet characterized in that rare earth magnet powder particles are bound with SiO 2 and / or Al 2 O 3 particles.
はAl2O3粒子で被覆されているとともに、その被覆厚み
が１〜１０μｍであることを特徴とする請求項１に記載
の高電気抵抗希土類磁石。2. The high electric resistance according to claim 1, wherein the rare earth magnet powder particles are coated with SiO 2 and / or Al 2 O 3 particles, and the coating thickness is 1 to 10 μm. Rare earth magnet.
土類磁石の表面が希土類磁石粉末粒子の耐食性を向上さ
せる樹脂で被覆されていることを特徴とする高電気抵抗
希土類磁石。3. The high electric resistance rare earth magnet according to claim 1, wherein the surface of the high electric resistance rare earth magnet according to claim 1 or 2 is coated with a resin for improving the corrosion resistance of the rare earth magnet powder particles.
有した超急冷磁石粉末、R2T14Bを主相とした異方性磁石
粉末、R-Co系磁石粉末のうちのいずれか１種または２種
以上であることを特徴とする請求項１乃至３のいずれか
に記載の高電気抵抗希土類磁石。4. A rare-earth magnet powder comprising an R 2 T 14 B phase, a super-quenched magnet powder having an R-rich phase, an anisotropic magnet powder having R 2 T 14 B as a main phase, and an R-Co magnet powder. The high electric resistance rare earth magnet according to any one of claims 1 to 3, wherein at least one of them is used.
ダーを添加し混練後、その混練スラリーを乾燥し、続い
てその乾燥したものを粉砕した粉末を成形し、さらにそ
の成形体を室温から200℃の温度範囲において硬化させ
ることを特徴とする高電気抵抗希土類磁石の製造方法。5. A rare earth magnet powder to which a liquid inorganic binder is added and kneaded, the kneaded slurry is dried, and the dried powder is pulverized to form a powder. A method for producing a high electric resistance rare earth magnet, wherein the magnet is cured in a temperature range of:
ｎｍの微細なSiO2および／またはAl2O3粉末粒子をＰＨ
８〜１２に調整した水溶液中に分散させたものであり、
混練スラリーを室温における真空脱水で乾燥させるとと
もに、成形時に前記粉砕粉に対してＰＨ７〜１２の水溶
液、アルコール、アセトンのいずれかを添加することを
特徴とする請求項５に記載の高電気抵抗希土類磁石の製
造方法。6. The liquid inorganic binder has a particle size of 10 to 100.
nm fine SiO 2 and / or Al 2 O 3 powder particles
Is dispersed in an aqueous solution adjusted to 8 to 12,
The high electric resistance rare earth according to claim 5, wherein the kneaded slurry is dried by vacuum dehydration at room temperature, and any one of an aqueous solution of PH7 to 12, an alcohol, and acetone is added to the pulverized powder during molding. Manufacturing method of magnet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9143169A JPH10321427A (en) | 1997-05-16 | 1997-05-16 | Rare-earth magnet of high electric resistance and manufacture thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9143169A JPH10321427A (en) | 1997-05-16 | 1997-05-16 | Rare-earth magnet of high electric resistance and manufacture thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10321427A true JPH10321427A (en) | 1998-12-04 |
Family
ID=15332529
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9143169A Pending JPH10321427A (en) | 1997-05-16 | 1997-05-16 | Rare-earth magnet of high electric resistance and manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10321427A (en) |
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| WO2002071424A1 (en) * | 2001-03-07 | 2002-09-12 | Shunichi Haruyama | Method for manufacturing ring-shaped magnet, material for the ring-shaped magnet, and cutting resin |
| US6585831B2 (en) | 1999-12-27 | 2003-07-01 | Sumitomo Special Metals Co., Ltd. | Method of making iron base magnetic material alloy powder |
| US6984271B2 (en) | 2003-03-28 | 2006-01-10 | Nissan Motor Co., Ltd. | Rare earth magnet, process for producing same, and motor using rare earth magnet |
| US7147686B2 (en) | 2002-06-27 | 2006-12-12 | Nissan Motor Co., Ltd. | Rare earth magnet, method for manufacturing the same, and motor using rare earth magnet |
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| JP2008130780A (en) * | 2006-11-21 | 2008-06-05 | Hitachi Ltd | Rare-earth magnet |
| US7608153B2 (en) | 2003-12-22 | 2009-10-27 | Nissan Motor Co., Ltd. | Rare earth magnet and method therefor |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6585831B2 (en) | 1999-12-27 | 2003-07-01 | Sumitomo Special Metals Co., Ltd. | Method of making iron base magnetic material alloy powder |
| WO2002071424A1 (en) * | 2001-03-07 | 2002-09-12 | Shunichi Haruyama | Method for manufacturing ring-shaped magnet, material for the ring-shaped magnet, and cutting resin |
| US7147686B2 (en) | 2002-06-27 | 2006-12-12 | Nissan Motor Co., Ltd. | Rare earth magnet, method for manufacturing the same, and motor using rare earth magnet |
| US6984271B2 (en) | 2003-03-28 | 2006-01-10 | Nissan Motor Co., Ltd. | Rare earth magnet, process for producing same, and motor using rare earth magnet |
| US7608153B2 (en) | 2003-12-22 | 2009-10-27 | Nissan Motor Co., Ltd. | Rare earth magnet and method therefor |
| KR100945068B1 (en) * | 2006-03-13 | 2010-03-05 | 가부시키가이샤 히타치세이사쿠쇼 | Magnet using a binding agent and method thereof |
| EP1835514A3 (en) * | 2006-03-13 | 2010-01-06 | Hitachi, Ltd. | Magnet using binding agent and method of manufacturing the same |
| JP2007281433A (en) * | 2006-03-13 | 2007-10-25 | Hitachi Ltd | Bound magnet produced using binder, and its manufacturing method |
| US7914695B2 (en) | 2006-03-13 | 2011-03-29 | Hitachi, Ltd. | Magnet using binding agent and method of manufacturing the same |
| JP2008130780A (en) * | 2006-11-21 | 2008-06-05 | Hitachi Ltd | Rare-earth magnet |
| US7927501B2 (en) * | 2006-11-21 | 2011-04-19 | Hitachi, Ltd. | Rare earth element magnet and method of manufacturing same |
| JP2013509734A (en) * | 2009-11-05 | 2013-03-14 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング | Method for manufacturing a magnet and magnet and electric machine |
| EP2497094A1 (en) * | 2009-11-05 | 2012-09-12 | Robert Bosch GmbH | Method for producing a magnet, magnet, and electric machine |
| US9147524B2 (en) | 2011-08-30 | 2015-09-29 | General Electric Company | High resistivity magnetic materials |
| US10049798B2 (en) | 2011-08-30 | 2018-08-14 | General Electric Company | High resistivity magnetic materials |
| DE102013213494A1 (en) * | 2013-07-10 | 2015-01-29 | Volkswagen Aktiengesellschaft | Method for producing a permanent magnet and permanent magnet and electric machine with such a permanent magnet |
| CN107301916A (en) * | 2016-04-15 | 2017-10-27 | 北京中科三环高技术股份有限公司 | Anisotropy neodymium iron boron binding magnet and preparation method thereof |
| CN111029074A (en) * | 2019-12-30 | 2020-04-17 | 江西师范大学 | Preparation method of sintered rare earth iron boron permanent magnet material for regulating grain boundary |
| CN111029074B (en) * | 2019-12-30 | 2022-05-17 | 江西师范大学 | Preparation method of sintered rare earth iron boron permanent magnet material for regulating grain boundary |
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