JPH07240331A - Manufacture of rare-earth intermetallic compound magnet - Google Patents
Manufacture of rare-earth intermetallic compound magnetInfo
- Publication number
- JPH07240331A JPH07240331A JP6031408A JP3140894A JPH07240331A JP H07240331 A JPH07240331 A JP H07240331A JP 6031408 A JP6031408 A JP 6031408A JP 3140894 A JP3140894 A JP 3140894A JP H07240331 A JPH07240331 A JP H07240331A
- Authority
- JP
- Japan
- Prior art keywords
- intermetallic compound
- rare earth
- lubricant
- earth intermetallic
- molded 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
- H01F1/0577—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 sintered
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は希土類金属間化合物磁石
の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rare earth intermetallic compound magnet.
【０００２】[0002]
【従来の技術】近年、電子機器や精密機械の小型化、軽
量化の市場動向に伴い、永久磁石においては従来のアル
ニコやフェライト磁石に代わり希土類磁石が多くの分野
で利用されるようになってきた。希土類磁石は一部の用
途を除いて粉末冶金法を利用し製造されている。希土類
磁石の中でもＮｄ-Ｆｅ-Ｂ系希土類金属間化合物永久磁
石の需要が増加している。Ｎｄ-Ｆｅ-Ｂ系希土類金属間
化合物磁石を粉末冶金法により製造する方法は、所望の
組成に合金を溶解しインゴットを得、これを平均粒子径
が２０〜５００μｍ程度まで粗粉砕し、これをさらに１
〜２０μｍ程度の粉末に微粉砕した後、成形し、焼結、
熱処理の工程を経る方法が一般的である。この工程の中
で、溶解鋳造インゴットから成形体を得るためには予め
機械的または化学的に２０〜５００μｍにした粗粉を１
〜２０μｍにまで微粉砕した粉末を金型中に充填した
後、０.５〜５トン／ｃｍ2で加圧することにより成形体
を得る。一般に高い磁気特性を得るために成形時に磁界
を印加し成形体に異方性を付与する。2. Description of the Related Art In recent years, along with the market trend of miniaturization and weight reduction of electronic devices and precision machines, rare earth magnets have been used in many fields in permanent magnets instead of conventional alnico and ferrite magnets. It was Rare earth magnets are manufactured using powder metallurgy except for some applications. Among rare earth magnets, the demand for Nd-Fe-B based rare earth intermetallic compound permanent magnets is increasing. A method of manufacturing an Nd-Fe-B system rare earth intermetallic compound magnet by powder metallurgy is to melt an alloy into a desired composition to obtain an ingot, which is roughly crushed to an average particle size of about 20 to 500 μm, 1 more
After finely pulverizing to a powder of about 20 μm, molding, sintering,
A method that goes through a heat treatment step is generally used. In this process, in order to obtain a molded body from the melt-casting ingot, 1 or less of coarse powder mechanically or chemically preliminarily made to 20 to 500 μm
The powder finely pulverized to ˜20 μm is filled in a mold and then pressed at 0.5 to 5 ton / cm 2 to obtain a molded body. Generally, in order to obtain high magnetic properties, a magnetic field is applied during molding to impart anisotropy to the molded body.
【０００３】しかしながら、希土類金属間化合物永久磁
石粉末の成形においては成形時に金型内壁と原料粉末あ
るいは成形体との摩擦により原料粉末が金型内壁に付着
し、金型内壁に傷を発生し金型を損傷させる。これを避
けるためには、金型ダイスの交換を繁盛に行わなければ
ならず、成形作業能率の低下、金型消却費の増加をもた
らしていた。これを避けるために、一般に金型内壁に粉
末状あるいは液状の潤滑剤を塗布する方法が実施されて
いるが、この方法では潤滑効果の永続性が無いため、繁
盛に潤滑剤の塗布を行わなければならず成形効率が低下
するという欠点を有する。However, in molding rare earth intermetallic compound permanent magnet powder, the raw material powder adheres to the inner wall of the mold due to friction between the inner wall of the mold and the raw material powder or the molded body during molding, and scratches occur on the inner wall of the mold. Damage the mold. In order to avoid this, the die dies must be exchanged vigorously, resulting in a decrease in molding work efficiency and an increase in die retirement costs. In order to avoid this, a method of applying a powdery or liquid lubricant to the inner wall of the mold is generally used, but this method does not have a permanent lubricating effect, so the lubricant must be applied vigorously. However, it has a drawback that the molding efficiency is lowered.
【０００４】金型内壁を潤滑する方法に代わる手段とし
て、原料粉末に成形性改良のための潤滑剤を添加するこ
とが提案されている。例えば、特公平５−６１３４０号
ではステアリン酸、ステアリン酸亜鉛、ビスアマイドの
少なくとも１種を、また特開平５−２１４４０６号では
固形パラフィン、樟脳のうち少なくとも１種を添加する
ことが提案されている。しかし、これらの提案は潤滑剤
を機械的な混合機で添加混合していたので以下のような
問題点がある。すなわち、機械的な混合機ではもともと
凝集性の高い潤滑剤を均一に分散させることが困難であ
り、そのため混合体に潤滑剤の凝集体が存在する。ま
た、希土類金属間化合物微粉末と潤滑剤の真比重が著し
く異なるため機械的混合においては潤滑剤を均一に分散
させることが困難である。したがって上記提案されてい
る、潤滑方法においては潤滑効果が不十分であり連続的
に成形を行うことは不可能である。また凝集した潤滑剤
が成形体中に存在すると磁気特性が劣化し品質の低下を
もたらすという欠点を有する。As an alternative to the method of lubricating the inner wall of the mold, it has been proposed to add a lubricant for improving the moldability to the raw material powder. For example, Japanese Patent Publication No. 5-61340 proposes to add at least one kind of stearic acid, zinc stearate and bisamide, and JP-A No. 5-214406 proposes to add at least one kind of solid paraffin and camphor. However, these proposals have the following problems because the lubricant is added and mixed by a mechanical mixer. That is, it is difficult to uniformly disperse a lubricant having a high cohesive property with a mechanical mixer, and therefore, a lubricant aggregate exists in the mixture. In addition, since the true specific gravities of the rare earth intermetallic compound fine powder and the lubricant are significantly different, it is difficult to uniformly disperse the lubricant in mechanical mixing. Therefore, the lubrication method proposed above has an insufficient lubrication effect, and continuous molding is impossible. Further, if the agglomerated lubricant is present in the molded body, it has a drawback that the magnetic properties are deteriorated and the quality is deteriorated.
【０００５】[0005]
【発明が解決しようとする課題】以上の問題点を解決す
る手段として、特開平４−１９１３０２号、特開平５−
９４９２２号では、以上の潤滑剤を添加した混合体を気
流式粉砕機により微粉砕し、次いで成形、焼結を行う製
造方法を提案している。（以後、粗粉潤滑という）この
粗粉潤滑によれば、潤滑剤は気流式粉砕により極めて均
一に分散する。したがって、潤滑剤は比較的少量の添加
ですみ、潤滑剤の凝集を防止することが可能である。As means for solving the above-mentioned problems, Japanese Patent Laid-Open No. 4-191302 and Japanese Patent Laid-Open No. 5-191302 are available.
Japanese Patent No. 94922 proposes a production method in which a mixture containing the above lubricant is finely pulverized by an air flow type pulverizer, and then molded and sintered. According to this coarse powder lubrication (hereinafter referred to as coarse powder lubrication), the lubricant is extremely uniformly dispersed by air flow type grinding. Therefore, it is possible to prevent the agglomeration of the lubricant by adding a relatively small amount of the lubricant.
【０００６】以上のように粗粉潤滑は極めて有効な技術
であるが、以下のような問題点を有する。すなわち、潤
滑剤が均一に分散する結果として成形体の強度が低下し
て、成形体に剥がれまたは亀裂が発生し、所望寸法精度
の焼結体を得ることが極めて困難になる。本発明は、上
記従来技術の欠点を解消し効率良く希土類金属間化合物
永久磁石粉末の成形を連続的に行うとともに、粉砕され
た微粉の耐酸化性を改善し大気中でも安定な微粉を供給
することを目的とする。本発明は、成形時の金型への粉
末の付着による金型損傷を解消し、成形体強度の低下を
引き起こすこと無く、かつ従来大気中で不安定なＮｄ-
Ｆｅ-Ｂ系希土類金属間化合物磁石粉末の連続成形を大
気中で行う手段を提供するものである。Although coarse powder lubrication is an extremely effective technique as described above, it has the following problems. That is, as a result of the uniform dispersion of the lubricant, the strength of the molded body is lowered, and peeling or cracking occurs in the molded body, making it extremely difficult to obtain a sintered body with desired dimensional accuracy. The present invention solves the above-mentioned drawbacks of the prior art and efficiently performs molding of rare earth intermetallic compound permanent magnet powder continuously, and improves the oxidation resistance of pulverized fine powder to supply fine powder stable in the atmosphere. With the goal. INDUSTRIAL APPLICABILITY The present invention eliminates mold damage due to adhesion of powder to a mold during molding, does not cause a decrease in strength of a molded body, and is Nd- which is conventionally unstable in the atmosphere.
The present invention provides a means for continuously molding Fe—B rare earth intermetallic compound magnet powder in the atmosphere.
【０００７】[0007]
【課題を解決するための手段】本発明は、Ｎｄ-Ｆｅ-Ｂ
系希土類金属間化合物永久磁石合金粗粉に炭化水素系潤
滑剤および酸化抑制剤を添加混合後に気流粉砕法により
微粉砕した後に成形、焼結をする希土類金属間化合物磁
石の製造方法であって、酸化抑制剤がトリアジンチオー
ルまたはその誘導体の１種または２種以上である希土類
金属間化合物磁石の製造方法である。SUMMARY OF THE INVENTION The present invention is based on Nd-Fe-B.
A method for producing a rare earth intermetallic compound magnet, in which a rare earth intermetallic compound permanent magnet alloy coarse powder is finely pulverized by an air flow pulverizing method after addition and mixing of a hydrocarbon lubricant and an oxidation inhibitor, and then sintered, A method for producing a rare earth intermetallic compound magnet, wherein the oxidation inhibitor is one kind or two or more kinds of triazine thiol or its derivative.
【０００８】以下本発明を詳述する。本発明において
は、まず希土類金属間化合物永久磁石合金粗粉に炭化水
素系潤滑剤および酸化抑制剤を添加混合する。混合は、
Ｖ型混合機、ヘンシエルミキサ−、ボ−ルミル等を利用
し乾式で行うかまたはアルコ−ル、アセトン、テトラヒ
ドロフランなどに潤滑剤と酸化抑制剤を溶解または分散
させた溶液中で湿式で行う。ここで、炭化水素系潤滑剤
としては流動パラフィン、天然パラフィン、マイクロク
リスタリンワックス、ポリエチレンワックス、合成パラ
フィン、塩素化ナフタリン等が有効である。また酸化抑
制剤としてトリアジンチオ−ルおよびその誘導体が有効
である。これらの添加混合体を次いでジェットミル等の
気流粉砕法にて１〜２０μｍに微粉砕する。微粉砕工程
において、炭化水素系潤滑剤は粉末表面に溶融固着し微
粉末表面に均一に塗布される。この溶融塗布された潤滑
剤は微粉末粒子間および粒子と金型内壁との摩擦を低減
する。添加する潤滑剤の形態は特に制約は無いが、効率
よく均一な分散を行うためには粉末状の潤滑剤が好まし
い。炭化水素系の潤滑剤の添加量が０.０５ｗｔ％以下
では十分な潤滑効果が得られない。また５.０ｗｔ％以
上の添加では成形体強度が著しく低下するばかりでな
く、焼結体中に許容範囲以上のＣが残留し磁気特性を著
しく低下させる。したがって、炭化水素系潤滑剤の添加
量は０.０５〜５.０ｗｔ％、さらに好ましくは０.５〜
２.０ｗｔ％である。酸化抑制剤として使用されるトリ
アジンチオ−ルまたはその誘導体の分解温度は３００℃
以下であることが好ましい。酸化抑制剤を混合すること
により希土類磁石粉末と潤滑剤との界面に酸化抑制剤の
膜が形成され微粉の酸化が抑制されるとともに、トリア
ジンチオ−ルはシランカップリング剤と同様カップリン
グ効果を有するため磁石粉末と潤滑剤の結合効果を強め
るため成形体強度が改善されるとともに、成形体離型時
の抜き圧が低下する。酸化抑制剤の添加量は０.０１〜
２ｗｔ％さらに好ましくは０.０１〜０.２％とするのが
良い。これら酸化抑制剤は一般にはヘキサン等の極性の
低い有機溶媒への溶解量が少ないため２ｗｔ％以上の添
加は成形体の脱脂を困難にし磁気特性の低下をもたら
す。The present invention will be described in detail below. In the present invention, first, a hydrocarbon-based lubricant and an oxidation inhibitor are added to and mixed with the rare earth intermetallic compound permanent magnet alloy coarse powder. Mixing
It is carried out by a dry method using a V-type mixer, a Henschel mixer, a ball mill or the like, or a wet method in a solution in which a lubricant and an oxidation inhibitor are dissolved or dispersed in alcohol, acetone, tetrahydrofuran or the like. Here, as the hydrocarbon-based lubricant, liquid paraffin, natural paraffin, microcrystalline wax, polyethylene wax, synthetic paraffin, chlorinated naphthalene, etc. are effective. Also, triazinethiol and its derivatives are effective as an oxidation inhibitor. These added mixtures are then finely pulverized to 1 to 20 μm by an air flow pulverization method such as a jet mill. In the pulverizing step, the hydrocarbon lubricant is melted and fixed on the surface of the powder and uniformly applied on the surface of the fine powder. The melt-coated lubricant reduces friction between fine powder particles and between the particles and the inner wall of the mold. The form of the lubricant to be added is not particularly limited, but a powdery lubricant is preferred for efficient and uniform dispersion. If the amount of the hydrocarbon-based lubricant added is 0.05 wt% or less, a sufficient lubricating effect cannot be obtained. Further, when added in an amount of 5.0 wt% or more, not only the strength of the molded body is remarkably lowered, but also C beyond the allowable range remains in the sintered body, and the magnetic properties are remarkably lowered. Therefore, the addition amount of the hydrocarbon lubricant is 0.05 to 5.0 wt%, more preferably 0.5 to 5.0 wt%.
It is 2.0 wt%. The decomposition temperature of triazinethiol or its derivative used as an oxidation inhibitor is 300 ° C.
The following is preferable. By mixing the oxidation inhibitor, a film of the oxidation inhibitor is formed at the interface between the rare earth magnet powder and the lubricant to suppress the oxidation of the fine powder, and triazinethiol has the same coupling effect as the silane coupling agent. Since this has the effect of strengthening the binding effect between the magnet powder and the lubricant, the strength of the molded body is improved, and at the same time, the release pressure at the time of releasing the molded body is reduced. The addition amount of the oxidation inhibitor is 0.01-
2 wt%, and more preferably 0.01 to 0.2%. Since these oxidation inhibitors generally have a small amount of dissolution in an organic solvent having low polarity such as hexane, addition of 2 wt% or more makes degreasing of the molded body difficult and causes deterioration of magnetic properties.
【０００９】成形は、無磁場または磁場中で行われる。
得られた成形体は有機溶剤中に所定時間浸漬することに
より脱脂処理する。有機溶剤として、トルエン、シクロ
ヘキサン、ノルマルヘキサン、ケロシン、キシレン、ミ
ネラルタ−ペン、などが好ましい。これらの有機溶媒中
に所定時間成形体を浸漬することにより、添加量の約９
０％の潤滑剤が除去される。潤滑剤の脱脂速度を促進す
るために、有機溶剤を加熱、攪拌、超音波振動を付与す
ることは有効である。The molding is performed without a magnetic field or in a magnetic field.
The obtained molded body is degreased by being immersed in an organic solvent for a predetermined time. As the organic solvent, toluene, cyclohexane, normal hexane, kerosene, xylene, mineral tape, etc. are preferable. By immersing the molded body in these organic solvents for a predetermined time, the added amount of about 9
0% of lubricant is removed. In order to accelerate the degreasing speed of the lubricant, it is effective to heat, stir and apply ultrasonic vibration to the organic solvent.
【００１０】予め、有機溶剤に浸漬された成形体は真空
あるいはアルゴン等の不活性雰囲気中で焼結される。有
機溶剤による前処理を行わない成形体を焼結する場合に
は、焼結工程に脱脂工程を必要とする。すなわち１００
〜５００℃で成形体を加熱保持し潤滑剤および粘結剤を
成形体より除去した後、１０００〜１２００℃にて本焼
結を行う必要がある。したがって、焼結工程には１６〜
２４時間を必要とし、工業上極めて生産効率が悪い。本
発明による、有機溶剤による前処理を行った成形体は焼
結工程中に脱脂工程を必要とせず、焼結温度で一定時間
成形体を保持することにより焼結を行うことが可能であ
り、また焼結炉にワックストラップや脱脂室などの特殊
な装置を必要としないため、焼結炉の設備費が著しく軽
減されるため工業上の利点は極めて大である。また本発
明による酸化抑制剤は材は微粉表面に均質な保護膜を形
成するため微粉の酸化防止に顕著な効果があり、大気中
に放置しても発熱、発火等の問題がなく成形が大気中で
行うことが可能である。本発明による微粉を使用した、
脱脂洗浄後の焼結体の酸素量は０.６ｗｔ％以下に抑制
される。脱脂洗浄後の焼結体の炭素量が０.１５％以上
では磁気特性が著しく低下する。またＣ量の下限につい
ては磁気特性上の制約はないが、潤滑剤および酸化抑制
剤の主元素が炭素であるため、脱脂洗浄を十分に行って
も、実質的に０.０３〜０.１０ｗｔ％の炭素が焼結体中
に残存することは避けられない。なお焼結体中に残存す
る炭素量は潤滑剤および粘結剤の添加量および組み合わ
せに依存する。本発明による粘結剤は有機溶媒中の溶解
量が極めて小さいため、大部分が焼結工程で分解飛散す
る、したがって分解温度あるいが３００℃以上の粘結剤
を使用することは磁気特性上好ましくない。The molded body previously immersed in the organic solvent is sintered in vacuum or in an inert atmosphere such as argon. In the case of sintering a molded body that is not pretreated with an organic solvent, a degreasing step is required in the sintering step. Ie 100
After the molded body is heated and held at ˜500 ° C. to remove the lubricant and the binder from the molded body, it is necessary to perform the main sintering at 1000 to 1200 ° C. Therefore, 16 to
It takes 24 hours, and the production efficiency is extremely poor in industry. According to the present invention, the green body pretreated with an organic solvent does not need a degreasing step during the sintering step, and it is possible to perform the sintering by holding the green body for a certain time at the sintering temperature, Further, since the sintering furnace does not require a special device such as a wax trap or a degreasing chamber, the facility cost of the sintering furnace is remarkably reduced, which is extremely advantageous in industry. Further, the oxidation inhibitor according to the present invention has a remarkable effect in preventing the oxidation of the fine powder because it forms a uniform protective film on the surface of the fine powder, and even if it is left in the air, there is no problem of heat generation, ignition, etc. It can be done in. Using the fines according to the invention,
The oxygen content of the sintered body after degreasing and cleaning is suppressed to 0.6 wt% or less. When the carbon content of the sintered body after degreasing and cleaning is 0.15% or more, the magnetic properties are remarkably deteriorated. Although there is no restriction on the lower limit of the amount of C in terms of magnetic properties, since the main element of the lubricant and the oxidation inhibitor is carbon, even if sufficient degreasing cleaning is performed, it is substantially 0.03 to 0.10 wt. It is inevitable that% of carbon remains in the sintered body. The amount of carbon remaining in the sintered body depends on the amount and combination of the lubricant and the binder. Since the binder according to the present invention has an extremely small amount of dissolution in an organic solvent, most of it decomposes and scatters in the sintering process. Therefore, it is magnetic properties that a binder having a decomposition temperature or 300 ° C. or higher is used. Not preferable.
【００１１】[0011]
【実施例】以下、本発明を実施例により具体的に説明す
る。なお本発明は以下実施例にのみ限定されるものでは
ない。EXAMPLES The present invention will be specifically described below with reference to examples. The present invention is not limited to the following examples.
【００１２】（実施例１）平均粒径４０μｍのＮｄ-Ｆ
ｅ-Ｂ系永久磁石合金粗粉にパラフィンワックスを２ｗ
ｔ％とトリアジンチオ−ル（商品名ジスネットＤＢ 三
協化成）を０.５ｗｔ％添加し、ヘンシエルミキサ−に
て３０秒間混合した。混合後、この粗粉をジェットミル
粉砕し平均粒径３.３μｍの微粉を得た。得られた微粉
を磁場中成形した時の潤滑効果と成形体強度、焼結体酸
素量を潤滑剤および酸化抑制剤を添加しない微粉と比較
した結果を表１に示す。本発明による微粉は１００００
回以上連続的に成形し成形体および金型に傷の発生が観
られなかったのに対し、無添加の微粉は２０回連続成形
行うと成形体に傷が発生し以後成形が継続出来なかっ
た。また、成形体強度は本発明の微粉によると約２倍に
増大していることが分かる。(Example 1) Nd-F having an average particle size of 40 μm
2w paraffin wax to e-B permanent magnet alloy coarse powder
t% and 0.5 wt% of triazinethiol (trade name: DISNNET DB Sankyo Kasei) were added and mixed for 30 seconds with a Henschel mixer. After mixing, this coarse powder was pulverized by a jet mill to obtain fine powder having an average particle size of 3.3 μm. Table 1 shows the results of comparison of the lubricating effect, the strength of the formed body, and the oxygen content of the sintered body when the obtained fine powder was molded in a magnetic field with the fine powder to which the lubricant and the oxidation inhibitor were not added. The fine powder according to the present invention is 10,000
While continuous molding was performed more than once, no scratch was observed on the molded body and the mold, whereas the additive-free fine powder was continuously molded 20 times, the molded body was damaged and the molding could not be continued thereafter. . Also, it can be seen that the strength of the molded body is increased by about 2 times according to the fine powder of the present invention.
【表１】 [Table 1]
【００１３】（実施例２）Ｎｄ-Ｆｅ-Ｂ系永久磁石合金
粗粉にパラフィンワックスを１ｗｔ％およびトリアジン
チオ−ル（ジスネットＦ）を０.２ｗｔ％添加し、ジェ
ットミル粉砕により平均粒径４.２μｍの微粉を得た。
この微粉を３０℃で相対湿度８０％の大気中に所定時間
放置し、酸化速度をワックスおよび酸化抑制剤を添加し
ない微粉と比較測定した結果を表２に示す。 本発明に
よる微粉では大気中に１００時間放置しても、ほとんど
酸素量の増加が観られなかったのに対し無添加微粉にお
いては、１００時間放置後の酸素量は１１０００ｐｐｍ
であった。またパラフィンワックスのみ添加した微粉で
は２０００回まで連続的に成形が可能であるが離型抵抗
が徐々に増加し、２０００回で離型が不可能となった。(Example 2) 1 wt% of paraffin wax and 0.2 wt% of triazinethiol (disnet F) were added to coarse powder of Nd-Fe-B type permanent magnet alloy, and the average particle size was 4 by jet milling. A fine powder of 0.2 μm was obtained.
Table 2 shows the results obtained by allowing this fine powder to stand in the air at 30 ° C. and a relative humidity of 80% for a predetermined period of time and comparing its oxidation rate with that of a fine powder to which wax and an oxidation inhibitor were not added. The fine powder according to the present invention showed almost no increase in oxygen content even after being left in the air for 100 hours, whereas in the additive-free fine powder, the oxygen content after standing for 100 hours was 11,000 ppm.
Met. Further, with fine powder containing only paraffin wax, continuous molding was possible up to 2000 times, but the mold release resistance gradually increased, and mold release became impossible after 2000 times.
【表２】 [Table 2]
【００１４】（実施例３）平均粒径４０μｍのＮｄ-Ｆ
ｅ-Ｂ系粗粉に天然ワックス１ｗｔ％およびジスネット
ＤＢを０.２ｗｔ％添加混合し、ジェットミル粉砕し平
均粒径３.８μｍの微粉を得た。この微粉を磁場中成形
した後、成形体をトルエン中に２時間浸漬した後、１０
００℃にて２時間焼結後、室温まで急冷した。焼結体の
磁気特性と残存ＣおよびＯ量を浸漬処理を行わなかった
焼結体との比較で示す。(Example 3) Nd-F having an average particle size of 40 μm
1 wt% of natural wax and 0.2 wt% of disnet DB were added to and mixed with the e-B type coarse powder, and the mixture was pulverized by a jet mill to obtain fine powder having an average particle diameter of 3.8 μm. After molding this fine powder in a magnetic field, the molded body was immersed in toluene for 2 hours, and then 10
After sintering at 00 ° C. for 2 hours, it was rapidly cooled to room temperature. The magnetic properties and the residual C and O contents of the sintered body are shown in comparison with those of the sintered body not subjected to the immersion treatment.
【表３】 [Table 3]
【００１５】（実施例４）平均粒径３０μｍのＮｄ-Ｆ
ｅ-Ｂ系永久磁石粗粉にマイクロワックスを０.０１〜６
ｗｔ％およびジスネットＦを０.２ｗｔ％添加混合しジ
ェットミル粉砕し得られた微粉を磁場中成形した後、ヘ
キサン中に成形体を３時間浸漬し、１１００℃で２時間
真空焼結した。添加量と連続成形性、焼結体保磁力、Ｃ
量、Ｏ量の関係を表４に示す。Example 4 Nd-F having an average particle size of 30 μm
Micro wax to e-B system permanent magnet coarse powder 0.01 to 6
After mixing 0.2 wt% of wt% and Disnet F and mixing them with a jet mill and molding the resulting fine powder in a magnetic field, the compact was immersed in hexane for 3 hours and vacuum sintered at 1100 ° C. for 2 hours. Addition amount and continuous formability, sintered body coercive force, C
Table 4 shows the relationship between the amount and the amount of O.
【表４】 [Table 4]
【００１６】（実施例５）平均粒径３０μｍのＮｄ-Ｆ
ｅ-Ｂ系永久磁石粗粉に流動パラフィンを１ｗｔ％およ
びジスネットＦを０.０１〜３ｗｔ％添加混合しジェッ
トミル粉砕し得られた微粉を磁場中成形した後、ケロシ
ン中に成形体を３時間浸漬し、１１００℃で２時間真空
焼結した。ポリエチレングリコ−ル添加量と連続成形
性、成形体強度、焼結体保磁力（表中にはiHcと記
す）、Ｃ、０量の関係を表５に示す。(Example 5) Nd-F having an average particle size of 30 μm
1 wt% of liquid paraffin and 0.01 to 3 wt% of Disnet F were added to and mixed with e-B type permanent magnet coarse powder, jet mill pulverized, and the fine powder obtained was molded in a magnetic field, and then the molded body was placed in kerosene for 3 hours. It was dipped and vacuum-sintered at 1100 ° C. for 2 hours. Table 5 shows the relationship among the amount of polyethylene glycol added, continuous moldability, molded body strength, sintered body coercive force (denoted by iHc in the table), C, and 0 amount.
【表５】 [Table 5]
【００１７】[0017]
【発明の効果】本発明によれば、成形時の金型の損傷お
よび成形体の剥がれおよび亀裂が解消され、Ｎｄ-Ｆｅ-
Ｂ系希土類永久磁石合金粉末の成形を半永久的に連続に
行うことが可能であり、また微粉の耐酸化性が優れるた
め成形を大気中で連続的に行っても、焼結体の酸素量を
６００ｐｐｍ以下に抑制することが可能である。さらに
高価な脱ワックス機構を有する専用焼結炉を使用するこ
と無く磁気特性の低下の無い永久磁石を得ることが可能
である。なお本発明の効果はＮｄ-Ｆｅ-Ｂ系希土類永久
磁石に限定されたものではなく希土類コバルト永久磁石
おいても同様の効果が得られる。According to the present invention, damage to the mold and peeling and cracking of the molded body during molding are eliminated, and Nd-Fe-
The B-based rare earth permanent magnet alloy powder can be molded semi-permanently and continuously, and the oxidation resistance of the fine powder is excellent. It can be suppressed to 600 ppm or less. Further, it is possible to obtain a permanent magnet without deterioration of magnetic properties without using a dedicated sintering furnace having an expensive dewaxing mechanism. The effects of the present invention are not limited to the Nd-Fe-B-based rare earth permanent magnets, and similar effects can be obtained with rare earth cobalt permanent magnets.
Claims (7)
磁石合金粗粉に炭化水素系潤滑剤および酸化抑制剤を添
加混合後に気流粉砕法により微粉砕した後に成形、焼結
をする希土類金属間化合物磁石の製造方法であって、酸
化抑制剤がトリアジンチオールまたはその誘導体の１種
または２種以上であることを特徴とする希土類金属間化
合物磁石の製造方法。1. A rare earth metal which is formed by sintering a Nd-Fe-B-based rare earth intermetallic compound permanent magnet alloy coarse powder with a hydrocarbon lubricant and an oxidation inhibitor, and then finely pulverized by an air flow pulverization method and then sintered. A method for producing an intermetallic compound magnet, wherein the oxidation inhibitor is one or more of triazine thiol or its derivative, and a method for producing a rare earth intermetallic compound magnet.
去する前処理を施した後に焼結することを特徴とする請
求項１に記載の希土類金属間化合物永久磁石の製造方
法。2. The method for producing a rare earth intermetallic compound permanent magnet according to claim 1, wherein after the molding, a pretreatment for removing a lubricant from the obtained molded body is performed and then the sintering is performed.
成形体を有機溶剤中に所定時間浸漬することを特徴とす
る請求項２に記載の希土類金属間化合物永久磁石の製造
方法。3. A pretreatment for removing the lubricant from the molded body,
The method for producing a rare earth intermetallic compound permanent magnet according to claim 2, wherein the molded body is immersed in an organic solvent for a predetermined time.
５．０ｗｔ％である請求項１ないし３のいづれかに記載
の希土類金属間化合物磁石の製造方法。4. The addition amount of the hydrocarbon lubricant is 0.05 to
The method for producing a rare earth intermetallic compound magnet according to claim 1, wherein the amount is 5.0 wt%.
０ｗｔ％である請求項１ないし３のいづれかに記載の希
土類金属間化合物磁石の製造方法。5. The addition amount of the hydrocarbon lubricant is 0.5 to 2.
It is 0 wt%, The manufacturing method of the rare earth intermetallic compound magnet in any one of Claim 1 thru | or 3.
ｗｔ％である請求項１ないし５のいづれかに記載の希土
類金属間化合物永久磁石の製造方法。6. The addition amount of the oxidation inhibitor is 0.01 to 2.0.
The method for producing a rare earth intermetallic compound permanent magnet according to claim 1, wherein the content is wt%.
ｗｔ％である請求項１ないし５のいづれかに記載の希土
類金属間化合物永久磁石の製造方法。7. The amount of the oxidation inhibitor added is 0.02 to 0.1.
The method for producing a rare earth intermetallic compound permanent magnet according to claim 1, wherein the content is wt%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6031408A JPH07240331A (en) | 1994-03-01 | 1994-03-01 | Manufacture of rare-earth intermetallic compound magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6031408A JPH07240331A (en) | 1994-03-01 | 1994-03-01 | Manufacture of rare-earth intermetallic compound magnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07240331A true JPH07240331A (en) | 1995-09-12 |
Family
ID=12330441
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6031408A Pending JPH07240331A (en) | 1994-03-01 | 1994-03-01 | Manufacture of rare-earth intermetallic compound magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07240331A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09190909A (en) * | 1995-11-10 | 1997-07-22 | Sumitomo Special Metals Co Ltd | Manufacture of r-t-n permanent magnet powder and of anisotropic bond magnet |
| JP2011228656A (en) * | 2010-03-31 | 2011-11-10 | Nitto Denko Corp | Permanent magnet, and method for manufacturing permanent magnet |
| CN103521758A (en) * | 2013-10-22 | 2014-01-22 | 爱科科技有限公司 | Method for manufacturing powder through neodymium iron boron alloy |
-
1994
- 1994-03-01 JP JP6031408A patent/JPH07240331A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09190909A (en) * | 1995-11-10 | 1997-07-22 | Sumitomo Special Metals Co Ltd | Manufacture of r-t-n permanent magnet powder and of anisotropic bond magnet |
| JP2011228656A (en) * | 2010-03-31 | 2011-11-10 | Nitto Denko Corp | Permanent magnet, and method for manufacturing permanent magnet |
| CN102511071A (en) * | 2010-03-31 | 2012-06-20 | 日东电工株式会社 | Permanent magnet and manufacturing method for permanent magnet |
| CN103521758A (en) * | 2013-10-22 | 2014-01-22 | 爱科科技有限公司 | Method for manufacturing powder through neodymium iron boron alloy |
| CN103521758B (en) * | 2013-10-22 | 2016-06-08 | 爱科科技有限公司 | A kind of method of Nd-Fe-B alloys powder process |
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