JP3418605B2 - Rare earth magnet manufacturing method - Google Patents
Rare earth magnet manufacturing methodInfo
- Publication number
- JP3418605B2 JP3418605B2 JP2000326482A JP2000326482A JP3418605B2 JP 3418605 B2 JP3418605 B2 JP 3418605B2 JP 2000326482 A JP2000326482 A JP 2000326482A JP 2000326482 A JP2000326482 A JP 2000326482A JP 3418605 B2 JP3418605 B2 JP 3418605B2
- Authority
- JP
- Japan
- Prior art keywords
- molded body
- rare earth
- oil agent
- earth magnet
- impregnation
- 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.)
- Expired - Lifetime
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
-
- 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
- H01F1/0555—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together
- H01F1/0557—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together sintered
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、希土類磁石の製造
方法に関する。より詳細には、酸素含有量を低減した希
土類合金粉末を用いて磁気特性に優れた希土類焼結磁石
を製造する方法に関している。TECHNICAL FIELD The present invention relates to a method for manufacturing a rare earth magnet. More specifically, the present invention relates to a method for producing a rare earth sintered magnet having excellent magnetic properties by using a rare earth alloy powder having a reduced oxygen content.
【０００２】[0002]
【従来の技術】Ｒ−Ｆｅ−Ｂ系希土類磁石（ＲはＹを含
む希土類元素）は、主にＲ2Ｆｅ14Ｂの正方晶化合物か
らなる主相、Ｎｄ等からなるＲリッチ相、およびＢリッ
チ相から構成されている。Ｒ−Ｆｅ−Ｂ系希土類磁石で
は、主相であるＲ2Ｆｅ14Ｂの正方晶化合物の存在比率
を増加させれば、その磁気特性が向上する。2. Description of the Related Art R-Fe-B rare earth magnets (R is a rare earth element containing Y) are mainly composed of a tetragonal compound of R 2 Fe 14 B, an R-rich phase composed of Nd, and B. It is composed of rich phases. In the R—Fe—B rare earth magnet, the magnetic characteristics are improved by increasing the abundance ratio of the tetragonal compound of R 2 Fe 14 B which is the main phase.
【０００３】Ｒリッチ相は液相焼結させるために最低量
は必要であるが、Ｒは雰囲気中の酸素と反応し、Ｒ2Ｏ3
なる酸化物を作るため、Ｒの一部は焼結に役立たない部
分に消費されてしまう。このため、酸化によって消費さ
れる分だけ余分のＲが必要であった。Ｒ2Ｏ3なる酸化物
の生成は、雰囲気中の酸素濃度が高いほど顕著になる。
そのため、これまでにも粉末作製時における雰囲気中の
酸素量を低減させることによってＲ2Ｏ3の生成を抑制
し、これによって焼結磁石の磁気特性を向上させること
が検討されてきた。The R-rich phase requires a minimum amount for liquid-phase sintering, but R reacts with oxygen in the atmosphere to form R 2 O 3
Therefore, a part of R is consumed in a portion that is not useful for sintering. For this reason, an extra R was needed as much as was consumed by the oxidation. The formation of the oxide R 2 O 3 becomes more remarkable as the oxygen concentration in the atmosphere is higher.
Therefore, it has been studied so far to suppress the generation of R 2 O 3 by reducing the amount of oxygen in the atmosphere during powder production, thereby improving the magnetic characteristics of the sintered magnet.
【０００４】[0004]
【発明が解決しようとする課題】このように、Ｒ−Ｆｅ
−Ｂ系磁石の製造に用いるＲ−Ｆｅ−Ｂ系合金粉末の酸
素量は少ないことが好ましい。しかしながら、Ｒ−Ｆｅ
−Ｂ系合金粉末の酸素量を低減することによって磁石特
性を改善する方法は、量産化技術としては実現しなかっ
た。その理由は、酸素濃度を低く管理した環境下でＲ−
Ｆｅ−Ｂ系合金粉末を作製し、合金粉末の酸素量を例え
ば４０００質量ｐｐｍ以下に落とすと、粉末が大気中の
酸素と激しく反応し、常温でも数分で発火するおそれが
あったためである。また、水素吸蔵法によって粉砕する
と合金の希土類リッチ部分から割れていくため、粉砕粉
の表面に希土類元素が露出することが多くなる。そのた
め、よりいっそう発火が生じやすくなる。As described above, R-Fe
It is preferable that the amount of oxygen in the R—Fe—B alloy powder used for manufacturing the —B magnet is small. However, R-Fe
A method of improving magnet characteristics by reducing the amount of oxygen in the B-based alloy powder has not been realized as a mass production technology. The reason is that R-
This is because if an Fe-B based alloy powder is produced and the amount of oxygen in the alloy powder is reduced to, for example, 4000 mass ppm or less, the powder reacts violently with oxygen in the atmosphere and may ignite in a few minutes at room temperature. Further, when pulverized by the hydrogen storage method, the rare earth-rich portion of the alloy is cracked, so that the rare earth element is often exposed on the surface of the pulverized powder. Therefore, ignition is more likely to occur.
【０００５】従って、磁気特性を向上させるためにはＲ
−Ｆｅ−Ｂ系合金粉末中の酸素量を低減することが望ま
しいことが理解されていても、実際には、含有酸素濃度
を低くしたＲ−Ｆｅ−Ｂ系合金粉末を工場などの生産現
場で取り扱うことは極めて困難であった。Therefore, in order to improve the magnetic characteristics, R
Even though it is understood that it is desirable to reduce the amount of oxygen in the —Fe—B alloy powder, in reality, the R—Fe—B alloy powder having a low oxygen content is used in a production site such as a factory. It was extremely difficult to handle.
【０００６】特に粉末を圧縮成形するプレス工程におい
ては、圧縮に伴う粉末同士の摩擦熱や、成形体取り出し
時に粉末とキャビティ内壁面との間で生じる摩擦熱によ
って、成形体の温度が上昇するため、発火の危険性が高
い。この発火を防止する目的で、プレス装置の周辺を非
酸素雰囲気とすることも考えられるが、原料の供給や成
形体取り出しが困難となるため実用的でない。また、成
形体をプレス装置から取り出すごとに、個々の成形体を
速やかに焼結すれば、発火の問題は回避できるかもしれ
ないが、それは極めて効率の悪い方法であり、量産化に
は向いていない。また、プレスから焼結工程までの間、
成形体を極低酸素濃度の雰囲気下で管理することも量産
設備では困難である。Particularly, in the pressing step of compressing and molding the powder, the temperature of the molded body rises due to the frictional heat between the powders due to the compression and the frictional heat generated between the powder and the inner wall surface of the cavity when the molded body is taken out. , High risk of fire. A non-oxygen atmosphere may be provided around the pressing device for the purpose of preventing the ignition, but it is not practical because it becomes difficult to supply the raw material and take out the molded body. Also, if each molded body is quickly sintered each time the molded body is taken out of the press machine, the problem of ignition may be avoided, but this is an extremely inefficient method and is suitable for mass production. Absent. Also, from the press to the sintering process,
It is also difficult for mass production facilities to manage the compact in an atmosphere with an extremely low oxygen concentration.
【０００７】なお、プレス工程前の微粉末に対して脂肪
酸エステルなどの液体潤滑剤を添加し、粉末の圧縮性ま
たは成形性を向上させることが行われている。このよう
な液体潤滑剤の添加によって、粉末粒子の表面には薄い
油性被膜が形成されるが、酸素濃度が４０００質量ｐｐ
ｍ以下の粉末の酸化を充分に防止することはできなかっ
た。A liquid lubricant such as a fatty acid ester is added to the fine powder before the pressing step to improve the compressibility or moldability of the powder. By adding such a liquid lubricant, a thin oil film is formed on the surface of the powder particles, but the oxygen concentration is 4000 mass pp.
It was not possible to sufficiently prevent the oxidation of the powder having a particle size of m or less.
【０００８】以上の理由から、Ｒ−Ｆｅ−Ｂ系合金を粉
砕するとき、意図的に雰囲気中へ微量酸素を導入し、そ
れによって微粉砕粉の表面を薄く酸化し、反応性を低下
させることが行われている。例えば、特公平第６−６７
２８号公報には、所定量の酸素を含有した超音速不活性
ガス気流によって希土類合金を微粉砕するとともに、粉
砕によって生まれた微粉末の粒子表面に薄く酸化被膜を
形成するという技術が開示されている。この技術によれ
ば、大気中の酸素は粉末粒子表面の酸化被膜によって遮
断されるため、酸化による発熱・発火が防止できる。た
だし、粉末粒子の表面に酸化被膜が存在するため、粉末
に含有される酸素量は増大してしまうことになる。従っ
て、焼結後の焼結体が含有する酸素量が増加（すなわ
ち、希土類酸化物の量が増加）し、得られる焼結磁石の
磁気特性が劣化し得る。For the above reasons, when crushing the R-Fe-B type alloy, a trace amount of oxygen is intentionally introduced into the atmosphere, whereby the surface of the pulverized powder is thinly oxidized and the reactivity is lowered. Is being done. For example, Japanese Patent Publication No. 6-67
Japanese Patent Publication No. 28 discloses a technique in which a rare earth alloy is finely pulverized by a supersonic inert gas flow containing a predetermined amount of oxygen, and a thin oxide film is formed on the surface of the fine powder particles produced by the pulverization. There is. According to this technique, oxygen in the atmosphere is blocked by the oxide film on the surface of the powder particles, so that heat generation and ignition due to oxidation can be prevented. However, since the oxide film is present on the surface of the powder particles, the amount of oxygen contained in the powder will increase. Therefore, the amount of oxygen contained in the sintered body after sintering increases (that is, the amount of rare earth oxide increases), and the magnetic properties of the obtained sintered magnet may deteriorate.
【０００９】これに対して、特開平１０−３２１４５１
号公報には、低酸素量のＲ−Ｆｅ−Ｂ系合金粉末を鉱物
油等に混合することによってスラリー化し、このスラリ
ーを用いて成形体を作製する技術（湿式成形法）が開示
されている。スラリー中の粉末粒子は大気と接触しない
ため、Ｒ−Ｆｅ−Ｂ系合金粉末の含有酸素量を低くしな
がら、発熱・発火を防止することができる。On the other hand, Japanese Patent Laid-Open No. 10-321451
The publication discloses a technique (wet molding method) of mixing a low oxygen content R-Fe-B alloy powder with mineral oil or the like to form a slurry, and using this slurry to prepare a molded body. . Since the powder particles in the slurry do not come into contact with the atmosphere, it is possible to prevent heat generation and ignition while reducing the oxygen content of the R-Fe-B alloy powder.
【００１０】なお、フェライト磁石を作製する場合にお
いても湿式成形法が広く採用されている。フェライト磁
石の製造では、スラリーを作製するために水を用いる。
これに対し、Ｒ−Ｆｅ−Ｂ系磁石では粉末と水とが反応
を起こすため水を用いることが困難であり、このため、
上述のように鉱物油などの油剤が用いられる。Ｒ−Ｆｅ
−Ｂ系磁石では、スラリーにした後、スラリーから揮発
する油剤の量を少なくするために、比較的揮発性の低い
鉱物油等が用いられることが多い。The wet molding method is also widely used in the production of ferrite magnets. In the manufacture of ferrite magnets, water is used to make the slurry.
On the other hand, in the R-Fe-B system magnet, it is difficult to use water because the powder and water react with each other.
As described above, an oil agent such as mineral oil is used. R-Fe
In the -B magnet, mineral oil or the like having a relatively low volatility is often used in order to reduce the amount of the oil agent volatilized from the slurry after being made into a slurry.
【００１１】しかしながら、上記従来技術によれば、ス
ラリー状のＲ−Ｆｅ−Ｂ系合金粉末をプレス装置のキャ
ビティ内に充填した後、油分を絞り出しながらプレス工
程を実行する必要があるため、生産性が低い。However, according to the above-mentioned prior art, it is necessary to carry out the pressing step while squeezing out the oil content after filling the slurry of the R-Fe-B based alloy powder in the cavity of the pressing apparatus. Is low.
【００１２】また、Ｒ−Ｆｅ−Ｂ系焼結磁石では、磁石
中に含まれる炭素量が増加すると磁気特性が低下するこ
とが知られている。従って、焼結後に優れた磁気特性を
有する希土類磁石を得るためには、上記スラリーを形成
するために用いた油剤を揮発させるために高温での脱油
工程を行う必要がある。しかし、上記従来技術では、成
形体作製後、成形体全体にわたって油剤が残存してお
り、その量も多いため、脱油工程に要する時間が長くな
る。このため、生産性が低くなるという問題が生じる。Further, it is known that in the R-Fe-B system sintered magnet, the magnetic characteristics are deteriorated when the amount of carbon contained in the magnet is increased. Therefore, in order to obtain a rare earth magnet having excellent magnetic properties after sintering, it is necessary to perform a deoiling process at high temperature in order to volatilize the oil agent used to form the slurry. However, in the above-mentioned conventional technique, the oil agent remains over the entire molded body after the molded body is manufactured, and the amount thereof is large. Therefore, the time required for the deoiling process becomes long. For this reason, there arises a problem that productivity is lowered.
【００１３】本発明はかかる諸点に鑑みてなされたもの
であり、その主な目的は、低酸素濃度の希土類合金粉末
を用いながら安全かつ効率的に希土類磁石を製造する方
法を提供することにある。The present invention has been made in view of the above points, and a main object thereof is to provide a method for safely and efficiently producing a rare earth magnet while using a rare earth alloy powder having a low oxygen concentration. .
【００１４】[0014]
【課題を解決するための手段】本発明によるＲ−Ｆｅ−
Ｂ系希土類磁石の製造方法は、酸素含有量４０００質量
ｐｐｍ以下の希土類合金粉末を乾式プレス法によって圧
縮成形し、それによって成形体を作製するプレス工程
と、前記成形体の表面から油剤を前記成形体に含浸させ
る工程と、前記成形体を焼結させる工程とを包含する。R-Fe-according to the present invention
The method for producing a B-based rare earth magnet includes a pressing step of compression-molding a rare earth alloy powder having an oxygen content of 4000 mass ppm or less by a dry pressing method, thereby producing a molded body, and forming an oil agent from the surface of the molded body. It includes a step of impregnating a body and a step of sintering the molded body.
【００１５】前記希土類合金粉末の平均粒径を１０μｍ
以下とすることが好ましい。The average particle diameter of the rare earth alloy powder is 10 μm.
The following is preferable.
【００１６】前記希土類合金粉末は、前記成形体を作製
するためのプレス装置のキャビティに充填されるまで、
酸素濃度５０００体積ｐｐｍ以下の不活性雰囲気ガス中
に置かれることが好ましい。The rare earth alloy powder is filled into the cavity of the press machine for producing the compact,
It is preferably placed in an inert atmosphere gas having an oxygen concentration of 5000 volume ppm or less.
【００１７】前記油剤は、２０℃で８Ｐａ以上の蒸気圧
を有することが好ましい。前記油剤は揮発油であっても
よい。The oil agent preferably has a vapor pressure of 8 Pa or more at 20 ° C. The oil agent may be volatile oil.
【００１８】前記含浸工程の後、前記油剤の揮発によっ
て、前記成形体の温度を少なくとも一時的に低下させる
ようにしてもよい。After the impregnation step, the temperature of the molded body may be lowered at least temporarily by volatilization of the oil agent.
【００１９】前記油剤は、炭化水素系溶剤から構成され
ていることが好ましい。さらに好ましくは、イソパラフ
ィンなどの飽和炭化水素系溶剤から構成される。The oil agent is preferably composed of a hydrocarbon solvent. More preferably, it is composed of a saturated hydrocarbon solvent such as isoparaffin.
【００２０】前記プレス工程前において、前記希土類合
金粉末に潤滑剤が添加されることが好ましい。A lubricant is preferably added to the rare earth alloy powder before the pressing step.
【００２１】前記成形体を焼結させる前に前記油剤を実
質的に除去する油剤除去工程を行った場合、前記油剤除
去工程の後、焼結までのあいだ、前記成形体を大気に接
触させないことが好ましい。When the oil agent removing step of substantially removing the oil agent is performed before sintering the molded article, the molded article should not be exposed to the atmosphere after the oil agent removing step and before the sintering. Is preferred.
【００２２】前記油剤除去工程は、減圧下で１００℃〜
６００℃で、０．１〜８．０時間行われることが好まし
い。In the oil agent removing step, the pressure is reduced to 100 ° C.
It is preferably carried out at 600 ° C. for 0.1 to 8.0 hours.
【００２３】好ましい実施形態では、前記プレス工程の
後、前記成形体の表面温度を測定し、前記表面温度が予
め設定されたレベル以上の場合には前記成形体に油剤を
含浸させず、前記表面温度が予め設定されたレベルを下
回る場合に、前記成形体に油剤を含浸させることが好ま
しい。この場合、赤外線温度測定器を用いて前記成形体
の表面温度を測定することが好ましい。また、前記表面
温度が予め設定されたレベル以上の成形体を密閉可能な
回収箱内に収納することが好ましい。In a preferred embodiment, after the pressing step, the surface temperature of the molded body is measured, and when the surface temperature is equal to or higher than a preset level, the molded body is not impregnated with an oil agent, When the temperature is below a preset level, it is preferable to impregnate the molded body with an oil agent. In this case, it is preferable to measure the surface temperature of the molded body using an infrared thermometer. Further, it is preferable that the molded body having the surface temperature of a preset level or higher is housed in a recoverable collection box.
【００２４】好ましい実施形態では、前記成形体を出し
入れするための開口部と前記開口部を閉じる得るシャッ
ターとを備えた含浸槽を用いて含浸工程を実行する。In a preferred embodiment, the impregnation step is carried out using an impregnation tank provided with an opening for taking in and out the molded body and a shutter capable of closing the opening.
【００２５】前記油剤を蓄える複数の含浸槽を用い、所
定個数の成形体を個々の含浸槽に分けて含浸工程を実行
するようにしてもよい。It is also possible to use a plurality of impregnation tanks for storing the oil agent and divide the predetermined number of molded bodies into individual impregnation tanks to execute the impregnation step.
【００２６】前記含浸槽には前記油剤を冷却する冷却器
が備え付けられていることが好ましい。The impregnation tank is preferably equipped with a cooler for cooling the oil agent.
【００２７】好ましい実施形態では、前記油剤の温度を
測定する温度測定器が前記含浸槽に取り付けられてい
る。In a preferred embodiment, a temperature measuring device for measuring the temperature of the oil agent is attached to the impregnation tank.
【００２８】好ましい実施形態では、前記含浸工程の
後、焼結前に前記成形体を不活性雰囲気中にて焼結台板
上に配置する。このようにする代わりに、前記含浸工程
の後、焼結前に前記成形体を不活性雰囲気中にて焼結ケ
ース内に収納してもよい。In a preferred embodiment, after the impregnation step and before sintering, the compact is placed on a sintering base plate in an inert atmosphere. Alternatively, after the impregnation step and before sintering, the compact may be housed in a sintering case in an inert atmosphere.
【００２９】本明細書において、「油剤」は疎水性の液
体であり、炭化水素系溶剤や潤滑剤などを含む。In the present specification, the "oil agent" is a hydrophobic liquid and includes a hydrocarbon solvent and a lubricant.
【００３０】[0030]
【発明の実施の形態】以下、本発明による希土類磁石の
製造方法の一実施形態を詳細に説明する。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the method for producing a rare earth magnet according to the present invention will be described in detail below.
【００３１】まず、Ｒ（但しＲはＹを含む希土類元素の
うち、少なくとも１種）：１０原子％〜３０原子％、
Ｂ：０．５原子％〜２８原子％、残部：Ｆｅ、および不
可避的不純物を含有するＲ−Ｆｅ−Ｂ系合金の溶湯を作
製する。ただし、Ｆｅの１部をＣｏ、Ｎｉの１種または
２種にて置換してもよいし、Ｂの一部をＣで置換しても
良い。本発明によれば、酸素含有量を低減し、希土類元
素Ｒの酸化物生成を抑制できるため、希土類元素Ｒの量
を必要最小限度に低く抑えることが可能である。なお、
本実施形態で用いるＲ−Ｆｅ−Ｂ系合金の組成としては
米国特許第４，７７０，７２３号、米国特許第４，７９
２，３６８号に記載のものが適用できる。First, R (where R is at least one of rare earth elements including Y): 10 atom% to 30 atom%,
A molten metal of R—Fe—B alloy containing B: 0.5 atomic% to 28 atomic%, balance: Fe, and unavoidable impurities is prepared. However, a part of Fe may be replaced with one or two kinds of Co and Ni, or a part of B may be replaced with C. According to the present invention, the oxygen content can be reduced and the oxide formation of the rare earth element R can be suppressed, so that the amount of the rare earth element R can be suppressed to a necessary minimum level. In addition,
The composition of the R-Fe-B based alloy used in the present embodiment includes U.S. Pat. No. 4,770,723 and U.S. Pat. No. 4,79.
Those described in No. 2,368 can be applied.
【００３２】次に、この合金溶湯をストリップキャスト
法（またはメルトスピニング法）などの適切な急冷法に
よって１０2〜１０4℃／秒の冷却速度で厚さ０．０３ｍ
ｍ〜１０ｍｍの薄板状に急冷凝固する。そして、Ｒリッ
チ相が５μｍ以下の微細なサイズで分散した組織を有す
る鋳片に鋳造した後、鋳片を容器に収容し、これを吸排
気可能なチャンバ内に収容する。チャンバ内を真空引き
した後、チャンバ内に圧力０．０３ＭＰａ（メガパスカ
ル）〜１．０ＭＰａのＨ2ガスを供給し、崩壊合金粉を
形成する。この崩壊合金粉は、脱水素処理後、不活性ガ
ス気流中で微粉砕される。Next, this molten alloy the strip casting process (or melt spinning process) thick at a suitable cooling rate of the quenching method 10 2 ~10 4 ℃ / sec, such as of 0.03m
It is rapidly solidified into a thin plate of m to 10 mm. Then, after casting into a slab having a structure in which the R-rich phase is dispersed in a fine size of 5 μm or less, the slab is housed in a container and housed in a chamber capable of suction and exhaust. After evacuating the chamber, H 2 gas having a pressure of 0.03 MPa (megapascal) to 1.0 MPa is supplied into the chamber to form a collapsed alloy powder. After the dehydrogenation treatment, the collapsed alloy powder is finely pulverized in an inert gas stream.
【００３３】本発明で使用する磁石材料の鋳片は、特定
組成の合金溶湯を単ロール法または双ロール法によるス
トリップキャスト法によって急冷することで好適に製造
される。作製する鋳片の板厚に応じて、単ロール法と双
ロール法とを使い分けることができる。鋳片が厚い場合
は双ロール法を用いることが好ましく、薄い場合は単ロ
ール法を用いることが好ましい。また、ストリップキャ
スト法以外の急冷法として、遠心鋳造法も採用できる。
このように急冷法によって作製された合金を使用する
と、主相の粒径が均一で微細となるため、インゴット法
によって作製された同一組成の合金を使用するのに比べ
て得られる永久磁石の保磁力を向上させることができ
る。The slab of the magnetic material used in the present invention is preferably manufactured by quenching a molten alloy having a specific composition by a strip casting method by a single roll method or a twin roll method. The single roll method and the twin roll method can be selectively used according to the plate thickness of the cast piece to be produced. The twin roll method is preferably used when the cast piece is thick, and the single roll method is preferably used when the cast piece is thin. A centrifugal casting method can also be adopted as a quenching method other than the strip casting method.
When the alloy produced by the quenching method is used in this way, the grain size of the main phase becomes uniform and fine, so that the preservation of the permanent magnet obtained by using the alloy of the same composition produced by the ingot method is used. The magnetic force can be improved.
【００３４】鋳片（フレーク状合金）の厚さが０．０３
ｍｍ未満になると急冷効果が大きくなるため、結晶粒径
が小さくなりすぎるおそれがある。結晶粒径が小さすぎ
ると、粉末化されたときに粒子個々が多結晶化し、結晶
方位を揃えられなくなるため、磁気特性の劣化を招来す
る。逆に鋳片の厚さが１０ｍｍを超えると、冷却速度が
遅くなるため、α−Ｆｅが晶出しやすく、Ｎｄリッチ相
の偏在も生じる。The thickness of the cast slab (flake alloy) is 0.03.
If it is less than mm, the quenching effect becomes large, so that the crystal grain size may become too small. If the crystal grain size is too small, the grains are polycrystallized when powdered, and the crystal orientation cannot be aligned, resulting in deterioration of magnetic properties. On the other hand, when the thickness of the slab exceeds 10 mm, the cooling rate becomes slow, so α-Fe is likely to crystallize, and uneven distribution of the Nd-rich phase also occurs.
【００３５】水素吸蔵処理は、例えば、次のようにして
行われ得る。すなわち、所定の大きさに破断した鋳片を
原料ケース内に挿入した後、原料ケースを密閉可能な水
素炉に装入し、その水素炉を密閉する。次に、その水素
炉内を十分に真空引きした後、圧力が３０ｋＰａ〜１．
０ＭＰａの水素ガスを炉内に供給し、鋳片に水素を吸蔵
させる。水素吸蔵反応は発熱反応であるため、炉の外周
には冷却水を供給する冷却配管を周設して炉内の昇温を
防止することが好ましい。水素の吸収吸蔵によって鋳片
は自然崩壊して脆化（一部は粉化）する。The hydrogen storage process can be performed, for example, as follows. That is, after a slab that has been broken into a predetermined size is inserted into the raw material case, the raw material case is loaded into a hermetically sealable hydrogen furnace, and the hydrogen furnace is hermetically sealed. Next, after the inside of the hydrogen furnace was sufficiently evacuated, the pressure was 30 kPa-1.
Hydrogen gas of 0 MPa is supplied into the furnace so that the slab absorbs hydrogen. Since the hydrogen storage reaction is an exothermic reaction, it is preferable to provide a cooling pipe for supplying cooling water around the outer periphery of the furnace to prevent the temperature rise in the furnace. Upon absorption and storage of hydrogen, the slab naturally collapses and becomes brittle (partially pulverized).
【００３６】水素吸蔵処理を受けた合金を冷却した後、
真空中で加熱することによって脱水素処理を行う。脱水
素処理によって得られた合金粉末の粒内には微細亀裂が
存在するため、その後に行うボール・ミル、ジェットミ
ル等で短時間で微粉砕され、所定の粒度分布を持った合
金粉末を作製することができる。水素粉砕処理の好まし
い態様については、特開平７−１８３６６号公報に開示
されている。After cooling the alloy that has undergone the hydrogen storage treatment,
Dehydrogenation treatment is performed by heating in vacuum. Since there are fine cracks in the grains of the alloy powder obtained by dehydrogenation, it is pulverized in a short time with a ball mill, jet mill, etc., which is subsequently performed, to produce an alloy powder with a prescribed particle size distribution. can do. A preferred embodiment of the hydrogen pulverization treatment is disclosed in JP-A-7-18366.
【００３７】上述の微粉砕は、不活性ガス（例えば、Ｎ
2やＡｒなど）を用いたジェット・ミルによって行うこ
とが好ましいが、有機溶媒（例えば、ベンゼンやトルエ
ン等）を用いたボールミルやアトライターによって行っ
ても良い。The above-mentioned fine pulverization is carried out by using an inert gas (for example, N 2
It is preferably performed by a jet mill using 2 or Ar), but may be performed by a ball mill or an attritor using an organic solvent (for example, benzene or toluene).
【００３８】以上の粉砕工程に際して、粉末に含有され
る酸素の量が低く抑えられるように雰囲気ガス中の酸素
濃度を低く（例えば５０００体積ｐｐｍ以下）に管理す
ることが好ましい。In the above pulverizing step, it is preferable to control the oxygen concentration in the atmosphere gas to be low (for example, 5000 vol ppm or less) so that the amount of oxygen contained in the powder can be kept low.
【００３９】また、原料合金の粉末には脂肪酸エステル
などを主成分とする液体潤滑剤やバインダを添加するこ
とが好ましい。添加量は例えば０．１５〜５．０質量％
である。脂肪酸エステルとしては、カプロン酸メチル、
カプリル酸メチル、ラウリン酸メチルなとが挙げられ
る。重要な点は、後の工程で潤滑剤が揮発し、除去され
得ることにある。また、潤滑剤それ自体が合金粉末と均
一に混合しにくい固形状のものである場合は、溶剤で希
釈して用いれば良い。溶剤としては、イソパラフィンに
代表される石油系溶剤やナフテン系溶剤等を用いること
ができる。潤滑剤添加のタイミングは任意であり、微粉
砕前、微粉砕中、微粉砕後の何れであっても良い。液体
潤滑剤は、粉末粒子の表面を被覆し、粒子の酸化防止効
果を発揮するとともに、プレスに際して成形体の密度を
均一化し、配向の乱れを抑制する機能を発揮する。Further, it is preferable to add a liquid lubricant or binder containing a fatty acid ester as a main component to the powder of the raw material alloy. The addition amount is, for example, 0.15 to 5.0 mass%
Is. As the fatty acid ester, methyl caproate,
Examples thereof include methyl caprylate and methyl laurate. The important point is that the lubricant can be volatilized and removed in a later step. Further, when the lubricant itself is in a solid form which is difficult to mix uniformly with the alloy powder, it may be diluted with a solvent before use. As the solvent, a petroleum solvent represented by isoparaffin, a naphthene solvent, or the like can be used. The timing of adding the lubricant is arbitrary, and may be before pulverization, during pulverization, or after pulverization. The liquid lubricant coats the surface of the powder particles, exerts an effect of preventing the particles from being oxidized, and also exerts a function of making the density of the molded body uniform during pressing and suppressing disorder of orientation.
【００４０】次に、図１に示すプレス装置を用いて、磁
界配向と圧縮成形とを行う。図１の装置１０は、貫通穴
を有するダイ１と、ダイ１の貫通穴を上下方向から挟み
込むパンチ２および３とを備えている。原料粉末４は、
ダイ１、および下パンチ２によって形成される空間（キ
ャビティ）内に充填され、下パンチ２と上パンチ３との
間隔が減少することによって圧縮成形される（プレス工
程）。図１のプレス装置１０は、磁界配向を行うために
コイル５および７を備えている。Next, magnetic field orientation and compression molding are carried out using the pressing apparatus shown in FIG. The apparatus 10 of FIG. 1 includes a die 1 having a through hole, and punches 2 and 3 that sandwich the through hole of the die 1 from above and below. The raw material powder 4 is
A space (cavity) formed by the die 1 and the lower punch 2 is filled, and compression molding is performed by reducing the distance between the lower punch 2 and the upper punch 3 (pressing step). The pressing device 10 of FIG. 1 comprises coils 5 and 7 for carrying out magnetic field orientation.
【００４１】粉末４の充填密度は、磁界配向を可能に
し、かつ、磁界除去後に磁粉の配向に乱れが生じにくく
なる範囲内に設定される。本実施形態の場合、充填密度
を真密度の例えば３０〜４０％とすることが好ましい。The packing density of the powder 4 is set within a range that enables magnetic field orientation and is less likely to cause disorder in the orientation of the magnetic powder after the magnetic field is removed. In the case of this embodiment, it is preferable that the packing density is, for example, 30 to 40% of the true density.
【００４２】粉末充填後、粉末４が充填されている空間
に配向磁界を形成し、粉末４の磁界配向を実行する。磁
界の向きとプレス方向とを一致させる平行磁界成形の場
合だけではなく、磁界の向きとプレス方向とを垂直にす
る垂直磁界成形の場合でも効果を奏する。なお、後述す
る油剤含浸工程において油剤を含浸した成形体が十分な
強度を有するように、成形体密度は３．６〜４．８ｇ／
ｃｍ3に設定されることが望ましい。After the powder filling, an orientation magnetic field is formed in the space filled with the powder 4 to perform the magnetic orientation of the powder 4. The effect is exerted not only in the case of parallel magnetic field molding in which the direction of the magnetic field and the pressing direction coincide, but also in the case of vertical magnetic field molding in which the direction of the magnetic field is perpendicular to the pressing direction. In addition, the density of the molded body is 3.6 to 4.8 g / in order that the molded body impregnated with the oil agent in the oil agent impregnation step described below has sufficient strength.
It is desirable to set it to cm 3 .
【００４３】成形体は、図１のプレス装置１０から取り
出された後、速やかに有機溶剤などの油剤による含浸処
理を受ける。図２は含浸処理工程の様子を示す図面であ
る。本実施形態では、成形体２０に含浸させる溶剤とし
て、イソパラフィンなどの飽和炭化水素系溶剤を使用す
る。この有機溶剤２１を図２に示すような溶剤槽２２に
入れ、成形体２０を溶剤槽２２内の有機溶剤２１中に浸
漬する。有機溶剤２１は成形体２０の表面（成形体の外
形で規定される面（外面））から成形体内に含浸され、
これにより、成形体２０が有機溶剤によって実質的に覆
われるため、成形体２０が大気中に酸素と直接接触する
ことが抑制される。その結果、成形体２０を大気中に放
置しても短時間で発熱・発火するおそれは大きく減じら
れる。The molded body, after being taken out from the pressing device 10 in FIG. 1, is immediately subjected to an impregnation treatment with an oil agent such as an organic solvent. FIG. 2 is a diagram showing a state of the impregnation treatment process. In this embodiment, a saturated hydrocarbon solvent such as isoparaffin is used as the solvent with which the molded body 20 is impregnated. The organic solvent 21 is put in a solvent tank 22 as shown in FIG. 2, and the molded body 20 is immersed in the organic solvent 21 in the solvent tank 22. The organic solvent 21 is impregnated into the molded body from the surface of the molded body 20 (the surface (outer surface) defined by the outer shape of the molded body).
Thereby, since the molded body 20 is substantially covered with the organic solvent, direct contact of the molded body 20 with oxygen in the atmosphere is suppressed. As a result, even if the molded body 20 is left in the atmosphere, the possibility of heat generation and ignition in a short time is greatly reduced.
【００４４】この含浸工程において、成形体を構成する
粉末粒子の全ての表面が有機溶剤（油剤）によって覆わ
れる必要はない。少なくとも成形体の表面領域における
粉末粒子の表面を油剤によって実質的に覆うことで、成
形体の周囲に存在する酸素と成形体との反応を防止し得
る。In this impregnation step, it is not necessary that the entire surface of the powder particles constituting the molded body be covered with the organic solvent (oil agent). By substantially covering at least the surface of the powder particles in the surface region of the molded body with the oil agent, the reaction between oxygen existing around the molded body and the molded body can be prevented.
【００４５】また、上記含浸工程では、粉末粒子の表面
を実質的に覆えばよく、油剤によって成形体中の気泡を
満たす必要はない。In the impregnation step, it is sufficient that the surface of the powder particles is substantially covered, and it is not necessary to fill the bubbles in the compact with the oil agent.
【００４６】成形体２０を有機溶剤２１中に浸す時間
（浸漬時間）は０．５秒以上であれば十分である。浸漬
時間が長くなると、成形体中に含まれる有機溶剤の量が
増えるが、これによって成形体が崩れるなどの問題は生
じない。従って、焼結工程を開始するまでの間、成形体
を有機溶剤中に浸しつづけても良いし、また、含浸工程
を複数回繰り返しても良い。It is sufficient that the time for immersing the molded body 20 in the organic solvent 21 (immersion time) is 0.5 seconds or more. When the immersion time becomes long, the amount of the organic solvent contained in the molded product increases, but this does not cause a problem such as the collapse of the molded product. Therefore, the molded body may be kept immersed in the organic solvent until the sintering step is started, or the impregnation step may be repeated a plurality of times.
【００４７】含浸処理に用いる有機溶剤としては、成形
性や配向度の向上を目的として粉末に添加される液体潤
滑剤と同様の材料を用いることができる。ただし、表面
酸化防止機能を持つ有機溶剤であることが必要であるた
め、イソパラフィンに代表される石油系溶剤やナフテン
系溶剤、カプロン酸メチル、カプリル酸メチル、ラウリ
ン酸メチルなどの脂肪酸エステル、高級アルコール、高
級脂肪酸などが特に好ましいと考えられる。As the organic solvent used for the impregnation treatment, the same material as the liquid lubricant added to the powder for the purpose of improving moldability and orientation can be used. However, since it is necessary to be an organic solvent having a surface antioxidant function, petroleum-based solvents such as isoparaffin and naphthene-based solvents, fatty acid esters such as methyl caproate, methyl caprylate and methyl laurate, and higher alcohols. , Higher fatty acids, etc. are considered to be particularly preferable.
【００４８】含浸処理に用いる有機溶剤としては、上述
のような飽和炭化水素系溶剤に限らず、α−ピネン、シ
クロブテン、シクロヘキセン、ジエチルベンゼンなどか
ら形成される不飽和炭化水素系溶剤を用いることもでき
る。ただし、不飽和炭化水素系溶剤は、粉砕工程を経て
活性な表面が露出した状態の粉体と反応する可能性があ
るため、飽和炭化水素系溶剤を用いることが好ましい。The organic solvent used for the impregnation treatment is not limited to the saturated hydrocarbon solvent as described above, but an unsaturated hydrocarbon solvent formed from α-pinene, cyclobutene, cyclohexene, diethylbenzene or the like can be used. . However, it is preferable to use a saturated hydrocarbon solvent because the unsaturated hydrocarbon solvent may react with the powder whose active surface is exposed after the pulverization step.
【００４９】含浸処理の後、成形体２０は、予熱工程
（脱油工程）、焼結工程、時効処理工程などの公知の製
造プロセスを経て最終的に永久磁石製品となる。油剤成
分に含まれる炭素（Ｃ）は、希土類磁石の磁気特性を劣
化させるため、成形体２０に含浸させる油剤は、予熱工
程および焼結工程に際して成形体から離脱するものが選
択される。そのため、油剤が磁石特性に悪い影響を及ぼ
すことは無い。油剤は、好適には、２０℃で８Ｐａ以上
の蒸気圧を有する。焼結前の予熱工程などによって油剤
が揮発した後は、その成形体を大気に接触させることな
く、酸素濃度の低い環境下に置くことが必要である。こ
のため、予熱工程や焼結工程を行う炉は連結し、成形体
が大気と直接に接触しないようにして炉間を移動させる
ことが好ましい。また、連続炉とすることが望ましい。After the impregnation treatment, the molded body 20 finally becomes a permanent magnet product through known manufacturing processes such as a preheating process (deoiling process), a sintering process and an aging treatment process. Since carbon (C) contained in the oil agent component deteriorates the magnetic properties of the rare earth magnet, the oil agent with which the compact 20 is impregnated is selected such that it is released from the compact during the preheating step and the sintering step. Therefore, the oil agent does not adversely affect the magnet characteristics. The oil solution preferably has a vapor pressure of 8 Pa or higher at 20 ° C. After the oil agent is volatilized by the preheating step before sintering, it is necessary to place the molded body in an environment with a low oxygen concentration without contact with the atmosphere. Therefore, it is preferable that the furnaces for the preheating step and the sintering step are connected to each other and moved between the furnaces so that the compact does not come into direct contact with the atmosphere. Further, it is desirable to use a continuous furnace.
【００５０】なお、上記のような有機溶剤を用いた場
合、これらの有機溶剤中の炭素は比較的除去され易いた
め、炭素の除去を促進する水素などを予熱工程において
用いる必要性がない。従って、鉱物油を使用する場合に
比べて脱油処理を短時間で行うことが可能となり、生産
性が向上する。When the above organic solvents are used, carbon in these organic solvents is relatively easy to be removed, so that it is not necessary to use hydrogen or the like for promoting the removal of carbon in the preheating step. Therefore, it becomes possible to perform the deoiling treatment in a shorter time as compared with the case of using mineral oil, and the productivity is improved.
【００５１】また油剤は、上述のように予熱工程や焼結
工程などにおいて成形体から除去される。油剤の除去の
ためには、減圧下で１００〜６００℃で０．１〜８．０
時間のあいだ成形体を加熱することが好ましい。Further, the oil agent is removed from the molded body in the preheating step, the sintering step and the like as described above. For removing the oil agent, 0.1 to 8.0 at 100 to 600 ° C. under reduced pressure.
It is preferred to heat the compact for a period of time.
【００５２】なお、本実施形態では、原料合金をストリ
ップキャスト法（例えば米国特許第５，３８３，９７８
号に記載）によって作製する例を説明したが、他の方法
（例えばインゴット法、直接還元法、アトマイズ法、遠
心鋳造法）によってもよい。In this embodiment, the raw material alloy is strip cast (see, for example, US Pat. No. 5,383,978).
However, other methods (eg, ingot method, direct reduction method, atomizing method, centrifugal casting method) may be used.
【００５３】次に、図５を参照しながら、本発明による
希土類磁石の製造方法の他の実施形態を説明する。図５
は、本実施形態で使用するプレス装置（プレス機）１
０、含浸槽４２、焼結ケース５８などを示している。本
実施形態において、プレス装置１０によって作製された
成形体２０は、温度検出部３０へと送られる。この温度
検出部３０には赤外線温度測定器３２が設けられてお
り、この測定器３２がプレス後における成形体２０の表
面温度を測定する。赤外線温度測定器３２を用いれば、
成形体２０に直接触れることなく迅速容易に温度測定を
行うことができる。Next, another embodiment of the method for manufacturing a rare earth magnet according to the present invention will be described with reference to FIG. Figure 5
Is a press machine (press machine) 1 used in this embodiment.
0, the impregnation tank 42, and the sintering case 58 are shown. In the present embodiment, the molded body 20 produced by the press device 10 is sent to the temperature detection unit 30. The temperature detecting unit 30 is provided with an infrared temperature measuring device 32, and the measuring device 32 measures the surface temperature of the molded body 20 after pressing. With the infrared temperature measuring device 32,
The temperature can be measured quickly and easily without directly touching the molded body 20.
【００５４】温度測定器３２によって測定された成形体
２０の表面温度が予め設定されたレベル（例えば４０℃
または４５℃）以上の場合、そのような成形体２０は、
油剤を含浸させられることなく排除装置（例えば、ロボ
ットアーム）３４によって回収箱３６へ廃棄される。回
収箱３６は、好適には開閉可能な密封容器から構成され
ており、成形体２０の搬送経路の近傍に配置されること
が好ましい。このような構成にすれば、例えば廃棄され
た成形体２０’が発火した場合でも、その成形体２０’
を回収箱３６内に密封して周囲の大気（酸素や水蒸気）
から遮断することによって、これを鎮火することができ
る。また、発火した成形体２０’の鎮火をさらに容易に
するために、回収箱３６の内部を窒素ガスなどの不活性
ガスで満たすようにしてもよい。The surface temperature of the molded body 20 measured by the temperature measuring device 32 is set to a preset level (for example, 40 ° C.).
Or 45 ° C.) or higher, such a molded body 20 is
Without being impregnated with the oil agent, it is discarded into the collection box 36 by the excluding device (for example, a robot arm) 34. The collection box 36 is preferably composed of an openable and closable sealed container, and is preferably arranged in the vicinity of the conveyance path of the molded body 20. With such a structure, even when the discarded molded body 20 'is ignited, for example, the molded body 20' is discarded.
Is sealed in the collection box 36 and the surrounding atmosphere (oxygen and water vapor)
It can be extinguished by shutting it off. Further, in order to make it easier to extinguish the fired molded body 20 ', the inside of the recovery box 36 may be filled with an inert gas such as nitrogen gas.
【００５５】一方、測定された成形体２０の表面温度が
設定されたレベルを下回る場合、成形体２０は、排除装
置３４によって廃棄されることなく、油剤含浸部４０へ
送られる。油剤含浸部４０には、油剤４１を収容した含
浸槽４２が設けられている。この含浸槽４２の上面にお
ける両端部には、シャッター４４によって開閉可能にさ
れた開口部４２ａが各々設けられている。これにより、
含浸槽４２は、その内部に成形体２０を出し入れでき、
かつ、槽内を実質的に密閉し得る。含浸槽４２の内部に
は、油剤４１を冷却するための冷却器４８が設けられて
おり、油剤温度が発火の危険性の高いレベルには上昇し
ないよう制御される。また、含浸槽内を不活性雰囲気と
すれば、より安全に作業を行うことができる。On the other hand, when the measured surface temperature of the molded body 20 falls below the set level, the molded body 20 is sent to the oil impregnating section 40 without being discarded by the excluding device 34. The oil agent impregnating section 40 is provided with an impregnation tank 42 containing an oil agent 41. Openings 42 a that can be opened and closed by shutters 44 are provided at both ends on the upper surface of the impregnation tank 42. This allows
The impregnation tank 42 allows the molded body 20 to be put in and taken out of the inside,
Moreover, the inside of the tank can be substantially sealed. Inside the impregnation tank 42, a cooler 48 for cooling the oil agent 41 is provided, and the oil agent temperature is controlled so as not to rise to a level where there is a high risk of ignition. In addition, if the inside of the impregnation tank is made an inert atmosphere, the work can be performed more safely.
【００５６】油剤含浸部４０へ送られた成形体２０は、
含浸槽４２の一端側の開口部４２ａから槽内へと延びる
下降ベルト４６ａによって油剤４１中に浸漬される。油
剤４１中に浸漬された成形体２０は、次に並進ベルト４
６ｂによって油剤４１中を移動させられ、この移動中に
おいて表面から油剤４１を含浸する。次に、この成形体
２０は、槽内から他端側の開口部４２ａへと延びる上昇
ベルト４６ｃによって油剤４１から引き上げられ、槽外
へと取り出される。The molded body 20 sent to the oil agent impregnation section 40 is
The impregnation tank 42 is immersed in the oil agent 41 by a descending belt 46a extending into the tank from an opening 42a on one end side. The molded body 20 dipped in the oil 41 is then transferred to the translation belt 4
The oil agent 41 is moved by 6b, and the oil agent 41 is impregnated from the surface during the movement. Next, the molded body 20 is pulled up from the oil agent 41 by the rising belt 46c extending from the inside of the tank to the opening 42a on the other end side, and taken out of the tank.
【００５７】この含浸工程において、含浸槽４２内の油
剤４１には、約４０℃程度の成形体２０が順次浸漬され
る。これにより、油剤４１の温度は徐々に上昇し、それ
に伴って油剤４１の一部は気化するおそれがある。気化
した油剤４１が槽外に放出されることを抑止するため、
含浸槽４２の開口部４２ａをシャッター４４によって閉
じることができる。また、上述の温度上昇によって油剤
４１が発火した場合でも、シャッター４４を用いて開口
部４２ａを閉じるようにすれば、槽内に炎を閉じ込める
ことができるので安全性が高い。また、含浸槽内を不活
性雰囲気とすれば、より効果的に成形体および油剤の発
火を抑制することができる。In this impregnation step, the molded body 20 at about 40 ° C. is successively immersed in the oil agent 41 in the impregnation tank 42. As a result, the temperature of the oil agent 41 gradually rises, and there is a risk that part of the oil agent 41 will vaporize. In order to prevent the vaporized oil agent 41 from being discharged outside the tank,
The opening 42 a of the impregnation tank 42 can be closed by the shutter 44. Further, even when the oil 41 is ignited by the above-mentioned temperature rise, if the shutter 42 is used to close the opening 42a, the flame can be confined in the tank, which is highly safe. Further, by setting the inert atmosphere in the impregnation tank, it is possible to more effectively suppress the ignition of the molded body and the oil agent.
【００５８】さらに、冷却器４８を適切に作動させれ
ば、成形体２０によって油剤４１の温度が上昇する場合
にも、これを所定の温度（例えば、ほぼ室温程度）に維
持することができる。油剤４１の温度をモニタリングす
るためには、含浸槽４２の内部に油剤温度を測定する温
度計を備えつけることが好ましい。この温度計によって
測定された油剤温度に基づいて、冷却器４８の動作を自
動的に制御するようにしてもよい。Further, if the cooler 48 is properly operated, even when the temperature of the oil agent 41 rises due to the molded body 20, it can be maintained at a predetermined temperature (for example, about room temperature). In order to monitor the temperature of the oil agent 41, it is preferable to equip the impregnation tank 42 with a thermometer for measuring the oil agent temperature. The operation of the cooler 48 may be automatically controlled based on the oil temperature measured by the thermometer.
【００５９】このような含浸工程を経たあと、油剤４１
を含浸した成形体２０は、その後の成形体２０の焼結工
程の準備を行うための焼結準備部５０へ送られる。焼結
準備部５０は、好適には囲い（パーティション）５２に
よって実質的に外気と遮断された空間内に設けられてい
る。この焼結準備部５０において、成形体２０は載置装
置（例えばロボットアーム）５４によって、焼結台板５
６上に所望の配置で載置される。その後、所定数の成形
体２０が載置された焼結台板５６は、焼結ケース５８内
に収容される。After passing through such an impregnation step, the oil agent 41
The molded body 20 impregnated with is sent to a sintering preparation unit 50 for preparing the subsequent sintering step of the molded body 20. The sintering preparation unit 50 is preferably provided in a space substantially isolated from the outside air by a partition (partition) 52. In the sintering preparation unit 50, the compact 20 is placed on the sintering base plate 5 by a mounting device (for example, a robot arm) 54.
6 is placed in the desired arrangement. After that, the sintering base plate 56 on which a predetermined number of compacts 20 are placed is housed in the sintering case 58.
【００６０】この焼結準備工程において、囲い５２の内
部には開口部５２ａを介して例えばアルゴンなどの不活
性ガスが供給されている。焼結台板５６や焼結ケース５
８への成形体２０の載置を不活性雰囲気中で行えば、成
形体２０の酸化を抑制することができる。In this sintering preparation step, an inert gas such as argon is supplied into the enclosure 52 through the opening 52a. Sintering base plate 56 and sintering case 5
If the molded body 20 is placed on the substrate 8 in an inert atmosphere, it is possible to suppress the oxidation of the molded body 20.
【００６１】本実施形態によれば、発火した成形体、ま
たは、発火に至る直前の成形体を含浸槽に投入すること
を防止できる。このため、含浸槽内の油剤が過度に熱さ
れることがなく、油剤が引火される危険を避けることが
できる。酸素濃度の低い希土類合金粉末をプレス成形す
る場合は、成形体をプレス装置のダイから抜き出した
後、最も発熱・発火の可能性が強まるが、本実施形態に
よれば、油剤引火を確実に防止し、含浸工程を安全に遂
行することが可能になる。According to the present embodiment, it is possible to prevent the molded body that has ignited or the molded body immediately before ignition from being introduced into the impregnation tank. Therefore, the oil agent in the impregnation tank is not excessively heated, and the risk of ignition of the oil agent can be avoided. When press-molding rare earth alloy powder with low oxygen concentration, the possibility of heat generation / ignition is maximized after the molded product is extracted from the die of the press machine.However, according to this embodiment, oil agent ignition is reliably prevented. Therefore, the impregnation process can be safely performed.
【００６２】次に、図６を参照しながら、本発明による
希土類磁石の製造方法の更に他の実施形態を説明する。
本実施形態でも、図５に示した形態と同様に、赤外線温
度測定器３２によって測定された成形体２０の表面温度
が予め設定されたレベル（例えば５０℃）以上の場合、
成形体２０に油剤６１を含浸させることなく、その成形
体２０を回収箱３６へ廃棄し、測定された表面温度が予
め設定されたレベルを下回る場合には、成形体２０に油
剤６１を含浸させる工程を実行する。ただし、本実施形
態は、油剤含浸部６０において複数の含浸槽６２を使用
している点で、図５に示した実施形態とは異なる。Next, still another embodiment of the method for manufacturing a rare earth magnet according to the present invention will be described with reference to FIG.
Also in the present embodiment, similarly to the embodiment shown in FIG. 5, when the surface temperature of the molded body 20 measured by the infrared temperature measuring device 32 is equal to or higher than a preset level (for example, 50 ° C.),
The molded body 20 is discarded in the collection box 36 without impregnating the molded body 20 with the oil agent 61, and when the measured surface temperature is lower than the preset level, the molded body 20 is impregnated with the oil agent 61. Execute the process. However, this embodiment is different from the embodiment shown in FIG. 5 in that a plurality of impregnation tanks 62 are used in the oil agent impregnation section 60.
【００６３】成形体２０の回収箱３６への廃棄および油
剤含浸部６０へ移送は、ロボットアーム等を用いて構成
された排除／投入装置７０によって実行される。排除／
投入装置７０は、測定器３２によって測定された表面温
度が設定されたレベルを下回る場合のみ、その成形体２
０をいずれかの含浸槽６２内に貯められた油剤６１中に
浸漬させるように動作する。The discarding of the molded body 20 into the collection box 36 and the transfer to the oil agent impregnating section 60 are executed by the excluding / charging device 70 configured by using a robot arm or the like. Exclusion /
The dosing device 70 only applies to the molded body 2 if the surface temperature measured by the measuring device 32 falls below a set level.
0 is immersed in the oil agent 61 stored in one of the impregnation tanks 62.
【００６４】この複数の含浸槽６２は、略水平面内を循
環するロータリー形式のコンベア６６上に載置されてい
る。また、含浸槽６２のそれぞれにはシャッター６４が
設けられている。含浸槽６２は、シャッター６４を開け
た状態で開口部６２ａから投入された成形体２０を収容
する。なお、図６には１個の含浸槽６２に対し、１個の
成形体を収容させた例が示されているが、１個の含浸槽
６２に対し複数個の成形体を収容させてもよい。また、
成形体２０を収容した含浸槽６２は、シャッター６４を
閉じた状態でコンベア６６上を移動させられ、この移動
中において成形体２０は油剤６１を吸収する。含浸後、
シャッター６４を開けて開口部６２ａから成形体２０を
取り出し、焼結台板５６上に載置する。この取り出し工
程は、例えば図に示すようなロボットアームを備えた取
り出し／載置装置７２によって実行される。焼結台板５
６上に載置された成形体２０は焼結ケース５８に収納さ
れ、その後、公知の焼結工程が実行されることになる。The plurality of impregnation tanks 62 are placed on a rotary type conveyor 66 that circulates in a substantially horizontal plane. Further, each impregnation tank 62 is provided with a shutter 64. The impregnation tank 62 accommodates the molded body 20 that is input from the opening 62a with the shutter 64 opened. Although FIG. 6 shows an example in which one molded body is accommodated in one impregnation tank 62, a plurality of molded bodies can be accommodated in one impregnation tank 62. Good. Also,
The impregnation tank 62 containing the molded body 20 is moved on the conveyor 66 with the shutter 64 closed, and the molded body 20 absorbs the oil agent 61 during this movement. After impregnation,
The shutter 64 is opened, the molded body 20 is taken out from the opening 62a, and placed on the sintering base plate 56. This take-out step is executed by a take-out / placement device 72 having a robot arm as shown in the figure, for example. Sinter base plate 5
The molded body 20 placed on the No. 6 is housed in the sintering case 58, and then a known sintering process is executed.
【００６５】本実施形態によれば、成形体２０の出し入
れ時以外、開口部６２ａをシャッター６４によって閉じ
ておくことが可能であるため、気化した油剤が含浸槽６
２の外部に放出されにくく、また、仮に含浸槽６２内の
油剤に引火した場合でも槽内に炎を閉じこめることが容
易である。さらに、本実施形態によれば、比較的小さい
寸法で形成された複数の含浸槽６２に分割して成形体２
０の含浸工程を行うので、複数の含浸槽６２のうちの何
れかの油剤に引火した場合でも、その影響が他の含浸槽
６２に及ばず、安全性がいっそう向上することになる。
なお、油剤の温度を安全な範囲内に確実に制御するため
には、各含浸槽６１の内側に冷却器（不図示）を設ける
ことが好ましい。According to the present embodiment, the opening 62a can be closed by the shutter 64 except when the molded body 20 is taken in and out.
2 is not easily released to the outside of the tank 2, and even if the oil agent in the impregnation tank 62 is ignited, it is easy to confine the flame in the tank. Furthermore, according to the present embodiment, the molded body 2 is divided into a plurality of impregnation tanks 62 formed with a relatively small size.
Since the impregnation step of 0 is performed, even if the oil agent in any of the plurality of impregnation tanks 62 is ignited, the influence does not reach the other impregnation tanks 62, and the safety is further improved.
In order to reliably control the temperature of the oil agent within a safe range, it is preferable to provide a cooler (not shown) inside each impregnation tank 61.
【００６６】以上、比較的大型の焼結ケース５８内に複
数の成形体２０を収納する例について本発明の実施形態
を説明してきたが、本発明はこれに限定されるものでは
ない。例えば、より小型の箱状焼結パック内に成形体２
０を収納した後、複数の終結パックを重ねた状態で焼結
炉内に搬入するようにしてもよい。また、成形体２０を
焼結台板５６上に配置した後、特に密閉することなく焼
結炉内に搬入するようにしてもよい。ただし、何れの場
合も、成形体を焼結台板５６に搭載する工程は不活性雰
囲気下で行うことが好ましい。Although the embodiment of the present invention has been described above with respect to an example in which a plurality of compacts 20 are housed in a relatively large sintered case 58, the present invention is not limited to this. For example, the compact 2 can be placed in a smaller box-shaped sintering pack.
After storing 0, a plurality of final packs may be loaded into the sintering furnace in a stacked state. Further, after the molded body 20 is placed on the sintering base plate 56, it may be loaded into the sintering furnace without being hermetically sealed. However, in any case, it is preferable that the step of mounting the compact on the sintering base plate 56 is performed in an inert atmosphere.
【００６７】＜実施例＞まず、Ｎｄ＋Ｐｒ（３０．０質
量％）−Ｄｙ（１．０質量％）−Ｂ（１．０質量％）−
Ａｌ（０．１質量％）−Ｆｅ（残部）の組成を有する合
金の溶湯を高周波溶解炉によって作製した。ロール式ス
トリップキャスターを用いて上記溶湯を冷却し、厚さ
０．３〜０．５ｍｍ程度の薄板状鋳片（フレーク状合
金）を作製した。このフレーク状合金の含有酸素濃度は
１５０質量ｐｐｍだった。Example First, Nd + Pr (30.0% by mass) -Dy (1.0% by mass) -B (1.0% by mass)-
A molten metal of an alloy having a composition of Al (0.1% by mass) -Fe (the balance) was produced by a high frequency melting furnace. The molten metal was cooled using a roll-type strip caster to prepare a thin plate-shaped cast piece (flake-shaped alloy) having a thickness of about 0.3 to 0.5 mm. The oxygen content of this flake alloy was 150 mass ppm.
【００６８】次に、フレーク状合金をケース内に収容
し、これを水素炉内に収容した。その炉内を真空引きし
た後、水素脆化を行うために炉内に水素ガスを２時間供
給した。炉内の水素分圧は２００ｋＰａとした。フレー
クが水素吸蔵による自然崩壊を起こした後、加熱しなが
ら真空引きし、脱水素処理を施した。そして炉内にアル
ゴンガスを導入し、室温まで冷却した。合金温度が２０
℃まで冷却された時点で水素炉から取り出した。この段
階で、合金の酸素含有量は１０００質量ｐｐｍだった。Next, the flaky alloy was housed in a case, which was then housed in a hydrogen furnace. After the inside of the furnace was evacuated, hydrogen gas was supplied into the furnace for 2 hours in order to embrittle hydrogen. The hydrogen partial pressure in the furnace was 200 kPa. After the flakes spontaneously disintegrated due to hydrogen occlusion, the flakes were evacuated while heating and subjected to dehydrogenation treatment. Then, argon gas was introduced into the furnace and cooled to room temperature. Alloy temperature is 20
It was taken out from the hydrogen furnace when it was cooled to ℃. At this stage, the oxygen content of the alloy was 1000 ppm by mass.
【００６９】その後、粉砕室内の酸素濃度が０．５体積
％（５０００体積ｐｐｍ）以下となるように管理された
ジェットミルによって粉砕を行い、平均粒径が４．４μ
mの粉末（原料１）と平均粒径が４．０μmの粉末（原料
２）を作製した。本実施形態では、このように酸素濃度
を低く管理した雰囲気中で微粉砕を行うことによって、
表面酸化の抑制された微粉砕粉を作製した。原料１の含
有酸素濃度は約３０００質量ｐｐｍ、原料２の含有酸素
濃度は約２０００質量ｐｐｍであり、何れも、含有酸素
濃度が３０００質量ｐｐｍ以下となった。なお、本明細
書中における「平均粒径」とは、質量中位径（メジアン
径）を指すものとする。After that, pulverization was performed by a jet mill controlled so that the oxygen concentration in the pulverization chamber was 0.5% by volume (5000 volume ppm) or less, and the average particle size was 4.4 μm.
m powder (raw material 1) and powder having an average particle size of 4.0 μm (raw material 2) were produced. In this embodiment, by performing fine pulverization in an atmosphere in which the oxygen concentration is controlled to be low,
A finely pulverized powder with suppressed surface oxidation was prepared. The raw material 1 had an oxygen concentration of about 3000 mass ppm, and the raw material 2 had an oxygen concentration of about 2000 mass ppm. In all cases, the oxygen content was 3000 mass ppm or less. In addition, in this specification, an "average particle diameter" shall refer to a mass median diameter (median diameter).
【００７０】次に、ロッキングミキサを用い、上記の微
粉砕粉（原料１および２）に対して０．４質量％の液体
潤滑剤を添加した。この潤滑剤は、カプロン酸メチルを
主成分とするものであった。Next, using a rocking mixer, 0.4% by mass of liquid lubricant was added to the finely pulverized powder (raw materials 1 and 2). This lubricant was mainly composed of methyl caproate.
【００７１】次に、図１に示す装置を用い、乾式プレス
法によって上記粉末から成形体を作製した。ここでいう
「乾式」とは、本実施例のように粉末が比較的少量の潤
滑剤（油剤）を含有する場合をも広く包含し、油剤を搾
り出す工程が不要なものを言う。Next, using the apparatus shown in FIG. 1, a molded body was produced from the above powder by the dry pressing method. The term "dry" as used herein broadly includes the case where the powder contains a relatively small amount of lubricant (oil agent) as in the present embodiment, and means that the step of squeezing out the oil agent is unnecessary.
【００７２】上記の原料１から２個の成形体を作製し、
原料２からは１個の成形体を作成した。成形体のサイズ
は、何れも３０ｍｍ×５０ｍｍ×３０ｍｍとし、成形体
密度は、４．３〜４．４ｇ／ｃｍ3とした。Two moldings were prepared from the above raw materials 1 and
One molded body was prepared from the raw material 2. The size of each molded body was 30 mm × 50 mm × 30 mm, and the molded body density was 4.3 to 4.4 g / cm 3 .
【００７３】次に、成形体の表面から油剤を成形体に含
浸させるための工程を行った。油剤としてはイソパラフ
ィンを用いた。この油剤に成形体の全体を２秒間浸漬し
た。Next, the step of impregnating the molded body with the oil agent from the surface of the molded body was carried out. Isoparaffin was used as the oil agent. The entire molded body was immersed in this oil agent for 2 seconds.
【００７４】液剤から取り出した成形体を室温の大気中
に放置し、成形体の温度を測定した。成形体中の希土類
元素が酸化すると、発熱が生じるため、成形体温度によ
って酸化の進行程度を評価することが可能である。The molded product taken out from the liquid agent was left in the atmosphere at room temperature, and the temperature of the molded product was measured. When the rare earth element in the molded body is oxidized, heat is generated, and therefore the degree of progress of oxidation can be evaluated by the temperature of the molded body.
【００７５】図３は、大気中での放置時間と成形体温度
との関係を示すグラフである。大気温度は室温（２５
℃）で、湿度は４０％だった。図３からわかるように、
成形体温度は含浸処理直後において４０℃以下であり６
００秒経過後においても５０℃を下回ったままであっ
た。また、成形体温度の上昇は約２０００秒経過後に停
止した。成形体温度の最高値は７０℃程度に過ぎず、成
形体を大気雰囲気中に長時間放置したとしても発火のお
それは無かった。FIG. 3 is a graph showing the relationship between the standing time in the atmosphere and the temperature of the molded body. Atmospheric temperature is room temperature (25
C.) and the humidity was 40%. As you can see from Figure 3,
The temperature of the molded body was 40 ° C or less immediately after the impregnation treatment, and 6
The temperature remained below 50 ° C. even after the elapse of 00 seconds. Moreover, the rise of the temperature of the molded body was stopped after about 2000 seconds had elapsed. The maximum temperature of the molded body was only about 70 ° C., and even if the molded body was left in the air atmosphere for a long time, there was no risk of ignition.
【００７６】また、含浸処理後、成形体温度が一時的に
（２〜３分間程度）低下していることもわかった。これ
は、成形体から油剤が揮発し、気化熱により成形体が冷
却されたためである。油剤としては、揮発油を用いても
よい。It was also found that after the impregnation treatment, the temperature of the molded body was temporarily lowered (for about 2 to 3 minutes). This is because the oil agent volatilized from the molded body and the molded body was cooled by the heat of vaporization. Volatile oil may be used as the oil agent.
【００７７】次に、油剤で表面が覆われた状態の成形体
に対して、２５０℃で２時間の予熱工程を行った後、１
０４０℃で６時間の焼結処理を行った。Next, the molded body whose surface was covered with the oil was subjected to a preheating step at 250 ° C. for 2 hours, and then 1
Sintering treatment was performed at 040 ° C. for 6 hours.
【００７８】このようにして作製した焼結磁石につき、
種々の磁気特性を評価した。原料１から作製した焼結磁
石の場合、酸素含有量は３１００質量ｐｐｍ、残留磁束
密度Ｂｒは１．４１Ｔ、最大磁気エネルギー積（ＢＨ）
maxは３８０ｋＪ／ｍ、保磁力ＨcJは１０００ｋＡ／ｍ
であった。また、原料２から作製した焼結磁石の場合、
酸素含有量は２２００質量ｐｐｍ、残留磁束密度Ｂｒは
１．４３Ｔ、最大磁気エネルギー積（ＢＨ）maxは３９
７ｋＪ／ｍ、保磁力ＨcJは１０００ｋＡ／ｍであった。Regarding the sintered magnet thus produced,
Various magnetic properties were evaluated. In the case of the sintered magnet produced from the raw material 1, the oxygen content is 3100 mass ppm, the residual magnetic flux density Br is 1.41T, and the maximum magnetic energy product (BH).
max is 380 kJ / m, coercive force H cJ is 1000 kA / m
Met. Further, in the case of a sintered magnet produced from raw material 2,
The oxygen content is 2200 mass ppm, the residual magnetic flux density Br is 1.43T, and the maximum magnetic energy product (BH) max is 39.
The coercive force H cJ was 7 kJ / m and 1000 kA / m.
【００７９】原料１から作製した焼結磁石と原料２から
作製した焼結磁石について磁気特性を比較すると、酸素
含有量の低減によって磁気特性が向上することがわか
る。A comparison of the magnetic characteristics of the sintered magnet made from the raw material 1 and the sintered magnet made from the raw material 2 shows that the magnetic characteristics are improved by reducing the oxygen content.
【００８０】なお、成形体に油剤を含浸させる方法とし
ては、本実施例の方法に代えて、スプレィ法や刷毛塗り
法などを採用しても同様の効果が発揮される。As a method of impregnating the molded body with the oil agent, the same effect can be obtained by adopting a spray method or a brush coating method instead of the method of this embodiment.
【００８１】また、本発明で用いる希土類磁石の原料組
成も上記実施例の組成に限定されないことは言うまでも
無く、大気中での酸化反応によって発熱・発火の危険が
ある低酸素濃度希土類合金の粉末に対して本発明は広く
適用可能である。Further, it goes without saying that the raw material composition of the rare earth magnet used in the present invention is not limited to the composition of the above-mentioned embodiment, and the composition of a low oxygen concentration rare earth alloy which may cause heat generation and ignition due to the oxidation reaction in the atmosphere is used. The present invention is widely applicable to powders.
【００８２】＜比較例＞比較例として、上記実施例と同
様にして原料１と原料２から、それぞれ成形体を作製し
た。図４は、原料１から作成した比較例１と原料２から
作成した比較例２について、放置時間と成形体温度との
関係を示している。<Comparative Example> As a comparative example, compacts were produced from the raw material 1 and the raw material 2 in the same manner as in the above-described example. FIG. 4 shows the relationship between the standing time and the temperature of the molded body for Comparative Example 1 made from the raw material 1 and Comparative Example 2 made from the raw material 2.
【００８３】実施例と比較例との差異は、比較例におい
ては油剤による含浸工程を行わなかった点にある。この
ため、比較例１の場合、図４のグラフに示すように、プ
レス直後から成形体温度は上昇し続け、６００秒経過前
に９０℃にも達したため、発火の危険が生じた。酸化に
よって発生した熱は周囲の粉末の酸化を促進するため、
いったん酸化が始まり出すと成形体の温度は急激に上昇
し、発火の危険性が著しく高まる。このような成形体
は、酸素濃度を比較的に低くした雰囲気ガスのケース内
に収納した場合でも、ケース内で徐々に酸化されつづ
け、成形体の内部で熱を蓄積してゆくと考えられる。そ
のため、やがては急激に発熱し、発火に至る危険性があ
る。The difference between the example and the comparative example is that the impregnation step with the oil agent was not performed in the comparative example. Therefore, in the case of Comparative Example 1, as shown in the graph of FIG. 4, the temperature of the molded body continued to rise immediately after pressing and reached 90 ° C. before the elapse of 600 seconds, causing a danger of ignition. The heat generated by oxidation accelerates the oxidation of the surrounding powder,
Once oxidation begins, the temperature of the molded body rises sharply and the risk of ignition increases significantly. It is considered that such a molded body continues to be gradually oxidized in the case even when it is housed in a case of an atmospheric gas having a relatively low oxygen concentration, and heat is accumulated inside the molded body. For this reason, there is a danger that heat will be generated rapidly and an ignition will occur.
【００８４】酸素濃度が約２０００質量ｐｐｍ以下の比
較例２の場合、成形体はプレス装置から取り出して約２
分経過後に大気中で発火した。In the case of Comparative Example 2 in which the oxygen concentration was about 2000 mass ppm or less, the molded product was taken out from the press machine to about 2
It ignited in the atmosphere after a lapse of minutes.
【００８５】[0085]
【発明の効果】本発明によれば、原料粉末の酸素含有量
を低減しながら発熱・発火の危険を避けることが可能に
なるため、安全かつ実用的に磁石の主相量を増加させ、
希土類磁石の磁石特性を向上させることが可能になる。According to the present invention, since it is possible to reduce the oxygen content of the raw material powder and avoid the danger of heat generation and ignition, it is possible to increase the amount of main phase of the magnet safely and practically.
It is possible to improve the magnet characteristics of the rare earth magnet.
【図１】磁性粉末の成形に好適に用いられるプレス装置
の概略構成を示す、断面図である。FIG. 1 is a cross-sectional view showing a schematic configuration of a press device suitably used for molding magnetic powder.
【図２】本発明の一実施形態における含浸工程を示す図
である。FIG. 2 is a diagram showing an impregnation step in one embodiment of the present invention.
【図３】本発明の実施例について、含浸処理後の経過時
間と成形体温度との関係を示すグラフである。FIG. 3 is a graph showing the relationship between the elapsed time after the impregnation treatment and the temperature of the molded body in the example of the present invention.
【図４】比較例について、プレス装置から成形体を取り
出してからの経過時間と成形体温度との関係を示すグラ
フである。FIG. 4 is a graph showing the relationship between the time elapsed after the molded product was taken out from the press machine and the molded product temperature in the comparative example.
【図５】本発明の他の実施形態で使用するプレス装置、
含浸槽、焼結ケースなどを示す図面である。FIG. 5 is a press device used in another embodiment of the present invention,
It is a drawing which shows an impregnation tank, a sintering case, and the like.
【図６】本発明の更に他の実施形態で使用するプレス装
置、含浸槽、焼結ケースなどを示す図面である。FIG. 6 is a view showing a pressing device, an impregnation tank, a sintering case and the like used in still another embodiment of the present invention.
１ ダイ ２ 下パンチ ３ 上パンチ ４ 原料粉末 ５ コイル ７ コイル １０ プレス装置 ２０ 成形体 ２１ 有機溶剤 ２２ 溶剤槽 ３０ 温度検出部 ３２ 赤外線温度測定器 ３４ 排除装置 ３６ 回収箱 ４０ 油剤含浸部 ４１ 油剤 ４２ 含浸槽 ４２ａ 開口部 ４４ シャッター ４６ｂ 並進ベルト ４６ｃ 上昇ベルト ４８ 冷却器 ５０ 焼結準備部 ５２ 囲い ５２ａ 開口部 ５４ 載置装置 ５６ 焼結台板 ５８ 焼結ケース 1 die 2 Lower punch 3 upper punch 4 Raw material powder 5 coils 7 coils 10 Press machine 20 molded body 21 Organic solvent 22 solvent tank 30 Temperature detector 32 infrared thermometer 34 Exclusion device 36 Collection Box 40 Oil agent impregnation part 41 Oil 42 Impregnation tank 42a opening 44 shutter 46b translation belt 46c lift belt 48 cooler 50 Sintering preparation department 52 enclosure 52a opening 54 Placement device 56 Sintered base plate 58 Sintered case
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) H01F 41/02 ─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. 7 , DB name) H01F 41/02
Claims (17)
土類合金粉末を乾式プレス法によって圧縮成形し、それ
によって成形体を作製するプレス工程と、 前記成形体の表面から油剤を前記成形体に含浸させる工
程と、 前記成形体を焼結させる工程と を包含し、 前記油剤は、２０℃で８Ｐａ以上の蒸気圧を有し、前記
含浸工程の後、前記油剤の揮発によって、前記成形体の
温度を少なくとも一時的に低下させる Ｒ−Ｆｅ−Ｂ系希
土類磁石の製造方法。1. A pressing step in which a rare earth alloy powder having an oxygen content of 4000 mass ppm or less is compression-molded by a dry pressing method to produce a molded body, and an oil agent is impregnated into the molded body from the surface of the molded body. And a step of sintering the molded body , wherein the oil agent has a vapor pressure of 8 Pa or higher at 20 ° C., and
After the impregnation step, the molded body is volatilized by volatilization of the oil agent.
A method for producing an R-Fe-B rare earth magnet , which lowers the temperature at least temporarily .
ｍ以下とする請求項１に記載のＲ−Ｆｅ−Ｂ系希土類磁
石の製造方法。2. The average particle size of the rare earth alloy powder is 10 μm.
The method for producing an R-Fe-B rare earth magnet according to claim 1, wherein the amount is m or less.
製するためのプレス装置のキャビティに充填されるま
で、酸素濃度５０００体積ｐｐｍ以下の不活性雰囲気ガ
ス中に置かれる請求項１に記載のＲ−Ｆｅ−Ｂ系希土類
磁石の製造方法。3. The rare earth alloy powder according to claim 1, wherein the rare earth alloy powder is placed in an inert atmosphere gas having an oxygen concentration of 5000 ppm by volume or less until it is filled in a cavity of a pressing device for producing the molded body. Method for manufacturing R-Fe-B rare earth magnet.
れている請求項１に記載のＲ−Ｆｅ−Ｂ系希土類磁石の
製造方法。4. The method for producing an R—Fe—B rare earth magnet according to claim 1, wherein the oil agent is composed of a hydrocarbon solvent.
成されている請求項４に記載のＲ−Ｆｅ−Ｂ系希土類磁
石の製造方法。5. The method for producing an R—Fe—B rare earth magnet according to claim 4, wherein the oil agent is composed of a saturated hydrocarbon solvent.
合金粉末に潤滑剤が添加される請求項１に記載のＲ−Ｆ
ｅ−Ｂ系希土類磁石の製造方法。6. The R-F according to claim 1, wherein a lubricant is added to the rare earth alloy powder before the pressing step.
Method for manufacturing e-B rare earth magnet.
実質的に除去する油剤除去工程を行い、前記油剤除去工
程の後、焼結までのあいだ、前記成形体を大気に接触さ
せない請求項１から６の何れかに記載のＲ−Ｆｅ−Ｂ系
希土類磁石の製造方法。7. An oil agent removing step of substantially removing the oil agent is performed before sintering the molded article, and the molded article is not exposed to the atmosphere after the oil agent removing step and before sintering. Item 7. A method for manufacturing the R-Fe-B rare earth magnet according to any one of Items 1 to 6 .
１００℃〜６００℃の温度範囲内で０．１〜８．０時間
行われる請求項７に記載のＲ−Ｆｅ−Ｂ系希土類磁石の
製造方法。8. The oil agent removing step is performed under reduced pressure,
The method for producing an R-Fe-B rare earth magnet according to claim 7, which is performed in a temperature range of 100 ° C to 600 ° C for 0.1 to 8.0 hours.
温度を測定し、前記表面温度が予め設定されたレベル以
上の場合には前記成形体に油剤を含浸させず、前記表面
温度が予め設定されたレベルを下回る場合には前記成形
体に油剤を含浸させることを特徴とする請求項１から８
の何れかに記載のＲ−Ｆｅ−Ｂ系希土類磁石の製造方
法。9. After the pressing step, the surface temperature of the molded body is measured, and when the surface temperature is equal to or higher than a preset level, the molded body is not impregnated with an oil agent, and the surface temperature is preset. If below a set level from claim 1, wherein the impregnating oil into the molded body 8
The method for producing the R-Fe-B rare earth magnet according to any one of 1.
の表面温度を測定する請求項９に記載のＲ−Ｆｅ−Ｂ系
希土類磁石の製造方法。10. The method of manufacturing an R—Fe—B rare earth magnet according to claim 9 , wherein the surface temperature of the molded body is measured using an infrared thermometer.
以上の成形体を密閉可能な回収箱内に収納することを特
徴とする請求項９に記載のＲ−Ｆｅ−Ｂ系希土類磁石の
製造方法。11. The method for producing an R—Fe—B rare earth magnet according to claim 9 , wherein the molded body having a surface temperature equal to or higher than a preset level is housed in a recoverable collection box. .
部と前記開口部を閉じる得るシャッターとを備えた含浸
槽を用いて含浸工程を実行することを特徴とする請求項
１から１１の何れかに記載のＲ−Ｆｅ−Ｂ系希土類磁石
の製造方法。12. any of claims 1 to 11, characterized in that to perform the impregnation step by using an impregnation vessel and a shutter to obtain closing the opening and the opening for loading and unloading the molded body The method for producing the R-Fe-B rare earth magnet according to 1.
い、所定個数の成形体を個々の含浸槽に分けて含浸工程
を実行することを特徴とする請求項１から１１の何れか
に記載のＲ−Ｆｅ−Ｂ系希土類磁石の製造方法。13. Using multiple impregnation vessel for storing the oil, from claim 1, characterized in that to perform the impregnation step separately molded body having a predetermined number in each impregnation vessel according to any one of 11 Method for manufacturing R-Fe-B rare earth magnet.
却器が備え付けられている請求項１２または１３に記載
のＲ−Ｆｅ−Ｂ系希土類磁石の製造方法。14. The method of manufacturing a R-Fe-B rare earth magnet according to claim 12 or 13 cooler is equipped wherein the impregnation vessel to cool the oil.
が前記含浸槽に取り付けられている請求項１２から１４
の何れかに記載のＲ−Ｆｅ−Ｂ系希土類磁石の製造方
法。15. Claims 12 to a temperature measuring device is attached to the impregnation vessel for measuring the temperature of the oil 14
The method for producing the R-Fe-B rare earth magnet according to any one of 1.
体を不活性雰囲気中にて焼結台板上に配置する請求項１
から１５の何れかに記載のＲ−Ｆｅ−Ｂ系希土類磁石の
製造方法。16. The molded body is arranged on a sintering base plate in an inert atmosphere after the impregnating step and before sintering.
16. The method for producing the R-Fe-B rare earth magnet according to any one of 1 to 15 .
体を不活性雰囲気中にて焼結ケース内に収納する請求項
１から１６の何れかに記載のＲ−Ｆｅ−Ｂ系希土類磁石
の製造方法。17. After the impregnation step, R-Fe-B based rare-earth according to any one of claims 1 to 16 for housing the shaped body before sintering in a sintering case in an inert atmosphere Magnet manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000326482A JP3418605B2 (en) | 1999-11-12 | 2000-10-26 | Rare earth magnet manufacturing method |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32300399 | 1999-11-12 | ||
| JP2000-120248 | 2000-04-21 | ||
| JP2000120248 | 2000-04-21 | ||
| JP11-323003 | 2000-04-21 | ||
| JP2000326482A JP3418605B2 (en) | 1999-11-12 | 2000-10-26 | Rare earth magnet manufacturing method |
Publications (2)
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| JP2002008935A JP2002008935A (en) | 2002-01-11 |
| JP3418605B2 true JP3418605B2 (en) | 2003-06-23 |
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Cited By (1)
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|---|---|---|---|---|
| WO2012105399A1 (en) | 2011-01-31 | 2012-08-09 | 日立金属株式会社 | Method for producing r-t-b system sintered magnet |
Families Citing this family (10)
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| JP4391897B2 (en) | 2004-07-01 | 2009-12-24 | インターメタリックス株式会社 | Manufacturing method and manufacturing apparatus for magnetic anisotropic rare earth sintered magnet |
| CN1989581A (en) * | 2005-03-14 | 2007-06-27 | 株式会社新王磁材 | Method for producing rare earth magnet and impregnation apparatus |
| JP2008274420A (en) * | 2007-03-30 | 2008-11-13 | Hitachi Metals Ltd | METHOD FOR PRODUCING R-Fe-B BASED RARE EARTH MAGNET |
| JP4819103B2 (en) * | 2008-07-28 | 2011-11-24 | インターメタリックス株式会社 | Manufacturing method and manufacturing apparatus for magnetic anisotropic rare earth sintered magnet |
| JP4819104B2 (en) * | 2008-08-04 | 2011-11-24 | インターメタリックス株式会社 | Manufacturing method and manufacturing apparatus for magnetic anisotropic rare earth sintered magnet |
| CN104607644A (en) * | 2015-01-19 | 2015-05-13 | 广州金南磁性材料有限公司 | Insulating treatment method for soft magnetic alloy powder core |
| JP6502765B2 (en) * | 2015-06-29 | 2019-04-17 | 住友電工焼結合金株式会社 | Apparatus for producing sintered body, and method for producing sintered body |
| EP3118863A1 (en) * | 2015-07-14 | 2017-01-18 | Kabushiki Kaisha Toshiba | Permanent magnet |
| JP6744445B2 (en) * | 2019-03-20 | 2020-08-19 | 住友電工焼結合金株式会社 | Sintered body manufacturing apparatus and sintered body manufacturing method |
| CN111180193B (en) * | 2020-01-17 | 2021-07-27 | 赣州诚正稀土新材料股份有限公司 | Unmanned flexible magnetic field forming method |
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2000
- 2000-10-26 JP JP2000326482A patent/JP3418605B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012105399A1 (en) | 2011-01-31 | 2012-08-09 | 日立金属株式会社 | Method for producing r-t-b system sintered magnet |
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| JP2002008935A (en) | 2002-01-11 |
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