JPH0776708A - Production of anisotropic rare earth alloy powder for permanent magnet - Google Patents
Production of anisotropic rare earth alloy powder for permanent magnetInfo
- Publication number
- JPH0776708A JPH0776708A JP5180071A JP18007193A JPH0776708A JP H0776708 A JPH0776708 A JP H0776708A JP 5180071 A JP5180071 A JP 5180071A JP 18007193 A JP18007193 A JP 18007193A JP H0776708 A JPH0776708 A JP H0776708A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- powder
- rare earth
- treatment
- permanent magnet
- 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.)
- Granted
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
- H01F1/0573—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 obtained by reduction or by hydrogen decrepitation or embrittlement
Landscapes
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
- Powder Metallurgy (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は、各種モーター、アク
チュエーター等に用いることが可能な高保磁力を有する
R(希土類元素)−T(鉄属元素)−(M)−B系のボ
ンド磁石用および焼結磁石用異方性永久磁石粉末の製造
方法に係り、本系粗粉砕粉を真空中または不活性ガス中
で昇温しH2ガス中で加熱処理して4相の混合組織とな
し、さらに所定雰囲気で加熱保持する脱H2処理を行
い、結晶粒を1μm以下の極微細結晶とした高保磁力を
有するR−T−(M)−B系永久磁石用異方性希土類合
金粉末の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an R (rare earth element) -T (iron group element)-(M) -B type bond magnet having a high coercive force which can be used in various motors, actuators and the like. According to a method for producing an anisotropic permanent magnet powder for a sintered magnet, the coarsely pulverized powder of this system is heated in a vacuum or in an inert gas and heat-treated in an H 2 gas to form a four-phase mixed structure, further subjected to de-H 2 process for heating and maintaining at a predetermined atmosphere, the production of the anisotropic rare-earth alloy powder for R-T- (M) -B based permanent magnet having a high coercive force obtained by the following ultrafine crystals 1μm grain Regarding the method.
【0002】[0002]
【従来の技術】希土類系永久磁石粉末を水素処理法によ
り製造する方法は、例えば特開平1−132106号公
報に開示されている。すなわち、かかる水素処理法と
は、R−T−(M)−B系原料合金インゴットまたは粉
末を、H2ガス雰囲気またはH2ガスと不活性ガスの混合
雰囲気中で温度500℃〜1000℃に保持して上記合
金のインゴットまたは粉末にH2吸蔵させた後、H2ガス
圧力13Pa(1×10-1Torr)以下の真空雰囲気
またはH2ガス分圧13Pa(1×10-1Torr)以
下の不活性ガス雰囲気になるまで温度500℃〜100
0℃で脱H2処理し、ついで冷却することを特徴とする
R−T−(M)−B系合金磁石粉末の製造方法である。2. Description of the Related Art A method for producing rare earth-based permanent magnet powder by a hydrogen treatment method is disclosed, for example, in JP-A-1-132106. That is, such a hydrogen treatment method means that an RT- (M) -B-based raw material alloy ingot or powder is heated to a temperature of 500 ° C. to 1000 ° C. in a H 2 gas atmosphere or a mixed atmosphere of H 2 gas and an inert gas. after H 2 occluded in ingot or powder of the alloy is held, the H 2 gas pressure 13Pa (1 × 10 -1 Torr) or less of vacuum atmosphere or H 2 gas partial pressure 13Pa (1 × 10 -1 Torr) or less Temperature of 500 ℃ to 100
A method for producing an RT- (M) -B based alloy magnet powder, which is characterized in that H 2 treatment is performed at 0 ° C. and then cooling is performed.
【0003】上記手法で製造されたR−T−(M)−B
系合金磁石粉末は、大きな保磁力と磁気異方性を有す
る。これは上記処理によって、非常に微細な再結晶粒
径、実質的には0.1μm〜1μmの平均再結晶粒径を
持つ組織となり、磁気的には正方晶Nd2Fe14B系化
合物の単磁区臨界粒径に近い結晶粒径となっており、な
おかつこれらの極微細結晶がある程度結晶方位を揃えて
再結晶しているためである。RT- (M) -B manufactured by the above method
The system alloy magnet powder has a large coercive force and magnetic anisotropy. This treatment results in a structure having a very fine recrystallized grain size, that is, an average recrystallized grain size of substantially 0.1 μm to 1 μm, which is magnetically a tetragonal Nd 2 Fe 14 B-based compound. This is because the crystal grain size is close to the magnetic domain critical grain size, and these ultrafine crystals are recrystallized with their crystal orientations aligned to some extent.
【0004】また、特開平2−4901号公報には水素
処理法による種々のヒートパターンが開示され、さら
に、インゴットの均質化処理を付加することも提案され
ており、例えば、インゴットを600℃〜1200℃で
均質化して、水素、真空又は不活性ガス雰囲気中で50
0℃以上まで昇温し、次いでH2又はH2と不活性ガスの
混合雰囲気中で500℃〜1000℃でH2吸蔵させ、
H2ガス分圧1×10-1Torr以下まで脱H2し、更に
冷却するという製造工程が示されている。さらに、特開
平3−146608号公報には、水素処理中の温度変化
による特性変動を小さくする手法として、蓄熱材ととも
に水素処理を行う方法が提案されている。すなわち、水
素処理法では、処理過程において大きな反応熱を伴う化
学反応が起こっており、この反応熱による温度変化のた
めに磁特性のにばらつきが生じる。そこで熱容量の大き
な蓄熱材を用いて反応熱による温度変化を最小限にしよ
うというものである。Further, Japanese Patent Application Laid-Open No. 2-4901 discloses various heat patterns by the hydrogen treatment method, and it is also proposed to add a homogenizing treatment of the ingot. Homogenize at 1200 ℃, 50 in hydrogen, vacuum or inert gas atmosphere
The temperature is raised to 0 ° C. or higher, and then H 2 is occluded at 500 ° C. to 1000 ° C. in a mixed atmosphere of H 2 or H 2 and an inert gas,
H 2 gas partial pressure 1 × 10 de H 2 to -1 Torr or less, is further illustrated manufacturing steps that cooling. Further, Japanese Patent Laid-Open No. 3-146608 proposes a method of performing hydrogen treatment together with a heat storage material as a method of reducing characteristic fluctuation due to temperature change during hydrogen treatment. That is, in the hydrogen treatment method, a chemical reaction accompanied by a large amount of heat of reaction occurs in the treatment process, and the magnetic characteristics vary due to the temperature change caused by the heat of reaction. Therefore, it is intended to minimize the temperature change due to the reaction heat by using a heat storage material having a large heat capacity.
【0005】[0005]
【発明が解決しようとする課題】ところが、上記手法で
製造されたR−T−(M)−B系磁石用合金粉末の磁気
的性質は、特に磁気異方性については不充分であり、原
料合金そのものが本質的に有する磁気異方性に達してお
らず、磁気特性的には残留磁束密度Brが小さいという
欠点があった。これは粉末粒子中に多数存在する結晶粒
の磁化容易方向が特定の一方向に十分そろっておらず、
その結果、粉末粒子の平均残留磁束密度が小さくなるこ
とによる。また、原料処理量によって磁気特性、特に保
磁力が変化するという、量産に不向きな非常に重要な問
題を内在していた。上述した蓄熱材を用いて温度変化を
小さくする方法では実用上、原料処理量に対して大きな
設備を要したり、熱容量が大きいため加熱、冷却に多大
の時間とエネルギーを要するという問題が新に生じる。
しかも、水素処理法による磁気特性、特に保磁力の変動
の原因が単に水素化時の発熱反応による温度上昇や脱水
素時の吸熱反応による温度低下ではないため、蓄熱材を
用いても保磁力のばらつきや低下の問題は解消されな
い。However, the magnetic properties of the R-T- (M) -B magnet alloy powder produced by the above method are insufficient in terms of magnetic anisotropy in particular. The alloy itself does not reach the magnetic anisotropy inherently possessed, and the magnetic properties have a drawback that the residual magnetic flux density Br is small. This is because the easy magnetization direction of many crystal grains present in powder particles is not aligned in one specific direction,
As a result, the average residual magnetic flux density of the powder particles becomes small. In addition, there is a very important problem that magnetic properties, especially coercive force, change depending on the amount of raw material processed, which is not suitable for mass production. In the method of reducing the temperature change using the heat storage material described above, there is a new problem that, in practice, a large facility is required for the amount of raw material to be processed and a large amount of heat capacity requires a lot of time and energy for heating and cooling. Occurs.
Moreover, the cause of the fluctuations in the magnetic properties, especially the coercive force, due to the hydrogen treatment method is not simply the temperature rise due to the exothermic reaction during hydrogenation or the temperature decrease due to the endothermic reaction during dehydrogenation, so even if a heat storage material is used, the coercive force The problems of variation and deterioration cannot be solved.
【0006】これらの問題は水素処理法において得られ
る磁性粉末が再結晶集合組織を有するとしながらも、再
結晶組織に決定的な影響を与える前組織、すなわち水素
吸蔵によって生成される分解生成物の金属組織を最適化
せず、また、その組織を得るための製造条件を何等限定
していないためである。These problems are caused by the fact that the magnetic powder obtained by the hydrotreating method has a recrystallized texture, but the prestructure which has a decisive influence on the recrystallized texture, that is, decomposition products produced by hydrogen storage. This is because the metal structure of No. 1 is not optimized, and the manufacturing conditions for obtaining the structure are not limited at all.
【0007】例えば、特開平2−4901号公報ではH
2中で810℃まで昇温しそのまま5時間保持した後、
810℃で排気を1時間行って後、炉内にArを導入し
て急冷する方法(実施例1)、真空中で500℃、60
0℃、700℃、750℃、800℃、850℃、90
0℃、および1000℃の各温度まで昇温した後に、そ
の各保持温度で1気圧のH2を導入し、10時間保持し
た後、排気を1時間行って、更にArガスにより急冷す
るという方法(実施例2)などが示されている。但し、
これらの方法によると、水素吸蔵後、真空排気直前の中
間生成物の組織がR水素化物、T−B化合物、およびT
相の3相となってしまい(例えば、P、J、Me Gu
ines;Jourual of the Less
Common Metals 162(1990)37
9頁)、脱水素(真空排気)過程の後、得られる再結晶
組織は実質的に磁気的に等方性となり、高い残留磁化は
得られない。For example, in Japanese Patent Laid-Open No. 2-4901, H
After heating to 810 ° C in 2 and holding for 5 hours,
After exhausting at 810 ° C. for 1 hour, Ar is introduced into the furnace to rapidly cool it (Example 1), 500 ° C. in vacuum at 60 ° C.
0 ° C, 700 ° C, 750 ° C, 800 ° C, 850 ° C, 90
A method of raising the temperature to 0 ° C. and 1000 ° C., introducing H 2 at 1 atm at each holding temperature, holding for 10 hours, exhausting for 1 hour, and then quenching with Ar gas. (Example 2) etc. are shown. However,
According to these methods, the structure of the intermediate product after hydrogen storage and immediately before evacuation is R hydride, T-B compound, and T
It becomes three phases (for example, P, J, Me Gu
ines; Journal of the Less
Common Metals 162 (1990) 37
(Page 9), after the dehydrogenation (vacuum evacuation) process, the recrystallized structure obtained is substantially magnetically isotropic and high remanent magnetization cannot be obtained.
【0008】この発明は、R−T−(M)−B系永久磁
石用希土類合金粉末を水素処理法により製造する方法に
おいて、原料合金そのものが本質的に有する磁気異方性
を完全に達成し、極微細結晶で高保磁力を発揮するR−
T−(M)−B系永久磁石用異方性希土類合金粉末を量
産性よく得ることができる製造方法の提供を目的として
いる。The present invention completely achieves the magnetic anisotropy inherent in the raw material alloy itself in the method for producing the R-T- (M) -B system rare earth alloy powder for permanent magnets by the hydrogen treatment method. , R- that exhibits high coercive force with ultrafine crystals
An object of the present invention is to provide a manufacturing method capable of obtaining anisotropic rare earth alloy powders for T- (M) -B type permanent magnets with good mass productivity.
【0009】[0009]
【課題を解決するための手段】この発明は、上記残留磁
束密度Brを大きくするため、原料組成および処理条件
の金属組織的検討を行った結果、水素化の条件を工夫す
ることで大きな異方性が得られることを見い出したもの
である。すなわち、発明者らは、水素処理法にてR−T
−(M)−B系永久磁石用希土類合金粉末を得る際に磁
性粉末を完全に異方性化する方法を目的に原料組成およ
び処理条件の金属組織的検討を種々行った結果、水素化
によって得られる中間生成物がR2T14B相を含有し、
その外にR−H、T−B化合物、T相が存在することが
高い残留磁化を得るための必須条件であること、そし
て、その中間生成物を生成させるための条件は、真空中
又は不活性ガスで750℃以上に加熱し、その後750
℃〜900℃で8時間以内の水素化を行うことが必要で
あることを知見し、この発明を完成した。さらに、脱水
素処理時の水素分圧をR水素化物の平衡水素解離圧、例
えばNdH2では850℃で1kPaより大きく下げる
ことなく、平衡水素解離圧近傍で徐々に脱水素反応を起
こさせることで、核生成量、核成長速度を適正化するこ
とにより、原料処理量にかかわらず高保磁力を得ること
ができることを知見し、この発明を完成した。In order to increase the residual magnetic flux density Br in the present invention, a metallographic examination of the raw material composition and the processing conditions was conducted, and as a result, a large anisotropy was obtained by devising the hydrogenation conditions. It has been found that sex can be obtained. That is, the inventors of the present invention have adopted the RT method by the hydrogen treatment
As a result of various metallographic examinations of raw material composition and processing conditions for the purpose of completely anisotroping the magnetic powder when obtaining the (M) -B rare earth alloy powder for permanent magnets, hydrogenation The resulting intermediate product contains the R 2 T 14 B phase,
The presence of RH, T-B compound and T phase in addition to the above is an essential condition for obtaining high remanence, and the condition for producing the intermediate product is in vacuum or under vacuum. Heat to 750 ° C or higher with active gas, then 750
The present invention has been completed by finding that it is necessary to carry out hydrogenation at 8 ° C to 900 ° C within 8 hours. Further, the hydrogen partial pressure during the dehydrogenation treatment can be gradually raised near the equilibrium hydrogen dissociation pressure without lowering the equilibrium hydrogen dissociation pressure of R hydride, for example, NdH 2 at 850 ° C. less than 1 kPa. It was found that a high coercive force can be obtained regardless of the amount of raw material processed by optimizing the amount of nucleation and the growth rate of nuclei, and completed the present invention.
【0010】すなわち、この発明は、 R:10〜20at%(R:Yを含む希土類元素の少な
くとも1種で、かつPrまたはNdの1種または2種を
Rのうち50at%以上含有)、 T:67〜85at%(T:FeまたはFeの一部を5
0at%以下のCoで置換)、 B:4〜10at%である合金鋳塊を粗粉砕して、平均
粒度が50〜5000μmの少なくとも80vol%以
上が正方晶構造Nd2Fe14B型化合物からなる粗粉砕
粉となした後、前記粗粉砕粉を原料粉末としてこれを真
空中または不活性ガス中で温度750℃以上の温度域に
昇温した後、炉内に10〜1000kPaのH2ガスを
導入して、前記水素ガス中で750℃〜900℃に30
分〜8時間加熱保持し、組織をR水素化物、T−B化合
物、T相、R2T14B化合物の少なくとも4相の混合組
織とした後、さらにArガス又はHeガスによる絶対圧
100Pa〜50kPaの減圧気流中にて700℃〜9
00℃に5分〜8時間の保持をする脱H2処理を行い、
ついで冷却して平均結晶粒径が0.05μm〜1μmで
ある磁気的に異方性を有する合金粉末を得ることを特徴
とする永久磁石用希土類合金粉末の製造方法である。That is, the present invention provides: R: 10 to 20 at% (at least one rare earth element including R: Y, and one or two Pr or Nd of 50 at% or more of R), T : 67 to 85 at% (T: Fe or a part of Fe is 5
Substituted with Co at 0 at% or less), B: 4 to 10 at% of an alloy ingot is roughly crushed, and at least 80 vol% or more having an average particle size of 50 to 5000 μm is composed of a tetragonal structure Nd 2 Fe 14 B type compound. After forming the coarsely pulverized powder, the coarsely pulverized powder is used as a raw material powder and heated to a temperature range of 750 ° C. or higher in a vacuum or an inert gas, and then H 2 gas of 10 to 1000 kPa is fed into the furnace. Introduced into the hydrogen gas at 750 ~ 900 ℃ 30
After heating and holding for minutes to 8 hours to make the structure a mixed structure of at least four phases of R hydride, T-B compound, T phase, and R 2 T 14 B compound, further, absolute pressure of 100 Pa by Ar gas or He gas 700 ° C to 9 in a reduced pressure air flow of 50 kPa
De-H 2 treatment for holding at 00 ° C. for 5 minutes to 8 hours,
Then, it is cooled to obtain a magnetically anisotropic alloy powder having an average crystal grain size of 0.05 μm to 1 μm.
【0011】また、この発明は、 R:10〜20at%(R:Yを含む希土類元素の少な
くとも1種で、かつPrまたはNdの1種または2種を
Rのうち50at%以上含有)、 T:67〜85at%(T:FeまたはFeの一部を5
0at%以下のCoで置換)、 M:10at%以下(M:Al、Ti、V、Cr、N
i、Ga、Zr、Nb、Mo、In、Sn、Hf、T
a、Wのうち1種または2種以上)、 B:4〜10at%である合金鋳塊を粗粉砕して平均粒
度が50μm〜5000μmの少なくとも80vol%
以上が正方晶構造Nd2Fe14B型化合物からなる粗粉
砕粉となした後、前記粗粉砕粉を原料粉末としてこれを
真空中または不活性ガス中で温度750℃以上の温度域
に昇温した後、炉内に10〜1000kPaのH2ガス
を導入して、前記水素ガス雰囲気中で750℃〜900
℃に30分〜8時間加熱保持し、組織をR水素化物、T
−B化合物、T相、R2T14B化合物の少なくとも4相
の混合組織とした後、さらにArガス又はHeガスによ
る絶対圧100Pa〜50kPaの減圧気流中にて70
0℃〜900℃に5分〜8時間の保持をする脱H2処理
を行い、ついで冷却して平均結晶粒径が0.05μm〜
1μmである磁気的に異方性を有する合金粉末を得るこ
とを特徴とする永久磁石用希土類合金粉末の製造方法で
ある。Further, the present invention provides R: 10 to 20 at% (at least one rare earth element including R: Y, and one or two Pr or Nd of 50 at% or more of R), T : 67 to 85 at% (T: Fe or a part of Fe is 5
Substituted with 0 at% or less of Co), M: 10 at% or less (M: Al, Ti, V, Cr, N
i, Ga, Zr, Nb, Mo, In, Sn, Hf, T
a, one or more of W), B: at least 80 vol% with an average particle size of 50 μm to 5000 μm by coarsely crushing an alloy ingot of 4 to 10 at%.
After the above is coarsely pulverized powder composed of tetragonal structure Nd 2 Fe 14 B type compound, the coarsely pulverized powder is used as raw material powder and heated to a temperature range of 750 ° C. or higher in vacuum or in an inert gas. Then, H 2 gas of 10 to 1000 kPa was introduced into the furnace, and 750 ° C. to 900 ° C. in the hydrogen gas atmosphere.
The composition is heated at 30 ° C. for 30 minutes to 8 hours, and the tissue is subjected to R hydride, T
-B compounds in T-phase, R 2 T 14 B was a mixed structure of at least 4 phases compound, further pressure reduction in a stream of absolute pressure 100Pa~50kPa with Ar gas or He gas 70
A de-H 2 treatment of holding at 0 ° C. to 900 ° C. for 5 minutes to 8 hours is performed, followed by cooling to obtain an average crystal grain size of 0.05 μm
A method for producing a rare earth alloy powder for a permanent magnet, characterized in that an alloy powder having a magnetic anisotropy of 1 μm is obtained.
【0012】組成の限定理由 この発明に使用する原料合金に用いるRすなわち希土類
元素は、Y、La、Ce、Pr、Nd、Sm、Gd、T
b、Dy、Ho、Er、Tm、Luが包括され、このう
ち少なくとも1種以上で、Pr、Ndのうち少なくとも
1種または2種をRのうち50at%以上含有し、さら
にRの全てがPr、Ndのうち1種または2種の場合が
ある。Rの50at%以上をPr、Ndのうち少なくと
も1種以上とするのは50at%未満では充分な磁化が
得られないためである。Rは、10at%未満ではαF
e相の析出により保磁力が低下し、また20at%を超
えると、目的とする正方晶Nd2Fe14B型化合物以外
に、Rリッチの第2相が多く析出し、この第2相が多す
ぎると合金の磁化を低下させる。従ってRの範囲は10
〜20at%とする。Reason for limiting the composition R used in the raw material alloy used in the present invention, that is, the rare earth element, is Y, La, Ce, Pr, Nd, Sm, Gd, T.
b, Dy, Ho, Er, Tm, and Lu are included, at least one of which contains at least one or two of Pr and Nd in an amount of 50 at% or more of R, and all of R is Pr. , Nd may be one or two. The reason why 50 at% or more of R is at least one of Pr and Nd is that sufficient magnetization cannot be obtained at less than 50 at%. R is less than 10 at% αF
When the coercive force decreases due to the precipitation of the e phase, and when it exceeds 20 at%, many R-rich second phases are precipitated in addition to the target tetragonal Nd 2 Fe 14 B type compound, and this second phase is often contained. If too much, the magnetization of the alloy is reduced. Therefore, the range of R is 10
~ 20 at%.
【0013】Tは鉄属元素であって、Fe、Coを包含
する。Tが67at%未満では低保磁力、低磁化の第2
相が析出して磁気的特性が低下し、また85at%を超
えるとαFe相の析出により保磁力、角型性が低下する
ため、Tは67〜85at%とする。また、Feのみで
も必要な磁気的性質は得られるが、Coの適量の添加
は、キュリー温度の向上に有用であり、Coは必要に応
じて添加できる。FeとCoの原子比においてFeが5
0%以下となるとNd2Fe14B型化合物の飽和磁化そ
のものの減少量が大きくなってしまうため、Tのうち原
子比でFeを50%以上とした。T is an iron group element and includes Fe and Co. When T is less than 67 at%, it has a low coercive force and low magnetization.
The phase is precipitated to deteriorate the magnetic properties, and when it exceeds 85 at%, the coercive force and the squareness are deteriorated due to the precipitation of the αFe phase, so T is set to 67 to 85 at%. Further, even if only Fe is used, the necessary magnetic properties can be obtained, but addition of an appropriate amount of Co is useful for improving the Curie temperature, and Co can be added if necessary. Fe is 5 in atomic ratio of Fe and Co
When it is 0% or less, the amount of decrease in the saturation magnetization itself of the Nd 2 Fe 14 B type compound becomes large, so that Fe in the atomic ratio of T is set to 50% or more.
【0014】添加元素Mの効果は、水素化時に母相の分
解反応を完全に終了させずに、母相すなわちR2T14B
相を安定化して故意に残存させるのに有効な元素が望ま
れる。特に顕著な効果を持つものとして、Ni、Ga、
Zr、Hfがある。また、Mのうち、Al、Ni、G
a、Zr、In、Sn、Hfは、脱H2処理時の再結晶
粒を0.1μm〜1μmのサイズにまで成長させ、粉末
に磁気異方性を付与するのに有用な元素である。Ti、
V、Cr、Nb、Mo、Ta、Wは、脱H2処理時の再
結晶粒が、1μm以上に粗大化するのを防止し、結果と
して保磁力が低下するのを抑制する効果を有する。従っ
て、Mとしては、上記の元素を目的に応じて組み合わせ
て用いることが得策である。添加量は、全く加えなくて
もよいが、添加する場合は10at%を超えると強磁性
でない第2相が析出して磁化を低下させることから、M
は10at%以下とした。The effect of the additional element M is that the decomposition reaction of the mother phase is not completely completed during hydrogenation, and the mother phase, that is, R 2 T 14 B
An element effective in stabilizing the phase and intentionally remaining is desired. Ni, Ga, and
There are Zr and Hf. Also, of M, Al, Ni, G
a, Zr, In, Sn, and Hf are elements useful for growing recrystallized grains at the time of H 2 removal treatment to a size of 0.1 μm to 1 μm and imparting magnetic anisotropy to the powder. Ti,
V, Cr, Nb, Mo, Ta, and W have the effect of preventing the recrystallized grains during the H 2 removal treatment from coarsening to 1 μm or more, and consequently suppressing the decrease in coercive force. Therefore, it is advisable to use, as M, a combination of the above elements according to the purpose. The addition amount may not be added at all, but if it exceeds 10 at%, the second phase that is not ferromagnetic precipitates to lower the magnetization.
Was 10 at% or less.
【0015】Bについては、正方晶Nd2Fe14B型結
晶構造を安定して析出させるためには必須である。添加
量は、4at%以下ではR2T17相が析出して保磁力を
低下させ、また減磁曲線の角型性が著しく損なわれる。
また、10at%を超えて添加した場合は、磁化の小さ
い第2相が析出して粉末の磁化を低下させる。従って、
Bは、4〜10at%とした。B is essential for stable precipitation of a tetragonal Nd 2 Fe 14 B type crystal structure. If the addition amount is 4 at% or less, the R 2 T 17 phase precipitates to lower the coercive force, and the squareness of the demagnetization curve is significantly impaired.
Further, when it is added in excess of 10 at%, the second phase having a small magnetization precipitates to reduce the magnetization of the powder. Therefore,
B was set to 4 to 10 at%.
【0016】この発明において、粗粉砕粉の80vol
%以上が正方晶Nd2Fe14B型化合物としたのは、該
化合物が80vol%未満であると磁気特性が低下す
る。より具体的には、混在する第2相がαFe相の場合
は保磁力を低下させ、Rリッチ相やBリッチ相の場合に
は磁化が低下するため、正方晶Nd2Fe14B型化合物
の存在比を80vol%以上とした。体積比で80%以
上の正方晶Nd2Fe14B型化合物を有する粗粉を得る
ためには、合金の鋳塊を900℃〜1200℃の温度で
1時間以上焼鈍するか、造塊工程で鋳型の冷却速度を制
御するなど、適当に選択すれば良い。In the present invention, 80 vol of coarsely crushed powder
% Or more is the tetragonal Nd 2 Fe 14 B type compound, the magnetic properties are deteriorated when the compound is less than 80 vol%. More specifically, the coercive force is reduced when the mixed second phase is the αFe phase, and the magnetization is reduced when the mixed second phase is the R-rich phase or the B-rich phase, so that the tetragonal Nd 2 Fe 14 B-type compound The abundance ratio was 80 vol% or more. In order to obtain a coarse powder having a tetragonal Nd 2 Fe 14 B type compound in a volume ratio of 80% or more, an alloy ingot is annealed at a temperature of 900 ° C. to 1200 ° C. for 1 hour or more, or in an ingot forming process. It may be appropriately selected, for example, by controlling the cooling rate of the mold.
【0017】製造条件の限定理由 水素処理法とは、所用粒度の粗粉砕粉が外観上その大き
さを変化させることなく、極微細結晶組織の集合体が得
られることを特徴とする。すなわち、正方晶Nd2Fe
14B型化合物に対し、高温、実際上は600℃〜900
℃の温度範囲でH2ガスと反応させると、RH2■3、α
Fe、Fe2Bなどに相分離し、さらに同温度域でH2ガ
スを脱H2処理により除去すると、再度正方晶Nd2Fe
14B型化合物の再結晶組織が得られる。しかしながら、
現実には、水素化処理条件によって分解生成物の結晶粒
径、反応の度合いが異なり、水素化状態の金属組織は、
水素化温度750℃未満と750℃以上で明らかに異な
る。この金属組織上の違いが、脱水素処理を行った後の
磁粉の磁気的性質に大きく影響する。さらに、脱水素化
処理条件によって、正方晶Nd2Fe14B型化合物の再
結晶状態が大きく影響を受け、水素処理法によって作成
した磁性粉の磁気的性質、特に保磁力に大きく影響す
る。Reasons for limiting production conditions The hydrogen treatment method is characterized in that a coarsely pulverized powder having a desired particle size does not change its size in appearance, and an aggregate having an extremely fine crystal structure can be obtained. That is, tetragonal Nd 2 Fe
14 B-type compound, high temperature, practically 600 ℃ ~ 900
When reacted with H 2 gas in the temperature range of ℃, RH 2 ■ 3 , α
When phase separation into Fe, Fe 2 B, etc. is carried out, and H 2 gas is removed by de-H 2 treatment in the same temperature range, tetragonal Nd 2 Fe is again obtained.
14 A recrystallized structure of the B-type compound is obtained. However,
In reality, the crystal grain size of the decomposition product and the degree of reaction differ depending on the hydrotreatment conditions, and the metallographic structure in the hydrogenated state is
The hydrogenation temperature is clearly different between less than 750 ° C and above 750 ° C. This difference in metal structure has a great influence on the magnetic properties of the magnetic powder after the dehydrogenation treatment. Further, the dehydrogenation treatment conditions greatly influence the recrystallized state of the tetragonal Nd 2 Fe 14 B type compound, and greatly affect the magnetic properties of the magnetic powder produced by the hydrogen treatment method, especially the coercive force.
【0018】出発原料の粗粉砕法は、従来の機械的粉砕
法やガスアトマイズ法の他、H2吸蔵による、いわゆる
水素粉砕法を用いてもよく、工程の簡略化のためにこの
水素粉砕による粗粉砕工程と、極微細結晶を得るための
水素処理法を同一装置内で連続して行っても良い。The starting material may be coarsely pulverized by a conventional mechanical pulverization method or a gas atomization method, or a so-called hydrogen pulverization method by H 2 occlusion may be used. The crushing step and the hydrogen treatment method for obtaining ultrafine crystals may be continuously performed in the same apparatus.
【0019】この発明において、粗粉砕粉の平均粒度を
50μm〜5000μmに限定したのは、50μm未満
では粉末の酸化による磁性劣化の恐れがあり、また50
00μmを超えると水素処理によって大きな磁気異方性
を持たせることが困難となるからである。In the present invention, the average particle size of the coarsely crushed powder is limited to 50 μm to 5000 μm. If the average particle size is less than 50 μm, there is a risk of magnetic deterioration due to oxidation of the powder.
This is because if it exceeds 00 μm, it becomes difficult to give a large magnetic anisotropy by hydrogen treatment.
【0020】この発明における真空中または不活性ガス
中での昇温は、昇温速度、保持時間などを特に規定する
ものではなく、目的は750℃以下で水素ガスと試料を
反応させないことである。従って、750℃以下での処
理条件は、雰囲気以外は特に規定しない。なお、ここで
の不活性ガスとはArガスまたはHeガスであって、通
常不活性ガスとして扱われることの多いN2ガスは、本
系原料と高温域で反応してしまうため、不活性ガスとし
ては好ましくない。In the present invention, the temperature rise in vacuum or in an inert gas does not particularly define the rate of temperature rise, the holding time, etc., and the object is to prevent the hydrogen gas and the sample from reacting at 750 ° C. or lower. . Therefore, the treatment conditions at 750 ° C. or lower are not specified except for the atmosphere. The inert gas here is Ar gas or He gas, and N 2 gas, which is often treated as an inert gas, reacts with the raw material of the present system in a high temperature range. Is not preferable.
【0021】この発明において、H2ガス中での熱処理
に際し、H2ガス圧力が10kPa未満では、前述の分
解反応が充分に進行せず、また1000kPaを超える
と処理設備が大きくなりすぎ、工業的にコスト面、また
安全面で好ましくないため、圧力範囲を10〜1000
kPaとした。さらに好ましい圧力範囲は50〜150
kPaである。[0021] In this invention, when heat treatment with H 2 gas, H in 2 gas pressure is less than 10 kPa, does not proceed sufficiently that the above decomposition reaction, also processing facility becomes too large and exceeds 1000 kPa, industrial Since it is not preferable in terms of cost and safety, the pressure range should be 10-1000.
It was set to kPa. More preferable pressure range is 50 to 150.
It is kPa.
【0022】H2ガス中での加熱処理温度は、600℃
未満ではRH2■3、αFe、Fe2Bなどへの分解反応
が起こらない。また、600℃〜750℃の温度範囲で
は分解反応がほぼ完全に進行してしまい、分解生成物中
に適量のR2T14B相が残存せず、脱水素処理後に磁気
的、また結晶方位的に充分な異方性が得られない。また
900℃を超えるとRH2■3が不安定となり、かつ生成
物が粒成長して正方晶Nd2Fe14B型化合物極微細結
晶組織を得ることが困難になる。水素化の温度範囲が7
50℃〜900℃の領域であれば、脱水素時の再結晶反
応の核となるR2T14B相が分散して適量残存するた
め、脱水素後のR2T14B相の結晶方位が残存R2T14B
相によって決定され、結果的に再結晶組織の結晶方位が
原料インゴットの結晶方位と一致し、少なくとも原料イ
ンゴットの結晶粒径の範囲内では大きな異方性を示す事
になる。そのため、水素化処理の温度範囲を750℃〜
900℃とする。また、加熱処理保持時間については、
上記の分解反応を充分に行わせるためには30分以上必
要であり、また、8時間を越えると残存R2T14B相が
減少するため、脱水素後の異方性が低下するので好まし
くない、よって、30分〜8時間の加熱保持とする。The heat treatment temperature in H 2 gas is 600 ° C.
If it is less than the above, the decomposition reaction into RH 2 3 , αFe, Fe 2 B, etc. does not occur. Further, in the temperature range of 600 ° C. to 750 ° C., the decomposition reaction proceeds almost completely, and an appropriate amount of R 2 T 14 B phase does not remain in the decomposition product. Sufficient anisotropy cannot be obtained. On the other hand, if the temperature exceeds 900 ° C., RH 2 3 becomes unstable , and the product grains grow to make it difficult to obtain a tetragonal Nd 2 Fe 14 B type compound ultrafine crystal structure. Hydrogenation temperature range is 7
In the range of 50 ° C. to 900 ° C., the R 2 T 14 B phase, which is the nucleus of the recrystallization reaction during dehydrogenation, disperses and remains in an appropriate amount, so the crystal orientation of the R 2 T 14 B phase after dehydrogenation Remains R 2 T 14 B
The crystal orientation of the recrystallized structure is determined by the phase, and as a result, the crystal orientation of the recrystallized structure matches the crystal orientation of the raw material ingot, and a large anisotropy is exhibited at least within the range of the crystal grain size of the raw material ingot. Therefore, the temperature range of the hydrotreatment is 750 ° C to
It is set to 900 ° C. Regarding the heat treatment holding time,
It is necessary for 30 minutes or more to sufficiently carry out the above decomposition reaction, and if it exceeds 8 hours, the residual R 2 T 14 B phase is decreased, and the anisotropy after dehydrogenation is decreased, which is preferable. Therefore, the heating is kept for 30 minutes to 8 hours.
【0023】この発明の脱H2処理は、Arガス又はH
eガスの減圧気流中にて行うが、これによって原料の周
囲の実質的なH2分圧をR水素化物の平衡水素解離圧、
例えばNdH2では850℃で1kPa程度となり、脱
H2反応は徐々に進行する。雰囲気をArガス又はHe
ガスに限定したのは、コスト面でArガスが使いよく、
またH2ガスの置換性や温度制御の点からHeガスが使
いよいことによる。さらに、不活性ガスとして一般的な
N2ガスは希土類系化合物と反応して窒化物を形成する
ため不適当であり、また他の希ガスでは性能上のメリッ
トがなくコストの面でも不利である。この発明の脱H2
処理時の雰囲気の絶対圧は、10Pa未満では脱H2反
応が急激に起こり、化学反応により温度が大きく低下
し、さらに脱H2反応が急激すぎるために冷却後の磁性
粉の組織に粗大な結晶粒が混在して保磁力が大きく低下
するため好ましくなく、また50kPaを超えると脱H
2反応に時間がかかりすぎて実用上問題となるため、絶
対圧10Pa〜50kPaの範囲とする。また、脱H2
処理を減圧気流中で行うのは脱H2反応によって、原料
から放出されるH2ガスよって、炉内圧力が上昇するの
を防止するためである。実用上は、一方から不活性ガス
を導入しながら、他方から真空ポンプで排気し、圧力の
制御は、供給口、排気口のそれぞれに取り付けられた流
量調整弁を用いて行うとよい。The H 2 removal treatment of the present invention is performed by using Ar gas or H 2
It is carried out in a reduced pressure gas flow of e gas, and by this, the substantial H 2 partial pressure around the raw material is changed to the equilibrium hydrogen dissociation pressure of R hydride,
For example, NdH 2 has a temperature of about 1 kPa at 850 ° C., and the H 2 removal reaction gradually proceeds. The atmosphere is Ar gas or He
Gas is limited to Ar gas because of its cost,
This is also because He gas can be used from the viewpoint of H 2 gas substitution property and temperature control. Further, N 2 gas, which is generally used as an inert gas, is unsuitable because it reacts with a rare earth compound to form a nitride, and other rare gases have no merit in performance and are disadvantageous in cost. . Removal of H 2 of this invention
If the absolute pressure of the atmosphere during the treatment is less than 10 Pa, the de-H 2 reaction rapidly occurs, the temperature greatly decreases due to the chemical reaction, and the de-H 2 reaction is too rapid, so that the structure of the magnetic powder after cooling is coarse. It is not preferable because the coercive force is greatly reduced due to the inclusion of crystal grains, and when the pressure exceeds 50 kPa, de-H
2 The reaction takes too much time and becomes a problem in practice, so the absolute pressure is set within the range of 10 Pa to 50 kPa. Also, de-H 2
The treatment is performed in a reduced pressure air flow in order to prevent the pressure inside the furnace from rising due to the H 2 gas released from the raw material due to the H 2 removal reaction. Practically, while introducing the inert gas from one side, the other side is evacuated by the vacuum pump, and the pressure control may be performed by using the flow rate adjusting valve attached to each of the supply port and the exhaust port.
【0024】この発明において、脱H2処理の温度が7
00℃未満では、RH2■3相からのH2の離脱が起こら
ないか、正方晶Nd2Fe14B型化合物の再結晶が充分
進行しない。また、900℃を超えると正方晶Nd2F
e14B型化合物は生成するが、再結晶粒が粗大に成長
し、高い保磁力が得られない。そのため、脱H2処理の
温度範囲は700℃〜900℃とする。In the present invention, the temperature for the H 2 removal treatment is 7
If the temperature is lower than 00 ° C., H 2 is not released from the RH 2 3 phase or recrystallization of the tetragonal Nd 2 Fe 14 B type compound does not proceed sufficiently. Further, when the temperature exceeds 900 ° C., tetragonal Nd 2 F
Although the e 14 B type compound is produced, recrystallized grains grow coarsely and a high coercive force cannot be obtained. Therefore, the temperature range of the H 2 removal treatment is 700 ° C. to 900 ° C.
【0025】また、加熱処理保持時間は、処理設備の排
気能力にもよるが、上記の再結晶反応を充分に行わせる
ことも重要であり、少なくとも5分以上保持する必要が
あるが、2次的な再結晶反応によって結晶が粗大化すれ
ば保磁力の低下を招くので、できる限り短時間の方が好
ましい。そのため、5分〜8時間の加熱保持で充分であ
る。脱H2処理は、原料の酸化防止の観点から、また処
理設備の熱効率の観点で、水素化処理に引き続いて行う
のがよいが、水素化処理後、一旦原料を冷却して、再び
改めて脱H2の為の熱処理を行っても良い。Although the heat treatment holding time depends on the evacuation capacity of the treatment equipment, it is also important to sufficiently carry out the above recrystallization reaction, and it is necessary to hold the heat treatment for at least 5 minutes. If the crystal is coarsened by a general recrystallization reaction, the coercive force is lowered, so that the time is preferably as short as possible. Therefore, heating and holding for 5 minutes to 8 hours is sufficient. De H 2 treatment, from the viewpoint of preventing oxidation of the raw materials, also in terms of thermal efficiency of the process equipment, but may be carried out following the hydrogenation process, after hydrogenation treatment, then once cooling the material, again again de heat treatment may be carried out for the H 2.
【0026】脱H2処理後の正方晶Nd2Fe14B型化合
物の再結晶粒径は実質的に0.05μm以下の平均再結
晶粒径を得ることは困難であり、またたとえ得られたと
しても磁気特性上の利点がない。一方、平均再結晶粒径
が1μmを超えると、粉末の保磁力が低下するため好ま
しくない。そのため、平均再結晶粒径を0.05μm〜
1μmとした。The recrystallized grain size of the tetragonal Nd 2 Fe 14 B type compound after the de-H 2 treatment is practically difficult to obtain, even if it is obtained. However, there is no advantage in magnetic characteristics. On the other hand, if the average recrystallized grain size exceeds 1 μm, the coercive force of the powder decreases, which is not preferable. Therefore, the average recrystallized grain size is from 0.05 μm to
It was 1 μm.
【0027】[0027]
【作用】この発明は、R−T−(M)−B系永久磁石用
希土類合金粉末を水素処理法により製造する方法におい
て、真空中または不活性ガス中で昇温しH2ガス中で加
熱処理して、R水素化物、T−B化合物、T相、R2T
14B化合物の少なくとも4相の混合組織とすることによ
り、原料合金そのものが本質的に有する磁気異方性を完
全に達成し、さらにArガス又はHeガスによる絶対圧
100Pa〜50kPaの減圧気流中で加熱保持する脱
H2処理を行い、極微細結晶で高保磁力を発揮するR−
T−(M)−B系永久磁石用異方性希土類合金粉末を処
理量にかかわらず量産性よく得ることができる。The present invention relates to a method for producing an RT- (M) -B rare earth alloy powder for permanent magnets by a hydrogen treatment method, wherein the temperature is raised in vacuum or in an inert gas and heated in H 2 gas. R hydride, TB compound, T phase, R 2 T
By having a mixed structure of at least four phases of 14 B compound, the magnetic anisotropy inherent in the raw material alloy itself is completely achieved, and further, in a reduced pressure air flow of 100 Pa to 50 kPa absolute pressure by Ar gas or He gas. R- which shows high coercive force with ultra-fine crystals by performing H 2 removal treatment by heating and holding
An anisotropic rare earth alloy powder for a T- (M) -B system permanent magnet can be obtained with good mass productivity regardless of the treatment amount.
【0028】[0028]
実施例1 高周波誘導溶解法によって溶製して得られた表1に示す
No.1〜12の組成の鋳塊を、1100℃、24時
間、Ar雰囲気中で焼鈍して、鋳塊中の正方晶Nd2F
e14B型化合物の体積比を90%以上とした。この鋳塊
を、Arガス雰囲気中(O2量0.5%以下)でスタン
プミルにて平均粒度500μmに粗粉砕した後、この粗
粉砕粉を管状炉に入れ、1Pa以下にまで真空排気し
た。真空排気には、ロータリーポンプおよび油拡散ポン
プを用いた。その後、表2に示すヒートパターン、水素
化処理条件で水素化処理を行った。こうして得た水素化
原料を、引き続き表2に示す脱水素処理条件に従って脱
水素処理を行った。なお、水素導入前の昇温速度はいず
れの場合も5℃/分の条件で行った。また、冷却は脱水
素処理時に使用した雰囲気ガスの吹きつけで行った。冷
却後、原料温度が50℃以下となったところで原料を取
り出した。このときの磁性粉末(No.1〜20)の磁
気特性を表2に示す。表2において、Isの値は、He
x=0.8MA/mの時の磁化を示す。Example 1 No. 1 shown in Table 1 obtained by melting by the high frequency induction melting method. The ingots having the compositions of 1 to 12 were annealed in an Ar atmosphere at 1100 ° C. for 24 hours to obtain tetragonal Nd 2 F in the ingot.
The volume ratio of the e 14 B type compound was 90% or more. This ingot was coarsely crushed in an Ar gas atmosphere (O 2 amount of 0.5% or less) by a stamp mill to an average particle size of 500 μm, and the coarsely pulverized powder was put into a tubular furnace and vacuum exhausted to 1 Pa or less. . A rotary pump and an oil diffusion pump were used for evacuation. After that, the hydrogenation treatment was performed under the heat pattern and the hydrogenation treatment conditions shown in Table 2. The hydrogenated raw material thus obtained was subsequently subjected to dehydrogenation treatment under the dehydrogenation treatment conditions shown in Table 2. The temperature rising rate before introducing hydrogen was 5 ° C./min in all cases. The cooling was performed by blowing the atmospheric gas used in the dehydrogenation treatment. After cooling, the raw material was taken out when the raw material temperature became 50 ° C. or lower. Table 2 shows the magnetic properties of the magnetic powders (Nos. 1 to 20) at this time. In Table 2, the value of Is is He
The magnetization when x = 0.8 MA / m is shown.
【0029】実施例2 実施例1で用いたNo.12の原料粉を用いて、磁気的
性質の処理量依存性を調査した。原料粒度は500μm
で、750℃までは昇温速度5℃/分で真空中で昇温
し、750℃から水素を導入した後、水素化処理は昇温
速度15℃/分として850℃で2時間、脱水素処理は
Arガスによる10kPaの減圧気流中で840℃で2
時間保持、冷却条件はArガス吹付冷却に条件を固定
し、処理量を2gから2kgまで変化させ、そのときの
磁性粉末の残留磁化Br、保磁力Hc、磁化容易方向お
よび困難方向の磁化Isを処理量に対してグラフ化し、
図1に示す。なお、処理量の2kgは実験装置の制約に
よるものであり、この発明の適用上限を示すものではな
い。また、磁化は、外部磁界0.8MA/mでの値とし
てあり、磁化容易方向と困難方向の値の差が大きいほど
磁気的な異方性が大きいことを示している。Example 2 No. used in Example 1 was used. Using 12 raw material powders, the dependence of the magnetic properties on the throughput was investigated. Raw material particle size is 500 μm
Then, the temperature was raised up to 750 ° C. in a vacuum at a temperature rising rate of 5 ° C./min, hydrogen was introduced from 750 ° C., and the hydrogenation treatment was carried out at 850 ° C. for 2 hours at a temperature rising rate of 15 ° C./min. The treatment is carried out at 840 ° C. in a reduced pressure air stream of 10 kPa with Ar gas for 2 hours.
The time holding and cooling conditions are fixed to Ar gas spray cooling, the treatment amount is changed from 2 g to 2 kg, and the residual magnetization Br, coercive force Hc, magnetization Is in the easy magnetization direction and the magnetization Is in the difficult direction at that time are changed. Graph against throughput,
As shown in FIG. The processing amount of 2 kg is due to the limitation of the experimental apparatus and does not indicate the upper limit of application of the present invention. Further, the magnetization is a value at an external magnetic field of 0.8 MA / m, and it is shown that the larger the difference between the values in the easy magnetization direction and the hard direction, the greater the magnetic anisotropy.
【0030】比較例 表1に示す実施例と同様の組成を有する12種類の組成
の粗粉砕粉について、この粗粉砕粉を管状炉に入れ、1
Pa以下にまで真空排気した。その後、純度99.99
99%以上のH2ガスを導入しつつ、表3に示す処理条
件で水素化処理および脱水素処理を行った。ここに示し
た脱水素処理時の水素分圧または処理温度がこの発明の
範囲外である。このときの磁性粉末(No.21〜3
7)の磁気特性を表3に示す。Comparative Example Regarding 12 kinds of coarsely pulverized powders having the same composition as the example shown in Table 1, the coarsely pulverized powders were put in a tubular furnace and 1
It was evacuated to Pa or less. Then, the purity is 99.99
While introducing 99% or more of H 2 gas, hydrogenation treatment and dehydrogenation treatment were performed under the treatment conditions shown in Table 3. The hydrogen partial pressure or the treatment temperature during the dehydrogenation treatment shown here is outside the scope of the present invention. Magnetic powder at this time (No. 21 to 3)
Table 3 shows the magnetic characteristics of 7).
【0031】[0031]
【表1】 [Table 1]
【0032】[0032]
【表2】 [Table 2]
【0033】[0033]
【表3】 [Table 3]
【0034】[0034]
【発明の効果】この発明によるR−T−(M)−B系永
久磁石用異方性希土類合金粉末の製造方法は、R−T−
(M)−B合金の粗粉砕粉を、真空中または不活性ガス
中で750℃以上の温度域まで昇温した後、水素ガスを
導入して750℃〜900℃で水素中の熱処理を行うこ
とにより、再結晶時の結晶方位を決める核としてのR2
T14B相を適量残存させることができ、引き続きArガ
ス又はHeガスによる絶対圧100Pa〜50kPaの
減圧気流中にて700℃〜900℃で脱水素熱処理を行
って冷却することにより、高い保磁力と大きな磁気異方
性を同時に有する、ボンド磁石および焼鈍磁石原料とし
て最適なR−T−(M)−B系永久磁石用異方性希土類
合金粉末を安定して得ることができる。The method for producing anisotropic rare earth alloy powder for RT- (M) -B permanent magnets according to the present invention is RT-.
After the coarsely pulverized powder of the (M) -B alloy is heated to a temperature range of 750 ° C. or higher in a vacuum or an inert gas, hydrogen gas is introduced and heat treatment is performed in hydrogen at 750 ° C. to 900 ° C. As a result, R 2 as a nucleus that determines the crystal orientation during recrystallization
The T 14 B phase can be left in an appropriate amount, and by subsequently performing a dehydrogenation heat treatment at 700 ° C. to 900 ° C. in a reduced pressure gas flow of 100 Pa to 50 kPa absolute pressure by Ar gas or He gas to cool it, a high coercive force can be obtained. It is possible to stably obtain an anisotropic rare earth alloy powder for a RT- (M) -B-based permanent magnet, which is optimal as a raw material for bonded magnets and annealed magnets and which has a large magnetic anisotropy at the same time.
【図1】磁性粉末の保磁力、磁化容易方向および困難方
向の磁化の変化を処理量に対して表したグラフである。FIG. 1 is a graph showing changes in coercive force of a magnetic powder and magnetization in an easy magnetization direction and a hard magnetization direction with respect to a processing amount.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 上原 稔 大阪府三島郡島本町江川2丁目15ー17 住 友特殊金属株式会社山崎製作所内 (72)発明者 広沢 哲 大阪府三島郡島本町江川2丁目15ー17 住 友特殊金属株式会社山崎製作所内 (72)発明者 富田 俊郎 大阪府大阪市中央区北浜4丁目5番33号 住友金属工業株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Minor Uehara Minoru Uehara 2-15-17 Egawa, Shimamoto-cho, Mishima-gun, Osaka Pref. Chome 15-17 Sumitomo Special Metals Co., Ltd. Yamazaki Works (72) Inventor Toshiro Tomita 4-53-3 Kitahama, Chuo-ku, Osaka City, Osaka Sumitomo Metal Industries Co., Ltd.
Claims (2)
土類元素の少なくとも1種で、かつPrまたはNdの1
種または2種をRのうち50at%以上含有)、T:6
7〜85at%(T:FeまたはFeの一部を50at
%以下のCoで置換)、B:4〜10at%である合金
鋳塊を粗粉砕して、平均粒度が50〜5000μmの少
なくとも80vol%以上が正方晶構造Nd2Fe14B
型化合物からなる粗粉砕粉となした後、前記粗粉砕粉を
原料粉末としてこれを真空中または不活性ガス中で温度
750℃以上の温度域に昇温した後、炉内に10〜10
00kPaのH2ガスを導入して、前記水素ガス中で7
50℃〜900℃に30分〜8時間加熱保持し、組織を
R水素化物、T−B化合物、T相、R2T14B化合物の
少なくとも4相の混合組織とした後、さらにArガス又
はHeガスによる絶対圧100Pa〜50kPaの減圧
気流中にて700℃〜900℃に5分〜8時間の保持を
する脱H2処理を行い、ついで冷却して平均結晶粒径が
0.05μm〜1μmである磁気的に異方性を有する合
金粉末を得ることを特徴とする永久磁石用希土類合金粉
末の製造方法。1. R: 10 to 20 at% (R: at least one kind of rare earth element including Y, and Pr or Nd of 1
Or 2 kinds of R in 50 at% or more), T: 6
7 to 85 at% (T: Fe or a part of Fe is 50 at
% Or less Co), B: 4 to 10 at% of the alloy ingot is roughly crushed, and at least 80 vol% or more having an average particle size of 50 to 5000 μm has a tetragonal structure Nd 2 Fe 14 B.
After the coarsely pulverized powder of the type compound is formed, the coarsely pulverized powder is used as a raw material powder and the temperature is raised to a temperature range of 750 ° C. or higher in a vacuum or an inert gas.
Introduce H 2 gas of 00 kPa, and add 7 in the hydrogen gas.
After heating and holding at 50 ° C. to 900 ° C. for 30 minutes to 8 hours to make the structure a mixed structure of at least four phases of R hydride, TB compound, T phase, and R 2 T 14 B compound, Ar gas or The H 2 gas is subjected to a de-H 2 treatment in which it is held at 700 ° C. to 900 ° C. for 5 minutes to 8 hours in a reduced pressure air flow having an absolute pressure of 100 Pa to 50 kPa and then cooled to have an average crystal grain size of 0.05 μm to 1 μm A method for producing a rare earth alloy powder for a permanent magnet, characterized in that the magnetically anisotropic alloy powder is obtained.
土類元素の少なくとも1種で、かつPrまたはNdの1
種または2種をRのうち50at%以上含有)、T:6
7〜85at%(T:FeまたはFeの一部を50at
%以下のCoで置換)、M:10at%以下(M:A
l、Ti、V、Cr、Ni、Ga、Zr、Nb、Mo、
In、Sn、Hf、Ta、Wのうち1種または2種以
上)、B:4〜10at%である合金鋳塊を粗粉砕して
平均粒度が50μm〜5000μmの少なくとも80v
ol%以上が正方晶構造Nd2Fe14B型化合物からな
る粗粉砕粉となした後、前記粗粉砕粉を原料粉末として
これを真空中または不活性ガス中で温度750℃以上の
温度域に昇温した後、炉内に10〜1000kPaのH
2ガスを導入して、前記水素ガス雰囲気中で750℃〜
900℃に30分〜8時間加熱保持し、組織をR水素化
物、T−B化合物、T相、R2T14B化合物の少なくと
も4相の混合組織とした後、さらにArガス又はHeガ
スによる絶対圧100Pa〜50kPaの減圧気流中に
て700℃〜900℃に5分〜8時間の保持をする脱H
2処理を行い、ついで冷却して平均結晶粒径が0.05
μm〜1μmである磁気的に異方性を有する合金粉末を
得ることを特徴とする永久磁石用希土類合金粉末の製造
方法。2. R: 10 to 20 at% (R: at least one of rare earth elements including Y, and Pr or Nd of 1
Or 2 kinds of R in 50 at% or more), T: 6
7 to 85 at% (T: Fe or a part of Fe is 50 at
% Or less Co replaced), M: 10 at% or less (M: A
l, Ti, V, Cr, Ni, Ga, Zr, Nb, Mo,
One or more of In, Sn, Hf, Ta, W), and B: 4 to 10 at% of the alloy ingot is coarsely crushed to have an average particle size of at least 80 v of 50 μm to 5000 μm.
ol% or more is made into a coarsely pulverized powder composed of a tetragonal structure Nd 2 Fe 14 B type compound, and the coarsely pulverized powder is used as a raw material powder in a temperature range of 750 ° C. or higher in a vacuum or an inert gas. After the temperature is raised, H of 10 to 1000 kPa is set in the furnace.
Introducing 2 gases, 750 ℃ ~ in the hydrogen gas atmosphere
After heating and holding at 900 ° C. for 30 minutes to 8 hours to form a structure having a mixed structure of at least four phases of R hydride, TB compound, T phase, and R 2 T 14 B compound, further using Ar gas or He gas. De-H that is maintained at 700 ° C to 900 ° C for 5 minutes to 8 hours in a reduced pressure air flow of 100 Pa to 50 kPa absolute pressure.
2 treatments followed by cooling to an average crystal grain size of 0.05
A method for producing a rare earth alloy powder for a permanent magnet, characterized in that an alloy powder having a magnetic anisotropy of 1 μm to 1 μm is obtained.
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JP18007193A JP3368294B2 (en) | 1993-06-25 | 1993-06-25 | Method for producing anisotropic rare earth alloy powder for permanent magnet |
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JP18007193A JP3368294B2 (en) | 1993-06-25 | 1993-06-25 | Method for producing anisotropic rare earth alloy powder for permanent magnet |
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Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10135017A (en) * | 1996-10-28 | 1998-05-22 | Aichi Steel Works Ltd | Manufacturing method of anisotropic magnet powder |
US5993732A (en) * | 1997-07-11 | 1999-11-30 | Mitsubishi Materials Corporation | Method for manufacturing a rare earth magnetic powder having high magnetic anisotropy |
US6444052B1 (en) | 1999-10-13 | 2002-09-03 | Aichi Steel Corporation | Production method of anisotropic rare earth magnet powder |
JPWO2005015580A1 (en) * | 2003-08-12 | 2006-10-05 | 株式会社Neomax | R-T-B system sintered magnet and rare earth alloy |
JP2006295140A (en) * | 2005-03-16 | 2006-10-26 | Tdk Corp | Rare earth permanent magnet |
CN104681268A (en) * | 2013-11-28 | 2015-06-03 | 湖南稀土金属材料研究院 | Processing method for improving coercive force of sintered neodymium-iron-boron magnet |
CN107931598A (en) * | 2017-11-16 | 2018-04-20 | 浙江中杭新材料科技有限公司 | The preparation method of hybrid exciting synchronous motor magnet steel |
CN107931621A (en) * | 2017-11-16 | 2018-04-20 | 浙江中杭新材料科技有限公司 | The preparation method of high temperature resistant synchronous motor magnet steel |
-
1993
- 1993-06-25 JP JP18007193A patent/JP3368294B2/en not_active Expired - Lifetime
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10135017A (en) * | 1996-10-28 | 1998-05-22 | Aichi Steel Works Ltd | Manufacturing method of anisotropic magnet powder |
US5993732A (en) * | 1997-07-11 | 1999-11-30 | Mitsubishi Materials Corporation | Method for manufacturing a rare earth magnetic powder having high magnetic anisotropy |
US6444052B1 (en) | 1999-10-13 | 2002-09-03 | Aichi Steel Corporation | Production method of anisotropic rare earth magnet powder |
JPWO2005015580A1 (en) * | 2003-08-12 | 2006-10-05 | 株式会社Neomax | R-T-B system sintered magnet and rare earth alloy |
JP4605013B2 (en) * | 2003-08-12 | 2011-01-05 | 日立金属株式会社 | R-T-B system sintered magnet and rare earth alloy |
JP2006295140A (en) * | 2005-03-16 | 2006-10-26 | Tdk Corp | Rare earth permanent magnet |
CN104681268A (en) * | 2013-11-28 | 2015-06-03 | 湖南稀土金属材料研究院 | Processing method for improving coercive force of sintered neodymium-iron-boron magnet |
CN107931598A (en) * | 2017-11-16 | 2018-04-20 | 浙江中杭新材料科技有限公司 | The preparation method of hybrid exciting synchronous motor magnet steel |
CN107931621A (en) * | 2017-11-16 | 2018-04-20 | 浙江中杭新材料科技有限公司 | The preparation method of high temperature resistant synchronous motor magnet steel |
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