JP2001115220A - Method of manufacturing rare earth alloy powder for permanent magnet - Google Patents
Method of manufacturing rare earth alloy powder for permanent magnetInfo
- Publication number
- JP2001115220A JP2001115220A JP29396599A JP29396599A JP2001115220A JP 2001115220 A JP2001115220 A JP 2001115220A JP 29396599 A JP29396599 A JP 29396599A JP 29396599 A JP29396599 A JP 29396599A JP 2001115220 A JP2001115220 A JP 2001115220A
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- Japan
- Prior art keywords
- hydrogen
- rare earth
- treatment
- dehydrogenation
- reaction
- 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.)
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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
- H01F1/0553—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 obtained by reduction or by hydrogen decrepitation or embrittlement
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- 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]
【発明の属する技術分野】この発明は、永久磁石用希土
類系合金粉末の製造方法の改良に係り、特に、各種モー
タ、アクチュエータ等に適した希土類系ボンド磁石なら
びに焼結磁石に用いられる永久磁石用希土類系合金粉末
の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for producing a rare earth alloy powder for permanent magnets, and more particularly to a rare earth bonded magnet suitable for various motors and actuators and a permanent magnet used for a sintered magnet. The present invention relates to a method for producing a rare earth alloy powder.
【0002】[0002]
【従来の技術】希土類系永久磁石用合金粉末の金属組織
制御法として、HDDR(Hydrogenation‐Disproportionati
on‐Desorption‐Recombination)処理法と呼ばれるもの
がある。HDDR処理とは、水素化(Hydrogenation)、不均
化(Disproportionation)、脱水素化(Desorption)、およ
び再結合(Recombination)を順次実行するプロセスであ
る。2. Description of the Related Art As a method for controlling the metallographic structure of rare earth-based permanent magnet alloy powders, HDR (Hydrogenation-Disproportionati
(On-Desorption-Recombination) processing method. The HDDR process is a process for sequentially executing hydrogenation (Hydrogenation), disproportionation (Disproportionation), dehydrogenation (Desorption), and recombination (Recombination).
【0003】このHDDR処理にて、永久磁石用の合金粉末を製
造するには、R‐T‐(M)‐B系原料合金(RはYを含む希土
類元素、TはFeまたはFeとCoとの混合物、Mは添加元素、
BはボロンでCにて一部又は全量置換可能、R2T14B系化合
物が主相となる)の鋳塊または粉末を、H2ガス雰囲気ま
たはH2ガスと不活性ガスとの混合雰囲気中で温度500℃
〜1000℃に保持し、それによって上記合金の鋳塊または
粉末に水素を吸蔵させた後、H2分圧13Pa以下の真空雰囲
気またはH2分圧13Pa以下の不活性ガス雰囲気になるま
で、温度500℃〜1000℃で脱水素処理し、次いで冷却す
る。[0003] In this HDR process, in order to produce an alloy powder for a permanent magnet, an RT- (M) -B-based raw material alloy (R is a rare earth element containing Y, T is Fe or Fe and Co and , M is an additive element,
B can be partly or entirely replaced by C with boron, R 2 T 14 B-based compound is the main phase) in an H 2 gas atmosphere or a mixed atmosphere of H 2 gas and inert gas 500 ℃ inside temperature
Held in to 1000 ° C., whereby After absorbing hydrogen in ingot or powder of the alloy until the following inactive gas atmosphere H 2 partial pressure 13Pa following vacuum atmosphere or H 2 partial pressure 13Pa, temperature Dehydrogenate at 500-1000 ° C, then cool.
【0004】HDDR処理法によって希土類系永久磁石用合金粉
末を製造する方法は、例えば特開平1-132106号公報に開
示されている。当該水素雰囲気での熱処理法で製造され
たR‐T‐(M)‐B合金磁石粉末は大きな保磁力を有してお
り、組成および処理条件の選択によっては磁気的な異方
性を有する。[0004] A method for producing an alloy powder for rare earth permanent magnets by the HDR treatment method is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-132106. The RT- (M) -B alloy magnet powder produced by the heat treatment in the hydrogen atmosphere has a large coercive force, and has magnetic anisotropy depending on the selection of composition and processing conditions.
【0005】このような性質を有するのは、金属組織が実質
的に0.1〜1μmの非常に微細な結晶の集合体となるため
である。より詳細には、上記HDDR処理によって得られる
極微細結晶の粒径が正方晶R2T14B系化合物の単磁区臨界
粒径に近いために高い保磁力を発揮し、しかも、極微細
結晶粒が結晶方位をある程度、揃えて集合しているため
である。[0005] The reason for having such properties is that the metal structure becomes an aggregate of very fine crystals of substantially 0.1 to 1 µm. More specifically, since the grain size of the ultrafine crystals obtained by the above-mentioned HDR process is close to the single domain critical grain size of the tetragonal R 2 T 14 B-based compound, a high coercive force is exhibited, and This is because they are aligned with a certain degree of crystal orientation.
【0006】また、特開平2-4901号公報には、HDDR処理法に
用いられ得る種々のヒートパターンが開示されている。
この公報では、原料合金に対して水素雰囲気熱処理の前
に均一化熱処理を行うことも提案されている。[0006] Japanese Patent Application Laid-Open No. 2-4901 discloses various heat patterns that can be used in the HDR processing method.
This publication also proposes performing a homogenizing heat treatment on the raw material alloy before the hydrogen atmosphere heat treatment.
【0007】R‐T‐(M)‐B系磁石では、用途に応じて種々の
減磁耐力が要求され、その要求に見合う保磁力の値を得
るために、磁石の組成そのものが調整される。一般に、
保磁力HcJを高めると残留磁束密度Brが小さくなる。[0007] In the RT- (M) -B magnet, various demagnetization proof strengths are required depending on the application, and the composition itself of the magnet is adjusted in order to obtain a coercive force value that meets the demand. . In general,
Increasing the coercive force HcJ decreases the residual magnetic flux density Br.
【0008】保磁力の値を大きくするには、重希土類である
DyやTbをRの一部として加える方法が採られている。こ
の方法は、同時に残留磁束密度を低下させる。前記HDDR
処理法でも、Rの一部をDyやTbで置換すると、高い保磁
力が得られることが知られており、保磁力の向上を狙っ
て添加されることがある。[0008] To increase the value of coercive force, heavy rare earth
Dy and Tb are added as part of R. This method simultaneously reduces the residual magnetic flux density. HDR
It is also known that a high coercive force can be obtained by substituting a part of R with Dy or Tb in the treatment method, and may be added for the purpose of improving the coercive force.
【0009】一方、HDDR処理法では、処理条件の適正化によ
ってその磁気特性を改良しようとする研究が盛んに行わ
れている。特開平5-163510号公報には、脱水素処理にお
いて、その反応が吸熱反応であるために温度低下が生じ
るが、この温度変化が50℃以内になるように制御する方
法及び装置が示され、この温度変化制御によって優れた
磁気特性が得られることを示している。[0009] On the other hand, in the HDR processing method, studies for improving the magnetic characteristics by optimizing the processing conditions have been actively conducted. Japanese Patent Application Laid-Open No. H5-163510 discloses a method and an apparatus for controlling the temperature change in the dehydrogenation process such that the reaction is an endothermic reaction. This shows that excellent magnetic properties can be obtained by this temperature change control.
【0010】特開平5-166616号公報には、脱水素処理中に処
理温度を徐々に下げることで、再結晶粒子の粒成長を防
止し、高い保磁力が得られることが示されている。ま
た、特開平7-90308号公報には、脱水素処理の真空度の
変化率を、特に脱水素処理の初期段階において所定範囲
に制御することで、優れた磁気特性を有する磁性粉末が
得られることが示されている。[0010] JP-A-5-166616 discloses that by gradually lowering the treatment temperature during the dehydrogenation treatment, the growth of recrystallized particles is prevented, and a high coercive force can be obtained. Also, JP-A-7-90308 discloses that a magnetic powder having excellent magnetic properties can be obtained by controlling the rate of change of the degree of vacuum in the dehydrogenation treatment to a predetermined range, particularly in the initial stage of the dehydrogenation treatment. It has been shown.
【0011】[0011]
【発明が解決しようとする課題】永久磁石の使用に当た
って、その使用環境で減磁をしないことが材料選定の基
準となる。減磁に対する対策は、温度上昇によって減磁
する不可逆熱減磁も含め、保磁力を高めることが実用的
であり、残留磁束密度を犠牲にしても高い保磁力の磁石
が要求されるのはこのためである。When using a permanent magnet, it is a criterion for selecting a material that no demagnetization occurs in the environment in which the permanent magnet is used. As a countermeasure against demagnetization, it is practical to increase the coercive force, including irreversible thermal demagnetization, which is demagnetized due to temperature rise, and a magnet with a high coercive force is required even at the expense of residual magnetic flux density. That's why.
【0012】しかしながら、前記方法では、合金の組成から
期待される保磁力が充分には得られておらず、そのた
め、目的の保磁力、減磁耐力を得るためには必要以上に
DyやTbを添加したり、R量を増やしたりして磁化を低下
させてしまう問題があった。また、重希土類であるDyや
Tbは高価な元素であり、これらの必要以上の使用はコス
ト上昇の要因になっていた。[0012] However, in the above method, the coercive force expected from the composition of the alloy is not sufficiently obtained, and therefore, in order to obtain the desired coercive force and demagnetization proof strength, it is unnecessary.
There is a problem that magnetization is lowered by adding Dy or Tb or increasing the amount of R. Also, Dy, which is heavy rare earth,
Tb is an expensive element, and its use beyond necessity has increased costs.
【0013】この原因は、HDDR処理が、水素化・不均化反
応、脱水素・再結合反応共に、固相-気相反応であり、
その化学反応速度に関する解析が不充分なことによる。
そのため、実操業では、処理量が変わるだけで磁気特性
が変動するなどの問題点もあった。[0013] The cause of this is that the HDR process is a solid-gas phase reaction for both the hydrogenation / disproportionation reaction, dehydrogenation / recombination reaction,
This is because analysis on the chemical reaction rate is insufficient.
Therefore, in actual operation, there was a problem that the magnetic characteristics fluctuated only by changing the throughput.
【0014】この発明は、上述のHDDR処理における種々の問
題点を鑑みてこれらを解消することを目的とし、各反応
速度の影響等の解析に基づき、組成的に高価な重希土類
元素を多量に用いることなく、残留磁化を低下させずに
安定して高い保磁力が得られる永久磁石用希土類系合金
粉末の製造方法の提供を目的としている。An object of the present invention is to solve these problems in view of the above-described HDR processing, and to analyze a large amount of expensive heavy rare earth elements based on the analysis of the influence of each reaction rate. An object of the present invention is to provide a method for producing a rare earth alloy powder for a permanent magnet, which can stably obtain a high coercive force without reducing residual magnetization without using it.
【0015】[0015]
【課題を解決するための手段】発明者は、組成的に高価
なDyやTbをできるだけ用いずに、大きな磁化を維持した
まま、粉末状態で大きな保磁力を得ることが可能な処理
方法を目的に鋭意検討した結果、HDDR処理における脱水
素時の水素放出速度の変化が再結合反応速度の変化とな
って、結果的に磁性粉末の磁気特性に大きく影響するこ
とを見出し、その反応速度を制御することで高い保磁力
が得られることを知見し、この発明を完成した。SUMMARY OF THE INVENTION An object of the present invention is to provide a processing method capable of obtaining a large coercive force in a powder state while maintaining a large magnetization without using Dy or Tb, which is expensive in composition, as much as possible. As a result of a thorough study, it was found that a change in the hydrogen release rate during dehydrogenation in the HDR process resulted in a change in the recombination reaction rate, and as a result, greatly affected the magnetic properties of the magnetic powder, and controlled the reaction rate. It has been found that a high coercive force can be obtained by performing the method, and the present invention has been completed.
【0016】すなわち、この発明は、R2T14B(BはCで一部又
は全量置換可能)型化合物が50vol%以上を占める合金か
らなる鋳塊または粉末を、例えば、温度650〜950℃にお
いて水素分圧10〜1000kPaの雰囲気中に保持し、水素化
・不均化反応を起こさせ、引き続き温度650〜1000℃に
おいて水素分圧100Pa以下に保持し、脱水素・再結合反
応を起こさせて後、冷却する、永久磁石用希土類系合金
粉末の製造方法において、脱水素・再結合反応の各反応
速度を、雰囲気の制御、例えば圧力及び/又は温度制御
により多段階に変化させることを特徴とする永久磁石用
希土類系合金粉末の製造方法である。That is, the present invention provides an ingot or powder made of an alloy in which an R 2 T 14 B (B can be partially or completely replaced by C) type compound accounts for 50 vol% or more, for example, at a temperature of 650 to 950 ° C. At a hydrogen partial pressure of 10 to 1000 kPa to cause a hydrogenation and disproportionation reaction, and subsequently at a temperature of 650 to 1000 ° C and a hydrogen partial pressure of 100 Pa or less to cause a dehydrogenation / recombination reaction. In the method for producing a rare earth alloy powder for a permanent magnet, the reaction rates of the dehydrogenation and recombination reactions are changed in multiple stages by controlling the atmosphere, for example, controlling pressure and / or temperature. Is a method for producing a rare earth alloy powder for a permanent magnet.
【0017】また、この発明は、上記の脱水素・再結合反応
において、水素放出速度の調整で再結合反応速度を変
え、被処理物中の水素濃度が所定の値に達するまでを第
1段階、それ以後を第2段階とし、第1段階の水素放出速
度が0.1wt%/h〜5.0wt%/h、第2段階の水素放出速度が0.0
1wt%/h〜0.20wt%/hであって、かつ第2段階の水素放出速
度を第1段階よりも小さな放出速度とすることを特徴と
する。[0017] Further, in the above dehydrogenation / recombination reaction, the recombination reaction rate is changed by adjusting the hydrogen release rate, and the dehydrogenation / recombination reaction is performed until the hydrogen concentration in the object reaches a predetermined value.
The first stage and the subsequent stages are the second stage, the first stage hydrogen release rate is 0.1 wt% / h to 5.0 wt% / h, and the second stage hydrogen release rate is 0.0
It is 1 wt% / h to 0.20 wt% / h, and the hydrogen release rate in the second stage is smaller than that in the first stage.
【0018】さらに、この発明は、脱水素・再結合反応の第
1段階は、反応開始から被処理物の水素濃度CHが次式の
範囲に達するまでとし、第2段階は被処理物の水素濃度
が最終的に100ppm以下に至る範囲とすることを特徴とす
る。但し、CHは合金中の水素濃度(wt%)、CRは合金中の
希土類成分濃度(wt%)である。 0.000725×CR≦CH≦0.00750×CR Further, the present invention relates to a dehydrogenation / recombination reaction.
1 stage, hydrogen concentration C H of the object to be processed from the beginning of the reaction is up to reach the range of the following expression, the second stage and characterized in that the range in which the hydrogen concentration of the object to be processed reaches the following final 100ppm I do. However, the C H hydrogen concentration (wt%) in the alloy, C R is a rare earth component concentration in the alloy (wt%). 0.000725 × C R ≦ C H ≦ 0.00750 × C R
【0019】[0019]
【発明の実施の形態】この発明は、HDDR処理法による永
久磁石用希土類系合金粉末の製造方法において、脱水素
・再結合反応の各反応速度を、例えば雰囲気の圧力や温
度の制御にて多段階に変化させることにより、重希土類
元素を多量に用いることなく、残留磁化を低下させずに
安定して高い保磁力が得られるることを特徴としてい
る。以下に好ましい実施条件を詳述する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing rare earth alloy powder for permanent magnets by the HDR treatment method, wherein the respective reaction rates of the dehydrogenation and recombination reactions are controlled by controlling the pressure and temperature of the atmosphere, for example. The characteristic feature is that a high coercive force can be stably obtained without using a large amount of heavy rare earth elements and without reducing the residual magnetization by changing the steps. Preferred conditions for the implementation will be described in detail below.
【0020】合金組成 この発明の対象とする合金組成は、R2T14B(BはCで一部
又は全量置換可能)型化合物が50vol%以上を占める合金
であり、また種々の添加元素Mを含有し得る。希土類元
素Rは、Yを含むいずれの希土類元素を含有することも制
限しないが、Rのうち少なくともNdまたはPrの一方、あ
るいはその両方を含む必要がある。また、Dy、Tb、Hoの
うち、1種以上を含有することは、最終的に得られる磁
石材料の保磁力を高める効果があり、好ましい。Alloy composition The alloy composition targeted by the present invention is an alloy in which an R 2 T 14 B (B can be partially or completely replaced by C) type compound accounts for 50 vol% or more, and various additive elements M May be contained. The rare earth element R is not limited to contain any rare earth element including Y, but needs to contain at least one of Nd and Pr or both of R. Further, it is preferable to contain at least one of Dy, Tb, and Ho, because it has an effect of increasing the coercive force of the finally obtained magnet material.
【0021】Rの量は、10〜20at%が望ましく、より好ましく
は11〜15at%である。R量が10at%未満では保磁力が低下
し、20at%を越えると強磁性相の比率が低下し、磁化が
小さくなる。[0021] The amount of R is desirably 10 to 20 at%, more preferably 11 to 15 at%. If the R amount is less than 10 at%, the coercive force decreases, and if it exceeds 20 at%, the ratio of the ferromagnetic phase decreases and the magnetization decreases.
【0022】Tは、鉄属元素であり、Fe、Co、Niが該当す
る。CoをFeと置換して添加すると、キュリー点が上昇す
る効果以外に、HDDR処理における磁気的な異方性をより
得やすくなり、高い磁化が得られる。Coの添加はTのう
ち50%まで可能で、50%を越えると磁化が低下するので好
ましくない。Niは、小量の添加では異方性の向上に効果
があるが、磁化を下げるのでTの5%以下の添加が望まし
い。T is an iron group element, and corresponds to Fe, Co, and Ni. When Co is added in place of Fe, in addition to the effect of increasing the Curie point, magnetic anisotropy in HDR processing is more easily obtained, and high magnetization is obtained. Co can be added up to 50% of T, and if it exceeds 50%, the magnetization is undesirably reduced. Ni is effective in improving anisotropy when added in a small amount, but it is desirable to add 5% or less of T because it lowers the magnetization.
【0023】Tの量は、67〜85at%が望ましく、67at%未満で
はR2T14B相の比率が低下して磁化が小さくなり、85at%
を越えると磁気的にソフトの相が生成し、保磁力が低下
する。The amount of T is desirably 67 to 85 at%. If the amount is less than 67 at%, the ratio of the R 2 T 14 B phase is reduced, and the magnetization is reduced.
If the temperature exceeds, a soft phase is generated magnetically, and the coercive force decreases.
【0024】Bは、その一部をCで置換することができ、ま
た、全量Cで置換することも可能である。Bの量は、4〜1
0at%が良く、4at%未満では磁気的にソフトの相が生成し
て保磁力が低下し、10at%を越えるとR2T14B相の比率が
低下して磁化が小さくなる。[0024] B can be partially substituted with C, or can be completely substituted with C. The amount of B is 4-1
0 at% is preferable, and if it is less than 4 at%, a magnetically soft phase is generated and the coercive force is reduced. If it exceeds 10 at%, the ratio of the R 2 T 14 B phase is reduced and the magnetization is reduced.
【0025】必要に応じて添加する添加元素Mは、磁気的な
異方性を高めたり、保磁力を高めることを目的に添加さ
れる。異方性向上に効果のある元素として、Ga、Zr、Hf
等が良く知られており、保磁力を高める元素としてCu、
Al等がある。このほか、Si、Ti、V、Cr、Mn、Zn、Ge、N
b、In、Sn、Ta、W、Pbなどを添加含有させることができ
る。The additive element M, which is added as required, is added for the purpose of increasing magnetic anisotropy or increasing coercive force. Ga, Zr, Hf as elements effective in improving anisotropy
Etc. are well known, and Cu,
Al and the like. In addition, Si, Ti, V, Cr, Mn, Zn, Ge, N
b, In, Sn, Ta, W, Pb and the like can be added and contained.
【0026】添加元素Mは、1種または2種以上を組み合わせ
て添加することが可能である。Mの添加量は、前記効果
を目的として添加する場合、5at%以下にすることが望ま
しい。添加量が5at%を越えると、磁性に寄与しない相が
増加して磁化が低下する。The additional element M can be added alone or in combination of two or more. When M is added for the purpose of the above effects, it is desirable that the amount of M be 5 at% or less. If the addition amount exceeds 5 at%, phases that do not contribute to magnetism increase and magnetization decreases.
【0027】水素化条件 水素化温度は、650℃未満であると、水素化・不均化反
応が充分に進行せず、950℃を超える、後述の雰囲気水
素分圧の範囲内では水素化・不均化反応が生じない条件
となるため、水素化温度範囲は650〜950℃が望ましい。Hydrogenation conditions If the hydrogenation temperature is lower than 650 ° C., the hydrogenation / disproportionation reaction does not proceed sufficiently, and the hydrogenation temperature exceeds 950 ° C. The hydrogenation temperature range is desirably 650 to 950 ° C., so that the disproportionation reaction does not occur.
【0028】水素化時の水素分圧は、10kPa未満では反応の
進行が不充分で、高い保磁力を発現することができず、
また1000kPaを超えると、装置に高い耐圧構造が要求さ
れ、またHDDR処理して得た合金粉末の磁気特性上のメリ
ットが特に認められないことから、水素分圧範囲は10〜
1000kPaが望ましい。If the hydrogen partial pressure during the hydrogenation is less than 10 kPa, the progress of the reaction is insufficient, and a high coercive force cannot be exhibited.
If the pressure exceeds 1000 kPa, a high pressure resistance structure is required for the device, and no particular advantage in the magnetic properties of the alloy powder obtained by the HDR treatment is observed.
1000 kPa is desirable.
【0029】なお、高い磁気異方性を有する高磁化の合金粉
末を得るには、さらに処理温度を750℃以上に限定し、
昇温速度を10℃/min以上で700℃以上の温度域まで昇温
することが好ましい。In order to obtain a high-magnetization alloy powder having high magnetic anisotropy, the treatment temperature is further limited to 750 ° C. or higher,
It is preferable to raise the temperature at a rate of 10 ° C./min or more to a temperature range of 700 ° C. or more.
【0030】脱水素条件と反応速度 HDDR処理時の雰囲気条件をの一例を図1に示す。水素化
・不均化反応は、雰囲気の水素分圧が10〜1000kPaの条
件で行う。通常、その終了時点で、雰囲気ガスを放出す
るか、Arガスを導入して雰囲気を大気圧に戻し、引き続
きArガスを大気圧で流気して雰囲気の水素ガスを追い出
す、Ar置換処理を行う。この時、雰囲気の水素分圧は徐
々に低下するので、水素放出反応の最初期の反応は始ま
っている。FIG. 1 shows an example of dehydrogenation conditions and reaction conditions in the atmosphere during HDDR processing. The hydrogenation and disproportionation reaction is performed under the condition that the hydrogen partial pressure of the atmosphere is 10 to 1000 kPa. Normally, at the end of the process, an atmosphere gas is released or an Ar gas is introduced to return the atmosphere to the atmospheric pressure, followed by flowing Ar gas at the atmospheric pressure to expel the hydrogen gas in the atmosphere, thereby performing an Ar substitution process. . At this time, since the hydrogen partial pressure of the atmosphere gradually decreases, the initial reaction of the hydrogen release reaction has begun.
【0031】この発明において、水素放出速度にはAr置換時
の水素放出反応を除外する。Ar置換処理は、引き続き行
う水素放出処理の安全性を確保するためにも有用であ
り、大きな残留磁化を得るためには所定時間行うことが
好ましい。なお、後続の工程も含め、Arに換えてHeやNe
等の希ガスを使用することができる。ガス種は使用する
装置や工程での至便性やコストなどで適宜選択するとよ
い。In the present invention, the hydrogen release rate excludes the hydrogen release reaction at the time of Ar substitution. The Ar substitution treatment is also useful for ensuring the safety of the subsequent hydrogen release treatment, and is preferably performed for a predetermined time to obtain a large residual magnetization. It should be noted that He and Ne are used in place of Ar, including the subsequent process.
And other rare gases can be used. The gas type may be appropriately selected depending on the convenience and cost of the equipment and process used.
【0032】Ar置換の処理時間は、短時間では大きな残留磁
化が得られず、長すぎると保磁力が小さくなる。このAr
置換処理の時間は、処理量、処理装置の内容積等で決定
される。なお、等方性の磁粉を得る場合は、当該処理は
必須ではない。As for the Ar substitution processing time, a large remanent magnetization cannot be obtained in a short time, and a coercive force decreases in a long time. This Ar
The replacement processing time is determined by the processing amount, the internal volume of the processing apparatus, and the like. In addition, when obtaining isotropic magnetic powder, the processing is not essential.
【0033】Ar置換処理に引き続き、脱水素・再結合反応工
程を実施する。R水素化物の水素解離条件は、例えばNd
水素化物の場合、温度650℃では水素分圧3Pa以下、温度
800℃では水素分圧を100Pa以下、温度850℃では水素分
圧を1000Pa以下であり、脱水素反応を進行させるには上
記条件の実施が必要である。Following the Ar substitution treatment, a dehydrogenation / recombination reaction step is performed. The hydrogen dissociation conditions for R hydride are, for example, Nd
In the case of hydride, at 650 ° C, the hydrogen partial pressure is 3Pa or less,
At 800 ° C., the partial pressure of hydrogen is 100 Pa or less, and at 850 ° C., the partial pressure of hydrogen is 1000 Pa or less.
【0034】この脱水素処理の具体的方法として、減圧Ar処
理を行う。脱水素処理では、雰囲気の水素分圧が水素放
出速度に効果的に作用するが、多量処理においては水素
放出量が多大になるため、ボイル-シャルルの法則に則
り、雰囲気の全ガス分子量を制御する必要がある。実処
理では雰囲気置換が効率的に行われないとミクロな原料
粉末表面近傍に水素濃度の高い領域が生じ、水素放出速
度を低下させてしまう。[0034] As a specific method of the dehydrogenation treatment, a reduced pressure Ar treatment is performed. In dehydrogenation treatment, the partial pressure of hydrogen in the atmosphere effectively affects the hydrogen release rate.However, in large-volume treatment, the amount of hydrogen released is large, so the total gas molecular weight in the atmosphere is controlled according to Boyle-Charles' law. There is a need to. In the actual treatment, if the atmosphere substitution is not performed efficiently, a region having a high hydrogen concentration is generated near the surface of the micro raw material powder, and the hydrogen release rate is reduced.
【0035】この現象を回避するには、減圧状態で充分な量
の雰囲気ガスを流気する方法が簡単で効果的である。実
際には、ロータリーポンプ等の雰囲気ガス排気手段で雰
囲気ガスを排気しながら、Arガスを導入し、炉内の全圧
を100Pa〜10kPaの範囲の一定値に維持する方法を用い
る。この雰囲気下で、R水素化物から水素ガスが放出で
きる条件が維持される。In order to avoid this phenomenon, a method of flowing a sufficient amount of atmospheric gas under reduced pressure is simple and effective. In practice, a method is used in which Ar gas is introduced while the atmosphere gas is exhausted by an atmosphere gas exhaust means such as a rotary pump, and the total pressure in the furnace is maintained at a constant value in the range of 100 Pa to 10 kPa. Under this atmosphere, conditions under which hydrogen gas can be released from the R hydride are maintained.
【0036】水素を放出させる脱水素処理法には、上記の減
圧Ar処理以外に種々の方法を採用できる。例えば、特開
平2-4901号公報などに示された真空排気による方法や、
単に大気圧や加圧条件でArガス等を流気する方法、ま
た、特開平5-156320号公報に示したような、密閉系で水
素吸蔵合金を用いて系内の水素分圧を制御する方法等が
挙げられる。As the dehydrogenation method for releasing hydrogen, various methods other than the above-described reduced pressure Ar treatment can be employed. For example, a method by evacuation shown in JP-A-2-4901 and the like,
A method of simply flowing Ar gas or the like under atmospheric pressure or pressurized conditions, or controlling the hydrogen partial pressure in the system by using a hydrogen storage alloy in a closed system as shown in JP-A-5-156320. Method and the like.
【0037】いずれの脱水素処理方法を採用する場合におい
ても、脱水素処理の初期(第1)段階での水素放出速度が
0.1wt%/h〜5.0wt%/hの範囲に調整できることが望まし
い。水素放出速度が0.1wt%/h未満であると、水素放出に
時間がかかりすぎて、得られる磁性粉末の保磁力が低下
してしまうため、好ましくない。また、水素放出速度が
5.0wt%/hを超えると、当該速度の実現のために例えば処
理量を著しく少なくするなど、実操業上の困難が多いた
め、第1段階における水素放出速度は、0.1wt%/h〜5.0wt
%/hの範囲が望ましい。In any of the dehydrogenation methods, the hydrogen release rate in the initial (first) stage of the dehydrogenation treatment is
It is desirable to be able to adjust in the range of 0.1 wt% / h to 5.0 wt% / h. If the hydrogen release rate is less than 0.1 wt% / h, it takes too much time to release hydrogen, and the coercive force of the obtained magnetic powder is undesirably reduced. Also, the hydrogen release rate
If it exceeds 5.0 wt% / h, there are many difficulties in actual operation such as, for example, significantly reducing the throughput to achieve the speed, so the hydrogen release rate in the first stage is 0.1 wt% / h to 5.0 wt% / h. wt
A range of% / h is desirable.
【0038】脱水素処理の多段化 従来の脱水素処理技術では、原料粉末中の残存水素量が
100ppm以下となって実用的な保磁力が発現するまで脱水
素・再結合反応処理を行うが、この発明では、さらに高
い保磁力を得るためには以下の処理を行う。[0038] Multi-stage dehydrogenation treatment In conventional dehydrogenation treatment technology, the amount of residual hydrogen in the raw material powder is reduced.
The dehydrogenation / recombination reaction treatment is performed until the practical coercive force is reduced to 100 ppm or less. In the present invention, the following treatment is performed to obtain a higher coercive force.
【0039】脱水素処理、例えば減圧Ar処理により、原料粉
末中の水素量CHが、下記式の範囲まで低下させた後、雰
囲気の減圧排気を止め、大気圧に復圧してAr流気のみで
徐々に水素放出させる。もちろん、この時の雰囲気制御
方法も、大気圧のAr流気法に限定されない。 0.000725×CR≦CH≦0.00750×CR (但し、CHは合金中の水素濃度(wt%)、CRは合金中の希土
類成分濃度(wt%)である。)The dehydrogenation process, for example by vacuum Ar treatment, hydrogen content C H in the raw material powder, after being lowered to the range of the following formula, stop the evacuation of the atmosphere, only pressure was regained by Ar Nagareki atmospheric pressure To release hydrogen gradually. Of course, the atmosphere control method at this time is not limited to the atmospheric pressure Ar flow method. 0.000725 × C R ≦ C H ≦ 0.00750 × C R (where C H is the hydrogen concentration (wt%) in the alloy, and C R is the rare earth component concentration (wt%) in the alloy.)
【0040】第2段階における水素放出速度は、0.2wt%/h以
下であり、かつ第1段階よりも小さな速度とする。水素
放出速度が0.2wt%/hを越えたり、また第1段階の水素放
出速度よりも大きくすると、保磁力の向上効果が認めら
れないため、好ましくない。また、水素放出速度が0.01
wt%/h未満の場合は、処理に多大の時間を要する他、処
理条件の設定が困難になるため、第2段階における水素
放出速度は、0.01wt%/h〜0.2wt%/hの範囲が好ましい。[0040] The hydrogen release rate in the second stage is 0.2 wt% / h or less and is lower than that in the first stage. If the hydrogen release rate exceeds 0.2 wt% / h or is higher than the first stage hydrogen release rate, the effect of improving the coercive force is not recognized, which is not preferable. In addition, the hydrogen release rate is 0.01
If it is less than wt% / h, it takes a lot of time for the treatment, and it becomes difficult to set the treatment conditions.Therefore, the hydrogen release rate in the second stage is in the range of 0.01 wt% / h to 0.2 wt% / h. Is preferred.
【0041】この発明によるHDDR処理における原料粉末中の
水素量変化の一例を図2に示す。図中、実線がこの発明
の処理例を示したものであり、破線で示したものが、第
1段階の条件のままで脱水素・再結合反応工程を継続し
た場合における水素量の時間変化の一例である。FIG. 2 shows an example of a change in the amount of hydrogen in the raw material powder in the HDR processing according to the present invention. In the figure, the solid line indicates a processing example of the present invention, and the one indicated by a broken line
It is an example of a temporal change of the amount of hydrogen when the dehydrogenation / recombination reaction step is continued under the condition of one step.
【0042】第1段階の脱水素・再結合反応終了時点での原
料粉末中の水素量CHの適正値は、原料合金のR成分量の
影響を受ける。CH＞0.00750×CRの場合は、保磁力の向
上効果がなく、また処理に多大な時間を要する。一方、
CH＜0.000725×CRの場合は、保磁力の向上効果がない。The proper value of the hydrogen content C H of the raw material powder in the dehydrogenation-recombination reaction completion time of the first stage, affected by the R component amount of the raw material alloy. When C H > 0.00750 × C R , there is no effect of improving the coercive force, and much time is required for the treatment. on the other hand,
For C H <0.000725 × C R, there is no effect of improving the coercive force.
【0043】なお、脱水素水素処理の第2段階では、反応速
度が小さいので、水素残存量を例えば0.002wt%(20ppm)
以下にするには多大な時間を要する。実用上、水素量が
0.01wt%(100ppm)以下であれば磁粉の磁気特性にはほと
んど変化は生じない。In the second stage of the dehydrogenation treatment, since the reaction rate is low, the remaining amount of hydrogen is reduced to, for example, 0.002 wt% (20 ppm).
It takes a lot of time to do the following. In practice, the amount of hydrogen
If it is 0.01 wt% (100 ppm) or less, there is almost no change in the magnetic properties of the magnetic powder.
【0044】より水素量を少なくするために、第2段階の脱
水素・再結合反応が終了し、原料粉末の水素量が0.01wt
%(100ppm)以下となった後に、再度雰囲気を減圧するな
どして原料粉末の水素量を低下させてもよい。In order to further reduce the amount of hydrogen, the second stage dehydrogenation / recombination reaction is completed, and the amount of hydrogen in the raw material powder is reduced to 0.01 wt.
% Or less, the amount of hydrogen in the raw material powder may be reduced by reducing the pressure again.
【0045】さらに、水素量の調整を行う熱処理は、本工程
の熱処理に引き続き行っても、一旦冷却した後、別途行
ってもよい。いずれにしても、磁気特性にはほとんど影
響はない。しかし、まだ明確にされていないが、水素量
は磁粉の耐酸化性などの安定性には影響する可能性があ
る。Further, the heat treatment for adjusting the amount of hydrogen may be performed subsequently to the heat treatment in this step, or may be separately performed after cooling once. In any case, the magnetic properties are hardly affected. However, although not yet clarified, the amount of hydrogen may affect stability such as oxidation resistance of the magnetic powder.
【0046】この発明において、水素量及び水素放出速度の
評価には水素量の測定が不可欠であるが、処理中の原料
粉末の水素量を連続的に監視し続けることは困難であ
る。そこで、実際の処理前に予め同一条件の水素量評価
用の処理を行い、予め処理時間と水素量の変化との関係
を求めておくことにより、処理時間の管理でこの発明の
工程を制御できる。In the present invention, measurement of the amount of hydrogen is indispensable for the evaluation of the amount of hydrogen and the rate of hydrogen release, but it is difficult to continuously monitor the amount of hydrogen in the raw material powder during processing. Therefore, the process of the present invention can be controlled by managing the processing time by performing the processing for evaluating the amount of hydrogen under the same conditions in advance before the actual processing and obtaining the relationship between the processing time and the change in the amount of hydrogen in advance. .
【0047】[0047]
【実施例】実施例1 27.5%Nd‐bal.Fe-9.5%Co-1.0%Ga-0.1%Zr-1.0%B(Wt%)の
組成の鋳塊を、Ar中1100℃24時間の均質化処理を行い、
さらに0.1MPa、10l/minの水素ガス流気中で400℃2時間
の水素脆化処理を行い、冷却した後、目開き425μmのふ
るいで整粒して原料粉末とした。この原料粉末50gを、
開口部寸法30×45mmのSUS310S製容器に充填し、インコ
ネル製炉心管を有する管状熱処理炉に装填し、HDDR処理
を行った。EXAMPLE 1 An ingot having a composition of 27.5% Nd-bal.Fe-9.5% Co-1.0% Ga-0.1% Zr-1.0% B (Wt%) was homogenized in Ar at 1100 ° C. for 24 hours. Do the processing,
Further, hydrogen embrittlement treatment was performed at 400 ° C. for 2 hours in a flow of hydrogen gas at 0.1 MPa and 10 l / min. After cooling, the particles were sized with a sieve having an opening of 425 μm to obtain raw material powder. 50g of this raw material powder,
The container was filled in a SUS310S container having an opening size of 30 × 45 mm, charged into a tubular heat treatment furnace having a core tube made of Inconel, and subjected to HDR treatment.
【0048】HDDR処理条件は、0.1MPaの水素雰囲気中(5l/mi
n流気)で840℃まで15℃/minで昇温し、その温度で2時間
保持した後、温度を維持しながら10l/minのArガスで5分
間、Ar置換を行い、引き続き同温度でArガスを20l/min
導入しながらロータリーポンプにより炉内を真空排気
し、炉内圧力を6kPaに所定時間維持する減圧Ar処理を行
った。The HDR processing conditions are as follows: in a hydrogen atmosphere of 0.1 MPa (5 l / mi
The temperature was raised to 840 ° C at 15 ° C / min and maintained at that temperature for 2 hours.After maintaining the temperature, Ar substitution was performed for 5 minutes with 10 l / min of Ar gas, and then at the same temperature. Ar gas at 20 l / min
The inside of the furnace was evacuated by a rotary pump while being introduced, and a reduced pressure Ar treatment was performed to maintain the furnace pressure at 6 kPa for a predetermined time.
【0049】所定時間経過後、炉温を維持したまま、真空排
気を止め、雰囲気圧力を大気圧まで復圧し、10l/minのA
rを流気しながら所定時間処理した後、冷却した。その
後、得られた磁性粉の磁気特性を測定した結果を表1に
示す。After a lapse of a predetermined time, while the furnace temperature is maintained, the evacuation is stopped, and the atmospheric pressure is restored to the atmospheric pressure.
After processing for a predetermined time while flowing r, the mixture was cooled. Thereafter, the results of measuring the magnetic properties of the obtained magnetic powder are shown in Table 1.
【0050】磁粉の組成から、この発明の特に好ましい範囲
に該当する、減圧脱水素終了時点での水素量CHは、0.02
0wt%(200ppm)以上、0.206wt%(2060ppm)以下である。表
中、*印で表示した条件は、上記の特に好ましい範囲外
の実施例(1G1,1G3)である。なお、前記処理と同様の処
理条件で減圧Ar処理まで行って冷却した原料粉末の不活
性ガス抽出法で測定した水素分析値を、表1の処理中の
減圧Ar処理後の水素量推定値として表中に併記する。[0050] From the composition of the magnetic powder, in particular corresponding to a preferred range, the hydrogen content C H at reduced dehydrogenation end of this invention, 0.02
0 wt% (200 ppm) or more and 0.206 wt% (2060 ppm) or less. In the table, the conditions indicated by * are Examples (1G1, 1G3) outside the above particularly preferred ranges. In addition, the hydrogen analysis value measured by the inert gas extraction method of the raw material powder that was cooled to a reduced pressure Ar treatment under the same treatment conditions as the above treatment was used as the estimated hydrogen amount after the reduced pressure Ar treatment during the treatment in Table 1. Also shown in the table.
【0051】表1に明らかなごとく、減圧Ar処理法による脱
水素処理で、原料粉末中の水素量が0.020〜0.206wt%と
なった時点で、Ar流気法による脱水素処理に切り替え、
水素量が最終的に0.010wt%以下となったときに高い保磁
力と大きな残留磁化が同時に得られたことが分かる。As is clear from Table 1, when the amount of hydrogen in the raw material powder becomes 0.020 to 0.206 wt% in the dehydrogenation treatment by the reduced pressure Ar treatment method, the dehydrogenation treatment is switched to the Ar flow gas treatment,
It can be seen that a high coercive force and a large remanent magnetization were simultaneously obtained when the amount of hydrogen finally became 0.010 wt% or less.
【0052】[0052]
【表1】 【table 1】
【0053】実施例2 29.5%Nd‐bal.Fe‐15.0%Co-0.3%Ga-0.1%Zr-1.0%B(Wt%)
の組成のインゴットを、Ar中1100℃24時間の均質化処理
を行い、さらに0.1MPa、10l/minの水素ガス流気中で400
℃2時間の水素脆化処理を行い、冷却した後、目開き425
μmのふるいで整粒して原料粉末とした。この原料粉末2
00gを、開口部寸法80×200mmのSUS310S製容器に充填
し、インコネル製炉心管を有する管状熱処理炉に装填
し、HDDR処理を行った。Example 2 29.5% Nd-bal.Fe-15.0% Co-0.3% Ga-0.1% Zr-1.0% B (Wt%)
The ingot of the composition of the above was subjected to a homogenization treatment at 1100 ° C. for 24 hours in Ar,
Perform hydrogen embrittlement treatment at 2 ° C for 2 hours, cool, and
It was sized with a sieve of μm to obtain a raw material powder. This raw material powder 2
00g was filled in a container made of SUS310S having an opening size of 80 × 200 mm and charged in a tubular heat treatment furnace having a core tube made of Inconel, and subjected to HDR treatment.
【0054】処理条件は、0.1MPaの水素雰囲気中(5l/min流
気)で820℃まで15℃/minで昇温し、その温度で2時間保
持した後、温度を維持しながら10l/minのArガスで5分間
Ar置換を行い、引き続き同温度でArガスを導入しながら
ロータリーポンプにより炉内を真空排気し、Ar導入量と
排気弁の開度を調節して所定の炉内圧力を所定時間維持
する減圧Ar処理を行った。The treatment conditions were as follows: the temperature was raised to 820 ° C. at 15 ° C./min in a hydrogen atmosphere of 0.1 MPa (5 l / min flowing air), and the temperature was maintained for 2 hours. 5 minutes with Ar gas
After performing Ar substitution, the inside of the furnace is evacuated by a rotary pump while introducing Ar gas at the same temperature, and the Ar pressure and the opening of the exhaust valve are adjusted to maintain a predetermined furnace pressure for a predetermined time. Processing was performed.
【0055】所定時間経過後、炉温を維持したまま、真空排
気を止め、雰囲気圧力を大気圧まで復圧し、10l/minのA
rを流気しつつ6.0ks処理した後、冷却した。その後、得
られた磁粉の磁気特性を測定し、その結果を表2に示
す。After elapse of a predetermined time, while the furnace temperature is maintained, the evacuation is stopped, the atmospheric pressure is restored to the atmospheric pressure, and the air pressure is reduced to 10 l / min.
The mixture was treated for 6.0 ks while flowing air, and then cooled. Thereafter, the magnetic properties of the obtained magnetic powder were measured, and the results are shown in Table 2.
【0056】磁粉の組成から、この発明の特に好ましい範囲
に該当する、減圧脱水素終了時点での水素量CHは、0.02
1wt%(210ppm)以上、0.221wt%(2210ppm)以下である。表
中、*印で表示した条件は、上記の特に好ましい範囲外
の実施例(2G2)である。なお、前記処理と同様の処理条
件で減圧Ar処理まで行って冷却した原料粉末の水素分析
値を、表2の処理中の減圧Ar処理後の水素量推定値とし
て表中に併記する。[0056] From the composition of the magnetic powder, in particular corresponding to a preferred range, the hydrogen content C H at reduced dehydrogenation end of this invention, 0.02
It is 1 wt% (210 ppm) or more and 0.221 wt% (2210 ppm) or less. In the table, the conditions indicated by * are Examples (2G2) outside the above particularly preferred ranges. Note that the hydrogen analysis value of the raw material powder that has been cooled to the reduced pressure Ar treatment under the same treatment conditions as the above treatment is also shown in Table 2 as the estimated hydrogen amount after the reduced pressure Ar treatment during the treatment in Table 2.
【0057】表2から明らかなように、第1段階の脱水素処理
における水素放出速度が0.1〜5.0wt%/hの範囲で保磁力
の向上効果が認められることが分かる。As is clear from Table 2, the effect of improving the coercive force is recognized when the hydrogen release rate in the first stage dehydrogenation treatment is in the range of 0.1 to 5.0 wt% / h.
【0058】[0058]
【表2】 [Table 2]
【0059】実施例3 実施例2で用いた原料粉末100gを、開口部寸法60×100mm
のSUS310S製容器に充填し、インコネル製炉心管を有す
る管状熱処理炉に装填し、HDDR処理を行った。処理条件
は、0.1MPaの水素雰囲気中(5l/min流気)で820℃まで15
℃/minで昇温し、その温度で2時間保持した後、温度を
維持しながら10l/minのArガスで5分間、Ar置換を行い、
引き続き同温度でArガスを導入しながらロータリーポン
プにより炉内を真空排気し、Ar導入量と排気弁の開度を
調節して所定の炉内圧力を所定時間維持する減圧Ar処理
を行った。Example 3 100 g of the raw material powder used in Example 2 was mixed with an opening having a size of 60 × 100 mm.
Of SUS310S, and loaded into a tubular heat treatment furnace having a core tube made of Inconel, and subjected to HDR treatment. The processing conditions are 15 minutes to 820 ° C in a 0.1MPa hydrogen atmosphere (5 l / min flowing air).
After raising the temperature at ° C / min and holding at that temperature for 2 hours, performing Ar substitution with 10 l / min Ar gas for 5 minutes while maintaining the temperature,
Subsequently, the inside of the furnace was evacuated by a rotary pump while introducing Ar gas at the same temperature, and a reduced-pressure Ar treatment was performed in which the amount of Ar introduced and the degree of opening of the exhaust valve were adjusted to maintain a predetermined furnace pressure for a predetermined time.
【0060】所定時間経過後、炉温を維持したまま、真空排
気を止め、雰囲気圧力を大気圧まで復圧し、10l/minのA
rを流気しつつ6.0ks処理した後、冷却した。この時得ら
れた磁粉の磁気特性を表3に示す。なお、前記処理と同
様の処理条件で減圧Ar処理まで行って冷却した原料粉末
の水素分析値を、表3の処理中の減圧Ar処理後の水素量
推定値として表中に併記する。After elapse of a predetermined time, while the furnace temperature is maintained, the evacuation is stopped, the atmospheric pressure is restored to the atmospheric pressure, and A
The mixture was treated for 6.0 ks while flowing air, and then cooled. Table 3 shows the magnetic properties of the magnetic powder obtained at this time. Note that the hydrogen analysis value of the raw material powder that has been cooled by performing the process up to the reduced pressure Ar process under the same processing conditions as the above process is also shown in Table 3 as an estimated hydrogen amount after the reduced pressure Ar process during the process in Table 3.
【0061】表3から明らかなように、第2段階の脱水素処理
における水素放出速度が、雰囲気全圧を制御することで
調節可能であり、0.01〜0.20wt%/hの範囲で、かつ第1段
階の脱水素処理における水素放出速度よりも小さい値で
あれば、特に保磁力の向上効果が認められることが分か
る。As is clear from Table 3, the hydrogen release rate in the second stage dehydrogenation treatment can be adjusted by controlling the total pressure of the atmosphere, and is in the range of 0.01 to 0.20 wt% / h. If the value is smaller than the hydrogen release rate in the one-stage dehydrogenation treatment, it can be seen that the effect of improving the coercive force is particularly recognized.
【0062】[0062]
【表3】 [Table 3]
【0063】[0063]
【発明の効果】この発明は、HDDR処理法における脱水素
工程において、原料粉末の水素量が0.2wt%(2000ppm)〜
0.050wt%(500ppm)に達するまで大きな水素放出反応速度
で、0.010wt%(100ppm)以下に達するまでを小さな反応速
度で処理を進行させることにより、組成に重希土類を多
く含有しなくとも、また残留磁化を低下させることな
く、高い保磁力を有した永久磁石用希土類系合金粉末を
製造することができる。According to the present invention, in the dehydrogenation step in the HDR processing method, the amount of hydrogen in the raw material powder is 0.2 wt% (2000 ppm) or less.
By proceeding with a large hydrogen release reaction rate until reaching 0.050 wt% (500 ppm) and a small reaction rate until reaching 0.010 wt% (100 ppm) or less, even if the composition does not contain much heavy rare earth elements, A rare earth alloy powder for a permanent magnet having a high coercive force can be produced without reducing the residual magnetization.
【図1】この発明によるHDDR処理工程を示すヒートパタ
ーン図である。FIG. 1 is a heat pattern diagram showing an HDR processing step according to the present invention.
【図2】HDDR処理工程における時間と原料粉末の水素量
との関係を示すグラフである。FIG. 2 is a graph showing the relationship between the time in the HDR processing step and the amount of hydrogen in the raw material powder.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｆ 1/06 Ｈ０１Ｆ 1/06 Ａ ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H01F 1/06 H01F 1/06 A
Claims (4)
化合物が50vol%以上を占める合金からなる鋳塊または粉
末を、水素化、不均化、脱水素化、再結合処理する希土
類系合金粉末の製造方法において、脱水素化の反応速度
を雰囲気の制御により多段階に変化させる永久磁石用希
土類系合金粉末の製造方法。An ingot or powder made of an alloy in which the R 2 T 14 B (B can be partially or completely replaced by C) type compound accounts for 50 vol% or more, by hydrogenation, disproportionation, dehydrogenation, A method for producing a rare earth alloy powder for permanent magnets, wherein the reaction rate of dehydrogenation is changed in multiple stages by controlling the atmosphere in a method for producing a rare earth alloy powder to be recombined.
は真空排気による雰囲気の全圧によって調節される請求
項1に記載の永久磁石用希土類系合金粉末の製造方法。2. The method for producing a rare earth alloy powder for a permanent magnet according to claim 1, wherein the dehydrogenation treatment is adjusted by a total pressure of an atmosphere in an inert gas stream and / or vacuum evacuation.
度が0.1wt%/h〜5.0wt%/h、第2段階の水素放出速度が0.0
1wt%/h〜0.20wt%/hであり、かつ第2段階の水素放出速度
を第1段階よりも小さな放出速度とする請求項1に記載の
永久磁石用希土類系合金粉末の製造方法。3. The dehydrogenation treatment has a first stage hydrogen release rate of 0.1 wt% / h to 5.0 wt% / h and a second stage hydrogen release rate of 0.0 wt% / h to 5.0 wt% / h.
2. The method for producing a rare earth alloy powder for a permanent magnet according to claim 1, wherein the hydrogen release rate in the second step is 1 wt% / h to 0.20 wt% / h and the release rate in the second step is lower than that in the first step.
から被処理物の水素濃度CHが次式の範囲に達するまでで
あり、第2段階は、水素濃度CHが0.01wt%以下となるまで
の範囲とする請求項3に記載の永久磁石用希土類系合金
粉末の製造方法。 0.000725×CR≦CH≦0.00750×CR 但し、CHは合金中の水素濃度(wt%)、CRは合金中の希土
類成分濃度(wt%)。4. The first stage in the dehydrogenation treatment is from the start of the reaction until the hydrogen concentration C H of the object to be treated reaches the range of the following formula, and the second stage is that the hydrogen concentration C H is 0.01 wt% or less. 4. The method for producing a rare-earth alloy powder for a permanent magnet according to claim 3, wherein the range is up to the following. 0.000725 × C R ≦ C H ≦ 0.00750 × C R where C H is the hydrogen concentration (wt%) in the alloy, and C R is the rare earth component concentration (wt%) in the alloy.
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|---|---|---|---|
| JP29396599A JP4244089B2 (en) | 1999-10-15 | 1999-10-15 | Method for producing rare earth alloy powder for permanent magnet |
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|---|---|---|---|
| JP29396599A JP4244089B2 (en) | 1999-10-15 | 1999-10-15 | Method for producing rare earth alloy powder for permanent magnet |
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| JP4244089B2 JP4244089B2 (en) | 2009-03-25 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101850425A (en) * | 2009-03-30 | 2010-10-06 | Tdk株式会社 | Rare earth alloy powder and manufacture method thereof, anisotropic bond magnet compound and anisotropic bond magnet |
| WO2012105346A1 (en) * | 2011-02-01 | 2012-08-09 | Tdk株式会社 | Process for production of rare earth alloy powder, anisotropic bonded magnet, and sintered magnet |
| CN103594243A (en) * | 2013-11-20 | 2014-02-19 | 宁波科田磁业有限公司 | Manufacturing method capable of preventing sintered neodymium iron boron magnet from cracking |
| KR101382234B1 (en) | 2013-03-15 | 2014-04-10 | 한국기계연구원 | Control method for desorption-recombination step of hddr process and rare earth magnetic powder manufactured using of desorption-recombination step |
| US10026531B2 (en) | 2011-10-28 | 2018-07-17 | Tdk Corporation | R-T-B based alloy powder, compound for anisotropic bonded magnet and anisotropic bonded magnet |
| CN111489889A (en) * | 2020-04-26 | 2020-08-04 | 浙江凯文磁业有限公司 | Preparation method of high-homogeneity high-performance rare earth permanent magnet |
-
1999
- 1999-10-15 JP JP29396599A patent/JP4244089B2/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101850425A (en) * | 2009-03-30 | 2010-10-06 | Tdk株式会社 | Rare earth alloy powder and manufacture method thereof, anisotropic bond magnet compound and anisotropic bond magnet |
| WO2012105346A1 (en) * | 2011-02-01 | 2012-08-09 | Tdk株式会社 | Process for production of rare earth alloy powder, anisotropic bonded magnet, and sintered magnet |
| US10026531B2 (en) | 2011-10-28 | 2018-07-17 | Tdk Corporation | R-T-B based alloy powder, compound for anisotropic bonded magnet and anisotropic bonded magnet |
| KR101382234B1 (en) | 2013-03-15 | 2014-04-10 | 한국기계연구원 | Control method for desorption-recombination step of hddr process and rare earth magnetic powder manufactured using of desorption-recombination step |
| CN103594243A (en) * | 2013-11-20 | 2014-02-19 | 宁波科田磁业有限公司 | Manufacturing method capable of preventing sintered neodymium iron boron magnet from cracking |
| CN111489889A (en) * | 2020-04-26 | 2020-08-04 | 浙江凯文磁业有限公司 | Preparation method of high-homogeneity high-performance rare earth permanent magnet |
| CN111489889B (en) * | 2020-04-26 | 2021-12-14 | 浙江凯文磁业有限公司 | Preparation method of high-homogeneity high-performance rare earth permanent magnet |
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