JPH04343203A - Production of permanent magnet powder - Google Patents
Production of permanent magnet powderInfo
- Publication number
- JPH04343203A JPH04343203A JP3145475A JP14547591A JPH04343203A JP H04343203 A JPH04343203 A JP H04343203A JP 3145475 A JP3145475 A JP 3145475A JP 14547591 A JP14547591 A JP 14547591A JP H04343203 A JPH04343203 A JP H04343203A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- gas
- less
- hours
- 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.)
- Pending
Links
- 239000000843 powder Substances 0.000 title claims abstract description 66
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 14
- 239000007789 gas Substances 0.000 claims abstract description 32
- 239000013078 crystal Substances 0.000 claims abstract description 24
- 238000010438 heat treatment Methods 0.000 claims abstract description 14
- 239000011261 inert gas Substances 0.000 claims abstract description 11
- 239000002245 particle Substances 0.000 claims abstract description 8
- 238000010298 pulverizing process Methods 0.000 claims description 8
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 238000005121 nitriding Methods 0.000 abstract description 17
- 238000000034 method Methods 0.000 abstract description 16
- 150000001875 compounds Chemical class 0.000 description 13
- 239000000203 mixture Substances 0.000 description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 230000007423 decrease Effects 0.000 description 8
- 238000000354 decomposition reaction Methods 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 3
- 150000004767 nitrides Chemical class 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- 229910000905 alloy phase Inorganic materials 0.000 description 2
- 238000006356 dehydrogenation reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003822 epoxy resin Substances 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 230000005381 magnetic domain Effects 0.000 description 2
- 238000005551 mechanical alloying Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229920000647 polyepoxide Polymers 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 229940126062 Compound A Drugs 0.000 description 1
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 229910052691 Erbium Inorganic materials 0.000 description 1
- 229910017061 Fe Co Inorganic materials 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- NLDMNSXOCDLTTB-UHFFFAOYSA-N Heterophylliin A Natural products O1C2COC(=O)C3=CC(O)=C(O)C(O)=C3C3=C(O)C(O)=C(O)C=C3C(=O)OC2C(OC(=O)C=2C=C(O)C(O)=C(O)C=2)C(O)C1OC(=O)C1=CC(O)=C(O)C(O)=C1 NLDMNSXOCDLTTB-UHFFFAOYSA-N 0.000 description 1
- 229910052689 Holmium Inorganic materials 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 229910052765 Lutetium Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 229910052775 Thulium Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000009689 gas atomisation Methods 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910001172 neodymium magnet Inorganic materials 0.000 description 1
- 125000004433 nitrogen atom Chemical group N* 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- -1 rare earth compounds Chemical class 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
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
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
チュエーターなどに用いられる高保磁力を有するR(希
土類元素)−T(鉄族元素)−N系のボンド磁石用およ
び焼結磁石用永久磁石粉末の製造方法に係り、本系粗粉
砕粉にH2ガス単独または不活性ガス(N2ガスを除く
)との混合気中での加熱処理並びに所定雰囲気で加熱保
持する脱H2処理を行い、微小結晶粒径を有する集合組
織粉体となし、さらに窒化処理することにより、粉末の
取扱いが容易でかつ高保磁力を得る永久磁石粉末の製造
方法に関する。[Industrial Application Field] This invention is a permanent magnet powder for bonded magnets and sintered magnets of R (rare earth element)-T (iron group element)-N system having high coercive force used in various motors, actuators, etc. According to the production method, this coarsely pulverized powder is subjected to heat treatment in H2 gas alone or in a mixture with inert gas (excluding N2 gas), and H2 removal treatment by heating and holding in a predetermined atmosphere to form fine crystal grains. The present invention relates to a method for producing permanent magnet powder that is easy to handle and has a high coercive force by forming a textured powder having a diameter and then nitriding the powder.
【0002】0002
【従来の技術】Nd−Fe−B系永久磁石用粉末として
は、超急冷法、メカニカルアロイング法などにより得ら
れた超微細組織を有する磁石用粉末が用いられてきた。BACKGROUND OF THE INVENTION Magnet powders having an ultrafine structure obtained by ultra-quenching, mechanical alloying, etc. have been used as Nd--Fe--B permanent magnet powders.
【0003】Nd−Fe−B系永久磁石用粉末は、キュ
ーリ点(Tc)が300℃前後と低くBr、iHcの温
度係数が大きいため、Co等の添加によりTcを上昇さ
せてBrの温度係数を高めることが可能であるが、Br
の温度係数αはせいぜい−0.08/deg程度が限度
であった。[0003] Nd-Fe-B powder for permanent magnets has a low Curie point (Tc) of around 300°C and a large temperature coefficient of Br and iHc, so by increasing Tc by adding Co etc. Although it is possible to increase Br
The temperature coefficient α was limited to about -0.08/deg at most.
【0004】最近、R2Fe17化合物はN2を吸蔵す
ることにより、Tcが絶対温度で2倍近く高くなり、N
d−Fe−B系のTcよりも160℃も高く、さらにS
m2Fe17窒化物ではR2Fe14Bの異方性を上回
る異方性磁界が得られることが報告されている。[0004]Recently, R2Fe17 compounds have become nearly twice as high in absolute temperature by absorbing N2;
It is 160℃ higher than Tc of d-Fe-B system, and S
It has been reported that m2Fe17 nitride provides an anisotropic magnetic field that exceeds the anisotropy of R2Fe14B.
【0005】[0005]
【発明が解決しようとする課題】前記Sm2Fe17窒
化物は、通常の製造方法では実用上必要とされるiHc
が6kOe以上得られる磁石用粉末が製造できず、必要
な超微細結晶の該磁石用粉末はメカニカルアロイング法
などの特殊な製造方法でのみ得られるため、工業的規模
の量産上問題があった。[Problems to be Solved by the Invention] The Sm2Fe17 nitride does not have the iHc that is practically required in the normal manufacturing method.
It is not possible to produce magnet powder that yields 6 kOe or more, and the required ultrafine crystal magnet powder can only be obtained by special manufacturing methods such as mechanical alloying, which poses problems in mass production on an industrial scale. .
【0006】また、Sm2Fe17窒化物を得るための
窒化反応は、反応速度が遅いため窒化処理前に原料粉を
予め10μm以下に微粉砕しておかないと、N原子が粉
末の内部まで拡散せず、しかも前記の10μm以下の微
粉砕粉は後工程での取扱いが困難で、細心の注意をはら
わないと、発火あるいは容易に酸化して特性が劣化、さ
らには腐食する問題があった。[0006] In addition, the nitriding reaction to obtain Sm2Fe17 nitride has a slow reaction rate, so unless the raw material powder is pulverized to 10 μm or less before the nitriding process, the N atoms will not diffuse into the interior of the powder. Moreover, the finely pulverized powder of 10 μm or less is difficult to handle in the subsequent process, and unless extreme care is taken, it may catch fire or easily oxidize, resulting in deterioration of properties and even corrosion.
【0007】この発明は、R−T−N系永久磁石におい
て、6kOe以上の保磁力が得られる超微細結晶の該磁
石用粉末を容易に製造でき、かつその後の粉末の取り扱
いが容易な永久磁石粉末の製造方法の提供を目的として
いる。[0007] The present invention provides a permanent magnet in which an ultrafine crystalline powder for a magnet that can obtain a coercive force of 6 kOe or more can be easily produced in an R-T-N system permanent magnet, and the powder can be easily handled thereafter. The purpose is to provide a method for producing powder.
【0008】[0008]
【課題を解決するための手段】この発明は、R 9〜
12at%(R:希土類元素の少なくとも1種でかつS
mを30%以上含有)、T 88〜91at%(T:
FeあるいはFeの一部を50%以下のCo、Niにて
置換)からなる鋳塊を、粗粉砕あるいは800℃〜12
00℃で1時間〜100時間の溶体化処理を行い、金属
組織中に含まれるFe基の初晶相を20vol%以下に
した後、粗粉砕して、平均粒度が50〜500μmの粗
粉砕粉となした後、前記粗粉砕粉を0.1〜10atm
(常温換算)のH2ガスまたはそれに等しいH2分圧を
有する不活性ガス(N2ガスを除く)中(但し全圧力は
常温換算で10atm以下)で、500〜900℃に3
0分〜8時間加熱保持し、さらにH2分圧1×10−2
Torr以下の真空中またはN2を除く不活性ガスとの
混合気中にて500〜900℃に30分〜8時間保持す
る脱H2処理を行い、平均結晶粒径が0.05〜0.5
μmの集合組織を有する粉体となし、次に前記粉体をN
2圧力(常温)0.5〜50atmのN2ガス中で35
0〜650℃に30分〜6時間保持した後、冷却して、
R 9〜12at%、T 88〜91at%、N
9.5〜13.6at%を含有し高保磁力を有する永
久磁石粉末を得ることを特徴とする永久磁石粉末の製造
方法である。[Means for Solving the Problems] This invention provides R 9 to
12 at% (R: at least one rare earth element and S
Contains 30% or more of m), T 88-91 at% (T:
An ingot consisting of Fe or a part of Fe replaced with 50% or less Co or Ni) is coarsely pulverized or heated at 800°C to 12°C.
After performing solution treatment at 00°C for 1 hour to 100 hours to reduce the primary crystal phase of Fe groups contained in the metal structure to 20 vol% or less, coarse pulverization is performed to obtain coarsely pulverized powder with an average particle size of 50 to 500 μm. After that, the coarsely pulverized powder was heated to 0.1 to 10 atm.
(converted to room temperature) in H2 gas or an inert gas (excluding N2 gas) with an equivalent H2 partial pressure (however, the total pressure is 10 atm or less in terms of room temperature) at 500 to 900℃.
Heated and held for 0 minutes to 8 hours, and further increased the H2 partial pressure to 1 x 10-2
H2 removal treatment is performed by holding at 500 to 900°C for 30 minutes to 8 hours in a vacuum of Torr or less or in a mixture with an inert gas excluding N2, and the average crystal grain size is 0.05 to 0.5.
A powder having a texture of μm is prepared, and then the powder is N
2 Pressure (normal temperature) 35 in N2 gas of 0.5 to 50 atm
After holding at 0 to 650°C for 30 minutes to 6 hours, cooling
R 9-12 at%, T 88-91 at%, N
This is a method for producing permanent magnet powder, characterized by obtaining permanent magnet powder containing 9.5 to 13.6 at% and having high coercive force.
【0009】[0009]
【作用】この発明は、R−T−N系永久磁石において、
粉体の取扱いが容易で、6kOe以上の保磁力が得られ
る超微細結晶からなる該磁石用粉末の製造方法を目的に
種々検討した結果、Sm2Fe17N2■3に代表され
るR−T−N化合物は母体であるR−T化合物を約0.
3μmの単磁区粒子臨界径程度の微結晶の集合組織を有
する粉体にした後、窒化処理することにより高保磁力を
有するR−T−N系永久磁石用粉末が得られることを知
見し、この発明を完成した。[Operation] This invention provides an R-T-N permanent magnet,
As a result of various studies with the aim of manufacturing a powder for magnets made of ultrafine crystals that is easy to handle and has a coercive force of 6 kOe or more, the R-T-N compound represented by Sm2Fe17N2 The parent RT compound is about 0.
It was discovered that powder for R-T-N permanent magnets with high coercive force could be obtained by nitriding the powder having a microcrystalline texture with a single magnetic domain particle critical diameter of 3 μm. Completed the invention.
【0010】すなわち、発明者らはH2ガス中でR−T
合金を加熱すると、R−T化合物はRH2■3とαFe
等に分解してさらに脱H2処理により以前と同じR−T
化合物が生成されること、さらにその際、H2ガス中加
熱及び脱H2処理の温度、保持時間を制御することによ
り生成するR−T化合物の結晶粒径を制御でき、その後
窒化処理することにより高保磁力を発現する超微細組織
を有するR−T−N系永久磁石用粉末が得られることを
知見した。That is, the inventors conducted R-T in H2 gas.
When the alloy is heated, the R-T compound becomes RH2■3 and αFe
The same R-T as before is obtained by further decomposing H2
Furthermore, by controlling the temperature and holding time of heating in H2 gas and H2 removal treatment, the crystal grain size of the generated RT compound can be controlled, and by subsequent nitriding treatment, high storage stability can be achieved. It has been found that an R-T-N permanent magnet powder having an ultrafine structure that exhibits magnetic force can be obtained.
【0011】さらに、R2Fe17化合物のみならず、
鉄族元素の希土類化合物は上述の如く、特定の条件のH
2ガス中加熱及び脱H2処理を行うことにより、超微細
結晶の集合組織にすることができ、後続のN2拡散処理
により磁石特性を制御できることを知見した。この発明
によるR−T−N系永久磁石用粉末は、所要平均粒度の
粗粉砕粉のままで平均結晶粒径が0.05〜0.5μm
の集合組織を有する粉体となすことができ、6kOe以
上の保磁力が得られるのみならず、後工程での粉末の取
扱いが極めて容易になる利点がある。[0011] Furthermore, not only R2Fe17 compounds but also
As mentioned above, rare earth compounds of iron group elements are
It was discovered that by performing heating in two gases and H2 removal treatment, an ultrafine crystal texture could be obtained, and that the magnetic properties could be controlled by the subsequent N2 diffusion treatment. The R-T-N based permanent magnet powder according to the present invention has an average crystal grain size of 0.05 to 0.5 μm as a coarsely pulverized powder with a required average grain size.
This has the advantage that not only can a coercive force of 6 kOe or more be obtained, but also that handling of the powder in subsequent steps is extremely easy.
【0012】製造条件の限定理由
この発明は、所要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、微細結晶組織の集合体が得られる
ことを特徴とし、この点が従来のH2吸蔵粉砕法と本質
的に異なるものである。出発原料の粗粉砕方法は従来の
機械的な粉砕方法やガスアト マイズ法のほか、H2
吸蔵粉砕法で粗粉砕してもよく、工程の簡略化のために
このH2吸蔵による粗粉砕法とこの発明による超微細結
晶化のためのH2ガス中加熱処理を組み合せて、同一装
置内で連続的に処理する方法を採用することも好ましい
。
この発明において、粗粉砕粉の平均粒度を50〜500
μm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500μmを超えると窒
化処理に長時間を要して好ましくないためである。Reasons for limiting manufacturing conditions The present invention is characterized in that a coarsely pulverized powder of a required particle size can be obtained as an aggregate of fine crystal structures without changing its size in appearance, and this point is different from the conventional H2 This method is essentially different from the occlusion pulverization method. In addition to the conventional mechanical crushing method and gas atomization method, the method of coarsely pulverizing the starting raw material is H2
Coarse pulverization may be carried out by the occlusion pulverization method.To simplify the process, this coarse pulverization method by H2 occlusion and the heat treatment in H2 gas for ultrafine crystallization according to the present invention are combined, and the process is continuously carried out in the same equipment. It is also preferable to adopt a method of treating In this invention, the average particle size of the coarsely pulverized powder is 50 to 500.
The reason why it is limited to μm is that if it is less than 50 μm, there is a risk of magnetic deterioration due to oxidation of the powder, and if it exceeds 500 μm, it will take a long time for the nitriding treatment, which is undesirable.
【0013】この発明において、H2ガス単独または不
活性ガス(N2ガスを除く)との混合気中での加熱に際
し、H2分圧が0.1atm(常温換算)未満では前述
の分解生成の十分な効果が得られず、10atmを超え
ると処理設備が大きくなりすぎ、工業生産コスト的に好
ましくないため、H2分圧を0.1〜10atmとする
。さらに好ましい範囲は0.5〜1.5atmである。
また、N2ガスを除く不活性ガスとH2ガスとの混合気
を前記H2分圧で用いる場合も、同様の理由により最大
圧力は10atm以下とする。[0013] In the present invention, when heating with H2 gas alone or in a mixture with inert gas (excluding N2 gas), if the H2 partial pressure is less than 0.1 atm (converted to room temperature), the above-mentioned decomposition and production will be insufficient. No effect can be obtained, and if it exceeds 10 atm, the processing equipment becomes too large, which is not preferable in terms of industrial production costs, so the H2 partial pressure is set to 0.1 to 10 atm. A more preferable range is 0.5 to 1.5 atm. Further, when using a mixture of an inert gas other than N2 gas and H2 gas at the above H2 partial pressure, the maximum pressure is set to 10 atm or less for the same reason.
【0014】H2ガス単独または不活性ガス(N2ガス
を除く)とH2ガスとの混合気中での加熱処理温度は、
500℃未満ではR−T化合物がH2吸蔵するのみで、
RH2■3とαFe等への分解が行われず、また900
℃を超えるとRH2■3が不安定となりかつ生成物が粒
成長して脱H2後、超微細組織を有するR−T化合物に
することが困難となるため、500〜900℃の範囲と
する。
また、加熱処理保持時間は上記の分解反応を十分に行わ
せるためには、30分〜8時間の加熱保持が必要である
。[0014] The heat treatment temperature in H2 gas alone or in a mixture of inert gas (excluding N2 gas) and H2 gas is:
Below 500°C, the RT compound only absorbs H2,
Decomposition into RH2■3 and αFe etc. is not carried out, and 900
If the temperature exceeds .degree. C., RH2 and 3 will become unstable and the product will grow into grains, making it difficult to form an RT compound with an ultrafine structure after dehydrogenation. Further, in order to sufficiently carry out the above-mentioned decomposition reaction, it is necessary to hold the heat treatment for 30 minutes to 8 hours.
【0015】この発明において、H2ガスの脱H2処理
の温度が500℃未満ではRH2■3の分解が進行せず
、900℃を超えると粒成長のため粗大な組織となり、
すぐれた高保磁力が得られないため、500〜900℃
の範囲とする。また、加熱処理保持時間は上記の分解反
応を十分に行わせるためには、30分〜8時間の加熱保
持が必要である。[0015] In the present invention, if the temperature of the H2 removal process of H2 gas is less than 500°C, decomposition of RH2-3 will not proceed, and if it exceeds 900°C, grain growth will result in a coarse structure.
500 to 900℃ because excellent high coercive force cannot be obtained.
The range shall be . Further, in order to sufficiently carry out the above-mentioned decomposition reaction, it is necessary to hold the heat treatment for 30 minutes to 8 hours.
【0016】脱H2処理時のH2分圧は、1×10−2
Torrを超えると処理に長時間を要し好ましくないた
め、1×10−2Torr以下とする。H2分圧がこの
範囲であれば、N2ガスを除く不活性ガス中でこの処理
を行ってもよく、これにより高気圧に耐える真空容器設
備が不要になり、設備が簡素化でき経済的である。[0016] The H2 partial pressure during the H2 removal process is 1×10-2
If it exceeds Torr, the processing will take a long time and is not preferable, so it is set to 1×10 −2 Torr or less. If the H2 partial pressure is within this range, this treatment may be carried out in an inert gas other than N2 gas, which eliminates the need for vacuum container equipment that can withstand high pressure, which simplifies the equipment and is economical.
【0017】脱H2処理後の粉末の平均結晶粒径を0.
05〜0.5μmに限定した理由は、0.05μm未満
では実際上生成が困難であり、0.05μm未満の結晶
が得られたとしても特性上の利点がなく、また0.5μ
mを超えると単磁区粒子臨界径より大きくなり、粉末の
保磁力が減少して永久磁石用粉末として好ましくないた
めである。[0017] The average crystal grain size of the powder after H2 removal treatment is 0.
The reason why crystals are limited to 0.05 to 0.5 μm is that crystals smaller than 0.05 μm are practically difficult to form, and even if crystals smaller than 0.05 μm are obtained, there is no advantage in terms of properties.
This is because if it exceeds m, the single magnetic domain particle critical diameter becomes larger and the coercive force of the powder decreases, making it undesirable as a powder for permanent magnets.
【0018】窒化処理時の温度を350〜650℃に限
定した理由は、350℃未満では窒化が進行せず、65
0℃を超えるとRNが生成してR−T化合物が分解して
磁石特性の劣化を招来するためである。窒化処理時の保
持時間は30分未満で十分な窒化が進行せず、また6時
間を超えると分解が起こり磁石特性の劣化を招来するた
め、30分〜6時間とする。The reason why the temperature during nitriding treatment was limited to 350 to 650°C is that nitriding does not proceed below 350°C.
This is because if the temperature exceeds 0° C., RN is generated and the RT compound is decomposed, leading to deterioration of magnetic properties. The holding time during the nitriding treatment is set to 30 minutes to 6 hours, since sufficient nitriding will not proceed if it is less than 30 minutes, and decomposition will occur if it exceeds 6 hours, resulting in deterioration of the magnetic properties.
【0019】窒化処理時のN2圧力(常温)を0.5〜
50atmに限定した理由は、0.5atm未満では窒
化反応速度が遅く、圧力を上げると反応は速やかに進行
するが、50atmを超えると、処理設備が大きくなり
すぎ、工業生産コスト的に好ましくないためである。[0019] N2 pressure (room temperature) during nitriding treatment is 0.5~
The reason for limiting the pressure to 50 atm is that if it is less than 0.5 atm, the nitriding reaction rate is slow, and if the pressure is increased, the reaction will proceed quickly, but if it exceeds 50 atm, the processing equipment will become too large, which is not desirable in terms of industrial production costs. It is.
【0020】この発明において、出発原料である合金粗
粉砕粉の金属組織が実質的にR2T17化合物で占めら
れることが必要であり、初晶として晶出するα−Feや
Fe−Co、Fe−Ni合金の残存量が全体の20vo
l%以下であることが好ましい。前記の初晶相は成分と
してR元素を含まないため、H2処理によって変化を受
けず、さらに後工程のN2処理においても磁気的性質が
変化せず、軟質磁性層として残存するため、得られる粉
末の磁石特性は劣化する。従って、α−Fe等の初晶相
の存在量は体積比で20%以下にする必要があり、その
ために真空中またはN2ガスを除いた不活性ガス中での
溶体化処理が行われるが、溶体化処理を800℃未満で
行うと、十分なる拡散反応が進行しないため初晶相の消
失に長時間を要し、また1200℃を超える温度では速
やかな溶体化が可能であるが、必須成分であるSmが蒸
発して組成ずれを起こす上、合金の化学的反応性が増大
して、合金 コンテナや炉壁に悪影響を与えるため、
溶体化処理温度は800℃〜1200℃とする。この発
明の組成範囲では初晶相はRを実質的に含まない合金相
であるが、この合金相の存在量は溶体化処理時間と共に
減少してゆく、またその減少速度は温度に依存して高温
ほど速くなるが、溶体化処理温度が1200℃の場合で
も、1時間以上の溶体化を行わないと初晶相の存在量を
体積比で20%以下にできず、また処理温度が800℃
で拡散速度が遅い場合でも、初晶相の存在量を体積比で
20%以下にするには100時間以下で十分であり、そ
れ以上の溶体化は不要である。[0020] In this invention, it is necessary that the metal structure of the coarsely pulverized alloy powder, which is the starting material, is substantially occupied by the R2T17 compound, and α-Fe, Fe-Co, and Fe-Ni crystals crystallize as primary crystals. The remaining amount of alloy is 20vo overall
It is preferably 1% or less. Since the primary phase does not contain the R element as a component, it is not changed by the H2 treatment, and its magnetic properties do not change even in the subsequent N2 treatment and remain as a soft magnetic layer, so the obtained powder The magnetic properties of will deteriorate. Therefore, the amount of primary crystal phases such as α-Fe needs to be kept below 20% by volume, and for this purpose solution treatment is performed in vacuum or in an inert gas excluding N2 gas. If solution treatment is carried out at a temperature below 800°C, a sufficient diffusion reaction will not proceed and it will take a long time for the primary crystal phase to disappear. At a temperature above 1200°C, rapid solution treatment is possible, but the essential components will be removed. In addition to evaporating Sm, which causes a composition shift, the chemical reactivity of the alloy increases, which adversely affects the alloy container and the furnace wall.
The solution treatment temperature is 800°C to 1200°C. In the composition range of this invention, the primary phase is an alloy phase that does not substantially contain R, but the amount of this alloy phase decreases with the solution treatment time, and the rate of decrease is dependent on the temperature. The rate increases as the temperature increases, but even when the solution treatment temperature is 1200°C, the amount of primary crystal phase cannot be reduced to 20% or less by volume unless solution treatment is performed for at least 1 hour, and the processing temperature is 800°C.
Even when the diffusion rate is slow, 100 hours or less is sufficient to reduce the amount of primary crystal phase to 20% or less by volume, and no further solution treatment is necessary.
【0021】粉末組成の限定理由
この発明の粉末組成において、希土類元素RはY、La
、Ce、Pr、Nd、Sm、Gd、Tb、Dy、Ho、
Er、Tm、Luが包含され、これらのうち1種以上を
含有し、かつ少なくともSmをRの30%以上含有する
もので、さらにSmがRの100%を占める場合もある
。Rの30%以上をSmとするのは、Smが30%未満
では一軸異方性が弱まり保磁力が減少するためである。
Rは、9at%未満ではFeの析出により保磁力が低下
し、また12at%を超えると低保磁力でしかもキュリ
ー点の低い他の化合物が生成して磁石特性が劣化するた
め、9〜12at%とする。Reasons for limiting the powder composition In the powder composition of the present invention, the rare earth element R is Y, La
, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho,
It includes Er, Tm, and Lu, contains one or more of these, and contains at least 30% or more of Sm relative to R, and in some cases, Sm may account for 100% of R. The reason why Sm accounts for 30% or more of R is that if Sm is less than 30%, the uniaxial anisotropy weakens and the coercive force decreases. If R is less than 9 at%, the coercive force will decrease due to the precipitation of Fe, and if it exceeds 12 at%, other compounds with low coercive force and low Curie point will be generated and the magnetic properties will deteriorate, so R should be 9 to 12 at%. shall be.
【0022】鉄族元素TはFe、Co、Niの少なくと
も1種を包含し、FeをTの50%以上含有することが
重要である。すなわち、T中のFeが50%未満ではコ
スト高となるとともに磁化が減少して好ましくない。T
は、88at%未満ではSm2Fe17化合物以外のR
リッチ相が現れて保磁力、キューリー点が低下し、90
at%を超えるとα−Fe析出により保磁力が低下する
ため、88〜91at%とする。[0022] The iron group element T includes at least one of Fe, Co, and Ni, and it is important that Fe is contained in an amount of 50% or more of T. That is, if the Fe content in T is less than 50%, the cost increases and the magnetization decreases, which is not preferable. T
is less than 88 at%, R other than Sm2Fe17 compound
A rich phase appears, the coercive force and Curie point decrease, and 90
If it exceeds at%, the coercive force decreases due to α-Fe precipitation, so it is set to 88 to 91 at%.
【0023】また窒化処理後の粉体に含有されるNは、
9.5at%未満ではキューリー点、保磁力ともに元の
Sm2Fe17化合物と大差がなく、13.6at%を
超えるとR−N化合物の析出によりR2Fe17NX化
合物が分解して好ましくないため、9.5〜13.6a
t%とする。[0023] Furthermore, the N contained in the powder after nitriding treatment is
If it is less than 9.5 at%, the Curie point and coercive force are not much different from the original Sm2Fe17 compound, and if it exceeds 13.6 at%, the R2Fe17NX compound will decompose due to the precipitation of the RN compound, which is undesirable. .6a
It is assumed to be t%.
【0024】[0024]
実施例
高周波溶解炉にて溶製して得られた表1に示すNo.1
〜7の組成の鋳塊を、Arガス雰囲気中でスタンプミル
にて平均粒度100μmに粗粉砕した後、この粗粉砕粉
をH2分圧が10atm(常温換算)のH2ガス中で8
00℃に加熱し2時間保持した後、H2分圧が1×10
−4Torrの雰囲気で800℃、1時間の脱H2処理
を行い、表1に示す平均結晶粒径の集合組織を有する粉
体を得た。その後、N2分圧が10atmのN2ガス中
で450℃、2時間の窒化処理したのち冷却して表1に
示す性状のR−T−N磁石粉末を得た。表1において、
αは20℃〜120℃におけるBrの温度係数である。Example No. 1 shown in Table 1 obtained by melting in a high frequency melting furnace. 1
After coarsely pulverizing the ingot having a composition of 7 to 7 with a stamp mill in an Ar gas atmosphere to an average particle size of 100 μm, the coarsely pulverized powder was pulverized in H2 gas with a H2 partial pressure of 10 atm (normal temperature equivalent).
After heating to 00℃ and holding for 2 hours, the H2 partial pressure becomes 1×10
A dehydrogenation treatment was performed at 800° C. for 1 hour in an atmosphere of −4 Torr to obtain a powder having a texture with an average crystal grain size shown in Table 1. Thereafter, it was subjected to nitriding treatment at 450 DEG C. for 2 hours in N2 gas with a N2 partial pressure of 10 atm, and then cooled to obtain R-T-N magnet powder having the properties shown in Table 1. In Table 1,
α is the temperature coefficient of Br at 20°C to 120°C.
【0025】R−T−N磁石粉末に2.0wt%のエポ
キシ樹脂を混合したのち、10kOeの磁場中で3.0
ton/cm2の圧力で圧縮成型し、さらに温度150
℃、30分の条件で樹脂硬化させてボンド 磁石を作
製した。得られたボンド 磁石の磁石特性を表2に示
す。[0025] After mixing 2.0 wt% epoxy resin with R-T-N magnet powder, 3.0 wt% epoxy resin was mixed in a magnetic field of 10 kOe.
Compression molded at a pressure of ton/cm2 and further heated to a temperature of 150°C.
A bonded magnet was produced by curing the resin at ℃ for 30 minutes. Table 2 shows the magnetic properties of the obtained bonded magnet.
【0026】比較例
表1の組成No.1と同一の粗粉砕粉を用いて、H2分
圧が2.0atm(常温換算)のH2ガス中で2時間保
持した後、余剰のH2ガスを排気してから加熱し、92
0℃、2時間、H2分圧1×10−4Torrで脱H2
処理して粉砕粉を得た。このときの平均結晶粒径を表1
に示す。さらに実施例と同一の窒化処理を施したのちの
R−T−N磁石粉末の性状を表1に示す。その後実施例
と同一の条件でボンド 磁石を作製し、その磁石特性
を表2に示す。Comparative Example Composition No. 1 in Table 1 Using the same coarsely pulverized powder as in 1, it was held in H2 gas with a H2 partial pressure of 2.0 atm (normal temperature equivalent) for 2 hours, and then heated after exhausting the excess H2 gas.
De-H2 at 0℃, 2 hours, H2 partial pressure 1 x 10-4 Torr
After processing, a ground powder was obtained. Table 1 shows the average grain size at this time.
Shown below. Furthermore, Table 1 shows the properties of the R-T-N magnet powder after it was subjected to the same nitriding treatment as in the example. Thereafter, a bonded magnet was produced under the same conditions as in the example, and its magnetic properties are shown in Table 2.
【0027】[0027]
【表1】[Table 1]
【0028】[0028]
【表2】[Table 2]
【0029】[0029]
【発明の効果】この発明によるR−T−N系永久磁石粉
末は、R−T系粗粉砕粉をH2ガス単独または不活性ガ
ス(N2ガスを除く)との混合気中での加熱処理並びに
所定雰囲気で加熱保持する脱H2処理を行い、所要平均
粒度の粗粉砕粉のままで平均結晶粒径が0.05〜0.
5μmの集合組織を有する粉体となすことができ、後工
程での粉末の取扱いが極めて容易になり、その後窒化処
理して実施例に明らかなように6kOe以上の保磁力が
得られる。Effects of the Invention The R-T-N permanent magnet powder according to the present invention can be obtained by heating coarsely pulverized R-T powder in H2 gas alone or in a mixture with an inert gas (excluding N2 gas); A deH2 treatment is carried out by heating and holding in a predetermined atmosphere, and the average crystal grain size is 0.05 to 0.05% while the coarsely pulverized powder has the required average grain size.
The powder can be made into a powder having a texture of 5 μm, which makes handling of the powder extremely easy in the subsequent process, and after that, by nitriding, a coercive force of 6 kOe or more can be obtained, as is clear from the examples.
Claims (2)
素の少なくとも1種でかつSmを30%以上含有)、T
88〜91at%(T:FeあるいはFeの一部を
50%以下のCo、Niにて置換)からなる鋳塊を粗粉
砕して、平均粒度が50〜500μmの粗粉砕粉となし
た後、前記粗粉砕粉を0.1〜10atm(常温換算)
のH2ガスまたはそれに等しいH2分圧を有する不活性
ガス(N2ガスを除く)中(但し全圧力は常温換算で1
0atm以下)で、500〜900℃に30分〜8時間
加熱保持し、さらにH2分圧1×10−2Torr以下
にて500〜900℃に30分〜8時間保持する脱H2
処理を行い、平均結晶粒径が0.05〜0.5μmの集
合組織を有する粉体となし、次に前記粉体をN2圧力(
常温)0.5〜50atmのN2ガス中で350〜65
0℃に30分〜6時間保持した後、冷却することを特徴
とする永久磁石粉末の製造方法。[Claim 1] R 9 to 12 at% (R: at least one rare earth element and containing 30% or more of Sm), T
After coarsely pulverizing an ingot consisting of 88 to 91 at% (T: Fe or a part of Fe replaced with 50% or less of Co or Ni) to a coarsely pulverized powder with an average particle size of 50 to 500 μm, The coarsely ground powder is 0.1 to 10 atm (converted to room temperature)
of H2 gas or an inert gas (excluding N2 gas) with an equivalent H2 partial pressure (however, the total pressure is 1 at room temperature).
H2 removal by heating and holding at 500 to 900°C for 30 minutes to 8 hours at 0 atm or less, and then holding at 500 to 900°C for 30 minutes to 8 hours at a H2 partial pressure of 1 x 10-2 Torr or less.
The powder was treated to have a texture with an average grain size of 0.05 to 0.5 μm, and then the powder was heated under N2 pressure (
room temperature) 350-65 in N2 gas of 0.5-50 atm
A method for producing permanent magnet powder, which comprises maintaining the powder at 0° C. for 30 minutes to 6 hours and then cooling it.
〜100時間の溶体化処理を行い、金属組織中に含まれ
るFe基の初晶相を20vol%以下にした後、粗粉砕
することを特徴とする請求項1記載の永久磁石粉末の製
造方法。2. The ingot is subjected to solution treatment at 800° C. to 1200° C. for 1 hour to 100 hours to reduce the Fe-based primary crystal phase contained in the metal structure to 20 vol% or less, and then coarsely pulverized. The method for producing permanent magnet powder according to claim 1, characterized in that:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3145475A JPH04343203A (en) | 1991-05-20 | 1991-05-20 | Production of permanent magnet powder |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3145475A JPH04343203A (en) | 1991-05-20 | 1991-05-20 | Production of permanent magnet powder |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04343203A true JPH04343203A (en) | 1992-11-30 |
Family
ID=15386113
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3145475A Pending JPH04343203A (en) | 1991-05-20 | 1991-05-20 | Production of permanent magnet powder |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04343203A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06220507A (en) * | 1993-01-28 | 1994-08-09 | Mazda Motor Corp | Production of permanent magnet material of rare earth-iron-nitride system |
-
1991
- 1991-05-20 JP JP3145475A patent/JPH04343203A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06220507A (en) * | 1993-01-28 | 1994-08-09 | Mazda Motor Corp | Production of permanent magnet material of rare earth-iron-nitride system |
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