JP7140185B2 - rare earth magnet - Google Patents

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JP7140185B2
JP7140185B2 JP2020507886A JP2020507886A JP7140185B2 JP 7140185 B2 JP7140185 B2 JP 7140185B2 JP 2020507886 A JP2020507886 A JP 2020507886A JP 2020507886 A JP2020507886 A JP 2020507886A JP 7140185 B2 JP7140185 B2 JP 7140185B2
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英一郎 福地
将志 伊藤
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
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    • 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
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    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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    • C22C38/00—Ferrous alloys, e.g. steel alloys

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Description

本発明は、希土類磁石に関する。 The present invention relates to rare earth magnets.

希土類磁石はその高磁気特性から年々生産量を伸ばしており、各種モータ用、各種アクチュエータ用、ＭＲＩ装置用など様々な用途に使用されている。 Rare earth magnets have been increasing in production volume year by year due to their high magnetic properties, and are used in various applications such as various motors, various actuators, and MRI apparatuses.

例えば、特許文献１に記載のＳｍ５Ｆｅ１７金属間化合物を主相とする磁石材料は、室温で３６．８ｋＯｅという非常に高い保磁力を得ている。したがって、有望な磁石材料であると考えられる。For example, a magnetic material having a Sm 5 Fe 17 intermetallic compound as a main phase described in Patent Document 1 has a very high coercive force of 36.8 kOe at room temperature. Therefore, it is considered to be a promising magnetic material.

しかしながら、Ｓｍ５Ｆｅ１７金属間化合物を主相とする磁石材料は、粒界相の制御技術が確立されていない。そして、Ｓｍ５Ｆｅ１７金属間化合物を主相とする磁石材料の高い保磁力を活かした磁石はいまだに実現されていない。However, a technique for controlling the grain boundary phase has not been established for a magnetic material having a Sm 5 Fe 17 intermetallic compound as a main phase. A magnet that makes use of the high coercive force of a magnetic material having a Sm 5 Fe 17 intermetallic compound as a main phase has not yet been realized.

非特許文献１では、放電プラズマ焼結法（ＳＰＳ法）を用いた焼結磁石が報告されている。ＳＰＳ法では通常の焼結法と比較して低温で焼結される。また、焼結時に加圧が必要である。しかし、非特許文献１に記載の焼結磁石は焼結体として密度が低い。また、副相として軟磁性相が存在している。さらに、一般的にはＳＰＳ法を用いる場合には通常の焼結法を用いる場合と比較して磁気特性が低下してしまう。以上より、非特許文献１に記載の焼結磁石は、焼結前の段階で期待されるほどの磁気特性が得られていない。さらに、ＳＰＳ法そのものが比較的量産に適さない焼結方法である。 Non-Patent Document 1 reports a sintered magnet using a spark plasma sintering method (SPS method). In the SPS method, sintering is performed at a lower temperature than in ordinary sintering methods. Moreover, pressurization is required during sintering. However, the sintered magnet described in Non-Patent Document 1 has a low density as a sintered body. Also, a soft magnetic phase exists as a subphase. Furthermore, in general, when the SPS method is used, the magnetic properties are lowered as compared with the case of using the normal sintering method. As described above, the sintered magnet described in Non-Patent Document 1 does not achieve the expected magnetic properties before sintering. Furthermore, the SPS method itself is a sintering method that is relatively unsuitable for mass production.

特開２００８－１３３４９６号公報JP-A-2008-133496

Ｍａｔｅｒｉａｌｓ Ｓｃｉｅｎｃｅ ａｎｄ Ｅｎｇｉｎｅｅｒｉｎｇ １（２００９）０１２０３２Materials Science and Engineering 1 (2009) 012032

本発明はこうした状況を認識してなされたものであり、Ｎｄ５Ｆｅ１７型結晶構造の化合物を主相とする希土類磁石であって、通常の焼結方法で焼成した場合でも焼結密度が高く、残留磁束密度Ｂｒおよび保磁力ＨｃＪが高い特性を持つ希土類磁石を得ることを目的とする。The present invention has been made in recognition of such circumstances, and is a rare earth magnet having a compound having a Nd 5 Fe 17 type crystal structure as a main phase, which has a high sintered density even when fired by a normal sintering method. An object of the present invention is to obtain a rare earth magnet having high remanence Br and high coercive force HcJ.

本発明は、Ｒ，ＴおよびＭを含む希土類磁石であって、
ＲはＳｍを必須とする１種以上の希土類元素、ＴはＦｅ単独またはＦｅおよびＣｏ、ＭはＣｕ，Ｚｎ，Ａｌ，Ｇａ，Ａｇ，Ａｕ，Ｓｉ，ＧｅおよびＳｎからなる群から選択される少なくとも１種であり、
Ｎｄ５Ｆｅ１７型結晶構造を有する結晶粒子からなる主相、および、前記主相以外の相である副相からなり、
前記副相の少なくとも一部がＭを含み、
前記副相におけるＭの平均含有割合が５ａｔ％以上３０ａｔ％以下であり、
前記希土類磁石の任意の切断面における前記副相の総面積割合が３％以上２５％以下であることを特徴とする。The present invention is a rare earth magnet comprising R, T and M,
R is one or more rare earth elements essentially including Sm, T is Fe alone or Fe and Co, M is at least selected from the group consisting of Cu, Zn, Al, Ga, Ag, Au, Si, Ge and Sn is one type,
Consists of a main phase composed of crystal grains having a Nd 5 Fe 17 -type crystal structure, and a subphase that is a phase other than the main phase,
at least a portion of said subphase comprises M;
The average content of M in the subphase is 5 at% or more and 30 at% or less,
It is characterized in that the total area ratio of the subphases on any cut surface of the rare earth magnet is 3% or more and 25% or less.

本発明の希土類磁石は上記の特徴を有するため、通常の焼結方法でも高い焼結密度が得られる。また、残留磁束密度Ｂｒおよび保磁力ＨｃＪも高くなる。すなわち、磁気特性が改善される。 Since the rare earth magnet of the present invention has the above characteristics, a high sintered density can be obtained even by a normal sintering method. Also, the residual magnetic flux density Br and the coercive force HcJ are increased. That is, the magnetic properties are improved.

本発明の希土類磁石は、さらにＣを含んでもよく、希土類磁石全体に対するＣの含有割合が０ａｔ％超１５ａｔ％以下であってもよい。 The rare earth magnet of the present invention may further contain C, and the content of C relative to the entire rare earth magnet may be more than 0 at % and 15 at % or less.

本発明の希土類磁石は、ＲとしてさらにＰｒおよび／またはＮｄを含んでもよく、
Ｒ全体に対するＳｍの含有割合が５０ａｔ％以上９９ａｔ％以下であってもよく、ＰｒおよびＮｄの合計含有割合が１ａｔ％以上５０ａｔ％以下であってもよい。The rare earth magnet of the present invention may further contain Pr and/or Nd as R,
The content rate of Sm with respect to the entire R may be 50 at % or more and 99 at % or less, and the total content rate of Pr and Nd may be 1 at % or more and 50 at % or less.

実施例３の反射電子像である。4 is a backscattered electron image of Example 3. FIG.

本発明を実施するための形態（実施形態）につき、詳細に説明する。以下の実施形態に記載した内容により本発明が限定されるものではない。また、以下に記載した構成要素には、当業者が容易に想定できるもの、実質的に同一のものが含まれる。さらに、以下に記載した構成要素は適宜組み合わせることが可能である。 A form (embodiment) for carrying out the present invention will be described in detail. The present invention is not limited by the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the components described below can be combined as appropriate.

本実施形態に係る希土類磁石１は、Ｎｄ５Ｆｅ１７型結晶構造（空間群Ｐ６３／ｍｃｍ）を有する結晶粒子を主相１１とする。そして、主相１１以外の相を副相１３とする。以下の記載では、Ｎｄ５Ｆｅ１７型結晶構造を有する結晶粒子からなる相をＲ５Ｔ１７結晶相と記載する。The rare earth magnet 1 according to this embodiment has a main phase 11 of crystal grains having a Nd 5 Fe 17 -type crystal structure (space group P6 3 /mcm). Phases other than the main phase 11 are referred to as subphases 13 . In the following description, the phase consisting of crystal grains having the Nd 5 Fe 17 -type crystal structure is referred to as the R 5 T 17 crystal phase.

副相１３の構造は任意である。例えば、Ｒ５Ｔ１７結晶相以外のＲ－Ｔ結晶相を含んでもよい。Ｒ－Ｔ結晶相としては、例えば、ＲＴ２結晶相、ＲＴ３結晶相、Ｒ２Ｔ７結晶相、ＲＴ５結晶相、ＲＴ７結晶相、Ｒ２Ｔ１７結晶相、ＲＴ１２結晶相などが挙げられる。副相１３には非晶質相が含まれても良い。ただし、Ｒ２Ｔ１７結晶相やＲＴ３結晶相など、軟磁性もしくは保磁力の低いＲ－Ｔ結晶相は少ないことが好ましい。また、本実施形態に係る希土類磁石１がどのような結晶を含むかについては、Ｘ線回折法（ＸＲＤ）や元素分析機能が付いた走査型電子顕微鏡（ＳＥＭ）などを用いて確認することができる。The structure of the subphase 13 is arbitrary. For example, it may contain an RT crystalline phase other than the R 5 T 17 crystalline phase. Examples of the RT crystal phase include RT 2 crystal phase, RT 3 crystal phase, R 2 T 7 crystal phase, RT 5 crystal phase, RT 7 crystal phase, R 2 T 17 crystal phase, RT 12 crystal phase, and the like. mentioned. The subphase 13 may contain an amorphous phase. However, it is preferable that the amount of soft magnetic or low coercive force RT crystal phases such as R 2 T 17 crystal phases and RT 3 crystal phases is small. In addition, what kind of crystals are included in the rare earth magnet 1 according to the present embodiment can be confirmed using an X-ray diffraction method (XRD), a scanning electron microscope (SEM) equipped with an elemental analysis function, or the like. can.

ここで、本実施形態に係る希土類磁石１がＭを含むことで、副相１３にＲおよびＭを含む化合物が生じる。以下、ＲおよびＭを含む化合物からなる相をＲ－Ｍ相とする。なお、Ｒ－Ｍ相にはさらにＴを含んでもよい。Ｒ－Ｍ相におけるＲの含有割合には特に限定はないが、例えば２４ａｔ％以上である。Ｒ－Ｍ相を構成するＲおよびＭを含む化合物は融点が低く、焼結により粒界相となりやすい。言いかえれば、Ｍが粒界相に拡散してＲおよびＭを含む化合物が生じる。なお、本実施形態での粒界相とは、複数のＲ５Ｔ１７結晶相の結晶粒子間に存在する副相のことである。Here, by including M in the rare earth magnet 1 according to the present embodiment, a compound including R and M is generated in the subphase 13 . A phase composed of a compound containing R and M is hereinafter referred to as an RM phase. Note that the RM phase may further contain T. Although there is no particular limitation on the content of R in the RM phase, it is, for example, 24 atomic % or more. A compound containing R and M that constitutes the RM phase has a low melting point and tends to form a grain boundary phase upon sintering. In other words, M diffuses into the grain boundary phase to produce a compound containing R and M. In addition, the grain boundary phase in the present embodiment means a subphase existing between crystal grains of a plurality of R 5 T 17 crystal phases.

Ｒ－Ｍ相が生じることで、Ｒ２Ｔ１７結晶相やＲＴ３結晶相など、Ｒ５Ｔ１７結晶相以外のＲ－Ｔ結晶相が析出しにくくなる。そして、均一な粒界相を形成しやすくなる。The formation of the RM phase makes it difficult to precipitate RT crystal phases other than the R 5 T 17 crystal phase, such as the R 2 T 17 crystal phase and the RT 3 crystal phase. And it becomes easy to form a uniform grain boundary phase.

この結果、従来よりも高温で焼結することが可能となり、加圧なしでも十分な焼結密度を有する希土類磁石１を得ることができる。さらに、十分な焼結密度を有することで得られる希土類磁石１の残留磁束密度Ｂｒおよび保磁力ＨｃＪを向上させることができる。 As a result, sintering can be performed at a higher temperature than before, and a rare earth magnet 1 having a sufficient sintered density can be obtained without pressurization. Furthermore, the residual magnetic flux density Br and the coercive force HcJ of the rare earth magnet 1 obtained by having a sufficient sintered density can be improved.

希土類磁石１において主相１１と副相１３とを区別する方法には特に制限はないが、例えばＳＥＭを用いて反射電子像を得て、各相におけるコントラストの違いから目視により区別することが出来る。反射電子像の具体例を図１に示す。なお、図１は後述する実施例３の試料の切断面をイオンミリングにより鏡面加工した後にＳＥＭを用いて得られた反射電子像である。 The method of distinguishing the main phase 11 and the subphase 13 in the rare earth magnet 1 is not particularly limited, but for example, a backscattered electron image is obtained using an SEM, and the differences in contrast between the phases can be visually distinguished. . A specific example of a backscattered electron image is shown in FIG. FIG. 1 is a backscattered electron image obtained using an SEM after a cut surface of a sample of Example 3, which will be described later, was mirror-finished by ion milling.

また、エネルギー分散型Ｘ線分光器（ＥＤＳ）のついたＳＥＭ（いわゆるＳＥＭ－ＥＤＳ）を用いることが好ましい。ＥＤＳを用いて元素マッピングを行い、後述するＲとＴの比率が概ね５：１７である相が主相１１であり、空孔を除くそれ以外の相が副相１３であると判断できる。反射電子像と元素マッピング画像とを組み合わせることで、より正確に主相１１と副相１３とを区別することができる。さらに、透過電子顕微鏡（ＴＥＭ）を用いたエネルギー分散型Ｘ線分光法（ＴＥＭ－ＥＤＳ）や電子回折法を併用することで、微小領域の結晶組織や非晶質相の区別が可能である。 Also, it is preferable to use an SEM with an energy dispersive X-ray spectrometer (EDS) (so-called SEM-EDS). Elemental mapping is performed using EDS, and it can be determined that the main phase 11 is the phase in which the ratio of R and T, which will be described later, is about 5:17, and the subphase 13 is the phase other than vacancies. By combining the backscattered electron image and the elemental mapping image, the main phase 11 and the subphase 13 can be distinguished more accurately. Furthermore, by combining energy dispersive X-ray spectroscopy (TEM-EDS) using a transmission electron microscope (TEM) and electron diffraction, it is possible to distinguish between crystal structures and amorphous phases in minute regions.

本実施形態に係る希土類磁石１は、副相１３の少なくとも一部がＭを含み、副相１３におけるＭの平均含有割合が５ａｔ％以上３０ａｔ％以下であり、任意の切断面における副相１３の総面積割合が３％以上２５％以下である。 In the rare earth magnet 1 according to the present embodiment, at least part of the subphase 13 contains M, the average content of M in the subphase 13 is 5 at% or more and 30 at% or less, and the subphase 13 in an arbitrary cross section The total area ratio is 3% or more and 25% or less.

Ｍの平均含有割合は５０μｍ×５０μｍ以上の大きさの測定範囲においてＳＥＭ－ＥＤＳを用いて測定範囲内の全ての副相１３におけるＭの含有割合を測定して平均することにより算出する。なお、測定範囲については単独で５０μｍ×５０μｍ以上の大きさの測定範囲となるようにしてもよく、複数の測定範囲の合計が５０μｍ×５０μｍ以上の大きさとなるようにしてもよい。 The average content of M is calculated by measuring and averaging the content of M in all subphases 13 within a measurement range of 50 μm×50 μm or more using SEM-EDS. The measurement range may be set to a size of 50 μm×50 μm or more independently, or the total size of a plurality of measurement ranges may be set to a size of 50 μm×50 μm or more.

副相１３におけるＭの平均含有割合を５ａｔ％以上３０ａｔ％以下とすることで希土類磁石１が緻密化しやすくなり密度が高くなりやすくなる。そして、Ｒ２Ｔ１７結晶相やＲＴ３相など、Ｒ５Ｔ１７結晶相以外のＲ－Ｔ結晶相の生成が抑制される。その結果、残留磁束密度Ｂｒおよび保磁力ＨｃＪが向上しやすくなる。By setting the average content ratio of M in the subphase 13 to 5 at % or more and 30 at % or less, the rare earth magnet 1 tends to be densified and its density tends to increase. In addition, the formation of RT crystal phases other than the R 5 T 17 crystal phase, such as the R 2 T 17 crystal phase and the RT 3 phase, is suppressed. As a result, the residual magnetic flux density Br and the coercive force HcJ are likely to be improved.

副相１３におけるＭの平均含有割合が小さすぎる場合には希土類磁石１が緻密化しにくくなり焼結密度が低下しやすくなる。また、Ｒ２Ｔ１７結晶相やＲＴ３結晶相など、Ｒ５Ｔ１７結晶相以外のＲ－Ｔ結晶相の生成が十分に抑制されなくなる。その結果、粒界相の組成が不均一になりやすくなる。さらに、残留磁束密度Ｂｒおよび保磁力ＨｃＪが低下しやすくなる。副相１３におけるＭの平均含有割合が大きすぎる場合には希土類磁石１が緻密化しにくくなり焼結密度が低下しやすくなる。また、粒界相におけるＭの分布が不均一になるため、残留磁束密度Ｂｒおよび保磁力ＨｃＪが低下しやすくなる。If the average content of M in the subphase 13 is too small, the rare earth magnet 1 is difficult to densify, and the sintered density tends to decrease. In addition, the formation of RT crystal phases other than the R 5 T 17 crystal phase, such as the R 2 T 17 crystal phase and the RT 3 crystal phase, is not sufficiently suppressed. As a result, the composition of the grain boundary phase tends to be uneven. Furthermore, the residual magnetic flux density Br and the coercive force HcJ tend to decrease. If the average content of M in the subphase 13 is too large, the rare earth magnet 1 is difficult to densify, and the sintered density tends to decrease. Moreover, since the distribution of M in the grain boundary phase becomes uneven, the residual magnetic flux density Br and the coercive force HcJ tend to decrease.

副相１３の総面積割合は５０μｍ×５０μｍ以上の大きさの測定範囲においてＳＥＭ－ＥＤＳを用いて測定範囲内の全ての副相１３の合計面積を算出し、測定範囲の面積で割ることにより算出する。なお、測定範囲については単独で５０μｍ×５０μｍ以上の大きさの測定範囲となるようにしてもよく、複数の測定範囲の合計が５０μｍ×５０μｍ以上の大きさとなるようにしてもよい。 The total area ratio of the subphases 13 is calculated by calculating the total area of all the subphases 13 within the measurement range using SEM-EDS in a measurement range of 50 μm×50 μm or more and dividing by the area of the measurement range. do. The measurement range may be set to a size of 50 μm×50 μm or more independently, or the total size of a plurality of measurement ranges may be set to a size of 50 μm×50 μm or more.

副相１３の総面積割合を３％以上２５％以下とすることで希土類磁石１が緻密化しやすくなり密度が高くなりやすくなる。そして、Ｒ２Ｔ１７結晶相やＲＴ３結晶相など、Ｒ５Ｔ１７結晶相以外のＲ－Ｔ結晶相の生成が抑制される。その結果、残留磁束密度Ｂｒおよび保磁力ＨｃＪが向上しやすくなる。By setting the total area ratio of the subphase 13 to 3% or more and 25% or less, the rare earth magnet 1 can be easily densified and its density can be easily increased. In addition, the formation of RT crystal phases other than the R 5 T 17 crystal phase, such as the R 2 T 17 crystal phase and the RT 3 crystal phase, is suppressed. As a result, the residual magnetic flux density Br and the coercive force HcJ are likely to be improved.

副相１３の総面積割合が小さすぎる場合には希土類磁石１が緻密化しにくくなり焼結密度が低下しやすくなる。また、Ｒ２Ｔ１７結晶相やＲＴ３相など、Ｒ５Ｔ１７結晶相以外のＲ－Ｔ相の生成が十分に抑制されなくなる。その結果、粒界相の組成が不均一になりやすくなる。さらに、残留磁束密度Ｂｒおよび保磁力ＨｃＪが低下しやすくなる。副相１３の総面積割合が大きすぎる場合には、希土類磁石１における主相１１の総面積割合が小さくなりすぎる。その結果、残留磁束密度Ｂｒが低下しやすくなる。If the total area ratio of the subphase 13 is too small, the rare earth magnet 1 is difficult to densify, and the sintered density tends to decrease. In addition, the formation of RT phases other than the R 5 T 17 crystal phase, such as the R 2 T 17 crystal phase and the RT 3 phase, is not sufficiently suppressed. As a result, the composition of the grain boundary phase tends to be uneven. Furthermore, the residual magnetic flux density Br and the coercive force HcJ tend to decrease. If the total area ratio of the secondary phase 13 is too large, the total area ratio of the main phase 11 in the rare earth magnet 1 becomes too small. As a result, the residual magnetic flux density Br tends to decrease.

本実施形態に係る希土類磁石１は、Ｒ，ＴおよびＭを含む希土類磁石である。ＲはＳｍを必須とする１種以上の希土類元素、ＴはＦｅ単独、またはＦｅおよびＣｏ、ＭはＣｕ，Ｚｎ，Ａｌ，Ｇａ，Ａｇ，Ａｕ，Ｓｉ，ＧｅおよびＳｎからなる群から選択される少なくとも１種である。ＭはＣｕ，Ｚｎ，Ａｌ，Ｇａ，ＡｇおよびＡｕからなる群から選択される少なくとも１種であってもよい。 The rare earth magnet 1 according to this embodiment is a rare earth magnet containing R, T and M. R is one or more rare earth elements essentially including Sm, T is Fe alone or Fe and Co, M is selected from the group consisting of Cu, Zn, Al, Ga, Ag, Au, Si, Ge and Sn At least one. M may be at least one selected from the group consisting of Cu, Zn, Al, Ga, Ag and Au.

希土類磁石１におけるＲの含有割合は任意であるが、１５ａｔ％以上３５ａｔ％以下であってもよく、２４．２ａｔ％以上３０．６ａｔ％以下であることが好ましい。Ｒの含有割合が小さすぎても大きすぎてもＲ５Ｔ１７結晶相が十分に形成されにくくなる。The content ratio of R in the rare earth magnet 1 is arbitrary, but may be 15 at % or more and 35 at % or less, preferably 24.2 at % or more and 30.6 at % or less. If the content of R is too small or too large, the R 5 T 17 crystal phase will not be sufficiently formed.

希土類磁石１におけるＴの含有割合は任意である。また、Ｔ全体に対するＣｏの含有割合は任意であるが、０ａｔ％以上２０ａｔ％以下としてもよい。Ｃｏの含有割合が小さいほど高保磁力となる傾向にある。また、Ｃｏの含有割合が大きいほど高磁束密度となる傾向にある。 The content ratio of T in the rare earth magnet 1 is arbitrary. Moreover, although the content ratio of Co to the entire T is arbitrary, it may be 0 at % or more and 20 at % or less. There is a tendency that the smaller the content of Co, the higher the coercive force. Also, the higher the Co content, the higher the magnetic flux density tends to be.

希土類磁石１におけるＭの含有割合は任意であるが、０．２ａｔ％以上１０ａｔ％以下であってもよく、０．３ａｔ％以上４．２ａｔ％であることが好ましい。希土類磁石１におけるＭの含有割合が小さすぎると副相１３にＲおよびＭを含む化合物（Ｒ－Ｍ相）が十分に形成されにくくなる。そして、後述する副相１３におけるＭの平均含有割合が小さくなりすぎる。Ｍの含有割合が大きすぎると副相１３におけるＭの平均含有割合が大きくなりすぎる。または、副相１３の総面積割合が大きくなりすぎる。 The content of M in the rare earth magnet 1 is arbitrary, but may be 0.2 at % or more and 10 at % or less, and preferably 0.3 at % or more and 4.2 at %. If the content of M in the rare earth magnet 1 is too small, it becomes difficult to sufficiently form a compound containing R and M in the subphase 13 (RM phase). Then, the average content of M in the subphase 13, which will be described later, becomes too small. If the content of M is too high, the average content of M in the subphase 13 will be too high. Alternatively, the total area ratio of the subphase 13 becomes too large.

また、本実施形態に係る希土類磁石１はさらにＣを含んでもよい。そして、希土類磁石１全体に対するＣの含有割合が０ａｔ％超１５ａｔ％以下であることが好ましく、１．０ａｔ％以上７．５ａｔ％以下であることがさらに好ましい。 In addition, the rare earth magnet 1 according to this embodiment may further contain C. The content of C in the entire rare earth magnet 1 is preferably more than 0 at % and 15 at % or less, more preferably 1.0 at % or more and 7.5 at % or less.

本実施形態に係る希土類磁石１はＣを含むことで保磁力ＨｃＪが向上する傾向にある。保磁力ＨｃＪが向上する理由は不明であるが、希土類磁石１がＣを含むことで、副相１３の粒界相にＲおよびＣを含む化合物が形成されやすくなると本発明者らは考えている。以下、ＲおよびＣを含む化合物からなる相をＲ－Ｃリッチ相とする。なお、Ｒ－Ｃリッチ相にはＭおよび／またはＴが含まれていてもよい。そして、Ｒ－Ｃリッチ相が非磁性相であり磁気分離効果が高いため、希土類磁石１の保磁力ＨｃＪが向上すると本発明者らは考えている。 The coercive force HcJ tends to be improved by including C in the rare earth magnet 1 according to the present embodiment. The reason why the coercive force HcJ is improved is unknown, but the present inventors believe that the inclusion of C in the rare earth magnet 1 facilitates the formation of a compound containing R and C in the grain boundary phase of the subphase 13. . A phase composed of a compound containing R and C is hereinafter referred to as an RC rich phase. Note that the RC rich phase may contain M and/or T. The present inventors believe that the coercive force HcJ of the rare earth magnet 1 is improved because the RC rich phase is a non-magnetic phase and has a high magnetic separation effect.

本実施形態に係る希土類磁石１について、Ｒに占めるＳｍの割合は多い方が好ましく、希土類磁石全体におけるＲ全体に対するＳｍの含有割合は５０ａｔ％以上であることが好ましい。 In the rare earth magnet 1 according to the present embodiment, the ratio of Sm to R is preferably large, and the content ratio of Sm to the entire R in the entire rare earth magnet is preferably 50 at % or more.

また、ＲとしてＰｒあるいはＮｄの１つ以上を含有する場合には、ＰｒあるいはＮｄの有効磁気モーメントがＳｍよりも大きいため、残留磁束密度が向上する傾向がある。さらに、ＰｒあるいはＮｄを含有する場合には、副相１３の中でもＲ２Ｔ１７結晶相やＲＴ３結晶相などの低保磁力成分の生成を抑制する効果が得られる。ただし、Ｒに占めるＰｒおよびＮｄの合計含有割合が大きすぎると保磁力ＨｃＪが低下しやすくなる。Moreover, when one or more of Pr and Nd are contained as R, the residual magnetic flux density tends to be improved because the effective magnetic moment of Pr or Nd is larger than that of Sm. Furthermore, when Pr or Nd is contained, the effect of suppressing the formation of low coercive force components such as the R 2 T 17 crystal phase and the RT 3 crystal phase among the subphases 13 can be obtained. However, if the total content of Pr and Nd in R is too large, the coercive force HcJ tends to decrease.

したがって、Ｒ全体に対するＳｍの含有割合が５０ａｔ％以上９９ａｔ％以下であることが好ましく、ＰｒおよびＮｄの合計含有割合が１ａｔ％以上５０ａｔ％以下であることが好ましい。また、ＲとしてＳｍ、ＰｒおよびＮｄ以外の希土類元素を磁気特性に大きな影響を与えない範囲で含有してもよい。Ｓｍ，ＰｒおよびＮｄ以外の希土類元素の含有量は、例えばＲ全体に対して５ａｔ％以下である。 Therefore, it is preferable that the content of Sm with respect to the entire R is 50 at % or more and 99 at % or less, and the total content of Pr and Nd is preferably 1 at % or more and 50 at % or less. In addition, as R, rare earth elements other than Sm, Pr and Nd may be contained within a range that does not significantly affect the magnetic properties. The content of rare earth elements other than Sm, Pr and Nd is, for example, 5 at % or less with respect to the entire R.

本実施形態に係る希土類磁石１においては、上記した元素以外の他の元素を含有してもよい。例えば、Ｂｉ，Ｔｉ，Ｖ，Ｃｒ，Ｍｎ，Ｚｒ，Ｎｄ，Ｍｏ，Ｍｇ等の元素を適宜含有させることができる。また、原料に由来する不純物を含んでもよい。上記した元素以外の他の元素の含有量は任意であるが、希土類磁石１全体に対して例えば３％以下である。 The rare earth magnet 1 according to this embodiment may contain elements other than the elements described above. For example, elements such as Bi, Ti, V, Cr, Mn, Zr, Nd, Mo and Mg can be contained as appropriate. In addition, impurities derived from raw materials may be included. The content of elements other than the elements described above is arbitrary, but is, for example, 3% or less with respect to the entire rare earth magnet 1 .

なお、本実施形態に係る希土類磁石１全体の組成比の分析にはＩＣＰ質量分析法が用いられる。また、必要に応じて酸素気流中燃焼－赤外線吸収法を併用してもよい。 ICP mass spectrometry is used to analyze the composition ratio of the entire rare earth magnet 1 according to this embodiment. In addition, if necessary, combustion in an oxygen stream-infrared absorption method may be used in combination.

以下、本実施形態に係る希土類磁石１の製造方法の好適な例について説明する。 A preferred example of the method for manufacturing the rare earth magnet 1 according to this embodiment will be described below.

希土類磁石１は、鋳造法、ストリップキャスト法、超急冷凝固法、蒸着法、ＨＤＤＲ法、焼結法、熱間加工法などを適宜組み合わせて製造することができるが、超急冷凝固法と焼結法を用いた製造方法の一例について説明する。 The rare earth magnet 1 can be manufactured by appropriately combining a casting method, a strip casting method, an ultra-rapid solidification method, a vapor deposition method, an HDDR method, a sintering method, a hot working method, and the like. An example of the manufacturing method using the method will be described.

超急冷凝固法には、具体的には、単ロール法、双ロール法、遠心急冷法、ガスアトマイズ法等の種類が存在するが、単ロール法を用いることが好ましい。単ロール法では、合金溶湯をノズルから吐出して冷却ロール周面に衝突させることにより、合金溶湯を急速に冷却し、薄帯状または薄片状の急冷合金を得る。単ロール法は、他の超急冷凝固法に比べ、量産性が高く、急冷条件の再現性が良好である。 Specific examples of the ultra-rapid solidification method include a single roll method, a twin roll method, a centrifugal quenching method, a gas atomization method, and the like, and it is preferable to use the single roll method. In the single roll method, the molten alloy is discharged from a nozzle and caused to collide with the peripheral surface of the cooling roll to rapidly cool the molten alloy to obtain a ribbon-like or flake-like quenched alloy. The single roll method has high mass productivity and good reproducibility of quenching conditions compared to other ultra-rapid solidification methods.

原料として、まず、所望の組成比を有する合金インゴットを準備する。原料合金は、Ｒ，ＴおよびＭなどを含む原料金属を不活性ガス、好ましくはＡｒ雰囲気中でアーク溶解等の溶解法により溶解させることで作製することができる。Ｃ、またはその他の元素を適宜含有させたい場合も同様にして含有させることができる。 As a raw material, first, an alloy ingot having a desired composition ratio is prepared. The raw material alloy can be produced by melting a raw material metal containing R, T, M, etc., in an atmosphere of an inert gas, preferably Ar, by a melting method such as arc melting. When C or other elements are desired to be contained as appropriate, they can be contained in the same manner.

上記方法で作製された合金インゴットから、超急冷凝固法により、急冷薄帯を作製する。超急冷凝固法としては、例えば上記の合金インゴットをスタンプミルなどにより小片化して小片を得て、得られた小片をＡｒ雰囲気中で高周波溶解して溶湯を得て、得られた溶湯を高速で回転している冷却ロール上に吐出して急冷凝固させるメルトスピン法を用いることができる。冷却ロールで急冷された溶湯は、薄帯状に急冷凝固された急冷薄帯になる。 A rapidly quenched ribbon is produced from the alloy ingot produced by the above method by a super-rapid solidification method. As the ultra-rapid solidification method, for example, the above alloy ingot is cut into small pieces by a stamp mill or the like to obtain small pieces, the obtained small pieces are melted by high frequency in an Ar atmosphere to obtain molten metal, and the obtained molten metal is melted at high speed. A melt spin method can be used in which the material is discharged onto a rotating chill roll and rapidly solidified. The melt that has been quenched by the cooling rolls becomes a quenched ribbon that has been quenched and solidified into a ribbon shape.

なお、小片化する方法はスタンプミルに限定されない。高周波溶解時の雰囲気はＡｒ雰囲気に限定されない。冷却ロールの回転速度は任意である。例えば１０ｍ／ｓ以上１００ｍ／ｓ以下としてもよい。冷却ロールの材質は任意であり、例えば冷却ロールとして銅ロールを用いてもよい。 In addition, the method of cutting into small pieces is not limited to a stamp mill. The atmosphere during high-frequency melting is not limited to the Ar atmosphere. The rotation speed of the chill roll is arbitrary. For example, it may be 10 m/s or more and 100 m/s or less. Any material may be used for the cooling roll, and for example, a copper roll may be used as the cooling roll.

次に、得られた急冷薄帯を粉砕して粒径数μｍ程度の微粉末を得る。粉砕は粗粉砕および微粉砕の２段階で行ってもよく、微粉砕のみの１段階で行ってもよい。 Next, the obtained quenched ribbon is pulverized to obtain a fine powder having a particle size of about several μm. The pulverization may be performed in two steps of coarse pulverization and fine pulverization, or may be performed in one step of fine pulverization only.

次に、得られた微粉末を所定の形状に成形して成形体を得る。成形時の圧力は任意である。例えば１０ＭＰａ以上１０００ＭＰａ以下である。 Next, the obtained fine powder is molded into a predetermined shape to obtain a compact. The pressure during molding is arbitrary. For example, it is 10 MPa or more and 1000 MPa or less.

次に、得られた成形体を焼結し、同時に結晶化を行うことで希土類磁石１を得ることができる。焼結は通常の焼結方法により行う。通常の焼結方法とは、焼結時に加圧を行わない焼結方法のことであり、一般的にはＳＰＳ法などと比べて高い焼結温度を必要とする。本実施形態に係る希土類磁石１は、焼結中に異相の一部が低融点の液相成分となることで、無加圧で、かつ従来よりも低い焼結温度で焼結することができる。焼結温度（結晶化温度）は具体的には５００℃以上とすることができる。また、７５０℃以下であってもよい。焼結時の雰囲気は任意である。例えばＡｒ雰囲気とすることができる。焼結時間（結晶化時間）は任意である。例えば１０分以上１０時間以下とすることができる。焼結後の冷却速度は任意である。例えば０．０１℃／ｓ以上３０℃／ｓ以下とすることができる。 Next, the obtained compact is sintered and crystallized at the same time to obtain the rare earth magnet 1 . Sintering is performed by a normal sintering method. A normal sintering method is a sintering method that does not apply pressure during sintering, and generally requires a higher sintering temperature than the SPS method or the like. The rare earth magnet 1 according to the present embodiment can be sintered without pressure and at a lower sintering temperature than before because part of the heterogeneous phase becomes a liquid phase component with a low melting point during sintering. . Specifically, the sintering temperature (crystallization temperature) can be 500° C. or higher. Also, the temperature may be 750° C. or lower. The atmosphere during sintering is arbitrary. For example, an Ar atmosphere can be used. The sintering time (crystallization time) is arbitrary. For example, it can be 10 minutes or more and 10 hours or less. The cooling rate after sintering is arbitrary. For example, it can be 0.01° C./s or more and 30° C./s or less.

また、希土類磁石１の異相中のＭの分布を向上させ、均一な粒界相を形成するために、焼結工程後の熱処理が有効である。この熱処理は５００℃以上６５０℃以下の熱処理温度に１０℃／ｓ以上３０℃／ｓ以下の速度で昇温し、次いで１０分間以上３００分間以下、前記熱処理温度にキープされることにより行われる。通常、これらの処理はＡｒ雰囲気で行う。 Further, in order to improve the distribution of M in the different phases of the rare earth magnet 1 and form a uniform grain boundary phase, heat treatment after the sintering process is effective. This heat treatment is carried out by raising the temperature from 500° C. to 650° C. at a rate of from 10° C./s to 30° C./s and then keeping the temperature at the heat treatment temperature for 10 minutes to 300 minutes. These treatments are usually performed in an Ar atmosphere.

また、１合金法を用いる場合にＲ、ＴおよびＭを含む急冷薄帯を粉砕前に結晶化してもよい。この場合の結晶化処理条件は任意である。例えば結晶化温度を５００℃以上７００℃以下、結晶化時間を１分以上５０時間以下、結晶化後の冷却速度を０．０１℃／ｓ以上３０℃／ｓ以下とすることができる。 Also, when using the one-alloy method, the quenched ribbon containing R, T and M may be crystallized before pulverization. Crystallization conditions in this case are arbitrary. For example, the crystallization temperature can be 500° C. or more and 700° C. or less, the crystallization time can be 1 minute or more and 50 hours or less, and the cooling rate after crystallization can be 0.01° C./s or more and 30° C./s or less.

また、上記の結晶化処理を行うことでＲおよびＴからなる合金がＲ５Ｔ１７結晶相の単磁区粒子となっている場合には、磁場中成形を行うことで異方性磁石とすることも可能である。In addition, when the above-described crystallization treatment causes the alloy of R and T to become single magnetic domain grains of the R 5 T 17 crystal phase, an anisotropic magnet can be obtained by performing compacting in a magnetic field. is also possible.

以上、本実施形態に係る希土類磁石１の製造方法の一例について説明したが、希土類磁石１の製造方法は任意である。 An example of the method for manufacturing the rare earth magnet 1 according to the present embodiment has been described above, but the method for manufacturing the rare earth magnet 1 is arbitrary.

例えば、上記の製造方法では１種類の急冷薄帯を用いる１合金法を用いているが、２種類の急冷薄帯を用いる２合金法を用いてもよい。また３種類以上の急冷薄帯を用いてもよい。 For example, in the above manufacturing method, the one-alloy method using one type of quenched ribbon is used, but the two-alloy method using two types of quenched ribbons may be used. Also, three or more types of quenched ribbons may be used.

具体的には、例えばＲおよびＴからなる急冷薄帯、および、ＲおよびＭからなる急冷薄帯を準備する。そして、各急冷薄帯の粉砕中または粉砕後に混合させることができる。２合金法による場合には、前記ＲおよびＴからなる急冷薄帯が主に主相１１となり、前記ＲおよびＭからなる急冷薄帯が主に副相１３となる。主に副相１３となる前記ＲおよびＭからなる急冷薄帯にＴを含有させ、Ｒ、ＴおよびＭからなる急冷薄帯としてもよい。また、Ｒ、ＴおよびＭの含有率が互いに異なる２種類以上の急冷薄帯を用いてもよい。なお、この場合には、全ての急冷薄帯がＲ、ＴおよびＭを全て含有しなくてもよい。全ての急冷薄帯がＲ、ＴおよびＭから選択される１つ以上を含有していればよい。そして、各急冷薄帯の混合比を制御することによっても副相１３の総面積割合などを制御することができる。少量であれば、急冷薄帯の代わりに単体の金属からなる粉末を用いてもよい。 Specifically, for example, a quenched ribbon made of R and T and a quenched ribbon made of R and M are prepared. Then, they can be mixed during or after pulverization of each quenched ribbon. In the two-alloy method, the quenched ribbon composed of R and T mainly becomes the main phase 11 , and the quenched ribbon composed of R and M mainly becomes the subphase 13 . The quenched ribbon composed of R and M as the main subphase 13 may contain T to form a quenched ribbon composed of R, T and M. Also, two or more types of quenched ribbons having different contents of R, T and M may be used. In this case, all the quenched ribbons may not contain all of R, T and M. All the quenched ribbons should contain one or more selected from R, T and M. The total area ratio of the subphase 13 can also be controlled by controlling the mixing ratio of each quenched ribbon. If the amount is small, a single metal powder may be used instead of the quenched ribbon.

また、２合金法を用いる場合には、ＲおよびＴからなる急冷薄帯のみを粉砕前に結晶化処理してもよい。特に、Ｒ：Ｔが５：１７に近い急冷薄帯を結晶化処理することでＲ５Ｔ１７結晶相を安定的に生成させることができる。この場合の結晶化処理条件は任意である。例えば結晶化温度を５００℃以上７００℃以下、結晶化時間を１分以上５０時間以下、結晶化後の冷却速度を０．０１℃／ｓ以上３０℃／ｓ以下とすることができる。なお、ＲおよびＴからなる急冷薄帯を２種類以上用いる場合には、Ｒ：Ｔが５：１７に近い急冷薄帯のみを結晶化処理してもよい。In the case of using the two-alloy method, only the quenched ribbon made of R and T may be crystallized before pulverization. In particular, the R 5 T 17 crystal phase can be stably generated by subjecting the quenched ribbon with R:T close to 5:17 to the crystallization treatment. Crystallization conditions in this case are arbitrary. For example, the crystallization temperature can be 500° C. or more and 700° C. or less, the crystallization time can be 1 minute or more and 50 hours or less, and the cooling rate after crystallization can be 0.01° C./s or more and 30° C./s or less. When two or more kinds of quenched ribbons composed of R and T are used, only the quenched ribbons having an R:T ratio of close to 5:17 may be crystallized.

また、上記の結晶化処理を行うことでＲおよびＴからなる合金がＲ５Ｔ１７結晶相の単磁区粒子となっている場合には、磁場中成形を行うことで異方性磁石とすることも可能である。In addition, when the above-described crystallization treatment causes the alloy of R and T to become single magnetic domain grains of the R 5 T 17 crystal phase, an anisotropic magnet can be obtained by performing compacting in a magnetic field. is also possible.

以下、本発明の内容を実施例及び比較例を用いて詳細に説明するが、本発明は以下の実施例に限定されるものではない。 EXAMPLES The content of the present invention will be described in detail below using examples and comparative examples, but the present invention is not limited to the following examples.

（実験例１）
まず、Ｓｍ，Ｐｒ，Ｎｄ，Ｆｅ，Ｃｕ，Ｚｎ，Ａｌ，Ｇａ，Ａｇ，Ａｕ，Ｓｉ，Ｇｅ，Ｓｎおよび／またはＣの単体または合金からなる原料を準備した。得られる磁石が下表１の組成となるように各原料を配合し、Ａｒ雰囲気中、アーク溶解することで合金インゴットを作製した。次にスタンプミルを用いて当該合金インゴットを小片化して小片を得た。次に当該小片を５０ｋＰａのＡｒ雰囲気で高周波溶解して溶湯を得た。次に当該溶湯から単ロール法にて急冷薄帯を得た。具体的には、当該溶湯を周速５０ｍ／ｓで回転させた冷却ロール（銅ロール）に吐出して急冷薄帯を得た。次に当該急冷薄帯を粗粉砕および微粉砕して平均粒径５μｍ程度の微粉末を得た。粗粉砕はスタンプミルで、微粉砕はジェットミルで行った。次に当該微粉末を無磁場、１００ＭＰａで１０ｍｍ×１５ｍｍ×１２ｍｍの直方体形状に成形した後に、昇温速度５℃／ｍｉｎ、焼結保持温度７００℃もしくは７２５℃、焼結保持時間１時間で結晶化および焼結した後、室温まで急冷した。冷却後の試料は、昇温速度２０℃／ｓ、熱処理温度５５０℃、熱処理保持時間３０分間の熱処理をおこない、希土類磁石とした。また、得られた焼結体の組成が表１に示す組成であることをＩＣＰ質量分析法および必要に応じて酸素気流中燃焼－赤外線吸収法を併用して確認した。具体的には、酸素気流中燃焼－赤外線吸収法はＣ量の測定に用いた。(Experimental example 1)
First, raw materials consisting of Sm, Pr, Nd, Fe, Cu, Zn, Al, Ga, Ag, Au, Si, Ge, Sn and/or C or alloys thereof were prepared. Each raw material was blended so that the resulting magnet would have the composition shown in Table 1 below, and an alloy ingot was produced by arc melting in an Ar atmosphere. A stamp mill was then used to cut the alloy ingot into small pieces. Next, the small piece was melted by high frequency in an Ar atmosphere of 50 kPa to obtain a molten metal. Next, a quenched ribbon was obtained from the molten metal by a single roll method. Specifically, the molten metal was discharged onto a cooling roll (copper roll) rotated at a peripheral speed of 50 m/s to obtain a quenched ribbon. Next, the quenched ribbon was coarsely pulverized and finely pulverized to obtain a fine powder having an average particle size of about 5 μm. Coarse pulverization was performed with a stamp mill, and fine pulverization was performed with a jet mill. Next, after molding the fine powder into a rectangular parallelepiped shape of 10 mm × 15 mm × 12 mm at 100 MPa without a magnetic field, the temperature rise rate is 5 ° C./min, the sintering temperature is 700 ° C. or 725 ° C., and the sintering time is 1 hour. After hardening and sintering, it was quenched to room temperature. After cooling, the sample was subjected to heat treatment at a heating rate of 20° C./s, a heat treatment temperature of 550° C., and a heat treatment holding time of 30 minutes to obtain a rare earth magnet. In addition, it was confirmed that the composition of the obtained sintered body had the composition shown in Table 1 using ICP mass spectrometry and, if necessary, combustion in an oxygen stream-infrared absorption method. Specifically, the combustion in an oxygen stream-infrared absorption method was used to measure the C content.

次に、得られた各試料の主相および副相を区別し、各相の組成を分析した。具体的には、得られた各試料を切断して得られた断面をイオンミリングにより鏡面加工し、走査電子顕微鏡（ＳＥＭ）を用いて反射電子像を観察した。なお、ＳＥＭは、エネルギー分散型Ｘ線分光器（ＥＤＳ）を備えたものを用いた。反射電子像のコントラストから各領域が主相であるか副相であるかが概ね判断できる。次に、反射電子像の画像から主相および副相を含む５０μｍ×５０μｍの観察領域を決定し、ＥＤＳを用いて元素マッピングを行った。元素マッピングのデータから、ＲとＴの比率が概ね５：１７である相を主相、空孔を除くそれ以外の領域を副相と判断した。最終的には、反射電子像のコントラストおよび元素マッピングのデータを併用して主相および副相を特定した。次に、副相部分の元素マッピングデータから副相の平均組成を特定し、副相中のＭの平均含有割合（ａｔ％）を特定した。また、１００×（副相の合計面積）／（観察領域の面積－空孔の面積）から副相の総面積割合（％）を特定した。上記の作業を４つの５０μｍ×５０μｍの観察領域について行い、その平均値を各試料における副相中のＭの平均含有割合、および副相の総面積割合とした。 Next, the main phase and subphase of each obtained sample were distinguished, and the composition of each phase was analyzed. Specifically, a cross section obtained by cutting each obtained sample was mirror-finished by ion milling, and a backscattered electron image was observed using a scanning electron microscope (SEM). The SEM used was equipped with an energy dispersive X-ray spectroscope (EDS). From the contrast of the backscattered electron image, it can be roughly determined whether each region is the main phase or the subphase. Next, an observation area of 50 μm×50 μm containing the main phase and the subphase was determined from the backscattered electron image, and elemental mapping was performed using EDS. From the elemental mapping data, it was determined that the phase in which the ratio of R and T was approximately 5:17 was the main phase, and the region other than the vacancies was the subphase. Finally, the main and subphases were identified using both the contrast of the backscattered electron image and the elemental mapping data. Next, the average composition of the subphase was specified from the elemental mapping data of the subphase portion, and the average content ratio (at %) of M in the subphase was specified. In addition, the total area ratio (%) of the subphases was determined from 100×(total area of subphases)/(area of observation region−area of pores). The above operation was performed on four observation areas of 50 μm×50 μm, and the average value was taken as the average content ratio of M in the subphase and the total area ratio of the subphase in each sample.

また、全ての実施例および比較例がＮｄ５Ｆｅ１７型結晶構造を有することについてＸＲＤを用いて確認した。そして、全ての実施例および比較例の試料についてＩＣＰ質量分析法および必要に応じて酸素気流中燃焼－赤外線吸収法を併用して表１に示す組成となっていることを確認した。Moreover, it was confirmed using XRD that all the examples and comparative examples had a Nd 5 Fe 17 -type crystal structure. All the samples of Examples and Comparative Examples were confirmed to have the compositions shown in Table 1 using ICP mass spectrometry and, if necessary, combustion in an oxygen stream-infrared absorption method.

試料の磁気特性は、パルス励磁型Ｂ－Ｈカーブトレーサを用いて測定した。本実施例では残留磁束密度Ｂｒが３．５ｋＧである場合を良好とした。また、保磁力ＨｃＪが３０ｋＯｅ以上である場合を良好とした。 The magnetic properties of the samples were measured using a pulse excitation BH curve tracer. In this example, the case where the residual magnetic flux density Br was 3.5 kG was regarded as good. Also, the case where the coercive force HcJ was 30 kOe or more was evaluated as good.

試料の相対密度（％）は、１００×（各試料の寸法および質量を実際に測定して得られた寸法密度）／（Ｓｍ５Ｆｅ１７結晶相の理論密度）により得た。なお、本実験例ではＳｍ５Ｆｅ１７結晶相の理論密度は文献値である７．９２２ｇ／ｃｍ３とした。試料の相対密度が８０％以上である場合を焼結密度が良好であるとした。The relative density (%) of the sample was obtained by 100×(the dimensional density obtained by actually measuring the size and mass of each sample)/(theoretical density of the Sm 5 Fe 17 crystal phase). In this experimental example, the theoretical density of the Sm 5 Fe 17 crystal phase was set to 7.922 g/cm 3 , which is a literature value. A sample with a relative density of 80% or more was considered to have a good sintered density.

Figure 0007140185000001
Figure 0007140185000001

表１より、副相の総面積割合が３～２５％であり、副相中のＭの平均含有割合が５～３０ａｔ％である各実施例は相対密度が高く、磁気特性も優れていた。これに対し、Ｍを含まず、副相の総面積割合が低かった比較例１は相対密度が低く、磁気特性も低下した。 From Table 1, each example in which the total area ratio of the subphases was 3 to 25% and the average content ratio of M in the subphases was 5 to 30 at% had high relative densities and excellent magnetic properties. On the other hand, Comparative Example 1, which did not contain M and had a low total area ratio of subphases, had a low relative density and poor magnetic properties.

（実験例２）
実験例２では、１種類の急冷薄帯を作製した実験例１とは異なり、下表２に示す組成からなる２種類の急冷薄帯を作製した。具体的には、ＲおよびＴを含有する急冷薄帯１、および、ＲおよびＭを含有する急冷薄帯２を作成した。急冷薄帯を作製するまでの製造方法は実験例１と同様である。(Experimental example 2)
In Experimental Example 2, unlike Experimental Example 1 in which one type of quenched ribbon was produced, two types of quenched ribbons having the compositions shown in Table 2 below were produced. Specifically, a quenched ribbon 1 containing R and T and a quenched ribbon 2 containing R and M were prepared. The production method up to the production of the quenched ribbon is the same as in Experimental Example 1.

次に、急冷薄帯１に対して結晶化処理を行った。具体的には、Ａｒ雰囲気中、昇温速度２０℃／ｍｉｎで６５０℃まで加熱し、６５０℃で３０時間保持した後に室温まで急冷した。 Next, the quenched ribbon 1 was subjected to a crystallization treatment. Specifically, it was heated to 650° C. in an Ar atmosphere at a heating rate of 20° C./min, held at 650° C. for 30 hours, and then rapidly cooled to room temperature.

次に、各急冷薄帯に対してスタンプミルを用いて粗粉砕を行い、各急冷薄帯の粗粉末を得た。そして、ジェットミルを用いて、各粗粉末を下表２に示す合金混合比率（重量比）で混合しつつ微粉砕を行い、微粉末を得た。 Next, each quenched ribbon was coarsely pulverized using a stamp mill to obtain a coarse powder of each quenched ribbon. Then, using a jet mill, each coarse powder was mixed at the alloy mixing ratio (weight ratio) shown in Table 2 below and pulverized to obtain a fine powder.

以後、実験例１と同様にして各試料の磁石を得て実験例１と同様にして評価した。結果を表２に示す。また、得られた焼結体の組成が表２に示す組成であることをＩＣＰ質量分析法にて確認した。 Thereafter, magnets of each sample were obtained in the same manner as in Experimental Example 1 and evaluated in the same manner as in Experimental Example 1. Table 2 shows the results. Also, it was confirmed by ICP mass spectrometry that the composition of the obtained sintered body had the composition shown in Table 2.

Figure 0007140185000002
Figure 0007140185000002

表２より、副相の総面積割合が３～２５％であり、副相中のＭの平均含有割合が５～３０ａｔ％である各実施例は相対密度が高く、磁気特性も優れていた。これに対し、副相中のＭの平均含有割合が小さすぎる比較例２は相対密度が低下し、残留磁束密度Ｂｒが低下した。副相中のＭの平均含有割合が大きすぎる比較例３は残留磁束密度Ｂｒおよび保磁力ＨｃＪが低下した。副相の総面積割合が大きすぎる比較例４は残留磁束密度Ｂｒが低下した。 From Table 2, each example in which the total area ratio of the subphases was 3 to 25% and the average content ratio of M in the subphases was 5 to 30 at% had high relative densities and excellent magnetic properties. On the other hand, in Comparative Example 2, in which the average content of M in the subphase was too small, the relative density decreased and the residual magnetic flux density Br decreased. In Comparative Example 3, in which the average content of M in the subphase was too large, the residual magnetic flux density Br and the coercive force HcJ were lowered. Comparative Example 4, in which the total area ratio of the subphases was too large, had a low residual magnetic flux density Br.

（実験例３）
実験例３の実施例２３、２４では、下表３に示す組成からなる３種類の急冷薄帯を作製した。具体的には、ＲおよびＴを含有する急冷薄帯１と、ＲおよびＴを含有するが急冷薄帯１とは組成が異なる急冷薄帯２と、ＭおよびＲまたはＴを含有する急冷薄帯３とを作成した。急冷薄帯を作製するまでの製造方法は実験例１と同様である。なお、実験例３の実施例２５では、急冷薄帯１および急冷薄帯２は実施例２３、２４と同様であるが、急冷薄帯３を用いず、代わりにＺｎ単体の微粉末を用いた。(Experimental example 3)
In Examples 23 and 24 of Experimental Example 3, three types of quenched ribbons having compositions shown in Table 3 below were produced. Specifically, a quenched ribbon 1 containing R and T, a quenched ribbon 2 containing R and T but having a composition different from that of the quenched ribbon 1, and a quenched ribbon containing M and R or T 3 was created. The production method up to the production of the quenched ribbon is the same as in Experimental Example 1. In Example 25 of Experimental Example 3, the quenched ribbon 1 and the quenched ribbon 2 were the same as those in Examples 23 and 24, but the quenched ribbon 3 was not used, and instead fine powder of Zn alone was used. .

次に、急冷薄帯１に対して結晶化処理を行った。具体的には、Ａｒ雰囲気中、昇温速度２０℃／ｍｉｎで６５０℃まで加熱し、６５０℃で３０時間保持した後に室温まで急冷した。 Next, the quenched ribbon 1 was subjected to a crystallization treatment. Specifically, it was heated to 650° C. in an Ar atmosphere at a heating rate of 20° C./min, held at 650° C. for 30 hours, and then rapidly cooled to room temperature.

次に、各急冷薄帯に対してスタンプミルを用いて粗粉砕を行い、各急冷薄帯の粗粉末を得た。そして、ジェットミルを用いて、各粗粉末（実施例２５では各粗粉末およびＺｎ単体の微粉末）を下表３に示す合金混合比率（重量比）で混合しつつ微粉砕を行い、微粉末を得た。 Next, each quenched ribbon was coarsely pulverized using a stamp mill to obtain a coarse powder of each quenched ribbon. Then, using a jet mill, each coarse powder (in Example 25, each coarse powder and a fine powder of Zn alone) was mixed and finely pulverized while being mixed at the alloy mixing ratio (weight ratio) shown in Table 3 below. got

以後、実験例１と同様にして各試料の磁石を得て実験例１と同様にして評価した。結果を表３に示す。また、得られた焼結体の組成が表３に示す組成であることをＩＣＰ質量分析法にて確認した。 Thereafter, magnets of each sample were obtained in the same manner as in Experimental Example 1 and evaluated in the same manner as in Experimental Example 1. Table 3 shows the results. Also, it was confirmed by ICP mass spectrometry that the composition of the obtained sintered body had the composition shown in Table 3.

Figure 0007140185000003
Figure 0007140185000003

表３より、副相の総面積割合が３～２５％であり、副相中のＭの平均含有割合が５～３０ａｔ％である各実施例は相対密度が高く、磁気特性も優れていた。 From Table 3, each example in which the total area ratio of the subphases was 3 to 25% and the average content ratio of M in the subphases was 5 to 30 at% had high relative densities and excellent magnetic properties.

１・・・希土類磁石
１１・・・主相
１３・・・副相



DESCRIPTION OF SYMBOLS 1... Rare-earth magnet 11... Main phase 13... Sub-phase

Claims (3)

Ｒ，ＴおよびＭを含む希土類磁石であって、
ＲはＳｍを必須とする１種以上の希土類元素、ＴはＦｅ単独またはＦｅおよびＣｏ、ＭはＣｕ，Ｚｎ，Ａｌ，Ｇａ，Ａｇ，Ａｕ，Ｓｉ，ＧｅおよびＳｎからなる群から選択される少なくとも１種であり、
Ｎｄ５Ｆｅ１７型結晶構造を有する結晶粒子からなる主相、および、前記主相以外の相である副相からなり、
前記副相の少なくとも一部がＭを含み、
前記副相におけるＭの平均含有割合が５ａｔ％以上３０ａｔ％以下であり、
前記希土類磁石の任意の切断面における前記副相の総面積割合が３％以上２５％以下であることを特徴とする希土類磁石。A rare earth magnet comprising R, T and M,
R is one or more rare earth elements essentially including Sm, T is Fe alone or Fe and Co, M is at least selected from the group consisting of Cu, Zn, Al, Ga, Ag, Au, Si, Ge and Sn is one type,
Consists of a main phase composed of crystal grains having a Nd 5 Fe 17 -type crystal structure, and a subphase that is a phase other than the main phase,
at least a portion of said subphase comprises M;
The average content of M in the subphase is 5 at% or more and 30 at% or less,
A rare earth magnet, wherein the total area ratio of the subphases in any cross section of the rare earth magnet is 3% or more and 25% or less. さらにＣを含み、前記希土類磁石全体に対するＣの含有割合が０ａｔ％超１５ａｔ％以下である請求項１に記載の希土類磁石。 2. The rare earth magnet according to claim 1, further comprising C, wherein the content of C is more than 0 at % and not more than 15 at % with respect to the entire rare earth magnet. ＲとしてさらにＰｒおよび／またはＮｄを含み、
Ｒ全体に対するＳｍの含有割合が５０ａｔ％以上９９ａｔ％以下であり、ＰｒおよびＮｄの合計含有割合が１ａｔ％以上５０ａｔ％以下である請求項１または２に記載の希土類磁石。Further containing Pr and/or Nd as R,
3. The rare earth magnet according to claim 1, wherein the content of Sm with respect to the entire R is 50 at % or more and 99 at % or less, and the total content of Pr and Nd is 1 at % or more and 50 at % or less.
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Citations (3)

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Publication number Priority date Publication date Assignee Title
JP2016178213A (en) 2015-03-20 2016-10-06 Tdk株式会社 Permanent magnet
WO2018101410A1 (en) 2016-11-30 2018-06-07 Tdk株式会社 Rare earth permanent magnet
JP2019160946A (en) 2018-03-09 2019-09-19 Tdk株式会社 Rare earth permanent magnet

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016178213A (en) 2015-03-20 2016-10-06 Tdk株式会社 Permanent magnet
WO2018101410A1 (en) 2016-11-30 2018-06-07 Tdk株式会社 Rare earth permanent magnet
JP2019160946A (en) 2018-03-09 2019-09-19 Tdk株式会社 Rare earth permanent magnet

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