JP7045905B2 - Soft magnetic powder and its manufacturing method - Google Patents

Soft magnetic powder and its manufacturing method Download PDF

Info

Publication number
JP7045905B2
JP7045905B2 JP2018069400A JP2018069400A JP7045905B2 JP 7045905 B2 JP7045905 B2 JP 7045905B2 JP 2018069400 A JP2018069400 A JP 2018069400A JP 2018069400 A JP2018069400 A JP 2018069400A JP 7045905 B2 JP7045905 B2 JP 7045905B2
Authority
JP
Japan
Prior art keywords
soft magnetic
mass
less
alloy particles
magnetic alloy
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.)
Active
Application number
JP2018069400A
Other languages
Japanese (ja)
Other versions
JP2019178402A (en
Inventor
亮介 越智
俊之 澤田
哲嗣 久世
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sanyo Special Steel Co Ltd
Original Assignee
Sanyo Special Steel Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sanyo Special Steel Co Ltd filed Critical Sanyo Special Steel Co Ltd
Priority to JP2018069400A priority Critical patent/JP7045905B2/en
Publication of JP2019178402A publication Critical patent/JP2019178402A/en
Application granted granted Critical
Publication of JP7045905B2 publication Critical patent/JP7045905B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Description

本発明は、軟磁性粉末に関する。 The present invention relates to soft magnetic powder.

従来、絶縁被膜で被覆された軟磁性金属粒子からなる軟磁性粉末を成形して得られる軟磁性体が知られている。このような軟磁性体としては、磁性シートや、磁心や、回転機、ソレノイド、リアクトル、チョークコイル、及びインダクタのコアなどの各種電磁気回路部品が例示される。特許文献1,2では、上記のような軟磁性体が、特許文献3では、上記のような軟磁性体の材料となる軟磁性粉末が、それぞれ開示されている。 Conventionally, a soft magnetic material obtained by molding a soft magnetic powder made of soft magnetic metal particles coated with an insulating film is known. Examples of such soft magnetic materials include magnetic sheets, magnetic cores, rotating machines, solenoids, reactors, choke coils, and various electromagnetic circuit components such as inductor cores. Patent Documents 1 and 2 disclose a soft magnetic material as described above, and Patent Document 3 discloses a soft magnetic powder as a material for the soft magnetic material as described above.

特許文献1の圧粉磁心(軟磁性体)は、酸化アルミニウムを主材とした絶縁被膜が形成されたFe-Si-Al系の軟磁性粒子からなる圧粉磁心用粉末を、成形したものである。この絶縁被膜の厚さは、150nm~2μmである。また、圧粉磁心用粉末の平均粒径は、20μm~450μmである。 The dust core (soft magnetic material) of Patent Document 1 is obtained by molding a powder for a powder magnetic core made of Fe—Si—Al-based soft magnetic particles having an insulating film made of aluminum oxide as a main material. be. The thickness of this insulating coating is 150 nm to 2 μm. The average particle size of the dust core powder is 20 μm to 450 μm.

特許文献2の軟磁性体は、鉄系酸化物からなる被膜で被覆された軟磁性金属粒子からなる粉末を、成形したものである。鉄系酸化物からなる被膜で被覆された軟磁性金属粒子は、軟磁性金属粒子を覆う鉄含有層と、軟磁性金属粒子と鉄含有層との間に形成された高抵抗層とを有する。被膜の厚さは、0.1μm~10μmである。 The soft magnetic material of Patent Document 2 is formed by molding a powder made of soft magnetic metal particles coated with a film made of an iron-based oxide. The soft magnetic metal particles coated with a film made of an iron-based oxide have an iron-containing layer covering the soft magnetic metal particles and a high resistance layer formed between the soft magnetic metal particles and the iron-containing layer. The thickness of the coating is 0.1 μm to 10 μm.

特許文献3の軟磁性粉末は、軟磁性粉末の表面が、Mg及びSiを含有する酸化物で被覆されたものである。このMi及びSi含有酸化物被覆軟磁性粉末は、酸化物被膜軟磁性体粉末に一酸化ケイ素の粉末を添加して加熱し、更に、マグネシウム粉末を添加し加熱することによって得たものである。 In the soft magnetic powder of Patent Document 3, the surface of the soft magnetic powder is coated with an oxide containing Mg and Si. The Mi and Si-containing oxide-coated soft magnetic powder was obtained by adding silicon monoxide powder to the oxide-coated soft magnetic powder and heating it, and then adding magnesium powder and heating it.

特開2016-4813号公報Japanese Unexamined Patent Publication No. 2016-4813 特開2014-60183号公報Japanese Unexamined Patent Publication No. 2014-60183 特開2007-13069号公報JP-A-2007-13069

上記のような軟磁性体のうち、磁性シートは、軟磁性粉末をポリマー材料に混練して、それをシート状に成形したものである。磁性シートは、磁力線を効率よく吸収させるために、高い透磁率が要求される。加えて、磁性シートは、磁気損失を低減するために、高い電気抵抗値(絶縁性)が要求される。ところが、一般に、軟磁性粉末の酸化物層の被膜が薄くなるに従って当該軟磁性粉末からなる軟磁性体の絶縁性が低くなる傾向があり、逆に、軟磁性粉末の酸化物層の被膜が厚くなるに従って当該軟磁性粉末からなる軟磁性体の透磁率が低くなる傾向がある。 Among the soft magnetic materials as described above, the magnetic sheet is obtained by kneading the soft magnetic powder with a polymer material and molding it into a sheet shape. The magnetic sheet is required to have a high magnetic permeability in order to efficiently absorb the magnetic field lines. In addition, the magnetic sheet is required to have a high electric resistance value (insulation property) in order to reduce the magnetic loss. However, in general, as the coating of the oxide layer of the soft magnetic powder becomes thinner, the insulating property of the soft magnetic material made of the soft magnetic powder tends to decrease, and conversely, the coating of the oxide layer of the soft magnetic powder becomes thicker. As a result, the magnetic permeability of the soft magnetic material made of the soft magnetic powder tends to decrease.

特許文献1及び特許文献2の軟磁性粉末は、酸化被膜が0.1μm以上と比較的厚いことから保磁力が高いことが予想される。特許文献3の軟磁性粉末は、特許文献1及び特許文献2の軟磁性粉末の製造工程と比較して工程数が多く、加えて、絶縁層に起因して保磁力が高いことが予想される。保磁力の高い軟磁性粉末からなる軟磁性体では、要求される高透磁率が得られないことがある。このように、特許文献1~3の軟磁性粉末では、高絶縁性と高透磁率とを併せ備えた軟磁性体を得ることが難しい。 The soft magnetic powders of Patent Document 1 and Patent Document 2 are expected to have a high coercive force because the oxide film is relatively thick at 0.1 μm or more. The soft magnetic powder of Patent Document 3 has a large number of steps as compared with the manufacturing steps of the soft magnetic powder of Patent Document 1 and Patent Document 2, and in addition, it is expected that the coercive force is high due to the insulating layer. .. A soft magnetic material made of a soft magnetic powder having a high coercive force may not obtain the required high magnetic permeability. As described above, it is difficult to obtain a soft magnetic material having both high insulation and high magnetic permeability with the soft magnetic powders of Patent Documents 1 to 3.

本発明は以上の事情に鑑みてされたものであり、その目的は、高絶縁性と高透磁率とを併せ備えた軟磁性体の材料となりうる軟磁性粉末を提案することにある。 The present invention has been made in view of the above circumstances, and an object of the present invention is to propose a soft magnetic powder which can be a material of a soft magnetic material having both high insulation and high magnetic permeability.

本発明の一態様に係る軟磁性粉末は、
酸化被膜が形成されたFe(鉄)-Si(ケイ素)-Al(アルミニウム)系軟磁性合金粒子からなり、
前記軟磁性合金粒子の平均粒径が10μm以上100μm以下であり、
前記酸化被膜は、10質量%以上30質量%以下のO(酸素),5質量%以上20質量%以下のSi(ケイ素),5質量%以上30質量%以下のAl(アルミニウム),残部Fe(鉄)及び不可避的不純物からなり、平均厚さが5nm以上40nm以下であることを特徴としている。なお、平均粒径は、メジアン径(D50)である。
The soft magnetic powder according to one aspect of the present invention is
It is composed of Fe (iron) -Si (silicon) -Al (aluminum) -based soft magnetic alloy particles on which an oxide film is formed.
The average particle size of the soft magnetic alloy particles is 10 μm or more and 100 μm or less.
The oxide film is O (oxygen) of 10% by mass or more and 30% by mass or less, Si (silicon) of 5% by mass or more and 20% by mass or less, Al (aluminum) of 5% by mass or more and 30% by mass or less, and the balance Fe ( It is composed of iron) and unavoidable impurities, and is characterized by having an average thickness of 5 nm or more and 40 nm or less. The average particle size is the median diameter (D50).

上記軟磁性粉末は、保磁力が50A/m以下であってよい。 The soft magnetic powder may have a coercive force of 50 A / m or less.

上記軟磁性粉末は、軟磁性合金粒子の平均粒径、酸化被膜の厚さ、及び酸化被膜の組成の組み合わせにより、高い電気抵抗(絶縁性)と低い保磁力とを併せ備える。その結果、この軟磁性粉末が成形されてなる軟磁性体は高絶縁性と高透磁率とを併せ備えることとなる。 The soft magnetic powder has both high electrical resistance (insulation property) and low coercive force depending on the combination of the average particle size of the soft magnetic alloy particles, the thickness of the oxide film, and the composition of the oxide film. As a result, the soft magnetic material obtained by molding this soft magnetic powder has both high insulation and high magnetic permeability.

本発明によれば、高絶縁性と高透磁率とを併せ備えた軟磁性体の材料となりうる軟磁性粉末を提供することができる。 According to the present invention, it is possible to provide a soft magnetic powder that can be used as a material for a soft magnetic material having both high insulation and high magnetic permeability.

以下、本発明の実施の形態を説明する。本実施形態に係る軟磁性粉末は、軟磁性合金粒子の表面に酸化被膜が形成されてなる被膜粒子の集合体である。この軟磁性粉末は、軟磁性合金粒子の平均粒径、酸化被膜の厚さ、及び酸化被膜の組成の組み合わせに特徴を有する。 Hereinafter, embodiments of the present invention will be described. The soft magnetic powder according to the present embodiment is an aggregate of coated particles in which an oxide film is formed on the surface of the soft magnetic alloy particles. This soft magnetic powder is characterized by a combination of the average particle size of the soft magnetic alloy particles, the thickness of the oxide film, and the composition of the oxide film.

軟磁性粉末の保磁力(Hc)は、50A/m以下であり、より好ましくは30A/m以下である。また、軟磁性粉末の充填体の体積抵抗率(ρ)は10Ω・cm以上が望ましい。 The coercive force (Hc) of the soft magnetic powder is 50 A / m or less, more preferably 30 A / m or less. Further, it is desirable that the volume resistivity (ρ) of the filler of the soft magnetic powder is 10 Ω · cm or more.

軟磁性合金粒子は、保磁力の値が低く、且つ、飽和磁化の値が高い粉末であることが好ましい。そこで、軟磁性合金粒子として、Fe(鉄)-Si(シリコン)-Al(アルミニウム)系軟磁性合金の球状粒子が採用される。一般に、Fe-Si-Al系合金は、保磁力の値及び飽和磁化の値に優れる。 The soft magnetic alloy particles are preferably powders having a low coercive force value and a high saturation magnetization value. Therefore, as the soft magnetic alloy particles, spherical particles of Fe (iron) -Si (silicon) -Al (aluminum) based soft magnetic alloy are adopted. In general, Fe—Si—Al alloys are excellent in coercive force value and saturation magnetization value.

軟磁性合金粒子の平均粒径(D50)は、酸化被膜で被覆されていない状態で、10μm以上100μm以下であり、15μm以上50μm以下であることが好ましく、20μm以上30μm以下であることが更に好ましい。 The average particle size (D50) of the soft magnetic alloy particles is preferably 10 μm or more and 100 μm or less, preferably 15 μm or more and 50 μm or less, and more preferably 20 μm or more and 30 μm or less in a state where the soft magnetic alloy particles are not coated with the oxide film. ..

軟磁性合金粒子の平均粒径が10μm未満では、軟磁性合金粒子に対する酸化被膜の体積率が過度に大きくなり、軟磁性粉末の保磁力が前述の保磁力範囲より高くなる。また、軟磁性合金粒子の平均粒径が100μmを超えて大きくなると、軟磁性合金粒子に対する酸化被膜の体積率が過度に小さくなり、十分な体積抵抗率が得られない。 When the average particle size of the soft magnetic alloy particles is less than 10 μm, the volume ratio of the oxide film with respect to the soft magnetic alloy particles becomes excessively large, and the coercive force of the soft magnetic powder becomes higher than the above-mentioned coercive force range. Further, when the average particle size of the soft magnetic alloy particles becomes larger than 100 μm, the volume ratio of the oxide film with respect to the soft magnetic alloy particles becomes excessively small, and a sufficient volume resistance cannot be obtained.

酸化被膜は、酸化被膜全体を100質量%として、10質量%以上30質量%以下のO(酸素),5質量%以上20質量%以下のSi(ケイ素),5質量%以上30質量%以下のAl(アルミニウム),残部Fe(鉄)及び不可避的不純物からなる。酸化被膜は、Fe-Si-Al系軟磁性合金粒子を大気雰囲気下で酸化させることにより、当該軟磁性合金粒子の表面に形成されたものであってよい。この場合、軟磁性合金粒子中のSi成分及びAl成分が表面に拡散して大気中の酸素と反応することにより、上記組成の酸化被膜が形成される。酸化被膜形成能は、Al>Si>Feの順に高いため、軟磁性合金粒子から被膜への拡散はAl成分が最も大きくなる傾向にある。 The oxide film is O (oxygen) of 10% by mass or more and 30% by mass or less, Si (silicon) of 5% by mass or more and 20% by mass or less, and 5% by mass or more and 30% by mass or less, assuming that the entire oxide film is 100% by mass. It consists of Al (aluminum), the balance Fe (iron) and unavoidable impurities. The oxide film may be formed on the surface of the soft magnetic alloy particles by oxidizing Fe—Si—Al-based soft magnetic alloy particles in an atmospheric atmosphere. In this case, the Si component and the Al component in the soft magnetic alloy particles diffuse to the surface and react with oxygen in the atmosphere to form an oxide film having the above composition. Since the oxide film forming ability increases in the order of Al> Si> Fe, the Al component tends to be the largest in the diffusion from the soft magnetic alloy particles to the film.

酸化被膜中のSi成分が5質量%未満、Al成分が5質量%未満、及び、O成分が10質量%未満のうち少なくとも1つが成立する場合には、酸化被膜の組成が純Feに近づいてしまい、酸化被膜が十分な絶縁性を備えない。一方、酸化被膜中のSi成分が20質量%を超える、Al成分が30質量%を超える、及び、O成分が30質量%を超えるのうち少なくとも1つが成立する場合には、軟磁性合金粒子の組成のセンダスト組成からのずれが大きくなることにより、軟磁性粉末の保磁力が前述の保磁力範囲より高くなる。なお、センダスト組成は、Fe-9.5質量%Si-5.5質量%Al近傍の組成であり、センダスト組成のFe-Si-Al系合金は透磁率が大きく磁気損失が小さい特性を有することが知られている。 When the Si component in the oxide film is less than 5% by mass, the Al component is less than 5% by mass, and the O component is less than 10% by mass, the composition of the oxide film approaches that of pure Fe. Therefore, the oxide film does not have sufficient insulating properties. On the other hand, when at least one of the Si component in the oxide film exceeding 20% by mass, the Al component exceeding 30% by mass, and the O component exceeding 30% by mass is established, the soft magnetic alloy particles are formed. The coercive force of the soft magnetic powder becomes higher than the above-mentioned coercive force range due to the large deviation of the composition from the sendust composition. The sendust composition has a composition in the vicinity of Fe-9.5 mass% Si-5.5 mass% Al, and the Fe—Si—Al alloy having a sendust composition has a characteristic of high magnetic permeability and small magnetic loss. It has been known.

酸化被膜は、その平均厚さが5nm以上40nm以下である。酸化被膜の平均厚さが5nm未満では、十分な体積抵抗率が得られない。一方、酸化被膜の平均厚さが40nmを超えると、保磁力が大きくなり、透磁率は低くなる傾向にあるため、好ましくない。 The oxide film has an average thickness of 5 nm or more and 40 nm or less. If the average thickness of the oxide film is less than 5 nm, sufficient volume resistivity cannot be obtained. On the other hand, when the average thickness of the oxide film exceeds 40 nm, the coercive force tends to be large and the magnetic permeability tends to be low, which is not preferable.

〔軟磁性粉末の製造方法〕
ここで、上記軟磁性粉末の製造方法を説明する。軟磁性粉末の製造方法は、大きく分けて、軟磁性合金粒子を作製する粒子作製工程、軟磁性合金粒子を熱処理する熱処理工程、及び、軟磁性合金粒子の表面に酸化被膜を形成する酸化工程を含む。
[Manufacturing method of soft magnetic powder]
Here, a method for producing the soft magnetic powder will be described. The method for producing soft magnetic powder is roughly divided into a particle production step for producing soft magnetic alloy particles, a heat treatment step for heat-treating the soft magnetic alloy particles, and an oxidation step for forming an oxide film on the surface of the soft magnetic alloy particles. include.

(粒子作製工程)
軟磁性合金粒子は、ガスアトマイズ法、水アトマイズ法、及びディスクアトマイズ法など各種アトマイズ法、又は、機械的粉砕法によって作製される。軟磁性合金粒子の含有酸素量は少ないことが好ましい。この観点から、粒子作製法として、上記の作製法の中ではガスアトマイズ法又はディスクアトマイズ法が好ましい。更に、量産性の観点からは、粒子作製法として、上記の作製法の中ではガスアトマイズ法が優れている。軟磁性合金粒子の含有酸素量を更に低減するために、不活性ガスを用いたガスアトマイズ法が好ましい。
(Particle preparation process)
The soft magnetic alloy particles are produced by various atomization methods such as a gas atomization method, a water atomization method, and a disc atomization method, or a mechanical pulverization method. It is preferable that the amount of oxygen contained in the soft magnetic alloy particles is small. From this point of view, the gas atomizing method or the disc atomizing method is preferable as the particle forming method among the above-mentioned producing methods. Further, from the viewpoint of mass productivity, the gas atomizing method is superior as the particle manufacturing method among the above-mentioned manufacturing methods. In order to further reduce the oxygen content of the soft magnetic alloy particles, the gas atomizing method using an inert gas is preferable.

軟磁性合金粒子の組成は、センダスト組成又はその近傍の組成であることが好ましい。即ち、軟磁性合金粒子は、好ましくは、8質量%以上11質量%以下のSi及び4質量%以上7質量%以下のAlを含むFe-Si-Al合金、より好ましくは、9質量%以上10質量%以下のSi及び5質量%以上6質量%以下のAlを含むFe-Si-Al合金である。 The composition of the soft magnetic alloy particles is preferably a sendust composition or a composition in the vicinity thereof. That is, the soft magnetic alloy particles are preferably an Fe—Si—Al alloy containing 8% by mass or more and 11% by mass or less of Si and 4% by mass or more and 7% by mass or less of Al, and more preferably 9% by mass or more and 10% by mass. It is a Fe—Si—Al alloy containing Si of 5% by mass or less and Al of 5% by mass or more and 6% by mass or less.

(熱処理工程)
熱処理工程では、被膜で被覆される前の軟磁性合金粒子に熱処理が施される。これにより、軟磁性合金粒子作製時に蓄積された軟磁性合金粒子内の歪みを緩和させ、軟磁性粉末の保磁力を低下させる効果が期待される。
(Heat treatment process)
In the heat treatment step, the soft magnetic alloy particles before being coated with the coating are heat-treated. This is expected to have the effect of alleviating the strain in the soft magnetic alloy particles accumulated during the production of the soft magnetic alloy particles and lowering the coercive force of the soft magnetic powder.

熱処理工程では、軟磁性合金粒子を、真空又は不活性ガス雰囲気、且つ、700℃以上900℃以下の温度域で、所定の熱処理時間だけ保持する。熱処理時間は、処理量や生産性に応じて任意の時間が設定される。但し、熱処理時間は、長時間となると生産性が低下するため、5時間以内が好適である。熱処理の雰囲気は、軟磁性合金粒子の酸化を抑えるために、真空下又は不活性ガス雰囲気下とされる。不活性ガスは、窒素ガスよりもAr(アルゴン)ガスを採用することが、軟磁性粉末の低保磁力を保持するうえで好ましい。 In the heat treatment step, the soft magnetic alloy particles are held in a vacuum or an inert gas atmosphere and in a temperature range of 700 ° C. or higher and 900 ° C. or lower for a predetermined heat treatment time. The heat treatment time is set to an arbitrary time according to the processing amount and productivity. However, the heat treatment time is preferably 5 hours or less because the productivity decreases when the heat treatment time is long. The atmosphere of the heat treatment is set to a vacuum or an inert gas atmosphere in order to suppress the oxidation of the soft magnetic alloy particles. As the inert gas, it is preferable to use Ar (argon) gas rather than nitrogen gas in order to maintain the low coercive force of the soft magnetic powder.

(酸化工程)
酸化工程では、熱処理された軟磁性合金粒子に酸化処理が施される。これにより、軟磁性合金粒子の表面に酸化被膜が形成される。
(Oxidation process)
In the oxidation step, the heat-treated soft magnetic alloy particles are subjected to an oxidation treatment. As a result, an oxide film is formed on the surface of the soft magnetic alloy particles.

酸化工程では、軟磁性合金粒子を大気雰囲気、且つ、300℃以上750℃以下の温度域で所定の酸化時間だけ保持する。酸化処理温度は、300℃以上750℃以下であるが、400℃以上600℃以下の温度域が更に好ましい。酸化処理温度が高いほど、酸化被膜の厚さが大きくなり、体積抵抗率が上昇する傾向があるが、一方で保磁力の値も上昇する傾向にある。従って、保磁力を上昇させないために、酸化処理温度は上記温度域内において低い値であることが好ましい。 In the oxidation step, the soft magnetic alloy particles are held in an atmospheric atmosphere and in a temperature range of 300 ° C. or higher and 750 ° C. or lower for a predetermined oxidation time. The oxidation treatment temperature is 300 ° C. or higher and 750 ° C. or lower, but a temperature range of 400 ° C. or higher and 600 ° C. or lower is more preferable. The higher the oxidation treatment temperature, the larger the thickness of the oxide film and the tendency for the volume resistivity to increase, but on the other hand, the value of the coercive force also tends to increase. Therefore, in order not to increase the coercive force, the oxidation treatment temperature is preferably a low value in the above temperature range.

酸化工程により軟磁性合金粒子の表面に形成される酸化被膜の厚さは、酸化処理温度及び酸化処理時間の調整によって、コントロールされる。また、軟磁性合金粒子の表面に形成される酸化被膜の組成は、酸化処理温度及び軟磁性合金粒子の組成の調整によって、コントロールされる。 The thickness of the oxide film formed on the surface of the soft magnetic alloy particles by the oxidation step is controlled by adjusting the oxidation treatment temperature and the oxidation treatment time. Further, the composition of the oxide film formed on the surface of the soft magnetic alloy particles is controlled by adjusting the oxidation treatment temperature and the composition of the soft magnetic alloy particles.

以上説明したように、本実施形態に係る軟磁性粉末は、酸化被膜が形成されたFe(鉄)-Si(ケイ素)-Al(アルミニウム)系軟磁性合金粒子からなる。軟磁性合金粒子の平均粒径が10μm以上100μm以下である。酸化被膜は、10質量%以上30質量%以下のO(酸素),5質量%以上20質量%以下のSi(ケイ素),5質量%以上30質量%以下のAl(アルミニウム),残部Fe(鉄)及び不可避的不純物からなり、平均厚さが5nm以上40nm以下である。 As described above, the soft magnetic powder according to the present embodiment is composed of Fe (iron) -Si (silicon) -Al (aluminum) -based soft magnetic alloy particles on which an oxide film is formed. The average particle size of the soft magnetic alloy particles is 10 μm or more and 100 μm or less. The oxide film is O (oxygen) of 10% by mass or more and 30% by mass or less, Si (silicon) of 5% by mass or more and 20% by mass or less, Al (aluminum) of 5% by mass or more and 30% by mass or less, and the balance Fe (iron). ) And unavoidable impurities, and the average thickness is 5 nm or more and 40 nm or less.

上記軟磁性粉末を、本実施形態では平均粒径が10μm以上100μm以下のFe-Si-Al系軟磁性合金粒子を作製する粒子作製工程と、軟磁性合金粒子を、真空又は不活性ガス雰囲気、且つ、700℃以上900℃以下の温度域で所定の熱処理時間保持する熱処理工程と、熱処理された軟磁性合金粒子を、大気雰囲気、且つ、300℃以上750℃以下の温度域で所定の酸化時間保持することにより、軟磁性合金粒子の表面に10質量%以上30質量%以下のO(酸素),5質量%以上20質量%以下のSi(ケイ素),5質量%以上30質量%以下のAl(アルミニウム),残部Fe(鉄)及び不可避的不純物から成り、平均厚さが5nm以上40nm以下の酸化被膜を形成する酸化処理工程とを含む製造方法により得ている。 In the present embodiment, the soft magnetic powder is used in a particle preparation step for producing Fe—Si—Al-based soft magnetic alloy particles having an average particle size of 10 μm or more and 100 μm or less, and the soft magnetic alloy particles are used in a vacuum or an inert gas atmosphere. In addition, a heat treatment step of holding the heat-treated soft magnetic alloy particles in a temperature range of 700 ° C. or higher and 900 ° C. or lower and a predetermined oxidation time of the heat-treated soft magnetic alloy particles in an atmospheric atmosphere and a temperature range of 300 ° C. or higher and 750 ° C. or lower. By holding, O (oxygen) of 10% by mass or more and 30% by mass or less, Si (silicon) of 5% by mass or more and 20% by mass or less, and Al of 5% by mass or more and 30% by mass or less on the surface of the soft magnetic alloy particles. It is obtained by a production method including an oxidation treatment step of forming an oxide film having an average thickness of 5 nm or more and 40 nm or less, which is composed of (aluminum), the balance Fe (iron) and unavoidable impurities.

上記軟磁性粉末は、以下に説明する実施例で説明されるように、高い電気抵抗(絶縁性)と低い保磁力とを併せ備える。その結果、この軟磁性粉末が成形されてなる軟磁性体は高絶縁性と高透磁率とを併せ備えることとなる。 The soft magnetic powder has both high electrical resistance (insulation) and low coercive force, as described in the examples described below. As a result, the soft magnetic material obtained by molding this soft magnetic powder has both high insulation and high magnetic permeability.

表1に示す番号1~22の試料を作製し、各試料を評価した。番号1~15は本発明の軟磁性粉末の実施例に係る試料であり、番号16~22は比較例に係る試料である。 Samples Nos. 1 to 22 shown in Table 1 were prepared and each sample was evaluated. Nos. 1 to 15 are samples according to Examples of the soft magnetic powder of the present invention, and Nos. 16 to 22 are samples according to Comparative Examples.

Figure 0007045905000001
Figure 0007045905000001

(試料作製手順)
1)ガスアトマイズ法を用いて所定の成分の軟磁性合金粒子(原料粒子)を作製した。具体的には、合金材料をアルミナ製坩堝に入れて溶融し、坩堝下の直径5mmのノズルから合金溶湯を出湯し、これに高圧Arを噴霧することにより、軟磁性合金粒子を得た。軟磁性合金粒子の成分は、表1に「原料粉末組成」として示す。
2)得られた軟磁性合金粒子を300μm以下に分級した。分級には分級篩を用いた。
3)分級した軟磁性合金粒子を、Ar雰囲気且つ700℃以上900℃以下の温度域で2時間保持することにより、軟磁性合金粒子に熱処理を施した。
4)熱処理後の軟磁性合金粒子を、大気雰囲気且つ300℃以上750以下の温度域で2時間保持することにより、軟磁性合金粒子に酸化処理を施した。
5)酸化処理後の軟磁性合金粒子(被覆粒子からなる軟磁性粉末)を自然冷却して、試料を得た。
(Sample preparation procedure)
1) Soft magnetic alloy particles (raw material particles) having a predetermined component were produced by using a gas atomizing method. Specifically, the alloy material was put into an alumina crucible and melted, and a molten alloy was discharged from a nozzle having a diameter of 5 mm under the crucible and sprayed with high-pressure Ar to obtain soft magnetic alloy particles. The components of the soft magnetic alloy particles are shown in Table 1 as "raw material powder composition".
2) The obtained soft magnetic alloy particles were classified to 300 μm or less. A classification sieve was used for classification.
3) The classified soft magnetic alloy particles were heat-treated by holding the classified soft magnetic alloy particles in an Ar atmosphere and a temperature range of 700 ° C. or higher and 900 ° C. or lower for 2 hours.
4) The soft magnetic alloy particles after the heat treatment were subjected to an oxidation treatment by holding the soft magnetic alloy particles in an atmospheric atmosphere and in a temperature range of 300 ° C. or higher and 750 or lower for 2 hours.
5) The soft magnetic alloy particles (soft magnetic powder composed of coated particles) after the oxidation treatment were naturally cooled to obtain a sample.

(軟磁性粉末の評価)
各試料について、平均粒径、保磁力、及び粉末充填体の体積抵抗率を測定した。各試料の平均粒径(D50)は、粒子径分布測定装置(日機装株式会社製 マイクロトラックMT3000)を用いて、レーザー回折法により測定した。各試料の保磁力の測定にはHcメーター(HJS社製 QumanoHC-801)を用い、直径6mm、高さ8mmの樹脂製容器に試料を充填して最大印加磁場144kA/mにおける保磁力を測定した。各試料の粉末充填体の体積抵抗率の測定には、粉体抵抗測定システム(株式会社三菱ケミカルアナリテック製 MCP-PD51)を用い、プローブシリンダー内に投入した試料に2kNの荷重がかかるように圧力を調整し、低抵抗率計(株式会社三菱ケミカルアナリテック製 Loresta-GX MCP-T700)で粉末充填体の体積抵抗率を測定した。
(Evaluation of soft magnetic powder)
For each sample, the average particle size, coercive force, and volume resistivity of the powder filler were measured. The average particle size (D50) of each sample was measured by a laser diffraction method using a particle size distribution measuring device (Microtrac MT3000 manufactured by Nikkiso Co., Ltd.). An Hc meter (Quanto HC-801 manufactured by HJS) was used to measure the coercive force of each sample, and the sample was filled in a resin container having a diameter of 6 mm and a height of 8 mm, and the coercive force at a maximum applied magnetic field of 144 kA / m was measured. .. A powder resistance measurement system (MCP-PD51 manufactured by Mitsubishi Chemical Analytec Co., Ltd.) is used to measure the volumetric resistance of the powder filler of each sample so that a load of 2 kN is applied to the sample placed in the probe cylinder. The pressure was adjusted, and the volumetric resistance of the powder filler was measured with a low resistance meter (Loresta-GX MCP-T700 manufactured by Mitsubishi Chemical Analytech Co., Ltd.).

更に、各試料について、酸化被膜の膜厚及び成分の評価を行った。具体的には、各試料をTEM(transmission electron microscope)を用いて観察し、粉末表面における酸化被膜の厚さを測定するとともに、酸化被膜の成分を分析した。 Furthermore, the film thickness and components of the oxide film were evaluated for each sample. Specifically, each sample was observed using a TEM (transmission electron microscope), the thickness of the oxide film on the powder surface was measured, and the components of the oxide film were analyzed.

各試料の評価結果は、表1に示されている。表1から、以下が明らかである。 The evaluation results of each sample are shown in Table 1. From Table 1, the following is clear.

実施例に係る番号1~15の試料では、酸化被膜の平均厚さが5nm以上34nm以下の十分に小さな値であった。加えて、番号1~15の試料では、保磁力(Hc)が13A/m以上38A/m以下であって、要求される値(50A/m以下)を十分に下回っていた。よって、番号1~15の試料に相当する軟磁性粉末からなる軟磁性体は、透磁率の実数部が大きく、高透磁率を備えることができる。更に、番号1~15の試料では、粉末充填体の体積抵抗率が要求される値(10Ω・cm以上)を十分に上回っていた。これにより、番号1~15の試料に相当する軟磁性粉末からなる軟磁性体は、高絶縁性を備えることができる。つまり、番号1~15の試料に相当する軟磁性粉末からなる軟磁性体は、高絶縁性と高透磁率とを併せ備えるものとなりうる。 In the samples of Nos. 1 to 15 according to the examples, the average thickness of the oxide film was 5 nm or more and 34 nm or less, which was a sufficiently small value. In addition, in the samples of Nos. 1 to 15, the coercive force (Hc) was 13 A / m or more and 38 A / m or less, which was sufficiently lower than the required value (50 A / m or less). Therefore, the soft magnetic material made of the soft magnetic powder corresponding to the samples of Nos. 1 to 15 has a large real part of the magnetic permeability and can have a high magnetic permeability. Further, in the samples of Nos. 1 to 15, the volume resistivity of the powder filler was sufficiently higher than the required value (10 Ω · cm or more). As a result, the soft magnetic material made of the soft magnetic powder corresponding to the samples of Nos. 1 to 15 can have high insulating properties. That is, the soft magnetic material made of the soft magnetic powder corresponding to the samples of Nos. 1 to 15 can have both high insulation and high magnetic permeability.

比較例に係る番号16,17の試料は、実施例(即ち、番号1~15の試料)と対比して酸化処理が行われていない点で相違する。番号16,17の試料では、酸化被膜が得られなかった。そのため、番号16,17の試料では、粉末充填体の体積抵抗率が実施例と比較して小さい。また、比較例に係る番号17の試料では、熱処理が施されていないため、実施例と比較して高い保磁力が示されている。 The samples of Nos. 16 and 17 according to the comparative examples are different from the examples (that is, the samples of Nos. 1 to 15) in that the oxidation treatment is not performed. No oxide film was obtained in the samples of Nos. 16 and 17. Therefore, in the samples of Nos. 16 and 17, the volume resistivity of the powder packing material is smaller than that of the examples. Further, since the sample No. 17 according to the comparative example has not been heat-treated, it shows a higher coercive force as compared with the examples.

比較例に係る番号18の試料は、原料粒子である軟磁性合金粒子の平均粒径(D50)が実施例と比較して大きい。なお、実施例の軟磁性合金粒子の平均粒径(D50)は14μm~87μmであるのに対し、番号18の試料の磁性合金粒子の平均粒径(D50)は108μmである。番号18の試料では、酸化被膜中の絶縁材料の割合が低下してしまい、粉末充填体の体積抵抗率が実施例と比較して小さい。 In the sample of No. 18 according to the comparative example, the average particle size (D50) of the soft magnetic alloy particles as the raw material particles is larger than that of the example. The average particle size (D50) of the soft magnetic alloy particles of the example is 14 μm to 87 μm, whereas the average particle size (D50) of the magnetic alloy particles of the sample No. 18 is 108 μm. In the sample No. 18, the proportion of the insulating material in the oxide film is reduced, and the volume resistivity of the powder packing material is smaller than that in the examples.

比較例に係る番号19の試料は、原料粒子である軟磁性合金粒子の平均粒径(D50)が実施例と比較して小さい。そのために、番号19の試料では、実施例と比較して高い保磁力が示されている。 In the sample of No. 19 according to the comparative example, the average particle size (D50) of the soft magnetic alloy particles as the raw material particles is smaller than that of the example. Therefore, the sample No. 19 shows a higher coercive force as compared with the examples.

比較例に係る番号20の試料は、酸化処理温度が実施例と比較して高い。なお、実施例の酸化処理温度が300℃~750℃であるのに対し、番号20の試料の酸化処理温度は800℃である。そのために、番号20の試料では、被膜厚さが実施例と比較して大きい。更に、番号20の試料では、酸化被膜の組成と原料粒子である軟磁性合金粒子の組成(原料粉末組成)との差異が大きく、その結果、実施例と比較して高い保磁力が示されている。 The sample No. 20 according to the comparative example has a higher oxidation treatment temperature than that of the example. The oxidation treatment temperature of the example is 300 ° C. to 750 ° C., whereas the oxidation treatment temperature of the sample No. 20 is 800 ° C. Therefore, in the sample No. 20, the film thickness is larger than that in the examples. Further, in the sample No. 20, the difference between the composition of the oxide film and the composition of the soft magnetic alloy particles as the raw material particles (raw material powder composition) is large, and as a result, a higher coercive force is shown as compared with the examples. There is.

比較例に係る番号21の試料は、軟磁性合金粒子の組成(原料粉末組成)のSi及びAlの割合が実施例と比較して低い。なお、実施例の軟磁性合金粒子の組成は、センダスト組成又はそれに類似する組成であるのに対し、番号21の試料の軟磁性合金粒子の組成は、Siが2.0質量%、Alが2.0質量%である。そのために、番号21の試料では、酸化被膜のSi及びAlの割合が実施例と比較して低い。これにより、番号21の試料は、十分な絶縁特性を示さず、粉末充填体の体積抵抗率が実施例と比較して小さい。更に、番号21の試料は軟磁性合金粒子の組成が純Feの組成に近づくため、実施例と比較して高い保磁力が示されている。 In the sample No. 21 according to the comparative example, the proportions of Si and Al in the composition of the soft magnetic alloy particles (raw material powder composition) are lower than those in the example. The composition of the soft magnetic alloy particles of the example is a sendust composition or a composition similar thereto, whereas the composition of the soft magnetic alloy particles of the sample of No. 21 is 2.0% by mass of Si and 2 in Al. It is 0.0% by mass. Therefore, in the sample No. 21, the proportions of Si and Al in the oxide film are lower than those in the examples. As a result, the sample No. 21 does not exhibit sufficient insulating properties, and the volume resistivity of the powder packing material is smaller than that of the examples. Further, since the composition of the soft magnetic alloy particles of the sample No. 21 approaches the composition of pure Fe, a higher coercive force is shown as compared with the examples.

比較例に係る番号22の試料は、酸化被膜の平均厚さが実施例と比較して小さい。なお、実施例の酸化被膜の平均厚さが5nm~34nmであるのに対し、番号22の試料の酸化被膜の平均厚さは3nmである。そのため、番号21の試料では、粉末充填体の体積抵抗率が実施例と比較して小さい。 In the sample of No. 22 according to the comparative example, the average thickness of the oxide film is smaller than that of the example. The average thickness of the oxide film of the examples is 5 nm to 34 nm, whereas the average thickness of the oxide film of the sample No. 22 is 3 nm. Therefore, in the sample No. 21, the volume resistivity of the powder packing material is smaller than that in the examples.

Claims (6)

酸化被膜が形成されたFe(鉄)-Si(ケイ素)-Al(アルミニウム)系軟磁性合金粒子からなり、
前記軟磁性合金粒子の平均粒径が10μm以上100μm以下であり、
前記酸化被膜は、10質量%以上30質量%以下のO(酸素),5質量%以上20質量%以下のSi(ケイ素),5質量%以上30質量%以下のAl(アルミニウム),残部Fe(鉄)及び不可避的不純物からなり、平均厚さが5nm以上40nm以下である、
軟磁性粉末。
It is composed of Fe (iron) -Si (silicon) -Al (aluminum) -based soft magnetic alloy particles on which an oxide film is formed.
The average particle size of the soft magnetic alloy particles is 10 μm or more and 100 μm or less.
The oxide film is O (oxygen) of 10% by mass or more and 30% by mass or less, Si (silicon) of 5% by mass or more and 20% by mass or less, Al (aluminum) of 5% by mass or more and 30% by mass or less, and the balance Fe ( It consists of iron) and unavoidable impurities, and has an average thickness of 5 nm or more and 40 nm or less.
Soft magnetic powder.
保磁力が50A/m以下である、
請求項1に記載の軟磁性粉末。
The coercive force is 50 A / m or less,
The soft magnetic powder according to claim 1.
前記酸化被膜の平均厚さが5nm以上8nm以下である、The average thickness of the oxide film is 5 nm or more and 8 nm or less.
請求項1又は2に記載の軟磁性粉末。The soft magnetic powder according to claim 1 or 2.
前記軟磁性合金粒子は、8質量%以上11質量%以下のSi及び4質量%以上7質量%以下のAlを含む、The soft magnetic alloy particles contain 8% by mass or more and 11% by mass or less of Si and 4% by mass or more and 7% by mass or less of Al.
請求項1乃至請求項3のいずれか一項に記載の軟磁性粉末。The soft magnetic powder according to any one of claims 1 to 3.
酸化被膜が形成されたFe-Si-Al系軟磁性合金粒子からなる軟磁性粉末の製造方法であって、A method for producing a soft magnetic powder made of Fe—Si—Al-based soft magnetic alloy particles on which an oxide film is formed.
平均粒径が10μm以上100μm以下であり、8質量%以上11質量%以下のSi及び4質量%以上7質量%以下のAlを含むFe-Si-Al系の軟磁性合金粒子を作製する粒子作製工程と、Particle production for producing Fe—Si—Al-based soft magnetic alloy particles containing Si having an average particle size of 10 μm or more and 100 μm or less and 8% by mass or more and 11% by mass or less and Al of 4% by mass or more and 7% by mass or less. Process and
前記軟磁性合金粒子を、真空又は不活性ガス雰囲気、且つ、700℃以上900℃以下の温度域で定の熱処理時間だけ保持することにより、軟磁性合金粒子を熱処理する熱処理工程と、A heat treatment step of heat-treating the soft magnetic alloy particles by holding the soft magnetic alloy particles in a vacuum or an inert gas atmosphere and in a temperature range of 700 ° C. or higher and 900 ° C. or lower for a fixed heat treatment time.
前記熱処理工程を終えた軟磁性合金粒子を、大気雰囲気、且つ、300℃以上750℃以下の温度域で所定の酸化時間だけ保持することにより、10質量%以上30質量%以下のO,5質量%以上20質量%以下のSi,5質量%以上30質量%以下のAl,残部Fe及び不可避的不純物からなり、平均厚さが5nm以上40nm以下の酸化被膜を軟磁性合金粒子の表面に形成する酸化工程とを、含む、By holding the soft magnetic alloy particles that have completed the heat treatment step in an atmospheric atmosphere and in a temperature range of 300 ° C. or higher and 750 ° C. or lower for a predetermined oxidation time, O, 5 mass of 10% by mass or more and 30% by mass or less % Or more and 20% by mass or less of Si, 5% by mass or more and 30% by mass or less of Al, balance Fe and unavoidable impurities, and an oxide film having an average thickness of 5 nm or more and 40 nm or less is formed on the surface of the soft magnetic alloy particles. Including the oxidation step,
軟磁性粉末の製造方法。Method for manufacturing soft magnetic powder.
前記酸化被膜の平均厚さが5nm以上8nm以下である、The average thickness of the oxide film is 5 nm or more and 8 nm or less.
請求項5に記載の軟磁性粉末の製造方法。The method for producing a soft magnetic powder according to claim 5.
JP2018069400A 2018-03-30 2018-03-30 Soft magnetic powder and its manufacturing method Active JP7045905B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2018069400A JP7045905B2 (en) 2018-03-30 2018-03-30 Soft magnetic powder and its manufacturing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2018069400A JP7045905B2 (en) 2018-03-30 2018-03-30 Soft magnetic powder and its manufacturing method

Publications (2)

Publication Number Publication Date
JP2019178402A JP2019178402A (en) 2019-10-17
JP7045905B2 true JP7045905B2 (en) 2022-04-01

Family

ID=68277842

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2018069400A Active JP7045905B2 (en) 2018-03-30 2018-03-30 Soft magnetic powder and its manufacturing method

Country Status (1)

Country Link
JP (1) JP7045905B2 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6909181B2 (en) * 2018-06-04 2021-07-28 デンカ株式会社 Insulation coated metal particles
JP6851448B2 (en) * 2018-10-30 2021-03-31 Dowaエレクトロニクス株式会社 Heat treatment method for soft magnetic powder
WO2020090849A1 (en) * 2018-10-30 2020-05-07 Dowaエレクトロニクス株式会社 Soft magnetic powder, soft magnetic powder heat treatment method, soft magnetic material, dust core, and dust core manufacturing method
JP7281319B2 (en) 2019-03-28 2023-05-25 太陽誘電株式会社 LAMINATED COIL COMPONENTS, MANUFACTURING METHOD THEREOF, AND CIRCUIT BOARD WITH LAMINATED COIL COMPONENTS
US11560934B2 (en) 2019-09-30 2023-01-24 Denso Corporation Speed reducer and speed reducer-equipped motor

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003109810A (en) 2001-09-28 2003-04-11 Nec Tokin Corp Dust core and its manufacturing method
JP2005209753A (en) 2004-01-21 2005-08-04 Sanyo Special Steel Co Ltd Soft magnetic flat powder
WO2009001641A1 (en) 2007-06-28 2008-12-31 Kabushiki Kaisha Kobe Seiko Sho Soft magnetic powders, soft magnetic compacts, processes for production of both

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003109810A (en) 2001-09-28 2003-04-11 Nec Tokin Corp Dust core and its manufacturing method
JP2005209753A (en) 2004-01-21 2005-08-04 Sanyo Special Steel Co Ltd Soft magnetic flat powder
WO2009001641A1 (en) 2007-06-28 2008-12-31 Kabushiki Kaisha Kobe Seiko Sho Soft magnetic powders, soft magnetic compacts, processes for production of both

Also Published As

Publication number Publication date
JP2019178402A (en) 2019-10-17

Similar Documents

Publication Publication Date Title
JP7045905B2 (en) Soft magnetic powder and its manufacturing method
JP6447938B2 (en) Magnetic core and coil component using the same
US11011305B2 (en) Powder magnetic core, and coil component
JP5022999B2 (en) Powder magnetic core and manufacturing method thereof
TWI294321B (en) Method for manufacturing of insulated soft magnetic metal powder formed body
EP2589450B1 (en) Composite magnetic material and process for production thereof
JP6601389B2 (en) Magnetic core, coil component, and manufacturing method of magnetic core
WO2007015378A1 (en) Soft magnetic material, process for production of the material, powder compressed magnetic core, and process for production of the magnetic core
JP2008028162A (en) Soft magnetic material, manufacturing method therefor, and dust core
JPWO2010084812A1 (en) Metallurgical powder manufacturing method, dust core manufacturing method, dust core and coil component
JP2014060183A (en) Soft magnetic material and method for manufacturing the same
JP2011089191A (en) Soft magnetic material, dust core and method for producing the core
KR102362736B1 (en) soft magnetic flat powder
JP2010236020A (en) Soft magnetic composite material, method for producing the same, and electromagnetic circuit component
WO2019031399A1 (en) Method for manufacturing powder magnetic core, and method for manufacturing electromagnetic component
JP5023041B2 (en) Powder magnetic core and manufacturing method thereof
JP6582745B2 (en) Composite soft magnetic material and manufacturing method thereof
JP4618557B2 (en) Soft magnetic alloy compact and manufacturing method thereof
JP2010016290A (en) Ferrous metal magnetic particle, soft magnetic material, powder magnetic core and manufacturing method of them
JP7307603B2 (en) Powder magnetic core and method for manufacturing powder magnetic core
JP7288341B2 (en) soft magnetic powder
JP2010185126A (en) Composite soft magnetic material and method for producing the same
JP2021093405A (en) Method of manufacturing dust core
JP2003347113A (en) Composite magnetic material and its manufacturing method
JP2024044442A (en) Method for producing powder for dust core and powder for dust core

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20210113

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20211109

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20211227

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20220222

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20220322

R150 Certificate of patent or registration of utility model

Ref document number: 7045905

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150