JP2006233268A - High electric resistance-magnetic powder, its production method, high electric resistance-magnetic powder compact and its production method - Google Patents
High electric resistance-magnetic powder, its production method, high electric resistance-magnetic powder compact and its production method Download PDFInfo
- Publication number
- JP2006233268A JP2006233268A JP2005048817A JP2005048817A JP2006233268A JP 2006233268 A JP2006233268 A JP 2006233268A JP 2005048817 A JP2005048817 A JP 2005048817A JP 2005048817 A JP2005048817 A JP 2005048817A JP 2006233268 A JP2006233268 A JP 2006233268A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic powder
- powder
- electric resistance
- electrical resistance
- high electric
- 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
- 239000006247 magnetic powder Substances 0.000 title claims abstract description 111
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- 239000000843 powder Substances 0.000 claims abstract description 38
- 238000010438 heat treatment Methods 0.000 claims abstract description 25
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 claims abstract description 13
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 6
- 238000005245 sintering Methods 0.000 claims abstract description 6
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 239000002245 particle Substances 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 238000000465 moulding Methods 0.000 claims description 3
- 239000000126 substance Substances 0.000 abstract description 13
- 239000000203 mixture Substances 0.000 abstract description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 16
- 229910052757 nitrogen Inorganic materials 0.000 description 10
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 6
- 230000004907 flux Effects 0.000 description 6
- 239000011810 insulating material Substances 0.000 description 6
- 239000011347 resin Substances 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 239000000696 magnetic material Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000002490 spark plasma sintering Methods 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910002060 Fe-Cr-Al alloy Inorganic materials 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000000635 electron micrograph Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000005121 nitriding Methods 0.000 description 1
- 239000000615 nonconductor Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- -1 phosphate compound Chemical class 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000004451 qualitative analysis Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
- Soft Magnetic Materials (AREA)
Abstract
Description
本発明は、例えば、自動車用モ−タの固定子や回転子等、交流磁場中で使用される磁性体の原材料となる高電気抵抗磁性粉末とその製造方法、ならびに該高電気抵抗磁性粉末を用いて成る高電気抵抗磁性粉末成形体とその製造方法に関するものである。 The present invention relates to a high electrical resistance magnetic powder as a raw material of a magnetic material used in an alternating magnetic field, such as a motor motor stator or rotor, a method for producing the same, and the high electrical resistance magnetic powder. The present invention relates to a high electric resistance magnetic powder molded body used and a method for producing the same.
従来、モ−タの固定子や回転子等、交流磁場中で使用される磁性体には、表面に電気絶縁物質が塗装された電磁鋼板を所定形状に打抜き後、積層した部品（以下、積層体と記す）が用いられている。電磁鋼板の表面に絶縁物質を塗装する目的は、積層体の板厚方向の電気抵抗を高めることによって、交流磁場中で発生する渦電流を抑え、高周波化に伴う損失の増加と比透磁率や磁束密度の低下、すなわち軟磁性の劣化を抑制することである。しかしながら、この絶縁層の存在により、積層された垂直方向の磁束密度が低く、磁気回路は２次元的設計に制約される。 Conventionally, magnetic materials used in alternating magnetic fields such as motor stators and rotors are made by punching electromagnetic steel sheets coated with an electrical insulating material on a surface into a predetermined shape and then stacking them (hereinafter referred to as stacking). Used as body). The purpose of coating an insulating material on the surface of an electrical steel sheet is to increase the electrical resistance in the thickness direction of the laminate, thereby suppressing eddy currents generated in an alternating magnetic field, increasing loss due to higher frequencies, and increasing relative permeability and It is to suppress a decrease in magnetic flux density, that is, deterioration of soft magnetism. However, due to the presence of this insulating layer, the stacked magnetic flux density in the vertical direction is low, and the magnetic circuit is restricted to a two-dimensional design.
この電磁鋼板の積層体に対し、近年、鉄粉に代表される磁性粉末の表面に燐酸塩化物等の絶縁物質を被覆し、この絶縁被覆された磁性粉末に結合剤の樹脂を添加して固化成形した磁性粉末成形体が開発されている（例えば、非特許文献１，２参照）。この磁性粉末成形体は、電磁鋼板の積層体と異なり等方的な磁気特性を示すので、磁気回路の自由度を高め、３次元的な回路設計も適用できるという点で優れた技術である。
上述した非特許文献１，２に開示される磁性粉末成形体は、その等方的な磁気特性ゆえに、３次元的な磁気回路設計も適用できる点では有利であるものの、製造工程において、磁性粉末の表面に絶縁物質を被覆するための高価な化学的処理が必要である。このような高価な化学的処理は、磁性粉末成形体をモ−タの固定子や回転子に実用化する上でコストを高める要因となる。本発明の目的は、この問題を解決し、高価な化学的処理を行わなくても、安価な方法により粉末表面を電気抵抗の高い物質で被覆した高電気抵抗磁性粉末とその製造方法、ならびにこの高電気抵抗磁性粉末を用いて成る高電気抵抗磁性粉末成形体とその製造方法を提供することである。 The magnetic powder molded bodies disclosed in Non-Patent Documents 1 and 2 described above are advantageous in that a three-dimensional magnetic circuit design can be applied because of their isotropic magnetic characteristics. Expensive chemical treatment is required to coat the surface of the insulating material. Such expensive chemical treatment becomes a factor that increases the cost when the magnetic powder compact is put to practical use as a motor stator or rotor. An object of the present invention is to solve this problem and to provide a high electrical resistance magnetic powder having a powder surface coated with a material having a high electrical resistance by an inexpensive method without performing an expensive chemical treatment, a method for producing the same, It is an object of the present invention to provide a high electrical resistance magnetic powder compact using a high electrical resistance magnetic powder and a method for producing the same.
本発明者の検討によると、磁性粉末の表面を被覆する物質は、非特許文献１、２に記される燐酸塩化物や樹脂のような完全な絶縁物質でなくても、磁性粉末の電気抵抗、ひいては該磁性粉末を用いて成る磁性粉末成形体の電気抵抗を高めることのできる物質であれば、高周波域での軟磁性劣化を抑制できる場合が多い。それ故、本発明者は、磁性粉末の表面に外的要素による別の絶縁物質を被覆するのではなく、磁性粉末自身の化学反応によって表面に高電気抵抗の物質を自己生成させることにより、絶縁被覆のための化学的処理を簡素化できることを見出した。 According to the study of the present inventor, even if the material covering the surface of the magnetic powder is not a complete insulating material such as a phosphate compound or a resin described in Non-Patent Documents 1 and 2, the electrical resistance of the magnetic powder As long as the substance can increase the electric resistance of the magnetic powder molded body using the magnetic powder, it is often possible to suppress soft magnetic deterioration in a high frequency range. Therefore, the present inventor does not coat the surface of the magnetic powder with another insulating material due to an external element, but allows the surface of the magnetic powder to self-generate a high electrical resistance material by a chemical reaction of the magnetic powder itself. It has been found that the chemical treatment for coating can be simplified.
そして、この高電気抵抗物質の自己生成が可能な磁性粉末として、最適な成分範囲の粉末を見出し、本発明に到達した。より具体的には、Ｆｅ−Ｃｒ−Ａｌ系を基本成分とする粉末を、窒素を含む雰囲気中において所定の温度範囲で熱処理することにより、粉末表面に窒化アルミニウムを主体とする高電気抵抗の皮膜を生成できること、及び、この皮膜で被覆された高電気抵抗磁性粉末の表面形態、電気抵抗とその製造方法を調査検討することにより、本発明に到達した。 As a magnetic powder capable of self-generation of this high electrical resistance substance, a powder having an optimum component range was found and the present invention was reached. More specifically, a powder having a high electrical resistance mainly composed of aluminum nitride on the powder surface is obtained by heat-treating a powder containing a Fe—Cr—Al base as a basic component in a nitrogen-containing atmosphere within a predetermined temperature range. The present invention has been achieved by investigating and studying the surface morphology of the high electrical resistance magnetic powder coated with this film, the electrical resistance and the production method thereof.
すなわち本発明は、質量％でＣｒ：１．０〜３０．０％、Ａｌ：１．０〜８．０％、残部が実質的にＦｅから成り、表面が窒化アルミニウムを主体とする皮膜で覆われていることを特徴とする高電気抵抗磁性粉末である。また、本発明は、質量％でＣｒ：１．０〜３０．０％、Ａｌ：１．０〜８．０％、残部が実質的にＦｅから成る粉末を、窒素を含む雰囲気中において８００〜１２５０℃の温度で熱処理して、粉末表面に窒化アルミニウムを主体とする皮膜を生成させることを特徴とする高電気抵抗磁性粉末の製造方法である。望ましくは、粉末を、雰囲気中に含まれる酸素を固定する易酸化性容器内で熱処理することを特徴とし、あるいはさらに、粉末を、振動を与えながら熱処理することを特徴とする上記の高電気抵抗磁性粉末の製造方法である。 That is, the present invention comprises Cr: 1.0 to 30.0% by mass, Al: 1.0 to 8.0%, the balance being substantially composed of Fe, and the surface covered with a film mainly composed of aluminum nitride. It is a high electrical resistance magnetic powder characterized by Further, the present invention provides a powder in which Cr: 1.0-30.0%, Al: 1.0-8.0%, and the balance substantially consisting of Fe in mass% in an atmosphere containing nitrogen, 800- A method for producing a high electrical resistance magnetic powder, characterized in that a film mainly composed of aluminum nitride is formed on a powder surface by heat treatment at a temperature of 1250 ° C. Preferably, the high electrical resistance is characterized in that the powder is heat-treated in an easily oxidizable container that fixes oxygen contained in the atmosphere, or further, the powder is heat-treated while applying vibration. It is a manufacturing method of magnetic powder.
また、本発明は、上記した本発明の高電気抵抗磁性粉末を用いて成る磁性粉末成形体であって、組織を構成する各粒子間の接触面のすべてが、窒化アルミニウムを含む皮膜により実質的に隔離されて成る高電気抵抗磁性粉末成形体である。更に、本発明は、質量％でＣｒ：１．０〜３０．０％、Ａｌ：１．０〜８．０％、残部が実質的にＦｅから成り、表面が窒化アルミニウムを主体とする皮膜で覆われた磁性粉末を、放電プラズマ焼結により固化成形することを特徴とする高電気抵抗磁性粉末成形体の製造方法である。 The present invention is also a magnetic powder molded body using the above-described high electrical resistance magnetic powder of the present invention, wherein all of the contact surfaces between the particles constituting the structure are substantially formed by a film containing aluminum nitride. It is a high electrical resistance magnetic powder compact isolated from each other. Furthermore, the present invention is a film whose mass% is Cr: 1.0-30.0%, Al: 1.0-8.0%, the balance is substantially made of Fe, and the surface is mainly composed of aluminum nitride. A method for producing a high electrical resistance magnetic powder molded body comprising solidifying and molding a covered magnetic powder by discharge plasma sintering.
本発明の高電気抵抗磁性粉末は、熱処理によって容易に窒化アルミニウムを主体とする高電気抵抗の皮膜を表面に生成させることができるので、高価な化学的処理を行わなくても、安価な方法で磁性粉末の電気抵抗を高めることができる。また、この高電気抵抗磁性粉末を用いて成る磁性粉末成形体は、組織を構成する各粒子が窒化アルミニウムを主体とする皮膜で覆われているので、電気抵抗が高い。それ故、交流磁場中での使用に適した磁性粉末成形体となることが期待され、モ−タの固定子や回転子への適用が期待できる。 Since the high electric resistance magnetic powder of the present invention can easily form a high electric resistance film mainly composed of aluminum nitride on the surface by heat treatment, it can be produced by an inexpensive method without performing an expensive chemical treatment. The electric resistance of the magnetic powder can be increased. In addition, the magnetic powder compact using this high electrical resistance magnetic powder has a high electrical resistance because each particle constituting the structure is covered with a film mainly composed of aluminum nitride. Therefore, it is expected to be a magnetic powder compact suitable for use in an alternating magnetic field, and application to a stator or rotor of a motor can be expected.
上述したように、本発明の第一の特徴は、熱処理によって表面に窒化アルミニウム（以下、ＡｌＮとも記載する）を主体とする高電気抵抗の皮膜を自己生成できる磁性粉末としてＦｅ−Ｃｒ−Ａｌ系の合金粉末を採用し、その最適な成分範囲をも明らかにしたことにある。以下、高電気抵抗磁性粉末の化学組成を規定した理由を述べる。なお、特に記載のない限り、質量％は、％として記す。 As described above, the first feature of the present invention is that the Fe—Cr—Al system is a magnetic powder capable of self-generating a high electrical resistance film mainly composed of aluminum nitride (hereinafter also referred to as AlN) on the surface by heat treatment. The alloy powder was adopted and the optimum component range was clarified. The reason why the chemical composition of the high electrical resistance magnetic powder is specified will be described below. Unless otherwise specified, mass% is expressed as%.
・Ｃｒ：１．０〜３０．０％
Ｃｒは、窒素を含む雰囲気中で磁性粉末を熱処理する際、粉末中に合金元素として含まれるＡｌを粉末表面に拡散させる役割を担う。すなわち、Ｃｒを含まないＦｅ−Ａｌ系磁性粉末では粉末表面へのＡｌの拡散が十分でないので、ＡｌよりもＦｅが優先的に窒化し、表面の皮膜中にＡｌＮが生成し難く、導電性のあるＦｅの窒化物が生成する。適量のＣｒを含有することにより、粉末表面へのＡｌの拡散が促進され、Ａｌの優先的な窒化が起こる。Ｃｒ量の範囲を１．０〜３０．０％としたのは、１．０％未満では窒化処理後の粉末表面でのＡｌＮの生成量が少なく、逆に３０．０％を超える範囲では、ＡｌＮの生成量は多いものの、磁性粉末成形体の磁束密度が低下するためである。Ｃｒ量のより望ましい範囲は、２．０〜１０．０％である。
・ Cr: 1.0-30.0%
When Cr heat-treats the magnetic powder in an atmosphere containing nitrogen, it plays a role of diffusing Al contained as an alloy element in the powder to the powder surface. In other words, since Fe-Al magnetic powder not containing Cr does not sufficiently diffuse Al to the powder surface, Fe is preferentially nitrided over Al, and AlN is not easily formed in the surface film, and the conductivity is low. A certain Fe nitride is formed. By containing an appropriate amount of Cr, Al diffusion to the powder surface is promoted, and preferential nitridation of Al occurs. The range of the amount of Cr is set to 1.0 to 30.0%. When the amount is less than 1.0%, the amount of AlN produced on the powder surface after nitriding is small, and conversely in the range exceeding 30.0%, This is because although the amount of AlN produced is large, the magnetic flux density of the magnetic powder compact is reduced. A more desirable range of the Cr content is 2.0 to 10.0%.
・Ａｌ：１．０〜８．０％
Ａｌは、窒素を含む雰囲気中で磁性粉末を熱処理する際、粉末表面にＡｌＮを生成させるために必要な元素である。Ａｌ量の範囲を１．０〜８．０％としたのは、１．０％未満では粉末を熱処理後の粉末表面でのＡｌＮの生成量が少なく、逆に８．０％を超える範囲では、磁性粉末成形体の磁束密度が低下するためである。Ａｌ量のより好ましい範囲は３．０〜６．０％である。
-Al: 1.0-8.0%
Al is an element necessary for generating AlN on the powder surface when the magnetic powder is heat-treated in an atmosphere containing nitrogen. The range of Al content is set to 1.0 to 8.0% when less than 1.0%, the amount of AlN produced on the powder surface after heat treatment of the powder is small, and conversely in the range exceeding 8.0%. This is because the magnetic flux density of the magnetic powder compact is reduced. A more preferable range of the amount of Al is 3.0 to 6.0%.
なお、残部は実質的にＦｅとするが、Ｃ，Ｓｉ，Ｍｎ，Ｐ，Ｓ，Ｏ，Ｎ等の不純物元素は、含有される。これらの元素は、磁性粉末成形体の磁気特性に悪影響の無い範囲として、下記の範囲で含有して良く、望ましい規制量である。
Ｃ≦０．１０％、Ｓｉ≦０．５０％、Ｍｎ≦０．５０％、
Ｐ≦０．０５％、Ｓ≦０．０５％、Ｏ≦０．０５％、Ｎ≦０．０５％
Although the balance is substantially Fe, impurity elements such as C, Si, Mn, P, S, O, and N are contained. These elements may be contained in the following ranges as a range that does not adversely affect the magnetic properties of the magnetic powder compact, and are desirable regulated amounts.
C ≦ 0.10%, Si ≦ 0.50%, Mn ≦ 0.50%,
P ≦ 0.05%, S ≦ 0.05%, O ≦ 0.05%, N ≦ 0.05%
また、磁性粉末の表面がＡｌＮを主体とする皮膜で覆われていることとしたのは、先述したように、磁性粉末の電気抵抗を高めるためである。尚、本発明において、ＡｌＮを主体とする皮膜とは、磁性粉末をエックス線回折により定性分析した際、粉末母相であるフェライト相以外に検出される回折ピ―クにおいて、回折強度の総和の５０％以上をＡｌＮのピ―クが占めている状態を指す。 The reason why the surface of the magnetic powder is covered with a film mainly composed of AlN is to increase the electric resistance of the magnetic powder as described above. In the present invention, the film mainly composed of AlN is 50% of the sum of diffraction intensities in a diffraction peak detected in addition to the ferrite phase which is a powder matrix when a magnetic powder is qualitatively analyzed by X-ray diffraction. This refers to the state in which AlN peaks account for over%.
次に、本発明の第二の特徴は、上記の高電気抵抗磁性粉末の製造方法を見出した点にあり、以下に製造方法の規定理由を述べる。質量％でＣｒ：１．０〜３０．０％、Ａｌ：１．０〜８．０％、残部が実質的にＦｅから成る粉末を熱処理する雰囲気を、窒素を含む雰囲気としたのは、熱処理中に粉末中に含まれるＡｌと雰囲気中に含まれるＮを反応させてＡｌＮとするためである。尚、窒素を含む雰囲気としては、例えばその雰囲気中に５０体積％以上の窒素を含んでいればよいが、最も容易で望ましいのは大気中である。 Next, the second feature of the present invention is that a method for producing the above high electrical resistance magnetic powder has been found, and the reasons for defining the production method will be described below. The atmosphere for heat-treating the powder consisting of Cr: 1.0 to 30.0% by mass, Al: 1.0 to 8.0%, and the balance substantially consisting of Fe is a nitrogen-containing atmosphere. This is because Al contained in the powder and N contained in the atmosphere are reacted to form AlN. As an atmosphere containing nitrogen, for example, the atmosphere may contain 50% by volume or more of nitrogen, but the easiest and desirable atmosphere is the atmosphere.
また、熱処理温度の下限を８００℃としたのは、８００℃未満では粉末表面へのＡｌの拡散が十分でないので、ＡｌＮの生成量が少ないためである。一方、熱処理温度の上限を１２５０℃としたのは、１２５０℃を超える範囲では、磁性粉末同士の付着が顕著に起こるためである。より望ましい熱処理温度の範囲は、９００〜１２００℃である。 Moreover, the lower limit of the heat treatment temperature is set to 800 ° C. because if the temperature is lower than 800 ° C., Al is not sufficiently diffused to the powder surface, and thus the amount of AlN produced is small. On the other hand, the reason why the upper limit of the heat treatment temperature is set to 1250 ° C. is that adhesion between the magnetic powders occurs remarkably in the range exceeding 1250 ° C. A more desirable heat treatment temperature range is 900 to 1200 ° C.
次に、望ましい製造方法として、上記の粉末を、雰囲気中に含まれる酸素を固定する易酸化性容器内で熱処理することとしたのは、例えば、窒素と酸素の混合体である大気中で磁性粉末の熱処理を行う場合、大気中の酸素は容器を酸化させることによって消費し、磁性粉末を大気中の窒素と反応させるためである。尚、本発明の易酸化性容器とは、高温で酸化し易く、かつ１２５０℃までの温度に耐えることができる容器であればよく、例としてＳＵＳ４３０等のフェライト系ステンレスやＳＵＳ３０４、ＳＵＳ３１６等のオーステナイト系ステンレス製の容器、あるいは黒鉛製の容器が適している。 Next, as a desirable manufacturing method, the above-mentioned powder is heat-treated in an easily oxidizable container that fixes oxygen contained in the atmosphere. For example, the powder is magnetic in the atmosphere that is a mixture of nitrogen and oxygen. When the heat treatment of the powder is performed, oxygen in the atmosphere is consumed by oxidizing the container, and the magnetic powder is reacted with nitrogen in the atmosphere. The easily oxidizable container of the present invention may be any container that is easily oxidized at a high temperature and can withstand temperatures up to 1250 ° C., and examples thereof include ferritic stainless steel such as SUS430 and austenite such as SUS304 and SUS316. A stainless steel container or a graphite container is suitable.
更に望ましい製造方法として、上記の粉末を、振動を与えながら熱処理することとしたのは、高温で熱処理中の粉末同士の付着を抑制するためである。本発明では、この熱処理時の振動数を特に規定しないが、２０〜１００Ｈｚであることが望ましい。 Further, as a desirable manufacturing method, the above-mentioned powder is heat-treated while applying vibration, in order to suppress adhesion of the powders during the heat-treatment at a high temperature. In the present invention, the frequency during this heat treatment is not particularly specified, but it is preferably 20 to 100 Hz.
そして、本発明の第三の特徴は、上記の高電気抵抗磁性粉末を用いて成る磁性粉末成形体とその製造方法にある。つまり、磁性粉末成形体の組織を規定した理由を述べると、組織を構成する各粒子間の接触面のすべてが、ＡｌＮを主体とする皮膜により実質的に隔離されて成ることとしたのは、各粒子間が電気抵抗の高い皮膜により隔離された磁性粉末成形体とすることによって、該磁性粉末成形体の電気抵抗を高め、交流磁場中で発生する渦電流損を低減するためである。 The third feature of the present invention resides in a magnetic powder compact using the above-mentioned high electrical resistance magnetic powder and a method for producing the same. That is, when the reason for defining the structure of the magnetic powder compact is described, all the contact surfaces between the particles constituting the structure are substantially separated by a film mainly composed of AlN. This is because by forming a magnetic powder molded body in which the particles are separated by a film having a high electric resistance, the electric resistance of the magnetic powder molded body is increased and eddy current loss generated in an alternating magnetic field is reduced.
この高電気抵抗磁性粉末成形体の製造方法としては、先述した本発明の磁性粉末を放電プラズマ焼結により固化成形すると良い。その理由は、放電プラズマ焼結ではＡｌＮやアルミナ（Ａｌ２Ｏ３）等の電気絶縁体をも焼結することができるので、樹脂のような結合剤を添加しなくても、粉末表面に生成したＡｌＮを主体とする皮膜同士を焼結することができるからである。本発明では、この放電プラズマ焼結時の焼結条件を特に規定しないが、高密度の磁性粉末成形体を得るためには、加熱温度８００〜１２５０℃、圧力１０〜１００ＭＰａ、保持時間１００〜１０００秒の範囲が望ましい。放電プラズマ焼結により成形された本発明の磁性粉末成形体は、樹脂を無添加であるが故に高密度である。それ故、交流磁場中での使用に適した高磁束密度の磁性粉末成形体となることが期待でき、モ−タの固定子や回転子への適用が期待できる。 As a method for producing this high electrical resistance magnetic powder compact, the above-described magnetic powder of the present invention is preferably solidified by discharge plasma sintering. The reason is that spark plasma sintering can also sinter electrical insulators such as AlN and alumina (Al 2 O 3 ), so that it can be formed on the powder surface without adding a binder such as resin. This is because the coatings mainly composed of AlN can be sintered. In the present invention, the sintering conditions at the time of spark plasma sintering are not particularly defined, but in order to obtain a high-density magnetic powder compact, a heating temperature of 800 to 1250 ° C., a pressure of 10 to 100 MPa, a holding time of 100 to 1000 A range of seconds is desirable. The magnetic powder molded body of the present invention formed by spark plasma sintering has a high density because no resin is added. Therefore, it can be expected to be a magnetic powder compact having a high magnetic flux density suitable for use in an alternating magnetic field, and application to a stator or rotor of a motor can be expected.
以下の実施例で本発明を更に詳しく説明する。
真空溶解により母合金を溶製後、ガスアトマイズ装置を用いて磁性粉末を作製した。粉末の化学組成（質量％）を表１に示す。表１の化学組成は、本発明の規定範囲内である。
The following examples further illustrate the present invention.
After melting the mother alloy by vacuum melting, magnetic powder was produced using a gas atomizer. Table 1 shows the chemical composition (% by mass) of the powder. The chemical composition in Table 1 is within the specified range of the present invention.
この磁性粉末の内、約５００ｇを易酸化性容器としてＳＵＳ３１６製の容器内に入れ、窒素を含む雰囲気として大気中で熱処理した。この際、ＳＵＳ３１６製の容器に取り付けられたモ―タ―により４０Ｈｚの振動を与えながら熱処理した。熱処理時の平均昇温速度は約２０℃／分、最高到達温度は１０００℃、１０００℃での保持時間は３０分とし、保持後は３００℃まで振動を与えたまま約６℃／分の平均冷却速度で冷却し、３００℃より低温では振動を止めて放冷した。この振動を与えながらの熱処理により、磁性粉末同士の顕著な付着を防ぐことができ、粉末状態のまま磁性粉末を回収することができた。 About 500 g of this magnetic powder was placed in a SUS316 container as an easily oxidizable container and heat treated in the atmosphere as an atmosphere containing nitrogen. At this time, heat treatment was performed while applying a vibration of 40 Hz by a motor attached to a container made of SUS316. The average heating rate during heat treatment is about 20 ° C / min, the maximum temperature reached is 1000 ° C, the holding time at 1000 ° C is 30 minutes, and after holding, the average is about 6 ° C / min with vibration up to 300 ° C. Cooling was performed at a cooling rate, and at a temperature lower than 300 ° C., vibration was stopped and the mixture was allowed to cool. By the heat treatment while applying this vibration, it was possible to prevent the magnetic powders from adhering to each other, and to recover the magnetic powder in the powder state.
上記熱処理後の磁性粉末、及び熱処理を施していない磁性粉末をエックス線回折により定性分析した結果を、それぞれ図１と図２に示す。図１より、熱処理後の磁性粉末からは、粉末母相のフェライト相とＡｌＮが検出されており、粉末母相であるフェライト相以外に検出される回折ピ―クにおいて、回折強度の総和の１００％をＡｌＮのピ―クが占めていることが分かる。すなわち、熱処理後の磁性粉末は、本発明で規定する磁性粉末となっている。一方、熱処理を施していない磁性粉末からは、図２に示すようにＡｌＮは検出されておらず、本発明の比較例である。 The results of qualitative analysis of the magnetic powder after the heat treatment and the magnetic powder not subjected to the heat treatment by X-ray diffraction are shown in FIGS. 1 and 2, respectively. From FIG. 1, the ferrite phase and AlN of the powder mother phase are detected from the magnetic powder after the heat treatment. In the diffraction peaks detected other than the ferrite phase that is the powder mother phase, the total diffraction intensity of 100 is obtained. It can be seen that the AlN peak occupies%. That is, the magnetic powder after the heat treatment is a magnetic powder defined in the present invention. On the other hand, AlN is not detected from the magnetic powder not subjected to heat treatment as shown in FIG. 2, which is a comparative example of the present invention.
熱処理によってＡｌＮを生成した本発明の磁性粉末と、熱処理を施さずにＡｌＮが検出されていない比較例の磁性粉末の表面形態を走査型電子顕微鏡により観察した像を、それぞれ図３と図４に示す。両者の表面形態は明らかに異なっており、熱処理によって生成したＡｌＮが、磁性粉末の表面を覆う皮膜として存在している。 FIGS. 3 and 4 show images obtained by observing, with a scanning electron microscope, the surface morphology of the magnetic powder of the present invention in which AlN was generated by heat treatment and the magnetic powder of a comparative example in which AlN was not detected without heat treatment, respectively. Show. The surface forms of both are clearly different, and AlN produced by heat treatment exists as a film covering the surface of the magnetic powder.
本発明の磁性粉末と比較例の磁性粉末から、それぞれ約２ｇずつ試料を取り出し、各磁性粉末別に純銅製の治具内に充填、圧粉して直径１１ｍｍ、厚さ３ｍｍ程度の２種類の圧粉体を得た。磁性粉末そのものの電気抵抗を測定することは困難であるため、このように磁性粉末を純銅製の治具内に詰めた圧粉体の電気抵抗を測定することで、磁性粉末の電気抵抗として代用する。各治具の両端に５００ｍＡの直流電流を流し、両端の電位差測定から、各磁性粉末の電気抵抗を決定した結果を表２に示す。 About 2 g of each sample is taken out from the magnetic powder of the present invention and the magnetic powder of the comparative example, filled in a jig made of pure copper for each magnetic powder, and compacted into two types of pressures of about 11 mm in diameter and about 3 mm in thickness. A powder was obtained. Since it is difficult to measure the electrical resistance of the magnetic powder itself, measuring the electrical resistance of the green compact filled with the magnetic powder in a pure copper jig in this way can be used as the electrical resistance of the magnetic powder. To do. Table 2 shows the results of determining the electrical resistance of each magnetic powder from a potential difference measurement at both ends by passing a DC current of 500 mA through both ends of each jig.
表２から、比較例の磁性粉末の電気抵抗が２．１１ｍΩであるのに対し、本発明の磁性粉末の電気抵抗は４．８８ｍΩと２倍以上に増加している。本実施例から、粉末表面にＡｌＮを主体とする皮膜を生成することにより、高価な化学的処理によって磁性粉末の表面に絶縁物質を被覆しなくても、高電気抵抗の磁性粉末が得られることが確認された。 From Table 2, the electric resistance of the magnetic powder of the comparative example is 2.11 mΩ, whereas the electric resistance of the magnetic powder of the present invention is 4.88 mΩ, which is more than doubled. From this example, by forming a film mainly composed of AlN on the powder surface, a magnetic powder having high electrical resistance can be obtained without coating the surface of the magnetic powder with an expensive chemical treatment. Was confirmed.
そして、この本発明の高電気抵抗磁性粉末を、放電プラズマ焼結機を用いて固化成形することで、組織を構成する各粒子間の接触面のすべてが、ＡｌＮを主体とする皮膜により実質的に隔離されて成る高電気抵抗の磁性粉末成形体となる。この高電気抵抗の磁性粉末成形体は、樹脂を無添加であるが故に高密度であり、高磁束密度の磁性粉末成形体となるから、交流磁場中で使用されるモ−タの固定子や回転子としての適用が期待できる。 Then, by solidifying and molding the high electrical resistance magnetic powder of the present invention using a discharge plasma sintering machine, all of the contact surfaces between the particles constituting the structure are substantially made of a film mainly composed of AlN. It becomes a magnetic powder molded body of high electrical resistance formed by being isolated by the above. This high electric resistance magnetic powder molded body has a high density because no resin is added, and becomes a magnetic powder molded body with a high magnetic flux density. Application as a rotor can be expected.
本発明は、安価な方法で磁性粉末の電気抵抗を高めることができる点が優れているので、交流磁場中で使用される自動車用モ−タの固定子や回転子として好適である。 Since the present invention is excellent in that the electric resistance of the magnetic powder can be increased by an inexpensive method, the present invention is suitable as a stator or a rotor of an automobile motor used in an alternating magnetic field.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005048817A JP2006233268A (en) | 2005-02-24 | 2005-02-24 | High electric resistance-magnetic powder, its production method, high electric resistance-magnetic powder compact and its production method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005048817A JP2006233268A (en) | 2005-02-24 | 2005-02-24 | High electric resistance-magnetic powder, its production method, high electric resistance-magnetic powder compact and its production method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2006233268A true JP2006233268A (en) | 2006-09-07 |
Family
ID=37041255
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005048817A Pending JP2006233268A (en) | 2005-02-24 | 2005-02-24 | High electric resistance-magnetic powder, its production method, high electric resistance-magnetic powder compact and its production method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2006233268A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014112483A1 (en) * | 2013-01-16 | 2014-07-24 | 日立金属株式会社 | Method for manufacturing powder magnetic core, powder magnetic core, and coil component |
| EP2993672A1 (en) | 2014-09-08 | 2016-03-09 | Toyota Jidosha Kabushiki Kaisha | Powder for magnetic core, method of producing dust core, dust core, and method of producing powder for magnetic core |
| JP2016058732A (en) * | 2014-09-08 | 2016-04-21 | 株式会社豊田中央研究所 | Dust core, powder for magnetic core, method for producing dust core, and method for producing powder for magnetic core |
| JP2018082014A (en) * | 2016-11-15 | 2018-05-24 | トヨタ自動車株式会社 | Dust core and manufacturing method of the same |
| US10535454B2 (en) | 2015-10-14 | 2020-01-14 | Toyota Jidosha Kabushiki Kaisha | Compressed powder core, powders for compressed power core, and method for producing compressed powder core |
-
2005
- 2005-02-24 JP JP2005048817A patent/JP2006233268A/en active Pending
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10008324B2 (en) | 2013-01-16 | 2018-06-26 | Hitachi Metals, Ltd. | Method for manufacturing powder magnetic core, powder magnetic core, and coil component |
| JP5626672B1 (en) * | 2013-01-16 | 2014-11-19 | 日立金属株式会社 | Dust core manufacturing method, dust core and coil component |
| JP2015053491A (en) * | 2013-01-16 | 2015-03-19 | 日立金属株式会社 | Powder magnetic core |
| WO2014112483A1 (en) * | 2013-01-16 | 2014-07-24 | 日立金属株式会社 | Method for manufacturing powder magnetic core, powder magnetic core, and coil component |
| US11011305B2 (en) | 2013-01-16 | 2021-05-18 | Hitachi Metals, Ltd. | Powder magnetic core, and coil component |
| EP2993672A1 (en) | 2014-09-08 | 2016-03-09 | Toyota Jidosha Kabushiki Kaisha | Powder for magnetic core, method of producing dust core, dust core, and method of producing powder for magnetic core |
| CN106471588A (en) * | 2014-09-08 | 2017-03-01 | 丰田自动车株式会社 | Dust core, magnetic core powder and their manufacture method |
| US20170263359A1 (en) * | 2014-09-08 | 2017-09-14 | Toyota Jidosha Kabushiki Kaisha | Powder magnetic core, powder for magnetic cores, and methods of manufacturing them |
| JP2016058732A (en) * | 2014-09-08 | 2016-04-21 | 株式会社豊田中央研究所 | Dust core, powder for magnetic core, method for producing dust core, and method for producing powder for magnetic core |
| CN106471588B (en) * | 2014-09-08 | 2019-05-10 | 丰田自动车株式会社 | Dust core, magnetic core powder and their manufacturing method |
| US10497500B2 (en) * | 2014-09-08 | 2019-12-03 | Toyota Jidosha Kabuhiki Kaisha | Powder magnetic core, powder for magnetic cores, and methods of manufacturing them |
| JP2016058496A (en) * | 2014-09-08 | 2016-04-21 | 株式会社豊田中央研究所 | Dust core, powder for magnetic core, method for producing dust core, and method for producing powder for magnetic core |
| US10535454B2 (en) | 2015-10-14 | 2020-01-14 | Toyota Jidosha Kabushiki Kaisha | Compressed powder core, powders for compressed power core, and method for producing compressed powder core |
| JP2018082014A (en) * | 2016-11-15 | 2018-05-24 | トヨタ自動車株式会社 | Dust core and manufacturing method of the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7871474B2 (en) | Method for manufacturing of insulated soft magnetic metal powder formed body | |
| JP6071211B2 (en) | Low magnetostrictive high magnetic flux density composite soft magnetic material and its manufacturing method | |
| JP4707054B2 (en) | Soft magnetic material, method for producing soft magnetic material, dust core, and method for producing dust core | |
| JP2005220438A (en) | Fe-Cr-Al BASED MAGNETIC POWDER, Fe-Cr-Al BASED MAGNETIC POWDER COMPACT, AND ITS PRODUCTION METHOD | |
| JP5227756B2 (en) | Method for producing soft magnetic material | |
| EP2589450B1 (en) | Composite magnetic material and process for production thereof | |
| JP6265210B2 (en) | Reactor dust core | |
| CN102361715B (en) | Powder for dust core, dust core made of the powder for dust core by powder compaction, and method of producing the powder for dust core | |
| JP4136936B2 (en) | Method for producing composite magnetic material | |
| EP2227344B1 (en) | Powder for magnetic core, method for manufacturing powder for magnetic core, and dust core | |
| JP2007088156A (en) | Soft magnetic material, manufacturing method thereof, powder magnetic core, and manufacturing method thereof | |
| JPWO2005083725A1 (en) | Soft magnetic material, dust core and method for producing the same | |
| TWI289487B (en) | Iron based soft magnetic powder | |
| JP3851655B2 (en) | Heat treatment of magnetic iron powder | |
| EP2963659B1 (en) | Soft magnetic member and reactor | |
| JP2006233268A (en) | High electric resistance-magnetic powder, its production method, high electric resistance-magnetic powder compact and its production method | |
| KR101639960B1 (en) | Iron powder for powder magnetic core and process for producing powder magnetic core | |
| JP2015088529A (en) | Powder-compact magnetic core, powder for magnetic core, and manufacturing method thereof | |
| JP2002121601A (en) | Soft magnetic metal powder particle and treating method thereof, and soft magnetic compact and its manufacturing method | |
| EP1662518A1 (en) | Soft magnetic material and method for producing same | |
| JP2007070719A (en) | DEPOSITION OXIDE FILM COATED Fe-Si BASED FERROUS SOFT MAGNETIC POWDER, AND METHOD FOR PRODUCING THE SAME | |
| JP2010016290A (en) | Ferrous metal magnetic particle, soft magnetic material, powder magnetic core and manufacturing method of them | |
| WO2007052772A1 (en) | Fe-Si TYPE IRON-BASED SOFT MAGNETIC POWDER COATED WITH OXIDE DEPOSIT FILM AND PROCESS FOR PRODUCING THE SAME | |
| US8845957B2 (en) | Method for producing a magnetizable metal shaped body | |
| JP2002275505A (en) | Method for producing soft magnetic compact and soft magnetic compact |