JP4609339B2 - Powder for powder magnetic core and method for producing powder magnetic core - Google Patents
Powder for powder magnetic core and method for producing powder magnetic core Download PDFInfo
- Publication number
- JP4609339B2 JP4609339B2 JP2006032708A JP2006032708A JP4609339B2 JP 4609339 B2 JP4609339 B2 JP 4609339B2 JP 2006032708 A JP2006032708 A JP 2006032708A JP 2006032708 A JP2006032708 A JP 2006032708A JP 4609339 B2 JP4609339 B2 JP 4609339B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- magnetic
- magnetic core
- sio
- loss
- 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.)
- Expired - Fee Related
Links
- 239000000843 powder Substances 0.000 title claims description 204
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 239000006247 magnetic powder Substances 0.000 claims description 61
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 37
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 36
- 239000000428 dust Substances 0.000 claims description 36
- 238000000465 moulding Methods 0.000 claims description 31
- 238000000137 annealing Methods 0.000 claims description 30
- 238000000034 method Methods 0.000 claims description 20
- 229910044991 metal oxide Inorganic materials 0.000 claims description 19
- 150000004706 metal oxides Chemical class 0.000 claims description 19
- 230000008569 process Effects 0.000 claims description 15
- 229910052710 silicon Inorganic materials 0.000 claims description 15
- 238000002156 mixing Methods 0.000 claims description 13
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 11
- 239000010703 silicon Substances 0.000 claims description 11
- 239000011812 mixed powder Substances 0.000 claims description 8
- 229920005989 resin Polymers 0.000 claims description 8
- 239000011347 resin Substances 0.000 claims description 8
- 229920002050 silicone resin Polymers 0.000 claims description 8
- 229910052782 aluminium Inorganic materials 0.000 claims description 7
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 5
- 238000002360 preparation method Methods 0.000 claims 1
- 238000000576 coating method Methods 0.000 description 28
- 239000011248 coating agent Substances 0.000 description 27
- 239000002245 particle Substances 0.000 description 24
- 239000010408 film Substances 0.000 description 23
- 239000000395 magnesium oxide Substances 0.000 description 23
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 23
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 23
- 238000010438 heat treatment Methods 0.000 description 21
- 229910052751 metal Inorganic materials 0.000 description 20
- 239000002184 metal Substances 0.000 description 20
- 229910017082 Fe-Si Inorganic materials 0.000 description 12
- 229910017133 Fe—Si Inorganic materials 0.000 description 12
- 229910052742 iron Inorganic materials 0.000 description 11
- 238000005261 decarburization Methods 0.000 description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 9
- 229910052799 carbon Inorganic materials 0.000 description 9
- 230000004907 flux Effects 0.000 description 9
- 230000003647 oxidation Effects 0.000 description 9
- 238000007254 oxidation reaction Methods 0.000 description 9
- 230000009467 reduction Effects 0.000 description 8
- 239000002131 composite material Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- 239000012298 atmosphere Substances 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910018125 Al-Si Inorganic materials 0.000 description 5
- 229910018520 Al—Si Inorganic materials 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000011863 silicon-based powder Substances 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- 230000006641 stabilisation Effects 0.000 description 5
- 238000011105 stabilization Methods 0.000 description 5
- 150000002739 metals Chemical class 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000005461 lubrication Methods 0.000 description 3
- 235000019353 potassium silicate Nutrition 0.000 description 3
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 3
- 230000001629 suppression Effects 0.000 description 3
- 229910018540 Si C Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 235000013312 flour Nutrition 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- 229910052718 tin Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000004610 Internal Lubricant Substances 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000004734 Polyphenylene sulfide Substances 0.000 description 1
- 229910004283 SiO 4 Inorganic materials 0.000 description 1
- 239000006087 Silane Coupling Agent Substances 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 235000013339 cereals Nutrition 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000005262 decarbonization Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000006392 deoxygenation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 229920000069 polyphenylene sulfide Polymers 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000012815 thermoplastic material Substances 0.000 description 1
- 229920006259 thermoplastic polyimide Polymers 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Images
Landscapes
- Powder Metallurgy (AREA)
- Soft Magnetic Materials (AREA)
Description
本発明は、モータ、リアクトル等の各種磁心として利用できる圧粉磁心と、その圧粉磁心の製造に適した磁心用粉末と、それらの製造方法に関するものである。 The present invention relates to a dust core that can be used as various magnetic cores such as a motor and a reactor, a magnetic core powder suitable for manufacturing the dust core, and a method for manufacturing the same.
変圧器（トランス）、電動機（モータ）、発電機、スピーカ、誘導加熱器、各種アクチュエータ等、我々の周囲には電磁気を利用した製品が多々ある。これらの製品は交番磁界を利用したものが多く、その交番磁界は、通常、磁心（軟磁石）を中央に配設したコイルによって発生される。このため、電磁機器の性能は、そのコイルの性能に左右され、コイルの性能は、上記磁心の性能に左右される。よって、電磁機器の性能向上や小型化等を図る上で、磁心の性能向上を図ることが非常に重要である。 There are many products that use electromagnetism around us, such as transformers, motors, generators, speakers, induction heaters, and various actuators. Many of these products use an alternating magnetic field, and the alternating magnetic field is usually generated by a coil having a magnetic core (soft magnet) disposed in the center. For this reason, the performance of the electromagnetic device depends on the performance of the coil, and the performance of the coil depends on the performance of the magnetic core. Therefore, it is very important to improve the performance of the magnetic core in order to improve the performance and size of the electromagnetic equipment.
このような磁心には、先ず、交番磁界中で大きな磁束密度が得られることが求められる。次に、交番磁界中で使用したときに、その周波数に応じて生じる高周波損失（鉄損）が少ないことが求められる。この高周波損失には、渦電流損、ヒステリシス損および残留損失があるが、主に問題となるのは、渦電流損とヒステリシス損である。 Such a magnetic core is first required to obtain a large magnetic flux density in an alternating magnetic field. Next, when used in an alternating magnetic field, it is required that the high frequency loss (iron loss) generated according to the frequency is small. The high-frequency loss includes eddy current loss, hysteresis loss, and residual loss. The main problems are eddy current loss and hysteresis loss.
また、電磁機器の部品に応じた磁心の成形性や小型化等を図るために、従来の電磁鋼板に替えて圧粉磁心が磁心として多用されつつある。圧粉磁心は、粒子表面に絶縁被膜を設けた磁性粉末を加圧成形したものである。絶縁被膜を設けることで比抵抗値を高めて渦電流損の低減を図れるし、その高密度化によって磁束密度等の磁気特性を高めることもできる。ちなみに、圧粉磁心に使用される絶縁被膜については、例えば、下記の特許文献１や特許文献２に開示がある。また、圧粉磁心の成形性等に関して、例えば、下記の特許文献３に開示がある。
Further, in order to achieve the formability and miniaturization of the magnetic core according to the parts of the electromagnetic equipment, a dust core is being frequently used as the magnetic core instead of the conventional electromagnetic steel sheet. The dust core is obtained by pressure-molding magnetic powder having an insulating coating on the particle surface. By providing an insulating film, the specific resistance value can be increased to reduce eddy current loss, and magnetic properties such as magnetic flux density can be enhanced by increasing the density. Incidentally, the insulating film used for the dust core is disclosed in, for example,
圧粉磁心の高性能化を図る上で、その高密度化による磁束密度の増加および比抵抗値の確保による渦電流損の低減を図ることは確かに重要である。しかし、最近では、モータのエネルギー効率等を一層向上させるために、その圧粉磁心による損失低減がより強く求められている。前述したように、圧粉磁心による主たる損失として渦電流損の他にヒステリシス損があるところ、このヒステリシス損の低減も非常に重要となっている。特に、数十〜数百ｋＨｚもの高周波数域でのみ圧粉磁心を使用する場合ならいざしらず、それ以下の周波数域で圧粉磁心を使用することを考えれば、ヒステリシス損の低減は圧粉磁心の全体的な損失低減を図る上で非常に重要である。 In order to improve the performance of the powder magnetic core, it is certainly important to increase the magnetic flux density by increasing the density and to reduce the eddy current loss by securing the specific resistance value. However, recently, in order to further improve the energy efficiency and the like of the motor, there is a strong demand for reducing the loss due to the dust core. As described above, as a main loss due to the dust core, there is a hysteresis loss in addition to the eddy current loss. Reduction of this hysteresis loss is also very important. In particular, if a dust core is used only in the high frequency range of several tens to several hundreds of kHz, considering the use of the dust core in a frequency range lower than that, the hysteresis loss can be reduced. This is very important in reducing the overall loss of the magnetic core.
ヒステリシス損の低減を図るには、圧粉磁心の保磁力の低減が有効である。この保磁力は、磁性粉末粒子内に残留する歪み（残留歪）の影響を受け、その歪が多いと保磁力も大きくなる。圧粉磁心は磁性粉末を加圧成形して得られるため、その構成粒子内には多かれ少なかれ残留歪が生じる。従って、ヒステリシス損の低減には、磁性粉末粒子内に一旦生じたその残留歪を除去することが有効である。この歪除去のために、下記特許文献３にもあるように、焼鈍等の熱処理がなされることが多い。磁性粉末の組成にも依るが、Ｆｅを主成分とする圧粉磁心で十分に歪みを除去するには、４５０℃以上、５００℃以上さらには７００℃以上にも加熱することが必要となる。
In order to reduce the hysteresis loss, it is effective to reduce the coercive force of the dust core. This coercive force is affected by the strain (residual strain) remaining in the magnetic powder particles, and the coercive force increases when the strain is large. Since the dust core is obtained by pressure-molding magnetic powder, a residual strain is produced in the constituent particles more or less. Therefore, to reduce the hysteresis loss, it is effective to remove the residual strain once generated in the magnetic powder particles. In order to remove the strain, as described in
圧粉磁心を高温加熱すると、例えば、上記特許文献１にあるリン酸塩からなる絶縁被膜や特許文献２にある熱可塑性材料からなる絶縁被膜は、結晶化して焼結・凝集を生じたり、分解、破壊等してしまう。その結果、ヒステリシス損の低減を図れたとしても、比抵抗値が急減して渦電流損が急増してしまい、結局、鉄損を低減することは難しい。
When the dust core is heated at high temperature, for example, the insulating coating made of phosphate described in
上記特許文献３には、水ガラスの絶縁被膜を表面に形成した磁性粉末からなる圧粉磁心に、７００℃ｘ１時間の焼鈍熱処理を施した実施例が開示されている。そこに記載された比抵抗値を観ると、焼鈍後においても相応の比抵抗値が確保されている。しかし、この場合、１６６６ＭＰａもの高圧で成形しているにも拘わらず、水ガラス量が多いために、言い換えるなら絶縁被膜が厚いために、相対密度が相当に低く、その結果、磁束密度も低いものとなっている。これでは、圧粉磁心の磁気特性向上と損失低減との両立を図れない。
なお、上記特許文献３には、Ｆｅ−Ｓｉ系磁性粉末の製造過程（アトマイズの過程）において、その表面にＳｉＯ２被膜が形成され、その電気抵抗率を高める上で好ましい旨が記載されている。しかし、このときに生じるＳｉＯ２被膜は、１００〜５００ｎｍ以上の被膜として生成している。この磁性粉末を用いて圧粉磁心を製造すると、その相対密度の増加が望めず、その磁束密度も向上しない。また、比較的厚いＳｉＯ２被膜が圧粉成形前から形成されている場合、高圧成形した際に、そのＳｉＯ２被膜が破壊されるため、圧粉磁心の電気抵抗率が却って低下することもある。圧粉磁心の比抵抗値の回復や維持を図るために、さらに、シリコーン系樹脂などを添加し熱処理を行うこともあるが、その場合、圧粉磁心の相対密度および磁束密度がさらに低下することとなる。そこで、磁性粉末の表面に、比較的薄く、耐熱性等に優れた絶縁被膜を形成することが求められていた。
In addition,
そこで、下記特許文献４には、磁性粉末の表面に形成する絶縁被膜を比較的薄く、かつ、耐熱性等に優れたものとすることによって、圧粉磁心の高磁気特性および低損失を両立し得る圧粉磁心用粉末が開示されている。即ち、ＦｅおよびＳｉを主成分とする磁性粉末と、この磁性粉末の粒子表面に形成された絶縁被膜とからなる磁心用粉末を加圧成形して得られる圧粉磁心であって、前記絶縁被膜は、前記磁性粉末を外部酸化処理して得られ、磁性粉末の単位表面積（ｍ２）あたりの酸素量（ｇ）を示す比酸素量（ｇ／ｍ２）が０．００５〜０．０５ｇ／ｍ２である圧粉磁心が開示されている。上記絶縁被膜は、薄くて耐熱性に優れるため、その絶縁被膜により被覆された磁性粉末を用いると、高磁束密度で低ヒステリシス損の圧粉磁心が得られる。
Therefore, in
また、下記特許文献５には、成形性に優れ熱処理温度を高くして十分な歪み取りを行い、磁気特性特にコア損失の優れた複合磁性体を提供することを目的として、金属磁性体と少なくともＡ群金属の酸化物を１種類以上含む構造からなる複合磁性体とした発明が開示されている。ここで、Ａ群金属とは、Ｆｅ，Ａｌ，Ｔｉ，Ｓｎ，Ｓｉ，Ｍｎ，Ｔａ，Ｚｒ，Ｃａ，Ｚｎのうち少なくとも１種類以上を含んだ金属単体あるいは合金である。Ａ群の金属は還元性が強く、他の酸化物あるいは雰囲気から酸素を奪いそれ自身は酸化され安定なＡ群金属の酸化物となり、金属磁性粉の周囲を絶縁し、渦電流損失を低減することができる。 Further, in Patent Document 5 below, for the purpose of providing a composite magnetic body having excellent moldability and high heat treatment temperature to remove sufficient strain and providing magnetic properties, particularly core loss, at least a metal magnetic body and An invention is disclosed in which a composite magnetic body having a structure containing at least one oxide of a group A metal is used. Here, the group A metal is a single metal or an alloy containing at least one of Fe, Al, Ti, Sn, Si, Mn, Ta, Zr, Ca, and Zn. Group A metals are highly reducible, deprive oxygen from other oxides or atmospheres themselves and oxidize to become stable Group A metal oxides, insulate the periphery of metal magnetic powder, and reduce eddy current loss. be able to.
しかしながら、特許文献４及び特許文献５の発明は、磁性粉末を外部酸化処理して絶縁被膜を得るものであり、「外部酸化」即ち「徐酸化処理（安定化処理）」を必要とするものであった。これら従来技術には下記の問題点があった。
However, the inventions of
(１)磁性金属粉末に異種金属、もしくは異種金属と酸化物を添加しているが、金属分は磁性金属粉末中に拡散する可能性があり、磁性金属粉末の純度を低下させ、純度の悪化は鉄損失を悪化させる。 (1) Although different metals or different metals and oxides are added to the magnetic metal powder, the metal content may diffuse into the magnetic metal powder, reducing the purity of the magnetic metal powder and deteriorating the purity. Worsens iron loss.
（２）高温で焼鈍（真空or雰囲気）を行うと、表面の脱炭反応が進行し、表面のＳｉＯ２濃度が薄くなるため、徐酸化処理（約８５０℃、Ｈ２＋Ｎ２雰囲気）を追加しＳｉＯ２濃度を厚くしている。このための「外部酸化」即ち「徐酸化処理（安定化処理）」工程が追加されることでコストアップになる。 (2) If annealing (vacuum or atmosphere) is performed at a high temperature, the surface decarburization reaction proceeds and the surface SiO 2 concentration becomes thin, so a slow oxidation treatment (about 850 ° C., H 2 + N 2 atmosphere) is added. The SiO 2 concentration is increased. For this purpose, an “external oxidation”, that is, a “gradual oxidation treatment (stabilization treatment)” step is added to increase the cost.
本発明は、このような事情に鑑みて為されたものであり、（１）圧粉磁心のヒステリシス損失（ヒス損）と渦電流損失（渦損）を更に低減できる材料を得ること、（２）高温真空焼鈍を行う際、粉末同士の焼結を抑制し、容易に粉末の解砕が可能（扁平粉などの接触面積の大きい粉末には特に有効）とすること、及び（３）徐酸化処理（安定化処理）を不要とし、工程を簡略化してコストダウンに貢献することを目的とする。 The present invention has been made in view of such circumstances, and (1) to obtain a material capable of further reducing hysteresis loss (his loss) and eddy current loss (eddy loss) of a dust core, (2 ) When high-temperature vacuum annealing is performed, sintering between the powders is suppressed, and the powder can be easily crushed (especially effective for powders having a large contact area such as flat powder), and (3) slow oxidation The purpose is to eliminate the need for processing (stabilization processing), simplify the process, and contribute to cost reduction.
本発明者は、Ｆｅ−Ｓｉ粉末またはＦｅ−Ａｌ−Ｓｉ粉末を高温で真空焼鈍する際に、特定の金属酸化物の混合物を添加することで、ヒステリシス損失（ヒス損）と渦電流損失（渦損）が同時に低減でき、同時に、圧粉磁心用粉末同士の焼結を抑制し容易に粉末の解砕が可能（扁平粉などの接触面積の大きい粉末には特に有効）となることを見出し、本発明に到達した。 The present inventor adds hysteresis metal loss (His loss) and eddy current loss (eddy current) by adding a mixture of specific metal oxides when vacuum-annealing Fe-Si powder or Fe-Al-Si powder at high temperature. It can be reduced at the same time, and at the same time, it can be easily pulverized by suppressing sintering of powders for powder magnetic cores (especially effective for powders with large contact areas such as flat powders) The present invention has been reached.
即ち、第１に、本発明は、鉄（Ｆｅ）およびケイ素（Ｓｉ）、または鉄（Ｆｅ）、アルミニウム（Ａｌ）およびケイ素（Ｓｉ）を主成分とする磁性粉末と、該磁性粉末の粒子表面に形成された絶縁被膜及び／又は絶縁粒子とからなる圧粉磁心用粉末の発明であって、該絶縁被膜及び／又は絶縁粒子は、ＳｉＯ２粉末，Ａｌ２Ｏ３粉末，ＣａＯ粉末，ＭｇＯ粉末，ＴｉＯ２粉末，Ｆｅ２Ｏ３粉末，Ｋ２Ｏ粉末、およびＮａ２Ｏ３粉末の群から選ばれる少なくとも２種以上の金属酸化物粉末の複合酸化物であることを特徴とする。 That is, first, the present invention relates to a magnetic powder mainly composed of iron (Fe) and silicon (Si), or iron (Fe), aluminum (Al) and silicon (Si), and a particle surface of the magnetic powder. The present invention relates to a powder for a powder magnetic core comprising an insulating coating and / or insulating particles formed on the insulating coating, and the insulating coating and / or insulating particles are SiO 2 powder, Al 2 O 3 powder, CaO powder, MgO powder. , TiO 2 powder, Fe 2 O 3 powder, K 2 O powder, and Na 2 O 3 powder, which is a composite oxide of at least two kinds of metal oxide powders.
また、本発明は、鉄（Ｆｅ）およびケイ素（Ｓｉ）、または鉄（Ｆｅ）、アルミニウム（Ａｌ）およびケイ素（Ｓｉ）を主成分とする磁性粉末と、該磁性粉末の粒子表面に形成された絶縁被膜及び／又は絶縁粒子と、これらの表面に形成された結合用樹脂とからなる圧粉磁心用粉末の発明であって、該絶縁被膜及び／又は絶縁粒子は、ＳｉＯ２粉末，Ａｌ２Ｏ３粉末，ＣａＯ粉末，ＭｇＯ粉末，ＴｉＯ２粉末，Ｆｅ２Ｏ３粉末，Ｋ２Ｏ粉末、およびＮａ２Ｏ３粉末の群から選ばれる少なくとも２種以上の金属酸化物粉末の複合酸化物であることを特徴とする。 In addition, the present invention is formed on the particle surface of magnetic powder having iron (Fe) and silicon (Si) or iron (Fe), aluminum (Al) and silicon (Si) as main components, and the magnetic powder. It is an invention of a powder for a powder magnetic core comprising an insulating coating and / or insulating particles and a binding resin formed on these surfaces, wherein the insulating coating and / or the insulating particles are SiO 2 powder, Al 2 O A composite oxide of at least two metal oxide powders selected from the group consisting of 3 powder, CaO powder, MgO powder, TiO 2 powder, Fe 2 O 3 powder, K 2 O powder, and Na 2 O 3 powder It is characterized by that.
本発明の圧粉磁心用粉末において、前記金属酸化物粉末がＳｉＯ２粉末とＭｇＯ粉末の組み合わせが特に好ましい。 In the powder for a powder magnetic core of the present invention, the metal oxide powder is particularly preferably a combination of SiO 2 powder and MgO powder.
また、本発明の圧粉磁心用粉末において、前記結合用樹脂としては、シリコーン樹脂、熱可塑性ポリイミド、ポリフェニレンサルファイド等の有機樹脂や、水ガラス等の無機バインダーを用いることができる。これらの中で、シリコーン樹脂が好ましく例示される。 In the powder for powder magnetic core of the present invention, as the binding resin, an organic resin such as silicone resin, thermoplastic polyimide, polyphenylene sulfide, or an inorganic binder such as water glass can be used. Among these, a silicone resin is preferably exemplified.
第２に、本発明は、上記の圧粉磁心用粉末が加圧成形され、熱処理された圧粉磁心である。 Secondly, the present invention is a dust core obtained by pressure-molding and heat-treating the above powder for dust core.
第３に、本発明は、圧粉磁心用粉末の製造方法の発明であり、鉄（Ｆｅ）およびケイ素（Ｓｉ）、または鉄（Ｆｅ）、アルミニウム（Ａｌ）およびケイ素（Ｓｉ）を主成分とする磁性粉末に、ＳｉＯ２粉末，Ａｌ２Ｏ３粉末，ＣａＯ粉末，ＭｇＯ粉末，ＴｉＯ２粉末，Ｆｅ２Ｏ３粉末，Ｋ２Ｏ粉末、およびＮａ２Ｏ３粉末の群から選ばれる少なくとも２種以上の金属酸化物粉末を添加して混合する第１混合工程と、該混合粉末を真空焼鈍する粉末焼鈍工程と、該真空焼鈍された混合粉末に結合用樹脂を添加して混合する第２混合工程とからなる。 3rdly, this invention is invention of the manufacturing method of the powder for powder magnetic cores, and iron (Fe) and silicon (Si), or iron (Fe), aluminum (Al), and silicon (Si) as a main component. At least two kinds selected from the group consisting of SiO 2 powder, Al 2 O 3 powder, CaO powder, MgO powder, TiO 2 powder, Fe 2 O 3 powder, K 2 O powder, and Na 2 O 3 powder The first mixing step of adding and mixing the above metal oxide powder, the powder annealing step of vacuum annealing the mixed powder, and the second mixing of adding and mixing a binding resin to the vacuum annealed mixed powder Process.
本発明の圧粉磁心用粉末の製造方法において、前記金属酸化物粉末としてＳｉＯ２粉末とＭｇＯ粉末の組み合わせが好ましいこと、及び前記結合用樹脂としてシリコーン樹脂が好ましいことは上述の通りである。 In the method for producing a powder for a powder magnetic core of the present invention, a combination of SiO 2 powder and MgO powder is preferable as the metal oxide powder, and a silicone resin is preferable as the binding resin, as described above.
第４に、本発明は、圧粉磁心の製造方法の発明であり、上記の圧粉磁心用粉末の製造工程の後、該圧粉磁心用粉末を加圧成形する工程と、該成形体を熱処理する工程とからなる。 4thly, this invention is invention of the manufacturing method of a powder magnetic core, the process of pressure-molding this powder for powder magnetic cores after the manufacturing process of said powder for powder magnetic cores, and this molded object And a heat treatment step.
鉄（Ｆｅ）およびケイ素（Ｓｉ）、または鉄（Ｆｅ）、アルミニウム（Ａｌ）およびケイ素（Ｓｉ）を主成分とする磁性粉末に、ＳｉＯ２粉末，Ａｌ２Ｏ３粉末，ＣａＯ粉末，ＭｇＯ粉末，ＴｉＯ２粉末，Ｆｅ２Ｏ３粉末，Ｋ２Ｏ粉末、およびＮａ２Ｏ３粉末の群から選ばれる少なくとも２種以上の金属酸化物粉末を添加して混合し、該混合粉末を真空焼鈍することにより、該磁性粉末の粒子表面に、これら金属酸化物粉末の複合酸化物からなる絶縁被膜及び／又は絶縁粒子が形成される。これにより、金属磁性粉末の不純物である炭素（Ｃ）の除去（脱炭：ヒステリシス損失損低減）と金属磁性粉末表面の絶縁コーティングの安定化（粉末表面の絶縁酸化物濃度の低下抑制：渦電流損失抑制）とを両立させることが可能となる。 Magnetic powder containing iron (Fe) and silicon (Si), or iron (Fe), aluminum (Al) and silicon (Si) as main components, SiO 2 powder, Al 2 O 3 powder, CaO powder, MgO powder, Adding and mixing at least two metal oxide powders selected from the group consisting of TiO 2 powder, Fe 2 O 3 powder, K 2 O powder, and Na 2 O 3 powder, and vacuum annealing the mixed powder Thus, an insulating coating and / or insulating particles made of a composite oxide of these metal oxide powders are formed on the surface of the magnetic powder particles. As a result, carbon (C), which is an impurity in the metal magnetic powder, is removed (decarburization: hysteresis loss loss is reduced) and the insulation coating on the surface of the metal magnetic powder is stabilized (inhibition of decrease in the concentration of insulating oxide on the powder surface: eddy current) Loss suppression).
図１に、従来と本発明の脱炭プロセスを模式図で示す。図１（ａ）は、磁性粉末に金属酸化物をまぶした際の従来の脱炭プロセスであり、不純物として炭素を含むＦｅ−Ｓｉ−Ｃ粉末の表面にＳｉＯ２粉末がまぶされている。粉末真空焼鈍時に磁性粉末中のＣは、
ＳｉＯ２＋２Ｃ＝Ｓｉ＋２ＣＯ
Ｃ＋Ｈ２Ｏ→ＣＯ＋Ｈ２
の反応により、ＣＯ及びＨ２ガスとなって拡散する。一部のＳｉＯ２は磁性粉末表面に薄膜を形成してとどまる。
FIG. 1 is a schematic diagram showing a conventional and decarburization process of the present invention. FIG. 1A shows a conventional decarburization process when a metal oxide is coated on a magnetic powder, and a surface of an Fe—Si—C powder containing carbon as an impurity is coated with SiO 2 powder. During powder vacuum annealing, C in the magnetic powder is
SiO 2 + 2C = Si + 2CO
C + H 2 O → CO + H 2
By this reaction, CO and H 2 gas are diffused. Some SiO 2 stays forming a thin film on the surface of the magnetic powder.
図１（ｂ）は、磁性粉末に特定の２種以上の金属酸化物（ＳｉＯ２とＭｇＯ）をまぶした際の本発明の脱炭プロセスであり、不純物として炭素を含むＦｅ−Ｓｉ−Ｃ粉末の表面にＳｉＯ２とＭｇＯ粉末がまぶされている。 FIG. 1B is a decarburization process of the present invention when two or more specific metal oxides (SiO 2 and MgO) are coated on magnetic powder, and Fe—Si—C powder containing carbon as an impurity. The surface is coated with SiO 2 and MgO powder.
この結果、磁性粉末表面の既存ＳｉＯ２だけではなく、酸化物を添加し積極的に脱炭反応を起こさせることができる。また、磁性粉末表面にＳｉＯ２、ＭｇＯが残り、結合剤であるシリコーン樹脂添加後のＳｉＯ２皮膜の安定性を改善させる。 As a result, not only the existing SiO 2 on the surface of the magnetic powder but also an oxide can be added to actively cause a decarburization reaction. Further, SiO 2 and MgO remain on the surface of the magnetic powder, and the stability of the SiO 2 film after the addition of the silicone resin as the binder is improved.
本発明の圧粉磁心用粉末は、Ｆｅ−Ｓｉ系又はＦｅ−Ａｌ−Ｓｉ系磁性粉末の表面に、薄くて均一な耐熱性に優れた複合金属酸化物被膜（絶縁被膜）が形成されたものである。先ず、この絶縁被膜は薄いために、圧粉磁心の高密度化が可能となり、ひいては圧粉磁心の磁気特性を向上させることができる。しかも、この絶縁被膜は均一で耐熱性に優れるため、熱処理を行った場合でも、あまり破壊等せず、圧粉磁心の比抵抗値も急減しない。 The powder for powder magnetic core of the present invention has a thin and uniform composite metal oxide coating (insulating coating) formed on the surface of an Fe-Si or Fe-Al-Si magnetic powder. It is. First, since this insulating film is thin, it is possible to increase the density of the powder magnetic core, and consequently improve the magnetic properties of the powder magnetic core. In addition, since this insulating film is uniform and excellent in heat resistance, even when heat treatment is performed, it does not break down so much and the specific resistance value of the dust core does not decrease rapidly.
従って、本発明の磁心用粉末を用いて加圧成形した粉末成形体に熱処理等を施してなる圧粉磁心は、高密度化による高磁気特性化に加えて、比抵抗値の急減抑止による低渦電流損の確保および保磁力の低下に伴って生じるヒステリシス損の低減を同時に可能とする。つまり、本発明の圧粉磁心によれば、磁気特性の向上および鉄損の低減を非常に高レベルで達成できる。 Accordingly, a powder magnetic core obtained by heat-treating a powder compact that is pressure-molded using the magnetic core powder of the present invention has a low magnetic resistance by suppressing the rapid decrease in specific resistance in addition to high magnetic properties by high density. It is possible to simultaneously secure eddy current loss and reduce hysteresis loss caused by a decrease in coercive force. That is, according to the dust core of the present invention, improvement of magnetic characteristics and reduction of iron loss can be achieved at a very high level.
本発明で行なう「粉末真空焼鈍」は、ＦｅおよびＳｉを主成分とする磁性粉末に、ＳｉＯ２粉末，Ａｌ２Ｏ３粉末，ＣａＯ粉末，ＭｇＯ粉末，ＴｉＯ２粉末，Ｆｅ２Ｏ３粉末，Ｋ２Ｏ粉末、およびＮａ２Ｏ３粉末の群から選ばれる少なくとも２種以上の金属酸化物粉末を混合したものを、１０−２〜１０−４Ｔｏｒｒ、８００〜１０００℃で真空焼鈍するのがよい。該「粉末真空焼鈍」により、該磁性粉末の表面に絶縁被膜が形成された磁心用粉末が得られる。
上述の優れた絶縁被膜の形態や生成メカニズム等の詳細は定かではない。
The “powder vacuum annealing” performed in the present invention is a magnetic powder containing Fe and Si as main components, SiO 2 powder, Al 2 O 3 powder, CaO powder, MgO powder, TiO 2 powder, Fe 2 O 3 powder, K 2 O powder, and a mixture of at least two or more metal oxide powder selected from Na 2 O 3 powder group, 10 -2 to 10 -4 Torr, it is preferable to vacuum annealing at 800 to 1000 ° C. . By this “powder vacuum annealing”, a magnetic core powder having an insulating coating formed on the surface of the magnetic powder is obtained.
Details such as the form of the excellent insulating film and the generation mechanism are not clear.
（１）絶縁被膜
Ｆｅ−Ｓｉ系磁性粉末の表面に形成される本発明の絶縁被膜は、二酸化ケイ素（ＳｉＯ２）、及び酸化マグネシウム（ＭｇＯ）等の金属酸化物によって安定生成したシリコン樹脂皮膜からなると考えられるが、現状、その組成や構造が詳細に解明されている訳ではない。
また、この絶縁被膜は耐熱性に優れる。Ｆｅ−Ｓｉ系磁性粉末からなる圧粉磁心を熱処理する際に、その温度を４５０℃以上、５００℃以上、６００℃以上さらには７００℃以上としても、完全に破壊されることはない。
(1) Insulating coating The insulating coating of the present invention formed on the surface of Fe-Si based magnetic powder is a silicon resin coating that is stably generated by metal oxides such as silicon dioxide (SiO 2 ) and magnesium oxide (MgO). However, at present, the composition and structure have not been elucidated in detail.
Moreover, this insulating film is excellent in heat resistance. When the powder magnetic core made of Fe-Si magnetic powder is heat-treated, even if the temperature is set to 450 ° C. or higher, 500 ° C. or higher, 600 ° C. or higher, or 700 ° C. or higher, it is not completely destroyed.
（２）磁性粉末
本発明で対象とする磁性粉末は、前述のように、ＦｅおよびＳｉを主成分とするＦｅ−Ｓｉ系、またはＦｅ−Ａｌ−Ｓｉ系磁性粉末である。Ｆｅ−Ｓｉ系、Ｆｅ−Ａｌ−Ｓｉ系磁性粉末は、電気抵抗率が比較的高く、比較的安価であることから、軟質磁性粉末として多用されている。そのＳｉ量は、圧粉磁心に求められる比抵抗値、磁束密度、強度、高周波特性、重畳特性等とのかね合いで決定される。例えば、Ｓｉ量は、１〜１０質量％であると好適である。Ｓｉ量が過少では電気抵抗率が小さく渦電流損の低減を図れず、Ｓｉ量が過多となると磁気特性が低下したり成形性が低下して好ましくない。本発明の場合、高圧成形した際の磁性粉末の成形性の点から、Ｓｉ量は０．５〜４．０％さらには１．０〜３．０％であると好ましい。
(2) Magnetic powder As described above, the magnetic powder targeted in the present invention is an Fe-Si-based or Fe-Al-Si-based magnetic powder mainly composed of Fe and Si. Fe-Si-based and Fe-Al-Si-based magnetic powders are frequently used as soft magnetic powders because of their relatively high electrical resistivity and relatively low cost. The amount of Si is determined by the balance with the specific resistance value, magnetic flux density, strength, high frequency characteristics, superposition characteristics, etc. required for the dust core. For example, the Si amount is preferably 1 to 10% by mass. If the amount of Si is too small, the electrical resistivity is small and eddy current loss cannot be reduced. If the amount of Si is too large, the magnetic properties are deteriorated or the formability is lowered, which is not preferable. In the case of the present invention, the Si content is preferably 0.5 to 4.0%, more preferably 1.0 to 3.0%, from the viewpoint of moldability of the magnetic powder during high pressure molding.
Ｆｅ−Ｓｉ系、Ｆｅ−Ａｌ−Ｓｉ系磁性粉末は、所定量のＳｉと残部Ｆｅと不可避不純物とからなる合金粉末でも良いし、その二元系に限らず、アルミニウム（Ａｌ）、スズ（Ｓｎ）、ニッケル（Ｎｉ）、コバルト（Ｃｏ）等を適宜含んでも良い。 The Fe-Si-based and Fe-Al-Si-based magnetic powder may be an alloy powder composed of a predetermined amount of Si, the remaining Fe, and inevitable impurities, and is not limited to the binary system, but may be aluminum (Al), tin (Sn). ), Nickel (Ni), cobalt (Co) or the like may be included as appropriate.
磁性粉末は、ガスアトマイズや水アトマイズ等のアトマイズ粉末でも良いし、合金インゴットをボールミル等で粉砕した粉砕粉でも良い。もっとも、球状の粒子からなるアトマイズ粉末よりも、各粒子の形状が異なる粉砕粉の方が形状効果によって高強度で高強度の圧粉磁心が得られる。 The magnetic powder may be atomized powder such as gas atomized or water atomized, or pulverized powder obtained by pulverizing an alloy ingot with a ball mill or the like. However, a pulverized powder having a different shape of each particle than the atomized powder made of spherical particles can provide a high-strength and high-strength powder magnetic core due to the shape effect.
磁性粉末の粒径は、圧粉磁心の高密度化の観点から、２０〜３００μｍ、さらには５０〜２００μｍであると好ましい。渦電流損の低減を図る観点からは、その粒径が細かい程好ましく、例えば、５０μｍ以下とすると良い。一方、ヒステリシス損の低減を図る観点からは、粒径を粗くする方が好ましく、例えば、１００μｍ以上とすると良い。なお、磁性粉末の分級は、篩い分法等により容易に行えるが、上記粒径は質量累積５０％の平均粒径で考えても良い。 The particle size of the magnetic powder is preferably 20 to 300 μm, more preferably 50 to 200 μm, from the viewpoint of increasing the density of the dust core. From the viewpoint of reducing eddy current loss, the smaller the particle size, the better, for example, 50 μm or less. On the other hand, from the viewpoint of reducing the hysteresis loss, it is preferable to make the particle diameter coarse, for example, 100 μm or more. The magnetic powder can be easily classified by a sieving method or the like, but the particle size may be considered as an average particle size with a mass accumulation of 50%.
（３）圧粉磁心の特性
本発明の圧粉磁心は、薄くて耐熱性のある絶縁被膜で被覆された磁性粉末からなるため、高密度化による高磁気特性と、渦電流損およびヒステリシス損の両面で優れたものとなり得る。
(3) Characteristics of the dust core Since the dust core of the present invention is made of a magnetic powder coated with a thin and heat-resistant insulating film, it has high magnetic characteristics due to high density, eddy current loss and hysteresis loss. It can be excellent on both sides.
（４）圧粉磁心の成形
本発明の圧粉磁心は、例えば、磁心用粉末を成形用金型へ充填する充填工程と、この磁心用粉末を加圧成形する成形工程とを経て得られる。成形用金型へ充填する磁心用粉末は、本発明の絶縁被膜を伴う磁性粉末に、シラン系カップリング剤や他の絶縁剤等を添加した混合粉末であっても良い。成形用金型へ充填した磁心用粉末（上記混合粉末を含む）の加圧成形は、冷間、温間、熱間を問わず、粉末中に内部潤滑剤等を混合した一般的な成形法により行っても良い。しかし、圧粉磁心の高密度化による磁気特性の向上を図る観点から、次に述べる金型潤滑温間加圧成形法を採用するのがより好ましい。これにより、成形圧力を大きくしても、成形用金型の内面と磁性粉末との間でかじりを生じたり抜圧が過大となったりせず、金型寿命の低下も抑制できる。そして、高密度な圧粉磁心を試験レベルではなく、工業レベルで量産可能となる。
(4) Molding of the dust core The dust core of the present invention is obtained, for example, through a filling step of filling the core powder into a molding die and a molding step of pressing the core powder. The magnetic core powder to be filled in the molding die may be a mixed powder obtained by adding a silane coupling agent, another insulating agent, or the like to the magnetic powder with the insulating coating of the present invention. Pressure molding of magnetic core powder (including the above mixed powder) filled in a molding die is a general molding method in which an internal lubricant or the like is mixed in the powder regardless of whether it is cold, warm or hot. May be performed. However, from the viewpoint of improving the magnetic characteristics by increasing the density of the powder magnetic core, it is more preferable to employ the mold lubrication warm pressing method described below. As a result, even if the molding pressure is increased, no galling occurs between the inner surface of the molding die and the magnetic powder, and the release pressure does not become excessive, and a reduction in the mold life can be suppressed. And it becomes possible to mass-produce high-density powder magnetic cores not at the test level but at the industrial level.
成形工程における加圧の程度は、圧粉磁心の仕様や製造設備等により適宜選択されるが、上記金型潤滑温間加圧成形法を用いた場合、従来の成形圧力を超越した高圧力下で成形可能である。このため、硬質なＦｅ−Ｓｉ系磁性粉末であっても、高密度な圧粉磁心を容易に得ることができる。その成形圧力は、例えば、７００ＭＰａ以上、７８５ＭＰａ以上、１０００ＭＰａ以上、１５００ＭＰａ以上、２０００ＭＰａさらには２５００ＭＰａともできる。成形圧力が高圧である程、高密度の圧粉磁心が得られる。もっとも、通常は、２０００ＭＰａ以下で十分である。そこまで高圧成形すると圧粉磁心の密度は真密度に近づき、それ以上の高密度化が実質的に望めず、また、金型寿命や生産性を考慮すればその必要性もないからである。そこで例えば、成形圧力を９８０〜２０００ＭＰａとすると好適である。 The degree of pressurization in the molding process is appropriately selected according to the specifications of the powder magnetic core, manufacturing equipment, etc., but when using the above mold lubrication warm press molding method, it is under a high pressure that exceeds the conventional molding pressure. Can be molded. For this reason, even if it is hard Fe-Si system magnetic powder, a high-density powder magnetic core can be obtained easily. The molding pressure can be, for example, 700 MPa or more, 785 MPa or more, 1000 MPa or more, 1500 MPa or more, 2000 MPa, or even 2500 MPa. The higher the molding pressure, the higher the density magnetic core. However, 2000 MPa or less is usually sufficient. This is because if the high-pressure molding is performed, the density of the powder magnetic core approaches the true density, and further increase in density cannot be substantially desired, and there is no need for it in consideration of the mold life and productivity. Therefore, for example, the molding pressure is preferably 980 to 2000 MPa.
ところで、磁心用粉末を加圧成形すると、その内部には残留応力や残留歪を生じる。これを除去するために、成形工程後の粉末成形体を加熱、徐冷する熱処理工程を施すと好適である。これにより、圧粉磁心の保磁力が低減され、ヒステリシス損が低減される。また、交番磁界に対する追従性等の良好な圧粉磁心が得られる。なお、焼鈍工程で除去される残留歪等は、成形工程前から磁性粉末の粒子内に蓄積された歪等であっても良い。 By the way, when the magnetic core powder is pressure-molded, residual stress and residual strain are generated inside. In order to remove this, it is preferable to perform a heat treatment step of heating and gradually cooling the powder compact after the molding step. Thereby, the coercive force of the dust core is reduced, and the hysteresis loss is reduced. In addition, a good dust core such as followability to an alternating magnetic field can be obtained. The residual strain removed in the annealing step may be strain accumulated in the magnetic powder particles before the molding step.
残留歪等は、熱処理温度が高い程、有効に除去される。もっとも、あまり熱処理温度が高すぎると、本発明の耐熱性を有する絶縁被膜であっても少なくとも部分的な破壊を生じる。そこで、絶縁被膜の耐熱性をも考慮して熱処理温度を決定することが好ましい。例えば、熱処理温度を４５０〜８００℃とすると、残留歪の除去と絶縁被膜の保護の両立を図れて好ましい。加熱時間は、効果と経済性とから考えて、１〜３００分、好ましくは５〜６０分である。 Residual strain and the like are effectively removed as the heat treatment temperature increases. However, if the heat treatment temperature is too high, at least partial destruction occurs even in the heat-resistant insulating film of the present invention. Therefore, it is preferable to determine the heat treatment temperature in consideration of the heat resistance of the insulating coating. For example, when the heat treatment temperature is 450 to 800 ° C., it is preferable to achieve both the removal of residual strain and the protection of the insulating film. The heating time is 1 to 300 minutes, preferably 5 to 60 minutes, in view of the effect and economy.
熱処理を行うときの雰囲気は、非酸化雰囲気中が好ましい。例えば、真空雰囲気や不活性ガス雰囲気である。なお、熱処理工程を非酸化雰囲気中で行うのは、圧粉磁心やそれを構成する磁性粉末が過度に酸化されて、磁気特性や電気特性が低下するのを抑止するためである。具体的には、ＦｅＯのスケールの生成やＦｅ２ＳｉＯ４層が生成する場合がある。また、前述した第２絶縁被膜の形成に加熱が必要な場合、つまり、第２絶縁被膜を焼成する場合、第２絶縁被膜の加熱処理として上記熱処理工程を兼用すると効率的で好ましい。 The atmosphere during the heat treatment is preferably a non-oxidizing atmosphere. For example, a vacuum atmosphere or an inert gas atmosphere. The reason why the heat treatment process is performed in a non-oxidizing atmosphere is to prevent the powder magnetic core and the magnetic powder constituting the powder core from being excessively oxidized and deteriorating the magnetic characteristics and electrical characteristics. Specifically, there is a case where a scale of FeO or a Fe 2 SiO 4 layer is generated. Further, when heating is necessary for the formation of the second insulating film, that is, when the second insulating film is baked, it is efficient and preferable that the heat treatment process is also used as the heat treatment of the second insulating film.
（５）圧粉磁心の用途
本発明の圧粉磁心は、例えば、モータ（特に、コアやヨーク）、アクチュエータ、トランス、誘導加熱器（ＩＨ）、スピーカ等の各種の電磁機器に利用できる。特に、本発明の被覆された磁性粉末からなる圧粉磁心は、高磁束密度と共に焼鈍等によるヒステリシス損の低減も図れ、比較的低周波数域で使用される機器等に有効である。
(5) Use of dust core The dust core of the present invention can be used for various electromagnetic devices such as motors (particularly, cores and yokes), actuators, transformers, induction heaters (IH), and speakers. In particular, the dust core made of the magnetic powder coated according to the present invention can reduce hysteresis loss due to annealing or the like with high magnetic flux density, and is effective for devices used in a relatively low frequency range.
以下、実施例を挙げて本発明をより具体的に説明する。
［１．製造工程］
（実施例）
（１）原料粉末
Ｆｅ−Ｓｉの水アトマイズ粉末又はガスアトマイズ粉末
（２）混合処理
Ｆｅ−１ｗｔ％Ｓｉ粉末＋ＳｉＯ２粉末（０．１４ｗｔ％、粒径：２５．６μｍ）＋ＭｇＯ粉末（０．７ｗｔ％、粒径：３．８μｍ）混合
（３）粉末焼鈍処理
１１００℃×４ｈ、真空中（真空度：１０−２Ｐａ）で処理
（４）コーティング処理
Ｆｅ−Ｓｉ粉末にシリコーン系樹脂０．２ｗｔ％を混合して攪拌、乾燥を実施
（５）粉末成形
金型潤滑温間成形法を用いて面圧１６００ＭＰａにて成形
（６）熱処理
６７５℃×４５ｍｉｎ、Ｎ２雰囲気中で処理
Hereinafter, the present invention will be described more specifically with reference to examples.
[1. Manufacturing process]
(Example)
(1) Raw material powder Fe-Si water atomized powder or gas atomized powder (2) Mixing treatment Fe-1 wt% Si powder + SiO 2 powder (0.14 wt%, particle size: 25.6 μm) + MgO powder (0.7 wt%, Particle size: 3.8 μm) Mixing (3) Powder annealing treatment 1100 ° C. × 4 h, treatment in vacuum (vacuum degree: 10 −2 Pa) (4) Coating treatment 0.2% by weight of silicone resin to Fe—Si powder Mixing, stirring and drying (5) Powder molding Molding at a surface pressure of 1600 MPa using mold lubrication warm molding method (6) Heat treatment 675 ° C x 45 min, treatment in N 2 atmosphere
（比較例）
比較のために、上記（２）のＦｅ−Ｓｉ粉末へのＳｉＯ２粉末とＭｇＯ粉末の混合を行なわずに、（３）粉末焼鈍処理→（４）コーティング処理→（５）粉末成形→（６）熱処理を行った。
(Comparative example)
For comparison, without mixing SiO 2 powder and MgO powder into the Fe—Si powder of (2) above, (3) powder annealing treatment → (4) coating treatment → (5) powder molding → (6 ) Heat treatment was performed.
［２．焼鈍処理による炭素量低減効果］
上記条件で粉末を焼鈍した場合、炭素量及び酸素量が低減された。図２に、未処理の粉と本発明の実施例で得られたＳｉＯ２粉末＋ＭｇＯ粉末混合焼鈍粉の炭素量の対比を示す。また、図３に、未処理の粉と本発明の実施例で得られたＳｉＯ２粉末＋ＭｇＯ粉末混合焼鈍粉の酸素量の対比を示す。
図２及び図３の結果より、本発明により脱炭素及び脱酸素が顕著であることが分かる。
[2. Carbon reduction effect by annealing treatment]
When the powder was annealed under the above conditions, the amount of carbon and the amount of oxygen were reduced. FIG. 2 shows a comparison of the carbon content of the untreated powder and the SiO 2 powder + MgO powder mixed annealing powder obtained in the examples of the present invention. FIG. 3 shows a comparison of the oxygen content of the untreated powder and the SiO 2 powder + MgO powder mixed annealing powder obtained in the example of the present invention.
2 and 3 show that decarbonization and deoxygenation are significant according to the present invention.
［３．鉄損低減効果］
図４に、未処理の粉と、単に真空焼鈍を行なった粉と、本発明の実施例で得られたＳｉＯ２粉末＋ＭｇＯ粉末混合焼鈍粉の、渦電流損とヒステリシス損を合わせた鉄損失の対比を示す。
図４の結果より、受入粉を１１００℃で真空焼鈍することで、Ｃ量の低減及び結晶粒径の粗大化によりヒステリシス損は低減するが、粉末表面のＳｉＯ２濃度が薄くなり、渦電流損が悪化する。それに対し、上記条件のＳｉＯ２及びＭｇＯを添加し、真空焼鈍を行うと、ヒステリシス損と渦電流損低減がはかれる。
[3. Iron loss reduction effect]
FIG. 4 shows the iron loss of the eddy current loss and hysteresis loss of the untreated powder, the powder simply vacuum-annealed, and the SiO 2 powder + MgO powder mixed annealing powder obtained in the example of the present invention. Comparison is shown.
From the results shown in FIG. 4, the hysteresis loss is reduced by vacuum annealing the received powder at 1100 ° C. by reducing the amount of C and increasing the crystal grain size, but the SiO 2 concentration on the powder surface is reduced and eddy current loss is reduced. Gets worse. In contrast, when SiO 2 and MgO under the above conditions are added and vacuum annealing is performed, hysteresis loss and eddy current loss can be reduced.
以上より、本発明によって下記の効果が得られることが分かる。
（１）金属磁性粉末中の不純物（炭素）が低減され、ヒステリシス損が低減する。
（２）粉末中の結晶粒が粗大化し、ヒステリシス損が低減する。
（３）粉末表面に酸化物が存在するために、シリコーン樹脂コーティングによる絶縁被膜が安定に生成し渦電流損が低減する。
（４）ＳｉＯ２及びＭｇＯは、焼結阻害材でもあるため、高温での熱処理時の粉末同士の固着、焼結を阻害し粉末の解砕を容易にする。これは、扁平粉などの表面積が大きく粉末同士の接触面積の大きな粉末には特に有効である。
From the above, it can be seen that the following effects can be obtained by the present invention.
(1) Impurities (carbon) in the metal magnetic powder are reduced, and hysteresis loss is reduced.
(2) The crystal grains in the powder are coarsened and the hysteresis loss is reduced.
(3) Since an oxide is present on the powder surface, an insulating film formed by a silicone resin coating is stably generated, and eddy current loss is reduced.
(4) Since SiO 2 and MgO are also sintering inhibitors, they prevent powders from sticking and sintering during heat treatment at high temperatures and facilitate the powder crushing. This is particularly effective for a powder having a large surface area such as a flat powder and a large contact area between the powders.
圧粉磁心を製造する際に、磁性粉末に、特定の金属酸化物粉末の２種以上を添加して混合し、該混合粉末を真空焼鈍することにより、該磁性粉末の粒子表面に、これら金属酸化物粉末の複合酸化物からなる絶縁被膜及び／又は絶縁粒子を形成することにより、金属磁性粉末の不純物である炭素（Ｃ）の除去（脱炭：ヒステリシス損失損低減）と金属磁性粉末表面の絶縁コーティングの安定化（粉末表面の絶縁酸化物濃度の低下抑制：渦電流損失抑制）とを両立させることが可能となる。また、従来技術で必要であった徐酸化処理（安定化処理）が不要であるので、工程が簡略化されコストダウンに貢献する。 When producing a powder magnetic core, two or more kinds of specific metal oxide powders are added to and mixed with the magnetic powder, and the mixed powder is subjected to vacuum annealing, whereby these metals are formed on the particle surface of the magnetic powder. By forming an insulating film and / or insulating particles composed of a composite oxide of oxide powder, carbon (C), which is an impurity of the metal magnetic powder, is removed (decarburization: hysteresis loss loss reduction) and the surface of the metal magnetic powder is removed. It is possible to achieve both stabilization of the insulating coating (suppression of decrease in the insulating oxide concentration on the powder surface: suppression of eddy current loss). Further, since the gradual oxidation treatment (stabilization treatment) required in the prior art is unnecessary, the process is simplified and the cost is reduced.
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006032708A JP4609339B2 (en) | 2006-02-09 | 2006-02-09 | Powder for powder magnetic core and method for producing powder magnetic core |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006032708A JP4609339B2 (en) | 2006-02-09 | 2006-02-09 | Powder for powder magnetic core and method for producing powder magnetic core |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2007214366A JP2007214366A (en) | 2007-08-23 |
| JP4609339B2 true JP4609339B2 (en) | 2011-01-12 |
Family
ID=38492525
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006032708A Expired - Fee Related JP4609339B2 (en) | 2006-02-09 | 2006-02-09 | Powder for powder magnetic core and method for producing powder magnetic core |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4609339B2 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4888784B2 (en) * | 2007-10-16 | 2012-02-29 | 富士電機株式会社 | Soft magnetic metal particles with insulating oxide coating |
| JP4589374B2 (en) | 2007-11-02 | 2010-12-01 | 株式会社豊田中央研究所 | Powder for magnetic core, dust core and method for producing the same |
| JP4560077B2 (en) | 2007-11-12 | 2010-10-13 | トヨタ自動車株式会社 | Powder for magnetic core and method for producing powder for magnetic core |
| JP5085471B2 (en) * | 2008-09-08 | 2012-11-28 | 株式会社東芝 | Core-shell magnetic material, method for manufacturing core-shell magnetic material, device device, and antenna device. |
| JP4847553B2 (en) * | 2009-04-09 | 2011-12-28 | 株式会社タムラ製作所 | Powder magnetic core and manufacturing method thereof |
| JP4995222B2 (en) * | 2009-04-09 | 2012-08-08 | 株式会社タムラ製作所 | Powder magnetic core and manufacturing method thereof |
| JP4908546B2 (en) * | 2009-04-14 | 2012-04-04 | 株式会社タムラ製作所 | Powder magnetic core and manufacturing method thereof |
| JP5232708B2 (en) * | 2009-04-14 | 2013-07-10 | 株式会社タムラ製作所 | Powder magnetic core and manufacturing method thereof |
| JP5232717B2 (en) * | 2009-04-27 | 2013-07-10 | 株式会社タムラ製作所 | Powder magnetic core and manufacturing method thereof |
| JP5739348B2 (en) * | 2009-12-25 | 2015-06-24 | 株式会社タムラ製作所 | Reactor and manufacturing method thereof |
| JP6891551B2 (en) * | 2017-03-09 | 2021-06-18 | Tdk株式会社 | Powder magnetic core |
| CN107610872A (en) * | 2017-10-31 | 2018-01-19 | 国网江苏省电力公司电力科学研究院 | A kind of composite core preparation method towards large power reactor magnetic conductivity equal to 60 |
| JP2019192868A (en) * | 2018-04-27 | 2019-10-31 | セイコーエプソン株式会社 | Insulator coating soft magnetic powder, dust core, magnetic element, electronic apparatus, and moving body |
| JP7269045B2 (en) * | 2019-03-22 | 2023-05-08 | 日本特殊陶業株式会社 | dust core |
| CN111370197B (en) * | 2019-12-16 | 2021-02-09 | 横店集团东磁股份有限公司 | Preparation method of iron-silicon soft magnetic powder |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001098331A (en) * | 1999-09-28 | 2001-04-10 | Sumitomo Metal Ind Ltd | Method of producing {100} texture silicon steel sheet |
| JP2003217919A (en) * | 2002-01-17 | 2003-07-31 | Nec Tokin Corp | Dust core and high-frequency reactor using the same |
| JP2003332116A (en) * | 2002-05-15 | 2003-11-21 | Hitachi Powdered Metals Co Ltd | Dust core and its manufacturing method |
| JP2005264192A (en) * | 2004-03-16 | 2005-09-29 | Toda Kogyo Corp | Soft magnetic material and method for manufacturing the same, dust core including soft magnetic material |
| JP2006089791A (en) * | 2004-09-22 | 2006-04-06 | Mitsubishi Materials Corp | Method for manufacturing composite soft-magnetic sintered material having high density, high strength, high specific resistance and high magnetic flux density |
| JP2007013069A (en) * | 2005-05-31 | 2007-01-18 | Mitsubishi Materials Pmg Corp | METHOD FOR PRODUCING SOFT MAGNETIC POWDER COATED WITH OXIDE CONTAINING Mg AND Si |
-
2006
- 2006-02-09 JP JP2006032708A patent/JP4609339B2/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001098331A (en) * | 1999-09-28 | 2001-04-10 | Sumitomo Metal Ind Ltd | Method of producing {100} texture silicon steel sheet |
| JP2003217919A (en) * | 2002-01-17 | 2003-07-31 | Nec Tokin Corp | Dust core and high-frequency reactor using the same |
| JP2003332116A (en) * | 2002-05-15 | 2003-11-21 | Hitachi Powdered Metals Co Ltd | Dust core and its manufacturing method |
| JP2005264192A (en) * | 2004-03-16 | 2005-09-29 | Toda Kogyo Corp | Soft magnetic material and method for manufacturing the same, dust core including soft magnetic material |
| JP2006089791A (en) * | 2004-09-22 | 2006-04-06 | Mitsubishi Materials Corp | Method for manufacturing composite soft-magnetic sintered material having high density, high strength, high specific resistance and high magnetic flux density |
| JP2007013069A (en) * | 2005-05-31 | 2007-01-18 | Mitsubishi Materials Pmg Corp | METHOD FOR PRODUCING SOFT MAGNETIC POWDER COATED WITH OXIDE CONTAINING Mg AND Si |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007214366A (en) | 2007-08-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4609339B2 (en) | Powder for powder magnetic core and method for producing powder magnetic core | |
| EP1840907B1 (en) | Soft magnetic material and dust core | |
| JP5501970B2 (en) | Powder magnetic core and manufacturing method thereof | |
| JP4278147B2 (en) | Powder for magnetic core, dust core and method for producing the same | |
| JP4134111B2 (en) | Method for producing insulating soft magnetic metal powder compact | |
| JP5218567B2 (en) | Manufacturing method of dust core | |
| JP2008028162A (en) | Soft magnetic material, manufacturing method therefor, and dust core | |
| JP3861288B2 (en) | Method for producing soft magnetic material | |
| JP2009174034A (en) | Amorphous soft magnetic alloy, amorphous soft magnetic alloy strip, amorphous soft magnetic alloy powder, and magnetic core and magnetic component using the same | |
| EP2153921B1 (en) | Process for producing metallic powder and a powder magnetic core | |
| JP2008172257A (en) | Method for manufacturing insulating soft magnetic metal powder molding | |
| JP2003142310A (en) | Dust core having high electrical resistance and manufacturing method therefor | |
| JP2011243830A (en) | Powder magnetic core and method for manufacturing the same | |
| JP2019178402A (en) | Soft magnetic powder | |
| JP2005286145A (en) | Method for manufacturing soft magnetic material, soft magnetic powder and dust core | |
| JP5427664B2 (en) | SOFT MAGNETIC POWDER FOR Dust Magnetic Material, Dust Magnetic Material Using the Same, and Manufacturing Method | |
| CA2891206C (en) | Iron powder for dust cores | |
| JP2007231330A (en) | Methods for manufacturing metal powder for dust core and the dust core | |
| WO2014171105A1 (en) | Iron powder for dust core and insulation-coated iron powder for dust core | |
| KR100396045B1 (en) | Silicon steel powder processing method for soft magnetic core material and soft magnetic core processing method using this powder | |
| JP6064539B2 (en) | Powder core powder manufacturing method and dust core powder | |
| JP2002075721A (en) | Dust core | |
| JP2021093405A (en) | Method of manufacturing dust core | |
| WO2005024858A1 (en) | Soft magnetic material and method for producing same | |
| JP2022145105A (en) | Powder for magnetic core, method for manufacturing the same, and dust core |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080401 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100215 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100302 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100427 |
|
| 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: 20100914 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100927 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131022 Year of fee payment: 3 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 4609339 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131022 Year of fee payment: 3 |
|
| LAPS | Cancellation because of no payment of annual fees |