JP4582848B2 - Magnetic circuit yoke - Google Patents
Magnetic circuit yoke Download PDFInfo
- Publication number
- JP4582848B2 JP4582848B2 JP2000016430A JP2000016430A JP4582848B2 JP 4582848 B2 JP4582848 B2 JP 4582848B2 JP 2000016430 A JP2000016430 A JP 2000016430A JP 2000016430 A JP2000016430 A JP 2000016430A JP 4582848 B2 JP4582848 B2 JP 4582848B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic circuit
- circuit yoke
- powder
- manufacturing
- yoke
- 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
Description
【０００１】
【発明が属する技術分野】
本発明は、磁気回路ヨーク及びその製造方法に関する。
【０００２】
【従来の技術】
磁気回路ヨークは、例えば、磁気ディスク装置のヘッド駆動用ボイスコイルモータの主要部として用いられており、磁気的性質として高い飽和磁束密度と低い保磁力が求められる。また、ヘッド駆動用ボイスコイルモータの小型化、高性能化に伴い、形状はより一層複雑となっている。
【０００３】
これらの要求を満足する磁気回路ヨークの製造方法としては、溶製材を切削加工をした後、複数の部品を組み立てて所定の形状とする方法がある。しかしながら、この方法は、工程数が多いために、生産性が低く、しかも複雑な形状の製品の製造は困難である。
【０００４】
また、焼結法の経済性と良好な成形性を生かして、粉末冶金法により磁気回路ヨークを作製することも試みられている。しかしながら、通常の粉末冶金法による焼結品は、７．２ｇ／ｃｍ3程度以下という低密度であり、空孔の大きさも不均一である。このため、磁気特性には限界があり、要求される特性を十分に満足することはできない。しかも焼結品を直接めっきすることが困難であるために、封孔性、耐食性等も不十分である。特に、部品からのガス発生を嫌うハードディスクドライブ（ＨＤＤ）等の精密機器内の部品としての使用には不適切である。
【０００５】
粉末冶金法による焼結体の密度を向上させる方法として、一旦成形品を仮焼した後、再度成形して焼結させる方法もあるが、この方法は、工程数が多く、生産性が低いことに加えて、得られる焼結体の空孔の大きさが不均一となりやすい。
【０００６】
【発明が解決しようとする課題】
本発明の主な目的は、磁気特性、封孔性、耐食性等が良好であって、しかも生産性がよく、形状の自由度も高い磁気回路ヨークを提供することである。
【０００７】
【課題を解決するための手段】
本発明者は、上記した如き問題点を解決するために、鋭意研究を重ねてきた。
その結果、鉄系合金粉末、パーマロイ系合金粉末等の原料粉末を温間成形法によって成形した後、焼結させる方法によれば、得られる焼結体は、従来の粉末冶金法による焼結体と比べて高密度を有し、空孔が小さく均一な焼結体となることを見出した。そして、この焼結体は、良好な磁気特性を有すると共に、直接メッキ処理を行うことが可能であり、これにより封孔性、耐食性等も簡単に向上させることができることを見出し、ここに本発明を完成するに至った。
【０００８】
即ち、下記の磁気回路ヨーク及びその製造方法を提供するものである。
１． 鉄系金属粉末及びパーマロイ系合金粉末から選ばれた少なくとも一種の原料粉末を温間成形によって成形した後、焼結させることを特徴とする、粉末合金法による焼結体からなり、密度が７．３ｇ／ｃｍ３以上である磁気回路ヨークの製造方法。
２． 焼結体の表面にメッキ皮膜を有する上記項１に記載の磁気回路ヨークの製造方法。
３． 磁気回路ヨークが、ハードディスクドライブ用磁気回路ヨークである上記項１又は２に記載のヨークの製造方法。
４． 焼結させた後、次いで、メッキ処理を行うことを特徴とする、上記項１〜３のいずれかに記載の磁気回路ヨークの製造方法。
５． 原料粉末温度１００〜２００℃、成形圧力４〜８ｔ／ｃｍ２で、成形体密度７．０〜７．６ｇ／ｃｍ３となるまで温間成形を行う上記項１〜４のいずれかに記載の磁気回路ヨークの製造方法。
６． 温間成形用潤滑剤を添加した原料粉末を用いる上記項１〜５のいずれかに記載の磁気回路ヨークの製造方法。
【０００９】
【発明の実施の形態】
本発明の磁気回路ヨークは、粉末冶金法による焼結体であって、７．３ｇ／ｃｍ3以上、好ましくは７．４ｇ／ｃｍ 3 程度以上の密度を有するものである。
【００１０】
上記した条件を満足する磁気回路ヨークは、鉄系金属粉末及びパーマロイ系合金粉末から選ばれた少なくとも一種の原料粉末を用い、温間成形法によって所定の形状に成形した後、焼結させることによって製造できる。
【００１１】
原料粉末としては、粉末合金用原料として知られている材料から、要求される特性に応じて適宜選択すればよい。鉄系金属粉末の例としては、純鉄粉末の他、Ｆｅ−Ｐ系合金、Ｆｅ−Ｓｉ系合金、Ｆｅ−Ｃｕ系合金等を挙げることができ、パーマロイ系合金粉末の例としては、Ｆｅ−Ｎｉ系合金等を挙げることができる。特に、原料単価が安く、経済的に有利な点で、純鉄粉末を原料粉末とすることが好ましい。
【００１２】
原料粉末の粒径については、特に限定的ではないが、通常、１０μｍから２００μｍ程度とすればよい。
【００１３】
本発明の磁気回路ヨークを製造するには、原料粉末の成形方法としては温間成形法を採用する。温間成形法を採用することによって、密度の高い成形体を簡単に得ることができ、この様な成形体を後述する焼結工程で焼結させることによって、７．３ｇ／ｃｍ3以上という高い密度を有し、しかも空孔が小さく均一な焼結体を製造することが可能となる。温間成形法としては、例えば、原料粉末を１００〜２００℃程度に加温した状態で、４〜８ｔ／ｃｍ2程度の成形圧力で所定の形状に成形すればよい。この際、成形体の密度は、７．０〜７．６ｇ／ｃｍ3程度とすることが好ましい。
【００１４】
特に、本発明では、温間成形の際に、原料粉末の流動性を向上するための潤滑剤を配合することが好ましい。この様な潤滑剤を添加して温間成形を行うことによって、上記した所定の密度範囲の成形体を簡単に製造できる。潤滑剤の種類については、温間成形の際に原料粉末の流動性を向上できる温間成形用潤滑剤として、公知のものを適宜選定して用いればよい。この様な温間成形用潤滑剤の具体例としては、例えば、特開平５−２７１７０９号公報に記載されている炭素数６〜１２の線状ジカルボン酸約１０〜３０重量％、炭素数１０〜２２のモノカルボン酸約１０〜３０重量％、及び一般式（ＣＨ2）ｘ（ＮＨ2）2（ｘは２〜６の整数）のジアミン約４０〜８０重量％の縮合体からなるアミド潤滑剤や、特開平１０−２１９３０２号公報に記載されているポリマー粉末（酸化ポリエチレン、ポリエチレン、ポリプロピレン、ポリアセタール等）と固体潤滑剤（ステアリン酸リチウム、ステアリン酸カルシウム、ステアリン酸マグネシウム、エチレンビスステアロアミド等）とを、好ましくは（ポリマー粉末／固体潤滑剤）＝０．２以上（重量比）の割合で含む潤滑剤等を挙げることができる。
【００１５】
潤滑剤の添加量については特に限定的ではなく、使用する潤滑剤の種類に応じて適当な量だけ用いればよいが、通常、原料粉末１００重量部に対して、０．１〜１重量部程度用いることが好ましく、０．４〜０．８重量部程度用いることがより好ましい。
【００１６】
次いで、得られた成形体を焼結させることによって、目的とする磁気回路ヨークを得ることができる。
【００１７】
焼結は、還元性雰囲気、不活性ガス雰囲気、真空雰囲気等の非酸化性雰囲気中で行えば良く、焼結温度は、特に限定的ではないが、通常、１０００〜１３００℃程度とすればよい。焼結時間についても、特に限定的ではないが、通常、１０分〜６０分程度とすればよい。
【００１８】
上記した方法によれば、従来の焼結法により得られる磁気回路ヨークにはない、７．３ｇ／ｃｍ3以上という高密度を有する磁気回路ヨークが得られる。この磁気回路ヨークは、焼結体中の空孔径が非常に小さく、均一であり、従来の焼結品と比べて、優れた磁気特性を有する。
【００１９】
更に、該焼結体は、空孔径が非常に小さいことから、直接メッキ処理を行うことによって、焼結体の表面全体に均一なメッキ皮膜を形成できる。通常は、ショットブラスト等の方法によって、焼結体表面にある空孔の目つぶれが生じる程度に空孔径を小さくした後、バレル処理によって、エッジ部のバリを除去した後、メッキ処理を行うことが好ましい。
【００２０】
メッキ方法については特に限定はなく、公知の電気メッキ法、無電解メッキ法等を適宜適用できる。メッキ金属としても特に限定はなく、用途に応じて適宜選定すればよいが、複雑な形状の製品に対して膜厚のムラが少なく均一なメッキ皮膜を形成できる点からは、無電解ニッケルメッキが好ましい。メッキ皮膜の膜厚についても、特に限定はないが、通常、５〜２０μｍ程度とすればよい。また、より封孔性を向上させるためには、下地として銅メッキ皮膜を形成することが好ましく、例えば、５〜１０μｍ程度の銅メッキ皮膜を形成した後、５〜２０μｍ程度の無電解ニッケルメッキ皮膜を形成する方法等が好適である。
【００２１】
この様な方法によれば、前記した方法で得られる焼結体が高密度で空孔径が小さいことから、焼結体の全体を均一なメッキ皮膜で直接被覆することができる。その結果、メッキ処理後の焼結体は、従来の焼結品と比べて、封孔性、耐食性等が大きく向上する。
【００２２】
本発明の磁気回路ヨークは、磁気回路ヨークとして、従来から公知の各種用途に使用できる。特に、本発明の磁気回路ヨークは、表面の空孔が小さく、しかもメッキ皮膜を形成した焼結体は、焼結体表面の空孔がメッキ皮膜で完全に覆われるため、部品からのガス発生を嫌うハードディスクドライブ（ＨＤＤ）等の精密機器用の磁気回路ヨークとして非常に有用性が高いものである。
【００２３】
【発明の効果】
本発明によれば、以下の様な顕著な効果が達成される。
（１）従来の焼結品と比べて、高密度であり、空孔が均一で小さいため、優れた磁気特性を有する。
（２）空孔径が小さいために、簡単な方法で均一なメッキ皮膜を形成できる。その結果、封孔性、耐食性等の良好な磁気回路用ヨークとなる。
（３）溶製材を用いて磁気回路ヨークを製造する方法と比較すると、工程数が少ないために生産性が高く、しかも形状の自由度が高い。
【００２４】
【実施例】
以下、実施例を挙げて本発明を更に詳細に説明する。
実施例１
純鉄粉（ヘガネス社製アトマイズ純鉄粉ＡＢＣ１００．３０、粒径３０〜２００μｍ）１００重量部に対して温間成形用潤滑剤を０．６重量部添加した温間成形用混合粉を原料粉末として用い、金型を１３０℃±５℃に加熱し、原料粉末を１２０℃±５℃に保温した状態で成形圧７ｔ／ｃｍ2で温間成形し、アンモニア分解ガス雰囲気中で１０５０℃±５℃で焼結させた。これをφ４４ｍｍ×φ３２ｍｍ×Ｌ６ｍｍの形状に切削加工して、試験用試料（本発明品）を作製した。
比較例１
純鉄粉（ヘガネス社製アトマイズ純鉄粉ＡＢＣ１００．３０、粒径３０〜２００μｍ）１００重量部に対して潤滑剤としてステアリン酸亜鉛を０．８重量部添加した混合粉を原料粉末として用い、成形圧７ｔ／ｃｍ2で常温で成形し、アンモニア分解ガス雰囲気中で１０５０℃±５℃で焼結させた。これをφ４４ｍｍ×φ３２ｍｍ×Ｌ６ｍｍの形状に切削加工して、試験用試料（比較品１）を作製した。
以上の方法で得た本発明品及び比較品１について、密度の測定結果を下記表１に示す。
【００２５】
更に、電磁誘導法による測定法（「実験物理学講座 １７磁気（共立出版（株）発行）」１８０頁１０行〜１８１頁下から５行参照）によって測定した磁気特性を表１に示す。尚、表１には、各製品について５種類の試料の平均値を示し、括弧内には、測定値の上限と下限を示す。
【００２６】
【表１】
以上の結果から、本発明の磁気回路ヨークは、従来の粉末合金法によって製造した磁気回路ヨーク（比較品１）と比べて、優れた磁気特性を有することが判る。
【００２８】
また、本発明の磁気回路ヨークと従来法による粉末成形品（比較品１）について、電子顕微鏡写真によって表面状態を観察したところ、本発明の磁気回路ヨークは、従来法による粉末成形品（比較品１）と比べて、表面の空孔径が非常に小さいものであった。
更に、本発明の磁気回路ヨークと従来法による粉末成形品（比較品１）について、厚さ２０μｍの無電解ニッケル皮膜を形成した後、下記の方法でフェロキシル試験、塩水噴霧試験、及び電子顕微鏡による断面観察を行った。
試験方法
（１）フェロキシル試験
ヘキサシアノ鉄（II）酸カリウム１０ｇ／ｌ、ヘキサシアノ鉄（III）酸カリウム１０ｇ／ｌ及び塩化ナトリウム６０ｇ／ｌを含有する試験液に濾紙を浸漬し、湿った状態の濾紙を試料上に貼り付け、５分後に濾紙を剥がした。次いで、濾紙を水洗し、水分を除去した後、濾紙上の青色斑点の有無を調べた。
（２）塩水噴霧試験
ＪＩＳ Ｚ２３７１−１９９４ Ｂ８５０２に準じた方法で塩水噴霧試験を１サイクル（２４時間）行った。
（３）電子顕微鏡観察
試料表面、及び試料を切断し断面を研磨した試料について、電子顕微鏡により４００倍の倍率で観察した。
フェロキシル試験の結果、本発明品では、青色斑点が全く生じなかったのに対して、従来法による粉末成形品（比較品１）では、青色斑点が発生した。この結果から、ニッケルメッキ皮膜を形成した本発明の磁気回路ヨークは、従来品と比べて封孔性が良好であることが判る。
【００２９】
また、塩水噴霧試験の結果、本発明品では錆が全く生じなかったのに対して、従来法による粉末成形品（比較品１）では若干の錆が認められた。この結果から、ニッケルメッキ皮膜を形成した本発明の磁気回路ヨークは、従来品と比べて耐食性が向上していることが判る。
【００３０】
また、電子顕微鏡による断面観察によれば、本発明品では、表面に形成されたニッケルメッキ皮膜は、従来法による粉末成形品（比較品１）上に形成されたニッケルメッキ皮膜と比べて、均一性が非常に良好であった。[0001]
[Technical field to which the invention belongs]
The present invention relates to a magnetic circuit yoke and a manufacturing method thereof.
[0002]
[Prior art]
The magnetic circuit yoke is used, for example, as a main part of a voice coil motor for driving a head of a magnetic disk device, and a high saturation magnetic flux density and a low coercive force are required as magnetic properties. In addition, the shape of the voice coil motor for driving the head is becoming more complicated as the size and performance of the voice coil motor are reduced.
[0003]
As a method of manufacturing a magnetic circuit yoke that satisfies these requirements, there is a method of cutting a molten material and then assembling a plurality of parts into a predetermined shape. However, since this method has many steps, productivity is low and it is difficult to manufacture a product having a complicated shape.
[0004]
In addition, taking advantage of the economic efficiency and good moldability of the sintering method, it has been attempted to produce a magnetic circuit yoke by a powder metallurgy method. However, a sintered product obtained by a normal powder metallurgy method has a low density of about 7.2 g / cm 3 or less and the size of the pores is not uniform. For this reason, there is a limit to the magnetic characteristics, and the required characteristics cannot be fully satisfied. Moreover, since it is difficult to directly plate the sintered product, the sealing property, corrosion resistance, and the like are insufficient. In particular, it is unsuitable for use as a component in precision equipment such as a hard disk drive (HDD) that dislikes gas generation from the component.
[0005]
As a method of improving the density of the sintered body by the powder metallurgy method, there is also a method in which the molded product is temporarily calcined and then molded and sintered again. However, this method has many steps and low productivity. In addition, the pore size of the obtained sintered body tends to be non-uniform.
[0006]
[Problems to be solved by the invention]
The main object of the present invention is to provide a magnetic circuit yoke having good magnetic properties, sealing properties, corrosion resistance, etc., good productivity, and high degree of freedom in shape.
[0007]
[Means for Solving the Problems]
The present inventor has intensively studied in order to solve the above problems.
As a result, according to a method in which raw powders such as iron-based alloy powder and permalloy-based alloy powder are formed by a warm forming method and then sintered, the obtained sintered body is a sintered body by a conventional powder metallurgy method. It has been found that the sintered body has a high density and small pores and a uniform sintered body. The sintered body has good magnetic properties and can be directly subjected to plating treatment, thereby finding that sealing performance, corrosion resistance, and the like can be easily improved. It came to complete.
[0008]
That is, the following magnetic circuit yoke and its manufacturing method are provided.
1. A powder alloy method sintered body characterized in that at least one raw material powder selected from iron-based metal powder and permalloy-based alloy powder is formed by warm forming and then sintered, and the density is 7. The manufacturing method of the magnetic circuit yoke which is 3 g / cm <3> or more.
2. Item 2. The method of manufacturing a magnetic circuit yoke according to Item 1, wherein the sintered body has a plating film on the surface.
3. Item 3. The method for manufacturing a yoke according to Item 1 or 2, wherein the magnetic circuit yoke is a magnetic circuit yoke for a hard disk drive .
4). Item 4. The method for manufacturing a magnetic circuit yoke according to any one of Items 1 to 3 , wherein after the sintering , plating is performed.
5 . Item 5. The item according to any one of Items 1 to 4, wherein warm forming is performed at a raw material powder temperature of 100 to 200 ° C. and a forming pressure of 4 to 8 t / cm 2 until the green body density is 7.0 to 7.6 g / cm 3 . A method of manufacturing a magnetic circuit yoke.
6 . Item 6. The method for producing a magnetic circuit yoke according to any one of Items 1 to 5 , wherein a raw material powder to which a warm-forming lubricant is added is used.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The magnetic circuit yoke of the present invention is a sintered body by powder metallurgy and has a density of 7.3 g / cm 3 or more, preferably about 7.4 g / cm 3 or more.
[0010]
A magnetic circuit yoke that satisfies the above-described conditions is formed by using at least one raw material powder selected from iron-based metal powders and permalloy-based alloy powders, forming them into a predetermined shape by a warm forming method, and then sintering them. Can be manufactured.
[0011]
The raw material powder may be appropriately selected from materials known as powder alloy raw materials according to required characteristics. Examples of iron-based metal powders include pure iron powders, Fe-P alloys, Fe-Si alloys, Fe-Cu alloys, and the like. Examples of permalloy alloy powders include Fe- Examples thereof include Ni-based alloys. In particular, it is preferable to use pure iron powder as a raw material powder because the raw material unit price is low and it is economically advantageous.
[0012]
The particle size of the raw material powder is not particularly limited, but is usually about 10 μm to 200 μm.
[0013]
In order to manufacture the magnetic circuit yoke of the present invention, a warm forming method is adopted as a forming method of the raw material powder. By adopting the warm forming method, it is possible to easily obtain a compact having a high density, and by sintering such a compact in a sintering step described later, it is as high as 7.3 g / cm 3 or more. A uniform sintered body having a density and small pores can be produced. As the warm forming method, for example, the raw material powder may be formed into a predetermined shape with a forming pressure of about 4 to 8 t / cm 2 in a state where the raw material powder is heated to about 100 to 200 ° C. At this time, the density of the molded body is preferably about 7.0 to 7.6 g / cm 3 .
[0014]
In particular, in the present invention, it is preferable to blend a lubricant for improving the fluidity of the raw material powder during warm forming. By performing warm forming by adding such a lubricant, a molded body having the above-described predetermined density range can be easily produced. About the kind of lubricant, what is necessary is just to select and use a well-known thing suitably as a lubricant for warm forming which can improve the fluidity | liquidity of a raw material powder in the case of warm forming. Specific examples of such a warm forming lubricant include, for example, about 10 to 30% by weight of a linear dicarboxylic acid having 6 to 12 carbon atoms described in JP-A-5-271709, and 10 to 10 carbon atoms. monocarboxylic acids from about 10 to 30 wt% of 22, and the general formula (CH 2) x (NH 2 ) 2 (x is an integer of from 2 to 6) amide lubricant consisting of diamines about 40 to 80 wt% of the condensate of And polymer powders (polyethylene oxide, polyethylene, polypropylene, polyacetal, etc.) and solid lubricants (lithium stearate, calcium stearate, magnesium stearate, ethylene bisstearamide, etc.) described in JP-A-10-219302 And the like, preferably (polymer powder / solid lubricant) = 0.2 or more (weight ratio).
[0015]
The amount of the lubricant added is not particularly limited, and may be used in an appropriate amount depending on the type of lubricant used. Usually, about 0.1 to 1 part by weight with respect to 100 parts by weight of the raw material powder. It is preferable to use about 0.4 to 0.8 part by weight.
[0016]
Subsequently, the target magnetic circuit yoke can be obtained by sintering the obtained molded body.
[0017]
Sintering may be performed in a reducing atmosphere, an inert gas atmosphere, a non-oxidizing atmosphere such as a vacuum atmosphere, and the sintering temperature is not particularly limited, but is usually about 1000 to 1300 ° C. . Although the sintering time is not particularly limited, it is usually about 10 to 60 minutes.
[0018]
According to the above method, a magnetic circuit yoke having a high density of 7.3 g / cm 3 or more, which is not found in a magnetic circuit yoke obtained by a conventional sintering method, can be obtained. This magnetic circuit yoke has a very small pore diameter in the sintered body, is uniform, and has excellent magnetic properties as compared with conventional sintered products.
[0019]
Furthermore, since the sintered body has a very small pore diameter, a uniform plating film can be formed on the entire surface of the sintered body by performing direct plating. Usually, after reducing the hole diameter to such an extent that clogging of the holes on the surface of the sintered body is generated by a method such as shot blasting, the burrs at the edge are removed by barrel treatment, and then plating is performed. Is preferred.
[0020]
The plating method is not particularly limited, and a known electroplating method, electroless plating method, or the like can be appropriately applied. There is no particular limitation on the plating metal, and it may be selected as appropriate according to the application. From the viewpoint of forming a uniform plating film with less unevenness of film thickness on products with complex shapes, electroless nickel plating is preferable. The thickness of the plating film is not particularly limited, but is usually about 5 to 20 μm. Further, in order to further improve the sealing performance, it is preferable to form a copper plating film as a base. For example, after forming a copper plating film of about 5 to 10 μm, an electroless nickel plating film of about 5 to 20 μm The method of forming is suitable.
[0021]
According to such a method, since the sintered body obtained by the above-described method has a high density and a small pore diameter, the entire sintered body can be directly coated with a uniform plating film. As a result, the sintered body after the plating treatment is greatly improved in sealing performance, corrosion resistance and the like as compared with a conventional sintered product.
[0022]
The magnetic circuit yoke of the present invention can be used for various known applications as a magnetic circuit yoke. In particular, the magnetic circuit yoke of the present invention has small pores on the surface, and the sintered body on which the plating film is formed, the holes on the surface of the sintered body are completely covered with the plating film. It is very useful as a magnetic circuit yoke for precision instruments such as hard disk drives (HDD) that do not like.
[0023]
【The invention's effect】
According to the present invention, the following remarkable effects are achieved.
(1) Compared to a conventional sintered product, it has a high density and uniform and small pores, so it has excellent magnetic properties.
(2) Since the pore diameter is small, a uniform plating film can be formed by a simple method. As a result, a magnetic circuit yoke having good sealing performance and corrosion resistance is obtained.
(3) Compared with the method of manufacturing a magnetic circuit yoke using a melted material, the number of steps is small, so the productivity is high and the degree of freedom in shape is high.
[0024]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
The raw powder is a mixed powder for warm molding, in which 0.6 parts by weight of a lubricant for warm molding is added to 100 parts by weight of pure iron powder (Atomized pure iron powder ABC 100.30, particle size 30 to 200 μm, manufactured by Höganäs). The mold was heated to 130 ° C. ± 5 ° C., the raw material powder was warm-molded at a molding pressure of 7 t / cm 2 while being kept at 120 ° C. ± 5 ° C., and 1050 ° C. ± 5 in an ammonia decomposition gas atmosphere. Sintered at ℃. This was cut into a shape of φ44 mm × φ32 mm × L6 mm to prepare a test sample (product of the present invention).
Comparative Example 1
Molding using as a raw material powder a mixed powder in which 0.8 parts by weight of zinc stearate as a lubricant is added to 100 parts by weight of pure iron powder (Atomized pure iron powder ABC 100.30, particle size 30 to 200 μm, manufactured by Höganäs) Molding was performed at normal temperature under a pressure of 7 t / cm 2 , and sintering was performed at 1050 ° C. ± 5 ° C. in an ammonia decomposition gas atmosphere. This was cut into a shape of φ44 mm × φ32 mm × L6 mm to prepare a test sample (Comparative Product 1).
Table 1 below shows the measurement results of the density of the product of the present invention and the comparative product 1 obtained by the above method.
[0025]
Further, Table 1 shows the magnetic properties measured by the measurement method by the electromagnetic induction method (see “Experimental Physics Course 17 Magnetism (issued by Kyoritsu Shuppan Co., Ltd.)”, page 180, line 10 to page 181, line 5 from the bottom). Table 1 shows the average values of five types of samples for each product, and the upper and lower limits of the measured values are shown in parentheses.
[0026]
[Table 1]
From the above results, it can be seen that the magnetic circuit yoke of the present invention has excellent magnetic properties as compared with the magnetic circuit yoke manufactured by the conventional powder alloy method (Comparative product 1).
[0028]
Further, when the surface state of the magnetic circuit yoke of the present invention and the powder molded product by the conventional method (Comparative product 1) was observed by an electron micrograph, the magnetic circuit yoke of the present invention was found to be a powder molded product by the conventional method (Comparative product). Compared with 1), the surface pore diameter was very small.
Furthermore, after forming an electroless nickel film having a thickness of 20 μm on the magnetic circuit yoke of the present invention and the powder molded product by the conventional method (Comparative product 1), the following method was used for the ferroxyl test, the salt spray test, and the electron microscope. Cross-sectional observation was performed.
Test method (1) Feroxyl test A filter paper immersed in a test solution containing 10 g / l of potassium hexacyanoferrate (II), 10 g / l of hexacyanoferrate (III) and 60 g / l of sodium chloride. Was pasted on the sample, and the filter paper was peeled off after 5 minutes. Next, the filter paper was washed with water to remove water, and then the presence or absence of blue spots on the filter paper was examined.
(2) Salt spray test One cycle (24 hours) of the salt spray test was performed by a method according to JIS Z2371-1994 B8502.
(3) Electron microscope observation The sample surface and the sample obtained by cutting the sample and polishing the cross section were observed with an electron microscope at a magnification of 400 times.
As a result of the ferroxyl test, no blue spots were generated in the product of the present invention, whereas blue spots were generated in the powder molded product by the conventional method (Comparative product 1). From this result, it can be seen that the magnetic circuit yoke of the present invention on which the nickel plating film is formed has better sealing performance than the conventional product.
[0029]
Further, as a result of the salt spray test, no rust was generated in the product of the present invention, whereas some rust was observed in the powder molded product by the conventional method (Comparative product 1). From this result, it can be seen that the magnetic circuit yoke of the present invention on which the nickel plating film is formed has improved corrosion resistance compared to the conventional product.
[0030]
In addition, according to the cross-sectional observation with an electron microscope, in the product of the present invention, the nickel plating film formed on the surface is more uniform than the nickel plating film formed on the powder molded product (comparative product 1) by the conventional method. The property was very good.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000016430A JP4582848B2 (en) | 2000-01-26 | 2000-01-26 | Magnetic circuit yoke |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000016430A JP4582848B2 (en) | 2000-01-26 | 2000-01-26 | Magnetic circuit yoke |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001210511A JP2001210511A (en) | 2001-08-03 |
| JP4582848B2 true JP4582848B2 (en) | 2010-11-17 |
Family
ID=18543562
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000016430A Expired - Fee Related JP4582848B2 (en) | 2000-01-26 | 2000-01-26 | Magnetic circuit yoke |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4582848B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1447824B8 (en) * | 2001-10-29 | 2015-10-28 | Sumitomo Electric Sintered Alloy, Ltd. | Composite magnetic material producing method |
| JP5931352B2 (en) * | 2011-05-26 | 2016-06-08 | 株式会社東芝 | Washing machine |
| KR101661602B1 (en) * | 2015-04-30 | 2016-09-30 | (주)창성 | Method for manufacturing soft magnetic yoke |
| KR101661604B1 (en) * | 2015-04-30 | 2016-09-30 | (주)창성 | Soft magnetic yoke |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04264707A (en) * | 1991-02-20 | 1992-09-21 | Hitachi Metals Ltd | Manufacture of sintered yoke |
| JPH10140207A (en) * | 1996-11-13 | 1998-05-26 | Kobe Steel Ltd | Lubricant for warm forming and mixture powder for warm forming |
| JPH11293420A (en) * | 1998-04-08 | 1999-10-26 | Tdk Corp | Ferrous soft magnetic sintered body and its production |
-
2000
- 2000-01-26 JP JP2000016430A patent/JP4582848B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04264707A (en) * | 1991-02-20 | 1992-09-21 | Hitachi Metals Ltd | Manufacture of sintered yoke |
| JPH10140207A (en) * | 1996-11-13 | 1998-05-26 | Kobe Steel Ltd | Lubricant for warm forming and mixture powder for warm forming |
| JPH11293420A (en) * | 1998-04-08 | 1999-10-26 | Tdk Corp | Ferrous soft magnetic sintered body and its production |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001210511A (en) | 2001-08-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA3051184C (en) | Soft magnetic powder, fe-based nanocrystalline alloy powder, magnetic component and dust core | |
| EP1024506B1 (en) | Rare earth metal-based permanent magnet, and process for producing the same | |
| JP2010518252A (en) | Amorphous Fe100-a-bPaMb alloy foil and method for producing the same | |
| CN100519013C (en) | Fe-Ni50 series alloy powder and magnetic powder core manufacturing method | |
| KR101537886B1 (en) | Iron-base soft magnetic powder for dust cores, manufacturing method thereof, and dust core | |
| CN102054551A (en) | Soft magnetic material, powder magnetic core and method for manufacturing the same | |
| JP2019178402A (en) | Soft magnetic powder | |
| JP4582848B2 (en) | Magnetic circuit yoke | |
| US7517555B2 (en) | Copper plating solution and method for copper plating | |
| JPH03173106A (en) | Rare earth permanent magnet with corrosion resistant film and manufacture thereof | |
| CN111243846B (en) | Method capable of simultaneously improving oxidation corrosion resistance of NdFeB powder and magnet | |
| JP2002105503A (en) | Method for manufacturing magnetic material, and magnetic material powder with rust preventive layer thereon and bonded magnet using it | |
| CN109680217B (en) | Method for manufacturing nonmagnetic powder metallurgy part and application | |
| JP4506965B2 (en) | R-T-M-B rare earth permanent magnet and method for producing the same | |
| JPH046806A (en) | Rare-earth element magnet with improved corrosion resistance and its manufacture | |
| JPH0247815A (en) | Manufacture of r-fe-b permanent magnet | |
| JP2018016829A (en) | Fe-based alloy composition | |
| JPH07176443A (en) | Manufacture of anisotropic rare-earth magnet | |
| CN108203792B (en) | Iron-based amorphous powder and preparation method thereof | |
| CN108231314B (en) | Iron-based amorphous alloy powder and production method thereof | |
| US3892601A (en) | Coated air-stable cobalt-rare earth alloy particles and method | |
| JPS63232304A (en) | Permanent magnet excellent in oxidation resistance and manufacture thereof | |
| TWI526544B (en) | Preparation of High Density Powder Metallurgy Metal Soft Magnetic Materials | |
| JP2001176709A (en) | High anticorrosion magnet superior in magnetic characteristics and manufacturing method therefor | |
| JPH08330121A (en) | Permanent magnet body |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20061106 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20090127 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20090204 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20090326 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20100113 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100412 |
|
| A911 | Transfer of reconsideration by examiner before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20100601 |
|
| 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: 20100811 |
|
| 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: 20100831 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130910 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |