Hitachi Metals, Ltd.

Proterial, Ltd.

Shin Noguchi

Kazunori Nishimura

Toshio Mihara

Tetsuro Kato

Tetsuroh Katoh

Shigeo Fujii

Chiharu Mitsumata

Hisao Kurosawa

Toshio Kobayashi

Yoshimasa Nishio

Motoki Ohta

Shigeho Tanigawa

Nobuhiko Chiwata

Nobuaki Yoshioka

Shuji Yamanaka

Masami Taguchi

Noriaki Nakayama

The invention provides a powder magnetic core and a method for manufacturing a powder magnetic core through simple compression molding and capable of manufacturing a complicatedly shaped powder magnetic core with reliable high strength and insulating properties. A method for manufacturing a powder magnetic core with a metallic soft magnetic material powder includes: a first step including mixing a soft magnetic material powder and a binder; a second step including compression molding the mixture obtained after the first step; a third step including performing at least one of grinding and cutting on the compact obtained after the second step; and a fourth step including heat-treating the compact after the third step, wherein in the fourth step, the compact is heat-treated so that an oxide layer containing an element constituting the soft magnetic material powder is formed on the surface of the soft magnetic material powder.

Method for manufacturing powder magnetic core, and powder magnetic core

A crystalline Fe-based alloy powder composed of Fe-based alloy particles containing, within a structure thereof, nanocrystal grains having an average grain size of 30 nm or less, and in which d50, which is a particle diameter corresponding to a cumulative frequency of 50% by volume, is from 3.5 &#x3bc;m to 35.0 &#x3bc;m in a cumulative distribution curve that is obtained by laser diffractometry and that shows the relationship between the particle diameter and the cumulative frequency from the small particle diameter side, and a ratio of Fe-based alloy particles having a particle diameter of 2 &#x3bc;m or less to the total of the Fe-based alloy particles, which is determined by laser diffractometry, is from 0% by volume to 8% by volume.

Crystalline Fe-based alloy powder and method for producing same

The invention provides a method for manufacturing a powder magnetic core through simple compression molding and capable of manufacturing a complicatedly shaped powder magnetic core with reliable high strength and insulating properties. The invention is directed to a method for manufacturing a powder magnetic core with a metallic soft magnetic material powder, the method including: a first step including mixing a soft magnetic material powder and a binder; a second step including compression molding the mixture obtained after the first step; a third step including performing at least one of grinding and cutting on the compact obtained after the second step; and a fourth step including heat-treating the compact after the third step, wherein in the fourth step, the compact is heat-treated so that an oxide layer containing an element constituting the soft magnetic material powder is formed on the surface of the soft magnetic material powder.

Method for manufacturing powder magnetic core

A powder magnetic core manufacturing method includes: a first step of mixing a binder with a soft magnetic material powder containing Fe-M (M: Al or Cr)-based alloy particles on which an insulating layer is formed; a second step of filling a pressing die with a mixture obtained through the first step, subjecting the mixture to pressing to obtain a green compact, and slidingly demolding the green compact from the pressing die; a third step of processing the green compact after the second step and removing expansion deformed matter of the alloy particles present in a region of pressing flaws formed on a surface of the green compact during the slidingly demolding; and a fourth step of subjecting the green compact after the third step to heat treatment to oxidize surfaces of the Fe-M (M: Al or Cr)-based alloy particles at high temperature, so that the oxide phase is formed.

A method of producing an atomized powder includes: an atomizing step of forming magnetic alloy particles from a molten metal by an atomizing method, to obtain a slurry in which the magnetic alloy particles are dispersed in an aqueous dispersion medium; a slurry concentration step of causing magnetic separation means to separate the magnetic alloy particles from the slurry to form a concentrated slurry having the magnetic alloy particles of more than 80% by mass, the magnetic separation means using a rotary drum including a magnetic circuit part fixedly disposed at a position where at least a part of the magnetic circuit part is immersed in the slurry and an outer sleeve capable of rotating outside the magnetic circuit part; and a drying step of causing drying means using an air flow dryer to dry the concentrated slurry to form a magnetic alloy powder.

Method of producing atomized powder and method of manufacturing magnetic core

A method for manufacturing a powder magnetic core using a soft magnetic material powder, wherein the method has: a first step of mixing the soft magnetic material powder with a binder, a second step of subjecting a mixture obtained through the first step to pressure forming, and a third step of subjecting a formed body obtained through the second step to heat treatment. The soft magnetic material powder is an Fe&#x2014;Cr&#x2014;Al based alloy powder comprising Fe, Cr and Al. An oxide layer is formed on a surface of the soft magnetic material powder by the heat treatment. The oxide layer has a higher ratio by mass of Al to the sum of Fe, Cr and Al than an alloy phase inside the powder.

Powder magnetic core, and coil component

A magnetic core has a high initial permeability and a small core loss, reducing a core loss at high frequencies; and a coil component including the same. This magnetic core is formed by binding a plurality of Fe-based alloy particles containing Al via an oxide layer containing an Fe oxide. In an X-ray diffraction spectrum of the magnetic core measured using Cu-K&#x3b1; characteristic X-rays, a peak intensity ratio (P1/P2) of peak intensity P1 of a diffraction peak derived from the Fe oxide having a corundum structure appearing in the vicinity of 2&#x3b8;=33.2&#xb0; to peak intensity P2 of a diffraction peak derived from the Fe-based alloy having a bcc structure appearing in the vicinity of 2&#x3b8;=44.7&#xb0; is 0.010 or less (excluding 0). A superlattice peak intensity of an FeAl ordered structure is at most a noise level within a range of 2&#x3b8;=20&#xb0; to 40&#xb0;.

Magnetic core and coil component

There is provided a magnetic core having both high strength and high resistivity, a coil component produced with such a magnetic core, and a magnetic core manufacturing method capable of easily manufacturing a magnetic core with high strength and high resistivity. A method for manufacturing a magnetic core having a structure including dispersed Fe-based soft magnetic alloy particles includes: a first step including mixing a first Fe-based soft magnetic alloy powder containing Al and Cr, a second Fe-based soft magnetic alloy powder containing Cr and Si, and a binder; a second step including pressing the mixture obtained after the first step; and a third step including heat-treating the compact obtained after the second step, wherein the heat treatment forms an oxide layer on the surface of Fe-based soft magnetic alloy particles and bonds the Fe-based soft magnetic alloy particles together through the oxide layer.

Method for manufacturing magnetic core

Provided are a magnetic core having a high initial permeability and a coil component including the same. The magnetic core has an X-ray diffraction spectrum of the magnetic core measured using Cu-K&#x3b1; characteristic X-rays, wherein a peak intensity ratio (P1/P2) of a peak intensity P1 of a diffraction peak of an Fe oxide having a corundum structure appearing in a vicinity of 2&#x3b8;=33.2&#xb0; to a peak intensity P2 of a diffraction peak of the Fe-based alloy having a bcc structure appearing in a vicinity of 2&#x3b8;=44.7&#xb0; is 0.015 or less; and in the X-ray diffraction spectrum, a peak intensity ratio (P3/P2) of a peak intensity P3 of a superlattice peak of an FeAl ordered structure appearing in a vicinity of 2&#x3b8;=26.6&#xb0; to the peak intensity P2 is 0.015 or more and 0.050 or less.

There is provided a magnetic core having high manufacturability and high magnetic permeability, to provide a method for manufacturing such a magnetic core, and to provide a coil component having such a magnetic core. The invention is directed to a magnetic core including: Fe-based soft magnetic alloy particles; and an oxide phase existing between the Fe-based soft magnetic alloy particles, wherein the Fe-based soft magnetic alloy particles include Fe&#x2014;Al&#x2014;Cr alloy particles and Fe&#x2014;Si&#x2014;Al alloy particles.

Magnetic core, method for producing magnetic core, and coil component

Provided are: a metal powder core having a configuration suitable for core loss reduction and strength improvement; a coil component employing this; and a fabrication method for metal powder core. The metal powder core is obtained by dispersing Cu powder among soft magnetic material powder comprising pulverized powder of Fe-based soft magnetic alloy and atomized powder of Fe-based soft magnetic alloy and then by performing compaction. The fabrication method for metal powder core includes: a mixing step of mixing together soft magnetic material powder containing thin-leaf shaped pulverized powder of Fe-based soft magnetic alloy and atomized powder of Fe-based soft magnetic alloy, Cu powder, and a binder and thereby obtaining a mixture; a forming step of performing pressure forming on the mixture obtained at the mixing step; and a heat treatment step of annealing a formed article obtained at the forming step.

Metal powder core, coil component employing same, and fabrication method for metal powder core

An object of the invention is to provide a method that is for manufacturing a powder magnetic core through simple compression molding and capable of manufacturing a complicatedly shaped powder magnetic core with reliable high strength and insulating properties. The invention is directed to a method for manufacturing a powder magnetic core with a metallic soft magnetic material powder, the method including: a first step including mixing a soft magnetic material powder and a binder; a second step including compression molding the mixture obtained after the first step; a third step including performing at least one of grinding and cutting on the compact obtained after the second step; and a fourth step including heat-treating the compact after the third step, wherein in the fourth step, the compact is heat-treated so that an oxide layer containing an element constituting the soft magnetic material powder is formed on the surface of the soft magnetic material powder.

Method for manufacturing powder magnetic core with a metallic soft magnetic material powder

In a metal powder core constructed from soft magnetic material powder and a coil component employing this, a configuration suitable for reduction of a core loss is provided. The metal powder core constructed from soft magnetic material powder is characterized in that Cu is dispersed among the soft magnetic material powder. It is characterized in that, preferably, the soft magnetic material powder is pulverized powder of soft magnetic alloy ribbon and that Cu is dispersed among the pulverized powder of soft magnetic alloy ribbon. Further, it is characterized in that, preferably, the soft magnetic alloy ribbon is a Fe-based nano crystal alloy ribbon or a Fe-based alloy ribbon showing a Fe-based nano crystalline structure and that the pulverized powder has a nano crystalline structure.

Metal powder core comprising copper powder, coil component, and fabrication method for metal powder core

A magnetic core includes alloy phaseseach made of Fe-based soft magnetic alloy grains including M1 (wherein M1 represents both elements of Al and Cr), Si, and R (wherein R represents at least one element selected from the group consisting of Y, Zr, Nb, La, Hf and Ta), and has a structure in which the alloy phasesare connected to each other through a grain boundary phase. In the grain boundary phase, an oxide region is produced. The oxide region includes Fe, M1, Si and R and further includes Al in a larger proportion by mass than the alloy phases

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Mishima-gun, Japan

Shin Noguchi