Hitachi Metals, Ltd.

Proterial, Ltd.

Toshio Mihara

Shin Noguchi

Kazunori Nishimura

Tetsuroh Katoh

Yoshimasa Nishio

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

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 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

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

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

Magnetic core, coil component and magnetic core manufacturing method

A magnetic core has a structure in which alloy phaseseach including Fe, Al, Cr and Si are dispersed and any adjacent two of the alloy phasesare connected to each other through a grain boundary phase. In this grain boundary phase, an oxide region is produced which includes Fe, Al, Cr and Si, and includes Al in a larger proportion by mass than the alloy phases. This magnetic core includes Al in a proportion of 3 to 10% both inclusive by mass, Cr in a proportion of 3 to 10% both inclusive by mass, and Si in a proportion more than 1% and 4% or less by mass provided that the sum of the quantities of Fe, Al, Cr and Si is regarded as being 100% by mass; and includes Fe and inevitable impurities as the balance of the core.

Method for manufacturing powder magnetic core, powder magnetic core, and coil component

A magnetic core has a structure in which Fe-based soft magnetic alloy particles are connected via a grain boundary. The Fe-based soft magnetic alloy particles contain Al, Cr and Si. An oxide layer containing at least Fe, Al, Cr and Si is formed at the grain boundary that connects the neighboring Fe-based soft magnetic alloy particles. The oxide layer contains an amount of Al larger than that in Fe-based soft magnetic alloy particles, and includes a first region in which the ratio of Al is higher than the ratio of each of Fe, Cr and Si to the sum of Fe, Cr, Al and Si, and a second region in which the ratio of Fe is higher than the ratio of each of Al, Cr and Si to the sum of Fe, Cr, Al and Si. The first region is on the Fe-based soft magnetic alloy particle side.

Growing community of inventors

Mishima-gun, Japan

Toshio Mihara