Magnetic core and coil component

Patent metadata

Field	Value
Publication number	US-10586646-B2
Application number	US-201716333091-A
Country	US
Kind code	B2
Filing date	Sep 15, 2017
Priority date	Sep 15, 2016
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

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-Kα 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 2θ=33.2° to peak intensity P2 of a diffraction peak derived from the Fe-based alloy having a bcc structure appearing in the vicinity of 2θ=44.7° is 0.010 or less (excluding 0). A superlattice peak intensity of an Fe 3 Al ordered structure is at most a noise level within a range of 2θ=20° to 40°.

First claim

The invention claimed is:

1. A magnetic core comprising Fe-based alloy particles containing Al,
wherein:
in an X-ray diffraction spectrum of the magnetic core measured using Cu-Kα characteristic X-rays, 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 2θ=33.2° to a peak intensity P2 of a diffraction peak of the Fe-based alloy having a bcc structure appearing in a vicinity of 2θ=44.7° is 0.010 or less (excluding 0); and
a superlattice peak intensity of an Fe 3 Al ordered structure is equal to or less than a noise level within a range of 2θ=20° to 40°.

2. The magnetic core according to claim 1 , wherein the magnetic core has a core loss (30 mT, 300 kHz, 25° C.) of 430 kW/m 3 or less, a core loss (10 mT, 5 MHz, 25° C.) of 1100 kW/m 3 or less, and an initial permeability of 45 or more.

3. The magnetic core according to claim 1 ,
wherein:
the Fe-based alloy is represented by a composition formula: aFebAlcCrdSi; and
in mass %, a+b+c+d=100, 6≤b<13.8, 0≤c≤7, and 0≤d≤1 are satisfied.

4. The magnetic core according to claim 3 , wherein 7≤b≤13.5 is satisfied in Al.

5. A coil component comprising the magnetic core according to claim 1 and a coil.

Assignees

• Hitachi Metals Ltd

Inventors

• Mihara Toshio
• Katoh Tetsuroh
• Nishimura Kazunori
• Noguchi Shin

Classifications

• H01F1/147 Primary

  Alloys characterised by their composition {(treatment thereof for enhancing their electromagnetic properties C21D8/12)} · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title

• H01F1/0551

  in the form of particles, e.g. rapid quenched powders or ribbon flakes · CPC title

• H01F1/33

  mixtures of metallic and non-metallic particles; metallic particles having oxide skin · CPC title

• H01F27/2823

  Wires (H01F27/2866 takes precedence) · CPC title