Magnetic composite

Patent metadata

Field	Value
Publication number	US-11948715-B2
Application number	US-202117408063-A
Country	US
Kind code	B2
Filing date	Aug 20, 2021
Priority date	Aug 21, 2020
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A magnetic composite contains metal magnetic particles and a resin. The metal magnetic particles contain at least one Fe-containing crystalline material, and [Formula 1]Bs×α×{log(γ×1/D+δ×Bs+ε)}{circumflex over ( )}β≥13T, where Bs and D are the saturation flux density in T and the median diameter of crystallites in μm, respectively, of the crystalline material, α=14.3, β=−0.67, γ=752, δ=512, and ε=−815.

First claim

What is claimed is:

1. A magnetic composite comprising first metal magnetic particles and a resin, wherein:
the first metal magnetic particles contain at least one Fe-containing crystalline material; and
Bs ×α×{log(γ×1/ D+δ×Bs +ε)}{circumflex over ( )}β≥13T,  [Formula 1]

where Bs and D are a saturation flux density in T and a median diameter of crystallites in μm, respectively, of the crystalline material, α=14.3,β=−0.67, γ=752, δ=512, and ε=−815, and
the Fe constitutes from 91 wt % to 98 wt % of the first metal magnetic particles, and a Si constitutes from 2 wt % to 9 wt % of the first metal magnetic particles.

2. The magnetic composite according to claim 1 , wherein
the first metal magnetic particles have a median diameter D50 of 10 μm or more and 40 μm or less.

3. The magnetic composite according to claim 1 , wherein
the median diameter of the crystallites of the crystalline material in the first metal magnetic particles is 5 μm or more.

4. The magnetic composite according to claim 1 , further comprising
second metal magnetic particles that have a smaller median diameter D50 than the first metal magnetic particles.

5. The magnetic composite according to claim 4 , wherein
the second metal magnetic particles are of at least one alloy selected from the group consisting of alloys containing Fe and Si, alloys containing Fe and Nb, alloys containing Fe and Cu, alloys containing Fe and P, and Fe-containing amorphous alloys or of Fe.

6. The magnetic composite according to claim 4 , wherein
the second metal magnetic particles have a Vickers hardness equal to or higher than a Vickers hardness of the first metal magnetic particles.

7. The magnetic composite according to claim 4 , wherein
the first metal magnetic particles constitute from 50% by volume to 90% by volume of a total volume of the first and second metal magnetic particles.

8. The magnetic composite according to claim 4 , wherein
the second metal magnetic particles have a median diameter D50 of from 0.5 μm to 6 μm.

9. The magnetic composite according to claim 8 , wherein
the median diameter D50 of the second metal magnetic particles is 2 μm or less, and the second metal magnetic particles have a D90 of 2.8 μm or less.

10. The magnetic composite according to claim 8 , wherein
the median diameter D50 of the second metal magnetic particles is from 3.5 μm to 6 μm.

11. The magnetic composite according to claim 4 , wherein
the second metal magnetic particles contain an Fe-containing crystalline material, and the crystalline material has a median diameter of crystallites equal to or larger than 0.5 times the median diameter D50 of the second magnetic particles.

12. The magnetic composite according to claim 4 , wherein
a ratio of the median diameter of the crystallites of the crystalline material in the first metal magnetic particles to a median diameter of crystallites of a crystalline material in the second metal magnetic particles is from 1.1 to 5.0.

13. An inductor comprising the magnetic composite according to claim 1 .

14. A magnetic composite comprising metal magnetic particles and a resin, wherein:
the first metal magnetic particles contain at least one Fe-containing crystalline material; and
( A ×Fe content in wt %+ B )×α×[log{γ×1/ D +δ×( A ×Fe content in wt %+ B )+ε}]{circumflex over ( )}β≥13,(in wt %)  [Formula 2],

where D is a median diameter of crystallites in μm of the crystalline material, α=14.3, β=−0.67, γ=752, δ=512, ε=−815, A=0.0637, and B=−4.21, and
the Fe constitutes from 91 wt % to 98 wt % of the first metal magnetic particles, and a Si constitutes from 2 wt % to 9 wt % of the first metal magnetic particles.

15. The magnetic composite according to claim 14 , wherein
the first metal magnetic particles have a median diameter D50 of 10 μm or more and 40 μm or less.

16. The magnetic composite according to claim 14 , wherein
the median diameter of the crystallites of the crystalline material in the first metal magnetic particles is 5 μm or more.

Assignees

• Murata Manufacturing Co

Inventors

• Sugiyama Mikito
• Odahara Mitsuru
• Ishida Takuya

Classifications

• H01F1/26 Primary

  by macromolecular organic substances · CPC title

• H01F17/04

  with magnetic core · CPC title

• H01F27/255

  made from particles (H01F27/26 takes precedence) · CPC title

• Y10T428/32

  Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer · CPC title

• H01F2017/048

  with encapsulating core, e.g. made of resin and magnetic powder · CPC title