Magnetic core powder, magnetic core and coil device using it, and method for producing magnetic core powder
A magnetic core powder including granular powder A of Fe-based, magnetic, crystalline metal material and granular powder B of Fe-based, magnetic, amorphous metal material; the particle size d50A of granular powder A at a cumulative frequency of 50 volume % being 0.5 μm or more and 7.0 μm or less, and the particle size d50B of granular powder B at a cumulative frequency of 50 volume % being more than 15.0 μm, in a cumulative distribution curve showing the relation between particle size and cumulative frequency from the smaller particle size side, determined by a laser diffraction method; the magnetic core powder meeting (d90M−d10M)/d50M of 1.6 or more and 6.0 or less, d10M being a particle size at a cumulative frequency of 10 volume %, d50M being a particle size at a cumulative frequency of 50 volume %, and d90M being a particle size at a cumulative frequency of 90 volume %.
1. A magnetic core powder comprising a granular powder A of an Fe-based, magnetic, crystalline metal material and a granular powder B of an Fe-based, magnetic, amorphous metal material;
said granular powder A having a composition of aFe bSi cCr dAl eC, wherein a=100−b−c−d−e, 0≤b≤12.0, 0≤c≤8.0, 0≤d<13.8, and 0≤e≤0.5, on a %-by-mass basis;
said granular powder B being an Fe—Si—B-based, amorphous, magnetic metal material having a composition of (Fe 1-x Cr x ) a (Si 1-y B y ) 100-a-b C b , wherein x and y meet 0<x≤0.06, and 0.3≤y≤0.7 by atomic ratio, and a and b meet 70≤a≤81, and 0<b≤2 by atomic %, and/or an Fe—P—C-based, magnetic, amorphous metal material having a composition of Fe 100-x-y P x C y , wherein 6.8%≤x≤13.0%, and 2.2%≤y≤13.0% by atomic %;
the particle size d50A of said granular powder A at a cumulative frequency of 50% by volume being 0.5 μm or more and 7.0 μm or less, and the particle size d50B of said granular powder B at a cumulative frequency of 50% by volume being more than 15.0 μm, in a cumulative distribution curve showing the relation between a particle size and a cumulative frequency from the smaller particle size side, which is determined by a laser diffraction method; and
said magnetic core powder meeting (d90M−d10M)/d50M of 1.6 or more and 6.0 or less, wherein d10M represents the particle size of said magnetic core powder at a cumulative frequency of 10% by volume, d50M represents the particle size of said magnetic core powder at a cumulative frequency of 50% by volume, and d90M represents the particle size of said magnetic core powder at a cumulative frequency of 90% by volume,
wherein said granular powder A is present in a mixing ratio of 30% by mass to 70% by mass, wherein the mixing ratio is a ratio of the mass of said granular powder A to the sum of the mass of said granular powder A and the mass of said granular powder B.
2. The magnetic core powder according to claim 1 , wherein said d50A is 1.0 μm or more and 5.0 μm or less.
3. The magnetic core powder according to claim 1 , wherein said Fe-based, magnetic, crystalline metal material is at least one magnetic crystalline material selected from the group consisting of pure iron, Fe—Si—based, magnetic, crystalline materials; Fe—Si—Cr-based, magnetic, crystalline materials; Fe—Si—Al-based, magnetic, crystalline materials; and Fe—Cr—Al-based, magnetic, crystalline materials.
4. A magnetic core using the magnetic core powder recited in claim 1 .
5. A coil device comprising the magnetic core recited in claim 4 .