To provide a method for producing an Fe-Si based composite soft magnetic sintered alloy having high density and mechanical strength and exhibiting a high relative permeability at high frequency.
Fe-Si based soft magnetic alloy powder has a first peak centering D1=30-200μm and a second peak centering D2=0.05-0.5×D1μm, in the particle size distribution. The first peak has a larger particle size distribution than that of the second peak, and is coated with a ferrite layer having spinel structure. 1-10 mass% of pure iron powder has a peak centering D3=0.05-0.5×D1μm in the particle size distribution or pure iron powder coated with a ferrite layer having spinel structure. 0.05-1.0 mass% of silicon dioxide powder has mean particle size not larger than 100nm. The above elements are mixed to constitute a composite soft magnetic powder of 100 mass% and then the mixture powder is compacted and sintered.
IGARASHI KAZUNORI
NAKAYAMA RYOJI
MORIMOTO KOICHIRO
Kutaro Kamoi