COMPOSITE SOFT MAGNETIC POWDER, METHOD FOR PRODUCING SAME, AND POWDER MAGNETIC CORE USING SAME

摘要

This composite soft magnetic powder comprises soft magnetic ferrous core particles, which have a particle size of 2-100 µm, and a layer, which has boron nitride as the primary constituent and covers at least a portion of the surface of the soft magnetic ferrous core particles, the covering layer being a polycrystalline layer that comprises boron nitride microcrystalline grains having an average crystal grain size of 3-15 nm and differing crystal axis orientations and that has an average thickness that is no greater than 6.6% of the average particle size of the soft magnetic ferrous core particles. The composite soft magnetic powder is produced by means of (1) mixing an iron nitride powder having an average particle size of 2-100 µm and a boron powder having an average particle size of 0.1-10 µm, (2) heat treating the obtained mixed powder at a temperature of 600-850°C in a nitrogen atomosphere, and (3) eliminating the non-magnetic components.