| 摘要 |
PROBLEM TO BE SOLVED: To provide: a powder-compact magnetic core low in core loss; a method for producing such a powder-compact magnetic core; and a coil part including such a powder-compact magnetic core.SOLUTION: A powder-compact magnetic core comprises: coated iron powder with an insulation coating; and an aliphatic lubricant. The coated iron powder has an average particle diameter of 200-450 μm; in the coated iron powder, the percentage of powder particles having particle diameters of 75 μm or less is 10 mass% or less. In the powder-compact magnetic core, the content of the aliphatic lubricant is 0.0045-0.02 mass%. A method for producing a powder-compact magnetic core comprises the steps of: filling, in a mold, a powder mixture including coated iron powder having an average particle diameter of 200-450 μm, in which the percentage of powder particles having particle diameters of 75 μm or less is 10 mass% or less, and 0.2-0.5 mass% of an aliphatic lubricant; then, compacting with pressure the powder mixture in the mold to produce a compact including 0.135-0.485 mass% of the aliphatic lubricant; and performing a thermal treatment on the compact, whereby the powder-compact magnetic core including 0.0045-0.02 mass% of the aliphatic lubricant is produced. |
