Wound magnetic core, alloy core, and method for manufacturing wound magnetic core

Abstract

A method for manufacturing a wound magnetic core of a nanocrystalline soft magnetic alloy ribbon, the method including: a first heat treatment step of subjecting a wound magnetic core, which is formed by winding an amorphous soft magnetic alloy ribbon capable of nanocrystallization, to a heat treatment at a temperature that is 300° C. or higher and below a crystallization start temperature, with a first inner shape correction jig for holding the wound magnetic core in a non-circular shape placed in an internal space of the wound magnetic core; and a second heat treatment step of subjecting the wound magnetic core to a heat treatment for nanocrystallization at a temperature equal to or higher than the crystallization start temperature, with the first inner shape correction jig removed and with at least one second inner shape correction jig placed in the internal space of the wound magnetic core, wherein: a cross section of the second inner shape correction jig perpendicular to a direction in which the second inner shape correction jig extends is smaller than a cross section of the first inner shape correction jig perpendicular to a direction in which the first inner shape correction jig extends; and a magnetic field is applied to the wound magnetic core over a partial period of the second heat treatment step.