Method for manufacturing magnetic core

A method for manufacturing a magnetic core having a structure comprising dispersed Fe-based soft magnetic alloy particles, the method comprising:

• a first step comprising mixing a first Fe-based soft magnetic alloy powder containing Al and Cr, a second Fe-based soft magnetic alloy powder containing Cr and Si, and a binder;
• a second step comprising pressing a mixture obtained after the first step;
• and
• a third step comprising heat-treating a compact obtained after the second step,
• wherein
• the heat treatment oxidizes the dispersed Fe-based soft magnetic alloy particles to form an oxide layer on a surface of the dispersed Fe-based soft magnetic alloy particles and bonds the dispersed Fe-based soft magnetic alloy particles together through the oxide layer,
• wherein a percentage of a number of alloy particles of the magnetic core with a maximum size of more than 40 μm is less than 1.0% in a cross-sectional observation image of the magnetic core.

A method for manufacturing a magnetic core having a structure comprising dispersed Fe-based soft magnetic alloy particles, the method comprising:

• a first step comprising mixing a first Fe-based soft magnetic alloy powder containing Al and Cr, a second Fe-based soft magnetic alloy powder containing Cr and Si, and a binder;
• a second step comprising pressing a mixture obtained after the first step;
• and
• a third step comprising heat-treating a compact obtained after the second step,
• wherein
• the heat treatment oxidizes the dispersed Fe-based soft magnetic alloy particles to form an oxide layer on a surface of the dispersed Fe-based soft magnetic alloy particles and bonds the dispersed Fe-based soft magnetic alloy particles together through the oxide layer,
• wherein the first Fe-based soft magnetic alloy powder has an Fe content of 80% by mass or more, a Cr content of 1.0% by mass or more and 9.0% by mass or less, an Al content of 2.0% by mass or more and 10.0% by mass or less, and a remainder being inevitable impurities, and wherein the second Fe-based soft magnetic alloy powder has an Fe content of 80% by mass or more, a Cr content of 1.0% by mass or more and 9.0% by mass or less, a Si content of 1.0% by mass or more and 10.0% by mass or less, and a remainder being inevitable impurities.