| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a metallic magnetic powder, wherein its grains are uniform and its high coercive force and high saturation magnetic flux density are obtained, even though its grains are very fine. SOLUTION: A manufacturing method for a metallic magnetic powder comprising a first reduction process for subjecting a very fine needle-form powder having as its main component iron oxyhydroxide to a heat treatment in a reducing atmosphere, a second reduction process for subjecting in a reducing atmosphere and at a different temperature from the first reduction process a first intermediate to a heat treatment, and a process for gradually oxidizing the second intermediate, wherein the length of the grain of iron oxyhydroxide is smaller than 0.3 μm, and the temperatures of the first and second reduction processes are respectively within a range of 400-450 deg.C and a range of 470-620 deg.C, and the processing time of the first reduction process is not longer than one- third of the sum of the times for the first and second reduction processes. |
