| 摘要 |
PROBLEM TO BE SOLVED: To efficiency manufacture alloy powder having a high coercive force and a high residual magnetic flux density in the scale of mass production by subjecting it to dehydrogenating treatment in a specific temperature range after hydrogen occluding treatment, and specifying the cooling rate from the temperature of the dehydrogenating treatment to a specific temperature. SOLUTION: Hydrogen occlusion treatment is performed on an R-T-B alloy (where, the R and T respectively represent one or two or more kinds of rare- earth elements, including Y and Fe or Fe and Co). Then the alloy is subjected to dehydrogenating treatment in the temperature range between of about 700 deg.C and about 900 deg.C. The dehydrogenating treatment is performed in an inert gas atmosphere of Ar gas, He gas, etc., under a vacuum. Then the dehydrogenated product is cooled by specifying the cooling rate from the starting temperature between 700 deg.C and 900 deg.C to about 650 deg.C or 400 deg.C within the range of about 5-50 deg.C/min. This cooling is also performed in an inert gas atmosphere other than N2 gas. Therefore, an alloy powder having high coercive force and high residual magnetic flux density can be manufactured efficiently on a mass production scale. |
