摘要 |
PROBLEM TO BE SOLVED: To provide a method which industrially mass produces rare earth based alloy powder for a permanent magnet, where a rare earth based bonded magnet and a sintered magnet which have stable high coercive force and large remanent magnetization can be obtained, when HDDR treatment of R-T-(M)-B material alloy is performed. SOLUTION: By completing first dehydrogenation treatment under specified conditions, large coercive force can be obtained in a powder state, while large magnetization is maintained in a second dehydrogenation treatment, where a great deal of treatment is enabled. That is, a material alloy of the intermediate product which is obtained in the first treatment can be left as it is, and a great deal of the material alloy for the intermediate product can be treated at a time in the second treatment. Thereby an HDDR-treated powder having high magnetic characteristic can be obtained. |