| 摘要 |
PURPOSE:To obtain the magnet having high magnetic characteristics by a method wherein a sintered body is multistage-aged when the MM(misch metal)-Fe-B magnet of specific composition is manufactured using a powder metallurgy method. CONSTITUTION:The MM, containing 99 wt. % of rare-earth element, Fe and ferroboron (about 20 wt. % of B) are used as raw material, they are fused by high frequency heating in an argon atmosphere, and the MM-Fe-B ingot consisting of MM of 30-60 wt. %, B of 0.5-3.5 wt.% and the remainder composed of Fe is obtained. Then, after said ingot has been coarse-pulverized, it is formed into fine power. After said powder has been molded in a magnetic field, the molded body is sintered. A multistage aging treatment is performed on the sintered body obtained as above at the temperature of 400 deg.C or above. As a result, high magnetic characteristics can be obtained, and an MM compositional region showing high characteristics can also be made larger. |
