| 摘要 |
PURPOSE:To manufacture a permanent magnet having high performance at low cost by subjecting the cast ingot of an allay in which rare earth elements, Fe and B are used as material essential components to remelting and casting, subjecting it to specified hot working and thereafter executing heat treatment at a specified temp. CONSTITUTION:R (where R denotes at least one kinds among rare earth elements including Y), Fe and B are used as material essential components. An alloy contg. the above essential components is melted and cast. Next, the cast ingot or the alloy obtd. by executing hot working to the above ingot is remelted and cast. After that, the cast ingot is hot-worked at >=500 deg.C and is then heat-treated at 250 to 1100 deg.C. Furthermore, for attaining its different high coercive force and high performance, after the hot working, it is heat-treated at 750 to 1100 deg.C and is thereafter heat-treated at 250 to 750 deg.C. In this way, the amt. of impurities therein is reduced, by which a fine and uniform columnar structure can be obtd. to the central part of the ingot. |
