| 摘要 |
PURPOSE:To provide an R-T-B sintered magnet (R is a rare earth element, and T is Fe, or Fe and Co) high in coercive force and also high in residual magnetic density, and provide an inexpensive thin magnet by obviating the polishing processing after sintering by suppressing the dimensional change at sintering when manufacturing such R-T-B sintered magnet. CONSTITUTION:A mixture between powder of mother alloy for main phase, which has a phase substantially composed of R2T14B, and alloy for grain boundary phase, which contains R by 70-97wt.% and the rest of which is substantially Fe and/or Co, is heat-treated so that the mother alloy for grain boundary phase may fuse, and then, is crashed and molded and sintered. Moreover, it is sintered so that the final density may be 7.2g/cm<3> or over, with molded item density being 5.5g/cm<3> or over, whereby it is made into a magnet which contains more than 2vol.% closed voids. |
