| 摘要 |
PURPOSE:To obtain a mother alloy for manufacturing a sintered magnet having high magnetic properties by preparing an alloy essentially consisting of rare earth elements, Fe and B and having columnar crystalline grains and grain boundaries essentially consisting of rare earth elements. CONSTITUTION:The molten metal of an alloy essentially consisting of, by weight, 27 to 38% R (rare earth elements including Y), 51 to 72% T (Fe, or Fe and Co) and 0.5 to 4.5% B is cooled from one direction or opposite two directions by a single roll method, a double roll method or the like. In this way, the objective mother alloy substantially consisting of tetragonal R2T14B and having columnar crystalline grains and grain boundaries essentially consisting of an R rich layer having R content higher than that in R2T14B is manufactured. By manufacturing an R-T-B sintered magnet by using this mother alloy, the objective sintered magnet improved in coercive force and residual magnetic flux density can be obtd. |
