| 摘要 |
PURPOSE:To manufacture a permanent magnet having high coercive force and free from deterioration in residual magnetic flux density by sintering an alloy powder in which rare earth elements, B, and Fe are properly blended and by subjecting the resulting sintered compact to heat treatment in a specific temp. range and then to rapid cooling. CONSTITUTION:The alloy powder consisting of 25-44wt% R (one or more kinds among rare earth elements including Y), 0.5-5wt% B, and the balance Fe with impurities is sintered at 900-1,200 deg.C. Subsequently, in order to increase the coercive force of the alloy, the sintered compact is heat-treated at 500-700 deg.C, followed by rapid cooling at >=50 deg.C/min cooling rate. As a result, the maximum energy product is increased and the temp. characteristics of coercive force can be improved. |
