| 摘要 |
PURPOSE:To obtain a resin bond magnet having a distinguished performance by a process having the steps of charging a die with a mixture containing magnetic powder of 2-17 rare earth metal and a specified amount of organic resin, and shaping the mixture in the die under the influence of a magnetic field at a temperature of 40- 150 deg.C. CONSTITUTION:A mold composed of a lower die 3, punch 4 and a peripheral die 6 is situated within a gap between a pair of solenoids each having a solenoid coil 1 and a pole piece 2. The die 6 is made of a non-magnetic stellite, while the punches 3 and 4 are made of normalized SuJ2. A mixture powder 5 contains R2TM17 rare earth metal magnetic powder consisting of a rare earth metal R and a transition metal TM, and 0.5-5wt% of organic resin as a binder. The mixture powder is charged in the die cavity formed in the die 6. The die is heated to a temperature of 40-150 deg.C by a heating medium which is circulated through a jacket 8 in a case 7 as indicated by arrows. In operation, a hydraulic press cylinder 11 is actuated to lower the punch 4 thereby compacting the mixture powder 5, while the mixture powder 5 is being heated by the heating medium and magnetized by a magnetic field developed between the pole pieces 2, 2. By this method, it is possible to obtain a permanent magnet which is superior both in magnetic property and mechanical strength. |
