| 摘要 |
PURPOSE:To increase the uniformity of the filling of permanent magnet powder to a metallic mold in order to decrease the variations in characteristics, and to enable a permanent magnet with good characteristics to be produced stably, by employing a series of processes in which permanent magnet powder material is magnetized, and the magnetized powder material is then cracked to perform granulation. CONSTITUTION:When a magnetic field is applied to permanent magnet powder material or the mixture of the permanent magnet powder material and binder, the permanent magnet powder material is magnetized. The magnetized powder material or the like is then cracked to perform granulation. Subsequently, for the granulated powder which is magnetized, the granulated powder in the fixed particle size range is separated from the other granulated powder through a mesh. Next, when the obtained powder is left as it is, a large number of the granulated permanent magnet powder which is magnetized so mass as to form the closed circuit from a north pole to a south pole, thereby being pelletized in a spherical shape. On the other hand, when the binder is employed, the coefficient of viscosity thereof is prepared in the range of 100-25000cm. poise, and the additional amount thereof is less than 6wt.% of the permanent magnet powder. Since the pelletized powder which is produced in such a manner can be filled into a metallic mold uniformly, the variations in characteristics can be decreased and the permanent magnet with good characteristics can be stably produced. |
