| 摘要 |
PURPOSE:To increase magnetic characteristics and to prevent damage to a mold by a method wherein vacuum suction is applied to the air at the space of each rare earth Co powder and between the powder and a molder and pressure mold is done in the magnetic field. CONSTITUTION:In a conventional method, the air is confined in the spaces among powders and when a dust substance 7 is taken out from a mold 3 by excluding pressure after pressure mold, the compressed air in the spaces of powders expands and applys pressure to the inside of the mold to damage the mold 8 to deteriorate the dimensional precision of the product. If a device applying press mold to magnetic powder in the magnetic field is accomodated in a vacuum tank 3 for vacuum suction 10 and mold is conducted in the magnetic field as usual, the occupancy rate of the air remarkably decreases. Therefore, magnetic characteristics will rapidly be improved and a relatively big sample can easily be obtained. |
