| 摘要 |
PROBLEM TO BE SOLVED: To provide a rare earth magnet manufacturing method capable of solving a problem that distortion occurring in a sintered body is distributed by shear friction force acting from an upper die and a lower die constituting a plastic working die when the sintered body is deformed sideward, which makes residual magnetization non-uniform.SOLUTION: A rare earth magnet manufacturing method comprises a first step of manufacturing a sintered body S by pressure-molding magnetic powder, and a second step of mounting a sintered body S' in a plastic working mold and pressing the sintered body S' to conduct hot plastic processing, thereby manufacturing rare earth magnet. The sintered body S' is manufactured in such a shape that at least one side surface out of four side surfaces constituting a rectangular parallelepiped shape has a concave portion which is concaved in a curved shape in step S1. The plastic working die prepared in the second step comprises a lower die, a rectangular frame-like side surface die, and an upper die. During hot setup processing as hot plastic processing, the side surface having the concave portion is deformed in the middle of the hot upset processing, and the whole faces of the side surface of the deformed sintered body S' are brought into contact with the corresponding side surfaces of the side surface die substantially simultaneously.SELECTED DRAWING: Figure 4 |
