| 摘要 |
PURPOSE:To obtain a magnet showing excellent magnetic properties in multipolar magnetization, by a method wherein a hollow billet is subjected to extrusion, with the axial direction of the billet and the extruding direction arranged to be parallel to each other, by employing a die having a predetermined opening area, thereby to apply to the billet a compressive strain in the extruding direction. CONSTITUTION:A hollow billet 1 made of a manganese-aluminum-carbon (Mn-Al-C) alloy for magnet is subjected to extrusion, with the axial direction of the billet and the extruding direction arranged to be parallel to each other, by employing a die having a hollow container part 21 smaller in opening area than a bearing part 23, thereby to apply to the billet 1 a compressive strain in the extruding direction. In this case, the opening area of the container part 21 means the sectional area of the hollow part thereof obtained when the die is cut through the container part 21 perpendicularly to the extruding direction, while the opening area of the bearing part 23 means the sectional area of the hollow part thereof obtained when the die is cut through the bearing part perpendicularly to the extruding direction. Thus, it is made possible to obtain a magnet showing excellent magnetic properties in multipolar magnetization. |
