| 摘要 |
PURPOSE:To increase the extrusion speed and to improve the product quality by forming a die body of a zirconia base ceramics. CONSTITUTION:A die body 1 consisting of a bearing part 1a and relief part 1b is made of a zirconia base ceramics whose composition is ZrO2 and a stabilizer of a prescribed amount as an additive. The zirconia base ceramics has many tetragonal phase in the structure even at room temp. in a partially stable state and has a toughness. Therefore, at the time of extrusion by use of the die body 1 consisting of the ceramics, generation of a boundary layer between an extruding material A and the bearing part 1a is restrained and generation of die lines and pickups is eliminated. Thus, the extrusion speed is increased and the product quality is improved. |
