| 摘要 |
PURPOSE:To provide a molding tool for a plastic disk which has excellent surface smoothness, corrosion resistance, etc., and is adequate for production of a video disk, etc., by constituting said tool of ZrO2 base ceramics essentially consisting of ZrO2 and having crystal grain sizes of a specific value or below. CONSTITUTION:The ZrO2 base ceramics raw material powder essentially consisting of ZrO2 and contg. 10-80wt.% Al2O3 is produced by a wet process such as co-deposition process. After this raw material is molded and calcined, the powder is subjected to hot isostatic pressing under the conditions of 1,300-16,00 deg.C and >=50atm. pressure to form the molding tool for the plastic disk consisting of the ZrO2 base ceramics having >=2mum crystal grain size. The purpose of adding the Al2O3 to the raw material lies in the improvement in hardness and heat conductivity. Wear resistance can be improved by the improved hardness; in addition, the disk molding cycle is shortened by improving the heat conductivity. |
