ファインセラミックス粉体のスリップキャスト・低圧射出成形法に関する研究

概要

論文の詳細を見る
Slip casting of Si3N4 powder in plaster mold was carried out. PVA binder gives the green body plasticity as well as strength. Mean flexural strength of sintered body of silicon nitride was 83.5 kgf/mm2 and Weibull constant was 21.3. In order to improve productivity of slip casting method, a high pressure casting apparatus, which enables to apply pressures up to 200 kgf/cm2 for slurry, was devised. The casting time of alumina compact of 10×50×70(mm) was shortened from 60 min of pressureless casting to 6 min of pressure casting with 200 kgf/cm2. The green compact obtained by pressure casting higher than 100 kgf/cm2 scarcely shows shrinkage during drying. Alumina and silicon nitride were prepared by low pressure injection molding. Weibull plot of flexural strength gave mean strength of 48 kgf/mm2 with Weibull constant of 14.5 for alumina and mean strength of 91.3 kgf/mm2 with Weibull constant of 11.9 for silicon nitride, respectively. A transparent mold with a window of a strengthened glass was devised. This mold enables to visualize the dynamic flow of the slurry through the glass window by VTR. Using this mold, the best condition of homogeneous molding without turbulence of injecting slurry was easily determined.
社団法人粉体粉末冶金協会の論文