Abstract
In the preparation of Al2O3 ceramics by the low pressure injection molding method, fine particles of raw material powder (mean particle size of 0.6μm) must be dispersed homogeneously into the organic binder in order to obtain high strength ceramics. Four different mixing methods were tested; stirrer equipped in the low pressure injection molding apparatus, automatic agate mortar, ceramic three roll mill and ball mill. It is concluded that the ball mill mixing method prepares the most uniform slurry among the four mixing methods. The specimen sintered at 1700°C for 3 hrs, after being shaped in the horizontal flow type mold from the slurry of the ball mill mixing method, shows a strength of 40.0 Kgf/mm2 and its Weibull constant is 6.9. Furthermore, the flexural strength of the sintered specimens increased from 40.0 Kgf/mm2 to 46.2 Kgf/mm2 and their Weibull constant increased from 6.9 to 14.5, as the metal mold was changed from horizontal into vertical flow type.
