Determination or alumina slurry viscosity of GI-II infiltrated ceramic

Objective: This study was to determine alumina slurry viscosity of GI-Ⅱ Infiltrated Ceramic for complications of its slip casting. Methods: The Two alumina slurries with powder-to-mixing liquid mass ratio of 8: 1, 7: 1, 6: 1, 5: 1, 4: 1, respectively,one of which was added plasticizer, were prepared. Their viscosity values were determined with rotation method. Results: The viscosity values declined along with powder/liquid ratios and rose with shear rate. The values changed much more slowly when powder/liquid ratios were 8: 1,7: 1,6: 1,5: 1,4: 1,respectively. And addition of the plasticizer into the slurries significantly reduced their viscosity values. Conclusions: It may be advisable to choose powder/liquid ratios of 7～4:1 and add plasticzer into alumina slurry before slip casting, while with enough ultrasonic vibration in order to distribute powder evenly in the slurry and remove possible air bubbles.