THE ROLE OF POWDER HOMOGENIZATION TECHNIQUES IN THE FABRICATION OF ZIRCONIA-TOUGHENED ALUMINA

Starting with conventionally produced commercial alumina and zirconia powders, different attrition milling procedures resulted in as-sintered materials with rather different microstructures but comparable strengths. Use of alumina and zirconia (Y-TZP) grinding balls during attrition necessitated different homogenization times and resulted in different microstructures for the same sintering program. This was a consequence of the extensive wear of both types of grinding balls during attrition. The wear significantly altered the concentrations of alumina, unstabilized zirconia, yttria-stabilized zirconia and silica in the ground powder used for subsequent production.