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-sintere d materials with rather different microstructures but comparable stren gths. Use of alumina and zirconia (Y-TZP) grinding balls during attrit ion necessitated different homogenization times and resulted in differ ent microstructures for the same sintering program. This was a consequ ence of the extensive wear of both types of grinding balls during attr ition. The wear significantly altered the concentrations of alumina, u nstabilized zirconia, yttria-stabilized zirconia and silica in the gro und powder used for subsequent production.