Effect of powder treatment on injection moulded zirconia ceramics

Agglomerated fine zirconia powder was exposed to dry and wet ball milling and to wet mixing. The subject of study was the effect of powder treatment on the disintegration of agglomerated particles, on the rheological properties of thermoplastic ceramic mixtures, and on the properties of sintered yttria-stabilized tetragonal zirconia polytrystalline ceramics (Y-TZP). Test specimens in the shape of bars and discs were produced by injection moulding of ceramic mixtures containing 52.5 and 49 vol% of powder. The powder treatment was found to yield improved rheological properties of ceramic mixtures and improved mechanical properties of sintered specimens in the case of 52.5 vol% of powder in the ceramic mixture. However, the same or even better mechanical properties of sintered components were found when the loading of ceramic mixture was reduced to 49 vol% of powder and non-treated powder was used.