Effect of powder treatment on injection moulded zirconia ceramics

Agglomerated fine zirconia powder was exposed to dry and wet ball milling a nd to wet mixing. The subject of study was the effect of powder treatment o n the disintegration of agglomerated particles, on the rheological properti es of thermoplastic ceramic mixtures, and on the properties of sintered ytt ria-stabilized tetragonal zirconia polytrystalline ceramics (Y-TZP). Test s pecimens 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 trea tment was found to yield improved rheological properties of ceramic mixture s and improved mechanical properties of sintered specimens in the case of 5 2.5 vol% of powder in the ceramic mixture. However, the same or even better mechanical properties of sintered components were found when the loading o f ceramic mixture was reduced to 49 vol% of powder and non-treated powder w as used. (C) 2000 Elsevier Science Ltd. All rights reserved.