Differential sintering in ceramic injection moulding: particle orientationeffects

The sintering shrinkage in three orthogonal directions was measured in sect ions cut from large rectangular injection moulded ceramic blocks. Two powde rs were used: a comminuted alumina and a chemically-derived zirconia. Prono unced anisotropy of shrinkage was observed in the former whereas the equiax ed zirconia showed uniform shrinkage throughout the moulding. The pattern o f shrinkage anisotropy was consistent,vith that observed by other investiga tors and indicates that slight particle anisotropy can introduce differenti al sintering. The sintering shrinkage in the alumina powder was found to be most pronounced perpendicular to the main flow direction. (C) 2001 Elsevie r Science Ltd. All rights reserved.