Processing and Sintering of Ultrafine MgO‐ZrO ₂ and (MgO, Y ₂ O ₃ )‐ZrO ₂ Powders

Abstract

Chemical coprecipitation was used to produce ultrafine and easily sinterable MgO‐stabilized and (MgO, Y 2 O 3 ) stabilized ZrO 2 powders. The sintering behavior is very sensitive to post‐precipitation washing because “hard” agglomerates form when the precipitated gels are washed with water, whereas “soft” agglomerates form when they are washed with ethanol. The soft agglomerates pack uniformly, resulting in homogeneous shrinkage of powder compacts to near‐theoretical density. The hard agglomerates result in compacts which have regions of localized densification and a signifiint fraction of residual porosity.