Processing and sintering of ultrafine MgO-ZrO2 and MgO,Y2O3-ZrO2 powders

This paper reports chemical coprecipitation used to produce ultrafine and easily sinterable MgO-stabilized and (MgO,Y2O3)-stabilized ZrO2 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 significant fraction of residual porosity