Consolidation and sintering of nanometric ceramic powders

Two powders containing 97 mol % ZrO2 and 3 mol % Y2O3 with different crystallite sizes have been prepared by the hydrothermal method and calcination of co-precipitated gel. The hydrothermal powder was filter pressed under 5 MPa and dry pressed under 20 to 200 MPa. Filter pressed samples showed a more uniform particle arrangement than dry pressed samples which resulted in a better densification of the samples during sintering. Milling in water, and subsequent sedimentation of the calcinated powder allowed selecting fine particles for the filter pressing process.