Some observations on filter pressing and sintering of yttria-stabilized zirconia nanopowder

The aim of this work was investigation of the sintering behaviour of a material prepared by filter pressing of an yttria-stabilized zirconia powder with grain sizes of about 8 nm. The water suspension of the powder was filter-pressed under 5 MPa. The early shrinkage of the filter-pressed sample, during its non-isothermal sintering was attributed to removal of water layers adsorbed on the powder surface. The observation of the microstructure evolution in samples heat-treated at different temperatures was performed. Pore growth during sintering was related both to presence of agglomerates, and to pore coalescence. Particle arrangement in the material was very uniform, which led to uniform densification of the material. Heat treatment of the sample for 30 min at 1200°C resulted in the material of 99.96% relative density, and grains within nanometric range.