Comparative evaluation of spark plasma (SPS), microwave (MWS),two stage sintering (TSS) and conventional sintering (CRH) on the densification and micro structural evolution of fully stabilized zirconia ceramics

Yttria stabilized zirconia (8YSZ) powders were subjected to densification studies employing various sintering techniques like spark plasma sintering (SPS), microwave sintering (MWS) and two-stage sintering (TSS). The densification and microstructural evolution of the samples are studied and compared with that of conventionally sintered samples (ramp and hold). Depending on the technique employed the samples were sintered at different temperatures to arrive at a minimum density of 99%TD. Detailed microstructural evaluation indicated that a low temperature densification leading to finer sintered grain sizes (~1 μm) could be achieved by spark plasma sintering followed by the two stage sintering technique with an average sintered grain size of 2.6 microns