Improvement of microstructural properties of 3Y-TZP materials by conventional and non-conventional sintering techniques

3 mol% Y2O3-stabilized zirconia nanopowders were fabricated using various sintering techniques; conventional sintering (CS) and non-conventional sintering such as microwave (MW) and pulsed electric current-assisted-sintering (PECS) at 1300 °C and 1400 °C. A considerable difference in the densification behaviour between conventional and non-conventional sintered specimens was observed. The MW materials attain a bulk density 99.4% theoretical density (t.d.) at 1300 °C, while the CS materials attain only 92.5% t.d. and PECS 98.7% t.d. Detailed microstructural evaluation indicated that a low temperature densification leading to finer grain sizes (135 nm) could be achieved by PECS followed by MW with an average sintered grain size of 188 nm and CS 225 nm. It is believed that the high heating rate and effective particle packing are responsible for the improvements in these properties.