Effect of current path on plasma assisted sintering (PAS) of 3YSZ ceramics

In this study, a facile device was designed to generate stable plasma at room temperature using a low-voltage/current power source. The setup, which uses carbon felts as electrodes in air atmosphere, enables a novel plasma assisted sintering (PAS) technique to consolidate 3 mol% yttria-stabilized zirconia (3YSZ) ceramics at room temperature. The activation voltage required for plasma formation is positively correlated with the distance between the electrodes, with a minimum threshold as low as 50 V. Remarkably, the relative density of the PAS-treated 3YSZ ceramics reached 97.4% within 40 s under a voltage of 80 V and a current of 1.7 A. The electrical power dissipation profile and densification of the PAS-treated 3YSZ ceramics were analyzed in detail. The results confirmed that the rapid densification of 3YSZ ceramics arises not only from plasma-induced thermal effects, but also from the athermal effects caused by the current passing through the sample. This novel PAS technique is a promising low-cost and rapid method for preparing high-performance ceramic materials.