Effect of Electric Field/Current on Sintering Behavior of Yttria during SPS Processing

Abstract

Effect of the electric current on the densification behavior of yttria (Y₂O₃) and zirconia (3YSZ) powders during the spark-plasma-sintering (SPS) process has been examined. The powders were densified by the SPS device under two types of die set-up; one is a conductive normal set-up, in which the powders loaded into a graphite die were sandwiched by carbon papers, another is an insulation set-up, in which the powders were sandwiched by BN powder in the die. For the 3YSZ powder, the shrinkage is independent of the die set-ups. Whereas for the Y₂O₃ powder, on the other hand, it was apparently accelerated during the initial and intermediate sintering stages and completed at more than 100 oC lower temperature in the normal die set-up than in the insulation set-up. It is expected that the DC pulsed current applied during the SPS processing enhanced the sintering of the Y₂O₃ powder. This suggests that during the SPS processing, applied pulsed electric field/current is likely to contribute to the sintering of Y₂O₃ ceramics.