Effects of heating rate and DC electric field during sintering on the grain size distribution in fully sintered tetragonal zirconia polycrystals stabilized with 3% molar yttria (3Y-TZP)

The effects of sintering temperature rate \( (\dot{T}\) = 1.5–50 °C/min) without and with an initial applied dc electric field (Eo = 14 V/cm) on the grain size distribution (GSD) of fully sintered 3 mol%, yttria-stabilized tetragonal zirconia (3Y-TZP) was determined from SEM micrographs of fractured and polished-and-etched surfaces. No clear difference between the measurements on the two surfaces was detected. The grain size parameters characterizing the GSD tended to decrease with \( \dot{T} \) and with Eo. All of the GSD’s however fit a single curve based on the Bitti–Di Nunzio grain coarsening model. This fit along with other considerations also give that the heating rate and electric field applied during sintering did not have a significant effect on the grain shape or the grain boundary energy in the fully sintered specimens. It is proposed that the decrease in grain size in the fully sintered condition by the application of an electric field during prior sintering results primarily from its effect on the driving force for grain growth, while the effect of the heating rate is on the grain mobility.