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)

Abstract

The effects of sintering temperature rate ð _ T = 1.5-50°C/min) without and with an initial applied dc electric field (E o = 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 _ T and with E o . 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.

Grain Boundary Curvatures Measurements in Annealed Yttria‐Stabilized Zirconia (3Y‐TZP) and Their Relation to Mean Grain Size

“…To be noted is that all of the data points fall on a single curve, which is essentially independent of annealing treatment. Moreover, the GSD curve for annealing is in accord with that reported for sintering . The combined results (sintering and annealing with and without electric field) thus give that the GSD relating to grain growth in 3 Y‐TZP is a unique function of the MLI grain size and is in accord with the Bitti‐Di Nunzio model …”

“…Moreover, the GSD curve for annealing is in accord with that reported for sintering. 15,16 The combined results (sintering and annealing with and without electric field) thus give that the GSD relating to grain growth in 3 Y-TZP is a unique function of the MLI grain size d and is in accord with the Bitti-Di Nunzio model. 17 The size d r of the grains for which r b was measured ranged between 2.4 and 2.6 times the MLI grain size d, with an average d r = 2.5 d (Fig.…”

“…The mean grain size and the corresponding grain size distribution (GSD) for each annealing treatment were determined in the conventional manner, as described in Ref. .…”

Transient-regime grain growth in nanocrystalline yttria-stabilized zirconia annealed without and with a DC electric field

“…As in our prior findings [21,22] the grains in the present investigation were relatively equiaxed. The maximum difference in d between the three locations was 10%; there was, however, no consistent difference between the locations from one electrode to the other.…”

An experimental setup for shrinkage evaluation during electric field-assisted flash sintering: Application to yttria-stabilized zirconia

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Electric current activated/assisted sintering, also named spark plasma sintering (SPS), requiring simultaneous application of pressure, has been also extensively studied. 14 Considerable shrinkage has been obtained by a new technique named flash sintering by Raj and co-workers by simply applying an electric field at temperatures well below the temperature required for attaining full density.…”