Continuum Mechanical Description of Sintering Nanocrystalline Zirconia

Abstract

Fig. 1. SEM fracture images of samples at 80.0, 67.9, and 68.5 %TD for: a) Z18, b) Z59, and c) YZ29.

Pressure effects and grain growth kinetics in the consolidation of nanostructured fully stabilized zirconia by pulsed electric current sintering

“…9. Taking into account the uncertainty of the experimental data, the activation energy for grain growth found in this study seems to be on the low end of the range of reported values available in the literature (226-340 kJ mol À1 ) [6][7][8]. Our values are particularly close to the activation energy found in the work of Dahl et al [8] (226 kJ mol À1 ) where nanocrystalline c-YSZ powder of similar size was consolidated in a hot press.…”

“…Grain growth of bulk micrometric c-YSZ has been analyzed by Chokshi [4] and experimentally investigated by Dahl et al [8], Kanters et al [6], and Tekili et al [7] during sintering in either a hot-press or a conventional furnace. In those studies the generalized parabolic growth model with n = 2 or 3 was found to be adequate to describe the grain growth behavior of this material at the temperatures used in these studies (P1250°C).…”

“…The latter are solutions of the differential equations shown in Eqs. (6) and (7), where "a" has an Arrhenius dependence on temperature and "b" is assumed to be constant. In the cited previous studies [6][7][8] the sintering temperature was high, thus "a" is expected to have a relatively large value.…”

“…Kanters et al [6] studied the sintering of t-YSZ by dilametric methods and concluded that pore drag rather than grain-boundary mobility controls grain growth. The sintering of undoped and alumina-doped cubic zirconia was investigated by Tekeli et al using pressureless sintering at temperatures in the range 1400-1600°C [7].…”

Cosintering Simulation and Experimentation: Case Study of Nanocrystalline Zirconia

“…All samples were heated in air at 50, 200, or 600 K/h to 1120°C and held for 8 h. Shrinkage and curvature were measured using optical dilatometry, as described elsewhere. 23 The white samples were placed in front of a dark plate of silicon carbide, illuminated by a lamp, and observed in situ using a video camera. Viewed from the top, the sample's flat face was detected by its contrast and analyzed for its area (A t ) as a function of time (t).…”