Apparent Sintering Activation Energy Estimated by Master Sintering Curves for 8 mol% Y₂O₃ Doped ZrO₂ Polycrystals during Shrinkage-Rate Controlled Flash Sintering

Abstract

The apparent activation energy of sintering for 8-mol%-Y₂O₃-doped ZrO₂ during shrinkage-rate-controlled flash sintering was determined using a master sintering curve. The activation energy during SCF sintering was found to decrease from approximately 700 to 430 kJ/mol with density. The activation energy in a high-density region is approximately similar value of lattice diffusion, 460 kJ/mol. The relative density range over which the decrease in activation energy occurred during SCF sintering was smaller than during thermal sintering and further moved to a lower temperature range. The increase in shrinkage rate at lower temperatures that occurs during SCF sintering could be considered to be related to this decrease in activation energy.

Fig. 8 Plots showing activation energy, red data for SCF sintering obtained in this study, blue data for thermal sintering obtained by MSC,³⁸⁾ and green data for thermal sintering obtained by Wang and Raj analysis.³⁸⁾