Finite element analysis of temperature distribution in 3YSZ ceramics during conventional sintering

The presence of a temperature gradient (if any) within the ceramic sample is casually ignored during the sintering of ceramic shapes. The present work exposes some serious repercussions of such a thought process and provides simple solutions to mitigate the same; 3 mol.% yttria-doped zirconia ceramic was used for this study. With the help of the combinatorial finite element analysis (FEA) model and real-life experiments, our work illustrates the complex interplay of heat transfer mechanisms and reveals the dynamic nature of temperature distribution during the heating and cooling cycles of ceramics. Although the rate of heating is usually assigned as the most important factor during sintering, the present study shows that variations in heat transfer mechanism and sample geometry contribute very strongly to overall temperature distribution during the heating, holding, and cooling cycles. Along with of vertical positioning of the samples (inside the furnace), a bottom supporting ceramic plate with a high thermal conductivity can also help in reducing the temperature gradient between the top and bottom of the ceramic samples. Overall, exposing the sample most for the radiative heat transfer holds the key to successful sintering in order to avoid any phase, compositional, or microstructural heterogeneity across the thickness of the specimen.