On the Hotspot Problem in Flash Sintering

A perturbation analysis has been conducted to evaluate the generation of hotspots inside an electrical loaded ceramic sample, which is assumed to have an Arrhenius-type conductivity. The results identified a critical size, above which a small temperature perturbations will be magnified and hotspots will be generated. It provides an estimate for the largest sample size suitable for flash sintering, beyond which hotspots are likely to form, resulting in inhomogeneous heating and sintering.