Thermal Schock Criteria of Refractory Ceramics: Limitations of Conventional Analyses and Some Numerical Approaches to Improve the Prediction of the Resistance to Thermal Schock

Significant advances in the mechanical design of ceramic parts were realized since the pioneer works of Kingery and Hasselman to define thermal shock resistance. But for high heterogeneous refractories and contrasted local phase properties the use of these criteria is not always convincing because the assumptions made are too simplicist. First, we underline how thermal shock resistance parameters helped to improve the global performance of ceramics and make some comments on their limitations for refractory materials. Then we show how numerical tools are useful for the design of refractory structures at high temperatures through several approaches we have developed for refractory structures: prediction of macroscopic thermal shock resistance of heterogeneous refractories using multi-scale analysis, finite element methods applied to a specific structure considering either a two-scale approach to describe the thermo-elastic quasi brittle behavior of heterogeneous materials, at the macroscopic scale approach considering homogeneous microstructure.