Modelling of sintering consolidation and thermal damage in a refractory ceramic

The sintering consolidation and thermal damage of an alumina mullite zirconia refractory is modelled during a thermal cycle. The dynamic Modulus of Elasticity (MOE) of the material is assumed to be a function of two variables representing sintering and damage degrees. Two evolution laws are proposed for these internal variables and the model is calibrated to describe properly the MOE of the refractory during a reference thermal cycle. The model is then validated by experimental confrontation for other thermal treatments. The model predicts reasonably well the evolution of the dynamic MOE for thermal cycles with different sintering temperatures, dwell times or heating/cooling rates. This phenomenological model provides the variation of the associated sintering and damage degrees and could be used in thermomechanical simulations to account for the thermal history dependence of the material mechanical behaviour.