Experimental and numerical analysis of thermal shock damages to alumina based ceramic disk samples

Thermal shock of an alumina-based ceramic material, which occurs widely in metallurgical furnaces, was studied in this paper. The water quench test was applied to determine the thermal shock resistance of the material. The behavior of the ceramics after thermal shock treatments was investigated. The level of degradation of the samples was monitored using image analysis tools and the defects morphology characteristics were simultaneously determined. The stress state of the samples with simplified damage shapes was simulated by the finite element method (FEM) and the influence of the surface damage geometry on the stress in the sample was examined. The analysis revealed that the surface defects tend to spread on the surface of the specimen instead of increasing their depth. This explained the morphology of defects and the way of propagation of the damage that were in accordance with experimental observations.