High temperature mechanical behavior of fused cast refractories

This study has been carried out owing to the French research program PROMETHEREF, which aims to improve the knowledge of thermal and mechanical properties of industrial refractories at high temperature. In this frame, this paper relates a collaborative study between Saint-Gobain CREE, R&D Centre for Saint-Gobain Ceramics & Plastics in Europe (Cavaillon), the Materials Center P.M. Fourt of Ecole des Mines de Paris (Evry) and the Research Group on Heterogeneous Materials (GEMH) of ENSCI (Limoges). Data collected at high temperatures by using different means (bending tests, ultrasonic measurements,...) allows the identification of the high temperature behavior of two fused cast materials, produced by Saint-Gobain group for the glass manufacturing industry. The results emphasize the importance of the transformation of zirconia and of the viscosity of the glassy intergranular phase on the mechanical behavior. Damage under the form of microcracking caused by thermal expansion mismatch between the phases is also observed during cooling down at low temperature, when the material is elastic.