Thermal Stress Failure of Pure Refractory Oxides

An investigation was carried out to study the thermal stress failure of three pure, dense refractory oxides, namely alumina, stabilized zirconia, and magnesia. Thermal stress resistances were determined by means of a direct test and by calculation from the physical properties of the material. The properties measured included strength, elasticity, and thermal expansion. All the tests were conducted within the temperature range 25° to 1500°C. For hollow cylindrical specimens, heated uniformly from the inner surface, resistance to fracture was expressed quantitatively by the heat flow at steady state required to cause fracture. This resistance was found to be a function of (1) the physical properties of the material, (2) the temperature range of testing, and (3) the temperature distribution within the specimen.