Temperature dependence of Young’s modulus, damping and dilatation during repeated thermal cycling of silica refractories for high-temperature thermal energy storage (TES)

Silica refractories are traditional materials for several important niche applications (e.g. coke oven linings and glass melter roofs) but are also potential candidates for modern high-temperature thermal energy storage. For this application all aspects of its high-temperature behavior must be thoroughly known. In this paper the temperature dependence of Young’s modulus and damping of silica refractories is investigated via impulse excitation during (three times repeated) heating to 900, 1100, 1300 and 1500 °C and cooling back to room temperature. Apart from the well-known hysteresis effects, induced by changes in the phase composition (based on tridymite and cristobalite) and microstructure (crack closure and re-opening), it is shown that cycling to 900 and 1100 °C leads to damage accumulation, while heating to 1300 and 1500 °C does not, and in the latter case a new type of elastic anomaly is observed during reheating. Damping and hysteresis parameters are discussed as well.