STUDY OF THE YOUNG'S MODULUS AND DAMPING CHANGES IN A REFRACTORY CASTABLE DUE TO THERMAL SHOCK DAMAGE

摘要

Thermal shock damage resistance is an important characteristic in refractory materials since it determines their performance and useful life in many applications. The aim of this work was to evaluate the potential of the damping and dynamic Young's modulus changes characterization to quantify the thermal shock damage and to monitor the crack nucleation and expansion in a more practical way. In this work were studied the damping and the retained Young's modulus changes, and its correlations with the mechanical strength, of a refractory castable for different thermal shock temperature changes and number of cycles.The retained Young's modulus and the damping changes were found to be proportional to the mechanical strength. It was also observed an anomalous behavior with a local maximum for the damping dependence on the number of thermal shock cycles, which did not occur with the Young's modulus. This fact can be attributed to different stages of cracks and micro-cracks nucleation and expansion for which the damping characterization appears to be more sensitive than the Young's modulus.