Thermal shock behavior of alumina based refractories: fracture resistance parameters and water quench test

Abstract

The prediction of refractories thermal shock behavior can be estimated on two basis: heat transfer conditions and/or fracture mechanics concept. Materials considered in our analysis were alumina based refractories with different (Al2O3 + TiO2) content from 28% to 78%. Model for temperature and stress distribution calculation was presented in this paper. The thermal and mechanical properties of the materials were measured using standard laboratory procedure. Thermal stability of the refractories was measured by water quench test (JUS. B. Ds. 319.). The samples were dried at 110 degrees C and then transferred into electric furnace at 950 degrees C and held there for 15 min. The pieces were then moved into water and left for 3 min before returning to the furnace at 950 degrees C. This procedure is repeated until failure. The number of quenches to failure was taken as a measure of a thermal shock resistance. From the average values of the thermal and mechanical properties fracture resistance parameters were calculated. Heat transfer coefficient and Blot number were calculated using the equations given by Holman assuming the free convection. Results from the linear regression analysis showed that fracture resistance parameters can be correlated with the measured number of cycles of water quench test.