Elastic behaviour of magnesia-chrome refractories at elevated temperatures

Abstract

An investigation of the high-temperature elastic behaviour of four varieties of magnesia-chrome products was conducted in the present work. The starting materials were characterized with XRF, XRD and SEM/EDS analyses. The measurements of the dynamic Young's modulus were performed in a temperature range of 20-1300 °C, using the acoustic method. Moreover, the dynamic Young's moduli, shear moduli and Poisson's ratios were established at ambient temperature for the original and after-heating samples. The obtained results showed similar characteristics, but the elastic behaviours of all the refractory test materials were distinguishable. The curve of the Young's modulus changed as a function of temperature, exhibiting a close-to-hysteresis character, with a decreasing area between the lower and upper curve as the Cr2O3 content increased in the material. The Young's modulus and the shear modulus at ambient temperature were lower for the after-heating samples when compared to the original ones.