Abstract

Carbon-bonded magnesia (MgO-C) with maximal magnesia grain sizes of 2 mm and a graphite content of 10 % was investigated regarding its mechanical properties. Therefore quasi-static and fracture mechanical tests were carried out at temperatures up to 1500°C under inert atmosphere. The tests were complemented by analysis of microstructure, density, porosity and dynamic Young’s modulus. The results showed change of mechanical behaviour in dependency of temperature. Besides changes in course of both stress-strain curve and force-crack displacement curve, a change of fracture mechanism was found. Investigations of microstructure revealed a change from fracture through matrix and MgO grains at low and intermediate temperatures to fracture only through the carbonaceous matrix at high temperatures.