Fracture energy and thermal shock damage resistance of refractory castables containing eutectic aggregates

One of the main reasons to investigate fracture energy of refractory castables is their need for superlative performance in resisting to thermal shock damage, which is one of the most crucial thermomechanical requirements in face to their industrial application. The fracture energy depends on toughening mechanisms, which will vary according to the material׳s microstructure. Considering this, the addition of eutectic electrofused aggregates is an interesting choice to increase toughness, since eutectic microstructures can deflect cracks during the fracture process. In that case, the crack deflection is likely to occur inside the aggregates during the transgranular fracture, which would increase the fracture energy. In the work herein, castables containing eutectic electrofused aggregates were investigated by the means of a comparison to blank materials, based on aggregates of white electrofused alumina. The fracture energy results were sensible to the variation of aggregate type, pointing out that the eutectic ones have a better performance regarding thermal shock damage resistance.