Initial stage of degradation process of alumina-silica refractory by molten Al-5Mg alloy

Initial stages of the refractory degradation process by molten Al-5Mg alloy were investigated by analyzing the degradation structures caused by an interaction with molten metal during heat cycles. The refractory aggregate, found to be poly-crystalline, consisting of cristobalite (SiO2) and mullite (Al6Si2O13), was deteriorated ahead of the surrounding matrix. Metal permeated into the refractory, forming a thin metal layer along the crucible surface below the molten metal line at an early stage of degradation process, which would later serve as the bases for the metal infiltration path through the refractory above the molten metal line. A discontinuous film (thickness