Characterization of Corrosion Mechanisms Occurring in a Sintered Sic Exposed to Basic Coal Slags

The high‐temperature reactions occurring between an a‐Sic and a basic coal slag were examined. The resulting corrosion behavior was found to involve at least three mechanisms, including passivation of the Sic via SiO 2 formation, dissolution of the SiO 2 by the coal slag, and formation of a localized Fe‐Ni silicide. This mechanism, which dominated when the slag thickness exceeded 100 μm, was also responsible for the degradation in high‐temperature strength.