Corrosion behavior and mechanism of the Y₂O₃–Al₂O₃–SiO₂ system during long-term corrosion in water-oxygen environment at 1350 °C

The effect of long-term corrosion in water-oxygen atmosphere at 1350 °C on the organization of eutectic glass of the Y₂O₃–Al₂O₃–SiO₂ (YAS) system was investigated and the corrosion mechanism was analysed. As corrosion time increases, the surface crystals of glass-ceramics, especially cristobalite, is gradually consumed, resulting in a gradual increase in the roughness of the surface. Subsequently, the thermal expansion mismatch of corrosion products causes internal stresses, which result in cracks and accelerate corrosion of the glass-ceramics. It is worth mentioning that this eutectic composition showed an unknown X-phase after 100 h of corrosion, and its structure was reasonably predicted.