CMAS corrosion resistance and mechanism of directionally solidified Al₂O₃/YAG eutectic ceramics at high temperatures of 1300–1500 ℃

The calcium-magnesium-alumina-silicate (CMAS) corrosion resistance of directionally solidified Al₂O₃/Y₃Al₅O₁₂ (YAG) eutectic ceramics prepared by the Czochralski technique was investigated at 1300–1500 °C. No corrosion traces were observed after 100 h of corrosion at 1300 °C. Under 1400 °C and 1500 °C after 50 h, the corrosion depth was increased to 306 and 316 μm, but the corrosion rate did not significantly improve. The corrosion resistance was attributed to the inhibition of CMAS penetration by the stable phase interface, the modulation of CMAS corrosion activity by the diffusion of elements, and forming a continuous and dense garnet layer.