Calcium magnesium aluminosilicate (CMAS) corrosion behaviors of apatite Ca₂La₈(SiO₄)₆O₂ thermal barrier coating material

The calcium magnesium aluminosilicate (CMAS) attack is becoming a critical obstacle to the application of thermal barrier coatings (TBCs). In this work, we prove that Ca₂La₈(SiO₄)₆O₂ is an effective TBCs material for resisting CMAS attack, and investigates its CMAS corrosion behaviors. The results indicate that no evidence of chemical reactions was found between CMAS and Ca₂La₈(SiO₄)₆O₂ heat-treated at 1300 °C and 1500 °C. The corrosion of apatite by CMAS occurs via dissolution and re-precipitation processes. At 1300 °C, the apatite Ca₂La₈(SiO₄)₆O₂ substrates have little evidence of damage. Moreover, the apatite can also effectively block the infiltration of CMAS up to 1500 °C.