Mechanisms of La 2 Ce 2 O 7 /YSZ Double-Ceramic-Layer Thermal Barrier Coatings against Volcanic Ash Corrosion.

To tackle the ever-increasing operating temperature of aero-engines, a La₂Ce₂O₇ (LCO)/yttria partially stabilized zirconia (YSZ) double-layer thermal barrier coating (TBC) was investigated. The LCO/YSZ double-layer samples were annealed with volcanic ash (VA) at 1250 °C to assess their stability in comparison with that of standard single-layer YSZ. The findings showed that the double-layer system exhibited greater resistance to VA damage than the single-layer YSZ coating. The corrosion mechanism was characterized by a rapid crystallization reaction between LCO and VA, where the kinetics of the solution's reprecipitation reaction outpaced the penetration rate into the coating's open pores. [ABSTRACT FROM AUTHOR]