Thermal cycling and CMAS corrosion resistance of plasma-sprayed Pr2(Zr0.7Ce0.3)2O7 thermal protective coating

To develop new thermal protective coatings (TPCs) for high-temperature applications, single- and dual-ceramiclayer systems based on the rare-earth zirconate Pr2(Zr0.7Ce0.3)2O7 (PZ7C3) were prepared using atmospheric plasma spraying (APS). The study investigated the influence of phase stability, thermal physical properties, mechanical performance, coating structure, and infrared radiation characteristics on the thermal cycling and calcium-magnesium-alumino-silicate (CMAS) corrosion resistance of the coatings, along with an analysis of failure mechanisms. The PZ7C3 coating exhibited excellent phase stability at 1600 degrees C and low thermal conductivity, measuring 0.68 W & sdot;m-1 & sdot;K-1 at 1200 degrees C. It also demonstrated an appropriate coefficient of thermal expansion (CTE) of 10.54x10-6 K-1 (600-1500 degrees C) and high emissivity (0.971 at 1000 degrees C). However, the thermal cycling life of the PZ7C3 single- and dual-ceramic-layer systems at 1100 degrees C was relatively short, primarily due to CTE mismatch and diminished mechanical properties of the PZ7C3 coating. Following CMAS exposure at 1300 degrees C for 20 h, a protective reaction layer formed on the coating, indicating favorable resistance to CMAS penetration.