Thermal cyclic life and failure mechanism of nanostructured 13 wt%Al2O3 doped YSZ coating prepared by atmospheric plasma spraying

Nanostructured 13 wt%Al2O3 doped nanostructured 8 wt% yttria stabilized zirconia (nano-13AlYSZ) coatings were deposited by atmospheric plasma spray (APS). The isothermal oxidation and thermal cyclic life of the nano-13AlYSZ coating at 1100 °C were investigated. The isothermal oxidation test results indicate that the oxidation kinetics of nano-13AlYSZ follows a parabolic law. The parabolic rate constant at 1100 °C is calculated 0.04365 mg2 cm−4 h−1. The thermal cyclic life of nano-13AlYSZ coating is about 953 times at 1100 °C. The failure of the nano-13AlYSZ coating occurs at the interface between the nano-13AlYSZ coating and the thermal growth oxide (TGO). A finite element method is employed to analyze the stress distribution in the nano-13AlYSZ coating. The results show that maximum stresses occur at the top coat/TGO interface.