Effect of YSZ Thickness on the Thermal Cyclic Fatigue Performance of Gadolinium Zirconate/YSZ double layered TBCs

Thermal barrier coatings (TBCs) play a vital role in allowing the gas turbine engines to operate at high temperatures. With higher operating temperatures (>1200°C), the standard TBC material, 7-8wt. % Yttria Stabilized Zirconia (YSZ), is susceptible to CMAS (Calcium Magnesium Alumino Silicates) degradation and undesirable phase transformation. New TBC materials such as gadolinium zirconate (GZ) have shown to be capable of overcoming the challenges faced by YSZ. However, GZ has inferior fracture toughness than YSZ. In this work, three double layered TBC variations with different GZ and YSZ thickness respectively were produced by suspension plasma spray (SPS) process. The objective was to investigate the influence of YSZ thickness in the GZ/YSZ double layered TBC on the thermal cyclic fatigue performance. The as sprayed TBCs were characterized by SEM, XRD and porosity measurements. Later, the TBCs were subjected to thermal cyclic fatigue test and the failed TBCs were analyzed by SEM/EDS.