Thermal shock behavior of nanostructured and microstructured thermal barrier coatings on a Fe-based alloy

Thermal barrier coatings (TBCs) of nanostructured and microstructured yttria stabilized zirconia (YSZ) were deposited on a Fe-based alloy of GH2132 by air plasma spray. The thermal shock behavior of both coatings was investigated in a comparative aspect. Scanning electron microscopy (SEM) and high resolution digital camera were employed to examine the surface and cross-sectional morphologies of coatings before and after thermal shock. Results revealed that nanostructured TBCs was superior to the microstructured TBCs in thermal shock performance. In the case of microstructured TBCs, both the TBC and the bond coat were separated from the substrate. However, the failure of nanostructured TBCs showed that only local TBC spalled and the penetrating cracks widened.