LAUSR

This paper presents a comparison of thermal fatigue behavior of sol–gel-derived dip-coated nanostructured nonconventional and conventional air plasma-sprayed seven percent weight of yttria-stabilized zirconia thermal barrier coatings (TBCs). The thermal fatigue test was performed on the thermal cyclic furnace in the temperature range of room temperature and 1100 °C. Microstructural evaluation and elemental analysis were done by using scanning electron microscopy/energy-dispersive spectroscopy, respectively. It was observed that the failure of both nanostructured and conventional TBCs ensured the crack-induced spallation of ceramic top coat. The results demonstrated that spinel oxide (mixed oxide of Cr, Co, Ni) formation over thermally grown oxides layer played a crucial role in both of the case of conventional TBCs and sol–gel-coated nonconventional TBCs. The thermal cyclic fatigue life of the sol–gel coatings was found to be 1.31 times higher than the conventional air plasma. The AFM images also confirmed the coating consisting of nanostructure as well as the surface irregularities which increased with rising temperature.