Development of controlled segmentation crackdensities in plasma sprayed-7%YSZ thick thermalbarrier coatings

Yttria stabilized zirconia (YSZ)-coatings are deposited on Ni-based superalloy IN738 by atmospheric plasma spraying (APS). For the first time, controlled segmentation crack densities are manually developed in the coatings, even after the APS deposition. Presented method is allowing the user to control segmentation densities as well as cracks depth, which could be designed as per coating thickness and required application. Thermal cycling test shows promising strain tolerance behavior for the segmented coatings, whereas coating without segmentation could not sustain even for its first thermal cycle period. Further, microstructural studies reveal that a very thin layer of TGO was formed and no coating failure or spallation was observed after thermal cycling test at 1150°C for 500 cycles.