Evaluation of thermal insulation capability of plasma-sprayed zirconia based thermal barrier coatings

Zirconia based thermal barrier coatings (TBCs) were extensively used in gas turbines engines to protect and provided thermal insulation for hot-section metal components. Consequently, the key parameter of these coatings is low thermal conductivity. The present paper deals with evaluation of effect of the microstructure and stabilizer type on zirconia based TBCs thermal insulation capability. For this scope, three type of coatings including conventional yttria stabilized zirconia (YSZ), conventional ceria and yttria stabilized zirconia (CYSZ) and nanostructured yttria stabilized zirconia have been prepared by atmospheric plasma spraying (APS) on NiCoCrAlY-coated Inconel 738 substrates. Microstructural evaluation and phase analysis were performed using field emission scanning electron microscope (FESEM) and X-ray diffractometry (XRD) respectively. Result srevealed that with employing of ceria stabilizer and fabrication of nano-structure in coating, the thermal insulation capability of zirconia based TBCs were enhanced.