Comparative Study of Plasma Sprayed Yittria and Ceria Stabilized Zirconia Properties

Thermal Barrier Coatings are subjected to spalling and destabilization due to hot corrosion. Recently, Ceria Stabilized Zirconia (CSZ)-based TBCs have been intensively investigated for the YSZreplacement because CSZ has a much lower thermal conductivity and a higher expected thermalexpansion coefficient than those of YSZ. In this research, Yttria stabilized zirconia (YSZ) and ceriastabilized zirconia (ZrO2 25CeO2 2.5Y2O3) TBCs were fabricated, followed by hot corrosion tests witha Na2SO4+V2O5 salt at 1050°C. The treated samples were characterized using XRD and SEM equippedwith EDS. From studies on microscopic failure behavior, the formation of YVO4 crystals and the amount of phase transformations of tetragonal ZrO2 to monoclinic lead to degradation of coatings. Results revealed that CSZ TBCs had better resistant to hot corrosion than YSZ TBCs. The amount ofYVO4 crystals and monoclinic ZrO2 in YSZ are much more than CSZ which leads to faster degradationof YSZ than CSZ. The strength of the Adhesive coatings of the substrate was also measured in thisstudy.

Keywords:

Thermal Barrier Coatings , Hot Corrosion , Bond Strength