Hot corrosion behaviour of plasma sprayed alumina plus YSZ particle composite coating

Karabas M., BAL E., Taptık İ. Y.

PROTECTION OF METALS AND PHYSICAL CHEMISTRY OF SURFACES, vol.53, no.5, pp.859-863, 2017 (SCI-Expanded) identifier identifier


Hot corrosion is one of the damage mechanisms in thermal barrier coatings (TBCs) due to the molten salt effects as a result of combustion of low quality fuel. In this study, the hot corrosion behaviour of alumina-yttria stabilized zirconia particle composite coatings produced by thermal spraying for use as a thermal barriers on industrial gas turbines and in jet engines was evaluated. Plasma sprayed coatings with three different amounts of alumina- yttria stabilized zirconia particle composite have been exposed to 50 wt % Na2SO4 + 50 wt % V2O5 corrosive molten salt temperatures at 1050A degrees C for 60 hours. Damages in the coatings surface and cross section after hot corrosion tests have been studied by using a scanning electron microscope to observe the microstructure and x-ray diffraction techniques to analyze the phase composition. The results have shown that the amount of YVO4 crystals on the surface of YSZ coatings decrease while Al2O3 increases in YSZ + Al2O3 composition, therefore, the hot corrosion resistance of TBC improves with the addition of Al2O3.