Article ID Journal Published Year Pages File Type
1470509 Corrosion Science 2011 6 Pages PDF
Abstract

Impedance spectroscopy as a non-destructive evaluation technique was employed to study the microstructural evolution of thermal barrier coatings exposed to Na2SO4 at 950 °C. The results showed that the resistance and capacitance of yttria-stabilized zirconia top coat increased with corrosion time. The resistance of thermally growth oxide (TGO) from 20 to 60 h decreased slowly, which indicates there is little change in the composition of TGO. The fast decrease in the resistance of TGO from 60 to 100 h may correspond to the compositional change of TGO from a-Al2O3 to more conductive NiO and Ni(Cr, Al)2O4 with corrosion time.

Research highlights► Microstructural evolution of TBC under hot corrosion environment was studied using IS. ► Resistance and capacitance of the YSZ top coat increase with hot corrosion time. ► Resistance of TGO is more sensitive to compositional change under Na2SO4 environment.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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