Corrosion behavior and thermos-physical properties of a promising Yb2O3 and Y2O3 co-stabilized ZrO2 ceramic for thermal barrier coatings subject to calcium-magnesium-aluminum-silicate (CMAS) deposition: Experiments and first-principles calculation

In this study, corrosion behavior of Yb2O3-Y2O3 co-stabilized ZrO2 (YbYSZ) was systematically investigated under CMAS melt attack. The result was found that YbYSZ exhibited a better CMAS resistance than yttria stabilized zirconia (YSZ), which was attributed to the excellent phase stability. The degradation of grain caused by CMAS attack was greatly related to the diffusion rate of element substantially. Yb3+ exhibited a low diffusion rate contributing to good phase stability during corrosion. A corresponding first-principles calculation further confirmed this conclusion. Besides, YbYSZ showed a higher thermal expansion coefficient and lower thermal conductivity as compared with YSZ counterpart.