Evaluation of Normal and Nanolayer Composite Thermal Barrier Coatings in Fused Vanadate-Sulfate Salts at 1000°C

[摘要] Hot corrosion behavior of yttria stabilized zirconia (YSZ), YSZ/normal Al2O3, and YSZ/nano-Al2O3coatings was investigated in the presence of molten mixture of Na2SO4 + V2O5at 1000°C. Microstructural characterization showed that the creation of hot corrosion products containing YVO4crystals and monoclinic ZrO2is primarily related to the reaction between NaVO3and Y2O3during hot corrosion. The lowest amount of hot corrosion products was observed in YSZ as an inner layer of YSZ/nano-Al2O3coating. Hence, it can be concluded that the presence of nanostructured Al2O3layer over the conventional YSZ coating can considerably reduce the infiltration of molten corrosive salts into the YSZ layer during hot corrosion which is mainly related to the compactness of nanostructured alumina layer (including nanoregions) in comparison with normal alumina layer.

[学科分类] 材料工程