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

Figure 12

FESEM micrographs of YVO₄ crystals on the surface of YSZ coatings: (a) thicker rod/flat crystals in conventional YSZ (b) thin rod/flat crystals in YSZ as inner layer of YSZ/normal Al₂O₃ coating and (c) thinner rod/flat or needle crystals in YSZ as inner layer of YSZ/nano-Al₂O₃ coating after hot corrosion testing.

(a)

(b)

(c)