Hot corrosion behavior in thermal barrier coatings with heterogeneous splat boundary

Abstract

In the present study, layered thermal barrier coatings (TBC) were fabricated with different surface layers with lanthanum zirconate (LZO), yttria-stabilized zirconia (YSZ), and YSZ/LZO blended layer. Their hot corrosion behaviors were investigated in the molten salt of Na2SO4 + V2O5 at 1100 degrees C. TBC with the YSZ/LZO blended layer showed a different hot corrosion behavior with a relatively shallow depth and densified reaction layer compared with those with the LZO and YSZ layers. The blended layer showed the most severely degraded microstructure above the planar reacted area, which can be more appropriate for a sacrificial layer to protect the substrate.