Al2O3-modified 7YSZ thermal barrier coatings for protection against volcanic ash corrosion

This is the authors' abstract. We don't add key points for this paper.

To prevent volcanic ash corrosion using thermal barrier coatings (TBCs), a novel method using Al 2 O 3 -modification was proposed to reduce molten CMAS wettability on TBCs surface through a lotus effect. Plasma spray-physical vapor deposition (PS-PVD), a third-generation method for TBCs fabrication, was adopted to deposit 7YSZ TBCs with a feather-like microstructure. Then, Al 2 O 3 modification was introduced to fabricate a dense Al 2 O 3 overlay with nano/micro-sized grains on the TBCs surface. The wetting ability of CMAS on APS/EB-PVD/PS-PVD 7YSZ TBCs was comparatively in situ observed at 1250 °C for 3600 s. The results indicated that the dense Al 2 O 3 overlay inhibited penetration of molten CMAS. Additionally, the micro/nano dual-sized structure, which is similar to the papillary structure of a lotus leaf, reduced molten CMAS wettability on the TBCs surface. The results demonstrated that the Al 2 O 3 -modified TBCs had better CMAS corrosion resistance than the as-deposited APS/EB-PVD/PS-PVD TBCs.