Femtosecond laser polishing yttria-stabilized zirconia coatings for improving molten salts corrosion resistance

In this study, we present a novel method of polishing thermal barrier coatings? surface using high-frequency femtosecond laser. Compared to the conventional mechanical micro-grinding, light trapping due to multiple reflection from porous-structure, which enhances its coupling into coating, resulted in desired effect of healing of the voids in performing a layer-by-layer laser ablation. Herein, the corrosion resistances of these coatings subjected to Na2SO4+V2O5 at 1000 degrees C was investigated. Three observed transport behaviors: (i) molten salts infiltration, (ii) Y-leaching, and (iii) V-in-diffusion, are discussed to illustrate corrosion mechanisms. Laser-polished coatings with smooth surface and healed voids show superior molten salts resistance and significantly alleviate leaching or in-diffusion of elements.

Automated summary

This study introduces a novel method of polishing thermal barrier coatings using high-frequency femtosecond laser, which results in improved corrosion resistance and enhanced molten salts resistance for the coatings. The research also discusses three observed transport behaviors and corrosion mechanisms of the coatings subjected to specific conditions.