Abstract
(Gd0.9Sc0.1)2Zr2O7/YSZ thermal barrier coatings (TBCs) were produced by air plasma spray (APS). Compared with agglomerated particles for thermal spray, (Gd0.9Sc0.1)2Zr2O7 coatings had the same phase structure and a close chemical composition. (Gd0.9Sc0.1)2Zr2O7/YSZ TBCs revealed a lamellar microstructure, and the (Gd0.9Sc0.1)2Zr2O7 coating had some porous zones with many fine particles among the splats. Hot corrosion tests in V2O5 at 700–1000 °C indicated that the coating was highly resistant to molten salt penetration, resulting from the formation of a continuous dense reaction layer on the surface. The thickness of the reaction layer was ~20 μm, independent on the corrosion temperature and time. After corrosion at 700 °C, the layer consisted of (Gd, Sc)VO4 and Sc2O3 doped ZrV2O7, while at higher temperatures, it was composed of (Gd,Sc)VO4 and monoclinic ZrO2. The mechanism by which these corrosion products formed is clarified based on phase diagrams and Lewis acid-base rule.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
