Insights into thermos-chemical attack of CMAS+NaVO3 mixtures on YSZ materials: an experimental and computational DFT study

Accompanied with working condition of advanced aero-engine becoming harsh, the state-of-art 6–8 wt.% Y2O3-stabilized-zirconia (YSZ) thermal barrier coatings (TBCs) degradation aroused by environmental deposits (CMAS and molten salt) has attracted growing concerning. In this context, attack behavior of CMAS+NaVO3 mixtures (CN) on YSZ TBCs was studied by experimental investigation and computational simulation to gain insights into the mechanism behind thermos-chemical degradation. Results from conventional TBCs/the melt interaction test showed that the molten CN exhibited superior permeability than CMAS counterpart, with infiltration depth exceeding 350 μm within 0.5 h. Additionally, accelerated precipitation of Y-rich c-ZrO2 grains was exclusively noted in CN-corroded specimen, potentially attributable to the decrease in Y-solubility. Microstructural evolution of YSZ particles in ceramic particles/the melt interaction test indicated an enhanced thermos-chemical corrosiveness of CN, and this phenomenon was further elucidated through a corresponding DFT simulation, which implicated that promoted transport behavior may be the underlying cause.