| Abstract Scope |
The first figure of merit for environmental barrier coating (EBC) materials was designed through a ranking system for material properties pertaining to established EBC failure modes in service. Seven past, present, and novel EBC candidate materials were used in the figure of merit design: SiO2, Ba0.75Sr0.25Al2Si2O8 (BSAS), HfSiO4, Yb2Si2O7, Yb2SiO5, Yb2O3, and YbPO4. Utilizing compiled data from the literature, the presented figure of merit verified Yb2Si2O7 as the state-of-the-art candidate with optimal EBC properties and inferred that YbPO4 should be considered as a potentially viable EBC material candidate. The figure of merit allows for holistic comparison of EBC candidates, informs experimental and computational search efforts for next generation complex EBCs, and guides materials development to achieve acceptable resistance against all major failure modes, which are interconnected. Novel compositionally complex EBC materials and layered EBC architectures show promise for optimization of material properties for long lifetime EBCs in combustion environments. |