Effects of property mismatch and interface morphology on thermal stress in rare earth silicate environmental barrier coatings

Material property mismatches and interface morphology significantly influence the thermal stress distribution and failure behavior of environmental barrier coatings (EBCs). The finite element method is utilized to investigate the effects of material properties and interface morphologies on the thermal stress distribution in EBCs. The thermal stress behavior during cooling from 1623 K to 298 K is assessed using several rare earth silicates as potential top coat candidates. Three representative interface morphologies: convex, concave, and cosine were analyzed to assess their impact on stress concentration and distribution. Stress profiles were extracted along various paths to characterize the relationship between interface morphology and internal stress behavior. The findings provide critical insights for optimizing material selection and interface design, enabling enhanced durability and prolonged service life of coating systems under extreme thermal conditions.