Comparison of thermal properties of conventional and nanostructured Lu₂Si₂O₇ environmental barrier coatings

The thermo-physical and thermal insulation properties are crucial for determining the service life of environmental barrier coatings. In this study, the novel nanostructured Lu₂Si₂O₇ coatings were prepared via atmospheric plasma spraying (APS). The microstructure, phase composition, and thermal properties of these coatings were characterized. In addition, conventional Lu₂Si₂O₇ coatings were deposited for comparative analysis. Results reveal that nanostructured Lu₂Si₂O₇ coatings exhibit lower thermal conductivity (0.53–1.27 W m^–1 K^–1) compared to conventional Lu₂Si₂O₇ coatings (0.70–1.37 W m^–1 K^–1). Despite a slightly higher thermal expansion coefficient of nanostructured coatings (3.8 × 10⁻⁶ K⁻¹) compared to that of conventional coatings (3.75 × 10⁻⁶ K⁻¹), their thermal insulation performance surpasses that of conventional coatings. In particular, at a surface temperature of 1350 °C, nanostructured Lu₂Si₂O₇ coatings demonstrate a thermal insulation temperature of 430 °C, whereas conventional coatings exhibit 400 °C. Our research results offer valuable insights for the development and application of next-generation environmental barrier coatings.