Aluminium surface modification of ytterbium silicate-based environmental barrier coatings
Ceramics International, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.ceramint.2026.07.555
- Dergi Adı: Ceramics International
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: CMAS, Environmental barrier coating, Plasma spraying, Thermal evaporation, Ytterbium silicate
- Hakkari Üniversitesi Adresli: Evet
Özet
Environmental Barrier Coatings (EBCs) based on ytterbium silicates are essential to protect silicon carbide (SiC)-based ceramic matrix composites from high-temperature degradation in gas turbine engines. In this study, an atmospheric plasma-sprayed silicon/mullite/ytterbium silicate multilayer EBC system was surface-modified with a thin aluminum (Al) film via thermal evaporation, followed by controlled oxidation to synthesize a dense, protective Al2O3 top barrier. Performance evaluations at 1400 °C demonstrated that the surface modification superiorly mitigated both calcium-magnesium-aluminum-silicate (CMAS) melt and hot corrosion attacks. Against molten CMAS attack, the Al2O3 barrier served as an effective physical and chemical shield, significantly suppressing molten silicate infiltration and restricting matrix decomposition. In hot corrosion tests under aggressive V2O5 + Na2SO4 molten salts, the modification successfully retarded the penetration of corrosive vanadium species, thereby preventing chemical desilicification and preserving the structural stability of the underlying ytterbium silicate phases. Microstructural characterizations confirmed that the pre-oxidized Al layer effectively sealed the inherent processing defects and microcracks of the plasma-sprayed coating. These findings reveal that thermal evaporation-based aluminum surface engineering provides a robust and highly efficient mechanism to enhance the chemical durability and thermochemical stability of advanced EBCs under severe engine environments.