Effects of molten silicate reactivity on high temperature erosion behavior of plasma sprayed Yb2Si2O7-based EBCs

• Published in: Surface & coatings technology 2024-10, Vol.494, p.131078, Article 131078
• Main Authors: Stokes, Jamesa L., Presby, Michael J., Hoffman, Leland C., Setlock, John A., Salem, Jonathan A., Harder, Bryan J.
• Format: Article
• Language: English
• Subjects: Burner rig; CMAS; Environmental barrier coating; Erosion; High temperature; Yb2Si2O7
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2024.131078

Particulate/debris damage caused by ingestion of calcium magnesium aluminosilicates (CMAS) hinders the durability of environmental barrier coatings (EBCs) used to protect SiC-based ceramic matrix composite components in next generation gas turbine engines. Similarly, ingestion of any debris in the engine can lead to mechanical damage and recession of coatings due to particulate erosion. Investigating particulate interactions at relevant engine conditions is crucial for determining limiting mechanisms in the operating lifetime of EBCs. This study assessed the effects of extrinsic phase formation and microstructural changes due to CMAS interactions on the erosion durability of Yb2Si2O7-based EBCs in a laboratory-scale combustion facility. CMAS exposures and erosion testing were carried out at 1316°C. Using 60 μm Al2O3 particles as the erodent material, the effects of CMAS loading on erosion durability at various impingement angles were evaluated. •The erosion behavior of Yb2Si2O7-based EBCs reacted with a molten silicate glass was explored.•The primary reaction product was Ca2Yb8(SiO4)6O2 apatite in reactions of the EBCs with CMAS.•Erosion durability increased with increased CMAS loading.•A transition from a brittle to ductile mode of erosion resulted in improved erosion durability and was theorized to be a result of increased apatite formation.