Thermochemical and microstructural contributions of high temperature particle erosion durability in CMAS exposed EBCs

Particulate/debris damage caused by ingestion of calcium magnesium aluminosilicates (CMAS) hinders the use of environmental barrier coatings (EBCs) 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 in determining limiting mechanisms in the operating lifetime of EBCs. This study assesses the effects of extrinsic phase formation and microstructural changes due to CMAS interactions on the erosion durability of Yb2Si2O7-based EBCs in NASA Glenn’s Erosion Burner Rig 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.