Feasibility assessment of self-grading metallic bond coat alloys for EBCs/TBCs to protect Si-Based ceramics

A sputtered γ (TiAl) + Laves TiAlCr coating formed an adherent Al2O3 scale on SN 282 Si3N4 when oxidized. A Ti-N rich layer was formed at the TiAlCr-Si3N4 interface, which effectively resulted in beneficial local Al enrichment underneath the growing Al2O3 scale, rather than detrimental Al loss to the substrate.