Title: Oxygen incorporation in Ti2AlC MAX phases as bond coats: Multi-scale simulations for enhanced thermal shock resistance

Journal: Journal of Materials Research and Technology

Year: 2026

Impact factor: 6.6

Abstract:

In thermal barrier coating (TBC) systems, MAX phases have emerged as potential alternatives to conventional metallic bond coats (BCs). Using multi-scale simulations, we examined how oxygen incorporation affects the high-temperature behavior of Ti2AlC. Although oxygen is typically considered harmful in BCs, Ti2Al(C1-xOx) showed different results that moderate oxygen incorporation lowers Young's modulus and increases the thermal expansion coefficient. This oxygen-induced softening effectively mitigates the large stiffness and thermal-expansion between the ceramic top coat and the superalloy substrate, thereby reducing thermal stress. Comparisons with CoNiCrAlY and (Ni,Pt)Al across several substrates showed that Ti2Al(C1-xOx) consistently produced lower stresses, particularly near the thermally grown oxide (TGO)–BC interface where failure usually initiates. These results indicate that oxygen incorporation, unavoidable in practical situations, can be used to tune Ti2AlC for improved reliability, supporting its use as a next-generation BC.