High-temperature CMAS resistance performance of Ti₂AlC oxide scales

Failure of thermal barrier coatings (TBCs) caused by glassy deposits mostly composed of calcium-magnesium-aluminium-silicate (CMAS) has become an urgent issue. The addition of Al and Ti elements in TBCs is beneficial to improve the CMAS resistance. In this paper, bi-layered oxide scales were formed through pre-oxidation of Ti₂AlC (POTAC) bulks at high temperatures. The wettability and spreading behaviors of CMAS on the oxide scales, as well as the interaction between them were investigated by a sessile-drop method. The glassy CMAS deposit on the Al₂TiO₅ layer revealed the largest equilibrium contact angle and slowest diffusion-limited spreading rate among all the samples.