National Aeronautics and Space Administration


Date of this Version



Journal of the European Ceramic Society 37 (2017) 23–34


U.S. Government Work


Alumina-forming commercial Ti2AlC (MAXthal 211)TM phase samples were exposed in a jet fueled, high pressure burner rig (HPBR) at 1100◦, 1200◦, and 1300◦C, operating at 6 atm (bar) and 25 m/s, in ∼10%water vapor. Weight change exhibited a rapid initial uptake associated with a TiO2 transient phase followed by cubic kinetics of a slow-growing α-Al2O3underlayer. The cubic rate constants, kc, were approximately 20% of those measured in static thermo-balance furnace tests. A small recession rate of −0.012 mg/cm2/h was measured at 1300◦C for a pre-oxidized sample. The loss rate was ∼15% that observed for SiO2scales subject to volatile Si(OH)4formation for SiC tested under similar conditions.These kinetic features were fitted in a modified cubic-linear law. From thermodynamic, XRD, and SEM analyses, it is proposed that volatile TiO(OH)2 was formed by the reaction of water vapor with TiO2 and TiAl2O5 outer layers.